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Hello students! Welcome to another tutorial on the integrated circuit in Proteus. Different integrated circuits are revolutionizing the electronic world and today we are discussing one of them. The core topic of this tutorial is the 74LS160 IC in the proteus but before that, we’ll understand the basics of this IC.

In this article, we’ll start learning the 74LS160 from scratch. We’ll see its introduction and datasheet in detail. You will see the truth table, logic diagram, and pinouts of this IC in detail, and then we’ll move on to the basic features of this IC. You will see the simulation of 74LS160 in Proteus and in the end, we’ll go through some important applications of this IC. Let’s move towards the introduction first.

Figure 1: Top view of 74LS160 IC

74LS160 Introduction

• 74LS160 is an integrated circuit (IC) that is used as a counter in digital electronics.

• It is a 4-bit binary synchronous counting device.

• It belongs to the family of the 74xx series of ICs and the letters LS indicate that these belong to the low-power Schottky series. 

• This IC is made with the transistor transistor logic (TTL) technology. 

• It is an edge-triggered and cascadable MSI building block for multiple purposes, such as counting, memory addressing, frequency division, etc.

• Moreover, it is widely used in digital circuits because it is presettable; that is, it can be used as the initial counter.

• A feature of this series is that it has an asynchronous Master Reset (Clear) input that acts as an independent input, and the cock or other inputs do not control it.

74LS160 Datasheet

Before using any digital IC, it is important to understand its structure and datasheet. The details given below will help you understand the workings of this IC:

74LS160 Pinout Configuration

The 74LS160 is 16 in IC and here is its connection diagram, DIP:

Figure 2: Pinout configuration of 74LS160

You can see that each pin has a name and number associated with it. The details of each pin can be seen in the table given next:

Table 1: Pinout configuration of 74LS160

74LS160 Logic Symbol

In different cases, when the 74LS160 is shown with the logic symbol given here:

Figure 3: Logic Symbol of 74LS160

Here, pin 16 is used for the power input and pin 8 is used as the ground. The names and numbers of the pins are the same as given before in the form of the table. 

74LS160 Truth Table

The truth table of this IC will help you understand the output of 74LS160 when the specific combination of inputs is fed into it. But before this, it is important to understand the following denotations in the table:

• X = Don't-care condition

• L = Logic low or ground

• H = Logic high or positive voltage

• CEP = Count Enable Parallel Input

• CET = Count Enable Trickle Input

• CP = Clock (Active HIGH Going Edge) Input

• MR = Master Reset (Active LOW) Input

• SR = Synchronous Reset (Active LOW) Input

Table 2: Truth table of 74LS160

74LS160 Working Principle

The working principle of 74LS160 can be understood with the help of some important points about its internal structure. The basis of its working principle is to understand that when the clock pulse is applied to the 74LS160, it responds to it and counts the binary values.  Here are the important points to understand this:

74LS160 Counter Bits

Since the beginning, we have been mentioning that it is a 4-bit counter. It means it can count from 0000 to 1111 in binary numbers.  

74LS160 Clock Input

As with other integrated circuits, the counter responds to the clock pulse applied to its clock input. The rise in the clock input stimulates the counter operations. 

74LS160 Parallel Load Inputs

The parallel load inputs are denoted by P0 to P3. The counter allows the parallel loading of the data when the appropriate pattern of signals is applied at the input pins.

74LS160 Cascading

Cascading is the process in which two or more integrated circuits are connected with each other in such a way that the output of one circuit becomes the input of the other. This is done to enhance the working ability of the system or is crucial when higher calculations are required using the counter.

The 74LS160 allows the cascading process. In this case, the ripple carry output (RCO) is connected with the clock input of the next counter.

74LS160 Simulation in Proteus

Now, it is better to understand how to create the circuit of this IC in the Porteus simulator before using it in the circuit. Here is the way to create the circuit:

Material Required

• 74LS160 

• Switch

• LED

• Clock

• Ground

• Power

Procedure

• Fire up the proteus software. 

• Choose the first three components from the list given above. 

• Place them in the working area to create the circuit.

• Now, go to terminal mode from the left side of the screen and choose ground terminal. Place it in the respected area. 

• Repeat the above step for the power terminal. 

• Now go to generation mode and choose the Dclock. 

• Place the clock on pin 2 of IC. 

• Connect the component through the connecting wires. 

• The circuit must look like the image given here:

Figure 4: Proteus Circuit for 74LS160

• The circuit is now ready to work. Click on the play button to start the working of the circuit. 

74LS160 Circuit Working

• The switches are used to provide the input signal to the circuit. When the switch is on, the input signal to the respective pin is HIGH, otherwise low.

• At the start, the LEDs are working in a particular manner that the output is on all the pins in a particular pattern. 

Figure 4: Changing the input of the 74LS160 circuit

• Change the input through the switches and you will observe the change in the output.

• You will observe a change in the values of output when the signal on the input signals is changed.

Figure 5: Getting the output of the 74LS160 Circuit simulation

• The inputs and outputs are the same as given in the truth table.  

If you want to have the design of the Proteus project I am using, then you can download it through the link given next:

Proteus simulation for the basic working of 74LS160

74LS160 Features and Specifications

The 74LS160 has different modes and studying all of these will help you to understand the features and specifications. 

74LS160 Counting Mode

• On reaching the clock edge, a pulse propagates that stimulates the counter to work. 

• The master-slave FF is the pulse that triggers the master-slave flip-flop structure of this IC. The state of the internal logic circuit is changed according to the structure of the IC. The details of these inputs are given in the table given before. 

• The logic gates of flip-flops determine the output of the IC. Usually, the output depends on the following factors:

• The current state of the pins

• Previous inputs of pins

• Feedback connections.

• In some versions, 75LS160 has the decade working, which means these can provide values between 0 and 9.

• The state of the master flip flop is transferred to the corresponding slave flip flop after some time. This is done to provide a stable and more synchronized output. 

74LS160 Preset Mode

• During the processing, the low signals on the load input activate the logic path of the IC. 

• All the values in the data inputs are transferred directly to the respective flip-flops. 

• The process of overriding the current counter bypasses the internal counter logic. It also sets the counter’s desired initial values and this is done by presetting the counter.  

74LS160 Reset Mode

• The reset pin is the active low pin, which means the output is reset when this pin has a zero value.

• The clearing of the flip flop is the situation when all the FFs are forced to reset their values, no matter what the values on their inputs or what the values of the clock are.

74LS160 Carry Out (CO)

• The logic gates in the structure of the integrated circuit determine the internal structure of the flip flops. These are particularly useful for the transition from 1001 to 0000, which is 9 to 0 in the decimal numbers. 

• When the transition of the carry-out goes high, it indicates that the count cycle is complete. 

• The carryout pulse can be used in the cascading counter to enhance the working ability of the circuit using 74LS160.

74LS160 Physical Dimensions

If you want to use the 74LS160 in your circuits, you must know the physical dimensions of this IC. There are two basic units to measure the physical dimensions of devices like ICs:

Metric Package

In the metric package, only metric units are used to represent the calculations. The following are some of the basic units in this system:

• Millimetres (mm)

• Centimeters (cm)

• Meters

• Kilograms

• Seconds 

Usually, in the representation of the physical dimensions of the ICs, like 74LS160, millimeters are used for metric packages. 

Imperial Package

The imperial units are also known as the British imperial units. The popular units in the imperial packages are:

• Inches

• Feet

• Pounds

The physical dimensions of the ICs in the imperial package are mostly inches. Here is the table that clearly shows the physical calculations of the 74LS160 IC:

Table 3: Physical dimensions of 74LS160

74LS160 Applications

The following are some prime applications where the 74LS160 is extensively used:

74LS160 as Digital Counter

The most common example of the application of this IC is to use it as a digital counter. When the clock pulse is applied to this IC, it represents the binary counting values. This is not only used as it is but usually other logic gates are combined with it to get the complex calculator to work. 

74LS160 Frequency Divider  

The frequency divider is the circuit that is designed to determine the value of frequency after dividing it by the power of 2. This circuit is incomplete without the 74LS160 IC. 

74LS160 Timer Circuits

This IC is incorporated into the time circuits, where its main job is to generate a time delay. Moreover, it also triggers specific events based on certain conditions. These conditions are set during the design process of the circuit. 

74LS160 in Sequential Logics

In the sequential logic, the 74LS160 is used as the counter. The output of this IC is used as the input of some other devices and this creates the basis of the sequential logic circuits.

74LS160 in Signal Processing Circuits

Signal processing is an important field where complex circuits are used. This IC is used in devices for signal processing where counting and timing functions are required.

Hence, today, we have seen the details of the 74LS160 Integrated Circuit. We started with the basic introduction of this IC and understood the structure and output of every pin through its datasheet. Through the logic diagram, logic circuit, truth table, and the pinouts of this IC we understood the details of its functionalities. Moreover, we saw its basic features and mode of operation. The physical dimensions of this IC made clear the domains of its usage in different circuits. We saw the simulation of the 74LS160 in the proteus and in the end, we shed light on different applications where the 74LS160 plays a vital role. I hope you have understood all the information but if you feel something missing or have any questions, you can ask us.

Hello pupils! Welcome to the next section of neural network training. We have been studying modern neural networks in detail, and today we are moving towards the next neural network, which is the Echo State Network (ESN). It is a type of recurrent neural network and is famous because of its simplicity and effectiveness. 

In this tutorial, we’ll start learning with the basic introduction of echo state networks. After that, we’ll see the basic concepts that will help us to understand the work of these networks. Just after this, we’ll see the steps involved in setting the ESNs. In the end, we’ll see te fields where ESNs are extensively used. Let’s start with the first topic:

Introduction to Echo State Networks (ESNs)

The echo state networks (ESNs) are a famous type of reservoir computer that uses recurrent neural networks for their functionalities. These are modern neural networks; therefore, their working is different from the traditional neural networks. During the training process, this does not rely on the randomly configured "reservoir" of neurons instead of backpropagation, as we observe in traditional neural networks. In this way, they provide faster and better performance. 

The connectivity of the hidden neurons and their weights are fixed and these are assigned randomly. This helps it provide temporal patterns. These networks have applications in signal processing and time-series prediction.  

Basic Concepts of Echo State Networks (ESNs)

Before going into detail about how it works, there is a need to clarify the basic concepts of this network. This not only clarifies the discussion of the work but will also clarify the basic introduction. Here are the important points to understand here:

Reservoir Computing in ESN

The basic feature of ESN is the presence of the concept of computing reservoir. This is a hidden layer that has randomly distributed neurons. This random distribution makes sure that the input data is captured by the network effectively and does not overfit the specific pattern as is done in some other neural networks. In simple words, the reservoirs are known as the randomly connected recurrent network because of their structure. These reservoirs are not trained but play their role randomly in the computing process. 

Comparing RNN with ESN

ESNs are members of a family of recurrent neural networks. The working of ESNs is similar to RNN but there are some distinctions as well. Let us discuss both:

• The RNN is a class of artificial neural networks that use sequential and temporal data for their work. The ESN has the same working principle; therefore, it can also maintain the memory of past responses.
• During the processing of RNN as well as the ESN, the order of the input elements affects the output.
• Both of these have long-term and short-term dependencies within the sequence; therefore, the role of sequence in these networks is important.

Now, here are some differences between these two:

ESN vs. RNN

The difference between the training approaches of both of these is given here:

• In the training process of RNN, all the work is done with backpropagation. This causes problems in the vanishing and exploding gradients. The ESNs have a fixed random recurrent weight matrix therefore, the structure is quite simpler than RNN because, here in the training, only output weights are adjusted.
• In RNN, all the weights, including the recurrent connections, are trainable. Whereas, in ESNs, the reservoirs are not only fixed but are randomly assigned during the process of initialization. During the processing, the calculations are done only with the neurons that are connected to the reservoirs. This not only makes it less complex but also lessens the processing time.
• In RNNs, the neurons in the network are fully connected but in ESNs, the concept of sparsity is present. According to this concept, each neuron is connected to a subset of the other neuron only. This makes the ESN more productive and simple.

Echo State Property in ESN

The ESN has a special property known as echo state property or ESP. According to this, the dynamics of the reservoirs are set in such a way that they have the fading memory of the past inputs. That means the structure of these neural networks must be created in such a way that it pays more attention to the new input concerning the memory. As a result, the old inputs will fade from memory with time. This makes it lightweight and simple. 

Non-linear Activation Function in ESN

In ESNs, the reservoir’s neurons have a non-linear activation function; therefore, these can deal with complex and nonlinear input data. As mentioned before, the ESNs employ fixed reservoirs that help them develop dynamic and computational capabilities. 

How Do Echo State Networks Work?

Not only the structure, but the working of the ESNs is also different from that of traditional neural networks. There are several key steps for the working of the ESNs. Here is the detail of each step:

Initialization in ESNs

In the first step, the initialization of the network is carried out. As we mentioned before, there are three basic types of layers in this network, named:

1. Input layer
2. Reservoir layer (hidden layer)
3. Output layer

This step is responsible for setting up the structure of the network with these layers. This also involves the assignment of the random values to the neuron weights. The internal dynamics of the reservoir layers evolve as more data is collected in these layers.

Usage of Echo State Property 

The echo state property of ESNs makes them unique among the other neural networks. Multiple calculations are carried out in the layers of the ESNs, and because of this property, the network responds to the newer inputs quickly and stores them in memory. Over time, the previous responses are faded out of memory to make room for the new inputs. 

Input Processing in ESNs 

In each step, the echo state network gets the input vector from the external environment for the calculation. The information from the input vector is fed into both the input layer and the reservoir layer every time. This is essential for the working of the network. 

Reservoir Dynamics in ESNs

This is the point where the working of the reservoir dynamic starts. The reservoir layer has randomly connected neurons with fixed weights, and it starts processing the data through the neurons. Here, the activation function starts, and it is applied to the dynamics of the reservoir. 

Updation of the Internal State

In ESNs, the internal state of the reservoir layer is updated with time. These layers learn from the input signals. The ESNs have dynamic memory that continuously updates the memory with the update in the input sequence. In this way, the internal state is updated all the time. 

Training Process of  ESNs 

One of the features of ESNs is their simplicity of the training process. Unlike traditional neural networks, the ESNs train only the connection of the reservoirs with the output layer. The weights are not updated in this case but these remain constant throughout the training process. 

Usually, a linear algorithm, such as linear regression, is applied to the output layer. This process is called teacher forcing. 

Output Generation in ESNs

In this step, the output layer gets information from the input and reservoir layers. The output of both of these becomes the input of the output layer. As a result, the output is obtained based on the current time step of the reservoir layer. 

Task-Specific Nature of ESNs

The ESNs are designed to be trained for the specific tasks such as:

• Time-series prediction
• Pattern recognition
• Signal processing

The ESNs are designed to learn from the relationship between the input sequence and the corresponding outputs. This helps it to learn in a comparatively simpler way.

Advantage of the Structure of ESNs

The above structure of the ESN helps them a lot to have better performance than many other neural networks. Some important points that highlight the advantage are given here:

Fast Learning with ESN

The structure of the ESNs clearly shows that these can learn quickly and more efficiently. The fixed reservoir weights allow it to learn at a rapid rate and the structure is also comparatively less expensive. 

Absence of Vanishing Gradients

The ESNs do not have the vanishing gradient because of the fixed reservoirs. This allows them to work in the long-term dependencies in the sequential data. The presence of this vanishing gradient in other learning algorithms makes them slow. 

Less Noise in ESNs

The ESNs are robust to the noise because of the reservoir layer. The structure is designed in such a way that these have better generalization of the unseen input data. This makes the structure easy and simple and avoids the noise at different steps. 

Flexibility in the Structure of ESNs

The simple and well-organized structure of ESN allows it to work more effectively and show flexibility in working as well as in the structure. These can adopt the various tasks and data types throughout their work and training. 

Applications of Echo State Networks 

Businesses and other fields are now adopting neural networks in their work so that they can get efficient working automatically. Here are some important fields where echo state networks are extensively used:

Time Series Prediction with ESN

The ESNs are effective in learning from the data for time series prediction. Their structure allows them to effectively predict by utilizing the time series data; therefore, it is used in the fields like:

• Stock price prediction.
• Weather forecasting.
• Energy consumption prediction.

Signal Processing in ESN

The signal processing and their analysis can be done with the help of the echo state networks. This is because these can capture the temporal pattern and dependencies in the signal. This is helpful in fields like:

• Speech recognition
• Physiological signal analysis
• Studying the speech signals and biomedical signals.

These procedures are used for different purposes where the signal plays an important role. 

Reservoir Computing Research with ESNs

There are different reservoir computing research centers where ESNs are widely used. These departments focus on the exploration of the capabilities of reservoir networks such as ESNs. Here, the ESNs are extensively used as a tool for studying the structure and working of recurrent neural networks. 

Cognitive Modeling with ESNs

The ESNs are employed to understand aspects of human cognition such as learning and memory. For this, they are used in cognitive modeling. They play a vital role in understanding and implementing the complex behaviors of humans. For this, they are implemented in dynamic systems. 

Control Systems and ESNs

An important field where ESNs are applied is the control system. Here, these are considered ideal because of their temporal dependencies. These learn from the control dynamic processes and have multiple applications like process control, adaptive control, etc. 

Time Series Classification with ESNs

The ESN is an effective tool for time series classification. Here, the major duty of ESN is to classify the sequence data into different groups and subgroups. This makes it useful in fields like gesture recognition, where pattern recognition for movement over time is important.

Speech Recognition Using ESNs

Multiple neural networks are used in the field of speech recognition and ESN is one of them. The echo state network can learn from the pattern of the speech of the person and as a result, they can recognize the speaking style and other features of that voice. Moreover, the temporal nature of this network makes it ideal for capturing phonetic and linguistic features. 

Echo State Networks in Robotics 

The temporal dependencies of the ESN also make it suitable for fields like robotics. Some important tasks in robotics where temporal dependencies are used are robot control and learning sequential motor skills. Such tasks are helpful for robotics to adapt to the changes in the environment and learn from previous experience. 

Natural Language Processing 

The ESNs are used in natural language processing tasks such as language modeling, sentiment analysis, etc. Here, the textual data is used to get the temporal dependencies.

Hence, we have learned a lot about the echo state networks. We started with the basic introduction of the ESNs. After that, we saw the basic concepts of the ESNs and their connection with the recurrent neural network. We understood the steps to implement the ESNs in detail. After that, when all the basic concepts were clear, we saw the applications of ESNs with the points that make them ideal for a particular field. I hope the echo state networks are clear to you now. If you have any questions, you can contact us.

Hello learners! Welcome to the next episode of Neural Networks. Today, we are learning about a neural network architecture named Vision Transformer, or ViT. It is specially designed for image classification. Neural networks have been the trending topic in deep learning in the last decade and it seems that the studies and application of these networks are going to continue because they are now used even in daily life. The role of neural network architecture in this regard is important.

In this session, we will start our study with the introduction of the Vision Transformer. We’ll see how it works and for this, we’ll see the step-by-step introduction of each point about the vision transformer. After that, we’ll move towards the difference between ViT and CNN and in the end, we’ll discuss the applications of vision transformers. If you want to know all of these then let’s start reading.

What is Vision Transformer Architecture?

The vision transformer is a type of neural network architecture that is designed for the field of image recognition. It is the latest achievement in deep learning and it has revolutionized image processing and recognition. This architecture has challenged the dominance of convolutional neural networks (CNN), which is a great success because we know that CNN has been the standard in image recognition systems. 

• The ViT works in the following way:
  It divides the images into patches of fixed-size

• Employs the transformer-like architecture on them

• Each patch is linearly embedded

• Position embeddings are added to the patches

• A sequence of vectors is created, which is then fed into the transformer encoder

We will talk more about how it works, but let’s look at how ViT was introduced in a market to understand its importance in image recognition.

Vision Transformer Publication

The vision transformer was introduced in a paper in 2020 titled “An Image is Worth 16x16 Words: Transformers for Image Recognition at Scale.” This paper was written by different researchers, including Alexey Dosovitskiy, Lucas Beyer, and Alexander Kolesnikov, and was presented at the conference on Neural Information Processing Systems (NeurIPS). This paper has different key concepts, including:

• Image Tokenization

• Transformer Encoder for Images

• Positional Embeddings

• Scalability

• Comparison with CNNs

• Pre-training and Fine-tuning

Some of these features will be discussed in this article. 

Features of Vision Transformer Architecture

The vision transformer is one of the latest architectures but it has dominated other techniques because of its remarkable performance. Here are some features that make it unique, among others:

Transformer Architecture in ViT

ViT uses the transform architecture for the implementation of its work. We know that transformer architecture is based on the self-attention mechanism; therefore, it can capture information about the different parts of the sequence input. The basic working of Vi is to divide the images into patches, so after that, the transformer architecture helps to get the information from different patches of the image.

Classification Token in ViT

• This is an important feature of ViT that allows it to extract and represent global information effectively. This information is extracted from the patches made during the implementation of ViT. 

• The classification token is considered a placeholder in the whole sequence created through the patch embeddings. The main purpose of the classification token is to act as the central point of all the patches. Here, the information from these patches is connected in the form of a single vector of the image. 

• The classification token is used with the sel-attention mechanism in the transformer encoder. This is the point where each patch interacts with the classification token and as a result, it gathers information about the image.  

• The classification token helps in the gathering of the final image after getting the information from the encoder layers. 

Training of the Large Datasets

The vision transformer architecture has the ability to train large datasets, which makes it more useful and efficient. The ViT is pre-trained on large sets such as ImageNet, which helps it learn from the general features of the images. Once it is fully trained, the training process using the small dataset is performed on it to get it working on the targeted domains. 

Scalability in ViT

One of the best features of ViT is its scalability, which makes it a perfect choice for image recognition. When the resolution of the images increases during the training process, the architecture does not change. The ViT has the working mechanisms to work in such scenarios. This makes it possible to work on high-resolution images and provide fine-grained information about them.

Working on the Vision Transformer Architecture

Now that we know the basic terms and working style of vision transformers, we can move forward with the step-by-step process of how vision transform architecture works. Here are these steps:

Image Tokenisation in ViT

The first step in the vision transformer is to get the input image and divide it into non-overlapping patches of a fixed size. This is called image tokenization and here, each patch is called a token. When reconnected together, these patches can create the original input image. This step provides the basis for the next steps. 

Linear Embedding in ViT

Till now, the information in the ViT is in pictorial format. Now, each patch is embedded with a vector to convert the information into a transformer-compatible format. This helps with smooth and effective working. 

Positional Embedding in ViT

The next step is to assign the patches all spatial information and for this, positional embeddings are required. These are added to the token embeddings and help the model understand the position of all the patches of images.  

These embeddings are an important part of ViT because, in this case, the spatial relationship among the image pixels is not inherently present. This step allows the model to understand the detailed information in the input. 

Transformer Encoding in ViT

Once the above steps are complete, the tokenized and embedded image patches are then passed to the transformer encoder for processing. It consists of multiple layers and each of them has a self-attention mechanism and feed forward neural network. 

Here, the self-attention mechanism is able to capture the relationship between the different parts of the input. As a result, it takes the following features into consideration:

• The global context of the image

• Long dependencies of the image

Working of Classification Head in ViT

As we have discussed before, the classification head has information on all the patches. It is a central point that gets information from all other parts and it represents the entire image. This information is fed into the linear classifier to get the class labels. At the end of this step, the information from all the parts of the image is now present for further action.

Training Process of ViT

The vision transformers are pre-trained on large data sets, which not only makes the training process easy but also more efficient. Here are two phases of training for ViT:

1. The pre-training process is where large datasets are used. Here, the model learns the basic features of the images. 

2. The fine-tuning process in which the small and related dataset is used to train the model on the specific features. 

Attention to the Global context

This step also involves the self-attention mechanism. Here, the model is now able to get all the information about the relationship among the token pairs of the images. In this way, it better captures the long dependencies and gets information about the global context.

All these steps are important in the process and the training process is incomplete without any of them.

Difference Between ViT and CNN

The importance and features of the vision transformer can be understood by comparing it with the convolutional neural network. CNNs are one of the most effective and useful neural networks for image recognition and related tasks but with the introduction of a vision transformer, CNNs are considered less useful. Here are the key differences between these two:

Feature Extraction

• The core difference between ViT and CNN is the way they adopt feature extraction. The ViT utilizes the self-attention mechanism for feature extraction. This helps it identify long-range dependencies. Here, the relationship between the patches is understood more efficiently and information on the global context is also known in a better way. 

• In CNN, feature extraction is done with the help of convolutional filters. These filters are applied to the small overlapping regions of the images and local features are successfully extracted. All the local textures and patterns are obtained in this way. 

Architecture of the Model

The ViT uses a transformer-based architecture, which is similar to natural language processing. As mentioned before, the ViT has the following:

• Encoder with multiple self-attention layers and a final classifier head. These multiple layers allow the ViT to provide better performance. 

• CNN uses a feed-forward architecture and the main components of the networks are:

• Convolutional layers

• Pooling layers

• Activation functions

Strength of Networks

Both of these have some important points that must be kept in mind when choosing them. Here are the positive points of both of these:

• The ViT has the following features that make it useful:

• Vit can handle global context effectively

• It is less sensitive to image size and resolution

• It is efficient for parallel processing, making it fast

• CNN, on the other hand, has some features that ViT lacks, such as:

• It learns local features efficiently

• It has the explicit nature of filters so it shows Interpretability

• It is well-established and computationally efficient

So all these were the basic differences, the following table will allow you to compare both of these side by side:

Recent Trends in Vision Transformer

The introduction of the ViT is not old and it has already been implemented in different fields. Here is the overview of some applications of the ViT where it is currently used:

Image Classification

The most common and prominent use of ViT is in image classification. It has provided remarkable performance with datasets like ImageNet and CIFAR-100. The vision transformer has classified the images into different groups that provide the user with a guarantee of their best performance.

Object Detection

The pre-training process of the vision transformer has allowed it to perform object detection in the images. This network is trained specially to detect objects from large datasets. It does it with the help of an additional detection head that makes it able to predict bounding boxes and confidence scores for the required objects from the images. 

Image Segmentation with ViT

The images can be classified into different groups using the vision transformer. It provides a pixel-level prediction that allows it to make decisions in great detail. This makes it suitable for applications such as medical imaging and autonomous driving. 

Generative Mdoeling with ViT 

The vision transformer is used for the generation of realistic images using the existing data sets. This is useful for applications such as image editing, content creation, artistic exploration, etc.

Hence, we have read a lot about the vision transformer neural network architecture. We have started with the basic introduction, where we see the core concepts and the flow of the vision transformer’s work. After that, we saw the details of the steps that are used in ViT and then we compared it with CNN to understand why it is considered better than CNN in many aspects. In the end, we have seen the applications of ViT to understand its scope. I hope you liked the content and if you are confused at any point, you can ask in the comment section.

Hello pupils! Welcome to the next session of the neural network series. I hope you are doing good. In the previous part of this series, I showed the double deep Q networks and discussed their differences from the deep Q network to make things clear. Today, I am going to visit a very popular neural network with you. This is the spiking neural network that mimics the functionality of the biological neurons with the help of spikes. This is a different neural network than the traditional networks and you will see the details of each point. 

In this lecture, we’ll understand the introduction of the spiking neural network. We’ll discuss all the basic terms that are used while studying the SNN. After that, we’ll move on to the steps of using SNN in detail. In the end, we’ll move towards the applications of the SNN and understand how its similar structure to the brain helps to improve different applications.

Introduction to Spiking Neural Networks

The spiking neural networks (SNN) show a unique and inspiring neural network approach that is a perfect combination of deep learning neural networks, biological structure, and computational neuroscience. For their performance, the SNN uses spikes or pulses of electrical conductivity to communicate the information from one place to another. It is defined as:

"The spiking neural networks (SNN) are deep learning artificial neural networks that are inspired by biological structure and mechanisms and work with the help of discrete and precisely designed events known as spikes."

In traditional neural networks, continuous values are used to represent the activation functions but here, the continuous values are smooth and easy to implement with better performance. 

History of Spiking Neural Networks

The last decade has witnessed the seamless applications and features of artificial neural networks. But the history of these networks is older than this. The spiking neural networks can be traced back to the early neural networks. Here are some important highlights of the introduction and growth of SNN:

• In 1952, Alan Hodgkin and Andrew Huxley were the first to publish their thoughts in research about squid giant axons’s action potential. This helped others understand the biophysical basis and this was the foundation for the idea of spiking. 

• In the same decade, Warren McCulloch and Walter Pitts presented the McCulloch-Pitts neuron, which is the first mathematical neuron model. This model is the foundation of early artificial neural networks. It utilizes the binary activation values. 

• In the 1960s, Frank Rosenblatt was successful in developing the perceptrons. It is a single-layer artificial neural network that is able to perform simple and basic tasks. This was first appreciated well but after that, people started criticizing it because it was useful on a very small level. 

• In 1970, Bernard Widrow and Ted Hoff presented Adaptive Linear Neuron (ADALINE). It is also a single-layer neural network but it works on continuously valued activation functions. Other people worked more on its improvements and as a result, better networks and outputs were seen during this time.  

• In the 2000s, research was performed on the neurons and this gave rise to mimicking structure in SNN. It resulted in the interest of other scientists in these techniques and the work on the spikings was boosted. This was the time when new algorithms and techniques were introduced for the SNN, and the improved performance not only showed more interest among the people but also broadened the domains of the SNN. 

• Currently, SNN is being used in different fields such as robotics, healthcare, artificial intelligence, etc. You will see the details of applications at the end of this article. 

Basic Concept of Spiking Neural Networks

It's better to understand the basic concepts to understand the working principles and applications of SNN. These are the terms often used when dealing with spiking neural networks:

What are Spikes in SNN?

• The spikes are the fundamental unit of communication in the spiking neural networks. These are also known as action potentials and are the brief pulses of electrical activity. 

• A spike is a sudden, rapid, and transient change that represents the output of the neuron. 

• These are in the form of firing neurons and are responsible for the transition of the neurons in the whole network. 

• The SNN relies on the spikes for the transmission of the data. This point is different from the traditional neural network where continuous activation functions are required for this purpose. 

• The information on the spikes like the timing and frequency are important factors of the network.

• If the spikes have a precise relative timing to each other then these can encode the temporal information. Hence the SNN capture the dynamic nature of the biological neural system. 

• Spikes also play a fundamental role in the computational capabilities. They have multiple features related to computational capabilities such as:

• Temporal data more effectively

• Handle the complex spatiotemporal pattern

• Potentially operate in a more energy-efficient manner (as compared to traditional artificial neural networks)

• The advancement in the spikes research is resulting in more powerful SNNs. 

Membrane Potential in Spiking Neural Network

• In biological neurons, the cell membrane is responsible for maintaining the difference between the intracellular and extracellular environments. A similar concept is also present in the membrane potential of the spiking neural networks. Usually, the membrane potential is different in both these environments. 

• The membrane potential is the key concept in SNN that describes the electric potential difference across the cell membrane. 

• This is the dynamic quantity therefore, it changes with time and determines if the neuron has to generate the spike or not. 

• The neuron in SNN has the threshold membrane potential (discussed below). If the potential is less than this, no change occurs in it, Otherwise, the spike is generated. 

What is the Threshold Potential in SNN?

• The threshold potential is a specific minimum voltage level that a neuron must reach to generate the action potential (spike). Hence, it can be considered as a border of potential values and this is described as: 

If 

Potential values

Then

Neuron does not produce a spike

If

Potential values>=threshold value

Then

Neuron produces spike

Synaptic Weight in Spike Neural Network

In SNN, the synaptic Weight is the measure of the connection strength of two neurons. This has an effect on the influence of one neuron on the other. Strong synaptic weight means a more substantial effect on the receiving neuron. As a result, there are more chances of firing the spike because of the incoming signal from such a neuron. The opposite case is in the weak neuron. 

Excitatory Input in SNN

As the name suggests, the excitatory input of the SNN is the type of input signal that results in more firing of spikes. The excitatory input results in the following processes in SNN:

• The input results in the depolarization of the neuron

• The membrane potential increases because of depolarization

• The potential may reach the threshold potential value

• The result of this value can be in the firing of a spike

Inhibitory Input in SNN

The inhibitory input is the opposite of the excitatory input. This results in the inhibition of the firing of spikes. The following processes occur in neurons when inhibitory input is added:

• The inhibitory input results in the hyperpolarization of the neuron

• The overall membrane potential decreases

• The neuron moves far from the threshold potential value

• There are less chances of spike firing

Post-Synaptic Potential (PSP) in SNN

• A better understanding of this concept will be achieved when you know the following terms:

• A presynaptic neuron is one that sends the signal to the other neuron. 

• The neuron that receives the signal from the presynaptic neuron.

• A port synaptic potential is any change in the membrane potential caused by the presynaptic neuron. 

• It is the combinational effect of the excitatory input and inhibitory input. 

• The collective effect of both of these changes the values of the membrane potential and if it touches the threshold potential, it results in the spike generation and vice versa. 

Temporal Coding in SNN

Temporal coding is the process of encoding the information in the neuron of SNN. Temporal coding is a more reliable method in SNN because it does not just rely on the firing rate of spikes but it also involves the information of the occurrence of spikes. In this way, the more precise and detailed information of the data. 

Rate Coding in SNN

The rate coding is another type of coding where the average timing of neuron firing is involved. 

 It involves information on the average firing rate of spikes. Other related information such as spikes in frequency over a given time. It is a different coding method from the temporal coding. 

Synaptic Plasticity

The synapses are an important concept in SNN and it is defined as:

"The synapses in SNN are the specialized junctions between two neurons and these play a crucial role in the communication between these two."

In synapses, the synaptic plasticity is their ability to change their strength according to the experience in the SNN. it is done by making changes in the weights of synapses and as a result, the connection is modified to a stronger or weaker force according to the case. This is an important feature to understand.

Learning in SNNs

Just like the biological learning principles, that move towards the optimization of the whole system according to environment, the learning process of SNN is intelligent enough to provide the best performance. It means the modification of the synaptic weights according to the current condition of the network. As a result, the system of SNN works to move towards stability and optimization according to the environment. 

Working of Spiking Neural Networks

Through the basic concepts of the spiking neural network, the working principle of the spiking neural network is clear to you. Now, there is a need to discuss the flow of all the processes occurring in SNN. The working in SNN is accomplished in five steps given next:

1. The setting of input and Synaptic Weights 

2. Membrane Potential Update process

3. Spike Generation in SNN

4. Spike Propagation in SNN

5. Learning and Plasticity for the final results in SNN

Here are the details of each step that will be easy for you to understand:

Initialization of Neurons in SNN

• The first step is to initialize the neurons to create the network. Each neuron has its specific features such as membrane potential, threshold values, etc. 

• The information of a specific neuron is based on the spikes. These have synaptic weights that determine the strength of the presynaptic neuron to the postsynaptic neuron. 

Update in the Membrane Potential of SNN

• Once the network is arranged successfully according to the requirements, the firing of the spikes occurs. Here, when the presynaptic neuron generates spikes, it transmits the signals. 

• There is an effect on the potential difference of postsynaptic neurons. The nature of synapses decides if the signal is an inhibitory input or an excitatory input (as discussed above).

• The membrane potential continuously updates throughout the whole process. The overall effect of both these inputs results in the final membrane potential of neurons at a specific point. 

Spike Generation in SNN

• The membrane potential has a specific threshold value.

•  If the potential reaches this value, the postsynaptic neuron fires the spikes. 

• The inhibitory and excitatory inputs collectively influence the timing of the spikes. 

• Every neuron can encode information like spiking frequency, etc. 

Spike Propagation in SNN

The firing of spikes results in the propagation of the signal to the next neuron in the network. This process is continuous throughout the network and results in the influence of the signal on sending and receiving neurons. 

Learning and Plasticity for the final results in SNN

The propagation of the spikes occurs throughout the network and after some time, the weight of the neuron is modified in the process of synaptic plasticity. This process depends on the multiple values in neurons and it affects the learning process of the network. This not only helps in the growth and learning of the network but allows it to adopt new information and stimulate multiple processes throughout the network. 

Applications of Spiking Neural Networks

Spiking neural networks are one of the most popular emerging techniques in deep learning. The working of these networks is different from that of traditional neural networks; therefore, they have a little bit different and complex applications. Here are some of the main domains where SNN is being used along with other neural networks but the output of the SNN is different from others:

Neuromorphic Computation with SNN

In neuromorphic computations, the SNN is used for the development of specialized hardware and software systems. These are the copies or mimicry of the structure and features of the human brain. These computing chips are used for different purposes where memory and related features are required. For instance, the SNN is used in neuromorphic chips that offer high processing speed and efficiency in energy usage.

Sensory Processing Using SNN

The SNN plays a role in areas where sensory information is required to get better output. For instance, in fields where vision or audio recognition is required for the output, SNN is used for better processing because these can work on the spatiotemporal patterns. As a result, SNN has major applications in speech, voice, and vision recognition systems. 

Spiking Neural Networks in Event-based Cameras 

The spiking neural networks are used in the specialized cameras. These are called event-based cameras and are designed to capture the changes of the event in the frame, unlike traditional cameras. These cameras have applications such as:

• Object tracking

• Motion analysis

• Gesture recognition

• Motion detection

Brain-Computer Interface (BCI) and SNN

There are different processes in the field of brain-computer interfaces that can be improved with the help of SNN. For instance, communication or control processes are made better using this neural network because it has the feature of temporal dynamics. This allows it to do better with spiking behaviours, just like the human brain. 

Cognitive Modeling Process using SNN

The brain-like working of SNN is suitable for cognitive modeling. Usually, the researchers use SNN to understand the functionality and working of the neural networks and learn how they deal with cognitive mechanisms and learning tasks. SNN can work on the temporal aspects that help them in processes like:

• Information processing

• Decision making

• Human cognition

This helps to improve the functionality of the system.

Use of SNN in Neuroprosthetics 

One of the important applications of SNN is in neuroprosthetics, where it is implemented on specialized hardware chips. These chips are designed to be used in processes like edge computation and processing using sensors. As a result, these present parallelism and efficiency.

Hence, today we have seen the details of spiking neural networks. These are the modern networks that are based on a similar structure of the brain. We started with the basic definition of SNN and saw the core concept that helped us understand the flow of the spiking neural network. After that, we have seen the details of the application of SNN to understand that it is widely used in domains where human brain-like behavior is required. I hope you find this article useful. If you have any questions, you can ask them in the comment section.

Hey pupils! Welcome to the next session on modern neural networks. We are studying the basic neural networks that are revolutionizing different domains of life. In the previous session, we read the Deep Q Networks (DQN) Reinforcement Learning (add link). There, the basic concepts and applications were discussed in detail. Today, we will move towards another neural network, which is an improvement in the deep Q network and is named the double deep Q network. 

In this article, we will point towards the basic workings of DQN as well so I recommend you read the deep Q networks if you don’t have a grip on this topic. We will introduce the DDQN in detail and will know the basic needs for improvement in the deep Q network. After that, we’ll discuss the history of these networks and learn about the evolution of this process. In the end, we will see the details of each step in the double-deep Q network. The comparison between DQN and DDQN will be helpful for you to understand the basic concepts.  This is going to be very informative so let’s start with our first topic.

What is a Double Deep Q Network?

The double deep Q network is the advanced form of the Dqqp Q Network (DQN). We know that DQN was the revolutionary approach in Atari 2600 games because it utilizes the deep learning algorithm to learn from the simple raw game input. As a result, it provides a super human-like performance in the games. Yet, in some situations, the overestimation was observed in the action’s value; therefore, a suboptimal situation is observed. After different research and feedback from the users, the Double Deep Q Learning method was introduced. The need for the double deep Q network will be understood by studying the history of the whole process. 

History of Double Deep Q Network

The history of the double deep Q network is interwoven with the evolution process of deep reinforcement learning. Here is the step-by-step history of how the double deep Q network emerged from the DQN. 

Rise of QDN

In 2013, a researcher from Google DeepMind named Volodymyr Mnih and the team published a paper in which they introduced deep networks. According to the paper, the Deep Q network (DQN) is a revolutionary network that combines neural networks and reinforcement learning together. 

The DQN made an immediate impact on the game industry because it was so powerful that it could surpass all the human players. Different researchers moved towards this network and created different applications and algorithms related to it.

Limitations of DQN 

The DQN gained fame soon and attracted a large audience, but there were some limitations to this neural network. As discussed before, the overestimation bias of DQN was the problem in some cases that led the researchers to make improvements in the algorithm. The overestimation was in the case of action values and it resulted in slow convergence in some specific scenarios. 

First Introduction to DDQN

In 2015, a team of scientists introduced the Double Deep Q Network as an improvement of its first version. The highlighted names in this research are listed below:

• Ziyu Zhang

• Terrance Urban

• Martin Wainwright

• Shane Legg (from Deep Mind)

They have improved it by applying the decoupling of action selection and action evaluation processes. Moreover, they have paid attention to deep reinforcement learning and tried to provide more effective performance. 

First Impression of DDQN

The DDQN was successful in providing a solid impact on different fields. The DQN was impactful on the Ataari 2600 games only but this version has applications in other domains of life as well. We will discuss the applications in detail soon in this article. 

The details of evolution at every step can be examined through the table given here:

How Does DDQN Work?

The working mechanism of the DDQN is divided into different steps. These are listed below:

1. Action Selection and Action Evaluation 

2. Q value Estimation Process 

3. Replay and Target Q-network Update

4. Main Q-network Update

Let’s find the details of each step:

1. Q value Estimation Process 

The DDQN has improved its working because it combines the action selection and action evaluation processes. For this, the DDQN has to use two separate Q networks. Here are the details of this network:

Main Q Network in DDQN

The main Q network is responsible for the selection of the particular action that has the highest prediction Q value. This value is important because it is considered the expected future reward of the network for the particular state.

Targeted Q Network

It is a copy of the main Q network and it is used to evaluate the Q values the main network predicts. In this way, the Q values are passed through two separate networks. The difference between the workings of these networks is that this network updates less frequently and makes the values more stable; therefore, these values are less overestimated. 

2. Q-value Estimation and Action Selection

The following steps are carried out in the Q value estimation selection:

• The first step is searching for state representation. The agent works and gets the state representation from the environment. This is usually in the form of visual input or some numerical parameters that will be used for further processing. 

• This state representation move is fed into the main Q network as an input. As a result of different calculations, the output values for the possible action are shown. 

• Now, among all these values, the agent selects the one Q value from the main Q value that has the highest prediction. 

3. Replay and Target Q-network Update

The values in the previous step are not that efficient. To refine the results, the DDQN applies the experience replay. It uses reply memory and random sampling to store past data and update the Q networks. Here are the details of doing this:

• First of all, the agent interacts with the environment and collects a stream of experiences. Each of the streams has the following information:

• The current state of the network

• Action taken

• The reward received in the network

• The next state of the network

• The results obtained are stored in replay memory.

•  The random batch of values from the memory is sampled at regular intervals. In this way, the evaluation of the action's performance is updated for each experience. It is done to get the Q values of the actions. 

4. Main Q-network Update

The target Q network updates the whole system by providing the accumulative errors therefore, the main Q network gets frequent updates and as a result, better performance is seen. The main Q network gets continuously learns and this results in better Q value updates. 

Comparison of DQN and DDQN

Both of these networks are widely used in different applications of life but the main purpose of this article is to provide the best information regarding the double deep Q networks. This can be understood by comparing it with its previous version which is a deep Q network. In research, the difference between the cumulative reward at periodic intervals is shown through the image given next:

Here is the comparison of these two on the basis of fundamental parameters that will allow you to understand the need of DDQN:

Overestimation Bias 

As discussed before, the basic point where these two networks are differentiated is the overestimation bias. Here is a short recap of how these two networks work with respect to this parameter:

• The traditional DQN is susceptible to overestimation bias therefore, Q values are overestimated and result in suboptimal policies. 

• The double deep Q networks are designed to deal with the overestimation and provide an accurate estimation of Q values. The separate channels to deal with the action selection and evaluation help it to deal with the overestimation. 

The presence of two networks not only helps in the overestimation but also in problems such as action selection and evaluation, Q value estimation, etc. 

Stability and Convergence

• In DQN, the overestimation results in the instability of the results at different stages which can cause the convergence in the overall results. 

• To overcome this situation, in DDQN, a special mechanism helps to improve the stability and as a result, better convergence is seen. 

Target Network Update in Q Networks

• The deep Q networks employ the target network for the purpose of training stabilisation. However these target networks are directly used for the action selection and evaluation therefore, it has less accuracy. 

• The issue is solved in DDQN because of the periodic updations and it is done with the parameter of the online network. As a result, a stable training process provides better output in DDQN. 

Performance of DQN VS DDQN

• The performance of DQN is appreciable in different fields of real life. The issue of overestimation causes errors in some cases. So, it has a remarkable performance as compared to different neural networks but less than the DDQN.

• In DDQN, fewer errors are shown because of the better network structure and working principle. 

Here is the table that will highlight all the points given above in just a glance:

The applications of both these networks seem alike but the basic difference is the performance and accuracy.

Hence, the double deep Q network is an improvement over the deep Q networks. The main difference between these two is that the DDQN has less overestimation of the action’s value. This makes it more suitable for different fields of life. We started with the basic introduction of the DDQN and then tried to compare it with the DQN so that you may understand the need for this improvement. After that, we read the details of the process carried out in DDQN from start to finish. In the end, we saw the details of the comparison between these two networks. I hope it was a helpful article for you. If you have any questions, you can ask them in the comment section.

Hello readers! Welcome to the next episode of the Deep Learning Algorithm. We are studying modern neural networks and today we will see the details of a reinforcement learning algorithm named Deep Q networks or, in short, DQN. This is one of the popular modern neural networks that combines deep learning and the principles of Q learning and provides complex control policies.

Today, we are studying the basic introduction of deep Q Networks. For this, we have to understand the basic concepts that are reinforcement learning and Q learning. After that, we’ll understand how these two collectively are used in an effective neural network. In the end, we’ll discuss how DQN is extensively used in different fields of daily life. Let’s start with the basic concepts.

What is Reinforcement Learning?

• Reinforcement learning is a subfield of machine learning that is different from other machine learning paradigms.
• It relies on the trial-and-error learning method and here, the agent learns to make decisions when it interacts with the environment.
• The agent then gets feedback in the form of rewards or penalties, depending on the result. In this process, the agent learns to have the optimal behavior to achieve the goals. In this way, it gradually learns to maximize the long-term reward.
  

Unlike this learning, supervised learning is done with the help of labeled data. Here are some important components of the reinforcement learning method that will help you understand the workings of deep Q networks:

Basic Concepts of Q Learning for Deep Q Networks

Q learning is a type of reinforcement learning algorithm that is denoted by Q(s,a). Here, here, 

• Q= Q learning function

• s= state of the learning

• a= action of the learning

This is called the action value function of the learning algorithm. The main purpose of Q learning is to find the optimal policy to maximize the expected cumulative reward. Here are the basic concepts of Q learning:

State Action Pair in Q Learning

In Q learning, the agent and environment interaction is done through the state action pair. We defined the state and action in the previous section. The interaction between these two is important in the learning process in different ways. 

Bellman Equation in Q learning

The core update rule for Q learning is the Bellman equation. This updates the Q values iteratively on the basis of rewards received during the process. Moreover, future values are also estimated through this equation. The Bellman equation is given next:

Q(s,a)←(1−α)⋅Q(s,a)+α⋅[R(s,a)+γ⋅maxa′​Q(s′,a′)]

Here, 

γ = discount factor of the function which is used to balance between immediate and future rewards. 

R(s, a) = immediate reward of taking the action “a” within the state “s”.

α= The learning rate that controls the step size of the update. It is always between 0 and maxa′Q(s′,a′) = The prediction of the maximum Q values over the next state s′ and action value a′

What is Deep Q Network (DQN)

The deep Q networks are the type of neural networks that provide different models such as the simulation of video games by using the Q learning we have just discussed. These networks use reinforcement learning specifically for solving the problem through the mechanism in which the agent sequentially makes a decision and provides the maximum cumulative reward. This is a perfect combination of learning with the deep neural network that makes it efficient enough to deal with the high dimensional input space.

This is considered the off-policy temporal difference method because it considers the future rewards and updates the value function of the present state-action pair. It is considered a successful neural network because it can solve complex reinforcement problems efficiently. 

Applications of Deep Q Network

The Deep Q network finds applications in different domains of life where the optimization of the results and decision-making is the basic step. Usually, the optimized outputs are obtained in this network therefore, it is used in different ways. Here are some highlighted applications of the Deep Q Networks:

Atari 2600 Games 

The Atari 2600 games are also known as the Atari Video Computer System (VCS). It was released in 1977 and is a home video controller system. The Atari 2600 and Deep Q Network are two different types of fields and when connected together, they sparked a revolution in artificial intelligence.

The Deep Q network makes the Atari games and learns in different ways. Here are some of the ways in which DQN makes the Atari 2600 train ground:

• Learning from pixels

• Q learning with deep learning

• Overcoming Sparse Rewards

DQN in Robotics

• Just like reinforcement learning, DQN is used in the field of robotics for the robotic control and manipulation of different processes. 

• It is used for learning specific processes in the robots such as:

• Grasping the objects

• Navigate to environments

• Tool manipulation

• The feature of DQN to handle the high dimensional sensory inputs makes it a good option in robotic training where these robots have to perceive and create interaction with their complex surrounding. 

Autonomous Vehicles with DQN

• The DQN is used in autonomous vehicles through which the vehicles can make complex decisions even in a heavy traffic flow. 

• Different techniques used with the deep Q network in these vehicles allow them to perform basic tasks efficiently such as:

• Navigation of the road

• Decision-making in heavy traffic

• Avoid the obstacles on the road

• DQN can learn the policies from adaptive learning and consider various factors for better performance. In this way. It helps to provide a safe and intelligent vehicular system. 

Healthcare and DQN 

• Just like other neural networks, the DQN is revolutionizing the medical health field. It assists the experts in different tasks and makes sure they get the perfect results. Some of such tasks where DQN is used are:

• Medical diagnosis

• Treatment optimization

• Drug discovery

• DQN can analyze the medical record history and help the doctors to have a more informed background of the patient and diseases. 

• It is used for the personalized treatment plans for the individual patients.

Resource Management with DQN

• Deep Q learning helps with resource management with the help of policies learned through optimal resource management. 

• It is used in fields like energy management systems usually for renewable energy sources. 

Deep Q Network in Video Streaming 

In video streaming, deep Q networks are used for a better experience. The agents of the Q network learn to adjust the video quality on the basis of different scenarios such as the network speed, type of network, user’s preference, etc. 

Moreover, it can be applied in different fields of life where complex learning is required based on current and past situations to predict future outcomes. Some other examples are the implementation of deep Q learning in the educational system, supply chain management, finance, and related fields. 

Hence in this way, we have learned the basic concepts of Deep Q learning. We started with some basic concepts that are helpful in understanding the introduction of the DQN. These included reinforcement learning and Q learning. After that, when we saw the introduction of the Deep Q network it was easy for us to understand the working. In the end, we saw the application of DQN in detail to understand its working. Now, I hope you know the basic introduction of DQN and if you want to know details of any point mentioned above, you can ask in the comment section.

Hello students! I hope you are doing great. Today, we are talking about the decoders in the proteus. We know that decoders are the building blocks of any digital electronic device. These electronic circuits are used for different purposes, such as memory addressing, signal demultiplexing, and control signal generation. These decoders have different types and we are discussing the 3 to 8 line decoders.

In this tutorial, we will start learning the basic concept of decoders. We’ll also understand what the 3-to-8line decoders are and how we connect this concept with the 74LS138 IC in proteus. We’ll discuss this IC in detail and use it in the project to present the detailed work. 

What is a 3 to 8 Line Decoder?

A three to eight line decoder is an electronic device that takes three inputs and based on their combination, provides one of its eight outputs. In simple words, the 3 to 8 line decoder gets three inputs and reads the binary combination of its input. As a result, the single output is obtained at the output of the decoder. Here are the basic concepts to understand its working:

Binary Input in 3 to 8 Decoder

A 3 to 8 line decoder has three input pins which are usually denoted as A, B and C. These correspond to the three bits of the binary code.  The term binary means these can only be 0 or 1 and no other digits are allowed. This can be the raw bits from the user or can be the output signal from the circuits’ device that becomes the input of the decoder.

Outputs of 3 to 8 Decoder

The 3 to 8 decoder has eight possible output pins. These are usually denoted as Y0, Y1, Y2,..., Y7  and the output is obtained only at one of these pins. The output depends on the binary combination of the input provided to it. In large circuits, its output is fed into any other component and the circuit works. 

Functionality of 3 to 8 Decoder

As mentioned before, the combination of the binary input decides the output. Only one of the eight output pins of the decoder gets high which means, only one output has the value of one and all others are zero. The high pin is considered active and all other pins are said to be inactive. 

Truth Table of 3 to 8 Decoder

The truth talbe of all the inputs and possible output of 3 to 8 decoders are given here:

Here, 

MSB= Most significant bit

LSB= Least significant bit

I hope the above concepts are now clear with the help of this truth table. 

Introduction to 74LS138 Decoder 

The 74LS138 is a popular integrated circuit IC that is commonly used 3 to 8 line decoder. It is one of the members of 74LS therefore, it is named so. The 74LS is a group of transistor transistor logic (TTL) chips. The basic feature of this IC is to get three inputs and provide the signal on only one pin of the output automatically based on the binary inputs. In addition to the input, output, and functionality of the 74LS138, there are some additional features listed below:

Features of 74LS138

• The 74LS138 has the cascading feature which means, two or more 74LS138 can be connected together to enhance the number of output lines. The circuit is arranged in such a way that the output of one 74LS138 IC becomes the input of the other and as a result, more than one ICs can work together. 

• The structure of this IC is designed in such a way that it provides high-speed operation. It is done because the decoders are supposed to decode the input so quickly that its output may stimulate other functions of the circuits. 

• The TTL compatibility of the 74LS138 makes it more accurate. The LS in its name indicate that these are part of low-power shotkey series therefore, these can be operated at the 5V power supply. This makes it ideal for multiple electronic circuits and these do not require any additional device to get accurate power. 

• These ICs are versatile because they come in different packages and the users can have the right set of ICs depending on the circuit he is using. Two common packages of this IC are given next:

• DIP (Dual Inline Package)

• SOP (Small Outline Package)

• It has multiple modes of operation therefore, it has versatile applications. 

74LS138 IC Pin Configuration

Before using any IC in the circuit, it is important to understand its pinouts. The 73LS138 has the 16 pins structure that which is shown here:

The detailed names and features of these pins can be matched with the table given below:

74LS138 in Proteus

The structure and working of this IC can be understood by creating a project with it and for this, we have chosen the Porteus to show the detailed working. Here are the steps to create the project of a 3 to 8 line decoder in Proteus:

• Open your Proteus software.

• Create a new project. 

• Go to the pick library by clicking the “P” button at the left side of the screen. It will show you a search box with details of the components. 

• Here, type 74LS138 and you will see the following search:
  

• Double click on the IC to collect it on your devices. 

• Selecting this IC, click on the working sheet to place it there. 

You can see the pins and labels of this IC. 

Designing a 3 to 8 Line Decoder with 74LS138

The 74LS138 requires some additional components to be used as a decoder. Here is the project where we are using it as 3 to 8 line decoder:

Components Required

• 74LS138 IC

• 8 LEDs of different colors

• Switch SPDT

• Switch  SPST

• Switch Mom

• Switch (simple)

• Connecting wires

Procedure

• Go to the pick library and get all the components of the circuits one after the other. 

• Set the 74LS138 IC in the working area.

• On the left side of the IC, arrange the switches to be used as the input devices.

• On the left side of the IC, arrange the LEDs that will indicate the output. 

• Go toto the terminal mode from the left side of the screen and arrange the ground and power terminals with the required devices. 

• The circuit at this point must look like the following image:

• Connect all of these with the help of connecting wires. For convenience, I am using the labels to have better work:

• Once you have connected all the components, the circuit is ready to use. In the left bottom corner, search for the play button and run the project. 

• Change the input with the help of switches and check for the output LEDs. You will see the circuit works exactly according to the truth table. 

Working of 74LS138 IC in Proteus

• The 74LS138 is designed to be used as a 3 to 8 line so there is no need to connect different ICs and components to design the working of this decoder.

• The input and output pins are present with this IC therefore, the user simply connects the switches as an input device. A switch has only two possible states that are either on or off therefore, it is an ideal way to present the binary input. 

• Usually, LEDs are used as the output devices so that when they get the signal, they are turned on and vice versa. 

• The ground and power terminals are used to complete the circuit. 

• Pins 4, 5, and 6 are called the enabled pins. These are labeled as E1, E2, and E3 pins. Out of these, E1 and E2 are considered as the active low pins which means, these are active only when they are pulled down. On the other hand, the E3 is considered an active high; hence it activates the output only when it is pulled high. 

• Once the circuit is complete, the user can change the binary inputs through the switches and check for the output LEDs. 

• The combination of inputs results in the required output hence the user can easily design the circuit without making any technical changes. 

Today, we have seen the details of 74LS138 decoder IC in Proteus. We started with the basic introduction of a decoder and saw what is the 3 to 8 line decoder isdecoder. After that, we saw the truth table and the features of a 3 to 8 line decoder. We saw how 74LS128 works and in the end, we designed the circuit of a 3 to 8 line decoder using 74LS138. The circuit was easy and we saw it working in detail. If you have any questions, you can ask in the comment section.

Step into the world of precision engineering—where custom CNC machined parts transform raw materials into the sinews and bones of your next big project. Like a tailor crafting a bespoke suit, CNC machining offers an unparalleled fit for your specific requirements.

The prospect of holding your idea in your hands, not just on paper, is the realm where imagination meets implementation. But what options lie at your fingertips? Let's explore the paths to turning those digital blueprints into tangible assets.

Materializing Visions: The Alloy of Choice

Before the whirring of machines begins, your quest starts with choosing the right material—a decision as critical as selecting the foundation for a skyscraper. Each material whispers its own strengths and secrets, waiting to align with your project's demands.

Aluminum

For starters, aluminum stands out as a front-runner in popularity due to its lightweight yet robust nature —an ally for components in aerospace or portable devices. Imagine the sleek body of a drone or the frame of a prototype sports car; they likely share an aluminum heartbeat.

Stainless Steel

Stainless steel steps forward for projects where endurance and rust resistance are paramount. Think of medical devices that can withstand repetitive sterilization or marine parts whispering secrets to ocean waves without fear of corrosion.

Image Source: Pixabay

Titanium

Delving deeper into specialties, titanium emerges when the strength-to-weight ratio is not just a preference but a necessity—ideal for high-performance sectors such as motorsports or prosthetics.

Brass

Brass occupies a niche where electrical conductivity must dance elegantly with malleability—perhaps in custom electronic connectors or intricate musical instruments.

Each material imparts its essence to your project, shaping not just function but also future possibilities. Which one will be the bedrock for your engineering aspirations?

Carving Precision: The Toolpath Less Traveled

The next step on our journey approaches like the unveiling of a trail in dense fog—selecting the appropriate CNC machining process that will breathe life into your vision. Each method manifests its prowess through sparks and shavings, ready to tackle complexity with finesse.

Better yet, since there are a variety of machines from Revelation Machinery on offer, with second-hand units representing better value than new equivalents, you can pick one of the following without breaking the bank or limiting yourself in terms of functionality and features.

Milling

3-axis milling is like the steadfast hiker; it's reliable and perfect for parts with fairly simple geometries. If your project involves creating a prototype bracket or a basic gear, this could be your marching tune. But when contours call for more intricate choreography, 5-axis milling pirouettes onto the stage. It invites you to envision turbine blades sculpted with aerodynamic grace or an ergonomic joystick that fits into hands as naturally as pebbles on a beach.

Image Source: Pixabay

Turning

Turning—the spinning dance between material and tool—offers cylindrical mastery manifested in objects rotating around their own axis. This is where items such as shafts for motors or precision rollers for conveyor systems are born from rotation's embrace.

EDM Options

But what if your piece hides complex internal features, akin to secret passages within a castle? Enter EDM—Electrical Discharge Machining —a process where electrical sparks rather than physical cutting tools unlock hidden gems. Ideal perhaps for making intricate molds used in injection molding machines that will churn out hundreds of thousands of perfectly replicated plastic knights.

As if wielding a magic wand, wire EDM carves with finesse where traditional tools cannot tread, slicing through hardened steel as easily as a hot knife through butter. Consider the labyrinthine path of a lightweight gear or the delicate framework of an instrument sensor—wire EDM is your guide through these intricate landscapes.

Then there’s the level-headed sibling in this family, plunge/sinker EDM—an ace up your sleeve when three-dimensional complexity calls. It's perfect for forming punch and die combinations used in manufacturing presses that shape sheet metal into automotive body panels or appliance housings with clockwork precision.

Decision Time

The truth nestled within these processes promises tailored solutions to even the most enigmatic engineering puzzles. Your custom CNC machined part will emerge from its fiery birthright not just created, but crafted with intent. In this emporium of efficiency and accuracy, which CNC sorcery will you enlist to transform your concept into creation?

Finishing Touches: The Symphony of Surfaces

Now that the form has been forged, it's time for the maestro—finishing—to step up and conduct a symphony of surfaces. This is where rough edges soften and exteriors gleam, ready for their grand debut.

Anodizing

Anodizing tiptoes onto stage left, offering its protective embrace to aluminum parts. It’s a finish that doesn't just add a splash of color but also bolsters resistance to wear and corrosion. Picture an aerospace fitting beaming with radiant blue or a fire engine red bicycle frame standing resilient against scratches and weathering.

Powder Coating

Powder coating strides in with its own brand of rugged beauty—a finish that cloaks objects in a uniform, durable skin impervious to the elements. Outdoor machinery basks in its shielding layer, flaunting colors that withstand sun, rain, and the passage of seasons.

Image Source: Pixabay

Precision Grinding

For components that need to glide together as smoothly as ballroom dancers, you’ll want to consider precision grinding. Imagine automotive pistons or mechanical bearing races—their surfaces milled down to microscopic levels for tolerances tighter than a drum skin.

Bead Blasting

Perhaps your masterpiece calls for an understated elegance; then bead blasting might brush across the scene. It leaves behind a matte texture that diffuses light and speaks to sophistication. Its application speaks volumes on products where glare is the enemy and understated aesthetics are paramount—like the dashboard of a luxury car or the casing of high-end audio equipment, where touch and sight merge into user experience.

Electroplating

Let's not forget electroplating—the alchemist's choice that transmutes base metals into gold, well, in appearance at least. Here we witness components such as plumbing fixtures or electronic connectors being vested in extra layers for improved conductivity and aesthetic appeal, shimmering with purpose and resilience.

Passivation

If subtlety is your aim, then passivation is your unassuming guardian. Stainless steel medical instruments or food processing parts bask in this chemical bath, emerging more stoic against rust and degradation—an invisible shield for an unspoken duty.

Etching

As the encore approaches with laser etching taking center stage, customization reaches another level. It allows you to adorn surfaces with serial numbers, logos, or intricate patterns—turning each part into a storyteller of its own journey from concept to finality.

The Last Word

All this info should set you up to make smart decisions ahead of creating custom CNC machined parts for any engineering project you have in the pipeline. And it’s worth restating that as well as choosing carefully, buying used machinery is another way to get great results that will make your budget manageable.

In today's digital age, remote workers are on the frontlines of an invisible war, battling unseen cyber threats. As they maneuver through the complex terrain of remote work environments, they're confronted with potential hazards at every turn.

From a compromised network and data breach to phishing attacks, remote workers are tasked with safeguarding the organization's digital fort.

Building a cybersecurity culture

The remote workforce is instrumental in building a cybersecurity culture where everyone becomes their own expert, advocating for security measures and promptly reporting suspicious activities. This culture is particularly significant in virtual office environments, where workers are the custodians of sensitive data.

As remote employees constantly face cybersecurity challenges, from unsecured Wi-Fi networks to malware attacks, their actions shape the security landscape of their organization.

This environment isn't built overnight but through continuous education and reinforcement of secured virtual office tools from trusted providers like iPostal1 .

Ensuring secure network access

While remote workers are integral to building a cybersecurity culture, it's equally essential to have secure network access, especially when working virtually. Remote work security risks are abundant. Hence, implementing cybersecurity solutions for remote working is critical.

Secure network access can be achieved through virtual private networks (VPNs), providing a safe conduit for data transmission.

However, a virtual private network alone isn't enough. Multi-factor authentication (MFA) adds an extra layer of security, reducing the possibility of unauthorized system access. With MFA, even if a cybercriminal cracks your password, they're still one step away from breaching your account.

Password protection and router security

Even though you've secured your network access, don't overlook the importance of password protection and router security in maintaining robust online network security.

Remote workers must change default passwords on home routers and ensure the creation of strong, unique ones. Regular reminders to change these passwords can also help strengthen the router's security.

Moreover, using a mix of characters, numbers, and symbols and avoiding easily guessable phrases can fortify password protection. Remember, the stronger the password, the more challenging it is for cybercriminals to breach it.

Staying ahead in the cybersecurity game requires continuously reviewing and enhancing these protection measures.

Instituting remote work cybersecurity policies

Building on the importance of password protection and router security, remote working involves instituting cybersecurity policies and best practices to further safeguard the virtual office environment.

While remote workers assess the cybersecurity challenges in virtual office environments, they must learn the vital role these policies play in protecting sensitive company data.

Cybersecurity policies cover all aspects of data handling, from remote access procedures to transfer and storage. It includes guidelines on secure network use, encryption protocols, and device security.

Businesses must ensure their policies are comprehensive to address all areas where sensitive company information might be at risk. Regularly reviewing and updating these policies will help organizations avoid emerging threats.

Anti-malware software and phishing Prevention

To ramp up the company's cybersecurity defenses, remote work leaders should prioritize installing robust anti-malware software and educating their team on how to avoid phishing scams.

Anti-malware software is the first line of defense against cybersecurity threats, capable of detecting and neutralizing malicious programs before they infiltrate the system.

But software alone isn't enough. Phishing prevention is equally important, as phishing attacks are increasingly sophisticated, often involving social engineering attacks. These scams trick remote workers into revealing sensitive information, compromising security.

The combination of both robust software and thorough education is vital to a secure virtual office environment.

Strengthening authentication methods

As remote workers fortify their virtual office's cybersecurity, focusing on security infrastructure and strengthening authentication methods is critical.

Robust authentication methods help to ensure that only authorized individuals have access to sensitive data. Remote work leaders must consider biometrics as an additional layer of security for personal devices.

Whether fingerprint scanning, facial recognition, or voice patterns, these technologies can add a more secure, personal touch to remote work authentication methods.

Implementing a zero-trust strategy

To enhance cybersecurity, remote work leaders must implement a zero-trust strategy for cloud security. A zero-trust approach assumes no user or device is trustworthy, be it inside or outside the network.

This strategy demands verification for every access request, thus reducing the cybersecurity risks of data breaches.

As virtual office environments become more prevalent, the cybersecurity risks and challenges they present require advanced strategies.

Before implementing a zero-trust strategy, assessing your data's sensitivity and storage locations is critical. Remember, zero trust should only be applied where it aligns with your organization's needs and capabilities.

This approach is particularly beneficial for protecting data stored in the cloud . By assessing cybersecurity challenges and adopting a zero-trust strategy, you bolster your defenses against potential threats.

New technologies and employee education

Just like implementing a zero-trust strategy, adapting to new technologies is crucial to fortifying your virtual office's cybersecurity. However, ensuring your employees are well-versed in these changes is equally vital.

Before introducing new systems or software, verifying compatibility with the existing tech stack is crucial. This step will help avoid potential conflicts or vulnerabilities arising from integrating new technology.

The next step is educating remote work staff. This part goes beyond simply training employees on how to use new software. It's about making them understand why these changes are necessary for security.

Educating remote work employees on the importance of cybersecurity can encourage a culture of vigilance and active participation in your defense strategy.

Regular training sessions, updates on emerging threats, and clear communication lines for reporting suspicions are essential. These measures will empower your workforce to contribute effectively to your cybersecurity efforts.

By keeping them informed and providing them with the remote working tools they need, employees can be an asset in protecting virtual office data from potential threats.

Final words

Balancing cost and robust security measures is no small feat. Yet, with diligent attention to network access, secure passwords, and comprehensive policies, remote workers can successfully navigate these murky waters. Embrace a zero-trust strategy and wield new technologies to be steadfast guardians. Remember, every vigilant eye is a lighthouse against potential threats in cybersecurity.

By using CNC-machined parts for your next engineering project, you can ensure precision, quality, and speed. So, let us take a look at three options for creating custom parts. 

What Is CNC Machining? 

Before we look at the three options available to you, it is worth briefly explaining what CNC machining is. CNC machining is short for Computer Numerical Control. It is a modern manufacturing method that involves the use of computer-controlled machinery to make custom parts.

The process begins with creating a CAD design of the part you want to make. The design is then translated into g-code and fed into the item of CNC machinery.

The machine then simply gets to work at creating your design with the utmost precision and consistency. The types of CNC machines range widely – from milling machines and lathes to routers and grinders. Each type has its unique advantages depending on your specific production needs.

CNC machining comes with numerous benefits. These include improved efficiency, enhanced safety, consistent quality, and significant time savings.

Additionally, this manufacturing method allows for a wide range of materials to be used. Metals like steel and aluminum are common. But plastics like nylon or ABS as well as wood can be processed.

Now, here are your three options for creating the custom CNC machined parts you need for your next engineering project . 

1. Purchase New CNC Machinery 

Firstly, you have the option to purchase new CNC machinery. If the scale of your project is substantial or if you foresee continuous use, investing in new machinery could well be the best economical choice in the long run.

New CNC machines represent the crux of modern manufacturing technology. They usually have more current features and capabilities compared to older models – including newer software, which offers advanced programming and control options that result in more accuracy and speed.

Remember, when it comes to large-scale repetitive tasks or projects demanding high precision and consistency, nothing beats the efficiency of these machines, so it could definitely be worth investing in the purchase of one or more CNC machines.

Furthermore, owning CNC machinery means you have unrestricted access anytime according to your production schedule’s needs.

Additionally, most new models come complete with warranties that offer maintenance services and part replacement plans from manufacturers. However, a critical factor here is the cost consideration, as top-tier CNC machinery can carry hefty price tags up front.

That being said, many businesses find that prices eventually pay off through improvements in production efficiency, product uniformity, and reductions in material waste.

Overall, acquiring new CNC machinery is not just an asset purchase but an investment towards improved operational efficiency and product quality for your upcoming projects. 

2. Purchase Used CNC Machinery 

A cheaper option is to buy used CNC machinery for your engineering project. This alternative can be particularly attractive if you are working with a limited budget or if the project is not continuous or large-scale.

Used CNC machines often come at a much lower price point in comparison to new ones. Depending on factors such as age, condition, and functional capacity, you might discover good deals that cater perfectly to your needs without straining your budget.

While they may lack some of the advanced functions found in the newest models, well-maintained used machines can still provide commendable performance in precision and repetitive tasks.

However, take note that maintenance consideration is key. Since warranties may not be available for older models, setting aside a budget for potential repairs is prudent. 

3. Use an Online CNC Machining Service

Lastly, you may want to consider using an online CNC machining service for manufacturing the custom machined parts you need for your next engineering project. This option can be the most suitable if you do not have the needed expertise in-house or you lack sufficient workspace. You can also avoid the hefty upfront costs of purchasing machinery.

Online CNC services open up a world of opportunities. They allow access to professional and experienced machinists who operate state-of-the-art machines that cater to virtually any custom specifications. This ensures high-quality parts with excellent precision.

Plus, using such services lifts off the time and effort normally needed for maintaining machines and training personnel. All you need is your digital design file. The service provider will take care of turning your design into a physical part or component. 

Types of CNC Machined Parts You Could Make for Your Next Engineering Project 

For your upcoming engineering project, the possibilities of CNC machined parts you could produce are vast. Whether your project demands small individual components or larger assemblies, CNC machining can cater to them all with unyielding precision.

You can easily manufacture custom components that are specifically tailored to your project’s needs. Here are just some of the common types of CNC machined parts used in engineering projects. 

Gears 

One common part that you can create using CNC machining is gears. Various types such as helical, bevel, or worm gears can be accurately machined. Gears are fundamental in various machinery configurations where power transmission is required. 

Flanges 

CNC machines are also perfect for creating flanges, which are flat rims that enhance strength or provide a method for attachment. As standard components in piping systems, flanges serve to connect pipes or aid in maintenance access points. 

Enclosures 

You can fabricate enclosures too – they serve as protective cases for delicate electrical or mechanical devices. Accurate machining ensures that interior elements fit perfectly while external dimensions comply with assembly requirements. 

Machined Plates 

Machined plates are another type of part you could manufacture with CNC machinery. They are used in numerous applications, ranging from mounting brackets to structural support elements. 

Shafts 

CNC machining is quite useful when making shafts from materials of your choice. Shafts serve as a mechanical component used in power transmission. The exact sizing and surface finish are critical for these elements, which CNC machining can accurately achieve. 

The above list is far from exhaustive. The versatility of CNC machining allows you to create almost any part that your specific engineering project might necessitate.

So, explore the options of buying new CNC machines or used CNC machines in comparison to outsourcing the manufacturing to determine which method to use for creating custom parts for your next project. You may also be interested in learning how industrial robots are revolutionizing engineering projects.