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All about Gradient Descent that One Needs to Know in the Context of Machine Learning

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In our everyday life, we are optimizing variables all the time based on our personal choices, requirements, and preferences even unconsciously. We use optimization techniques all day, for instance, we choose the shortest route to avoid traffic when going to work, figure out and decide to take a quick walk around the campus during our free time, and schedule cabs in advance to reach on time. Most of the optimizations we do are about saving time because time is very important in today’s world. 

Optimization has become an integrated part of our lives and as our lives revolve around technologies, it has also become an integrated part of technological products. Optimization is the ultimate goal present at the heart of all statistical and Machine Learning techniques that are widely used in data science. As a result optimization algorithms have been created; one such algorithm is Gradient Descent in Machine Learning

What is Gradient Descent?

Gradient Descent is an optimization algorithm that is used for finding the minimum of a function. In terms of Machine Learning, it is used for updating parameters in a model. Based on the algorithms that were used, parameters can be of various types – coefficients (in linear regression) and weights (in neural networks). To understand the concept of Gradient Descent through a real-life example, think of a hypothetical situation in which a person has to descend into a valley blindfolded. Anyone in a situation like this would firstly take careful steps to find a slope. Once they find a downward slope, they’ll follow it and repeat their steps until they’ve completely descended into the valley, in other words, reached the minima.

This is exactly what the Gradient Descent Algorithm does in a machine. The inclination or slope is the cost function and the role of Gradient Descent is to provide direction and velocity (rate of learning) of movement to find a point where the cost is minimum or in other words, the minima of the cost function. A cost function is“a function that maps an event or values of one or more variables onto a real number intuitively representing some ‘cost’ associated with the event.”

The Application of Gradient Descent

The foremost goal of any Machine Learning algorithm is to build a model. A model is a hypothesis, which can be used to find out estimation for Y based on X. For example – Let’s say we have some data about different houses regarding their price, size, material, etc. and we want to predict the cost of a house based on its size. For one house, one may do it by a manual comparative analysis but let’s assume we need to know the cost for many houses. In such cases, we would like to predict a continuous output for a given number of inputs. It’s a regression problem that can be solved by an optimization algorithm of Machine Learning, such as Gradient Descent. Gradient descent can help to find a line of best fit for a given number of inputs (X values) and provide any number of outputs (Y values).

Types of Gradient Descent Algorithms

  • Batch Gradient Descent – It is used to process training examples for all the iterations. It can get computationally expensive when there are a lot of training examples. In such cases, other types of Gradient Descents are preferred.
  • Stochastic Gradient Descent – The word ‘stochastic’ refers to a ‘random probability’. For a random probability, a random selection is done. Thus, in a Stochastic Gradient Descent, instead of selecting the whole data set, random samples are selected for all the iterations. Since this type of Gradient Descent only uses a single sample to perform all the iterations, it is not computationally expensive. The sample is randomly shuffled and selected from the dataset. The parameters get updated after each repetition; therefore, it’s faster than Batch Gradient Descent.
  • Mini Batch Gradient Descent  It is the fastestform ofGradient Descent which can be used even when there is a large number of training examples. It processes the batch at once. It uses very less iterations, regardless of the number of training samples

Challenges Faced in the Execution of Gradient Descent

Gradient Descent is a very useful optimization algorithm but it is not perfect and has some drawbacks. There are many cases in which gradient descent cannot be used or doesn’t perform well. It happens when one faces different sorts of challenges during the execution of Gradient Descent. There are mainly three types of challenges:

Data Challenges

If the data is arranged in a way that causes a non-convex optimization problem then performing Gradient Descent on it becomes troublesome. Gradient Descent only works for data arranged to cause a well-defined convex optimization problem. In a convex optimization problem, there are many minimal points. The lowest point is called the global minimum whereas the rest, are local minima. It is important to reach the global minimum by avoiding local minima. Furthermore, Gradient Descent cannot be used in a saddle point problem as well. In such a problem, the gradient can be zero even for a non-optimal point.

Gradient Challenges

An improper execution while using Gradient Descent can cause several problems such as a vanishing gradient problem. It happens when the size of the gradient is either too large or too small, which leads to no convergence. 

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Portrait Photography Techniques: Creating Expressive Images

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Creating expressive portraits requires not only the ability to handle the camera but also an understanding of psychology and working with the model. Portrait is the art of capturing not only a person’s appearance but also their emotions, character, and personality. 

Importance of light

Light is very important for creating the atmosphere and therefore the expressiveness of a portrait in several aspects at once.

  • Light determines the shape, texture, and volume of an object, in this case, the model’s face.
  • The right lighting will help to emphasize the best features of the face and hide flaws. If the camera still “noticed” some defects, you can remove them in the process of retouching. For example, if you want to get a smooth skin app Retouchme will fix the photo in a couple of clicks.
  • Lighting effects and shadows can be used to create emotionally rich portraits. Soft lighting can create a gentle and romantic mood, while harsh shadows add drama and intrigue.

If you choose to shoot in natural light, avoid high sun: it gives harsh shadows. The optimal time to work is the photographer’s golden hour. If the day is cloudy, the light will be soft and diffused, so you can shoot even at noon.

Studio portrait photography uses softboxes, light panels, and reflectors to control the direction and intensity of the flow. Professional lighting is usually more predictable and controllable, so the photographer will be able to create the effects they want and adjust their work on the fly.

Flashes when shooting a model help create bright contrasting portraits and are also used to soften shadows when working with natural light.

Composition and angle

For a model to “read” well in the frame, you need to think about the position of the face and the direction of the lens. What basic techniques does the photographer rely on?

1. Rule of thirds.

Divide the frame into nine equal parts. Position the main subject (in this case, the model’s face) near the intersection of the lines.

2. Diagonal lines.

Use diagonal lines in your composition to direct the viewer’s eye toward the face. Position the model so that the eye line tends to run along the diagonal line.

3. Positioning the main object.

Place the main subject (the face) in the center of the frame – this is how you get a confident and focused image. Use the golden ratio by positioning the model on one of the lines to achieve a balance between the main object and the space around it.

4. Use of negative space.

Leave enough space around the model’s face to create a sense of “breathing” and depth.

5. Work with foreshortening.

Experiment with shooting directions, such as a high or low angle.

6. Use background.

Include prominent details such as trees or architecture to create an interesting background. Use surrounding elements as a frame for the model’s face to draw attention to the main subject of the portrait.

These tips will help you shoot expressive portraits just by working with composition alone.

Creative angles: unconventional approaches to portraiture

Experiment with blurred backgrounds or using macro photography to create unconventional effects in portraits. This can help highlight the main subject and add dynamics to the image.

  • Use mirrored or reflective surfaces (glass, water, metal) to create unique effects in portraits. 
  • Try using the model’s movement while shooting by setting a slow shutter speed.
  • Use aerial platforms, drones or other devices to get unconventional angles from above or below. 

Is the background important for an expressive image?

The choice of surroundings plays a key role in creating the overall image that the viewer will see. Here are a few techniques that will add just the right amount of expression to your images.

  • Try to achieve contrast between the background and the model’s face or, conversely, create harmony by using complementary colors and textures.
  • Take into account the style and character of the portrait. For example, use natural surroundings if you want to achieve a calm image, or add abstract details for a non-basic role.
  • Match the background to the mood you want to convey, such as light and bright colors for a joyful and optimistic portrait or darker tones for a mysterious and dramatic mood.
  • A minimalistic background, such as a solid-colored wall, will focus the viewer’s attention on the model’s face. A rich environment with interesting objects and textures will set the mood before the camera is even turned on.

As you can see, the right choice of frame filling will enhance the expressiveness of the portrait and emphasize its character.

Shooting portraits is not just a process of creating images, it is an opportunity to see the moments of life, to express the individuality and uniqueness of each person. With the right techniques, the photographer captures images that will inspire.

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Tips for Online Security

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Online security is a growing concern for individuals and businesses alike. Cyber threats are increasing due to the increasing amount of sensitive information shared and stored online.

There are a few common but effective ways to ensure your security online, ranging from having strong passwords to making sure that you visit only safe and secure sites. Following these tips and staying aware of what is going on in terms of online security threats will help you arm yourself from getting hurt by those threats.

Top 5 Tips for Online Security

Now, with more online activities and games, it’s become pretty easy and comfortable for people to stay out of all market hustle-bustle and play online at their own pace. At the same time, the awareness of potential risks also needs to be there.

This also includes the online casino security, which is a very vital point in the online gambling industry. When a player is gambling over the internet, he or she literally confides all personal and financial details to the online casino. It is, therefore, necessary for online casinos to take preventive measures towards ensuring that the information of the players is secure.

Normally, online casinos like Betway incorporate different kinds of encryptions and securities through which they protect the data for the players in matters relating to finance and personal information.

Some of these measures include 128-bit encryption, SSL certificates, firewalls, anti-fraud measures, and multi-factor authentication to ensure that players’ information is never compromised and that they can enjoy their online gambling experience without any worries.

At the same time, as players, you should do your part to avoid falling into the trap of cyber attacks. Here are the top 5 tips for online security in this digital realm.

Making Sure The Site is Secure

Before entering any personal or financial information on any website, it is important to ensure that the site is secure. Look for the padlock symbol in the address bar and make sure the URL starts with “https” instead of “http”. This indicates that the site is using encryption to protect your information.

Creating Strong Passwords

Avoid using easily guessable passwords, such as ‘password’ or ‘123456’, but rather combine letters with numbers and symbols, for example ‘C@tseatfish2468!’. Also, be sure to have a variety of passwords for each site to avoid access to multiple accounts once a single site’s password is compromised.

Protecting Personal Information

Some websites such as online casinos and online shopping platforms will require personal information such as name, address, and date of birth to verify identity and prevent fraud. However, make sure such information is shared only with reputable sites and not at the location of public Wi-Fi network.

Never ever under any circumstance share such information on the basis of phone call or email request.

Installing Latest Anti-virus and Firewall Software

Install new anti-virus and firewall software in order to protect your computer from malware and hackers who are more current. Update your anti-virus and firewall software regularly, and often scan your computer for viruses and other types of malicious software.

Using VPN

Using a Virtual Private Network (VPN) can protect your online activity. The service encrypts an internet connection by hiding an IP address also known as masking. It is perfect to use under above-mentioned conditions and while traveling, especially when connecting to public Wi-Fi zones or having the need to access websites from countries with strict regulations regarding the use of the internet.

Conclusion

Cybersecurity is one of the very critical facets of our digital lives, which we should never take for granted. It is important to realize that the internet may not be a safe place, and one shall do everything possible to ensure protection for themselves and the information they give out.

That said, implementing the tips discussed in this article, such as using strong and unique passwords and visiting only secure sites will significantly reduce the risk of falling victim to cyber attacks.

It is also important to stay informed about the latest threats and to keep software and security measures up to date. When you remain vigilant and take proactive steps, you can enjoy the benefits of the internet while minimizing the risks.

Always remind yourself that online security is a process that one needs to always keep at the back of your mind and let it proactively work. Do ensure to make yourself informed of the threats that go a long way in keeping safe and secure in this digital age.

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Car Battery Technology: Decoding the Jargon

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Hey there, fellow car enthusiast! Have you ever found yourself scratching your head when confronted with the baffling array of technical terms surrounding car batteries?

Fear not, for today, we’re going to demystify the world of car battery technology. So buckle up, sit back, and let’s dive into the nitty-gritty of what powers your beloved ride.

Understanding the Basics: Car Battery 101

Let’s start with the basics. A car battery is like the heart of your vehicle, providing the electrical energy needed to start the engine and power all the electrical components. Without a healthy battery, your car simply won’t budge. But what exactly goes on inside this seemingly ordinary box of power?

Inside the Battery: The Anatomy of Power

Imagine you’re peering under the hood of your car, and there it is—the humble car battery. But don’t be fooled by its unassuming appearance; inside, it’s a powerhouse of chemical reactions. Picture this: tiny, energetic ions zipping around, generating electricity through a process called electrochemical reaction. It’s like a mini chemistry lab right in your car!

Anecdote: Ici, the Unsung Hero

Speaking of chemistry, let me tell you a little anecdote about a word you might have encountered in the world of car batteries: ici. Now, you might wonder, what on earth is ici?

Well, it’s short for “”internal resistance.”” Sounds complicated, right? But here’s the thing—ici plays a crucial role in determining how efficiently your battery can deliver power to the starter motor.

Think of it as the traffic jam on the road to starting your car. The lower the ici, the smoother the journey. So next time you start your engine effortlessly, remember to thank ici for its silent but vital contribution.

The Power of Connection: The Role of Clamps

Ah, the trusty clamps—the unsung heroes of car battery replacement. These seemingly simple metal contraptions are what connect your battery to the rest of your car’s electrical system. But have you ever stopped to think about the significance of these tiny components?

Anecdote: The Saga of the Lost Clamp

Let me share a little anecdote with you about clamps. Picture this: You’re in the middle of nowhere, stranded with a dead battery. You pop open the hood, ready to jump-start your car, only to realize that one of the clamps is missing!

Panic sets in as you frantically search your trunk for a replacement. Turns out, that little clamp holds more power than you ever realized. Moral of the story? Always double-check your clamps before hitting the road!

Deciphering the Code: Understanding EXIF

Now, let’s talk about a term that might sound more at home in the world of photography than car batteries: EXIF. But fear not, it’s not as complicated as it seems.

In the realm of car batteries, EXIF stands for “”electrolyte level indicator.”” Think of it as a built-in sensor that keeps tabs on the health of your battery’s electrolyte levels.

Anecdote: The Tale of the Mysterious EXIF Reading

Imagine this scenario: You’re diligently checking your car battery’s EXIF reading, hoping for a clean bill of health. But to your dismay, the reading is off the charts! Panic sets in as you wonder what could be wrong with your trusted car battery.

After a thorough inspection, you realize that a loose connection was causing false readings. Crisis averted! This little anecdote reminds us that sometimes, the simplest solutions can save the day.

Navigating the World of Car Battery Replacement

Now that we’ve unraveled some of the mysteries surrounding car battery technology, let’s talk about the inevitable: car battery replacement. Whether your battery is on its last legs or you simply want to upgrade to a more powerful model, understanding the ins and outs of replacement is crucial.

Choosing the Right Battery: A Personalized Approach

When it comes to choosing a new battery for your car, one size does not fit all. Factors like climate, driving habits, and vehicle specifications all come into play. So before you rush out to buy the first battery you see, take a moment to consider your unique needs. Trust me, your car will thank you for it.

Anecdote: The Quest for the Perfect Replacement

Picture yourself standing in front of a towering wall of car batteries, feeling utterly overwhelmed. This was me not too long ago, on a quest to find the perfect replacement for my trusty old battery.

But with a little research and guidance from the experts, I emerged victorious, armed with the perfect battery to keep my car running smoothly for years to come.

So there you have it, folks—car battery technology, decoded! From the inner workings of your battery to the crucial role of clamps and EXIF readings, we’ve covered it all. Remember, when it comes to your car’s battery, a little knowledge goes a long way.

So the next time you pop open the hood of your car, you’ll be armed with the confidence to tackle any battery-related challenge that comes your way. Happy driving!

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