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How do machine learning professionals make data readable and accessible? What techniques do they use to dissect raw information?
One of these techniques is clustering. Data clustering is the process of grouping items in a data set together. These items are related, allowing key stakeholders to make critical strategic decisions using the insights.
After preparing data, which is what specialists do 50%-80% of the time, clustering takes center stage. It forms structures other members of the company can understand more easily, even if they lack advanced technical knowledge.
Clustering in machine learning involves many techniques to help accomplish this goal. Here is a detailed overview of those techniques.
Clustering Techniques
Data science is an ever-changing field with lots of variables and fluctuations. However, one thing’s for sure – whether you want to practice clustering in data mining or clustering in machine learning, you can use a wide array of tools to automate your efforts.
Partitioning Methods
The first groups of techniques are the so-called partitioning methods. There are three main sub-types of this model.
K-Means Clustering
K-means clustering is an effective yet straightforward clustering system. To execute this technique, you need to assign clusters in your data sets. From there, define your number K, which tells the program how many centroids (“coordinates” representing the center of your clusters) you need. The machine then recognizes your K and categorizes data points to nearby clusters.
You can look at K-means clustering like finding the center of a triangle. Zeroing in on the center lets you divide the triangle into several areas, allowing you to make additional calculations.
And the name K-means clustering is pretty self-explanatory. It refers to finding the median value of your clusters – centroids.
K-Medoids Clustering
K-means clustering is useful but is prone to so-called “outlier data.” This information is different from other data points and can merge with others. Data miners need a reliable way to deal with this issue.
Enter K-medoids clustering.
It’s similar to K-means clustering, but just like planes overcome gravity, so does K-medoids clustering overcome outliers. It utilizes “medoids” as the reference points – which contain maximum similarities with other data points in your cluster. As a result, no outliers interfere with relevant data points, making this one of the most dependable clustering techniques in data mining.
Fuzzy C-Means Clustering
Fuzzy C-means clustering is all about calculating the distance from the median point to individual data points. If a data point is near the cluster centroid, it’s relevant to the goal you want to accomplish with your data mining. The farther you go from this point, the farther you move the goalpost and decrease relevance.
Hierarchical Methods
Some forms of clustering in machine learning are like textbooks – similar topics are grouped in a chapter and are different from topics in other chapters. That’s precisely what hierarchical clustering aims to accomplish. You can the following methods to create data hierarchies.
Agglomerative Clustering
Agglomerative clustering is one of the simplest forms of hierarchical clustering. It divides your data set into several clusters, making sure data points are similar to other points in the same cluster. By grouping them, you can see the differences between individual clusters.
Before the execution, each data point is a full-fledged cluster. The technique helps you form more clusters, making this a bottom-up strategy.
Divisive Clustering
Divisive clustering lies on the other end of the hierarchical spectrum. Here, you start with just one cluster and create more as you move through your data set. This top-down approach produces as many clusters as necessary until you achieve the requested number of partitions.
Density-Based Methods
Birds of a feather flock together. That’s the basic premise of density-based methods. Data points that are close to each other form high-density clusters, indicating their cohesiveness. The two primary density-based methods of clustering in data mining are DBSCAN and OPTICS.
DBSCAN (Density-Based Spatial Clustering of Applications With Noise)
Related data groups are close to each other, forming high-density areas in your data sets. The DBSCAN method picks up on these areas and groups information accordingly.
OPTICS (Ordering Points to Identify the Clustering Structure)
The OPTICS technique is like DBSCAN, grouping data points according to their density. The only major difference is that OPTICS can identify varying densities in larger groups.
Grid-Based Methods
You can see grids on practically every corner. They can easily be found in your house or your car. They’re also prevalent in clustering.
STING (Statistical Information Grid)
The STING grid method divides a data point into rectangular grills. Afterward, you determine certain parameters for your cells to categorize information.
CLIQUE (Clustering in QUEst)
Agglomerative clustering isn’t the only bottom-up clustering method on our list. There’s also the CLIQUE technique. It detects clusters in your environment and combines them according to your parameters.
Model-Based Methods
Different clustering techniques have different assumptions. The assumption of model-based methods is that a model generates specific data points. Several such models are used here.
Gaussian Mixture Models (GMM)
The aim of Gaussian mixture models is to identify so-called Gaussian distributions. Each distribution is a cluster, and any information within a distribution is related.
Hidden Markov Models (HMM)
Most people use HMM to determine the probability of certain outcomes. Once they calculate the probability, they can figure out the distance between individual data points for clustering purposes.
Spectral Clustering
If you often deal with information organized in graphs, spectral clustering can be your best friend. It finds related groups of notes according to linked edges.
Comparison of Clustering Techniques
It’s hard to say that one algorithm is superior to another because each has a specific purpose. Nevertheless, some clustering techniques might be especially useful in particular contexts:
- OPTICS beats DBSCAN when clustering data points with different densities.
- K-means outperforms divisive clustering when you wish to reduce the distance between a data point and a cluster.
- Spectral clustering is easier to implement than the STING and CLIQUE methods.
Cluster Analysis
You can’t put your feet up after clustering information. The next step is to analyze the groups to extract meaningful information.
Importance of Cluster Analysis in Data Mining
The importance of clustering in data mining can be compared to the importance of sunlight in tree growth. You can’t get valuable insights without analyzing your clusters. In turn, stakeholders wouldn’t be able to make critical decisions about improving their marketing efforts, target audience, and other key aspects.
Steps in Cluster Analysis
Just like the production of cars consists of many steps (e.g., assembling the engine, making the chassis, painting, etc.), cluster analysis is a multi-stage process:
Data Preprocessing
Noise and other issues plague raw information. Data preprocessing solves this issue by making data more understandable.
Feature Selection
You zero in on specific features of a cluster to identify those clusters more easily. Plus, feature selection allows you to store information in a smaller space.
Clustering Algorithm Selection
Choosing the right clustering algorithm is critical. You need to ensure your algorithm is compatible with the end result you wish to achieve. The best way to do so is to determine how you want to establish the relatedness of the information (e.g., determining median distances or densities).
Cluster Validation
In addition to making your data points easily digestible, you also need to verify whether your clustering process is legit. That’s where cluster validation comes in.
Cluster Validation Techniques
There are three main cluster validation techniques when performing clustering in machine learning:
Internal Validation
Internal validation evaluates your clustering based on internal information.
External Validation
External validation assesses a clustering process by referencing external data.
Relative Validation
You can vary your number of clusters or other parameters to evaluate your clustering. This procedure is known as relative validation.
Applications of Clustering in Data Mining
Clustering may sound a bit abstract, but it has numerous applications in data mining.
- Customer Segmentation – This is the most obvious application of clustering. You can group customers according to different factors, like age and interests, for better targeting.
- Anomaly Detection – Detecting anomalies or outliers is essential for many industries, such as healthcare.
- Image Segmentation – You use data clustering if you want to recognize a certain object in an image.
- Document Clustering – Organizing documents is effortless with document clustering.
- Bioinformatics and Gene Expression Analysis – Grouping related genes together is relatively simple with data clustering.
Challenges and Future Directions
- Scalability – One of the biggest challenges of data clustering is expected to be applying the process to larger datasets. Addressing this problem is essential in a world with ever-increasing amounts of information.
- Handling High-Dimensional Data – Future systems may be able to cluster data with thousands of dimensions.
- Dealing with Noise and Outliers – Specialists hope to enhance the ability of their clustering systems to reduce noise and lessen the influence of outliers.
- Dynamic Data and Evolving Clusters – Updates can change entire clusters. Professionals will need to adapt to this environment to retain efficiency.
Elevate Your Data Mining Knowledge
There are a vast number of techniques for clustering in machine learning. From centroid-based solutions to density-focused approaches, you can take many directions when grouping data.
Mastering them is essential for any data miner, as they provide insights into crucial information. On top of that, the data science industry is expected to hit nearly $26 billion by 2026, which is why clustering will become even more prevalent.
For most people, identifying objects surrounding them is an easy task.
Let’s say you’re in your office. You can probably casually list objects like desks, computers, filing cabinets, printers, and so on. While this action seems simple on the surface, human vision is actually quite complex.
So, it’s not surprising that computer vision – a relatively new branch of technology aiming to replicate human vision – is equally, if not more, complex.
But before we dive into these complexities, let’s understand the basics – what is computer vision?
Computer vision is an artificial intelligence (AI) field focused on enabling computers to identify and process objects in the visual world. This technology also equips computers to take action and make recommendations based on the visual input they receive.
Simply put, computer vision enables machines to see and understand.
Learning the computer vision definition is just the beginning of understanding this fascinating field. So, let’s explore the ins and outs of computer vision, from fundamental principles to future trends.
History of Computer Vision
While major breakthroughs in computer vision have occurred relatively recently, scientists have been training machines to “see” for over 60 years.
To do the math – the research on computer vision started in the late 1950s.
Interestingly, one of the earliest test subjects wasn’t a computer. Instead, it was a cat! Scientists used a little feline helper to examine how their nerve cells respond to various images. Thanks to this experiment, they concluded that detecting simple shapes is the first stage in image processing.
As AI emerged as an academic field of study in the 1960s, a decade-long quest to help machines mimic human vision officially began.
Since then, there have been several significant milestones in computer vision, AI, and deep learning. Here’s a quick rundown for you:
- 1970s – Computer vision was used commercially for the first time to help interpret written text for the visually impaired.
- 1980s – Scientists developed convolutional neural networks (CNNs), a key component in computer vision and image processing.
- 1990s – Facial recognition tools became highly popular, thanks to a shiny new thing called the internet. For the first time, large sets of images became available online.
- 2000s – Tagging and annotating visual data sets were standardized.
- 2010s – Alex Krizhevsky developed a CNN model called AlexNet, drastically reducing the error rate in image recognition (and winning an international image recognition contest in the process).
Today, computer vision algorithms and techniques are rapidly developing and improving. They owe this to an unprecedented amount of visual data and more powerful hardware.
Thanks to these advancements, 99% accuracy has been achieved for computer vision, meaning it’s currently more accurate than human vision at quickly identifying visual inputs.
Fundamentals of Computer Vision
New functionalities are constantly added to the computer vision systems being developed. Still, this doesn’t take away from the same fundamental functions these systems share.
Image Acquisition and Processing
Without visual input, there would be no computer vision. So, let’s start at the beginning.
The image acquisition function first asks the following question: “What imaging device is used to produce the digital image?”
Depending on the device, the resulting data can be a 2D, 3D image, or an image sequence. These images are then processed, allowing the machine to verify whether the visual input contains satisfying data.
Feature Extraction and Representation
The next question then becomes, “What specific features can be extracted from the image?”
By features, we mean measurable pieces of data unique to specific objects in the image.
Feature extraction focuses on extracting lines and edges and localizing interest points like corners and blobs. To successfully extract these features, the machine breaks the initial data set into more manageable chunks.
Object Recognition and Classification
Next, the computer vision system aims to answer: “What objects or object categories are present in the image, and where are they?”
This interpretive technique recognizes and classifies objects based on large amounts of pre-learned objects and object categories.
Image Segmentation and Scene Understanding
Besides observing what is in the image, today’s computer vision systems can act based on those observations.
In image segmentation, computer vision algorithms divide the image into multiple regions and examine the relevant regions separately. This allows them to gain a full understanding of the scene, including the spatial and functional relationships between the present objects.
Motion Analysis and Tracking
Motion analysis studies movements in a sequence of digital images. This technique correlates to motion tracking, which follows the movement of objects of interest. Both techniques are commonly used in manufacturing for monitoring machinery.
Key Techniques and Algorithms in Computer Vision
Computer vision is a fairly complex task. For starters, it needs a huge amount of data. Once the data is all there, the system runs multiple analyses to achieve image recognition.
This might sound simple, but this process isn’t exactly straightforward.
Think of computer vision as a detective solving a crime. What does the detective need to do to identify the criminal? Piece together various clues.
Similarly (albeit with less danger), a computer vision model relies on colors, shapes, and patterns to piece together an object and identify its features.
Let’s discuss the techniques and algorithms this model uses to achieve its end result.
Convolutional Neural Networks (CNNs)
In computer vision, CNNs extract patterns and employ mathematical operations to estimate what image they’re seeing. And that’s all there really is to it. They continue performing the same mathematical operation until they verify the accuracy of their estimate.
Deep Learning and Transfer Learning
The advent of deep learning removed many constraints that prevented computer vision from being widely used. On top of that, (and luckily for computer scientists!), it also eliminated all the tedious manual work.
Essentially, deep learning enables a computer to learn about visual data independently. Computer scientists only need to develop a good algorithm, and the machine will take care of the rest.
Alternatively, computer vision can use a pre-trained model as a starting point. This concept is known as transfer learning.
Edge Detection and Feature Extraction Techniques
Edge detection is one of the most prominent feature extraction techniques.
As the name suggests, it can identify the boundaries of an object and extract its features. As always, the ultimate goal is identifying the object in the picture. To achieve this, edge detection uses an algorithm that identifies differences in pixel brightness (after transforming the data into a grayscale image).
Optical Flow and Motion Estimation
Optical flow is a computer vision technique that determines how each point of an image or video sequence is moving compared to the image plane. This technique can estimate how fast objects are moving.
Motion estimation, on the other hand, predicts the location of objects in subsequent frames of a video sequence.
These techniques are used in object tracking and autonomous navigation.
Image Registration and Stitching
Image registration and stitching are computer vision techniques used to combine multiple images. Image registration is responsible for aligning these images, while image stitching overlaps them to produce a single image. Medical professionals use these techniques to track the progress of a disease.
Applications of Computer Vision
Thanks to many technological advances in the field, computer vision has managed to surpass human vision in several regards. As a result, it’s used in various applications across multiple industries.
Robotics and Automation
Improving robotics was one of the original reasons for developing computer vision. So, it isn’t surprising this technique is used extensively in robotics and automation.
Computer vision can be used to:
- Control and automate industrial processes
- Perform automatic inspections in manufacturing applications
- Identify product and machine defects in real time
- Operate autonomous vehicles
- Operate drones (and capture aerial imaging)
Security and Surveillance
Computer vision has numerous applications in video surveillance, including:
- Facial recognition for identification purposes
- Anomaly detection for spotting unusual patterns
- People counting for retail analytics
- Crowd monitoring for public safety
Healthcare and Medical Imaging
Healthcare is one of the most prominent fields of computer vision applications. Here, this technology is employed to:
- Establish more accurate disease diagnoses
- Analyze MRI, CAT, and X-ray scans
- Enhance medical images interpreted by humans
- Assist surgeons during surgery
Entertainment and Gaming
Computer vision techniques are highly useful in the entertainment industry, supporting the creation of visual effects and motion capture for animation.
Good news for gamers, too – computer vision aids augmented and virtual reality in creating the ultimate gaming experience.
Retail and E-Commerce
Self-check-out points can significantly enhance the shopping experience. And guess what can help establish them? That’s right – computer vision. But that’s not all. This technology also helps retailers with inventory management, allowing quicker detection of out-of-stock products.
In e-commerce, computer vision facilitates visual search and product recommendation, streamlining the (often frustrating) online purchasing process.
Challenges and Limitations of Computer Vision
There’s no doubt computer vision has experienced some major breakthroughs in recent years. Still, no technology is without flaws.
Here are some of the challenges that computer scientists hope to overcome in the near future:
- The data for training computer vision models often lack in quantity or quality.
- There’s a need for more specialists who can train and monitor computer vision models.
- Computers still struggle to process incomplete, distorted, and previously unseen visual data.
- Building computer vision systems is still complex, time-consuming, and costly.
- Many people have privacy and ethical concerns surrounding computer vision, especially for surveillance.
Future Trends and Developments in Computer Vision
As the field of computer vision continues to develop, there should be no shortage of changes and improvements.
These include integration with other AI technologies (such as neuro-symbolic and explainable AI), which will continue to evolve as developing hardware adds new capabilities and capacities that enhance computer vision. Each advancement brings with it the opportunity for other industries (and more complex applications). Construction gives us a good example, as computer vision takes us away from the days of relying on hard hats and signage, moving us toward a future in which computers can actively detect, and alert site foremen too, unsafe behavior.
The Future Looks Bright for Computer Vision
Computer vision is one of the most remarkable concepts in the world of deep learning and artificial intelligence. This field will undoubtedly continue to grow at an impressive speed, both in terms of research and applications.
Are you interested in further research and professional development in this field? If yes, consider seeking out high-quality education in computer vision.
Algorithms are the essence of data mining and machine learning – the two processes 60% of organizations utilize to streamline their operations. Businesses can choose from several algorithms to polish their workflows, but the decision tree algorithm might be the most common.
This algorithm is all about simplicity. It branches out in multiple directions, just like trees, and determines whether something is true or false. In turn, data scientists and machine learning professionals can further dissect the data and help key stakeholders answer various questions.
This only scratches the surface of this algorithm – but it’s time to delve deeper into the concept. Let’s take a closer look at the decision tree machine learning algorithm, its components, types, and applications.
What Is Decision Tree Machine Learning?
The decision tree algorithm in data mining and machine learning may sound relatively simple due to its similarities with standard trees. But like with conventional trees, which consist of leaves, branches, roots, and many other elements, there’s a lot to uncover with this algorithm. We’ll start by defining this concept and listing the main components.
Definition of Decision Tree
If you’re a college student, you learn in two ways – supervised and unsupervised. The same division can be found in algorithms, and the decision tree belongs to the former category. It’s a supervised algorithm you can use to regress or classify data. It relies on training data to predict values or outcomes.
Components of Decision Tree
What’s the first thing you notice when you look at a tree? If you’re like most people, it’s probably the leaves and branches.
The decision tree algorithm has the same elements. Add nodes to the equation, and you have the entire structure of this algorithm right in front of you.
- Nodes – There are several types of nodes in decision trees. The root node is the parent of all nodes, which represents the overriding message. Chance nodes tell you the probability of a certain outcome, whereas decision nodes determine the decisions you should make.
- Branches – Branches connect nodes. Like rivers flowing between two cities, they show your data flow from questions to answers.
- Leaves – Leaves are also known as end nodes. These elements indicate the outcome of your algorithm. No more nodes can spring out of these nodes. They are the cornerstone of effective decision-making.
Types of Decision Trees
When you go to a park, you may notice various tree species: birch, pine, oak, and acacia. By the same token, there are multiple types of decision tree algorithms:
- Classification Trees – These decision trees map observations about particular data by classifying them into smaller groups. The chunks allow machine learning specialists to predict certain values.
- Regression Trees – According to IBM, regression decision trees can help anticipate events by looking at input variables.
Decision Tree Algorithm in Data Mining
Knowing the definition, types, and components of decision trees is useful, but it doesn’t give you a complete picture of this concept. So, buckle your seatbelt and get ready for an in-depth overview of this algorithm.
Overview of Decision Tree Algorithms
Just as there are hierarchies in your family or business, there are hierarchies in any decision tree in data mining. Top-down arrangements start with a problem you need to solve and break it down into smaller chunks until you reach a solution. Bottom-up alternatives sort of wing it – they enable data to flow with some supervision and guide the user to results.
Popular Decision Tree Algorithms
- ID3 (Iterative Dichotomiser 3) – Developed by Ross Quinlan, the ID3 is a versatile algorithm that can solve a multitude of issues. It’s a greedy algorithm (yes, it’s OK to be greedy sometimes), meaning it selects attributes that maximize information output.
- 5 – This is another algorithm created by Ross Quinlan. It generates outcomes according to previously provided data samples. The best thing about this algorithm is that it works great with incomplete information.
- CART (Classification and Regression Trees) – This algorithm drills down on predictions. It describes how you can predict target values based on other, related information.
- CHAID (Chi-squared Automatic Interaction Detection) – If you want to check out how your variables interact with one another, you can use this algorithm. CHAID determines how variables mingle and explain particular outcomes.
Key Concepts in Decision Tree Algorithms
No discussion about decision tree algorithms is complete without looking at the most significant concept from this area:
Entropy
As previously mentioned, decision trees are like trees in many ways. Conventional trees branch out in random directions. Decision trees share this randomness, which is where entropy comes in.
Entropy tells you the degree of randomness (or surprise) of the information in your decision tree.
Information Gain
A decision tree isn’t the same before and after splitting a root node into other nodes. You can use information gain to determine how much it’s changed. This metric indicates how much your data has improved since your last split. It tells you what to do next to make better decisions.
Gini Index
Mistakes can happen, even in the most carefully designed decision tree algorithms. However, you might be able to prevent errors if you calculate their probability.
Enter the Gini index (Gini impurity). It establishes the likelihood of misclassifying an instance when choosing it randomly.
Pruning
You don’t need every branch on your apple or pear tree to get a great yield. Likewise, not all data is necessary for a decision tree algorithm. Pruning is a compression technique that allows you to get rid of this redundant information that keeps you from classifying useful data.
Building a Decision Tree in Data Mining
Growing a tree is straightforward – you plant a seed and water it until it is fully formed. Creating a decision tree is simpler than some other algorithms, but quite a few steps are involved nevertheless.
Data Preparation
Data preparation might be the most important step in creating a decision tree. It’s comprised of three critical operations:
Data Cleaning
Data cleaning is the process of removing unwanted or unnecessary information from your decision trees. It’s similar to pruning, but unlike pruning, it’s essential to the performance of your algorithm. It’s also comprised of several steps, such as normalization, standardization, and imputation.
Feature Selection
Time is money, which especially applies to decision trees. That’s why you need to incorporate feature selection into your building process. It boils down to choosing only those features that are relevant to your data set, depending on the original issue.
Data Splitting
The procedure of splitting your tree nodes into sub-nodes is known as data splitting. Once you split data, you get two data points. One evaluates your information, while the other trains it, which brings us to the next step.
Training the Decision Tree
Now it’s time to train your decision tree. In other words, you need to teach your model how to make predictions by selecting an algorithm, setting parameters, and fitting your model.
Selecting the Best Algorithm
There’s no one-size-fits-all solution when designing decision trees. Users select an algorithm that works best for their application. For example, the Random Forest algorithm is the go-to choice for many companies because it can combine multiple decision trees.
Setting Parameters
How far your tree goes is just one of the parameters you need to set. You also need to choose between entropy and Gini values, set the number of samples when splitting nodes, establish your randomness, and adjust many other aspects.
Fitting the Model
If you’ve fitted your model properly, your data will be more accurate. The outcomes need to match the labeled data closely (but not too close to avoid overfitting) if you want relevant insights to improve your decision-making.
Evaluating the Decision Tree
Don’t put your feet up just yet. Your decision tree might be up and running, but how well does it perform? There are two ways to answer this question: cross-validation and performance metrics.
Cross-Validation
Cross-validation is one of the most common ways of gauging the efficacy of your decision trees. It compares your model to training data, allowing you to determine how well your system generalizes.
Performance Metrics
Several metrics can be used to assess the performance of your decision trees:
Accuracy
This is the proximity of your measurements to the requested values. If your model is accurate, it matches the values established in the training data.
Precision
By contrast, precision tells you how close your output values are to each other. In other words, it shows you how harmonized individual values are.
Recall
Recall is the number of data samples in the desired class. This class is also known as the positive class. Naturally, you want your recall to be as high as possible.
F1 Score
F1 score is the median value of your precision and recall. Most professionals consider an F1 of over 0.9 a very good score. Scores between 0.8 and 0.5 are OK, but anything less than 0.5 is bad. If you get a poor score, it means your data sets are imprecise and imbalanced.
Visualizing the Decision Tree
The final step is to visualize your decision tree. In this stage, you shed light on your findings and make them digestible for non-technical team members using charts or other common methods.
Applications of Decision Tree Machine Learning in Data Mining
The interest in machine learning is on the rise. One of the reasons is that you can apply decision trees in virtually any field:
- Customer Segmentation – Decision trees let you divide customers according to age, gender, or other factors.
- Fraud Detection – Decision trees can easily find fraudulent transactions.
- Medical Diagnosis – This algorithm allows you to classify conditions and other medical data with ease using decision trees.
- Risk Assessment – You can use the system to figure out how much money you stand to lose if you pursue a certain path.
- Recommender Systems – Decision trees help customers find their next product through classification.
Advantages and Disadvantages of Decision Tree Machine Learning
Advantages:
- Easy to Understand and Interpret – Decision trees make decisions almost in the same manner as humans.
- Handles Both Numerical and Categorical Data – The ability to handle different types of data makes them highly versatile.
- Requires Minimal Data Preprocessing – Preparing data for your algorithms doesn’t take much.
Disadvantages:
- Prone to Overfitting – Decision trees often fail to generalize.
- Sensitive to Small Changes in Data – Changing one data point can wreak havoc on the rest of the algorithm.
- May Not Work Well with Large Datasets – Naïve Bayes and some other algorithms outperform decision trees when it comes to large datasets.
Possibilities are Endless With Decision Trees
The decision tree machine learning algorithm is a simple yet powerful algorithm for classifying or regressing data. The convenient structure is perfect for decision-making, as it organizes information in an accessible format. As such, it’s ideal for making data-driven decisions.
If you want to learn more about this fascinating topic, don’t stop your exploration here. Decision tree courses and other resources can bring you one step closer to applying decision trees to your work.
Any tendency or behavior of a consumer in the purchasing process in a certain period is known as customer behavior. For example, the last two years saw an unprecedented rise in online shopping. Such trends must be analyzed, but this is a nightmare for companies that try to take on the task manually. They need a way to speed up the project and make it more accurate.
Enter machine learning algorithms. Machine learning algorithms are methods AI programs use to complete a particular task. In most cases, they predict outcomes based on the provided information.
Without machine learning algorithms, customer behavior analyses would be a shot in the dark. These models are essential because they help enterprises segment their markets, develop new offerings, and perform time-sensitive operations without making wild guesses.
We’ve covered the definition and significance of machine learning, which only scratches the surface of this concept. The following is a detailed overview of the different types, models, and challenges of machine learning algorithms.
Types of Machine Learning Algorithms
A natural way to kick our discussion into motion is to dissect the most common types of machine learning algorithms. Here’s a brief explanation of each model, along with a few real-life examples and applications.
Supervised Learning
You can come across “supervised learning” at every corner of the machine learning realm. But what is it about, and where is it used?
Definition and Examples
Supervised machine learning is like supervised classroom learning. A teacher provides instructions, based on which students perform requested tasks.
In a supervised algorithm, the teacher is replaced by a user who feeds the system with input data. The system draws on this data to make predictions or discover trends, depending on the purpose of the program.
There are many supervised learning algorithms, as illustrated by the following examples:
- Decision trees
- Linear regression
- Gaussian Naïve Bayes
Applications in Various Industries
When supervised machine learning models were invented, it was like discovering the Holy Grail. The technology is incredibly flexible since it permeates a range of industries. For example, supervised algorithms can:
- Detect spam in emails
- Scan biometrics for security enterprises
- Recognize speech for developers of speech synthesis tools
Unsupervised Learning
On the other end of the spectrum of machine learning lies unsupervised learning. You can probably already guess the difference from the previous type, so let’s confirm your assumption.
Definition and Examples
Unsupervised learning is a model that requires no training data. The algorithm performs various tasks intuitively, reducing the need for your input.
Machine learning professionals can tap into many different unsupervised algorithms:
- K-means clustering
- Hierarchical clustering
- Gaussian Mixture Models
Applications in Various Industries
Unsupervised learning models are widespread across a range of industries. Like supervised solutions, they can accomplish virtually anything:
- Segment target audiences for marketing firms
- Grouping DNA characteristics for biology research organizations
- Detecting anomalies and fraud for banks and other financial enterprises
Reinforcement Learning
How many times have your teachers rewarded you for a job well done? By doing so, they reinforced your learning and encouraged you to keep going.
That’s precisely how reinforcement learning works.
Definition and Examples
Reinforcement learning is a model where an algorithm learns through experimentation. If its action yields a positive outcome, it receives an award and aims to repeat the action. Acts that result in negative outcomes are ignored.
If you want to spearhead the development of a reinforcement learning-based app, you can choose from the following algorithms:
- Markov Decision Process
- Bellman Equations
- Dynamic programming
Applications in Various Industries
Reinforcement learning goes hand in hand with a large number of industries. Take a look at the most common applications:
- Ad optimization for marketing businesses
- Image processing for graphic design
- Traffic control for government bodies
Deep Learning
When talking about machine learning algorithms, you also need to go through deep learning.
Definition and Examples
Surprising as it may sound, deep learning operates similarly to your brain. It’s comprised of at least three layers of linked nodes that carry out different operations. The idea of linked nodes may remind you of something. That’s right – your brain cells.
You can find numerous deep learning models out there, including these:
- Recurrent neural networks
- Deep belief networks
- Multilayer perceptrons
Applications in Various Industries
If you’re looking for a flexible algorithm, look no further than deep learning models. Their ability to help businesses take off is second-to-none:
- Creating 3D characters in video gaming and movie industries
- Visual recognition in telecommunications
- CT scans in healthcare
Popular Machine Learning Algorithms
Our guide has already listed some of the most popular machine-learning algorithms. However, don’t think that’s the end of the story. There are many other algorithms you should keep in mind if you want to gain a better understanding of this technology.
Linear Regression
Linear regression is a form of supervised learning. It’s a simple yet highly effective algorithm that can help polish any business operation in a heartbeat.
Definition and Examples
Linear regression aims to predict a value based on provided input. The trajectory of the prediction path is linear, meaning it has no interruptions. The two main types of this algorithm are:
- Simple linear regression
- Multiple linear regression
Applications in Various Industries
Machine learning algorithms have proved to be a real cash cow for many industries. That especially holds for linear regression models:
- Stock analysis for financial firms
- Anticipating sports outcomes
- Exploring the relationships of different elements to lower pollution
Logistic Regression
Next comes logistic regression. This is another type of supervised learning and is fairly easy to grasp.
Definition and Examples
Logistic regression models are also geared toward predicting certain outcomes. Two classes are at play here: a positive class and a negative class. If the model arrives at the positive class, it logically excludes the negative option, and vice versa.
A great thing about logistic regression algorithms is that they don’t restrict you to just one method of analysis – you get three of these:
- Binary
- Multinomial
- Ordinal
Applications in Various Industries
Logistic regression is a staple of many organizations’ efforts to ramp up their operations and strike a chord with their target audience:
- Providing reliable credit scores for banks
- Identifying diseases using genes
- Optimizing booking practices for hotels
Decision Trees
You need only look out the window at a tree in your backyard to understand decision trees. The principle is straightforward, but the possibilities are endless.
Definition and Examples
A decision tree consists of internal nodes, branches, and leaf nodes. Internal nodes specify the feature or outcome you want to test, whereas branches tell you whether the outcome is possible. Leaf nodes are the so-called end outcome in this system.
The four most common decision tree algorithms are:
- Reduction in variance
- Chi-Square
- ID3
- Cart
Applications in Various Industries
Many companies are in the gutter and on the verge of bankruptcy because they failed to raise their services to the expected standards. However, their luck may turn around if they apply decision trees for different purposes:
- Improving logistics to reach desired goals
- Finding clients by analyzing demographics
- Evaluating growth opportunities
Support Vector Machines
What if you’re looking for an alternative to decision trees? Support vector machines might be an excellent choice.
Definition and Examples
Support vector machines separate your data with surgically accurate lines. These lines divide the information into points close to and far away from the desired values. Based on their proximity to the lines, you can determine the outliers or desired outcomes.
There are as many support vector machines as there are specks of sand on Copacabana Beach (not quite, but the number is still considerable):
- Anova kernel
- RBF kernel
- Linear support vector machines
- Non-linear support vector machines
- Sigmoid kernel
Applications in Various Industries
Here’s what you can do with support vector machines in the business world:
- Recognize handwriting
- Classify images
- Categorize text
Neural Networks
The above deep learning discussion lets you segue into neural networks effortlessly.
Definition and Examples
Neural networks are groups of interconnected nodes that analyze training data previously provided by the user. Here are a few of the most popular neural networks:
- Perceptrons
- Convolutional neural networks
- Multilayer perceptrons
- Recurrent neural networks
Applications in Various Industries
Is your imagination running wild? That’s good news if you master neural networks. You’ll be able to utilize them in countless ways:
- Voice recognition
- CT scans
- Commanding unmanned vehicles
- Social media monitoring
K-means Clustering
The name “K-means” clustering may sound daunting, but no worries – we’ll break down the components of this algorithm into bite-sized pieces.
Definition and Examples
K-means clustering is an algorithm that categorizes data into a K-number of clusters. The information that ends up in the same cluster is considered related. Anything that falls beyond the limit of a cluster is considered an outlier.
These are the most widely used K-means clustering algorithms:
- Hierarchical clustering
- Centroid-based clustering
- Density-based clustering
- Distribution-based clustering
Applications in Various Industries
A bunch of industries can benefit from K-means clustering algorithms:
- Finding optimal transportation routes
- Analyzing calls
- Preventing fraud
- Criminal profiling
Principal Component Analysis
Some algorithms start from certain building blocks. These building blocks are sometimes referred to as principal components. Enter principal component analysis.
Definition and Examples
Principal component analysis is a great way to lower the number of features in your data set. Think of it like downsizing – you reduce the number of individual elements you need to manage to streamline overall management.
The domain of principal component analysis is broad, encompassing many types of this algorithm:
- Sparse analysis
- Logistic analysis
- Robust analysis
- Zero-inflated dimensionality reduction
Applications in Various Industries
Principal component analysis seems useful, but what exactly can you do with it? Here are a few implementations:
- Finding patterns in healthcare records
- Resizing images
- Forecasting ROI
Challenges and Limitations of Machine Learning Algorithms
No computer science field comes without drawbacks. Machine learning algorithms also have their fair share of shortcomings:
- Overfitting and underfitting – Overfitted applications fail to generalize training data properly, whereas under-fitted algorithms can’t map the link between training data and desired outcomes.
- Bias and variance – Bias causes an algorithm to oversimplify data, whereas variance makes it memorize training information and fail to learn from it.
- Data quality and quantity – Poor quality, too much, or too little data can render an algorithm useless.
- Computational complexity – Some computers may not have what it takes to run complex algorithms.
- Ethical considerations – Sourcing training data inevitably triggers privacy and ethical concerns.
Future Trends in Machine Learning Algorithms
If we had a crystal ball, it might say that future of machine learning algorithms looks like this:
- Integration with other technologies – Machine learning may be harmonized with other technologies to propel space missions and other hi-tech achievements.
- Development of new algorithms and techniques – As the amount of data grows, expect more algorithms to spring up.
- Increasing adoption in various industries – Witnessing the efficacy of machine learning in various industries should encourage all other industries to follow in their footsteps.
- Addressing ethical and social concerns – Machine learning developers may find a way to source information safely without jeopardizing someone’s privacy.
Machine Learning Can Expand Your Horizons
Machine learning algorithms have saved the day for many enterprises. By polishing customer segmentation, strategic decision-making, and security, they’ve allowed countless businesses to thrive.
With more machine learning breakthroughs in the offing, expect the impact of this technology to magnify. So, hit the books and learn more about the subject to prepare for new advancements.
AI investment has become a must in the business world, and companies from all over the globe are embracing this trend. Nearly 90% of organizations plan to put more money into AI by 2025.
One of the main areas of investment is deep learning. The World Economic Forum approves of this initiative, as the cutting-edge technology can boost productivity, optimize cybersecurity, and enhance decision-making.
Knowing that deep learning is making waves is great, but it doesn’t mean much if you don’t understand the basics. Read on for deep learning applications and the most common examples.
Artificial Neural Networks
Once you scratch the surface of deep learning, you’ll see that it’s underpinned by artificial neural networks. That’s why many people refer to deep learning as deep neural networking and deep neural learning.
There are different types of artificial neural networks.
Perceptron
Perceptrons are the most basic form of neural networks. These artificial neurons were originally used for calculating business intelligence or input data capabilities. Nowadays, it’s a linear algorithm that supervises the learning of binary classifiers.
Convolutional Neural Networks
Convolutional neural network machine learning is another common type of deep learning network. It combines input data with learned features before allowing this architecture to analyze images or other 2D data.
The most significant benefit of convolutional neural networks is that they automate feature extraction. As a result, you don’t have to recognize features on your own when classifying pictures or other visuals – the networks extract them directly from the source.
Recurrent Neural Networks
Recurrent neural networks use time series or sequential information. You can find them in many areas, such as natural language processing, image captioning, and language translation. Google Translate, Siri, and many other applications have adopted this technology.
Generative Adversarial Networks
Generative adversarial networks are architecture with two sub-types. The generator model produces new examples, whereas the discriminated model determines if the examples generated are real or fake.
These networks work like so-called game theory scenarios, where generator networks come face-to-face with their adversaries. They generate examples directly, while the adversary (discriminator) tries to tell the difference between these examples and those obtained from training information.
Deep Learning Applications
Deep learning helps take a multitude of technologies to a whole new level.
Computer Vision
The feature that allows computers to obtain useful data from videos and pictures is known as computer vision. An already sophisticated process, deep learning can enhance the technology further.
For instance, you can utilize deep learning to enable machines to understand visuals like humans. They can be trained to automatically filter adult content to make it child-friendly. Likewise, deep learning can enable computers to recognize critical image information, such as logos and food brands.
Natural Language Processing
Artificial intelligence deep learning algorithms spearhead the development and optimization of natural language processing. They automate various processes and platforms, including virtual agents, the analysis of business documents, key phrase indexing, and article summarization.
Speech Recognition
Human speech differs greatly in language, accent, tone, and other key characteristics. This doesn’t stop deep learning from polishing speech recognition software. For instance, Siri is a deep learning-based virtual assistant that can automatically make and recognize calls. Other deep learning programs can transcribe meeting recordings and translate movies to reach wider audiences.
Robotics
Robots are invented to simplify certain tasks (i.e., reduce human input). Deep learning models are perfect for this purpose, as they help manufacturers build advanced robots that replicate human activity. These machines receive timely updates to plan their movements and overcome any obstacles on their way. That’s why they’re common in warehouses, healthcare centers, and manufacturing facilities.
Some of the most famous deep learning-enabled robots are those produced by Boston Dynamics. For example, their robot Atlas is highly agile due to its deep learning architecture. It can move seamlessly and perform dynamic interactions that are common in people.
Autonomous Driving
Self-driving cars are all the rage these days. The autonomous driving industry is expected to generate over $300 billion in revenue by 2035, and most of the credits will go to deep learning.
The producers of these vehicles use deep learning to train cars to respond to real-life traffic scenarios and improve safety. They incorporate different technologies that allow cars to calculate the distance to the nearest objects and navigate crowded streets. The vehicles come with ultra-sensitive cameras and sensors, all of which are powered by deep learning.
Passengers aren’t the only group who will benefit from deep learning-supported self-driving cars. The technology is expected to revolutionize emergency and food delivery services as well.
Deep Learning Algorithms
Numerous deep learning algorithms power the above technologies. Here are the four most common examples.
Backpropagation
Backpropagation is commonly used in neural network training. It starts from so-called “forward propagation,” analyzing its error rate. It feeds the error backward through various network layers, allowing you to optimize the weights (parameters that transform input data within hidden layers).
Stochastic Gradient Descent
The primary purpose of the stochastic gradient descent algorithm is to locate the parameters that allow other machine learning algorithms to operate at their peak efficiency. It’s generally combined with other algorithms, such as backpropagation, to enhance neural network training.
Reinforcement Learning
The reinforcement learning algorithm is trained to resolve multi-layer problems. It experiments with different solutions until it finds the right one. This method draws its decisions from real-life situations.
The reason it’s called reinforcement learning is that it operates on a reward/penalty basis. It aims to maximize rewards to reinforce further training.
Transfer Learning
Transfer learning boils down to recycling pre-configured models to solve new issues. The algorithm uses previously obtained knowledge to make generalizations when facing another problem.
For instance, many deep learning experts use transfer learning to train the system to recognize images. A classifier can use this algorithm to identify pictures of trucks if it’s already analyzed car photos.
Deep Learning Tools
Deep learning tools are platforms that enable you to develop software that lets machines mimic human activity by processing information carefully before making a decision. You can choose from a wide range of such tools.
TensorFlow
Developed in CUDA and C++, TensorFlow is a highly advanced deep learning tool. Google launched this open-source solution to facilitate various deep learning platforms.
Despite being advanced, it can also be used by beginners due to its relatively straightforward interface. It’s perfect for creating cloud, desktop, and mobile machine learning models.
Keras
The Keras API is a Python-based tool with several features for solving machine learning issues. It works with TensorFlow, Thenao, and other tools to optimize your deep learning environment and create robust models.
In most cases, prototyping with Keras is fast and scalable. The API is compatible with convolutional and recurrent networks.
PyTorch
PyTorch is another Python-based tool. It’s also a machine learning library and scripting language that allows you to create neural networks through sophisticated algorithms. You can use the tool on virtually any cloud software, and it delivers distributed training to speed up peer-to-peer updates.
Caffe
Caffe’s framework was launched by Berkeley as an open-source platform. It features an expressive design, which is perfect for propagating cutting-edge applications. Startups, academic institutions, and industries are just some environments where this tool is common.
Theano
Python makes yet another appearance in deep learning tools. Here, it powers Theano, enabling the tool to assess complex mathematical tasks. The software can solve issues that require tremendous computing power and vast quantities of information.
Deep Learning Examples
Deep learning is the go-to solution for creating and maintaining the following technologies.
Image Recognition
Image recognition programs are systems that can recognize specific items, people, or activities in digital photos. Deep learning is the method that enables this functionality. The most well-known example of the use of deep learning for image recognition is in healthcare settings. Radiologists and other professionals can rely on it to analyze and evaluate large numbers of images faster.
Text Generation
There are several subtypes of natural language processing, including text generation. Underpinned by deep learning, it leverages AI to produce different text forms. Examples include machine translations and automatic summarizations.
Self-Driving Cars
As previously mentioned, deep learning is largely responsible for the development of self-driving cars. AutoX might be the most renowned manufacturer of these vehicles.
The Future Lies in Deep Learning
Many up-and-coming technologies will be based on deep learning AI. It’s no surprise, therefore, that nearly 50% of enterprises already use deep learning as the driving force of their products and services. If you want to expand your knowledge about this topic, consider taking a deep learning course. You’ll improve your employment opportunities and further demystify the concept.
Think for a second about employees in diamond mines. Their job can often seem like trying to find a needle in a haystack. But once they find what they’re looking for, the feeling of accomplishment is overwhelming.
The situation is similar with data mining. Granted, you’re not on the hunt for diamonds (although that wouldn’t be so bad). The concept’s name may suggest otherwise, but data mining isn’t about extracting data. What you’re mining are patterns; you analyze datasets and try to see whether there’s a trend.
Data mining doesn’t involve you reading thousands of pages. This process is automatic (or at least semi-automatic). The patterns discovered with data mining are often seen as input data, meaning it’s used for further analysis and research. Data mining has become a vital part of machine learning and artificial intelligence as a whole. If you think this is too abstract and complex, you should know that data mining has found its purpose for every company. Investigating trends, prices, sales, and customer behavior is important for any business that sells products or services.
In this article, we’ll cover different data mining techniques and explain the entire process in more detail.
Data Mining Techniques
Here are the most popular data mining techniques.
Classification
As you can assume, this technique classifies something (datasets). Through classification, you can organize vast datasets into clear categories and turn them into classifiers (models) for further analysis.
Clustering
In this case, data is divided into clusters according to a certain criterion. Each cluster should contain similar data points that differ from data points in other clusters.
If we look at clustering from the perspective of artificial intelligence, we say it’s an unsupervised algorithm. This means that human involvement isn’t necessary for the algorithm to discover common features and group data points according to them.
Association Rule Learning
This technique discovers interesting connections and associations in large datasets. It’s pretty common in sales, where companies use it to explore customers’ behaviors and relationships between different products.
Regression
This technique is based on the principle that the past can help you understand the future. It explores patterns in past data to make assumptions about the future and make new observations.
Anomaly Detection
This is pretty self-explanatory. Here, datasets are analyzed to identify “ugly ducklings,” i.e., unusual patterns or patterns that deviate from the standard.
Sequential Pattern Mining
With this technique, you’re also on the hunt for patterns. The “sequential” indicates that you’re analyzing data where the values are in a sequence.
Text Mining
Text mining involves analyzing unstructured text, turning it into a structured format, and checking for patterns.
Sentiment Analysis
This data mining technique is also called opinion mining, and it’s very different from the methods discussed above. This complex technique involves natural language processing, linguistics, and speech analysis and wants to discover the emotional tone in a text.
Data Mining Process
Regardless of the technique you’re using, the data process consists of several stages that ensure accuracy, efficiency, and reliability.
Data Collection
As mentioned, data mining isn’t actually about identifying data but about exploring patterns within the data. To do that, you obviously need a dataset you want to analyze. The data needs to be relevant, otherwise you won’t get accurate results.
Data Preprocessing
Whether you’re analyzing a small or large dataset, the data within it could be in different formats or have inconsistencies or errors. If you want to analyze it properly, you need to ensure the data is uniform and organized, meaning you need to preprocess it.
This stage involves several processes:
- Data cleaning
- Data transformation
- Data reduction
Once you complete them, your data will be prepared for analysis.
Data Analysis
You’ve come to the “main” part of the data mining process, which consists of two elements:
- Model building
- Model evaluation
Model building represents determining the most efficient ways to analyze the data and identify patterns. Think of it this way: you’re asking questions, and the model should be able to provide the correct answers.
The next step is model evaluation, where you’ll step back and think about the model. Is it the right fit for your data, and does it meet your criteria?
Interpretation and Visualization
The journey doesn’t end after the analysis. Now it’s time to review the results and come to relevant conclusions. You’ll also need to present these conclusions in the best way possible, especially if you conducted the analysis for someone else. You want to ensure that the end-user understands what was done and what was discovered in the process.
Deployment and Integration
You’ve conducted the analysis, interpreted the results, and now you understand what needs to be changed. You’ll use the knowledge you’ve gained to elicit changes.
For example, you’ve analyzed your customers’ behaviors to understand why the sales of a specific product dropped. The results showed that people under the age of 30 don’t buy it as often as they used to. Now, you face two choices: You can either advertise the product and focus on the particular age group or attract even more people over the age of 30 if that makes more sense.
Applications of Data Mining
The concept of data mining may sound too abstract. However, it’s all around us. The process has proven invaluable in many spheres, from sales to healthcare and finance.
Here are the most common applications of data mining.
Customer Relationship Management
Your customers are the most important part of your business. After all, if it weren’t for them, your company wouldn’t have anyone to sell the products/services to. Yes, the quality of your products is one way to attract and keep your customers. But quality won’t be enough if you don’t value your customers.
Whether they’re buying a product for the first or the 100th time, your customers want to know you want to keep them. Some ways to do so are discounts, sales, and loyalty programs. Coming up with the best strategy can be challenging to say the least, especially if you have many customers belonging to different age groups, gender, and spending habits. With data mining, you can group your customers according to specific criteria and offer them deals that suit them perfectly.
Fraud Detection
In this case, you analyze data not to find patterns but to find something that stands out. This is what banks do to ensure no unwanted guests are accessing your account. But you can also see this fraud detection in the business world. Many companies use it to identify and remove fake accounts.
Market Basket Analysis
With data mining, you can get answers to an important question: “Which items are often bought together?” If this is on your mind, data mining can help. You can perform the association technique to discover the patterns (for example, milk and cereal) and use this valuable intel to offer your customers top-notch recommendations.
Healthcare and Medical Research
The healthcare industry has benefited immensely from data mining. The process is used to improve decision-making, generate conclusions, and check whether a treatment is working. Thanks to data mining, diagnoses have become more precise, and patients get more quality services.
As medical research and drug testing are large parts of moving the entire industry forward, data mining found its role here, too. It’s used to keep track of and reduce the risk of side effects of different medications and assist in administration.
Social Media Analysis
This is definitely one of the most lucrative applications. Social media platforms rely on it to pick up more information about their users to offer them relevant content. Thanks to this, people who use the same network will often see completely different posts. Let’s say you love dogs and often watch videos about them. The social network you’re on will recognize this and offer you even more dog videos. If you’re a cat person and avoid dog videos at all costs, the algorithm will “understand” this and offer you more videos starring cats.
Finance and Banking
Data mining analyzes markets to discover hidden patterns and make accurate predictions. The process is also used to check a company’s health and see what can be improved.
In banking, data mining is used to detect unusual transactions and prevent unauthorized access and theft. It can analyze clients and determine whether they’re suitable for loans (whether they can pay them back).
Challenges and Ethical Considerations of Data Mining
While it has many benefits, data mining faces different challenges:
- Privacy concerns – During the data mining process, sensitive and private information about users can come to light, thus jeopardizing their privacy.
- Data security – The world’s hungry for knowledge, and more and more data is getting collected and analyzed. There’s always a risk of data breaches that could affect millions of people worldwide.
- Bias and discrimination – Like humans, algorithms can be biased, but only if the sample data leads them toward such behavior. You can prevent this with precise data collection and preprocessing.
- Legal and regulatory compliance – Data mining needs to be conducted according to the letter of the law. If that’s not the case, the users’ privacy and your company’s reputation are at stake.
Track Trends With Data Mining
If you feel lost and have no idea what your next step should be, data mining can be your life support. With it, you can make informed decisions that will drive your company forward.
Considering its benefits, data mining will continue to be an invaluable tool in many niches.
Have you ever played chess or checkers against a computer? If you have, news flash – you’ve watched artificial intelligence at work. But what if the computer could get better at the game on its own just by playing more and analyzing its mistakes? That’s the power of machine learning, a type of AI that lets computers learn and improve from experience.
In fact, machine learning is becoming increasingly important in our daily lives. According to a report by Statista, revenues from the global market for AI software are expected to reach 126 billion by 2025, up from just 10.1 billion in 2018. From personalized recommendations on Netflix to self-driving cars, machine learning is powering some of the most innovative and exciting technologies of our time.
But how does it all work? In this article, we’ll dive into the concepts of machine learning and explore how it’s changing the way we interact with technology.
What is Machine Learning?
Machine learning is a subset of artificial intelligence (AI) that focuses on building algorithms that can learn from data and then make predictions or decisions and recognize patterns. Essentially, it’s all about creating computer programs that can adapt and improve on their own without being explicitly programmed for every possible scenario.
It’s like teaching a computer to see the world through a different lens. From the data, the machine identifies patterns and relationships within it. Based on these patterns, the algorithm can make predictions or decisions about new data it hasn’t seen before.
Because of these qualities, machine learning has plenty of practical applications. We can train computers to make decisions, recognize speech, and even generate art. We can use it in fraud detection in financial transactions or to improve healthcare outcomes through personalized medicine.
Machine learning also plays a large role in fields like computer vision, natural language processing, and robotics, as they require the ability to recognize patterns and make predictions to complete various tasks.
Concepts of Machine Learning
Machine learning might seem magical, but the concepts of machine learning are complex, with many layers of algorithms and techniques working together to get to an end goal.
From supervised and unsupervised learning to deep neural networks and reinforcement learning, there are many base concepts to understand before diving into the world of machine learning. Get ready to explore some machine learning basics!
Supervised Learning
Supervised learning involves training the algorithm to recognize patterns or make predictions using labeled data.
- Classification: Classification is quite straightforward, evident by its name. Its goal is to predict which category or class new data belongs to based on existing data.
- Logistic Regression: Logistic regression aims to predict a binary outcome (i.e., yes or no) based on one or more input variables.
- Support Vector Machines: Support Vector Machines (SVMs) find the best way to separate data points into different categories or classes based on their features or attributes.
- Decision Trees: Decision trees make decisions by dividing data into smaller and smaller subsets from a number of binary decisions. You can think of it like a game of 20 questions where you’re narrowing things down.
- Naive Bayes: Naive Bayes uses Bayes’ theorem to predict how likely it is to end up with a certain result when different input variables are present or absent.
Regression
Regression is a type of machine learning that helps us predict numerical values, like prices or temperatures, based on other data that we have. It looks for patterns in the data to create a mathematical model that can estimate the value we are looking for.
- Linear Regression: Linear regression helps us predict numerical values by fitting a straight line to the data.
- Polynomial Regression: Polynomial regression is similar to linear regression, but instead of fitting a straight line to the data, it fits a curved line (a polynomial) to capture more complex relationships between the variables. Linear regression might be used to predict someone’s salary based on their years of experience, while polynomial regression could be used to predict how fast a car will go based on its engine size.
- Support Vector Regression: Support vector regression finds the best fitting line to the data while minimizing errors and avoiding overfitting (becoming too attuned to the existing data).
- Decision Tree Regression: Decision tree regression uses a tree-like template to make predictions out of a series of decision rules, where each branch represents a decision, and each leaf node represents a prediction.
Unsupervised Learning
Unsupervised learning is where the computer algorithm is given a bunch of data with no labels and has to find patterns or groupings on its own, allowing for discovering hidden insights and relationships.
- Clustering: Clustering groups similar data points together based on their features.
- K-Means: K-Means is a popular clustering algorithm that separates the data into a predetermined number of clusters by finding the average of each group.
- Hierarchical Clustering: Hierarchical clustering is another way of grouping that creates a hierarchy of clusters by either merging smaller clusters into larger ones (agglomerative) or dividing larger clusters into smaller ones (divisive).
- Expectation Maximization: Expectation maximization is quite self-explanatory. It’s a way to find patterns in data that aren’t clearly grouped together by guessing what might be there and refining the guesses over time.
- Association Rule Learning: Association Rule Learning looks to find interesting connections between things in large sets of data, like discovering that people who buy plant pots often also buy juice.
- Apriori: Apriori is an algorithm for association rule learning that finds frequent itemsets (groups of items that appear together often) and makes rules that describe the relationships between them.
- Eclat: Eclat is similar to apriori, but it works by first finding which things appear together most often and then finding frequent itemsets out of those. It’s a method that works better for larger datasets.
Reinforcement Learning
Reinforcement learning is like teaching a computer to play a game by letting it try different actions and rewarding it when it does something good so it learns how to maximize its score over time.
- Q-Learning: Q-Learning helps computers learn how to take actions in an environment by assigning values to each possible action and using those values to make decisions.
- SARSA: SARSA is similar to Q-Learning but takes into account the current state of the environment, making it more useful in situations where actions have immediate consequences.
- DDPG (Deep Deterministic Policy Gradient): DDPG is a more advanced type of reinforcement learning that uses neural networks to learn policies for continuous control tasks, like robotic movement, by mapping what it sees to its next action.
Deep Learning Algorithms
Deep Learning is a powerful type of machine learning that’s inspired by how the human brain works, using artificial neural networks to learn and make decisions from vast amounts of data.
It’s more complex than other types of machine learning because it involves many layers of connections that can learn to recognize complex patterns and relationships in data.
- Neural Networks: Neural networks mimic the structure and function of the human brain, allowing them to learn from and make predictions about complex data.
- Convolutional Neural Networks: Convolutional neural networks are particularly good at image recognition, using specialized layers to detect features like edges, textures, and shapes.
- Recurrent Neural Networks: Recurrent neural networks are known to be good at processing sequential data, like language or music, by keeping track of previous inputs and using that information to make better predictions.
- Generative Adversarial Networks: Generative adversarial networks can generate new, original data by pitting two networks against each other. One tries to create fake data, and the other tries to spot the fakes until the generator network gets really good at making convincing fakes.
Conclusion
As we’ve learned, machine learning is a powerful tool that can help computers learn from data and make predictions, recognize patterns, and even create new things.
With basic concepts like supervised and unsupervised learning, regression and clustering, and advanced techniques like deep learning and neural networks, the possibilities for what we can achieve with machine learning are endless.
So whether you’re new to the subject or deeper down the iceberg, there’s always something new to learn in the exciting field of machine learning!
Data is the heartbeat of the digital realm. And when something is so important, you want to ensure you deal with it properly. That’s where data structures come into play.
But what is data structure exactly?
In the simplest terms, a data structure is a way of organizing data on a computing machine so that you can access and update it as quickly and efficiently as possible. For those looking for a more detailed data structure definition, we must add processing, retrieving, and storing data to the purposes of this specialized format.
With this in mind, the importance of data structures becomes quite clear. Neither humans nor machines could access or use digital data without these structures.
But using data structures isn’t enough on its own. You must also use the right data structure for your needs.
This article will guide you through the most common types of data structures, explain the relationship between data structures and algorithms, and showcase some real-world applications of these structures.
Armed with this invaluable knowledge, choosing the right data structure will be a breeze.
Types of Data Structures
Like data, data structures have specific characteristics, features, and applications. These are the factors that primarily dictate which data structure should be used in which scenario. Below are the most common types of data structures and their applications.
Primitive Data Structures
Take one look at the name of this data type, and its structure won’t surprise you. Primitive data structures are to data what cells are to a human body – building blocks. As such, they hold a single value and are typically built into programming languages. Whether you check data structures in C or data structures in Java, these are the types of data structures you’ll find.
- Integer (signed or unsigned) – Representing whole numbers
- Float (floating-point numbers) – Representing real numbers with decimal precision
- Character – Representing integer values as symbols
- Boolean – Storing true or false logical values
Non-Primitive Data Structures
Combine primitive data structures, and you get non-primitive data structures. These structures can be further divided into two types.
Linear Data Structures
As the name implies, a linear data structure arranges the data elements linearly (sequentially). In this structure, each element is attached to its predecessor and successor.
The most commonly used linear data structures (and their real-life applications) include the following:
- In arrays, multiple elements of the same type are stored together in the same location. As a result, they can all be processed relatively quickly. (library management systems, ticket booking systems, mobile phone contacts, etc.)
- Linked lists. With linked lists, elements aren’t stored at adjacent memory locations. Instead, the elements are linked with pointers indicating the next element in the sequence. (music playlists, social media feeds, etc.)
- These data structures follow the Last-In-First-Out (LIFO) sequencing order. As a result, you can only enter or retrieve data from one stack end (browsing history, undo operations in word processors, etc.)
- Queues follow the First-In-First-Out (FIFO) sequencing order (website traffic, printer task scheduling, video queues, etc.)
Non-Linear Data Structures
A non-linear data structure also has a pretty self-explanatory name. The elements aren’t placed linearly. This also means you can’t traverse all of them in a single run.
- Trees are tree-like (no surprise there!) hierarchical data structures. These structures consist of nodes, each filled with specific data (routers in computer networks, database indexing, etc.)
- Combine vertices (or nodes) and edges, and you get a graph. These data structures are used to solve the most challenging programming problems (modeling, computation flow, etc.)
Advanced Data Structures
Venture beyond primitive data structures (building blocks for data structures) and basic non-primitive data structures (building blocks for more sophisticated applications), and you’ll reach advanced data structures.
- Hash tables. These advanced data structures use hash functions to store data associatively (through key-value pairs). Using the associated values, you can quickly access the desired data (dictionaries, browser searching, etc.)
- Heaps are specialized tree-like data structures that satisfy the heap property (every tree element is larger than its descendant.)
- Tries store strings that can be organized in a visual graph and retrieved when necessary (auto-complete function, spell checkers, etc.)
Algorithms for Data Structures
There is a common misconception that data structures and algorithms in Java and other programming languages are one and the same. In reality, algorithms are steps used to structure data and solve other problems. Check out our overview of some basic algorithms for data structures.
Searching Algorithms
Searching algorithms are used to locate specific elements within data structures. Whether you’re searching for specific data structures in C++ or another programming language, you can use two types of algorithms:
- Linear search: starts from one end and checks each sequential element until the desired element is located
- Binary search: looks for the desired element in the middle of a sorted list of items (If the elements aren’t sorted, you must do that before a binary search.)
Sorting Algorithms
Whenever you need to arrange elements in a specific order, you’ll need sorting algorithms.
- Bubble sort: Compares two adjacent elements and swaps them if they’re in the wrong order
- Selection sort: Sorts lists by identifying the smallest element and placing it at the beginning of the unsorted list
- Insertion sort: Inserts the unsorted element in the correct position straight away
- Merge sort: Divides unsorted lists into smaller sections and orders each separately (the so-called divide-and-conquer principle)
- Quick sort: Also relies on the divide-and-conquer principle but employs a pivot element to partition the list (elements smaller than the pivot element go back, while larger ones are kept on the right)
Tree Traversal Algorithms
To traverse a tree means to visit its every node. Since trees aren’t linear data structures, there’s more than one way to traverse them.
- Pre-order traversal: Visits the root node first (the topmost node in a tree), followed by the left and finally the right subtree
- In-order traversal: Starts with the left subtree, moves to the root node, and ends with the right subtree
- Post-order traversal: Visits the nodes in the following order: left subtree, right subtree, the root node
Graph Traversal Algorithms
Graph traversal algorithms traverse all the vertices (or nodes) and edges in a graph. You can choose between two:
- Depth-first search – Focuses on visiting all the vertices or nodes of a graph data structure located one above the other
- Breadth-first search – Traverses the adjacent nodes of a graph before moving outwards
Applications of Data Structures
Data structures are critical for managing data. So, no wonder their extensive list of applications keeps growing virtually every day. Check out some of the most popular applications data structures have nowadays.
Data Organization and Storage
With this application, data structures return to their roots: they’re used to arrange and store data most efficiently.
Database Management Systems
Database management systems are software programs used to define, store, manipulate, and protect data in a single location. These systems have several components, each relying on data structures to handle records to some extent.
Let’s take a library management system as an example. Data structures are used every step of the way, from indexing books (based on the author’s name, the book’s title, genre, etc.) to storing e-books.
File Systems
File systems use specific data structures to represent information, allocate it to the memory, and manage it afterward.
Data Retrieval and Processing
With data structures, data isn’t stored and then forgotten. It can also be retrieved and processed as necessary.
Search Engines
Search engines (Google, Bing, Yahoo, etc.) are arguably the most widely used applications of data structures. Thanks to structures like tries and hash tables, search engines can successfully index web pages and retrieve the information internet users seek.
Data Compression
Data compression aims to accurately represent data using the smallest storage amount possible. But without data structures, there wouldn’t be data compression algorithms.
Data Encryption
Data encryption is crucial for preserving data confidentiality. And do you know what’s crucial for supporting cryptography algorithms? That’s right, data structures. Once the data is encrypted, data structures like hash tables also aid with value key storage.
Problem Solving and Optimization
At their core, data structures are designed for optimizing data and solving specific problems (both simple and complex). Throw their composition into the mix, and you’ll understand why these structures have been embraced by fields that heavily rely on mathematics and algorithms for problem-solving.
Artificial Intelligence
Artificial intelligence (AI) is all about data. For machines to be able to use this data, it must be properly stored and organized. Enter data structures.
Arrays, linked lists, queues, graphs, and stacks are just some structures used to store data for AI purposes.
Machine Learning
Data structures used for machine learning (MI) are pretty similar to other computer science fields, including AI. In machine learning, data structures (both linear and non-linear) are used to solve complex mathematical problems, manipulate data, and implement ML models.
Network Routing
Network routing refers to establishing paths through one or more internet networks. Various routing algorithms are used for this purpose and most heavily rely on data structures to find the best patch for the incoming data packet.
Data Structures: The Backbone of Efficiency
Data structures are critical in our data-driven world. They allow straightforward data representation, access, and manipulation, even in giant databases. For this reason, learning about data structures and algorithms further can open up a world of possibilities for a career in data science and related fields.
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