Reinforcement learning is a very useful (and currently popular) subtype of machine learning and artificial intelligence. It is based on the principle that agents, when placed in an interactive environment, can learn from their actions via rewards associated with the actions, and improve the time to achieve their goal.
In this article, we’ll explore the fundamental concepts of reinforcement learning and discuss its key components, types, and applications.
Definition of Reinforcement Learning
We can define reinforcement learning as a machine learning technique involving an agent who needs to decide which actions it needs to do to perform a task that has been assigned to it most effectively. For this, rewards are assigned to the different actions that the agent can take at different situations or states of the environment. Initially, the agent has no idea about the best or correct actions. Using reinforcement learning, it explores its action choices via trial and error and figures out the best set of actions for completing its assigned task.
The basic idea behind a reinforcement learning agent is to learn from experience. Just like humans learn lessons from their past successes and mistakes, reinforcement learning agents do the same – when they do something “good” they get a reward, but, if they do something “bad”, they get penalized. The reward reinforces the good actions while the penalty avoids the bad ones.
Reinforcement learning requires several key components:
- Agent – This is the “who” or the subject of the process, which performs different actions to perform a task that has been assigned to it.
- Environment – This is the “where” or a situation in which the agent is placed.
- Actions – This is the “what” or the steps an agent needs to take to reach the goal.
- Rewards – This is the feedback an agent receives after performing an action.
Before we dig deep into the technicalities, let’s warm up with a real-life example. Reinforcement isn’t new, and we’ve used it for different purposes for centuries. One of the most basic examples is dog training.
Let’s say you’re in a park, trying to teach your dog to fetch a ball. In this case, the dog is the agent, and the park is the environment. Once you throw the ball, the dog will run to catch it, and that’s the action part. When he brings the ball back to you and releases it, he’ll get a reward (a treat). Since he got a reward, the dog will understand that his actions were appropriate and will repeat them in the future. If the dog doesn’t bring the ball back, he may get some “punishment” – you may ignore him or say “No!” After a few attempts (or more than a few, depending on how stubborn your dog is), the dog will fetch the ball with ease.
We can say that the reinforcement learning process has three steps:
- Interaction
- Learning
- Decision-making
Types of Reinforcement Learning
There are two types of reinforcement learning: model-based and model-free.
Model-Based Reinforcement Learning
With model-based reinforcement learning (RL), there’s a model that an agent uses to create additional experiences. Think of this model as a mental image that the agent can analyze to assess whether particular strategies could work.
Some of the advantages of this RL type are:
- It doesn’t need a lot of samples.
- It can save time.
- It offers a safe environment for testing and exploration.
The potential drawbacks are:
- Its performance relies on the model. If the model isn’t good, the performance won’t be good either.
- It’s quite complex.
Model-Free Reinforcement Learning
In this case, an agent doesn’t rely on a model. Instead, the basis for its actions lies in direct interactions with the environment. An agent tries different scenarios and tests whether they’re successful. If yes, the agent will keep repeating them. If not, it will try another scenario until it finds the right one.
What are the advantages of model-free reinforcement learning?
- It doesn’t depend on a model’s accuracy.
- It’s not as computationally complex as model-based RL.
- It’s often better for real-life situations.
Some of the drawbacks are:
- It requires more exploration, so it can be more time-consuming.
- It can be dangerous because it relies on real-life interactions.
Model-Based vs. Model-Free Reinforcement Learning: Example
Understanding model-based and model-free RL can be challenging because they often seem too complex and abstract. We’ll try to make the concepts easier to understand through a real-life example.
Let’s say you have two soccer teams that have never played each other before. Therefore, neither of the teams knows what to expect. At the beginning of the match, Team A tries different strategies to see whether they can score a goal. When they find a strategy that works, they’ll keep using it to score more goals. This is model-free reinforcement learning.
On the other hand, Team B came prepared. They spent hours investigating strategies and examining the opponent. The players came up with tactics based on their interpretation of how Team A will play. This is model-based reinforcement learning.
Who will be more successful? There’s no way to tell. Team B may be more successful in the beginning because they have previous knowledge. But Team A can catch up quickly, especially if they use the right tactics from the start.
Reinforcement Learning Algorithms
A reinforcement learning algorithm specifies how an agent learns suitable actions from the rewards. RL algorithms are divided into two categories: value-based and policy gradient-based.
Value-Based Algorithms
Value-based algorithms learn the value at each state of the environment, where the value of a state is given by the expected rewards to complete the task while starting from that state.
Q-Learning
This model-free, off-policy RL algorithm focuses on providing guidelines to the agent on what actions to take and under what circumstances to win the reward. The algorithm uses Q-tables in which it calculates the potential rewards for different state-action pairs in the environment. The table contains Q-values that get updated after each action during the agent’s training. During execution, the agent goes back to this table to see which actions have the best value.
Deep Q-Networks (DQN)
Deep Q-networks, or deep q-learning, operate similarly to q-learning. The main difference is that the algorithm in this case is based on neural networks.
SARSA
The acronym stands for state-action-reward-state-action. SARSA is an on-policy RL algorithm that uses the current action from the current policy to learn the value.
Policy-Based Algorithms
These algorithms directly update the policy to maximize the reward. There are different policy gradient-based algorithms: REINFORCE, proximal policy optimization, trust region policy optimization, actor-critic algorithms, advantage actor-critic, deep deterministic policy gradient (DDPG), and twin-delayed DDPG.
Examples of Reinforcement Learning Applications
The advantages of reinforcement learning have been recognized in many spheres. Here are several concrete applications of RL.
Robotics and Automation
With RL, robotic arms can be trained to perform human-like tasks. Robotic arms can give you a hand in warehouse management, packaging, quality testing, defect inspection, and many other aspects.
Another notable role of RL lies in automation, and self-driving cars are an excellent example. They’re introduced to different situations through which they learn how to behave in specific circumstances and offer better performance.
Gaming and Entertainment
Gaming and entertainment industries certainly benefit from RL in many ways. From AlphaGo (the first program that has beaten a human in the board game Go) to video games AI, RL offers limitless possibilities.
Finance and Trading
RL can optimize and improve trading strategies, help with portfolio management, minimize risks that come with running a business, and maximize profit.
Healthcare and Medicine
RL can help healthcare workers customize the best treatment plan for their patients, focusing on personalization. It can also play a major role in drug discovery and testing, allowing the entire sector to get one step closer to curing patients quickly and efficiently.
Basics for Implementing Reinforcement Learning
The success of reinforcement learning in a specific area depends on many factors.
First, you need to analyze a specific situation and see which RL algorithm suits it. Your job doesn’t end there; now you need to define the environment and the agent and figure out the right reward system. Without them, RL doesn’t exist. Next, allow the agent to put its detective cap on and explore new features, but ensure it uses the existing knowledge adequately (strike the right balance between exploration and exploitation). Since RL changes rapidly, you want to keep your model updated. Examine it every now and then to see what you can tweak to keep your model in top shape.
Explore the World of Possibilities With Reinforcement Learning
Reinforcement learning goes hand-in-hand with the development and modernization of many industries. We’ve been witnesses to the incredible things RL can achieve when used correctly, and the future looks even better. Hop in on the RL train and immerse yourself in this fascinating world.
-
From the same author
Read the articleReinforcement learning is a very useful (and currently popular) subtype of machine learning and artificial intelligence. It is based on the principle that agents, when placed in an interactive environment, can learn from their actions via rewards associated with the actions, and improve the time to achieve their goal.
In this article, we’ll explore the fundamental concepts of reinforcement learning and discuss its key components, types, and applications.
Definition of Reinforcement Learning
We can define reinforcement learning as a machine learning technique involving an agent who needs to decide which actions it needs to do to perform a task that has been assigned to it most effectively. For this, rewards are assigned to the different actions that the agent can take at different situations or states of the environment. Initially, the agent has no idea about the best or correct actions. Using reinforcement learning, it explores its action choices via trial and error and figures out the best set of actions for completing its assigned task.
The basic idea behind a reinforcement learning agent is to learn from experience. Just like humans learn lessons from their past successes and mistakes, reinforcement learning agents do the same – when they do something “good” they get a reward, but, if they do something “bad”, they get penalized. The reward reinforces the good actions while the penalty avoids the bad ones.
Reinforcement learning requires several key components:
- Agent – This is the “who” or the subject of the process, which performs different actions to perform a task that has been assigned to it.
- Environment – This is the “where” or a situation in which the agent is placed.
- Actions – This is the “what” or the steps an agent needs to take to reach the goal.
- Rewards – This is the feedback an agent receives after performing an action.
Before we dig deep into the technicalities, let’s warm up with a real-life example. Reinforcement isn’t new, and we’ve used it for different purposes for centuries. One of the most basic examples is dog training.
Let’s say you’re in a park, trying to teach your dog to fetch a ball. In this case, the dog is the agent, and the park is the environment. Once you throw the ball, the dog will run to catch it, and that’s the action part. When he brings the ball back to you and releases it, he’ll get a reward (a treat). Since he got a reward, the dog will understand that his actions were appropriate and will repeat them in the future. If the dog doesn’t bring the ball back, he may get some “punishment” – you may ignore him or say “No!” After a few attempts (or more than a few, depending on how stubborn your dog is), the dog will fetch the ball with ease.
We can say that the reinforcement learning process has three steps:
- Interaction
- Learning
- Decision-making
Types of Reinforcement Learning
There are two types of reinforcement learning: model-based and model-free.
Model-Based Reinforcement Learning
With model-based reinforcement learning (RL), there’s a model that an agent uses to create additional experiences. Think of this model as a mental image that the agent can analyze to assess whether particular strategies could work.
Some of the advantages of this RL type are:
- It doesn’t need a lot of samples.
- It can save time.
- It offers a safe environment for testing and exploration.
The potential drawbacks are:
- Its performance relies on the model. If the model isn’t good, the performance won’t be good either.
- It’s quite complex.
Model-Free Reinforcement Learning
In this case, an agent doesn’t rely on a model. Instead, the basis for its actions lies in direct interactions with the environment. An agent tries different scenarios and tests whether they’re successful. If yes, the agent will keep repeating them. If not, it will try another scenario until it finds the right one.
What are the advantages of model-free reinforcement learning?
- It doesn’t depend on a model’s accuracy.
- It’s not as computationally complex as model-based RL.
- It’s often better for real-life situations.
Some of the drawbacks are:
- It requires more exploration, so it can be more time-consuming.
- It can be dangerous because it relies on real-life interactions.
Model-Based vs. Model-Free Reinforcement Learning: Example
Understanding model-based and model-free RL can be challenging because they often seem too complex and abstract. We’ll try to make the concepts easier to understand through a real-life example.
Let’s say you have two soccer teams that have never played each other before. Therefore, neither of the teams knows what to expect. At the beginning of the match, Team A tries different strategies to see whether they can score a goal. When they find a strategy that works, they’ll keep using it to score more goals. This is model-free reinforcement learning.
On the other hand, Team B came prepared. They spent hours investigating strategies and examining the opponent. The players came up with tactics based on their interpretation of how Team A will play. This is model-based reinforcement learning.
Who will be more successful? There’s no way to tell. Team B may be more successful in the beginning because they have previous knowledge. But Team A can catch up quickly, especially if they use the right tactics from the start.
Reinforcement Learning Algorithms
A reinforcement learning algorithm specifies how an agent learns suitable actions from the rewards. RL algorithms are divided into two categories: value-based and policy gradient-based.
Value-Based Algorithms
Value-based algorithms learn the value at each state of the environment, where the value of a state is given by the expected rewards to complete the task while starting from that state.
Q-Learning
This model-free, off-policy RL algorithm focuses on providing guidelines to the agent on what actions to take and under what circumstances to win the reward. The algorithm uses Q-tables in which it calculates the potential rewards for different state-action pairs in the environment. The table contains Q-values that get updated after each action during the agent’s training. During execution, the agent goes back to this table to see which actions have the best value.
Deep Q-Networks (DQN)
Deep Q-networks, or deep q-learning, operate similarly to q-learning. The main difference is that the algorithm in this case is based on neural networks.
SARSA
The acronym stands for state-action-reward-state-action. SARSA is an on-policy RL algorithm that uses the current action from the current policy to learn the value.
Policy-Based Algorithms
These algorithms directly update the policy to maximize the reward. There are different policy gradient-based algorithms: REINFORCE, proximal policy optimization, trust region policy optimization, actor-critic algorithms, advantage actor-critic, deep deterministic policy gradient (DDPG), and twin-delayed DDPG.
Examples of Reinforcement Learning Applications
The advantages of reinforcement learning have been recognized in many spheres. Here are several concrete applications of RL.
Robotics and Automation
With RL, robotic arms can be trained to perform human-like tasks. Robotic arms can give you a hand in warehouse management, packaging, quality testing, defect inspection, and many other aspects.
Another notable role of RL lies in automation, and self-driving cars are an excellent example. They’re introduced to different situations through which they learn how to behave in specific circumstances and offer better performance.
Gaming and Entertainment
Gaming and entertainment industries certainly benefit from RL in many ways. From AlphaGo (the first program that has beaten a human in the board game Go) to video games AI, RL offers limitless possibilities.
Finance and Trading
RL can optimize and improve trading strategies, help with portfolio management, minimize risks that come with running a business, and maximize profit.
Healthcare and Medicine
RL can help healthcare workers customize the best treatment plan for their patients, focusing on personalization. It can also play a major role in drug discovery and testing, allowing the entire sector to get one step closer to curing patients quickly and efficiently.
Basics for Implementing Reinforcement Learning
The success of reinforcement learning in a specific area depends on many factors.
First, you need to analyze a specific situation and see which RL algorithm suits it. Your job doesn’t end there; now you need to define the environment and the agent and figure out the right reward system. Without them, RL doesn’t exist. Next, allow the agent to put its detective cap on and explore new features, but ensure it uses the existing knowledge adequately (strike the right balance between exploration and exploitation). Since RL changes rapidly, you want to keep your model updated. Examine it every now and then to see what you can tweak to keep your model in top shape.
Explore the World of Possibilities With Reinforcement Learning
Reinforcement learning goes hand-in-hand with the development and modernization of many industries. We’ve been witnesses to the incredible things RL can achieve when used correctly, and the future looks even better. Hop in on the RL train and immerse yourself in this fascinating world.
-
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Computer Science is fast becoming one of the most valuable fields of study, with high levels of demand and high-salaried career opportunities for successful graduates. If you’re looking for a flexible and rewarding way to hone your computing skills as part of a supportive global community, the BSc in Computer Science at the Open Institute of Technology (OPIT) could be the perfect next step.
Introducing the OPIT BSc in Computer Science
The OPIT BSc in Computer Science is a bachelor’s degree program that provides students with a comprehensive level of both theoretical and practical knowledge of all core areas of computer science. That includes the likes of programming, databases, cloud computing, software development, and artificial intelligence.
Like other programs at OPIT, the Computer Science BSc is delivered exclusively online, with a mixture of recorded and live content for students to engage with. Participants will enjoy the instruction of world-leading lecturers and professors from various fields, including software engineers at major tech brands and esteemed researchers, and will have many paths open to them upon graduation.
Graduates may, for example, seek to push on with their educational journeys, progressing on to a specialized master’s degree at OPIT, like the MSc in Digital Business and Innovation or the MSc in Responsible Artificial Intelligence. Or they could enter the working world in roles like software engineer, data scientist, web developer, app developer, or cybersecurity consultant.
The bullets below outline the key characteristics of this particular course:
- Duration: Three years in total, spread across six terms.
- Content: Core courses for the first four terms, a student-selected specialization for the fifth term, and a capstone project in the final term.
- Focus: Developing detailed theoretical knowledge and practical skills across all core areas of modern computer science.
- Format: Entirely online, with a mixture of live lessons and asynchronous content you can access 24/7 to learn at your own pace.
- Assessment: Progressive assessments over the course of the program, along with a capstone project and dissertation, but no final exams.
What You’ll Learn
Students enrolled in the BSc in Computer Science course at OPIT will enjoy comprehensive instruction in the increasingly diverse sectors that fall under the umbrella of computer science today. That includes a close look at emerging technologies, like AI and machine learning, as well as introductions to the fundamental skills involved in designing and developing pieces of software.
The first four terms are the same for all students. These will include introductions to software engineering, computer security, and cloud computing infrastructure, as well as courses focusing on the core skills that computer scientists invariably need in their careers, like project management, quality assurance, and technical English.
For the fifth term, students will have a choice. They can select five electives from a pool of 27, or select one field to specialize in from a group of five. You may choose to specialize in all things cybersecurity, for example, and learn about emerging cyber threats. Or you could focus more on specific elements of computer science that appeal to your interests and passions, such as game development.
Who It’s For
The BSc in Computer Science program can suit a whole range of prospective applicants and should appeal to anyone with an interest or passion for computing and a desire to pursue a professional career in this field. Whether you’re seeking to enter the world of software development, user experience design, data science, or another related sector, this is the course to consider.
In addition, thanks to OPIT’s engaging, flexible, and exclusively online teaching and learning systems, this course can appeal to people from all over the globe, of different ages, and from different walks of life. It’s equally suitable for recent high school graduates with dreams of making their own apps to seasoned professionals looking to broaden their knowledge or transition to a different career.
The Value of the BSc in Computer Science Course at OPIT
Plenty of universities and higher education establishments around the world offer degrees in computer science, but OPIT’s program stands out for several distinctive reasons.
Firstly, as previously touched upon, all OPIT courses are delivered online. Students have a schedule of live lessons to attend, but can also access recorded content and digital learning resources as and when they choose. This offers an unparalleled level of freedom and flexibility compared to more conventional educational institutions, putting students in the driving seat and letting them learn at their own pace.
OPIT also aims not merely to impart knowledge through lectures and teaching, but to actually help students gain the practical skills they need to take the next logical steps in their education or career. In other words, studying at OPIT isn’t simply about memorizing facts and paragraphs of text; it’s about learning how to apply the knowledge you gain in real-world settings.
OPIT students also enjoy the unique benefits of a global community of like-minded students and world-leading professors. Here, distance is no barrier, and while students and teachers may come from completely different corners of the globe, all are made to feel welcome and heard. Students can reach out to their lecturers when they feel the need for guidance, answers, and advice.
Other benefits of studying with OPIT include:
- Networking opportunities and events, like career fairs, where you can meet and speak with representatives from some of the world’s biggest tech brands
- Consistent support systems from start to finish of your educational journey in the form of mentorships and more
- Helpful tools to expedite your education, like the OPIT AI Copilot, which provides personalized study support
Entry Requirements and Fees
To enroll in the OPIT BSc in Computer Science and take your next steps towards a thrilling and fulfilling career in this field, you’ll need to meet some simple criteria. Unlike other educational institutions, which can impose strict and seemingly unattainable requirements on their applicants, OPIT aims to make tech education more accessible. As a result, aspiring students will require:
- A higher secondary school leaving certificate at EQF Level 4, or equivalent
- B2-level English proficiency, or higher
Naturally, applicants should also have a passion for computer science and a willingness to study, learn, and make the most of the resources, community, and support systems provided by the institute.
In addition, if you happen to have relevant work experience or educational achievements, you may be able to use these to skip certain modules or even entire terms and obtain your degree sooner. OPIT offers a comprehensive credit transfer program, which you can learn more about during the application process.
Regarding fees, OPIT also stands out from the crowd compared to conventional educational institutions, offering affordable rates to make higher tech education more accessible. There are early bird discounts, scholarship opportunities, and even the option to pay either on a term-by-term basis or a one-off up-front fee.
The Open Institute of Technology (OPIT) provides a curated collection of courses for students at every stage of their learning journey, including those who are just starting. For aspiring tech leaders and those who don’t quite feel ready to dive directly into a bachelor’s degree, there’s the OPIT Foundation Program. It’s the perfect starting point to gain core skills, boost confidence, and build a solid base for success.
Introducing the OPIT Foundation Year Program
As the name implies, OPIT’s Foundation Program is about foundation-level knowledge and skills. It’s the only pre-bachelor program in the OPIT lineup, and successful students on this 60-ECTS credit course will obtain a Pre-Tertiary Certificate in Information Technology upon its completion. From there, they can move on to higher levels of learning, like a Bachelor’s in Digital Business or Modern Computer Science.
In other words, the Foundation Program provides a gentle welcome into the world of higher technological education, while also serving as a springboard to help students achieve their long-term goals. By mixing both guided learning and independent study, it also prepares students for the EQF Level 4 experiences and challenges they’ll face once they enroll in a bachelor’s program in IT or a related field.
Here’s a quick breakdown of what the OPIT Foundation Program course involves:
- Duration: Six months, split into two terms, with each term lasting 13 weeks
- Content: Three courses per term, with each one worth 10 ECTS credits, for a total of 60
- Focus: Core skills, like mathematics, English, and introductory-level computing
- Format: Video lectures, independent learning, live sessions, and digital resources (e-books, etc.)
- Assessment: Two to three assessments over the course of the program
What You’ll Learn
The OPIT Foundation Program doesn’t intensely focus on any one particular topic, nor does it thrust onto you the more advanced, complicated aspects of technological education you would find in a bachelor’s or master’s program. Instead, it largely keeps things simple, focusing on the basic building blocks of knowledge and core skills so that students feel comfortable taking the next steps in their studies.
It includes the following courses, spread out across two terms:
- Academic Skills
- Mathematics Literacy I
- Mathematics Literacy II
- Internet and Digital Technology
- Academic Reading, Writing, and Communication
- Introduction to Computer Hardware and Software
Encompassing foundational-level lessons in digital business, computer science, and computer literacy, the Foundation Program produces graduates with a commanding knowledge of common operating systems. Exploring reading and writing, it also helps students master the art of communicating their ideas and responses in clear, academic English.
Who It’s For
The Foundation Year program is for people who are eager to enter the world of technology and eventually pursue a bachelor’s or higher level of education in this field, but feel they need more preparation. It’s for the people who want to work on their core skills and knowledge before progressing to more advanced topics, so that they don’t feel lost or left behind later on.
It can appeal to anyone with a high school-level education and ambitions of pushing themselves further, and to anyone who wants to work in fields like computer science, digital business, and artificial intelligence (AI). You don’t need extensive experience or qualifications to get started (more on that below); just a passion for tech and the motivation to learn.
The Value of the Foundation Program
With technology playing an increasingly integral role in the world today, millions of students want to develop their tech knowledge and skills. The problem is that technology-oriented degree courses can sometimes feel a little too complex or even inaccessible, especially for those who may not have had the most conventional educational journeys in the past.
While so many colleges and universities around the world simply expect students to show up with the relevant skills and knowledge to dive right into degree programs, OPIT understands that some students need a helping hand. That’s where the Foundation Program comes in – it’s the kind of course you won’t find at a typical university, aimed at bridging the gap between high school and higher education.
By progressing through the Foundation Program, students gain not just knowledge, but confidence. The entire course is aimed at eliminating uncertainty and unease. It imbues students with the skills and understanding they need to push onward, to believe in themselves, and to get more value from wherever their education takes them next.
On its own, this course won’t necessarily provide the qualifications you need to move straight into the job market, but it’s a vital stepping stone towards a degree. It also provides numerous other advantages that are unique to the OPIT community:
- Online Learning: Enjoy the benefits of being able to learn at your own pace, from the comfort of home, without the costs and inconveniences associated with relocation, commuting, and so on.
- Strong Support System: OPIT professors regularly check in with students and are on hand around the clock to answer queries and provide guidance.
- Academic Leaders: The OPIT faculty is made up of some of the world’s sharpest minds, including tech company heads, experienced researchers, and even former education ministers.
Entry Requirements and Fees
Unlike OPIT’s other, more advanced courses, the Foundation Program is aimed at beginners, so it does not have particularly strict or complex entry requirements. It’s designed to be as accessible as possible, so that almost anyone can acquire the skills they need to pursue education and a career in technology. The main thing you’ll need is a desire to learn and improve your skills, but applicants should also possess:
- English proficiency at level B2 or higher
- A Secondary School Leaving Certificate, or equivalent
Regarding the fees, OPIT strives to lower the financial barrier of education that can be such a deterrent in conventional education around the world. The institute’s tuition fees are fairly and competitively priced, all-inclusive (without any hidden charges to worry about), and accessible for those working with different budgets.
Given that all resources and instruction are provided online, you can also save a lot of money on relocation and living costs when you study with OPIT. In addition, applicants have the option to pay either up front, with a 10% discount on the total, or on a per-term basis, allowing you to stretch the cost out over a longer period to ease the financial burden.
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