Cooperative Reinforcement Learning Using an Expert-Measuring Weighted Strategy with WoLF

Gradient descent learning algorithms have proven effective in solving mixed strategy games. The policy hill climbing (PHC) variants of WoLF (Win or Learn Fast) and PDWoLF (Policy Dynamics based WoLF) have both shown rapid convergence to equilibrium solutions by increasing the accuracy of their gradient parameters over standard Q-learning. Likewise, cooperative learning techniques using weighted strategy sharing (WSS) and expertness measurements improve agent performance when multiple agents are solving a common goal. By combining these cooperative techniques with fast gradient descent learning, an agent’s performance converges to a solution at an even faster rate. This statement is verified in a stochastic grid world environment using a limited visibility hunter-prey model with random and intelligent prey. Among five different expertness measurements, cooperative learning using each PHC algorithm converges faster than independent learning when agents strictly learn from better performing agents

TEACHING READING COMPREHENSION THROUGH JIGSAW TECHNIQUE

The research investigated “Teaching Reading Comprehension Through Jigsaw Technique” for the seconds grade students of SMP Negeri 3 Cidaun in Jl. Patriot no 10 Cimaragang, Cidaun, Cianjur in the academic year 2019/2020. The aims of the research are to know the significant difference in the result of jigsaw technique and the conventional technique in teaching narrative reading text, and to know the effectiveness by using jigsaw technique in teaching narrative reading text. A quasi experimental design was use to conduct the research. The population of this study was the second grade students of SMP Negeri 3 Cidaun in Cidaun,Cianjur. The sample of this study was 50 students. It was divided into groups. Twenty five students were as experimental group and twenty five were as control group. The experimental group was given the treatment by using jigsaw technique. The researcher gave the test, those were pre-test and post-test. The research finding showed that jigsaw technique is effective. It can be seen from the result after the treatments, t obtained is 9.353. the result of t-table is 2.021 the t-test value is bigger than that of t-table (9.353 > 2.021). It means that jigsaw technique as a technique of teaching narrative reading text to the seconds grade students of SMP Negeri 3 Cidaun in Cidaun, Cianjur has significantly better result than that of the conventional technique. It means that this technique is effective. The writer suggest that the English teacher should apply jigsaw technique in teaching reading, especially in teaching narrative reading text.Keywords: Reading Comprehension, Jigsaw Techniqu

Decision Making in Reinforcement Learning Using a Modified Learning Space Based on the Importance of Sensors

Many studies have been conducted on the application of reinforcement learning (RL) to robots. A robot which is made for general purpose has redundant sensors or actuators because it is difficult to assume an environment that the robot will face and a task that the robot must execute. In this case, Q-space on RL contains redundancy so that the robot must take much time to learn a given task. In this study, we focus on the importance of sensors with regard to a robot\u27s performance of a particular task. The sensors that are applicable to a task differ according to the task. By using the importance of the sensors, we try to adjust the state number of the sensors and to reduce the size of Q-space. In this paper, we define the measure of importance of a sensor for a task with the correlation between the value of each sensor and reward. A robot calculates the importance of the sensors and makes the size of Q-space smaller. We propose the method which reduces learning space and construct the learning system by putting it in RL. In this paper, we confirm the effectiveness of our proposed system with an experimental robot

Application of Fuzzy State Aggregation and Policy Hill Climbing to Multi-Agent Systems in Stochastic Environments

Reinforcement learning is one of the more attractive machine learning technologies, due to its unsupervised learning structure and ability to continually even as the operating environment changes. Applying this learning to multiple cooperative software agents (a multi-agent system) not only allows each individual agent to learn from its own experience, but also opens up the opportunity for the individual agents to learn from the other agents in the system, thus accelerating the rate of learning. This research presents the novel use of fuzzy state aggregation, as the means of function approximation, combined with the policy hill climbing methods of Win or Lose Fast (WoLF) and policy-dynamics based WoLF (PD-WoLF). The combination of fast policy hill climbing (PHC) and fuzzy state aggregation (FSA) function approximation is tested in two stochastic environments; Tileworld and the robot soccer domain, RoboCup. The Tileworld results demonstrate that a single agent using the combination of FSA and PHC learns quicker and performs better than combined fuzzy state aggregation and Q-learning lone. Results from the RoboCup domain again illustrate that the policy hill climbing algorithms perform better than Q-learning alone in a multi-agent environment. The learning is further enhanced by allowing the agents to share their experience through a weighted strategy sharing

Behaviour design in microrobots:hierarchical reinforcement learning under resource constraints

In order to verify models of collective behaviors of animals, robots could be manipulated to implement the model and interact with real animals in a mixed-society. This thesis describes design of the behavioral hierarchy of a miniature robot, that is able to interact with cockroaches, and participates in their collective decision makings. The robots are controlled via a hierarchical behavior-based controller in which, more complex behaviors are built by combining simpler behaviors through fusion and arbitration mechanisms. The experiments in the mixed-society confirms the similarity between the collective patterns of the mixed-society and those of the real society. Moreover, the robots are able to induce new collective patterns by modulation of some behavioral parameters. Difficulties in the manual extraction of the behavioral hierarchy and inability to revise it, direct us to benefit from machine learning techniques, in order to devise the composition hierarchy and coordination in an automated way. We derive a Compact Q-Learning method for micro-robots with processing and memory constraints, and try to learn behavior coordination through it. The behavior composition part is still done manually. However, the problem of the curse of dimensionality makes incorporation of this kind of flat-learning techniques unsuitable. Even though optimizing them could temporarily speed up the learning process and widen their range of applications, their scalability to real world applications remains under question. In the next steps, we apply hierarchical learning techniques to automate both behavior coordination and composition parts. In some situations, many features of the state space might be irrelevant to what the robot currently learns. Abstracting these features and discovering the hierarchy among them can help the robot learn the behavioral hierarchy faster. We formalize the automatic state abstraction problem with different heuristics, and derive three new splitting criteria that adapt decision tree learning techniques to state abstraction. Proof of performance is supported by strong evidences from simulation results in deterministic and non-deterministic environments. Simulation results show encouraging enhancements in the required number of learning trials, robot's performance, size of the learned abstraction trees, and computation time of the algorithms. In the other hand, learning in a group provides free sources of knowledge that, if communicated, can broaden the scales of learning, both temporally and spatially. We present two approaches to combine output or structure of abstraction trees. The trees are stored in different RL robots in a multi-robot system, or in the trees learned by the same robot but using different methods. Simulation results in a non-deterministic football learning task provide strong evidences for enhancement in convergence rate and policy performance, specially in heterogeneous cooperations

A Unified Framework for Solving Multiagent Task Assignment Problems

Multiagent task assignment problem descriptors do not fully represent the complex interactions in a multiagent domain, and algorithmic solutions vary widely depending on how the domain is represented. This issue is compounded as related research fields contain descriptors that similarly describe multiagent task assignment problems, including complex domain interactions, but generally do not provide the mechanisms needed to solve the multiagent aspect of task assignment. This research presents a unified approach to representing and solving the multiagent task assignment problem for complex problem domains. Ideas central to multiagent task allocation, project scheduling, constraint satisfaction, and coalition formation are combined to form the basis of the constrained multiagent task scheduling (CMTS) problem. Basic analysis reveals the exponential size of the solution space for a CMTS problem, approximated by O(2n(m+n)) based on the number of agents and tasks involved in a problem. The shape of the solution space is shown to contain numerous discontinuous regions due to the complexities involved in relational constraints defined between agents and tasks. The CMTS descriptor represents a wide range of classical and modern problems, such as job shop scheduling, the traveling salesman problem, vehicle routing, and cooperative multi-object tracking. Problems using the CMTS representation are solvable by a suite of algorithms, with varying degrees of suitability. Solution generating methods range from simple random scheduling to state-of-the-art biologically inspired approaches. Techniques from classical task assignment solvers are extended to handle multiagent task problems where agents can also multitask. Additional ideas are incorporated from constraint satisfaction, project scheduling, evolutionary algorithms, dynamic coalition formation, auctioning, and behavior-based robotics to highlight how different solution generation strategies apply to the complex problem space