VLDB 2026 Research / reviewers in the wild / expert
Ichiro Nishizaki
dblp:35/1984
· DBLP profile ↗
42ranked-venue papers
10as first author
6since 2021 · last 2025
0000-0002-0060-4360ORCID · verified
Domains — the database's venue-derived domains; a paper can count in several
Artificial intelligence and machine learning · 23 · 6 first-author · 2 since 2021Human-computer interaction and ubiquitous computing · 14 · 1 first-author · 4 since 2021Applied, interdisciplinary, general and emerging computing · 14 · 3 first-author · 3 since 2021Theory of computation · 1 · 1 first-author
| Year | Publication | Venue | Position |
|---|---|---|---|
| 2025 | Data sharing procedure for effective learnings in deep reinforcement learning of multiagent systemsabstractIn recent years, reinforcement learning has made significant progress in a wide range of domains, including autonomous driving, behavior analysis in electricity markets, and robotic control. Many of these studies have demonstrated the effectiveness of applying Multi-Agent Systems (MAS), where multiple agents act cooperatively or competitively. However, a major challenge in MAS lies in the increased environmental uncertainty caused by the influence of other agents, which can lead to instability in the learning process. To address this issue, various approaches have been proposed that aim to improve learning efficiency by leveraging the experience data of other agents. Previous studies have reported that sharing full experience data among agents can enhance learning efficiency in both cooperative and competitive settings. Furthermore, there are cases where sharing only partial experience data has also led to performance improvements. In this paper, we focus on the similarity between agents as a key criterion for selecting shared data and demonstrate its effectiveness in improving learning performance in MAS. Specifically, we propose a novel method that selectively shares experience data based on agent similarity and utilizes this data to complement an agent’s own experiences. Through simulations with heterogeneous (asymmetric) agents, we show that the proposed method enhances learning efficiency in multi-agent environments. Tomohiro Hayashida, Kotaro Asano, Shinya Sekizaki, Ichiro Nishizaki |
SMC | 4 |
| 2024 | WIP: Machine Learning Models for Predicting Student Performance in IoT-Enhanced EducationabstractThis work in progress resaerch-to-practice mainly contributes the development of a multistage classification method to distinguish between learners who are easily predictable and those who exhibit more complex patterns. This methodological innovation not only supports the efficient allocation of educational resources but also aids in customizing learning materials for learning management systems, enhancing the relevance and effectiveness of educational content. In Japan, the GIGA School Concept, which involves the use of one internet-connected electronic device per student, has been introduced in all elementary and junior high schools since 2020. The integration of IoT (Internet of Things) technology supported by such initiatives represents a significant shift towards creating more interactive and tailored learning environments. This evolution aims not only to enhance educational outcomes by providing individual electronic devices to learners but also to optimize learning results and operational efficiency. These technological tools enable learners to progress through their educational journey at their own pace, promoting a more learner-centered approach known as “Personalized Learning.” Simultaneously, educators can more effectively monitor and manage the learning process, enabling a more responsive and adaptive educational experience. At the central of this transformation is the role of machine learning models (such as neural networks and random forests) used to predict learners' performance based on past academic achievements. This predictive capability allows for the grouping of learners based on the predictability of their performance, further refining educational strategies to meet diverse learning needs. Furthermore, this study explores the practical application of these models through numerical experiments using actual learner data. The results highlight the potential of combining IoT technology and machine learning to revolutionize the educational domain by providing personalized learning experiences. Such an approach promises not only to improve learning outcomes by aligning educational content and strategies with individual learners' profiles but also to streamline the educational process, reduce the burden on educators, and optimize the overall educational environment. In conclusion, the integration of IoT and machine learning into education presents a visionary method for addressing the unique needs and potential of individual learners. Tomohiro Hayashida, Shin Wakitani, Kento Tsutsumi, Takuya Kinoshita, Ichiro Nishizaki, Shinya Sekizaki |
FIE | 5 |
| 2024 | Integrating Task Allocation and Hierarchical Reinforcement Learning for Optimized Cargo Transport RoutingabstractIn recent years, there have been growing expectations for the improvement of operational efficiency through the use of artificial intelligence (AI: Artificial Intelligence) in various fields such as healthcare, industry, and services. Additionally, advancements in robotics technology have enabled widespread collaborative operations among multiple autonomous mobile robots. Since the 1980s, there has been active research on improving the efficiency of coordinated actions by multiple autonomous mobile robots using Multi-Agent Robot Systems (MARS) (Cao et al.; 1997, Yan et al.; 2013, Ismail and Sariff; 2019). This study focuses on robots that transport cargo within a warehouse and aims to develop learning methods for effective division of labor among multiple robots. In large and complex environments, agents need to undergo extensive repetitive learning to make appropriate action choices solely through machine learning techniques such as reinforcement learning. Traditional multi-agent methods like QMIX (Monotonic Value Function Factorisation for Deep Multi-Agent Reinforcement Learning) (Rashid et al.; 2020) and MADDPG (Multi-Agent Deep Deterministic Policy Gradient) (Lowe et al.; 2017) require substantial computational time for environmental exploration, presenting a significant challenge. Therefore, this paper proposes a two-tiered learning model that separates overall optimization, such as establishing a general procedure for task performance, from individual optimization based on local situational judgments. Additionally, to demonstrate the effectiveness of the proposed method, a simulation system tailored to the target environment is constructed, and simulation analysis based on this system is conducted. Tomohiro Hayashida, Shinya Sekizaki, Ryuya Furukawa, Ichiro Nishizaki |
SMC | 4 |
| 2023 | Improving TCPSO Solution Search Performance Using Gaussian Process RegressionabstractParticle Swarm Optimization tends to converge prematurely to local solutions. To improve such a problem, TCPSO (Two-swarm Cooperative PSO) has been proposed. TCPSO employs a group of slave particles for intensive solution search and a group of master particles for global solution search. If the solution search process of TCPSO results in a small update range of solutions, the approximate shape of the function can be estimated based on known input data. This estimation can be done using Gaussian process regression to model the distribution with mean and variance, and improves the solution search process of TCPSO. Yuki Kashihara, Tomohiro Hayashida, Ichiro Nishizaki, Shinya Sekizaki |
KES | 3 |
| 2023 | Two-Swarm Cooperative Particle Swarm Optimization Including Prediction Using Gaussian Process RegressionabstractThis study presents a novel approach to enhance the performance of TCPSO by integrating Gaussian process regression into the solution search process. By leveraging Gaussian process regression to estimate the underlying function of the target problem, our proposed method aims to improve the algorithm's exploration capabilities and enable the discovery of more precise and reliable solutions. Through extensive experimentation and comparisons with existing approaches on diverse benchmark problems, we demonstrate the effectiveness and superiority of our approach in achieving improved search performance and solution quality. Tomohiro Hayashida, Ichiro Nishizaki, Shinya Sekizaki, Yuki Kashihara |
SMC | 2 |
| 2021 | Multiobjective Bimatrix Game with Fuzzy Payoffs and Its Solution Method using Necessity Measure and Weighted Tchebycheff Norm
Hitoshi Yano, Ichiro Nishizaki |
IJCCI | 2 |
| 2020 | Study on an Adaptive Learning Support System Design based on Model-based DevelopmentabstractThis research proposes an adaptive smart learning support system, whose target is a typing support system, based on the Model-Based Development (MBD) approach. The proposed typing support system adaptively adjusts the level of work so that the typing skill of a learner is smoothly grown. In this paper, the goal of an adaptive smart learning support system is briefly explained, and a concrete design scheme of a part of the support system based on the MBD approach is presented. This paper also mentions the work in progress of developing an actual typing support system. Shin Wakitani, Takuya Kinoshita, Tomohiro Hayashida, Toru Yamamoto, Ichiro Nishizaki |
FIE | 5 |
| 2020 | Improvement of Particle Swarm Optimization Focusing on Diversity of the Particle SwarmabstractPSO (Particle Swarm Optimization) is attracting attention in recent years to solve the multivariate optimization problems. In PSO, multiple individuals (particles) which records its own position and velocity information are placed in the corresponding search space, and the particle swarm move to discover the optimal solution by sharing information with other particles. The search process of PSO has problem such that it is difficult to deviate from the local solution because of convergence speed of the swarms is too fast. In TCPSO (Two-Swarm Cooperative PSO), particle swarm consists of two different types of particles (a master particle swarm and a slave particle swarm) with different characteristics of search process. Experimental results of using several benchmark problems indicate that TCPSO has high performance of finding optimal solutions for multidimensional and nonlinear problems. This study introduces the concept of specificity of each master particle which indicates the diversity of master particle swarm, and proposes an algorithm that improves the efficiency of the solution search process in TCPSO by periodically analyzing the behavior of master particle swarm. This study conducts several numerical experiments for verifying the effectiveness of the proposed method. Tomohiro Hayashida, Ichiro Nishizaki, Shinya Sekizaki, Yuki Takamori |
SMC | 2 |
| 2019 | Feature Extraction and Classification of Learners Using Neural NetworksabstractThis paper to Practice Full Paper presents about a procedure to generate the learners' data using a learner model based on first-order lag system to generate learners data. By using the generated data, the learners are classified into several groups and some learners with low understanding degree can be extracted by using the neural networks. It is necessary to provide learning support corresponding to the understanding degree of each learner in a class to improve effective learning. By providing additional education for the learners who are predicted as low degree by the proposed procedure, it is expected to take countermeasures for not becoming “dropout students” in early stage. For this purpose, predicting the understanding degree is important, and this paper employs a recurrent neural network as the predictor. Hayashida et al. (2018) have constructed to classify the learners by understanding degree at the end of the class based on some observed data such as result of quizzes, or report tasks by using FNN (Feedforward Neural Network). This paper uses a RNN (Recurrent Neural Network) which consists of feedforward signal processing and structure of the signal feedbacks because of the observed data is time-series data. This paper proposes a learner model based on first-order lag system to generate learner data for training RNNs. As experimental result of the simulation, this paper succeeds in extracting the learner group with low understanding degree in future. Tomohiro Hayashida, Toru Yamamoto, Shin Wakitani, Takuya Kinoshita, Ichiro Nishizaki, Shinya Sekizaki, Yusuke Tanimoto |
FIE | 5 |
| 2018 | Feature extraction and classification of learners using neural networksabstractThe aim of this study is to predict the achievement degree of each student at the end of a lecture, based on a simple questionnaire result which regularly surveys degree of the subjective understanding conducted to students in a class. In this study, the feedforward neural networks (FNNs) and decision tree are used for the prediction and the classification. A FNN which is with a multiple input and multiple output structure is well known that it has high performance for multidimensional data prediction or classification. Therefore, FNNs are considered to be suitable for the problem dealt with in this study such that student classification based on multiple questionnaire results. Additionally, it is possible to analyze students' learning process in detail by using a decision tree that can obtain student classification rules in an explicit form. This study conducts an experiment using data of a classification six times questionnaire surveys and a final examination and constructed a system for student classification based on the the answers of three questionnaire. Experiment has succeeded in roughly classifying learners into three clusters based on achievement degree. It means that the proposed method is predict the potential comprehension degree of a student. Sequentially, by providing additional education for the students who are classified as a low degree, it is expected to be able to take countermeasures for not becoming “dropout” in early stage. Tomohiro Hayashida, Toru Yamamoto, Shin Wakitani, Ichiro Nishizaki, Shinya Sekizaki, Yusuke Tanimoto |
FIE | 4 |
| 2018 | Development of a Classifier System for Continuous Environment Using Neural NetworkabstractIn order to carry out simulation using an environment in the real world, reinforcement learning techniques are improved to be applied on continuous environment. Real values are available as the input and output value of neural networks, however, it can not be applied to the multi step problem. Although the classifier system can preserve the value of actions and its prediction accuracy, there exists a problem when applying on continuous environment, because the bit string in the condition part should be long. In order to compensate for the disadvantages of both the neural network and the classifier system, this paper proposes N-XCS (Neural network eXtended Classifier System) in which the merits of these two methods are twisted together. Additionally, the usefulness of the proposed method is indicated based on the result of some numerical experiments. Tomohiro Hayashida, Ichiro Nishizaki, Shinya Sekizaki, Yuki Ogasawara |
SMC | 2 |
| 2017 | Improved anticipatory classifier system with internal memory for POMDPs with aliased statesabstractACSM (Hayashida et al., 2014) consists of a method of discerning the aliased states in a POMDP (Partially Observable Markov Decision Process) which is one of Markov decision process such that an agent observes local information about the environment, and choosing the appropriate action based on the internal memory and the sensory information which an agent obtains from the environment. Though ACSM achieves the highest performance in the existing methods based on classifier systems, it requires a huge number of memories for the internal memories, and spends long time for some large scaled problems. This paper improves a classifier system, ACSM (Anticipatory Classifier System with Memory) focused on the process of learning of ACSM, and the aim of this paper is to make the system more efficient. The improved method is named ACSMr in this paper, and some numerical experiments using 5 kinds of maze problems which are well used as benchmark problems for POMDPs are executed. ACSMr achieves greater experimental result than the existing classifier systems for the maze problems. Tomohiro Hayashida, Ichiro Nishizaki, Shinya Sekizaki, Hiroaki Takeuchi |
KES | 2 |
| 2016 | Distance-based clustering of population and intergroup Cooperative Particle Swarm OptimizationabstractSun and Li (2014) have proposed TCPSO(Two-swarm Cooperative Particle Swarm Optimization) that the swarms are divided into two groups with different migration rules. TCPSO has higher performance for high-dimensional nonlinear optimization problems. This study revises TCPSO to avoid inappropriate convergence of the swarms. The quite feature of the proposed method is that the population have same migration rules. However, through that the swarms are divided into some clusters based on distance measure, k-means clustering method, both diversity and centralization of search process are maintained, and it increases the potential of attainment to the global optimal solution. This study conducts numerical experiments using several types of functions, and the experimental results indicate that the proposed method has higher performance than the TCPSO for large-scale optimization problems. Tomohiro Hayashida, Ichiro Nishizaki, Shinya Sekizaki, Shunsuke Koto |
SMC | 2 |
| 2014 | Aliased States Discerning in POMDPs and Improved Anticipatory Classifier SystemabstractThis paper improves a classifier system, ACS (Anticipatory Classifier System). The suggested classifier system is named ACSM (ACS with Memory) which consists of a method of discerning the aliased states in a POMDP (Partially Observable Markov Decision Process), and choosing the proper action based on the internal memory and the sensory information around the agent. A POMDP is one of Markov decision process such that an agent observes local information about the environment. This paper executes some numerical experiments using eight kinds of maze problems which are well used as benchmark problems for POMDPs. ACSM achieves greater experimental result than the existing classifier systems for the maze problems. Tomohiro Hayashida, Ichiro Nishizaki, Ryosuke Sakato |
KES | 2 |
| 2014 | Agent-based simulation for simultaneous ultimatum gamesabstractThe aim of this research is behavioral analysis of the human subjects in laboratory experiments of simultaneous ultimatum game through agent-based simulation. Andreoni and Blanchard (2006) conducted a laboratory experiments using human subjects, and they observed that deviant behavior of the subjects from Nash equilibrium. Similarly, in several laboratory experiments of ultimatum games in a form of sequential game, deviant behavior of the human subjects from subgame perfect equilibrium are observed. The related literature have suggested a mathematical model incorporating fairness of payoffs (Duffy and Hopkins; 1999), and adaptive models based on reinforcement learning (Duffy and Feltovich; 1999). This study constructs simulation model using adaptive agents which makes decision by trial and error approach based on neural networks and genetic algorithms. The experimental result indicates that the behavior of subjects can explained by decision mechanism by trial and error approach, interaction between human subjects, and risk attitude. Tomohiro Hayashida, Ichiro Nishizaki, Koji Saiki |
SMC | 2 |
| 2012 | Multiobjective Evolutionary Optimization of Training and Topology of Recurrent Neural Networks for Time-Series PredictionabstractThis paper provides a new evolutionary multiobjective optimization method for automatically optimizing the network topology of recurrent neural networks (NNs). To obtain NNs with higher prediction capability for time-series data, the proposed method is constructed by focusing on the intensively exploration of a feasible region including solutions with small training errors on the Pareto frontier, unlike existing evolutionary multiobjective optimization methods, which aim to find a whole set of the Pareto optimal solutions. Our method is characterized by the ideas of self-adaptive mutation probability setting, elite preservation strategies and archive for the preservation of local optimal solutions. Through the comparison with the performances of the most promising existing method by Delgado et al. using benchmark time-series data instances, it is shown that the proposed method is superior to the existing effective algorithm with respect to the capability of time-series prediction. Hideki Katagiri, Ichiro Nishizaki, Tomohiro Hayashida, Takanori Kadoma |
Comput. J. | 2 |
| 2012 | A hybrid algorithm based on tabu search and ant colony optimization for k-minimum spanning tree problems
Hideki Katagiri, Tomohiro Hayashida, Ichiro Nishizaki, Qingqiang Guo |
Expert Syst. Appl. | 3 |
| 2011 | Agent-Based Simulation for Equilibrium Selection and Coordination Failure in Minimum Strategy Coordination Games
Ichiro Nishizaki, Tomohiro Hayashida, Noriyuki Hara |
KES-AMSTA | 1 |
| 2009 | An Agent-Based Simulation Model for Analysis on Marketing Strategy Considering Promotion Activities
Hideki Katagiri, Ichiro Nishizaki, Tomohiro Hayashida, Takahiro Daimaru |
KES-AMSTA | 2 |
| 2009 | Agent-Based Simulation Analysis for Equilibrium Selection and Coordination Failure in Coordination Games Characterized by the Minimum Strategy
Ichiro Nishizaki, Tomohiro Hayashida, Hideki Katagiri, Noriyuki Hara |
KES-AMSTA | 1 |
| 2009 | A Hybrid Algorithm Based on Tabu Search and Ant Colony Optimization for k-Minimum Spanning Tree Problems
Hideki Katagiri, Tomohiro Hayashida, Ichiro Nishizaki, Jun Ishimatsu |
MDAI | 3 |
| 2008 | A network in a society composed of individuals characterized by the ultimatum bargaining gamesabstractIn some published papers of the network formation, it is assumed that each player pays the same amount of cost for forming or maintaining a link, or a player who offers to form new link pays all of the link cost. In this paper, however, we construct two types of network formation models with general allocation procedures of the link cost, and examine stability of the network. In the first model, a pair of players share the cost unequally with a fixed fraction, and in the second model, the players divide the link cost in accordance with the procedure of the ultimatum bargaining games. Tomohiro Hayashida, Ichiro Nishizaki, Hideki Katagiri |
SMC | 2 |
| 2008 | Agent-based simulation analysis for social normsabstractWith existence of the social custom or norm, Naylor demonstrates a possibility of stable long-run equilibria of support for a strike in a labor market, and this implies that at least some individuals will behave cooperatively and hence the prisoners' dilemma could be escaped. In this paper, we develop an agent-based simulation system in which artificial adaptive agents have mechanisms of decision making and learning based on neural networks and genetic algorithms, and compare the result of our simulation analysis with that of the mathematical model by Naylor. Especially, while the Naylor model is based on rationality about maximization of individual utility, our agent-based simulation model employs adaptive behavior of agents; agents make decisions by trials and errors and they learn from experiences to make better decisions. Ichiro Nishizaki, Hideki Katagiri, Toshihisa Oyama, Tomohiro Hayashida |
SMC | 1 |
| 2008 | Nondominated equilibrium solutions of a multiobjective two-person nonzero-sum game in extensive form and corresponding mathematical programming problem
Ichiro Nishizaki, Takuma Notsu |
J. Glob. Optim. | 1 |
| 2006 | Interactive decision making using possibility and necessity measures for a fuzzy random multiobjective 0-1 programming problemabstractThis article deals with a multiobjective 0–1 programming problem involving fuzzy random variable coefficients. A novel decision-making model based on stochastic programming and possibilistic programming is proposed. The aim of this article is to seek a solution to maximize expected degrees of possibility or necessity for which objective function values satisfy fuzzy goals. It is shown that the problem, including fuzziness and randoness, equivalently is transformed into a deterministic multiobjective stochastic 0–1 programming problem. In order to find a satisficing solution of the problem for a decision maker, interactive decision making is constructed using the reference point method. Hideki Katagiri, Masatoshi Sakawa, Ichiro Nishizaki |
Cybern. Syst. | 3 |
| 2005 | Interactive fuzzy random multiobjective programming on M-α-Pareto optimality and stochastic programming modelsabstractThis paper deals with multiobjective linear programming problems involving fuzzy random variable coefficients and provides new solution concepts based on M-/spl alpha/-Pareto optimality and stochastic programming models. Fuzzy goals are introduced to consider the imprecise of the decision maker's judgment for objective functions. After the formulated problem is transformed into the deterministic one, an interactive algorithm based on the reference point method is constructed to solve the deterministic problem. Hideki Katagiri, Masatoshi Sakawa, Kosuke Kato, Ichiro Nishizaki, Hiroki Danjyo |
SMC | 4 |
| 2005 | Computational methods through genetic algorithms for obtaining stackelberg solutions to two-level integer programming problemsabstractIn this article, we present a method for obtaining Stackelberg solutions to two-level integer problems through genetic algorithms, which have received much attention as a promising computational method for complex problems. Assuming that there exist the upper- and the lower-bounds constraints with respect to integer variables, we employ a zero-one bit string as an individual in our artificial genetic systems. It is required that each individual satisfies the constraints of the given problem and a response of the lower level decision maker with respect to a decision that the upper level decision maker is rational. Therefore, individuals not satisfying the two conditions are penalized in the artificial genetic systems. To demonstrate the feasibility and efficiency of the proposed methods, computational experiments are carried out and comparisons between the Moore and Bard method based on the branch-and-bound techniques and the proposed methods are provided. Ichiro Nishizaki, Masatoshi Sakawa |
Cybern. Syst. | 1 |
| 2003 | Book Review: "Fuzzy cooperative games" in "Studies in Fuzziness and Soft Computing", Vol. 72, by M. Mares, Physica-Verlag, Heidelberg; New York, 2001, 177pp., ISBN 3-7908-1392-3
Masatoshi Sakawa, Ichiro Nishizaki |
Fuzzy Sets Syst. | 2 |
| 2002 | Interactive fuzzy programming for decentralized two-level linear programming problems
Masatoshi Sakawa, Ichiro Nishizaki |
Fuzzy Sets Syst. | 2 |
| 2002 | Interactive fuzzy programming for two-level nonconvex programming problems with fuzzy parameters through genetic algorithms
Masatoshi Sakawa, Ichiro Nishizaki |
Fuzzy Sets Syst. | 2 |
| 2001 | Computational Methods for Two-level Linear Programming Problems With Fuzzy Parameters Through Genetic AlgorithmsabstractFrom the observation that possible values of parameters involved in objective functions and constraints of mathematical programming problems are often only imprecisely or ambiguously known to experts, we consider two-level linear programming problems with fuzzy parameters represented by fuzzy numbers. A computational method, which is based on genetic algorithms, for obtaining the Stackelberg solution to the two-level linear programming problem with fuzzy parameters is developed. To demonstrate the efficiency of the proposed computational method, computational experiments are carried out. Keiichi Niwa, Ichiro Nishizaki, Masatoshi Sakawa |
FUZZ-IEEE | 2 |
| 2001 | Interactive fuzzy programming for two-level linear fractional programming problems
Masatoshi Sakawa, Ichiro Nishizaki |
Fuzzy Sets Syst. | 2 |
| 2001 | Interactive fuzzy programming for multi-level 0-1 programming problems with fuzzy parameters through genetic algorithms
Masatoshi Sakawa, Ichiro Nishizaki, Masatoshi Hitaka |
Fuzzy Sets Syst. | 2 |
| 2000 | Computational Methods through Genetic Algorithms for Obtaining Stackelberg Solutions to Two-level Mixed Zero-one Programming ProblemsabstractIn this paper, we develop computational methods for obtaining Stackelberg solutions to two-level mixed zero-one programming problems in which the decision maker at the upper level controls zero-one variables and the decision maker at the lower level controls real variables. To illustrate two-level mixed zero-one programming problems, we formulate a facility location and transportation problem as a two-level mixed zero-one programming problem. We develop computational methods through genetic algorithms for obtaining Stackelberg solutions. To demonstrate the feasibility and efficiency of the proposed methods, computational experiments are carried out and comparisons between the methods based on the branch-and-bound techniques and the proposed methods are provided. Ichiro Nishizaki, Masatoshi Sakawa |
Cybern. Syst. | 1 |
| 2000 | Fuzzy cooperative games arising from linear production programming problems with fuzzy parameters
Ichiro Nishizaki, Masatoshi Sakawa |
Fuzzy Sets Syst. | 1 |
| 2000 | Solutions based on fuzzy goals in fuzzy linear programming games
Ichiro Nishizaki, Masatoshi Sakawa |
Fuzzy Sets Syst. | 1 |
| 2000 | Equilibrium solutions in multiobjective bimatrix games with fuzzy payoffs and fuzzy goals
Ichiro Nishizaki, Masatoshi Sakawa |
Fuzzy Sets Syst. | 1 |
| 2000 | Interactive fuzzy programming for two-level linear fractional programming problems with fuzzy parameters
Masatoshi Sakawa, Ichiro Nishizaki, Yoshio Uemura |
Fuzzy Sets Syst. | 2 |
| 2000 | Interactive fuzzy programming for multi-level linear programming problems with fuzzy parameters
Masatoshi Sakawa, Ichiro Nishizaki, Yoshio Uemura |
Fuzzy Sets Syst. | 2 |
| 1998 | The alpha-core of fuzzy linear production gamesabstractIn this paper we consider a production model in which multiple decision-makers pool resources to produce finished goods. Such a production model, which is assumed to be linear, can be formulated as a mathematical programming problems with fuzzy parameters from the viewpoint of experts' imprecise or fuzzy understanding of the nature of parameters in a problem-formulation process. It is shown that a cooperative game with values of coalitions represented by fuzzy numbers arises from the linear production programming problem with fuzzy parameters, and such a game is referred to as a fuzzy linear production programming game. The values of coalitions of the game can be obtained by employing a parametric approach to solving the linear production programming problem with fuzzy parameters. It is proven that the /spl alpha/-core of the game is not empty, and an interval in the /spl alpha/-core is computed by using the ideas of sensitivity analysis and the duality theory of linear programming problems. Ichiro Nishizaki, Masatoshi Sakawa |
KES (1) | 1 |
| 1998 | Decentralized two-level 0-1 programming through genetic algorithms with double stringsabstractWe consider two-level programming problems in which there are one decision maker (the leader) at the upper level and two or more decision makers (the followers) at the lower level and decision variables of the leader and the followers are 0-1 variables. We assume that there is coordination among the followers while between the leader and the group of all the followers, there is no motivation to cooperate each other, and fuzzy goals for objective functions of the leader and followers are introduced in order to take fuzziness of their judgments into consideration. The leader maximizes the degree of satisfaction and the followers choose in concert so as to maximize a minimum among their degrees of satisfaction. A computational method, which is based on the genetic algorithms, for obtaining a solution to the above mentioned problem is developed. To demonstrate the feasibility and efficiency of the proposed algorithm, numerical experiments are carried out. Keiichi Niwa, Ichiro Nishizaki, Masatoshi Sakawa |
KES (2) | 2 |
| 1998 | Interactive fuzzy programming for multi-level linear programs with fuzzy numbersabstractIn the fuzzy programming for multi-level linear programming problems developed by Lai et al. (1996), since the fuzzy goals are determined for both an objective function and decision variables at the upper level, undesirable solutions are produced when these fuzzy goals are inconsistent. In order to overcome such problems, after eliminating the fuzzy goals for decision variables, interactive fuzzy programming for multi-level linear programming problems with fuzzy parameters is presented. In our interactive method, after determining the fuzzy goals of the decision makers at all levels, a satisfactory solution is derived efficiently by updating the satisfactory degrees of decision makers at the upper level with considerations of overall satisfactory balance among all levels. An illustrative numerical example for three-level linear programming problems is provided to demonstrate the feasibility of the proposed method. Masatoshi Sakawa, Ichiro Nishizaki, Yoshio Uemura |
KES (1) | 2 |