Nonlinear Control System Design by Hybrid Dynamic Programming Algorithm

　本論文では,先に開発した動的計画法複合アルゴリズムを用いて時間領域における非線形制御系の新しい設計法を提案する.この手法はプラントのアクチュエータあるいはプラント自身に種々の非線形要素を含む非線形制御系に対し,最小時間制御,最小燃料消費制御,あるいは,より汎用的な評価基準のもとで試行錯誤を含まない設計手段を与える.本法によって得られる表形式の制御器は1入力-1出力系だけでなく多入力-多出力系の非線形制御システムに適用可能である.この制御器をプラントのアナログシミュレーションに組み入れて試験した結果,極めて効果的に機能することが確かめられた.この方法は,従来の記述関数設計法の適用上の難しさを克服する可能性を示唆している

A hybrid dynamic programming for solving a mixed-model sequencing problem with production mix restriction and free interruptions

In this article, we propose a hybrid procedure based on bounded dynamic programming assisted by linear programming to solve the mixed-model sequencing problem with workload minimization with serial workstations, free interruption of the operations and with production mix restrictions. We performed a computational experiment with 23 instances related to a case study of the Nissan powertrain plant located in Barcelona. The results of our proposal are compared with those obtained by mixed integer linear programming.Peer ReviewedPostprint (author's final draft

Scheduling for yard cranes based on two-stage hybrid dynamic programming

Making operational plans for Yard Cranes (YCs) to enhance port efficiency has become vital issues for the container terminals. This paper discusses the load-scheduling problem of multiple YCs. The problem is to schedule two YCs at different container blocks, which serve the loading operations of one quay crane so as to minimize the total distance of visiting paths and the make-span at stack area. We consider the container handling time, the YC visiting time, and the waiting time of each YC when evaluating the make-span of the loading operation by YCs. Both the container bay visiting sequences and the number of containers picked up at each visit of the two YCs are determined simultaneously. A mathematical model, which considers interference between adjacent YCs, is provided by means of time-space network to formulate the problem and a two-stage hybrid algorithm composed of greedy algorithm and dynamic programming is developed to solve the proposed model. Numerical experiments were conducted to compare performances of the algorithm in this study with actual scheduling rules. First published online 08 December 201

Optimization on the container loading sequence based on hybrid dynamic programming

Retrieving export containers from a container yard is an important part of the ship loading process during which arranging the retrieving sequence to enhance port efficiency has become a vital issue. This paper presents a twophase hybrid dynamic algorithm aiming at obtaining an optimized container loading sequence for a crane to retrieve all the containers from the yard to the ship. The optimization goal is to minimize the number of relocation operations which has a direct impact upon container loading operation efficiency. The two phases of the proposed dynamic algorithms are designed as follows: at the first phase, a heuristic algorithm is developed to retrieve the containers subset which needs no relocation and may be loaded directly onto the ship; at the second phase, a dynamic programming with heuristic rules is applied to solve the loading sequence problem for the rest of the containers. Numerical experiments showed the effectiveness and practicability of the model and the algorithm by comparing with the loading proposals from an existing research and actual rules respectively. First published online: 14 Jan 201

Approximate String Matching With Dynamic Programming and Suffix Trees

The importance and the contribution of string matching algorithms to the modern society cannot be overstated. From basic search algorithms such as spell checking and data querying, to advanced algorithms such as DNA sequencing, trend analysis and signal processing, string matching algorithms form the foundation of many aspects in computing that have been pivotal in technological advancement. In general, string matching algorithms can be divided into the categories of exact string matching and approximate string matching. We study each area and examine some of the well known algorithms. We probe into one of the most intriguing data structure in string algorithms, the suffix tree. The lowest common ancestor extension of the suffix tree is the key to many advanced string matching algorithms. With these tools, we are able to solve string problems that were, until recently, thought intractable by many. Another interesting and relatively new data structure in string algorithms is the suffix array, which has significant breakthroughs in its linear time construction in recent years. Primarily, this thesis focuses on approximate string matching using dynamic programming and hybrid dynamic programming with suffix tree. We study both approaches in detail and see how the merger of exact string matching and approximate string matching algorithms can yield synergistic results in our experiments

Optimal downlink rate allocation in multicell CDMA networks

We study downlink rate allocation for a three cells CDMA system. Based on the discretized cell model, the rate optimization problem that maximizes the total downlink rate allocation is formulated. We propose an approximation procedure for obtaining a rate allocation in three cells case. Via numerical examples, we show that this procedure gives a good approximation of the optimal downlink rate allocation

An interactive dynamic programming approach to multicriteria discrete programming

AbstractSeveral interactive schemes for solving multicriteria discrete programming problems are developed under a dynamic programming framework. It is assumed that the decision maker's preference structure satisfies the conditions of transitivity, monotonicity, and nonsatiation. Hybrid procedures are also structured by including branch and bound ideas into the recursions. Initial computational results are offered