Study on efficient planning for advanced logistics network model based on robust genetic algorithm

制度:新 ; 報告番号:甲3000号 ; 学位の種類:博士(工学) ; 授与年月日:2010/2/22 ; 早大学位記番号:新525

The transportation problem with exclusionary side constraints.

We consider the so-called Transportation Problem with Exclusionary Side Con- straints (TPESC), which is a generalization of the ordinary transportation problem. We determine the complexity status for each of two special cases of this problem, by proving NP-completeness, and by exhibiting a pseudo-polynomial time algorithm. For the general problem, we show that it cannot be approximated with a constant perfor- mance ratio in polynomial time (unless P=NP). These results settle the complexity status of the TPESC.

Solving the nonlinear transportation problem by global optimization

The aim of this paper is to present the suitability of three different global optimization methods for specifically the exact optimum solution of the nonlinear transportation problem (NTP). The evaluated global optimization methods include the branch and reduce method, the branch and cut method and the combination of global and local search strategies. The considered global optimization methods were applied to solve NTPs with reference to literature. NTPs were formulated as nonlinear programming (NLP) optimization problems. The obtained optimal results were compared with those got from literature. A comparative evaluation of global optimization methods is presented at the end of the paper to show their suitability for solving NTPs. First published online: 10 Feb 201

Relaxations and Cutting Planes for Linear Programs with Complementarity Constraints

We study relaxations for linear programs with complementarity constraints, especially instances whose complementary pairs of variables are not independent. Our formulation is based on identifying vertex covers of the conflict graph of the instance and generalizes the extended reformulation-linearization technique of Nguyen, Richard, and Tawarmalani to instances with general complementarity conditions between variables. We demonstrate how to obtain strong cutting planes for our formulation from both the stable set polytope and the boolean quadric polytope associated with a complete bipartite graph. Through an extensive computational study for three types of practical problems, we assess the performance of our proposed linear relaxation and new cutting-planes in terms of the optimality gap closed

Using MapReduce Streaming for Distributed Life Simulation on the Cloud

Distributed software simulations are indispensable in the study of large-scale life models but often require the use of technically complex lower-level distributed computing frameworks, such as MPI. We propose to overcome the complexity challenge by applying the emerging MapReduce (MR) model to distributed life simulations and by running such simulations on the cloud. Technically, we design optimized MR streaming algorithms for discrete and continuous versions of Conway’s life according to a general MR streaming pattern. We chose life because it is simple enough as a testbed for MR’s applicability to a-life simulations and general enough to make our results applicable to various lattice-based a-life models. We implement and empirically evaluate our algorithms’ performance on Amazon’s Elastic MR cloud. Our experiments demonstrate that a single MR optimization technique called strip partitioning can reduce the execution time of continuous life simulations by 64%. To the best of our knowledge, we are the first to propose and evaluate MR streaming algorithms for lattice-based simulations. Our algorithms can serve as prototypes in the development of novel MR simulation algorithms for large-scale lattice-based a-life models.https://digitalcommons.chapman.edu/scs_books/1014/thumbnail.jp

Testing the Efficacy and Potential Consequences of Fencing As A Wildlife Management Tool

This dissertation examines how various anthropogenic barriers affect wildlife movement, and in particular, how fencing affects movement and behavior of both migratory prey and predators in semi-porous environments. I chose to examine this subject as our planets last remaining ecosystems are threatened by human encroachment due to population pressure, agriculture, and a myriad of other ecological stressors. In order to mitigate the encroachment, conservation fencing is rapidly becoming the norm even though constraining wildlife movement is fraught with ecological issues. My interest in conservation fencing was to examine the potentially hidden or understudied consequences of its usage. The introduction discusses human-wildlife conflicts and the role of fences. Chapters 1 and 2 review the literature concerning animal movement and landscape ecology and set the general framework from which follows the series of specific studies in Chapters 3-6. Chapter 3 compares basic monitoring methods that lie at the core of the studies that follow. In this chapter, a comparison of traditional track monitoring to modern camera trapping methods demonstrated the power of mechanical vigilance but also the importance of timely monitoring for managerial decisions. Chapter 4 examines the effectiveness of fence-gaps, a wildlife management tool designed to compromise between complete isolation by fencing and an open landscape. The results of this study showed that most of the species in situ have indeed discovered these fence-gaps. Chapter 5 explores the potentially unintended consequences of the creation of fence-gaps as these structures funnel migration movement and thus could act as prey-traps. Using a spatial analysis of carcass locations, the results of this study demonstrated that predation locations did not cluster near the fence-gaps. Chapter 6 examines predation near the perimeter fencing and within fenced areas designed to exclude elephant. Results showed that lion predation was not over-represented near the perimeter fences and that exclosures provided good hunting grounds for lion but these exclosures did not create prey-traps. The dissertation concludes that fencing is a useful conservation tool that requires reliable monitoring to understand how wildlife functions with fencing, and to permit managers to react to issues through an adaptive management framework