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Full-Text Articles in Operations Research, Systems Engineering and Industrial Engineering

Evaluation Of Computer Input Devices For Use In Standard Office Applications While Moving In An Off-Road Vehicle , Thorsten Baldus Jan 2006

Evaluation Of Computer Input Devices For Use In Standard Office Applications While Moving In An Off-Road Vehicle , Thorsten Baldus

Retrospective Theses and Dissertations

Advances in modern farming technology provide automation features that lighten the workload for operators of farming equipment. One of the many technologies incorporated in modern agricultural equipment is automated steering systems like the John Deere's Green-Star Auto-Trac System(TM), which is a hands-free steering system for straight-line driving applications. When using a machine that is equipped with one of these systems, the work load of the operator is lightened and enables the operator to perform other tasks while doing field work. Many people believe a tractor cab could become a mobile office in the near future with the operator ...


Capacity Expansion Under A Service Level Constraint For Uncertain Demand With Lead Times , Rahul Ratnakar Marathe Jan 2006

Capacity Expansion Under A Service Level Constraint For Uncertain Demand With Lead Times , Rahul Ratnakar Marathe

Retrospective Theses and Dissertations

For a service provider, stochastic demand growth along with expansion lead times and economies of scale may complicate a capacity planning problem. We consider a service provider who has to maintain certain minimum level of service and is interested in knowing the optimal timings and sizes of the future capacity expansions. This service level is defined in terms of unsatisfied demand over an expansion cycle. Under this service level constraint, the service provider wants to minimize the infinite time horizon cost of expansion. We assume a stationary policy where the timing and the sizes of the expansions are determined as ...


A New Metric For Detecting Conflict In Functional Software Requirements , Adegboyega Oladayo Sanni Jan 2006

A New Metric For Detecting Conflict In Functional Software Requirements , Adegboyega Oladayo Sanni

Retrospective Theses and Dissertations

Typically, the development of software system starts with a goal. The goal is implemented by following a methodology consisting of phases. Initially, the goal is formulated as functional requirements when stakeholders of the software system meet and discuss what the software system should do in order fulfill satisfy needs. The functional software requirement document is then converted to software design document either through conceptual model, software code or both. After, the system is tested rigorously before it is implemented. Since the development of a software system consists of phases with each phase depending on prior stages, an inconsistency made in ...


Retailer-Driven Closed-Loop Supply Chains With Product Remanufacturing , Jie Li Jan 2006

Retailer-Driven Closed-Loop Supply Chains With Product Remanufacturing , Jie Li

Retrospective Theses and Dissertations

In this paper, we study a closed-loop supply chain (CLSC) consisting of a manufacturer and a retailer of a single product with numerous end product customers. The key feature differentiating this paper from the extant literature in CLSC is that our model is retailer-driven while the traditional CLSC models have been manufacturer-driven. This study is motivated by the emergence of super retailers such as Wal-Mart. Under these circumstances, we show how the retailer leads and the manufacturer follows in determining the wholesale and retail prices in the forward flow and the used product collecting and return prices in the reverse ...


Stochastic Flow Shop Scheduling Model For The Panama Canal , Zoila Yadira Guerra De Castillo Jan 2006

Stochastic Flow Shop Scheduling Model For The Panama Canal , Zoila Yadira Guerra De Castillo

Retrospective Theses and Dissertations

The Panama Canal can be modeled as a stochastic flexible flow shop for the purpose of scheduling. A metaheuristic stochastic optimization method (Nested Partition) was used to determine if current scheduling practices could be improved by reducing the makespan for vessel traffic. Results indicate that classifying the vessels according to the time that they spend transiting the canal and using some rules and metaheuristic technique for parallel flow shop improves the makespan. The schedules produced by this method show distinct patterns as described by the sequence of vessel types.


A General Queuing Network Model To Optimize Refurbishing Policies For Returned Products , Jumpol Vorasayan Jan 2006

A General Queuing Network Model To Optimize Refurbishing Policies For Returned Products , Jumpol Vorasayan

Retrospective Theses and Dissertations

We focus on the original equipment manufacturers (OEMs) who sell both new and refurbished products directly to consumers, such as a computer maker who sells products online. New products are produced according to a make-to-order policy while returned products will be refurbished and ready to ship to consumers immediately according to a make-to-stock policy. The open queueing network combines the demand functions of new and refurbished products with a generalized open queueing network that simulates the closed-loop supply chain including manufacturing, sales, return, evaluation, refurbishing and resale processes. A mathematical model is developed to find the optimal price and quantity ...


Application Of Data Mining In Scheduling Of Single Machine System , Xiaonan Li Jan 2006

Application Of Data Mining In Scheduling Of Single Machine System , Xiaonan Li

Retrospective Theses and Dissertations

The rapidly growing field of data mining has the potential of improving performance of existing scheduling systems. Such systems generate large amounts of data, which is often not utilized to its potential. The problem is whether it is possible to discover the implicit knowledge behind scheduling practice and then, with this knowledge, we could improve current scheduling practice. In this dissertation, we propose a novel methodology for generating scheduling rules using a data-driven approach. We show how to use data mining to discover previously unknown dispatching rules by applying the learning algorithms directly to production data. We also consider how ...


Outsourcing Analysis For Reverse Logistics Systems: A Qualitative Study And A Markov Decision Model , Marco Antonio Serrato García Jan 2006

Outsourcing Analysis For Reverse Logistics Systems: A Qualitative Study And A Markov Decision Model , Marco Antonio Serrato García

Retrospective Theses and Dissertations

Reverse Logistics (RL) has recently been considered as an improvement area if it is focused correctly. Every manufacturing, distribution or sales firm, irrespective of its size, types of products or geographic location, can benefit from planning, implementing and controlling RL activities;Given the nature of the RL field, one of the most important decisions to be taken by any firm is whether to outsource such functions or not. This comes from the fact that RL does not represent a core activity for a firm, given that the purpose of any company is not to manage the flow of products taken ...


Yield Improvement Of Chemical Mechanical Planarization Processes , Sutee Eamkajornsiri Jan 2005

Yield Improvement Of Chemical Mechanical Planarization Processes , Sutee Eamkajornsiri

Retrospective Theses and Dissertations

Chemical mechanical polishing (CMP) is a planarization process that produces high quality surfaces both locally and globally. It is one of the key process steps during fabrication of very large scale integrated (VLSI) chips in integrated circuit (IC) manufacturing. High and reliable wafer yield is critical in the CMP process; it is dependent upon uniformity of material removal rate across the entire wafer.;The focus on this research is the development of control algorithm for CMP process. Wafer-scale and die-scale models are the two scales used in this study. To achieve improvement in wafer yield, three control strategies are formulated ...


Transport Effort: A Metric For The Evaluation And Benchmarking Of Automotive Assembly Plants , David Paul Sly Jan 2004

Transport Effort: A Metric For The Evaluation And Benchmarking Of Automotive Assembly Plants , David Paul Sly

Retrospective Theses and Dissertations

Automotive assembly plants are unique from other industrial facilities in that they combine high output volume with high part counts (over 4,000 per vehicle) and high variety in a product flow layout involving a large quantity of fixed position material handling equipment. While assembly plants share common factory layout issues such as, dock placement, storage placement, transport batch sizes and aisle design, it is the high material flow volumes of large and heavy products coupled with the less layout flexibility, due to fixed equipment, that make automotive assembly plants uniquely suited for the evaluation and benchmarking metrics proposed in ...


Order Batching And Picking Optimization In Terms Of Supply Chain Management (Scm) , Jaeyeon Won Jan 2004

Order Batching And Picking Optimization In Terms Of Supply Chain Management (Scm) , Jaeyeon Won

Retrospective Theses and Dissertations

In distribution center (DC), at the time of forming a batch, by considering the order holding time and picking time in the system, an algorithm based on the first-come, first served based (FCFS) rule is presented. In the proposed algorithm, both order picking factor and order holding factor are used in order to reflect the throughput of the system and response of orders.;Furthermore, some simple batching policies for considering the order holding time in the system are presented. They may result in meeting its customers' requirements for larger numbers of smaller orders and rapid turnaround. They reflect the well-known ...


Scalable Optimization-Based Feature Selection With Application To Recommender Systems , Jaekyung Yang Jan 2003

Scalable Optimization-Based Feature Selection With Application To Recommender Systems , Jaekyung Yang

Retrospective Theses and Dissertations

Along with development of a variety of data mining techniques, numerous feature selection methods have been introduced to reduce dimensionality. This may improve scalability and make interpreting learning models easier. In this dissertation a new optimization based feature selection method using the nested partition (NP) approach is presented, including both basic analysis of the NP framework and numerical results on various experiment problems. The numerical results show how the optimal structure of the NP makes contributions on a feature selection process. Further, it is addressed how the new intelligent partitioning method obtains very high quality partition efficiently. The feature selection ...


Process Monitoring In End Milling , Yong-Hoon Choi Jan 2003

Process Monitoring In End Milling , Yong-Hoon Choi

Retrospective Theses and Dissertations

Monitoring cutting forces in end milling is a necessary step toward the full automation of milling. To monitor the end milling process successfully, the selection of an appropriate signal and signal processing algorithm is very important. In this research, cutting force trends and tool wear effects in ramp cut machining are experimentally observed as machining progresses.;Ramp cuts are unique in the sense that the depth of cut is continuously changing. Traditionally, a series of straight slot cuts are used to machine a deep slot. Ramp cuts in which the depth of cut is continuously changing offers an alternative. Cutting ...


Studies Of Compressive Forces On L5/S1 During Dynamic Manual Lifting , Iwan Budihardjo Jan 2002

Studies Of Compressive Forces On L5/S1 During Dynamic Manual Lifting , Iwan Budihardjo

Retrospective Theses and Dissertations

The lifting task is the major activity contributing to the risk of lower back injury. The purpose of this study was to examine the mechanical stresses on the lower back during manual lifting and to analyze how people adapt to the stresses. This purpose was accomplished by approaching the mechanical stresses on the lower back from three different perspectives. The effects of manual lifting tasks were measured as: the fatigued condition, the knowledge of load and the previous lifts, and effort in lifting over a constraining barrier. A biomechanical model (linked segment and rigid body) was applied to estimate the ...


Operational Strategies For Cross Docking Systems , Wooyeon Yu Jan 2002

Operational Strategies For Cross Docking Systems , Wooyeon Yu

Retrospective Theses and Dissertations

Cross docking is a warehouse management concept in which items delivered to a warehouse by delivery trucks are immediately sorted out and reorganized based on customer demands and are routed and loaded into shipping trucks for delivery to customers without actually being held in inventory in the warehouse. Because accuracy in material management is required in such operations, a cross docking operation is heavily dependent on accurate flow of information. In this research, three out of thirty-two different models identified were studied. All three models assume there is one receiving dock and one shipping dock at the warehouse.;The first ...


Optimization Under Uncertainty With Application To Data Clustering , Jumi Kim Jan 2002

Optimization Under Uncertainty With Application To Data Clustering , Jumi Kim

Retrospective Theses and Dissertations

A new optimization technique with uncertainty that extends the pure nested partition (NP) algorithm is presented in this thesis. This method is called the nested partition with inheritance. The basic idea of a NP algorithm is very simple. At each iteration, the most promising region is partitioned and the performance of the partitioned region is evaluated using sampling. Based on the performance evaluation, the most promising region is chosen for the next iteration. These procedures are repeated until it satisfies the termination condition.;Even though the pure NP method guarantees the convergence to the optimal solution, it has several shortcomings ...


Analysis Of Delayed Product Differentiation Under Pull Type Policies , Heedong Kim Jan 2002

Analysis Of Delayed Product Differentiation Under Pull Type Policies , Heedong Kim

Retrospective Theses and Dissertations

Delayed product differentiation (DPD) increases manufacturers' competitiveness in the market by enabling them to more quickly respond to changes in customers' demands. DPD has also been shown to require less Work-in-Process (WIP) than a non-DPD setup in some cases. Previous research was mainly focused on the level of semi-finished and/or finished good inventory under a base-stock policy. The control of WIP inventory was not considered. DPD may also improve response times under pull inventory control schemes, in which the amount of WIP is controlled directly. These systems can be modeled as closed queueing networks in which a fixed number ...


A General Stochastic Model For Product Development Processes , Yi-Chiuan Lai Jan 2002

A General Stochastic Model For Product Development Processes , Yi-Chiuan Lai

Retrospective Theses and Dissertations

The pressure to reduce product development time has increased due to rapidly changing technology and customer's needs. Therefore, a shortened product development time has become a critical issue for many enterprises. Being first to market is a major strategy for establishing product identity and capturing market share. Axiomatic design can be used to structure the design processes and reduce the complexity of product development. Using a hierarchical design structure tree (DST) created using design axioms, several theorems have been derived for modeling the product development process. These theorems capture successive iterations of design activities and provide a basis for ...


The Impact Of Fixturing Error On Feature Tolerance Allocation , Supapan Sangnui Jan 2002

The Impact Of Fixturing Error On Feature Tolerance Allocation , Supapan Sangnui

Retrospective Theses and Dissertations

Fixtures are used to locate, hold and support workpieces during the operation. An accuracy of the workpiece is decided by a relative location and orientation of the workpiece coordinate system with respect to that of the fixture. The impact of surface variability at contact points on the variability of workpiece location and orientation will be analyzed. Methods of estimating moments will be implemented to evaluate the distribution of the workpiece variability. When surface errors exist and the workpiece is fixtured for machining, inconsistency in feature location and orientation is expected. Hence, in order to derive efficient tolerance allocation for the ...


Human-Computer Interaction In E-Business , Hong-In Cheng Jan 2002

Human-Computer Interaction In E-Business , Hong-In Cheng

Retrospective Theses and Dissertations

E-business has brought much change to our daily life and will become a necessary part of business, economy, and society. At least for the foreseeable future, e-business will keep growing. Each study of this dissertation was devoted to human-computer interaction (HCI) in e-business to improve website usability. First, data input tools were compared and optimal design characteristics were suggested for usable web based interaction. When proper input tools are employed, higher usability can be achieved. Second, a practical design process and the use of web elements were studied through the simulation of an e-bookstore. Web design influences e-business traffic and ...


Characterization Of Dea Ranking Models , Sung-Kyun Choi Jan 2002

Characterization Of Dea Ranking Models , Sung-Kyun Choi

Retrospective Theses and Dissertations

Other than measuring relative efficiency, DEA (Data Envelopment Analysis) has been used in a number of other ways to elaborate further on the performance of individual units. Also researchers have developed methods for using DEA as a ranking model. We classified DEA ranking models into two categories based on whether preferences (weights) are given or not.;Since the ranking result from each model is determined by the characteristics each model has, it is important to understand these characteristics. This hopefully can help decision makers to make a better decision. In this dissertation, we analyze the characteristics of A-P (Andersen-Peterson) model ...


Strategic And Operational Decisions In Supply Chains , Sameh Tawfiq Al-Shihabi Jan 2002

Strategic And Operational Decisions In Supply Chains , Sameh Tawfiq Al-Shihabi

Retrospective Theses and Dissertations

In this work, we develop models that supply chains can employ to satisfy periodic and stochastic demand effectively. These models combine the strategic and operational decisions to cost function. Strategic decisions are represented by the size of capacity acquired, while operational decisions are represented by the parameters of the inventory policy employed.;In addition to combining the strategic and operational decisions, the developed models study three alternatives that can reduce the cost of satisfying the demand by relying on external production to outsource or subcontract some of the demand. Outsourcing is studied where a fixed amount of the product is ...


Pull-Based Supply Chain Allocation For Multi-Product In Multi-Echelon Distribution System, Pongchai Athikomrattanakul Jan 2002

Pull-Based Supply Chain Allocation For Multi-Product In Multi-Echelon Distribution System, Pongchai Athikomrattanakul

Retrospective Theses and Dissertations

In today's highly competitive market environment, only companies with a highly efficient supply chain management, which integrates all decisions in various levels of planning and operations, can survive. These decisions must be coordinated and under the same goal, which is to minimize the total systemwide costs of the firm while products are manufactured and distributed to end-customers or retailers. In this study, the focus is on a pull-based supply chain, customer demand driven, multiple products and multiple echelon distribution system consisting of m manufacturing centers, n distribution centers, and p retailers or customers. The objectives of this study can ...


Individual Differences And Situation Awareness , Jaruwan Klamklay Jan 2002

Individual Differences And Situation Awareness , Jaruwan Klamklay

Retrospective Theses and Dissertations

This study is divided into five sections, each with an objective to: (1) examine the attention and memory limitations of engineering students; (2) examine the effects of automation, pace, and task duration on situation awareness and task performance of novice operators of a complex system; (3) examine the effects of attention limitations on situations awareness and task performance; (4) examine the effects of memory limitations on situation awareness and task performance; and (5) identify the effects of individual differences on the relationships among workload, situation awareness, and task performance, respectively.;Eighty undergraduate engineering students performed nine psychological tests to measure ...


Generation Planning For Electric Power Utilities Under Market Uncertainties: A Real Options Approach , Chung-Hsiao Wang Jan 2001

Generation Planning For Electric Power Utilities Under Market Uncertainties: A Real Options Approach , Chung-Hsiao Wang

Retrospective Theses and Dissertations

The generation business in the U.S. is currently undergoing a transition from a regulated monopoly toward an uncertain, competitive market. Under the competitive market, the price of electric power as well as the corresponding revenue may be much less certain than before. These market uncertainties have increased the significance of two critical factors in generation planning. These factors are financial risks and managerial flexibilities.;In order to quantitatively and objectively address these two factors in generation planning, in this dissertation, we design and analyze a series of mathematical models based on the real options approach for generation planning. Hence ...


Development Programs For One-Shot Systems Using Multiple-State Design Reliability Models , Suntichai Shevasuthisilp Jan 2001

Development Programs For One-Shot Systems Using Multiple-State Design Reliability Models , Suntichai Shevasuthisilp

Retrospective Theses and Dissertations

Design reliability at the beginning of a product development program is typically low and development costs account for a large proportion of the total product cost. Our research focuses on how to conduct "development programs" (series of tests and redesigns) to both achieve high final design reliability and spend as little of a fixed budget as possible on development. Multiple-state reliability models are used. We consider one-shot systems, which are destroyed at first use or during testing. Dynamic programming is used to identify the best test-and-redesign strategy and is shown to presently be computationally feasible for at least 5 state ...


Design Of A Web-Based Integrated Material Handling System For Manufacturing Applications , Chiwoon Cho Jan 2001

Design Of A Web-Based Integrated Material Handling System For Manufacturing Applications , Chiwoon Cho

Retrospective Theses and Dissertations

In this research, a Web-based system called DESIGNER for the design of integrated material handling systems is developed. DESIGNER models the material handling system design processes including the material handling equipment (MHE) selection and employs information on the most common MHE types used in material movement, storage, and positioning.;The system designs the material handling system for an application through three phases. In Phase I, the procedure identifies the most appropriate MHE type among the alternatives that are suitable for the application. Knowledge-based rules are employed to identify alternative handling equipment for each material flow link. To select the final ...


Interval Estimators Of Parameters For Normal One Sample And Balanced One-Way Random Effects Models When Data Are Rounded , Chiang-Sheng Lee Jan 2001

Interval Estimators Of Parameters For Normal One Sample And Balanced One-Way Random Effects Models When Data Are Rounded , Chiang-Sheng Lee

Retrospective Theses and Dissertations

In standard statistical analysis, data are typically assumed to be essentially exact. But in fact, all real data are reported to some smallest unit of measure related to the precision of the device used to produce them. We might call such data "rounded" because they are really obtained by "rounding to something." We first discuss the interval estimation of the parameters mu and sigma, when a single rounded sample comes from the N(mu, sigma 2) distribution with both parameters unknown. Then we discuss the interval estimation of variance components sigma and sigmatau if rounded data are from a balanced ...


Statistical Modeling And Design For Cmm-Type Data Locating Known Two-Dimensional Geometries , Dewi Rahardja Jan 2001

Statistical Modeling And Design For Cmm-Type Data Locating Known Two-Dimensional Geometries , Dewi Rahardja

Retrospective Theses and Dissertations

This research was motivated by a problem from a car-manufacturer that needed to compare/analyze two hood assembly fixtures. The consistency of the car hood placement was examined for both fixtures. A "constant width" gap between the hood and the car's body is preferred. A "wide" gap at one point and a "narrow" gap at another constitutes a bad quality placement of the car hood, and will affect customer satisfaction.;3-D data were taken using a Coordinate Measuring Machine (CMM) with 12 (fixed) probe paths to the hood. For each fixture, ten "12-dimensional" vectors were taken and the original ...


Athletic Game Scheduling , Hyoung-Ro Lee Jan 2000

Athletic Game Scheduling , Hyoung-Ro Lee

Retrospective Theses and Dissertations

An athletic game scheduling (AGS) problem can be formulated using 0-1 integer program with minor constraints and can be solved partially using traditional operations research methods. However, the constraints that each team and the league requested of the AGS scheduler make the problem no longer practical by typical operations research methods. In most real world problems, many constraints cannot be formulated into mathematical forms. We, therefore, developed heuristic algorithms that can generate reasonably good solutions in a short period. In this research, we propose two algorithms, multi echelon simulated annealing and multi echelon tabu search. In the beginning of the ...