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Articles 9181 - 9210 of 13835

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

Inventory Pooling In Petroleum Upstream Logistics Network, Sulaiman Hamad Al Jedaie Jan 2014

Inventory Pooling In Petroleum Upstream Logistics Network, Sulaiman Hamad Al Jedaie

Industrial, Manufacturing, and Systems Engineering Dissertations - Archive

The petroleum industry is heading toward the era of efficiency and cost reduction. Oilfield service companies have to raise their efficiency to stay competitive. This dissertation explores the efficiency issues facing an existing upstream petroleum logistics network, with 30 products, 30 countries and two hubs, for an international Oilfield Service Company (OSC). Inventory control was found to be a main source for inefficiency. Safety stock was studied by implementing inventory pooling concept, joint ordering, demand outliers analysis, demand bucket size analysis and regional distribution centers.Six-sigma (DMAIC) approach was used to diagnose the issues in this network and propose alternative solutions. …

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Unmanned Aerial Vehicle Routing In The Presence Of Threats, Kamil A. Alotaibi Jan 2014

Unmanned Aerial Vehicle Routing In The Presence Of Threats, Kamil A. Alotaibi

Industrial, Manufacturing, and Systems Engineering Dissertations - Archive

The use of Unmanned Aerial Vehicles (UAVs) and the importance of its role have evolved and increased recently in both civilian and military operations. In this research, we study the routing of Unmanned Aerial Vehicles (UAVs) in the presence of the risk of enemy threats. The main goal for this research is to find optimal routes that consider the targets visited, expected fuel burn, threat exposure, and travel time. We formulate two mixed integer linear programs. In first formulation, we minimize the total expected fuel burn for multiple UAVs in order to visit multiple targets while maintaining the total threat …

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An Exploration And Exploitation Pareto Approach To Surrogate Optimization, John F. Dickson Jan 2014

An Exploration And Exploitation Pareto Approach To Surrogate Optimization, John F. Dickson

Industrial, Manufacturing, and Systems Engineering Dissertations - Archive

The experiments or simulations conducted by computers can be a tedious task,requiring substantial computational time. To find a global solution using a computerexperiments process, we usually need to perform many function evaluations of thecomputer model. This research focuses on developing an optimization method to find aglobally optimal solution efficiently using surrogates. The surrogates represent thecomputer model or the system that reads the inputs and generates the output responsesof interest, so that these surrogate models can be used in place of time-consumingsimulations runs. In surrogate based optimization, we iteratively build a surrogate model(a.k.a, approximate model or a metamodel) and conduct an …

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A Systems Thinking Approach To Apply Water Sustainability In Hospitals, Misagh Faezipour Jan 2014

A Systems Thinking Approach To Apply Water Sustainability In Hospitals, Misagh Faezipour

Industrial, Manufacturing, and Systems Engineering Dissertations - Archive

One of the most critical challenges the world is facing is to ensure everyone has access to an adequate and quality supply of water. As the population increases, the demand for water rises. Water needs to be sustained for current and future generations. Sustainability acts to balance the resource supply and demand. Hospitals are a major consumer of water. Unfortunately water is facing the challenges of diminishing resources and increasing demands. Therefore, considering water sustainability in hospitals is of significant importance. Water sustainability in hospitals is also important since hospitals offer services to help people improve the quality and health …

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Evaluating The Impact Of A Shared Pharmaceutical Supply Chain Model To Minimize Counterfeit Drugs, Diverted Drugs, And Drug Shortages, Jae Bong Choi Jan 2014

Evaluating The Impact Of A Shared Pharmaceutical Supply Chain Model To Minimize Counterfeit Drugs, Diverted Drugs, And Drug Shortages, Jae Bong Choi

Industrial, Manufacturing, and Systems Engineering Dissertations - Archive

The pharmaceutical supply chain in the United States of America (USA) is getting complicated and is often not controllable due to a globally open market, increasing online market, and many illegal activities. Consumers who cannot afford to buy high priced genuine products are tempted by easily accessible counterfeit drugs on illegal web site pharmacies in or out of the USA. Many corrupt participants, such as wholesalers or pharmacies in the supply chain, take advantage of weak enforcement and a flawed drug supply chain for financial gain. The public health system and numerous patients are in, or could be in, painful …

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Facility Capital Equipment And Labor Decision Support System Using A Discrete-Event Simulation And Bottleneck Detection Approach, Mohammed Almansouri Jan 2014

Facility Capital Equipment And Labor Decision Support System Using A Discrete-Event Simulation And Bottleneck Detection Approach, Mohammed Almansouri

Industrial, Manufacturing, and Systems Engineering Dissertations - Archive

Market demand is constantly changing. Therefore, it is critical for companies to be flexible and willing to adapt in order to remain competitive. This study will evaluate bottleneck detection techniques that have been identified in previous research by comparing the performance of each method on all case study models that can be replicated from the literature. The purpose of this analysis is to identify the most efficient and reliable bottleneck detection algorithm(s) which are capable of supporting constraint identification on a wide range of production system classes and configurations. The primary objective will be to identify a robust bottleneck detection …

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Interpolation-Based Super-Resolution Reconstruction: Effects Of Slice Thickness, Amir Pasha Mahmoudzadeh, Nasser H. Kashou Jan 2014

Interpolation-Based Super-Resolution Reconstruction: Effects Of Slice Thickness, Amir Pasha Mahmoudzadeh, Nasser H. Kashou

Biomedical, Industrial & Human Factors Engineering Faculty Publications

Standard clinical magnetic resonance imaging (MRI) is acquired in two-dimensions where the in-plane resolution is higher than the slice select direction. These acquisitions include axial, coronal, and sagittal planes. To date, there have been few attempts to combine the information of these three orthogonal orientations. This paper aims to take advantage of the different in-plane resolution acquired from each plane orientation and combine them into one volume in order to attain a higher resolution image. This combination of MRI data will allow the detection of smaller areas that would otherwise be missed using only one slice orientation. A comparison of …

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An Unsupervised Consensus Control Chart Pattern Recognition Framework, Siavash Haghtalab Jan 2014

An Unsupervised Consensus Control Chart Pattern Recognition Framework, Siavash Haghtalab

Electronic Theses and Dissertations

Early identification and detection of abnormal time series patterns is vital for a number of manufacturing. Slide shifts and alterations of time series patterns might be indicative of some anomaly in the production process, such as machinery malfunction. Usually due to the continuous flow of data monitoring of manufacturing processes requires automated Control Chart Pattern Recognition(CCPR) algorithms. The majority of CCPR literature consists of supervised classification algorithms. Less studies consider unsupervised versions of the problem. Despite the profound advantage of unsupervised methodology for less manual data labeling their use is limited due to the fact that their performance is not …

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Phase I Monitoring With Applications In Manufacturing And Healthcare, Smriti Neogi Jan 2014

Phase I Monitoring With Applications In Manufacturing And Healthcare, Smriti Neogi

Industrial, Manufacturing, and Systems Engineering Dissertations - Archive

This research develops statistical methods for quality monitoring in complex systems. Quality monitoring typically consists of two phases called Phase I analysis (or offline monitoring) and Phase II analysis (or online monitoring). This research is focused on Phase I monitoring. Two application areas are considered, complex manufacturing processes and healthcare delivery processes. In the first application, a robust strategy for Phase I analysis of optical profiles in low-E glass manufacturing is developed. The proposed approach aims to solve the problems such as violation of normality, high dimensionality, detection of multiple change points, etc. It will provide a convenient process monitoring …

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Fast Feature Selection In A Gpu Cluster Using The Delta Test, Alberto Guillén, M. Isabel García Arenas, Mark Van Heeswijk, Dusan Sovilj, Amaury Lendasse, Luis Javier Herrera, Héctor Pomares, Ignacio Rojas Jan 2014

Fast Feature Selection In A Gpu Cluster Using The Delta Test, Alberto Guillén, M. Isabel García Arenas, Mark Van Heeswijk, Dusan Sovilj, Amaury Lendasse, Luis Javier Herrera, Héctor Pomares, Ignacio Rojas

Engineering Management and Systems Engineering Faculty Research & Creative Works

Feature or Variable Selection Still Remains an Unsolved Problem, Due to the Infeasible Evaluation of All the Solution Space. Several Algorithms based on Heuristics Have Been Proposed So Far with Successful Results. However, These Algorithms Were Not Designed for Considering Very Large Datasets, Making their Execution Impossible, Due to the Memory and Time Limitations. This Paper Presents an Implementation of a Genetic Algorithm that Has Been Parallelized using the Classical Island Approach, But Also Considering Graphic Processing Units to Speed Up the Computation of the Fitness Function. Special Attention Has Been Paid to the Population Evaluation, as Well as to …

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Long-Term Time Series Prediction Using Op-Elm, Alexander Grigorievskiy, Yoan Miche, Anne Mari Ventelä, Eric Séverin, Amaury Lendasse Jan 2014

Long-Term Time Series Prediction Using Op-Elm, Alexander Grigorievskiy, Yoan Miche, Anne Mari Ventelä, Eric Séverin, Amaury Lendasse

Engineering Management and Systems Engineering Faculty Research & Creative Works

In This Paper, an Optimally Pruned Extreme Learning Machine (Op-Elm) is Applied to the Problem of Long-Term Time Series Prediction. Three Known Strategies for the Long-Term Time Series Prediction I.e. Recursive, Direct and Dirrec Are Considered in Combination with Op-Elm and Compared with a Baseline Linear Least Squares Model and Least-Squares Support Vector Machines (Ls-Svm). among These Three Strategies Dirrec is the Most Time Consuming and its Usage with Nonlinear Models Like Ls-Svm, Where Several Hyperparameters Need to Be Adjusted, Leads to Relatively Heavy Computations. It is Shown that Op-Elm, Being Also a Nonlinear Model, Allows Reasonable Computational Time for …

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Conquering Complexity: Challenges And Opportunities: Preface, Cihan H. Dagli Jan 2014

Conquering Complexity: Challenges And Opportunities: Preface, Cihan H. Dagli

Engineering Management and Systems Engineering Faculty Research & Creative Works

No abstract provided.

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How To Rein In The Volatile Actor: A New Bounded Perspective, Abhijit Gosavi Jan 2014

How To Rein In The Volatile Actor: A New Bounded Perspective, Abhijit Gosavi

Engineering Management and Systems Engineering Faculty Research & Creative Works

Actor-critic algorithms are amongst the most well-studied reinforcement learning algorithms that can be used to solve Markov decision processes (MDPs) via simulation. Unfortunately, the parameters of the so-called "actor" in the classical actor-critic algorithm exhibit great volatility - getting unbounded in practice, whence they have to be artificially constrained to obtain solutions in practice. The algorithm is often used in conjunction with Boltzmann action selection, where one may have to use a temperature to get the algorithm to work, but the convergence of the algorithm has only been proved when the temperature equals 1. We propose a new actor-critic algorithm …

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Carbon Constrained Integrated Inventory Control And Truckload Transportation With Heterogeneous Freight Trucks, Dinçer Konur Jan 2014

Carbon Constrained Integrated Inventory Control And Truckload Transportation With Heterogeneous Freight Trucks, Dinçer Konur

Engineering Management and Systems Engineering Faculty Research & Creative Works

This paper analyzes an integrated inventory control and transportation problem with environmental considerations. Particularly, explicit transportation modeling is included with inventory control decisions to capture per truck costs and per truck capacities. Furthermore, a carbon cap constraint on the total emissions is formulated by considering emission characteristics of various trucks that can be used for inbound transportation. Due to complexity of the resulting optimization problem, a heuristic search method is proposed based on the properties of the problem. Numerical studies illustrate the efficiency of the proposed method. Furthermore, numerical examples are presented to show that both costs and emissions can …

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Study Of The Use Of A Genetic Algorithm To Improve Networked System-Of-Systems Resilience, Charles O. Adler, Cihan H. Dagli Jan 2014

Study Of The Use Of A Genetic Algorithm To Improve Networked System-Of-Systems Resilience, Charles O. Adler, Cihan H. Dagli

Engineering Management and Systems Engineering Faculty Research & Creative Works

Large scale failures or degradation resulting from smaller initial failures or disruptions in networked system-of-systems are an issue in multiple areas - for example cascading failures in electrical power grids or large disruptions in national air traffic due to local or regional weather conditions. The system architecture can have a significant impact on system-of-systems susceptibility to large scale failures. The study presented in this paper uses a simple interdependent networked system-of-systems failure model, integrated into a unique objective function that addresses both the overall level of failure and the rate of failure progression, and a genetic algorithm to demonstrate an …

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Computational Complexity Measures For Many-Objective Optimization Problems, David M. Curry, Cihan H. Dagli Jan 2014

Computational Complexity Measures For Many-Objective Optimization Problems, David M. Curry, Cihan H. Dagli

Engineering Management and Systems Engineering Faculty Research & Creative Works

Multi-objective Optimization Problems (MOPs) are commonly encountered in the study and design of complex systems. Pareto dominance is the most common relationship used to compare solutions in MOPs, however as the number of objectives grows beyond three, Pareto dominance alone is no longer satisfactory. These problems are termed "Many-Objective Optimization Problems (MaOPs)". While most MaOP algorithms are modifications of common MOP algorithms, determining the impact on their computational complexity is difficult. This paper defines computational complexity measures for these algorithms and applies these measures to a Multi-Objective Evolutionary Algorithm (MOEA) and its MaOP counterpart.

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On The Flexibility Of Systems In System Of Systems Architecting, Dincer Konur, Hadi Farhangi, Cihan H. Dagli Jan 2014

On The Flexibility Of Systems In System Of Systems Architecting, Dincer Konur, Hadi Farhangi, Cihan H. Dagli

Engineering Management and Systems Engineering Faculty Research & Creative Works

System of Systems (SoS) architecting requires analyzing a set of individual but interconnected systems simultaneously in order to build a communicating SoS, which can provide the capabilities needed. In general, the systems can provide a set of capabilities and the SoS architect needs to decide which systems to include in the SoS so that each capability is provided by at least one system. In this case, the systems are inflexible, i.e., a selected system will contribute to the SoS with all the capabilities it can provide. On the other hand, if SoS architect can incentivize systems to contribute specific capabilities …

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A Hybrid Genetic Algorithm And Particle Swarm Optimization With Type-2 Fuzzy Sets For Generating Systems Of Systems Architectures, Siddhartha Agarwal, Louis E. Pape, Cihan H. Dagli Jan 2014

A Hybrid Genetic Algorithm And Particle Swarm Optimization With Type-2 Fuzzy Sets For Generating Systems Of Systems Architectures, Siddhartha Agarwal, Louis E. Pape, Cihan H. Dagli

Engineering Management and Systems Engineering Faculty Research & Creative Works

Both modeling and simulating a system of systems (SoS) are difficult due not only to a changing environment but also the unique behavior that is linked to different participating systems. Generating architectures for a SoS is a multi-objective optimization problem with large number of variables and constraints. The paper presents several of computational intelligence techniques that can generate SoS architectures, such as genetic algorithms (GA), and particle swarm optimization (PSO) combined with Type 2 Fuzzy logic nets. The Maritime search and rescue (SAR) were used as a SoS domain scenario to both implement and demonstrate the architecting methodology. SAR utilizes …

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การลดสิ่งแปลกปลอมในกระบวนการสร้างเส้นลายวงจรในโรงงานผลิตแผงวงจรไฟฟ้าชนิดอ่อน, ปิยะนันท์ สยนานนท์ Jan 2014

การลดสิ่งแปลกปลอมในกระบวนการสร้างเส้นลายวงจรในโรงงานผลิตแผงวงจรไฟฟ้าชนิดอ่อน, ปิยะนันท์ สยนานนท์

Chulalongkorn University Theses and Dissertations (Chula ETD)

งานวิจัยนี้มีวัตถุประสงค์เพื่อลดปริมาณของเสียที่เกิดจากปัญหาสิ่งแปลกปลอมในกระบวนการสร้างเส้นลายวงจรในโรงงานผลิตแผงวงจรไฟฟ้าชนิดอ่อน โดยการประยุกต์ใช้แนวคิด ซิกซ์ ซิกมา งานวิจัยเริ่มจากการนิยามปัญหาสิ่งแปลกปลอมในกระบวนการสร้างเส้นลายวงจร การวัดเพื่อกำหนดสาเหตุของปัญหาได้เลือกปัจจัยนำเข้าหลักมาพิสูจน์ความมีนัยสำคัญ การวิเคราะห์สาเหตุของปัญหาโดยการประยุกต์ใช้การออกแบบการทดลองเชิงแฟคทอเรียลแบบ 2 ระดับ (2k Factorial Design) เพื่อศึกษาอิทธิพลของปัจจัยที่มีผลต่อการทำให้เกิดของเสีย โดยพบว่ามี 3 ปัจจัยหลักที่เกี่ยวข้องกับของเสียที่เกิดขึ้น คือ ความเข้มของแสง UV ในกระบวนการถ่ายเส้นลายวงจร ความเข้มข้นของสารละลายโซเดียมไฮดรอกไซด์ และอุณหภูมิของสารละลายโซเดียมไฮดรอกไซด์ในกระบวนการลอกลายเส้นลายวงจร ซึ่งเมื่อทําการทดลองเพื่อหาระดับปัจจัย สรุปได้ว่าระดับของปัจจัยที่เหมาะสมในการลดปัญหาสิ่งแปลกปลอม คือ ความเข้มของแสง UV 50 mJ/cm2 ในกระบวนการถ่ายเส้นลายวงจร อุณหภูมิของสารละลายโซเดียมไฮดรอกไซด์ 48°C และ ความเข้มข้นของสารละลายโซเดียมไฮดรอกไซด์ 3.5%wt ในกระบวนการลอกลายเส้นลายวงจร จากนั้นจึงกำหนดแผนการควบคุมตัวแปรต่างๆ โดยจัดทำเป็นมาตรฐานวิธีการปฏิบัติงาน ผลหลังการปรับปรุงพบว่าค่าเฉลี่ยของเสียลดลงจาก 0.27% เหลือเพียง 0.004% โดยการประเมินปริมาณการผลิตคาดว่ามูลค่าความสูญเสียจะลดลงได้ถึง 336,770 บาทต่อเดือน

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Dispatch, Delivery, And Location Logistics For The Aeromedical Evacuation Of Time-Sensitive Military Casualties Under Uncertainty, Benjamin Grannan Jan 2014

Dispatch, Delivery, And Location Logistics For The Aeromedical Evacuation Of Time-Sensitive Military Casualties Under Uncertainty, Benjamin Grannan

Theses and Dissertations

Effective aeromedical evacuation of casualties is one of the most important problems in military medical systems because high-priority casualties will not survive without timely medical care. The decision making process for aeromedical evacuation consists of the following components: (1) identifying which aeromedical evacuation asset (see figure 1) to dispatch to the casualty, (2) locating aeromedical evacuation assets strategically in anticipation of incoming demand, and (3) deciding which medical treatment facility to transport the casualty. These decisions are further complicated because prioritization of casualties is based on severity of injury while aeromedical evacuation assets and medical treatment facilities operate with varying …

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Rheological Model Of Force Transmission Through The Helmet And Concussion Sensitivity, Isiah Kendall, Anthony Vicini, Tarun Goswami Jan 2014

Rheological Model Of Force Transmission Through The Helmet And Concussion Sensitivity, Isiah Kendall, Anthony Vicini, Tarun Goswami

Biomedical, Industrial & Human Factors Engineering Faculty Publications

In contact sports, head-to-head collisions can lead to concussions, which pose serious health risks to players. This research aims to understand the force transfer from the helmet to the brain that causes concussions in collisions using a rheological model. Experimental data was gathered from players in the National Football League and testing of one type of helmet and padding. The rheological model was verified with published data and good correlation was achieved. Further sensitivity analysis of concussion risk was performed with respect to force, body weight, mass, and impact duration fit to normal and Weibull distributions using Monte Carlo simulations …

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Positioning Automated Guided Vehicles In A General Guide-Path Layout, Abraham Mendoza, Jose A. Ventura Jan 2014

Positioning Automated Guided Vehicles In A General Guide-Path Layout, Abraham Mendoza, Jose A. Ventura

13th IMHRC Proceedings (Cincinnati, Ohio. USA – 2014)

The locations of dwell points for idle vehicles in an automated guided vehicle (AGV) system determine the response times for pick-up requests and thus affect the performance of automated manufacturing systems. In this study, we address the problem of optimally locating dwell points for multiple AGVs in general guide-path layouts with the objective of minimizing the maximum response time in the system. We propose a mixed integer linear programming (MILP) formulation for the problem. We also develop a generic genetic algorithm (GA) to find near optimal solutions. The MILP model and GA procedure are illustrated using a two-dimensional grid layout …

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Integrating Analysis Into A Warehouse Design Workflow, Leon Mcginnis, Timothy Sprock Jan 2014

Integrating Analysis Into A Warehouse Design Workflow, Leon Mcginnis, Timothy Sprock

13th IMHRC Proceedings (Cincinnati, Ohio. USA – 2014)

Supply chain analyses, including those related to material handling systems, are typically purpose-built to answer specific questions and therefore have many different implementations depending on the question, the instance data, and the solver. The purpose-built nature of these models makes it difficult to integrate them into an iterative design workflow. Despite the myriad analysis implementations, the fundamental structure of these systems and their problem domain remains unchanged, suggesting that perhaps analyses could be automatically generated on demand, given an appropriate specification of the particular system to be analyzed. We apply model-based systems engineering (MBSE) methodologies to explore this possibility in …

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Throughput Analysis Of S/R Shuttle Systems, Georg Kartnig, Jörg Oser Jan 2014

Throughput Analysis Of S/R Shuttle Systems, Georg Kartnig, Jörg Oser

13th IMHRC Proceedings (Cincinnati, Ohio. USA – 2014)

Shuttle systems are used in high performance automated storage/retrieval unit load systems. Each storage level is serviced by one transfer car travelling in dual command operation. One buffer slot is located at both ends of each level. This decouples horizontal travel from vertical input/output moves, which in this case requires two independent vertical reciprocating lifts at each end of the aisle. Other systems work with only one lift used in lower throughput applications. The content of this paper is treated in the following sections starting with a problem definition and a literature survey. This is followed by a detailed functional …

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Variation In Lifting Behavior During A Highly Repetitive Manual Material Task, Steven A. Lavender Jan 2014

Variation In Lifting Behavior During A Highly Repetitive Manual Material Task, Steven A. Lavender

13th IMHRC Proceedings (Cincinnati, Ohio. USA – 2014)

Presenters will provide.

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Clickstream Big Data And “Delivery Before Order Making” Mode For Online Retailers, Yeming Yale Gong, Haoxuan Xu Jan 2014

Clickstream Big Data And “Delivery Before Order Making” Mode For Online Retailers, Yeming Yale Gong, Haoxuan Xu

13th IMHRC Proceedings (Cincinnati, Ohio. USA – 2014)

Our research is inspired by a leading online retailer using clickstream big data to estimate customer demand and then ship items to customers or hubs near customers by a mode of “delivery before order making” (DBOM) mode. Using clickstream data to obtain advance demand information in order quantities, we integrate the forecasting with a singleitem uncapacitated dynamic lot sizing problem in a rolling-horizon environment. Using the simulated clickstream data, we evaluate the performance of DBOM mode.

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Comparing Industry And Academic Perspectives On Cross-Docking Operations, Paul Buijs, Iris F.A. Vis Jan 2014

Comparing Industry And Academic Perspectives On Cross-Docking Operations, Paul Buijs, Iris F.A. Vis

13th IMHRC Proceedings (Cincinnati, Ohio. USA – 2014)

This paper performs a comparative analysis on the industry and academic perspectives on cross-docking operations. Detailed descriptions are provided for three typical cross-dock settings by means of case illustrations. The purpose of these descriptions is to inspire break-through innovations in future cross-docking research by identifying constraints, decision problems, and performance indicators that are thoroughly anchored in current practice.

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Comparison Of Alternative Configurations For Dense Warehousing Systems, Kevin R. Gue, G. Don Taylor Jan 2014

Comparison Of Alternative Configurations For Dense Warehousing Systems, Kevin R. Gue, G. Don Taylor

13th IMHRC Proceedings (Cincinnati, Ohio. USA – 2014)

In heavily constrained environments requiring very high density storage, traditional aisle-based warehousing may not provide viable options. One feasible manifestation of high density storage systems is the ‘puzzle-based’ system, in which unit loads are moved through the system via manipulation of empty (escort) locations to retrieve desired items. Another option would be the use of movable concentric rings, with escorts being utilized to enable lateral movements of unit loads between the rings. In this paper, the authors present analytical results to compare retrieval time performance for these two types of high density storage systems for randomly demanded items under various …

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Analysis Of Class-Based Storage Strategies For The Mobile Shelf-Based Order Pick System, Shobhit Nigam, Debjit Roy, Rene De Koster, Ivo J.B.F. Adan Jan 2014

Analysis Of Class-Based Storage Strategies For The Mobile Shelf-Based Order Pick System, Shobhit Nigam, Debjit Roy, Rene De Koster, Ivo J.B.F. Adan

13th IMHRC Proceedings (Cincinnati, Ohio. USA – 2014)

Mobile Shelf-based Order Pick (MSOP) systems are gaining significant in- terest for e-commerce fulfillment due to their rapid deployment capability and dynamic organization of storage pods based on item demand profiles. In this research, we model the MSOP system with class-based storage strategies and alternate pod storage policies using multi-class closed queuing networks. We observe that though closest-open location pod storage policy do not allow to efficiently use the storage spaces in comparison to random location pod storage policy in an aisle, it increases the system throughput for all item classes.

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A Two-Level Stochastic Model To Estimate Vessel Throughput Time, Debjit Roy, Vibhuti Dhingra, Rene De Koster Jan 2014

A Two-Level Stochastic Model To Estimate Vessel Throughput Time, Debjit Roy, Vibhuti Dhingra, Rene De Koster

13th IMHRC Proceedings (Cincinnati, Ohio. USA – 2014)

A good estimate of the vessel sojourn time is essential for better planning and scheduling Of container terminal resources,such as berth scheduling,quay crane(qc)assignment And scheduling,and fleet size planning. However,estimating the expected vessel so journ Time is a complex exercise because the time is dependent on several terminal operating Parameters such as the size of the vessel,the number of containers to be loaded and Unloaded,and the through put of the qcs. The through put of the qcs in turn depends On the type and number of transport vehicles,number of stack blocks,the topology of The vehicle travel path,the layout of the terminal,and …

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