Open Access. Powered by Scholars. Published by Universities.®

Operations Research, Systems Engineering and Industrial Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 12 of 12

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

Modeling And Solving A Large-Scale Generation Expansion Planning Problem Under Uncertainty, Shan Jin, Sarah M. Ryan, Jean-Paul Watson, David L. Woodruff Nov 2011

Modeling And Solving A Large-Scale Generation Expansion Planning Problem Under Uncertainty, Shan Jin, Sarah M. Ryan, Jean-Paul Watson, David L. Woodruff

Industrial and Manufacturing Systems Engineering Publications

We formulate a generation expansion planning problem to determine the type and quantity of power plants to be constructed over each year of an extended planning horizon, considering uncertainty regarding future demand and fuel prices. Our model is expressed as a two-stage stochastic mixed-integer program, which we use to compute solutions independently minimizing the expected cost and the Conditional Value-at-Risk; i.e., the risk of significantly larger-than-expected operational costs. We introduce stochastic process models to capture demand and fuel price uncertainty, which are in turn used to generate trees that accurately represent the uncertainty space. Using a realistic problem instance ...


The Effect Of A Lower Extremity Kinematic Constraint On Lifting Biomechanics, Sangeun Jin, Gary A. Mirka Nov 2011

The Effect Of A Lower Extremity Kinematic Constraint On Lifting Biomechanics, Sangeun Jin, Gary A. Mirka

Industrial and Manufacturing Systems Engineering Publications

Leaning against a stationary barrier during manual materials handling tasks is observed in many industrial environments, but the effects of this kinematic constraint on low back mechanics are unknown. Thirteen participants performed two-handed lifting tasks using both a leaning posture and no leaning posture while trunk kinematics, muscle activity and ground reaction force were monitored. Results revealed that lifting with the leaning posture required significantly less activity in erector spinae (26% vs. 36% MVC) and latissimus dorsi (8% vs. 14% MVC), and less passive tissue moment compared with the no leaning posture. Peak sagittal accelerations were lower when leaning, but ...


Ergonomic Interventions For Commercial Crab Fishermen, Gary A. Mirka, Xiaopeng Ning, Sangeun Jin, Omid Haddad, Kristen L. Kucera Sep 2011

Ergonomic Interventions For Commercial Crab Fishermen, Gary A. Mirka, Xiaopeng Ning, Sangeun Jin, Omid Haddad, Kristen L. Kucera

Industrial and Manufacturing Systems Engineering Publications

Work tasks in the commercial fishing industry require strength, endurance and coordination and these tasks expose fishermen to many of the recognized risk factors for the development of work-related musculoskeletal disorders. The focus of the current study was the design, development and testing of two simple ergonomic interventions to reduce exposure to these risk factors in small-scale commercial crab fishermen. In a laboratory study of these interventions, EMG and motion analysis systems were used to quantify changes in muscle force and body postures. The results of laboratory evaluation of the intervention designed to reduce the low back stress associated with ...


Optimal Replacement In The Proportional Hazards Model With Semi-Markovian Covariate Process And Continuous Monitoring, Xiang Wu, Sarah M. Ryan Jul 2011

Optimal Replacement In The Proportional Hazards Model With Semi-Markovian Covariate Process And Continuous Monitoring, Xiang Wu, Sarah M. Ryan

Industrial and Manufacturing Systems Engineering Publications

Motivated by the increasing use of condition monitoring technology for electrical transformers, this paper deals with the optimal replacement of a system having a hazard function that follows the proportional hazards model with a semi-Markovian covariate process, which we assume is under continuous monitoring. Although the optimality of a threshold replacement policy to minimize the long-run average cost per unit time was established previously in a more general setting, the policy evaluation step in an iterative algorithm to identify optimal threshold values poses computational challenges. To overcome them, we use conditioning to derive an explicit expression of the objective in ...


Methodology For Assessing Measurement Error For Casting Surface Inspection, G. Daricilar, Frank E. Peters Jul 2011

Methodology For Assessing Measurement Error For Casting Surface Inspection, G. Daricilar, Frank E. Peters

Industrial and Manufacturing Systems Engineering Publications

Visual assessment of objects is critical to many fields including metalcasting. While the output for such a task is often a simple attribute, theproblem studied here is for inspection tasks requiring an output that defines shape, size and location of anomalous areas, which are random and are not defined a priori. This paper defines a methodology to quantify the amount of repeatability and reproducibility variation. The application of the methodology for the visual surface assessment of steel castings reveals significant repeatability and reproducibility error. The work presented here is the impetus for current efforts that are defining the capabilities of ...


Virtual Reality Integrated Welder Training, Richard T. Stone, Kristopher Patrick Watts, Peihan Zhong Jul 2011

Virtual Reality Integrated Welder Training, Richard T. Stone, Kristopher Patrick Watts, Peihan Zhong

Industrial and Manufacturing Systems Engineering Publications

Training in the welding industry is a critical and often costly endeavor; this study examines the training potential, team learning, material consumption, and cost implications of using integrated virtual reality technology as a major part of welder training. In this study, 22 participants were trained using one of two separate methods (traditional training (TT) and virtual reality integrated training (VRI)). The results demonstrated that students trained using 50% virtual reality had training outcomes that surpassed those of traditionally trained students across four distinctive weld qualifications (2F, 1G, 3F, 3G). In addition, the VRI group demonstrated significantly higher levels of team ...


Handling Material Problems As They Arise, David P. Sly Mar 2011

Handling Material Problems As They Arise, David P. Sly

Industrial and Manufacturing Systems Engineering Publications

No abstract provided.


A Computational/Experimental Platform For Investigating Three- Dimensional Puzzle Solving Of Comminuted Articular Fractures, Thaddeus P. Thomas, Donald D. Anderson, Andrew Willis, Pengcheng Liu, Matthew C. Frank, J. Lawrence Marsh, Thomas D. Brown Jan 2011

A Computational/Experimental Platform For Investigating Three- Dimensional Puzzle Solving Of Comminuted Articular Fractures, Thaddeus P. Thomas, Donald D. Anderson, Andrew Willis, Pengcheng Liu, Matthew C. Frank, J. Lawrence Marsh, Thomas D. Brown

Industrial and Manufacturing Systems Engineering Publications

Reconstructing highly comminuted articular fractures poses a difficult surgical challenge, akin to solving a complicated three-dimensional (3D) puzzle. Pre-operative planning using CT is critically important, given the desirability of less invasive surgical approaches. The goal of this work is to advance 3D puzzle solving methods toward use as a pre-operative tool for reconstructing these complex fractures. Methodology for generating typical fragmentation/dispersal patterns was developed. Five identical replicas of human distal tibia anatomy, were machined from blocks of high-density polyetherurethane foam (bone fragmentation surrogate), and were fractured using an instrumented drop tower. Pre- and post-fracture geometries were obtained using laser ...


Medial Longitudinal Arch Deformation During Walking And Stair Navigation While Carrying Loads, Elizabeth Rose Hageman, Michelle Hall, Eric Gerard Sterner, Gary A. Mirka Jan 2011

Medial Longitudinal Arch Deformation During Walking And Stair Navigation While Carrying Loads, Elizabeth Rose Hageman, Michelle Hall, Eric Gerard Sterner, Gary A. Mirka

Industrial and Manufacturing Systems Engineering Publications

Background:

Understanding the biomechanics of the medial longitudinal arch (MLA) may provide insights into injury risk and prevention, as well as function of the arch-supporting structures. Our understanding of MLA deformation is currently limited to sit-to-stand, walking, and running.

Material and Methods:

Three-dimensional deformation of the MLA of the right foot was characterized in 17 healthy participants during several simulated activities of daily living. MLA deformation was quantified by both changes in arch length and navicular displacement during the stance phase of three motions: walking, stair ascent, and stair descent. Three levels of load were also evaluated: no load, a ...


Capacity Expansion In The Integrated Supply Network For An Electricity Market, Shan Jin, Sarah M. Ryan Jan 2011

Capacity Expansion In The Integrated Supply Network For An Electricity Market, Shan Jin, Sarah M. Ryan

Industrial and Manufacturing Systems Engineering Publications

Constraints in fuel supply, electricity generation, and transmission interact to affect the welfare of strategic generators and price-sensitive consumers. We consider a mixed integer bilevel programming model in which the leader makes capacity expansion decisions in the fuel transportation, generation, and transmission infrastructure of the electricity supply network to maximize social welfare less investment cost. Based on the leader's expansion decisions, the multiple followers including the fuel suppliers, ISO, and generation companies simultaneously optimize their respective objectives of cost, social welfare, and profit. The bilevel program is formulated as a mathematical program with complementarity constraints. The computational challenge posed ...


The Effect Of Stance Width On Trunk Kinematics And Trunk Kinetics During Sagitally Symmetric Lifting, Christopher Sorenson, Omid Haddad, Samuel Campbell, Gary Mirka Jan 2011

The Effect Of Stance Width On Trunk Kinematics And Trunk Kinetics During Sagitally Symmetric Lifting, Christopher Sorenson, Omid Haddad, Samuel Campbell, Gary Mirka

Industrial and Manufacturing Systems Engineering Publications

Lifting technique can have a significant impact on spine loading during lifting. The sports biomechanics literature has documented changes in trunk and lower extremity kinematics and muscle coactivation patterns as a function of stance width during high force dead lift and squat exercises. The focus of the current study was to explore whether these lifting stance width effects might translate into the occupational setting under more moderate load level conditions. Twelve subjects performed repetitions of a sagittally symmetric lifting and lowering task (10 kg load) under three stance width conditions: narrow (feet together), moderate (feet shoulder width) and wide (feet ...


Influence Of Asymmetry On The Flexion Relaxation Response Of The Low Back Musculature, Xiaopeng Ning, Omid Haddad, Sangeun Jin, Gary Mirka Jan 2011

Influence Of Asymmetry On The Flexion Relaxation Response Of The Low Back Musculature, Xiaopeng Ning, Omid Haddad, Sangeun Jin, Gary Mirka

Industrial and Manufacturing Systems Engineering Publications

Background

The flexion relaxation phenomenon has been extensively studied in sagittally symmetric postures. Knowledge about this phenomenon in asymmetric trunk postures is less well understood, and may help to reveal the underlying physiology of the passive tissue/active tissue load-sharing mechanism in the lumbar region.

Methods

Twelve participants performed fifteen controlled, full range trunk flexion–extension motions toward three asymmetric lifting postures (0° (sagittally symmetric), 15°, and 30° from the mid-sagittal plane). The electromyographic activity data from the paraspinals at the L3 and L4 levels and trunk kinematics data from motion sensors over the C7, T12 and S1 vertebrae were ...