Injuries of the neck and shoulders are common among workers who perform overhead tasks. In order to develop an injury-free working environment with regards to occupational musculoskeletal stress, it is pivotal to understand the pathophysiology of mechanical stress on the musculoskeletal system. The objective of this research was to study the effect of overhead lifting on the sternocleidomastoid and upper Trapezius muscles. Upper body joint angles were also analyzed using APAS during the overhead lifting. This study was conducted using two devices. The set of equipment incorporates an electromyography device, and the APAS. Two electrodes were placed at the muscle belly of the sternocleidomastoid and the upper Trapezius muscles to record the muscle activity. Each participant was asked to lift 15%, 30% and 45% of his/her MVC, The MVC was determined by a non dynamic lifting task. ANOVA was performed to test the effect of different loads on the muscle activity. Correlation analysis was performed to observe the effect of increasing the lifted weight on the joint angles of the upper body extremities. Results of this research show a strong relationship between neck muscle activities and overhead lifting. The level of sternocleidomastoid activity increased 11.8% from a 15% MVC load to a 30% MVC load and increased 16.53% from a 30%MVC to a 45% MVC. All these values were statistically significant. At the trapezius: a 10.64% increase from 15% MVC to 30% MVC, and a 7.76 % increase from 30% MVC to 45% MVC. The significance level of alpha = 0.05 reveals that weight increase has a significant effect on the MAV EMG of the neck muscles. A slight increase in the elbow joint angle of 0.1% was recorded from 15% MVC to 30% MVC. A 2.88% increase in elbow joint angle was recorded from 30% MVC to 45% MVC, with an overall 2.98% increase from 15% MVC to 45% MVC. There was no effect of changing elbow angles on the sternocleidomastoid muscle. On the other hand, flexion of the shoulder angle in the sagital plane had a significant effect on both the Trapezius and the sternocleidomastoid muscles.

This thesis research implemented an existing thermomechanical model of friction stir welding process, and studied the surrogate model-based optimization approach to obtain optimal process parameters for the modeled friction stir welding process. As an initial step, the thermomechanical model developed by Zhu and Chao for friction stir welding of 304L stainless steel was replicated using ANSYS. The developed model was then used to conduct parametric studies to understand the effect of various input parameters like total rate of heat input, welding speed and clamping location on temperature distribution and residual stress in the workpiece. With the data from the simulated model, linear and nonlinear surrogate models were constructed using regression analysis to relate the selected input process parameters with response variables. Constrained optimization models were formulated using surrogate models and optimization of process parameters for minimizing cost and maximizing throughput was carried out using improved harmony search algorithm. To handle the constraints, Debs parameter-less penalty method was used and implemented in the algorithm. It is learned from this research that: (1) heat input is mainly constrained by the lower bound of the temperature for making good welds; (2) the optimal welding speed must balance the loss of heat input and the gain in productivity; (3) clamping closer to the weld is better than away from the weld in terms of lowering the peak residual stresses. Moreover, the nonlinear surrogate models resulted in a slightly better optimal solution than the linear models when wide temperature range was used. However, for tight temperature constraints, optimization on linear surrogate models produced better results. The implemented improved harmony search algorithm seems not able to converge to the best solution in every run. Nevertheless, the non-converged solution it found was very close to the best.

Track and field runners, especially sprinters and mid-distance runners, face many problems due to walking in spike shoes. Due to the fact that track and field spike shoes are designed specifically for running, the runners feet remain in an uncomfortable, flexed position when walking between workouts and races. Problems caused by the dangerous foot-positioning include, but are not limited to, the following: back pain, shin splints, bone spurs, blisters, and overall decreased level of running performance. Over time, runners wearing improper footwear for walking may face chronic injuries such as plantar fasciitis, shin splints, Achilles tendinitis, chondromalacia, and iliotibial band syndrome. To address this problem, a modified spike shoe was tested. The modification consists of adding a removable heel to the shoe. The removable heels were attached to the sole after exercise or between races to shoe angle of flexion, so that the foot can be leveled. The modified shoes were tested in terms of health and comfort through the use of two experimental protocols. Nine healthy, resistance-trained participants volunteered to perform walking drills on a treadmill. They walked with regular spikes at 2 mph and 3 mph. Then, they repeated the drill with the redesigned spike shoes. EMG measurements were used to evaluate the participants muscle activity, fatigue, and stress during the exercise. The analyzed muscles were the tibialis anterior and the medial gastrocnemius. The statistical tool used for the mathematical interpretation of the data was ANOVA, the hypotheses being tested with the softwares Statistix 9.0. and SAS 9.0 English version. Complementarily, participants were individually asked to rate their discomfort on a scale of 1 to 10, using a body map as a further evaluation of the effects of the removable heel. Results showed a 22 % average decrease in EMG muscle activity from walking without heels to walking with heels in the tibialis anterior and a 24.25% average decrease in the gastrocnemius. Results were consistent for all participants. Similarly, when rating discomfort from walking without heels to walking with heels, the body map survey results indicate that participants noticed an average superior comfort of 2.7 points in the knees, 2.6 points in the calves, 3.9 points in the ankles, and 4.2 points in the feet on an ergonomic scale of 10 discomfort points. Thus, results showed that the removable heel helps reduce muscle fatigue and stress and therefore its related musculoskeletal problems.

The liquid and gas pipeline community has recently been faced with the challenge of new governmental regulations set forth by congress which are being implemented by PHMSA (an arm of the DOT). These new governmental regulations need to understand the role of the human in the loop as part of alarm management systems. To investigate alarm rate standards a repeated measures design was developed that included a series of ten (10) simulated liquid pipeline operator scenarios utilizing high fidelity liquid pipeline simulation software (Stoner Pipeline Simulator). A total of 39 participants volunteered for this study. Participants completed two subsets of experiments, five were completed using an alarm display presenting alarms by time (chronological) and the remaining five experiments were completed using a categorical alarm display. Statistically significant differences were found to exist in participant response time, acknowledgement time, and accuracy of response given different alarm display types and alarm rates. Use of the categorical alarm display resulted in significantly reduced alarm acknowledgement and response times. Also, a severe operator performance reduction with regard to alarm handling was observed when the alarm rate was increased from ten alarms per ten minutes (10-alarms/10-minutes) to twenty alarms per ten minutes (20-alarms/10-minutes).

The process of joining metals is called welding. At times, selecting a poor quality material or improper usage of welding technologies may cause defects in welded joints. Some of these welded joints have to be tested nondestructively, because their failure can cause lot of damage, for instance in power plants. Radiography is a very common method for non-destructive testing of welds. It is done by certified weld inspectors who have knowledge about weld flaws, looking at the radiograph of the welded joint with naked eye. The judgment of the weld inspector can be biased; subjective, because it is dependent on his/her experience. This manual method can also become very time consuming. Many researches were exploring computer aided examination of radiographic images in early 1990s. With much advancement in computer vision and image processing technologies, they are being used to find more effective ways of automatic weld inspection. These days, fuzzy based methods are being widely used in this area too. The first step in automatic weld inspection is to locate the welds or find a Region of Interest (ROI) in the radiographic image [7]. In this thesis, a Standard Hough Transform (SHT) based methodology is developed for weld extraction. Firstly, we have done binarization of image to remove the background and non-welds. For binarization, optimal binary threshold is found by a metaheuristic Simulated annealing. Secondly, we use SHT to generate the Hough Transform matrix of all non-zero points in the binary image. Thirdly, we have explored two different paths to find a meaningful set of lines in the binarized image that are welds. Finally, these lines are verified as weld using a weld-peak detection procedure. Weld-peak detection is also helpful to remove any non-welds that were remaining. We have used 25 digitized radiographic images containing 100 welds to test the method in terms of true detection and false alarm rate.

Since its introduction, the concept of integrated inventory supply chain has received a considerable amount of attention. The majority of studies in the last three decades revealed an increase in holding cost as product moves further down the chain or up the chain. A recent study Hoque (2008) considered vendors setup cost and inventory holding cost. Some research also considered fixed transportation cost, which is unrealistic. This study focuses on a single-vendor, multi-buyer scenario and presents three models. First, two models illustrate the transferring of equally-sized batches. Then, a third model considers the transferring of unequally-sized batches in a lot. This study relaxes the assumption that vendors holding cost must be greater than or less than all buyers holding costs in the system. Also, this research facilitates unequal transportation time and cost for different buyers for greater flexibility. The total system cost is calculated by summing the annual operational cost for all the parties in the system. Optimum values of the decision variables are determined using a direct search method. As presented by the third model, a numerical example demonstrates that the total system cost is less when compared with other two models presented. This study also presents the following: solution procedures to solve each model, many numerical examples to support mathematical findings, and performance comparisons among three findings. In order to justify the lot-splitting approach for solving the integrated inventory problem, alternative models with no lot splitting are devised and tested under the same circumstances. Alternative models with no lot splitting produce similar or better results. Under the same circumstances, the alternate third model is observed to be offering the least total cost for the system. This study also presents a sensitivity analysis to check the robustness of the three models. The future extension of this research may involve considering storage capacity constraint and random demand.

Safety research and practice have shifted focus away from accident rates and accident causal information to a more proactive approach that may predict organizational safety trends. This proactive approach involves the concept of an organizational safety culture and the use of surveys to measure organizational safety climate or snapshot‟ of the organizational safety culture. Surveys were administered to line workers, supervisors, and managers at a modular home manufacturing company before and after safety climate information was presented to supervisors and managers in an attempt to measure the effect of the supervisors‟ and managers‟ increased awareness of the factors that define organizational safety climate as well as investigate potential differences between line workers and supervisors/managers perceptions of the organizational safety climate. Two-way, mixed design analysis of variance (ANOVA) found no significant differences in the survey responses within each group (line workers, supervisors/managers) between two surveys, and between the groups in each survey. Additionally, the survey responses were divided into groups based on the nine safety climate factors that the questions measured and the same analysis was conducted, with no significant differences found. While the safety climate information presentation led to no significant changes in the overall perceived safety climate of the company, the time factor in the study was a limitation and the potential for the application of similar methods in additional studies exists.

Many organizational problems are related to job dissatisfaction, job-related stress, and lack of commitment in workers. Employees Affective Attitude (EAA) involves these three factors: job satisfaction, job stress, and commitment. This research is aimed at measuring the impact of Lean concepts on EAA factors. While providing an overview of Lean production and construction, this study focuses on one fundamental Lean concept, Kaizen. This thesis describes a case study showcasing the application of Lean concepts through Kaizen events and its impact on EAA for a modular homebuilder company. Based on previous literature a conceptual model was developed describing the potential links between Kaizen events and EAA factors. The conceptual model also took into account employees seniority level (work experience) which might have an impact on the three factors of EAA. To measure three factors of EAA, an Employees Affective Attitude Questionnaire (EAAQ) was compiled from other validated questionnaires. The research methodology entailed two phases Phase I aimed at developing a company-wide baseline of the current levels of EAA at a modular homebuilding company without Lean practices. In addition, Phase I analyzed any variation due to employees seniority level on their EAA factors. Phase II aimed to characterize the state of EAA factors after implementing Lean concepts through a Kaizen event. After surveying 82 employees in Phase I and conducting a Kaizen event at one department in Phase II, results revealed an increase in job satisfaction (11.5%) and commitment level (15.9%); whereas there a decrease in job stress level (6.7%). Results from Phase I- (pre- Kaizen), indicated that employees had moderate level of job satisfaction, commitment, and job stress for all seniority level. After conducting the Kaizen event, results of Phase II revealed that employee experienced increase in their job satisfaction and commitment level, and a decrease in job stress level among all seniority levels. In general, the case study results suggested that Lean concepts (e.g. eliminating production waste, improving productivity, and enhancing workers role perception) were also good concepts for improving EAA factors among different seniority levels at the modular homebuilder company.

While many residential contractors, architects, and home-buyers today are concerned about the environment and interested in sustainable construction technologies, the perceived higher initial costs of innovative materials and methodologies and a lack of life-cycle cost and performance data present significant barriers in the implementation of such techniques. Research regarding an integrated design process has suggested that performance based decision making is key to the successful implementation of sustainable building practices. Therefore, a need exists for the development of whole building design and evaluation models to allow decision making in all phases of a building project. This research seeks information regarding residential framing systems and the corresponding expected energy performance, as well as to present a case-study utilizing the integration of building information modeling and energy simulation. The primary goals of this research are 1) assess the ability of BIM integrated energy simulation modeling to accurately predict the energy performance of a building and 2) compare the predicted energy performance for four different residential framing systems through the integration of BIM, energy simulation and performance monitoring. These research goals will be accomplished through a case-study approach utilizing the Louisiana State University Agricultural Centers showcase home, known as the LaHouse, which serves as a display of sustainable construction materials and technologies. This research focuses on the integration of design software Autodesk® Revit Architecture with energy simulation modeling. Models based on the LaHouse were created in Autodesk® Revit Architecture and will be used to simulate the energy utilization of four different framing systems: insulated concrete forms, structural insulated panels, advanced framing and standard framing, all of which were used in the construction of LaHouse. The energy utilization obtained by the performance monitoring systems installed in the LaHouse Garage will be compared with simulation results.

One of the common goals which most companies have is to maximize profits. There are two way to increase profit: increasing revenue or reducing cost. Lacking of ability to keep the cost down could potentially drive the companies out of the business. In recent years, many researchers have been paying more attention on improving supply chain system due to high potential of creating cost savings. The supply chain network considered in this research is a tree-type, three-echelon single producer, multiple distributors, and multiple retailers system. The goal of this research is to develop a replenishment policy which satisfies customers demand and minimizes the total production-inventory system cost. Three inventory models are developed here. First, tree-type, three-echelon distribution (producer, distributor and retailers) model with end customers backorders (TDB) at retailers level is developed. Second, the variation of downstream holding cost (DHV) is studied and a model is developed to investigate the effect downstream holding cost structure. Third, a model is developed to improve the retailers service rate (ISR). This model combines the features of TDB and DHV models together (allowable backorder and reduced delivery interval at retailers level). Operational schedules of TDB are constructed and the limitations of DHV model are established. The improvement in the ISR model is confirmed and demonstrated through numerical examples. Significance and conclusions of this research are highlighted along with an indication of future research.