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Human Flesh Search (HFS), originated in China, has become an explosive Web phenomenon. HFS episodes typically start with news events. Participants pay close attention to the events, get together online, investigate, try to solve the real world problems and find the truth. In HFS episodes, participants form online communities, share information and collaborate with each other. Such online communities are unique subjects of social network study. This dissertation presents the first systematic empirical study and data-driven modeling of HFS. We give the formal definition of HFS, summarize the typical HFS process and classify the episodes based on their topics. We study network measurements of the social networks corresponding to the communities of individual HFS episodes. The communities are strongly centralized, and have small world property. Information diffusion within the communities restricts by the central hubs of the networks. To understand the overall properties of HFS communities, HFS core network is built to study the connections of participants in all episodes. The result shows that HFS core network is a small world and scale-free network. Since the HFS communities do not follow any existing network model, a modified network model is purposed to explain the characteristics of HFS episode networks.

The goal of this study was to explore the proposed relationship between employee satisfaction, ergonomics, and safety while implementing a Kaizen event. In order to address this goal, two Kaizen events (K1 and K2) were conducted in a heavy equipment manufacturing plant. Before and after both events, levels of employee satisfaction were documented for Kaizen and Non-Kaizen (NK) participants using the Job Diagnostic Survey (JDS). The objective of the first event (K1) was to improve the efficiency of the task of torqueing the rear axle bolts in Station #1- skid assembly. The K1 methodology followed a traditional Kaizen structure, enhanced with ergonomic and safety evaluation tools, Rapid Entire Body Assessment (REBA) and Job Hazard Analysis (JHA) respectively. During the event (K1), problem areas caused by the current skid were identified, analyzed, and a new skid was developed and implemented via a prototype. After testing the prototype all skids were replaced for full implementation. Ergonomic and safety was again evaluated. By using this approach to redesign the process, it was possible to improve productivity (83%), while reducing employee safety (5 JHA hazards to 1 hazard) and ergonomics (Employee #1 REBA score 13 to 11). The objective of the second kaizen event (K2) was to improve the efficiency of the manufacturing process for the welding subassembly station. The K2 methodology followed a traditional Kaizen structure, where the team identified the key problems for the welding subassembly station, analyzed the concerns for the material arrival, developed a solution for more consistent material delivery, and implemented a solution. By using Kaizen as a tool to address scheduling and material movement it was possible to improve the manufacturing process efficiency (36%). The JDS evaluation revealed mixed results for the impact of a Kaizen event on job satisfaction- some employees job satisfaction levels increased when others decreased. The findings also show that some characteristics (Feedback from Agents (p=0.036), Experienced Meaningfulness of the Work (p=0.036), Growth Satisfaction (p=0.027), Satisfaction with Compensation (p=0.034), and Motivating Potential Score (p=0.025)) were significantly different across participants groups (e.g. K1, K2 and NK). The events helped to encourage communication and involvement making the new processes more efficient and less frustrating for employees. Findings from this research contribute to a better understanding of the impact of lean on employees ergonomics, safety, and job satisfaction.

<p> Disasters strike suddenly and cause destruction which disrupts the availability of basic survival supplies for people living in affected areas. The efficiency of humanitarian organizations in providing relief has a direct and crucial impact on the survival, health, and recovery of affected people and their communities. To better prepare to respond to disasters, many relief organizations use supply pre-positioning. However, the real and potential needs of different locations change over time and when an organization uses traditional warehouse pre-positioning, relief operations are limited by set inventory locations that are difficult to alter. For this reason, a well known organization recently considered including a large supply holding ship in its operations. By holding inventory on a ship, the organization would be able to dynamically relocate its inventory over time in response to changing relief supply demand forecasts. </p><p> To our knowledge, the research contained herein is the first to examine dynamic inventory relocation for responding to disasters over time. Specifically, we examine how to optimally relocate and manage inventory for a single mobile inventory to serve stochastic demand at a number of potential disaster sites over time. While we keep in mind the motivating example of a supply holding ship in the disaster relief setting throughout this dissertation, the model and most of the results are applicable to any type of mobile inventory, facility, or server in any setting. </p><p> We first examine the dynamic relocation problem. We model the problem using dynamic programming and develop analytical and numerical results regarding optimal relocation policies, the optimal path and speed of relocation decisions, and the value of inventory mobility over traditional warehouse pre-positioning. To help overcome the computational complexity of the problem, we develop a heuristic which solves relatively large problem instances in our numerical experiments within 0.5% of optimality in less than 0.1% of the time required by an exact algorithm. </p><p> As it is suboptimal to consider relocation decisions and inventory management decisions separately, we also examine the joint dynamic relocation and inventory management problem. To our knowledge, we are the first to examine the dynamic relocation and inventory management problem with stochastic demand. Similarly to the dynamic relocation problem, we model this problem using dynamic programming. We develop a number of analytical results characterizing the optimal relocation and inventory management policies. </p><p> As the first to examine these problems, we hope this research serves as a catalyst for other research in this area; accordingly, we conclude this dissertation by discussing a number of areas for future research.</p>

<p> Research with human participants involves a complex combination of procedural elements in order to establish internal, external and measurement validity. Examining the accuracy of research equipment and methods that elicit similar behaviors as the general public is difficult. This research used driving as a model to address elements in the procedures that participants experience to elicit realistic behaviors. </p><p> An instrumented vehicle (IV) and driving simulator (SIM) measured experimental behaviors for average approach speed (in the 20m before the legal stop line); lateral distance from curb at 20m; lateral distance from curb at legal stop line (0m) and the stopping location (distance before or after 0m); and, compared with measured general driving public behaviors at stop-controlled intersections. The linear mixed effect analyses combined two experiments. In both, surveys were administered to gather driver&rsquo;s trait anxiety, driving anxiety and social desirability scores. Experiment One drivers (36% female) were grouped as Novice (5, 16-17 year olds who just obtained driving license), Young (4, 16-17 year olds who obtained license over a year ago) and Adult (5, 30-55 year olds licensed near age 16). Experiment Two drivers (47 SIM, 44 IV; 35% female) were College age (18-21 year olds licensed near age 16) and exposed to 1 of 16 different combinations (one of those treatments matched Experiment One&rsquo;s procedure) of procedural changes for: researcher attire (casual or formal), researcher proximity (control room, front or rear passenger seat), mode of instruction delivery (spoken, read or video) and hypothesis statement (none or explicit). At the end of Experiment Two, participants&rsquo; understanding of the experiment was coded into three debriefing variables. </p><p> Absolute behavioral validity of the IV to public behavior was achieved in one treatment (formal, front seat, spoken and no hypothesis) and including the debriefing variables in the model; no SIM combination achieved this. Trait anxiety scores appeared to explain behaviors in the IV or SIM and improved result interpretation as interactions with other independent variables. For improved research methods, it is recommended that coded debriefing variables, specific procedural elements, and trait anxiety scores be included and used to explain interactions or differences in participant behaviors. </p>

<p> Time series models have been widely used in simulating financial data sets. Finding a nice way to estimate the parameters is really important. One of the traditional ways is to use maximum likelihood estimation to make an approach. However, when the error terms don&rsquo;t have normality, MLE would be less efficient. Quasi maximum likelihood estimation, also regarded as Gaussian MLE, would be more efficient. Considering the heavy-tailed financial data sets, we can use non-Gaussian quasi maximum likelihood, which needs less assumptions and conditions. We use real financial data sets to compare these estimators. </p>

<p> A mixed-integer linear program is proposed to model the dynamic network expansion problem of improving oil spill response capabilities to support energy exploration in the Arctic. Oil spill response operations in this region can be hampered by a lack of existing infrastructure, limited pre-positioned response equipment, and the possibility that response equipment might not arrive in time to mitigate the impact of a spill because of distance and infrastructure limitations. These considerations are modeled by two inter-related constraint sets with the objective of minimized total weighted response time for a set of potential oil spill incidents. One constraint set determines how to dynamically allocate response equipment and improve the infrastructures necessary to stockpile them within a network of response sites. The other set determines how to utilize this stockpile to respond to each task necessary for an incident by scheduling the equipment to complete tasks. These task completion times are subject to deadlines which, if not met, can, instead, require costlier follow-on tasks to be scheduled. The model, its assumptions, and data requirements were assessed by subject matter experts in the United States (U.S.) Coast Guard and a major Oil Spill Response Organization in the context of oil spill response logistics to support energy exploration initiatives in the U.S. Arctic.</p>

The advantages of using polymer matrix composites in various applications are very well known throughout many industries. Their introduction and subsequent development since the 1940's has led to major cost savings due to their lightweight and excellent mechanical properties. Off late, product designers have been taking advantage of improved thermal properties (CTE, thermo-oxidative stability) that these composite materials have to offer. This began with the development of PMR-15, a high temperature polyimide resin back in the 1970's. The aerospace industry has increasingly turned towards high temperature polymer matrix composites (HTPMC) to replace other heavier materials in engine components thus improving the thrust to weight of the engine. But, PMR-15 has a major drawback related to high safety standards that are needed during processing. The implementation of these controls during processing resulted in huge costs to the industry. This led to the development of a new polyimide high temperature resin system called RP-46 at NASA Langley research center. RP-46 has excellent thermal and mechanical properties comparable to PMR-15 and is safer to handle due to the absence of the lethal MDA monomer, a carcinogen. This research investigates the issues related to processing of RP-46 resin system using the Vacuum Assisted Resin Transfer Molding (VARTM) process, a cost effective method for manufacturing composite materials. The entire process is setup keeping in consideration the requirement of high temperature environments for processing of RP-46. A number of initial trials helped understand the dynamics of the process and identify critical factors and key parameters. The various laminates that were made were tested for mechanical properties (ASTM D3039 - Tensile strength and modulus) and thermal properties (Dynamic Mechanical Analysis, Thermal Mechanical Analysis, Thermal Gravimetric Analysis) were performed and the results were compared with RP-46 samples made using autoclave processing. Although the VARTM laminates had issues related to void contents and the release of volatiles during the infusion stage of the process, the VARTM process was found to be feasible to make composites with RP-46. / A Thesis submitted to the Department of Industrial Engineering in partial fulfillment of the requirements for the degree of Master of Science. / Degree Awarded: Spring Semester, 2004. / Date of Defense: April 16, 2004. / High Temperature Composites, VARTM / Includes bibliographical references. / Chuck Zhang, Professor Directing Thesis; Okenwa Okoli, Committee Member; Zhiyong Liang, Committee Member.

Carbon nanotube (CNT) fibers are very promising materials for many applications. Strong interactions among individual CNTs could produce a dense yarn results in exceptional properties. These properties are used in the application of high-performance reinforcement for composites. As the reinforcement, the primary function is to provide outstanding load bearing capability. Currently literatures use a variety of measurement techniques and gauge lengths that have not been uniform for CNT yarn tests. The need for a standardized testing method for characterization is necessary in generating reproducible and comparable data for CNT yarn or fiber materials. In this work, the strength of CNT fibers was characterized using three different types of tensile test method: the film and fiber test fixtures from dynamics mechanic analysis (DMA), and TS 600 tensile fixture. Samples that underwent the film and TS 600 tensile fixture were attached with a thick paper tabbing methodology based on ASTM standard D3379. As for the fiber fixture was performed with the test material attached directly to the fixture based on the fiber test instruction from TA Instrument. The results of the three different methods provided distinct variance in stress, strain, and modulus. A design of experiment (DoE) was established and performed on the DMA film fixture as determined from the preliminary experiment. The DoE was successful in quantifying the critical parameters' ranges that attributed to standard deviation of average stress. These parameters were then tested on 30 more samples with an improved additive manufactured tab. The results significantly decreased all mechanical testing parameters' standard deviations. Most importantly, the results prove the probability of a valid gauge break increased to more than 400%. / A Thesis submitted to the Department of Industrial and Manufacturing Engineering in partial fulfillment of the Master of Science. / Fall Semester 2015. / November 13, 2015. / Additive Manufacturing, Manufacturing, Material Science, Quality Engineering, Statistics / Includes bibliographical references. / Zhiyong Liang, Professor Directing Thesis; Mei Zhang, Committee Member; Arda Vanli, Committee Member.

Carbon nanotubes have excellent electrical, thermal, and mechanical properties as determined theoretically and experimentally. Their properties make them great candidates for use in a number of applications ranging from lightning strike protection for airplanes to computer heat sink. However, carbon nanotubes are incredibly small, with diameters as small as 1nm and just a few micrometers long. The nanoscale size makes carbon nanotubes impractical to be used individually for many industrial purposes, thus methods have been developed to fabricate macroscale networks of carbon nanotubes. The carbon nanotube networks, also called Buckypaper, have showed mechanical, thermal and electrical properties inferior to those of individual nanotubes. Extensive work has been conducted to develop and optimize suitable production methods of producing high quality Buckypaper and enhance their properties. Many approaches are capable of producing a carbon nanotube network, but most are not able to scale up for industrial applications due to size and production rate limitations. This research focuses on two aspects of Buckypaper manufacturing improvements. The first is to test 90 mm samples of Buckypaper disks to determine the impact of each processing parameter on the quality and properties. Statistic analysis was used to reveal the effect of processing parameters. Utilizing these results, a long sample of Buckypaper was produced and examined for property and quality consistency along the sample length, using modified customer-made continuous filter devices. Additionally, long samples with larger width were produced to demonstrate production rate of continuous Buckypaper manufacturing. Through this research it was found that the electrical conductivity of the Buckypaper was affected positively by an increase in sonication pressure. Additionally, increases in pressure and increase in power of sonication led to an increase of Buckypaper strength. Strength and electrical properties of the continuous Buckypaper were considered consistent throughout the length. These results provide essential understanding of the continuous Buckypaper manufacturing process. / A Thesis submitted to the Department of Industrial and Manufacturing Engineering in partial fulfillment of the requirements for the degree of Master of Science. / Degree Awarded: Summer Semester, 2009. / Date of Defense: July 21, 2009. / Carbon Nanotubes / Includes bibliographical references. / Zhiyong Liang, Professor Directing Thesis; Ben Wang, Committee Member; Chuck Zhang, Committee Member; Arda Vanli, Committee Member.