Operations Research, Systems Engineering and Industrial Engineering Commons^™

การศึกษาการเกิดเศษโลหะของเหล็กกล้าไร้สนิม ในกระบวนการผลิตวาล์วควบคุมแรงดัน สำหรับอุตสาหกรรมยานยนต์, พยุห์ เกิดจงรักษ์

Chulalongkorn University Theses and Dissertations (Chula ETD)

งานวิจัยนี้มีวัตถุประสงค์เพื่อศึกษาการเกิดเศษโลหะของเหล็กกล้าไร้สนิม เนื่องจากพบปัญหาเศษโลหะติดอยู่ในรูของชิ้นงาน จากการเก็บข้อมูลของเสียระหว่างเดือนสิงหาคม-ตุลาคม พ.ศ.2562 ในไลน์การผลิตที่ 1 และไลน์การผลิตที่ 2 พบว่าทั้งสองไลน์การผลิตมีสัดส่วนของเสียเฉลี่ยอยู่ที่ร้อยละ 0.11 หรือคิดเป็น 1,130 PPM ต่อเดือน ในการดำเนินการวิจัยแบ่งออกเป็น 5 ระยะ โดยในระยะที่ 1 ทำการวิเคราะห์สาเหตุของปัญหา พบว่าปัญหาเศษโลหะติดอยู่ในรูชิ้นงานเกิดในกระบวนการกลึงปาดหน้าด้วยมีดตัดหยาบเนื่องจากลักษณะของเศษโลหะที่เกิดปัญหากับเศษโลหะในกระบวนการมีความใกล้เคียงกันทั้งขนาดและรูปร่าง ระยะที่ 2 ศึกษาทฤษฎีที่เกี่ยวข้องกับการเกิดเศษโลหะ โดยพบว่ามีปัจจัยที่เกี่ยวข้องกับการแตกหักและทิศทางของเศษโลหะคือเงื่อนไขการตัด ที่ประกอบด้วย ความลึกตัด อัตราป้อนตัดและความเร็วรอบสปินเดิล ระยะที่ 3 กำหนดขั้นตอนในวิธีดำเนินการวิจัย ระยะที่ 4 ผลการวิเคราะห์ข้อมูล ปัจจุบันเศษโลหะมีโอกาสตกลงไปในรูของชิ้นงานทุกระยะตัด จากผลการเปลี่ยนเงื่อนไขการตัด พบว่าเงื่อนไขที่เหมาะสมคือเงื่อนไขที่ 1 คือการเพิ่มความลึกตัดให้มากสุดที่ไม่ส่งผลต่อขนาดของชิ้นงาน เนื่องจากเศษโลหะจะมีความหนาเพิ่มขึ้นทำให้แตกหักง่าย มีความโค้งงอที่ลดลง จาก 2.04-3.12 มิลลิเมตร เป็น 0.56-1.48 มิลลิเมตร ทิศทางการแตกหักจะชนกับชิ้นงานทำให้กระเด็นไปทางอื่น ผลทดลองกับกลุ่มตัวอย่างจำนวน 20 ข้อมูล ไม่พบปัญหาเศษโลหะติดอยู่ในรูชิ้นงานเนื่องจากขนาดของเศษโลหะที่เล็กลง สรุปได้ว่าเงื่อนไขการตัดหลังปรับปรุงมีความเหมาะสมในการลดโอกาสที่ทำให้เศษโลหะติดค้างในรูชิ้นงานได้ และระยะที่ 5 สรุปผลการทดลอง ข้อเสนอแนะและอุปสรรคในการทดลอง

Reliability Estimation Of Reciprocating Seals Based On Multivariate Dependence Analysis And It's Experimental Validation, Chao Zhang, Rentong Chen, Shaoping Wang, Yujie Qian, Mileta M. Tomovic

Engineering Technology Faculty Publications

Accurate reliability estimation for reciprocating seals is of great significance due to their wide use in numerous engineering applications. This work proposes a reliability estimation method for reciprocating seals based on multivariate dependence analysis of different performance indicators. Degradation behavior corresponding to each performance indicator is first described by the Wiener process. Dependence among different performance indicators is then captured using D-vine copula, and a weight-based copula selection method is utilized to determine the optimal bivariate copula for each dependence relationship. A two-stage Bayesian method is used to estimate the parameters in the proposed model. Finally, a reciprocating seal degradation …

Training The Active Duty Naval Workforce Using The Digital Thread To Design/Redesign Basic Models With Validation Through The Additive Manufacturing, Vukica M. Jovanovic, Anthony W. Dean, Karina Arcaute, Michel Audette, Dipankar Ghosh

Engineering Technology Faculty Publications

This digest will showcase one approach to teaching engineering graphics and design for the active duty naval workforce. Sailors are exposed to solid modeling fundamentals during the two-day long workshop. Solid modeling is taught in connection to concepts of digital thread and design for additive manufacturing. Engineering graphics fundamentals are introduced with the emphasis on a deeper understanding of machinist approach, often used for an easier understanding of Boolean algebra, which is embedded within the Computer Aided Design tools and discusses how the design for additive manufacturing would differ from that approach. Moreover, special attention is given to understanding the …

Literature Survey Of Wet-Waste And Hydrothermal Carbonization System: A Comparative Evaluation, Ramat Olaide Yusuf

Dissertations and Theses

This thesis describes the process of Hydrothermal carbonization and a comparative assessment on recent work done on the process using different feedstocks such as Raw Apple (RA), Apple chip pomace (ACP), apple juice pomace (AJP), grape pomace (GP), macadamia nut-shell (MNS), Sewage Sludge (SS), Poultry Litter (PL) and Grape Marc (GM). The data obtained from the literature survey was compared with the data obtained by the CCL team on the SWPS gasifier (HTC of poultry litter) to obtain how carbon conversion efficiency, syngas composition, thermal efficiency, char production rate, gas production rate and energy utilization vary with carbonization process conditions, …

Self-Leadership To Servant Leadership: A Metatheoretical Antecedent To Positive Social, Allen Lloyd Carn

Walden Dissertations and Doctoral Studies

A majority of current leadership programs are failing to deliver a comprehensive approach to leadership development by not providing middle and frontline managers the skills to enhance their potential to develop others. In failing to generate a comprehensive system, animosity towards all types of leadership has been festering for over 40 years as first identified by Greenleaf in 1977. The purpose of the study was to establish a link between the theoretical paradigms of servant leadership and self-leadership using the lens of emotional intelligence to generate an integral leadership development framework. The conceptual framework used Goleman et al.'s version of …

Stochastic Optimization And Applications With Endogenous Uncertainties Via Discrete Choice Models, Mengnan Chen

Electronic Theses and Dissertations

Stochastic optimization is an optimization method that solves stochastic problems for minimizing or maximizing an objective function when there is randomness in the optimization process. In this dissertation, various stochastic optimization problems from the areas of Manufacturing, Health care, and Information Cascade are investigated in networks systems. These stochastic optimization problems aim to make plan for using existing resources to improve production efficiency, customer satisfaction, and information influence within limitation. Since the strategies are made for future planning, there are environmental uncertainties in the network systems. Sometimes, the environment may be changed due to the action of the decision maker. …

A Lagrangian-Based Heuristic To Consolidate Perishable Products, Samir Babu Bhetwal

Graduate Research Theses & Dissertations

A consolidation center with multiple suppliers and multiple destinations for a perishable product is considered in this research. Perishable products deteriorate with time and this research includes a deterioration cost to measure this behavior. The model considers a variety of suppliers ranging from small to mid-sized. Due to dependencies of inventory and shipment release decisions, an integrated approach of making the operational decisions is necessary. This coordinated approach considers deterioration cost, inventory cost, and transportation cost.

Tradeoff decisions between different supply chain costs are not straightforward as the problem contains constraints like inventory capacity and transportation constraints from suppliers to …

Analysis Of The Integration Of Dfm Techniques And Effective Machining Parameter Selection In Metal Parts Manufacturing, Omar Ahmed Al-Shebeeb

Graduate Theses, Dissertations, and Problem Reports (ETD)

This dissertation investigates the minimization of part design with self-locating features. The research focuses primarily on self-fastening characteristics, standardization of parts, and minimal use of fasteners. Further, the present research studies the design for base parts in the construction of a moving joint system, in order to locate potential part and system design improvements. This process may then be extended to industrial applications in the manufacturing industry. Relatively little work to date has examined the significance of Design for Manufacturing Techniques (DFMT), with their inherent machine element systems and machining parameters to investigate which DFMT has the most influence on …

Energy Efficiency Evaluation Of Blower Heater Non-Purge Compressed Air Dryers, Alexandra M. Botts

Graduate Theses, Dissertations, and Problem Reports (ETD)

There are several compressed air dryers available for industrial use including, refrigerant, desiccant, and membrane. This research focuses on twin tower regenerative closed loop desiccant dryers, specifically: blower heater non-purge (BHNP) with and without cooling water pumps, Compressed-air Heater Purge (CHP), Blower Heater Purge (BHP), and Pressure Swing Heaterless (PSH). These styles of dryers are used mainly in industries that require extremely dry air such as, food manufacturing, medical air, or sensitive technology manufacturers. The research was conducted by collecting and analyzing real time current draw data on air compressors and associated dryers at eight different facilities (13 compressor systems) …

Enhancing Group Social Perceptiveness Through A Swarm-Based Decision-Making Platform, David A. Askay, Lynn E. Metcalf, Louis Rosenberg, Gregg Willcox

Industrial Technology and Packaging

Swarm Intelligence is natural phenomenon that enables social animals to make group decisions in real-time systems. This process has been deeply studied in fish schools, bird flocks, and bee swarms, where collective intelligence has been observed to emerge. The present paper describes swarm.ai—a collaborative technology that enables swarms of humans to collectively converge upon a decision as a real-time system. Then we present the results of a study investigating if groups working as “human swarms” can amplify their social perceptiveness, a key predictor of collective intelligence. Results showed that groups reduced their social perceptiveness errors by more than half when …

Measuring Group Personality With Swarm Ai, Gregg Willcox, David Askay, Louis Rosenberg, Lynn Metcalf, Bryan Kwong, Richard Liu

Industrial Technology and Packaging

The aggregation of individual personality tests to predict team performance is widely accepted in management theory but has significant limitations: the isolated nature of individual personality surveys fails to capture much of the team dynamics that drive real-world team performance. Artificial Swarm Intelligence (ASI), a technology that enables networked teams to think together in real-time and answer questions as a unified system, promises a solution to these limitations by enabling teams to take personality tests together and converge upon answers that best represent the group’s disposition. In the present study, the group personality of 94 small teams was assessed by …

Towards A Framework For Smart Manufacturing Adoption In Small And Medium-Sized Enterprises, Sameer Mittal

Graduate Theses, Dissertations, and Problem Reports (ETD)

Smart Manufacturing (SM) paradigm adoption can scale production with demand without compromising on the time for order fulfillment. A smart manufacturing system (SMS) is vertically and horizontally connected, and thus it can minimize the chances of miscommunication. Employees in an SME are aware of the operational requirements and their responsibilities. The machine schedules are prepared based on the tasks a machine must perform. Predictive maintenance reduces the downtime of machines. Design software optimizes the product design. Production feasibility is checked with the help of simulation. The concepts of product life cycle management are considered for waste reduction. Employee safety, and …

Development Of A Task Analysis Tool To Estimate Shoulder Strain During A Lifting Task, Christopher Wayne Moore

Graduate Theses, Dissertations, and Problem Reports (ETD)

Musculoskeletal disorders of the shoulder have a huge impact on the workplace and employees. Due to the complexity and high mobility of the shoulder, developing a task analysis tool with a focus on the shoulder is difficult, and while there are some ergonomic analysis tools that do consider the shoulder to varying degrees in the analysis, none focus purely on the shoulder. Therefore, this research was undertaken in an attempt to develop a shoulder-based task analysis tool for the shoulder. However, since the scope of work involving the shoulder is so vast, the tool in this research focuses on unobstructed, …

Analysis Of User Preference With N95 And Powered Air-Purifying Respirators In A Healthcare Work Environment, Brittany Renee Carver

Graduate Theses, Dissertations, and Problem Reports (ETD)

For those working in the healthcare field, personal protective equipment is vital. Healthcare workers are often first responders when it comes to dealing with patients who are infected or when a disease outbreak occurs. The Occupational Safety and Health Administration (OSHA) requires all healthcare operations to provide employee protection against blood borne pathogens. With the increase of life-threatening disease outbreaks, such as SARS in 2003 and Ebola in 2014, it is of the upmost importance to make sure respirators are best suited for users and acceptable for long term use. It has been shown through previous studies that due to …

Pharmaceutical Scheduling Using Simulated Annealing And Steepest Descent Method, Bryant Jamison Spencer

Graduate Theses, Dissertations, and Problem Reports (ETD)

In the pharmaceutical manufacturing world, a deadline could be the difference between losing a multimillion-dollar contract or extending it. This, among many other reasons, is why good scheduling methods are vital. This problem report addresses Flexible Flowshop (FF) scheduling using Simulated Annealing (SA) in conjunction with the Steepest Descent heuristic (SD).

FF is a generalized version of the flowshop problem, where each product goes through S number of stages, where each stage has M number of machines. As opposed to a normal flowshop problem, all ‘jobs’ do not have to flow in the same sequence from stage to stage. The …

Effect Of Metacarpal Gloves On Pinch And Grip Strength, Aaron Anthony Fonner

Graduate Theses, Dissertations, and Problem Reports (ETD)

Hand Injuries are common in industrial settings. In 2014 alone, there were 137,440 total cases of hand injuries in the United States that required days away from work. Hand injuries can be classified into six general categories: lacerations, fractures and dislocations, soft tissue injuries and amputations, infections, burns and high pressure injuries. Some of these injuries can be prevented with proper personal protective equipment. In recent times, metacarpal gloves are widely used to protect the workers against hand/metacarpal injuries in various industries including mining. The benefits of wearing metacarpal gloves for protection are unquestionable, but little is known about how …

Can Fitts' Throughput Be A Predictor Of Muscle Fatigue – A Study Based On Metacarpal Gloves?, Sachin Sah

Graduate Theses, Dissertations, and Problem Reports (ETD)

In this study, Fitts’ throughput was used to estimate throughput for metacarpal gloves. Fitts’ throughput combines speed and accuracy during target transfer/movement tasks into a single performance index. It was hypothesized that the throughput will be affected by the glove condition and it will exhibit a relationship with the physiological response of hand muscles and perceived exertions. Fifteen healthy participants (10 males, 5 females) were recruited for data collection. Each participant performed a series of target transfer tasks using four glove conditions: (1) a pigskin leather (glove 1); (2) a synthetic fiber glove (glove 2); (3) a goat-grain leather glove …

Validation Of A Low-Cost Sensor For Development Of Wearable And Handheld Spectrometers, Justin Leslie Cathey

Graduate Research Theses & Dissertations

This study examined the possibility of creating a quantitative radiometric spectrometer from a low-cost relative radiometric spectrometer sensor through the use of statistical analysis and development of a correction factor (p > 0.05). Radiometric spectrometers are able to measure and fully characterize the radiometric and photometric characteristics of light, while relative spectrometers are not able to fully, quantitatively characterize the radiometric response from a light source, thus they are less expensive. The spectrometer created in this research is able to measure and produce comparative lighting parameters as well as an actual radiometer spectrometer.

The photoreceptors cells within the human eye allow …

Sky Surveys Scheduling Using Reinforcement Learning, Andres Felipe Alba Hernandez

Graduate Research Theses & Dissertations

Modern cosmic sky surveys (e.g., CMB S4, DES, LSST) collect a complex diversity of astronomical objects. Each of class of objects presents different requirements for observation time and sensitivity. For determining the best sequence of exposures for mapping the sky systematically, conventional scheduling methods do not optimize the use of survey time and resources. Dynamic sky survey scheduling is an NP-hard problem that has been therefore treated primarily with heuristic methods. We present an alternative scheduling method based on reinforcement learning (RL) that aims to optimize the use of telescope resources for scheduling sky surveys.

We present an exploration of …

Knot Optimization For Univariate Cubic L^1 Spline Fits With Application In Change Point Detection, Manfei Xie

Graduate Research Theses & Dissertations

Cubic $L^1$ spline fits, as a type of $L^1$ approximating splines, have shown superior performance in shape preservation of geometric data with great changes. To better construct a cubic $L^1$ spline fit, the number and the location of the spline knots should be optimized rather than predetermined. This research investigates knot optimization methods for univariate cubic $L^1$ spline fits. When the number of knots is given, we design an optimization-based method to determine the best location of the knots. When the number and the location are unknown, we propose a heuristic method to find proper knot number and location. Numerical …

Minimizing Total Number Of Tardy Jobs In Parallel Batch Processing Machines Using Column Generation And Simulated Annealing, Sameer Neupane

Graduate Research Theses & Dissertations

This research considers a scheduling problem where jobs need to be grouped into batches and the batches need to be scheduled on parallel batch processing machines with an objective to minimize the total number of tardy jobs. The jobs are assigned to batches in such a way that machine capacity is not violated. This research considers jobs with unequal ready times, unequal processing times and unequal sizes. The machines are identical in processing capabilities; however, their capacities are different. This research aims to develop effective solution approaches to solve the problem under study. A Mixed Integer Linear Programming (MILP) model …

Computational Methods For Bicubic L1 Splines, Priyesh Koyu Rai

Graduate Research Theses & Dissertations

The past two decades have seen the development of L1 splines for interpolation and approximation of geometric data. L1 splines have been shown to preserve shapes better than the conventional L2 splines, especially for data with abrupt changes in the magnitude of spacing. Efficient computation plays an important role in the practical application of L1 splines. This thesis creates new computational methods for constructing bicubic L1 interpolating splines and bicubic L1 spline fits. The bicubic splines in this study are piecewise bicubic polynomials defined on a rectangular grid generated by the tensor product of nodes. We developed a hybrid computational …

Point-Of-Care Assessment At A Free, Out-Of-Hours Orthopedic Clinic, Whitney M. Graves, Zachary K. Winkelmann, Kenneth E. Games

Clinical Practice in Athletic Training

Access to healthcare is a challenge for many Americans living in rural communities. Hospital systems have created programs and developed models to improve access to care. However, documentation of the role of these clinics serving different populations and various types of communities is quite scarce. The purpose of this article is to describe the patient satisfaction and procedures assessed at the point-of-care during a 14-week, out-of-hours free orthopedic clinic in the Southeastern United States. One hundred and twenty-nine patients attended the orthopedic clinic and completed a patient satisfaction survey following their patient encounter. At the end of the 14-week, 89% …

Managing Variability In Assembly Lines, Sumanth Gokapai

All Graduate Theses, Dissertations, and Other Capstone Projects

Every successful company have a diversified product portfolio based on their customer demand. Though products are branded as different variants, versions etc. most of them are similar products with little variations in their features or functions they perform. With the traditional, product centric approach to handle variation, new techniques like Clone and own were implemented in which engineers pick the most similar one available, copy it, make changes to it and present it as a new variant. Even though this approach employs reuse, but the savings occur once and only once. This project discussed how companies can exploit the commonality …

Assessment Of Adaptability Of A Supply Chain Trading Agent’S Strategy: Evolutionary Game Theory Approach, Yoon Sang Lee, Riyaz T. Sikora

Journal of International Technology and Information Management

With the increase in the complexity of supply chain management, the use of intelligent agents for automated trading has gained popularity (Collins, Arunachalam, B, et al. 2006). The performance of supply-chain agents depends on not just the market environment (supply and demand patterns) but also on what types of other agents they are competing with. For designers of such agents it is important to ascertain that their agents are robust and can adapt to changing market and competitive environments. However, to date there has not been any work done that assesses the adaptability of a trading agent’s strategy in the …

Freeform Extrusion Fabrication Of Advanced Ceramics And Ceramic-Based Composites, Wenbin Li

Doctoral Dissertations

"Ceramic On-Demand Extrusion (CODE) is a recently developed freeform extrusion fabrication process for producing dense ceramic components from single and multiple constituents. In this process, aqueous paste of ceramic particles with a very low binder content ( < 1 vol%) is extruded through a moving nozzle to print each layer sequentially. Once one layer is printed, it is surrounded by oil to prevent undesirable water evaporation from the perimeters of the part. The oil level is regulated just below the topmost layer of the part being fabricated. Infrared radiation is then applied to uniformly and partially dry the top layer so that the yield stress of the paste increases to avoid part deformation. By repeating the above steps, the part is printed in a layer-wise fashion, followed by post-processing. Paste extrusion precision of different extrusion mechanisms was compared and analyzed, with an auger extruder determined to be the most suitable paste extruder for the CODE system. A novel fabrication system was developed based on a motion gantry, auger extruders, and peripheral devices. Sample specimens were then produced from 3 mol% yttria stabilized zirconia using this fabrication system, and their properties, including density, flexural strength, Young's modulus, Weibull modulus, fracture toughness, and hardness were measured. The results indicated that superior mechanical properties were achieved by the CODE process among all the additive manufacturing processes. Further development was made on the CODE process to fabricate ceramic components that have external/internal features such as overhangs by using fugitive support material. Finally, ceramic composites with functionally graded materials (FGMs) were fabricated by the CODE process using a dynamic mixing device"--Abstract, page iv.

Quantifying Restoration Costs In The Aftermath Of An Extreme Event Using System Dynamics And Dynamic Mathematical Modeling Approaches, Akhilesh Ojha

Doctoral Dissertations

"Extreme events such as earthquakes, hurricanes, and the like, lead to devastating effects that may render multiple supply chain critical infrastructure elements inoperable. The economic losses caused by extreme events continue well after the emergency response phase has ended and are a key factor in determining the best path for post-disaster restoration. It is essential to develop efficient restoration and disaster management strategies to ameliorate the losses from such events. This dissertation extends the existing knowledge base on disaster management and restoration through the creation of models and tools that identify the relationship between production losses and restoration costs. The …

Biofuel Supply Chain Restructuring -- An Economic Viability And Environmental Sustainability Investigation For Enhancing Second Generation Biofuel Adoption, Rajkamal Kesharwani

Doctoral Dissertations

"Biofuel is a promising clean alternative to fossil fuels. Currently, first generation biofuels are commercially produced by using corn grain as biomass feedstock. However, the use of edible matter of crops, may lead to a competition between food and fuel. Therefore, there is a significant push in both industry and academia to commercialize second generation biofuel manufacturing technology, which uses non-edible matter from crops. Most research focuses on individual manufacturing processes for producing second generation biofuel, but the economic and environmental impacts of a large-scale adoption of second generation biofuel manufacturing have been less widely reported.

This work investigates the …

Application Of Computational Intelligence To Explore And Analyze System Architecture And Design Alternatives, Gene Lesinski

Doctoral Dissertations

"Systems Engineering involves the development or improvement of a system or process from effective need to a final value-added solution. Rapid advances in technology have led to development of sophisticated and complex sensor-enabled, remote, and highly networked cyber-technical systems. These complex modern systems present several challenges for systems engineers including: increased complexity associated with integration and emergent behavior, multiple and competing design metrics, and an expansive design parameter solution space. This research extends the existing knowledge base on multi-objective system design through the creation of a framework to explore and analyze system design alternatives employing computational intelligence. The first research …

Aircraft Interior Design And Satisfaction For Different Activities; A New Approach Toward Understanding Passenger Experience, Golnoosh Torkashvand, Lucas Stephane, Peter Vink

International Journal of Aviation, Aeronautics, and Aerospace

Among airlines and aircraft manufacturers there is much attention for passenger experience. However, there is not much literature on how the activities of passengers can be supported by the aircraft interior. The current study focuses on the need finding and requirements analysis of flight passengers. Twenty-three activities were defined based on retrospective interviews and brainstorming sessions. Respondents were asked to rate their overall perception related to the importance of each of those 23 activities on a Linkert scale, from “not at all important” to “extremely important”. On a separate question they were also asked to rate their overall satisfaction by …