Browsing by Author "Terpenny, Janis P."

Now showing 1 - 13 of 13
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    A Data Clustering Approach to Support Modular Product Family Design
    Sahin, Asli (Virginia Tech, 2007-09-21)
    Product Platform Planning is an emerging philosophy that calls for the planned development of families of related products. It is markedly different from the traditional product development process and relatively new in engineering design. Product families and platforms can offer a multitude of benefits when applied successfully such as economies of scale from producing larger volumes of the same modules, lower design costs from not having to redesign similar subsystems, and many other advantages arising from the sharing of modules. While advances in this are promising, there still remain significant challenges in designing product families and platforms. This is particularly true for defining the platform components, platform architecture, and significantly different platform and product variants in a systematic manner. Lack of precise definition for platform design assets in terms of relevant customer requirements, distinct differentiations, engineering functions, components, component interfaces, and relations among all, causes a major obstacle for companies to take full advantage of the potential benefits of product platform strategy. The main purpose of this research is to address the above mentioned challenges during the design and development of modular platform-based product families. It focuses on providing answers to a fundamental question, namely, how can a decision support approach from product module definition to the determination of platform alternatives and product variants be integrated into product family design? The method presented in this work emphasizes the incorporation of critical design requirements and specifications for the design of distinctive product modules to create platform concepts and product variants using a data clustering approach. A case application developed in collaboration with a tire manufacturer is used to verify that this research approach is suitable for reducing the complexity of design results by determining design commonalities across multiple design characteristics. The method was found helpful for determining and integrating critical design information (i.e., component dimensions, material properties, modularization driving factors, and functional relations) systematically into the design of product families and platforms. It supported decision-makers in defining distinctive product modules within the families and in determining multiple platform concepts and derivative product variants.
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    An Empirical Investigation of Performance Measurement System Use and Organizational Performance
    Chearskul, Pimsinee (Virginia Tech, 2010-12-15)
    This study contributes to the performance measurement (PM) literature by providing validated measures of PM system use and increased understanding of the impact of PM use on organizational outcomes. The purpose of this study was to articulate and test the relationships between PM system use, organizational learning, and organizational performance by taking into account the effects of PM-related technical factors (namely, PM system maturity and review process (RP) maturity). The concept of PM use was explored through the examination of its underlying processes, as reflected in the literature and two case studies, and a set of practices delineating PM use processes were proposed. Following a scale development approach, a measurement instrument of PM use was developed and validated with empirical data collected through a web-based questionnaire. The results from factor analysis showed the need to revise the initial set of PM use practices into five dimensions: monitoring, problem-finding, problem-solving, validating causal relationships, and validating improvement actions. Additionally, new measures were developed to assess PM and RP maturity factors. The factor analysis results identified four maturity variables: managed RP, optimized RP, PM design and PM implementation. Data from 216 managers participating in RP meetings were used to test the hypothesized relationships via partial least square (PLS). The results provide varying support for the hypotheses defined. First, the results show that monitoring directly impacts organizational performance while problem-finding, problem-solving and validating causal relationships indirectly impact organizational performance through shared vision and team learning. These indirect effects were positive in some cases and negative in others, depending on the direction of the relationship between the use variable and the organizational learning variable. Second, validating improvement actions did not influence organizational outcomes. Finally, the only moderating effect found was managed RP on the relationship between validating causal relationships and financial performance. Because of the weak support for moderating effects, an alternative model was proposed, exploring these maturity variables as antecedents of PM use. The results provided substantial support for this alternate model. Practical implications and areas for future research are also identified and discussed.
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    Harnessing Product Complexity: An Integrative Approach
    Orfi, Nihal Mohamed Sherif (Virginia Tech, 2011-12-12)
    In today's market, companies are faced with pressure to increase variety in product offerings. While increasing variety can help increase market share and sales growth, the costs of doing so can be significant. Ultimately, variety causes complexity in products and processes to soar, which negatively impacts product development, quality, production scheduling, efficiency and more. Product variety is just one common cause of product complexity, a topic that several researchers have tackled with several sources of product complexity now identified. However, even with such progress, product complexity continues to be a theoretical concept, making it difficult for companies to fully implement advances and fully manage product complexity. More and more companies are relying on product family design to handle product variety. Broadly, a product family can be defined as a group of products sharing common elements. The advantages for companies using product family strategies can be significant: they enable efficient derivation of product variants, reduce inventory and handling costs, as well as setup and retooling time. The design challenge however, is to select the product platform to generate a variety of products with minimum deviation from individual requirements. Accordingly, the structure of product families makes designing and evaluating them a challenging process. In order to fully embrace the relationships between variety, product complexity, and product families an understanding of product complexity causes and impacts is essential. This research begins by introducing four main dimensions of product complexity within the context of a generalized definition. Product complexity indicators suitable in product design, development and production are derived. By establishing measurements for the identified indicators and using clustering techniques, a complexity evaluation approach for product family designs is also developed in this research. The evaluation approach is also applied on a component basis, to identify Critical Components that are main sources and contributors of complexity within product families. By standardizing identified Critical Components, product complexity levels and associated costs can be managed. A case application of three product families from a tire manufacturing company is used to verify that this research approach is suitable for evaluating and managing product complexity in product families.
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    The Impact of Simulation-Based Learning in Aircraft Design on Aerospace Student Preparedness for Engineering Practice: A Mixed Methods Approach
    Butler, William M. (Virginia Tech, 2012-05-02)
    It has been said that engineers create that which never was. The university experience is a key component in preparing engineers who support the creation of products and systems that improve the world we live in. The way in which engineers have been trained in universities has changed throughout history in America, moving from an apprentice-like approach to the still-used engineer scientist. Some in industry and academia feel that this model of engineer preparation needs to change in order to better address the complexities of engineering in the 21st century, and help fill a perceived gap between academic preparation and 21st century industrial necessity. A new model for student preparation centering on engineering design called the Live Simulation Based Learning (LSBL) approach is proposed based upon the theories of situated learning, game-based learning, epistemic frames, and accidental competencies. This dissertation discusses the results of a study of the application of LSBL in a two term capstone design class in aerospace engineering aircraft design at Virginia Tech. It includes LSBL's impact on student professional and technical skills in relation to aerospace engineering design practice. Results indicate that the participants found the LSBL experience to be more engaging than the traditional lecture approach and does help students respond and think more like aerospace engineering practicing professionals and thus begin to address the "gap" between academia and industry.
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    Knowledge Representation and Decision Support for Managing Product Obsolescence
    Zheng, Liyu (Virginia Tech, 2011-12-09)
    Fast moving technologies have caused high-tech components to have shortened life cycles, rendering them obsolete quickly. Technology obsolescence creates significant problems for product sectors that use components that are only available for a short period of time for manufacture and maintenance of long field-life systems. Technology obsolescence can make design changes of systems prohibitively expensive, and results in high life cycle costs of systems. While the impact and pervasiveness of obsolescence problems are growing, existing tools and solutions are lacking the needed information and knowledge to do much more than focus on reactively managing obsolescence. Current methods and tools are limited by data conflicts and data inexplicitness, incompleteness, and inconsistency. In response to the drawbacks of current tools, comprehensive knowledge representation that allows information sharing, reuse, and collaboration on obsolescence issues across different organizations is required. Further, decision making tools that can support proactive and strategic obsolescence management are needed. The purpose of this research is to establish an ontology-based knowledge representation scheme for information sharing, reuse, and collaboration on obsolescence issues, and develop decision making models to support proactive and strategic management for overall cost savings in managing obsolescence. Three primary aspects of this research are investigated. First, ontologies for obsolescence knowledge representation are developed in a systematic way with the use of UML diagrams. The generality of the developed ontology is demonstrated with distinct examples. Diminishing Manufacturing Sources and Material Shortages (DMSMS) obsolescence provides the basis for this study. Second, an ontology-based hybrid approach for integrating heterogeneous data resources in existing obsolescence management tools is proposed. Third, decision support models are developed and formalized, and include the obsolescence forecasting method for proactively managing obsolescence, and the mathematical models to determine the optimal design refresh plan to minimize the product life cycle cost for strategic obsolescence management. Finally, the design of the obsolescence management information system is provided along with a system evaluation methodology. Ultimately, the research contributes to the field of knowledge representation as well as design for managing product obsolescence.
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    Mentoring in Engineering Capstone Design Courses: Beliefs and Practices across Disciplines
    Pembridge, James Joseph (Virginia Tech, 2011-10-24)
    Capstone courses provide senior students in engineering with a culminating experiential learning environment, allowing them to apply the knowledge they have developed throughout their undergraduate education. Through anecdotal descriptions of the course, faculty roles have been classified as mentoring. Yet, there have been few systematic and empirical studies that aid in the exploration of the pedagogy and its effectiveness. This study used Kram's model of mentoring as a lens to explore mentoring in the capstone course more systematically. In addition, the learning theories that support project-based learning provided additional understanding into the functions and practices that faculty mentors use to support the students' career and psychosocial development. This study used a sequential mixed methods design to explore the prominent mentoring functions seen in engineering capstone courses, identify the factors related to those mentoring functions, and analyze how the functions are related to perceived learning outcomes. Data collection included a survey of 491 capstone faculty, interviews of 25 survey respondents using the critical decision method, and a survey of 139 students of the interviewees. Quantitative data analysis included the calculation of descriptive statistics for the faculty and student survey item responses as well as a correlation analyses between the items representing mentoring functions and items representing factors of mentoring. Qualitative analysis involved a phenomenological analysis of the data through the coding of interview responses using Kram's mentoring functions as a framework. Findings identified the mentoring practices associated with the career development and psychosocial functions. Additional findings indicated that: 1) challenging assignments, protection, and acceptance-and-confirmation are the dominant functions, 2) faculty background is a potential important factor of mentoring, whereas institutional and department demographics are negligible, and 3) most learning outcomes are associated with challenging assignments, with the exception of ethical understanding, which is developed through coaching, counseling, and role modeling. The findings resulted in the development of a model of capstone mentoring. The model provides a holistic, research-based view of the role that faculty assume when mentoring capstone students. While this study did not systematically prove the model's effect on student learning, positive effects are supported by both student self-reports and learning theories associated with project-based learning. As such, the model can be used as a general guide for the development of pedagogical skills and assessment of teaching practices in project-based capstone courses.
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    Motivation, Usability and Their Interrelationships in a Self-paced Online Learning Environment
    Hu, Ying (Virginia Tech, 2008-08-29)
    This study addressed how usability improvement and motivational design affect learners' motivation and learning performance in a self-paced, online learning environment. The study also investigated the interrelationships between commonly-used usability measures and the motivation measures based on Keller's ARCS model. A two-phase study approach was used. In Phase I, an existing self-paced, online safety training tutorial was used as the baseline. Two alternative designs were developed with improved usability and motivational design based on the ARCS model. In Phase II, the effects of the three interface designs were evaluated through a three-group, generalized randomized block covariate design experiment. A total of seventy-two college students (48 males and 24 females) participated in the usability testing and the online training session using one of the interface designs. Both quantitative and qualitative data were collected and analyzed. Results suggested a significant interface design effect on learner motivation. Learners who used the interface design with both usability improvement and motivational design applied (the UM group) showed the highest level of motivation. In particular, the attention level of the learners in the UM group was significantly higher than the baseline group. Results also indicated motivation differences between genders. Females showed higher scores than males in overall motivation score and in each of the four subscales of attention, relevance, confidence, and satisfaction. No significant difference in learning performance was found among the three treatment groups using different interface designs. None of the usability or motivation measures was a significant predictor of learning performance. Small to medium positive correlations were found between usability satisfaction and three motivation measures, i.e., attention, relevance and satisfaction. Content analysis identified a number of interface design components to be relevant to learners' motivation components: overall appearance, graphics/multimedia, text appearance, page layout, navigation, and paging/scrolling. Implications and design recommendations for online tutorial interface design were discussed. Additional discussion was provided regarding the online learning environment and the integration of usability, motivation, and instructional design and technology.
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    Multi-platform strategy and product family design
    Li, Yanfeng (Virginia Tech, 2010-02-22)
    The application of product families and platforms has gained attention as a promising approach to achieving organizational objectives that provide customers with mass customized products while allowing for significant savings from commonality and reuse strategies. While the single-platform strategy has been widely studied, it may lead to the over expansion of the product family. Designers have to either continuously extend the exiting platform and/or impose strict constraints on new variants in order that there is a fit. On the one hand, continuously “extending“ or “'stretching“ the platform forces the platform to become overburdened and less efficient. On the other hand, imposing strict constraints on new variants will force new variants to compromise performances. In this research, the concept of a multi-platform strategy has been put forward to reduce or eliminate negative effects of the single-platform strategy by coordinating products in a complex product family into two or more platforms to provide enough product variety as well as commonality. The method is developed by adopting and synthesizing various tools and concepts from different research areas, such as design management tools, clustering analysis, statistics, decision analysis, mathematical programming, and engineering costing. The product assets that can be shared by the products are determined through product asset value analysis and redesign effort analysis. The number of platforms is flexibly determined by a hierarchical clustering method based on product similarity/dissimilarity. The product-platform assignment problem is simultaneously solved during the clustering process. A multi-objective optimization model is formulated to determine the design specifications and address the product positioning. A Consistent Aggregate Function Formation Method (CAF2M) is put forward to convert the multi-objective optimization model into a single-dimension problem that can quantitatively balance the tradeoff among the multiple objectives. To evaluate the economic benefit from the platform-based product development, an adjusted Activity-Based Costing approach is utilized to identify the cost savings with the consideration of learning effects. A case application with seven automobile models is utilized to illustrate the proposed multi-platform strategy. The method was found helpful for determining and integrating critical design information into the design of product families and platforms.
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    Ontology Development and Utilization in Product Design
    Chang, Xiaomeng (Virginia Tech, 2008-04-23)
    Currently, computer-based support tools are widely used to facilitate the design process and have the potential to reduce design time, decrease product cost and enhance product quality. PDM (Product Data Management) and PLM (Product Lifecycle Management) are two types of computer-based information systems that have been developed to manage product lifecycle and product related data. While promising, significant limitations still exist, where information required to make decisions may not be available, may be lacking consistency, and may not be expressed in a general way for sharing among systems. Moreover, it is difficult for designers to consider multiple complex technical and economical criteria, relations, and objectives in product design simultaneously. In recent years, ontology-based method is a new and promising approach to manage knowledge in engineering, integrate multiple data resources, and facilitate the consideration of the complex relations among concepts and slots in decision making. The purpose of this research is to explore an ontology-based method to solve the limitations in present computer-based information systems for product design. The field of Design for Manufacturing (DFM) is selected for this study, and three primary aspects are investigated. First, a generalized DFM ontology is proposed and developed. The ontology fulfills the mathematical and logical constraints needed in DFM, as well as ontology editor capabilities to support the continuous improvement of the ontology. Second, the means to guide users to the proper information and integrate heterogeneous data resources is investigated. Third, based on the ontology and information integration, a decision support tool is developed to help designers consider the design problem in a systematic way and make design decisions efficiently based on accurate and comprehensive data. The methods and tools developed in this research are refined using example cases provided by the CFSP (The NSF Center for Friction Stir Processing). This includes cost models and a decision support environment. Errors that may occur in the research are categorized with management methods. An error ontology is built to help root cause analysis of errors and further reduce possible errors in the ontology and decision support tool. An evaluation methodology for the research is also investigated.
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    Preparing for an Academic Job Search
    Ross, Nancy L.; Terpenny, Janis P. (Virginia Tech, 2007-10-04)
    Overview of Academic Job Search Begin by determining personal and institutional "fit" - Develop dossier (CV, cover letter, etc.) based on your chosen career path and institutional type - Look over job ads in your field, making sure to research institutions thoroughly and tailor your materials to a specific institution - Prepare for the academic job interview - Consider how to negotiate if and when the job offer is made
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    Preparing for an Academic Job Search: Application Materials
    Terpenny, Janis P. (Virginia Tech, 2007-10-04)
    Basic Guidelines for Preparing for an Academic Job Search: • Read announcements carefully • Follow instructions closely • Taylor materials to each application • Present a professional package • Keep a status file for each application • Follow-up!
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    Towards the Development, Application, and Evaluation of the Student Success - Oriented System Design Methodology
    Gilbert, Tracee Walker (Virginia Tech, 2010-12-03)
    For over 70 years, researchers have been attempting to unravel the complexities associated with enhancing student success in higher education (Berger & Lyon, 2005). This research has resulted in a better understanding of why some students decide to leave while others persist on to graduation. Despite a sizable body of knowledge that has identified the various factors associated with student success in higher education, little work has been devoted to translating the various theoretical findings into specific strategies that will guide institutions in improving student success outcomes (Tinto, 2005; Tinto & Pusser, 2006). This study, therefore, represents a unique attempt to bridge the gap between research and practice. Specifically, it integrates relevant findings on student success with a growing body of knowledge on system design and performance improvement in order to address the following pressing need: How can institutional leaders in higher education translate theoretical concepts into actionable solutions that will facilitate student success? In order to provide a concrete course of action for institutional leaders to design practices that meaningfully impact student success, this dissertation describes the development, application, and evaluation of a Student Success-Oriented System Design (S2OSD) methodology. The proposed methodology shifts the focus from trying to understand why students leave or stay, which is a well-researched topic in the literature, to examining how to satisfy student needs in ways that will improve student success outcomes. By doing so, this study focuses on assessing, understanding, and satisfying student needs within the context of student success theoretical perspectives. Moreover, this research proposes a methodology that institutions can use to tailor their practices to fit the unique needs of their students (Berger & Lyon, 2005). In summary, this research study was devised to achieve the following goals: • Develop a research process that combines empirical and design methods in order to create, apply, and evaluate a system design methodology; • Develop a guiding framework that provides practitioners with a set of mutually reinforcing principles, which is supported by a methodology designed to meet student needs; • Develop a participatory design method and supporting tools to execute each phase of the methodology; • Develop a performance-based evaluation framework to evaluate the usability of the S2OSD methodology; and • Develop a validated questionnaire to assess engineering student success needs.
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    Usable Accessibility and Haptic User Interface Design Approach
    Kim, Hyung Nam (Virginia Tech, 2010-04-02)
    Many people have visual impairment and make up a population that is increasing each year. Haptic technology is often used to assist members of this population by providing a way of understanding visual information. Although haptic technology is relatively new, it is widely applied across a variety of domains (research and industry). However, a great number of users are dissatisfied with their assistive technology applications. Unfortunately, such dissatisfaction is likely to cause abandonment of the technology devices. In particular, recent research shows that the adoption rate of haptic technology is low. Discontinuing the use of assistive technology devices ultimately results in a waste of time, money, freedom, and reduced function for individuals with disabilities. Of all the factors that lead to abandonment, the most significant is the failure to meet user needs. Whether existing design approaches properly reflect assistive technology user needs should be explored, especially for haptic technology. Existing design approaches have rarely considered the heterogeneous needs of users in the same disability category (i.e., visual disability). Most previous studies on assistive technology have been oriented towards those with total blindness as opposed to those with residual vision (also referred to as low vision). In addition, researchers have paid less attention to older adults with low vision in terms of individual differences in haptic user interface (HUI) needs. There is also some doubt about the applicability of existing design approaches in such design contexts as users with visual disabilities using haptic user interfaces. The aim of this research was to investigate individual differences in users' capabilities in the haptic modality and user needs in HUIs. Particularly, age-related and vision-related individual differences were explored. Another aim was to develop a more accessible design approach applicable to users with visual disabilities and HUIs. The magnitude estimation technique was employed to examine how participants (classified by vision and age) perceive the same objective stimulus, such as haptic perception, differently. Brain plasticity theory was primarily applied to modify the existing design approach, PICTIVE. The effectiveness of modified and original PICTIVE methods was investigated in terms of the frequency of statements, gestures, satisfaction, and time to complete a given design task. HUI user needs were elicited from participants and were analyzed to understand age-related and vision-related individual differences. It was found that the haptic perception of the same objective stimulus was not significantly different between younger and older participants with low vision. The two age groups' overall preferences for a set of HUI user needs were not significantly different. In addition, the haptic perception of the same objective stimulus was not significantly different between sighted participants and those with low vision. The two vision groups' overall preferences on a set of HUI user needs were not significantly different as well. The two design methods resulted in significantly different outcomes. First, participants in the modified PICTIVE method made a significantly higher number of statements. Second, participants in the modified PICTIVE method showed a significantly higher number of gestures. Third, participants in the modified PICTIVE method took significantly more time because they had more design ideas to deliver. Last, both groups were satisfied with a given design method. In short, the research outcomes contribute to the advancement of knowledge and understanding of more "usable" accessibility for users with visual impairment and a more "accessible" participatory design approach to nontraditional user interfaces (i.e., haptic user interfaces) for users with visual impairment.