Department of Electrical and Computer Engineering

Learning to diagnose by doing

Jayant Kalagnanam et al. — Wed, 23 May 2012 13:11:52 PDT

Abstract: "This paper is a study on the process of evolution of a novice to an expert in a diagnostic context. In this paper, we have chosen an abstract example of a diagnostic problem. The results in this article are based on a longitudinal study of a single subject. The empirical base is a protocol of the subject as he solved this problem until he mastered the most sophisticated strategy. Based on an analysis of the protocol, we have identified four different strategies that were used by the subject to solve the given set of problems. These strategies vary in their efficiency of diagnosis and in their modes of reasoniing. We also identify the different operators that were used by the subject to transform one strategy into a more efficient one. The learning process has been implemented as a computer simulation. Finally, we discuss the hypotheses that are suggested by this experiment and the implications of our observations."

Quality innovation in design and manufacturing : an economic model

Hubert Vasseur et al. — Wed, 23 May 2012 13:11:37 PDT

Abstract: "Due to several possible production modes, an industrial output may have different quality levels. Production processes and quality assurance plans are chosen and adjusted, generally as a lagged reaction to customers' input and competitors' strategy. Different techniques based on cost benefit analysis have existed to assess beforehand the overall benefits to society of such decisions; however, these techniques do not necessarily provide any insight as to the resulting influence on corporate profits. This paper presents a context in which social and corporate optimum can be compared from an engineering perspective. The reasons for a manufacturer to improve the quality of its products are studied under several market conditions. The incentive is the strongest in a competitive environment where the benefits of quality innovation are twofold: quality innovation increases consumers' demand and allows the manufacturer to keep more substantial profit margins."

Quantifying industrial quality in economic models

Hubert Vasseur et al. — Wed, 23 May 2012 13:11:24 PDT

Abstract: "Due to several possible production modes, an industrial output may have different quality levels. We present a method to select the optimum production mode, based on cost and quality considerations. We introduce the idea of a Pareto efficient quality level that we relate with the concept of value loss. The traditional tradeoff cost versus quality is studied in a formalism that allows industrial quality to be treated as an economic variable. For validation and forecasting purposes, the effects of quality differences are studied in various contexts: perfect competitive market, monopoly, and oligopoly situation. In each case, consequences are drawn in terms of prices and profits. Depending on the economic situation considered, failure to produce at the Pareto efficient quality level is shown to have different detrimental effects."

An MINLP process synthesizer for a sequential modular simulator

U. M. Diwekar et al. — Wed, 23 May 2012 13:11:12 PDT

Abstract: "This paper deals with the development of an MINLP synthesizer for sequential modular simulators. Firstly, a variant of the OA/ER/AP algorithm for MINLP problems is presented that makes use of Benders cuts in previous or subsequent iterations. An automatic process synthesis environment is then described for the ASPEN simulator using this algorithm, with the decomposition strategy by Kocis and Grossman (1989). The application of this new capability is demonstrated with several examples including the structural optimization of the hydrodealkylation of tolune process."

Industrial quality : a missing economic variable

Hubert Vasseur et al. — Wed, 23 May 2012 13:11:00 PDT

Abstract: "Industrial quality is presented as a direct result of manufacturing practices (e.g. tolerance allocation, process selection, inspection procedures). A quality indicator is developed that allows for the computation of a function representing the cost of an industrial product versus its quality level. This cost function is then incorporated in an economic model that estimates the consumer's demand for the product as a function of both its price and quality level. The profit maximizing values of the price and quality level are derived, and in turn indicate the optimum production mode."

Decision making in design for quality

Hubert Vasseur et al. — Wed, 23 May 2012 13:10:48 PDT

Abstract: "We consider the design issues of characterizing and appropriately choosing the quality of a product for maximum customer satisfaction and maximum corporate profit. We assume that the basic design configuration of a product is determined and that the designer must select the product quality by imposing statistical tolerances (manufacturing accuracy specifications) and choosing appropriate manufacturing processes. We claim that these design considerations, although often neglected, impact the behavior, cost, and even marketability of the product. A design concept without these specifications is incomplete because i) its feasibility is questionable ii) its cost of production is undetermined iii) its performance is unknown.The design process is seen here as an exploratory activity constrained by the manufacturing systems available. In particular, we provide a decision-analytic methodology to reason about the quality of product and the influences on profit resulting in a specification of manufacturing process and machine accuracy to match customer demands. The method has been implemented and applied to the design of a simple three component assembly to illustrate its capabilities."

Analysis of integrated voice and data communication network

Lih-Hsing Chang — Wed, 23 May 2012 13:10:36 PDT

A Knowledge Based System Approach to Predict

J. Suni et al. — Wed, 23 May 2012 12:45:06 PDT

Defect prediction, using the knowledge based system approach, is being developed for the case of longitudinal surface cracks. Knowledge about longitudinal cracking is in the form of databases, mathematical models and qualitative information. Much of this comes from the technical literature on related topics, but is supplemented by plant experience, as well. Knowledge based systems provide the facility for handling such types of knowledge, with control particulars left up to the system builder The current implementation is forward chaining and uses the OPS5 inference engine. The system involves the use of all three types of knowledge, but more mathematical models are being sought.

Requirements analysis for information web (IWEB) : an issue-based, information modeling and management environment for software engineering

Robert Coyne et al. — Wed, 09 May 2012 14:03:57 PDT

Abstract: "The IWEB project is focused on creating an improved management environment for team-based software engineering. This includes support for information structuring and communication during a project as well as maintenance and (re)use of project histories across projects. With this in mind, we are experimenting primarily within the context of the project based software engineering courses 15-413 (the basic course offered each Fall semester) and 15-499 (the advanced course offered each Spring) in the School of Computer Science at Carnegie Mellon University. These courses reflect much that is typical of the 'state of the art' and outstanding issues in the current practice of software engineering. They are large (60 students, teaching assistants and instructors in F'93), require the delivery of a running prototype to a real client, and generally attempt to provide, as realistic as possible, software engineering experience to the participants. This document summarizes the requirements for IWEB based on general case studies of engineering work conducted at the EDRC (and elsewhere) and integrates the experience of the authors as students, teaching assistants and instructors in the courses. We accumulated insights and studied information problems and communication breakdowns from three different perspectives: direct observation, student surveys, and quantitative analysis of project communication records and documents. IWEB incorporates ideas from previous issue-based support systems, such as gIBIS (graphical issue-based information system), and intends to build on top of a more general information modeling perspective by adapting a prototype of the n-dim (n-dimensional information modeling) environment. To capture the functional requirements for IWEB we employ a development method structured around the viewpoint of prospective users of the system (actors) and that produces descriptions of all of the transactions these actors will engage in with the system as use cases. Though we are focusing on software engineering for the initial prototype of IWEB, we expect that it will have broader application within any team- based or collaborative work context."

Very rapid prototyping of wearable computers : a case study of custom versus off-the-shelf design methodologies

Smailagic — Wed, 09 May 2012 14:03:48 PDT

Abstract: "The Wearable Computer Project is a testbed integrating research on rapid design and prototyping. Based on representative examples from six generations of wearable computers, the paper focuses on the differences in rapid prototyping using custom design versus off-the-shelf components. The attributes characterizing these two design styles are defined and illustrated by experimental measurements. The off-the-shelf approach required ten times the overhead, 30% more cost, fifty times the storage resources, 20% more effort, five times more power, but 30% less effort to port software than the embedded approach."

Microstructural investigation of SDM microcasting droplets

C. M. Bishop — Wed, 09 May 2012 14:03:40 PDT

Abstract: "Our research efforts seek to improve the fundamental understanding of the deformation and solidification of metal droplets, which is applicable to Shape Deposition Manufacturing (SDM) Microcasting. Research includes direct numerical simulations of the process and a variety of experimental techniques to validate the numerical models. This report details our use of microstructural characterization as a validation technique. Individual microcasting droplets are cross-sectioned, etched and examined by optical microscope. Energy dispersive x-ray analysis (EDX) is also used to identify material composition in samples that involve dissimilar materials. Using these techniques we are able to gain a qualitative understanding of the cooling process through variations in microstructure, and quantitative estimates of both cooling rates (through dendrite arm spacing measurements) and substrate remelting (through structure change in the substrate). This information is being compared with numerical results to confirm the accuracy of our numerical models."

Shape deposition manufacturing with microcasting

Cristina H. Amon — Wed, 09 May 2012 14:03:31 PDT

Abstract: "This paper provides a brief overview of an emerging application for solid freeform fabrication known as Shape Deposition Manufacturing (SDM) with Microcasting. The SDM microcasting process has been used to manufacture complex geometric shapes from CAD models. This novel manufacturing process is briefly described, and a sample artifact is shown. Our current research is described, involving the thermal behavior of the process, the bonding of deposited layers, and droplet fluid dynamics. We have gained significant understanding of the relationship between process parameters and the final quality of artifacts created by microcasting, and continue to investigate the effect of process parameters to develop a systematic representation of the parameter design space; current efforts are directed towards improving the numerical simulations to more accurately predict and control the microcasting process."

Orthogonal defect classification applied to a multidisciplinary design

Alex Amezquita et al. — Wed, 09 May 2012 14:03:22 PDT

Abstract: "Orthogonal Defect Classification (ODC) is a tool used in software engineering to manage, control, and improve a design process. ODC enables administration and designers to gain feedback on the design during the development process. This paper provides a basis for expanding ODC from a single discipline (i.e. software) to a multiple discipline environment (i.e. software, hardware, and mechanical). This paper describes ODC and the multiple discipline environment; defines the structure of the attributes used in the extended implementation of ODC; provides the taxonomy for each attribute with definitions and examples; and presents preliminary data from two complete product design cycles."

Equations aren't enough : informal modeling in design

Eswaran Subrahmanian et al. — Wed, 09 May 2012 14:03:12 PDT

Abstract: "Arguing that design is a social process, we expand the meaning of modeling and analysis to include all activities facilitating continual refinement and criticism of the design requirements, process and solutions. We do not assume any a priori methods for modeling or analysis; rather, we provide a framework and an approach to study designers and give them whatever modeling and analysis capabilities they choose. Our approach is the basis for a support tool, n-dim, currently under development."

The ecological impact of batteries

Colleen Dillon et al. — Wed, 09 May 2012 14:03:02 PDT

Abstract: "There is still much that needs to be known about the specific problems that are presented to the ecosystem as a result of battery disposal in landfills. This report explores the various effects that the toxic metals in batteries (specifically mercury, cadmium, lead, nickel, zinc, and lithium) have on the entire ecosystem, detailing the damages that these metals may cause to the human body. The most predominant effects that these metals have on humans include neurological damage, kidney damage, birth defects, and cancer. Next, lithium-based battery technology is explored, highlighting the development of these batteries and the various applications they are used for. An assessment of the risks that lithium battery disposal poses to the environment is also performed, using estimated lithium battery consumption information. The environmental policies of the United States, Europe and industry are described as well."

Documenting the current pollution patterns on the Cathedral of Learning

Eric Dieckman et al. — Wed, 09 May 2012 14:02:54 PDT

Abstract: "During the summer of 1994, as part of the Careers in Science and Applied Technology (CAST) program, seven high school students and an elementary school teacher worked together to document the current pollution patterns on the Cathedral of Learning on the University of Pittsburgh campus. This report presents the results of their research in which they used surveying, sketching and photography to document the pollution patterns. They also recorded their data in an AutoCAD model of the Cathedral. This project was part of a larger study being done for the National Park Service on Acid Deposition on Limestone Buildings. The project was also sponsored by the Engineering Design Research Center under the Green Design initiative."

Asynchronous-teams based collision avoidance in PAWS

Ju-Hsien Kao et al. — Wed, 09 May 2012 14:02:45 PDT

Abstract: "This paper describes the Asynchronous Teams (A-Teams) based collision avoidance algorithm in the Programmable Automated Welding System's Off-line Programming (PAWS-OLP) system. A-teams organize different software or operators in an asynchronous way so that a variety of simple or sophisticated agents can cooperate to produce better results in a global sense. Joint limits, minimal joint motion, smooth joint motion, and task quality are also considered in this collision avoidance algorithm. An example, using a six degree of freedom robot PUMA 762, is investigated."

An experiment in supporting geographically distributed engineering design

Bill Chan et al. — Wed, 09 May 2012 14:02:35 PDT

Abstract: "Many of the research projects currently underway and being considered for the future at the Engineering Design Research Center involve geographically distributed project teams. The extent of interaction within this distributed team may vary from that of distant vendors who are not members of the project team but whose performance and synchronization with the project are vital -- to members of the design team actively collaborating on a project to the extent of discussing detailed design, systems interface issues, and joint authoring of documentation. This report presents issues encountered in creating and operating an infrastructure to support such a distributed design team. Our approach is to identify requirements for supporting collaboration in an engineering design project from the perspective of types of information used and interactions between participants involved in the process, examining the set of available tools from this framework, as well as the changes in the design process necessitated due to constraints imposed by geographical remoteness of team members and limitations of existing technology. Recommendations are made for future engineering design projects considering the use of computer supported collaboration tools."

Strictly class-based modeling considered harmful

Birgitte Krogh et al. — Wed, 09 May 2012 14:02:27 PDT

Abstract: "Many object-oriented methods have assumed class-based approaches, without considering prototype-based ones. Some authors, while admitting prototypes as a useful concept, only envision their application in early phases of systems development. Others consider only the use of the prototype concept in programming environments and not with respect to the whole systems development process. We propose that these omissions are neither necessary nor useful and often can be harmful, in that methods grounded in purely class-based assumptions do not reflect the nature of problems inherent in modeling. In this paper, we argue, using the principle of limited reduction, that both class-based and prototype-based approaches should be used in object-oriented methods, respectively for controlling complexity, and capturing enough detail for evolution."

An accounting of the materials flows for lithium

Matt Stone et al. — Wed, 09 May 2012 14:02:18 PDT