105 research outputs found

    A decision-based perspective for the design of methods for systems design

    Get PDF
    Organization of material, a definition of decision based design, a hierarchy of decision based design, the decision support problem technique, a conceptual model design that can be manufactured and maintained, meta-design, computer-based design, action learning, and the characteristics of decisions are among the topics covered

    A flexible high-density sensor network

    Get PDF
    Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2008.Includes bibliographical references (p. 171-174).This thesis explores building and deploying a scalable electronic sensate skin that was designed as a dense sensor network. Our skin is built from small (1" x 1") rigid circuit boards attached to their neighbors with flexible interconnects. Each boardcontained an embedded processor together with a suite of thirteen sensors, providing dense, multimodal capture of proximate and contact phenomena. In addition to the design of the physical system, this thesis develops protocols for internode communication (both neighbor-neighbor and global), and power-efficient wake-on-phenomena operation. The system was rigorously tested with an array of up to 4x3 nodes subject to a variety of sensor stimuli. Although there were some robustness issues in the final design (particularly in the wired interconnects, which were not the focus of this thesis work), the skin that we developed showed good flexibility for a prototype, ran quickly and efficiently, and could detect and respond to a variety of stimuli.by Behram Farrokh Thomas Mistree.M.Eng

    The design of aircraft using the decision support problem technique

    Get PDF
    The Decision Support Problem Technique for unified design, manufacturing and maintenance is being developed at the Systems Design Laboratory at the University of Houston. This involves the development of a domain-independent method (and the associated software) that can be used to process domain-dependent information and thereby provide support for human judgment. In a computer assisted environment, this support is provided in the form of optimal solutions to Decision Support Problems

    Dependence, independence, and interdependence in world politics

    Get PDF
    Thesis (S.M. and S.B.)--Massachusetts Institute of Technology, Dept. of Political Science, 2006.Includes bibliographical references (p. 150-156).We implement techniques of graph theory to international trade in order to empirically inspect the international system of trade. Examining macro and submacro levels of the international system of trade from 1962-2003, we find the presence of a Scale-Free Network with a Multiscalar Hierarchy. Such structures are resilient to bottom-up economic collapse, but are susceptible to top-down and horizontal economic failures. Our findings are based upon an especially novel approach for examining submacro systems, applying latent community identification analysis to identify trading communities that are not necessarily formalized or institutionalized as trading blocs. Following this analysis, we examine the role of international institutions in the international trade network, specifically considering macro level institutions for stability solutions and examining the effects of joining a trade bloc. We find evidence that supports the intergovernmentalist framework, whereby certain types of trade blocs seem to succeed while others fail, leading to different results in integration and unification.by Dinsha Mistree.S.M.and S.B

    A method for robust design in a coupled decision environment

    Get PDF
    The design of a connected engineered system requires numerous design decisions that influence one another. In a connected system that comprises numerous interacting decisions involving concurrency and hierarchy, accounting for interactions while also managing uncertainties, it is imperative to make robust decisions. In this article, we present a method for robust design using coupled decisions to identify design decisions that are relatively insensitive to uncertainties. To account for the influence among decisions, design decisions are modelled as coupled decisions. They are defined using three criteria: the types of decisions, the strength of interactions and the decision levels. In order to make robust decisions, robust design methods are classified based on sources of uncertainty, namely, Type I (noise factors), Type II (design variables) and Type III (function relationship between design variables and responses). The design of a one-stage reduction gearbox is used as a demonstration example. To illustrate the proposed method for robust design using coupled decisions, we present the simultaneous selection of gear material and gearbox geometry in a coupled decision environment while managing the uncertainties involved in designing gearboxes.Ye

    Simulation reduction using the Taguchi method

    Get PDF
    A large amount of engineering effort is consumed in conducting experiments to obtain information needed for making design decisions. Efficiency in generating such information is the key to meeting market windows, keeping development and manufacturing costs low, and having high-quality products. The principal focus of this project is to develop and implement applications of Taguchi's quality engineering techniques. In particular, we show how these techniques are applied to reduce the number of experiments for trajectory simulation of the LifeSat space vehicle. Orthogonal arrays are used to study many parameters simultaneously with a minimum of time and resources. Taguchi's signal to noise ratio is being employed to measure quality. A compromise Decision Support Problem and Robust Design are applied to demonstrate how quality is designed into a product in the early stages of designing

    Designing Platforms for Customizable Produces and Processes in Markets of Non-Uniform Demand

    Get PDF
    This definitive article is located at http://cer.sagepub.com. Copyright (2007) Sage Publications. DOI: 10.1177/1063293X07079328.The foremost difficulty in making the transition to mass customization is how to offer product variety affordably. The answer to this quandary lies in the successful management of modularity and commonality in the development of products and their production processes. While several platform design techniques have emerged as a means to offer modularity and commonality, they are limited by an inability to handle multiple modes of offering variety for multiple design specifications. The Product Platform Constructal Theory Method (PPCTM) is a technique that enables a designer to develop platforms for customizable products while handling issues of multiple levels of commonality, multiple product specifications, and the inherent trade-offs between platform extent and performance. The method is limited, however, by its inability to handle multiple design objectives and its reliance on the assumption that demand in the market is uniform for each product variant. The authors address these limitations in this paper by infusing the utility-based compromise Decision Support Problem and demand modeling techniques. The authors further augment the PPCTM by extending it use to a new domain: the design of process parameter platforms. The augmented approach is illustrated through a tutorial example: the design of a product and a process parameter platform for the realization of a line of customizable cantilever beams.National Science Foundation (Grants #DMI-0085136 and #DMI-9900259)
    corecore