124,107 research outputs found

    Improving Organizations by Replacing the "Mechanical" Model with the "Organic" one

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    Organizations are currently viewed as artificial structures. However, in our opinion, organizations seem to match a biological structure much better. This paper explores this new approach with some interesting conclusions and results: organizations aim at perpetual exis-tence and continuous adaptation. We advance the ideas of organizational "instincts", organizational pathology and organizational optimization using genetic algorithms. In competitive markets, organizations are in a natural selection process, which actually is part of a natural genetic algorithm. This process may be simulated in an artificial multidisciplinary optimization environment, based on minimizing a Total Costs and Risks objective function. Unlike the gradient optimization methods, the genetic algorithms may be applied to such problems with thousands of degrees of freedom. This opens the way to the organizational structure optimization through genetic algorithms.organization, genetic algorithms, multidisciplinary optimization, organizational analysis, organizational structure

    Integrated multidisciplinary design optimization of rotorcraft

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    The NASA/Army research plan for developing the logic elements for helicopter rotor design optimization by integrating appropriate disciplines and accounting for important interactions among the disciplines is discussed. The optimization formulation is described in terms of the objective function, design variables, and constraints. The analysis aspects are discussed, and an initial effort at defining the interdisciplinary coupling is summarized. Results are presented on the achievements made in the rotor dynamic optimization for vibration reduction, rotor structural optimization for minimum weight, and integrated aerodynamic load/dynamics optimization for minimum vibration and weight

    Aircraft design optimization with multidisciplinary performance criteria

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    The method described here for aircraft design optimization with dynamic response considerations provides an inexpensive means of integrating dynamics into aircraft preliminary design. By defining a dynamic performance index that can be added to a conventional objective function, a designer can investigate the trade-off between performance and handling (as measured by the vehicle's unforced response). The procedure is formulated to permit the use of control system gains as design variables, but does not require full-state feedback. The examples discussed here show how such an approach can lead to significant improvements in the design as compared with the more common sequential design of system and control law

    MULTIDISCIPLINARY OPTIMIZATION IN URBAN SERVICES MANAGEMENT

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    Optimization methods may be applied to the services operations management. A comprehensive objective function (a cost-function to be minimized) leads to a multidisciplinary optimization, considering all aspects of a services business unit. However, this introduces a very large number of variables (examples with tens of thousands of variables are presented), making classical optimization methods inadequate. The paper introduces the use of genetic algorithms and illustrates it in one example: leisure services. Multidisciplinary optimizations may play a crucial role in the success of any services business, and genetic algorithms are the most adequate computation resource in this type of optimizations.optimization, urban services management, total cost, risk, leisure services

    Multidisciplinary optimization applied to a transport aircraft

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    Decomposition of a large optimization problem into several smaller subproblems has been proposed as an approach to making large-scale optimization problems tractable. To date, the characteristics of this approach have been tested on problems of limited complexity. The objective of the effort is to demonstrate the application of this multilevel optimization method on a large-scale design study using analytical models comparable to those currently being used in the aircraft industry. The purpose of the design study which is underway to provide this demonstration is to generate a wing design for a transport aircraft which will perform a specified mission with minimum block fuel. A definition of the problem; a discussion of the multilevel composition which is used for an aircraft wing; descriptions of analysis and optimization procedures used at each level; and numerical results obtained to date are included. Computational times required to perform various steps in the process are also given. Finally, a summary of the current status and plans for continuation of this development effort are given

    Validation of the procedures

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    Validation strategies are described for procedures aimed at improving the rotor blade design process through a multidisciplinary optimization approach. Validation of the basic rotor environment prediction tools and the overall rotor design are discussed

    The potential application of the blackboard model of problem solving to multidisciplinary design

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    The potential application of the blackboard model of problem solving to multidisciplinary design is discussed. Multidisciplinary design problems are complex, poorly structured, and lack a predetermined decision path from the initial starting point to the final solution. The final solution is achieved using data from different engineering disciplines. Ideally, for the final solution to be the optimum solution, there must be a significant amount of communication among the different disciplines plus intradisciplinary and interdisciplinary optimization. In reality, this is not what happens in today's sequential approach to multidisciplinary design. Therefore it is highly unlikely that the final solution is the true optimum solution from an interdisciplinary optimization standpoint. A multilevel decomposition approach is suggested as a technique to overcome the problems associated with the sequential approach, but no tool currently exists with which to fully implement this technique. A system based on the blackboard model of problem solving appears to be an ideal tool for implementing this technique because it offers an incremental problem solving approach that requires no a priori determined reasoning path. Thus it has the potential of finding a more optimum solution for the multidisciplinary design problems found in today's aerospace industries

    An initiative in multidisciplinary optimization of rotorcraft

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    Described is a joint NASA/Army initiative at the Langley Research Center to develop optimization procedures aimed at improving the rotor blade design process by integrating appropriate disciplines and accounting for important interactions among the disciplines. The activity is being guided by a Steering Committee made up of key NASA and Army researchers and managers. The committee, which has been named IRASC (Integrated Rotorcraft Analysis Steering Committee), has defined two principal foci for the activity: a white paper which sets forth the goals and plans of the effort; and a rotor design project which will validate the basic constituents, as well as the overall design methodology for multidisciplinary optimization. The optimization formulation is described in terms of the objective function, design variables, and constraints. Additionally, some of the analysis aspects are discussed and an initial attempt at defining the interdisciplinary couplings is summarized. At this writing, some significant progress has been made, principally in the areas of single discipline optimization. Results are given which represent accomplishments in rotor aerodynamic performance optimization for minimum hover horsepower, rotor dynamic optimization for vibration reduction, and rotor structural optimization for minimum weight

    Multidisciplinary design optimization: An emerging new engineering discipline

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    This paper defines the Multidisciplinary Design Optimization (MDO) as a new field of research endeavor and as an aid in the design of engineering systems. It examines the MDO conceptual components in relation to each other and defines their functions
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