• Structural Engineering and Mechanics
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• v.37 no.5
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• pp.543-560
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• 2011

In structural engineering there are randomness inherently exist on determination of the loads, strength, geometry, and so on, and the manufacturing of the structural members, workmanship etc. Thus, objective and constraint functions of the optimization problem are functions that depend on those randomly natured components. The constraints being the function of the random variables are evaluated by using reliability index or performance measure approaches in the optimization process. In this study, the minimum weight of a space truss is obtained under the uncertainties on the load, material and cross-section areas with harmony search using reliability index and performance measure approaches. Consequently, optimization algorithm produces the same result when both the approaches converge. Performance measure approach, however, is more efficient compare to reliability index approach in terms of the convergence rate and iterations needed.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.23 no.1
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• pp.37-43
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• 2010

In this paper, a reliability-based design optimization is developed for the topology design of linear structures using a performance measure approach. Spatial domain is discretized using three dimensional Reissner-Mindlin plate elements and design variable is taken as the material property of each element. A continuum based adjoint variable method is employed for the efficient computation of sensitivity with respect to the design and random variables. The performance measure approach of RBDO is employed to evaluate the probabilistic constraints. The topology optimizationproblem is formulated to have probabilistic displacement constraints. The uncertainties such as material property and external loads are considered. Numerical examples show that the developed topology optimization method could effectively yield a reliable design, comparing with the other methods such as deterministic, safety factor, and worst case approaches.

• Journal of the Korean Magnetics Society
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• v.23 no.2
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• pp.62-67
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• 2013

This paper introduces an effective methodology for reliability-based design optimization of electromagnetic products, where a performance measure approach is adopted to accurately assess probabilistic constrains. Two design problems consisting of a loudspeaker and a superconducting magnetic energy storage system are considered. The efficiency of the proposed method in evaluating the failure probability of performances during the optimization process are compared with the existing method based on the reliability index approach. Moreover, in term of the accuracy of probability failure values, optimized design results are examined with reference values obtained from the Monte Carlo simulation.

• Korean System Dynamics Review
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• v.8 no.1
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• pp.211-227
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• 2007

Like the saying "You can't manage what you can't measure," performance measurement is considered as one of the most important management activities for the organizations in either private or public sector. Performance measurement, however, has thus far relied too much on financial statements. Realizing the importance of a more scientific and comprehensive performance measurement, many organizations have adopted several different systems in order to objectively estimate their balanced performance results. The Balanced Scorecard (BSC) has become a popular means to measure performance. But the BSC has also received some criticisms. In this paper four limitations in the use of the BSC are discussed : BSCs focus on unidirectional causality, are unable to distinguish delays between actions and their impacts on performance, integrate insufficiently strategy with operational measures, and lead to internal biases. We propose a system dynamics approach with causal loop diagram(CLD) to develop a Dynamic BSC in order to overcome these limitations. The results suggest that developing a BSC with system dynamics is a promising approach to supplement existing BSC frameworks.

• Nuclear Engineering and Technology
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• v.55 no.3
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• pp.861-869
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• 2023

This article proposes a novel approach to measure the performance of Safety-Critical Systems (SCS). Such systems contain multiple processing nodes that communicate with each other is modeled by a Petri nets (PN). The paper uses the PN for the performance evaluation of SCS. A set of ordinary differential equations (ODEs) is derived from the Petri net model that represent the state of the system, and the solutions can be used to measure the system's performance. The proposed method can avoid the state space explosion problem and also introduces new metrics of performance, along with their measurement: deadlock, liveness, stability, boundedness, and steady state. The proposed technique is applied to Shutdown System (SDS) of Nuclear Power Plant (NPP). We obtained 99.887% accuracy of performance measurement, which proves the effectiveness of our approach.

• Journal of Fisheries and Marine Sciences Education
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• v.25 no.2
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• pp.307-320
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• 2013

The purpose of this study is to inquire into present conditions and problems of current performance test and to try to come up with a fundamental alternative of it. Eventually, the studies of performance test so far can be labelled 'prescription' as a prospective approach. On the contrary, the fundamental alternative can be labelled 'understanding' as a retrospective approach. It can be seen that these 'prescription' and 'understanding' do not separate but represent both extreme ends of problem-solving.'Prescription' exists for 'understanding' and the latter can be acquired through the former. Just under this assumption, it can be accepted that 'prescription' as a prospective approach of performance test is an inevitable measure to achieve the purpose of it. However, the ultimate purpose of 'prescription' should proceed to 'understanding' as a retrospective approach.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2009.04a
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• pp.284-287
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• 2009

In order to plan and manage public facilities effectively and efficiently, it is necessary to diagnose the current status of facilities and decide the objective features. Performance measurement is to provide managers with the information they need to measure competitive advantages. This paper discusses public facility performance in order to establish the conceptual framework for performance measurement for public facilities. In order to develop the measurement of public facility performance, a pilot study was conducted with facilities managers of facilities management corporation of public districts in Seoul. We investigated how public facilities management teams have assessed their performance and collected data regarding financial aspects, service aspects, community aspects, and building aspects. There is no standard format to measure facility performance since building sizes, programs, community needs widely differ. However, it is necessary to have a more consistent system to measure facility performance. In addition, each public municipal district needs to empower each district facilities management corporation to participate in managerial decisions and budget control.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.26 no.1
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• pp.37-43
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• 2018

There has been the migration to a performance-based approach in many areas which include transition planning at global, regional and local levels, performance-based navigation and safety management. Achieving continuous success of Air Traffic Management (ATM) systems would require a performance-based approach to raise productivity and efficiency of it through performance measurements and reviews. This paper considers establishment planning of performance measurement and evaluation system for ATM. Related to key performance areas proposed by International Civil Aviation Organization, performance indicators and metrics which could be used to measure and evaluate ATM performance are presented. Also, organizational system and operational planning for efficient operation of ATM are presented.

• International Journal of Automotive Technology
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• v.6 no.1
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• pp.71-77
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• 2005

This paper presents a systematic approach which determines the optimal period to minimize performance measure subject to the schedulability constraints of a real-time control system by formulating the scheduling problem as an optimal problem. The performance measure is derived from the summation of end-to-end response times of processed I/Os scheduled by the static cyclic method. The schedulability constraint is specified in terms of allowable resource utilization. At first, a uniprocessor case is considered and then it is extended to a distributed system connected through a communication link, local-inter network, UN. This approach is applied to the design of an automotive body control system in order to validate the feasibility through a real example. By using the approach, a set of optimal periods can easily be obtained without complex and advanced methods such as branch and bound (B&B) or simulated annealing.

• Korean Management Science Review
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• v.13 no.3
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• pp.173-186
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• 1996

This paper presents an approach for classifying scheduling problems and selecting a heuristic rule to yield best solution in terms of certain performance measure(s). Classification parameters are employed from previous studies on job shop scheduling and project scheduling. Neural network is used for learning and estimating the performance of heuristic rules. In addition, multi-criteria decision making techniques are employed to combine the preferences for each performance measure and heuristic rule for the problems with multi-objectives.