• Proceedings of the Safety Management and Science Conference
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• 2002.11a
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• pp.17-23
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• 2002

Value can be defined as function divided by cost. The ultimate goal of VE (Value Engineering) is to simultaneously reduce cost and to enhance function in given projects. In general, there are eight phases (Selection, Investigation, Speculation, Evaluation, Development. Presentation, Implementation, and Audit) to perform VE. This paper presents analysis of important factors for VE in construction fields using QFD (Quality Function Deployment) technique. QFD was introduced in 1972 to help design supertanker in Mitsubish's shipyards in Kob, Japan and formally defined by the American Supplier Institute in 1987 as a system for translating consumer requirements into appropriate company requirements at every stage, from research, through product design and development, to manufacture, distribution, installation, and marketing, sales and services. The objective of this paper is to provide and analyze the trend on the viewpoint of efficient value engineering of field workers. The data are collected by questionnaires. The samples for this study are chosen from 13 companies in Korea during 2 months (2002. 7 ∼ 2002. 8). The results of this study will play an important role not only for the efficient value engineering but also for preparing of life cycle cost analysis.

• Nuclear Engineering and Technology
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• v.45 no.2
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• pp.179-190
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• 2013

A station blackout experiment called SBO-01 was performed at the ATLAS facility. From the SBO-01 test, the station blackout scenario can be characterized into two typical phases: A first phase characterized by decay heat removal through secondary safety valves until the SG dryouts, and a second phase characterized by an energy release through a blowdown of the primary system after the SG dryouts. During the second phase, some physical phenomena of the change over a pressurizer function, i.e., the pressurizer being full before the POSRV $1^{st}$ opening and then its function being taken by the RV, and the termination of normal natural circulation flow were identified. Finally, a core heatup occurred at a low core water level, although under a significant amount of PZR inventory, whose drainage seemed to be hindered owing to the pressurizer function by the RV. The transient of SBO-01 is well reproduced in the calculation using the MARS code.

• Structural Engineering and Mechanics
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• v.56 no.4
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• pp.549-567
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• 2015

A first-order moment method (FORM) reliability analysis is commonly used for structural stability analysis. It requires the values and partial derivatives of the performance to function with respect to the random variables for the design. These calculations can be cumbersome when the performance functions are implicit. A Gaussian process (GP)-based response surface is adopted in this study to approximate the limit state function. By using a trained GP model, a large number of values and partial derivatives of the performance functions can be obtained for conventional reliability analysis with a FORM, thereby reducing the number of stability analysis calculations. This dynamic renewed knowledge source can provide great assistance in improving the predictive capacity of GP during the iterative process, particularly from the view of machine learning. An iterative algorithm is therefore proposed to improve the precision of GP approximation around the design point by constantly adding new design points to the initial training set. Examples are provided to illustrate the GP-based response surface for both structural and non-structural reliability analyses. The results show that the proposed approach is applicable to structural reliability analyses that involve implicit performance functions and structural response evaluations that entail time-consuming finite element analyses.

• Proceedings of the Korea Information Processing Society Conference
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• 2013.05a
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• pp.972-975
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• 2013

This work developed a code analysis & extraction tool named Function Network Analyzer (FNA) to reduce the cost of software safety analysis. FNA analyzes functions and variables which a given function depends on, and extracts subset of code that can be compiled of automotive operating system, final resulting a well-ordered code sequence that can be compiled for model checking technique. And the experimental result illustrates that FNA can get 100% accurate rate and over 96% reduction rate by testing API functions from trampoline system.

• Journal of the Korea Safety Management & Science
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• v.11 no.1
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• pp.213-222
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• 2009

Two functions are considerable in the record management of policy management system operation. The first one is to prove that shows the conforming status of the management system requirements. The second one is to prove that shows the performing status whether the policy management system is operating effectively to the company. However, the second function requires the high level data analysis techniques, and it is more important for the decision making of the company operations. That is, the second function is more closer than the first function to the top manager's policy management tool. This paper is prepared to offer a study on the desirable record management which is necessary to the scientific decision making process. The scientific decision making requires the analysis of data derived from the reliable records. It is also aimed to enlighten the relations between the reliability of records and the adoption of the results of analysis in associated with the top manager's decision making.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.22 no.51
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• pp.63-72
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• 1999

Many firms have applied flexible manufacturing systems as a means of increasing productivity, profitability, and quality. Therefore, the purpose of this paper is to develop the more efficient justification model through an analytical scoring model with the quantitative factors, flexibility factors, and safety factors under uncertainty. In this paper, the three factors for properly comparing and evaluating of flexible manufacturing systems are presented. Especially, this paper has emphasized the flexibility and safety factor; the one consists of organization assessment, process treatment function, products and products quantity, useful life assesment, and software function, the other presents risk assesment, Y2K problem, safety device analysis, total productive management system, safety management. Finally, a normalized scoring model by the new flexibility and safety factors can be used in real fields for flexible manufacturing systems project selection under uncertainty.

• Journal of Applied Reliability
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• v.15 no.1
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• pp.27-32
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• 2015

Functional safety is part of the overall safety relating to the equipment under control (EUC) and the EUC control system that depends on the correct functioning of the electrical/electronic/programmable electronic (E/E/PE) safety-related systems. Since the complexity of the medical equipment is increased, manufactures have to obtain functional safety as well as basic safety. This study proposes a perspective for applying functional safety to medical equipment. The research is carried out with respect to overall safety life-cycle of functional safety and essential performance of the medical equipment. The relationship between functional safety and essential performance is identified centered on the safety function. The essential performance using E/E/PE systems is defined as a safety function of functional safety. This approach is applied to a ultrasound imaging system as a case study.

• Journal of Auto-vehicle Safety Association
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• v.12 no.3
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• pp.27-33
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• 2020

In this paper, the process of predicting efficient durability performance for vibration durability test of automobile parts using vibration test load on automobile fuel tank is presented. First of all, the common standard load that can be applied to the initial development process of the automobile was used for the fuel tank and the vulnerability of the fuel tank to the vibration fatigue load was identified through frequency response analysis. In addition, the vulnerability of the fuel tank was re-enacted through vibration durability test results, and the scale factor was applied to the standard load. In order to predict the vibration durability performance required for detailed design, vibration fatigue analysis was performed on the developed vehicle with the frequency of vibration severity equivalent to the durability test, and the vulnerability and life span of the fuel tank were identified through the process of applying weights to these selected standard loads, thereby reducing the test time of the development vehicle.

• Journal of the Korean Society of Safety
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• v.16 no.3
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• pp.117-124
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• 2001

This paper introduces m analysis framework and procedure for the support of the cognitive error analysis of emergency tasks in nuclear poler plants. The framework provides a new perspective in the utilization of influencing factors into error prediction. The framework can be characterized by two features. First, influencing factors that affect the occurrence of human error me classified into three groups, i.e., task characteristic factors(TCF), situation factors(SF), and performance assisting factors(PAF). This classification aims to support error prediction from the viewpoint of assessing the adequacy of PAF under given TCF and SF. Second, the assessment of influencing factors is made by each cognitive function. Through this, influencing factors assessment and error prediction can be made in an integrative way according to each cognitive function. In addition, it helps analysts identify vulnerable cognitive functions and error factors, and obtain specific nor reduction strategies. The proposed framework was applied to the error analysis of the bleed and feed operation of nuclear emergency tasks.

• Geomechanics and Engineering
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• v.24 no.4
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• pp.399-406
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• 2021

It is a key issue in the tunnel design to evaluate the stability of the excavation face. Two efficient analytical models in the context of the limit equilibrium method (LEM) and the limit analysis method (LAM) are used to carry out the deterministic calculations of the safety factor. The safety factor obtained by these two models agrees well with that provided by the numerical modelling by FLAC 3D, but consuming less time. A simple probabilistic approach based on the Mote-Carlo Simulation technique which can quickly calculate the probability distribution of the safety factor was used to perform the probabilistic analysis on the tunnel face stability. Both the cumulative probabilistic distribution and the probability density function in terms of the safety factor were obtained. The obtained results show the effectiveness of this probabilistic approach in the tunnel design.