• Journal of the Korea Safety Management & Science
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• v.14 no.3
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• pp.151-158
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• 2012

The objective of this paper is to propose a method of how to perform risk assessment in the early stage of defense research and development for the acquisition of weapon systems. An advanced method for risk assessment and its associated objective functions are developed first based on the concept of systems engineering. The developed method is then applied to carry out the analysis of alternatives in the trade-off environments. As a case study, the multi-purpose training ship is considered, where it is performed using the notions of technology readiness levels, degrees of difficulty, and technology need values to facilitate design space visualization and decision maker interaction. It is noted that decision makers can benefit from our approach as an improved risk assessment method in the context of multi-criteria decision making.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.14 no.9 s.90
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• pp.819-826
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• 2004

A multi-step optimum strategy for the selection of the locations and directions of strain gauges is proposed in this paper to capture at best the modal response of blade in a series of modes on fan blades. It is consist of three steps including two pass reduction step, genetic algorithm and fine optimization to find the locations-directions of strain gauges. The optimization is based upon the maximum signal-to-noise ratio(SNR) of measured strain values with respect to the inherent system measurement noise, the mispositioning of the gauge in location and gauge failure. Optimal gauge positions for a fan blade is analyzed to prove the effectiveness of the multi-step optimum methodology and to investigate the effects of the considering parameters such as the mispositioning level, the probability of gauge failure, and the number of gauges on the optimal strain gauge position.

• Proceedings of the KIEE Conference
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• 2000.07d
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• pp.3047-3049
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• 2000

The ability to efficiently and robustly recover accurate 3D terrain models from sets of stereoscopic images is important to many civilian and military applications. To develop an effective and practical terrain modeling system. We propose the methods which detect unreliable elevations in digital elevation maps (DEMs). and fuse several DEMs from multiple sources into an accurate and reliable result. This paper focuses on two key factors for generating robust 3D terrain models. the ability to detect unreliable elevation estimates. and to fuse the reliable elevations into a single optimal terrain model. We apply the correlation score methodology to reconstruct accurate DEM for multi-image and show the method is more effective than the conventional averaging method. The photo-realistic simulator is used for generating four simulated images from ground truth DEM and orthoimage.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.21 no.45
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• pp.11-23
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• 1998

This paper presents a more efficient evaluation of alternatives by use of multi-criteria decision making methodlogy under fuzzy intersectional dependence relations. The performance evaluation of most systems such as weapons, enterprise systems etc. are multiple criteria decision making problems. The descriptions and judgements on these systems are usually linguistic and fuzzy. The traditional methods of Analytic Hierarchy Process(AHP) are mainly used in crisp(non-fuzzy) decision applications with a very unbalanced scale of judgements and rank reversal. To overcome these problems, we will propose a new, general decision making method for evaluation models using fuzzy AHP(FAHP) under fuzzy intersectional dependence relations. The T.M.S alternatives A, B and C will be evaluted by the Fuzzy Analytic Hierachy Process (FAHP) based on entropy weight in this study. We will use symmetric triangular fuzzy numbers to indicate the relative strength of the elements in the hierachy and degree of intersection between criteria. These problems are evaluated by five criteria : tactical criteria, technology criteria, maintenance criteria, economy criteria, advacement criteria.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.33 no.2
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• pp.1-8
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• 2010

A vendor selection problem consists of two different kinds of decision making. First one is to choose the best suppliers among all possible suppliers and the next is to allocate the optimal quantities of orders among the selected vendors. In this study, an integration of the technique for order preference by similarity to ideal solution (TOPSIS) and a multi-objective mixed integer programming (MOMIP) is developed to account for all qualitative and quantitative factors which are used to evaluate and choose the best group of vendors and to decide the optimal order quantity for each vendor. A solution methodology for the vendor selection model of multiple-vendor, multiple-item with multiple decision criteria and in respect to finite vendor capacity is presented.

• International Journal of Reliability and Applications
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• v.14 no.1
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• pp.41-54
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• 2013

In this paper, cost analysis is conducted using inter-failure interval under renewable warranty subject to imperfect repair for multi-component system. One way to model the imperfect repair is to use the quasi-renewal process (Wang and Pham 1996). Two alternative quasi-renewal processes were suggested by Park and Pham (2010) using quasi-renewal process; first is an altered quasi-renewal process with random variable parameter and second is a mixed quasi-renewal process considering replacement service and repair service, simultaneously. In this study, we use the altered and mixed quasi-renewal processes and develop the warranty cost model to obtain the expected value of warranty cost and to help company make important decisions regarding the warranty policy. Numerical examples are used to demonstrate the applicability of the methodology derived in the paper.

• The Research Journal of the Costume Culture
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• v.18 no.4
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• pp.703-716
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• 2010

The objective of the study is to analyze expressions of modern fashion in relation to design principle of a science theory, fractal geometry, in order to identify various and multi-layered expressions of fashion. As for methodology, the study interprets principle and characteristics of fractal geometry based on literature review in areas of linguistic, philosophy, sociology and science. The research identifies expressive characteristics of fractal through empirical studies, and applies them to fashion in order to analyze how fractal design principles are reflected in modern fashion in terms of form and significance. Fractal aesthetics pursue order, balance, diversity and openness among disorder and insecurity. They are closely related to the function of modern fashion that works as a multi-layered code, instead of being confined to conventional idea about fashion that "functions" as "wear."

• Journal of Satellite, Information and Communications
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• v.7 no.1
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• pp.102-107
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• 2012

In this paper, we presented interference scenarios and an evaluation methodology for the co-frequency radio interference between a multi-beam mobile satellite communication system and a mobile communication system in 2.1 GHz band. Radio interferences between these systems are calculated using a minimum coupling loss method and an assesment for minimum separation distances was conducted for coexistence of a mobile satellite system and a mobile system in the same geographical area.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2005.11a
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• pp.147-156
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• 2005

In developing the ubiquitous computing technology based services (ubiquitous services), evaluating how much value of those services is created or added is very crucial. The efforts to evaluate the ubiquitous services have been progressed in two perspectives - technical perspective and behavioral perspective. Despite its importance, however, the methodologies which integrate both perspectives have been still very rare. Hence, this paper aims perspectives have been still very rare. Hence, this paper aims to propose an integrated ubiquitous service valuation methodology based on the multi-layered approach including technical and behavioral perspectives. To do so, we conducted a case study with currently existing location based service (LBS) such as navigation systems by conducting focus group interview (FGI) and field survey.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2008.05a
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• pp.142-145
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• 2008

Process simulation requires accurate and reliable data for a wide variety of material properties, ranging from thermal conductivity to flow stress curves. Traditionally such data are gathered from experimental sources, which has significant disadvantages in that not all of the required data is readily available, it may be from various sources that are themselves inconsistent, measurement of high temperature properties is expensive, and furthermore the properties can be sensitive to microstructure as well as to alloy composition. This article describes the development of a new multi-platform software program called JMatPro, which is based on CALPHAD methodology, for calculating the properties and behavior of multi-component alloys. A feature of the JMatPro is that the calculations are based on sound physical principles rather than purely statistical methods. Thus, many of the shortcomings of methods such as regression analysis can be overcome.