• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.5
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• pp.89-94
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• 2003

Rolling stock structures such as bogie frame and car body play an important role for the support of vehicle leading. In general, more than 25 years' durability is needed for them. A lot of study has been carried out for the prediction of the fatigue life of the bogie frame and car body in experimental and theoretical domains. One of the new methods is a probabilistic fatigue lift evaluation. The objective of this paper is to estimate the fatigue lift of the bogie frame of an electric car, which was developed by the Korea Railroad Research Institute (KRRI). We used two approaches. In the first approach probabilistic distribution of S-N curve and limit state function of the equivalent stress of the measured stress spectra are used. In the second approach, limit state function is also used. And load spectra measured by strain gauges are approximated by the two-parameter Weibull distribution. Other probabilistic variables are represented by log-normal and normal distributions. Finally, reliability index and structural integrity of the bogie frame are estimated.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.19 no.4
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• pp.336-344
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• 2007

A method is developed to evaluate partial safety factors for armor units, by which uncertainties of random variables in reliability function as well as wave height distribution with service periods could take into account straightforwardly. It is found that partial safety factors for resistance and wave height are correctly increased with improving target levels on failure of coastal structures at the same return and service periods. Therefore, it nay be possible to determine design variables through the same processes as those of deterministic method by using the partial safety factors for resistance and wave height evaluated in this paper, since uncertainties of random variables and the effects of service periods and target probability failure are directly considered in the processes of evaluation of partial safety factors.

• IE interfaces
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• v.9 no.3
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• pp.81-91
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• 1996

현대의 전기 통신망은 통신서비스의 단순한 제공 수단에서 국가적인 사회간접자본으로 그 역할이 변화되고 있다. 이와 같은 통신망의 역할 변화와 함께 초고속화, 집중화 되는 통신망의 안정성에 대한 체계적인 연구의 중요성은 매우 중요한 문제이다. 통신망의 안정성은 시스템 설계의 신뢰성 확보, 재난에 대한 예방 대책, 재난 관리 시스템 운용, 재해 복구 대책, 사업자간 제휴 등으로 예방 및 대처가 부분적으로 가능하지만 망 사업자의 입장에서는 가능한 자원을 최적으로 활용하여 외부 재해나 내부 장애에도 강건한 구조의 통신망으로 계획하고 설계함이 가장 기초적인 안정성 대책이 된다. 본 논문은 이와 같은 통신망의 안정성을 체계적으로 계획하고 이에 맞게 통신망을 설계하는 일관된 과정(Integrated Network Design Process)을 위한 통신망 안정성에 대한 계층적 모형을 설명하고, 유사동기식 전송 기술에서 최근의 동기식 전송 기술로 대체되고, 향후 ATM 전달 모드로의 진화되는 추세를 감안할 때 필수적인 새로운 통신망 안정성 모형을 제시한다. 특히 기존에는 Logical Layer와 Transmission System Layer로 나누어 계획되고 설계되는 일련의 과정들이 동기식 장비들의 개선된 interworking과 ATM의 유연한 망구조의 장점 때문에 통합되어 계획/설계되어야 하는 필요성과 장단점을 설명하고 최근의 최적화 기술은 이와 같은 통합된 설계 모형에도 효율적이 해결 방안을 제공함을 보여준다. 이와 같은 제시된 통합 방법론/모형과 함께 한국통신의 기간 전송망의 계획과 설계에 사용된 사례를 제시하고, 향후 국가적으로 중요한 관심 사항인 초고속통신망/BISDN의 구축에 효율적으로 응용되기 위한 추가적인 연구 주제와 기대성과를 논의한다.

• Asia Marketing Journal
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• v.3 no.2
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• pp.41-68
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• 2001

최근 20년간 마케팅을 비롯하여 사회과학 전반에 걸쳐 기업이론에 관하여 새로운 패러다임으로 각광을 받아온 신제도학파 접근방법은 이익극대화를 기업의 중심적 행동으로 가정하고 있는 신고전학파의 맹점을 극복하여 조직문제를 포괄적으로 다룰 수 있음을 보여주고 있다. 이 이론은 한정된 합리성, 기회주의, 자산 특수성, 지배구조, 신뢰 및 협동 등의 핵심적 개념들이 동태적 환경 하에서 활동하고 있는 기업의 경제적 행동을 분석하고 이해하는데 크게 기여하였음이 입증되고 있다. 이것은 다수의 실증적 문헌들에서 엿볼 수 있다. 그러나 신제도학파의 이론적 틀은 두 가지 면에서 주요 결점을 안고 있다. 그 하나는 이론의 정당성을 입증하기 위한 실증적 연구결과물을 무수하게 찾아볼 수 있으나, 대부분이 연구의 타당성이 결여되어 있다는 점이고, 또 하나의 결정적 결함은 신고전학파와 마찬가지로 비교정태적 접근방법을 택함으로써 역사적 관점이 도외시되고 기업의 전략개발과 구조적 변동을 이해하는데 필수적인 조직과 기술간의 동태적 상호작용의 중요성을 간과하고 있다는 점이다. 이에 따라 본고에서는 국제교역 이론가들이 제시한 기업 특유의 경쟁우위에 관한 착상과 그러한 우위가 기업 내외의 네트워크 형성을 포함하여 결집된 조직역량에서 도출된다는 견해를 거래비용이론에 접목시킴으로써 기업의 성격과 그 성장방식을 보다 설득력있게 이해할 수 있으리라는 관점을 제시하려 하였다. 이와 같이 거래비용이론과 진화론을 결합하면 신제도학파 기업이론의 결점이 보완되고 이론의 발전이 한 단계 진일보할 것으로 기대된다. 특히 마케팅 연구자들이 거래비용이론의 경우와 마찬가지로 본고에서 제시한 통합이론에 대해서도 실증적 연구를 행하면 이론개발에 크게 기여할 것으로 생각된다.

• Journal of the Korea institute for structural maintenance and inspection
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• v.12 no.2
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• pp.193-200
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• 2008

Cohesive and frictional materials such as concrete and soil are pressure dependent. In general, failure criterion for such materials inclined with respect to positive hydrostatic axis in Haigh-Westergaard stress space. Consequently, inelastic volumetric strain always positive with associated flow rule. In this study, to overcome this shortcoming, non-associated flow rule which controls volumetric component of plastic flow is adopted. Numerical analysis based on a constitutive model using nonuniform hardening plasticity with five parameter failure criterion and non-associated flow rule has conducted to predict concrete behavior under multi-axial stress state and verified with experimental result.

• The Journal of Information Systems
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• v.24 no.2
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• pp.209-240
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• 2015

Purpose This study investigates the relationships between various attributes of smart banking (convenience, security, convergence, and economy), user features (familiarity and innovativeness), perceived usefulness, trust, satisfaction, and continuance intentions and provides a comparison of Google's Android OS and Apple's iOS. Design/methodology/approach We considered a sample of 245 respondents and used structural equation modeling to analyze the data. Findings The results indicate that convergence and familiarity significantly affected perceived usefulness and that security and economy significantly affected perceived trust in smart banking services. The relationships of security, economy, and innovativeness to perceived usefulness and those of convenience and familiarity to perceived trust were stronger for the Android OS than for iOS. The study contributes by proposing an integrated framework and providing a comparison between the Android OS and iOS in the context of smart banking.

• Journal of Digital Convergence
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• v.10 no.10
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• pp.237-245
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• 2012

This study deals with the influencing factors for satisfaction and the emotional value perception of mobile voucher service user. Thus researcher examined a structural equation modeling methodology of the paths within word of mouth, satisfaction, and other exogenous variables (economic/rational value, trust, joyfulness, innovativeness). As a result of this study, First, it was confirmed that the emotional value, and innovativeness affected user's trust for coupon service and joyfulness for using mobile voucher. Second, it was confirmed that trust and joyfulness affected user's satisfaction and word of mouth activities. Therefore, in cases of utilizing the emotional appeal of mobile voucher as part of a marketing tool, corporate can maximize efficiency by using their mobile voucher service & event from the point of view of customer's satisfaction & voluntary word of mouth. Researcher's consideration is that this paper's theoretical and practical contribution point is the propose of the one of the post adoption model with the quantitative study of the mobile voucher service user's emotional perception in the initial development stages of high-tech industry.

• Journal of Digital Convergence
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• v.15 no.2
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• pp.199-206
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• 2017

Embedded control system is widely spreaded and used in various fields including military defence, aviation, medical, etc. due to extended use of smart phones, connected car, IoT. Increasing examples are introduced where embedded control system that perform their unique role such as smart phone and network system organically configure to create new system. According to this trend, organic interface and reliability of each embedded control system are becoming important evaluation factors. The purpose of this paper is to develop quality evaluation criteria method for automobile embedded system, among the fields that use embedded control systems. In order to satisfy high quality level requirements of automobile embedded control system, we surveyed latest trend of automobile embedded control system, analyzed structure and application technology of embedded control system, to establish quality evaluation criteria and method for automobile embedded control system by referring international standard for software (ISO/IEC 9126), and international standard for electric & electronic products (ISO 26262).

• Journal of the Korean Geotechnical Society
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• v.22 no.6
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• pp.51-61
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• 2006

An efficient and accurate hybrid reliability analysis method is proposed in this paper to quantify the risk of an axially loaded single pile considering pile-soil interaction behavior and uncertainties in various design variables. The proposed method intelligently integrates the concepts of the response surface method, the finite difference method, the first-order reliability method, and the iterative linear interpolation scheme. The load transfer method is incorporated into the finite difference method for the deterministic analysis of a single pile-soil system. The uncertainties associated with load conditions, material and section properties of a pile and soil properties are explicitly considered. The risk corresponding to both serviceability limit state and strength limit state of the pile and soil is estimated. Applicability, accuracy and efficiency of the proposed method in the safety assessment of a realistic pile-soil system subjected to axial loads are verified by comparing it with the results of the Monte Carlo simulation technique.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.25 no.5
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• pp.317-326
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• 2013

Probabilistic design methods can consider uncertainties of design variables and are widely used in the design of vertical breakwaters. The probabilistic design methods include a partial safety factor method, reliabilitybased design method, and performance-based design method. Especially the performance-based design method calculates the accumulated sliding distance during the lifetime of the breakwater or during a design storm. Recently a time-dependent performance-based design method has been developed based on the first-passage probability of individual sliding distance during a design storm. However, because the allowable criteria in the first-passage probability method are not established, the stability of structures cannot be quantitatively evaluated. In this study, the allowable first-passage probabilities for two limit states are proposed by calculating the first-passage probabilities for the cross-sections designed with various water depths and characteristics of extreme wave height distributions. The allowable first-passage probabilities are proposed as 5% and 1%, respectively, for the repairable limit state (allowable individual sliding distance of 0.03 m) and ultimate limit state (allowable individual sliding distance of 0.1 m). The proposed criteria are applied to the evaluation of the effect of wave-height increase due to climate change on the stability of the breakwater.