• Journal of KIISE:Computer Systems and Theory
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• v.34 no.7
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• pp.288-295
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• 2007

The illegal copying and redistribution of digitally-stored information is a crucial problem to distributors who electronically sell digital data. fingerprinting scheme is a technique which supports copyright protection to track redistributors of electronic information using cryptographic techniques. Anonymous asymmetric fingerprinting scheme prevents the merchant from framing a buyer by making the fingerprinted version known to the buyer only. And this scheme allows the buyer to purchase goods without revealing her identity to the seller. In this paper, a new anonymous asymmetric fingerprinting scheme with TTP is introduced. The buyer's fingerprint is generated by the Fingerprint Certificate Authority which is a TTP. When the seller embeds the fingerprint in the digital data, the protocol uses the homomorphic encryption scheme. Thus the seller cannot know the buyer's fingerprint and the buyer's anonymity is guaranteed by using anonymous key pair.

• 전기의세계
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• v.28 no.10
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• pp.9-16
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• 1979

근래 우리나라의 국민소득이 높아짐에 따라 가전제품의 수요가 늘고, 중화학공업의 발달에 따라 전력수요가 급격히 증가하고 있다. 이에 반하여 석유가는 매년 증가하고 있으므로 기력발전소를 지양하고 대용량의 원자력, 양수발전소, 석탄발전소가 건설되고 있는 경향이 있다. 발전소는 입지조건상 해안 또는 강변에 위치하고 있으며 수요지와는 거리가 멀고 또는 계통의 안전도(Stability), 신뢰도(Reliability)를 높이기 위하여 154KV와 345KV 송전선으로 전계통을 연계하고 있다. 송전선의 전력운송능력을 증대시키기 위하여 복도체 또는 사도체로 하고 있으며 전선도 ACSR에서 TACSR로 하는 나라도 있다. 현재 미국에서는 765KV Canada에서는 735KV 송전선으로 운전되고 있으며 장차 1500KV 송전선도 곧 실용화된다고 한다. 이에 따라 송전선의 지지물인 철탑도 대형화되어가고 높이도 증가하게 되어 이의 제작및 건설비가 막대하게 들게되며 앞으로는 용지확보도 더욱 어렵게 되어 송전선의 회전수를 2 또는 4회선으로 건설하여야 될것이다. 송전선철탑설계는 종래에는 Cremona도식해법에 의하여 설계하였으나 이의 작도및 하중조건이 많아지면 부재의 정확한 설계하중을 산출하는 데는 많은 시간과 노력이 필요하다. 이러한 불편을 헤소하기 위하여 Ritter의 수치해석법(moment 방법)을 이용한 전산화 및 설계이론에 대하여 소개하고자 한다.

• Composites Research
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• v.31 no.3
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• pp.99-103
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• 2018

This paper visualizes the full-field permittivity distribution at the standard specimens having known electromagnetic characteristics using a scanning free space measurement (SFSM) system. First, in the two Teflon specimens with different thicknesses, the real and loss tangent of permittivity could be measured and the results agreed to the theoretical and other measurement values. Then the system has been applied to Glass/epoxy and visualized different permittivity distribution depending on the material kind. Therefore, this approach will overcome the point measurement limitation of FSM and can be used for even sub-structural full-field electromagnetic evaluation of stealth and radome structures.

• International Journal of Highway Engineering
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• v.13 no.4
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• pp.71-79
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• 2011

Korean national highway has been increased 2 times more for the past ten years because of many highway geometric improvements and new routes since 2000. According to the reasons, maintenance cost has been increased continuously. Deterioration of concrete bridge decks caused by asphalt pavement deformation occupies a high proportion of overall bridge management budget. The number of current highway bridges has reached over 7,800 in 2011, and It is difficult to determine to some future budget. This study predicted the remaining life of concrete bridge decks using the reliability analysis based on Weibull distribution. and The expected future maintenance cost was estimated.

• Journal of KIISE:Computer Systems and Theory
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• v.35 no.6
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• pp.248-262
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• 2008

As the number of large size multimedia files increases and the importance of individual's digital data grows, storage devices have been advanced to store more data into smaller spaces. In such circumstances, a physical damage in a storage device can destroy large amount of important data. Therefore, it is needed to verify the robustness of various physical faults in storage device before certain systems are used. We developed SOAR(Storage Reliability Analyzer), Storage Reliability Analyzer, to detect physical faults in diverse kinds of HDD hardware components and to recover the systems from those faults. This is a useful tool to verify robustness and reliability of a disk. SOAR uses three unique methods of creating physical damages on a disk and two unique techniques to apply the same feature on file systems. In this paper, we have performed comprehensive tests to verify the robustness and reliability of storage device with SOAR, and from the verification result we could confirm SOAR is a very efficient tool.

• Journal of the Korean Geotechnical Society
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• v.26 no.3
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• pp.35-45
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• 2010

The mechanism of load transfer by punching shear in pile-supported embankments is investigated. Based on the geometric configuration of the punching shear observed in sand fills on soft ground, a theoretical analysis is carried out to predict the embankment loads transferred on a cap beam according to punching shear developed in pile-supported embankments. The equation presented by the theoretical analysis was able to consider the effect of various factors affecting the vertical loads transferred on the cap beam. The reliability of the presented theoretical equation is investigated by comparing it with the results of a series of model tests. The model tests were performed on cap beams, which had two types of width; one is narrow width and the other is wide width. Sand filling was performed through seven steps. Two types of loading pattern were applied at each filling step; one is the long-term loading, in which sand fills at each filling step were kept for 24 hours, the other is the short-term loading, in which sand fills at each filling step were kept for 2 hours. The vertical loads measured in all model tests show good agreement with the ones predicted by the theoretical equation. Finally, the predicted vertical loads also show good agreement with the vertical loads measured in a well-instrumented pile-supported embankment in field, where cap beams were placed on too wide space.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.13 no.4
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• pp.101-109
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• 1993

On the basis of Nikuradse laboratory experiments. two transition flow regimes are defined with respect to the characteristics of boundary layer. One is the transitional turbulent flow which has a transitional characteristics between smooth turbulent flow and rough turbulent flow, and the other may be called as transitional laminar flow which has transitional features between laminar flow and turbulent flow. The laboratory results of Nikuradse are carefully re-examined, and the flow regions are clearly defined. The velocity profile of the transitional turbulent flow is described by newly formulated equation, and the Darcy-Weisbach friction coefficient for the transitional turbulent flow is determined based on the theoretical form of profile equation, which is far better accurate than Colebrook-White equation. Difficulties still arise for the description of velocity profile when the flow undergoes from laminar to turbulent. In this case a linear interpolation procedure is proposed for the estimation of friction coefficient.

• Journal of Korean Ophthalmic Optics Society
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• v.10 no.3
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• pp.215-220
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• 2005

On entering new millenium, there has been an important switchover in the divergent View and its cases on commercial marketing. This study is to focus on the related influence factors of the optician's marketing. Aiming to improve the relationship of the manager and the manager and the clients, this study tried to find out the influences of the marketing. We defined quality of relation as three element, trust, satisfaction, absorption. We investigated how it influenced optician's characters, goods, service, price, physical convenience and communication to the quality of relation. Moreover, we investigated how it influenced optician characters like knowledge information, good impression, contact and relation marketing of dissatisfaction solution, also quality of relation could or not influence about repurchase intension and Big Mouth marketing. Optician's characters affect on affirmative effect to trust and absorption, but little affirmative effect to satisfaction. Since optician's characters are trust and absorption rather than satisfaction influence, they actively should improve customer-oriented variety of goods, service, physical convenience, communication. As price and communication structure of optician was formed so not modernized, we realized these have not influenced their trust, satisfaction, absorption to customer. Optician's characters influenced more affirmative effect to satisfaction than thrust and absorption. quality of relations mostly provided affirmative effect to the result of relation. The opticians should make efforts to influence on customer satisfied with goods and service, also to have trust and absorption for customer, should maintain good partnership with customer.

• Journal of Aerospace System Engineering
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• v.12 no.4
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• pp.98-105
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• 2018

The satellite is exposed to various launch environments such as random vibrations and shock. Accordingly, structural design of electronic equipment mounted on satellite must meet reliability requirements at the box level. In addition, it is essential to secure the reliability of the solder joint applied to electronic equipment. In this paper, we performed a modal and quasi-static analysis for the purpose of satisfaction of the design requirements of the CCB (Camera Controller Box) present on the 500 kg-class compact advanced satellite (CAS500). In addition, structural safety of electronic components was verified by the Steinberg's method and random equivalent static analysis.

• 한국IT서비스학회:학술대회논문집
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• 2003.11a
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• pp.194-201
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• 2003

본 연구는 최근 국내 SI 기업의 활발한 해외시장 진출과 관련하여 일반적인 IT 서비스의 성질을 도출해 고객의 구매결정을 방해하는 요인을 찾아내고 이를 해결하기에 적합한 시장진출유형을 제시하는 것을 목적으로 한다. 또한 거래비용 관점에서 SI 기업에게 가장 효율적인 진출유형이 무엇인지를 도출하는 것이다. IT 서비스는 구매계약이 체결된 이후에 생산이 시작되므로 일단 사용해 본 후에야 품질평가가 가능한 경험적 성질을 갖는다. 따라서 해당 SI 기업과의 사업경험이 없는 고객은 구매 전에 IT 서비스의 품질을 평가할 수 없기 때문에 구매에 대한 높은 불확실성을 인식하게 되고 이것은 구매결정을 방해하는 요인으로 작용한다. 이러한 문제는 SI 기업이 새로이 해외시장에 진출할 때 현지에서 명성과 신뢰를 쌓고 있는 기업과의 합작투자를 통해 해결될 수 있다. 왜냐하면 이럴 경우 IT 서비스와 관련해서는 아직 사업경험이 없다고 할지라도 현지 기업의 명성이나 신뢰, 또는 기존의 돈독한 사업관계를 통해 SI 기업이 자신을 속이거나 배반하지 않을 것이라는 기본적인 믿음을 통해 고객의 불확실성을 감소시킬 수 있기 때문이다. 또한 시장거래비용과 관리적 거래비용 측면에서 순수 자회사 설립보다는 현지 시장 및 고객환경에 밝은 현지 기업과의 합작회사 설립을 통해 진출하는 것이 보다 효율적이다. 이와는 달리 최근 국내 대형 SI 기업의 해외진출 현황을 살펴보면 자회사 설립을 통한 진출을 선호하는 것으로 나타났는데 이것은 이들이 속한 그룹사들이 많은 해외시장 경험을 통해 해당 시장환경에 익숙하기 때문에 현지 기업의 도움 없이도 시장개척이나 고객확보가 가능하다고 판단했기 때문이라고 해석된다. 본 연구결과는 특히 해외시장 경험이 아직 부족한 국내 SI 기업들이 해외시장에 진출할 때 유용한 자료로 활용될 수 있다.