• 대한전기학회논문지:전력기술부문A
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• 제53권4호
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• pp.238-247
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• 2004

This paper describes the insulation coordination scheme of line in distribution system when the direct lightning surge strikes. The BIL that is applied to distribution system is not properly considered the performance and operation of arresters. Because of that, the high BIL is being used at partial system. This paper variously analyses the lightning overvoltage of line and equipment with earth of overhead grounding wire and installation types of arrester. From these result. authors examine the rationality of BIL.

• KIEE International Transactions on Power Engineering
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• 제5A권2호
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• pp.186-192
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• 2005

As the power industry moves towards open competition, there has been a call for methodology to evaluate power system reliability by using customer interruption costs. This paper presents an evaluation of the interruption costs for public customers in Korea using customer survey methodology. When various research results are examined, the evaluation of direct interruption costs becomes much more simplified. Especially, in the case of public customers, it is known that the evaluation of direct interruption costs is more useful. Accordingly, this paper selected the customer survey method to evaluate the interruption costs for public customers in Korea considering interruption and customer characteristics.

• 대한기계학회논문집A
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• 제21권1호
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• pp.144-153
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• 1997

The determination of the direct kinematics of the parallel mechanism is a difficult problem but has to be solved for any practical use. This paper presents the efficient formulation of the direct kinematics for double parallel robot arm. The robot arm consists of two parallel mechanism, which generate positional and orientational motions, respectively. These motions are decoupled by a passive central axis which is composed of four revolute joints and one prismatic joint. For a set of given lengths of linear actuators, the direct kinematics will find the joint displacements of th central axis from geometric constraints in each parallel mechanism. Then the joint displacements will be converted into the position and the orientation of the end effector of the robot arm. The proposed formulation is decoupled and compacted so that it will be implemented as a real-time direct kinematics. With the proposed formulation, we analyze the motion of the double parallel robot and show its characteristics. Specially, we investigate the workspace in terms of positional space as well as orientational space.

• 한국자동차공학회논문집
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• 제13권2호
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• pp.44-51
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• 2005

According to the increasing concern on the global environment, the $CO_2$ regulation has been discussed including automobile emission regulation. In order to cope with this rapid changing circumstances, the development of an ultra low emission and super fuel economy automobile is essential. Direct injection LPG engine is the one of the possible future engine to maximize the engine efficiency. This experimental study for the development of direct injection LPG engine technology is promoted with two parts; spray characteristics of high pressure swirl injector, and performance characteristics of direct injection LPG engine. Engine characteristics according to the fuel was analyzed in order to establish stratified combustion technology for LPG engine by using the DISI engine. In the engine experiment, control system was manufactured for gasoline and LPG fuel. The engine was modified 2,000 cc GDI engine (fuel supply device, fuel injection device). Through this experiment, engine operating condition, engine speed and spark timing (MBT), fuel injection position, and fuel rate were investigated.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2001년도 학술대회지
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• pp.11-16
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• 2001

본 연구는 하도급법 제14조에 규정된 하도급대금의 직접지급에 따른 계약관리방안을 제시하는 것을 목적으로 한다. 이를 위하여 문헌조사 및 연역적 논증의 방법을 이용하였다. 본 연구의 결과를 요약하면 다음과 같다. (1) 하도급대금직접지급의 요건과 효과를 고찰하여 그 의미와 내용을 명확히 하였다. (2) 하도급대금직접지급과 관련한 실무상·이론상 쟁점에 대한 검토와 논증을 통하여 타당한 해석을 제시하였다. (3) 하도급대금의 직접지급에 따른 발주자·원수급인·하수급인의 계약관리방안을 제시하였다.

• 전기학회논문지P
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• 제59권4호
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• pp.473-476
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• 2010

In this paper, we analyzed the short circuit current of a low voltage direct current distribution system. For the analysis, we performed the modeling of the low voltage direct current distribution system with a 6-pulse three-phase thyristor rectifier using the PSCAD/EMTDC, surveyed impedance of sources, transformers and distribution lines to run a simulation. A result of the simulation is that short circuit currents of the direct current distribution system with the rectifier decreased due to a thyristor-ON-resistance(Ron). But in case of the low thyristor-ON resistance, output fault current of the rectifier increased over three-phase short circuit current of an AC power system without a rectifier by regular ratio of the rectifier. Because the output fault current of the rectifier can increase over interrupting the capacity of circuit breakers, studying short circuit currents of a low voltage direct current distribution system with a rectifier is necessary for introducing the direct current distribution systems.

• 한국정보과학회논문지:데이타베이스
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• 제35권3호
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• pp.199-207
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• 2008

FP-tree(Frequency Pattern Tree) 연관 규칙 탐사 알고리즘은 DB 스캔에 대한 부담을 획기적으로 절감시킴으로써 전체적인 성능을 향상시키고자 제안되었고, 따라서 다른 기법에 기반하는 알고리즘보다 성능이 매우 우수한 것으로 알려져 있다. 그러나, FP-tree 알고리즘은 기본적으로 DB에 저장된 거래 내용 중 빈발 항목을 포함하는 모든 거래를 트리에 저장해야 하기 때문에 그만큼 많은 메모리를 필요로 한다. 이 논문에서는 범용 운영체제인 유닉스 시스템 환경에서 FP-tree 알고리즘을 구현하여 소요 메모리와 실행시간 등 두 가지 성능 관점에서 해시 트리 및 직접 해시 테이블을 사용하는 DHP(Direct Hashing and Pruning) 알고리즘과 비교한다. 그 결과로서 알려진 바와는 크게 다르게 시스템 메모리가 충분한 상황에서도 대형 편의점 수준의 규모에 적용 가능한 거래 건수 100K, 전체 항목 개수 $1K{\sim}7K$, 평균 거래 길이 $5{\sim}10$, 평균 빈발 항목 집합 크기 $2{\sim}12$인 데이타에 대해서 FP-tree 알고리즘이 DHP 알고리즘보다 열등한 경우가 존재함을 보인다.

• 무역상무연구
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• 제15권
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• pp.59-87
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• 2001

In recent years electronic fund transfers covered by the Electronic Fund Transfer Act 1978 for consumer protection and the Article 4A of Uniform Commercial Code(U.C.C.) 1989 for wholesale electronic payments in United States. Electronic fund transfers carried out by use of a wire transfer network, automated clearing house, or other communication system of a clearing house or other association of banks such as direct deposit, Fedwire, automated teller machine, point-of-sale, and credit card transactions have been increasingly common in consumer transactions and wholesale transactions. Especially, the Article 4A of U.C.C. governs the rights and obligations associated with transactions such as an issue and acceptance of payment order, execution of sender's payment order by receiving bank, and payment. These legal frameworks in connection with electronic fund transfers in United States can play a leading role in establishing model not only within the United States, but also as a basis for developments of electronic commerce law in Korea including other countries.

• 통상정보연구
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• 제12권4호
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• pp.405-427
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• 2010

This legal study is to compare the Electronic Transactions Act in Thailand(hereinafter 'ETA') with mainly other countries electronic transactions acts, such as UNCITRAL MLEC, UECIC, VETA, UCITA and Korea' Electronic Transactions Act The ETA is consisted of 6 chapters which included preamble and definitions. Each chapter's main point as follows. Preamble is related to the name, time of legal effect, scope and definitions. Chapter 1 is not only general principles of electronic transactions, required restriction in addition to specify the limit of application, documentation, evidential weight in reference to the data message, but also the conditions of offer and acceptance through data message, time and place of dispatch and receipt of data message, certification between origination and addressee. According to media-neutrality and the effectiveness security requirement of data message under the information system, legal certification is related to the exchange's declaration of intention, define about origination-addressee of data message. Chapter 2 is composed to provide expressly about the effectiveness security in electronic signature. Those contents are to compare the MLEC, UECIC and Electronic Transactions Act in Korea. Chapter 3 is related to legal definitions that present legal requirement about service relating electronic transaction which contents accept domestic law, the adequate requirement as eligibility, satisfied matter, self-reliance ratio of finance and other detail standard Chapter 4 is deal with the transaction which are public sector and those application requirements. And also this chapter are composed regulations about direct-indirect purpose of Thailand domestic electronic government.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제54권1호
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• pp.23-29
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• 2005

This paper presents the characteristics of leakage currents flowing through ZinC Oxide(ZnO) surge arrester blocks under mixed direct and 60 Hz alternating voltages. A mixed voltage, in which an alternating voltage is superimposed upon a direct voltage, appears on the HVDC system network. The mixed direct and alternating voltage generator with a peak open-circuit of 10 kV was designed and fabricated. The leakage currents and V-I curves for the fine and used ZnO surge arrester blocks were measured as a function of the voltage ratio k, where the voltage ratio k is defined as the ratio of the peak of alternating voltage to the peak of the mixed voltages. The resistive component in the leakage current in the low conduction region is significantly increased with increasing the voltage ratio k. The V-I characteristic curves for the mixed voltages lies between the direct and alternating characteristics, and the cross-over phenomenon in the high conduction region was appeared.