• 한국유체기계학회 논문집
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• 제15권5호
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• pp.20-26
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• 2012

An APU(Auxiliary Power Unit) for helicopters has been developed in Korea and tested at the AETF(altitude engine test facility) in KARI(Korea Aerospace Research Institute) for the purpose of the military qualification. A cell correlation test was performed before the official test, and the results are within the tolerance. The APU has the capability of supplying electric power as well as compressed air to the helicopters. It was tested at bleed extraction conditions, electric power extraction conditions, and maximum continuous concurrent power conditions within the entire helicopter flight envelop. Some special test equipments were implemented for the measurement of air flowrate, electric power and so on. The tests were successfully performed and their results satisfy the requirements of the helicopters.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2010년도 제35회 추계학술대회논문집
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• pp.135-140
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• 2010

The high specific impulse of the ramjet engine, combined with the ability of a gel to carry metal particles, make the Gel Fuel Ramjet a most adequate solution for a mid-high range sustainer. The goal of the present study is to verify experimentally the feasibility of such a concept. A test facility and a lab-scale motor have been designed and built to investigate atomization, ignition and firing processes of a gel hydrocarbon fuel, with and without metal additives, as well as to check the ramjet operation as a whole. The present paper presents the experimental system in detail as well as qualitative results of a few firing tests.

• International Journal of Internet, Broadcasting and Communication
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• 제10권3호
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• pp.88-97
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• 2018

Chronic diseases management can be effectively achieved through early detection, continuous treatment, observation, and self-management, rather than a radar approach where patients are treated only when they visit a medical facility. However, previous studies have not been able to provide integrated chronic disease management services by considering generalized services such as hypertension and diabetes management, and difficult to expand and link to other services using only specific sensors or services. This paper proposes clinical rule flow model based on medical data analysis to provide personalized care for chronic disease management. Also, we implemented that as Rule-based Smart Healthcare System (RSHS). The proposed system executes chronic diseases management rules, manages events and delivers individualized knowledge information by user's request. The proposed system can be expanded into a variety of applications such as diet and exercise service in the future.

• 한국음향학회지
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• 제21권4호
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• pp.170-170
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• 2002

The goal of the present research is to improve a quality of life of the elderly with a dementia. In this paper, it is realized by developing the dialog system that is controlled by three kinds of modules such as speech recognition engine, graphical agent, or database classified by a nursing schedule. The system was evaluated in an actual environment of a nursing facility by introducing it to an older male patient with dementia. The comparison study between dialog system and professional caregivers was then carried out at nursing home for 5 days in each case. The evaluation results showed that the dialog system was more responsive in catering to needs of dementia patient than professional caregivers. Moreover, the proposed system led the patient to talk more than caregivers did.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 B
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• pp.1323-1325
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• 2003

In field of Urban transit safely, It must be not only secured vehicle but also every areas like power, signal, communication, track, tunnel, operating facilities. Likewise it is very important not only hardware system like vehicles, facilities but also software system like action of engine driver, duty officer. In other to secure safety of hardware, soft ware, it is very important systemic process. In Korea, Many operating companies neglect to invest in safely and ignore technical development about safety because of management. Safely was considered in subway system and many studies were accomplished about safety in subway system in advanced county like U.K, USA. Hence, in this paper, Conditions and improvement of minimum considerable hardware and software are proposed for safe operation in Urban transit.

• 대한토목학회논문집
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• 제42권6호
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• pp.763-773
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• 2022

산업환경시설은 국가 성장동력 지원시설로서 자연재해에 의한 하중을 포함한 다양한 하중 조건에 대해서 구조적 안전성을 확보해야 하며 그 공정을 유지하여 생산활동을 지속하는 것이 매우 중요하다. 이 연구에서는 구조적 안전성을 확보하기 위한 기존 국내외 구조 및 내진설계기준을 개선하여, 산업환경시설의 구조적 안전성 확보와 설비의 운전성 유지를 위한 설계기준을 제안하고자 한다. 이 설계기준에서는 산업환경시설의 특성을 반영하여 다양한 하중을 고려하고, 구조설계를 위해 강도설계법과 허용응력설계법의 하중조합을 제시한다. 산업환경시설의 내진설계를 위해, 단위산업시설 중요도와 단위공정 중요도에 따른 단위공정의 내진등급, 설계지진 수준 및 내진성능수준을 설정하여 산업환경시설의 이원화된 내진성능목표를 달성하고자 한다. 더불어, 대표적인 예제 산업환경시설을 선정하여 새로운 구조 및 내진설계기준의 적용성을 검토한다.

• 대한기계학회논문집
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• 제16권1호
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• pp.122-131
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• 1992

본 연구에서는 동력전달용 치차설계 전문가 시스템을 구축하기 위한 일단의 연구로서 먼저 동력전달용 치차의 치차파손의 원인과 대책의 진단을 위한 전문가 시스 템을 개발하였으며, 본 논문에서는 치차의 강도를 기준으로 삼아 원통치차를 설계할 수 있는 강도 기준 치차설계 전문가 시스템을 개발한다. 즉, 전문가 시스템은 치차 설계에 필요한 지식을 체계적으로 지식 베이스에 구축하며, 이를 이용하여 새로운 설 계안을 도출해 낼수 있는 추론엔진을 구성하고, 설계광정중에 변화하는 설계의 중간결 과 등을 저장하기 위한 임시작업영역을 기본요소로 구축한다. 또한 과거의 설계예를 데이터 베이스로 구축하여 설계시에 참조 할 수 있도록 하며, 새로운 치차의 설계뿐아 니라 설계되어 있는 치차의 강도평가도 할 수 있도록 한다. 전문가 시스템에 사용자 인터페이스, 설명기능, 지식획득기능 등을 추가함으로써 치차분야에 초심자라 할지라 도 개발된 전문가 시스템과의 문답식 대화를 통하여 손쉽게 치차를 설계할 수 있도록 한다.전문가 시스템을 기술하는 프로그램 언어는 PROLOG를 사용하여 퍼스널컴퓨 상 에서 구동될 수 있도록 하며, 강도평가시 많은 수치계산이 필요한 부분은 FORTRAN언어 를 사용하여 기술한 후 PROLOG와 연결(interface)함으로써 전체 전문가 시스템을 구축 한다.

• 항공우주시스템공학회지
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• 제14권5호
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• pp.26-32
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• 2020

본 연구에서는 액체로켓 연소기의 연소 불안정 모사를 위해 극저온 유체인 액체질소를 공급하는 설비를 구축하였다. 가압 및 공급 성능을 예측하였으며 실험을 통하여 검증하였다. 액체질소 공급 시스템은 가압식 공급 시스템으로 구성하였으며, 가압제 압력 조정은 돔 레귤레이터를 사용하였다. 액체질소 공급 유량 제어는 캐비테이션 벤추리를 사용하였으며, 액체 질소 공급 조건은 초당 유량 2.55 kg/s, 벤추리 입구 압력은 100 bar 이상이다. 초기 실험 결과 예측된 가압제의 양이 충분히 공급되지 못하여, 탱크압력 강하가 발생해 목표 유량을 공급하지 못하였다. 구축된 설비의 변경 및 보완을 통하여, 최종적으로 목표 유량 공급에 성공하여 극저온 액체질소 공급 설비를 검증하였다.

• Tribology and Lubricants
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• 제32권5호
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• pp.154-159
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• 2016

This paper presents an experimental study of the leakage performance and endurance performance of a mechanical face seal in the 7-ton-class turbopump of the Korea Space Launch Vehicle 2 third-stage engine. We install a mechanical face seal between the fuel pump and turbine to prevent the mixing of the fuel and turbine gas. We design and manufacture a prototype mechanical face seal, which has two parts, namely, a bellows seal assembly and mating ring. We set up a test facility to measure the leakage and endurance of the mechanical face seal. For the similarity tests, we use water under real operating conditions such as high rotational speed, high temperature, and high pressure. Through investigation of the leakage and carbon wear rate, it is possible to evaluate the performance of the mechanical face seal. The results of the leakage and endurance performance test demonstrate the absence of any leakage from the prototype mechanical face seal after a trial run and clarify that the acceptable wear rate fully satisfies the turbopump requirements. Finally, we install a qualified mechanical face seal in a 7-ton-class turbopump and perform a validation test in the turbopump real-propellant test facility in the Korea Aerospace Research Institute. The test results confirm that the mechanical face seal works well under real operating conditions.

• 한국중재학회지:중재연구
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• 제16권3호
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• pp.161-189
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• 2006

This paper is aiming at analyzing case law of India in relation with reasonable time to make decision whether to accept or to refuse the documents received from the presenter in credit transactions. As specified in UCP, the failure to refuse to accept the documents within a reasonable time precludes the Issuing Bank, Confirming Bank (if any) and Nominated Bank from asserting that they are discrepant. Compliance of the stipulated documents on their face with the terms and conditions of the credit shall be determined by international standard banking practice as reflected in this Articles of UCP 500. The Issuing bank is only to be held responsible for honoring the documents presented by beneficiary through the nominated banks if they are strictly in compliance with terms and conditions of the Credit. As any well experienced banker knows, however, a word-by-word, letter-by-letter correspondence between the documents and the credit terms means a practical impossibility. Thus the notion of reasonable care in conjunction with the doctrine of strict compliance mixed with International Standard Banking Practices has not played a right functional standard for checking the documents as stipulated in the credit and UCP 500. And so the rejection rate is highly estimated at approximately 50% in EU and 40 to 70% according to their geographical locations in the USA. As a result, it can possibly be inferred from this fact that the credit industry would be facing the functional failure as the international trade credit facility, if not supported with motive power as a relevant scheme in UCP 500. It is quite important to note that UCP 500 Article 13(b) which specify the time limit for the banks to notify the presenter their decision not to accept the documents within a reasonable time not to exceed seven banking days following the day of receipt of documents would be the motive engine to improve the negotiability of documents in international trade financial facility.