• 한국시뮬레이션학회논문지
• /
• 제26권2호
• /
• pp.59-65
• /
• 2017

M&S의 발전과 더불어 국방 M&S등 인간의 의사결정을 포함하는 분야의 요구가 증대되는 현실에서 AI기술을 활용한 모델링 연구가 각광받고 있다. AI는 복잡한 문제 해결을 위한 방법임은 분명하나 M&S에서 요구되는 입력시점과 처리시간 등의 논리적 시간을 고려하지 않았다. 따라서 본 논문에서는 대표적인 AI 기술인 규칙기반 전문가시스템을 논리적 시간을 고려한 규칙구조 "IF-THEN-AFTER"와 추론엔진으로 재설계한 시간기반의 전문가 시스템을 제안하고, 기존의 규칙기반 전문가 시스템과의 차이를 설명하기 위한 간단한 예제를 들어 논리적 분석을 시도하였다. 그 결과로 제안하는 시간기반의 전문가 시스템 모델은 일반적인 규칙기반 전문가시스템과 다르게 입력시점과 추론시간에 따라 다른 결과를 보임을 알 수 있으며, 이는 M&S에서 요구되는 논리적 시간을 고려한 AI의 문제해결이 가능함을 의미한다.

• 한국시뮬레이션학회논문지
• /
• 제24권3호
• /
• pp.1-8
• /
• 2015

M&S 결과의 신뢰도를 확보하기 위한 방법으로, 선진국을 중심으로 개발된 VV&A(검증 확인 및 인정) 절차가 국내에도 소개되어 다양한 분야에 적용되고 있다. VV&A는 가용한 자원과 필요에 따라 그 절차를 선택적으로 적용하도록 가이드라인에 명시되어 있고, 방위사업청 무기체계 개발에 VV&A 관한 규정에도 인정(A)은 필요시 수행하도록 권고하고 있다. 본 연구에서는 V&V 절차를 소개하고, 이를 통해 무기체계 M&S 도구에 대한 신뢰도를 확보할 수 있는 방안에 대해 서술하였다. 또한 체계개발 중인 보병용 중거리 유도무기 '현궁'의 체계통합시뮬레이터에 V&V 절차를 적용하여 신뢰도를 확보한 사례를 제시하였다.

• 대한산업공학회지
• /
• 제6권1호
• /
• pp.1-7
• /
• 1980

An exact solution technique for M/M/s multi-server demanding queue is introduced, and a general form of the curves representing service rates of the system is presented. As the number of customers in the system increases, the service rate is shown to increase initially, then decrease, and finally converge to a certain value. It is also shown that this phenomenon persists regardless of the numbers of servers and customer types.

• 대한디지털의료영상학회논문지
• /
• 제12권2호
• /
• pp.133-138
• /
• 2010

The purpose of this study was to survey and test quality control of mammography system. The conclusion of this study is as follows ; First, The rate of pass for phantom image test shows that Film-Screen mammography system(F/S) and computed mammography system(CR) is 80%, Indirect digital mammography system(DR) is 100%. Second, The test of exposure dose shows that F/S is 921 mR. CR is 1,140 mR, DR is 474 mR. The grade of this testament is CR > F/S > DR. Third, The test of average glandular dose shows that F/S is 1,336 mGy, CR is 1,635 mGy, DR is 1,26 mGy. The grade of this testament is CR > F/S > DR. Fourth, The testament of resolution shows as follows F/S is 11~13 Lp/mm, CR is 4~5 Lp/mm, and DR is 5~7 Lp/mm(F/S > DR > CR) Fifth, The survey of projection, cassette, development and reading shows that user are indifference.

• 정보처리학회논문지:컴퓨터 및 통신 시스템
• /
• 제8권2호
• /
• pp.41-56
• /
• 2019

제조 클라우드는 여러 공장이 연결되어 단일 공장처럼 구성되어 사용자의 요구사항에 유연하게 대처할 수 있는 새로운 제조 패러다임이다. 이러한 기능을 제공하는 제조 클라우드 시스템은 클라우드 컴퓨팅, 사물인터넷, 인공지능과 같은 컴퓨팅 기술을 활용하여 분산되어 있는 제조 시설 간의 협업을 통한 유연 생산에서 안정성, 고신뢰성, 연동성 등을 제공하는 일종의 대규모 CPS이다. 제조 클라우드 CPS는 많은 수와 다양한 종류의 이기종 서브시스템들로 구성되어 있는데 이 때문에 서브시스템 간 연동, 데이터 교환, 시스템 통합 등에 문제가 발생할 수 있어 대규모의 제조 클라우드 CPS을 구성하는데 어려움을 겪고 있다. 본 논문에서는 이러한 어려움을 극복하기 위하여 제조 클라우드를 체계적으로 분석하고 분석 결과를 바탕으로 제조 클라우드 CPS를 효과적으로 지원할 수 있는 플랫폼 참조 모델을 제안한다. CPS 분석 방법론인 CPS 프레임워크를 활용하여 제조 클라우드 CPS의 기능적, 인간적, 신뢰성, 시간적, 데이터 및 구성의 측면에서 사용자 요구사항을 도출하고 이들을 분석하여 확장성, 구성성, 상호 작용성, 신뢰성, 시간성, 상호 운용성, 지능성의 영역에서 시스템 요구사항을 정의한다. 정의된 제조 클라우드 CPS 시스템 요구사항을 바탕으로 플랫폼을 구성하기 위하여 IoT 플랫폼 표준인 oneM2M의 요구사항에 매핑하고 oneM2M 구현물인 Mobius를 통하여 요구사항 지원성 검증 실험을 수행하였다. 수행 결과를 분석하여 현재 사물인터넷 플랫폼의 제조 클라우드 CPS 지원성을 확인하고 이를 확장하여 대규모 제조 클라우드 생산을 지원하는 플랫폼 참조 모델을 제안한다.

• 한국군사과학기술학회지
• /
• 제13권6호
• /
• pp.1080-1090
• /
• 2010

A study for improvement of credibility on test & evaluation result of interoperability in battle management information system which focused in C4I systems is very essential in rapid change of battle field environment. Realization of effective operation process with integration of developed IT also core factor for reducing of operational response time such as information gathering from sensor to shooter, time for commander's decision making. Therefore, by required to meet of high technical T&E, meet of complex software's user requirement, long-term system development period, system integration ability's request by various linkage of systems, it is high a M&S dependency to optimal performance, interpoerability's guarantee. Especially credibility on test & evaluation using M&S is very important. This paper will propse a VV&A applied methods using other VV&A case to improve credibility of M&S on test & evaluation.

• Korean Chemical Engineering Research
• /
• 제48권2호
• /
• pp.198-204
• /
• 2010

가압순환유동층 적용을 위해 루프씰(loop-seal: 내경 0.10 m)을 갖는 고체재순환부(직경 0.10 m, 높이 2.25 m)에서 층 물질로 silica sand 입자($d_p=240{\mu}m$, ${\rho}_s=2582kg/m^3$)를 사용하여 시스템 압력 변화(0.10~0.71 MPa)에 따른 고체흐름 특성을 연구하였다. 루프씰을 통한 고체질량플럭스는 공기주입량이 증가할수록 선형적으로 증가하였고, 동일한 공기주입속도에 대해 시스템 압력이 증가할수록 증가하였다. downcomer 내 압력변이는 시스템 압력이 증가할수록 동일한 공기주입속도에 대해 증가하였고, 흐름 내 고체속도 및 기체 속도 또한 증가하였다. 고체질량플럭스로부터 downcomer 에서의 압력변이를 예측할 수 있는 상관관계식을 Transportation number와 Pressure drop number를 이용하여 제안하였다. 루프씰에서의 압력강하는 시스템 압력에 관계없이 고체질량플럭스가 증가할수록 증가하였다. 각각의 시스템 압력에서 공기주입속도 변화에 따른 고체질량플럭스 및 Transportation number를 예측할 수 있는 상관관계식을 제안하였다.

• 한국태양에너지학회:학술대회논문집
• /
• 한국태양에너지학회 2009년도 추계학술발표대회 논문집
• /
• pp.404-408
• /
• 2009

The liquid desiccant air-conditioning system has been proposed as an alternative to the conventional vapor compression cooling systems to control air humidity. The complete system of liquid desiccant air-conditioning system is consisted two main components those are humidifier (regeneration) and dehumidifier. Humidifier part is connected to the load when summer season which is the air condition is hot and humid have to be turned into comfort condition on human. This paper purpose is performances study of air flow rate effect on a structured packed tower on cooling and dehumidifier system using liquid lithium chloride as the desiccant. Experimental apparatus used in this present study is consisted of three components those are load chamber, packed tower and chiller. Load chamber’s volume is $40m^3$, and packed tower dimension is cubic with length 0.4m occupied with packed column. Totally, 15 experimental has done using 5 times repeat on each variable of air velocity that varying on 2m/s, 3m/s and 4m/s with other conditions are controlled. Air inlet initial temperature and relative humidity are set respectively on $30^{\circ}C$ and 52%, desiccant flow rate is 0.63 kg/s, desiccant temperature is $10^{\circ}C$ and desiccant concentration is 0.4. The result of this study shows that averagely, the moisture removal rate and the heat transfer rate are influenced by the air velocity. Higher air velocity will increase the heat transfer and decreasing the moisture removal rate. At adiabatic condition the air velocity of 2 m/s respectively is having the higher moisture removal rate acceleration then the air velocity of 3m/s and 4 m/s until the steady state condition.

• 한국병원경영학회지
• /
• 제3권1호
• /
• pp.34-61
• /
• 1998

A study on cooperative medical treatment system between oriental and western medical practitioners was conducted from March through August 1997 in order to determine a productive model of cooperation of two medical parts for treatment of patients. Questionnaires were distributed to 195 medical doctors(M.D.) and 195 doctors of oriental medicine(O.M.D.) working in clinics and hospitals in six major cities. Statistical analysis tools used for this study were frequency, t-test and multiple regression by using SPSS/P.C package. The results are summarized as follows: 1. The respondents were composed of male docotors(78%) and female doctors(22%) and 68.2% of M.D. and 97% of O.M.D. were interested in the other medical part. The doctors of both disciplines had some limitation on treatment of patients but they were reluctant to refer their patients to other doctors in different discipline. 2. M.D assumed that oriental medicine was more effective for chronic diseases, and O.M.D. thought that western medicine was more effective for acute diseases. 92.3% of O.M.D.s responded that even though they do not utilize western medical technology for diagnosis, they believed the results of diagnoses by western medical technology. 3. 60.5% of O.M. and 93.3% of O.M.D. said that cooperative medical treatment system could be necessary for patients and it would be effective for control of diseases and 69% of western medical doctors and 99% of oriental medical doctors agreed that oriental medical practice would be more effective for cerebellar vascular accidents than other diseases. 77.4% of western medical doctors and 92.3% of oriental medical doctors responded that the students of two different disciplines have to be taught on the other disciplines. 82.6% of western medical doctors and 83.3% oriental medical doctors agreed that it would be necessary to have collaborative research between scientists in two disciplines. 81.5% of M.D.s and 93.3% of O.M.D.s believed that they had prejudice and distrust on other discipline 4.90% of the doctors were not satisfied with the government medical policies on health insurance, legal matters, and health delivery system. 5. 75.4% of M.D.s and 50.2% of O.M.D.s said that two medical disciplines should be integrated, but they were skeptical on that. 75.3% of M.D.s thought that western hospitals should employ O.M.D.s Finally this study recommended that western medical students study oriental medicine and the vice versa, and M.D.s and O.M.D.s should have seminars and workshops to exchange knowledge, and experiences. It is also recommended that medical laws be revised to allow medical doctors refer the patients whom they can not handle to oriental medical doctors and the vice versa.

• 대한산업공학회지
• /
• 제34권1호
• /
• pp.98-107
• /
• 2008

The purpose of this paper is to present an optimization scheme that aims at minimizing the expected cost per unittime. This study considers a linear connected-(r, s)-ouI-of-(m, n):f lattice system whose components are orderedlike the elements of a linear (m, n)-matrix. We assume that all components are in the state 1 (operating) or 0(failed) and identical and s-independent. The system fails whenever at least one connected (r, s)-submatrix offailed components occurs. To find the optimal threshold of maintenance intervention, we use a simulatedannealing(SA) algorithm for the cost optimization procedure. The expected cost per unit time is obtained byMonte Carlo simulation. We also has made sensitivity analysis to the different cost parameters. In this study,utility maintenance model is constructed so that minimize the expense under full equipment policy throughcomparison for the full equipment policy and preventive maintenance policy. The full equipment cycle and unitcost rate are acquired by simulated annealing algorithm. The SA algorithm is appeared to converge fast inmulti-component system that is suitable to optimization decision problem.