• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 A
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• pp.3-5
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• 2001

When a fault occurs on distribution network. blackout region may happen, then it should be restored as fast as possible to minimize interruption of electric service. In this paper. A near optimal method to restore distribution network is proposed. For an optimal restoration, the number or switching operations must be minimized. The proposed method generates a general restoration plan for any distribution network fault and designed to reduce switching operations considering available load transfers. In this method overall process time can reduce with heuristic rules, which make a reduction of search space before restoration process. To achieve a near optimal solution, multiple load transfer algorithm is proposed too.

• 대한안전경영과학회지
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• 제22권4호
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• pp.45-52
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• 2020

Recently, a multi facility, multi product and multi period industrial problem has been widely investigated in Supply Chain Network(SCN). One of keys issues in the current SCN research area involves minimizing both production and distribution costs. This study deals with finding an optimal solution for minimizing the total cost of production and distribution problems in supply chain network. First, we presented an integrated mathematical model that satisfies the minimum cost in the supply chain. To solve the presented mathematical model, we used a genetic algorithm with an excellent searching ability for complicated solution space. To represent the given model effectively, the matrix based real-number coding schema is used. The difference rate of the objective function value for the termination condition is applied. Computational experimental results show that the real size problems we encountered can be solved within a reasonable time.

• 천문학회지
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• 제50권1호
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• pp.7-20
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• 2017

We carry out the study of $850{\mu}m$ sources in a part of the XMM-LSS field. The $850{\mu}m$ imaging data were obtained by the SCUBA-2 on the James Clerk Maxwell Telescope (JCMT) for three days in July 2015 with an integration time of 6.1 hours, covering a circular area with a radius of 15'. We choose the central area up to a radius of 9'.15 for the study, where the noise distribution is relatively uniform. The root mean square (rms) noise at the center is 2.7 mJy. We identify 17 sources with S/N > 3.5. Differential number count is estimated in flux range between 3.5 and 9.0 mJy after applying various corrections derived by imaging simulations, which is consistent with previous studies. For detailed study on the individual sources, we select three sources with more reliable measurements (S/N > 4.5), and construct their spectral energy distributions (SEDs) from optical to far-infrared band. Redshift distribution of the sources ranges from 0.36 to 3.28, and their physical parameters are extracted using MAGPHYS model, which yield infrared luminosity $L_{IR}=10^{11.3}-10^{13.4}L_{\odot}$, star formation rate $SFR=10^{1.3}-10^{3.2}M_{\odot}yr^{-1}$ and dust temperature $T_D=30-53K$. We investigate the correlation between $L_{IR}$ and $T_D$, which appears to be consistent with previous studies.

• Journal of Mechanical Science and Technology
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• 제14권4호
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• pp.369-379
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• 2000

In industrial production-distribution systems, production and purchasing rates, associated inventories, and sales are very critical for the profits of each component in the system. The objective of this study is to investigate an effective information control scheme for a production -distribution system by automatic feedback control techniques. In this work, a dynamic control scheme that has an integrated -error with state-feedback and filtering (ISFF) is proposed as a new algorithm for a dynamic controller. Generalized formulations of the dynamic control are proposed in the continuous-time and discrete-time cases. A methodology for an evaluation of ISFF controller gains using the eigen structure property is presented. When an upper-limit is imposed on the production capability by available factory space and capital equipment, supervisory control is provided to avoid integrator-windup and deterioration of system performance.

• 한국방사선학회논문지
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• 제7권1호
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• pp.45-50
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• 2013

전산화단층촬영장치(Computed Tomography:CT)등장은 인체의 검사 시에 비 침습적인 검사로서 환자의 병변을 발견하는데 사용된다. 전산화단층촬영장치가 주는 정보는 3차원 영상구현에 중요한 역할을 하고 있다. 과학이 발전함에 따라 최근에는 전산화단층촬영장치를 사용하여 물리학적인 또한 생물학적 연구에 적용할 수 있는 장비가 필요하게 되었다. 따라서 좀 더 세밀하고 구체적인 정보를 제공해주는 마이크로 시티(Micro-CT)가 등장하였다. 마이크로 시티가 주는 영상정보는 더욱 더 세밀하고 구체적인 영상 정보이며 따라서 생명공학과 고분자 재료공학 발전에 크게 기여하고 있다. 그러나 아직까지 마이크로 시티의 사용자에 관한 피폭선량의 한도에 관한 공간선량 측정 정보가 정확하게 보고된바 없다. 또한 마이크로 시티를 사용함으로써 원치 않게 발생 할 수 있는 산란선에 관하여 공간 피폭 선량이 보고되지 않았다. 마이크로 시티는 장비의 외관은 피폭 산란선 제거용 납으로 구성되어 있다. 따라서 산란선에 의한 피폭을 충분히 예방할 수 있지만 시간이 흐르고 장비가 노후되어짐에 따라 꾸준한 장비의 관리가 필요 할 것이다. 우리는 우연치 않게 발생 될 수 있는 마이크로 시티를 직접적으로 사용하고 있는 운영자의 산란선 피폭에 관해 공간선량을 측정하였다. 결론적으로 마이크로 시티의 사용자로 하여금 원치 않게 발생되는 산란선에 관하여 피폭 관리가 필요하다고 알리고 싶다.

• 한국ITS학회 논문지
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• 제14권6호
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• pp.37-49
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• 2015

Space Syntax에서 개별링크의 통합도가 크면 네트워크에서 접근이 편리함을 나타낸다. 보행자가 통합도가 높은 링크들의 연결성을 경험하도록 보행로를 설계하거나 집적도가 높은 토지이용을 유도하는 것이 타당하다. 보행자 통행배정모형은 보행수요(보행자)의 불편도(통행거리 및 시간) 등을 최소화하는 경로선택을 반영한다. 이는 보행자의 불편을 최소화하는 실제 통행패턴을 제시한다. 본 연구는 Space Syntax와 보행자 통행배정모형을 통합하는 방안을 제시하는데 목적이 있다. 인천시 부평역을 대상으로 통합모형의 유효성을 검증하는 실증분석을 실시하였다. 분석결과 부평역 주변은 통합도가 매우 높게 나타나나 보행전용구역인 역 북부지역은 상대적으로 통합도가 낮게 나타났다. 모형의 구조는 통합도가 높은 지역에 실제 이동수요를 반영하여 통합도가 적합하게 유지되는지 설명이 가능하다. 통합모형은 Space Syntax의 네트워크에 대한 가시거리를 나타내는 축선도와 건물과 도로로 구획된 링크를 결합하는 방식과 보행자 통행배정모형의 기종점의 유사경로를 파악하여 균일 배정하는 방안을 도입한다. 제안된 모형은 보행개선지역 및 사업의 사전/사후평가 등에 활용이 가능할 것으로 기대된다.

• Journal of Astronomy and Space Sciences
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• 제1권1호
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• pp.55-65
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• 1984

A total of 618 photoelectric observations (302 in yellow and 316 in bule) is made in 1982 at the Yonsei University Observatory. Except that of the secondary eclipse the homogeneous coverage of observations successfully secured B, V, and B-V light curves. Enhanced distortions in the light curves are appeared at the phases aroung $0.^P1$, which supports the wave-like migration period of 9.7 years(Rodono 1981). One epoch time of the primary minimum was made by combining the observations in three nights. This minimum time shows that the O-C values are still decreasing and there seems to indication of increasing. B and V light curves of the primary minimum are in strong asymmetry which show less luminous in the third and fourth contacts compared to those of the first and second ones. This asymmetry may be as a result of the reflection of the wave minimum at $0.^P1$, and B-V curve also shows asymmetry, redder at the third contact than the second one by about $0.^m04$. This color difference apperature distribution on the surface of cooler, larger component(KO IV star).

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제30권6호
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• pp.497-503
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• 2004

One of the most difficult problems to damage in dentistry is an odontogenic infection. These infections may range from low-grade, well-localized infections that require only minimal treatment to a severe, life-threatenig fascial space infection. Although the overwhelming majority of odontogenic infections are easily managed by minor surgical procedures and supportive medical therapy that includes antibiotic administration, the practitioner must constantly bear in mind that these infections may become severe in a very short time. We made an investigation was targeting on 78 male and 47 female patients (125 patients in total) who had been hospitalized because of the fascial space abscess on the oral and maxillofacial area and gained a complete recovery in Daegu Catholic University Hospital, Oral & Maxillofacial Surgery from January 1999 to December 2003. By tracing their charts, we could grasp the characteristics such as age, gender, the time of breakout and specific areas of the attacks, making a conclusive study of the statistical analysis and finally, we could reach conclusions. Now, we report the conclusion from the investigation with the literature. The proportion of males and females was approximately 3 to 2, and in age group, patients under 10 years old marked the highest, 22.4%. The patients between the age of 10 and 40 were only 14.4%, yet those who were between 40 and 80 marked 53.6% in contrast. In the monthly distribution, the order was Dec.(13.6%)-Sep.(12%)-Jan.(10.4%) and in seasonal distribution, it was winter(30.4%)-fall(28%)- summer(24.4%)- spring(19.2%). Considering the medical history, D.M. was the highest which was 30.3%, hypertension marked 24.4%, and the patients with both D.M. and hypertension were 9.0%. The major cause of infection of oral and maxillofacial areas was odontogenic infection, which marked about 96%, and especially the cases related to dental caries occurred most frequently, which was 51.2%. In the number of relaxed fascial space, single fascial space was 81.6%, and in the degree of relaxation of fascial space, the buccal space abscess marked 40.8%, following submandibular space abscess, which was 30.4%.

• Journal of the Korean Statistical Society
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• 제25권4호
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• pp.529-544
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• 1996

This paper deals with the problem of estimating the autoregressive random coefficient of a first-order random coefficient autoregressive time series model applied to panel data of time series. The autoregressive random coefficients across individual units are assumed to be a random sample from a truncated normal distribution with the space (-1, 1) for stationarity. The estimates of random coefficients are obtained by an empirical Bayes procedure using the estimates of model parameters. Also, a Monte Carlo study is conducted to support the estimation procedure proposed in this paper. Finally, we apply our results to the economic panel data in Liu and Tiao(1980).

• 한국화재소방학회:학술대회논문집
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• 한국화재소방학회 2008년도 춘계학술논문발표회 논문집
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• pp.290-293
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• 2008

In this study, the Computational Fluid Dynamics (CFD) has been used to analyze the smoke movement and the carbon monoxide concentration distribution, both vertically and longitudinally, in a compartment, based on conservation laws. The Fire Dynamics Simulator (FDS) developed by National Institute of Standards and Technology (NIST) was used for numerical simulations using Reynolds averaged Navier-Stokes equations (RANS) model to solve for time-averaged properties. Results show, as a function of time, a detailed distribution of temperature and carbon monoxide concentration changing against the height above the floor and those changes alongside the distance away from the fire source. Fire-induced smoke and toxic gases like CO are more dangerous in a confined space. The result of study may contribute in designing the smoke evacuation system based on the precise tenable condition.