• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 한국추진공학회 2011년도 제37회 추계학술대회논문집
• /
• pp.104-108
• /
• 2011

Insensitive Munitions(IM) test methods and passing criteria of MIL-STS-2105D revised in April 2011 were studied since MIL-STD-2105(NAVY) had been created in 1982. Passing criteria of each IM tests has not been established because domestic database of IM tests for rocket motors was not enough, even though IM test and evaluation methods were well established with the same level of advanced countries. In this study, direction of the development for IM of our country was suggested through investigation and analysis of revised test methods and passing criteria.

• Journal of IKEEE
• /
• 제22권2호
• /
• pp.324-329
• /
• 2018

As the environment of power systems changes, the demand and necessity for new electrical energy market are increasing. Especially, efforts to increase the efficiency of electric energy use by using demand response programs are being studied constantly in advanced countries and it is operated as a real market. This paper presents a study on the baseline load estimation required in the new power market, such as demand response, P2P electricity trading etc. The proposed method estimates the baeline load through analysis of the load pattern and verifies the effectiveness of the proposed method using actual data.

• The Journal of the Korea Contents Association
• /
• 제14권10호
• /
• pp.87-100
• /
• 2014

The objective of this study is to explore audience perceptions of and responses to broadcasting deliberation and analyze their characteristics. The study employed factor and cluster analyses to categorize audience perceptions of broadcasting deliberation, resulting in the identification of six types of preferences: strict standards applied to positive deliberation etc. The results indicate that audiences, which can be categorized into three types, are more likely to prefer positive deliberation over broadcasting codes. The ratio of civil compliance to a minimum standard of positive deliberation is higher than ratios involving the other standards that were included in the study. The study applied a range of theories, such as cognitive dissonance, inconsistency of perception and response, and psychological reactance, to examine and distinguish audience perceptions and responses. The study's findings provide valuable information for researchers and interested organizations and can help to lay a cornerstone for systematically classifying audience perceptions and needs in the future.

• Proceedings of the Korea Water Resources Association Conference
• /
• 한국수자원학회 2020년도 학술발표회
• /
• pp.148-148
• /
• 2020

산업의 고도화가 진행됨에 따라 화학원료의 사용이 증가하고 있고 독성을 가진 화학물질이 하천으로 유입되는 사고가 빈번하게 발생하고 있다. 수환경으로 유입되는 유해화학물질은 주로 무색무취의 물질들로 사고가 발생하더라도 초기 발견이 어려워 어류폐사를 유발하거나 취수시설에서 용수로 취수되는 경우가 발생하기 때문에 이에 대한 대응책 마련이 필수적이다. 하천에 유입된 오염물질의 거동을 신속하게 예측하기 위해 1차원 오염물질 추적 모형이 활용되는데, Fickian 이송-분산 모형(Fickian Advection-dispersion equation model; FADE)이 주로 사용되고 있다. 하지만 FADE는 오염물질이 하천 저장대에서 지체되는 현상을 반영하지 못하기 때문에 농도곡선의 왜곡도를 구현하지 못하는 단점을 가지고 있다. 따라서 본 연구에서는 하천저장대모형(River Storage Model; RSM)을 개발하고 이를 국가하천인 감천에 적용하였다. 본 연구에서 개발한 RSM은 분산계수, 본류대 면적, 저장대 면적, 저장대 교환계수의 네 가지 매개변수를 통해서 하천의 물질 저장 및 교환 특성를 구현한 non-Fickian 모형으로서, 생화학반응, 휘발, 흡·탈착항을 추가하여 유해화학물질의 혼합 거동을 정확하게 모의할 수 있도록 개발하였다. 저장대 모형의 매개변수를 산정하기 위해서 하천 유량과 지형자료를 기반으로 HEC-RAS를 모의하여 계산된 수리특성을 입력변수로 사용하였다. 저수기, 평수기, 풍수기 유량을 기준으로 세 경우의 시나리오 모의를 수행하였는데, 5ton의 톨루엔이 김천산업단지에서 감천으로 유입된 경우 약 20km 하류에 위치한 취수장에서 톨루엔의 농도변화를 예측했다. 보존성 물질에 대한 모의 결과, 풍수기의 경우 저수기에 비해 유속이 크기 때문에 취수장에서 20.56시간 먼저 기준농도에 도달하고, 7.21시간 더 짧게 머무는 것으로 나타났다. 유해화학물질의 반응특성에 대한 민감도 분석을 시행한 결과, 생화학적 반감기가 18.98시간보다 길고, 옥탄올-물 분배계수가 2.267 이하인 물질은 생분해 및 흡·탈착 반응에 둔감한 것으로 나타났다. 1m 수심 기준 0.114m/s 이하 유속에서의 하천 수리조건에서는 화학물질의 휘발성을 무시할 수 있는 것으로 밝혀졌다.

• Proceedings of the Korea Air Pollution Research Association Conference
• /
• 한국대기환경학회 2001년도 추계학술대회 논문집
• /
• pp.354-355
• /
• 2001

DOAS (Differential Optical Absorption Spectroscopy) System은 대기 중에 존재하는 기준물질들이 특정 파장영역에서 빛을 흡수하는 원리를 이용하고 있다. 현재 독일을 중심으로 한 유럽과 선진국에서는 대기 환경 기준물질의 모니터링 기술들이 주로 광 투과방식을 이용한 Open path의 모니터링 기술들을 개발하고 있다. 기존의 측정 방법과 Open Path 모니터링의 기법을 비교 할 때 Open path 시스템은 실시간 측정 및 분석이 가능하므로 기존의 화학적 측정방법에서 제기되어져왔던 화학 반응시의 방해 물질의 간섭제거 및 시간 분해도 향상등에 큰 장점이 있다. (중략)

• Proceedings of the Korean Society of Disaster Information Conference
• /
• 한국재난정보학회 2022년 정기학술대회 논문집
• /
• pp.288-289
• /
• 2022

본 연구에서는 FDS(Fire dynamic simulation)를 이용하여 대형물류창고 화재에 대한 국내 스프링클러 설비 설치기준(NFSC)과 미국 방화협회규정(NFPA)의 스프링클러 설비 설치기준을 각각 시뮬레이션하여 발열량 및 반응물질, 초기 화재진화 정도 등의 데이터를 비교 분석하여 대형물류창고에 대한 스프링클러설비 설치기준 개선방안을 제시하고자 한다.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
• /
• 한국에너지공학회 1999년도 춘계 학술발표회 논문집
• /
• pp.207-212
• /
• 1999

화학반응이 일어나는 고정층 반응기의 성능을 모사하고 해석하기 위해서는 반응베드의 열 및 물질전달 특성을 정확히 아는 것이 중요하다. 본 연구에서는 화학열펌프에 사용되는 금속염-팽창흑연 다공성 반응매체의 유효열전도도와 기체투과도를 측정하였다. 유효열전도도는 전이 일차원 열류기법을 이용하여 측정하였고, 기체투과도는 Darcy's law를 이용하여 측정하였다. 팽창흑연이 함유된 반응베드의 유효열전도도와 기체투과도는 흑연을 기준으로 한 겉보기밀도에 따라 각각 14.1-36.5 W/mK, 8.0x$10^{-15}$-$10^{-12}$ $m^2$의 범위에 있었다.

• Parasites, Hosts and Diseases
• /
• 제33권2호
• /
• pp.117-124
• /
• 1995

This study was performed to evaluate diagnostic sensitivity and specificity of sonography on clonorchiasis. During the 9 months from March to November 1994, sonography skin test, stool examination, and medical examination were performed to 609 volunteers of Pohang which is located along the Hyongsan-gang (Rivers and is one of well-known endemic areas of clonorchiasis. The sensitivity of sonography was either 21% if the intrahepatic ducts dilatation was assumed to be the only positive anding or 52% if the periductal echogenicity was also included as one of positive findings. The sensitivity of skin test was 62%. The sensitivity was 46% if the diagnostic criteria were arbitrarily assumed as being positive in skin test and having either sonographic findings. The sonographic finding of fusiform, non-shadowing, weakly echogenic foci in gallbladder or in billiaiy tree indicating the flukes or aggregates of flukes was not obvious in this study. The specificity of sonography was either 95% if the intrahepatic ducts dilatation was assumed to be the only positive finding or 82% if the periductal echogenicity was also included as one of positive findings. The specificity of skin test was 52%. The specificity was 90% if the diagnostic criteria was arbitrarily assumed as being positive in skin test and having either sonographic findings.

• Korean Chemical Engineering Research
• /
• 제58권2호
• /
• pp.184-189
• /
• 2020

Van de Vusse reactors show the maximum points in input-output steady state maps and dramatic changes in their dynamic characteristics around those maximum points. According to their operating regions, there appear sign changes in steady state gains and nonlinear characteristics such as non-minimum phase dynamics which cause difficulties in applying controllers. Many nonlinear controllers that are available and newly designed are applied to these Van de Vusse reactor processes and their performances are tested. Reactor examples with real reactions have been reported. However, due to difficulties in constructing and operating chemical reactor systems, they are not adequate to be used for real applications of control experiments and hence most of results are based on simulations studies. Here, we propose a liquid level system that realizes most of the steady state and dynamic characteristics of Van de Vusse reactor, and two nonlinear control methods that can be used as base methods to compare nonlinear controllers newly designed. Liquid level experimental system and two nonlinear control methods are very simple and can be used to test performances of nonlinear controllers in practice.

• Journal of the Earthquake Engineering Society of Korea
• /
• 제15권1호
• /
• pp.39-48
• /
• 2011

In this present study, a response modification factor for a lightweight steel panel-modular system which is not clarified in a current building code was proposed. As a component of the response modification factor, an over-strength factor and a ductility factor were drawn from the nonlinear static analysis curves of the systems modeled on the basis of the performance tests. The final response modification factor was then computed by modifying the previous response modification factor with a MDOF (Multi-Degree-Of-Freedom) base shear modification factor considering the MDOF dynamic behaviors. As a result of computation for the structures designed as a dual frame system, ranging from 2-story to 5-story, the value of 4 was estimated as a final response modification factor for a seismic design, considering the value of 5 as an upper limit of the number of stories.