• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 B
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• pp.1400-1402
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• 2004

The safety of staff, customers and of general Public in general viewed as one of the most important requirements in the urban transit. The maintenance computerization system for car of urban transit is a part of standardization and development of urban transit system. and We have been performed the establishment of maintenance computerization system from 2001 to 2005. The RAMS (reliability. availability. maintainability and safety) estimation for maintenance computerization system are utilized in a variety of computerization system for user's convenience and safety in maintenance. Ever since its inception though. the urban transit has searched for ways to improve reliability. availability. maintainability and safety of the railway subsystem. Provision of a reliable maintenance system include RAMS of the vehicles plays a very important role in achieving a safe system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.1179-1180
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• 2007

Urban transit is system that offer target Performance and function because various lower part system such as vehicles, signaling, power supply, rail track is consisted as complex. It is important first of all that describe correctly system requirement until configuration of system, design, manufacture, installation and test verification so that the complicated urban transit system is to act safety and reliable and to display target Performance and function properly. The system requirement assist the system developer to comprehensive the performance and function of system in basic design. Therefore, In this paper wishes to study way to analyze system of system requirement and apply to Urban transit.

• 한국환경생물학회:학술대회논문집
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• 한국환경생물학회 2002년도 춘계공동학술대회 및 심포지움 초록집
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• pp.28-28
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• 2002

• 한국환경생물학회:학술대회논문집
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• 한국환경생물학회 2002년도 춘계공동학술대회 및 심포지움 초록집
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• pp.29-29
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• 2002

• 한국대기환경학회:학술대회논문집
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• 한국대기환경학회 1998년도 한국대기보전학회 춘계학술대회 요지집
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• pp.115-115
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• 1998

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2009년도 학술발표회 초록집
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• pp.415-420
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• 2009

공학 분야에 있어서 수치 해석적 연구가 많은 주목을 받고 있다. 경제적 측면을 비롯한 다양한 측면에 있어서 모의의 간편성으로 인해 하천에서의 수리학적 거동모의에 수치해석 모의 분석법이 쓰이고 있는데 모의결과의 비교 및 검증을 위해서는 현장 실험 혹은 모형실험이 선행되어야만 한다. 본 연구에서는 강재로 제작된 S자 형태의 만곡부를 두 개 갖고 있는 사행수로 실험 장치를 제작하여 두 가지 유량조건 (30, 60 ${\ell}$/sec.)과 두 가지 하류단 수위조건 (30, 40 cm)에 대하여 수평 2차원 유속분포 자료를 이용하였다. 유속장의 자료는 Sontek사에의 3차원 micro-ADV(Acoustic Doppler Velocimeter)를 이용하여 측정하였다. 주 흐름은 직선구간에서는 중앙에서 최대 유속을 나타내며, 좌우대칭적인 유속분포의 모습을 보이고, 만곡부에서는 수로안쪽을 따라 최대유속이 발생하였다. 이는 만곡부의 정점부분에서의 이차류 발생 및 소멸에 의한 연직방향 유속분포를 통해 발생되는 현상이라 사료된다. 또한 본 연구에서는 2차원 하천해석 상용프로그램인 RAMS (베타버젼)와 SMS를 이용하여 흐름해석을 수행하였다. 실험 자료와의 비교를 통하여 두 가지 상용프로그램의 경우 모두 다소 과대 산정되는 것을 알 수 있었고, 만곡부와 직선부의 유속분포에 대한 모의결과는 RAMS (RAM2)의 결과가 보다 실험결과와 잘 일치하는 것으로 분석되었다. 위와 같은 유속분포의 분석을 통하여 각각의 상용소프트웨어의 적용성을 비교해 보았으며 향후 오염물질 거동해석 모형을 실험수로에 적용하여 그 결과를 비교할 수 있을 것으로 예상한다.

• 한국대기환경학회지
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• 제22권1호
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• pp.73-84
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• 2006

Hazardous Air Pollutants (HAPs) are characterized by being relatively heavier and denser than that of ambient air due to the various reasons such as higher molecular weight, low temperature and other complicated chemical transformations (Witlox, 1994). In an effort to investigate transport and diffusion from instantaneous emission of heavy gas, Lagrangian Particle Dispersion Model (LPDM) coupled with the RAMS output was employed. Both deposition process and buoyancy term were added on the atmospheric diffusion equations of LPDM, and the locations and concentrations of dense gas particle released from instantaneous single point source (emitting initially for 10 minutes only) were analyzed. The result overall shows that adding deposition process and buoyancy terms on the diffusion equation of LPDM has very small but detectable effect on the vertical and horizontal distribution of Lagrangian particles that especially transported for a fairly long traveling time. Also the slumping of dense gas can be found to be ignored horizontally compared to the advection by the horizontal wind suggesting that it was essential to couple the Lagrangian particle dispersion model coupled with the RAMS model in order to explain the dispersion of HAPs more accurately. However, during the initial time of instantaneous emission, buoyancy term play an important role on the vertical locations of dense particles for near surface atmosphere and around source area, indicating the importance of densities of HAPs in the beginning stage or short duration for the risk assessment of HAPs or management of heavy vapors during the explosive accidents.

• Asian-Australasian Journal of Animal Sciences
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• 제20권6호
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• pp.925-932
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• 2007

This study was designed to measure the effect of regrowth age of Digitaria decumbens (D. decumbens) on the intake and dynamics of digesta in the rumen of rams. Six Black-belly rams (mean liveweight: 51.6 (s.d. 0.68) kg) fitted with rumen cannulae were fed twice daily a 14-, 28-, 42- and 56-day old fresh D. decumbens successively for 4 experimental periods. The daily dry matter intake decreased curvilineary from 75.2 to 48.5 (s.e. 2.0) g/kg $BW^{0.75}$ as the age of the D. decumbens grass increased from 14 to 56 days. Dry matter intake for the first 3 h after the morning meal was 863.6, 598.3, 576.4 and 401.5 (s.e. 55.6) g for the 14-, 28-, 42- and 56-day old grasses respectively. The pool of NDF in the rumen at the end of the 3-h feeding period did not vary significantly among the four diets. Twelve hours after the beginning of the morning meal, the pool of NDF increased with the forage regrowth age. Within the total pool of NDF, the pool of large particles tended to increase with the regrowth age. It was concluded that high intake was associated with fast evacuation of NDF from the rumen. Moreover, digestion (cellulolysis) rate and degree of particle reduction by rumination are highly correlated, though speed of physical degradation of forage seems to be the driving force behind intake.

• Genomics & Informatics
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• 제1권1호
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• pp.40-49
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• 2003

The genes related to specific events or pathways in bacteria are frequently localized proximate to the genome of their neighbors, as with the structures known as operon, but eukaryotic genes seem to be independent of their neighbors, and are dispersed randomly throughout genomes. Although cases are rare, the findings from structures similar to prokaryotic operons in the nematode genome, and the clustering of housekeeping genes on human genome, lead us to assess the genomic association of genes as functional subunits. We evaluated the genomic association of neighboring genes on chromosomes 4 and 5 of Arabidopsis thaliana with and without respectively consideration of the scaffold/matrix­attached regions (S/MAR) loci. The observed number of functionally identical bigrams and trig rams were significantly higher than expected, and these results were verified statistically by calculating p-values for weighted random distributions. The observed frequency of functionally identical big rams and trig rams were much higher in chromosome 4 than in chromosome 5, but the frequencies with, and without, consideration of the S/MAR in each chromosome were similar. In this study, a genomic association among functionally related neighboring genes in Arabidopsis thaliana was suggested.

• 한국철도학회논문집
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• 제13권4호
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• pp.412-418
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• 2010

본 논문에서는 최근 들어 철도신호시스템분야에서 중요한 이슈로 부각되고 있는 소프트웨어 측면에서의 신뢰성과 안전성 수준을 국제규격(IEC 62279)에 부합할 수 있도록 하기 위한 접근방법을 모색하며, 실제 적용사례(국토해양부 및 한국건설교통기술평가원이 주관하는 국가 대형연구개발 실용화 사업인 "도시형 자기부상열차 실용화사업 시범노선 건설 열차제어시스템 구매/설치")를 통하여 현실적이고 접근가능한 구체적인 활동 사항들을 프로젝트 수행과 연관하여 기술한다. 또한 열차제어시스템의 안전성 인증 획득을 위한 소프트웨어를 포함한 시스템 보증활동 및 시스템 보증을 위한 조직체계를 확립하고, 요구사항 관리 및 프로젝트 공정에 따른 절차적 시스템 보증 활동과 안전성평가 활동과의 연관관계, 시스템 전반에 걸친 RAMS 및 소프트웨어 품질보증 활동과 안전성 평가를 통한 인증활동에 대한 부분을 상세 제시하고자 한다. 본 활동을 통하여 지금까지 국제규격에 따른 활동기준에 대해서 모호하거나, 명확하게 정의되지 않은 사항들이 체계적으로 정리될 수 있을 것으로 사료되며, 타 사업 및 국내 철도신호시스템 적용을 위한 소프트웨어 품질 및 안전 무결성 수준 확보에 따른 안전성 확보방안의 구체적인 케이스 모델이 될 것으로 기대된다.