• Nuclear Engineering and Technology
• /
• v.20 no.1
• /
• pp.47-53
• /
• 1988

The objective of this study is to evaluate the reliability of the High Head Safety Injection System (HHIS) of KNU 5, 6, 7 and 8 following the removal of safety injection signal (s-signal) from the mini-flow bypass line valves of charging/safety injection pumps. The unavailability of HHSIS and the rupture probability of a charging/safety injection pump have been computed for two different cases; with s-signal on and removed. The results show that when the s-signal is removed from the mini-flow bypass line valves, the unavailability of HHSIS slightly increases while the rupture probability of a charging/safety injection pump is significantly reduced. Hence, based upon the results of this study we conclude that it is more reasonable to remove the s-signal from the mini-flow bypass line valves of KNU 5, 6, 7 and 8 in the normal plant operation. And to improve the availability of HHSIS, the modification of operational procedures and the emphasis on operator training are recommended.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.34 no.1
• /
• pp.223-233
• /
• 2014

This study empirically analyzes the relationships among the road and traffic experts' personal characteristics, the driving behavior and factors being expected to have an effect on the satisfaction about roundabout operation. The factors are drawn and grouped through the principle component analysis to clarify driving environment satisfaction on roundabout operation. Each group is named as personal attribute, driving behavior attribute, and satisfaction. After the variables are refined by confirmatory factor analysis, satisfaction model is developed with personal attribute and driving behavior attributes as exogenous variables and roundabout driving awareness and emotion attributes as endogenous variables. As a result, driving satisfaction of roundabout operation is directly influenced by delay reduction, safety improvement, capacity increase, sight improvement, severity accident reduction, and bicycle convenience and indirectly gender, age, driving time, and driving experience. Law obeyance, driving concession, traffic sign obeyance, and interposition do not statistically shows significant on satisfaction. As a result of Analytical Hierarchy Process (AHP), the turning radius of geometry and the driving behavior are important elements for roundabout safety.

• Korean Journal of Culture and Social Issue
• /
• v.15 no.2
• /
• pp.251-271
• /
• 2009

This research measured a concept of mobility which is included objective travel behavior as well as psychological and physical mechanism that influenced travel behavior. And then, this research examined the relation between mobility and the quality of life in elderly drivers. In research 1, to evaluate the reliability and validity of "Mobility Questionnaire(MQ)", we tested "MQ" to 207 drivers aged 20 years and older. In research 2, we examined the mobility level of elderly drivers. Also we investigated the influence that mobility of elderly drivers impacts on their quaility of life. we used "MQ", "Psychological Well-Being Questionnaire(PWBQ)" to 91 drivers aged 65 years and older. To factor analysis, MQ consisted of 'Safe Driving Ability(ADA)', 'Travel Increase(TI)', 'Travel Decrease(TD)', 'Social Activity(SA)', and 'Driving Situational Adaptability(DSA)'. The amount and speed of driving of elderly drivers reduced driving behavior than other drivers. Also, elderly drivers negatively assessed their physical abilities for safe driving and felt a low confidence in specific driving situation. On the other hand, elderly drivers take parts in social activity constructively. A review of the relation of mobility and quality of life showed that mobility of elderly drivers had positive correlation with PWB. Specially, 'ADA', 'SA', and 'DSA' had significant correlations with PWB of elderly drivers. The mobility of elderly drivers had an effect on 'Autonomy', 'Environmental mastery', 'Self-acceptance', and 'Positive relations with others'.

• Journal of Korean Society of Transportation
• /
• v.31 no.6
• /
• pp.34-42
• /
• 2013

The reasons of traffic accidents can be classified into the vehicle, road environment and human factors. In development of vehicle and road technologies, the human factor is the most important. The emotion research recently carried out showed that emotions play an important role in human judgment and decision making. They are also expected to partly determine driving behavior. The purpose of this study was to investigate the effects of drivers' emotions on their driving behavior. The results of this study showed that positive emotions do not affect driving behavior. As for negative emotions, however, safe driving(SD) and comfort driving(CD) factors have a negative correlation, and violence driving(VD) and regulation violation(RO) factors have a positive correlation. This study is significant as a basic study for establishing and determining a policy for reducing traffic accidents and for educating drivers.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 1990.10a
• /
• pp.125-128
• /
• 1990

조사후 시험시설(Post Irradiated Examination Facility, PIEF)은 내진범주 1 급 구조물로서 현재 각종 실험 및 연구가 진행중인 원자력 안전관련시설물 이다. 한편 이 건물로부터 30m - 120m 정도 떨어져 있는 다목적연구로 (Korea Multipurpose Research Reactor, KMRR) 및 조사재시험시설 (Irradiation Material Examination Facility, IMEF)의 건조사업을 위하여 기 초암반의 굴착작업을 수행할 경우 발파작업에 따른 그 진동 및 폭풍압영향 이 염려되어, 그 안전성 평가를 위하여 시험발파를 수행해야 할 필요가 제기 되었다. 우선 운전중인 원자력안전 시설물에서의 발파에 따른 진동허용 기준 을 설정하고, 둘째로 거리에 따른 폭발량을 경험식에 따라 잠정 결정한 후, 세째로 시험발파에 의한 진동 측정을 수행하여 그 영향을 평가하고, 끝으로 이에 따라 거리별 제한 폭발량을 결정한후 실제 본발파에 적용하고자 한다. 이로써 운전중인 원자력 안전관련시설물인 PIEF의 안전 운전을 도모하고 KMRR및 IMEF 시설의 건조를 원만하게 이룰 수 있을 것이다.

• Proceedings of the Korean Society of Disaster Information Conference
• /
• 2016.11a
• /
• pp.261-262
• /
• 2016

교통사고의 발생요인에는 다양한 원인들이 있지만 본 연구에서는 공간적으로 접근하여 사고유형별 분포특성을 도출하기 위해 공간적 자기상관성 분석을 수행하였다. 논문에서는 2012년부터 2014년까지 울산광역시에서 발생된 교통사고를 대상으로 분석을 수행하였다. 그 결과 울산시 전체 교통사고 약 53%는 안전운전불이행이며 다음으로는 안전거리미확보, 신호위반 순으로 나타났다. 밀도분석 결과는 사고유형별로 분포가 차이가 있었으며 안전운전불이행의 경우 가장 큰 군집은 중심시가지인 달동과 삼산동 중심에 나타났으며 중앙선침범은 도시의 중심부 보다는 면지역에 넓게 퍼져서 발생되었으며 산업단지가 있는 동구지역에 군집이 크게 나타났다. 따라서 읍면동별 공간적 특성을 파악하기 위해 Moran's I분석과 LISA분석을 수행한 결과 안전운전불이행, 안전거리미확보, 신호위반, 교차로운행방해 모두 중심시가지인 신정동, 달동, 삼산동이 공간적 자기상관성이 높았으며 중앙선침범의 경우 밀도분석 결과와 마찬가지로 중심시가지 이외에 읍면 지역도 자기상관성이 더 높게 나타났다. 이를 통해 사고유형별 공간의존성 및 이질성을 파악하여 교통사고 다발지역을 도출하고 이를 토대로 지역특성에 맞는 저감 대책 마련에 활용되고자 한다.

• Proceedings of the KSR Conference
• /
• 2003.05a
• /
• pp.456-461
• /
• 2003

기존선 속도 향상 및 병목현상 해소와 안전운행을 위해 국내 철도 현황의 주요 분야를 검토한 후, 국내 17년동안 사용으로 안전성이 검증된 신호기술을 바탕으로 국내 실정에 적합하며, 기존의 ATS 장치를 개선한 정보형 ATS(ATPS)를 개발하여 이를 제시하였다. 본 시스템은 운행 중인 열차의 제동특성을 고려하여 구간별 제한속도를 상향 조정하여 운행 효율을 증가 시킬 수 있다. 또, 안전성과 신뢰성 보장을 위해 Fail-Safe 및 이중계(redundancy)로 제작 하였고, 기존의 차상자와 발진기를 통합함으로써 Q factor를 개선하여 무응동 방지 및 기준 응동시간 비교방식을 통해 오동작을 개선하였다. 그리고, 정보기록 장치를 추가함으로써 이미 기록되어있는 차량정보데이터와 지상정보데이터를 연산하여 운전정보를 제공하고 기록한다. 또한, 이 운전정보는 정보 분석용 PC 및 프로그램에 의해 쉽게 분석, 관리가 가능하다. 무엇보다도 기존 ATS 구간과의 겸용사용으로 영업 운전시 안전한 연속 운행 보장 및 지상설비 개량 없이 안전을 확보할 수 있다. 다양한 종류의 동력차에 설치, 인터페이스 및 지상설비 개량이 용이하다. 향후 틸팅 시스템과 연계하여 틸팅 제어/감시 신호를 제공하는 기능을 갖는다.

• Nuclear industry
• /
• v.6 no.12 s.46
• /
• pp.32-34
• /
• 1986

원자력발전플랜트의 운전효율을 평가하는데 있어 최선의 방법은 무엇인지에 대한 논의가 최근 원자력계에서 활발히 전개되고 있다. 여기에 EDF 발전처 운전/원자력안전부의 Daniel Glorian차장의 이에 대한 견해를 소개한다.

• Nuclear Engineering and Technology
• /
• v.27 no.4
• /
• pp.470-482
• /
• 1995

The Ulchin 3&4, which are 2825 MWt PWRs, adopted Safety Depressurization System (SDS) to mitigate the beyond design basis event of Total Less of Feedwater(TLOFW). In this study the results and methodology of the analyses for the determination of SDS bleed capacity are discussed. The SDS design bleed capacity has been determined from the CEFLASH-4AS/REM simulation according to the following design criteria : 1) Each SDS flow path, in conjunction with one of two High Pressure Safety Injection (HPSI) pumps, is designed to have a sufficient capacity to prevent core uncovery if one SDS path is opened simultaneously with the opening of the Pressurizer Safety Valves (PSVs). 2) Both SDS bleed paths are designed to have sufficient total capacity with both HPSI pumps operating to prevent core uncovery if the Feed and Bleed (F&B) initiation is delayed up to thirty minutes from the time of the PSVs lift. To verify the results of CEFLASH-4AS/REM simulation a comparative analysis kas also been per-formed by more sophisticated computer code, RELAP5/MOD3. The TLOFW event without operator recovery and TLOFW event with F&B are analyzed. The predictions by the CEFLASH-4AS/REM of the transient too phase system behavior are in good qualitative and quantitative agreement with those by the RELAP5/MOD3 simulation. Both of the results of analyses by CEFLASH-4AS/REM and RELAP5/MOD3 have demonstrated that decay heat removal and core inventory make-up can be successfully accomplished by F&B operation during now event for the Ulchin 3&4.

• Journal of Korean Society of Transportation
• /
• v.24 no.3 s.89
• /
• pp.113-123
• /
• 2006

This article evaluates the effects of eight traffic safety policies such as traffic accident reduction campaign, the seat belt law, three strike out driving while intoxicated, rewarding for reporting traffic offenders on the number of accidents and fatalities. Intervention analysis of time series is used to compare the monthly accident and fatalities with the before and after reinforcement. The results indicate that no significant impact of the traffic enforcement measures on reducing the number of accidents and fatalities.