• 한국안전학회지
• /
• 제31권6호
• /
• pp.99-104
• /
• 2016

Road Sink Phenomenon (RSP) is one of the major issues in South Korea. National and local governments are trying to develop effective preventive measures against the RSP. Developing the policy-oriented RSP management is most important to minimize possible losses induced by RSP. In this study, we employed the Futures Wheel (FW) method to derive influence factors for RSP management. FW method is widely used for predicting future social-environmental condition. In addition, RAND Corporation's method is used to derive potential strategic agenda based on derived influence factors by FW method. These derived strategic agenda can contribute to develop the policies related with RSP management.

• 한국터널지하공간학회 논문집
• /
• 제13권2호
• /
• pp.115-131
• /
• 2011

최근 들어 방재 및 환경훼손 측면을 고려하여 병설터널의 시공 사례가 증가하고 있다. 병설터널의 굴착 시 필라(Pillar)부에 응력이 집중되어 터널의 안정성이 저하된다. 필라부의 거동에 대한 기존 연구들은 주로 수치해석과 실내 모형 실험을 통한 병설터널의 거동평가 및 지표침하 경향 분석 등에 국한되어 있어서, 필라부의 정량적 안정성 평가에는 한계가 있다. 따라서 본 연구에서는 병설터널의 필라폭이 터널의 안정성에 미치는 영향을 정량적으로 살펴보았다. 이를 위해 토피고가 다른 두 단면에 대해 전단강도 감소법을 이용한 수치해석적 방법으로 구한 터널 전체 안전율, Matsuda 등이 제안한 식을 이용하여 구한 필라부 국부안전율, 및 필라부의 강도/응력비를 산정하고 결과를 분석하였다. 합리적인 병설터널의 필라부 설계를 위해, 평균 강도/응력비, Matsuda 제안식에 의한 안전율, 수치해석적으로 구한 전체 안전율이 독립적으로 사용되기보다는 유기적으로 사용되어야 할 것으로 판단되었다.

• Nuclear Engineering and Technology
• /
• 제42권4호
• /
• pp.450-459
• /
• 2010

The present paper investigates the collapse pressure of cylinders with intermediate thickness subjected to external pressure based on detailed elastic-plastic finite element (FE) analyses. The effect of the initial ovality of the tube on the collapse pressure was explicitly considered in the FE analyses. Based on the present FE results, the analytical yield locus, considering the interaction between the plastic collapse and local instability due to initial ovality, was also proposed. The collapse pressure values based on the proposed yield locus agree well with the present FE results; thus, the validity of the proposed yield locus for the thickness range of interest was verified. Moreover, the partial safety factor concept based on the structural reliability theory was also applied to the proposed collapse pressure estimation model, and, thus, the priority of importance of respective parameter constituting for the collapse of cylinders under external pressure was estimated in this study. From the application of the partial safety factor concept, the yield strength was concluded to be the most sensitive, and the initial ovality of tube was not so effective in the proposed collapse pressure estimation model. The present deterministic and probabilistic results are expected to be utilized in the design and maintenance of cylinders subjected to external pressure with initial ovality, such as the once-through type steam generator.

• Nuclear Engineering and Technology
• /
• 제40권1호
• /
• pp.37-48
• /
• 2008

Flow fields inside feeder pipes have been simulated numerically using a CFD (computational fluid dynamics) code to calculate the shear stress distribution, which is the most important factor in predicting the local regions of feeder pipes highly susceptible to FAC (flow-accelerated corrosion)-induced wall thinning. The CFD approach, with schemes used in this study, to simulate the flow situations inside the CANDU feeder pipes has been verified as it showed a good agreement between the investigation results for the failed feedwater pipe at Surry unit 2 plant in the U.S. and the CFD calculation. Sensitivity studies of the three geometrical parameters, such as angle of the first and second bends, length of the first span between the grayloc hub and the first bend, and length of the second span between the first and the second bends have been performed. CFD analysis reveals that the local regions of feeder pipes of Wolsung unit 1 in Korea, on which wall thickness measurements have been performed so far, are not coincident with the worst regions predicted by the present CFD analysis located in the connection region of straight and bend pipe near the inlet part of the bend intrados. Finally, based on the results of the present CFD analysis, a guide to the selection of the weakest local positions where the measurement of wall thickness should be performed with higher priority has been provided.

• EDISON SW 활용 경진대회 논문집
• /
• 제6회(2017년)
• /
• pp.324-329
• /
• 2017

The purpose of this study is to optimize the artificial lumbar spine with the most lightweight three - dimensional porous structure while satisfying the safety factor of 3. We have introduced representative volumes to proceed with a local analysis and studied the maximum porosity distribution that meets allowable stress. The maximum porosity was studied at 12 points and the intermediate values were predicted based on this points. If the lumbar spine is designed according to this predicted results, the optimal design will be achieved.

• 한국실내디자인학회논문집
• /
• 제24권2호
• /
• pp.11-20
• /
• 2015

To make provision for the super-aged society, the senior welfare facility which is a kind of typical physical environment of the nursing service would be expected to perform a very important role in local community. This study was conducted to identify the constructs of the servicescapes of senior welfare facility and to draw analysis indicators of it. For this, we performed literature review based on domestic & foreign government guide, service marketing theory and interior architectural results concerning the physical environment of the senior welfare facility. The result of this study showed as follows: servicescapes of the senior welfare facility could be explained as "a whole set of physical environment to support a variety of services provided by the senior welfare facility for the elderly or services of the kind of tangible clues". Analysis indicators of the senior welfare facility's servicescape could be explained as five factors: safety factor, functional factor, aesthetic factor, ambient factor and social factor. In addition we developed 37 pieces of detailed factors referred to five factors. The evaluation and verification of analysis indicators was carried out through 8 experts in-depth interviews. We inspected importance factor using a 5-point Likert scale, therefore safety factor was 4.41, functional factor was 4.27, aesthetic factor was 3.66, ambient factor was 4.20 and social factor was 4.25. More than anything else, in this study, there is a sense that it has established the concept of servicescape adapted to the senior welfare facility and contained a social element between the employees and the physical environment. Theoretical and practical implications of findings are discussed, and future research directions are proposed. we expect to be a little or benefits to the senior welfare facility corresponding to the future of the super-aged society.

• 한국철도학회논문집
• /
• 제6권3호
• /
• pp.156-162
• /
• 2003

Due to almost all tracks of new Kyoungbu high-speed lines(HSL) consisting of bridges and tunnels, HSR operational safety management is very important factor for passenger safety and preventing catastrophic event. Especially, it is important to approach the scene of the accident and assist in saving lives as soon as possible under emergency conditions. Therefore it is essential to prepare access methods and available resources in advance in order to support emergency correspodances promptly and effectively. This paper persents an application of geographical information system(GIS) for developing emergency management system as well as batabase system on tracks and facilities, electric/communication equipment and safety equipment required to support emergencies. The on-site information on the proximity of HSL is expressed on the numerical map, which can be helpful to call external supports such as medical service, local authorities, police offices, fire brigades, and etc. for the emergency situations.

• 대한안전경영과학회지
• /
• 제3권3호
• /
• pp.33-44
• /
• 2001

Needs of each enterprises for safety managers ability should be clarified and then the result should be taken into account regular curriculum and assessed it regularly. Keeping the student competance without this series of feedback will not be possible. A method, to assess the effectiveness of curriculum course, DACUM(Developing A Curriculum) could be applied in order to find out what subject will be useful. Questionnaire results with weight factor could be put into this study Task Analysis method and the importance determining method have been introduced here. As a further study, it is concealed that a study taking into account of company size, nature, local situation are needed to find out more useful application.

• 한국터널지하공간학회 논문집
• /
• 제10권1호
• /
• pp.25-36
• /
• 2008

해저 지하구조물을 시공할 경우는 높은 수압 및 침투압 등의 영향이 무시될 수 없으므로 지하구조물의 정확한 거동평가를 위해서는 수리-역학적 연계해석이 수행되어야만 한다. 또한, 실무에서는 암반이완하중을 고려하여 터널의 콘크리트 라이닝을 설계하며, 이를 위해 이완하중고($H_{relaxed}$)를 터널 주변의 국부안전율 분포를 이용하여 수치해석에 의해 산정하는 방법이 제안된 바 있다. 따라서 본 연구에서는 해저터널을 대상으로 수리-역학적 연계해석 시 국부안전율을 이용한 이완하중고 산정 기법의 타당성을 살펴보았다. 3 등급 암반을 대상으로 숏크리트 수리특성을 이용한 유도 배수방법과 집수정펌핑을 이용한 유도 배수 방법을 비교한 결과 집수정 펌핑을 이용한 유도 배수방법이 보다 신뢰할 수 있는 결과를 준다고 발표된 바 있다. 따라서 본 연구에서는 집수정의 펌핑을 이용한 유도 배수방법을 이용하여 1, 3, 5 등급 암반을 대상으로 이완하중고를 산정하여 제안식들과 적용성을 비교하였다. 연구 결과 연계해석 시 해저 시설물의 이완하중고를 정확하게 산정하기 위해서는 기존에 제시된 이론식 보다는 집수정의 펌핑을 이용하여 유도 배수하는 모델링 방법이 보다 정확하고 일관성 있는 결과를 얻을 수 있었다.

• 대한기계학회논문집B
• /
• 제36권8호
• /
• pp.783-789
• /
• 2012

본 연구에서는 나선형 튜브내의 난류 열전달 및 하중 특성을 수치해석 방법을 이용하여 파악하였다. 열교환기와 같은 공학적 설비에서 관내 열전달을 향상시키기 위해 튜브의 형상을 나선형으로 설계한다. 이에 나선형 튜브내의 열전달 및 난류 특성에 대한 많은 실험적 연구가 이루어 졌으나, 대부분의 연구가 압력 강하 및 열전달 상관관계에 초점이 맞추어 진행되었다. 나선형 튜브내의 유동은 원심력에 의해 튜브 바깥쪽에서는 상대적으로 높은 열전달 및 전단응력이 발생하지만, 안쪽에서는 낮은 열전달 및 전단응력이 발생하게 된다. 따라서 본 연구에서는 튜브의 원주방향으로 발생하는 전단 응력 및 Nusselt 수의 변화를 Reynolds 수와 나선 코일의 지름을 변경하며 정량적으로 살펴보았다. 나선 코일 안쪽에서 국부적인 전단응력과 열전달율이 크게 낮게 특정되었으며, 이는 튜브 재질의 안정성에 영향을 미칠 것으로 판단되었다. 또한 본 연구에서는 마찰계수와 Nusselt 수에 대한 기존 상관관계식을 검증하였으며, 직관에서의 마찰계수와 Nusselt 수의 상관관계식이 나선형 튜브의 형상에도 적용될 수 있음을 관측하였다. 본 연구의 결과는 열교환기나 증기발생기의 안전성 평가를 위해 중요한 데이터로 활용될 수 있을 것이다.