• Structural Engineering and Mechanics
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• v.51 no.6
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• pp.1005-1016
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• 2014

Roles of reactor internals are to support nuclear fuel, provide insertion and withdrawal channels of nuclear fuel control rods, and carry out core cooling. In case of functional loss of the reactor internals, it may lead to severe accidents caused by damage of nuclear fuel assembly and deterioration of reactor vessel due to attack of fallen out parts. The present study is to examine fluid flows in reactor internals subjected to hydrodynamic loads. In this context, an integrated model was developed and applied to two kinds of numerical analyses; one is to analyze periodic loading effect caused by pump pulsation and the other is to analyze random loading effect employing different turbulent models. Acoustic pressure distributions and flow velocity as well as pressure and temperature fields were calculated and compared to establish appropriate analysis techniques.

• Journal of Biosystems Engineering
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• v.18 no.1
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• pp.21-29
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• 1993

The purpose of this study was to develope a potato combine which can be attached to and controlled by three-point hitch of tractors. A vibrating mechanism was designed and constructed to dig potatoes, and to evaluate the effects of vibration on the potato harvesting performance of the test machine, potato separation from soil, harvesting loss, and damage to the potatoes. Three types of potato pick-up mechanisms were constructed and tested. Digging performance and material flow on the blade were improved as the vibrating amplitude and frequency increased and as the travel speed decreased. The sum of unrecovered and damaged potatoes was up to 7.8%. Three pick-up devices were not found to be useful by failing to elevate about 30% of dug potatoes to a given height.

• Journal of Korean Society for Geospatial Information Science
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• v.24 no.2
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• pp.95-106
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• 2016

Landslide is one of the natural hazards, triggered by rainfall or earthquake and it leads to damage and loss of properties and lives especially in hilly and mountainous regions. Inventory maps of the area is of much importance in order to understand the landslide phenomena in detail, conduct further studies on landslide, prepare susceptibility map and minimize risk. Inventory maps of landslides can be constructed by several methods, using multiple images through visual interpretation, using algorithms in multi-spectral or SAR images or verification from field investigation. The possible methods were explored for Sindhupalchowk district of Nepal, which was struck by massive earthquake on 2015 and landslide inventory was prepared. The inventory was analyzed for its frequency over elevation, slope aspect and dominant soil classes and also the information value for their occurrence probability.

• Molecules and Cells
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• v.22 no.3
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• pp.247-253
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• 2006

Protein modification by small ubiquitin-like modifier (SUMO) controls diverse cellular functions of protein targets including transcription factors and coregulators mainly in the nucleus and participates in maintaining cellular homeostasis. In addition, SUMO system plays important roles in DNA damage repair and maintaining genome integrity. Thus, in some cases, the loss of control on SUMOylation or deSUMOylation processes causes a defect in maintaining homeostasis and hence gives a cue to cancer development. Furthermore, recent study showed that SUMO system is also involved in cancer metastasis. In this review, we will summarize and discuss the possible role of SUMO system in cancer development and metastasis.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2004.05a
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• pp.90-95
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• 2004

Ail of the world, unification and extension of market enlarged scale of international commerce. Thus, not only production but also circulation of goods is brought into relief and transportation of most freights is performed using container. Container vessels are equipped with marry kinds of securing equipments such as Lashing, twistlock. Lashing is installed mainly in container vessel for the container stack with more than 3 containers. Damage of containers often arise from irrelevant lashing arrangement and bring economical loss. Much time and cost is requested for the Calculation of forces on container and determination of lashing arrangement In this study, We developed lashing analysis simulator which performs calculation and presenst relevant lashing arrangement. It will provide more convenient and efficient environment for lashing analysis.

• Proceedings of the Society of Korea Industrial and System Engineering Conference
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• 2002.05a
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• pp.25-30
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• 2002

The problem of qualitative reliability system is very important issue in the digitalized nuclear power plant, because the failure of its system brings about extravagant economic loss, extensive environment destruction, and fatal damage of human. Therefore this study is to develop the reliability evaluation model through the normalized scoring model by the quantitative and qualitative factors considering the advanced safety factors In the Advanced Pressurized water Reactor 1400MWe(APR 1400) under uncertainty Especially, the qualitative factors considering the information and human factors for the systematic and rational justification have been closely analyzed. The reliability evaluation model can be simply applied in real fields in order to minimize the industrial accident and human error in the digitalized nuclear power plant.

• Journal of Electrical Engineering and Technology
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• v.6 no.1
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• pp.123-127
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• 2011

To clarify the relations of optical properties to the main factors responsible for the loss and damage of luminous efficacy, a 20 min turn-on/turn-off test for 2,000 h for a ceramic metal halide lamp is conducted. The corrosion rates of the arc tube wall and electrode are estimated based on thermal stress. Wall blackening is attributed to the tungsten being transported from the hot electrode tips to the relatively cold arc tube wall. Furthermore, the grain boundaries of the arc tube are changed by the degradation. Distortion of the electrode is observed, and the ignition and the driving voltage of the load both increase. Finally, the color rendering index and the color coordinates are changed after the degradation. The luminous flux and the intensity of the luminous distribution are decreased significantly.

• Wind and Structures
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• v.19 no.6
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• pp.603-621
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• 2014

Past high speed wind events have exposed the vulnerability of the roof systems of existing light-framed wood structures to uplift loading, contributing greatly to economic and human loss. This paper further investigates the behaviour of light-framed wood structures under the uplift loading of a realistic pressure distribution. A three-dimensional finite-element model is first developed to capture the behaviour of a recently completed full-scale experiment. After describing the components used to develop the numerical model, a comparison between the numerical prediction and experimental results in terms of the deflected shape at the roof-to-wall connections is presented to gain confidence in the numerical model. The model is then used to analyze the behaviour of the truss system under realistic and equivalent uniform pressure distributions and to perform an assessment of the use of the tributary area method to calculate the withdrawal force acting on the roof-to-wall connections.

• International Journal of Highway Engineering
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• v.16 no.3
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• pp.59-66
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• 2014

PURPOSES : This study is to suggest heavy snow risk analysis in Seoul. METHODS : Recently, the increase of extreme weather caused by global warming raises the occurrences of unpredictable natural disasters and the loss potential of human disasters by land use facilities accumulation. It is necessary to develop the risk analysis for the natural and human disasters. RESULTS : In this study, heavy snow risk analysis among natural disasters in Seoul was suggested. The spatial unit of risk analysis level was established for the lines and administrative districts. CONCLUSIONS : The risk analysis was performed using risk matrix of disaster occurrence score and disaster damage score. The components affecting the risk disaster analysis by types were analyzed and the application of heavy snow risk analysis was suggested.

• 한국방재학회:학술대회논문집
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• 2008.02a
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• pp.605-608
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• 2008

Storm and flood damage management systems in national disaster management system(NDMS) were organized into three operation systems. They are prevention, preparation, response, and recovery systems. Disaster resources in each system must be promptly and exactly applied to minimize casualties and loss of properties. However, the disaster resources in current management system can not be immediately used in calamity situation due to the lack of efficiency in statistical data. Therefore, it is necessary to classify the emergency restoration equipment for efficient management and mobilization of disaster resources in disaster situation. In this study, field survey was executed to appropriately classify the emergency restoration equipment. Problems and reformation points of the disaster resources system were also presented to improve the classification technique and to construct the data base.