• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.1B
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• pp.15-25
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• 2006

Using kinematic wave equation, the influence of moving storms to runoff was analysised with a focus on watersheds. Watershed shapes used are the oblong, square and elongated shape, and the distribution types of moving storms used are uniform, advanced and intermediate type. The runoff hydrographs according to the rainfall distribution types were simulated and the characteristics were explored for the storms moving down, up and cross the watershed with various velocity. The shape, peak time and peak runoff of a runoff hydrograph are significantly influenced by spatial and temporal variability in rainfall and watershed shapes. A rain storm moving in the cross direction of channel flow produces a higher peak runoff than in the downstream direction and upstream direction. A peak runoff from a storm moving downstream exceeds that from a storm moving upstream. For storms moving downstream peak time was more delayed than for other storm direction in the case of elongated watershed. The runoff volume and time base of the hydrograph decreased with the increasing storm speed.

• Journal of Bio-Environment Control
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• v.27 no.1
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• pp.64-70
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• 2018

In this study, eleven major coastal areas were selected and the climate environment and the greenhouse direction were analyzed. This research investigates the greenhouse heat loss according to the wind environment at target areas. The target areas were selected based on heated greenhouse cultivation area and wind environment standard. Temperature, wind speed, and wind direction among weather data for 30 years were collected and analyzed. The data were divided into the minimum, average, and maximum temperatures and the Meteorological Agency criteria applied to the weather and wind direction criteria. Data were collected in the range of $0{\sim}180^{\circ}$ considering the symmetry of the shape of the greenhouse. In addition, the wind direction is different for each region and the applied wind direction can be different when referring to the longitudinal direction of the greenhouse and the data are collected in the range of $0{\sim}90^{\circ}$. The results of this study are expected to be used to calculate the heating load of greenhouse installed in places wind speed high.

• The KIPS Transactions:PartB
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• v.11B no.3
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• pp.309-316
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• 2004

In this paper, we proposed the TDS(T-shape Diamond Search) based on the directions of above, below, left and right points to estimate the motion vector fast and more correctly in this method, we exploit the facts that most motion vectors are enclosed in a circular region with a radius of 2 fixels around search center(0,0). At first, the 4 points in the above, below, left and right around the search center is calculated to decide the point of the MBD(Minimum Block Distortion). And then w. above point of the MBD is checked to calculate the SAD. If the SAD of the above point is less than the previous MBD, this process is repeated. Otherwise, the right and left points of MBD are calculated to decide The points that have the MBD between right point and left point. Above processes are repeated to the predicted direction for motion estimation. Especially, if the motions of image are concentrated in the crossing directions, the points of other directions are omitted. As a result, we can estimate motion vectors fast. Experiments show that the speedup improvement of the proposed algorithm over Diamond Search algorithm(DS) and HEXgon Based Search(HEXBS) can be up to 38∼50％ while maintaining similar image Quality.

• Journal of Korean Tunnelling and Underground Space Association
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• v.18 no.5
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• pp.499-509
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• 2016

In recent years, the use of underground spaces becomes more frequent and the demands for urban tunnels are rapidly increasing. The urban tunnels constructed in the ground with a shallow and soft cover might be deformed in various forms on the face, which would lead, the tunnels to behavior 3-dimensionally, which may have a great impact on the longitudinal load transfer. The tunnel face might deform in various forms depending on the construction method, overburden and the heterogeneity of the ground. And accordingly, the type and size of the distribution of the load transferred to the ground adjacent to the tunnel face as well as the form of the loosened ground may appear in various ways depending on the deformation form of the tunnel face. Therefore, in this study was conducted model tests by idealizing the deformation behavior of the tunnel face, that were constant deformation, the maximum deformation on the top and the maximum deformation on the bottom. And the test results were analyzed focusing on the deformation of the face and the longitudinal load transfer at the ground above the tunnel. As results, it turned out that the size and the distribution type of the load, which was transferred to the tunnel as well as the earth pressure on the face were affected by the deformation type of the face. The largest load was transferred to the tunnel when the deformation was in a constant form. Less load was transferred when the maximum deformation on the bottom, and the least load was transferred when the maximum deformation on the top. In addition, it turned out that, if the cover became more shallow, a longitudinal load transfer in the tunnel would limited to the region close to the face; however, if the cover became higher than a certain value, the area of the load transfer would become wider.

• Journal of the Korean association of regional geographers
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• v.13 no.4
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• pp.396-408
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• 2007

Natural disasters occurred in Inje and Pyeongchang in 2006 show that unusual changes of weather, which Korean Peninsula has not experienced before, are becoming quite common phenomenon nowadays. In future we have to proceed in the direction of preventing such disasters so as to minimize the damage, by analyzing character and cause of various disasters whenever necessary, performing modeling in simulated real world, and applying the results in disaster prevention policy next year. Applying GIS in this process, the best information for decision-making can be offered. This study has also progressed proceeding from such point of view. The results of this study show that local concentrated heavy rain, caused by the primary topographical factor in the Sulak mountain region, was the main cause of flood disaster occurred in Inje-Gun area in July of 2006. Local concentrated heavy rain is greatly affected by topography. Namely, if there is a mountainous region behind, the area opposite to the direction of rain clouds motion will have high possibility of local concentrated heavy rain.

• Journal of Korean Society of Forest Science
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• v.106 no.3
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• pp.330-339
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• 2017

In Korea, metropolitan cities and provinces are responsible for setting up their own Regional Forest Plans to manage the forests at regional scales distinguished by administrative boundaries, and the role of the plans are very crucial by linking the Forest Basic Plan for nationwide forest management policy with Forest Management Plans for local-level forest management practices. Thus, the analysis of forest resources at regional levels is required to make more efficient regional forest plans by properly reflecting regional forest situations. This study aims to present which species are concentrated at each individual metropolitan city or province, contributing to more efficiently establishing its regional forest plan. In order to measure the concentration levels of species for each region, Location Quotient and Relative-Specialization Index are computed using area- and volume-data for the major species selected in the Statistical Yearbook of Forestry. As a result, the ranks among the indices of the major species for each individual municipal city and province are presented. The results from this study can contribute to the selection of regional target species and establishment of regional forest management objectives. Further study regarding the differences between the results from area-based and volume-based indices will be helpful to consider regional level productivity by species into the regional forest plans.

• Review of Culture and Economy
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• v.21 no.1
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• pp.3-20
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• 2018

This study investigates a comprehensive context between the vertical integration and concentration of Korean film market. The concentration of distribution and screening markets are result of industrial strategy to defend demand uncertainty and to pursue economies of scale. Major distributors are increasingly inclined to defend industrial risk by concentrating resources on blockbusters and bargaining power of the multiplex is getting strengthened by distribution competition to secure as many screens as possible. Vertically integrated multiplexes operate discriminatory preferential treatment to their affiliates, however, there is a difference in degree of discrimination between vertically integrated groups. Furthermore, it is difficult to exclude each other from the distribution competition in which the largest screen number has to be secured. It is difficult for multiplex only to pursue the interests of affiliates and make negative choices in screening performance. As the number of screening screens increases, the seat occupancy also increases. As a result, the polarization of the distribution and screening markets, including the screen monopoly, is a phenomenon that occurs commercial films centered markets and the unfair behavior of the vertically affiliated multiplex has a limited effect on the movie market.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.12
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• pp.1581-1587
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• 2020

With the emergence of convolutional neural network in the field of machine learning, the model for solving image processing problems has seen rapid development. However, the computing resources required are also rising, making it difficult to learn from a typical environment. Attention mechanism is originally proposed to prevent the gradient vanishing problem of the recurrent neural network, but this can also be used in a direction favorable to learning of the convolutional neural network. In this paper, attention mechanism is applied to convolutional neural network, and the excellence of the proposed method is demonstrated through the comparison of learning time and performance difference at this time. The proposed model showed that both learning time and performance were superior in object detection based on YOLO compared to models without attention mechanism, and experimentally demonstrated that learning time could be significantly reduced. In addition, this is expected to increase accessibility to machine learning by end users.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.89-89
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• 2015

항만 및 어항 구조물을 구성하는 다양한 해안구조물은 파랑의 천수효과, 굴절, 회절, 부분반사, 해저마찰, 쇄파의 영향 등을 고려해야하며 파고 및 파향 등의 해양특성의 검토가 반드시 이루어져야 한다. 실제의 해양파가 방향스펙트럼을 갖는 다방향 불규칙파라는 것은 잘 알려져 있으며, 기존의 해안구조물의 내파설계 또는 천해역의 파랑변형 검토에 있어서도 실제 해양파에 보다 가까운 다방향 불규칙파를 이용한 수리모형실험에 의해 파랑현상을 정도 높게 재현하는 것은 매우 중요하다. 본 연구에서는 실제 해양파를 정도 높게 재현할 수 있는 다방향 불규칙파 조파장치를 사용하여 구조물 전면해역에서의 파랑스펙트럼을 재현하고, 심해에서 발달된 파랑이 천해로 진행될 때 지형에 의해 발생되는 천수변형과 구조물 주위에서 나타나는 파랑변형의 현상을 고려하여 항내로 유입되는 파랑의 분포 특성을 검토하였다. 특히, 다방향 불규칙파로 인한 항내 파고분포 특성을 검토하기 위하여 동일 파랑에 대한 규칙파 및 불규칙파랑을 조파하여 그 결과를 상호 비교하였다. 아울러, 정온수역유지를 위한 월파현상을 수리적으로 재현할 수 있는 3차원 수리모형실험 수행하여 월파현상이 항내정온도에 미치는 영향을 고찰, 해석하여 항만 시설물 계획시 안정한 정박 및 이용에 대한 가능한 정온유지여부를 검토하였다.

• Journal of the Earthquake Engineering Society of Korea
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• v.9 no.1 s.41
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• pp.17-24
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• 2005

Response of reinforced concrete (RC) column-bent piers subjected to bidirectional seismic loadings was experimentally investigated. RC column-bent piers represent one of the most popular shapes of piers used in Korea highway bridges. Four column-bent piers were constructed in 400 mm diameter and 2,000 mm height. Each pier has two circular supporting columns. These piers were tested under bidirectional lateral load reversals with an axial load of $0.1f_{ck}A_g$. The test parameters included : different transverse reinforcement contents and lap-spliced longitudinal reinforcing steels. Test results indicate that the lap splice of longitudinal reinforcing steels have significantly influenced on hysteretic response of column-bent piers similar to previous test results for single columns with corresponding test parameters. Column capacity was changed with the level of transverse confinement. From the comparison of test result for single column under unidirectional loading, the damage of single column was concentrated on lower plastic hinge region but the damage of column-bent piers was scattered to upper and lower plastic hinge region.