• Journal of Internet Computing and Services
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• v.16 no.3
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• pp.21-32
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• 2015

Since spatio-temporal local features for video representation have become an important issue of modeless bottom-up approaches in action recognition, various methods for feature extraction and description have been proposed in many papers. In particular, BoF(bag of features) has been promised coherent recognition results. The most important part for BoF is how to represent dynamic information of actions in videos. Most of existing BoF methods consider the video as a spatio-temporal volume and describe neighboring 3D interest points as complex volumetric patches. To simplify these complex 3D methods, this paper proposes a novel method that builds BoF representation as a way to learn 2D interest points directly from video data. The basic idea of proposed method is to gather feature points not only from 2D xy spatial planes of traditional frames, but from the 2D time axis called spatio-temporal frame as well. Such spatial-temporal features are able to capture dynamic information from the action videos and are well-suited to recognize human actions without need of 3D extensions for the feature descriptors. The spatio-temporal BoF approach using SIFT and SURF feature descriptors obtains good recognition rates on a well-known actions recognition dataset. Compared with more sophisticated scheme of 3D based HoG/HoF descriptors, proposed method is easier to compute and simpler to understand.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.39 no.6
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• pp.623-629
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• 2002

In transmitting compressed video bit-stream over Internet, packet losses cause error propagations in both spatial and temporal domains, which in turn leads to severe degradation I image quality. In this paper, a new error concealment algorithm, called EBMA(Edge Detection based Boundary Matching Algorithm), is proposed to repair damaged portions of the video frames in the receiver. Conventional BMA(Boundary Matching Algorithm) assumes that the pixels on the boundary of the missing block and its neighboring blocks are very similar, but has no consideration of edges across the boundary. In our approach, the edges are detected across the boundary of the lost or erroneous block. Once the orientation of each edge is found, only the pixel difference along the expected edges across the boundary is measured instead of the calculation of difference along the expected edges across the boundary is measured instead of the calculation of differences between all adjacent pixels on the boundary Therefore, the proposed approach needs very few computations and the experiment shows and improvement of the performance over the conventional BMA in terms of both subjective and objective quality of video sequences.

• Korean Journal of Ecology and Environment
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• v.51 no.2
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• pp.160-167
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• 2018

The role played by reservoirs in the biogeochemical cycles of elements is a subject of ongoing debate. Recent research has revealed that reservoirs emit significant levels of greenhouse gases. To assess the importance of reservoirs in monsoon climate areas as a source of methane gas into the atmosphere, we investigated variations in organic carbon (OC) input into the reservoir, oxic state changes, and finally the amount of methane emitted (focusing on the ebullition pathway) in Lake Soyang, which is the largest reservoir in South Korea. Total organic carbon (TOC) concentrations were higher during summer after two years of heavy rainfall. The sedimentation rates of particulate organic carbon (POC) and particulate organic nitrogen (PON) were higher in the epilimnion and hypolimnion than the metalimnioin, indicating that autochthonous and allochthonous carbon made separate contributions to the TOC. During stratification, oxygen depletion occurred in the hypolimnion due to the decomposition of organic matter. Under these conditions, $H_2S$ and $CH_4$ can be released from sediment. The methane emissions from the reservoir were much higher than from other natural lakes. However, the temporal and spatial variations of methane ebullition were huge, and were clearly dependent on many factors. Therefore, more research via a well-organized field campaign is needed to investigate methane emissions.

• Journal of Life Science
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• v.27 no.1
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• pp.89-94
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• 2017

DNA sequences of the intergenic spacer 1 and intergenic spacer 2 of the nineteen plants belonging Vitis genus were collected from the Genbank. DNA sequences of the same regions of Vitis thunbergii var. sinuata and Ampelopsis brevipedunculata var. heterophylla, both common plants in Korea, were not available in Genbank. Those two plants were collected, their genomic DNA encoding 18S rRNA, intergenic spacer 1, 5.8S rRNA, intergenic spacer 2 and part of 28S rRNA amplified and DNA sequence determined. DNA sequences of twenty-one plants including two Korean plants were aligned by the Multiple sequence comparison by log-expectation(MUSCLE) algorithm and the alignment was used to calculate neighbor-joining tree and pairwise distance. The results indicate DNA sequences of the two Korean plants are highly homologous with each other, but they are quite distantly related to the other Vitis plants. Distant relationship of the two Korean plants with the other Vitis plants might be due to independent evolution of those two plants in geographically isolated environment. Those two Korean plants are classified in different genera based on the morphology, one in Vitis genus and the other in Ampelopsis genus, providing another example of discrepancy between morphological and genetic classification.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.31 no.4
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• pp.423-434
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• 1995

It was used boundary element method(BEM) and analysed axisymmetric problem to solve hydraulic cylinder for large vessel acting uniform internal pressure(25N/m super(2)) within elastic limit. This paper was utilized the carbon steel tubes for machine structural purposed model, inner radius was 150mm and outer radius was 250mm, axial length was semi-infinite and the isoparametric element was used. The important results obtained in this study were summarized as follows. Radial, tangential and shearing stress occured the maximum stresses(48, -20 and 34MPa) at the inner radius and the minimum stresses(32, -4 and 18MPa) at the outer radius of the hydraulic cylinder for large vessel. But negative signs have meaning compressive stress and stress diminution ratio was about 0.15MPa/mm. The use of isoparametric element raised accuracy and the increment of input data lessened the error in internal point but computer run-time was increased. The double node was improved the internal solutions to settle discontinuity at corner and the double exponential formula lessened error of stress value at boundary neighborhood. And then coincidence between the analytical and exact results is found to be fairly good, showing that the proposed analytical by BEM is reliable.

• Korean Journal of Remote Sensing
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• v.30 no.6
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• pp.777-786
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• 2014

Mt. Ontake is the second highest volcano in Japan. On 02:52 Universal Time Coordinated(UTC), 27th September 2014, Ontake volcano began on the large eruption without notice. Due to the recent eruption, 55 people were killed and around 70 people injured. Therefore, This paper performed numerical experiment to analyse damage effect of volcanic ash corresponding to Ontake volcano erupt. The forecast is based on the outputs of the HYSPLIT Model for volcanic ash. This model, which is based on the UM numerical weather prediction data. Also, a quantitative analysis of the ash dispersion area, it has been detected using satellite images from optical Communication, Ocean and Meterological Satellite-Geostationary Ocean Color Imager (COMS-GOCI) images. Then, the GOCI detected area and simulated ash dispersion area were compared and verified. As the result, the similarity showed the satisfactory result between the detected and simulated area. The concordance ratio between the numerical simulation results and the GOCI images was 38.72 % and 13.57 %, Also, the concordance ratio between the JMA results and the GOCI images was 9.05 % and 11.81 %. When the volcano eruptions, volcanic ash range of damages are wide more than other volcanic materials. Therefore, predicting ash dispersion studies are one of main way to reduce damages.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.237-241
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• 2006

최근에 들어 도시지역에서는 국지성 집중호우에 의한 홍수피해가 증가하는 경향이 있으며, 우수설비 시스템이 비교적 갖추어진 개발 지역에서도 기존의 우수설비시스템의 용량이 초과되어 큰 침수피해가 발생하고 있다. 홍수규모가 배수시스템의 용량을 초과할 경우 건물, 공공기반시설 등 재산 및 인명 등에 있어 많은 피해를 야기하고 있으며, 도로의 침수는 운송 시스템의 기능에 문제를 일으키게 되어 도시의 산업과 기능을 마비시킨다. 이러한 도시지역 홍수에 대비하여 도시지역의 복잡한 지형 형상과 인위적 배수시스템을 함께 고려하여 해석할 수 있는 침수해석모형의 개발이 필요하다. MOUSE와 SWMM(Storm Water Management Model) 계열 모형들(EPA SWMM, MIKE SWMM, XP SWMM, PC SWMM)(Huber and Dickinson, 1988)은 도시유출해석에 많이 이용되고 있다. 그러나, 이들 모형들은 과부하된 유입구에서의 범람되는 홍수유량곡선만을 제공하며 지표면 범람 지역, 수심, 및 침수기간에 대한 상세한 정보를 제공하지 못한다. 따라서, 도시배수체계모형과 도시침수모형에 대해 상호연계를 수행할 수 있는 새로운 도시범람 모형이 도시지역에서 홍수로 인한 침수해석을 모의하는데 필요하다. 배수시스템 해석 모형의 계산결과를 이용하여 침수해석을 수행하는 연계모형의 경우 침수초기 월류지점으로부터의 침수진행과정을 잘 모의할 수 있다. 그러나, 지형의 기복이 있는 유역에서 배수시스템을 통한 지표침수유량의 배수과정을 고려하지 못함으로 인하여, 월류발생이 끝난 후 일부지점이 계속 침수된 채 있게 된다. 이러한 연계모형의 한계로 인하여 두 모형의 통합모형이 필요하다. 즉, 강우 혹은 월류유량으로 발생한 지표유량 중 일부분이 과부하가 발생하지 않는 유입구 지점을 통과할 때 배수시스템으로 유입되는 것을 고려할 수 있고, 유입된 유량은 배수시스템 내의 흐름에 반영되도록 배수시스템과 침수해석모형을 통합한 모형 개발이 필요하다. 그러기 위해서는 지표면과 배수시스템에 대한 수리학적 관계를 정립하여야 한다. 본 연구에서는 배수시스템 해석 모형과 도시침수해석 모형을 통합하고, 두 모형간의 유량의 전송과정을 수리학적 관계를 고려한 dual-drainage 도시침수해석모형을 개발하였다. 이를 위해 도시지역 배수시스템 해석 모형으로 널리 이용되고 있는 SWMM모형을 이용하여 지표면으로의 월류량을 산정하고 유입된 지표유량에 대해서 배수시스템에서의 흐름해석을 수행하였다. 그리고, 침수해석을 위해서는 2차원 침수해석을 위한 DEM기반 침수해석모형을 개발하였고, 건물의 영향을 고려할 수 있도록 구성하였다. 본 연구결과 지표류 유출 해석의 물리적 특성을 잘 반영하며, 도시지역의 복잡한 배수시스템 해석모형과 지표범람 모형을 통합한 모형 개발로 인해 더욱 정교한 도시지역에서의 홍수 범람 해석을 실시할 수 있을 것으로 판단된다. 본 모형의 개발로 침수상황의 시간별 진행과정을 분석함으로써 도시홍수에 대한 침수위험 지점 파악 및 주민대피지도 구축 등에 활용될 수 있을 것으로 판단된다.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.785-789
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• 2006

유역 수자원의 효율적인 관리 및 배분을 위해서는 세밀한 강우-유출관계의 규명이 무엇보다 중요하다. 이를 위해서는 먼저 하천 유출지점의 정확한 유량정보가 획득되어야 하며, 장기간에 걸쳐 신뢰성 있는 유량자료의 확보는 더욱 중요한 사항이다. 본 연구에서는 하천에서 관측된 유량자료를 장기간(1983년${\sim}$2004년)에 걸친 유출성분으로 분리하는 기법을 활용하여 제어지점의 유출량을 검증하였다. 유량자료를 출구지점의 관측유량$(Q_{ob})$을 회귀수$({\alpha}Q_e)$, 상류유입량$(Q_{up})$ 및 관측강우-유출량$({\beta}Q_{Rain})$의 성분으로 구분하여 산정하는 방식으로 유출량을 추정하였다. 여기서, 회귀수$({\alpha}Q_e)$란 유역 및 하도내 용수이용량의 회귀수, 상류유입량$(Q_{up})$은 상류 유출 제어지점의 관측유량으로 대청댐 방류량, 관측강우-유출량$({\beta}Q_{Rain})$은 유역내 강우에 의한 자연유출량이다. 여기서 사용된 수문기초자료는 대청댐 방류량, 대전 및 청주권 취수량, 강우에 의한 자연유출량, 공주관측유량 등으로 각 성분별로 생성된 일자료를 이용하여 공주지점의 월별, 분기별, 년도별 유출량을 산정하였다. 이 결과는 금강유역에 이미 구축되어있는 SSARR모형을 기반으로 한 RRFS(Rainfall Runoff Forecasting System, 유출예측 시스템)의 결과 및 관측치와 비교되었다. 계산결과 RRFS에 의한 유출량과 대청-공주구간의 유출성분분리에 의한 유출량은 관측값과 전반적으로 근사함을 확인하였으며, 검증지점의 정확한 유출율을 산정할 수 있다면, 관측자료의 연속성 및 신뢰도를 파악하는 척도를 제공할 수 있을 것으로 판단된다.측결과 있는 대상유역에 대한 적용이 요구된다.-Moment 방법에 의해 추정된 매개변수를 사용한 Power 분포를 적용하였으며 이들 분포의 적합도를 PPCC Test를 사용하여 평가해봄으로써 낙동강 유역에서의 저수시의 유출량 추정에 대한 Power 분포의 적용성을 판단해 보았다. 뿐만 아니라 이와 관련된 수문요소기술을 확보할 수 있을 것이다.역의 물순환 과정을 보다 명확히 규명하고자 노력하였다.으로 추정되었다.면으로의 월류량을 산정하고 유입된 지표유량에 대해서 배수시스템에서의 흐름해석을 수행하였다. 그리고, 침수해석을 위해서는 2차원 침수해석을 위한 DEM기반 침수해석모형을 개발하였고, 건물의 영향을 고려할 수 있도록 구성하였다. 본 연구결과 지표류 유출 해석의 물리적 특성을 잘 반영하며, 도시지역의 복잡한 배수시스템 해석모형과 지표범람 모형을 통합한 모형 개발로 인해 더욱 정교한 도시지역에서의 홍수 범람 해석을 실시할 수 있을 것으로 판단된다. 본 모형의 개발로 침수상황의 시간별 진행과정을 분석함으로써 도시홍수에 대한 침수위험 지점 파악 및 주민대피지도 구축 등에 활용될 수 있을 것으로 판단된다. 있을 것으로 판단되었다.4일간의 기상변화가 자발성 기흉 발생에 영향을 미친다고 추론할 수 있었다. 향후 본 연구에서 추론된 기상변화와 기흉 발생과의 인과관계를 확인하고 좀 더 구체화하기 위한 연구가 필요할 것이다.게 이루어질 수 있을 것으로 기대된다.는 초과수익률이 상승하지만, 이후로는 감소하므로, 반전거래전략을 활용하는 경우 주식투자기간은 24개월이하의 중단기가 적합함을 발견하였다. 이상의 행태적 측면과 투자성과측면의 실증결과를 통하여 한국주식시장에 있어서 시장수익률을 평균적으로 초과할 수 있는 거래전략은 존재하므로 이러한 전략을 개발 및 활용할 수 있으며, 특히, 한국주식시장에 적합한 거래전략은 반전거래전략이고, 이 전략의 유용성은 투자자가 설정한 투자기간보다 더욱 긴

• The Korean Journal of Zoology
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• v.39 no.3
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• pp.257-265
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• 1996

Previously, we demonstrated that estradiol (E$_2$) was produced by medium sized follicles of Rana nigromaculata and Rana dybowskii in vitro. Present experiments were carried out to determine when the growing follicles have obtained the ability to produce E$_2$. Follicles in different growth stages were isolated and cultured for 6 hours in the presence or absence of frog pituitary homogenates (FPH, 0.1 pituitary/2m1) or various steroid precursors (200 ng/2m1). levels of progesterone (P$_4$), 17 -hydroxyprogesterone (17$\alpha$-OHP), androstenedione (AD), testosterone Cr) or E$_2$ in the medium were measured by RIA. The smallest follicles failed to produce steroids, whereas the smaller follicles produced considerable amounts of steroids (211 pg/follicle), and the medium sized follicles produced a large amounts of steroids (1653 pg/follicle) in response to FPH. Addition of pregnenolone (P5) resulted in a marked increase in P$_4$ but not in other steroids by the smallest follicles whereas the treatment resulted in a marked increase in P$_4$, 17$\alpha$-OHP, AD, T and E$_2$by the smaller and medium follicles. When the amounts of steroids are calculated on the basis of unit surface area (pg/mm$_2$), the ability of the smallest follicles to produce P$_4$ from P5 was similar to those of smaller and medium sized follicles. However, the smallest follicles failed to metabolize P$_4$ to other steroids whereas the smaller and medium follicles did. Taken together, the data suggest that the smallest follicles do not response to FPH in terms of steroid production but they have capacity to convert P5 to P$_4$ and that the smaller follicles have potential to produce E$_2$ although much less efficient than medium sized follicles.

• Korean Journal of Agricultural and Forest Meteorology
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• v.4 no.2
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• pp.95-102
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• 2002

Spatial interpolation has become a common procedure in converting temperature forecasts and observations at irregular points for use in regional scale ecosystem modeling and the model based decision support systems for resource management. Neglection of terrain effects in most spatial interpolations for short term temperatures may cause erroneous results in mountainous regions, where the observation network hardly covers full features of the complicated terrain. A spatial interpolation model for daytime hourly temperature was formulated based on error analysis of unsampled site with respect to the site topography. The model has a solar irradiance correction scheme in addition to the common backbone of the lapse rate - corrected inverse distance weighting. The solar irradiance scheme calculates the direct, diffuse and reflected components of shortwave radiation over any surfaces based on the sun-slope geometry and compares the sum with that over a reference surface. The deviation from the reference radiation is used to calculate the temperature correction term by an empirical conversion formula between the solar energy and the air temperature on any sloped surfaces at an hourly time scale, which can be prepared seasonally for each land cover type. When this model was applied to a 14 km by 22 km mountainous region at a 10 m horizontal resolution, the estimated hourly temperature surfaces showed a better agreement with the observed distribution than those by a conventional method.