• KSCE Journal of Civil and Environmental Engineering Research
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• v.40 no.1
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• pp.127-133
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• 2020

Most sewage treatment plants located offshore are discharged to the shore either directly or through rivers. Therefore, the water quality of the treated water discharged from the sewage treatment plant affects the water quality of the river water discharged to the river and the ocean. In this study, field surveys and numerical simulations were conducted to investigate the effect of treated water from the sewage treatment plant adjacent to the coastal environment. As a result of analyzing the water quality and sediment quality with the samples collected from the river and the estuary where the treated water was discharged to understand the impact on the coast, the treated water discharged from the sewage treatment plant was discharged to the river without exceeding the design criteria. However, the water quality discharged to the shore through estuaries was more contaminated than treated water. The cause of water quality deterioration of coastal effluent is due to the sedimentation of estuary temporarily by longshore sediment sransport which appeared around the estuary, the occurrence of estuary obstruction, and the increase of stagnant time in the estuary. As it was released and discharged, it was analyzed to affect the water quality, water quality and marine life around the estuary. Therefore, in the case of the east coast where the longshore sediment transport is strong, when planning the sewage treatment facility discharged to the ocean, it is necessary to closely examine the water quality change of the river water in the treated water such as the river mouth occlusion by the longshore sediment transport.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.1716-1720
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• 2007

연안 해역에서의 표사는 하천에서의 유사가 주요한 공급원이므로 산지-하천-해안을 통합한 유사 및 표사에 관한 관리가 필요하며, 해안수리 및 환경적인 측면에서 강성 연안구조물의 건설을 통하지 않고 연안에서의 침식을 억제해야하는 방지대책의 수립 요구가 증대하고 있는 실정이다. 즉 연안에서의 침식, 퇴적관계는 토사공급원의 장기적인 확보여부가 중요하며 하천에서 해안역으로 공급되는 유사량을 예측하고 또한 이들이 어떻게 효과적으로 연안 해역으로 이송되어 가는가를 파악하는 것은 연안표사문제를 이해하는데 매우 중요한 요소이다. 이를 위해서는 무엇보다도 하천에서 연안 해역으로의 유사량을 파악하는 것이 중요하며 그리고 하천 유사량이 하구에 사주를 형성하고 어떤 형태를 거쳐 연안표사로 이동하는가 하는 특성을 파악할 필요가 있다. 울산광역시 울주군 온산읍에 위치한 회야강의 하구폐색은 1990년대 중반부터 연구의 관심이 되어오고 있으며, 1986년 회야강 상류 회야댐 건설 이후 하구폐색이 가속화됨에 따라 매년 회야강 하구에서의 준설이 필요한 실정이다. 특히 회야강 하구부에서는 파랑류, 취송류와 하천류 뿐만 아니라 해류나 조류 등에 의한 흐름과 지형특성등 복합적으로 발생하는 하구현상에 의해 하구에서의 사주 발달이 상대적으로 강하여 하구폐색이 강하게 나타나고 있다. 이의 대책으로 최근 회야강 하구부에 도류제가 건설되었으며 이에 따른 장기적인 하구부 하상변동특성과 토사이동의 특성 파악이 요구되고 있는 실정이다. 본 연구에서는 이 같은 관점에서 회야강 하구부의 도류제 설치에 따른 하구에서의 지형변동과 유송토사량의 특성을 파악하기 위해 하천 상류부에서는 동적 평형상태의 유사량을 가정하고 하상재료 및 유사는 혼합입경으로 하여 하상고 및 하상교환층 중의 입도조성의 시간변화를 구하여 1차원적인 하상변동과 토사이동 특성을 해석하였다.했을 때, 대표입경을 통해 얻은 조도계수가 보정 조도계수보다 다소 작은 것으로 해석되었다.하고자 한다.해결책을 얻어내는 상호보완적인 결과를 추구한다. 그가 디자인하는 작품은 전형적인 이미지를 내포하지 않는다. 즉 그의 작품은 기존의 가치와 이념적인 것은 배제하고, 창의적인 개념을 도출하였다.형모서리는 건물 특화 성격이 강하므로 불가피할 경우 소형 액센트 광고 위치를 미리 벽면으로 할애하는 것이 경관 및 입면계획에 유리한 것으로 분석되었다. 불확실도 해석모형 등의 새로운 기능을 추가하여 제시하였다. 모든 입출력자료는 프로젝트 단위별로 운영되어 data의 관리가 손쉽도록 하였으며 결과를 DB에 저장하여 다른 모형에서도 적용할 수 있도록 하였다. 그리고 HyGIS-HMS 및 HyGIS-RAS 모형에서 강우-유출-하도 수리해석-범람해석 등이 일괄되게 하나의 시스템 내에서 구현될 수 있도록 하였다. 따라서 HyGIS와 통합된 수리, 수문모형은 국내 하천 및 유역에 적합한 시스템으로서 향후 HydroInformatics 구현을 염두에 둔 특화된 국내 수자원 분야 소프트웨어의 개발에 기본 토대를 제공할 것으로 판단된다.았다. 또한 저자들의 임상병리학적 연구결과가 다른 문헌에서 보고된 소아 신증후군의 연구결과와 큰 차이를 보이지 않음을 알 수 있었다. 자극에 차이가 있지 않나 추측되며 이에 관한 추후 연구가 요망된다. 총대장통과시간의 단축은 결장 분절 모두에서 줄어들어 나타났으나 좌측결장 통과시간의 감소 및 이로 인한 이 부위의 통과시간 비율의 저하가 가장 주요하였다. 이러한 결과는 차가운 생수 섭취가 주로 결장 근위부를 자극하는 효과를 발휘하는 것이 아닌가 해석된다. 이와 같은 연구결과를 통해 생다시마를 주원료로 개발된 생다시마차와 생다시마 음료가 만성 기능성 변비 증세를 개선하는 효능이 잠재적으로 있음을 확인하였다.

• Tuberculosis and Respiratory Diseases
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• v.42 no.6
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• pp.913-922
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• 1995

Background: When we define the pressure of pulmonary vasculature in which a recruitment of blood flow occurs as $P_I$ and the proportion of change in pulmonary artery to that in cardiac output as IR and then we compare PI and IR with pulmonary vascular resistance, we would find some problems in pulmonary vascular resistance. In other words, it is the theory that, IR should be increased mainly in pulmonary embolism in which decreases the cross sectional area of pulmonary vasculature. But there are many contradictory reports resulted from various researches and the fact is known widely that any difference exists between PVR and PI, IR. For this reason, the purpose of this study is to observe how PI and IR change at the time of the outbreak and during treatment of the pulmonary embolism, and to find out the meaning of these new indicators and the difference from the pulmonary vascular resistance used generally when we subdivide the pulmonary vascular resistance into PI and IR. Method: After making AV fistula in experimental dog, we controlled cardiac output at the intervals of 15 minute in case of three kinds(all AV fistula are obstructed, only one of fistula is open and all of fistula is open), and after evoking massive pulmonary embolism with radioactive autologous blood clots, we measured the mean pulmonary artery pressure, and calculated PI and IR. We observed the pattern of change in PI and IR, without giving the control group any specific treatment and with injecting intravenously rtPA in the Group 1 and Group 2 at the dose of 1mg per kg, for 15 minutes fot the former and 3 hours for the latter. Result: 1) Pulmonary vascular resistance showed a change similar to that of pulmonary artery pressure and in all three group, PVR increased significantly, but group 1 and group 2 showed tendency that PVR keeps on decreasing after treatment, and the rate of decrease in group 1 is more rapid than group 2 significantly. 2) Both intersection(PI) and degree(IR) are proved statistically significant, in view of the straight line relationship between cardiac output and pulmonary artery pressure, calculated by minimal regression method. 3) PI changed similarly to pulmonary vascular resistance, while in the IR which is theoretically more similar to PVR, there was no significant difference or change after rtPA infusion. Conclusion: In the pulmonary embolism, Both change in IR which means real resistance of pulmonary vasculature and PI which was developed due to secondary vasoconstriction by pulmonary embolism are reflected same time.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.6
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• pp.1-8
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• 2006

One of the most important subjects to develop a LPDi engine is to suppress the bubble generated inside the liquid LPG direct injector. For the purpose of this, the analogy visualization injector to visualize the generation and behaviors of bubble is manufactured, and the bubbling phenomenon and behaviors of bubble are visualized and investigated according to the change of the temperature around an injector wall, fuel pressure and a needle configuration. As results, it was found that the bubble inside the injector is generated around an injector hole and after rising by buoyancy it disappears around the top of a nozzle. The number of bubbles generated is little changed regardless of the lapse of time but it remarkably increases as the temperature around the injector increases. Also, it was known that as the sac volume in LPDi injector decreases the generation of bubble is more active and the rising velocity of bubble generated is increased.

• Journal of the Korean Geotechnical Society
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• v.33 no.12
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• pp.93-105
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• 2017

This study presents direct shear tests, model tests, and numerical simulations to assess the effect of reduction of soil strength because of saturation during formation of ground cave-in caused by damaged sewer pipe lines. The direct shear test results show that the saturation affects the cohesion of soil significantly although it does not influence the friction angle of soil. To experimentally reproduce ground cave-in, the model tests were performed. As ground cave-ins were accompanied with extreme deformation, conventional finite element method has difficulty in simulating them. The present study relies on generalized interpolation material point method, which is one of meshless methods. Although there are differences between the model test and numerical simulation caused by boundary conditions, incomplete saturation, and exclusion of groundwater flow, similar ground deformation characteristics are observed both in the model test and numerical simulation.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.5
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• pp.1217-1230
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• 2010

The dynamic programming based methods, a kind of globally optimizing stereo matching methods, has the inherent advantage that the occlusion regions can be found during the process. But it also has a serious drawback of streaking phenomena. This paper focuses on reducing the streaking phenomena by adjusting the penalties in calculating the cost matrix and re-establishing the optimal path in the back-tracing process using the boundary information of the image. Especially we use a pixel expansion method in re-establishing the path, which is the results from expanding the pixel information of the ones just left the boundaries. Experiments with the four image pairs provided by the Middlebury site showed the results that the proposed method has the disparity error ratio of 6.33% and the rank is 29, which is competitive to the best method among the previously published dynamic programming based methods.

• Journal of the Korean Geotechnical Society
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• v.34 no.11
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• pp.33-41
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• 2018

Soil internal erosion is a phenomenon in which fines attached to the solid skeleton are detached by fluid flow, and this continuous fine migration weakens the hydro-mechanical characteristics of the ground structure. This paper proposed governing equations for fine migration in pore spaces and its related scheme for the numerical analysis. Phase diagram for fine particles includes three different states: detached fines in the liquid phase ($c_e$), attached fines in the solid phase (${\sigma}_a$), and pore-clogged fines in the solid phase (${\sigma}_s$). Numerical formulations for finite element method are developed based on the hydraulic governing equations of pore fluid and fine migration. This study proposed a method of estimating model parameters for fine detachment, attachment, and clogging from 1D erosion experiments. And it proposed an analytical formula for hydraulic permeability function considering fine clogging. Numerical analysis of the previous erosion test developed the numerical scheme and verified the adequacy of fine migration models.

• Spatial Information Research
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• v.23 no.1
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• pp.59-68
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• 2015

As part of an effort to leap smart cadastre system by doing rearrangement of various mismatches in the land register, the cadastre renovation project is being recently conducted. In response to this demand, this paper proposes an image-based rapid parcel boundary demarcation plan using the high resolution aerial image with a GSD (Ground Sample Distance) of 5cm that matches to real ground boundary situation in residential area. To review the feasibility and accuracy of this proposed methodology, we compared the accuracy of parcel boundary point and parcel area extracted from the digital stereo plotting on the basis of results of cadastral boundary surveying and land register over the selected two test areas. The comparative accuracy result of all boundary points by digital stereo plotting is satisfied with accuracy requirement according to the criteria of the enforcement regulation of cadastral surveying, whereas it exceeded allowable error of ${\pm}0.07m$, more strictly specified in the Special Act on Cadastral Renovation. And about 20% of the total 70 parcels extracted by digital plotting are out of area tolerance in Jecheon study area, and 10% of the total 19 parcels in Suwon study area. The parcels exceeding accuracy limit are mostly due to the occlusion caused by building roof or eaves, and the obstacles such as trees existing on the boundary. Furthermore, an object identification is impossible in image because of vague boundary reference in case of nonexistence of man-made structures or natural features. Therefore, the utilization of boundary identification stickers is recommended as a solution for these types of land parcel.

• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.2
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• pp.485-500
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• 2018

The behavior of cement-based permeation grouting is divided into three different groups depending on the grain size distribution of the soils: (1) zone of cement-based permeation grouting not feasible; (2) zone of cement-based permeation grouting feasible; and (3) zone in which an accelerating agent should be added to limit the penetration depth. In the cement-based permeation grouting feasible zone, the concept of a representative pore radius was proposed. The ratios of the representative pore radius to the mean pore radius were obtained by performing laboratory test and comparing with clogging theory; these values were in the range of 1.07 and 1.35 depending on the grain size distribution of the soils. In addition, a functional relationship between the lumped parameter (${\theta}$), the representative pore radius and the w/c ratio were derived by comparing and matching experimental results with predictions from theory. In the zone in which the accelerating agent should be added, the controlling process of gel time to limit the penetration depth was experimentally verified. The test results matched well with those obtained from theory utilizing the developed grout penetration program on condition that the viscosity increasing tendency of grout suspension with time is properly taken into account.

• Smart Media Journal
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• v.3 no.4
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• pp.28-34
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• 2014

Recently the depth-image-based rendering (DIBR) method is usually used in 3D image application filed. Virtual view image is created by using a known view with associated depth map to make a virtual view point which did not taken by the camera. But, disocclusion area occur because the virtual view point is created using a depth image based image 3D warping. To remove those kind of disocclusion region, many hole filling methods are proposed until now. Constant color region searching, horizontal interpolation, horizontal extrapolation, and variational inpainting techniques are proposed as a hole filling methods. But when using those hole filling method some problem occurred. The different types of annoying artifacts are appear in texture region hole filling procedure. In this paper to solve those problem, the multi-directional extrapolation method is newly proposed for efficiency of expanded hole filling performance. The proposed method is efficient when performing hole filling which complex texture background region. Consideration of directionality for hole filling method use the hole neighbor texture pixel value when estimate the hole pixel value. We can check the proposed hole filling method can more efficiently fill the hole region which generated by virtual view synthesis result.