• Journal of the Korean Society of Marine Environment & Safety
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• v.16 no.2
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• pp.169-174
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• 2010

To obtain more accurate meteorological data for analyzing the river discharge characteristics at the Nakdong River Estuary, we investigated the characteristics of the release barrage discharge observed during the 13-year period from 1996 to 2008 and calculated the differences using meteorological data for the Busan and Gimhae weather stations. The river discharge estimated using a tank model was compared to the real river barrage discharge. We discussed the correlation between the discharge and the meteorological factors that affected the estuary water environment. This study found that total annual discharge from the Nakdong river basin for the 13 years was $272,653.3{\times}10^6\;m^3$/month. The largest monthly mean release discharge occurred in July at $73,212.9{\times}10^6\;m^3$/month (26.9% for the year), followed by August and September in that order with 22.0% and 18.9%, respectively.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1992.10a
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• pp.3-3
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• 1992

타이어 Curing공정은 공기압 타이어의 제조시 상당히 정교한 단계를 거쳐서 이루어지며, 이는 타이어 설계에 큰 영향을 줄 뿐만아니라, 타이어의 성능에도 관건이 있다. 본 연구에서는 유한요소법을 이용하여 타이어의 molding 공정을 분석하였다. 유한요소해석 프로그램인 MARC가 Cured 타이어 내부의 Curing Bladder 팽창과정해석에 이용되었다. 비압축성 요소로 Curing Bladder를 모형화하였으며, MARC의 접촉문제해석기법(contact option)을 이용하여 Cured 타이어 내부와 Curing Bladder 외부의 접촉부위를 Simulation하였다. 본 연구의 주요 관심내용으로서는 Curing Bladder의 형상변화에 따른 Curing Bladder의 팽창거동해석과, Cured타이어와 Curing Bladder의 접촉부위에서 얻을 수 있는 접촉압력의 비교.검토이다. 타이어 Curing시 타이어와 Bladder의 Contact과정을 해석하여, 아래와 같은 결과를 도출하였다. Bladder의 형상은 Cylinderical 형상 보다는 Toroidal 형태가 접촉압 분포의 균일성 및 크기 측면에 서 우수한 것으로 판단된다. Curing Bladder의 증심선 부위 보다 이에서 약간 떨어진 부위에서 최대 접촉압력이 발생되며, 이는 타이어 내면의 굴곡현상과 깊은 관련이 있윰 것으로 사료된다. 타이어 Bead부의 Carcass 자연평형현상이 유지된 제품을 얻기위해서는, Side-Bead구간의 접촉압력 증가가 필요하며, 이를 위하여는 Bladder 형상이 Cylinderical 보다는 Toroidal 형태가 유리하고, Bead부의 Gage Down, 전체직경의 증가 및 높이의 증가가 유리한 것으로 판단된다. 본 연구 결과를 이용하여, 타이어 Curing과정에서 발생되는 불량제품의 원인파악 및 타이어 설계자가 원하는 제품생산의 불가능한 원인을 파악하는데 도움을 줄 것이다.를 C의 structure와 pointer를 기반으로 하게끔 변경시키고 이에 따르는 제반 변경 사항을 수정 보완하여 프로그램의 분석을 용이하게 하며 기능의 변경 및 추가가 수월하게 하였고 메모리를 동적으로 관리할 수 있게 하였다. 또한 기존의 smpl에 디버깅용 함수 및 설비(facility) 제어용 함수를 추가하여 시뮬레이션 프로그램 작성을 용이하게 하였다. 예를 들면 who_server(), who_queue(), pop_Q(), push_Q(), pop_server(), push_server(), we(), wf(), printfct() 같은 함수들이다. 또한 동시에 발생되는 사건들의 순서를 조종하기 위해, 동시에 발생할 수 있는 각각의 사건에 우선순위를 두어 이 우선 순위에 의하여 사건 리스트(event list)에서 자동적으로 사건들의 순서가 결정되도록 확장하였으며, 설비 제어방식에 있어서도 FIFO, LIFO, 우선 순위 방식등을 선택할 수 있도록 확장하였다. SIMPLE는 자료구조 및 프로그램이 공개되어 있으므로 프로그래머가 원하는 기능을 쉽게 추가할 수 있는 장점도 있다. 아울러 SMPLE에서 새로이 추가된 자료구조와 함수 및 설비제어 방식등을 활용하여 실제 중형급 시스템에 대한 시뮬레이션 구현과 시스템 분석의 예를 보인다._3$", chain segment, with the activation energy of carriers from the shallow trap with 0.4[eV], in he amorphous regions.의 증발산율은 우기의 기상자료를 이용하여 구한 결과 0.05 - 0.10 mm/hr 의 범위로서 이로 인한 강우손실량은 큰 의미가 없음을 알았다.재발이 나타난 3례의 환자를 제외한 9례 (75%)에서는 현재까지 재발소견을 보이지 않고 있다. 이러한 결과는 다른 보고자들과 유사한 결과를 보이고 있지만 아직까지 증례가 많지 않기 때문에 생존율을 얻

• Journal of Korea Water Resources Association
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• v.48 no.5
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• pp.345-355
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• 2015

Climate change impact on urban drainage system are analyzed in Seoul by using high-resolution climate change scenario comparing 2000s (1971~2000) with 2020s (2011~2040), 2050s (2041~2070) and 2080s (2071~2100). The historical hourly observed rainfall data were collected from KMA and the climate change scenario-based hourly rainfall data were produced by RegCM3 and Sub-BATS scheme in this study. The spatial resolution obtained from dynamic downscaling was $5{\times}5km$. The comparison of probability rainfalls between 2000s and 2080s showed that the change rates are ranged on 28~54%. In particular, the increase rates of probability rainfall were significant on 3, 6 and 24-hour rain durations. XP-SWMM model was used for analyzing the climate change impacts on urban drainage system. As the result, due to the increase of rainfall intensities, the inundated areas as a function of number of flooded manhole and overflow amounts were increasing rapidly for the 3 future periods in the selected Gongneung 1, Seocho 2, Sinrim 4 drainage systems. It can be concluded that the current drainage systems on the selected study area are vulnerable to climate change and require some reasonable climate change adaptation strategies.

• Proceedings of the ESK Conference
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• 1993.10a
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• pp.223-235
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• 1993

요통(Lowback Pain)을 유발하는 주요원인으로 알려져있는 MMH(Manual Materials Handling) 작업에 있어서 작업조건의 변화가 근육의 활동과 피로도에 미치는 영향을 평가하기 위해 4가지 서로 다른 작업조건하에서 몸통부위(Trunk)의 주요근육에 대한 EMG 파형분석을 실시 하였다. 본 연구에서의 분석대항작업은 실제 작업조건과 유사하레 설계된 120분간의 단속적인 인양(Lifting)/하역(Lowering) 작업으로서 작업중량은 작업자의 MVIS(Maximum Voluntary Isometric Strength)를 기준으로 설정되었으며, 매 10분 간격으로 EMG 측정이 이루어졌다. 작업물이 작업자의 정면에 위치한 대칭형(Symmetric) 작업의 경우 배면부(Dorsal) 근육인 천극근(Erector Spinae)과 활배근(Latissimus Dorsi)이 활동근(Active Muscle)인 것으로 나타났으며, 정중면(Medial Plane)을 중심으로 좌우측 근육이 동일한 근력을 발휘하였다. 작업물이 작업자의 한쪽 측면에 위치한 90도 비대칭형(Asymmetric) 작업의 경우 천극근과 활배근외에 작업물과 반대쪽 외사근(External Oblique)이 활동근으로 추가되었으며, 작업물과 반대쪽의 근육들이 더욱 큰 근력을 발휘하였다. 작업의 반복에 따른 근육의 피로도를 평가하기 위해 실시한 EMG 파형의 Spectral Analysis 결과, 비대칭형 작업시 작업물과 반대쪽의 천극근에서 작업시간의 경과에 따라 중위주파수(Median Power Frequency)가 저주 파수대로 천이(Lower Shift)하는 현상이 나타났으며, 일정한 작업량이라도 작업중량을 줄이고 작업 빈도를 높여서 작업할 경우에 이러한 현상이 더욱 두드러졌다. 작업시간의 경과에 따른 MVIS의 감소 현상은 작업빈도가 높고 비대칭형 작업일 때 가장 크게 나타났다. 총손실을 줄이고, 상대적 비용절감효과를 갖게할 수 있다고 하였다. 따라서 본 연구에서는 성인 여성기성복의 치수적합성을 높이기위하여 출산 후 중년에 접어 들면서 체형이 변화되는 것을 고려하여 연령을 분류하고(18세-34세, 30세-51세), 각 연령 집단에 따른 체형을 각각 3가지로 분류하였다. 이에 따라 의복 생산시의 총손실을 줄이기위한 상의, 하의생산시 필요한 부위별 최적규격치 간격을 제시하였다.적인 기능으로 보여지는 것에 좁혀서 작업능력의 연령증가 변화에 대하여다원적 평가를 하는 것이 실제적이라고 할 수 있다. 따라서 본 연구에서는 인간이 가지고 있는 다수의 기능중에서 수지교 치성과 연령증가와의 관계를 조사한다. 만약 연령증가 만으로 수지교치성을 평가 할 수 없는 경우에는 어떠한 요인이 수지기민성의 변화에 영향을 미치는가를 검토한다.t list)에서 자동적으로 사건들의 순서가 결정되도록 확장하였으며, 설비 제어방식에 있어서도 FIFO, LIFO, 우선 순위 방식등을 선택할 수 있도록 확장하였다. SIMPLE는 자료구조 및 프로그램이 공개되어 있으므로 프로그래머가 원하는 기능을 쉽게 추가할 수 있는 장점도 있다. 아울러 SMPLE에서 새로이 추가된 자료구조와 함수 및 설비제어 방식등을 활용하여 실제 중형급 시스템에 대한 시뮬레이션 구현과 시스템 분석의 예를 보인다._3$", chain segment, with the activation energy of carriers from the shallow trap with 0.4[eV], in he amorphous regions.의 증발산율은 우기의 기상자료를 이용하여 구한 결과 0.05 - 0.10 mm/hr 의 범위로서 이로 인한 강우손실량은 큰 의미가 없음을 알았다.재발이 나타난 3례의 환자를 제외한 9례 (75%)에서는 현재까지 재발소견을 보이지 않고 있다. 이러한 결과는 다른 보고자들과 유사한 결과를

• Water for future
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• v.27 no.3
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• pp.71-82
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• 1994

A statistical characteristics, relations of calendar and water year, and frequencies of precipitaion which are necessary for water resources planning were analyzed with long historical data(1905-1991 years). And the analysis of precipitation of the drought periods in 1967-1968 years was carried out. The study basins are the five major rivers in Korea. As a results of this study, annual precipitation shows an increasing trend but its variation has no statistical significance. The rellations of calendar and water year precipitation is presented, it shows that there are little difference of the total precipitation between them. The annual minimum series of total precipitation for the periods of 3, 6, 9, and 12 months by water year are constructed, and frequency precipitation for each periods using 2-parameter lognormal distribution is presented. The analysis of the precipitation in 1967-1968 years shows in a natural river basins that it would be a moderate drought, if dry seasons(Oct-May) or wet seasons(Jun-Sep) has 75 percents of historical mean precipitation of the same periods. And if it has less than 60 percents of historical mean precipitation, it would be a severe drought.

• Journal of Korea Water Resources Association
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• v.43 no.3
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• pp.295-308
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• 2010

As an attempt to explore the impact of droughts which may be worse by the climate change, the change in the water balance of the Han-river basin is analyzed. To accomplish it, we suggest a procedure consisting of three successive sub-procedures: daily rainfall generation for 70 years by the RegCM3 RCM ($27{\times}27\;km$) with the A2 scenario, daily discharge simulations by SLURP using the generated daily rainfall data, and monthly water balance analysis by K-WEAP (Korean Water Evaluation and Planning System) based on the SLURP simulation. Since significant uncertainty is involved in forecasting the future water consumption and water yields, we assumed three water consumption scenarios and fifty water yields scenarios. Three water consumption scenarios are, namely, "LOW", "MEDIUM", and "HIGH" according to the expected amount of water consumption. The fifty daily discharges are obtained from the SLURP simulations during the drought period. Finally, water balance analysis is performed by K-WEAP based on 150 combinations from three water consumption scenarios and the fifty daily discharges. Analysis of water scarcity in small basins of the Han River basin showed concentration of water scarcity in some small basins. It was also found that water scarcity would increase in all small basins of the Han River basin.

• Journal of Korea Water Resources Association
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• v.51 no.9
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• pp.769-782
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• 2018

Estimation of design floods is typically required for hydrologic design purpose. Design floods are routinely estimated for water resources planning, safety and risk of the existing water-related structures. However, the hydrologic data, especially streamflow data for the design purposes in South Korea are still very limited, and additionally the length of streamflow data is relatively short compared to the rainfall data. Therefore, this study collected a large number design flood data and watershed characteristics (e.g. area, slope and altitude) from the national river database. We further explored to formulate a scaling approach for the estimation of design flood, which is a function of the watershed characteristics. Then, this study adopted a Hierarchical Bayesian model for evaluating both parameters and their uncertainties in the regionalization approach, which models the hydrologic response of ungauged basins using regression relationships between watershed structure and model. The proposed modeling framework was validated through ungauged watersheds. The proposed approach have better performance in terms of correlation coefficient than the existing approach which is solely based on area as a predictor. Moreover, the proposed approach can provide uncertainty associated with the model parameters to better characterize design floods at ungauged watersheds.

• Journal of the Korean earth science society
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• v.30 no.2
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• pp.185-195
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• 2009

We investigated the change of several meteorological variables due to deforestation. We established two sets of automatic weather observation system: one on a hill where forest was destructed by lumbering (Point 1) and the other in a neighboring district (Point 2) of fairly preserved forest. The observations were continued for one year (2006. 12-2007. 12). In this study, we analysed the data observed for one week from the nea day after summertime rainfall. The results showed that the air temperatures of Point 1 were about $1.5^{\circ}C$ higher than those of Point 2 during the daytime. But there were small gaps between the two poults during the nighttime. The relative humidities also differed greatly between the two during the daytime. It was as high as about 10% at Point 2. The surface and underground (15 cm in depth) soil temperatures were also fealty different between the two points during the daytime. They were $3-10^{\circ}C$ higher at Point 2 than those of Point 1. And the gaps reduced drastically during the nighttime. The averaged soil moistures were 7.1% at Point 1 and 19.5% at Point 2 during the observation period, respectively. The differences of wind direction were small, but the wind speeds differed between the two points. The observed wind speeds during the observation period were roughly estimated to be about 0.5m/s at Point 1 and 0.3m/s at Point 2. The heat budget analysis was also performed based on the observation data.

• Journal of Korean Society of Disaster and Security
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• v.11 no.1
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• pp.7-14
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• 2018

The Benangkimi wetland, which serves as a stopover place for migratory birds in the Dadohae Marine National Park in Wando-gun, Jeollanam-do, is a place where various species and a large number of migratory birds are observed. In order to provide an effective and scientific management plan for the habitat environment of migratory birds, we carried out field survey of Benangkimi wetland. The field survey and survey on habitat use of migratory birds were conducted in parallel to obtain the basic data of hydraulics and hydrology. The hydraulic and hydrological survey of Benangkimi wetland was conducted 1-2 times a year during the period of 2015-2016 (two years). It was classified into 4 sectors according to the topography and geology, rainfall, hydraulic characteristics, and wetland conditions. The 3 sectors same as the migratory birds survey sector and the 1 sector as the inflow of the wetland were analyzed. The survey also focused on small migratory birds arriving at Benangkimi wetland during the spring and autumn season. As a result of investigating the population and species in each section, the habitat environment was different according to the water depth, sediment thickness and salinity. Migratory birds prefer hydraulic and hydrological characteristics. This study will be used for the scientific management of Benangkimi wetland, which serves as a stopping point for migratory birds, and it will contribute to basic data of ecology - hydraulics by examining the relationship between habitat environment and hydrological data.

• Journal of Korea Water Resources Association
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• v.51 no.7
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• pp.617-627
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• 2018

In this study, CMIP5 GCMs rainfall data (2011~2099) based on RCP scenarios were used to analyze the extreme drought evaluation for the future period. For prospective drought assessment, historical observations were used based on the Automated Surface Observing System (ASOS) data (1976~2010) of the Korea Meteorological Administration. Through the analysis of various indicators, such as average annual rainfall, rainy days, drought spell, and average drought severity was carried out for the drought evaluation of the five major river basins (Han river, Nakdong river, Geum river, Sumjin river, and Youngsan river) over the Korean peninsula. The GCMs that predicted the most severe future droughts are CMCC-CMS, IPSL-CM5A-LR and IPSL-CM5A-MR. Moderate future droughts were predicted from HadGEM2-CC, CMCC-CM and HadGEM2-ES. GCMs with relatively weak future drought forecasts were selected as CESM1-CAM5, MIROC-ESM-CHEM and CanESM2. The results of this study might be used as a fundamental data to choose a reasonable climate change scenario in future extreme drought evaluation.