• Journal of Korea Water Resources Association
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• v.44 no.12
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• pp.929-940
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• 2011

In this study, the future expected discharges are analyzed for Daecheong and Yongdam Dam Watershed in Geum River watershed using A1B scenario based RCM with 27 km spatial resolutions from Korea Meteorological Agency and SWAT model. The direct use of GCM and RCM data for water resources impact assessment is practically hard because the spatial and temporal scales are different. In this study, the problems of spatial and temporal scales were settled by the spatial and temporal downscaling from watershed scale to weather station scale and from monthly to daily of RCM grid data. To generate the detailed hydrologic scenarios of the watershed scale, the multi-site non-stationary downscaling method was used to examine the fluctuations of rainfall events according to the future climate change with considerations of non-stationary. The similarity between simulation and observation results of inflows and discharges at the Yongdam Dam and Daecheong Dam was respectively 90.1% and 84.3% which shows a good agreement with observed data using SWAT model from 2001 to 2006. The analysis period of climate change was selected for 80 years from 2011 to 2090 and the discharges are increased 6% in periods of 2011~2030. The seasonal patterns of discharges will be different from the present precipitation patterns because the simulated discharge of summer was decreased and the discharge of fall was increased.

• Journal of Korea Water Resources Association
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• v.46 no.1
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• pp.73-85
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• 2013

The researches on the parameter estimation for storage function method have been conducted for a long time using different methods. However, the determination of the optimal parameters takes a long time and there is a controversy that the proposed optimal parameters do not likely represent the physical characteristics of watershed. In this study, the characteristics of the continuity and storage function equation was analyzed and sensitivities were evaluated. As the result, the only optimal solution is suggested among several local optimums. It is also shown that the lag time is able to be determined using the direct runoff starting time of the watershed. From the sensitivity analysis, it is also proved that the determination of the lag time is very important and the only optimal solution could be found easily after selecting the lag time. Therefore, unlike the traditional optimization method, the proposed method does not take a long time to find the optimal solution which is depending on the characteristics of the rainfall events. The fixed coefficient method which is a method to estimate the optimal parameters of storage function method has been modified using the proposed method. Therefore, the practical efficiency to apply storage function method could be enhanced by applying the proposed method. While the traditional method takes care only the error of the runoff hydrograph, it is very important that the proposed method considers the characteristics of the watershed.

• Journal of Korea Water Resources Association
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• v.48 no.3
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• pp.221-231
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• 2015

This is a continuous study on the dam effects for the spatial extension of flood data. In this study, flood reduction rates of dams and their influences on downstream using the spatially extended flood data were implemented. Nam-Han River was selected for measuring the impacts of ChoongJu and HoangSung dams. In the evaluations of flood reduction rate at dams, the larger flood events have the lower flood reduction rates for both dams. At the YeoJoo water level station, the analyses of the relations between flood reduction rates and the sizes of watersheds dams located were performed. the sizes of watersheds having a functional dam have highly influenced on the reduction rates of flood. The average of flood reduction rates was smaller than the area rate. For instances, area rates of HoangSung (0.02) and ChoongJu dams (0.6) are larger than the average flood reduction rates for HoangSung (0.01) and ChoongJu dams (0.51), respectively. However, the water level station follows the dam flood reduction characteristics of dams themselves. The spatial effects of dam flood reductions are analyzed based on the three water level stations (GangChun, YeoJoo, YangPyung). The distance of flood reduction rates lower than 0.1 as average flood reduction rate was the area 7 times of watershed having a dam with 0.02 as a minimum reduction rate.

• Journal of KIISE:Computer Systems and Theory
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• v.32 no.11_12
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• pp.663-674
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• 2005

We propose a system aimed at achieving high energy-delay efficiency by using adaptive victim caches. Particularly, we investigate methods to improve the hit rates in the first level of memory hierarchy, which reduces the number of accesses to mort power consuming memory structures such as L2 cache. Victim cache is a memory element for reducing conflict misses in a direct-mapped L1 cache. We present two techniques to fill the victim cache with the blocks that have higher probability to be re-reqeusted by processor. Hit-based victim cache ks tilled with the blocks which were referenced frequently by processor. Replacement-based victim cache is filled with the blocks which were evicted from the sets where block replacements had happened frequently According to our simulations, replacement-based victim cache scheme outperforms the conventional victim cache scheme about $2\%$ on average and refutes the power consumption by up to $8\%$.

• Journal of KIISE:Computer Systems and Theory
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• v.27 no.8
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• pp.719-729
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• 2000

Prefetching aims at reducing memory latency by fetching, in advance, data that are likely to be requested by the processor in a near future. The effectiveness of prefetching is determined by how accurate the prediction on the needed instructions and data is. Most previous studies on prefetching were limited to proposing a particular prefetch scheme and its performance evaluation, paying little attention to theoretical aspects of prefetching. This paper focuses on the theoretical aspects of instruction prefetching. For this purpose, we propose a clairvoyant prefetch model that makes use of perfect history information. Based on this theoretical model, we analyzed upper limits on the prefetch prediction accuracies of the SPEC benchmarks. The results show that the prefetch prediction accuracy is very high when there is no cache. However, as the size of the instruction cache increases, the prefetch prediction accuracy drops drastically. For example, in the case of the spice benchmark, the prefetch prediction accuracy drops from 53% to 39% when the cache size increases from 2Kbyte to 16Kbyte (assuming 16byte block size). These results indicate that as the cache size increases, most localities are captured by the cache and that instruction prefetching based on the information extracted from the references that missed in the cache suffers from prediction inaccuracies

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.3
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• pp.579-588
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• 2015

Recent climage changes have resulted in increases in rainfall intensity and flood frequency as well as the risk of flood damage due to typhoons during the summer season. Water-friendly facilities such as ecological parks and sports facilities have been established on floodplains of rivers since the river improvement project was implemented and increases in the flood levels of rivers due to typhoons can lead to direct flood damage to such facilities. To analyze the hydraulic influence of these water-friendly facilities on floodplains or to evaluate their stability, numerical analysis should be performed in advance. In addition, it is crucial to address the drying and wetting processes generated by water level fluctuations. This study uses a Nays2D model, which analyzes drying and wetting, to examine its applicability to simple terrain in which such fluctuations occur and to natural rivers in which drying occurs. The results of applying this model to sites of actual typhoon events are compared with values measured at water level observatories. Through this comparison, it is determined that values of coefficient of determination ($R^2$), mean absolute error (MAE), and root-mean-square error (RMSE) are 0.988, 0.208, and 0.239, respectively, thus showing a statistically high correlation. In addition, the results are used to calculate flood risk indices for evaluation of such risk for water-friendly facilities constructed on floodplains.

• Journal of Science of Art and Design
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• v.9
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• pp.89-115
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• 2006

한국근대미술은 유화 도입기인 1910년대를 한국미술사의 중요한 시작점이다. 1910년경부터 형성되기 시작한 유화 도입배경과 그것이 당시 사회의 절실한 요청에 의한 것이었는지, 그렇다면 그것이 무엇인지 규명하는 것이 한국근대미술 초기를 알 수 있는 중요한 문제일 것이다. 일본근대 유화의 역사는 국수주의와 서구주의 물결이 반복하는 과정에서 점차 일본화된 소재의 등장과 일본정서에 부합하는 화풍을 만들어 나가게 되는 것이 1890년대부터 1910때까지의 일본근대 유화계의 상황이라고 할 수 있다. 이 시기를 다시 요약하면 외광파와 인상파가 절충된 양식에 일본의 메이지낭만주의에 부합하는 소재 즉 일본전통이라고 할 수 있는 풍경에 대한 애착 등이 전체 유화의 기류로 나타나는 시기라고 할 수 있다. 실제 새로운 문화의 하나였던 유화는 점차 세계의 다양한 미술사조 속에서 일본화다운 것으로 발전하는 모습을 보여준다. '구로다 세이키'(黑田淸輝) 이전에 이미 형성되었던 일본근대 유화양식과 구로다의 외광파 양식, 또 외광파가 일본 근대유화의 주류로 형성하게 되는 계기, 여기에 프랑스에서 직접 배워 온 작가들에 의한 인상파 도입 그리고 일본 '메이지낭만주의'(明治浪漫主義)의 등장으로 인한 사회 환경구조의 변화 속에서 양성된 그들의 절충양식의 초기유학생들에게 큰 영향을 미쳤다. 우리근대미술은 '민족적 자부심'과 '민족적 열등감'이 동시에 존재하는 사회적 배경논리에서 출발하지 않으면 안 된다. 즉 근대미술의 사상적 배경에는 민족 개량주의적 발상과 계몽주의적 문화 활동에 있었다고 할지라도 근본적으로는 미술자체를 근대사회 발전의 연장선 속에서 파악하지 못했고, 따라서 미술자체를 새로운 문명수입이라는 근대적 풍물 정도로만 파악했던 것이 어쩔 수 없는 근대미술의 한계라고 할 수 있다. 이 시기에 미술을 주목한 이유는 근대적 사회로 발전하기 위한 하나의 필수적인 요소로 미술자체를 파악하고 나아가, 식산흥업(殖産興業)의 수단으로 인식 했던 신지식층에 의해 시작되었다고 할 수 있다. 문명의 발달이 미술의 발달에서 연원한다는 '미술문명론' 같은 시각이 미술자체가 성격이나 창작의 방향과는 무관하게 어떤 미술이든 그것을 활성화시키는 것이 근대 즉 문명화된 세계로 나아갈 수 있다고 하는 관점에서 비롯된 것이라고 할 수 있다. 한국근대미술에 있어서 아카데미즘 역시 일본근대미술과 불가분의 관계가 있음을 부인할 수 없다. 초기유학생들은 그 당시 일본의 잡지나 화단에서 일어나는 여러 가지 시안들을 피상적으로 이해하는 정도였을 것으로 파악할 수 있다. 이러한 맥락에서 보면 한국근대미술에 있어서 초기유학생들의 작품과 그 이후 선전에서 입선하는 작품들은 일본아카데미즘의 영향 밑에 있다고 해야 할 것이다. 일본 근대 유화에서 형성된 외광파의 요소와 인상파 요소들이 일본 낭만주의로 표면화된 하나의 일본근대 유화의 형식 그대로가 한국아카데미즘의 성격을 결정하고 있다고 할 수 있다. 게다가 1922년에 시작된 선전은 심사위원 대부분이 동경미술학교 교수이면서 구로다의 제자이거나 동료였다는 것은 이러한 사실을 더욱 확고하게 뒷받침하고 있는 것이다. 초기유학생들이 남긴 작품들은 완전한 인상파에 대한 지식이나 깊은 자아의식을 가지고 제작된 것은 아니라, 일본 동경미술학교에서 가르치고 있었던 것들을 그대로 수용했다고 할 수 있다. 따라서 이들의 그림은 구로다의 외광파라고 부르는 것들의 영향보다는, 인상파를 보고 배웠던 동경미술학교 교수들의 영향을 더 많이 받았다고 할 수 있다. 그리고 이들의 영향은 그대로 한국 근대미술의 아카데미즘을 형성하는데 커다란 영향을 미치고 있음을 부인할 수 없다.

• Journal of Korea Water Resources Association
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• v.31 no.1
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• pp.13-25
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• 1998

It is necessary to develop methodologies for the application of artificial neural network into hydrologic rainfall-runoff process, although there is so much applicability by using the functions of associative memory based on recognition for the relationships between causes and effects and the excellent fitting capacity for the nonlinear phenomenon. In this study, some problems are presented in the application procedures of artificial neural networks and the simulation of runoff hydrograph experiences are reviewed with nonlinear functional approximator by artificial neural network for rainfall-runoff relationships in a watershed. which is regarded as hydrdologic black box model. The neural network models are constructed by organizing input and output patterns with the deserved rainfall and runoff data in Pyoungchang river basin under the assumption that the rainfall data is the input pattern and runoff hydrograph is the output patterns. Analyzed with the results. it is possible to simulate the runoff hydrograph with processing element of artificial neural network with any hydrologic concepts and the weight among processing elements are well-adapted as model parameters with the assumed model structure during learning process. Based upon these results. it is expected that neural network theory can be utilized as an efficient approach to simulate runoff hydrograph and identify the relationship between rainfall and runoff as hydrosystems which is necessary to develop and manage water resources.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.6 no.3_4
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• pp.112-122
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• 1973

Philometroides carassii (ISHII, 1931) is a parasitic nematode of Carassius auratus and gold fish. Recently a large number of parasitized fishes by this nematode have been reported by fish farmers in Korea. The present investigation was aimed to find out the life cycles of the parasites and effects of chemotherapeutic medicines on the emerged larvae from the adult parasites. Results of the study are summarized as follows : 1. Intermediate host of p. cararsii is a freshwater copepod, Cyclops sp. and the invaded lavae in the body cavity of copepod are capable for parasitizing the fish host after 3 hours of invasion. 2. The lavae eaten directly by the fish host are digested or excreted. 3. The larvae invaded in the fish intestine through the intermediate host pass into the body cavity in 1 to 10 days, and become subadult stage. After 18 to 20 months the subadults parasitic in the body cavity of the Carassius auratus, penetrate through muscle fissile into tile caudal fin where they become adults. Whereas those parasitic in the body cavity of the gold fish, 7 to 8 months the sutadults penetrate through muscle tissue into the caudal fin where they become adults. 1. Male subadults found in the body cavity of the Carassius auratus and gold fish, were larger than females, This is the first record of male subadults occurring in the fish host. 5. Among four different :drugs tested, most of all larvae died in 4 ppm of dipterex in 5 days. But no adults were harmed even in 6 ppm dipterex in 11 days.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.401-404
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• 2008

Bridges are exposed to very severe environment and experience, as service life increased, elevated traffic load and traffic flow, in addition to natural disasters. In comparing to other road structures, bridges may cause more significant damage, such as human-involved accidents, to the society in the event of collapse. A certain level of service shall be necessarily secured to assure the minimum safety of users. The cost for manage and preserve bridges will increase gradually and more restrictions will be loaded to efficiently distribute the limited resources, such as monetary budget and human resource etc. In order to enhance performance and serviceability of bridges with the limited resource, asset management technique has been applied into the bridge management system, which capitalizes the road infrastructures including bridges and assess them in accordance with the government finance report. In the application of asset management, there must be a tool for assess the performance of bridges and this study introduces the basic information on the definition and role of performance measures for asset management for bridges.