• 유체기계공업학회:학술대회논문집
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• 2005.12a
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• pp.742-747
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• 2005

A model, which can analyze the hydrological performance for small hydropower(SHP) plants having no flow duration characteristics has been studied and developed. System performance of existing SHP plant under operating was analyzed by using the developed model. The annual operational rate of SHP plant showed that the data were in good agreement with predicted results from the model. Based on these results, several SHP sites to be exploited were selected and the performance characteristics were analyzed by using the developed model. Also, primary design values such as design flow rate, plant capacity, and operational rate were suggested. As a result, it was found that the methodology used in this study is useful tool to predict the hydrological system performances of SHP sites.

• Proceedings of the Korea Water Resources Association Conference
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• 2004.05b
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• pp.903-907
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• 2004

평저수시 유량측정법인 유속-단면적법의 대안으로 제시할 수 있는 기존 보를 활용한 유량측정법은 수위를 체크함으로서 손쉽게 유량을 알 수 있다는 장점이 있다. 표준유량측정구조물에 비해 정확도는 떨어지지만 기존 보에 대한 수위-유량관계곡선을 작성해 놓게 되면 높은 정확도에서 유량을 알 수 있게 된다. 구조물의 형태, 구조물 상하류조건, 수위-유량관계 곡선 개발시 정밀유량측정의 정도에 의존하겠지만 홍수시보다는 평저수시 크게 활용성이 있을 것으로 사료된다. 시험사이트로 탄천 1개소, 곡릉천 2개소의 보를 선정하여 수위-유량관계곡선과 유량공식을 개발해 보았다.

• Water for future
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• v.22 no.1
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• pp.91-98
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• 1989

This study was aimed to determine a discharge coefficient of flow through gate piers. The coefficient was Calbrated with water stage data observed during 1984 to 1987 at the Young San Estuary Dam. The coefficient is the function of the dimensionless parameters combined with the difference between up and down stream water level to down stream water depth ratio and water surface draw down ratio. From the verification with existing methods and actual drainages, drainages predicted by the relationship have the most consistency with the actual drainages, also Matthai's method can be used within the proposed condition originally.

• Magazine of the Korean Society of Agricultural Engineers
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• v.22 no.2
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• pp.64-82
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• 1980

The aim of this thesis, when water permeates dam, is to study the shape of seepage line and seepage quantity. As for the process, various sand model dams of same capacity were constructed in the water tank : they are a central, middle, inclined, up and down stream point of which is paralled, and filter-installed types. And the slope of seepage line and seepage quantity in these various models for experiment were measured, observed data were analyzed, and several formulas which already published were compared and examined. As for the shape of seepage line, the relation between upstream water level and exit: slope of seepage line, near the entrance and exit point, geometrically similar model, and the shape of seepage line filter-installed were examined. As regards to the seepage quantity, several formulas which already published and testing result values were compared and examined, and relation with the slope of seepage line, the seepage quantity, the slope of upstream point, and the upstream water level were mutually studied. Particulary, when horizontal filter was installed, propriety of the existing formulas for effective filter length w as examined, and the relative position of exit point in various. conditions was also studied.

• 한국지구물리탐사학회:학술대회논문집
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• 2007.06a
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• pp.237-240
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• 2007

The evaluation of shear modulus (or shear wave velocity) profile of site is very important in the various fields of geotechnical engineering. To obtain shear wave velocity profile, various in-situ seismic methods using surface waves have been developed. These surface wave based in-situ seismic methods have their own strength and weakness. In this study, new seismic site characterization method using the harmonic wavelet analysis of wave (HWAW) was proposed to overcome some of weaknesses in the existing surface wave based seismic site characterization methods. HWAW method which is based on time-frequency analysis using harmonic wavelet transform have been developed to determine phase and group velocities of waves. In order to estimate the applicability of HWAW method, field tests were performed. Through field applications and comparison with other test results, the applicability of the proposed method were verified.

• ETRI Journal
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• v.23 no.3
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• pp.129-137
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• 2001

A random sampling or systematic sampling method is commonly used to assess the accuracy of classification results. In remote sensing, with these sampling methods, much time and tedious work are required to acquire sufficient ground truth data. So, a more effective sampling method that can represent the characteristics of the population is required. In this study, fractal analysis is adopted as an index for reference sampling. The fractal dimensions of the whole study area and the sub-regions are calculated to select sub-regions that have the most similar dimensionality to that of the whole area. Then the whole area's classification accuracy is compared with those of sub-regions, and it is verified that the accuracies of selected sub-regions are similar to that of whole area. A new kind of reference sampling method using the above procedure is proposed. The results show that it is possible to reduce sampling area and sample size, while keeping the same level of accuracy as the existing methods.

• Journal of Environmental Science International
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• v.6 no.3
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• pp.205-211
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• 1997

For the prediction of multi-site rainfall with radar data and ground meteorological data, a rainfall prediction model was proposed, which uses the neural network theory, a kind of artifical Intelligence technique. The Input layer of the prediction model was constructed with current ground meteorological data, their variation, moving vectors of rain- fall field and digital terrain of the measuring site, and the output layer was constructed with the predicted rainfall up to 3 hours. In the application of the prediction model to the Pyungchang river basin, the learning results of neural network prediction model showed more Improved results than the parameter estimation results of an existing physically based model. And the proposed model comparisonally well predicted the time distribution of ralnfall.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.209-218
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• 2009

In this study, properties of shear wave velocity of core zone in filldams are analyzed. Shear wave velocity is derived using analysis of surface wave method that can be used nondestructively on the surface of filldams. These values are acquired through the tests for the core zone of six filldams by SASW and HWAW methods. Existing 2 more results are added. Shear wave velocity according to the depth and confining pressure are estimated, respectively. These analytical results are compared with the frequently used empirical method by Sawada and Takahashi.

• Journal of Navigation and Port Research
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• v.33 no.9
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• pp.615-621
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• 2009

Road and maritime transport which connecting main cities in the world is already fully saturated, and the loss cost caused by recent high oil prices is getting bigger. Transportation by inland waterway is rising as an alternative method of them. Concerning this, the GI Waterway is on construction to connect the Yellow sea and Seoul. Nevertheless, there are no existing aids to navigation around the area and no studies have been carried out for them. As the construction progresses, installation of proper aids to navigation should be considered and profound studies need to be carried out. This study focused on introduction of the cases and the systems of other countries inland waterway aids to navigation and suggested a suitable navigation aids system along the inland waterways in Korea and a way of installation for that system.

• Proceedings of the KIEE Conference
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• 2000.07d
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• pp.3063-3065
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• 2000

The appearance and popularization of Internet changes the existing restrictive management system into the new management system on Web. In this paper, We developed real-time management System controlling all sorts of informations from Dong-Hwa dam. Informations from MMI(Man Machine Interface) is stored for DB and Wherever User can use Internet, User can get this informations. We also developed Editor modifying Client Display.