• Nuclear Engineering and Technology
• /
• 제55권1호
• /
• pp.100-108
• /
• 2023

In this study, a neural network model inspired by a one-dimensional convolution U-net is developed to automatically accelerate edge localized mode (ELM) detection from big diagnostic data of fusion devices and increase the detection accuracy regardless of the hyperparameter setting. This model recognizes the input signal patterns and overcomes the problems of existing detection algorithms, such as the prominence algorithm and those of differential methods with high sensitivity for the threshold and signal intensity. To train the model, 10 sets of discharge radiation data from the KSTAR are used and sliced into 11091 inputs of length 12 ms, of which 20% are used for validation. According to the receiver operating characteristic curves, our model shows a positive prediction rate and a true prediction rate of approximately 90% each, which is comparable to the best detection performance afforded by other algorithms using their optimized hyperparameters. The accurate and automatic ELM-burst detection methodology used in our model can be beneficial for determining plasma properties, such as the ELM frequency from big data measured in multiple experiments using machines from the KSTAR device and ITER. Additionally, it is applicable to feature detection in the time-series data of other engineering fields.

• 한국생산제조학회지
• /
• 제6권4호
• /
• pp.72-79
• /
• 1997

A study is a experiment which is figure out to optimum discharge cutting condition of the surface roughness, electronic discharging speed and electrode wear ration with Ton , Toff and V(voltage) as an input condition according to the current(Ip) in an electric spark machine : 1) Electrode is utilized Cu and Graphite. 2) Work piece is used the material of carbon steel. The condition of experiment is : 1) Current is varied 0.7(A) to 50(A) and the time of electric discharging to work piece in each time is 30(min) to 60(min). 2) After the upper side of work piece was measured in radius(5$\mu$m) of stylus analyzed the surface roughness to ade the table and graph of Rmax by yielding data. 3) Electro wear ratio is : \circled1Cooper was measured ex-machining and post-machining by the electronic balance. \circled2The ex-machining of graphite measured by it, the post-machining was found the data from volume $\times$specific gravity and analyzed to made its table and graph on ground the data. 4) In order to keep the accuracy of voltage affected to the work piece was equipped with the A.V. R and the memory scope was sticked to the electric spark machine. 5) In order to preserve the precision of current, to get rid of the noise occured by internal resistance of electric spark machine and to force injecting for the discharge fluid , it made the fixed table for a work piece to minimize the work error by means of one's failure during the electric discharging.

• 한국농공학회논문집
• /
• 제59권2호
• /
• pp.69-79
• /
• 2017

In this study, we developed real-time urban stream discharge forecasting model using short-term rainfall forecasts data simulated by a regional climate model (RCM). The National Centers for Environmental Prediction (NCEP) Climate Forecasting System (CFS) data was used as a boundary condition for the RCM, namely the Global/Regional Integrated Model System(GRIMs)-Regional Model Program (RMP). In addition, we make ensemble (ESB) forecast with different lead time from 1-day to 3-day and its accuracy was validated through temporal correlation coefficient (TCC). The simulated rainfall is compared to observed data, which are automatic weather stations (AWS) data and Tropical Rainfall Measuring Mission (TRMM) Multisatellite Precipitation Analysis (TMPA 3B43; 3 hourly rainfall with $0.25^{\circ}{\times}0.25^{\circ}$ resolution) data over midland of Korea in July 26-29, 2011. Moreover, we evaluated urban rainfall-runoff relationship using Storm Water Management Model (SWMM). Several statistical measures (e.g., percent error of peak, precent error of volume, and time of peak) are used to validate the rainfall-runoff model's performance. The correlation coefficient (CC) and the Nash-Sutcliffe efficiency (NSE) are evaluated. The result shows that the high correlation was lead time (LT) 33-hour, LT 27-hour, and ESB forecasts, and the NSE shows positive values in LT 33-hour, and ESB forecasts. Through this study, it can be expected to utilizing the real-time urban flood alert using short-term weather forecast.

• 한국방재학회:학술대회논문집
• /
• 한국방재학회 2008년도 정기총회 및 학술발표대회
• /
• pp.739-742
• /
• 2008

표면영상유속계(SIV)는 기존의 입자영상유속계(PIV)의 원리를 이용하여 하천의 표면유속을 측정하는 방법이다. 본 연구에서는 경제적이고 효율적인 유속측정 기법인 SIV 기법을 이용하여 국내 3개 하천에 대하여 현장 유량측정에 적용하였다. 현장 영상분석은 다중카메라 방식을 이용하였고 영상분석과정에 필요한 참조점과 횡단면 자료는 측량을 통하여 획득하였다. SIV로 측정된 유속을 검증하는 수로 실험의 결과, 평균오차 10% 이내의 정확도를 보여 정확한 유속측정이 가능함을 확인하였다. 그러나, 실제 하천에의 적용에서는 저수위시와 악천후시에 대해서는 20 % 이내의 오차를 보이는 것으로 나타났다. 향후 SIV 기법의 문제점들을 해결한다면 언제 어디서나 효율적이고 경제적인 유량측정을 할 수 있을 것이다. 그리고 이를 활용하여 실시간 하천정보시스템으로 발전시킴으로써 하천 관리에 큰 도움이 될 것이라 판단된다.

• Journal of Forest and Environmental Science
• /
• 제10권1호
• /
• pp.57-65
• /
• 1994

본(本) 연구(硏究)는 강원대학교(江原大學校) 임과대학(林科大學) 부속연습림(附屬演習林)의 임도개설유역(林道開設流域)을 중심으로 우기(雨期)의 계류수(溪流水)에 함유되어 있는 부유토사량(浮遊土砂量)을 측정하므로써 임도개설(林道開設)에 따른 토사유출(土砂流出) 변화(變化)를 파악하고자 진행하였다. 이를 위해 임도개설유역(林道開設流域)의 강우량(降雨量)과 유출량(流出量), 유출량(流出量)과 부유토사량(浮遊土砂量)의 관계를 규명하였으며, 아울러 임도개설유역(林道開設流域)과 미개설유역(未開設流域)의 강우량(降雨量)에 따른 부유토사량(浮遊土砂量)의 변화에 대하여 비교, 분석하였다. 1. 임도개설유역(林道開設流域)에 있어서 우기(雨期)의 강우량(降雨量)과 유출량(流出量)의 관계는 Table 3 및 Fig. 3와 같이 수문곡선(水文曲線)의 Peakpoint는 강우강도(降雨强度) 및 전강우량(前降雨量) 등에 따라 형성시간(形成時間)과 높이가 상이하였다. 즉 6월(月)12일(日)의 강우(降雨)(a)(20mm이상이 4시간 지속)에서는 3시간 경과 후에 $1514m^3/hour$, 8월(月) 8일(日)의 강우(降雨)(b)(최대(最大) 시우량(時雨量) 40mm)경우는 동일(同一) 시간대(時間帶)에서 $1246m^3/hour$, 그리고 8월(月) 20일(日)의 강우(降雨)(c)(최대(最大) 시우량(時雨量) 17.2mm)의 경우는 2시간 경과 후에 $1245m^3/hour$의 Peak point가 형성되었다. 2. 임도개설유역(林道開設流域)에서 유출량(流出量)과 부유토사량(浮遊土砂量)의 관계는 유출량(流出量)에 비례하여 부유토사량(浮遊土砂量)도 증가하였다(Table 4 및 Fig. 4). 즉 강우(降雨)(a)는 최대유출량(最大流出量)이 $1514m^3/hour$일 때 부유토사량(浮遊土砂量) 1261mg/l가 1시간 후에 나타났고, 강우(降雨)(b) 및 (c)는 각각 최대유출량(最大流出量) $1246m^3/hour$과 $1245m^3/hour$일 때 최대부유토사량(最大浮遊土砂量) 4952mg/l와 472mg/l가 동일시간대(同一時間帶)에서 나타났다. 3. 강우중(降雨中)의 부유토사량(浮遊土砂量)의 농도(濃度)는 강우강도(降雨强度)에 강하게 영향받고 있으며, 특히 강우강도(降雨强度)가 강할수록 곡선회귀(曲線回歸)의 형태(形態)로 증가하였다. 임도개설유역(林道開設流域)에서의 부유토사농도(浮遊土砂濃度)의 Peak point는 강우(降雨)(a)의 경우 1261mg/l와 125mg/l, 강우(降雨)(b)는 4952mg/l와 44mg/l, 그리고 강우(降雨)(c)는 472mg/l와 4mg/l로서 유역간(流域間)에 현격한 차이가 나타났다.

• 대한전기학회논문지
• /
• 제41권9호
• /
• pp.1060-1070
• /
• 1992

In this paper, characteristics of Acoustic Emission in Low Density Polyethylene were studied from tree initiation to breakdown under long-term inhomogeneous alternative electrical field. The voltage levels used were 9, 11 and 14[kV]. Especially, a newly developed automatic measuring system was used to measure time variations of AE average amplitude, AE pulse number, AE pulse distribution patterns due to polarities. The patterns wer specially the variated patterns, when tree propagated. Also, parameters for dielectric breakdown prediction, which were suggested by Okamoto, were calculated. The result was analysed by tree shapes and partial discharge activities in tree due to tree initiation and propagation.

• 한국화재소방학회논문지
• /
• 제9권1호
• /
• pp.20-29
• /
• 1995

The sprinkler head is a component of the sprinkler system intended to discharge water for automatic detection and extinguishment of fires. On this study, thermal characteristic values affecting the sensitivity of the fusible alloy type sprinkler head were obtained and analyzed under heated air stream condition which had constant temperature and velocity. The experiment was carried out under the forced convection condition with both the conductive heat loss considered and neglected. The thermal characteristic values of the sprinkler head were obtained in accordance with the material and shape of the heat responsive element and the conditions of the main body.

• 한국수자원학회:학술대회논문집
• /
• 한국수자원학회 2005년도 학술발표회 논문집
• /
• pp.474-477
• /
• 2005

The Industrial development and the Increase in population have brought out a rapid increase of wastewater discharge. To deal with this matter, much estimate has been spend on construction and management of a large scale sewage treatment plant. Although every effort has been carried out, river water quality has no significantly improved. Especially. the aggravation of the water quality in dry season is brought out a serious social problem. The purpose of this study Is the development of an optimal water quality management technique considering the efficient control of the multiple pollutant load associated with the total pollutant load control. A GUI(Graphical User Interface) system named 'QL2-XP' model is developed by object-oriencted language for the user convenience and practical usage. Suggested GUI system consist of hydraulic analysis. water quality analysis, optimized model calibration processes, and postprocessing the simulation results.

• 한국안전학회지
• /
• 제14권3호
• /
• pp.69-77
• /
• 1999

As the use of automatic handling equipment for sensitive semiconductor devices is rapidly increased, manufacturers of electronic components and equipment need to be more alert to the problem of electrostatic discharges(ESD). Semiconductor devices such as IC, LSI, VLSI become a high density pattern of being more fragile by ESD phenomena. One of the most common causes of electrostatic damage is the direct transfer of electrostatic charge from the human body or a charged material to the electrostatic discharge sensitive devices. Accordingly, characteristics of electrostatic attenuation in domestic semiconductor devices is investigated to evaluate the ESD phenomina in the semiconductors in this paper. The required data are obtained by Static Honestmeter. Also The results in this paper can be used for the prevention of semiconductor failure by ESD.

• 전자공학회논문지 IE
• /
• 제46권3호
• /
• pp.26-32
• /
• 2009

반도체 산업에서, 웨이퍼가 오염되는 불량률 원인의 70%는 웨이퍼 자체의 대전이다. 본 논문은 기존의 고전압을 이용한 코로나 방전식의 송풍형 정전기 제거장치를 개발하였다. 이 시스템은 방전 침 세정 기능을 자동으로 구현하여 균형하게 이온을 방출하도록 하였고, 이온 방출 상태를 감지하여 최적의 이온량을 조절하도록 하였으며, Zigbee 통신모듈을 이용하여 전 시스템을 모니터링하도록 하였다.