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  • Title/Summary/Keyword: 우수유출

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Network analysis using frequency of cross-citation and comparing citation index of accounting journals (회계학 관련 학술지의 인용지수 비교 및 상호인용 빈도를 이용한 네트워크 분석)

  • Choi, Kyoung-Ho;Oh, Hee-Hwa;Kwag, Hee-Jong
    • Journal of Digital Convergence
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    • v.12 no.2
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    • pp.143-149
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    • 2014
  • Currently, despite the quantitative growth of domestic journal, objective and metric criterion to evaluate the contents and quality of those journals is inadequate. As a result, depending on a foreign citation index like SCI to evaluate the research result is causing some problems such as, thesis of an excellent standard being presented and published in foreign countries, thus, neglecting journals written in Korean. Hereat, the Korea Citation Index(KCI) is constructing a database of the journals published by academic associations; scientific paper information, articles information, and bibliographic, analyzing the quoting relation. Consequently, KCI is providing the basic information and the corresponding quoting relations of journals and papers on its webpage. This study compares the impact level of domestic accounting related journals by KCI and analyzes the network among journals using the cross-citation frequency from a social network analysis point of view. As a result, Accounting-related journals are now more desirable than the location in order to have a variety of interdisciplinary research needs to be encouraged. Through this exchange of other disciplines and actively made, which is the phase of apparent accounting-related journals expect to be greatly enhanced looks.

Video Assisted Thoracoscopic Surgery, 31 Cases (비디오 흉강경을 이용한 흉부수술 31예)

  • Sung, Sook-Whan;Kim, Kwhan-Mien;Kim, Joo-Hyun
    • Tuberculosis and Respiratory Diseases
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    • v.40 no.5
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    • pp.468-473
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    • 1993
  • Background: Recent advance in video technology, endoscopic equipments, and surgical techniques have expanded the use of thoracoscopy from diagnosis of the pleural diseases to treatment of the various intrathoracic diseases. Video Assisted Thoracoscopic Surgery(VATS) is a pretty new and fascinating thoracic surgical modality, and so we present our early VATS resuls. Methods: Using Video Thoracoscopic techniques in 30 patients for 10 months from July 1992 to April 1993, we had performed a variety of procedures. These incuded (1) bleb resections in 18 patients (19 cases), (2) mediastinal tumor excision in 4, (3) lung biopsies for parenchymal pulmonary disease in 3, (4) pleural biopasies in 3, (5) pleural tumor excision in 1, (6) and pleuropericardial window in 1. Results: There were no mortality associated with the procedures. We had minor 8 complications; prolonged air leak in 3 patients, prolonged serous drainage in 2, recurrence of pneumothorax in 1, Honer's syndrome in 1, and hoarseness in 1 patient. None of the 30 patients had reverted to the conventional full thoracotomies. Mean postoperative hospital stay of non-complicated pneumothoraces was about 5 days, which was a little shorter than conventional thoracotomy group. Conclusion: Though we had somewhat higher postoperative complication rate due to lack of experiences in the begining, we were able to convince that VATS had benifical value for patients; lesser postoperative pain, shorter hospitalization, quicker recovery time, and cosmetically superior scar. The role of VATS can be expanded to the diagnosis and treatment of various thoracic diseases, even to the cardiovascular diseases, with satisfactory outcome and less postoperative morbidity.

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Decision of G/R Ratio for the Correction of Mean-Field Bias of Radar Rainfall and Linear Regression Problem (레이더 강우의 평균보정을 위한 G/R 비의 결정과 선형 회귀 문제)

  • Yoo, Chulsang;Park, Cheolsoon;Yoon, Jungsoo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.31 no.5B
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    • pp.393-403
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    • 2011
  • This study theoretically reviewed the empirical G/R ratio by considering three regression and trend lines; the general linear regression curve, linear regression curve passing the origin, and the line passing the origin and the mass center of observed data. This review included the problem of choosing the independent variable and that of considering the zero measurements. This review result was also applied to the Typhoon Maemi in 2003 for their evaluation. Additionally, those regression and trend lines were compared using the RMSE between the corrected radar rainfall and observed rain gauge rainfall to select the most appropriate G/R ratio. Summarizing the results is as follows. First, the results of selecting the rain gauge rainfall as the independent variable were found better than the opposite case. Second, the effect of zero measurements varies depending on the structure of radar and rain gauge rainfall. Finally, the results from the comparison of three regression and trend lines shows that the slope of the regression line passing the origin with its independent variable of rain gauge rainfall would be used most appropriately for the G/R ratio, especially when the corrected radar rainfall is used for the flood analysis. The effect of zero measurements in this case was found not so significant.

Assessment of uncertainty associated with parameter of gumbel probability density function in rainfall frequency analysis (강우빈도해석에서 Bayesian 기법을 이용한 Gumbel 확률분포 매개변수의 불확실성 평가)

  • Moon, Jang-Won;Moon, Young-Il;Kwon, Hyun-Han
    • Journal of Korea Water Resources Association
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    • v.49 no.5
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    • pp.411-422
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    • 2016
  • Rainfall-runoff modeling in conjunction with rainfall frequency analysis has been widely used for estimating design floods in South Korea. However, uncertainties associated with underlying distribution and sampling error have not been properly addressed. This study applied a Bayesian method to quantify the uncertainties in the rainfall frequency analysis along with Gumbel distribution. For a purpose of comparison, a probability weighted moment (PWM) was employed to estimate confidence interval. The uncertainties associated with design rainfalls were quantitatively assessed using both Bayesian and PWM methods. The results showed that the uncertainty ranges with PWM are larger than those with Bayesian approach. In addition, the Bayesian approach was able to effectively represent asymmetric feature of underlying distribution; whereas the PWM resulted in symmetric confidence interval due to the normal approximation. The use of long period data provided better results leading to the reduction of uncertainty in both methods, and the Bayesian approach showed better performance in terms of the reduction of the uncertainty.

One-month lead dam inflow forecast using climate indices based on tele-connection (원격상관 기후지수를 활용한 1개월 선행 댐유입량 예측)

  • Cho, Jaepil;Jung, Il Won;Kim, Chul Gyium;Kim, Tae Guk
    • Journal of Korea Water Resources Association
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    • v.49 no.5
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    • pp.361-372
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    • 2016
  • Reliable long-term dam inflow prediction is necessary for efficient multi-purpose dam operation in changing climate. Since 2000s the teleconnection between global climate indices (e.g., ENSO) and local hydroclimate regimes have been widely recognized throughout the world. To date many hydrologists focus on predicting future hydrologic conditions using lag teleconnection between streamflow and climate indices. This study investigated the utility of teleconneciton for predicting dam inflow with 1-month lead time at Andong dam basin. To this end 40 global climate indices from NOAA were employed to identify potential predictors of dam inflow, areal averaged precipitation, temperature of Andong dam basin. This study compared three different approaches; 1) dam inflow prediction using SWAT model based on teleconneciton-based precipitation and temperature forecast (SWAT-Forecasted), 2) dam inflow prediction using teleconneciton between dam inflow and climate indices (CIR-Forecasted), and 3) dam inflow prediction based on the rank of current observation in the historical dam inflow (Rank-Observed). Our results demonstrated that CIR-Forecasted showed better predictability than the other approaches, except in December. This is because uncertainties attributed to temporal downscaling from monthly to daily for precipitation and temperature forecasts and hydrologic modeling using SWAT can be ignored from dam inflow forecast through CIR-Forecasted approach. This study indicates that 1-month lead dam inflow forecast based on teleconneciton could provide useful information on Andong dam operation.

Development of an Integrated Inundation Analysis Model for Urban Flood Inundation Analysis (도시지역의 침수해석을 위한 통합침수해석모형의 개발)

  • Kim, Dong-Il;Son, Ah-Long;Son, In-Ho;Han, Kun-Yeun
    • Proceedings of the Korea Water Resources Association Conference
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    • 2011.05a
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    • pp.135-135
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    • 2011
  • 지구온난화와 이상기후에 따라 최근 우리나라를 둘러싼 기후패턴의 변화가 가속화되고 있으며 한반도는 장마기간이 소강상태를 보이는 반면, 장마 후 국지성 집중호우가 증가하고 태풍이 내습하는 현상이 빈번해짐으로써 홍수에 대한 위험과 피해규모도 증가하고 있다. 특히 도시지역에서는 강우규모가 배수시스템의 용량을 초과하거나, 하천수위 상승으로 관로 내에 역류가 발생하는 등 우수 배제 기능을 제대로 수행하지 못할 경우 발생하는 지표침수로 인해 심각한 인명 및 재산피해가 발생하고 있다. 실제로 현재 홍수해석 및 홍수위험지도 작성시 내수시스템을 반영하지 않아 침수면적 및 범위의 오차가 존재하며 홍수위험지도 작성시 내수범람과 외수범람을 따로 고려하는 문제점이 있다. 따라서 도시 침수 해석시 내수시스템을 반영한 정확한 침수심 및 침수면적계산뿐만 아니라 이상기후에 대비한 복합적 요인으로 인한 침수해석이 필요하다. 따라서 본 연구에서는 하천해석을 위해 1차원 하천 해석 모형인 FLDWAV모형을 적용하고 가상의 제방 파제 시나리오를 통하여 외수범람 영향을 구하였으며, 배수시스템의 SWMM모형과 제내지에서 내수와 외수범람의 영향을 고려한 DEM기반의 2차원 범람해석을 연계한 Dual-Drainage모형에 대하여 외수범람 영향에 따른 흐름의 양상, 침수심, 침수위 등을 분석하였다. 개발한 모형에 대한 적용성을 검토하기 위하여 대구 신암5동 유역을 선정하였고 대상유역의 수치지도를 활용하여 정형 격자 20m 크기로 지형자료를 구성하였으며, 건물의 영향도 고려하기 위해 DEM에 건물자료를 합성하였다. 침수해석 결과 내수시스템의 영향을 고려하지 않을 때가 고려하였을 때 보다 Node(맨홀)에서의 재유입의 영향으로 인하여 최대 침수심이 더 높게 나왔으며 침수면적도 넓게 나타나는 것을 확인하였고, 기존의 홍수위험지도 작성시 외수침수와 내수침수를 구분하여 해석하였던 것을 본 연구에서 통합하여 외수범람의 영향을 고려한 통합침수해석을 실시하여 내수에서 발생할 수 있는 유출량과 내수시스템의 월류량 등에 대한 고려가 없는 외수침수만 해석시 보다 최대침수심이 더 높게 나타났으며 침수면적 또한 넓게 나타남을 알 수 있었다. 본 연구를 통해서 도시홍수, 돌발홍수 등의 발생시 정확한 도시 침수 해석이 가능하며 도시침수구역에 대한 적절한 예 경보 및 피난대책 수립에 활용될 수 있을 것으로 사료된다. 또한 국내의 홍수위험지도나 도시 침수해석과 연계하여 선행시간을 확보한 정확도 높은 홍수정보시스템 구축에 크게 기여할 것으로 판단된다.

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Application of Yeongdong Illite to Remove Radiocesium for Severe Nuclear Accidents (원자력 중대 사고에 대비한 영동 지역 일라이트의 방사성 세슘 흡착 특성 평가)

  • Hwang, Jeonghwan;Choung, Sungwook;Park, Chan-Soo;Han, Jeong-Hee;Jeon, Sodam
    • Journal of the Mineralogical Society of Korea
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    • v.29 no.4
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    • pp.229-238
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    • 2016
  • This study evaluated potential application of illite, which is produced at Yeongdong area in Korea, to remove radiocesium released to environmental system through severe nuclear accidents. The Yeongdong illite was formed by metamorphose of micaceous schist in hydrothermal condition, and composed of quartz, illite, and albite. Sorption distribution coefficient (Kd) of cesium by the Yeongdong illite was higher than the Kd values for other clay minerals. It may be affected by preferential adsorption of cesium to Frayed Edge Sites (FES) on illite. Nonlinear isotherm models were suitable to describe the sorption processes for the Yeongdong illite. Its max. single layer capacity was 250,000μgkg1 for cesium. Therefore, the Yeongdong illite could be an efficient and economic sorbent to prevent dispersion of radiocesium, and apply for remediation.

Assessment of Acid Rock Drainage Production Potential and Damage Reduction Strategy: A Case Study of Tunnel Construction Area (암석의 산성배수 발생개연성 평가 및 피해저감대책: 터널건설예정구간 사례)

  • Kim, Jae-Gon;Lee, Jin-Soo;Kim, Tong-Kwon
    • Economic and Environmental Geology
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    • v.41 no.3
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    • pp.335-344
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    • 2008
  • The acid rock drainage (ARD) production potential of rock was assessed for a tunnel construction area, Kimhae and the damage reduction strategy was discussed based on the ARD risk evaluation. The geology of the studied area consisted of Mesozoic quartz porphyry, sandstone, tuff and granite. Sulfides occurred as a disseminated type in quartz porphyry and granite, and a vein type in sandstone. Quartz porphyry and sandstone with a high content of sulfide were classified as a potentially ARD forming rock. The drainage originated from those rocks may acidify and contaminate the surrounding area during the tunnel construction. Therefore, the drainage should be treated before it is discharged. A slope stability problem due to the ARD was also expected and the coating technology was recommended for the reduction of ARD generation before the application of supplementary work for enhancing slope stability such as shotcrete and anchor. From the ARD risk analysis, those rocks should not be used as aggregate and be used as bank fill material with the system for the minimum contact with rain water and ground-water.

Study on Design Technology of Heat Pump Cycle for High Temperature Performance (고온 생산용 열펌프 사이클 설계)

  • Kim, Jong-Ryul;Kim, Seok-Young;Kim, Yong-Min;Lee, Kong-Hoon;Kim, Ook-Joong;Yi, Sung-Chul;Jung, Chi-Young;Kim, Jong-Ryeol
    • Journal of Energy Engineering
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    • v.19 no.4
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    • pp.228-233
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    • 2010
  • About 55% of total energy is consumed in the industrial division. The industrial heat pump application will show magnificent energy saving effect as well as higher cost efficiency because of larger energy consuming volume of each facility and longer operation hour and higher stability against seasonal temperature change. Over 90% of dryer for industrial usage has hot wind heat source and hot wind dryer is the representative type covering 68.7% while its 30 ~ 50% lower heat efficiency causes lots of energy loss by exhaust air. Re-usage of exhaust air can improve energy efficiency of dryer because 68% heat energy or 78% of hot air lose in exhaust air. Therefore, high temperature heat pump dryer can be the best alternative. Comparing to the existing dryer with 30% ~ 50% energy efficiency, newly developing high temperature heat pump dryer will enhance energy efficiency up to 60% ~ 80% efficiency. In this paper, heat pump system for high temperature was designed, constructed and tested. The results have shown that system COPh is estimated as 3.3.

Changes of Properties and Gas Components according to Accelerated Aging Test of Vegetable Transformer Oil (식물성 절연유의 가속열화에 따른 주요 성분 및 물성 변화)

  • Lee, Donmin;Lee, Mieun;Park, Cheonkyu;Ha, Jonghan;Park, Hyunjoo;Jun, Taehyun;Lee, Bonghee
    • Journal of Energy Engineering
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    • v.25 no.3
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    • pp.18-26
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    • 2016
  • Mineral oil is the most widely used for electrical transformer, though some factors should be considered such as their environmentally harmfulness when it spill and low flash point. To cover these disadvantages, vegetable oil has developed because of its high biodegradability and thermal stability. However, it is necessary that many studies should conduct to reveal the detailed impacts of long-term operation as transformer oil. In this paper, we applied the accelerated aging test which simulate the real transformer circumstances using insulation paper, coil, steel at 150C, which is higher than normal operation, for 2 weeks. To figure out the oxidation characteristics between mineral oil and vegetable oil test major properties and components such as total acid number, dielectric breakdown and dissolved gas components during that period. As a result of these tests, we found that vegetable oil has higher electric insulation ability than mineral oil though poor total acid number by hydrophile property. Vegetable oil also kept its thermal stability under the given circumstances.