• 제목/요약/키워드: point-like source

검색결과 127건 처리시간 0.032초

도로 유형별 비점오염원 유출특성 분석 (Analysis of Nonpoint Sources Runoff Characteristic by Road Types)

  • 윤영삼;권헌각;이윤정;유재정;이춘식;이재관
    • 한국환경과학회지
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    • 제19권11호
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    • pp.1375-1384
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    • 2010
  • Growth in population and urbanization has progressively increased the loading of pollutants from nonpoint sources as well as point sources. Especially in case of road regions such as city trunk road, national road and highway are rainfall and pollutants runoff intensive landuses since they are impervious and emit a lot of pollutants from vehicle activity. This research was conducted to investigate the nonpoint sources concentration and quantifying stormwater pollutants which are contained in rainfall runoff water. Three different monitoring sites in Jinju and Changwon city were equipped with an automatic rainfall gauge and flow meter for measuring rainfall and the volume of rainfall runoff. In the case of average EMC value, city trunk road was shown the highest value in target water quality items like as BOD, COD, SS, TN and TP. Or the amount of runoff loads by water quality items showed the highest value in city trunk road. And runoff load in city trunk road was 43.8 times high value compared to highway by value of city trunk road $356.7 mg/m^2$, highway $8.150 mg/m^2$, national road $19.99 mg/m^2$ in the case of BOD.

Implementation of JDAM virtual training function using machine learning

  • You, Eun-Kyung;Bae, Chan-Gyu;Kim, Hyeock-Jin
    • 한국컴퓨터정보학회논문지
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    • 제25권11호
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    • pp.9-16
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    • 2020
  • TA-50 항공기는 공중전에 대비하여 공대공, 공대지 사격 훈련 등 다양한 상황에 대한 모의 훈련을 수행하고 있다. 또한 조종사의 실전 배치 전 훈련용으로도 사용되고 있다. 그러나 TA-50은 스마트 무장 운용 능력을 보유하고 있지 않아 훈련에 제한이 되고 있다. 이에 본 연구에서는 TA-50 항공기에 스마트 무장 중 하나인 합동정밀직격탄(JDAM)의 가상훈련이 가능하도록 구현하고자 하였다. 먼저, TA-50 항공기와 유사한 기종인 FA-50 항공기에 구현된 JDAM 기능을 분석하였다. 또한 FA-50 항공기에 구현된 기능은 소스코드의 직접 활용이 불가능하므로 머신러닝 기법(TensorFlow)을 활용하여 알고리즘을 추출하였다. 본 기능을 구현함으로써 실 무장을 장착하지 않아도 실제와 유사한 훈련이 가능할 것으로 기대된다. 마지막으로 본 연구 결과를 바탕으로 연구의 한계점을 보완하여 실제와 동일하게 구현할 수 있는 방안을 제안하고자 한다.

KASINICS 광학계의 고스트 분석 (GHOST ANALYSIS FOR THE OPTICS SYSTEM OF THE KASINICS)

  • 이성호;육인수;진호;박수종;한정열;이대희;공경남;조승현;박영식;박장현;한원용
    • 천문학논총
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    • 제20권1호
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    • pp.151-161
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    • 2005
  • The reimaging optics of the KASINICS (KASI Near Infrared Camera System) includes many transparent components like an entrance window, band-pass filters, and blocking filters. As observational targets or in-field background objects, bright stars may cause optical ghosts that can significantly degrade the system performance of the KASINICS. We estimated analytically the relative brightness of ghost components with respect to a point source and examined the effects of tilting optical components as a method of suppressing ghosts. We also performed numerical ray tracings including all the optical components and found the results are consistent with those of the analytic estimations. We conclude that the KASINICS will not suffer from significant ghost effects with appropriate anti-reflection coatings and fittings for the optical components.

The audit method of cooling energy performance in office building using the Simple Linear Regression Analysis Model

  • Park, Jin-Young;Kim, Seo-Hoon;Jang, Cheol-Young;Kim, Jong-Hun;Lee, Seung-Bok
    • KIEAE Journal
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    • 제15권5호
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    • pp.13-20
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    • 2015
  • Purpose: In order to upgrade the energy performance of existing building, energy audit stage should be implemented first because it is useful method to find where the problems occur and know how much time and cost consumption for retrofit. In overseas researches, three levels of audit is proposed whereas there are no standards for audit in Korea. Besides, most studies use dynamic simulation in detail like audit level 3 even though the level 2 can save time and cost than level 3. Thus, this paper focused on audit level 2 and proposed the audit method with the simple linear regression analysis model. Method: Two parameters were considered for the simple regression analysis, which were the monthly electric use and the mean outdoor temperature data. The former is a dependent variable and the latter is a independent variable, and the building's energy performance profile was estimated from the regression analysis method. In this analysis, we found the abnormal point in cooling season and the more detailed analysis were conducted about the three heat source equipments. Result: Comparing with real and predicted models, the total consumption of predicted model was higher than real value as 23,608 kWh but it was the results that was reflected the compulsory control in 2013. Consequently, it was analyzed that the revised model could save the cooling energy as well as reduce peak electric use than before.

Effect of deposition parameters on structure of ZnO films deposited by an DC Arc Plasmatron

  • Penkov, Oleksiy V.;Chun, Se-Min;Kang, In-Jae;Lee, Heon-Ju
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2011년도 제40회 동계학술대회 초록집
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    • pp.255-255
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    • 2011
  • Zinc oxide based thin films have been extensively studied in recent several years because they have very interesting properties and zinc oxide is non-poisonous, abundant and cheap material. ZnO films are employed in different applications like transparent conductive layers in solar cells, protective coatings and so on. Wide industrial application of the ZnO films requires of development of cheap, effective and scalable technology. Typically used technologies don't completely satisfy the industrial requirements. In the present work, we studied effect of the deposition parameters on the structure and properties of ZnO films deposited by DC arc plasmatron. The varied parameters were gas flow rates, precursor composition, substrate temperature and post-deposition annealing temperature. Vapor of Zinc acetylacetone was used as source materials, oxygen was used as working gas and argon was used as the cathode protective gas and a transport gas for the vapor. The plasmatron power was varied in the range of 700-1500 watts. Flow rate of the gases and substrate temperature rate were varied in the wide range to optimize the properties of the deposited coatings. After deposition films were annealed in the hydrogen atmosphere in the wide range of temperatures. Structure of coatings was investigated using XRD and SEM. Chemical composition was analyzed using x-ray photoelectron spectroscopy. Sheet conductivity was measured by 4-point probe method. Optical properties of the transparent ZnO-based coatings were studied by the spectroscopy. It was shown that deposition by a DC Arc plasmatron can be used for low-cost production of zinc oxide films with good optical and electrical properties. Increasing of the oxygen content in the gas mixture during deposition allow to obtain high-resistive protective and insulation coatings with high adhesion to the metallic surface.

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Rice as an alternative feed ingredient in swine diets

  • Kim, Sheena;Cho, Jin Ho;Kim, Hyeun Bum;Song, Minho
    • Journal of Animal Science and Technology
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    • 제63권3호
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    • pp.465-474
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    • 2021
  • It has become important to explore alternative feed ingredients to reduce feed costs, which are burdensome for livestock production. In addition, it is desirable to find efficient and functional alternative ingredients for traditional feed ingredients in pig diets, considering the stress and sensitivity of disease of pig. Rice is produced around the world like corn that is the typical energy source in pig diets. Although the nutritional quality varies depending on the degree of milling, rice, except whole grains (paddy rice), contains more starch than corn and its structure and granule size are easier to digest than corn. In addition, the fact that rice has fewer non-starch polysaccharides (NSP) and anti-nutritional factors (ANFs) is also effective in improving digestibility and various polyphenols in rice can help modulation of immune responses, which can be beneficial to the gastrointestinal environment and health of pig. Many studies have been conducted on rice focusing on things such as degree of milling, substitution rates of corn, granule size, and processing methods. Most results have shown that rice can be partially or completely used to replace corn in pig diets without negatively affecting pig growth and production. While further research should focus on the precise biological mechanisms at play, it was confirmed that the use of rice could reduce the use of antibiotics and pig removal and protect pigs from gastrointestinal diseases including diarrhea. From this point of view, rice can be evaluated as a valuable feed ingredient for swine diets.

스페인 이민자 사회 내 한인공동체의 위상과 현황 (Korean community in the society of immigrants in Spain: its prestige and trend)

  • 전용갑;황수현
    • 비교문화연구
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    • 제29권
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    • pp.177-199
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    • 2012
  • Nowadays migrations between the countries are getting each day more active and a mixture of people with different cultural backgrounds strengthens the hybridism, whereupon the point of view on the migration of Koreans has been changed from a diasporan perspective to an transnational one. The expansion of the transnationalism affects the identity of the subsequent generations of the immigration giving way to a psychologically deterritorialized social identity, which is an important consideration in the study of subsequent generations of the immigration. This study examined the Korean immigration history and the current status of the Korean community in Spain since the 1960s. The early immigrants like fishing vessel crew members, instructors of Taekwondo, chicken sexers who, despite the limits of foreigners in Spain, went to find out the source of life with no hesitation, overcame the difficulties of the early settlers and finally managed to achieve local success. Current history of immigration that began in the mid-1960s went through the maturity during the 1970s and 80s and the Koreans in Spain these days, who have undergone differentiation in the occupational structure because of the crisis of pelagic fisheries, face new challenges due to changes in the environment of the country they reside. The Korean community is regarded as an 'exemplary minority group (Model Minority)' even though it is a minority group in number. Now that the interest for overseas Koreans is higher than ever at home and abroad, due to the economic growth of the Republic of Korea, the spread of its cultural influence -the Korean Wave as proof-, and the overseas Koreans suffrage conducted, the research of the Korean residents in Spain will be important as an advanced research of an unexplored field, as well as an opportunity to broaden the horizons of the existing study area that has mainly dealt with major regions only.

Diagnostic Accuracy of the Quidel Sofia Rapid Influenza Fluorescent Immunoassay in Patients with Influenza-like Illness: A Systematic Review and Meta-analysis

  • Lee, Jonghoo;Song, Jae-Uk;Kim, Yee Hyung
    • Tuberculosis and Respiratory Diseases
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    • 제84권3호
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    • pp.226-236
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    • 2021
  • Background: Although the Quidel Sofia rapid influenza fluorescent immunoassay (FIA) is widely used to identify influenza A and B, the diagnostic accuracy of this test remains unclear. Thus, the objective of this study was to determine the diagnostic performance of this test compared to reverse transcriptase-polymerase chain reaction. Methods: A systematic literature search was performed using MEDLINE, EMBASE, and the Cochrane Central Register. Pooled sensitivity, specificity, diagnostic odds ratio (DOR), and a hierarchical summary receiver-operating characteristic curve (HSROC) of this test for identifying influenza A and B were determined using meta-analysis. A sensitivity subgroup analysis was performed to identify potential sources of heterogeneity within selected studies. Results: We identified 17 studies involving 8,334 patients. Pooled sensitivity, specificity, and DOR of the Quidel Sofia rapid influenza FIA for identifying influenza A were 0.78 (95% confidence interval [CI], 0.71-0.83), 0.99 (95% CI, 0.98-0.99), and 251.26 (95% CI, 139.39-452.89), respectively. Pooled sensitivity, specificity, and DOR of this test for identifying influenza B were 0.72 (95% CI, 0.60-0.82), 0.98 (95% CI, 0.96-0.99), and 140.20 (95% CI, 55.92-351.54), respectively. The area under the HSROC for this test for identifying influenza A was similar to that for identifying influenza B. Age was considered a probable source of heterogeneity. Conclusion: Pooled sensitivities of the Quidel Sofia rapid influenza FIA for identifying influenza A and B did not quite meet the target level (≥80%). Thus, caution is needed when interpreting data of this study due to substantial betweenstudy heterogeneity.

Pillared Bentonite Materials as Potential Solid Acid Catalyst for Diethyl Ether Synthesis: A Brief Review

  • Puji Wahyuningsih;Karna Wijaya;Aulia Sukma Hutama;Aldino Javier Saviola;Indra Purnama;Won-Chun Oh;Muhammad Aziz
    • 한국재료학회지
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    • 제34권5호
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    • pp.223-234
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    • 2024
  • This review explores the potential of pillared bentonite materials as solid acid catalysts for synthesizing diethyl ether, a promising renewable energy source. Diethyl ether offers numerous environmental benefits over fossil fuels, such as lower emissions of nitrogen oxides (NOx) and carbon oxides (COx) gases and enhanced fuel properties, like high volatility and low flash point. Generally, the synthesis of diethyl ether employs homogeneous acid catalysts, which pose environmental impacts and operational challenges. This review discusses bentonite, a naturally occurring alumina silicate, as a heterogeneous acid catalyst due to its significant cation exchange capacity, porosity, and ability to undergo modifications such as pillarization. Pillarization involves intercalating polyhydroxy cations into the bentonite structure, enhancing surface area, acidity, and thermal stability. Despite the potential advantages, challenges remain in optimizing the yield and selectivity of diethyl ether production using pillared bentonite. The review highlights the need for further research using various metal oxides in the pillarization process to enhance surface properties and acidity characteristics, thereby improving the catalytic performance of bentonite for the synthesis of diethyl ether. This development could lead to more efficient, environmentally friendly synthesis processes, aligning with sustainable energy goals.

퍼플골드를 위한 열증착법으로 제조된 Au-Al 합금 박막의 물성연구 (The Properties of Au-Al Alloy Thin Films with a Thermal Evaporator for Purple Gold)

  • 김준환;송오성
    • 한국진공학회지
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    • 제17권5호
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    • pp.466-472
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    • 2008
  • 퍼플골드는 78wt%Au-22wt%Al로 이루어진 합금으로 화학식은 $AuAl_2$로 표현된다. 최근 화이트골드, 핑크골드와 더불어 특유의 적자색 (보라색)이 나는 유색골드의 하나로 장신구나 의장용 소재로 활용되고 있다. 퍼플골드는 Au와 Al의 중간상으로 연성과 주조성이 나쁜 특성이 있어 단조와 주조작업을 통하여 원하는 형상의 퍼플골드를 얻기 힘든 단점이 있다. 따라서 절단과 연마공정만으로 최종제품을 제작하거나 박막으로 증착하여 의장용 소재로 활용하는 것이 가능하다. 본 연구는 순수한 Au와 Al을 소오스로 각각 200nm$SiO_2$/Si기판에 78:22의 무게비로 증착시킨 후 열처리를 시행한 경우와, $AuAl_2$를 용융을 통하여 벌크형으로 얻은 후 이를 소오스로 사용하여 유리기판에 기판온도를 상온으로 유지하면서 진공증착을 통하여 표면처리를 한 경우로 나누어 실험을 진행하였다. 완성된 시편은 육안검사, 미세구조분석, 면저항분석, 색차분석, XRD 분석을 통하여 증착된 퍼플골드의 색과 두께를 위주로 한 물성을 측정하였다. 12.5nmAu/40nmAl/200nm$SiO_2$/Si 구조로 제작하고 열처리 한 경우 과도한 표면응집현상이 일어나면서 퍼플골드가 형성되지 않았다. $AuAl_2$ 소오스로부터 직접 열증착한 경우는 벌크상태와 동일한 적자색을 보였으며 퍼플골드의 의장용으로서 심미적 기능이 가능한 것으로 판단되었다.