• Title/Summary/Keyword: Water quality analyze

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The Monitoring of Sediment on the Basin Using LiDAR Data (LiDAR 자료를 이용한 유역의 퇴적물 모니터링)

  • Kang Joon-Mook;Kang Young-Mi
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.24 no.1
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    • pp.27-36
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    • 2006
  • Most of domestic multipurpose dams were basin area to be large, therefore, soil loss were occurred by downpour in the rainy season, They have caused to accumulate sediments on the river and dam reservoir that brought the decrease of storage volume and difficulties of the quality management of water. Until now, the measurement cycle of sediments surveying was long and it was designed to use surveying the degree of sediments, Thus there were many difficult things to secure accuracy. In this study, it was intended to analyze the origin position tracing of sediments and the movement route, for this purpose, aerial LiDAR technology was applied to precise sediments surveying. The amount and location of soil loss were evaluated by classified properties of soil, land-cover, and topographical conditions in detail. Therefore, the reliance could be maintained in analyzing the route of soil loss by extracting the flow within a watercourse and using the advanced accurate DEM.

A Comparison Study of Volumetric Modulated Arc Therapy Quality Assurances Using Portal Dosimetry and MapCHECK 2

  • Jin, Hosang;Jesseph, Fredrick B.;Ahmad, Salahuddin
    • Progress in Medical Physics
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    • v.25 no.2
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    • pp.65-71
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    • 2014
  • A Varian Portal Dosimetry system was compared to an isocentrically mounted MapCHECK 2 diode array for volumetric modulated arc therapy (VMAT) QA. A Varian TrueBeam STx with an aS-1000 digital imaging panel was used to acquire VMAT QA images for 13 plans using four photon energies (6, 8, 10 and 15 MV). The EPID-based QA images were compared to the Portal Dose Image Prediction calculated in the Varian Eclipse treatment planning system (TPS). An isocentrically mounted Sun Nuclear MapCHECK 2 diode array with 5 cm water-equivalent buildup was also used for the VMAT QAs and the measurements were compared to a composite dose plane from the Eclipse TPS. A ${\gamma}$ test was implemented in the Sun Nuclear Patient software with 10% threshold and absolute comparison at 1%/1 mm (dose difference/distance-to-agreement), 2%/2 mm, and 3%/3 mm criteria for both QA methods. The two-tailed paired Student's t-test was employed to analyze the statistical significance at 95% confidence level. The average ${\gamma}$ passing rates were greater than 95% at 3%/3 mm using both methods for all four energies. The differences in the average passing rates between the two methods were within 1.7% and 1.6% of each other when analyzed at 2%/2 mm and 3%/3 mm, respectively. The EPID passing rates were somewhat better than the MapCHECK 2 when analyzed at 1%/1 mm; the difference was lower for 8 MV and 10 MV. However, the differences were not statistically significant for all criteria and energies (p-values >0.05). The EPID-based QA showed large off-axis over-response and dependence of ${\gamma}$ passing rate on energy, while the MapCHECK 2 was susceptible to the MLC tongue-and-groove effect. The two fluence-based QA techniques can be an alternative tool of VMAT QA to each other, if the limitations of each QA method (mechanical sag, detector response, and detector alignment) are carefully considered.

Ecological Comparisons of Stream Conditions Between the Unimpacted and Impacted Sites: Case Study

  • Lee, Jae-Hoon;Lee, Sang-Jae;An, Kwang-Guk
    • Korean Journal of Ecology and Environment
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    • v.41 no.4
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    • pp.441-448
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    • 2008
  • The purpose of this study was to analyze chemical water quality, fish trophic guilds, tolerance indicators, and fish community conditions in the Gap Stream and to compare the stream conditions between the unimpacted site and impacted site. This study was conducted in the physically stable season (May 2008) to minimize physical impacts such as flow and hydrological disturbance, and applied the study in the Gap Stream with two sites of unimpacted upstream site (Unim-S), mainly surrounded by forested area and impacted site (Im-S), influenced by the wastewater disposal plants and industrial complex in the urban region. Chemical data analysis showed that the degree of organic matter pollution, based on BOD, and COD, was $2{\sim}3$ fold greater in the Im-S than the Unim-S, and that TP, as eutrophication indicators, was 4.7 fold greater in the Im-S. Also, $NH_3-N$ was in 8.2 fold greater in the Im-S ($6.25\;mg\;L^{-1}$) than the Unim-S ($0.76\;mg\;L^{-1}$), indicating a massive influence of wastewater from the disposal plant. Similar results were found in other chemical parameters. Thus, chemical impacts in the Im-S were evident, compared to the unimpacted site. Evaluations of tolerant indicator species indicated that sensitive species were dominant in the Unim-S (23.9%) and tolerant species were dominant (97.8%) in the Im-S. Condition factor (CF) was averaged 0.95 ($0.68{\sim}1.18$) in the Unim-S and 1.08 ($0.93{\sim}1.22$) in the Im-S. Fish community in the Unim-S and Im-S was categorized as Zacco-community and Hemibarbus-community, respectively, and the community diversity index (H') was significantly (p<0.05) higher in the Unim-S (0.810) than the Im-S (0.466). Overall, our results suggest that the comparison approach of various chemical and ecological indicators provide important information in identifying multiple stressors in the stream ecosystems.

An Exploratory Content Analysis of Beer Advertisements in Korea (국내 주류광고에 대한 탐색적 연구: 동영상 맥주광고 내용분석)

  • Lee, Jae-Kyoung;Chung, Sul-Ki;Park, Jae-Eun
    • Korean Journal of Health Education and Promotion
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    • v.29 no.2
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    • pp.47-58
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    • 2012
  • Objectives: The purpose of this study is to analyze contents of beer advertisements in Korea. Research has suggested the influence of alcohol advertisements on viewer's drinking behavior, attitude, and expectancies. Korea's policy on alcohol advertising relies on limited government regulation and self regulation among alcohol industries. This study is expected to lay a foundation for further discussion on regulating alcohol advertising in Korea. Methods: A total of 81 beer advertisements broadcasted between 2008 and 2011 were analyzed. The contents were categorized into themes (22 themes were used), models, and presentation techniques. Results: The themes most frequently appeared in beer advertisements were quality (66.7%), relaxation (44%), camaraderie (41%), and individuality (39.5%), respectively. Analysis of models revealed that most advertisements had more than three models (64.2%), and most of them were in their 20s (68%). As much as 82% of advertisements used celebrity models. Analysis on presentation techniques showed that 91.4% displayed drinking scenes, and 27% displayed gulping down the whole bottle or the glass. Finally, about 10% of ads showed drinking in hazardous situations such as during water sports. Conclusion: The results of the study reflect the minimal regulation of alcohol advertising in Korea. The need for joint effort by legislators, researchers, alcohol industries, and advertising agencies is discussed in order to establish healthier drinking environment.

An Experimental Study on Selective Withdrawal from Linear Stratified Tank (선형 성층수조에서의 선택취수에 관한 실험적 연구)

  • Kim, Young Do;Park, Jae Hyeon;Son, Byung Ju
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.31 no.6B
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    • pp.499-505
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    • 2011
  • The mixing behavior of turbidity currents in a reservoir is closely related with the annual temperature change of the reservoir. In the summer, the reservoir has a well defined structure: one or two thermoclines and some layers of different densities. This density stratification inhibits vertical mixing and affects various hydrodynamic processes within the reservoir. Therefore, many reservoirs can be operated to release water of the specific quality with the selective withdrawal. In this study, the hydraulic experiments were performed to analyze the efficiency of selective withdrawal. The velocity distributions are measured with PIV in the stratified tank with the "two-tank" method. The relationship between the Richardson number and the selective withdrawal efficiency are provided using the measured velocity distributions.

Research on Environmentally-Sound Forest Road Construction( I ) -Recently forest road conservation in Japan- (유역(流域)의 환경보전(環境保全)을 고려한 합리적인 임도시공(林道施工)에 관한 연구(硏究)( I ) -일본에 있어서 최근의 임도사업(林道事業)을 중심으로-)

  • Chun, Kun-Woo;Ezaki, Tsugio;Oh, Jae-Man
    • Journal of Forest and Environmental Science
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    • v.12 no.1
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    • pp.26-36
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    • 1996
  • In our country, nation-wide forest road works are being carried out as one of the efforts to bolster the international competitiveness of agriculture, however such environmental problems as sediment discharge and water quality degradation accompany such efforts more often than not. Hence, in this research report, we compile and analyze the Japanese sources dealing with the "research direction of the forest road construction", "environmental impact assessment upon the watershed of the forest road construction", "environmentally-sound forest road construction and its research method" in consideration of the fact that natural environment of Japan is similar to that of our country and Japanese forest road works has a long history. We hope that this report be useful to the reasonable watershed management and the environmentally-sound forest road works.

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Comparison of Heavy Metals Analysis in Sediment (호소내 퇴적물의 중금속 분석 비교)

  • Park, Sun-Ku;Song, Ki-Bong;Cho, Ki-Hwan
    • Analytical Science and Technology
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    • v.14 no.2
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    • pp.173-179
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    • 2001
  • The study was carried out to analyze the pollutant Fe, Cu, Cr, Zn, Cd for sediments collected from lake in K river basin. Three analytical methods currently used in Korea, Japan, U.S.A, were compared. Pretreatment using microwave digestion showed higher analytical results for Fe, Cu, Cr, Zn, Cd than Korean Official Method(KOM) and American Toxicity Characteristic Leaching Procedure(TCLP) Method. Also, analytical results using microwave digestion, TCLP and KOM were as follows: 38.1-48.0 mgFe/kg, 10.2-15.9 mgFe/kg AND 3.5-12.6 mgFe/kg, 37.0-50.1 mgCu/kg, 0.06-0.24 mgCu/kg and 0.01-0.03 mgCu/kg, 137.0-152.0 mgZn/kg, 0.67-0.82 mgZn/kg and 0.3-0.5 mgZn/kg, respectively. From this result, a new analytical method for the determination of heavy metal in sediment should be developed for the accurate estimation of pollution degree in sediment.

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Use of Multivariate Statistical Approaches for Decoding Chemical Evolution of Groundwater near Underground Storage Caverns (다변량통계기법을 이용한 지하저장시설 주변의 지하수질 변동에 관한 연구)

  • Lee, Jeonghoon
    • Journal of the Korean earth science society
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    • v.35 no.4
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    • pp.225-236
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    • 2014
  • Multivariate statistical analyses have been extensively applied to hydrochemical measurements to analyze and interpret the data. This study examines anthropogenic factors obtained from applications of correspondence analysis (CA) and principal component analysis (PCA) to a hydrogeochemical data set. The goal was to synthesize the hydrogeochemical information using these multivariate statistical techniques by incorporating hydrogeochemical speciation results calculated by the program, commonly used, WATEQ4F included in the NETPATH. The selected case study was LPG underground storage caverns, which is located in the southeastern Korea. The highly alkaline groundwaters at this study area are an analogue for the repository system. High pH, speciation of Al and possible precipitation of calcite characterize these groundwaters. Available groundwater quality monitoring data were used to confirm these statistical models. The present study focused on understanding the hydrogeochemical attributes and establishing the changes of phase when two anthropogenic effects (i.e., disinfection activity and cement pore water) in the study area have been introduced. Comparisons made between two statistical results presented and the findings of previous investigations highlight the descriptive capabilities of PCA using calculated saturation index and CA as exploratory tools in hydrogeochemical research.

Investigation on the Repeatability of Modified Proctor Test for Roller Compacted Concrete Pavement (롤러 전압 콘크리트 포장을 위한 수정다짐시험의 반복재현성 고찰)

  • Hwang, Seok Hee;Rith, Makara;Hong, Seong Jae;Lee, Seung Woo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.35 no.4
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    • pp.931-940
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    • 2015
  • Roller Compacted Concrete Pavement (RCCP), is a type of pavement using compaction roller and asphalt finisher on concrete mixture that contains low amount of water. RCCP strength and durability are greatly affected by compaction level. Quality control is performed by ensuring the degree of compaction at site based on dry density. In the field, Modified Proctor Test is used in order to obtain optimum dry density. However, there is no clear compaction curve analysis criteria of Modified Proctor Test for RCCP. In this study, compaction curve built by three samples of Modified Proctor Test was produced and it was used to compare with compaction curve contented lower number of samples (one and two samples) in order to analyze their reliability. Thus, a conclusion was drawn from the results; by comparing to the result from Modified Proctor Test of three samples, the use of two samples represented result with only 0.5% of error which means the reliability is 99.5%.

Literature Review of Clinical Research Electro-Acupuncture Treatment on Post-stroke Dysphagia (뇌졸중 후 연하장애 전침 치료의 임상연구에 대한 고찰)

  • Byun, Sung Bum;Yu, Ju Hee;Moon, A Ji;Park, Bong Woo;Lee, Seon Yeop;Yun, Jong Min;Moon, Byung Soon
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.28 no.3
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    • pp.280-287
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    • 2014
  • The aim of this study was to collect and analyze clinical studies on electro-acupuncture therapies of post-stroke dysphagia to suggest the methods of the study about electro-acupuncture therapy. In this study, electronic searches were performed with searching sites. Searched words such as '중풍', '뇌졸중', '연하장애', '전침', 'stroke', 'dysphagia', 'deglutition disorders', 'electro-acupuncture' were used as a single keyword or in combinations. Through searching, 27 studies were selected and analyzed. In comparison of results before and after electro-acupuncture treatment, there were statistically significant improvement in 26 studies by using assessment such as video fluoroscopy swallowing study, swallowing water function test. The study of electro-acupuncture treatment for post-stroke dysphagia needs to be standardized and high-quality study models should be introduced.