• Journal of Korean Society for Atmospheric Environment
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• 제11권E호
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• pp.13-21
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• 1995

This Pilot study identifies potential dioxin and furan sources and medical plastic wastes produced from hospital solid waste streams. In this study, air emissions of dioxins and furans from sources in the U.S., which were estimated by the U.S. Environmental Protection Agency (EPA), were summarized. Potential loading routes of dioxins and furans to the U.S.-Canada Great Lakes region have also been identified in trcent surveys. In addition, medical and hospital solid wastes produced in typical large city hospitals were characterized as important potential sources of dioxins and furans. Plastic contents in medical Plastics Characterization Survey (MMPCS), plastics composition data were obtained from a survey of five Massachusetts Hospitals and Medical Centers. By identifying plastic wastes as a percentage of total hospital wastes, we were able to use data from a preliminary study that analyzed the waste stream of 16 major New York City hospitals (NYCMWS) characterizing the plastic content of the wasters. This study determined the types of plastic wastes included in each medical waste stream (regulated medical waste or non regulated medical waste) and it discussed the potential for recyclibility of hospital plastic wastes. The combination of the NYCMWS and the MMPCS surveys provides for the first overview of the size of the recycling task of hospital plastic wastes and the potential of dioxin elimination if dioxin generating plastics were to be eliminated from hospital use.

• 환경영향평가
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• 제10권3호
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• pp.223-234
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• 2001

In this study, we conducted a survey to examine the runoff characteristics of nonpoint sources, which wash off pollutants from the surface of basin during rainfall and affect water pollution of streams. An Anyangchun basin in the region Ewiwang City was selected as a study site. The basin divided into several subbasins such as Wanggokchun, Ojeonchun, and Anyangchun based on the tributaries, which confluence to the main stream of Anyangchun. Four times of field examination had been carried out between July and August of 2000, and water quality data collected from the surveys had been analysed. The survey includes in-situ flow, DO and PH measurements in the outlet of catchment. Laboratory analysis includes BOD, TN, TP. From the result, pollutant by runoff of nonpoint sources were washed out along with stormwater in the beginning of rainfall, and flowed into streams resulted in stream pollution. In case of BOD, the load from Ojeonchun catchment, most of which included urban areas, took up 50% of the total load from the entire watershed. Thus, by the results, it is clear that runoff load by urban nonpoint sources plays an important role in the control and management of nonpoint sources for the watershed.

• 한국어류학회지
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• 제20권4호
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• pp.279-284
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• 2008

호산천에 서식하는 멸종위기어종인 한둑중개의 섭식생태에 대하여 2006년 9월부터 2007년 8월까지 계절별로 채집하여 조사, 연구하였다. 한둑중개의 소화관 내용물에서 확인된 먹이생물로는 대부분이 수서곤충이었고 그 이외에 선충, 소형어류, 어류의 알, 다슬기 등이 조사되었다. 먹이생물로 이용되는 수서곤충의 상대적중요성지수비는 파리목 (Diptera), 날도래목 (Trichoptera), 하루살이목 (Ephemeroptera), 강도래목 (Plecoptera) 순이었다. Chironomidae sp. 1 (White type)과 Hydropsyche kozhantschikovi가 가장 중요한 먹이생물로 조사되었다. 건조 중량비에 따른 계절적 먹이생물의 변동으로서 봄과 여름에는 Trichoptera의 비율이 가장 높았고, 가을에는 Diptera, 겨울에는 Plecoptera가 가장 비율이 높았다.

• 농촌계획
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• 제6권1호
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• pp.29-37
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• 2000

The purpose of this study was to propose section designs for the ecological improvement of streams in rural villages in Korea. According to the survey about ecological conditions of rural streams of 10 selected rural villages (sep., 1996), the streams could be classified into three divisions(upstream, inner village, downstream), and the average width of streams was 9m, and the height of banks 3.1m. The slopes of basin were 7.33%, 2.67%, 1.39% at upstream, inner village, downstream respectively. The survey about the residents' usage of stream and the preferred activities(jun., 1997) showed that the streams were most frequently used for the supply of agricultural water use(39%), for the washing(15%) and for the recreation and rippling(10%), etc.. Three standard designs were presented for upstream, inner village, and downstream, and three standard sections were made by each designs. For the upstream division, it was designed to be used for the recreational activities in summer and the major stream bank materials were base rock and existing boulders with least artificiality. As the streams in the residential area were expected to be frequent access and used by the residents, most facilities for the streamside activity such as waterfront, water holes, shallows, walk were concentrated in this part with some artificiality. The downstream was designed for the agricultural activities such as water supply, space for the preparation of work and some break during the work.

• 한국환경과학회지
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• 제25권8호
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• pp.1165-1176
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• 2016

The accuracy of digital elevation models (DEMs) is crucial for properly estimating flood inundation area. DEM pixel size is especially important when generating flood inundation maps of small streams with a channel width of less than 50 m. In Korea, DEMs with large spatial resolutions of 30 m have been widely applied to generate flood inundation maps, even for small streams. Additionally, when making river master plans, field observations of stream cross-sections, as well as reference points in the middle of the river, have not previously been used to enhance the DEM. In this study, it was graphically demonstrated that high-resolution DEMs can increase the accuracy of flood inundation mapping, especially for small streams. Also, a methodology was proposed to modify the existing low-resolution DEMs by adding additional survey reference points, including river cross-sections, and interpolating them into a high spatial resolution DEM using the inverse distance weighting method. For verification purposes, the modified DEM was applied to Han stream on Jeju Island. The modified DEM showed much better accuracy when describing morphological features near the stream. Moreover, the flood inundation maps were formulated with the original 30 m pixel DEM and the modified 0.1 m pixel DEM using HEC-RAS modeling of the actual flood event of Typhoon Nari, and then compared with the flood history map of Nari. The results clearly indicated that the modified DEM generated a similar inundation area, but a very poor estimate of inundation area was derived from the original low-resolution DEM.

• 한국환경과학회지
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• 제18권1호
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• pp.99-111
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• 2009

In this study vegetation structure was monitored focusing on slanting surface of stream for the purpose of developing a management plan and ecological restoration of small stream in Paju. The study was conducted by types of geographical structure, yearly flora, naturalization rate changes, actual vegetation changes, plant community changes. Slope area of small stream in Paju was varied in the slope range of $10{\sim}35^{\circ}$. The survey results of yearly flora showed that 37 species appeared in 2000, 55 species in 2001, 95 species in 2002, and 125 species in 2003. Therefore, the trend of continuous increase of flora each year was observed. In the case of yearly changes of actual vegetation, indigenous wetland herb community including Phragmites communis$(19.99%{\rightarrow}18.42%{\rightarrow}19.60%)$ did not show substantial changes in the area, while the influence of controlled flora such as Humulus scandens$(8.86%{\rightarrow}5.26%{\rightarrow}9.73%)$, and Ambrosia artemisiifolia$(1.06%{\rightarrow}1.43%{\rightarrow}6.93%)$ were increased. The vegetation structure investigated by 18 preset belt-transects also indicated that Phragmites communis and Miscanthus sacchariflorus were maintaining the status or decreasing the population, while the population of Humulus scandens, Ambrosia artemisiifolia, Setaria viridis, and Erigeron canadensis were greatly increased. Our proposal management to restore ecology is as follows: first, preservation and restoration of Phragmites communis landscape; second, restoration of potential stream vegetation community; third, selection and removal of controlled plants.

• Parasites, Hosts and Diseases
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• 제22권2호
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• pp.161-171
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• 1984

An epidemiological study on Metagenimus yokegawai infection was performed in Samcheok-Bun, Kangwon Province during the period from November 1983 to October 1984. Formalin-ether concentration technique and Stoll's dilution egg counting method were employed to figure out the prevalence and infection intensity of M. yrtkogawai infection. The results are summarized as follow: 1. The Prevalence of M. yokogawai infection was 13.3% among 1,172 examined; 18.0% (114 out of 632) in male and 7.8% (42 out of 540) in female. 2. The Prevalence rates were different by stream; 15.5% in Ohsip-chon (stream), 11.8% in Maeup-chon and 1.6% in Gagok-chon. 3. Along the basin of Oship-chon; 8.2% at the lower reaches in Samcheok-eup, 25.9% at the middle reaches in Miro-myon and 6.2% at the upper reaches in Dogeoe-eup, respectively. 4. By age group, the highest fate (18.3∼20.2%) was observed in 30∼49 years of age (male 24.1∼28.7%, female 11.2∼13.2%). 5. By social strata, the positive rate was 15.0% (120 out of 799) in general inhabitants and 9.7% (36 out of 373) in school children. 6. Intensity by EPG count in feces was 419 in average; the light infection (less than 400 EPG) was 70.4%, moderate infection (401∼1,000 EPG) 19.4% and heavy infection (more than 1,001 EPG) 10.25 respectively. 7. All the 67 sweetfish (length 10.3∼18.5cm) which were caught from Ohsip-stream were infected with metacercariae of M. yokogawai and the number of metacercariae detected were 382 per fish in average (323 in June and 382 in September). 8. Experiences of intake of raw fresh-water fish [Plecoglossus altivelis and Leuciscus (Tribolodon〕 were present in 50.3U (354 out of 704) of the inhabitants along Ohsip-stream according to questionnaire study. The results of this survey indicated that the middle reaches of Ohsip-stream in Miro-myon, Samcheok-gun is the endemic region for M. yokogawai infection.

• 한국환경복원기술학회지
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• 제14권5호
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• pp.81-101
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• 2011

This study was conducted to understand the environmental and ecological function of habitat through evaluation of water environment, soil environment, vegetation characteristics, macro-invertebrate characteristics, and visual habits environment evaluation (SVAP) in Hongdong stream located in Hongseong-Gun, Chungnam Province, and hereafter to utilize the results for the habits reconstruction and improvement project. As the results of water quality analysis, BOD, COD, T-P was almost below the standard quality from upper stream to down stream. The construction of small reservoir, wetland and water purification facility, and the management of non-point pollution are proposed to improve these problems. The soil texture was sandy soil, which is unfitted with vegetation development. The construction of shallows and bogs, and induction of soil sedimentation and biotope formation are proposed to improve these problems. In the plant flora, total 90 kinds were observed with 81 species and nine varieties in total 36 families and 85 genera, and the naturalization rate was higher at down area than upper area. As the results of macro-invertebrate fauna survey, total 26 species and 297 individuals in 20 families and 22 genera were collected. Peltodytes sinensis, Chironomidae sp., and Culicidae sp., which are observed at polluted environment, were collected as dominant species. An appropriate vegetation management party idea is necessary, and it is done an idea in consideration of the soil and a physical characteristic. Visual habits environment evaluation (SVAP) result was mostly determined with below normal (Fair) grade. Pollution source interception, purification pond establishment, and various bog establishment are proposed to improve these problems. With the above results, the ecological environment was determined with bad condition, and the improvement of biotope was urgently needed through sustainable monitoring and management of streams habitat in rural area.

• 한국컴퓨터정보학회논문지
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• 제26권8호
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• pp.229-237
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• 2021

본 논문의 연구 목적은 이론과 실증 분석을 통해 중국 사용자의 라이브방송 구매 참여동기와 영향 요소를 연구하고, 사용자의 수요 변화를 파악하여 트랜드에 맞는 마케팅 전략을 수립하는 것이다. 연구목적을 달성하기 위해 중국 라이브방송 구매자 대상으로 설문조사를 실시해 필요한 데이터를 수집했다.실증 분석은 SPSS와 AMOS 분석 소프트웨어를 사용해 통계 분석, 신뢰성 및 유효성 분석, 구조 방정식 모델 분석을 수행하여 가설에 대해 검증하였다. 분석 결과를 보면 단편 동영상 업계의 핵심 경쟁력과 브랜드 개성이 사용자의 가치 인식에 반영되어 사용 동기에도 영향을 미치는 것으로 나타났다. 즉, 사용자의 라이브 쇼핑 참여는 맹목적인 순종이 아니며 능동적인 선택권이 있는 전자 상거래 속성을 더욱 강화하고 "허위 만족"을 없애야 정보가 효과적으로 전파될 수 있다. 브랜드측은 사용자의 구매 동기를 부여하기 위해 온라인 마케팅의 개성을 강화하고 사용자의 가치를 존중하는 것이 필요하다.

• 한국물환경학회지
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• 제39권4호
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• pp.316-328
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• 2023

In this study, the characteristics of nonpoint pollutant outflow and contribution rate of pollution in Songya-stream mainstream and tributaries were analyzed. Further, water pollution management and improvement measures for pollution-oriented rivers were proposed. An on-site investigation was conducted to determine the inflow of major pollutants into the basin, and it was found that pollutants generated from agricultural land and livestock facilities flowed into the river, resulting in a high concentration of turbid water. Based on the analysis results of the pollution load data calculated through actual measurement monitoring (flow and water quality) and the occurrence and emission load data calculated using the national pollution source survey data, the S3 and S6 were selected as the concerned pollution tributaries in the Songya-stream basin. Results of cluster analysis using Pearson correlation coefficient evaluation and Density based spatial clustering of applications with noise (DBSCAN) technique showed that the S3 and S6 were most consistent with the C2 cluster (a cluster of Songya-stream mainstream owned area) corresponding to the mainstream of Songya-stream. The analysis results of the major pollutants in the concerned pollution tributaries showed that livestock and land pollutants were the major pollutants. Consequently, optimal management techniques such as fertilizer management, water gate management in paddy, vegetated filter strip and livestock manure public treatment were proposed to reduce livestock and land pollutants.