• 한국축산시설환경학회지
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• 제2권1호
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• pp.63-78
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• 1996

The main purpose of this research project is to monitor the present state of agricultural environment and to develope the countermeasures for the protection of the environment from the pollution by animal wastes. The results of this research were described largely 3 parts, 1) Monitoring of present state of environmental pollution by animal wastes, 2) Monitoring of animal wastes treatment technology, 3) Strategies for the protection of environmental pollution from animal wastes in future. The current most important problems from animal wastes are water pollution and air pollution commonly regardless of domestic or foreign country. Especially, intensive livestocks breeding pattern in restricted area is actually a real reason of eutrophication, soil acidification, ground water contamination, irrigation water pollution. As a result from this research project, authors recommend the 3 type of strategies for the protection of environmental pollution by animal wastes, 1 . Development of non-discharge type of wastes treatment technology 2. Manufacturing local structure for animal waste recycling system 3. Development of new international environmental program for transfer bioresource and soil environment prevention.

• 한국관개배수논문집
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• 제13권1호
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• pp.82-90
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• 2006

The practical date of rice growing stages and the date for calculating the water demand in paddy field have differences. The causes are rice planting water requirement, nursery bed area and change of average temperature and so on. Some recent papers have shown the same results. So we have investigated the nursery period, rice transplanting period and mid-summer drainage and developed a system for estimating water demand. And we calculated the water demand by using the system. The result showed that calculation by using the new system is more appropriate than the calculation by using the established period. But because water losses in canals and crop coefficient are not determined appropriately, we can calculate the agricultural water demand more accurately by dstablishing canal losses ratio, crop coefficient and so on.

• 한국관개배수논문집
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• 제13권1호
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• pp.50-62
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• 2006

In order to improve areas lagged behind well-developed others ing the balanced national development. Development Promotion Areas(DPA)was designated in 1996. This study aims to develop a rational evaluation system for projects of DPA. This system has 3 evaluation steps. The first step is to evaluate 10-unit operations which are tourism, recreation, road, water supply and drainage, life environment, and so on. The second step is to evaluate 3 sub-programs such as tourism and recreation, local infrastructures and specialized industry. The third step is to evaluate comprehensively in entire area. A tentative system for project evaluation of DPA was proposed by brainstorming of expert-group. Weighting values of items in PDA were calculated through pair-comparison works of expert group using stepwise matrix sheets by AHP(Analytic Hierarchy Process).

• 자원환경지질
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• 제54권3호
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• pp.331-352
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• 2021

The relationship of both heavy metals and major elements in soil, plants, and groundwater was studied in a hyper-arid area and depends completely on the groundwater to cover its all needs. The study reviles that 27.3% of the studied groundwater was strongly acidic and has very low pH values (

• 한국농공학회지
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• 제42권1호
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• pp.73-82
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• 2000

Large quantitive of polllutants are washed into reservoirs during storm events. These polllutants contribute to eutrophication, such as algal blooms and fish kills. This study was conducted for the purpose of assessing the pollutant removal possibilities of sedimentation pool formed by deep dredging of a reservoir inlet. Water quality data were collected in the Masan reservoir, whose inlet has been dredged deep like sedimentation pool. The average concentration of chemical oxygen demand(COD) , toatal nitrogen(T-N) and total phosphrous(T-P) in the deep dredged area were 8.7 ~20.5mg/ι (T-N), 0.17~0.84mg/ι(T-P), which were 4.9%(COD), 29.0%(T-N) and 44.8%(T-P) higher than those of middle part of the reservior. The texture of sediment in the dredged area was silty loam, while that of the middle part was sandy clay loam. Organic matter contents, T-N and T-P of the bottom soil in the dredge area showed higher values than the middle part of the reservoirs. From these results, it was considered thedeep dredged area in the inlet of reservoir might play a key role to settle pollutant particulate. Based on the result of water quality analysis, deep dredging of the reservoir inlet could be assessed to reduce T-N and T-P of the reservoir about 6.5% , 8.3%, respectively. However, the effect of the sedimentation pool would be raised if the settled particles were taken into account in assessing water quality improvement for the reservoir. Accordingly, dredging of a reservoir inlet to make a shape of sedimentation pool is recommended for water quality improvement of reservoir in the stage of dredging plan.

• Journal of Periodontal and Implant Science
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• 제51권4호
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• pp.276-284
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• 2021

Purpose: The aim of this randomized clinical trial was to assess whether chemical cleansing using a sulfonic/sulfuric acid gel solution (HBX) as an adjunct to scaling and root planing (SRP) resulted in a decrease in residual plaque and calculus in deep periodontal pockets compared to SRP alone. Methods: Fifty-six patients with 56 hopeless posterior teeth, scheduled for extraction due to severe periodontitis, were enrolled in this study. Each tooth was randomly assigned to 1 of the 2 experimental procedures. The test teeth were subjected to the irrigation of the subgingival area with HBX for 2 minutes, followed by SRP with hand and ultrasonic instruments for 14 minutes, and then extracted. The control teeth received only mechanical instrumentation before extraction. Residual biofilm was evaluated on photographs and measured as total area and percentage of root surface covered by remaining plaque (RP) or calculus (RC) after treatment. Results: The initial pocket depth (PD) and total subgingival root surface area were similar between the 2 treatment groups. After treatment, the total subgingival root area covered by RP and RC was statistically significantly larger (P<0.001) in the control group than in the test group. The test teeth showed a lower percentage of RP, but a higher percentage of RC than the control teeth (both P<0.001). Complete calculus removal was achieved in 42% of the control teeth surfaces and in 25% of the test teeth surfaces for a PD of 4 mm. Conclusions: The additional chemical cleansing with HBX resulted in a statistically significant improvement in bacterial plaque removal during SRP of deep pockets, but it was not effective in reducing calculus deposits.

• 한국농공학회논문집
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• 제63권3호
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• pp.47-57
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• 2021

Drought monitoring over paddy field area is an important role as the frequency and intensity of drought due to climate change increases. This study analyzed the applicability of drought monitoring on paddy crops using MODIS-based field surveys. As a satellite-based drought index using evapotranspiration for quantitative drought determination, ESI (Evaporative Stress Index), was applied and calculated through the ratio of MODIS- based actual and potential evapotranspiration. For the irrigated areas of Idong, Gosam, Geumgwang, and Madun reservoirs the availability of irrigation water supply, ponding depth, precipitation, paddy growth were investigated for the paddy field within one grid of MODIS. In addition, the percentile-based ESI drought severity was calculated to compare the growth process of paddy and changes in the drought category of ESI. The Idong area was irrigated about a week later than other reservoirs for the period of water supply, transplanting, and water drainage and the ESI drought category tended to be different. The Gosam, Geumgwang, and Madun area expressed moderate drought prior to the farming season, and indicated normal as the water was supplied. During the water drainage, the drought category intensified, indicating that the water available on land was decreasing. These results demonstrated that the MODIS-based ESI could be an effective tool for agricultural drought monitoring over paddy field area.

• 한국농공학회논문집
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• 제63권3호
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• pp.1-12
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• 2021

Optimal water management is to efficiently and equally supply an appropriate amount of water by using irrigation facilities. Therefore, it is necessary to evaluate water supply capacity through distribution simulation between the designed distribution rate and re-distributed rate according to the changed farming conditions. In this study, we recalculated the agricultural water supply amount of Geumcheon main canal, which beneficiary area was reduced due to the development of Gwangju-Jeonnam innovation city, and we constructed a canal network using the SWMM model to simulate the change in supply rate of each main canal according to the re-distributed rate. Even though the supply amount of the Geumcheon main canal was reduced from 1.20 m³/s to 0.90 m³/s, it showed a similar supply rate to the current, and the reduced quantity could be supplied to the rest of the main canal. As a result, the arrival time at the ends of all main canal, except for the Geumcheon main canal, decreased from 1 to 3 hours, and the supply rate increased from 4 to 17.0% at the main canal located at the end of the beneficiary area of Naju reservoir.

• 농업과학연구
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• 제6권2호
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• pp.166-184
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• 1979

Dam에 저수(貯水)한 물이 흙수로(水路)에 의(依)해서 도수(導水)되는 과정(過程)에서 많은 손실(損失)을 보게 된다. 특(特)히 이들 용수로(用水路)가 사력층(砂礫層)과 같은 투수성지반(透水性地盤)을 통과(通過)할 때 용수로(用水路)의 누수방지(漏水防止)를 위(爲)해서 Lining을 실시(實施)하여 왔다. 이들 용수로(用水路)의 누수방지(漏水防止)를 위(爲)한 Lining 방법(方法)은 많은 연구(硏究)가 계속(繼續)되어 왔고 최근(最近)에는 plastic film 혹은 polyethylene film 등(等)으로 Lining 하는 방법(方法)이 고안(考案)되어 연구(硏究)하고 있다. 그러나 이들 재료(材料)는 강도(强度)가 약(弱)하여 파손(破損)될 위험성(危險性)이 있고 또 모래나 자갈 입자(粒子)와 접촉(接觸)하면 pin-hole이 생겨서 누수(漏水)하게 된다. 본(本)연구(硏究)에서는 이와 같은 흠점(欠點)을 보완(補完)하기 위(爲)하여 polypropylene mat에 vinyl을 coating해서 매설(埋設) Lining하는 방법(方法)을 시험(試驗)하였다. Polypropylene mat 매설(埋設) 혹은 노출(露出)에 따르는 내구성(耐久性)의 변화(變化), Asphalt 부착부(附着部)의 내구성(耐久性) 및 동해(凍害) 등(等)은 장기간(長期間)의 시험(試驗)이 필요(必要)하므로 아직도 미비(未備)된 점(點)이 있으나 본시험(本試驗)에서 얻은 결과(結果)를 요약(要約)하면 다음과 같다. 1. 수로(水路)의 저면(底面)과 양측사면(兩側斜面)의 연결부(連結部)는 곡선(曲線)으로 설치(設置)하는 것이 사면(斜面)의 안정도(安定度)가 크고 공사비(工事費)가 절약(節約)된다. 곡급부(曲級部)의 곡율변화(曲率變化)와 polypropylene mat의 감소량(減少量) 및 절토(切土)의 감소량(減少量)과의 관계(關係)를 사면(斜面)의 경사(傾斜)로 유도(誘導)해서 그림 7~그림 9에 표시(表示)하였다. 2. Polypropylene mat의 보호(保護)를 위(爲)해서 피복재료(被覆材料)를 덮어야 하고 이 두께는 수심(水深), 사면(斜面)의 안정(安定), 수로내((水路內) 침전물(沈澱物)의 제거작업(除去作業), 통행(通行), 비관개기(非灌漑期)의 back pressure 등(等)을 고려(考慮)해서 30cm 이상(以上)으로 함이 바람직하다. 3. 피복재료(被覆材料)는 사면침식(斜面侵蝕)을 방지(防止)하기 위(爲)해서 모래질(質)흙은 속에 넣고 표면(表面)은 조립질(粗粒質)의 자갈을 덮는 것이 수로사면(水路斜面)의 안정(安定)을 위(爲)해서도 좋을 것이다. 4. 용수로(用水路)의 사면안정검토(斜面安定檢討)는 수로저면(水路底面)의 수동부(受動部)를 고려(考慮)함이 타당(妥當)하고 사면안정(斜面安定), 허용유속(許容流速) 및 소유력(掃流力)을 고려(考慮)해서 1 : 2정도(程度)의 경사(傾斜)로 설치(設置)함이 바람직하다. 5. Earth Lining의 공사비(工事費)와 비재(比載)할 때 Vinyl로 coating 한 polypropylene mat의 Linging은 흙의 운반거리(運搬距離) 500m 일 때는 28%, 700m 일 때는 37%의 공사비(工事費)를 절약(節約)할 수 있다. 6. Vinyl로 coating 한 'polypropylene mat로 Lining 하면 거의 완벽(完壁)할 정도(程度)로 누수(漏水)를 방지(防止)할 수 있으나 Asphalt로 접합(接合)시켰을 때 polypropylene mat의 강도(强度)에 변화(變化)가 오는 것이 예상(豫想)되므로 경과시간(經過時間)에 따르는 강도변화(强度變化)는 계속(繼續)해서 연구(硏究)해야 할 것으로 생각된다.

• 한국토양비료학회지
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• 제38권3호
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• pp.150-156
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• 2005

논토양에서 관개 깊이를 조절하여 온난화가스 배출특성을 구명하고, 그에 따른 온난화가스 배출량를 추정하여 온난화가스 배출 저감기술을 확립하고자 연구를 수행하였다. 볏짚시용후 담수 8 cm의 시기별 $CH_4\;flux$는 이앙 32일 경에 $23.9mg\;m^{-2}\;h^{-1}$로 가장 높았으며, 이앙 35일 이후부터 감소하기 시작하여 중간낙수 이후에는 $CH_4\;flux$가 급격히 감소하였다. 포화용수량 처리구의 시기별 $CH_4\;flux$는 이앙 32일에 $19.9mg\;m^{-2}\;h^{-1}$ 로 가장 높았으며, 전 생육시기 동안 담수 8 cm와 담수 4 cm에 비하여 $CH_4\;flux$는 적었다. 볏짚 무시용후 시기별 $CH_4\;flux$는 이앙 20일경 $2.2-3.8mg\;m^{-2}\;h^{-1}$의 범위를 보였으며 그 이후부터는 처리별 차이가 컸으나 이앙 50일 이후부터는 비슷한 경향을 보였다. 토양 Eh 변화는 벼 이앙후 20일부터 -100 mV로 낮아 졌으며, 중간낙수 이후인 이앙 60일경에는 50 mV로 상승하였고 논물 담수심이 낮을수록 토양 Eh는 높았다. 볏짚을 시용하지 않았던 구와 포화용수량 처리구에서의 토양 Eh변화는 볏짚 시용구에 비하여 벼 전 생육기간에 걸쳐서 높았다. 처리별 지구온난화지수는 볏짚 시용후 담수 8 cm 처리구가 $6,939kg\;CO_2\;ha^{-1}$, 담수 4 cm 처리구는 $6,431kg\;CO_2\;ha^{-1}$, 포화용수량 처리구는 $5,222kg\;CO_2\;ha^{-1}$ 이었다. 그리고 볏짚을 시용하지 않은 담수 8cm 처리구의 지구온난화지수는 $4,449kg\;CO_2\;ha^{-1}$, 담수 4 cm 처리구는 $3,702kg\;CO_2\;ha^{-1}$, 포화용수량 처리구는 $3,561kg\;CO_2\;ha^{-1}$ 이었다.