• Water Engineering Research
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• 제5권1호
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• pp.17-36
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• 2004

This paper evaluated the water resources aspect of the operating results of the Daecheong Multipurpose Dam for the last 21 years. The elements that were evaluated included the amount of water supply from the dam. volume of outflow from the regulating dam, changes in the runoff volume at the dam site and downstream, and variations in the water supply capacity of the Daecheong Multipurpose Dam and the Geum River Barrage Dam situated in the estuary. The rainfall-runoff model was used to evaluate the changes in the runoff volume, and the water balance analysis system was used to evaluate the variations in the dams'water supply capacities. The volume of domestic and industrial water supply from the Daecheong Multipurpose Dam increased to 6.1 times for the last 21 years from 61${\times}$$10^6$$m^3$ in 1981 to 375${\times}$$10^6$$m^3$in 2001. The rate of outflow to inflow of the Daecheong Dam was analyzed 1.30 times in dry season, 1.12 times in semi-dry season, and 0.90 times in rainy season. The volume of inflow to the Geum River Barrage Dam down- stream after the dam's construction increased to 1.25 times in dry season and 1.02 times in semi-dry season and decreased to 0.94 times in rainy season. The water supply capacity of the estuary barrage dam almost did not change in cases with or without the Daecheong Multipurpose Dam, but storages were largely affected by the outflows of the Daecheong Multipurpose Dam.

• 한국환경과학회지
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• 제14권10호
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• pp.937-944
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• 2005

Presently, aquatic plants are used for the water purification in inland water. This study was carried out to investigate the water purification effect of aquatic plants, Oenanthe javanica and Typha angustata, The experiment was conducted in outdoor flowing water was conducted for ten days, Water quality was measured in terms of water temperature, COD(chemical oxygen demand), SS(suspended solids), Total N, Total P. The results of field experimentation showed that hydraulic retention time was the earliest in July and August 2003, and there were not any particular changes of monthly water temperature in inflow water and outflow water. As we look at the changes taken place in inflow water and outflow water throughout the whole experiment period, the change of water quality in summer was salient, especially SS removal ratio showed distinguished change as $25\%$, when the pebble filter and aquatic were attached to it. The removal rate of COD, total N total P were $14,7\%,\;8\%\;and\;9\%$, respectively. In relating the length of water extension to the change in water quality, the water quality tended to get lower generally in proportion to hydraulic retention time.

• 동력기계공학회지
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• 제18권1호
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• pp.63-68
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• 2014

The numerical analysis of fluid flow in the tube cleaning system is examined. The working flow used in this study is seawater, and the temperature change is not considered as the temperature change of seawater in the tube cleaning system is negligible. Also, the analysis is performed under the assumption of steady state. The screens of complicated morphologies are simplified for the analysis, and only one fourth of the tube cleaning system is modeled as the system has a symmetrical shape. The velocity inlet boundary condition is employed for the seawater inlet, whereas the outflow boundary condition is employed for two seawater outlets. In applying the outflow boundary condition for the system with more than two outlets, the flow rate can be arbitrarily assigned. In the analysis, the finite-volume method based numerical analysis tool, the pressure based solver, the standard k-$\varepsilon$ model are utilized, and the under relaxation factor is modified appropriately. From the analysis, the distribution of velocity vectors, pressure and path lines are obtained, and the physical characteristics of fluid flow in the tube cleaning system is well-examined.

• 한국수산과학회지
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• 제52권1호
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• pp.74-80
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• 2019

Nonylphenol is an endocrine-disrupting chemical that is the degradation product of the nonionic surfactants nonylphenol ethoxylates. To understand the contamination and behavioral characteristics of nonylphenol, we measured the nonylphenol concentrations in surface water in the lower reaches of the Suyeong River, Korea. The results were used to estimate the material balance. The target area was divided into three regions to estimate the material balance of nonylphenol. In region 1, in flux of the dissolved nonylphenol was 282.3 g/day and the nonylphenol influx in particulate suspended solids was 1,582.8 g/day. The dissolved nonylphenol outflow discharged toward region 2 was 192.5 g/day, while the adsorption to particulate suspended solids was 89.8 g/day. Within the particulate suspended solids, the outflow to region 2 was 1,250.0 g/day, while the estimated amount settling in the sediments was 422.7 g/day. The adsorption of dissolved nonylphenol to the particulate suspended solids in regions 1 and 2 was 31.8% and 54.9%, respectively. In region 3, the desorption rate was 8.8%.

• 한국경제지리학회지
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• 제21권4호
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• pp.321-334
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• 2018

국가 내 지역불균형 발전의 원인 중 하나는 지역 내 생산액 또는 지역의 부가 지역 외로 유출되는 것이다. 본 연구는 우리나라 시군구의 지역내총생산(GRDP)과 지역총소득(GRNI)을 비교하여 지역의 생산액 유출 현상을 분석하고자 하는 것을 목적으로 한다. 시군구 단위의 지역총소득은 지방소득세 자료를 이용하여 추정하였으며 이를 지역내총생산과 비교하여 시군구 단위의 생산액 유출을 분석하였다. 연구의 결론은 다음과 같다. 첫째, 지역내총생산 보다 지역총소득의 지역적 집중 현상이 뚜렷함을 알 수 있었다. Moran / 분석과 Local Moran / 분석을 통해 지역내총생산 보다 지역총소득 데이터에서 공간적 자기상관이 뚜렷하고, 공간적 클러스터가 두드러짐을 알 수 있었다. 둘째, 소수의 지역으로 지역내총생산의 유출이 집중됨을 알 수 있었다. 약 80%의 시군구에서 순유출이 발생하였고, 순유출이 큰 지역은 제조업이 발달한 도시였으며, 군지역이 대부분인 순유출 비율 상위 20위 지역에서는 지역내총생산의 70-80%의 생산액이 유출되었다. 순유입이 큰 지역은 기업의 본사가 위치한 서울을 비롯한 대도시 일부 지역이었으며, 서울의 서초구, 용산구, 강남구 등은 순유입의 규모가 지역내총생산액의 90% 이상일 정도로 순유입 비율이 높았다.

• Journal of Chest Surgery
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• 제57권2호
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• pp.178-183
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• 2024

Background: The superficial veins are commonly used in conventional autogenous arteriovenous fistulas and the placement of prosthetic grafts. When they are unsuitable, however, the use of the deep veins (venae comitantes) is generally considered to be a reasonable alternative. This study conducted a comparative analysis of clinical outcomes for arteriovenous grafts between 2 groups based on the type of venous outflow: superficial veins or venae comitantes. Methods: In total, 151 patients who underwent arteriovenous grafts from November 2005 to March 2022 were retrospectively analyzed. The patients were divided into 2 groups: group A (superficial veins, n=89) and group B (venae comitantes, n=62). The primary, secondary patency, and complication rates were analyzed in each group. A propensity score-matched analysis was performed. Results: In total, 55 well-balanced pairs were matched. Kaplan-Meier analysis revealed no significant differences in the primary patency rate between the 2 groups at 1-year, 3-year and 5-year intervals (group A, 54.7%, 35.9%, 25.4% vs. group B, 47.9%, 16.8%, 12.6%; p=0.14), but there was a difference in the secondary patency rate (group A, 98.2%, 95.3%, 86.5% vs. group B, 87.3%, 76.8%, 67.6%; p=0.0095). The rates of complications, simple percutaneous transluminal angioplasty, and stent insertion were comparable between the groups. Conclusion: Although this study demonstrated not particularly favorable secondary patency rates in the venae comitantes group, the venae comitantes may still be a viable option for patients with unsuitable superficial veins because there were no significant differences in the primary patency and complication rates between the 2 groups.

• The Journal of Asian Finance, Economics and Business
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• 제7권12호
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• pp.43-52
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• 2020

This paper examines how macroeconomic variables, such as interest rate differences, inflation, exchange rates, economic growth and external debt growth, affect capital flight in the ASEAN-8 countries. We apply a panel data model with fixed effect estimation for the data for eight countries from the period 1994 to 2018. We use the residual approach used by the World Bank to measure the value of capital flight. The results show that the interest rate differences, exchange rates, economic growth and foreign debt growth had a positive and significant effect on outward capital flight. A further implication of this finding is that the interest rate differences, exchange rate, economic growth and foreign debt growth are factors that trigger an increase in capital outflow in the ASEAN-8 countries. Nonetheless, inflation rate is not considered to be the main factor influencing capital flight, as average inflation in the ASEAN-8 countries remains relatively stable. This paper will be beneficial for policymakers in the ASEAN-8 countries and encourage them to constantly pay attention to these four variables, as they significantly influence capital flight, whereas they can disregard the impact of the inflation variable that is not significant in influencing capital flight.

• 생태와환경
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• 제44권3호
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• pp.264-271
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• 2011

댐이나 보와 같은 하천내 구조물의 건설시 어도의 설치는 어류의 이동에 있어서 중요한 역할을 한다. 탐진강에 건설되어 있는 장흥 다목적댐에는 어류의 상류로 이동을 원활히 하기 위해 엘리베이터식 어도에 포함되는 트럭식 댐체어도가 방류구 옆쪽에 위치하고 있다. 이러한 종류의 어도는 효율적으로 어류를 포집하기 위한 트랩이 함께 설치된다. 본 연구에서는 장흥댐에 설치되어 있는 어도 트랩의 어류 이용정도를 파악하기 위하여 PIT telemetry 방식을 적용, 총 15종 254개체의 어류에 tag을 삽입하여 모니터링을 하였다. 붕어, 떡붕어, 돌고기, 갈겨니, 피라미, 눈동자개 6종 36개체가 감지되어 14.2%의 감지율을 나타냈다. 붕어가 43개체 중 19개체가 감지되어 44.2%로 가장 높은 감지 비율을 보였고 돌고기는 14.3%의 비율을 나타냈으며, 갈겨니와 피라미는 각각 5%와 7.7%의 감지 비율을 나타냈다. 일부 개체들은 한번에 어도내로 이동하지 않고 장기간에 걸쳐 꾸준히 신호가 감지되었다. 이동한 개체들과 이동하지 않은 개체들 사이에 크기 (전장, 체장, 체중)는 차이가 없었으며(Mann-Whitney U test, p>0.05), 주로 댐에서 방류가 이루어지는 시간에 트랩으로 이동하는 것으로 파악되었다 (Mann-Whitney U test, p<0.001). 시간대별 분석에서는 주로 야간시간대보다 주간시간대에서 더 높은 감지빈도를 보였다(Mann-Whitney U test, p<0.001). 본 연구의 결과에 의하면, 어류가 트랩으로 이동하는 데는 방류시간과 같은 외적인 요소와 각 종별 생태적 특성(산란기, 주행성, 야행성)이 중요한 역할을 하고 있었다. 따라서 어류의 어도 이용율을 높이기 위해서는 어류의 생태적 특성을 고려하여 방류량과 더불어 방류시간, 방류시간대를 적절하게 변화시키는 전략적 방류가 필요할 것으로 판단된다.

• Journal of Chest Surgery
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• 제27권11호
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• pp.893-901
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• 1994

Forty nine patients [M: 31, F: 18], age from 2 months to 17 years [mean= 4.9 years], underwent operations, from April 1986 to December 1992, for the relief of subvalvular aortic stenosis in normal atrioventricular and ventriculoarterial connections.There were 4 anatomic types of subaortic stenosis : membranous in 29 cases [59.2%], fibromuscular in 11 [22.4%], diffuse tunnel type in 7 [14.3%], and miscellaneous in 2 cases. Thirty four patients [69.4%] had associated cardiac anomalies, of which ventricular septal defect was the most common [27 cases]. Other anomalies were patent ductus arteriosus, coarctation of the aorta, valvular aortic stenosis, double chambered right ventricle [DCRV], infundibular pulmonic stenosis, persistent left superior vena cava, and rigt aortic arch. Mean systolic pressure gradient between the left ventricle and ascending aorta was 26.4$\pm$17.6 mmHg : 13.1$\pm$17.6mmHg in the membranous type, 22.0$\pm$18.4mmHg in the fibromucular type, and 56.1$\pm$38.4mmHg in the diffuse tunnel type. Operative procedures were determined according to the type of subvalvular aortic stenosis : simple excision of subaortic membrane in the membranous type [29 cases], left ventricular myectomy with or without myotomy or fibrous tissue excision in the fibromuscular type [11 cases]. Among the 7 of diffuse tunnel type cases, ventricular myectomy was performed in 2 and a modified Konno operation was performed in 5 . Postoperative follow up was made with periodic echocardiography. The Mean postoperative follow up period was 33.8 months. There were 2 hospital mortalities [4.1%] and 2 late deaths. Residual stenosis remained in 3 cases and recurrence developed in 2 cases during the follow up period. 5 years actuarial survival rate was 91.8$\pm$3.9% and 5 year complication free rate was 72.3$\pm$10.4%. Conclusions : 1. Subvalvular aortic stenosis should be relieved completely as soon as possible when diagnosed, regardless of left ventricular outflow tract pressure gradient. 2. Good results were obtained using only simple excision of subaortic membrane in the membranous type of subaortic stenosis. However, aortoventriculoplasty [modified Konno prodedure] was necessary for good results in the diffuse tunnel type. 3. Periodic postoperative echocardiography was helpful in detecting the progression of residual stenosis and development of new stenosis.

• 환경위생공학
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• 제15권4호
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• pp.59-77
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• 2000

This study was carried out to investigate on several factors, which contaminative the water quality through the water pipe during feeding water, in 42 largescaled apart-ments(total 84 cases) and assayed the Volatile Organic Compounds(VOCs) and concen-tration of heavy metals that inflow and outflow in reservior water in Jeonnam area(Mokpo, Suncheon, Yeosu) from January 1999 to December 1999. The results obtained were summarized as follows ; 1. The quality of the water pipe composition in the order of frequency in the quality of water pipes were Copper(45.2%)> Zinc(38.9%)> Stainless steel(9.5%)> PVC(4.8%)> PM(2.4%) in observing 42 sites. All of the drain pipes were used the cast iron quality. 2. The result of certification curve from 12 items(17kind) of VOCs was $1.0-4.0{\mu{g}}/{\ell}$ range, a coefficient of correlation was shown 0.99 over. A MDL of each substance range was within $0.1-1.0{\mu{g}}/{\ell}$. 3. The result of the assay, 5 kinds(Viny chloride, Dichloromethane, Ethylbenzene, M,P-xylene, Styrene) of the VOCs of 14 kinds was not detected and the other items were detected slightly. The detection rate of one item and over in total VOCs samples, were 25.9% in inflow and 27.9% in outflow. And frequency of detect in inflow/outflow of THM(Chloroform, Bromodichloro-methane, Dibromochloromethane, Bromoform) were shown higher than 94.1%, 97.0% each stages. It comes to the conclusion that all of the samples were reason able for drinking water standards. 4. The coefficient of correlation were reasonable, it shown 0.999 over in $0.1-1.0{\mu{g}}/{\ell}$ of a measuring range conditions of 4kinds in organic substance(Zn, Cu, Fe, Mn). 5. The results were showed suitability in 78 cases(92.9%) and unsuitability in 6 cases (7.1%), in 84 cases of in organic substances. Compare to inflow stage, mean concentrations of heavy metal, were increased slightly in Zn, Cu, Fe except Mn than outflow stage. The result of the mean concentration in organic substance inflow and outflow in the apartment water tank using Pair-compared T-test, in 95% reliance index, were $0.179mg/{\ell}(0.151-0.307mg/{\ell})$ in Zinc, $0.136mg/{\ell}(0.113-0.230mg/{\ell})$ in Copper, $0.052mg/{\ell}(0.048-0.098mg/{\ell})$ in Fe, and there was a bit growing tendency but there was no differece in Mn. 6. The mean concentration of Copper which used Cu pipe as a water supply pipe in apartment were $0.216mg/{\ell}(0.161-0.338mg/{\ell})$ in case of the Zine pipe were $0.286mg/{\ell}(0.204-0.435mg/{\ell})$. It shows that the detection rate was more higher than the other material used in Cu or Zn as the water supply pipe. We supposed to Cu and Zn substance were gushing out water supply pipe.