• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.255-259
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• 2009

1997년 하수종말처리장의 민간위탁을 시작으로 국내 수도산업의 효율화에 대한 논의는 정부부처와 전문기관, 학계 등을 중심으로 제시되어 왔다. 수도산업 구조개편 논의는 지방상수도와 하수도산업의 규모의 영세성을 극복하기 위한 수직적 수평적 통합, 지방자치단체의 직영으로 인한 비효율성 제거를 위한 경영형태의 변화 등 크게 두 가지 흐름으로 정리할 수 있다. 상 하수도 사업의 수직적 수평적 통합은 주로 164개 수도사업자를 대략 9개 또는 12개 대규모 권역, 26개 또는 31개 중규모 권역으로 통합하는 방안들이 논의되고 있는데, 이와 같은 광역화 방안에 대해서는 정부부처, 연구기관, 전문가그룹 등에서 전반적인 합의가 형성되고 있다. 하지만 경영형태의 변화는 공사화와 민영화가 가장 큰 논의의 흐름으로, 이에 대해서는 집단과 지역 등 이해관계자간 상이한 견해들로 사회적인 합의를 이루지 못하고 있다. 한편 선진 수도사업을 구축하고 있는 프랑스, 네덜란드, 이스라엘 등지 에서는 수도산업의 효율성뿐만 아니라 공공성 제고 관점에서 구조적인 변화를 꾀하고 있다. 프랑스 파리시는 과거 150여 년 동안 유지되어 오던 수도사업의 민간운영을 전문공기업에 의한 위탁운영 방식으로 전환하는가 하면, 이스라엘은 정부와 민간기업간의 역할 분리를 통하여 물산업 수출국가로 발전하였다. 또한 네덜란드에서는 민영화 도입을 둘러싼 사회적 역량을 보다 발전적인 방향으로 유도하고자 법률로써 민영화를 금지하였다. 이에 본 연구는 글로벌 수도산업의 구조적인 변화 등을 살펴봄으로써 국내 수도산업이 효율성과 공공성을 제고하기 위한 경영 개선에 앞서 고려되어야 할 선결과제를 다음과 같이 제시한다. 첫째, 본 연구에서 살펴본 글로벌 수도산업의 구조적 변화(민영화에서 전문공기업화)는 수도사업의 정보의 비대칭성 및 투자저하가 효율적인 규제 메커니즘 부재에서 비롯되었다는 인식에서 추진되었다. 반면 국내시장은 산업 경제 전반이 정부주도로 이루어짐에 따라 적절한 규제의 틀과 문화가 정착되어 있지 않을 뿐만아니라 규제를 위한 전문인력도 상당히 부록한 실정이다. 따라서 효과적인 민영화의 도입을 위해서는 인적 제도적 인프라 형성이 선결과제이다. 둘째, 신규 또는 개량 투자에 대한 수요 발생, 생산원가에 미달하는 요금회수율 등은 민영화 도입 이후요금인상의 압박요인으로 작용할 것이다. 따라서 생산원가를 저감시키기 위한 광역화, 통합관리체계 등에 의한 원가절감 노력을 통하여 수도산업을 효율화하고 요금회수율을 현실화 등의 과제가 선결되어야 할 것이다.

• Journal of Physiology & Pathology in Korean Medicine
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• v.26 no.3
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• pp.273-280
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• 2012

Scutellaria baicalensis Georgi, which has been known to be able to clear away heat and remove dampness, was used for febrile disease. It is now clear that Advanced glycation end products (AGEs) play major roles in the pathogenesis of diabetic complications such as atherosclerosis. In this study, we examined whether Scutellaria baicalensis Georgi suppress the AGE mediated inflammatory responses in the THP-1 cells. AGE treatment increased the gene expression of pro-inflammatory cytokines such as tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$), interleukin-$1{\beta}$ (IL-$1{\beta}$), monocyte chemotactic protein-1 (MCP-1) and cyclooxygenase-2 (COX-2). Reverse transcriptase-polymerase chain reaction and Western blot analysis revealed that S. baicalensis had inhibitory effects on the expression of pro-inflammatory genes and protein levels in AGE-treated THP-1 cells. S. baicalensis had also reduced the production of ROS in the AGE-treated THP-1 cells. These results suggest that S. baicalensis has inhibitory effects for the development of diabetic vascular complication.

• The Korean Journal of Malacology
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• v.31 no.2
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• pp.151-158
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• 2015

This study was conducted to find out the changes of survival, respiration and organ structure of Tegillarca granosa exposed to copper (Cu). Experimental period was four weeks. Experimental groups were composed of one control condition and three copper exposure conditions (0.125, 0.250 and 0.500 mg/L). The results of the study confirmed that copper induces reduction of survival rate and respiration rate and histopathology of organ structure of the bivalve. In the copper concentration of 0.500 mg/L, mortality was 66.7% after Cu exposure of 4 weeks. Respiration rate was observed exposure groups lower than control decline by 18%. Histological analysis of organ system illustrated degeneration of epithelial layer and connective tissue layer of the mantle. Also, histological degenerations as epithelial atrophy and disappearance of lateral cilia are recognized in the gill and it was observed expansion of hemolymph sinus, disruption of epithelial layer, acidification of mucous and degeneration of muscle fiber bundles in the foot. In the digestive diverticulum, it was showed atrophy and destruction of basophilic cell and epithelial cell in the digestive tubules.

• Journal of Physiology & Pathology in Korean Medicine
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• v.23 no.6
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• pp.1305-1313
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• 2009

Saengjihwangeum-ja (SJHEJ) was recorded in DongEuiBoGam as being able to be used for treatment of Sogal whose concept had been applied to Diabetes Mellitus (DM). Modification of proteins by long term circulation of glucose leads to the formation of advanced glycation end product(AGE). Recent immunological studies demonstrated that ligation of AGE play an important role in the development of diabetic complications including atherosclerosis, which includes activation, adhesion, and migration of monocytes. Also, AGE and Maillard reaction product(MRP) could augment monocyte inflammatory responses via ligation of AGE receptor. In this study, the effects of SJHEJ extracts on the expression of inflammatory response-related genes such as tumor necrosis factor-$\alpha$, monocyte chemoattractant protein-1, interferon-g-inducible protein-10, and cyclooxygenase-2 in the human monocyte cell line, THP-1 cells. Reverse transcriptase-polymerase chain reaction revealed that SJHEJ had inhibitory effects on the expression of the TNF-a, MCP-1, IP-10, COX2, IL-1b genes in MRP-induced THP-1 cells. Treatment with SJHEJ had reduced reactive oxygen production in THP-1 cells stimulated by MRP. These inhibitory effects might be exerted via prevention of oxidative stress in activated monocytes. In addition, radical scavenging activity of SJHEJ was increased. These results suggest that SJHEJ has a beneficial effects for improve diabetic vascular complication.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.30 no.4
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• pp.328-331
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• 2019

A linear frequency modulated pulse train waveform can be cost-effective in achieving high range resolution, and thus the synthetic aperture radar may be benefited by using the mixer output of the received signal. However, the image formation process from a mixer output is vulnerable to errors caused by stop-and-go approximation. In this paper, a nadir-looking imaging radar based on time domain correlation is proposed. Furthermore, to prevent the occurrence of ghosting effect in images, antenna placement on a rotating disk is proposed. Simulation results indicate that ghosting effect can be eliminated by employing the proposed antenna placement structure.

• Journal of Advanced Navigation Technology
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• v.26 no.1
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• pp.9-14
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• 2022

In this paper we investigate the advantages when the GPS Antenna is installed on the rear missile body. In conventional design the GPS antenna locates on the front part of missile. However it causes degraded GPS positioning performance since the missile body blocks the GPS signals. This paper proposes the GPS array antenna design which locates on the rear part of missile body and has the tilted antenna patches to achieve the maximum area of receiving GPS signals. We simulate LOS region of receiving signals and conducted anechoic chamber test to define the effective signal receiving region. And we conduct field test and flight test to check out the enhancement of signal receiving area.

• Economic and Environmental Geology
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• v.42 no.4
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• pp.315-333
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• 2009

In this study, the hydrochemical and the isotopic characteristics of major streams in the Daejeon area were investigated during rainy and dry seasons. The stream water shows the electrical conductivity of the range of $37{\sim}527{\mu}s$/cm, and pH $6.21{\sim}9.83$. The chemical composition of stream waters can be grouped as three types: the upper streams of Ca(Mg)-$HCO_3$ type, Ca(Mg)-$SO_4(Cl)$ type of middle streams flowing through urban area, and Na(Ca)-$HCO_3$(Cl, $SO_4$) type of the down streams. Based on in-situ investigation, the high pH of stream waters flowing through urban area is likely to be caused by the inflow of a synthetic detergent discharging from the apartment complex. The electrical conductivity of stream waters at a dry season is higher than those of at a rainy season. We suggest that the hydro-chemical composition of stream waters in the Daejeon area was affected by the discharging water from the sewage treatment facilities and anthropogenic contaminants as well as the interaction with soil and rocks. ${\delta}D$ and ${\delta}^{18}O$ values of the stream waters show the relationship of ${\delta}D=6.45{\delta}^{18}O-7.4$, which is plotted at a lower area than global meteoric water line(GMWL) of Craig(1961). It is likely that this isotopic range results from the evaporation effect of stram waters and the change of an air mass. The isotope value shows an increasing trend from upper stream to lower stream, that reflects the isotopic altitude effect. The relationship between ${\delta}^{13}C$ and $EpCO_2$ indicates that the carbon as bicarbonate in stream water is mainly originated from $CO_2$ in the air and organic materials. The increasing trend of ${\delta}^{13}C$ value from upper stream waters to lower stream waters can be attributed to the following reasons: (1) an increasing dissolution of $CO_2$ gas from a contaminated air in downtown area of the Daejeon, and (2) the increment of an inorganic carbon of groundwater inflowed into stream by base flow. Based on the relationship between ${\delta}^{34}S$ and $SO_4$ of stream waters, the stream waters can be divided into four groups. $SO_4$ content increases as a following order: upper and middle Gab stream${\delta}^{34}S$ value decreases as above order. ${\delta}^{34}S$ value indicates that sulfur of stream waters is mainly originated from atmosphere, and is additionally supplied by pyrite source according to the increase of sulfate content. The sulfur isotope analysis of a synthetic detergent and sewage water as a potential source of the sulfur in stream waters is furtherly needed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.2
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• pp.660-667
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• 2018

This study examined the optimal manufacturing conditions of RDF using heat-dried sludge from sewage treatment plant in Cheonan with the oil-drying method. The amounts of oil evaporation and oil drying of the heat-dried sludge were measured at different temperatures to evaluate the value of the product. The performance of the product was then measured using a calorimeter and TGA. In addition, the concentration of odor, NH3, H2S, and TVOC during drying was determined using a portable odor-meter. Ingredient analysis was performed by EDS. Considering mass-production, the oil to heat-dried sludge weight ratio was fixed to 4:1. At $130^{\circ}C$, only physical mixing occurred after the instantaneous drying of internal water. Considering the eco-friendly aspects, there was no significant difference in the drying efficiency between $160^{\circ}C$ and $190^{\circ}C$. Therefore, the optimal conditions were a drying temperature of $160^{\circ}C$ within 5 minutes. Finally, the RDF manufactured in this study and fuel used in the thermal power plants were compared. The calorific value was 4,449kcal/kg, the water content was 2% and the ash content was 34%, which is higher than the fuel of thermal power plants. Therefore, it is believed that coal energy as well as wood pellets can be replaced.

• Korean Journal of Ecology and Environment
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• v.42 no.1
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• pp.39-47
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• 2009

Spatial and temporal analysis of water quality was performed for eleven monitoring stations in Dongjin River watershed in order to determine the trends of monthly water quality. The monthly water quality data of biochemical oxygen demand (BOD), total nitrogen (TN) and total phosphorus (TP) during $1995{\sim}2004$, were analyzed utilizing Seasonal Mann-Kendall test, LOWESS and three-dimensional graphic approaches. The results indicated that BOD and TN concentrations had the downward trend, but TP showed the upward trend, especially in Gobucheon. This numerical and graphic analysis is the useful tool to analyze the long-term trend of water quality in a large river system.

• Korean Journal of Environmental Agriculture
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• v.10 no.1
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• pp.33-49
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• 1991

In order to disclose the contamination of the Mushim-Cheon by pollutants and to establish the countermeasures, the water samples collected in November of 1989(lst sample), February(2nd), May(3rd) and August of 1990(4th) were analyzed to obtain the following results : 1. The water temperatures of the seasonal samples ranged from 8.6 to 16.2, 8.3 to 25.2, 18 to 26, and 24 to 32$^{\circ}C$, in the 1st, 2nd , 3rd, and 4th samples, respectively. 2. The pHs of all the samples ranged from 6.5 to 8.5. 3. In the 3rd sample, especially, DO was observed to fall down to 0.8 ppm at the downstream of St 13, which is not allowed even for agricultural use. 4. The BOD and COD values in sewers were much higher than those in the main stream, and especially the values of St 14-A reached 107-608 and 176-635 ppm, respectively, which far exceeded the limit of 40 ppm, the allowed value for the discharges from the disposal facilities. The SS value of St 14A ranged from 142 to 1, 900 ppm, which far exceeded the limit of 70 ppm, the allowed value for the discharges from the disposal facilities. 5. It turned out that the water quality of the Mushim-Cheon flowing through Cheong Ju was more worsened at sewers than the main stream, and at the downstream than the upstream of the surveyed area. Accordingly, the sewage disposal plant and the expansion of the disposal facilities are urgently needed.