• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.47-47
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• 2011

하도 내 수역이 식생으로의 천이가 진행되고 최종적으로는 육상 식물들이 활착하게 되는 육역화 현상은 하도의 수리학적 문제 및 환경생태적 측면에서 큰 문제를 발생시킬 가능성을 내포하고 있다. 최근 하천복원의 필요성이 강조됨에 따라 물골공법 및 국부세굴 유도형 공법 등 실용성을 포함시킨 다양한 하천 복원공법이 제시되고 있다. 물골공법은 자연적인 물골형상에 의한 유사퇴적방지, 홍수시 유속저감 및 생물서식처를 조성하는 하상 생태복원 공법을 의미하며, 본 연구에서는 수리모형실험 및 3차원 수치모의를 이용하여 다양한 하도육역화 방지 공법 중 물골공법의 효과 및 적용성을 검토하였다. 물골공법의 특성 중 유사퇴적방지의 효율성 분석을 위해 부정류(unsteady state)상태에 대해 연구를 수행하였으며 홍수 이후 수위하강시 고수부지 및 물골 주변에서의 흐름특성을 재현하였다. 수위하강 모의를 위해 임의의 수위하강시간을 선정하여, 수위하강이 진행되는 시간( )을 각각의 수위하강시간으로 무차원 화한 후 무차원된 시간(t/�� )에 따른 흐름특성을 비교 분석하였으며 모의 및 분석결과, 수위하강시간이 80초 이상일 경우 주요 지점에서의 유속의 변화는 무차원된 시간에 대하여 일치하였으며 수리모형실험 및 수치모의에 적용할 수위하강시간으로 선정할 수 있었다. 물골 전구간에 대한 부정류 실험을 위해 LSPIV(Large-Scale Particle Image Velocimetry)장치를 이용하여 수위하강에 따른 물골주변의 흐름특성을 관측하였으며 3차원 수치모의를 통해 검증하였다. 실험 분석결과, 수위하강에 따라 고수부지 위로 흐르는 유수가 물골 내부로 유입되어 물골을 따라 흘러 물골 합류부로 이동하는 것으로 나타났으며, 이는 홍수시 유수와 함께 떠다니는 부유사(suspended load)가 물골로 유입되어 물골 합류부로 이동하므로 물골의 유사배제 가능성을 판단할 수 있었다. 또한 물골의 유사배제능력을 평가를 위해 실험을 통하여 산정된 최대 및 최소 마찰속도(U )와 유사이동 한계곡선을 이용하여 물골의 통한 배제 가능한 유사의 입경을 분석하였다. 분석결과, 최소 2mm에서 최대 4mm로 나타났으며 이 입경 이하인 유사에 대해서는 퇴적되지 않고 물골을 통하여 배제될 수 있을 것으로 예상되었다. 본 연구 결과 물골공법 적용시 수위하강에 따라 물골에서 하도방향으로 유사의 수세(flushing)효과가 나타났으며 유사의 부상 및 이송이 효과적으로 발생하여 고수부지 내 유사퇴적 방지가 효과적인 것으로 판단되었다. 추후 다양한 형상의 물골에 대한 능력검토가 보완된다면 물골설계지침 제안을 위한 자료로 활용 가능할 것이다.

• Journal of the Korea Organic Resources Recycling Association
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• v.16 no.3
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• pp.29-37
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• 2008

The objective of this research is to evaluate the optimum treatment methods for disposal sludge cake at different temperatures and periods of time. The disposal dehydrated sewage cake used in this study was obtained from N wastewater treatment plant in the P City. This system consists of continuous conveyer thermal dryer and pyrolysis. The continual conveyer thermal dryer was operated to evaluate the optimum conditions with temperature settings, ranges from 130 to $180^{\circ}C$, loading rates of 650~750 kg/hr and operating times of 110~120 minutes. The continual pyrolysis was also operated to evaluate the optimum conditions with temperature settings, ranges from 650 to $750^{\circ}C$, loading rates of 100~158 kg/hr and operating times of 20~40 minutes. The sewage sludge cake has a moisture content of 78~80% (wt) which decreased up to 1~3%(wt) resulted in breaking of cell wall after operating the continuous conveyer thermal dryer and pyrolysis. Important parameters which were operating times, moisture contents, loading rates, conveyer velocities and rotary velocities effects on the thermal kinetics and dynamics were investigated to evaluate the optimum conditions for the continual thermal dryer and pyrolysis.

• Ecology and Resilient Infrastructure
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• v.5 no.1
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• pp.19-24
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• 2018

Water quality is affected by the pollutants flowing into rivers since the interaction between water bodies and sediments in various environmental conditions. Especially, accumulation of sediments increases in the stagnant water areas due to a relative long hydrological retention time in the water bodies. Therefore, it is an important factor of water quality to understand characterization of the material behavior in water bodies and sediments. In this study, the objective of the conditional experiments was small and medium sized streams located in Gyeonggi-do. To estimate how the changes of fluoride behavior, depending on the pH, ion type, concentration, and clay contents. The pH results showed a trend that adsorption amount of fluorine decreased and the dissolution of fluorine increased following by pH increasing. The concentration and type of ions results showed that $Cl^-$ and $SO{_4}^{2-}$ ions had no significant effect on the adsorption ability of fluorine, the amount of dissolution was increased because $OH^-$ ion had active competition with fluorine in the reaction. The ingredient of sediment results showed that the amounts of fluoride adsorption and dissolution were reduced in samples, which contain relatively large amounts of Silt and Clay components. This means that the environmental conditions of water bodies greatly affect the adsorption and dissolution of fluoride in the sediments, so that proper management of fluoride in the sediments must precede an understanding of the environmental conditions of the water bodies.

• Proceedings of the Korea Water Resources Association Conference
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• 2004.05b
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• pp.731-736
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• 2004

강우-유출과정의 수문학적 현상을 보다 정확히 분석하고 예측하는 기법으로 강우에 의한 유출의 반응을 나타내는 지체시간, 도달시간 등 수문학적 반응시간을 유역의 지형형태학적 인자들과 연계하는 방법이 많이 이용되고 있다. 이에 본 연구에서는 Clark방법과 지형형태학적 순간단위도(GIUH)를 이용하여 계측유역의 강우-유출반응을 모의하였고, 이를 관측된 값과 비교하여 미계측유역의 적용성 여부를 검토해보았다. 대상 유역의 하상지형인자 및 지형형태학적 특성은 Arc-View를 이용하여 구하였으며, 이를 기존의 문헌자료와 비교해보았다. Clark방법의 매개변수의 결정에 있어서 시간-면적곡선은 HEC-1의 무차원 식을 이용하였고, 도달시간은 Kirpich 공식을 이용하여 구하였으며, 저류상수는 Clark방법에 의해 추정된 순간단위도의 첨두유량이 Horton의 차수비의 함수로 구한 철두유량과 같아지는 값으로 결정하였다. 본 연구는 전적비교를 출구점으로하는 유역면적 $8.5km^2$인 설마천을 대상유역으로 하였으며, 모의된 강우-유출반응과 비교하기 위해 사용된 강우사상은 2002년의 8월 4일과 2002년 10월 6일의 10분 단위 우량이다. Clark방법과 GIUH를 이용하여 모의한 유출곡선과 관측된 유출곡선을 비교해본 결과 첨두유량은 8월의 강우사상 때는 $21\%$크게, 10월의 강우사상 때는 $35\%$작게 나타났다. 첨두시간은 모의된 경우가 각각 10분, 20분 빨리 도달하였다. 또한 이러한 결과는 유역의 도달시긴에 가장 민감하게 반응함을 알 수 있었다. 따라서, 유역의 도달시간 산정에 주의를 요한다면 프랙탈 차원이 유사한 미계측유역의 수문곡선 산정에 있어서 Clark방법과 GIUH를 이용하는 방법도 유용하다고 사료된다. 주는 각 수문인자 중 강우시간분포와 유효우량 산정방법 그리고 유출모형에 대해 자자 검토하였으며, 최종적으로 면적에 따른 임계지속기간과 유출량의 변화를 검토해 보았다.이를 각각의 경우의 해석해 결과와 비교${\cdot}$분석하였다. 후방추적 퍼프모형은 전방추적 퍼프모형에 비하여 사용된 퍼프수와 관계없이 작은 오차를 발생하였으며, 전체적으로 퍼프 모형이 입자모형보다는 훨씬 적은 수의 계산을 통해서도 작은 오차를 나타낼 수 있다는 것을 알 수 있었다. 그러나 Gaussian 분포를 갖는 퍼프모형은 전단흐름에서의 긴 유선형 농도분포를 모의할 수 없었고, 이에 관한 오차는 전단계수가 증가함에 따라 비선형적으로 증가하였다. 향후, 보다 다양한 흐름영역에서 장${\cdot}$단점 분석 및 오차해석을 수행한 후에 각각의 Lagrangian 모형의 장점만을 갖는 모형결합 방법을 제시할 수 있을 것으로 판단된다.mm/$m^{2}$로 감소한 소견을 보였다. 승모판 성형술은 전 승모판엽 탈출증이 있는 두 환아에서 동시에 시행하였다. 수술 후 1년 내 시행한 심초음파에서 모든 환아에서 단지 경등도 이하의 승모판 폐쇄 부전 소견을 보였다. 수술 후 조기 사망은 없었으며, 합병증으로는 유미흉이 한 명에서 있었다. 술 후 10개월째 허혈성 확장성 심근증이 호전되지 않아 Dor 술식을 시행한 후 사망한 예를 제외한 나머지 6명은 특이 증상 없이 정상 생활 중이다 결론: 좌관상동맥 페동맥이상 기시증은 드물기는 하나, 영유아기에 심근경색 및 허혈성 심근증 또는 선천성 승모판 폐쇄 부전등을 초래하는 심각한 선천성 심질환이다. 그러나 진단 즉시 직접 좌관상동맥-대동맥 이식술로 수술적 교정을 해줌으로써 좋은 성적을 기대할 수 있음을 보여주었다.특히 교사들이 중요하

• Journal of Wetlands Research
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• v.16 no.4
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• pp.371-378
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• 2014

The subject of this study is the Gongchon-cheon which is one of the largest streams in Incheon and is closely related to lives of citizen. Comparative analysis is made on the changes of the environment and the ecological condition of Gongchon-cheon after the stream naturalization construction which is completed in July 2009. From the results of the survey, 32 species in 2004, 22 species in 2009 and 46 species in 2010 have been recorded. The number of the species decreased from 2004 to 2009 due to the disturbance of the river environment, and it increased in a short time from 2009 to 2010 because of the recovery of the environment. It demonstrates the stream naturalization construction providing enough environments (dikes and rapids) for the benthic macro invertebrates. The result of the present study is similar with the river's biology index, ESB index, and KSI index, and also it is similar with the pattern of the appearance, which illustrates that the species decreased during the naturalization construction, and increased after the stabilization since the finish of the naturalization construction, and it has been confirmed that the naturalization construction provides the better environment for the inhabitation of organisms.

• Archives of design research
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• v.15 no.1
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• pp.379-388
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• 2002

Since policies of each local government toward regional development have been focusing on only development of the individual applied items such as a character merchandise, co-regional brand, and developing a speciality for the region, the adverse effects of design have been came out. So we carried out this research to minimize the adverse effect of design and also we would like to give the opportunity of thinking of a new way to activate local economy, to create regional identity and to develop local resources by applying the Cl program which have bean used as the way of business improvement coping with the conceptional change of competitiveness with a comprehensive view. Therefore, for design to play an important role in regional development, as standing on the basis of regional development it is necessary to attain the various goals such as activating administrative organization, improving the administrative image, and making the local in go unique. And also it is necessary to develop the communicational strategy as an innovative and expressive program which can consider human network development as an regional resource. To carry out this communicational strategy effectively, in particular, it is not only inevitable to operate the strategic and comprehensive programs promoting the regional development according to the of 6 stages design develop cent program which consists of region's self-verification and self-recognition, self-determination, development of self-innovation, visibility to unify the regional images, creating the design system, and carrying out and verifying the program, but also it is necessary to apply regional development system which can change the regional basic plan, aiming at regional development, into unique regional trait that has an future image by improving the program with constant management and feedback through verifying the design program.

• Journal of Food Hygiene and Safety
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• v.27 no.3
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• pp.209-214
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• 2012

The purpose of this study was to evaluate microbiological contamination of fresh-cut produce salads and raw cabbage toward climate change. Total aerobic bacteria, coliform and Escherichia coli were monitored to get the contamination levels and E. coli O157:H7, Staphylococcus aureus, Bacillus cereus, Listeria monocytogenes and Salmonella spp. to detect pathogens with risk of foodborne disease from samples. Collection of 360 samples (180 fresh-cut produce salads and 180 raw cabbage), including 60 samples from each area after setting 3 areas depending on annual temperature and annual rainfall. As a result, total aerobic bacteria and coliform group were different was performed areas in raw cabbage but there was no difference between areas in fresh-cut produce salads. In addition foodborne pathogens including E. coli were not isolated from fresh-cut produce salads.

• Korean Journal of Ecology and Environment
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• v.44 no.2
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• pp.226-238
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• 2011

Ichthyological fauna and community structure were surveyed in the Naeseong Stream around the planed Yeongju Dam, Yeongju City, Gyeongsangbuk-do from April 2007 to October 2009, During the survey period, 27 species (25 genera, 10 families) were collected. Cyprinid fish comprised 63.0% (17 species) and cobitid fish comprised 7.4% (2 species). Ten of the 27 species (37.0%) were endemic species. The dominant and subdominant species based on the number of individuals was Zacco platypus (43.2%) and Zacco koreanus (15.8%), respectively. Introduced from the other native rivers and exotic fish were Opsariichthys uncirostris amurensis, Leiocassis ussuriensis, and Micropterus salmoides (11.1%). The declining population density of Zacco koreanus and its subdominant status represents a change, since, up until the mid 1990's, it was widely distributed throughout the area and was the dominant species. The distribution area of Zacco koreanus decreased in size; by 2009, it no longer inhabited the lower reaches of the Naeseong Stream. On the other hand, Zacco platypus remained the dominant species throughout the area, except for the upper-reaches of the water-course. Gobiobotia naktongensis inhabited all areas of Naeseong Stream, which mainly has a sandy bottom. Analyses of the fish community revealed species diversity, even-ness and dominant indices were 0.881, 0.615, and 0.230 respectively. These results showed that the main river, in which the water width and flow are abundant and which has various habitats, has a higher species diversity (0.829) than the tributary (0.735).

• Korean Journal of Food Science and Technology
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• v.37 no.6
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• pp.957-961
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• 2005

Spoilage yeast was isolated from spoiled rice-syrup and identified by Microbial Identification system (MIDI) as Zygosaccharomyces bailii based on composition of fatty acids exhibiting carbon skeleton of 16:0, 16.1 $({\Delta}cis\;7)$, 18:2 $({\Delta}cis\;9)$, 18:1 $({\Delta}cis\;9)$, and 18:1. Increase in sugar content $(1^{\circ}brix)$ resulted in decreased moisture concentration (1%), and water activity decreased from 0.72 to 0,63 when sugar concentration increased from 77 to $83^{\circ}brix$. Yeast showed very slow growth during three weeks post-inoculation in rice-syrup at 17 and $79^{\circ}brix$, and maximal level of Z. bailii was found at 6 and 10 weeks storage at 15 and $25^{\circ}C$, respectively. At over $81^{\circ}brix$ its growth slowly decreased at beginning of storage, indicating rice-syrup could be preserved safely at above $81^{\circ}brix$ sugar content without Z. bailii contamination.

• Applied Biological Chemistry
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• v.50 no.2
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• pp.111-115
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• 2007

To modify the physical properties of alginate film, the gamma ray irradiation was performed, and alginate film properties such as elongation strength (ES), elongation rate (ER), water vapor permeability(WVP), and water solubility (WS) were measured. The film made from 1.75% alginate solution (w/w) with the addition of 2% CaCl$_2$ solution suggested a good application for a film preparation in that elongation strength(ES) increased 5 fold by CaCl$_2$ treatment and water vapor permeability was decreased by 17${\sim}$22%. A solid form of alginates were irradiated with Co$^{60}$ gamma rays in the dose range of 2 to 10 kGy to make a low molecular weight alginate film, and then the intrinsic viscosity and the molecular weight of alginates were measured. Increasing the dose range of 2 to 10 kGy produced lower intrinsic viscosity and lower molecular weight, causing the decrease in the ES and WS. However, ER increased four times compared to that of without gamma ray dose, which is an indication of the different properties of algiante film. WVP of the films did not show any significant change at different doses.