• The Journal of Engineering Geology
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• v.24 no.4
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• pp.487-499
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• 2014

While the vertical open type of heat exchanger is more effective in areas of abundant groundwater, and is becoming more widely used, the heat exchanger most commonly used in geothermal heating and cooling systems in Korea is the vertical closed loop type. In this study, we performed numerical simulations of the optimal utilization of geothermal energy based on the hydrogeological and thermal properties to evaluate the efficiency of the vertical open type in areas of abundant groundwater supply. The first simulation indicated that the vertical open type using groundwater directly is more efficient than the vertical closed loop type in areas of abundant groundwater. Furthermore, a doublet system with separated injection and extraction wells was more efficient because the temperature difference (${\Delta}$) between the injection and extraction water generated by heat exchange with the ground is large. In the second simulation, we performed additional numerical simulations of the optimal utilization of geothermal energy that incorporated heat transfer, distance, flow rate, and groundwater hydraulic gradient targeting a single well, SCW (standing column well), and doublet. We present a flow diagram that can be used to select the optimal type of heat exchanger based on these simulation results. The results of this study indicate that it is necessary to examine the adequacy of the geothermal energy utilization system based on the hydrogeological and thermal properties of the area concerned, and also on a review of the COP (coefficient of performance) of the geothermal heating and cooling system.

• Korean Journal of Ecology and Environment
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• v.39 no.4 s.118
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• pp.489-497
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• 2006

The feasibility of the Natural and Ecological Wastewater treatment System (NEWS) was examined for rural wastewater treatment in Korea. The intermittent trickling biofilter with high hydrophilic filter media was used for pretreatment for suspended solids and organic pollutants. The subsequent constructed wetland with porous granule materials was used for promoting nutrient removal. The results show that the removal efficiencies of the system were high with respect to the water quality parameters except COD. Even if the effluent from the biofilter did not meet the guidelines for wastewater treatment plant effluent in Korea in terms of $BOD_5$ and TN, the final effluent of the system meets the guidelines us to good performance of the constructed wetland. The regression analysis between pollutant loading rate and removal rate indicated that the system could have stable removal for SS, $BOD_5$, TN, and TP in the given influent ranges. The analysis in the winter period indicated that the wetland covered with transparent polycarbonate glass had the statble performance during the winter period dus to increase of temperature inside the wetland without any heating system. With the stable performance, effective poilutant removal, low maintenance, and cost-effectiveness, the NEWS could be considered as an alternative treatment system for decentralized regions and rural communities in Korea.

• Korean Journal of Ecology and Environment
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• v.39 no.2 s.116
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• pp.219-225
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• 2006

Bacterial community structure in the Juam Reservoir was analysed using fluorescent in situ hybridization (FISH) technique from April 2005 to January 2006. Total bacterial numbers varied in the range of 1.58 ${\sim}\;2.73{\times}\;10^6\;cells\;mL^{-1}$ proportional to the concentration of chi-a and had the minimal value in January. The ratios of ${\alpha}\;{\cdot}\;{\beta}\;{\cdot}\;{\gamma}$-subclass proteobacteria and Cytophaga-Flavobacterium (CF) group to total bacteria ranged from 45.1% to 77.5%, and the ratios of ${\alpha}\;{\cdot}\;{\beta}\;{\cdot}\;{\gamma}$-subclasses to total bacteria in June and September with the concentration of chi-a measured were lower than those ratios in April and January. It suggests that enriched growth of Microcystis aeruginosa may inhibit the metabolic activlty of ${\alpha}\;{\cdot}\;{\beta}\;{\cdot}\;{\gamma}$-subclass proteobacteria. However, the ratio of CF group bacteria represented no large change depending on algal bloom. In terms of nitrifying bacteria, the numbers of ammonia-oxidizing bacteria ranged from 9.9 ${\times}\;10^4\;to\;25.5\;{\times}10^4\;cells\;mL^{-1}$ with sharp fluctuation whereas those of nitrite-oxidizing bacteria varied in 8.7${\sim}9.8{\times}10^4\;cells\;mL^{-1}$ without noticeable change except the maximal value of $20.3{\times}10^4\;cells\;mL^{-1}$ in January maybe due to the high DO.

• Korean Journal of Food Science and Technology
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• v.19 no.6
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• pp.499-505
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• 1987

The functional properties of lupin seed protein concentrate (LPC) were examined and compared to those of soybean protein isolate (SPI) and Na-caseinate. LPC-50, of which protein level was 50%, was prepared by a two phase solvent (hexane: alcohol: water= 10:7:3) extraction method. LPC-70 was made from LPC-50 by removing the fractions solubilized by carbohydrate decomposing enzymes. The solubilities of LPC-50 and LPC-70 were similar to that of of SPI but slightly higher at pH 4-5, and less susceptible to the added salt. The apparent viscosity of LPC increased exponentially as the concentration increased over 6% level, and the change was similar to that of Na-caseinate. LPC showed strong pseudoplastic non-Newtonean flow behavior, which was similar to that of SPI The emulsifying capasity of LPC-70 was similar to that of SPI when salt was added. The foaming capacity of LPC was comparable to that of SPI. LPC showed high oil and water absorption capacities, which increased as the protein level was elevated. LPC-70 showed the highest oil absorption capacity of all the samples tested.

• Journal of Korean Home Economics Education Association
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• v.16 no.4 s.34
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• pp.1-8
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• 2004

The purpose of this study was to investigate as to how much of changes has occurred in the newly revised Home Economics Textbooks required by the 7th Curriculum as compared to those by the former 6th Curriculum. and to seek future policy direction which can be improved even better. if any. for further revision. To implement this proposal, this study employed 8 different textbooks published among 12 textbooks developed for the 7th Curriculum for data base. The results of this study were as follows: It was covered such areas of change and develope in the composition of category and system in the Home Economics Textbooks required by the 7th Curriculum as compared to those by the former 6th Curriculum. The whole system of textbook was composed of cover page, the inside of a book cover. the title page, introduction. table of contents. appendices. It was same in the total pages with the exception of table of contents. appendices. the inside of a book cover and it was much alike in contents of introduction. In the aspect of the unit system of the textbooks. their whole flows were similar to each other. but the writers' intention and the stress on the focal points had appeared well in topic introduction and texts for the units of the textbooks. In addition. it can be said desirable that much more middle school teachers took a participation in the development of textbooks as textbook writers than before. In the organizational aspect of the sub-area organization of textbooks in the 7th Curriculum, it was not dispersed in grade 1, 2, and 3, but was centralized in a certain grade to increase its efficiency. The number of activity and experiment & practice that students could try to do actually were drastically increased compared to the 6th Curriculum. but it showed a wide difference between textbooks.

• Food Industry
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• s.181
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• pp.38-67
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• 2004

예로부터 인간은 단맛에 강한 욕구를 가지고 있었다. 따라서 설탕, 포도당, 과당 등 단맛이 강한 감미료를 선호하여 왔고, 현재까지도 식품 제조시 가장 널리 사용되고 있다. 그러나 최근에는 국민의 건강에 대한 관심이 고조 되고 설탕으로 대표되는 전통적인 일반 감미료의 충치, 비만, 당뇨병 유발 등의 부정적인 측면이 부각되고 있을 뿐만 아니라, 식품에 대한 건강 기능성이 강조되면서 기능성 감미료가 주목 받고 있다. 특히 고도의 경제성장 및 국민 소득의 향상에 따라 차별화된 기능성 감미료의 생산을 요구하는 실정이다. 이와 관련하여, 현재 식품 산업계에서는 올리고당류, 당알콜류, 고감미 감미료류 등에 많은 관심을 가지고 연구 개발에 집중하고 있다. 올리고당류의 대표적인 제품은 프락토올리고당, 갈락토올리고당, 이소말토올리고당 등이다. 현재 올리고단 시장은 성숙기로서 성장속도가 둔화되고 있으나, 최근 American Association of Cereal Chemists(AACC)등 세계적인 협회에서 수용성 식이섬유를 다당류, 올리고당, 리그닌 등을 포함하여 새롭게 정의하였고 이에 따라 해외에서는 프락토올리고당을 중심으로 수용성 식이섬유로 용도 사용이 가능하게 되었을 뿐만 아니라, 식이섬유로 표기도 가능하게 되어 수요가 증가할 것으로 예상된다. 국내에서는 아직 올리고당을 식이섬유로 사용하지는 못하고 있으나, 식품 공전 개정을 통해 식이섬유로 표기 가능하도록 수정될 전망이다. 당알콜류는 솔비톨 및 자일리톨이 주류를 이루고 있다. 솔비톨은 시장에 가장 먼저 소개된 당알콜류인데 저가여서 그동안 가장 큰 시장을 형성하고 있었으나 최근 3년 동안 자일리톨껌이 최대의 히트 상품이 되면서 자일리톨이 급성장하였다. 그 외에는 만니톨, 에리스리톨, 말티톨, 이소말트 등이 있다. 최근에는 말티톨을 중심으로 다양한 응용 연구 및 이소말트 및 에리스리톨 등을 생산 판매하고 있는 다국적 기업의 판촉 활동 등으로 당알콜류 시장의 새로운 변화가 예상된다. 고감미 감미료류는 스테비오사이드와 아스파탐이 주류를 이루고 있었지만, 최근 아세설팜 K 및 수크랄로스가 잇따라 식품으로써 사용 허가를 받으면서 시장이 재편되고 있다. 하지만, 해외에 비하여 국내의 고감미 감미료 시장은 매우 작고 성장률도 낮은 편인데 그 이유로는 국민 정서상 천연이 아닌 합성에 대한 부정적 인식과 맛에 대한 거부감 때문인 것으로 생각된다. 이와 관련하여 최근에는 다양한 감미질 및 Multi sweetener system 연구를 통해 설탕과 유사한 맛을 내는 혼합 기술 개발에 관한 연구가 진행되고 있다. 따라서 향후에는 해외의 선진국과 같이 고감미 감미료 시장도 점차적으로 확대될 것으로 예상된다. 기타 대체 감미료로는 타가토스, 트레할로스, 아라비노스 등이 있다. 이중에서 특히 해외에서 크게 기대를 모으고 있는 타가토스는 최근 국내 인증을 받아 시장 진출을 준비 중에 있다. 아라비노스는 양질의 감미를 갖는 천연 펜토오스인데 연구용 시약 이외에는 지금까지 거의 이용되지 않았다. 그러나 최근 아라비노스가 설탕의 소화흡수를 선택적으로 억제한다는 흥미 있는 결과가 임상 및 동물실험에서 확인되어 향후 제품으로써 개발을 기대할 수 있게 되었다. 이들 감미료는 기존 설탕이 가지는 문제점을 많은 부분 극복할 것으로 여겨지며, 이로 인해 수요는 점차 증가할 것으로 생각되며, 높은 경제적 부가 가치를 창출할 것으로 예상되어 진다. 생산 기술 적인 측면에서 건강 지향적 천연소재 감미료에 대한 선호가 날로 증가하는 추세에 따라 기존에 주로 사용되었던 화학합성법보다는 천연 이미지의 생물공학적인 방법에 의한 감미료 생산이 각광을 받을 것으로 예상된다. 생물공학적인 방법을 감미료 소재 개발에 응용하게 되면, 기존에 사용되었던 화학합성법 등이 가지는 환경적인 문제, 반응 부산물 생성에 따른 분리, 정제에서의 비용증가 등의 문제점을 해결할 수 있을 것으로 여겨지며, 고정화 방법의 도입 등을 통해 생산성 향상을 도모할 수 있다. 본 장에서는 감미료 소재 개발에 건강 지향적 국민 정서를 반영하고, 국내외 감미료 시장의 흐름을 파악하여 당류 산업의 발전적인 변화에 대처하고자 하였으며, 이를 통해 당류산업의 고부가가치 첨단산업으로서의 육성방안을 논의하고자 하였다.

• Journal of Life Science
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• v.25 no.3
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• pp.257-262
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• 2015

The genetic variability of four species of the genus Zoysia collected from South Korea was analyzed using an inter-simple sequence repeat (ISSR) marker system. Polymerase chain reactions (PCR) with eight ISSR primers generated 86 amplicons, 76 (87.1%) of which were polymorphisms. The polymorphism information content (PIC) value of the ISSR marker system was 0.848. The percentage of polymorphic loci (P_p) ranged from 41.2% to 44.7%. Nei’s gene diversity (H) ranged from 0.149 to 0.186, with an average overall value of 0.170. The mean of Shannon’s information index (I) value was 0.250. Total genetic diversity values (H_T) varied between 0.356 (ISSR-1) and 0.418 (ISSR-16), for an average overall polymorphic loci of 0.345. Interlocus variation in within-species genetic diversity (H_S) was low (0.170). On a per-locus basis, the proportion of total genetic variation due to differences among species (G_ST) was 0.601. This indicated that about 60.1% of the total variation was among species. Thus, about 39.9 of genetic variation was within species. The estimate of gene flow, based on G_ST, was very low among species of the genus Zoysia (N_m = 0.332). The phylogenic tree showed three distinct groups: Z. macrostachya and Z. tenuifolia clades and other species were formed the separated clusters. In conclusion, the ISSR assay was useful for detecting genetic variation in the genus Zoysia, and its discriminatory power was comparable to that of other genotyping tools.

• Journal of Life Science
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• v.17 no.7 s.87
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• pp.1019-1022
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• 2007

Thrombolytic therapy with tissue plasminogen activator (tPA) can improve the clinical outcome of ischemic stroke patients. However, its clinical application is limited by narrow therapeutic time windows and elevated risks of cerebral hemorrhage and brain injury. In part, these effects of tPA has been related to matrix metalloproteinase-9 (MMP-9) dysregulation. Here, we investigate that the effects of alteplase (tPA with short half-life) and pamiteplase (a modified tPA with long half-life) on the MMP-9 regulation in neurovascualr unit. The total levels of MMP-2 and MMP-9 in neuronal cells are lower than astrocytes. Alteplase (1-10 ${\mu}g/ml$) induced upregulation of MMP-2 and MMP-9 in rat cortical neurons and astrocytes, respectively. Whereas pamiteplase in a wide range of dose did not affect the MMP-2 and MMP-9 responses in both of cells. These results suggest that pamiteplase with long half-life can be provided as a agent that overcome the side effects of alteplase.

• Journal of Korean Society for Geospatial Information Science
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• v.22 no.2
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• pp.33-40
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• 2014

At present, Cadastral map of 2 dimensional is in the stream of changing it to 3 dimensional type supported by GPS and laser techniques. In addition, this steam can be explained at the same time with improvement of equipment of storing much information, support of equipment for imaginative 3D spatial information, and support of equipment of expressing land in 3D Cadastral. This study suggest to apply airborne lidar survey technique on cadastral map to acquire comparably and quickly detailed height of ground. For doing this, this study checked out credibility regarding accuracy of airborne lider survey. After choosing research area, this study has done the airborne lidar survey and acquire the result after surveying Cadastral Comparison Point to check out the accuracy of acquired results. In addition, this study check out the result of Cadastral Comparison Point and airborne lidar survey applied by paired sample t-test based on actual results. The result is that test statistics is 0.322 which is 5 % similar level and null hypothesis cannot be rejected, so this study found out that result of both survey ways are the same. Therefore, the result of airborne lidar survey can be utilized to build up 3D Cadastral information hereafter.

• Microbiology and Biotechnology Letters
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• v.35 no.3
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• pp.203-209
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• 2007

Soybean milk cake (SMC) was used for the solid-state fermentation by Bacillus subtilis PUL-A isolated from soybean milk cake. In the presence of 5% glutamate the maximum production of biopolymer (59.9 g/kg) was performed by fermentation at $42^{\circ}C$ for 24 hr. The recovered biopolymer was consisted of 87% $\gamma$-polyglutamic acid with molecular weight of $1.3{\times}10^6$ dalton and other biopolymer. The biopolymer solution showed the great decrease in consistency below pH 6.0, regardless of the molecular weight of PGA. Biopolymer solution has a typical pseudoplastic flow behavior and yield stress. The consistency of biopolymer solution was greatly decreased by increasing heating time and temperature in acidic condition compared to the alkaline condition. In kaolin clay suspension, the flocculating activity of biopolymer was the highest value with 15 mg/L biopolymer and 4.5 mM $CaCl_2$, but decreased greatly with $FeCl_3$. The flocculating activity of biopolymer was maximum at pH5, but decreased drastically by heating at $60{\sim}100^{\circ}C$. In particular, biopolymer with native PGA showed the efficient flocculating activity compared to that of modified biopolymer containing low molecular weight of PGA.