• Journal of Korean Society on Water Environment
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• v.33 no.1
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• pp.90-96
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• 2017

Many sewage treatment plants have applied the advanced technology of chemical coagulant system to remove phosporus in Korea. However there are some problems for the injection of optimum coagulant dosage. In order to solve these problems, the research related to the more cost-effective automatic total phosphorus coagulation control system using an EC(Electrical Conductivity) have been in progress. This study was conducted by the same process and operation method as the Lab-scale for public small town sewage treatment plant. First, it confirmed the correlation among the EC, PO4-P and coagulant dosage in the Lab-scale MSBR(Membrane Sequencing Batch Reactor) process. Next, it analyzed that correlation coefficient of EC and the coagulant dosage was 0.92 in the Full-scale MSBR process. As a result, not only T-P removal efficiency was doubled but also it satisfied the effluent water quality standard in a stable manner. In addition, by applying the automatic control system using the EC, compared to the fixed coagulant injection system the coagulant dosage could be reduced by 28%.

• Magazine of the Korean Society of Agricultural Engineers
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• v.31 no.1
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• pp.96-105
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• 1989

This laboratory study was performed to produce basic data for the estimation of water requirements for desalinization, through analyzing changes of the electrical conductivity and the exchangeable sodium percentage during the desalinization of reclaimed tidelands. Desalinization experiments were carried out by two water management practices, namely, the leaching method by subsurface drainage and the rinsing method by surface drainage, using samples of silt loam soil and silty clay loam soil collected in reclaimed tidelands. The results obtained from this study were summarized as follows : 1. The sample soils used in this study were saline-sodic soils with the high electrical conductivity and the high exchangeable sodium percentage. 2. Changes of the electrical conductivity and the exchangeable sodium percentage with water requirements for desalinization showed a similar tendency in the desalinization experiment by the same water management practice. 3. The regression equation between the relative electrical conductivity(EC/EC) and water requirements for desalinization(Dw/Ds) could be described by Dw/Ds=O. 29x(EC/EC.) -0.982 (Leaching method), Dw/Ds=3. 678X0. 030(EC/EC ) (Rinsing method). 4. The regression equation between the relative exchangeable sodium percentage (ESP/ESP ) and water requirements for desalinization (Dw/Ds) could be expressed in Dw/Ds = 0.039 x (ESP/ESP. ) - 1. 134 (Leaching method), Dw/Ds=7. 197X0. 024(ESP/ESP ) (Rinsing method). 5. It was estimated that water requirements for the adequate desalinization would be Dw/Ds=0.3 (Leaching method) and Dw/Ds=3.0 (Rinsing method)

• Korean Journal of Agricultural Science
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• v.42 no.2
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• pp.93-98
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• 2015

This study was conducted to evaluate the efficacy of herbicide in winter cereal crops, barley and wheat. The efficacy of soil-applied herbicides, linuron EC and pendimethalin, thiobencarb GR was greater than that of butachlor EC. Linuron EC controlled average 95% and pendimethalin, thiobencarb GR controlled average 97% within 150 days after soil-applied treatment. When compared with untreated control, no visual injuries were detected at single and double dosage of linuron EC and pendimethalin, thiobencarb GR. The yield of barley increased in linuron EC and wheat increased in pendimethalin, thiobencarb GR treatments when compared with butachlor EC. The efficacy of foliage treatment, bentazone+propanil ME was greater than that of bentazone SL. Bentazone+propanil ME controlled average 96% in barley and 97% in wheat, within 30 days after foliage treatment. When compared with untreated control, no visual injuries were detected at single and double dosage of bentazone+propanil ME. The yield of barley and wheat increased in bentazone+propanil ME treatments when compared with bentazone SL. Based on these data, combinations of these herbicides could be applied to provide effective weed management in barley and wheat field.

• The Korean Journal of Physiology and Pharmacology
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• v.19 no.1
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• pp.35-42
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• 2015

In cardiovascular disorders, understanding of endothelial cell (EC) function is essential to elucidate the disease mechanism. Although the mouse model has many advantages for in vivo and in vitro research, efficient procedures for the isolation and propagation of primary mouse EC have been problematic. We describe a high yield process for isolation and in vitro culture of primary EC from mouse arteries (aorta, braches of superior mesenteric artery, and cerebral arteries from the circle of Willis). Mouse arteries were carefully dissected without damage under a light microscope, and small pieces of the vessels were transferred on/in a Matrigel matrix enriched with endothelial growth supplement. Primary cells that proliferated in Matrigel were propagated in advanced DMEM with fetal calf serum or platelet-derived serum, EC growth supplement, and heparin. To improve the purity of the cell culture, we applied shearing stress and anti-fibroblast antibody. EC were characterized by a monolayer cobble stone appearance, positive staining with acetylated low density lipoprotein labeled with 1,1'-dioctadecyl-3,3,3',3'-tetramethyl-indocarbocyanine perchlorate, RT-PCR using primers for von-Willebrand factor, and determination of the protein level endothelial nitric oxide synthase. Our simple, efficient method would facilitate in vitro functional investigations of EC from mouse vessels.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2003.05a
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• pp.377-384
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• 2003

B2B EC에서 지능형 에이전트에 대한 요구의 증가와 함께 기업구매자가 직접 전자시장으로부터 구매하는 데스크탑 구매의 요구도 증가하고 있는 추세이다. 본 논문에서는 B2B 상에서 전자시장으로부터의 효율적인 구매를 지원하는 b-Cart 기반 에이전트 시스템의 설계 사례에 대해서 기술한다. b-Cart는 구매자가 소유하고 사용되는 구매자 사이트에 위치한 쇼핑카트로서, 본 논문에서는 B2B EC에서의 b-Cart 기반 에이전트 시스템의 요구 기능을 사용자식별(Identification), 사용자 다이알로그(User Dialog), 상품정보수집(Collection), 물품정보제거(Trashing), 개별 구매의사결정지원(Individual Purchase Decision Support), 조직 구매의사결정지원(Organizational Purchase Decision Support), 협상(Negotiation), 주문처리(Ordering), 지불처리(Payment), 진행사항 추적(Tracking), 구매기록(Recording), 전자구매시스템에 구매기록 전송(Record Transmission), 지식베이스에 새로운 지식 유지(Knowledge Maintenance)으로 정의하고, b-Cart 기반 에이전트 시스템의 메시지 인터페이스를 설계하고 시스템의 구조를 설계하여 프로토타입 시스템인 AgentB의 설계 사례를 소개한다. b-Cart 기반 에이전트시스템은 기업구매자의 전자시장으로부터 구매자 증가함에 따라 분산된 정보를 관리 해주고 통합적으로 구매처리를 해줄수 있는 효과적인 시스템이다. 향 후 B2B EC의 에이전트 시스템은 b-Cart를 기반으로 할 것으로 예측할 수 있다.

• Journal of Korean Medicine Rehabilitation
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• v.29 no.2
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• pp.189-194
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• 2019

Objectives The purpose of this study was to examine comparison of tension according to the type of sling cord during the bridging exercise with sling in stroke patients. Methods Twenty six stroke patients were recruited for this study. Subjects were randomly performed sling bridging exercise with three types of sling cords such as nonelastic cord with affected side-nonelastic cord with non affected side (NC-NC), nonelastic cord with affected side-elastic cord with non affected side (NC-EC), and elastic cord with affected side-nonelastic cord with non affected side (EC-NC). They were measured tension with a tensiometer of sling cord during the bridging exercise with sling. Results The tension of sling cord was significantly different in affected side, non affected side, and tension ratio of affected side/non affected side. There were significant differences tension in NC-EC from NC-NC and EC-NC and the NC-EC method was increased tension of affected side and decreased tension of non affected side. Conclusions These results showed that the NC-EC method was improved the symmetry of affected side and non affected side. Sling exercise with appropriate type of sling cord should be increased activities of affected side and improved recovery in stroke patients.

• Journal of Animal Science and Technology
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• v.63 no.2
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• pp.461-464
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• 2021

Escherichia coli normally colonizes the lower intestine of animals and humans, but some serotypes are foodborne pathogens. The Escherichia coli K_EC180 was isolated from swine feces that were collected from a weaner pig. In this genome announcement, E. coli K_EC180 was sequenced using PacBio RS II and Illumina NextSeq 500 platforms. The complete chromosome of E. coli K_EC180 is composed of one circular chromosome (5,017,281 bp) with 50.4% of guanine + cytosine (G + C) content, 4,935 of coding sequence (CDS), 88 of tRNA, and 22 of rRNA genes. The complete genome of E. coli K_EC180 contains the toxin genes such as shiga-like toxins (stxA and stxB).

• The Bulletin of The Korean Astronomical Society
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• v.44 no.2
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• pp.68.2-68.2
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• 2019

Most of the stellar mass accretes during the early evolutionary stage of protostars. However, the accretion process in protostars is in a veil of the thick envelope. Monitoring the submillimeter emission from the envelope is a way to trace the accretion process in protostars since the submillimeter emission linearly responses to the temperature of the envelope, which is heated by the accretion process at the center. In the JCMT transient Survey, we detected a submillimeter variable, EC 53. EC 53 is a Class 1 protostar that was known to have a periodic variation at NIR. EC 53 has been monitored with United Kingdom InfraRed Telescope (UKIRT), Liverpool telescope, and JCMT/SCUBA-2 since we detected the 850 ㎛ flux enhancement in the JCMT transient survey. We also adopt the photometric data sets of Wide-field Infrared Survey Explorer (WISE). Over all wavelengths from NIR to submillimeter, we see two modes of variation, a 1.5-years periodic variation and a long-term increase. We present the light curves of EC 53 at multi-wavelengths and discuss the cause of variability in EC 53.

• Journal of Bio-Environment Control
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• v.27 no.2
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• pp.185-190
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• 2018

This study was conducted to investigate the optimum electrical conductivity (EC) levels of nutrient solution for growth of mother plants and increasing occurrence of daughter plants of strawberry ($Fragaria{\times}ananassa$ Duch. cv. Maehyang) using hydroponics. The mother plants of strawberry were transplanted in cultivation pot ($61{\times}27{\times}18cm$) filled with coir medium on March 22, 2017. Nutrient solution was supplied by the drip tape at $0.6dS{\cdot}m^{-1}$ of EC levels for rooting during 11 days. After rooting, the mother plants of strawberry was treated at the EC levels of 0.6, 1.2 or $1.8dS{\cdot}m^{-1}$, respectively. Growth characteristics, such as mother plants and daughter plants of strawberry were measured at 100 days after transplanting. The plant height of mother plant was significantly higher at $0.6dS{\cdot}m^{-1}$ treatment, and the crown diameter of mother plant was significantly greater at $1.8dS{\cdot}m^{-1}$ treatment. The fresh and dry weights of shoot were higher at both 0.6 and, $1.2dS{\cdot}m^{-1}$ treatments. The number of runners was not significantly different in all treatments. The fresh and dry weights of runner were heavier at $0.6dS{\cdot}m^{-1}$ than other treatments. The number of daughter plants was the highest, 16.7 at the $1.2dS{\cdot}m^{-1}$ treatment. However, the fresh and dry weights of third daughter plant were the heaviest at $0.6dS{\cdot}m^{-1}$ treatment. Although the daughter plants were a large of production at $1.2dS{\cdot}m^{-1}$ treatment, the low EC levels of strawberry were positive in terms of seedling quality during nursery. These results indicated that growth of mother plant and occurrence of daughter plants were greater at the EC $0.6dS{\cdot}m^{-1}$ nutrient solution for hydroponic cultivation of 'Maehyang' strawberry during nursery period.

• Korean Journal of Soil Science and Fertilizer
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• v.37 no.2
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• pp.83-90
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• 2004

A pot experiment was conducted to find out the effects of nitrogen content of irrigation water and soil EC on lettuce growth under plastic film house conditions. The square-pots with 42 x 54.5 x 22 cm in length, width and height, were filled with two different soils of different EC. Lettuce was grown with different nitrogen fertilizer application levels including non fertilization (Non-F), decrement of 50% of nitrogen fertilizer recommended by soil testing (DNFRST-50) and fertilization recommended by soil testing (FRST). Two kinds of irrigation water of different nitrogen contents, $6.6mg\;L^{-1}$ and $21.0mg\;L^{-1}$, were used for the experiment. In the low EC soil irrigated with low nitrogen water, fresh weights of lettuce were 6,733, 11,933 and $12,733kg\;ha^{-1}$ for the treatments of Non-F, DNFRST-50 and FRST, respectively. While with high nitrogen water, the yields were 9,733, 13,400 and $12,800kg\;ha^{-1}$, respectively. In the high EC soil irrigated with low nitrogen water, lettuce yields of the Non-F, DNFRST-50 and FRST treatments were 12,400, 12,867 and $10,400kg\;ha^{-1}$, respectively, and with high nitrogen irrigated water lettuce yields of the Non-F, DNFRST-50 and FRST treatments were 13,600, 14,067 and $10,733kg\;ha^{-1}$, respectively. Nitrogen uptake of lettuce from ferilizer in DNFRST-50 was higher than of FRST. Nitrogen uptake of lettuce from irrgation water was found in soils of low EC, but it was not found in soils of high EC. These results suggest that both soil EC and nitrogen content of irrigation water should be considered when we recommend the level of fertilizer application for lettuce.