• Korean Journal of Soil Science and Fertilizer
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• v.26 no.4
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• pp.236-240
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• 1993

This study was conducted to investigate the chemical properties of soils under plastic house cultivation in northern Gyeonggi province(Yangju gun and Paju gun) in 1992. The results are summarized as follows: 1. Distributions of soil texture were in the order of sand loam(65%), silt loam(25%) and loam(5%). 2. Content of soil nutrient varied with difference with soil management practices and years of cultivation and chemical properties of soils. 3. Soil pH, Ca/Mg ratio and Mg/K ratio tended to be low, while other parameters high. 4. The average application rates of poultry dropping, cow dung and piggery waste were 6.0, 4.5, and 2.0ton/10a, respectively.

• Korean Journal of Organic Agriculture
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• v.11 no.3
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• pp.55-64
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• 2003

It was investigated the possibility to use charcoal powder as beneficial soil conditioner, which used frequently in environmentally friendly agricultural farming system. For this purpose, the effects of charcoal powder on the growth of red pepper and chemical and microbiological properties of soil were also determined. The application of charcoal powder resulted in no significant differences of pH and EC in the soil compared to those of control. However, small particle size of charcoal powder increased yield of red pepper while large charcoal powder resulted in decrease of root growth of red pepper. Furthermore, the application of charcoal powder resulted in changes of soil microflora relating to plant growth stage. The number of the nitrogen fixing bacteria and fungi increased at the early growth stage, while phosphate releasing fungi in the soil increased at the late stage of growth by charcoal powder application. These beneficial effect of charcoal powder on the soil microbial properties was larger by the use of smaller particle size of charcoal powder. Therefore, it indicated that the small size of charcoal powder might be more influential on the red pepper yield and soil microbial properties may be due to large capacity of nutrients uptake for the plant and microorganisms. Additionally the optimal application amount of charcoal powder for the red pepper could be suggested as much as 300kg 10a$^{-1}$ for the both purposes of improvement of crop yield and retardation of the nutrients accumulation by excess charcoal application.

• Korean Journal of Environmental Agriculture
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• v.27 no.3
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• pp.267-273
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• 2008

Energy efficiency and nutrient balance are good methods for environmental assessment of the environmentally-friendly agriculture. The objectives of this study were 1) to estimate the energy efficiency and nutrient balance of the organic rice farming, and 2) to suggest a solution to improvement the energy efficiency and nutrient balance. The set of estimation was performed at the organic rice farming area (8.9 ha) in Wanju-gun during the paddy cultivation period from 2006 to 2007. The organic farming complex consists of four weeding methods using 1) duck, 2) apple snail, 3) duck and apple snail and 4) hands and machinery. Results from this estimation should that the organic rice farming area was less efficient than conventional rice farming. The efficiency of organic farming area in 2006 was higher than in 2007. For the calculation of the nutrient balance, the N, P and K contents of input materials (cattle manure, milk vetch, mixed oilcake, rice bran, rice straw and barley straw) and output (farm products) were analysed. Annual environmental loads of N, $P_2O_5$ and $K_2O$ were estimated at 4.4 kg/10a, 13.8 kg/10a and 14.5 kg/10a, respectively. Cattle manure had the largest portion among the inputs items and nutrient concentration of cattle manure was high. Thus energy efficiency and nutrient balance depend on cattle manure input. Therefore it is necessary to control the manure input to improve the efficiency of organic rice farming.

• Korean Journal of Soil Science and Fertilizer
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• v.29 no.4
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• pp.419-423
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• 1996

Municipal sewage sludge produced at the Daegu Dalseo River Municipal Sewage Treatment Station was applied to radish(cv. Altari) to develop as an organic fertilizer. The sludge contained 53.59% of organic matter, 2.89% of nitrogen, and 3.5% of phosphate, so it seems to be enough to use as an organic fertilizer. Although the Cd and Pb contents of the sludge were lower than the official standard levels for the by-product fertilizer, it seems to be needed more researches due to the accumulation of the heavy metals both in soil and plants. Application of the sludge increased soil pH, organic matter, total nitrogen, available phosphate, exchangeable Ca and Mg contents, and CEC. Also application of the sludge tended to increase Cd and Pb contents slightly in soil. Application of the sludge increased N, $P_2O_5$, Cd, and Pb contents in plant and among the heavy metals Cd accumulated more than Pb. Yield of radish increased up to 1.000kg/10a of sludge in addition to the standard chemical fertilization or 3,000kg/10a of the sludge only.

• Korean Journal of Organic Agriculture
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• v.5 no.2
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• pp.71-84
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• 1997

유기농산물은 질 좋은 농산물이며 그 생산농법이 환경친화적인 것으로 이해하고 있어 참여농가수도 증가일로에 있고 소비자들에 의한 유기농산물 구입 역시 점차 증가 추세에 있으나, 한국유기농업은 국제적 유기농업에 다르게 잘못 정의된 채 확산되고 있어, 그 핵심기술의 환경영향평가의 과학화에 대한 시대적 요청과 유기농업 기본규약 제정 필요성이 학계 일부에서 제기 되고 있는 등 한국유기농업은 최근 발전을 위한 진통을 겪고 있다. 이에 본 논문은 한국유기농업이 태동된 배경과 70년대 말로부터 80년대 초에 걸쳐 태생된 한국유기농업이 국민적 관심을 얻게된 배경과 정농회, 한국유기농업협회, 한국자연농업협회, 한 살림 등의 유기농업단체와 한국유기농업학회, 환경보전형농업생산소비단체협의회, 흙살림연구소 등의 발전과정 및 활동을 소개하고 있다. 또한 서울에서 개최된 IFOAM Asia대회, 한국자연농업협회의“자연농업연구소”, 한국유기농업협회의“건강과 자연농업”등에 관해서 뿐만 아니라 우리 정부의 21세기를 향한 농림환경정책중 유기농업부문에 대한 각종 장기지원책, 즉 중소농대책의 일환의 유기-자연농업 지원책, 유기농산물에 대한 품질인증제 및 팔당상수원보호구역내 유기농업지원 등이 소개되고 있다. 한편 한국유기농업기술의 핵심내용이었던 유기질비료 과다시용 문제가“유기농산물 채소의 고 질산염 함량”으로 촉발된 식품안정성 논쟁 후에 유기질비료의 추천시용량이 다다익선적 개념에서 80t/㏊으로 낮아졌다가 다시 50t/㏊으로 낮아졌으며 1996년 6월부터는 20t/㏊로 크게 낮추어 졌음을 보고하고 있다. 또한 일부 선도적 유기독농가의 경험적 기술이 토대가 되어 성립된 현 유기농업기술은 과학적 기술검증을 거쳐야 함과 퇴비사용 만으로 실시하는 현 유기농업 기술에 의해 야기되는 근권내 질산 미치 인산염 집적을 회피하기 위해서는 윤작, 녹비작물 및 두과작물의 재배로 토양비옥도 향상을 통한 유기농업 기술 개발이 필요하며 IFOAM 기본규약과 FAO/WHO Codex의 핵심 내용을 수용하는 한국유기농업 기본규약 제정이 제정이 절실히 요구됨을 강조하고 있다. 마지막으로 한국유기농업의 핵심기술에 대한 환경영향평가와 기본규약제정 필요성을 역설하고 한국유기농업의 과학화와 질 좋은 유기농산물 생산을 위해 노력하고 있는 소비자 문제를 연구하는 시민의 모임 등 몇몇 단체들의 최근 활동이 언급되고 유기농업에 대한 농과대학내 연구와 강의 등이 소개되었다.

• Korean Journal of Soil Science and Fertilizer
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• v.36 no.6
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• pp.407-416
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• 2003

Although the requirement and optimum soil level of Si for oriental melon are still not well understood, silicate fertilizer is commonly applied to the oriental melon in plastic film houses where soil silicate level is relatively high. In this research the effects of silicate fertilizer on growth, fruit yield and fruit quality of oriental melon, and soil properties were investigated in plastic film house where the soil available silicate was $212mg\;SiO_2\;kg^{-1}$. Silicate fertilizer was applied in the rates of 100, 200, and $300kg\;10a^{-1}$. The application of silicate fertilizer could not increase the early growth of oriental melon, and also the fruit yield and quality were not different among the treatments. Available Si and P contents in soils and also Si and P contents in leaf of oriental melon of the different treatments were not significantly different. In the relationship between total Si in oriental melon leaf and soil silicate extracted by 1 N sodium acetate, optimum soil available silicate level for oriental melon was found to be around $100mg\;SiO_2\;kg^{-1}$. These results indicate that the additional silicate fertilization in soils of available silicate higher than $100mg\;SiO_2\;kg^{-1}$ is unnecessary, and such application of silicate can not have any beneficial effect on the growth and fruit yield of oriental melon.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.12 no.2
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• pp.52-62
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• 2013

Design Hourly Factor(DHF) is defined as the ratio of design hourly volume(DHV) to Average Annual Daily Traffic(AADT). Generally DHV used the 30th rank hourly volume. But this case DHV is affected by holiday volumes so the road is at risk for overdesigning. Computing K factor is available for counting 8,760 hour traffic volume, but it is impossible except permanent traffic counts. This study applied three method to make DHF, using 30th rank hourly volume to make DHF(method 1), using peak hour volume to make DHF(method 2). Another way to make DHF, rank hourly volumes ordered descending connect a curve smoothly to find the point which changes drastic(method 3). That point is design hour, thus design hourly factor is able to be computed. In addition road classified 3 type for national highway using factor analysis and cluster analysis, so we can analyze the characteristic of DHF by road type. DHF which was used method 1 is the largest at any other method. There is no difference in DHF by road type at method 2. This result shows for this reason because peak hour is hard to describe the characteristic of hourly volume change. DHF which was used method 3 is similar to HCM except recreation road but 118th rank hourly volume is appropriate.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.3
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• pp.1650-1662
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• 2014

This study aimed to develop smartphone application contents for the medication reconciliation of high-alert medications and to evaluate the satisfaction for this application. The xcode 4.5 and ios 6.1 SDK(software development kit) were used for constructing screen of the system. After implementation during 4 weeks, thirty five ICU(Intensive Care Unit) nurses were asked function related, contents related, and usage related satisfaction using 12 items. And differences of satisfaction according to the number of daily use and the frequency of use were evaluated. Data were analyzed using descriptive analysis, ANOVA with the SPSS 18.0. We developed the formula for drug dosage calculation, the alarming procedure, and the information of the high alert medication. In the satisfaction items, the mean score of 'This application is helpful to perform drug dosage calculation' was 3.14. However, 'I satisfy this application' was relatively low as 2.94. There were no differences in satisfaction according to the daily use and frequency of use. Based on the results of this study, more advanced smartphone application for medication reconciliation of high-alert medications will provide an important platform for patient safety.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.9
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• pp.261-268
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• 2018

The use of electric cable was limited due to the installation time and large space as the increase of power demand and load quantity in side line. In order to solve these problems, the application of busway system which can supply the large current was increasing. But it was lack of methods of performance tests to evaluate the reliability and results of test for busway system. In this paper, we presented items to evaluate the reliability test for epoxy coated busway system with reference to IEC 61349-6. In addition, we proposed items to evaluate the reliability and long term life cycle test for the epoxy coated busway system. The combined acceleration deterioration test that reflects actual conditions of the survey as much as possible was conducted considering both thermal and electrical stresses. The deterioration condition was selected to satisfy fifty years life expectation and the insulation performance verification test of the busway system confirmed the long term life prediction. Furthermore, as test items for reliability assessment of compliance with the environment for the use of temperature, humidity and load current where busway system was installed, thermal overload test, water immersion test, cold shock temperature test and thermal cycle test were performed. And we examined changes in characteristics and abnormality after tests. From results, the test items presented to evaluate performance and reliability of the epoxy insulated busway system were confirmed to be appropriate in this paper, and the performance of the product was also confirmed to be excellent for reliability tests.

• Tunnel and Underground Space
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• v.11 no.3
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• pp.279-288
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• 2001

Jointed rock mass can be analyzed by either continuum model or discontinuum model. Finite element method or finite difference method is mainly used for continuum modelling. Although discontinuum model is very attractive in analyzing the behavior of each block in jointed blocky rock masses, it has shortcomings such that it is difficult to investigate each joint exactly with the present technology and the amount of calculation in computer becomes trio excessive. Moreover, in case of the jointed blocky rock mass which has more than 2 dominant joint sets, it is impossible to model the behavior of each block. Therefore, a model such as ubiquitous joint model theory which assumes the rock mass as a continuum, is required. In the case of tunnels, unlike slopes, it is not easy to obtain safety factor by utilizing analysis method based on limit equilibrium method because it is difficult to assume the shape of failure surface in advance. For this reason, numerical analyses for tunnels have been limited to analyzing stability rather than in calculating the safety factor. In this study, the behavior of a tunnel excavated in jointed rock mass is analyzed numerically by using ubiquitous joint model which can incorporate 2 joint sets and a method to calculate safety factor of the tunnel numerically is presented. To this end, stress reduction technique is adopted.