• 품질경영학회지
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• 제46권3호
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• pp.641-650
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• 2018

Purpose: This article provides a cause of breakage and a method for improving reliability of the headlight system installed in the main battle tank K2. Method: The natural frequency of the headlight system is estimated by using the finite element method. In addition, the allowable stress level under the severe conditions is provided through vibration test of a single item and a system level. Results: Based on the finite element analysis and the vibration test in the frequency domain, the lamp of the left headlight system fails by the resonance effect. Conclusion: For improving the reliability of the headlight system, the thickness of protector frame is increased to avoid the resonance effect.

• 한국초지조사료학회지
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• 제14권3호
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• pp.230-237
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• 1994

본 시험은 경사 척박지에서 초지조성시 양축 농가에서 부수적으로 생산되는 액상구비를 시용하여 목초의 정착과 조기생육을 원활하게 하고 동시에 부숙된 액상구비를 초지에 환원하여 초지상태의 비옥도를 증진시키고자 수원과 여주지방에서 3년간 수행하였다. 1. 목초의 정착율은 오차드그라스 단파구와 혼파구 공히 무처리구보다 처리구가 좋았다(무처리구에 비해 진압, 액비, 시용구, 지오라이트구에서 5% 유의성) 2. 조기생육에서 초장은 무처리보다 처리구가 0.5cm~2.1cm 길었다. 3. 월동율은 액비시용구, 진압구, 진압 + 액비구순으로 많았으며액비처리구의 평균작도 3~4%많았다. 4. 수량은 진압 + 액비구, 지오라이트구에서 무처리에 비하여 10~15% 증진되었다. 5. 토양 pH의 교정효과가 컸으며, 유기물 함량이 현저히 증가하였다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.369-369
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• 2017

To improve the reclaimed land soil, we put organic materials (Chopped kenaf, decomposed rice hull, rice straw, pellet type manure compost) into reclaimed land for 3,000 kg per 10a. As a result, EC of reclaimed soil was lowered by 58% ($1.2dS/m{\rightarrow}0.5$), content of soil organic material was risen from 6.7 g/kg to 16.0 (1.4 fold ${\uparrow}$), porosity of soil was elevated from 1.57 % to 1.31 (16.6% ${\downarrow}$), soil hardness was reduced from 20.2 mm to 17.9 (11.4% ${\downarrow}$) and plow layer soil was deepen from 19.8 cm to 26.8 (35% ${\uparrow}$). In the wake of physiochemical improvement of reclaimed soil, the growth phase of crops became better contrast to non-treatment. For example the plant height of Kenaf (Hibiscus cannabinus L.) cultivated in reclaimed land containing organic materials was lengthen by 18.8%. Especially, the improvment effect of pellet type manure compost and rice straw was more preferable. When the kenaf was cultivated in reclaimed land containing organic materials, the yield was become higher. The average yield of organic materials treatment was 9,218 kg/10a, and it was 2.1 times higher than non-treatment (4,368kg/10a). And the effective treatments to increase yields were pellet type manure compost (10,848 kg/10a, 148% ${\uparrow}$), rice straw (120% ${\uparrow}$) and chopped kenaf (95% ${\uparrow}$). To intensify the effect of physicochemical enhancement of reclaimed land soil and improving yields, we put into various physical types of organic materials (pellet type, liquid type, powdered type). The most effective organic materials type for enhancement of physicochemical properties (EC of reclaimed soil was lowered, content of soil organic material was risen, porosity of soil was elevated, soil hardness was reduced, plow layer soil was deepen) was pellet. And source to maintain better growth phase and get more yield were liquid and pellet types. When we used pellet type organic material, the plant height of kenaf was lengthen by 41% in comparison with non-treatment and yield was more than 122% more. And also liquid type could get more yield (by 127%) and growth phase (by 38%)

• 한국산학기술학회논문지
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• 제21권6호
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• pp.266-274
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• 2020

본 연구는 소형전술차량에 적용된 탑재형 발전기에 의해 발생되는 이상 소음 개선방안에 대한 것이다. 소형전술차량은 탑재형 발전기의 장착 유·무로 구분되며, 개발 시험 시 이에 따른 소음 크기의 차이는 없었다. 하지만, 차량을 운용하면서 사용자가 느끼기에 불쾌한 소음(이상 소음)이 발생된다는 지속적인 문제제기에 따라 품질개선을 수행하게 되었다. 품질개선을 수행하기에 앞서 탑재형 발전기 단품 및 장착 구조와 문제가 제기된 차량에 대한 현상 확인 및 원인 분석을 수행하였다. 이를 통해 탑재형 발전기 장착에 따라 발생하는 이상 소음은 래틀소음에 의한 것임을 확인하였다. 엔진 구동계에서 래틀소음이 발생되는 일반적인 원인은 엔진 폭발 행정시 발생되는 불규칙한 회전력의 전달과 엔진 연결기와 회전자 조립체 간 스플라인-세레이션 연결 구조에서 발생되는 기어 백래쉬에 의한 것이었다. 따라서, 본 연구에서는 원인으로 분석된 이상 소음의 원인을 해소하기 위해 댐퍼형 연결기를 적용하는 개선방안을 수립하였다. 개선 방안에 대해서는 엔진의 불규칙한 회전력의 영향성, 소음의 정도, 동특성 해석 및 단품 내구시험 등을 통해 개선효과를 확인하였다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2006년도 춘계 학술발표회 논문집
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• pp.838-845
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• 2006

Recently construction work in Korea, demands of favorable condition ground had been increased with industrialization acceleration and economic growth. However, because of limited land space, it was so hard to ensure favorable condition grounds that construction work proceeds until soft ground area on plans of road, railroad and industrial complex. In this case, soft ground improvement was required such as a stone column method. Stone column method, making a compaction pile using crushed stone, is a soft ground improvement method. However, stone column method is difficult to apply to the ground which is not mobilized enough lateral confine pressure because no bulging failure resistance. Hence, in present study, evaluates the stone columns reinforced by geogrid for settlement reduction and wide range of application of stone columns. Triaxial compression tests were conducted for evaluation which is about behavior characteristics of stone column on replacement rate. Then, 3-dimensional numerical analysis were conducted for application of stone column reinforced by geogrid as evaluate behavior characteristics and settlement reduction effect of stone column reinforced by geogrid on reinforcing depth change of geogrid.

• Geomechanics and Engineering
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• 제24권2호
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• pp.129-141
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• 2021

The vacuum preloading method has been used in many countries for soil improvement and land reclamation. However, the treatment time is long and the improvement effect is poor for the straight-line vacuum preloading method. To alleviate such problems, a novel combined air booster and straight-line vacuum preloading method for shallow ground treatment is proposed in this study. Two types of traditional vacuum preloading and combined air booster and straight-line vacuum preloading tests were conducted and monitored in the field. In both tests, the depth of prefabricated vertical drains (PVDs) is 4.5m, the distance between PVDs is 0.8m, and the vacuum preloading time is 60 days. The prominent difference between the two methods is when the preloading time is 45 days, the injection pressure of 250 kPa is adopted for combined air booster and straight-line vacuum preloading test to inject air into the ground. Based on the monitoring data, this paper systematically studied the mechanical parameters, hydraulic conductivity, pore water pressure, settlement and subsoil bearing capacity, as determined by the vane shear strength, to demonstrate that the air-pressurizing system can improve the consolidation. The consolidation time decreased by 15 days, the pore water pressure decreased to 60.49%, and the settlement and vane shear strengths increased by 45.31% and 6.29%, respectively, at the surface. These results demonstrate the validity of the combined air booster and straight-line vacuum preloading method. Compared with the traditional vacuum preloading, the combined air booster and straight-line vacuum preloading method has better reinforcement effect. In addition, an estimation method for evaluating the average degree of consolidation and an empirical formula for evaluating the subsoil bearing capacity are proposed to assist in engineering decision making.

• 농촌계획
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• 제15권2호
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• pp.1-8
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• 2009

The purpose of this study is to find a way to improve damaged forest in rural area in terms of both landscape . quality and regulation. Mountain and forest cover 65% of total land in Korea, and the shortage of areas for developing housing, road and facilities made us to use forest area for above purposes. This led various types of damages on the sensitive rural landscape visually and ecologically. There are rules and regulations for decreasing damaging effect by constructions on forest area, but it was not so effective because theses rules focused on quantitative issues only. This study will consist of three phases, 1. analyse landscape damage types by development tendencies in forest area 2. find diminution plan on each damage types 3. set improvement on rules and regulations both qualitatively and quantitatively. This study will meet the goal of improving and managing rural and forest landscape by providing objective standards, rational procedure and amelioration plan.

• 토지주택연구
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• 제4권1호
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• pp.107-117
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• 2013

본 연구의 목적은 현행 임대주택 ABS방식을 평가하고 한계를 개선하는 방향으로 ABS 구조의 재설계를 위한 개선방안을 제시하는 것이다. 따라서 기존 공공임대주택 ABS사례에 대한 평가를 크게 세 가지로 요약하면 다음과 같다. 부외금융효과 측면에서 볼 때, 감독당국의 현행 회계처리지침상 분양전환대금 등 장래채권의 유동화에서는 부외금융효과를 누리고 있지 못하다. 더욱이 국제회계기준(IFRS)이 도입되면서 LH가 SPC를 '사실상 지배'하는 구조를 벗어나지 않는 한 장래채권을 기초자산으로 하는 임대주택 ABS는 더 이상 부외금융효과를 기대하기 힘들다. 금융비용 측면에서 볼 때, 유동화 대상자산을 부외처리하지 않아 ABS가 LH의 신용도와 연결되어 있으면서도 LH 일반채권보다 ABS에 금리가 가산되는 것은 매우 비합리적인 현상이다. 한편 유동성 개선효과 측면에서 볼 때, 자산보유자인 LH가 심각한 유동성위기에 처한 상황에서 ABS가 자금조달 다각화 수단으로 역할을 한 것은 인정된다. 이상의 평가결과를 바탕으로 임대주택 자산유동화 개선방안은 크게 두 가지로 요약할 수 있다. 첫째, 부외금융효과를 제고하는 것이다. 이를 위하여 현재채권인 임대료 ABS의 회계처리방식을 변경하여 임대료에 해당하는 양도가액 만큼을 임대주택 자산가액에서 차감하는 방식을 제안한다. 둘째, 구조화 비용 및 금리를 절감하는 것이다. 이를 위하여 임대주택 ABS의 포괄 유동화 구조가 가능하도록 자산유동화법 개정을 통해 단일 SPC에 의한 복수의 유동화계획 수행이 가능하도록 하는 방안, LH법 개정을 통하여 자기신탁구조를 허용하는 방안, 임대주택 유동화에 대해서도 법제화 CB의 근거를 마련하는 방안을 제안한다.

• 토지주택연구
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• 제7권4호
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• pp.291-297
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• 2016

최근 국외 건설사들은 BIM 설계를 통하여 건설 생산성 및 품질향상의 효과를 얻고 있다. 반면에 국내의 BIM 설계는 추가 비용 및 전문 인력부족 등의 문제로 침체되어 있는 실정이다. 건설경기의 불황 등의 이유로 건설시장 규모가 축소되어 있는 시기인 만큼 일차적으로 공공기관을 중심으로 BIM 설계를 활성화하여 설계 초기 단계뿐만 아니라 시공분야까지 BIM을 적극적으로 도입하고 그에 따른 성과의 확산 및 국내 BIM 기술발전을 도모할 수 있어야 한다. 본 연구에서는 BIM 설계 활성화를 위해서 일차적으로 공공기관의 BIM 설계를 활성화시킬 수 있는 방안을 제시하였다. 이를 위하여 한국토지주택공사(LH) 사례를 통하여 BIM 설계 추진상의 문제점들을 분석하였고, 그에 따른 개선방향 및 구체적인 설계 적용 방안을 제안하였다. 또한, 제시된 방안을 단계적으로 수행하기 위해 "LH BIM 설계 적용 로드맵"을 수립하였으며, 그에 따른 기대효과를 제시하였다. 제안된 연구 내용은 한국토지주택공사에서 시범사업으로 적용될 예정이다.

• The Journal of Korean Physical Therapy
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• 제23권3호
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• pp.29-35
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• 2011

Purpose: The purpose of study was to measure stroke patients' ability to balance and their degrees of clinical function and to examine the effect of the aquatic exercise method using tasks related to these features. Methods: Twenty stroke patients were randomly assigned to an aquatic task exercise group and a land task exercise group. Both groups used the same exercise method for 60 minutes each session, three times a week for 12 weeks at the same time point and with the same amount of exercise. Results: Before and after the exercise, static balance was measured using balance measuring instruments locomotive faculties, muscular strength, and dynamic balance were assessed through the Berg balance and 10 m gait tests. Finally, gait abilities were measured, and the data obtained were analyzed to generate the results. Conclusion: Both groups showed significant improvement, but the aquatic exercise group showed slightly more significant results in static balance, Berg balance, and upright walking tests. It is thought that the improvement of stroke patients' balance and gait ability can be triggered through the application of aquatic exercise programs in the future.