• 대한기계학회논문집
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• 제10권3호
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• pp.419-426
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• 1986

본 연구에서는 가공삭도의 선로설계에 최적화기법을 도입하여 시행착오법보다 신속.정확하면서도 경제성이나 승차감등이 항상된 설계를 위한 절차를 개발하고자 한 다. 이를 위하여 먼저 본 논문에서는 설계에 적용될 선로의 기본이론들을 정리, 혹 은 유도 하였다. 특히 기존의 포물곡선이론의 정확성을 규명하기 위하여 엄밀해인 현수곡선이론을 여러경우에 대하여 유도하고 그 오차를 계산하였다. 계산된 오차는 오차해석을 통하여 추측 될 수 있었으며 본 연구에서는 정의된 무차원군들과의 연관 성도 검토되었다.

• 대한기계학회논문집
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• 제11권1호
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• pp.26-35
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• 1987

본 연구에서는 (1) 삭도설계에 더욱 정확한 값을 얻기 위하여 엄밀해를 가진 현수곡선이론을 바탕으로 하여 설계변수들과의 관계를 유도 및 체계화 시켰다. (2) 다목적 함수를 벡터최소화함에 따라, 얻어지는 Pareto 최적해를 구할 수 있었다. Pareto 최적해를 구하는 방법에는 중첨법, 제한법, 추정법이 있다. 여기서는 삭도의 최적화에 대한 특성과 평가값은 서로 복잡한 trad off관계를 가지고 있으므로 다목적 인 두개의 목적함수에 중첩시켜 단일목적 함수로 변환하는 가운데 Kunn-Tuck최적생의 필요조건을 적용하면 목적함수의 값 범위를 해석적으로 정하고 Pareto최적해 집합을 해석적으로 구한다. (3) 이들의 해석에 관한 수치예를 들어 설계에 기준이 되는 로 우프의 규격과 초기장력을 결정하였다.

• 헤리티지:역사와 과학
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• 제35권
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• pp.82-99
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• 2002

This is to study about the saddle rope from Cheonmachong Tomb in Gyeongju. Saddle rope was made by leather on 5-6th century in Korea, there was excavated in 1973 but reported yet. At that time the analysis was tried about burials, but this remains was omitted. In recent times this remains is confirmed newly. This is important thing to restruction of harness. The working methods of saddle rope is not simple, but complicated-double up, sewing and double fasten with precessed leather. The saddle rope is restructed with no-decorated and simple leather line to recent times. Now, restruction of ancient saddle rope must be used by this way.

• 환경영향평가
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• 제11권3호
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• pp.129-143
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• 2002

This study was executed environmental assessment to determine whether or not the national landuse planning change on the reserved area for a rope way in the ice valley(Eoreurngol) of Miryang. The selected survery area is $1,633,442m^2$ and assessed with flora, actual vegetation, degree of green naturality(DGN), sere stage and wild birds. The flora was summarized as 132 taxa which is 90 genera, 117 species, 12 varieties and 3 forms. The actual vegetation was classified 24 types and nature forests like Quercus and deciduous-broad leaf community was distrubuted broadly. Especially Quercus and deciduous-broadleaf communities were assessed high rarity value in Miryang. From the analysis of DGN, it were found out that DGN 8 is 72.5% and DGN 9 is 3.9%. At the analysis of sere stage, the communities were divided 4 with Quercus mongolica, Pinus densiflora, Carpinus laxiflora and deciduous-broadleaf community. Wildbirds was observated as 30 species and 161 ea and Aix galericulata (natural monument no. 327) especially inhabited there. From the above nature ecosystem assessment, the survey area has high quality naturalness, so it was turned out that a rope way construction might be not suitable in survery area.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 A
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• pp.679-681
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• 2005

The materials for transmission line construction were transported by road which opened in mountainous areas until the mid 1990s, However, from the mid 1990s, as social interest in the environment standard increases, a cable way and helicopter transport methods of construction have been applied to minimize damage to the environment and to build an environmental friendly system. The current cable way method is a single cable way system which has a lower section base to load materials into a carriage and carry them to the tower construction site by use of an engine and a main rope. Then the carriage lowers itself via a slope between the tower construction site and the lower section base. The single cable way system has the demerits of site acquisition for the lower section base, forest felling when installing the wire rope, and it is not applicable to a even topology Also it has to be installed separately at each tower site. Accordingly, to carry materials without forest felling and regardless of slope, the chain cable way system was developed to provide materials for more than two towers consecutively by use of an engine carriage and winch.

• 한국보건간호학회지
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• 제25권1호
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• pp.38-47
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• 2011

Purpose: The study investigated the effects of 9 weeks of group music rope-jumping training on health-related physical fitness and blood lipid in obese elementary school boys and girls. Method: Subjects were randomly assigned to either a training group (37 boys and 18 girls) or control group (36 boys and 19 girls). The training group exercised for 1 hour, 2 days per week during the 9-week supervised music rope-jumping training program. The control group was asked to maintain their normal daily physical activities. The effects of the interventions on physical fitness and blood lipids were analyzed by two-way repeated measures ANOVA (group ${\times}$ time). Results: There were significant group ${\times}$ time interaction effects on body weight (p<.023), %body fat (p=.09), body mass index (p=.018), and body fat mass (p=.019) in school girls. However, there was not an interaction effect on serum lipids in both genders. Conclusion: The 9-week music rope-jumping training program used was effective for improving body composition in obese elementary school girls.

• International Journal of Fluid Machinery and Systems
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• 제9권2호
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• pp.182-193
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• 2016

Introduction of intermittent electricity production systems like wind and solar power to electricity market together with the deregulation of electricity markets resulted in numerous start/stops, load variations and off-design operation of water turbines. Hydraulic turbines suffer from the varying loads exerted on their stationary and rotating parts during load variations since they are not designed for such operating conditions. Investigations on part load operation of single regulated turbines, i.e., Francis and propeller, proved the formation of a rotating vortex rope (RVR) in the draft tube. The RVR induces pressure pulsations in the axial and rotating directions called plunging and rotating modes, respectively. This results in oscillating forces with two different frequencies on the runner blades, bearings and other rotating parts of the turbine. This study investigates the effect of transient operations on the pressure fluctuations exerted on the runner and mechanism of the RVR formation/mitigation. Draft tube and runner blades of the Porjus U9 model, a Kaplan turbine, were equipped with pressure sensors for this purpose. The model was run in off-cam mode during different load variations. The results showed that the transients between the best efficiency point and the high load occurs in a smooth way. However, during transitions to the part load a RVR forms in the draft tube which induces high level of fluctuations with two frequencies on the runner; plunging and rotating mode. Formation of the RVR during the load rejections coincides with sudden pressure change on the runner while its mitigation occurs in a smooth way.

• 한국의류학회지
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• 제41권6호
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• pp.1098-1108
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• 2017

This paper investigated stretchability with fabric mechanical properties of one-way and two-way stretch fabrics. For this purpose, 1-way and 2-way woven fabrics were prepared using 150d PET/spandex covered yarns with different thermal treatment according to 4 kinds of wet thermal machines subsequently, fabric mechanical properties were measured and compared with regular PET fabrics. In addition, the garment formability of stretch fabrics was predicted and compared to regular fabrics according to wet thermal treatment. The weft stretchability of 2-way stretch fabric was about 10% higher than the 1-way stretch fabric. The compressibility of the stretch fabrics was 1.5 times higher than regular fabrics. The compressibility of stretch fabrics treated with CPB and rope type wet thermal machine showed higher values than other types of wet thermal machines. The bending rigidity of 2-way stretch fabric was lower than 1-way stretch fabric. Shear rigidity of 2-way stretch fabric was higher than 1-way and regular fabrics. Garment formability of 2-way stretch fabric was higher than regular and one-way stretch fabrics. Garment formability of 2-way stretch fabrics treated with wet thermal conditions under low tension showed the highest values.

• 수산해양기술연구
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• 제38권1호
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• pp.58-68
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• 2002

본 연구에서는 동해구트롤선(750ps)을 대상으로 현용어구에 대한 모형망을 제작하여 발줄과 저질의 종류에 따른 어구의 저항특성을 구하고자하여, 수중무게 5.4g인 체인형, 와이어형, 기본형의 발줄 3종류의 발줄에 대하여 실제 예망속도인 2.0~2.5knots의 범위에 해당되는 실험예망속도 0.4m/s일 때의 저항을 실험.분석하였으며, 나아가 체인형 발줄에 대해서는 발줄무게에 따른 저항의 변화를, 와이어형 발줄에 대해서는 발줄의 굵기에 따른 저항의 변화를 실험 .분석하였다. 한편, 예망속도에 따른 발줄의 종류별 저항특성을 구하고자 수중무게가 5.4g인 체인형, 와이어형, 기본형의 3종류의 발줄에 대하여 예망속도를 0.1m/s 0.2m/s 0.3m/s 0.4m/s 변화시키면서 저항을 측정하고, 어구에 대한 발줄 저항비 및 저항계수를 각각 구하였다. 그 결과를 요약하면 다음과 같다. 1. 어구저항은 저질이 모래와 펄 모두에서 체인형이 가장 크고, 기본형, 와이어형 순으로 작게 나타났다. 2. 저질의 종류에 따른 저항은 모래에서는 체인형이 가장 크고, 와이어형, 기본형 발줄의 순으로 작았으며, 필에서는 체인형이 가장 크고, 기본형, 와이어형순으로 작게 나타났다. 3. 발줄의 무게에 따른 저항은 거의 직선형으로 증가하고 있으며 저질이 펄인 경우, 체인형 발줄의 무게가 5.4g 10g 20g 일 때 저항은 각각 36g 45g 65g으로 줄의 무게가 20g일 때가 10g일 때 보다 약 44% 더 컸으며, 모래의 경우에는 각각 38g 51g 74g으로 발줄의 무게가 20g일 때가 109일 때보다 약 45%로 컸다. 4.발줄의 굵기에 따른 저항은 예망 속도가 0.4m/s에서 와이어형의 굵기가 ø 65mm 기준으로 2, 3, 4, 5배로 증가함에 따라 저항은 23g, 25g, 32g, 42g으로 각각 증가하였다. 5. 예망속도의 증가에 따른 발줄의 종류별 저항은 직선에 가까운 지수 함수적으로 증가하였고, 저질이 펄인 경우, 체인형이 가장 크며 다음으로 기본형, 와이어형 순으로 작게 나타났다. 6. 어구저항에 대한 발줄 저항의 비는 필에서 체 인형이 가장 크고, 기본형, 와이어형 순으로 나타났으며, 모래에서는 체인형이 가장 높았고, 와이어형, 기본형의 순으로 작게 나타났다. 7. 저항계수는 펄에서는 체인형 발줄이 약 10.0~55.7, 와이어형은 약 3.0~l6.0, 기본형은 약 1.5~8.5이며, 모래에서는 체인형 발줄이 약 10.0~60.0, 와이어형은 약 3.0~l4.0, 기본형은 약 1.2~6.0이었다. 그리고, 전체적으로 절과 모래 모두에서 저항계수가 체인형이 다른 두 종류의 발줄에 비해 상대적으로 가장 크고, 와이어형, 기본형의 순으로 작게 나타났다.

• 천문학회보
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• 제40권1호
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• pp.66.3-67
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• 2015

Without scrutinizing reflection, the plasma comprising a coronal loop is usually regarded to reside within a flux rope. This picture seems to have been adopted from laboratory plasma pinches, in which a plasma of high density and pressure is confined in the vicinity of the flux rope axis by magnetic tension and magnetic pressure of the concave inward magnetic field. Such a configuration, in which the plasma pressure gradient and the field line curvature vector are almost parallel, however, is known to be vulnerable to ballooning instabilities (to which belong interchange instabilities as a subset). In coronal loops, however, ideal MHD (magnetohydrodynamic) ballooning instabilities are impeded by a very small field line curvature and the line-tying condition. We, therefore, focus on non-ideal (resistive) effects in this study. The footpoints of coronal loops are constantly under random motions of convective scales, which twist individual loop strands quite randomly. The loop strands with the axial current of the same direction tend to coalesce by magnetic reconnection. In this reconnection process, the plasma in the loop system is redistributed in such a way that a smaller potential energy of the system is attained. We have performed numerical MHD simulations to investigate the plasma redistribution in coalescence of many small flux ropes. Our results clearly show that the redistributed plasma is more accumulated between flux ropes rather than near the magnetic axes of flux ropes. The Joule heating, however, creates a different temperature distribution than the density distribution. Our study may give a hint of which part of magnetic field we are looking to in an observation.