• Journal of Advanced Marine Engineering and Technology
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• 제37권6호
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• pp.623-630
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• 2013

본 연구는 기 개발된 인플래터블 카약(RPO-2)과 새롭게 개발된 인플래터블 카약(RD-FK-11, RD-FK-12)의 유체역학적인 성능평가를 위하여 경사시험과 선회시험은 해양공학수조에서 저항시험은 축소된 모형선을 제작하여 회류수조에서 수행되었다. 결론적으로 각각의 카약에 대한 다양한 성능시험결과 복원성 측면에서는 KONA가 유리하고, 선회력과 무게중심 측면에서는 RD-FK-12가 우수하고, 저항성능 측면에서는 RD-FK-11이 KONA와 RPO-2에 비해 우수하였다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2005년도 춘계 학술발표회 논문집
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• pp.89-98
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• 2005

Preliminary pile load tests for the design of large diameter drilled shaft were performed on two of reduced scale(D=1370mm) test piles. The maximum loads of 2350 tonf in each direction were applied using bi-directional hydraulic jacks(Osterberg Cell) at toe. Neither of the test piles yielded in terms of skin friction and end bearing. Comparisons of the test results with several methods that estimate pile capacity show that the method of Horvath and Kenney(1979) for skin friction and Zhang and Einstein(1998) for end bearing were most appropriate for the site. The test results were directly applied to pile design in case RQD of skin and toe was larger than that of the test pile. It is desirable, therefore, to consider not only unconfined compression strength but also rock mass properties(i.e. TCR, RQD) for skin friction and end bearing evaluation in the future.

• 대한기계학회논문집B
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• 제20권9호
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• pp.2924-2932
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• 1996

As the environmental pollution can be greatly reduced and the waste heat can be also recovered through a combustion of municipal solid waste, the incineration begins to be highlighted recently in our country. But it is very difficult to be operated with constant combustion conditions for a long time as the domestic waste is composed of various components, contains a large percentage of water, and has a low heating value. Therefore, the cold flow test and partial hot flow test were conducted in the incinerator by use of injection angles of a secondary air affecting fluid flow as the first action to maintain the optimum combustion conditions. A model to a scale of 1:10 was designed and manufactured through the similarity of model and prototype flows. Velocities and temperatures were measured through the experiment. From the results, fluid flows of secondary air obtained from partial hot flow test correspond almost well with those of main flow obtained from cold flow test. Consequently, injection angles of secondary air are proved to affect main flow decisively.

• 한국유체기계학회 논문집
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• 제19권5호
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• pp.50-60
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• 2016

A design methodology of the modeled test facility to conserve an injection performance of a passive safety injection system is proposed. This safety injection system is composed of a core makeup tank and a safety injection tank. Individual tanks are connected with pressure balance line on the top side and injection line on the bottom side. It is important to conserve the scaled initial injection flow rate and total injection time since this system can be operated by small gravity head without any active pumps. Differential pressure distribution of the injection line induced by the gravity head is determined by the vertical length and elevation of each tank. However, the total injection time is adjustable by the flow resistance coefficient of the injection line. The scaling methodology for the tank and flow resistance coefficient is suggested. A key point of this test facility design is a scaling analysis for the flow resistance coefficient. The scaling analysis proposed on this paper is based on the volume scaling law with the same vertical length to the prototype and can be extended to a model with a reduced vertical length. A set of passive injection test were performed for the tanks with the same volume and the different length. The test results on the initial flow rate and total injection time showed the almost same injection characteristics and they were in good agreement with the design values.

• 대한기계학회논문집A
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• 제34권8호
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• pp.1091-1096
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• 2010

본 연구는 풍하중 하에서 컨테이너 크레인의 전도사고 예방을 위한 경보시스템용 기준데이터를 도출하기 위하여 수행되었다. 분석방법으로 유동구조연성해석과 풍동실험이 사용되었으며, 크레인의 안정성에 대한 풍하중의 영향을 평가하기 위하여 컨테이너 터미널에서 널리 사용되고 있는 50 톤급 컨테이너 크레인이 해석모델로 선정되고, 19 가지 풍향이 설계변수로 채택되었다. 연구방법은 먼저 경계층풍동을 사용하여 풍향에 따른 컨테이너 크레인 모형에 대한 풍동실험을 수행한 후, ANSYS 와 CFX 를 사용하여 실제 크레인의 유동구조연성해석을 수행하였다. 다음으로 유동구조연성해석을 통해 산출된 부상력과 풍동실험을 통해 도출된 부상력을 비교하여 두 방법에 있어서 차이을 보정하기 위한 식을 제시하였다.

• 한국화재소방학회논문지
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• 제30권5호
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• pp.54-59
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• 2016

구조재료 중에서 강재는 불연성 재료이지만 열전도가 높고, 온도상승에 의하여 강성의 저하가 높은 편이다. 일반적으로 강재의 항복강도 및 탄성계수는 $350^{\circ}C$에서 70%, $600^{\circ}C$에서 50% 이하로 감소하기 때문에 고온에서의 철골구조의 재하능력은 급격히 감소하게 된다. 통상 내화구조로 인정받기 위해서는 공인기관으로부터의 품질시험을 거쳐야 한다. 하지만, 실물내화실험은 공간과 시간의 제약, 고비용의 문제점을 안고 있으므로, 본 연구에서는 ABAQUS 프로그램의 유한요소법을 이용한 열해석을 수행하여 압축을 받는 H-형강기둥의 내화실험과의 비교로 해석모델의 신뢰성을 입증하고, 실물실험의 보완책으로의 가능성을 제시한다.

• The Journal of Korean Physical Therapy
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• 제16권1호
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• pp.157-182
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• 2004

The purpose of this study was to evaluate effects of lumbar stabilizing exercise on the functional recovery and the range of motion of low back pain patients. The subjects were consisted of sixty patients who had non specific chronic low back pain(32 females. 28 males; mean aged 37.3) from 19 to 65 years of age(mean age : 37.3). All subjects randomly assigned to the lumbar stabilizing exercise group, the modalities treatment group, the manual treatment group. Lumbar stabilizing exercise group received manual treatment with lumbar stabilizing exercise for 30minutes, modalities treatment group received hot pack used thermal therapy for 20minutes and ICT used electrical therapy for 20minutes and US or MWD used deep thermal therapy for 15minutes, manual treatment group received modalities treatment with therapeutic massage for 10minutes and joint mobilization or manipulation for 10minutes per day and three times a week during 4 weeks period. The Multilevel Roland-Morris Disability Questionnaire(MR-MDQ) was used to measure functional disability level. Visual Analogue Scale(VAS) was used to measure subjective pain level. Remodified Schober test(RST) was used to measure forward flexion range of motion of lumbar segment. Finger-to-Floor test(F-T-FT) was used to measure forward flexion range of motion of full spine of low back pain patients. All measurements of each patients were measured at pre-treatment and 4 week post-treatment. The results of this study were summarized as follows : 1. The MR-MDQ of lumbar stabilizing exercise group, modalities treatment group, and manual treatment group was significantly reduced between pre-treatment and post-treatment(p<.05). 2. The VAS of lumbar stabilizing exercise group, modalities treatment group, and manual treatment group was significantly reduced between pre-treatment and post-treatment(p<.05). 3. The RST of lumbar stabilizing exercise group, modalities treatment group, and manual treatment group was significantly reduced between pre-treatment and post-treatment(p<.05). 4. The F-T-FT of lumbar stabilizing exercise group, modalities treatment group, and manual treatment group was significantly reduced between pre-treatment and post-treatment(p<.05). 5. The results of analyzed effects of MR-MDQ, RST, F-T-FT were significantly reduced (p<.05), but VAS wasn't significantly reduced(p>.05) between treatment type of lumbar stabilizing exercise group and modalities treatment group and manual treatment group according to pre-treatment and post-treatment. 6. The results of LSD post-hoc to find difference between treatment type of lumbar stabilizing exercise group and modalities treatment group and manual treatment group according to pre-treatment and post-treatment that MR-MDQ was significantly reduced stabilizing exercise group than modalities treatment group(p<.05), and VAS wasn't significantly reduced all treatment group(p>.05), and RST was significantly reduced stabilizing exercise group than modalities treatment group(p<.05), and F-T-FT was significantly reduced stabilizing exercise group than modalities treatment group and manual treatment group (p<.05).

• 대한물리의학회지
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• 제11권2호
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• pp.1-11
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• 2016

PURPOSE: This study was conducted to assess the effects of local vibration on ankle plantarflexion spasticity and clonus in patients with spinal cord injury. METHODS: The subjects were 14 inpatients with complete or incomplete spinal cord injury (SCI) whose scores were higher than 1 on the Modified Ashworth Scale (MAS) and Spinal Cord Assessment Tool for Spastic Reflexes (SCATS) scale of paraplegia. A randomized single-blind cross-over design was used. Vibration treatment involved a single application of vibration for 10 min in the sitting position, and placebo treatment involved the patient remaining in the sitting position for 10 min. One day after treatment, vibration and placebo treatments were crossed over. Spasticity was measured by using the MAS, and resistance force, by using a hand-held dynamometer; clonus was gauged by using the SCATS scale and clonus burst duration. Additionally, the burst maximal frequency and voluntary ankle dorsiflexion angle of the triceps surae were measured. RESULTS: The application of vibration treatment in the sitting position significantly reduced the MAS scores and resistance force, but significantly increased the dorsiflexion angle of the ankle joint (p<0.05). Furthermore, the vibration treatment diminished the clonus burst duration and SCATS score significantly (p<0.05). Although it reduced the burst maximal frequency of the lateral gastrocnemius and medial soleus, this was significant only for the lateral gastrocnemius. The placebo treatment did not significantly affect any of the test parameters. CONCLUSION: Vibration treatment in the sitting position was effective in cases of spasticity and clonus caused by SCI.

• 한국전산구조공학회논문집
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• 제25권4호
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• pp.323-330
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• 2012

본 연구진은 최근 U자 형태인 액체댐퍼의 수직관을 다수의 셀(사각 기둥)로 나누어 셀 상부를 개폐함에 따라 다양한 고유진동수를 쉽게 재현하는 새로운 멀티셀 액체댐퍼를 제시하였다. 이러한 댐퍼를 1층 건물 모형에 설치하여 진동대 실험을 수행하여 건물응답이 감소되는 것을 검증하였다. 64층의 풍응답인 가속도를 제어할 수 있도록 댐퍼를 설계하기 위하여 건물을 1자유도계로 축소하였다. 가속도 기반 상사비인 1/20를 적용하여 1층 건물 모형과 새로운 댐퍼를 제작하였다. 설계 진동수인 0.65Hz가 구현되도록 모형건물의 질량과 강성을 쉽게 조절할 수 있도록 탈부착식으로 제작하였다. 모형건물은 중량을 부담하는 질량부와 하부에 스프링과 LM guide가 설치된 구동부로 나누어서 제작되었다. 18개의 셀을 가지는 액체댐퍼를 제작하여 고유진동수 조절 범위가 0.65Hz~0.81Hz인 것을 파악하였다. 대형 진동대에 설치한 모형건물의 일방향 가진을 통하여 모형의 응답을 측정하고 모형상부에 멀티셀 액체댐퍼가 설치되었을 경우 모형의 응답을 측정하여 비교하였다. 진동대 가속도를 입력과 모형건물의 가속도를 출력으로 하는 전달함수를 통해 결과를 나타내었다. 예상한 바와 같이 멀티셀 액체댐퍼의 고유진동수를 건물의 진동수에 동조시켰을 경우 건물의 가속도 응답이 감소함을 알 수 있었다.

• 한국화재소방학회논문지
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• 제14권2호
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• pp.21-32
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• 2000

본 연구는 터널에서의 화재성상을 파악하기 위해 실물 실험의 대안으로서 축소 모형 실험을 수행하였고 또한 실험결과와 비고분석하기 위하여 터널내에서의 화재에 대하여 연기거동을 수치해석하였다. 터널내에서의 연기유동은 Buoyancy force에 의해 지배되므로 Froude scaling링에 의해 얻어진 축소법칙에 따라 실물터널을 1/20로 축소한 모형에서 실험 수행하였고 검증하였다. 여기서 얻어진 결과를 수치해석 결과와 비교하였다. 수치해석은 3D 비정 렬 격자, PISO 알고리즘, 부력 Plume 모델등을 사용하였다. 분석결과 실험과 수치해석 결과가 어느정도 일침함을 확인하였고, 연층의 전달 속도, 온도 구배, 하강 높이를 확인할 수 있었다.