• Title/Summary/Keyword: Scale down test

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Fundamental Study for Ocean Wave Energy Converter Using a Rack-Pinion Gear Based One-way Mechanism (일방향 기구 기반 랙-피니언 기어를 이용한 병진형 파력발전장치에 대한 기초연구)

  • Lee, Junkyoung;Cho, Sungil;Lee, Sehan;Lee, Sangchun;No, Hyunchul
    • 한국신재생에너지학회:학술대회논문집
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    • 2011.05a
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    • pp.167.1-167.1
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    • 2011
  • Sustainable energy generation is becoming extremely imperative due to the expected limitations in current energy resources and to reduce pollution. Especially, because of its considerable energy potential, ocean wave energy has been investigated with regard to power generation. To develop large high power wave generator system, it is important to make a small scale proto type and to test that. Thus the objective of this research is to examine the characteristics of a mechanically excited generator system having small power capacity experimentally. The water reservoir (4 m length, 1.5 m width and 1.8 m depth) having a wave maker to make arbitrary height and period of the water wave was made. The proto type consists of three main parts; a buoy, rack-pinion base one-way mechanism, and a wave generator(Fig.1). The water wave is going up and down and the hexahedron buoy is following the wave. The rack gear attached to the buoy is also going up and down to roll the pinion connected to an electric generator then it produces electricity. The experiments were performed with several conditions of water waves, and the power outputs over 30 W could be measured for some conditions. In future works, to achieve higher performance for the proto type, the effects of primary parameters (buoy shape and mass, etc.) on the system efficiency will be identified.

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Developing High Altitude Long Endurance (HALE) Solar-powered Unmanned Aerial Vehicle (UAV) (고고도 장기체공 태양광 무인기 개발)

  • Hwang, SeungJae;Kim, SangGon;Lee, YungGyo
    • Journal of Aerospace System Engineering
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    • v.10 no.1
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    • pp.59-65
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    • 2016
  • Korea Aerospace Research Institute (KARI) is developing an electric-driven HALE UAV in order to secure system and operational technologies since 2010. Based on the 5 years of flight tests and design experiences of the previously developed electric-driven UAVs, KARI has designed EAV-3, a solar-powered HALE UAV. EAV-3 weighs 53 kg, the structure weight is 21 kg, and features a flexible wing of 19.5 m in span with the aspect ratio of 17.4. Designing the main wing and empennage of the EAV-3 the amount of the bending due to the flexible wing, 404 mm at 1-G flight condition based on T-800 composite material, and side wind effects due to low cruise speed, V_cr = 6 m/sec, are carefully considered. Also, unlike the general aircraft there is no center of gravity shift during the flight. Thus, the static margin cuts down to 28.4% and center of gravity moves back to 31% of the Mean Aerodynamic Chord (MAC) comparing to the previously developed scale-down HALE UAVs, EAV-2 and EAV-2H, to minimize a trim drag and enhance a performance of the EAV-3. The first flight of the EAV-3 has successfully conducted on the July 29, 2015 and the test flight above the altitude 14 km has efficiently achieved on the August 5, 2015 at the Goheung aviation center.

The Influence of Clinical Symptoms and Self-Efficacy on Function in Women With Osteoarthritis (골관절염 여성의 임상적 특성 및 자기효능감이 기능수행에 미치는 영향)

  • Jung, Kyong-Ah;Lee, Wan-Hee
    • Physical Therapy Korea
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    • v.14 no.1
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    • pp.55-63
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    • 2007
  • This study was designed to examine the relationship between clinical symptoms, self-efficacy, and performance of women with osteoarthritis. It is a survey study of 60 women who were diagnosed as osteoarthritis and given medical treatments from September, 2005 to October, 2005 in hospital 'H' located in Yongin-si. For clinical symptoms, radiographs of the subjects' knees were taken and evaluated the pathology grade by the Kellgren-Lawrence grade. Pain and stiffness was measured by the measure of WOMAC (Western Ontario and McMaster Universities Osteoarthritis Index), and functional reach test was measured in order to examine balancing abilities. Self-efficacy was measured by a tool which has revised the ASES (Arthritis Self-Efficacy Scale), and performance was measured by recording the difficulty of the WOMAC measurements themselves, and the time taken for 20 m walking, going up and down 9 stairs, and 5 sit-down and stand-up repetitions. The resulting differences in the other variables according to performance and the relationship between performance with variables are the following. First, an increase in pain in women with osteoarthritis led to decreased functional ability. Second, an increase in stiffness in women with osteoarthritis led to a decrease in functional ability. Third, a decrease in balance in women with osteoarthritis led to a decrease in functional ability. Fourth, a decrease in self-efficacy in women with osteoarthritis led to a decrease in functional ability. Fifth, the variables for estimating the performance by self-report were pain and self-efficacy. The variables for estimating the performance by recording the time taken was balance and self-efficacy. As a result factors such as pain, balance and self-efficacy in women with osteoarthritis were closely related to performance. Based on the results, it seems that physical therapy programs to decrease pain and to increase the balance in women with osteoarthritis, and psychological approaches to increasing self-efficacy are needed. I hope that the results of this study will be useful data for clinical management and intervention for women with osteoarthritis.

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A Study on the Characteristic Behavior of the Lateral Load Piles using the Strain Wedge Model and Laboratory Model Test (실내모형실험과 변형률 쐐기모델을 이용한 수평하중을 받는 말뚝의 거동 특성에 관한 연구)

  • Kim, HongTaek;Han, YeonJin;Kim HongLak
    • Journal of the Korean GEO-environmental Society
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    • v.13 no.2
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    • pp.103-112
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    • 2012
  • The most of original horizontal bearing capacity theory of the pile is not efficiently to consider interaction between soil and pile because it is only to consider the earth pressure theory and separately the ground form pile. In recent, in order to improve the pile technology, it is necessary to confirm the real behaviour characteristics of pile under lateral load. Hence, to evaluate the behaviour characteristics of the single and group pile under lateral loads using the strain wedge model that could consider the interaction between soil and piles. Primarily, laboratory scale down model tests was carried out to predict the behaviour characteristics on real size piles using the strain wedge model. The comparative analyses between model test and numerical analysis for the evaluation of whole behaviour were conducted.

Evaluation of Structural Performance of RC Beams Retrofitted Steel Fiber consequential Replacement of Recycled Coarse Aggregate and Ground Granulated Blast Furnace Slag (순환골재와 고로슬래그 미분말을 치환한 강섬유 보강 RC보의 구조성능 평가)

  • Ha, Gee-Joo;Yi, Dong-Ryul;Ha, Jae-Hoon
    • Journal of the Korea Concrete Institute
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    • v.25 no.5
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    • pp.477-484
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    • 2013
  • In this study, eleven reinforced concrete beams, ground granulated blast furnace slag, replacing recycled coarse aggregate (BRS series) and recycled coarse aggregate with steel fiber (BSRS series), and standard specimen (BSS) were constructed and tested under monotonic loading. Experimental programs were carried out to improve and evaluate the shear performance of such test specimens, such as the load-displacement, the failure mode and the maximum load carrying capacity. All the specimens were modeled in 1/2 scale-down size. Test results showed that test specimens (BSRS Series) was increased the compressive strength by 9%, the maximum load carrying capacity by 1~6% and the ductility capacity by 1.02~1.13 times in comparison with the standard specimen (BSS). And the specimens (BSRS Series) showed enough ductile behavior and stable flexural failure.

The Effect of Balance Task-Related Circuit Training on Chronic Stroke Patients (뇌졸중 환자의 균형 향상 과제 중심 순환 훈련의 효과)

  • Lee, Han-Suk;Kim, Myung-Chul
    • The Journal of Korean Physical Therapy
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    • v.21 no.4
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    • pp.23-30
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    • 2009
  • Purpose: This study investigated the efficacy of task-related circuit training aimed at improving balance in individuals discharged from rehabilitation facilities following a stroke. Methods: We recruited 12 stroke patients (34-66 years of age) to participate in a task-related circuit training program. Baseline assessment included a history of stroke and an assessment using the Mini-Mental State Examination Korea (MMSE-K). After a baseline assessment, follow-up assessments were administered pre- and post-training. These included Berg Balance Scale (BBS), Functional Reach Test (FRT), and the Time Up & Go Test (TUG). Physiotherapists trained study subjects under the one-to-one supervision of students from the department of physical therapy. Circuit class study participants attended 90-minute treatment sessions, one day a week for 12 weeks (from September to December 2008). The program consisted of a light warm-up period (10 min), physical exercises for improving balance (20 min), tasks focused on improving balance (50 min) and a cool-down period (10 min). Results: Scores for the BBS assessment increased significantly (from 43.2 to 49.7) after the training (p<0.05). Reach distance on the FRT increased substantially (from 27.7 cm to 47.0 cm), although the improvement was not significant (p>0.05). The average time on the TUG test decreased significantly (from 23.7 sec to 19.5 sec) after the training (p<0.05). Conclusion: The task-related circuit training program improved the balance and mobility of subjects, indicating that such a group program is useful for stroke patients who are discharged from the hospital. More such task-related programs set in a community environment should be developed.

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Improvement and Evaluation of Structural Performance of Reinforced Concrete Beam using High Ductile Fiber-Reinforced Mortar with Ground Granulated Blast Furnace Slag (고로슬래그미분말을 혼입한 고인성섬유 복합모르타르를 이용한 철근콘크리트 보의 구조성능 평가 및 개선)

  • Ha, Gee-Joo;Lee, Dong-Ryul
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.14 no.6
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    • pp.142-152
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    • 2010
  • In this study, eleven reinforced concrete beams, without stirrup, using high ductile fiber-reinforced mortar with ground granulated blast furnace slag(SHF Series, SHFSC Series) and standard specimens without or with stirrup(SSS, BSS) were constructed and tested under monotonic loading. Experimental programs were carried out to improve and evaluate the shear performance of such test specimens, such as the load-displacement, the failure mode, the maximum strength, and shear strength. All the specimens were modeled in scale-down size. Test results showed that test specimens(SHF Series, SHFSC Series) was increased respectively the shear strength carrying capacity by 26%, 20% and the ductility capacity by 5.27, 5.75 times in comparison with the standard specimen without stirrup(SSS). And the specimens(SHF Series, SHFSC Series) showed enough ductile behavior and stable flexural failure.

Improvement of Structural Performance of RC Beams retrofitted Hybrid Fiber using Recycled Coarse Aggregate and Ground Granulated Blast Furnace Slag (순환굵은골재 및 고로슬래그 미분말을 사용한 하이브리드섬유보강 철근콘크리트 보의 구조성능 개선)

  • Yi, Dong-Ryul;Ha, Gee-Joo
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.18 no.6
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    • pp.1-10
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    • 2014
  • In this study, thirteen reinforced concrete beams, ground granulated blast furnace slag, replacing recycled coarse aggregate with PVA fiber (BSPG series) and recycled coarse aggregate with hybrid fiber ($BSPGR_1$, $BSPGR_2$ series), and standard specimen (BSS) were constructed and tested under monotonic loading. Experimental programs were carried out to improve and evaluate the Structural performance of such test specimens, such as the load-displacement, the failure mode, and the maximum load carrying capacity. All the specimens were modeled in 1/2 scale-down size. Test results showed that test specimens ($BSPGR_1$, $BSPGR_2$ series) was increased the compressive strength by 13%, the maximum load carrying capacity by 4~21% and the ductility capacity by 4~28% in comparison with the standard specimen (BSS). And the specimens ($BSPGR_1$, $BSPGR_2$ series) showed enough ductile behavior and stable flexural failure.

Face recognition rate comparison with distance change using embedded data in stereo images (스테레오 영상에서 임베디드 데이터를 이용한 거리에 따른 얼굴인식률 비교)

  • 박장한;남궁재찬
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.41 no.6
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    • pp.81-89
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    • 2004
  • In this paper, we compare face recognition rate by PCA algorithm using distance change and embedded data being input left side and right side image in stereo images. The proposed method detects face region from RGB color space to YCbCr color space. Also, The extracted face image's scale up/down according to distance change and extracts more robust face region. The proposed method through an experiment could establish standard distance (100cm) in distance about 30∼200cm, and get 99.05% (100cm) as an average recognition result by scale change. The definition of super state is specification region in normalized size (92${\times}$112), and the embedded data extracts the inner factor of defined super state, achieved face recognition through PCA algorithm. The orignal images can receive specification data in limited image's size (92${\times}$112) because embedded data to do learning not that do all learning, in image of 92${\times}$112 size averagely 99.05%, shows face recognition rate of test 1 99.05%, test 2 98.93%, test 3 98.54%, test 4 97.85%. Therefore, the proposed method through an experiment showed that if apply distance change rate could get high recognition rate, and the processing speed improved as well as reduce face information.

A Comparison of Perceived Nursing Needs among Oncology Nurses, Patients with Non-terminal Cancer and Patients with Terminal Cancer (간호사, 비말기 암환자 및 말기 암환자가 지각한 간호요구의 중요도와 제공정도에 대한 비교)

  • Choi, Ja Yun
    • Journal of Korean Academy of Nursing
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    • v.35 no.6
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    • pp.1135-1143
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    • 2005
  • Purpose: The purpose of this study was to compare the perceived importance and the perceived caring of nursing needs among oncology nurses, patients with non-terminal cancer and patients with terminal cancer. Method: A total of 83 oncology nurses, 56 patients with non-terminal cancer and 39 patients with terminal cancer served as subjects. Data was collected based on the 4-point Likert scale using a self-administered questionnaire from Mar. to Sept. 2004. Finally, data was analyzed using mean, SD, paired-test,. and ANOVA. Results: The score of the perceived importance of nursing needs was higher than that of the perceived performance of nursing needs in all three groups. There was also a difference in the degree of perceived performance of nursing needs among the three groups. In contrast, there was no difference in the total score of the perceived importance of nursing needs among the three groups, unlike the importance of informational and physical needs as a subgroup of perceived importance, where a difference was noted. Conclusions: Strategies should be developed to narrow down these gaps between nurses and patients. In particular, informational and educational programs should be designed for patients with terminal cancer.