• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2009년도 추계학술대회 논문집
• /
• pp.431-434
• /
• 2009

Conceptual study of an open-circuit type low-speed wind tunnel for test of wind turbine blade is conducted. The tunnel is constituted of a settling chamber, a contraction, closed and open test sections, a diffuser, two corners, a cross leg and a fan and motor. For the performance test, the closed test section width of 1.8 m, height of 1.8 m and length of 5.25 m is selected. The open test section with dimension width of 1.8 m, height of 1.8 m and length of 4.14 m is adopted for aeroacoustic test. The contraction ratio is 9 to 1 and maximum speed in the closed test section is 67 m/sec. Input power in the tunnel is about 238 kW and its energy ratio is 3.6. The wind tunnel designed in present study will be an effective tool in research and development of wind turbine.

• 대한물리의학회지
• /
• 제19권1호
• /
• pp.1-10
• /
• 2024

PURPOSE: This pre-post intervention study aimed to examine the effects of a 12-week supervised modified Taekwondo exercise program on the functional fitness of community-dwelling older adults. METHODS: 10 participants (mean age: 72.3 ± 4.6 years) completed the program over a 12-week period. The intervention consisted of Taekwondo-based exercises modified for older persons. Changes to functional fitness were measured using the finger-to-nose test, functional reach test, timed up and go test, 30-second sit-to-stand test, 30-second arm curl test, Chester step test, chair sit-and-reach test, and back scratch test. Participants were assessed prior to the training and after the final training session, changes were measured using descriptive statistics and paired sample 't' tests. RESULTS: Effect sizes ranged from small to large (Cohen's d = .22 to 1.23). The exercise program was well- tolerated by participants, with a high level of engagement and no attrition for the duration of the program. Results showed significant improvements in most measures of functional fitness (p < .05) except for the back scratch test (p = .051). CONCLUSION: These findings suggest a well-designed, supervised, modified Taekwondo exercise program can significantly improve functional fitness in older adults.

• 응용통계연구
• /
• 제24권1호
• /
• pp.35-43
• /
• 2011

이 논문에서는 이산코사인변환(discrete cosine transform) 계수를 이용하여 AR(1) 과정에서 단위근을 검정하는 방법을 소개한다. 제안하고자 하는 방법의 이론적 타당성을 보이기 위해 정상 AR(1) 과정과 확률보행과정 하에서의 이산코사인변환 계수의 통계적 성질을 비교한다. 비교 결과를 이용하여 단위근 여부를 확인할 수 있는 검정통계량을 제안하고 붓스트랩을 활용하여 검정통계량의 분포를 유도한다. 모의실험을 통해 기존 Dickey-Fuller 검정과 검정력 비교를 실시하였다.

• 수산해양기술연구
• /
• 제22권1호
• /
• pp.24-28
• /
• 1986

The maneuverabilities of the M. S. PUSAN 402 are studied, based on maneuvering indices and the data obtained from her Z test. The results obtained are summarized as follows: 1. The maneuvering indices K' and T' of the M. S. PUSAN 402 are 1. 490, 1.030 at 10$^{\circ}$ Z test and 2.644, 1.153 at 20$^{\circ}$ Z test and 3.382. 1. 027 at 30$^{\circ}$ Z test respectively. The above calculated values K', T' showed that her maneuverabilities are more increased when the rudder is used to large angle than to smaIl angle. 2. As her maneuvering indices K' and T' at 10$^{\circ}$ Z test are higher than the standard maneuvering indices of fishing boats, her turning ability was found to be higher but her obeying ability lower. 3. When the M. S. PUSAN 402 took a turn at her 10$^{\circ}$ test, running distance was about 8.4 times her own length and didn't exceed the standard maneuvering distance, 5 to 11 times ship's own length, therefore she was considered to have good maneuverabilities syntheticaIly.

• 한국안전학회지
• /
• 제15권4호
• /
• pp.8-14
• /
• 2000

The remaining life estimation for the aged components in power plants as well as chemical plants are very important because mechanical properties of the components are degraded with time of service exposure in the high temperature. Since it is difficult to take specimens from the operating components to evaluate mechanical properties of components, accelerated aging technique are needed to estimate and analyse the material degradation. In the this study, test materials with 4 different degradation levels were prepared by isothermal aging heat treatment at $630^{\circ}C$. And tensile test, $k_{IC}$ test, hardness test and Scanning Electron Microscope analysis were performed in order to evaluate the degradation of 1Cr-1Mo-0.25V steels.

• Communications for Statistical Applications and Methods
• /
• 제11권3호
• /
• pp.643-655
• /
• 2004

L$_1$-estimator in the linear regression model is widely recognized to have superior robustness in the presence of vertical outliers. While the L$_1$-estimation procedures and algorithms have been developed quite well, less progress has been made with the hypothesis test in the multiple L$_1$-regression. This article suggests computer-intensive resampling approaches, jackknife and bootstrap methods, to estimating the variance of L$_1$-estimator and the scale parameter that are required to compute the test statistics. Monte Carlo simulation studies are performed to measure the power of tests in small samples. The simulation results indicate that bootstrap estimation method is the most powerful one when it is employed to the likelihood ratio test.

• Journal of Yeungnam Medical Science
• /
• 제8권1호
• /
• pp.42-52
• /
• 1991

최근 널리 사용되고 있는 제조회사가 다른 두가지 요시험지봉(Combur-9-test$^{(R)}$ RL & Multistix$^{(R)}$-SG)으로 요검사를 실시하면, 그 결과치의 표현에 있어 차이가 있으므로, 결과치 판정시 질병의 진단이나 치료의 효과 판정 및 경과관찰에 있어서 발생할 수 있는 혼란을 줄이고자, 환자검체와 표준검체에서 실시한 요시험지봉 검사결과를 비교 검토하여 아래와 같은 결론을 얻었다. 또한 두 시험지봉검사에 결과를 교환함에 있어 상응하는 결과치도 조사하였다. Combur-9-test RL 및 Multistix-SG를 이용하여, 1990년 12월 16일 부터 15일간 영남대학교 의과대학 부속병원 임상병리과에 요검사가 의뢰된 501명의 환자검체를 대상으로 하여 요시험지봉으로 화학적검사를 반정량적으로 시행한 결과 대체로 ${\pm}1$등급 범위내에서 일치하였다. Combur-9-test RL을 이용한 leukocyte esterase 검사와 요침사검사간의 비교에서 현미경적 농뇨와의 일치율은 83.7%, 민감도 48.1%, 특이도 90.3%, 양성예측율 47.4% 및 음성예측율 90.5%로 나타났다. Combur-9-test RL을 사용한 nitrite검사와 요배양검사간의 비교에서 요배양 양성과의 일치율은 93.0%, 민감도 19.4%, 특이도 84.7%, 양성예측율 53.8% 및 음성예측율 94.1%로 나타났다. 단백의 주 성분이 알부민 및 글로부린인 검체에서 실시한 요단백검사에서는 양자 모두에서 sulfosalicylic acid 법이 가장 민감하였고, 다음은 Multistix-SG, Combur-9-test RL의 순이었다. 요빌리루빈 및 요당검사에서는 두시험지봉이 비슷한 민감도를 나타내었다. 요중 백혈구검사에서는 요침사검사가, 요중 잠혈검사에서는 Combur-9-test RL이 가장 민감하였다.

• 한국전기전자재료학회논문지
• /
• 제18권1호
• /
• pp.96-103
• /
• 2005

To analyze the reason of aging deterioration in transmission line insulators, we performed a various kind of test and investigated mechanical and electrical characteristics of insulators. Test samples consisted of K-1989(36,000lbs), K-1995(36,000lbs) and K-2001(36,000lbs) type insulators which have been used in domestic 154 kV transmission lines. As a result of this test, the facts turned out K-2001 insulator which contain 17 wt.% alumina has better physical characteristics than K-1989 insulator which contain 8 wt% alumina. Relativity density and fracture toughness of K-1989 porcelain are 94.2 % and 1.4 MPa\ulcornerm$^{1}$2// but relativity density and fracture toughness of K-2001 porcelain are 96 % and 1.7 MPa\ulcornerm$^{1}$2//. K-2001 insulators show a good performance not only in a physical property test but also in power arc test and steep front of wave flashover test which is performed to evaluate electrical characteristics.

• 한국신뢰성학회지:신뢰성응용연구
• /
• 제16권2호
• /
• pp.125-133
• /
• 2016

Purpose: The purpose of this study is to evaluate durability of platform safety step system in railway. Method: We performed finite element analysis & durability analysis of platform safety step system with VPD (Virtual Product Development) techniques and examined the durability standard & qualification life through the rig test during no failure test time in reliability qualification test. We continued to test 1 million cycles in KRS (Korea Railway Standard) for system's robust design performance. Result: FEM analysis results are 14.9MPa & 14.7MPa of pin-joint, pivot and durability analysis result is above 1 million cycles. we calculated theoretically no failure test time 855,000 cycles and through the 1 million cycles durability rig test in KRS standard we confirmed product quality. Conclusion: This platform safety step system was designed very safe in terms of a mechanical strength & durability.

• 한국식품위생안전성학회지
• /
• 제11권4호
• /
• pp.307-314
• /
• 1996

The European Economic Community four plate test(EEC 4-plate test, FPT, EU) has been used for monitoring antimicrobial drug residues in meat by Local Veterinary Service Center in Korea. This study was performed to evaluate sensitivity and group specificity of some antimicrobial drugs in FPT and to compare FPT with Charm II test. The minimal detectable levels of targeted antimicrobial drugs tested with standard solutions were 0.025∼1.0 ppm for 7 beta-lactams, 0.5∼1.0 ppm for 4 aminoglycosides, 0.05∼0.5 ppm for 5 macrolides, 0.05∼0.25 ppm for 3 tetracyclines and 0.25&1.0 ppm for 6 sulfonamides. In comparison of FPT and Charm II test, the results of FPT were not accord with those of Charm II test having the group specificity of seven families of antimicrobial drugs in meat samples except some families like tetracyclines.