• 동력기계공학회지
• /
• 제18권2호
• /
• pp.31-36
• /
• 2014

In this paper, pneumatic valve which consists of valve body, valve controller, nozzle and a multi-bender PZT actuator was suggested and fabricated. The fabricated pneumatic valve was experimented for performance evaluation. From the experimental results, we know that the flow rate of the suggested valve is 23 lpm at the pressure difference of 1bar and the maximum flow rate is 30 lpm at the pressure difference of 4 bar. The flow rates after endurance test of 9.8 million were 22.57 lpm and 28.62 lpm at the pressure difference of 1bar and 4bar, respectably. Finally, it was verified that the B10 life of the suggested pneumatic valve is over 50 million.

• 한국추진공학회:학술대회논문집
• /
• 한국추진공학회 2010년도 제34회 춘계학술대회논문집
• /
• pp.226-230
• /
• 2010

본 논문에서는 배터리와 전기모터 방식의 추진장치를 사용하는 소형무인항공기의 비행성능을 분석한다. 비행시험을 통해 얻은 데이터로부터 공력특성을 예측하고, 이를 활용하여 비행성능을 예측한다. 최대 항속시간을 얻을 수 있는 적정 비행속도를 제시하고, 비행속도에 따른 항속시간 및 항속거리를 예측한다.

• 한국정밀공학회지
• /
• 제22권6호
• /
• pp.47-54
• /
• 2005

A dangerous event occurred at the field industry and mechanical system. At developed by SUNGGOKNANOTECH corp. a R-L clutches of a small and high capacity serves safety device from a variety environment of mechanical system, it permits transmission of driving torque from input to output shaft in both directions of rotation, but restrains any feedback torque of the driven load from rotating the output shaft in either direction. This study was carried out to demonstrate through finite element method and durability estimation for safety of the R-L clutches without sliding during the engagement process. As results, we organized about endurance test method when applied rated torque.

• Clinics in Shoulder and Elbow
• /
• 제27권1호
• /
• pp.52-58
• /
• 2024

Background: Deficiency in scapular muscle endurance (SME) is a risk factor for rotator-cuff-related shoulder pain (RCRSP). However, the exact relationship among SME, pain, and functionality remains unclear. This study aims to compare SME, pain, and functionality in RCRSP patients to those in age-sex-matched healthy controls. Methods: Twenty-three patients with RCRSP and 23 age-sex matched healthy controls were included in the study. SME was measured using a 1-kg dynamometer. Self-reported pain level was assessed using a visual analog scale. The Functional Impairment Test-Hand, Neck, Shoulder, and Arm (FIT-HaNSA) was also used to assess functional impairment. Results: The control group had higher SME and total FIT-HaNSA scores than the patient group (P<0.05). There was a statistically significant and positive correlation between SME and FIT-HaNSA scores in both groups (P<0.05). Conclusions: SME was affected by RCRSP. Pain and functional impairment were correlated with low SME.

• 한국임상수의학회지
• /
• 제30권6호
• /
• pp.449-452
• /
• 2013

본 연구는 제주산마의 hill test 및 운동 강도별 심폐지구력 측정으로 승용능력 평가를 위한 기초 자료로 활용하기 위해 수행하였다. 분석에 이용된 제주산마 9두는 경사도 30도 내외의 경사로 800 m를 주행하는 hill test를 실시하였으며, 이 중 6 두는 운동 강도별(moderate, heavy, very heavy) 심폐지구력을 측정하였다. Hill test 주행시간은 평균 205 초였으며, 개체간 편차는 큰 것으로 확인 되었고, moderate exercise와 높은 상관관계를 보였다. 운동 강도별 평균 심박수는 유의적인 차이가 없었으나, 개체간 평균 심박수는 차이가 큰 것으로 나타났다. 회복 심박수는 heavy exercise와 very heavy exercise에서 높은 상관관계를 확인할 수 있었다. 본 실험결과, 운동 강도별 평균 심박수 차이는 확인 할 수 없었으나, 개체간의 차이는 큰 것으로 확인되었다.

• 환경위생공학
• /
• 제24권4호
• /
• pp.49-59
• /
• 2009

The purpose of this study was to examine the effects of an aquarobics exercise program on the physical fitness and blood lipids in elderly women. The subjects of the study were twenty-six elderly women enrolled in an Aquarobics exercise program consisting of 60 minutes per session, 3 times a week during the period of 12 weeks. The effects of the program were assessed using the instruments to measure physical fitness and blood lipids before and after the aquarobics exercise program. Data was collected between September and December in 2006, and analyzed by frequency, paired with a t-test, using a SPSS. The results were statistically significant in muscle strength, muscle endurance, flexibility, and cardiopulmonary endurance, but no significant differences were found in agility, total cholesterol, triglycerides and high density lipoprotein cholesterol. Aquarobics exercise can be an effective nursing intervention to improve muscle strength, muscle endurance, flexibility and cardiopulmonary endurance in elderly women.

• 한국전문물리치료학회지
• /
• 제14권4호
• /
• pp.35-43
• /
• 2007

The purpose of this study was to compare the static balance in a sitting position between a group with adolescent idiopathic scoliosis (AIS) and a normal aged-matched group. Forty-nine subjects were included in this study. Thirty-one healthy subjects and eighteen AIS subjects were participated. Each group was tested with the Lumbar Trunk Muscle Endurance Test (LTMET) and Balance Performance Monitor (BPM). The parameters for static balance were sway area, sway path, mean balance, maximum velocity, anterior-posterior angle, and left-right angle of each group with eyes opened and closed. Results from the LTMET showed significantly more increase in the normal group than in the AIS group in the flexor and extensor endurance. The BPM tested showed significantly difference beteen the groups in parameters of sitting balance such as maximum velocity and anterior-posterior sway angle. For the AIS subjects, there were no significant differences in all parameters of sitting balance between eyes opened and eyes closed. In comparisons of the groups with eyes opened there were no significant differences in all parameters of sitting balance. In comparisons of the groups with eyes closed there were significant differences in the sway area, maximum velocity, anterior-posterior sway angle and left-right sway angle. These results suggest that the AIS group relies much more on proprioception than on vision, and develops compensatory passive postures of the spine. Further study is needed to measure many AIS patients with morphologic and electromyographic data for clinical application.

• 대한정형도수물리치료학회지
• /
• 제15권2호
• /
• pp.1-7
• /
• 2009

Purpose : to investigate change of isokinetic muscle strength and isokinetic muscle endurance of quadriceps femoris and hamstring after application of taping and static stretching. Methods : For this study, 14 male members of college soccer team participated in this research. Participants were divided into two groups: seven was assigned to a taping group(n=7) and the others were assigned to a static stretching exercise group(n=7). Main outcome was measured by using biodex. The isokinetic muscle strength test was processed at the speed of the $60^{\circ}$/sec five times, and isokinetic muscle endurance was processed at the speed of $180^{\circ}$/sec ten times. Results : From the outcomes of the measurement, the results show that there is a more significant difference in the taping group than in a static stretching exercise group. Conclusion : These results will be utilized for the preliminaries in the future.

• Transactions on Electrical and Electronic Materials
• /
• 제17권1호
• /
• pp.25-28
• /
• 2016

We investigate the effect of interface states on the endurance of a charge trap flash (CTF) NOR array using charge pumping methods. The endurance test was completed from one cell selected randomly from 128 bit cells, where the memory window value after 10² program/erase (P/E) cycles decreased slightly from 2.2 V to 1.7 V. However, the memory window closure abruptly accelerated after 10³ P/E cycles or more (i.e. 0.97 V or 0.7 V) due to a degraded programming speed. On the other hand, the interface trap density (Nit) gradually increased from 3.13×10¹¹ cm⁻² for the initial state to 4×10¹² cm⁻² for 10² P/E cycles. Over 10³ P/E cycles, the Nit increased dramatically from 5.51×10¹² cm⁻² for 10³ P/E cycles to 5.79×10¹² cm⁻² for 10⁴ P/E cycles due to tunnel oxide damages. These results show good correlation between the interface traps and endurance degradation of CTF devices in actual flash cell arrays.

• 항공우주시스템공학회지
• /
• 제13권2호
• /
• pp.1-9
• /
• 2019

본 논문에서는 고고도 장기체공 무인항공기의 임무 비행을 위한 방향축 유도, 제어 알고리즘에 대해 기술 하였다. 먼저 방향축 제어 알고리즘은 임무 기간 중 무인항공기가 전진비행을 할 수 없을 맞바람에 대해 제어 변수를 전환하는 알고리즘을 설계하였다. 유도법칙은 항로점 비행을 위해 Fly-over, Fly-by, Hold 속성에 대한 각각의 알고리즘을 적용하였다. 무인항공기의 비선형 시뮬레이션을 통해 각 유도, 제어 알고리즘의 설계 결과를 확인하였다. 본 연구는 설계 결과를 토대로 실제 임무 비행을 수행하는 것을 목적으로 한다. 따라서 본 연구 내용을 기반으로 비행 시험을 통해 설계한 유도 제어 알고리즘의 비행 운용성을 확인하였다.