• Title/Summary/Keyword: Endurance performance

Search Result 356, Processing Time 0.024 seconds

A Study on Assessment of Penetration Seals Performance of Nuclear Power Plants (원자력발전소 관통부 충전구조의 내화성능평가에 관한 연구)

  • Cho Hong-Seok;Park Jun-Hyen;Son Bong-Sae;Im Jung-Soon
    • Fire Science and Engineering
    • /
    • v.18 no.4
    • /
    • pp.93-102
    • /
    • 2004
  • The function of fire barrier penetration sealing is highly important to confine a fire propagation a fire severity within a fire area where the fire started. Especially for the penetration seals at the nuclear power plants with the long-term operated history, it is needed to make it clear that the conformance to the sealing requirements has been proven to guarantee the fire-resistive performance of fire barrier penetration parts. If there are any parts of fire barrier penetration sealing which can not meet the required rating for the fire endurance performance, the relevant parts must be modified to meet regulatory requirements. At this paper, the engineering analysis methodology was established to approximate the fire endurance rating for the fire barrier penetration seals. With this study, the method of engineering analysis to decide fire endurance rating for the fire barrier penetration seals was established and this way can be utilized to check the performance of the fire rating for the penetration seal at the domestic nuclear power plants.

Efficiency Estimation on Propulsion System of an Electric Powered UAV (전기동력 무인항공기의 추진시스템 효율 추정에 관한 연구)

  • Ahn, Il-Young;Yang, Yong-Man;Ju, Young-Chul;Park, SangHyuk;Bae, Jae-Sung
    • Journal of the Korean Society for Aviation and Aeronautics
    • /
    • v.23 no.3
    • /
    • pp.1-7
    • /
    • 2015
  • In the present study, we conducted the research on the high efficiency propulsion system for the development of long-endurance UAV with an electric propulsion system. For the long endurance UAV, fair aerodynamic characteristics with the high efficiency of the propulsion system is required because the flight power and the duration time of the long-endurance UAV vary greatly depending on the efficiency of the propulsion system. Therefore, in this study, the tracking program which records the performance of motor, propeller was developed because of their wide variation in the efficiency depending on the using condition, and records from the existing flight test program were utilized to check the accuracy of the program we had developed. For the development of future long-endurance solar UAV, we confirmed the applied voltage of motor, the optimal rotation of propeller and the gear ratio of reduction gear in order to get the highest efficiency on the propulsion system at the optimal flying condition.

Characteristics of Sitting Balance and Trunk Muscle Endurance in Patients With Adolescent Idiopathic Scoliosis

  • Shin, Seung-Sub;Woo, Young-Keun
    • Physical Therapy Korea
    • /
    • v.14 no.4
    • /
    • 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.

  • PDF

Finite Element Analysis on the Sealing Contact Stress of a CNG Fueling Nipple for Vehicles (자동차용 CNG 충전니플의 밀봉접촉응력에 관한 유한요소해석)

  • Kim, Chung Kyun;Yoo, Jae Wook
    • Journal of the Korean Institute of Gas
    • /
    • v.16 no.6
    • /
    • pp.67-72
    • /
    • 2012
  • In this study, the leak-free performance and sealing endurance safety of CNG fueling nipple in which are related to the contact normal stress and equivalent true stress have been analyzed for CNG automobile using a finite element analysis. For the conventional circular o-rings and new double-lip o-rings with an initial compression rate of 15 percentages, the leak-free performance of double-lip o-rings with two contact sealing spots is 41% higher than that of the conventional circular o-rings with a contact sealing spot. The FEM computed results present that the leak-free endurance safety of double-lip o-rings with two contact sealing spots is 5% higher than that of the conventional circular o-rings for initial compression ratio of 15 percentages and a gas compression pressure of 8MPa. And, the maximum equivalent true stress of double-lip o-rings is 10.2% higher than that of the conventional circular o-rings for the leak-free endurance safety. This means that the double-lip o-ring may guarantee the extended sealing life compared to that of a conventional circular o-ring.

A Study on the Development of Low-Altitude and Long-Endurance Solar-Powered UAV from Korea Aerospace University (3) - Flight Test Results and Analysis of Solar Powered UAV - (한국항공대학교 저고도 장기체공 태양광 무인기 개발에 관한 연구 (3) - 태양광 무인기 비행실험 결과 및 분석 -)

  • Kim, Doyoung;Kim, Taerim;Jeong, Jaebaek;Park, Sanghyuk;Bae, Jae-Sung;Moon, Seokmin
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.50 no.7
    • /
    • pp.489-496
    • /
    • 2022
  • This paper introduces the system for KAU-SPUAV, which is designed and developed by Korea Aerospace University, and verifies its performance through flight test. Specification of two versions of KAU-SPUAV, avionics system, and Ground Control System (GCS) are introduced. Three missions are performed with suggested UAVs: LTE signal mapping, circumnavigation of Jeju island seashore, and long endurance flight. Each mission consists of long distance and long endurance flight which takes advantage of KAU-SPUAV. Research team of KAU-SPUAV confirmed its versatility through suggested flight data. Also based on flight results, the team found the potential of performance improvement of KAU-SPUAV.

Frequency of the Angiotensin - Converting Enzyme (ACE) Gene Polymorphism in the General Population and the Elite Endurance Students in Korea

  • Choung, Ho-Jin;Yoon, Song-Ro;Choi, Soo-Kyung
    • Journal of Genetic Medicine
    • /
    • v.3 no.1
    • /
    • pp.11-13
    • /
    • 1999
  • Recently it was reported that Insertion/Deletion polymorphism in the gene coding for Angiotensin-Converting Enzyme (ACE) is associated with human capacity for physical performance. This study was performed to genotyping of the ACE gene to determine the correlation between elite endurance performance and ACE I/D gene polymorphism. DNA sample was obtained from peripheral blood, hair roots and mouth epithelial cell in 739 general population and 200 elite athletic performance students. The ACE gene was amplified by polymerase chain reaction (PCR) using allele specific oligonucleotide primers. 155, 525 bp and 237 bp PCR products indicating the presence of insertion(I) and deletion(D) alleles, respectively, were clearly resolved after electrophoresis on a 2% agarose gel with ethidium bromide. Of the 200 elite athletic performance population subjects, 68(34%) showed ACE genotype 11,100(50%) genotype ID and 32(16%) genotype DD. Of the 739 general population subjects, 259(35.1%) showed ACE genotype 11,363(49.1%) genotype ID and 117(15.8%) genotype DD. Therefore ACE I/D gene polymorphism was not associated with human capacity for physical performance.(p>0.05)

  • PDF

Proposal of VO2max estimation formula for elderly men and women using functional performance measurement

  • KWON, Young-Ae;LEE, Wan-Young;KIM, Jun-Su
    • The Korean Journal of Food & Health Convergence
    • /
    • v.8 no.1
    • /
    • pp.21-30
    • /
    • 2022
  • This study proposed a multiple regression equation for predicting VO2max of elderly men and women using functional performance variables required to conduct daily activities. The subjects of this study were 58 elderly men (72.4±5.9 yrs) and 117 elderly women (73.4±4.5 yrs) aged 65-90 who belong to the senior welfare center. The maximal graded exercise test using a cycle ergometer and functional performance representing muscle strength, endurance, static and dynamic flexibility, mobility, and agility were measured. For statistical processing, multiple regression analysis was performed, and the statistical significance level was α = .05. As a result, the VO2max estimation formula for the elderly was 0.419 (standing up and sitting down a chair) + 0.199 (leg endurance against wall) + 5.383, and R2=0.406. In addition, the VO2max estimation formula for elderly women is - 0.737 (standing up from a supine position) - 0.144 (waking around two cones in a figure 8) - 0.135 (%body fat) + 0.042 (one leg balance with eyes open) + 29.395, R2=0.367 was calculated. The conclusion is that if the maximal graded exercise test is not available, it is considered that VO2max of the elderly can be predicted properly by using the estimation formula calculated based on the functional performance variable.

New convergence scheme to improve the endurance characteristics in flash memory (새로운 Convergence 방법을 이용한 플래시 메모리의 개서 특성 개선)

  • 김한기;천종렬;이재기;유종근;박종태
    • Proceedings of the IEEK Conference
    • /
    • 2000.06b
    • /
    • pp.40-43
    • /
    • 2000
  • The electrons and holes trapped in the tunneling oxide and interface-states generated in the Si/SiO$_2$ interface during program/erase (P/E) operations are known to cause reliability problems which can deteriorate the cell performance and cause the V$_{th}$ window close. This deterioration is caused by the accumulation of electrons and holes trapped in the oxide near the drain and source side after each P/E cycle. we propose three new erase schemes to improve the cell's endurance characteristics: (1)adding a Reverse soft program cycle after the source erase operation, (2)adding a detrapping cycle after the source erase operation, (3)adding a convergence cycle after the source erase operation. (3) is the most effective performance among the three erase schemes have been implemented and shown to significantly reduce the V$_{th}$ window close problem. And we are able to design the reliable periperal circuit of flash memory by using the (3).(3).

  • PDF

Development of the Limit Switch Box for a Ship and Its Performance Evaluation against Salt Water

  • Lee, Seung-Heui;Go, Seok-Jo;Lee, Min-Cheol;Kim, Chang-Dong
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 2005.06a
    • /
    • pp.1334-1338
    • /
    • 2005
  • A limit switch box is used for an indicator of a valve actuator. This device indicates an opening and closing of a valve or a throttle in the valve actuator. In a ship, equipments require safety and robustness because of a rough environment and a specific condition during a voyage. However, the limit switch box has been used in an indoor environment generally. This study developed a new limit switch box which can be used at an outdoor environment. This study designed the new limit switch box. The housing of the limit switch box was made by an aluminum die cast method with surface painting after anodizing or chromate coating. In order to evaluate the endurance of the housing, the endurance tests against salt water have been conducted. Experiment results showed that the proposed device provides a reliable performance against salt water.

  • PDF

An Analysis on the Physical Strength Factor of the Collegians Majoring in Security Services (경호전공대학생의 체력요인 분석)

  • Jeon, Man-Joong
    • Korean Security Journal
    • /
    • no.14
    • /
    • pp.431-447
    • /
    • 2007
  • The purpose of this study was to investigate the An analysis on the physical strength factor of the Collegians majoring in Security Services. In order to accomplish this purpose, subjects of this study were 80 person J university student men. Physical fitness tests was grip strength, back strength, sit-ups, stand long jump, 50m run, side step test, shuttle run, 2000m run, standing trunk flexion, and closed eye foot balance. Factor analysis applied for analysis factorial structure of each physical fitness components. The results of this study were as follow; First, the factor affecting the performance of the Collegians majoring in Security Services of their was appeared with the Power, Balance and Strength. Second, the factor affecting the performance of the Collegians majoring in Security Services of their was appeared with the Taekwondo major group with the Balance, Power, Strength and Cardiovascular Endurance. Third, the factor affecting the performance of the Collegians majoring in Security Services of their was appeared with the Judo major group with the Power, Flexibility and Strength. Fourth, the factor affecting the performance of the Collegians majoring in Security Services of their was appeared with the Hapkido major group with the Muscular Endurance, Strength, Cardiovascular Endurance and Flexibility. Fifth, the factor affecting the performance of the Collegians majoring in Security Services of their was appeared with the Gumdo major group with the Cardiovascular Endurance and Power.

  • PDF