• Title/Summary/Keyword: speed difference

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MERITS OF COMBINATION OF ACTIVE AND PASSIVE MICROWAVE SENSORS FOR DEVELOPING ALGORITHMS OF SST AND SURFACE WIND SPEED

  • Shibata, Akira;Murakami, Hiroshi
    • Proceedings of the KSRS Conference
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    • v.1
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    • pp.138-141
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    • 2006
  • In developing algorithms to retrieve the sea surface temperature (SST) and sea surface wind speed from the Advanced Microwave Scanning Radiometer (AMSR) aboard the AQUA and the Advanced Earth Observation Satellite-II (ADEOS-II), data from the SeaWinds aboard ADEOS-II were helpful. Since features of the ocean microwave emission (Tb) related with ocean wind are not well understood, in case of using only AMSR data, combination of AMSR and SeaWinds revealed pronounced features about the ocean Tb. Two results from combinations of the two sensors were shown in this paper. One result was obtained at wind speeds over about 6m/s, in which the ocean Tb varies with the air-sea temperature difference, even though the SeaWinds wind speed is fixed at the same values. The ocean Tb increases as the air-sea temperature difference becomes negative, i.e., the boundary condition becomes unstable. This result indicates that the air temperature should be included in AMSR SST algorithm. The second result was obtained from comparison of two wind speeds between AMSR and SeaWinds. There is a small difference of two wind speeds, which might be related with several mechanisms, such as evaporation and plankton.

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Effects of Spiral Balance Taping on Postural Balance Ability in Stroke Patient (뇌졸중 환자에서 스파이랄 테이핑이 자세 안정성에 미치는 영향)

  • Lee, Jeong-Hun;Jeong, Hyun-Woo;Kim, Kyung-Yoon;Park, Jong-Hang;Kim, Chan-Kyu
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.23 no.4
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    • pp.908-913
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    • 2009
  • This study was conducted to investigate the influence that it has on the application pre and post balance index using method with spiral and reaction point balance taping application against 20 stroke patients. The taping application pre and post static eye opening balance index was statistically no significant difference in the Mean X Speed, and the Extent in X Dirction but in the Mean Y Speed, the Velocity Moment, and Extent in Y Direction, there were statistically significant difference(p<0.05). The taping application pre and post static eye closing balance inde was statistically no significant difference in the Mean X Speed, in Y Direction, there were statistically significant difference(p<0.05). From above results, the method of the applied taping was the equilibrium stability performance of the Y-axis than the stability of the balance of the X-axis, therefore it is considered to study the taping application method in the balance of detail stroke patients.

Effect of Using Computer Interface on Learning Speed Concept in the Korean Elementary School (국민학교 아동들의 속력 개념 형성에서 컴퓨터 인터페이스 활용 효과)

  • Kim, Hyoung-Soo;Kwon, Jae-Sool
    • Journal of The Korean Association For Science Education
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    • v.15 no.2
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    • pp.164-172
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    • 1995
  • In this study, the researcher tried to find out the effect of using a computer interface in teaching speed concept in the elementary school. The 4th and 5th pupils were sampled for this study. The school is located in a sub-urban agricultural area in Korea. In the study, the subjects were divided into two groups: experimental and comparison group. From the pretest, two groups did not show any difference in the understanding of speed concept. The computer interface and the programs to operate the interface and data analysis were developed by researcher. The interface is a modular type and designed ready to connect to microcomputer. The test items were consisted of (1) comparison of speed, (2) change of motion, (3) acceleration, and (4) deceleration. As the result, the researcher found the following results: 1. In case of speed comparison, no significant difference was found between experimental and comparison group. 2. In case of change of motion, acceleration, and deceleration, the experimental groups showed higher achievement both in 4th grade and 5th grade. However, the 4th graders showed more learning than the 5th graders. In conclusion, this study showed that the use of computer interface seemed to be very effective in teaching and learning speed concept in elementary school.

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Train Performance Characteristics of Korean Rubber-Tired AGT System by TPS (TPS를 이용한 한국형 고무차륜경량전철(K-AGT)의 성능특성 분석)

  • Lee Dong-Hyong;Goo Dong-Hoe
    • Proceedings of the KSR Conference
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    • 2005.11a
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    • pp.799-804
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    • 2005
  • In this work, the characteristics of train performance of Korean rubber-tired AGT system(K-AGT) are evaluated by using TPS(Train Performance Simulation) and these results are compared to those of other LRT(Light Rail Transit) systems. The performance characteristics of K-AGT was analyzed by comparing the scheduled speed and the energy consumption in case of station interval change and rail track condition change in, the scheduled construction line. In the scheduled construction line, scheduled speed of K-AGT was no difference with other systems and energy consumption was less than other LRT's. In case station intervals are increased, scheduled speed of K-AGT shows similar increasing rate and in curved and graded track conditions K-AGT has no difference in scheduled speed with other systems. As a simulation result by track condition change, when the track which is smaller than curved line of 250m dominates more than $50\%$ in whole track, K-AGT is similar to other systems to the point of scheduled speed and there is advantage in energy consumption.

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Design of High-Speed Comparators for High-Speed Automatic Test Equipment

  • Yoon, Byunghun;Lim, Shin-Il
    • IEIE Transactions on Smart Processing and Computing
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    • v.4 no.4
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    • pp.291-296
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    • 2015
  • This paper describes the design of a high-speed comparator for high-speed automatic test equipment (ATE). The normal comparator block, which compares the detected signal from the device under test (DUT) to the reference signal from an internal digital-to-analog converter (DAC), is composed of a rail-to-rail first pre-amplifier, a hysteresis amplifier, and a third pre-amplifier and latch for high-speed operation. The proposed continuous comparator handles high-frequency signals up to 800MHz and a wide range of input signals (0~5V). Also, to compare the differences of both common signals and differential signals between two DUTs, the proposed differential mode comparator exploits one differential difference amplifier (DDA) as a pre-amplifier in the comparator, while a conventional differential comparator uses three op-amps as a pre-amplifier. The chip was implemented with $0.18{\mu}m$ Bipolar CMOS DEMOS (BCDMOS) technology, can compare signal differences of 5mV, and operates in a frequency range up to 800MHz. The chip area is $0.514mm^2$.

The Influences of Speed desire frustration on Driving Stress (운전자의 속도 욕구좌절이 운전 스트레스에 미치는 영향)

  • Soon yeol Lee ;Soon chul Lee
    • Korean Journal of Culture and Social Issue
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    • v.15 no.2
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    • pp.319-338
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    • 2009
  • This study was intended to recognize whether speed desire frustration influences in driving stress. Stress desire frustration is the difference between prefer speed and normal speed. As a result, driver's the prefer speed is higher than the normal speed on 4 road condition(high-way, urban-way, residential-way, rural-way). Also, driver's speed desire frustration caused statistical effect in driving stress on 4 road condition. speed desire frustration effect Driving Stress Scale(DSS) 5 sub-scale factors(progress obstacle, traffic circumstance, accident & regulation, regulation obedience, time pressure). This is that driver who experience much speed desire frustration creates high driving stress. Speed desire frustration analyzed high driver and low driver's Driving Stress Scale(DSS) score and overspeed regulation and traffic accident experience difference. As analysis result, speed desire frustration high driver driving stress high appear. However, difference of overspeed regulation experience or traffic accident experience by speed desire frustration did not appear.

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The Effects of the Inline-Skating Exercise on the Static Balance (인라인 스케이트 운동이 정적균형에 미치는 영향)

  • Shin, Ki-Sang;Lee, Su-Jung;Jang, Su-Youl;Han, Min-Young;Han, Ji-Hye;Lee, Sam-Cheol;Son, Kyung-Hyun;Cho, Nam-Jung;Choi, Won-Jye
    • Journal of the Korean Academy of Clinical Electrophysiology
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    • v.6 no.1
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    • pp.91-101
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    • 2008
  • The purpose of this study was to investigate the effects of Inline-skating exercise on the static balance. Total 10 subjects with common were recruited from university for student in Kwangyang, and the Inline-skating exercise was conducted 3times at a week during 2 weeks. Balance test was measured by using Good Balance with overall index, NSEO(normal standing when eye open), NSEC(normal standing when eye close), OLREO(one leg right standing when eye open), OLREC(one leg right standing when eye close), OLLEO(one leg left standing when eye open), OLLEC(one leg left standing There was statistically significant difference of the balance ability of the left-right only between the before and the after exercise in the case of NSEO position. however, the statistically difference was not found in terms of the Mean X speed, Mean Y speed, Velocity moment between the before and the after exercise in the case of NSEC position. There was statistically significant difference of the balance ability of the Mean X speed, Mean Y speed between the before and the after exercise in the case of OLLEO and OLLEC position, however, the statistically difference was not found in terms of the Velocity moment between the before and the after exercise in this case. There was statistically significant difference of the balance ability of all the terms between the before and the after exercise in the case of OLREO. however, the statistically difference was not found in terms of the Mean Y speed only between the before and the after exercise in the case of OLREC. In this case, the statistically difference was found in terms of Velocity moment between the before and the after exercise. This study showed that Inline-skating exercise was effected on the improvement of the balance ability in normal peoples.

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Critical Speed Analysis of a 75 Ton Class Liquid Rocket Engine Turbopump due to Load Characteristics (75톤급 액체로켓엔진 터보펌프의 하중 특성에 따른 임계속도 해석)

  • Jeon, Seong-Min;Kwak, Hyun-D.;Hong, Soon-Sam;Kim, Jin-Han
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2011.11a
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    • pp.22-29
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    • 2011
  • Critical speed of high thrust liquid rocket engine turbopump is obtained through a rotordynamic analysis and a unloaded turbopump test is peformed for validation of the numerical model. The first critical speed predicted by the numerical analysis is correlated well with the test result for the bearing unloaded rotor condition only considering mass unbalance load. Using the previous rotordynamic model, critical speed variation is estimated as a function of varied bearing stiffness due to pump and turbine radial loads with relative angle difference. From the numerical analysis, it is found that the relative angle difference of pump and turbine radial loads greatly affects the critical speed. However, additional axial load reduces the effect derived from the relative angle difference of radial loads.

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Critical Speed Analysis of a 75 Ton Class Liquid Rocket Engine Turbopump due to Load Characteristics (75톤급 액체로켓엔진 터보펌프의 하중 특성에 따른 임계속도 해석)

  • Jeon, Seong-Min;Kwak, Hyun-D.;Hong, Soon-Sam;Kim, Jin-Han
    • Journal of the Korean Society of Propulsion Engineers
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    • v.16 no.4
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    • pp.42-49
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    • 2012
  • Critical speed of high thrust liquid rocket engine turbopump is obtained through a rotordynamic analysis and a unloaded turbopump test is peformed for validation of the numerical model. The first critical speed predicted by the numerical analysis is correlated well with the test result for the bearing unloaded rotor condition only considering mass unbalance load. Using the previous rotordynamic model, critical speed variation is estimated as a function of varied bearing stiffness due to pump and turbine radial loads with relative angle difference. From the numerical analysis, it is found that the relative angle difference of pump and turbine radial loads greatly affects the critical speed. However, additional axial load reduces the effect derived from the relative angle difference of radial loads.

Assessment of Gait Ability of Subjects With Chronic Ankle Instability During an Inter-trial Variability Gait Task According to Changes in Gait Speed

  • Jeonghan Kwon;Jongduk Choi
    • Physical Therapy Korea
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    • v.30 no.4
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    • pp.268-274
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    • 2023
  • Background: Ankle sprains occur frequently among humans who undertake various body movements. Diverse walking environments and dual tasks, that can affect ankle sprains, have been studied. However, there is a lack of research on inter-trial variability according to the changes in gait speed. Objects: The purpose of this study was to compare the adaptive ability of walking between the subjects with chronic ankle instability and healthy adults while performing a walking task with different walking speeds. Methods: In this study, 24 people in the chronic ankle instability group and 24 people in the healthy ankle group were selected as subjects. The length of the pre-measurement and the actual walking measurement were both set to 4.6 m. Once the subjects entered the measurement section, they changed their gait speed according to the randomly assigned speed change. Gait was measured twice and the average value was used for the analysis. Results: The coefficient of variation (CV) of cycle time in subjects with chronic ankle instability showed a significant difference in all cases except when the subjects changed their speed from preferred to slow and from slow to preferred. The CV of step length demonstrated a significant difference in all cases except for the change from slow to preferred and from preferred to fast. The cycle time and step length differential showed a significant difference only when the subjects changed the speed from slow to fast. Conclusion: The subjects with chronic ankle instability were found to have significantly reduced walking adaptability while performing inter-trial variability tasks with different gait speeds compared to healthy subjects.