• 제목/요약/키워드: speed difference

검색결과 2,560건 처리시간 0.031초

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

  • Shibata, Akira;Murakami, Hiroshi
    • 대한원격탐사학회:학술대회논문집
    • /
    • 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume I
    • /
    • pp.138-141
    • /
    • 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.

  • PDF

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

  • 이정훈;정현우;김경윤;박종항;김찬규
    • 동의생리병리학회지
    • /
    • 제23권4호
    • /
    • pp.908-913
    • /
    • 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.

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

  • 김형수;권재술
    • 한국과학교육학회지
    • /
    • 제15권2호
    • /
    • pp.164-172
    • /
    • 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.

  • PDF

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

  • 이동형;구동회
    • 한국철도학회:학술대회논문집
    • /
    • 한국철도학회 2005년도 추계학술대회 논문집
    • /
    • pp.799-804
    • /
    • 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.

  • PDF

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

  • Yoon, Byunghun;Lim, Shin-Il
    • IEIE Transactions on Smart Processing and Computing
    • /
    • 제4권4호
    • /
    • pp.291-296
    • /
    • 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 $0.514mm^2$.

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

  • 이순열 ;이순철
    • 한국심리학회지 : 문화 및 사회문제
    • /
    • 제15권2호
    • /
    • pp.319-338
    • /
    • 2009
  • 본 연구는 차량 운전 중 운전자가 원하는 속도만큼 속도를 내지 못하는 상황이 운전 스트레스에 어떠한 영향을 미치는지를 알아보고자 실시되었다. 운전자의 속도에 대한 욕구좌절은 희망 주행속도와 실제 주행속도의 차이로 구성개념화 되었다. 연구결과 4가지 도로조건(고속도로, 국도도로, 시내도로, 시골도로) 모두에서 운전자들의 희망 주행속도는 실제 주행속도보다 높게 나타났다. 4가지 도로조건(고속도로, 국도도로, 시내도로, 시골도로)을 종합한 평균 속도 욕구좌절은 운전 스트레스 척도 모든 점수(전체 DSQ점수, 전체 DSI점수, 전체 DSF점수, 진행장애 요인, 운전환경 요인, 사고단속 요인, 교통법규 요인, 시간압력 요인)들에 정적으로 유의한 영향을 미치는 것으로 나타났다. 특히, 속도 욕구좌절이 높아짐에 따라 운전 스트레스 척도의 강도 점수와 진행장애 요인, 시간압력 요인 등이 다른 운전 스트레스 척도 점수들보다 더 큰 영향을 받는 것으로 나타났다. 평균 속도 욕구좌절을 백분위 점수에 따라 4가지 수준으로 구분하여 운전 스트레스 척도 점수들과 과속단속 그리고 가해·피해 교통사고 경험 차이를 분석하였다. 분석결과 속도 욕구좌절이 높은 운전자들은 속도 욕구좌절이 낮은 운전자들보다 운전 스트레스 척도의 점수들도 유의하게 높은 것으로 나타났다. 하지만, 속도 욕구좌절 정도에 따른 과속단속 경험이나 가해·피해사고 경험은 차이가 나타나지 않았다.

  • PDF

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

  • 전성민;곽현덕;홍순삼;김진한
    • 한국추진공학회:학술대회논문집
    • /
    • 한국추진공학회 2011년도 제37회 추계학술대회논문집
    • /
    • pp.22-29
    • /
    • 2011
  • 고추력 액체 로켓 엔진용 터보펌프의 무부하 회전 시험을 통하여 얻어진 임계속도를 회전체동역학 해석으로부터 예측된 임계속도와 상호 비교하여 해석 모델의 타당성을 검토하였다. 질량 불평형 하중만을 고려한 베어링 무부하 하중조건에서 해석으로부터 얻어지는 1차 임계속도의 예측치는 시험에서 얻어진 결과와 잘 일치하였다. 상기 회전체동역학 모델을 이용하여 유동해석 및 성능시험 결과를 바탕으로 얻어진 펌프와 터빈의 반경하중으로부터, 반경하중 상대 각도에 따른 베어링 강성 변화를 고려하여 임계속도 변화를 예측하였다. 수치해석 결과 펌프와 터빈의 반경하중 상대 각도는 임계속도에 지대한 영향을 미치고 있는 것으로 나타났다. 반면 추가로 축하중이 부과되는 경우 반경하중의 상대 각도에 대한 영향은 감소하는 것으로 나타났다.

  • PDF

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

  • 전성민;곽현덕;홍순삼;김진한
    • 한국추진공학회지
    • /
    • 제16권4호
    • /
    • pp.42-49
    • /
    • 2012
  • 고추력 액체 로켓 엔진용 터보펌프의 무부하 회전 시험을 통하여 얻어진 임계속도를 회전체동역학해석으로부터 예측된 임계속도와 상호 비교하여 해석 모델의 타당성을 검토하였다. 질량 불평형 하중만을 고려한 베어링 무부하 하중조건에서 해석으로부터 얻어지는 1차 임계속도의 예측치는 시험에서 얻어진 결과와 잘 일치하였다. 상기 회전체동역학 모델을 이용하여 유동해석 및 성능시험 결과를 바탕으로 얻어진 펌프와 터빈의 반경하중으로부터, 반경하중 상대 각도에 따른 베어링 강성 변화를 고려하여 임계속도 변화를 예측하였다. 수치해석 결과 펌프와 터빈의 반경하중 상대 각도는 임계속도에 지대한 영향을 미치고 있는 것으로 나타났다. 반면 추가로 축하중이 부과되는 경우 반경하중의 상대 각도에 대한 영향은 감소하는 것으로 나타났다.

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
    • 한국전문물리치료학회지
    • /
    • 제30권4호
    • /
    • pp.268-274
    • /
    • 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.

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

  • 신기상;이수정;장수열;한민영;한지혜;이삼철;손경현;조남정;최원제
    • 대한임상전기생리학회지
    • /
    • 제6권1호
    • /
    • pp.91-101
    • /
    • 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.

  • PDF