• Title/Summary/Keyword: "S" characteristic

검색결과 8,633건 처리시간 0.039초

OTA-based precision full-wave rectifier

  • Riewtuja, V.;Chaikla, A.;Tammarugwattana, N.;Julsereewong, P.;Surakampontorn, W.
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1999년도 제14차 학술회의논문집
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    • pp.259-261
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    • 1999
  • An operational transconductance amplifier (OTA) based precision full-wave rectifier circuit is presented in this article. The proposed circuit has a very sharp corner in the DC transfer characteristic and simple configuration comprised three OTAs and one current mirror. The temperature dependence of the OTA transconductance is reduced. Experimental results demonstrating the characteristic of the circuit are included.

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미지물체를 안전하게 잡기 위한 6축 로봇손가락 힘/모멘트센서의 개발 (Development of a 6-axis Robot's Finger Force/Moment Sensor for Stably Grasping an Unknown Object)

  • 김갑순
    • 한국정밀공학회지
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    • 제20권7호
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    • pp.105-113
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    • 2003
  • This paper describes the development of a 6-axis robot's finger force/moment sensor, which measures forces Fx, Fy, Fz, and moments Mx, My, Mz simultaneously, for stably grasping an unknown object. In order to safely grasp an unknown object using the robot's gripper, it should measure the force in the gripping direction and the force in the gravity direction, and perform the force control using the measured forces. Thus, the robot's gripper should be composed of 6-axis robot's finger force/moment sensor that can measure forces Fx, Fy, Fz, and moments Mx, My, Mz simultaneously. In this paper, the 6-axis robot's finger force/moment sensor for measuring forces Fx, Fy, Fz, and moments Mx, My, Mz simultaneously was newly modeled using several parallel-plate beams, designed, and fabricated. The characteristic test of made sensor was performed. and the result shows that interference errors of the developed sensor are less than 3%. Also, Robot's gripper with the 6-axis robot's finger force/moment sensor for the characteristic test of force control was manufactured, and the characteristic test for grasping an unknown object was performed using it. The fabricated gripper could grasp an unknown object stably. Thus, the developed 6-axis robot's finger force/moment sensor may be used for robot's gripper.

로봇의 그리퍼 제작을 위한 6 축 로봇손가락 힘/모멘트센서의 개발 (Development of a 6-axis robot's finger force/moment sensor for making a robot's gripper)

  • 김갑순;이헌두;박인철;손영훈
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2003년도 춘계학술대회
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    • pp.758-763
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    • 2003
  • This paper describes the development of a 6-axis robot's finger force/moment sensor, which measures forces Fx, Fy, Fz, and moments Mx, My, Mz simultaneously, for making a robot's gripper. In order to safely grasp and unknown object using the robot's gripper, it should measure the force in the gripping direction and the force in the gravity direction, and perform the force control using the measured forces. Thus, the robot's gripper should be composed of 6-axis robot's finger force/moment sensor that can measure forces Fx, Fy, Fz, and moments Mx, My, Mz simultaneously. In this paper, the 6-axis robot's finger force/moment sensor for measuring forces Fx, Fy, Fz, and moments Mx, My, Mz simultaneously was newly modeled using several parallel-plate beams, designed, and fabricated. The characteristic test of made sensor was performed. Also, Robot's gripper with the 6-axis robot's finger force/moment sensor for the characteristic test of force control was manufactured, and the characteristic test for grasping an unknown object was performed using it.

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패션 브랜드 모바일 SNS의 특성에 관한 실험적인 질적 연구 - 모바일 페이스북(Facebook)을 중심으로 - (An experimental qualitative study on the characteristics of fashion brand's mobile SNS - Focusing on mobile Facebook -)

  • 이유정;이영주
    • 복식문화연구
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    • 제21권6호
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    • pp.877-890
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    • 2013
  • This study was an experimental qualitative study on the characteristics of fashion brand's mobile SNS. The study was focused on mobile Facebook and identified the characteristics of fashion brand's mobile SNS. In-depth interviews were conducted with 10 people in the 20s, who have used fashion brand's mobile Facebook application and currently live in Seoul or Gyeonggi province. After analysis of the in-depth interview data, four characteristics of fashion brand's mobile SNS were identified as follows. First, it was possible to access fashion brand's mobile SNS at any time anywhere, if users needed brand-related information. In this study, this characteristic was named 'fashion accessibility'. Second, it was possible to access update-information using fashion brand's mobile SNS or get up-to-date information about the brand in real-time. In this study, this characteristic was named 'fashion recentness'. Third, it was possible to store or capture fashion brand-related images and texts. In this study, this characteristic was named 'ease of storage of fashion data'. Fourth, fashion brand's mobile SNS was useful in various ways to fashion consumers, so this characteristic was named 'fashion usefulness' in this study. The study extracted 10 sub-characteristics of the characteristics of fashion brand's mobile SNS based on the results of a qualitative study. This study has significant value which suggests directions for future research. Also, this paper is expected to provide managerial implications to fashion companies that need to develop mobile SNS marketing strategies.

Application of Multiple Parks Vector Approach for Detection of Multiple Faults in Induction Motors

  • Vilhekar, Tushar G.;Ballal, Makarand S.;Suryawanshi, Hiralal M.
    • Journal of Power Electronics
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    • 제17권4호
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    • pp.972-982
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    • 2017
  • The Park's vector of stator current is a popular technique for the detection of induction motor faults. While the detection of the faulty condition using the Park's vector technique is easy, the classification of different types of faults is intricate. This problem is overcome by the Multiple Park's Vector (MPV) approach proposed in this paper. In this technique, the characteristic fault frequency component (CFFC) of stator winding faults, rotor winding faults, unbalanced voltage and bearing faults are extracted from three phase stator currents. Due to constructional asymmetry, under the healthy condition these characteristic fault frequency components are unbalanced. In order to balanced them, a correction factor is added to the characteristic fault frequency components of three phase stator currents. Therefore, the Park's vector pattern under the healthy condition is circular in shape. This pattern is considered as a reference pattern under the healthy condition. According to the fault condition, the amplitude and phase of characteristic faults frequency components changes. Thus, the pattern of the Park's vector changes. By monitoring the variation in multiple Park's vector patterns, the type of fault and its severity level is identified. In the proposed technique, the diagnosis of faults is immune to the effects of unbalanced voltage and multiple faults. This technique is verified on a 7.5 hp three phase wound rotor induction motor (WRIM). The experimental analysis is verified by simulation results.

Characteristic Changes of the Changma Season in the 2000s

  • Lee, Jun-Youb;Yoon, Ill-Hee
    • 한국지구과학회지
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    • 제33권5호
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    • pp.422-433
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    • 2012
  • The purpose of this study is to investigate the characteristic changes of the Changma season in the 2000s. To accomplish this goal, we have used daily rainfall data collected over nearly 40 years (1971 to 2010). The average summer precipitation data including the Changma season were collected from 16 weather stations that are placed across the three major regions (i.e. central region, southern region, and Jeju region) as Korea Meteorological Administration divided. These precipitation data were analyzed to find out characteristic changes of the Changma season. Results of the precipitation data comparison among the major regions that, monthly average precipitation in the central region was the highest in July; its precipitation tended to increase from May to September. In the southern region, the precipitation amount was lowest in June and tended to increase in May, September, and August. In the Jeju region, the precipitation has been the highest in June and July for the past 30 years, whereas September has been highest month in the last 10 years. The precipitation amount in the Jeju region decreased both in June and July, whereas it tended to grow in May, August and September. A correlation coefficient formula by Karl Pearson has been used to find out correlations between the Changma season and the precipitation of the major regions in 2000s and normal years. It was found that the correlation coefficient has decreased from 0.723 to 0.524 in the 2000s (2001 to 2010) compared to normal years (1971 to 2000).