• 제목/요약/키워드: Direct Sampling Method

검색결과 223건 처리시간 0.03초

시스템 매개변수 직접추정법의 특성 (Characteristics of a direct system parameter estimation method)

  • 주영호;조광환;이건명
    • 대한기계학회논문집A
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    • 제21권9호
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    • pp.1480-1490
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    • 1997
  • A method by which the system parameter matrices can be estimated from measured time data of excitation force and acceleration has been studied. The acceleration data are integrated numerically to obtain the velocities and displacements, and the systm parameters are estimated from these data by solving equations of motion. The characteristics of the method have been investigated through its application to simulated data of 1 DOF and 2 DOF systems and experimental data measured from a simple structure. It was found that the method is very sensitive to measurement noise and the accuracy of the estimated parameters can be improved by averaging the repeatedly measured data and removing the noise. One of the main advantages of the parameter estimation method is that no a priori information about the system under test is required. The method can be easily extended to non-linear parameter estimation.

장애인의 차량 탑승 시 휠체어 수납에 대한 만족도 조사 (The Research of People with Disabilities Satisfaction about Loading Wheelchair while Boarding on Vehicle)

  • 이근민;이진현;이수철
    • 재활복지공학회논문지
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    • 제3권1호
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    • pp.1-6
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    • 2009
  • 본 조사는 휠체어를 사용하는 장애인이 차량을 탑승할 때 휠체어 수납에 대한 불편함을 파악하여, 향후 관련 제품 개발에 개념설계를 하고자 실시하였다. 연구는 수동휠체어를 사용하고 있으며, 자가 운전을 할 수 있는 장애인 50명을 대상으로 직접 면담하는 설문조사 방식으로 실시하였다. 그 결과 설문에 참여한 88%의 장애인이 차량에 휠체어를 수납할 수 있는 보조 장치의 개발이 필요하다고 응답하였다. 이러한 장치로써 차량 트렁크에서 로봇팔이 차량의 운전석 문까지 나와서 휠체어를 트렁크에 수납하는 방법을 가장 선호하였다.

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어머니의 촉진적 의사소통이 아동의 사회적 적응에 미치는 영향과 자기조절 능력의 매개효과 (The Effect of Mother's Facilitative Communication on Children's Social Adjustment and the Mediating Effect of Self-Regulation)

  • 김영희;정희정
    • 한국지역사회생활과학회지
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    • 제18권4호
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    • pp.671-679
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    • 2007
  • This study investigated the relationship between maternal facilitative communication perceived by children and the social adjustment which was measured as pro-social behaviors and aggressive behaviors in children. Special attention was given to the mediating effect of the child's self-regulation on the relationship. The subjects, selected by convenience sampling method, were 193 fourth and fifth grade elementary school students. Data was analyzed through Pearson's correlation, reliability analysis, and multiple regression using the SPSS 12.0. The findings of the study were as follows. First, the mother's facilitative communication perceived by the child was positively associated with the pro-social behavior, while, it was negatively correlated with the aggressive behavior of the child. Second, the mother's facilitative communication had direct effect on the prosocial behavior and the aggressive behavior of the child. Third, the direct impact of facilitative communication on social adjustment was mediated by the self-regulation variable. Based on these findings, this study proposes strategies for the improvement of children's adjustment during late childhood.

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유도전동기 직접토크제어의 히스테리시스 밴드 크기의 최적화에 관한 연구 (A Study of Using Optimal Hysteresis Band Amplitude for Direct Torque Control of Induction Motor)

  • 정병호;김성결;박정국;오금곤;조금배;백형래
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2003년도 춘계전력전자학술대회 논문집(2)
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    • pp.812-815
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    • 2003
  • Most of all, DTC drive is very simple in its implementation because it needs only two hysteresis comparator and switching vector table for both flux and torque control. The switching strategy of a conventional direct torque control scheme which is based on hysteresis comparator results in a variable switching frequency which depends on the speed, flux, stator voltage and the hysteresis of the comparator. The amplitude of hysteresis band greatly influences on the drive performance such as flux and torque ripple and inverter switching frequency. In this paper the influence of the amplitudes of flux and torque hysteresis bands and sampling time of control program on the torque and flux ripples are investigated. Simulation results confirm the superiority of the DTC under the proposed method over the conventional DTC.

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직접반사형 포토센서를 이용한 스톨 사육 모돈의 인공수정적기 예측 장치 개발 (Development of a Device for Estimating the Optimal Artificial Insemination Time of Individually Stalled Sows Using Direct-reflex Photo-sensors)

  • 김동주;연성찬;장홍희
    • Journal of Biosystems Engineering
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    • 제29권6호
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    • pp.515-520
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    • 2004
  • A device far estimating the optimal artificial insemination time consisted of a computer, RS module, and six direct-reflex photo-sensors. Program was written in LabWindows CVI. In order to establish references for estimating optimal artificial insemination time, lying rate of the thirty three $Berkshire{\times}Hampshire crossbred sows (parity 5 to 6) was recorded from 2 days after moving into stalls to artificial insemination using a time lapse VCR and was measured every hour with one minute interval using the scan point sampling method. Twenty low hours in a day were divided into three comparing periods : 21:00 to 06:59, 07:00 to 13:59, and 14:00 to 20:59. If sum of the percentages of tying during a comparing period was less than the reference value, the starting hour of the comparing period was considered as onset of estrus and the optimal artificial insemination time was estimated at 20 to 24 hours after onset of estrus. The experimental device was evaluated with twenty five $Berkshire{\times}Hampshire$ crossbred sows (parity 2 to 7) and 23 of 25 sows $(92\%)$ were pregnant. This result suggests that the experimental device is excellent in performance for estimating optimal artificial insemination time.

How Customer Experience Management Can Improve the Distribution of Marketing Performance

  • Sri, SAFITRI;Achmad, SUDIRO;Fatchur, ROHMAN;Mugiono, MUGIONO
    • 유통과학연구
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    • 제21권2호
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    • pp.53-63
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    • 2023
  • Purpose: This study aims to determine the effect of Customer Experience Management (CEM) on the distribution of Marketing Performance mediated by Digital Business Innovation (DBI), Digital Operational Excellence (DOE), and Digital Value Co-Creation (DVC) in Indonesia Information & Technology (IT) industry. Research design, data, and methodology: This research was conducted in two stages, namely exploratory and explanatory on IT companies in Indonesia. The authors took 132 samples using proportionate random sampling method in three groups of companies. Results: The results showed that CEM had no significant positive effect on the distribution of Marketing Performance. CEM has no direct effect on the distribution of Marketing Performance through the mediation of DBI. CEM has direct effect on the distribution of Marketing Performance through the mediation of DOE and DVC. DBI has no significant effect in increasing the distribution of Marketing Performance. However, DOE and DVC have a significant effect in increasing the distribution of Marketing Performance. Conclusion: The distribution of Marketing Performance can be indicated better through CEM through mediation.

The Effect of Entrepreneurial Orientation and Talent Management on Business Performance of the Creative Industries in Indonesia

  • MUDJIJAH, Slamet;SURACHMAN, Surachman;WIJAYANTI, Risna;ANDARWATI, Andarwati
    • The Journal of Asian Finance, Economics and Business
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    • 제9권1호
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    • pp.105-119
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    • 2022
  • This study aims to develop a concept based on empirical research on improving optimal business performance. This goal is achieved by examining the relationship between variables of entrepreneurial orientation, talent management, market orientation, and business performance. The construction of the relationship between research variables, namely entrepreneurial orientation, talent management, on business performance is mediated by market orientation on handicraft businesses in Indonesia. The sampling method was used to collect data from 145 businessmen in Indonesia, using surveys and questionnaires. Data was collected using a survey technique carried out from June 2020 to December 2020. The data obtained was analyzed using the PLS Pro 19. This study developed 9 hypotheses that were tested directly, indirectly, and through mediation. This study has five findings. First, Entrepreneurship Orientation does not directly affect Business Performance. Second, Entrepreneurship Orientation also has a significant direct effect on Talent Management and market orientation. Third, Talent Management and market orientation have a direct and significant impact on business performance. Fourth, market orientation mediates the effect of entrepreneurial orientation on business performance. Fifth, talent management mediates the effect of entrepreneurial orientation on business performance. The results show that entrepreneurial orientation mediated by talent management and market orientation can improve creative industry business performance for the better.

B 스플라인 보간을 이용한 고화질 볼륨 가시화 (High quality volume visualization using B-spline interpolation)

  • 신용하;계희원
    • 한국컴퓨터그래픽스학회논문지
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    • 제22권3호
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    • pp.1-9
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    • 2016
  • 볼륨 가시화의 샘플링 단계에서는 보통 선형 보간이 사용된다. 선형 보간은 일반적으로 좋은 화질의 영상을 생성하지만 의료영상 소프트웨어는 높은 화질의 영상이 필요하기 때문에 경우에 따라 높은 기대에 미치지 못한다. 본 연구는 샘플링 단계에서 B 스플라인을 기반으로 하는 삼차 보간을 수행한다. 기존의 B 스플라인은 제어점을 지나지 않는 근사 함수이므로, 본 연구는 제어점을 이동하여 생성된 곡선이 원래의 제어점을 지나도록 하였다. 가시화 단계에서는 속도를 향상하기 위해 빈공간 도약을 적용 가능하다. 빈공간을 파악하기 위해서는 각 블록에 대한 최대값과 최소값을 계산해야 한다. B 스플라인은 볼록포 성질이 있어서, 제어점의 값을 최대값과 최소값으로 사용할 수 있다. 그 결과로 삼차 보간 기반의 볼륨 가시화가 대화적 속도로 가능하다.

Multichannel Analysis of Surface Waves (MASW) Active and Passive Methods

  • Park, Choon-Byong
    • 한국지구물리탐사학회:학술대회논문집
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    • 한국지구물리탐사학회 2006년도 공동학술대회 논문집
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    • pp.17-22
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    • 2006
  • Shear modulus is directly linked to material's stiffness and is one of the most critical engineering parameters. Seismically, shear-wave velocity (Vs) is its best indicator. Although methods like refraction, down-hole, and cross-hole shear-wave surveys can be used, they are generally known to be tougher than any other seismic methods in field operation, data analysis, and overall cost. On the other hand, surface waves, commonly known as ground roll, are always generated in all seismic surveys with the strongest energy, and their propagation velocities are mainly determined by Vs of the medium. Furthermore, sampling depth of a particular frequency component of surface waves is in direct proportion to its wavelength and this property makes the surface wave velocity frequency dependent, i.e., dispersive. The multichannel analysis of surface waves (MASW) method tries to utilize this dispersion property of surface waves for the purpose of Vs profiling in 1-D (depth) or 2-D (depth and surface location) format. The active MASW method generates surface waves actively by using an impact source like sledgehammer, whereas the passive method utilizes those generated passively by cultural (e.g., traffic) or natural (e.g., thunder and tidal motion) activities. Investigation depth is usually shallower than 30 m with the active method, whereas it can reach a few hundred meters with the passive method. Overall procedures with both methods are briefly described.

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유전자 알고리즘을 이용한 차량 승차감 개선에 관한 연구 (A Study on the Improvement of Vehicle Ride Comfort by Genetic Algorithms)

  • 백운태;성활경
    • 한국자동차공학회논문집
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    • 제6권4호
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    • pp.76-85
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    • 1998
  • Recently, Genetic Algorithm(GA) is widely adopted into a search procedure for structural optimization, which is a stochastic direct search strategy that mimics the process of genetic evolution. This methods consist of three genetics operations maned selection, crossover and mutation. Contrast to traditional optimal design techniques which use design sensitivity analysis results, GA, being zero-order method, is very simple. So, they can be easily applicable to wide area of design optimization problems. Also, owing to multi-point search procedure, they have higher probability of converge to global optimum compared to traditional techniques which take one-point search method. In this study, a method of finding the optimum values of suspension parameters is proposed by using the GA. And vehicle is modelled as planar vehicle having 5 degree-of-freedom. The generalized coordinates are vertical motion of passenger seat, sprung mass and front and rear unsprung mass and rotate(pitch) motion of sprung mass. For rapid converge and precluding local optimum, share function which distribute chromosomes over design bound is introduced. Elitist survival model, remainder stochastic sampling without replacement method, multi-point crossover method are adopted. In the sight of the improvement of ride comfort, good result can be obtained in 5-D.O.F. vehicle model by using GA.

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