• 드라이브 ㆍ 컨트롤
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• 제18권4호
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• pp.77-83
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• 2021

With the progress in virtual reality technology, various virtual objects can be displayed using head-mounted displays (HMD). However, force feedback sensations such as pushing against a virtual object are not possible with an HMD only. Focusing on force feedback, desktop-type devices are generally used, but the user cannot move in a virtual space because such devices are fixed on a desk. With a wearable force feedback device, users can move around while experiencing force feedback. Therefore, the authors have developed a wearable force feedback device using a magnetorheological fluid clutch and pneumatic rubber artificial muscle, aiming at presenting the elasticity, friction, and viscosity of an object. To date, we have developed a wearable four-degree-of-freedom (4-DOF) force feedback device and have quantitatively evaluated that it can present commanded elastic, frictional, and viscous forces to the end effector. However, sensory evaluation with a human has not been performed. In this paper, therefore, we conduct a sensory evaluation of the proposed method. In the experiment, frictional and viscous forces are rendered in a virtual space using a 4-DOF force feedback device. Subjects are asked to answer questions on a 1- to 7-point scale, from 1 (not at all) to 4 (neither) to 7 (strongly). The Wilcoxon signed rank test was used for all data, and answer 4 (neither) was used as compared standard data. The experimental results confirmed that the user could feel the presence or absence of viscous and frictional forces. However, the magnitude of those forces was not sensed correctly.

• 대한안전경영과학회지
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• 제12권4호
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• pp.265-272
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• 2010

This study examined the relative effects of weekly and daily group feedback on the customer service behaviors in a gas station. Participants were four employees providing full services to the customers. Four target service behaviors, which were identified from the job description for the employees, served as the dependent variables. The data were collected by a supervisor. The independent variable was the frequency of group feedback on the four service behaviors: weekly and daily group feedback. An ABC within group design was adopted. After baseline (A), the weekly group feedback condition (B) was introduced. In the next phase, the daily group feedback condition (C) was introduced. Both weekly and daily group feedback were presented in a graph form and posted at a conspicuous location. Results showed that both weekly feedback and daily feedback conditions were effective in increasing the target behaviors. And, there was difference in the effects between the two conditions.

• 대한안전경영과학회지
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• 제7권5호
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• pp.213-231
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• 2005

Assignable causes producing temporary deviation from the underlying system can influence on process adjustment and process monitoring in dynamic feedback control system. In this paper, the influence of assignable causes on EWMA forecasts and compensatory variables are derived for a dynamic feedback control system. An example is presented to confirm the impact numerically through the analysis of a data.

• 정보처리학회논문지:소프트웨어 및 데이터공학
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• 제6권2호
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• pp.91-102
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• 2017

많은 웨어러블 스마트 피트니스 장치들이 심박수와 관련된 서비스를 제공한다. 이러한 서비스는 통계를 기반으로 사전 결정한 고정 수치를 기준으로 이용한다. 그러나 사람들의 신체조건은 개개인마다 다르기 때문에, 모든 개개인을 같은 기준으로 적용하는 서비스는 신뢰성이 낮다. 본 논문에서는 사용자의 운동 능력에 맞추어 심박수의 기준이 변동하는 피드백-RFC 모델과, 모델을 구현하는 방법을 제안한다. 그리고 12명의 실험참가자들로부터 심장박동 데이터를 수집하여 모델을 평가함으로써 제안 모델의 효용성을 보인다.

• 한국산학기술학회논문지
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• 제16권5호
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• pp.3220-3229
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• 2015

본 연구의 목적은 환경적 요인으로서 팀 피드백 환경이 팀원들의 피드백 추구행동에 미치는 영향을 알아보고, 더 나아가 업무성장활력과 팀 몰입에 미치는 영향에 대해 검증하는 것이다. 또한, 개인적 요인으로서 팀원들의 자기효능감이 팀 피드백 환경 내에서 피드백 추구행동에 미치는 조절효과를 검증하고자 하였다. 201명의 직장인들로부터 설문자료를 수집하였고, 상관관계분석과 위계적 회귀분석, 조절회귀분석을 실시하였다. 가설검증 결과, 팀 피드백 환경은 팀원들의 피드백 추구행동과 양(+)의 관계를 나타냈고, 자기효능감이 높은 팀원일수록 팀 피드백 환경 내에서 피드백 추구행동을 더 활발하게 보이는 것으로 나타났다. 또한, 피드백 추구행동은 업무성장활력 및 팀 몰입과 양(+)의 관계를 나타냈다. 이러한 결과는 피드백 추구행동이 직무성과에는 물론 직무태도 및 일터에서의 활력 및 에너지에도 중요한 영향을 미친다는 것을 보여주고, 피드백 추구행동을 활성화시키는 긍정적인 팀 피드백 환경이 조성되는 것이 중요하다는 것을 시사한다.

• 한국간호교육학회지
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• 제25권2호
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• pp.186-196
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• 2019

Purpose: This study was conducted to identify types of peer feedback in nursing skills performance training and to investigate emotional response, perceived quality of feedback and self-efficacy for learning from peer feedback. Methods: A total of 110 second-year nursing students attending fundamentals of nursing classes at a university participated in 2017. Participants received peer feedback from one selected colleague who observed their skills performance, and completed a questionnaire. Contents of peer feedback video recordings were transcribed and classified into seven types of feedback. Data were analyzed using an independent t-test, ANOVA and Pearson correlation. Results: Participants mostly received feedback of 'correcting' and 'providing information.' Positive emotional responses from peer feedback were above medium, and negative emotional responses were low. The perceived quality of peer feedback was moderate and self-efficacy for learning was high. Quality of feedback correlated with negative emotional response (r=-.24, p=.014), and self-efficacy for learning (r=.35, p<.001). Self-efficacy for learning correlated with intimacy with peers (r=.24, p=.011) and positive emotional response (r=.21, p=.028). Conclusion: The results suggest that peer feedback in skill training could be used in terms of emotional response and self-efficacy for learning.

• Journal of Electrical Engineering and information Science
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• 제3권1호
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• pp.126-130
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• 1998

In this paper, a new interference rejection filter using the data-recycling technique is presented. The reference signal of the interference rejection filter is formed by using chip decisions, which is correlated with the narrowband interference components of the received signal. The decision feedback techniques reduce the distortion of the desired signal, which is introduced by the interference rejection filter through he use of feedback chip decisions. In order to update the filter coefficients a simple and efficient data-recycling technique that has improved performance over the conventional LMS algorithm is used. The performance of the proposed interference rejection filter is compared to filter with conventional LMS linear filter. The results show that the convergence speed of the proposed interference rejection filter using decision feedback and data-recycling technique is significantly faster than that of the conventional filters. Also, BER performance of the interference rejection filter demonstrates the superiority of the proposed filter algorithm.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2004년도 춘계학술대회 논문집
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• pp.235-240
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• 2004

The equipment of industrial robot in manufacturing and assembly lines has rapidly increased. In order to achieve high productivity and flexibility, it becomes very important to develop the visual feedback control system with Off-Line Programming System(OLPS). We can save much efforts and time in adjusting robots to newly defined workcells by using OLPS. A proposed visual calibration scheme is based on position-based visual feedback. The calibration program firstly generates predicted images of objects in an assumed end-effector position. The process to generate predicted images consists of projection to screen-coordinates, visible range test and construction of simple silhouette figures. Then camera images acquired are compared with predicted ones for updating position and orientation data. Computation of error is very simple because the scheme is based on perspective projection which can be also expanded to experimental results. Computation time can be extremely reduced because the proposed method does not require the precise calculation of tree-dimensional object data and image Jacobian.

• 한국융합학회논문지
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• 제10권12호
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• pp.503-510
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• 2019

본 연구에서는 간호대학생을 대상으로 교수 피드백이 제공된 성찰일지 작성이 학습동기, 학습태도 및 학업적 자기효능감에 미치는 효과를 검증하고자 하였다. 연구대상은 2018년-2019학년도 건강사정 및 실습수업을 이수한 간호대학생 190명을 대상으로 분석한 후향적 조사연구이다. 교수피드백이 적용된 성찰일지 작성 효과를 확인하기 위해 학습동기, 학업적 자기효능감은 독립표본 t 검정으로 분석하였고 학습태도는 사전점수를 공변량 처리하여 공분산분석으로 분석하였다. 연구결과, 학습동기(t=2.10, p=.037), 학습태도(t= 4.54, p=.034)에서 시행군과 대조군에 유의한 차이를 보였고 학업적 자기효능감은 유의한 차이가 없는 것으로 나타났다. 본 연구결과를 기반으로 간호대학생의 교과목에 교수의 피드백이 제공된 성찰일지 작성을 적용한다면 학습동기, 학습태도 향상을 가져온다고 할 수 있겠다.

• 한국운동역학회지
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• 제30권3호
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• pp.247-253
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• 2020

Objective: This study aimed to examine the effects of real-time visual feedback gait training on gait stability in older adults. Method: Twelve older adults participated in this study, being divided into 2 groups including a) visual feedback (VF) and b) non-visual feedback (NVF) groups. For 4 weeks, VF performed a treadmill walking training with real-time visual feedback about their postural information while NVF performed a normal treadmill walking training. For evaluations of gait stability, kinematic data of 15-minute treadmill walking were collected from depth-based motion capture system (30 Hz, exbody, Korea). Given that step lengths in both right and left sides were determined based on kinematic data, three variables including step difference, coefficient of variation, approximate entropy were calculated to evaluate gait symmetry, variability and complexity, respectively. Results: For research findings, VF exhibited significant improvements in gait stability after 4-week training in comparison to NVF, particularly in gait symmetry and complexity measures. However, greater improvement in gait variability was observed in NVF than VF. Conclusion: Given that visual feedback walking gives potential effectiveness on gait stability in older adults, gait training with visual feedback may be a robust therapeutic intervention in people with gait disturbances like instability or falls.