• Title/Summary/Keyword: psychophysical method

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Psychophysical Stress of Arm Motions at Varying External Load and Repetition (외부 부하와 반복에 따른 팔 동작의 심물리학적 자세 부하)

  • Kee, Do-Hyung
    • IE interfaces
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    • v.17 no.2
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    • pp.218-225
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    • 2004
  • This study aims to investigate effect of external load and motion repetitiveness on perceived discomfort. An experiment was performed for measuring discomfort scores at varying conditions, in which external load, motion repetitiveness and arm posture were employed as experimental variables. The arm posture was controlled by shoulder flexion and abduction, and by elbow flexion. Fifteen healthy college-age students without history of musculoskeletal disorders voluntarily participated in the experiment. The results showed that the effect of external load, motion repetitiveness and shoulder posture on discomfort were statistically significant, but that elbow posture did not significantly affect discomfort ratings. The effect of external load was much larger than that of any other variables, and that of repetitiveness was second only to external load. Discomfort scores significantly increased linearly as the levels of external load and motion repetitiveness increased. This implies that although they were not fully reflected in the existing posture classification scheme such as OWAS, RULA, etc., the effect of external load and motion repetitiveness should be taken into consideration for precisely quantifying work load in industry. Based on regression analysis, equivalent values of external load and motion repetitiveness in terms of discomfort scores were provided, which would be useful for better understanding the degree of their effect on work load.

A Study of Correlation between Self Concept and Climacteric Symptoms in Middle-Aged Women (일 지역 중년기 여성의 자아개념과 갱년기 증상과의 관계 연구)

  • Kim Jung-Ae
    • Journal of Korean Academy of Fundamentals of Nursing
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    • v.10 no.1
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    • pp.78-86
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    • 2003
  • Purpose: The purpose of this study was to investigate the relationship between self concept and the climacteric symptoms in middle-aged women. Method: From a convenience sample of 123 women between 40 and 59 years of age living in P-city data were collected using a structured questioanaire. It included a self concept scale and climacteric symptom scale. With spss/pc(+), data were analyzed using descriptive statistics, t-test, ANOVA and Pearson's correlation coefficients. Result: 1 The mean score for self concept was $108.73{\pm}16.24$. 2. The variables that influenced the self concept of middle-aged women most were 'health state' and 'marriage satisfaction'. They were statistically significant at the .01 level. 3. The mean score for climacteric symptoms was 3.13. Of psychophysical, physical and psychological symptoms the scores for psychophysical symptoms were the highest. 4. There were significant negative correlations between self concept and climacteric symptoms (r=-.333, p=.000). Conclusion: This study suggests that positive self concept can reduce climacteric symptoms in middle-aged women.

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Psychophysical Discomfort Evaluation of Complex Trunk Postures (복합적인 몸통 자세의 심물리학적 불편도 평가)

  • Lee, In-Seok;Ryu, Hyung-Gon;Chung, Min-K.;Kee, Do-Hyung
    • Journal of Korean Institute of Industrial Engineers
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    • v.27 no.4
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    • pp.413-423
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    • 2001
  • Low back disorders (LBDs) are one of the most common and costly work-related musculoskeletal disorders. One of the major possible risk factors of LBDs is to work with static and awkward trunk postures, especially in a complex trunk posture involving flexion, twisting and lateral bending simultaneously. This study is to examine the effect of complex trunk postures on the postural stresses using a psychophysical method. Twelve healthy male students participated in an experiment, in which 29 different trunk postures were evaluated using the magnitude estimation method. The results showed that subjective discomfort significantly increased as the levels of trunk flexion, lateral bending and rotation increased. Significant interaction effects were found between rotation and lateral bending or flexion when the severe lateral bending or rotation were assumed, indicating that simultaneous occurrence of trunk flexion, lateral bending and rotation increases discomfort ratings synergistically. A postural workload evaluation scheme of trunk postures was proposed based on the angular deviation levels from the neutral position. Each trunk posture was assigned numerical stress index depending upon its discomfort rating, which was defined as the ratio of discomfort of a posture to that of its neutral posture. Four qualitative action categories for the stress index were also provided in order to enable practitioners to apply corrective actions appropriately. The proposed scheme is expected to be applied to several field areas for evaluating trunk postural stresses.

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Observer Preferable Sharpness Enhancement Considering Distributions of Edge Characteristics (경계선 특성을 고려한 관측자 선호 선예도 개선 방법)

  • 홍상기;정재영;김대희;조맹섭
    • Proceedings of the IEEK Conference
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    • 2002.06d
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    • pp.275-278
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    • 2002
  • Sharpness enhancement, which strengthen the edge(high frequency) of image, is widely studied for image processing research area. In this paper, psychophysical experiment is conducted by the 20 observers with simple linear unsharp masking for sharpness enhancement. The experimental results extracted using z-score analysis and linear regression suggests observer preferable sharpness enhancement method for digital television.

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A study on applying the direct estimation method to determining maximum acceptable weight in symmetric lifting task (직접추정법의 대칭적인 들기 작업의 최대허용하중 결정에의 적용에 관한 연구)

  • 이관석;박희석
    • Journal of the Ergonomics Society of Korea
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    • v.14 no.1
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    • pp.1-7
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    • 1995
  • In this paper, the effectiveness and accuracy of using the direct estimation method were investigated in determining a worker's lifting capacity or the maximum acceptable weight of lifting (MAWOL) of symmetrical fifting tasks in the workplace were investigated. Six lifting tasks involving two vertical fifting start-end points (0-80cm, 47-102cm) and three lifting frequencies (1, 2, and 4 lifts/minute) were studied. Ten young, male subjects performed the six lifting tasks to predict the MAWOL using the psychophysical method and the direct estimation method. The main results indicated that there were no significant differences between the MAWOLs determined by the two methods except for the lifting frequency of 4 lifts/minute. Analysis of variance was performed on the task rating data to check the consistency of the task rating across subjects, which revealed no significant difference.

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Evaluation Method of Riding Comfort of Train by using HRV (Heart Rate Variability) (심전도를 이용한 열차 승차감 평가 방법 연구)

  • Song, Yong-Soo;Kim, Baek-Hyun;Kim, Yong-Kyu
    • Proceedings of the KSR Conference
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    • 2010.06a
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    • pp.1017-1025
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    • 2010
  • The Purpose of this paper is to characteristics and analysis of ride comfort by using HRV. Although the riding comfort of trains has been managed by setting allowable accelerations of 3-axis motion in cabins, it is impossible for this approach to express the psychophysical relationship between various vibrational factors and riding comfort. in order to propose a function to evaluate the riding comfort of train on conventional railroad, an experiment was performed with the Korea Tilting Tran eXpress(TTX). As a result, by referring to some international standards on the method of evaluating ride comfort, a modified method was proposed to evaluate the lateral vibration in addition to the roll motion on carve transitions.

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Evaluation Method of Riding Comfort of Tilting Train Passing Transition Curves (틸팅열차 완화 곡선 주행시 승차감 평가 방법 연구)

  • Song, Yong-Su;Go, Tae-Hwan;Han, Seong-Ho
    • Proceedings of the KSR Conference
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    • 2009.05a
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    • pp.1566-1573
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    • 2009
  • Although the riding comfort of tilting trains has been managed by setting allowable limits of roll motion in Korea, it is impossible for this approach to express the psychophysical relationship between various vibrational factors and riding comfort. in order to propose a function to evaluate the riding comfort of tilting train on transition curves, an experiment was performed with the Korea Tilting Tran eXpress(TTX). As a result, by referring to some international standards on the method of evaluating ride comfort, a modified method was proposed to evaluate the lateral vibration in addition to the roll motion on carve transitions.

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The Relationship between Visual Analogue Scale and R(III) Nociceptive Flexion Reflex (Visual Analogue Scale과 R(III) Nociceptive Flexion Reflex와의 상관관계)

  • Kim, Yong-Ik;Kim, Sang-Hyun;Lee, Ju-Chul;Jeon, Jae-Soo;Hwang, Kyung-Ho;Park, Wook
    • The Korean Journal of Pain
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    • v.13 no.2
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    • pp.175-181
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    • 2000
  • Background: Pain is often measured using psychophysical scaling techniques. However, all of these methods found their limits, since they were based on the subjective sensations reported by the subjects. It is, therefore, desirable to validate psychophysical pain measures by simultaneously measuring some physiological correlate of nociception. We studied an objective method for measuring pain in human volunteer using R(III) nociceptive flexion reflex. Methods: Four different intensity of electrical stimuli between perception and 1.4 times the R(III) nociceptive flexion threshold were delivered to the sole of the feet in 8 normal volunteers. We measured the flexion reflex activity in the skin over the ipsilateral tibialis anterior muscle and subjects rated each stimulus on a visual analog scale (VAS) Results: Both R(III) nociceptive flexion reflex activity and VAS ratings showed a linear relationship with stimulus intensity and with each other in all volunteers. Conclusions: R(III) nociceptive flexion reflex elicited through electrical stimulation may used as an objective pain measurement, previsionary based on our study paradigm.

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A Evaluation method for the Color Preference of CRT Monitors (컬러모니터의 색상선호도 평가방법에 관한 연구)

  • 최재호;박승옥;김홍석
    • Proceedings of the Korean Society for Emotion and Sensibility Conference
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    • 1998.04a
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    • pp.141-146
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    • 1998
  • This study investigated the evaluation method for the users' color preference of CRT monitors. And also the users' preference of the colors displayed on CRT monitor using the park's color reproduction system was evaluated. Subjects conducted a series of psychophysical experiments to compare the colors displayed on a CRT monitor using the park's system to the colors without the system, Three evaluation methods were investigated: comparing one colors of same hue with diverse luminance and saturation. the results showed that subjects preferred the colors reproduced using the park's system, and thd evaluation methods significantly affected thd color preference.

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Rankings for Perceived Discomfort of Static Joint Motions for Females Based on Psychophysical Scaling Method (심물리학적 방법을 이용한 정적 관절 동작에 대한 여성의 지각 불편도 Ranking)

  • Kee, Do-Hyung
    • IE interfaces
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    • v.16 no.1
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    • pp.85-93
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    • 2003
  • The purposes of this study are to investigate perceived discomfort for static joint motions, and to propose rankings for the joint motions based on the perceived discomfort. The perceived discomfort was measured through an experiment using the free modulus method of the magnitude estimation, in which ten healthy college-age female students participated. The results showed that joints, joint motions and their levels significantly affected the perceived discomfort at $\alpha$=0.01, and that the interaction of joints and joint motion levels was also significant. Based on the experimental results, three rankings were proposed by joint and joint motions, by joints and by joint motions, which were very different from the existing ones. Especially, the proposed rankings were different from the males' published before in their order and magnitude. These rankings can be used as a valuable tool for better understanding potentially adverse effects of poor working postures in industrial sites, and as basic data for developing the postural classification scheme.