• 한국산학기술학회논문지
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• 제19권4호
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• pp.229-238
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• 2018

본 연구의 목적은 자살시도를 한 중학생의 스트레스 인자와 주관적 행복감의 관계에서 잠으로 피로회복, 주관적 건강인지를 이용하여 다중매개효과 차이를 파악하고자 함이다. 2016년(제 12차) 청소년건강형태온라인조사 원시자료에서 최근 12개월 동안 자살시도를 한 적이 있는 중학생 820명을 대상으로 IBM SPSS 23과 IBM SPSS AMOS 23 프로그램을 이용하여, 경로분석, 부트스트래핑, 팬텀변수, 다중집단분석으로 분석하였다. 연구결과 스트레스 인지와 주관적 행복감의 관계에서 잠으로 피로회복과 주관적 건강인지는 간접효과(${\beta}=-.12$, p=.003)가 통계적으로 유의하였다. 스트레스 인지와 주관적 행복감의 관계에서 잠으로 피로회복 간접효과는 -.05(p=.004), 주관적 건강인지 간접효과는 -.09(p=.004)로, 두 변수의 간접효과 크기 차이는 주관적 건강인지가 잠으로 피로회복보다 -.02(p=.028) 효과크기가 큰 것으로 나타났다. 남 여 중학생 집단별 경로 간 효과 크기의 차이를 본 결과 남학생집단(${\beta}=.44$, p<.001)이 여학생집단(${\beta}=.23$, p<.001) 보다 효과가 큰 것으로 나타났다. 연구결과를 바탕으로 자살시도 중학생의 행복감 증진에 도움이 되는 스트레스인지, 잠으로 피로회복, 주관적 건강인지 내용이 포함된 교육 프로그램의 개발 및 적용되어야 할 것이다.

• 대한인간공학회지
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• 제24권2호
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• pp.51-56
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• 2005

Human perceptional speed is different from its real speed. There is lack of research that the perceptional speed is different from real speed in 2-dimension, because most research of speed perception has concentrated on points and lines. This research investigates the effects of object size on speed perception. In this research, we used 2-D circular objects of the different size, 0.9, 1.8 and $3.6^{\circ}$. The objects moved 9.0, 13.5 and $18.0^{\circ}$ with three different speeds, 6.0, 9.0 and $18.0^{\circ}$/s. Six participants were exposed to the environment with standard scene(size: $1.8^{\circ}$, speed: $9.0^{\circ}$/s and travel distance: $13.5^{\circ}$). After the first scene, another scene in which the object had changed to different sizes, speeds and distances, was shown to the participants. A magnitude estimation method was used to construct a scale of the perceived speed level. The relationship between the perceived and the actual speed level was explained by Stevens's power law that the value was 0.978 with the exponent of 0.992. The size of object had an effect on the speed perception but travel distance was not. The perceptional speed of bigger object was lower than of smaller object. It showed that the degrees of perceptional speed decreased as size of object increased.

• 대한산업공학회지
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• 제30권2호
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• pp.76-83
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• 2004

This study aimed to empirically investigate perceived discomfort depending upon external load, upper limb postures and their holding time. Discomfort was obtained through an experiment, in which external load, wrist flexion/extension, elbow flexion, shoulder flexion and adduction/abduction were used as experimental variables. The subjects were instructed to hold given postures for 60s and to rate their subjective discomfort scores at 5s, 20s, 40s and 60s by using the free modulus method of magnitude estimation. The results showed that while only external load and elbow flexion were statistically significant at the holding time of 5s at ${\alpha}=0.05$ or 0.10, external load and upper limb postures excluding shoulder adduction/abduction significantly affected discomfort ratings at 20s, 40s and 60s at ${\alpha}=0.01$ or 0.05. Discomfort scores were also significantly different between four posture holding times at ${\alpha}=0.01$. The effects of external load and holding time were much larger than those of upper limb postures. Based on the results of this study, it is recommended that external load and holding time as well as working postures betaken into consideration to precisely quantify postural load in industry.

• 한국전문물리치료학회지
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• 제13권4호
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• pp.10-15
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• 2006

This study examined the ability of human subjects to match a force in their quadriceps muscle during fatigue. Twenty subjects (mean age: 23.4 yrs, mean height: 167.8 cm, mean weight, 62.6 kg) were enrolled in the experiment. In the force-matching task, the quadriceps muscle generated 50% of the MVIC (maximum voluntary isometric contraction) torque under visual control and then without visual feedback. After inducing fatigue in the quadriceps muscle, the subjects were required to match 50% of the MVIC torque without visual feedback. The perceived magnitude of the force and force-matching errors were measured. 50% of the MVIC torque was perceived from 39.96 Nm in the pre-fatigue condition to 44.95 Nm in the post-fatigue condition. 50% of the MVIC torque-matching errors increased significantly from .55% in the pre-fatigue condition to 9.6% in the post-fatigue condition (p<.001). in addition, there were significantly more force-matching errors in women than in men (p<.01). In conclusion muscle fatigue can interfere with a subject's ability to match a force. This suggests that muscle fatigue may contributes to the sensitization of the proprioception.

• 대한인간공학회지
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• 제22권1호
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• pp.43-56
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• 2003

Observational methods such as OWAS, RULA, and REBA have been widely used to identify posture-related risks of musculoskeletal disorders in industry, since they are useful and efficient in evaluating postural stresses. However. there are few studies comparing the methods and providing guidelines for selecting and using the methods. They have been developed based on different backgrounds and with different application areas. Each method has its own characteristics. which must be considered in selecting and using them. In this study. 17 male subjects evaluated 42 different working postures that frequently assumed in the automobile assembly line using a psychophysical method. The postures were then evaluated by different observational methods. The results of the observational methods were compared with psychophysically evaluated stresses. The observational methods resulted in different values of stresses for certain postures. For some postures showing high values of perceived discomfort. the observational methods showed different values of stresses. These results showed that the observational methods should be used differently according to application area and they have some weak points to be improved.

• 디자인학연구
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• 제19권5호
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• pp.181-190
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• 2006

본 연구는 배경과 시각도, 물리적 크기, 자간, 인지방향 등의 요소가 대상 문자의 크기지각에 어떠한 영향을 미치고 있는지에 대해 검토한 것으로 실험 I에서는 숫자를 대상으로 실험 II에서는 한글을 대상으로 크기지각에 대한 실험연구를 진행했다. 실험 I에서는 숫자를 대상으로 2수준의 배경과 3수준의 시각도, 9수준의 물리적 크기를 변화시킨 54 종류의 Task에 대한 크기평가가 시행되었으며, 실험 II에서는 한글을 대상으로 9수준의 물리적 크기, 2수준의 배경, 3수준의 방향, 2수준의 자간요소들을 변화시킨 108 종류의 Task에 대한 크기평가가 실시되었다. 실험 I, II 모두 크기지각에 대한 측정방법으로는 매그니튜드 측정법이 사용되었다. 실험 I의 결과, 숫자의 크기지각에 배경과 시각도, 물리적 크기가 영향을 미치고 있음이 증명되었으며, 물리적 크기 100 (기준자극의 크기) 이상의 대상들에 대해 지각적 크기의 과소시가, 100이하의 대상들에 대해서는 과대시 경향이 나타났다. 그리고 이러한 경향은 Delboeuf 착시효과가 문자의 크기지각에도 나타나고 있음을 시사했다. 실험 II의 결과, 한글의 크기지각에 있어 물리적 크기, 자간, 인지방향 등의 요소가 대상의 지각에 영향을 미치고 있음이 증명되었으며, 자간, 인지방향에 의한 크기착시 역시 주변 문자와의 관계에 의한 것으로 고찰 검토되었다.

• 한국콘텐츠학회논문지
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• 제20권8호
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• pp.598-617
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• 2020

많은 기업에서 조직 구성원의 비윤리적 행동에 따른 기업의 피해는 줄어들지 않고 오히려 피해규모의 크기나 발생 빈도는 증가하는 상황으로, 조직 관리 차원에서 이에 대한 관리 방안과 실질적인 원인이 되는 변인을 규명하고, 비윤리적 친조직 행동을 줄여주는 조절변인에 대한 연구가 필요한 시점이다. 이에 본 연구는 사회교환이론을 근간으로 하는 비윤리적 친조직 행동의 선행요인으로, 조직지원인식과 심리적 특권의식에 주목하고, 이들 변인 간의 반응 메커니즘을 연구하고자 한다. 특히 현재 직장에 근무하고 있는 노동참여 인구의 연령이 밀레니엄세대(1978년 이후세대) 혹은 Y세대라고 불리는 이들이 노동시장에 대거 참여하고 있는 상황으로 이들의 심리적 특권의식이 조직 내에서 문제가 되고 있기 때문이다. 선행연구를 통해 조직지원인식이 비윤리적 친조직 행동에 미치는 영향과 심리적 특권의식이 비윤리적 친조직 행동에 미치는 영향을 살펴보고 심리적 특권의식이 조직지원인식과 비윤리적 친조직 행동에 조절효과를 갖는지를 실증 분석하였다. 밀레니얼세대에 해당하는 조직 구성원을 대상으로 유효한 185명의 데이터를 바탕으로 회귀분석을 진행하였으며, 조직지원인식과 비윤리적 친조직 행동 간에 심리적 특권의식이 조절효과를 나타내는 것으로 분석결과가 나타났다. 이러한 연구 결과를 바탕으로 비윤리적 친조직 행동과 심리적 특권의식에 대한 이론적·실무적 시사점을 제안하고, 이에 대한 연구를 확장하는데 기여하고자 한다.

• 한국대기환경학회지
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• 제26권3호
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• pp.253-264
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• 2010

This study investigates the relationship between daily mortality and heat stress in Seoul, using perceived temperatures (PT) derived from a heat budget model. During the summer season, observed PT intensity showed the biggest magnitude of summer heat stress from the middle 10 days of July to the first 10 days of August. The elderly (65 and above) were found to be the most vulnerable to heat stress. The threshold PT, with a significant increase in excess mortality, was $38^{\circ}C$. No time lagged effect was observed with summer heat stress, while a high correlation was observed between anomalies in PT and relative deviation of mortality. A comparison of the heat index and the discomfort index with excess mortality revealed that the discomfort index underestimated excess mortality, whereas the heat index could not appropriately explain the increase in excess mortality correlated with the increase in excess heat. In contrast, PT was found to be the weather element that best represents excess mortality due to heat stress, and is thus expected to serve as a more reliable forecast index of human biometeorology.

• 대한간호학회지
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• 제30권4호
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• pp.836-846
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• 2000

This Meta-Analysis of 18 studies was conducted to determine the magnitude of th relationship between health promotion behavior and each of explanatory variables. The studies were measured using Health Promoting Life Style(HPLP) developed by Walker and others based on Pender's definiton of health promoting behavior. The sample was collected by searching for The Journal of Korean Academy Nursing Society, The Journal of Korean Women's Health Nursing Academic Society,The Journal of Korean Academic Society of Adult Nursing, Journal of Korean Community Nursing, The Journal of Fundamentals of Nursing, The Journal of Korean Nursing Administration Academic Society, The Korean Journal of Child Health Nursing, The Journal of Korean Psychiatric Academic Society, the dissertations for mater degree or doctoral dissertations for the period from 1980 to 1998. The explanatory variables measured more than 2 times in studies were self-efficacy, perceived health status, self-esteem, internal, powerful-others and chance dimensions of health locus of control, perceived benefits, hardiness, wellbeing and clinical demensions of health concepts, and quality of life(life satisfaction). Effect sizes were calculated by unweighted mean r, weighted mean r by sample size and weighted mean r by quality index score after homogeneity test. The mean r effect size indicator range of each predictor variable were as follows; quality of life (0.50- 0.52), self-efficacy (0.46-0.47), hardiness (0.42-0.44), self-esteem(0.41-0.43), health locus of control- internal(0.32-0.34), health locus of control- powerful others (0.25-0.31), perceived health status(0.18-0.19) and clinical dimensions of health concepts (0.16-0.17).

• 전자공학회논문지B
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• 제31B권7호
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• pp.33-41
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• 1994

A single channel adaptive noise canceling (ANC) technique with a recursive time delay estimator (RTDE) is presented for removing effects of additive noise on the speech signal. While the conventional method makes a reference signal for the adaptive filter using the pitch estimated on a frame basis from the input speech, the proposed method makes the reference signal using the delay estimated recursively on a sample-by-sample basis. As the RTDEs, the recursion formulae of autocorrelation function (ACF) and average magnitude difference function (AMDF) are derived. The normalized least mean square (NLMS) and recursive least square (RLS) algorithms are applied for adaptation of filter coefficients. Experimental results with noisy speech demonstrate that the proposed method improves the perceived speech quality as well as the signal-to-noise ratio and cepstral distance when compared with the conventional method.