• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2013.06a
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• pp.293-295
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• 2013

최근 3D 비디오의 흥행과 더불어 사람들이 스테레오스코픽 비디오를 쉽게 접할 수 있게 되었다. 하지만 부적절한 스테레오 스코픽 비디오는 시청자로 하여금 어지럼증, 눈의 피로 등을 느끼게 할 수 있다. 따라서 비디오 컨텐츠를 분석하여 피로도를 예츨할 수 있는 지표의 개발이 필요하다. 스테레오스코픽 비디오에서 피로도를 유발시키는 원인은 여러 가지가 있으며, 본 논문에서는 비디오의 카메라 움직임 정보에 집중한다. 카메라의 흔들림은 심각한 멀미를 유발할 수 있다. 이는 스테레오스코픽 비디오에서 더욱 강렬하게 나타나게 된다. 우리는 스테레오스코픽 비디오의 흔들림을 측정하기 위해 3D 복원 기술을 사용한다. 특히, 좌안 비디오와 우안 비디오의 정보를 모두 활용하는 최적화된 알고리즘을 제안한다. 이를 통해 우리는 각 프레임의 카메라 위치와 방향 정보를 획득할 수 있다. 마지막으로 획득한 3차원 카메라 움직임 정보로부터 카메라의 흔들림을 잘 표현할 수 있는 점수를 계산한다.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.4 s.97
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• pp.13-18
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• 1999

섬유강화금속적층재(Fiber Reinforced Metal Laminates. FRMLs)는 고강도금속과 섬유강화복합재료(Fiber Reinforced Composite Materials)를 적층한 새로운 종류의 하이브리드 재료이다. 국산 아라미드 섬유인 헤라크론(Heracron, 코오롱)과 국내 복합재료 제작기술(한국화이바)을 사용하여 섬유강화금속적층재를 제작하고, 이를 HERALL(Heracron Reinforced Aluminum Laminate)이라 명명하였다. HERALL(Heracron Reinforced Aluminum Laminate)의 피로균열성장특성 및 피로균열진전 방해기구를 ARALL(Aramid-fiber Reinforced Aluminum alloy Laminates) 및 Al 2024-T3과 비교해석하였다. HERALL과 ARALL은 균열진전을 저지하는 아라미드 섬유로 인해 뛰어난 피로균열성장특성 및 피로저항성을 보여주었다. 아라미드 섬유의 균열브리드징으로 인한 $K_{max}$의 감소량과 Al 2024-T3의 균열닫힘으로 인한 $K_{max}$의 증가량을 구할 수 있는 응력-COD법을 사용하여 실제로 균열성장에 영향을 준 유효응력확대계수범위를 측정하였다. 균열선단으로부터 균열을 가공하면서 COD 변화량을 측정하여 균열브리징 영역을 구하였다.

• Composites Research
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• v.22 no.1
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• pp.15-21
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• 2009

In this paper, static compressive test and compression-compression fatigue test of carbon/epoxy composites which have different micro-structures were carried out with respect to the bias angle. In order to find out the effect of the micro-structure of the fabric composite on compressive characteristics the specimens made of UD carbon/epoxy composite comprising the same fiber and matrix system as the fabric composite were also prepared. The compressive strength and modulus were measured and these values were used to develop a semi-empirical formula for predicting compressive strength of the fabric composite with bias angles. The fatigue behavior of the fabric composite with respect to the bias angle variation was also investigated.

• Journal of the Korea Convergence Society
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• v.10 no.8
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• pp.21-26
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• 2019

This paper proposes a fatigue recognition method using the C4.5 algorithm. Based on domestic and international studies on fatigue evaluation, we have completed the fatigue self - assessment scale in combination with lifestyle and cultural characteristics of Chinese people. The scales used in the text were applied to 58 sub items and were used to assess the type and extent of fatigue. These items fall into four categories that measure physical fatigue, mental fatigue, personal habits, and fatigue outcomes. The purpose of this study is to analyze the leading causes of fatigue formation and to recognize the degree of fatigue, thereby increasing the personal interest in fatigue and reducing the risk of cerebrovascular disease due to excessive fatigue. The recognition rate of the fatigue recognition system using the C4.5 algorithm was 85% on average, confirming the usefulness of this proposal.

• Journal of the KSME
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• v.36 no.9
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• pp.855-866
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• 1996

승요차 앞자축에 장착되어 회전하면서 동력을 전달하는 드라이브축은 운행중에 주로 비틀림하중을 받는다. 따라서 동 부품의 피로해석 및 설계를 위해서는 실제 운행중에 받는 서비스토크의 크기, 주파수 등에 관한 데이터가 필요하다. 차량에 탑재된 엔진의 토크와 회전수 등의 규격으로부터 드라이브축에 부가되는 최대 토크 값을 예측할 수 있으나, 자동차 운행주에는 승차인원, 도로조건, 운전자의 운전습관 등 여러가지 외적인 영향으로 인하여 서비스토크가 불규칙하게 변할 것으로 예상되므로 서비스토크를 정확히 예측하기는 어려운 실정이다. 또한, 최근의 자동차 구조부품에 대한 설계개념이 무한수명 설계에서 경량화 설계로 변화되고 있으며, 따라서 자동차 드라이브축도 실제 운용하중을 바탕으로 한 정확한 수명예측 및 강도설계가 요구되고 있다. 본 연구에서는 4륜구동형 승용차용 드라이브축에 대해 실제 운용하중에서의 피로수명을 예측하기 위해 1)텔리메트리를 이용하여 토크를 측정하고, 2) 일정진촉하중하에서의 드라이브축의 비틀림 피로시험을 수행하고, 3) 일정진폭하중하에서의 드라이브축의 비틀림 피로시험을 수행하고, 4) 축류 소재의 피로특성 데이터를 구성하여 5) 자체 개발한 프로그램으로 피로수명을 예측하고자 한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.9C
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• pp.887-898
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• 2005

In this paper, we introduce a probabilistic model based on Bayesian networks BNs) for recognizing human fatigue. First of all, we measured face feature information such as eyelid movement, gaze, head movement, and facial expression by IR illumination. But, an individual face feature information does not provide enough information to determine human fatigue. Therefore in this paper, a Bayesian network model was constructed to fuse as many as possible fatigue cause parameters and face feature information for probabilistic inferring human fatigue. The MSBNX simulation result ending a 0.95 BN fatigue index threshold. As a result of the experiment, when comparisons are inferred BN fatigue index and the TOVA response time, there is a mutual correlation and from this information we can conclude that this method is very effective at recognizing a human fatigue.

• Journal of Navigation and Port Research
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• v.38 no.5
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• pp.479-484
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• 2014

This paper presents the crew members fatigue survey in order to understand the current state of various fatigue causal factors and personnel fatigue subjective symptoms, and then analyzes the survey items. The results of this survey are as follows. Firstly, many crew members were struggling with the lack of sleep and rest hour. Secondly, environmental factors such as weather, ship motion and vibration, noise, accommodation condition etc. disturbed the sleep of crew members. In third, their duty hours were more than 10 hours per day in certain types of ship. In fourth, they felt fatigue a lot when they were on board because of the workload and stress. Lastly, in some measurement items of fatigue symptoms(physical, mental, emotional), many crew members were experiencing more than moderate fatigue symptoms.

• Journal of Digital Convergence
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• v.11 no.11
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• pp.545-551
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• 2013

This study aimed to compare the effects of microcurrent stimulation and rest on the fatigue index by applying both to subjects who had accumulated fatigue after performing short-duration physical activity. The experiment was performed at S University from December 2012 to February 2013, on 22 healthy men in their 20s, who were right-handed, and without peripheral or musculoskeletal diseases. All subjects lifted a 10-kg box lift and lower 100 times in 15 minutes. Immediately after that, muscle fatigue index (Median Frequency: MF) and blood fatigue index (Creatine Kinase Lactate: CK, Lactate Dehydrogenase: LDH) were measured by using surface electromyography. The subjects were divided into two groups, and microcurrent stimulation and rest were mediated to the experimental and control groups, respectively, for 20 minutes. After intervention, muscle fatigue index and blood fatigue index were measured and the changes in the accumulated fatigue index were compared. Both groups manifested significantly decreased cumulative fatigue after applying the mediation compared to the pre-intervention level (p < .05), the only exception being the fatigue index of the left erector spinae in the rest group. Compared to the rest group, the microcurrent stimulation group showed a significant decrease in muscle fatigue index (p < .05) but no significant differences were found in the blood fatigue index. Given the results of this study, microcurrent stimulation is considered to be helpful in muscle fatigue recovery for workers who have to perform repetitive movements lifting weights, and additional studies on the correlations of the fatigue recovery with respect to the long-term follow-up of fatigue index and mediation time are necessary.

• Journal of Korea Game Society
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• v.13 no.3
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• pp.5-18
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• 2013

This study analyzed the effect by comparing it with 2D game using playtest experimental treatment methodology to verify the video effect, materiality and fatigue effect of 3D video game. First, for the hypothesis to verify the difference of video experience of users for 3D and 2D games, visual clarity was rejected, but materiality, tangibility and presence hypotheses were all accepted. Second, it was shown that there was no difference in eye fatigue and physical fatigue in 3D and 2D games. It was different from results of existing research which claimed that fatigue occurred due to video distortion occurring in 3D video and fatigue inducing factors. Third, the results of measurement of changes in brain wave occurring in the course of playing 3D and 2D games showed that there was no difference in average amplitude of EEG alpha wave, but EEG beta wave occurred in higher amplitude. This study proved the cerebral physiological change and difference in the process of experience to use 3D video game by complementing the methodology in measurement in EEG brain wave in the traditional experimental method.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.2
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• pp.160-166
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• 2016

Crew fatigue has been recognized as a major cause of maritime accidents. Systematic study on crew fatigue has a direct impact on the human factor, but the various measures being taken to prevent human error account for most of the causes of marine accidents situation are still insufficient. In this study, 128 people who have a variety of career and job types boarded the T/S Hanbada were analyzed the changes of fatigue during the 87-days a Maritime Silk Road Sailing Expedition. Crew fatigue was measured by period of time onboard classified as mental, physiological and physical changes through survey responses and individual interviews of nurses. Also, it was identified the fatigue factor through quantitative statistical analysis. As a result of repeated measures analysis of variance for the changes of fatigue in position and gender criteria in accordance with boarded period, the position-specific analysis was that Professor Rating group has appeared to feel more mental and physical fatigue than the student population. Also, the results of fatigability about the sex-specific analysis have been found that women feel more physical fatigue than men.