• Safety and Health at Work
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• 제12권4호
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• pp.462-470
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• 2021

Background: Fatigue is pervasive, under-reported, and potentially deadly where flight operations are concerned. The aviation industry appears to lack a standardized, practical, and easily replicable protocol for fatigue risk assessment which can be consistently applied across operators. Aim: Our paper sought to present a framework, supported by real-world data with subjective and objective parameters, to monitor aircrew fatigue and performance, and to determine the safe crew configuration for commercial airline operations. Methods: Our protocol identified risk factors for fatigue-induced performance degradation as triggers for fatigue risk and performance assessment. Using both subjective and objective measurements of sleep, fatigue, and performance in the form of instruments such as the Karolinska Sleepiness Scale, Samn-Perelli Crew Status Check, Psychomotor Vigilance Task, sleep logs, and a wearable actigraph for sleep log correlation and sleep duration and quality charting, a workflow flagging fatigue-prone flight operations for risk mitigation was developed and trialed. Results: In an operational study aimed at occupational assessment of fatigue and performance in airline pilots on a three-men crew versus a four-men crew for a long-haul flight, we affirmed the technical feasibility of our proposed framework and approach, the validity of the battery of assessment instruments, and the meaningful interpretation of fatigue and work performance indicators to enable the formulation of safe work recommendations. Conclusion: A standardized occupational assessment protocol like ours is useful to achieve consistency and objectivity in the occupational assessment of fatigue and work performance.

• 한국주거학회논문집
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• 제7권2호
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• pp.139-151
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• 1996

The Purpose of this study is to examine residents' subjective satisfaction of the elderly housing environment and to suggest some major factors which can be used as basic design guidelines for the elderly housing. as the number of the elderly is growing in Japan For this purpose. data were collected through a questionnaire survey method, Some questions on their hope for the conditions of the elderly housing were asked to 265 old People living in the suburbs of Chiba city. Japan. Based on the findings of the statistical factor analysis, the major factors which affected on the elderly housing environment of the study can be summarized as follows ;(1)Factor1 is correlated with the space design element represented by the elderly dwelling performance and overall efficiency for the dwelling exterior space design (2)Factor2 is relative to the interior environmental element with Physiological and sensitive performance for borne services system. (3)Factor3 can be explained the moving and communication performance for Physical uneasiness of outdoor activities and request of public cultural spaces. (4)Factor4 is relative to the mental rest element with safety accidents for moving activities etc. and psychological isolation for the elderly.

• 전자공학회논문지S
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• 제36S권7호
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• pp.134-135
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• 1999

본 논문에서는 최근에 널리 연구되고 잇는 다해상도 신호해석 방법인 웨이브렛 변환, 웨이브렛 패킷, 그리고 코사인 패킷 알고리듬을 잡음음성의 음질개선에 이용하여 각각의 성능을 비교하였으며, 또한 이를 기존의 스펙트럼 차감법의 성능과 비교 분석하였다. 성능비교의 척도로는 SNR과 켑스트럼 거리를 이용하였다. 실험결과 SNR면에서는 코사인 패킷이 가장 좋은 결과를 보였고 켑스트럼 거리의 경우 코사인 패킷과 웨이브렛 패킷이 훨씬 나은 결과를 보였다. 주관적인 청취결과 역시 코사인 패킷이 가장 좋은 결과를 보였으며, 기존의 스펙트럼 차감법은 musical noise의 영향으로 인해 상대적으로 다른 방식에 비해 합성음의 음질이 많이 떨어짐을 확인할 수 있었다.

• Journal of Ginseng Research
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• 제31권1호
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• pp.34-43
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• 2007

Background: Previous research has suggested that single doses of a standardised Panax ginseng extract can decrease fasted blood-glucose levels and modulate cognitive performance in healthy young volunteers. The latter has generally been seen in terms of improved secondary memory performance. However, both the cognitive effects of chronic administration of ginseng and the potential modulation of working memory have received comparatively little research attention. Aims: The current double-blind, placebo-controlled, balanced cross-over study investigated the effects of 8-weeks administration of Korean ginseng extract (200 mg) on cognitive performance, gluco-regulatory parameters and ratings of subjective mood and 'quality of life'. Methods: 'Eighteen healthy young participants were assessed pre-dose and 3 hours post-dose on the mornings of Day 1, Day 29 and Day 57 of 8 week treatment regimens of both placebo and ginseng. A four-week placebo wash-out separated the treatment phases. Each assessment included the Cognitive Drug Research battery, computerised working memory tasks, and Bond-Lader mood scales. The WHO Quality of Life scale (WHOQOL-BREF) was completed once per visit. Gluco-regulatory parameters were assessed with assays of blood glucose, insulin and HbA1c. Results: Data from the 16 participants that completed the study showed that there were no significant, acute treatment related differences on Day 1 of treatment, or in gluco-regulatory parameters throughout the study. However, time related performance improvements were evident following chronic administration of ginseng on the '3-Back' and 'Corsi-block' computerised working memory tasks. Ginseng was also associated with an improved score on the 'social relations' subscale of the WHOQOL-100, and a significant shift on the 'calm' factor of the Bond-Lader mood scales (from calm/relaxed towards excited/tense). Conclusion: The results of the current study suggest that Korean ginseng extract can modulate working memory performance and subjective ratings of 'quality of life' and mood. Replication with a larger sample size may further elucidate the actions of this product.

• 감성과학
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• 제15권2호
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• pp.249-258
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• 2012

본 연구는 작업속성에 따른 스마트폰의 심미성이 주관적 사용성과 객관적 사용성에 미치는 영향을 살펴보았다. 기존의 여러 연구에서 심미성이 주관적 사용성과 객관적 사용성에 미치는 영향에 대해 살펴보았지만, 아직까지도 심미성과 객관적 사용성의 관계는 모호했다. 본 연구에서는 동일한 기능을 가지지만 다른 심미성을 가진 스마트폰을 사용하여 36명의 피실험자에게 3가지 타입의 작업(정보입력작업, 정보검색작업, 정보유희작업)을 수행하도록 하였으며, 이때의 수행도와 주관적 평가가 기록되었다. 그 결과 높은 심미성이 낮은 심미성에 비해 주관적 사용성이 사용 전과 후에 높게 평가되었지만, 사용 전에 비해 사용 후에는 그 차이가 줄어들었다. 또한 심미성이 높은 것이 작업수행시간이 더 오래 소요되었다. 하지만 작업속성과 심미성에 의한 교호작용은 보이지 않았다. 본 연구의 결과는 심미성은 감성적 만족도뿐만 아니라 다양한 효과를 가진다는 것을 보여주었다. 본 연구의 결과는 사용성 평가에서 심미성이 주관적 사용성과 객관적 사용성에 미치는 영향을 예측할 수 있게 해줄 것이라고 기대된다.

• 방송공학회논문지
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• 제12권2호
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• pp.177-184
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• 2007

본 논문에서는 멀티미디어 응용을 위한 동영상의 주관적 품질평가방법으로 널리 사용되는 DSCQS(Double Stimulus Continuous Quality Scale method) 및 ACR(Absolute Category Rating)방법을 비교분석하였다. 두 가지 방법을 비교 실험한 결과 MOS (Mean Opinion Score) 값의 경우 DSCQS와 ACR의 평가치가 매우 높은 상관도를 보이는 것을 확인할 수 있었다. 또한 DMOS (Difference Mean Opinion Score)값의 경우에는 DSCQS와 ACR 방법이 MOS 값의 경우보다 약간 낮은 정도의 상관도를 보였다. 이 같은 결과는 ACR 방식이 DSCQS에 필적하는 성능을 제공하며 많은 수의 영상을 평가 할 수 있는 효율적인 주관적 품질평가 방법임을 보여주고 있다.

• 대한인간공학회지
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• 제31권6호
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• pp.785-791
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• 2012

Objective: The aim of this study was to investigate the correlation between 3D visual fatigue and physiological measures by canonical correlation analysis enabling to categorical correlation. Background: Few studies have been conducted to investigate the physiological mechanism underlying the visual fatigue caused by processing 3D information which may make the cognitive mechanism overloaded. However, even the previous studies lack validation in terms of the correlation between physiological variables and the visual fatigue. Method: 9 Female and 6 male subjects with a mean age of $22.53{\pm}2.55$ voluntarily participated in this experiment. All participants were asked to report how they felt about their health sate at after viewing 3D. In addition, Low & Hybrid measurement test(Event Related Potential, Steady-state Visual Evoked Potential) and for evaluating cognitive fatigue before and after viewing 3D were performed. The physiological signal were measured with subjective fatigue evaluation before and after in watching the 3D content. For this study suggesting categorical correlation, all measures were categorized into three sets such as included Visual Fatigue set(response time, subjective evaluation), Autonomic Nervous System set(PPG frequency, PPG amplitude, HF/LF ratio), Central Nervous System set(ERP amplitude P4, O1, O2, ERP latency P4, O1, O2, SSVEP S/N ratio P4, O1, O2). Then the correlation of three variables sets, canonical correlation analysis was conducted. Results: The results showed a significant correlation between visual fatigue and physiological measures. However, different variables of visual fatigue were highly correlated to respective HF/LF ratio and to ERP latency(O2). Conclusion: Response time was highly correlated to ERP latency(O2) while the subjective evaluation was to HF/LF ratio. Application: This study may provide the most significant variables for the quantitative evaluation of visual fatigue using HF/LF ratio and ERP latency based human performance and subjective fatigue.

• 한국치위생학회지
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• 제19권2호
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• pp.287-295
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• 2019

Objectives: The purpose of this study was to investigate the factors affecting subjective oral symptoms according to the gender of youth from multi-cultural families in Korea using data from the 14th (2018) Korean Youth Health Behavior Survey. Methods: The independent variables used in this study consisted of gender and sweet drink intake. The dependent variable was experience of subjective oral symptoms. Compensation variables consisted of general characteristics of school type, academic performance, economic status, drinking status, smoking status, and number of tooth brushings day before. The subjects of the study were 835 children of multi-cultural families whose parents were foreigners. All statistical analyses were performed by complex samples cross-tabulation analysis and complex samples logistic regression analysis. Statistical analysis was performed using the PASW statistical package 21.0 (Statistical Packages for Social Science Inc., Chicago, IL, USA). A significance level of 0.05 was used for statistical significance. Results: The composite sample logistic regression analysis showed that there was a statistically significant difference between gender and intake of sweet drinks in experience of subjective oral symptoms. Conclusions: These results suggest that factors influence subjective oral symptoms in Korean multi-cultural adolescents. Therefore, I hope that they will be used as basic data for the introduction and development of a customized oral health education program for improving oral health of multi-cultural adolescents.

• 융합정보논문지
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• 제9권8호
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• pp.268-273
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• 2019

본 연구는 서울 경기지역 만 65세 이상의 건강한 재택 노인을 대상으로 항목별 일상생활수행능력에 따른 주관적 건강상태, 즉 건강불안감의 정도를 알아보는 서술적 조사연구이다. 대상자에게 일상생활수행능력(ADLs)에 따른 1-5점까지 주관적 건강상태(건강불안감)를 설문하고, 항목별 일상생활수행능력의 정도에 따라 4개의 집단(매우 어려움, 어려움, 쉬움, 매우 쉬움)으로 나누어 Jonckheere-Terpstra검정과 선형회귀선을 활용하여 순위추세를 비교하였다. Jonckheere-Terpstra검정에서 "화장실 이용하기", "목욕하기", "물건 사러가기" 항목에 어려움을 호소할수록 주관적 건강상태의 불안감이 상응하는 순위차이를 보였고, 선형회귀선 상에서 "화장실 이용하기"의 기울기가 가장 큰 것으로 나타났다. 건강한 재택 거주 노인의 경우 "화장실 이용하기", "목욕하기", "물건 사러가기"가 어려울수록 건강불안의 증가 즉, 주관적 건강상태가 나빠지므로 이에 적절한 다각적인 사회복서비스를 개발할 필요가 있다.

• The Journal of Korean Physical Therapy
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• 제35권5호
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• pp.156-161
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• 2023

Purpose: This study examined the effects of subjective visual vertical perception and head orientation on static balance control. Methods: The subjects were 25 young and healthy adults. The vertical perception was measured using a subjective visual vertical (SVV), and the Center of pressure (COP) parameter was analyzed by continuously measuring the movement of the COP to determine the changes in static postural control. The group was divided based on a deviation of 3° in SVV (11 of SVV≥3°, 14 of SVV<3°) and measured with different head orientations: front, up, down, left, and right in the upright and tandem positions, respectively. Results: In the upright position, the SVV≥3° group had significantly larger values for all COP parameters (Sway length, Surface, Delta X, Delta Y, and Average speed) compared to the SVV<3° group (p<0.05). In the tandem stance, only the Ellipse Surface value was significantly larger among the COP parameters in the group with SVV≥3° compared to the group with SVV<3°(p<0.05). In contrast, the other COP parameters were not significantly different (p>0.05). The effects of static balance control on the head orientation were not statistically significant (p>0.05), and the interactions between the subjective vertical perception and head orientation were not significant (p>0.05). Conclusion: These results suggest that pathological deviations in SVV are associated with impaired static balance performance. This study can provide a therapeutic rationale for using visuospatial cognitive feedback training to improve the static balance.