• 조명전기설비학회논문지
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• 제22권1호
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• pp.24-32
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• 2008

본 연구에서는 한국인의 시각적 특성을 반영한 불쾌글레어의 합리적인 예측을 위해 국내에 실제적으로 적용 가능한 불쾌글레어 예측식을 작성하는 것이 최종목표로 하고 있으며, 본 논문에서는 주변의 일반적인 사무실 건물의 조명환경을 대상으로 기본 단위로 구획하여 실물대모형(Mock-up)을 제작하여 실험을 진행하고 글레어에 최대 영향요인인 광원휘도를 비롯한 배경휘도, 입체각, 광원면적, 루버종류와 불쾌글레어의 관계를 도출하는 것을 목적으로 하였다. 본 연구는 다음과 같이 4단계로 나누어 연구를 진행하였다. 첫째, 불쾌글레어 평가등급을 정의하고 분류하기 위하여 선행연구에서 사용된 평가등급을 조사하여 연구목적에 부합되도록 수정하여 실험에 적용할 수 있도록 하였다. 둘째, 기존 불쾌글레어 평가실험식에 대한 검토를 통해 실험변수, 변수범위, 평가대상, 평가내용 등을 선정하였다. 셋째, 연구의 목적에 부합되도록 실험변인을 조절할 수 있는 실물대모형(Mock-up)을 제작하여 불쾌글레어 평가실험을 실시하였다. 최종적으로 불쾌글레어감과 광원휘도, 루버종류, 광원면적, 피험자위치간의 관계분석을 통해 실험변수의 민감도를 분석하였다. 연구 결과 인공광원의 불쾌글레어감에 영향을 주는 주요 변수는 광원휘도, 루버의 유무, 광원면적, 피험자위치(입체각) 순으로 영향을 미치는 것으로 나타났다.

• Journal of information and communication convergence engineering
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• 제12권4호
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• pp.246-251
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• 2014

The recent rise of the three-dimensional television (3DTV) industry has led to a wide exploitation of the dual-lens stereoscopic camera. However, when the zoom-in function is used, it is possible that a camera object is magnified only with a fixed convergence point, thereby leading to visual discomfort. In this paper, we propose several methods based on which a convergence point can be adjusted to prevent visual discomfort during zoom-in for a dual-lens stereoscopic camera. Further, we produce 3D contents by applying the proposed methods to certain cases and at certain distances and conduct a subjective evaluation. On the subjective evaluation, 48 subjects watch the 3D contents created by the proposed methods and score the stages of the visual comfort. The result of the subjective evaluation shows that some of the proposed methods are more efficient than the others. We hope that these proposed high-efficiency methods can be applied to produce a dual-lens stereoscopic camera that allows convenient stereoscopic photography.

• KIEAE Journal
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• 제7권5호
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• pp.29-34
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• 2007

Discomfort glare from windows is an important issue in window and daylighting design. This study aims to investigate the effect of luminance difference between the lower and the upper part of a large glare source. Experiments were conducted using a luminous body divided into two parts, the upper part and the lower part. The degree of discomfort glare from the luminous body was examined. The result shows that the part with lower luminance is perceived as a glare source when the part has higher luminance then the background luminance. The degree of discomfort glare was estimated for the experimental conditions, and compared to the observations. The estimation was made using two methods: one summed the glare sensation for each section, and the other used the average luminance of the whole luminous body. The result of the comparison shows that the method using the average luminance has approximate values to the observations. Consequently, the use of the average luminance was proposed for evaluation of discomfort glare from non-uniform large glare sources.

• 대한인간공학회지
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• 제33권3호
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• pp.215-227
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• 2014

Objective: The purpose of this study was to evaluate Korea's Honam express train's first- and second-class seat discomfort by using pressure measurement, subjective discomfort rating, and physical compatibility. Background: Over the years, the demand for an express train service is continually increasing. A comfortable ride is important to achieving passenger satisfaction. A train seat plays a significant role in fulfilling passenger seating comfort. With this in view, a field survey and pressure measurements were performed on the selected train seat. Method: The pressure ratio at the body-seat interface (thigh and buttock regions) was measured by the pressure mat system. The interface pressure ratio was calculated and compared. The subjective discomfort rating scale was used to evaluate the subjects' overall feeling. The dimensions of train seats were analysed according to the anthropometric and demographic characteristics of the population data from Size Korea. Results: The results highlighted that the interface pressure ratio was greater while participants sat on the second-class seat than the first-class seat in the left- and right-side thigh regions. Also the pressure ratio was greater for the participants in the 1st~25th percentile height groups (149.8~160.8cm). The subjects rated higher discomfort for the second-class seat than the first-class seat. The physical compatibility results showed that the second-class seat's breadth was inadequate for the 95th and 99th percentile male. Conclusion: Overall, interface pressure measurement, subjective discomfort score and physical compatibility results showed that the second-class seat was more uncomfortable for the passengers than the first-class seat. Application: The adopted methodologies could be used to measure the seating comfort of the train seats.

• 대한산업공학회지
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• 제28권2호
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• pp.216-222
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• 2002

The ergonomic human model can be considered as a tool for the evaluation of ergonomic factors in vehicle design process. The proper anthropometric data on driver's postures are needed in order to apply a human model to vehicle design. Although studies on driver's posture have been carried out for the last few decades, there are still some problems for the posture data to be applied directly to the human model due to the lack of fitness because such studies were not carried out under the conditions for the human model application. In the traditional researches, the joint angles were evaluated by the categorized data, which are not appropriate for the human model application because it is so extensive that it can not explain the posture evaluation data in detail. And the human models require whole-body posture evaluation data rather than joint evaluation data. In this study a postural evaluation function was developed not by category data but by the concept of the loss function in quality engineering. The loss was defined as the discomfort in driver's posture and measured by the magnitude estimation technique in the experiment using a seating buck. Four loss functions for the each joint - knee, hip, shoulder, and elbow were developed and a whole-body postural evaluation function was constructed by the regression analysis using these loss functions as independent factors. The developed postural evaluation function shows a good prediction power for the driver's posture discomfort in validation test. It is expected that the driver's postural evaluation function based on the loss function can be used in the human model application to the vehicle design process.

• 대한산업공학회지
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• 제27권4호
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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.

• Asian Pacific Journal of Cancer Prevention
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• 제14권7호
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• pp.4053-4056
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• 2013

Background: Colposcopy is the gold standard procedure for evaluating cervical cytological abnormalities. Although it is essentially a minimally invasive intervention, referral for colposcopy may cause significant distress on patients. In this study, we aimed to determine if pre-procedural anxiety levels have a significant association with procedure related pain and discomfort in women undergoing colposcopy for evaluation of abnormal cervical cytology. We also assessed the impact of various clinical factors on anxiety, pain and discomfort in these patients. Materials and Methods: This prospective study was performed at the gynecologic oncology department of Zekai Tahir Burak Women's Health Education and Research Hospital in Ankara, Turkey between January and June 2013. After taking informed consent, State-Trait Anxiety Inventory (STAI) form and a 14-item questionnaire were filled for women who were admitted to our outpatient colposcopy unit for evaluation of abnormal cervical cytology. STAI scores were calculated for each participant. Immediately after the procedure, visual analog scale (VAS) scores for procedure-related pain and discomfort were obtained. Associations between STAI and VAS scores were investigated using correlation analyses. The effect of various contributing factors on anxiety, pain and discomfort were evaluated with linear regression analysis. The p values less than 0.05 were considered statistically significant. Results: A total of 222 women met the inclusion criteria within the study period. Mean patient age was $38.5{\pm}9.6$. Median state and trait anxiety scores were 47 and 46, respectively. Median VAS scores for pain and discomfort were 4 for both variables. State anxiety had a significant correlation with procedure related discomfort (p=0.02). Colposcopy related pain VAS scores were significantly affected by state anxiety level, marital status and prior gynecological examination (p<0.05). Colposcopy related discomfort VAS scores were significantly affected by state anxiety level, marital status, prior gynecological examination and educational status. Conclusions: Additional measures should be implemented in women that carry higher risk for experiencing pain and discomfort. Social, cultural and lifestyle issues may also affect women's experiences during colposcopy, therefore further studies are needed to define specific determining factors in various populations.

• 대한인간공학회지
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• 제33권6호
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• pp.565-575
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• 2014

Objective: The aim of this study is to evaluate the effect of weight of load and time on the physical workload of repetitive upper-limb tasks with handling light weight loads using EMG and perceived discomfort, and to investigate the relationship between EMG and perceived discomfort for those repetitive tasks of moving light weight loads. Background: Repetitive upper-limb motion is known as one of the main risk factors of musculoskeletal disorders, and a lot of repetitive tasks are carried out while handling light weight loads in the industry. In evaluating the workload of repetitive tasks handling light weight loads, EMG and perceived discomfort can be used, though their relationship in those work conditions are not much investigated. Method: A laboratory experiment with 18 healthy males were conducted to record EMG signals from 5 muscle sites of the right arm and shoulder and rate perceived discomforts for the body parts and the whole body while carrying out repetitive materials-handling tasks for 52min. The subjects were divided into 3 groups which handled the loads of 1kg, 2kg and 3kg, respectively. ANOVAs were conducted to analyze the effects of the weight and time on RMS of EMG amplitude (normalized RMS: NRMS), median frequency of power spectrum of EMG (normalized MDF: NMDF) and perceived discomfort. The correlations between NRMS and NMDF and perceived discomfort were also analyzed. Results: Statistically significant muscular fatigue effects were not found from NRMS and NMDF in most muscles, while there were significant increases of discomfort as the task time elapsed. It was shown that there were an increasing trend of the muscular activity as the weight of load increased and a decreasing trend of median frequency of EMG of upper and lower arms as time elapsed. It was found that there were significant negative correlations between NMDFs from the lower arm and discomfort ratings, though the relationships were weak. Conclusion: It can be concluded that the working conditions adopted in this study were not enough to induce muscular fatigue, while there was significant increase in perceived discomfort. A further study is necessary to integrate the objective and subjective measures for more reliable and sensitive evaluation of workload of repetitive tasks of handling light weight loads. Application: This study can be used as a basic study for the evaluation of workload of repetitive tasks handling light weight loads.

• KIEAE Journal
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• 제10권2호
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• pp.25-30
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• 2010

The daylited space can improve visual comfort and occupant's well-being. However discomfort glare from the daylight is a common problem in indoor environments and in general, the window is the main glare sources. Some formulas have been proposed for predicting glare from the daylight, however, they do not consider the effect on glare of the view through a window and some studies proved that they are inadequate in real daylight situation. This research aims to identify the relationship between view and discomfort glare considering the subjective impressions. As a preliminary experiment, this paper sets up the experimental protocol to reveal relationships between views from a window and visual perception in a controlled laboratory experiment. $1.2m{\times}1.2m$ artificial window was developed and $0.9m{\times}0.9m$ view image was placed on the window. Discomfort glare and impression evaluation was carried out under four different views and one blank view as a reference condition. The results showed that the subjects evaluated discomfort glare differently with the views even under the same luminance conditions and tended to feel less glare with distance views compared to near views.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2014년도 추계학술대회 논문집
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• pp.247-249
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• 2014

The beating phenomenon occurs because of various causes, when idle vibration was happened. In this study, the beating phenomenon was divided into several parameters and controlled by the parameter. It was hypothesized that the beating parameter is related to discomfort of idle vibration. The three-down one-up method was performed for evaluating discomfort of controlled vibrations, which is widely used in the field of psychophysics. As a result in pilot test, a subject responds beating vibration more discomfort than normal idle vibration. In the future, the study will be implemented to know how much the parameters of beating signal affect to the discomfort at idle vibration in passenger vehicle.