• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.3
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• pp.7-15
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• 2013

In lighting design, the calculation of maintenance factor is performed by calculation considering light source, characteristics of luminaire and environmental factors. The method to calculate the current maintenance factor applied to tunnel lighting design takes into consideration only pollution factors in tunnels. In addition, the calculation method should be change in response to changes of tunnel conditions and used light sources. In this study, the calculated factor of the maintenance factor in tunnel is determine by four calculation factors generally applied to the calculation of maintenance factor. This study examined the method of calculating the maintenance factor of tunnel lighting that can be applied according to the installation conditions in designing tunnel lighting by applying the actual installation data of luminaire.

• Journal of the Korean Society of Safety
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• v.21 no.2 s.74
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• pp.114-120
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• 2006

Inspection works are mainly carried out with the help of human sensory organs and are relatively simple and repetitive, so that the workers easily become to feel fatigue and monotony, and their mental activity levels attenuate. Consequently, during the work time, it is natural that various lighting conditions around the workplaces may have in-fluence on work performance. This study aimed to analyze cortical fatigue of inspection workers. Thus, an inspection work was simulated on a computer monitor under various lighting conditions, and CFF, EEG, EOG, and HRV were analyzed. According to the results, fatigue symptoms turned up about $60{\sim}90$ minutes after the onset of the work. The work performance also decreased when the fatigue symptoms due to lighting conditions turned up. The variations of fatigue and work performance were affected by illuminators, illumination levels, or interaction of those two factors. The spiral fluorescent lamp seemed improper to the inspection work, because the work performance under that condition was lower than under any other illuminators.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.12
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• pp.42-47
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• 2011

The design of road lighting is aiming illuminance and luminance requirements for road lighting. In the process, various factors associated with luminaires such as luminous efficacy, light distribution, mounting height, spacing and maintenance factor are considered. However, there has been no restriction on lighting power density. In this study, lighting power density has been comparatively analyzed through a study of related data and a result of measurements on domestic roads. And, it has been analyzed by simulation results for road in which lighting conditions are variable. In terms of the limitation on power density for road lighting, road lighting can be designed using high efficacy lighting systems for energy saving.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.5
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• pp.9-17
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• 2013

Preferred combinations of illuminance and color temperature of lighting depend on daily living activities. We investigated whether the illumination stimuli of LED lighting can enhance attention and relaxation level by controlling color temperature and illuminance level according to activities. Illuminations and color temperatures of LED flat panels are controlled in accordance with activities such as office work and resting. The attention and relaxation level under the task specific lightings are compared with those under normal lighting condition. Single channel EEG signals from the NeuroSky's Mindset are used to estimate attention and relaxation level of human subjects under different lighting conditions. Experiment results show that high color temperature with high illuminance of LED lightings (6600K, 800lx) shows improved attention level compared with conventional lighting conditions (4000K, 500lx).

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.24 no.6
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• pp.497-508
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• 2012

Occupants' visual perception, psychological responses and spatial satisfaction under various indoor lighting environments were analyzed in this study. Field measurements and surveys were conducted in four coffeeshop space where different lighting conditions were used. Results imply that worse visual comfort was reported under direct lighting conditions that exposed light sources to occupants. To improve spatial satisfaction in space, lighting environments should lessen visual thresholds and distraction. Also, necessary illuminance levels should be kept with appropriate color of light that occupants prefer. Worse spatial satisfaction was reported under direct lighting environments, and spatial satisfaction was strongly relevant to visual comfort. Psychological comfort for space was positive in space where visual thresholds were minimized and visual comfort was positively evaluated. Psychological and spatial satisfaction was relevant each other. Occupants preferred to stay longer in space where psychological and spatial satisfaction was positively achieved due to less visual thresholds and improved visual comfort. Better psychological and spatial satisfaction was achieved in space where temporary mood and visual perception were favorably evaluated under indirect lighting environments.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.23 no.3
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• pp.231-242
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• 2011

This study examines influences of a daylight dimming control system on the variation of indoor illuminance and lighting energy savings in a small office space. Field measurements and a series of computation were performed for typical types of sky conditions in summer. Results indicate that the daylight illuminance under clear and partly-cloudy sky were close to the target illuminance during a majority of time due to a higher ratio of window to wall. However, the target illuminance was not kept successfully due to the variation of photosensor signals which were strongly influenced by desktop illuminance. The system with partially-shielded conditions succeeded to keep target illuminance under clear sky conditions. The system failed under overcast sky conditions since the electric light output from fixtures caused excessive signals to photosensors due to insufficient daylight on a desktop. Unshielded and fully-shielded conditions were not recommended for effective controls of the systems. The influence of lighting fixtures on photosensors should be minimized to achieve successful lighting controls by daylight dimming systems.

• International Journal of Control, Automation, and Systems
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• v.6 no.5
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• pp.746-754
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• 2008

This paper proposes a method to detect calibration patterns for accurate camera calibration under complicated backgrounds and uneven lighting conditions of industrial fields. Required to measure object dimensions, the preprocessing of camera calibration must be able to extract calibration points from a calibration pattern. However, industrial fields for visual inspection rarely provide the proper lighting conditions for camera calibration of a measurement system. In this paper, a probabilistic criterion is proposed to detect a local set of calibration points, which would guide the extraction of other calibration points in a cluttered background under irregular lighting conditions. If only a local part of the calibration pattern can be seen, input data can be extracted for camera calibration. In an experiment using real images, we verified that the method can be applied to camera calibration for poor quality images obtained under uneven illumination and cluttered background.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2005.11a
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• pp.147-150
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• 2005

Fixed lighting of public ways for both vehicles and pedestrians can create a nighttime environment in which people see comfortably and can quickly and accurately identify objects on the roadway being travelled roadway lighting can improve traffic safety, achieve efficient traffic movement and promote the general use of the facility during darkness. The design of a roadway lighting system involves consideration of visibility, economics, esthetics, safety and environmental conditions. This paper describe estimation of horizontal illuminance by actual measurement at main streets in Jejusi. We try to evaluate Jejusi Roadway Lighting Conditions for modeling by computer simulation.

• International Journal of Highway Engineering
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• v.14 no.4
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• pp.125-131
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• 2012

PURPOSES : Road lighting facilities increase the visibility of road at night in order to improve traffic driver safety and comfort. Generally speaking, current pole lighting has a tendency to create problems of glare and flicker. The phenomenon of glare gives discomfort due to increase of scattered light, when high luminance is in driver's field of view. The phenomenon of flicker occurs due to the driver passing through discontinuous pockets of pole lighting areas. These phenomenon increase eye strain and decrease driver safety. METHODS : Low height line lighting that distributes light lower than driver's eye level has been developed and evaluated to reduce the problems linked to current pole lighting. A test was undertaken with 4 conditions(turn on the general pole lighting, turn off alternate pole lighting, turn on the line lighting and line lighting with 50% dimming). A driver written survey was conducted in order to gain driver feedback. RESULTS : Pupil size and brow frequency compared with degree in pole lighting are reduced. CONCLUSIONS : Low height line lighting environment makes drivers more comfortable than pole lighting environment and is positive lighting method in the energy saving and landscape aspect.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.7
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• pp.9-14
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• 2005

In this study, we investigated the actual conditions of illumination environment of study rooms in detached houses. From the results, fluorescent lamp as a lighting source and direct lighting method were mainly used. The additional use of local lighting was 48.2[%], and it was not efficient for detailed work. The average illuminance of general lighting and local lighting were 131.41[lx] and 322.57[lx], respectively, and these level were only 54[%] of the lowest illumination standard. This indicates that the lighting levels and the environment are so poor. The satisfaction level of users, however, was relatively high, suggesting insufficient recognition of importancy of lighting for efficient work.