• Proceedings of the KIPE Conference
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• 전력전자학회 1998년도 전력전자학술대회 논문집
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• pp.314-318
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• 1998

This paper discusses the development of electronic ballast for neon lamp as an application of a zero voltage switching high frequency inverter. Abnormal increase of secondary voltage due to grounded fault or partial damage of serial arranged loads is clarified and the protection circuit for this abnormal voltage increase is proposed. Also stable lighting condition for removing the unstable characteristics due to different load conditions is proposed.

• Journal of the Korean Society of Safety
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• 제12권2호
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• pp.119-132
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• 1997

According to the construction environmental changes due to the trend of large scale and complicated building construction, many construction methods(such as : TOPDOWN )are more often used. However, it is pointed out that occupational pulmonary diseases, reduction of the machinery lifetime and productivity caused to be narrow visual field and collision between the workers. Therefore, this study is mainly dealing with the views of productivity and safety improvement in order to improve work efficiency and to insure the safety in underground construction environment.

• Journal of rehabilitation welfare engineering & assistive technology
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• 제11권1호
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• pp.45-52
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• 2017

EEG signals that are the same as those that have the same disabled people. So, the EEG signals are becoming the next generation. In this paper, we propose an internet of things system that controls the indoor environment using EEG signal. The proposed system consists EEG measurement device, EEG simulation software and indoor environment control device. We use data as EEG signal data on emotional imagination condition in a comfortable state and logical imagination condition in concentrated state. The noise of measured signal is removed by the ICA algorithm and beta waves are extracted from it. then, it goes through learning and test process using SVM. The subjects were trained to improve the EEG signal accuracy through the EEG simulation software and the average accuracy were 87.69%. The EEG signal from the EEG measurement device is transmitted to the EEG simulation software through the serial communication. then the control command is generated by classifying emotional imagination condition and logical imagination condition. The generated control command is transmitted to the indoor environment control device through the Zigbee communication. In case of the emotional imagination condition, the soft lighting and classical music are outputted. In the logical imagination condition, the learning white noise and bright lighting are outputted. The proposed system can be applied to software and device control based BCI.

• Journal of Bio-Environment Control
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• 제24권2호
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• pp.106-112
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• 2015

The objective of this study was to examine the growth reaction of strawberry plants to the mixed red and blue LED sources and their installation method. The artificial light sources were : LED PAR(PPFD $2{\sim}4{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$), LED BAR(PPFD $100{\sim}120{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$) and incandescent(PPFD $2{\sim}4{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$) lamp. The lighting treatment was started at the first cluster flowering period as a night breaking lighting and was applied during 3 hours, between 22:00 and 01:00 every day. Plant height and leafstalk length were longer in plants treated with incandescent lamp, where as fresh and dry weight of shoot were heavier in LED PAR compared to incandescent lamp treatment. LED PAR treatment also resulted in the largest leaf area, chlorophyll content was increased by $0.36mg{\cdot}g^{-1}$ after 60 days from the starting of the artificial lighting. According to the experimental results application of 16W LED PAR lamps and W-type installation method can improve light environment in strawberry lighting culture.

• Horticultural Science & Technology
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• 제30권1호
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• pp.6-12
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• 2012

Early growth, pigmentation, protein content, and phenylalanine ammonia-lyase (PAL) activity of red curly lettuces (Lactuca sativa L.) grown under different lighting conditions were investigated. Fluorescent lamps (control), blue, red, and blue plus red light-emitting diodes (LEDs) were used as light sources for 10 days. An equal proportion (1:1) of blue and red LEDs was used in the mixed radiation condition. Compared with the control, monochromic red or blue lighting increased fresh and dry weights of 'Ttuksum' and 'Jaju' lettuces. Anthocyanin synthesis was also significantly promoted by the mixed radiation of blue and red LEDs. The mixed radiation also increased the protein content and PAL enzyme activity of 'Ttuksum' leaves by about 200% compared to other treatments. Anthocyanin content was the highest in lettuces subjected to the mixture radiation of blue and red light treatment, while anthocyanin synthesis was inhibited by monochromic red light. The results of the present study indicate that growth and pigment synthesis in lettuces are significantly enhanced by exposure to mixed radiation from blue and red LEDs.

• Journal of the Korean Institute of Landscape Architecture
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• 제32권1호
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• pp.23-32
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• 2004

This study aims to examine constraints on visits to urban community parks and to find ways to elevate the efficient use of parks. To achieve this, the study relied on empirical study method and the descriptive method; additionally, present condition survey was performed with a user interview, on the assumption that a park visit is a form of leisure. As a result, the item of 'insufficient lighting facilities' shows the highest mean and the item of 'low quality of park' follows Previous research also revealed that the item of 'the lack of lighting facilities' is a major factor on user dissatisfaction, so a design and management program for night time users are fully researched and elaborately accomplished. Also, the high response of 'low quality of park' shows that the park supply policy in Korea focusses mainly on quantity so far, and it shows that user's dissatisfaction for park facilities becomes one of the major constraints of park visit. The factor analysis, on the object of 35 items except 2 items, appeared 5 factors: accessibility, inner discord, companion, family matters, park-itself-matters. Oneway Anova test showed that 4 factors except 'park-itself-matters' have reliable difference in constraint cognition by age and education. The visit constraint of 'park-itself-matters' did not appear different by any personal characteristics. Without regard to personal characteristics, it is regarded that this factor has the greatest effect upon park visits. In general, people who are disadvantaged strongly cognize constraints even in leisure such as a park visit, which is a simple and inexpensive leisure activity. Therefore, a park like a pocket park, which is small but located in a neighborhood, is more needed than a central park like a symbolic and huge park in every new city. Careful concern for night activity should be accomplished in the planning process.

• Journal of the Korean Solar Energy Society
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• 제23권3호
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• pp.63-71
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• 2003

According to the recent report, the lighting energy consumption of commercial buildings reaches to $30%\sim40%$ of the total energy consumption. It is more than that of cooling & heating energy consumption and it is the major target of energy-saving policy. It is obvious that they are interested in natural lighting device such as Light-shelf for the purpose of raising the lighting energy-saving efficiency. In most of highly developed countries, a thorough study on Light-shelf makes it possible to propose a practical plan while at home there leaves much to be desired to study a guiding principle of optimum plan in spite of its efficiency based on experiments using scale4 model and analysis of simulation. Aiming at making an optimum plan of Light-shelf suitable for the domestic situation, this study is worked by experiments using light-shelf and analysis of variables using illumination program. The experiments is to analyse the efficiency of Light-shelf on condition of the sky and the analysis is to make the simulation using illumination program. This study is composed of 1) the analysis of light with some variables such as presence of light-shelf and degree of angle using 1/2 scaled model 2) making the simulation using Lightscape, illumination program, In brief, concerning presence of light-shelf, it causes little difference in its efficiency in the overcast sky, whereas it decreases an illuminance of window side and provides inner side with the light, which decreases the ratio of the maximum to the minimum inner illuminance and makes the inner of illuminance to range evenly in the clear sky. On degree of angle, as the daylight increases in proportion of degree of angle, the ratio of the maximum to the minimum inner illuminance decreases, which makes it possible to increase the proportion of inner daylight.

• Proceedings of the IEEK Conference
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• 대한전자공학회 2004년도 학술대회지
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• pp.862-866
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• 2004

Non-intrusive methods based on active remote IR illumination for eye tracking is important for many applications of vision-based man-machine interaction. One problem that has plagued those methods is their sensitivity to lighting condition change. This tends to significantly limit their scope of application. In this paper, we present a new real-time eye detection and tracking methodology that works under variable and realistic lighting conditions. Based on combining the bright-pupil effect resulted from IR light and the conventional appearance-based object recognition technique, our method can robustly track eyes when the pupils are not very bright due to significant external illumination interferences. The appearance model is incorporated in both eyes detection and tracking via the use of support vector machine and the mean shift tracking. Additional improvement is achieved from modifying the image acquisition apparatus including the illuminator and the camera.

• Journal of Information Technology Services
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• 제17권3호
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• pp.53-61
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• 2018

In this paper, we propose a car sealing monitoring system combined with ICT Technology. The automobile sealer is an adhesive used to bond inner and outer panels of doors, hoods and trunks of an automobile body. The proposed car sealer monitoring system is a system that can accurately and automatically inspect the condition of the automobile sealer coating process in the general often factory production line where the lighting change is very severe. The sealer inspection module checks the state of the applied sealer using an area scan camera. The vision inspection algorithm is adaptive to various lighting environments to determine whether the sealer is defective or not. The captured images and test results are configured to send the task results to the task manager in real-time as a smartphone app. Vision inspection algorithms in the plant outdoors are very vulnerable to time-varying external light sources and by configuring a monitoring system based on smart mobile equipment, it is possible to perform production monitoring regardless of time and place. The applicability of this method was verified by applying it to an actual automotive sealer application process.

• Journal of Korea Multimedia Society
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• 제12권7호
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• pp.941-946
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• 2009

As supplying of automatic surveillance or patrol systems based on image processing, the needs on object extraction technology from images increases. The extraction is more difficult when the lighting condition is changed from time to time. There are many approaches to extract objects from images excluding shadow. They have a common problem something like loss of object region according with shadow removal. In this paper a restoration method using color information of objects to complement the problem is presented. The usefulness of the method is verified using images taken from different lighting conditions and selected from well-known DB.