• Journal of Korea Society of Digital Industry and Information Management
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• v.18 no.4
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• pp.23-30
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• 2022

Recently, traffic congestion and environmental pollution have occurred due to population concentration and vehicle increase in large cities. Various studies are being conducted to solve these problems. Most of the traffic congestion in cities is caused by traffic signals at intersections. This paper proposes a dynamic traffic light control (DTLC) scheme to support safe vehicle operation and smooth traffic flow using real-time traffic information based on VANET. DTLC receives instantaneous speed and directional information of each vehicle through road side units (RSUs) to obtain the density and average speed of vehicles for each direction. RSUs deliver this information to traffic light controllers (TLCs), which utilize it to dynamically control traffic lights at intersections. To demonstrate the validity of DTLC, simulations were performed on average driving speed and average waiting time using the ns-2 simulator. Simulation results show that DTLC can provide smooth traffic flow by increasing average driving speed at dense intersections and reducing average waiting time.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.10
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• pp.4740-4744
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• 2012

The purpose of this paper was to make a LED light control module using Zigbee. The module was made so that brightness of the LED light changes according to the ambient brightness. A 8-bit microcontroller was used to implement the module to enable LED dimming and wireless light intensity measurement. Using the proposed method, power consumption can be improved by up to 48% on average, with 3.4-0.4W changes in power. The measured ambient light intensity values are converted from analog to digital and outputted as a PWM waveform. According to the output waveform and changes in the current outputted from the LED driver, the brightness of the LED light is controlled. Also, Zigbee with close-range wireless communication capabilities was used to enable wireless transmission of light intensity measurements.

• Women's Health Nursing
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• v.21 no.3
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• pp.197-206
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• 2015

Purpose: The purpose of this study was to examine the effects of light therapy on sleep disturbance and depression in climacteric women with menopausal symptoms. Methods: The research design was a nonequivalent control group pre test-post test design. Data were collected from September 29, 2013 to November 11, 2013. Participants included 17 climacteric women in an artificial light therapy group, 17 climacteric women in a sun light therapy group and 16 climacteric women in a control group. Measures consisted of the sleep disturbance, depression, melatonin, and serotonin. Results: There was a statistically significant difference of Korean Sleep Scale A (F=53.87, p<.001), and melatonin (F=31.19, p<.001) among three groups. There was a statistically significant difference of Self-Rating Depression Scale (F=121.86, p<.001), and serotonin (F=102.37, p<.001) among three groups. Conclusion: Artificial and sun light therapy can be applied as a supportive nursing intervention to subjects with sleep disturbance and depression in climacteric women with menopausal symptoms. Artificial and sun light therapy is expected to be a complementary alternative intervention for health management of the subjects with sleep disturbance and depression in climacteric women with menopausal symptoms.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.52 no.3
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• pp.191-196
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• 2016

In order to establish the basic data for the growth of fish in the aquaculture industry, the behavior analysis of rockfish (Sebastes inermis) depending on the temperature and LED lights was conducted. In this study, water temperatures were set from $3^{\circ}C$ to $30^{\circ}C$ were used. One red light (wave length: 622 nm; light power: 811 mW) and one green lights (wave length: 518 nm; light power: 648 mW) were used. Behavior of the rockfish was expressed as average moving distance (AMD) for 1 minutes and a rate of movement. The mean AMD depending on the temperature was 1.0 m and the mean rates of movement was 50%. The mean AMD were 1.5 m, 1.9 m and 0.7 m in the red LED light, green LED light and control condition respectively. The mean rates of movement were 54%, 65% and 45% in the red LED light, green LED light and control condition respectively.

• Journal of Institute of Control, Robotics and Systems
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• v.22 no.10
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• pp.811-816
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• 2016

In light of recently developed 3D printers for rapid prototyping, there is increasing attention on the 3D scanner as a 3D data acquisition system for an existing object. This paper presents a prototypical 3D scanner based on a striped laser light image. In order to solve the problem of shadowy areas, the proposed 3D scanner has two cameras with one laser light source. By using a horizontal rotation table and a rotational arm rotating about the latitudinal axis, the scanner is able to scan in all directions. To remove an additional optical filter for laser light pixel extraction of an image, we have adopted a differential image method with laser light modulation. Experimental results show that the scanner's 3D data acquisition performance exhibited less than 0.2 mm of measurement error. Therefore, this scanner has proven that it is possible to reconstruct an object's 3D surface from point cloud data using a 3D scanner, enabling reproduction of the object using a commercially available 3D printer.

• Journal of Bio-Environment Control
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• v.24 no.1
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• pp.1-7
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• 2015

Irrigation control plays an important role in improving productivity of paprika which is very sensitive to moisture condition. Among environmental factors, light intensity and distribution are not easily controlled and showed a big difference depending on season and region. For adequate irrigation control, therefore, transpiration and irrigation amounts considering light environmental data should be estimated. In current study, modified transpiration model was used for more precise estimation of transpiration. Seasonal transpiration and irrigation amounts at different regions were compared by using light environmental data provided from Korea Meteorological Administration. The transpiration amount in summer was rather smaller than those in spring and autumn seasons in Korea due to large deviations in light intensity as well as rainy period in summer. Irrigation system capacities at various regions could be recommended by using the transpiration amount in the spring having the longest photoperiod in the year. These results will be useful to the design of irrigation system and optimization of input energy in greenhouse.

• Restorative Dentistry and Endodontics
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• v.45 no.4
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• pp.55.1-55.12
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• 2020

Objectives: This study investigated the effects of physically damaged and resin-contaminated tips on radiant emittance, comparing them with new undamaged, non-contaminated tips using 3 pieces of spectrophotometric laboratory equipment. Materials and Methods: Nine tips with damage and/or resin contaminants from actual clinical situations were compared with a new tip without damage or contamination (control group). The radiant emittance was recorded using 3 spectrophotometric methods: a laboratory-grade thermopile, a laboratory-grade integrating sphere, and a portable light collector (checkMARC). Results: A significant difference between the laboratory-grade thermopile and the laboratory-grade integrating sphere was found when the radiant emittance values of the control or damaged/contaminated tips were investigated (p < 0.05), but both methods were comparable to checkMARC (p > 0.05). Regardless of the method used to quantify the light output, the mean radiant emittance values of the damaged/contaminated tips were significantly lower than those of the control (p < 0.05). The beam profile of the damaged/contaminated tips was less homogeneous than that of the control. Conclusions: Damaged/contaminated tips can reduce the radiant emittance output and the homogeneity of the beam, which may affect the energy delivered to composite restorations. The checkMARC spectrophotometer device can be used in dental offices, as it provided values close to those produced by a laboratory-grade integrated sphere spectrophotometer. Dentists should assess the radiant emittance of their light-curing units to ensure optimal curing in photoactivated, resin-based materials.

• Journal of Applied Biological Chemistry
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• v.57 no.3
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• pp.255-257
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• 2014

This study was conducted to determine the attractive effects of Plutella xylostella adults to light emitting diode (LED) trap in greenhouse and compared with those of no light trap and black-light which is typically used in commercial luring lamp. The green LED trap captured more P. xylostella when compared with black-light trap, whereas the no light trap was a little attractive to P. xylostella adults. These results indicated that the green LED traps could be used for environmental insect pest control.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.26 no.6
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• pp.275-286
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• 2014

Light shelf is an efficient system that reduces the energy consumption by bringing the natural light down to the deep spaces inside of a building. However, the existing light shelves have limits in reducing energy usage, because the direction of the light flow is determined by the external environment such as the altitude of the sun and the azimuth. This current study presents a system that increases the efficiency of the light shelf by applying the Location-Awareness technology, in which the efficiency was verified through the performance evaluation. According to the examination of the technology for the Location-Awareness within residential space, 'Zigbee' type appears to be the most appropriate. The Location-Awareness technology operates the light shelf based on both the angle control axis and the light shelf angle control axis through the modularization of the reflector surface which is less affected by the external environment. The results of the performance evaluation showed that the movable light shelf that employs the Location-Awareness technology can reduce the energy consumption for lighting by 98.3% compared to the fixed light shelf and by 97.3% compared to the movable light shelf without Location-Awareness.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.8 no.5
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• pp.221-227
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• 2008

This paper is to show the designing for LED lights driver unit. The main purpose of driver designing is high electrical efficient performance and intelligent control LED driver. Nowadays, a lightning system with some of charactestics such as an environmentally friendly purposes with a possible reduction of electric power consumptions. We constitute a intelligent contron LED control system that helps to save an electric energy, and a communication system to control the system. This LED driver can be used for intelligent light control. This product expects to improve the light control by dimming instead of interlace on/off light control that increases the social cost such as car accidents and etc.