• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.9 no.5
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• pp.49-58
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• 2010

The traffic signal controllers being used in the domestic currently are being manufactured based on the korean national police standard which was developed for controlling the quad-light traffic signal having the red, yellow, left-turn arrow, and green lights. But according to the national policy for the traffic operation, they have to be changed to be able to switch the tri-light signal having red, yellow and green lights. In this study, a new tri-light traffic signal controller was designed and developed by the way improving the Signal Control Unit of the existing quad-light standard traffic controller. The Load Signal Unit(LSU) was improved to output 6 signals which are the two assemblies of three signal indications having the red, yellow, and green lights. To enough traffic signals output to control each directional movements and the various transport modes which are car, bus, bike, and pedestrian etc., the connector bus system was designed to be able to accommodate maximum 96 signals outputs being constructed by 16 LSUs. Flasher device was developed to be able to support maximum 32 red signals. In the software, the communication protocol between traffic control center and the traffic signal controller was improved and new signal map code values were defined for the developed LSU controlling the quad-light traffic signal. A model of the quad-light traffic signal controller developed and was tested three operations, protocol-operation, remote-command and control-mode. The test result operated all of them successfully.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.4
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• pp.342-347
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• 2016

This paper dealt with the economic analysis on the application of shipboard LED (Light Emitting Diode) luminaires to replace incandescent and fluorescent lamps, which account for over 80 % of light source on a training or naval vessel. The rates of savings achieved in the power consumption, initial investment, maintenance cost, and fuel cost were analyzed. The break-even points and the $CO_2$ emissions were also calculated. For the training vessel, the initial investment was increased by 3.8 times, while the maintenance cost over five years was reduced by 51 %. When 40 %, 50 %, and 60 % of luminaires were turned on, the calculated break-even points were 11 months, 9 months, and 7 months, respectively. On the other hand, the initial investment was increased by 3.5 times while the maintenance cost over five years was saved by 55 % for the naval vessel. The break-even points were calculated as 15 months, 12 months, and 10 months, respectively. Moreover, the $CO_2$ emissions of the training and the naval vessels were reduced by 69 % and 65 %, respectively. From the results, it was revealed that the maintenance cost can be reduced by more than 50 %, and that the power consumption, fuel cost, and $CO_2$ emissions can be reduced by more than 60 % if LED luminaires are used on two types of vessels.

• Journal of the Korean Professional Engineers Association
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• v.19 no.2
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• pp.10-20
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• 1986

This paper describes a countermeasure of electric utilities and customer equipment in order to minimize an effect of sensitive electrical and electronic equipment on the voltage disturbances. After being studied, some schemes to solve were discovered. Firstly, in the electric utilities, the reduction of frequency and influence of voltage drop's time are not easy to realize because of the standpoint of effect and economy. Secondly, in the customer equipment, there are some equipment to minimize the voltage disturbances, Such as an UPSs, a noise suppressors and a power conditioners. One of them should be established on the computer control and automated systems, the electromagnetic switch of delay-release type should be adopted on the electromagnetic switch, the controlling circuit should be adopted on the variable speed motors which is being considered a countermeasure for a momentary under-voltage drops, the luminaire adhering a instantaneous restrike device should be adopted on the HID lamp. And also, the scheme of extending a setting time of relay on the undervoltage relay and the forming method of sequence which is automatic reclosing at this time of instantaneous suspension of an electric supply have been studied.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2008.05a
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• pp.25-28
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• 2008

수은이 함유된 방전등과 같은 조명기구의 사용이 제한되는 특수구역의 산업용 조명설비로 200 W 이상의 높은 소비전력의 백열등기구들이 사용되고 있다. 인공광원으로 백열전구는 매우 낮은 발광효율로 전력소모가 많고, 높은 방사열로 인해 화재의 염려가 있어 램프보호유리구를 장착하므로 낮은 조명률로 광 손실이 높게 발생한다. 또한 산업지역 내에서는 일반적으로 각종 전동기 및 공기조화 설비의 가동으로 진동이 심하며 여기에 백열전구 사용 시 당초 예상되는 수명보다 더욱 단축되고 있다. 이러한 지역에 설치된 백열등을 조명등기구 효율(Luminaire Efficacy)이 높은 친환경 에너지 절감형 차세대 광원인 LED조명등으로 대체하여 산업설비 지역 내 공급되는 조명용 소비전력을 크게 줄여 에너지 절약효과를 높임과 동시에 양호한 조명율의 LED광원을 사용함으로써 조명환경 개선에 따른 작업능률을 높이기 위해 특수지역의 산업용 LED조명등을 개발하였다.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.10 no.1
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• pp.31-37
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• 2017

In this paper, we implemented for the development of a high output induction lamp system, which lamp design is optimized by gas type, mixing ratio, pressure and discharge tube size, amalgam type and mixing ratio, and characteristics of ferrite core in the lamp. It's the circuit design by improving the power factor and efficiency according to the driving method, which has analyzing the characteristics according to the waveform and frequency. Finally, luminaries design part for applying the optimal lighting system considering the surrounding environment, the characteristics of the lighting circuit for electrodeless lamp has analyzed and the improvement has been proceeded. In conclusion, the driving frequency has optimized at 135kHz with degrading $7{\sim}10^{\circ}C$ based on the results of the optical characteristics of the induction lamp on peak noise FET(Q3,Q4) damage.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.5
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• pp.271-276
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• 2010

This study manufactured spot lighting fixtures for the broadcasting stage and LED lighting fixtures, measured the illumination, dimming, and color temperature, and installed LED lighting and spot Fresnel lighting to the camera by turns with the same subject to confirm and look into the possibility of replacement of LED lighting fixtures by shooting the figures and comparing them. The analysis of the photographed subject found that the lighting apparatus of LED 144[W] was superior to the tungsten halogen illuminator of 1 [kW] in terms of brightness and color of an image. The measuring of the energy used in 144 [W] LED lighting equipment and tungsten halogen 1[kW] lighting equipment suggested that LED saved more than 80 [%] of energy in the same intensity of illumination. The comparison of the light distribution and light intensity distribution of halogen tungsten illuminator of 1[kW] and LED 144[W] lighting apparatus found that when a subject received concentrated lighting, effective lighting is possible because the illumination intensity on the surface of the lighted subject was high. In performance halls or studios of about 6 [m] height, there is no problem of illumination intensity in LED 144 [W] illuminator. Therefore, it is possible to replace the existing tungsten halogen 1 [KW] illuminator one to one.

• The korean journal of orthodontics
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• v.30 no.5 s.82
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• pp.591-598
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• 2000

This study was designed to analysis the airway which affects to breathing, speech and facial growth pattern in unilateral cleft lip and palate patients. Upper airway and the position of hyoid bone pattern were analyzed on the lateral cephalometric radiographs of the 78 subjects of complete unilateral cleft lip and palate group and each group was divided two sub-groups by circumpubertal growth peak and gender. These data were statistically analyzed to examine the difference between pre-circumpubertal growth peak group and post-circumpubertal growth peak one, and between male and female group. The results of this study were as follows: 1. After circumpubertal growth peak stage, the position of hyoid bone was lower than before in both male and female group. 2. After circumpubertal growth peak stage, the measurement were increased in CV3ia-APH, PNS-ad which related to the volume of pharyngeal space. This was due to the decrease of adenoid and anteroiferior growth of mandible and affected to breathing and speech after circumpubertal growth peak. 3. During circumpubertal growth peak stage, all measurements increased more in male than female group, which due to the different amount of growth in different gender. 4. The position of hyoid bone was lower in male than female group in all age group. 5. After circumpubertal growth peak stage, CV3ia-APH increased more in male. This was due to the more growth in madible of male which resulted in the activation of digastric muscle.

• Journal of dental hygiene science
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• v.10 no.4
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• pp.265-271
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• 2010

This study was to investigate the level of knowledge, recognition, behavior of radiographic safety control and job stress in dental hygienists and to determine the relationship among variables. The subjects were 256(56.9%), who were worked in dental hospital and clinic with mean age of $29.59{\pm}7.30$. Data was collected using a self administrated questionnaire from April 4 to May 15, 2010. Behavior of radiographic safety control was measured using the 15-items and job stress was measured using the 5-items with 5-point likert scale. The data were analyzed with t-test, one-way ANOVA and pearson correlation coefficient using the SPSS WIN 17.0 program. Regarding job stress, the subjects was a mean of 2.63 out of a maximum 5 points. The level of knowledge, recognition, behavior of radiographic safety control a mean of 3.11, 4.08 and 3.43 out of a maximum 5 points. Recognition and behavior of radiographic safety control was negative related job stress in this study. Based on the findings, behavior of radiographic safety control is associated with job stress. These results suggest that various program should be considered for radiation safety control of dental hygienists.