• Journal of Industrial Technology
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• v.30 no.B
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• pp.109-112
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• 2010

Unlike the general lighting systems, stage lighting system requires accurate dimming control and reduction of flicker phenomenon. In this paper, we studied PWM dimming control and linear voltage level control methods. PWM Dimming is easy control and flicker phenomenon of linear voltage level dimming does not happen by experiment result. We concluded that stage lighting dimming system required to combine two techniques of the PWM and linear voltage level dimming control method.

• Journal of Convergence for Information Technology
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• v.8 no.5
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• pp.153-158
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• 2018

In this paper, we have studied a dimming level control method to satisfy both lighting and communication performance in visible light communication system. In the case of the most commonly used OOK and RZ-OOK modulation schemes, continuous Burst Zero Duration will seriously degrade the lighting function. This causes not only the illumination but also the performance of the entire system to deteriorate. Through this study, we analyzed the dimming level characteristics of the existing system and proposed the Illegal Pulse Insertion (IPI) algorithm as a technique to increase the dimming level. Through this, it is possible to effectively control the dimming level and improve the QoS of both lighting and communication by resolving the flicker phenomenon and dimming level reduction in the existing modulation and demodulation system.

• Journal of the Korean Solar Energy Society
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• v.28 no.5
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• pp.36-48
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• 2008

This study examines the influence of control algorithms on dimming performance to determine appropriate control setting when direct/indirect lighting is controlled by a daylight dimming system. Computer simulation were performed for a small office with double skin envelope under various daylight conditions. A retractable fabric shading and Venetian blind were applied for internal and external envelopes under three CIE standard sky conditions. Unshielded and partially-shielded photosensors were used, and three control algorithms were applied for the sensors. In general, dimming level was too excessive due to the direct impact of light from lighting fixture to the photosensor. Providing insufficient lighting output, the unshielded photosensor completely failed to secure required illuminance under any daylight condition. When a partially-shielded photosensor was applied under clear sky, three setting points functioned effectively. Less sensitivity for the partially-shielded photosensor was effective to control the dimming system optimally with reasonable energy saving. However, the daylight dimming control system for direct/indirect lighting does not appear to be energy effective when photosensors without enough shielded area is installed on ceiling where light from fixtures reaches directly.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.27 no.1
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• pp.14-23
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• 2015

Although research and technology developments have recently increased to save lighting energy within buildings, such research and technology development are judged to be unsuitable for energy savings since they are limited in the sense that the application of the technology is fragmented. This study proposes a user and location awareness technology applied to dimming lighting control system and verified the effectiveness of energy savings by building a test bed. The results were as follows : 1) This study suggested a user and location awareness technology applied to dimming lighting control system. 2) The system shows 96.6% and 82.8% energy saving rates, respectively, on the basis of one user, compared to an on/off lighting control and the user and location awareness technology applied to on/off lighting control system. 3) The energy consumption of the user and location awareness technology applied to on/off lighting control system and the user and location awareness technology applied to dimming lighting control system increased to 96.6%, 88.3%, and 59.6% and 82.8%, 85.0%, 51.5%, respectively, on the basis of one, two, and three users, compared to the on/off lighting control system. This study confirmed the energy saving performance of the user and location awareness technology applied to the dimming lighting control system through performance evaluation. In this regard, further study needs to be undertaken to evaluate the performance at night time.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.17 no.5
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• pp.15-21
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• 2003

This paper presents field measurements on daylighting and electric lighting with dimming controlled systems for a small office in Seoul, Korea. And the main purpose of this study is to provide the evaluation data of lighting energy performance when a dimming system is installed. For the performance evaluation, the mock-up room(3.6x7.2x2.6[m]) was used for the actual test. The results of this study were as follows; 1) The correlation between daylight illuminance at a workplane(Ed) and the photosensor signal(Sd) was an important factor affecting the performance of daylight responsive dimming system, 2) The mock-up office space gained a sufficient workplace illuminance of 579[lux] with the dimming control system 3) About 53[%J of monthly lighting energy could be saved using the dimming control system.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2005.11a
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• pp.167-172
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• 2005

This study based on the experimental data on the daylight responsive dimming systems performance. The purpose of this study increases the energy-saving effects by reducing excessive intensity of radiation of artificial lighting through analyzing incident daylight. The photosensor sends amounts of detected luminous flux to digital control unit(DCU) as a signal and then, it can decide dimming ratios, by received a proper dimming signal from DCU. Generally it is effective to control artificial lighting with the different control ratio of each row by setting a photosensor as same numbers and rows as artificial lighting. However, it is ineffective to do in initial costs of systems aspect in offices. By analyzing the data of this performance and finding regular ration between photosensors. we will execute different dimming ratios to each row of artificial lighting by a single photosensor.

• KIEAE Journal
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• v.10 no.6
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• pp.33-39
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• 2010

Visual Environment and productivity are correlated. So we need to create a comfortable visual environment and maintain proper workplane illumination level. We can obtain lighting energy savings and comfortable visual environment using daylight and LED lights. In this study, we characterized the indoor illuminance level according to the sky condition and proposed dimming control strategy of LED lights. Energy savings in On/Off control mode are 40% at clear sky and 28% at intermediate sky. In dimming control mode, energy savings are 77.2% at clear sky and 64.1% at intermediate sky. Then we obtain the appropriate dimming control strategy of LED lights based on data. Dimming rates are 0-14.2-80(min-avg-max, %) for LED 1, 0-19.9-60% for LED 2 and 30-61.4-90% for LED 3. Lighting energy savings are 68.2% for LED dimming system applied this control method.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.4
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• pp.8-15
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• 2009

In this paper, a new demand-side evaluation for the technical potential of lighting dimming control and its applications in electricity markets have been presented. The California standard practice test has been widely used to estimate the economic value of demand-side resources. However, as the advent of deregulation and restructuring of power industry, the California test has been facing some limitations to adopt in the new market environments. In particular the conventional DC test is appropriate for the traditional vertically integrated utility, not for the restructured unbundled utility. Thus, this paper presents a new method to evaluate the economic value of demand-side resource, especially of controllable lighting dimming resource in terms of the energy service provider in market environments. We, therefore, first estimate the technical potential of the lighting dimming control and evaluate the value of the lighting dimming control based on the Korean electricity market data in 2006. The study result shows that the lighting dimming control is a cost effective option for the energy service provider.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.1
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• pp.109-113
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• 2011

This paper analyzes the noise sources of an LED lighting module with TRIAC dimming control and proposes an improved EMI filter design for the reduction of conducted noise emission. TRIAC dimming invokes problems of input oscillation and capacitor overvoltage at the lighting module. The proposed double LC filter reduces high noise level from the circuit. The experimental and simulation results show that this approach can make significant contributions to the reduction of conducted noise emission from an LED lighting module with TRIAC dimming control.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.7
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• pp.1-7
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• 2013

LED lamps are appropriate to the light source for use in broadcasting lighting. When the lighting frequency of LED lamp is different from the shutter frequency of camera, however, the flicker appears on the moving image which is taken by the camera under the dimmed light of LED lamp with conventional dimming methods. In this study, a new dimming method for the LED lamps used as the broadcasting lighting is proposed to minimize the flicker. A lighting period in the proposed dimming method is divided into the several sub-periods which have weight of the bits. Also, the proposed dimming method has characteristics that are optimizing the turn-on timings of two LED lamps to reduce the turn-off periods of the lamps and not to overlap the turn-on periods of the lamps. In the experiments, the incidence of the flicker is taken by the camera under several lighting conditions of the conventional dimming methods and the proposed dimming method. In addition, the brightness values of the frames are obtained in the moving image, and incidence of the flicker is evaluated and compared with conventional methods. From the results, the incidence of the flicker in the proposed method is more improved than the conventional methods.