• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.11 no.2
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• pp.51-55
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• 1997

The high frequency fluorescnet lighting systems are widely used because of their high luminous efficacy. However, the performance of the fluorescnet lamp at high frequency reveals significant changes depending upon operating frequency, lamp shape, lamp voltage and current while adapting either an electronic or an magnetic ballast. Therefore the matching between the fluorescent lamp and the ballast is the major concern in designing a lighting system. In this paper, high frequency characteristics of the FHF32W lamp is measured in a range of frequencies from 12kHz to 50kHz. And we presented a model of a fluorescnet lamp with non-linear impedance depending on the lamp current. Finally, after identifying the operating condition under negative imped¬ance behavior as lamp current changing, we proposed a method of choosing the optimal parameter of a high frequency fluorescnet lamp and the result is analyzed.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2002.11a
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• pp.19-21
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• 2002

Electroded lamps operated at a high enough frequency can usually be modeled for the purpose of ballast design, as a resistor. Electrodeless fluorescent lamps include other components such as the arc tube's inductance. But that's impedance is small and so will be neglected in this paper. So, electrodeless fluorescent lamps is modeled as a resistor. A SPICE compatible model was developed for an electrodeless fluorescent lamp(OSRAM SYLVANIA ICETRON/ENDURA 150W).

• Proceedings of the Korean Society for Quality Management Conference
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• 2006.04a
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• pp.69-75
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• 2006

As the level of technology and the standard of living improve, product reliability plays an Increasingly significant role. This study has been performed to build a reliability model of electronic ballasts for the low wattage fluorescent lamp. Telcordia SR-332, one of the most widely used reliability specifications, was selected for the model development. We briefly reviewed the basic concepts of the electronic ballast. We then developed a reliability model for the ballast using SR-332 concepts and the reliability has been examined.

• Korean Journal of Agricultural and Forest Meteorology
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• v.24 no.3
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• pp.179-189
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• 2022

Ice and water droplets rise and fall above the freezing altitude under the effects of strong updrafts and downdrafts, grow into hail, and then fall to the ground in the form of balls or irregular lumps of ice. Although such hail, which occurs in a local area within a short period of time, causes great damage to the agricultural and forestry sector, there is a paucity of domestic research toward predicting hail. The objective of this study was to introduce Land-Atmosphere Modeling Package (LAMP) hail prediction and measure its performance for 50 hail events that occurred from January 2020 to July 2021. In the study period, the frequency of occurrence was high during the spring and during afternoon hours. The average duration of hail was 15 min, and the average diameter of the hail was 1 cm. The results showed that LAMP predicted hail events with a detection rate of 70%. The hail prediction performance of LAMP deteriorated as the hail prediction time increased. The radar reflectivity of actual cases of hail indicated that the average maximum reflectivity was greater than 40 dBZ regardless of altitude. Approximately 50% of the hail events occurred when the reflectivity ranged from 30~50 dBZ. These results can be used to improve the hail prediction performance of LAMP in the future. Improved hail prediction performance through LAMP should lead to reduced economic losses caused by hail in the agricultural and forestry sector through preemptive measures such as net coverings.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.54 no.11
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• pp.553-560
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• 2005

This paper presents a study on the dimming control of electrodeless fluorescent lamp. To do this the equivalent model of electrodeless fluorescent lamp (ENDURA 100w Type) was first established. The resulted model of the lamp was applied to the two kinds of dimming control method, one is the variable switching frequency method and the other is the variable dc link voltage method. And the comparison results of the dimming characteristics between the two methods was presented. Theoretical predictions were verified by the experimental results on the ENDURA 100W type electrodeless fluorescent lame.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.8
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• pp.8-17
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• 2012

Unlike traditional lightings, LED lighting is one of objects that sends user an emotional segments through brightness control from various color temperature and dimming control. Also, within present interior lighting environment, emotional researches about traditional fluorescent lamp and newly implemented LED lighting environment are in active progress. Despite the fact adjectives describing emotions and scale modeling have been repeatedly used in many cases for a long time, there seems to be a lack of results in reliability, and there is a limitation for applying into actual lighting design. The purpose of this study is to construct an actual sized test-bed, which is used to draw out one's emotional words of behavior patterns from inner emotional experiences about lighting environment in an office space. Also, having fluorescent lamp and LED lighting as the main test subjects, we have tested emotional parts according to the changes of color temperature and adjective vocabularies chosen from user's action, and we have compared and analyzed the drawn out data. Also, having fluorescent lamp and LED lighting as the main test subjects, we have tested emotional parts according to the changes of color temperature and adjective vocabularies chosen from user's action, and we have compared and analyzed the drawn out data.

• Proceedings of the KIPE Conference
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• 2017.07a
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• pp.231-232
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• 2017

This paper describes the design and implementation of a 2.5kW (500V, 5A) simmer circuit that maintains the ionization of xenon gas inside the lamp. The design is based on a LCC resonant converter in continuous conduction mode (CCM) with above resonant frequency to take advantage of high power density from using parasitic elements such as the leakage inductance in a power transformer. In addition, since the converter has current source output characteristics, it is suitable for maintaining ionization of the lamp having the negative resistance load characteristic. To verify this converter design, PSpice modeling was performed. Finally, the developed simmer circuit is verified by a resistive load of rated performance and the Ionization maintenance operation of the xenon flash lamp.

• Journal of Auto-vehicle Safety Association
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• v.11 no.4
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• pp.16-21
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• 2019

In recent years, most automobile manufacturers have been using slim light source images to imprint their own brand image and identity. A light guide type lamp is widely used for making these kinds of a slim light source image. A light guide lamp means using a light emitting diode light source at one end of a long cylindrical pipe. The light from the light emitting diode source moves through the pipe by total reflection principle. Moving light is sent forward by various optic structures which is applied in the cylindrical pipe. However, the light guide lamp has a problem that the image of the light differs depending on the viewing direction, and in some cases there is dark section. It means light guide has low quality about lighting image. In this paper, trying to improve the fundamental problems of the light guide mentioned above by using various triz methods. Through functional modeling, estimating the factors affecting the light in the light guide lamp and make various ideas to improve the lighting image using the chain effect cause analysis, function oriented search scientific database techniques. Using these kinds of various TRIZ methods, finally find solutions that can improve the brightness and lighting uniformity of the light guide lamp. The ideas obtained in this paper were applied to actual vehicle development, and several patents achievements were obtained. In conclusion, it is proved that TRIZ method is useful for making ideas in actual automobile industrial field and is also a useful method for acquiring patent.

• Korean Journal of Agricultural and Forest Meteorology
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• v.23 no.4
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• pp.415-423
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• 2021

Recently, an R-based point time series data validation system has been established for the statistical post processing and improvement of the National Center for AgroMeteorology-Land Atmosphere Modeling Package (NCAM-LAMP) medium-range prediction data. The time series verification system was used to compare the NCAM-LAMP with the AWS observations and GDAPS medium-range prediction model data operated by Korea Meteorological Administration. For this comparison, the model latitude and longitude data closest to the observation station were extracted and a total of nine points were selected. For each point, the characteristics of the model prediction error were obtained by comparing the daily average of the previous prediction data of air temperature, wind speed, and hourly precipitation, and then we tried to improve the next prediction data using Support Vector Machine( SVM) method. For three months from August to October 2017, the SVM method was used to calibrate the predicted time series data for each run. It was found that The SVM-based correction was promising and encouraging for wind speed and precipitation variables than for temperature variable. The correction effect was small in August but considerably increased in September and October. These results indicate that the SVM method can contribute to mitigate the gradual degradation of medium-range predictability as the model boundary data flows into the model interior.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.2606-2611
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• 2003

Comprehensive study on the control system design for a RTP process has been conducted. The purpose of the control system is to maintain maximum temperature uniformity across the silicon wafer achieving precise tracking for various reference trajectories. The study has been carried out in two stages: thermal balance modeling on the basis of a semi-empirical radiation model, and optimal iterative learning controller design on the basis of a linear state space model. First, we found through steady state radiation modeling that the fourth power of wafer temperatures, lamp powers, and the fourth power of chamber wall temperature are related by an emissivity-independent linear equation. Next, for control of the MIMO system, a state space modeland LQG-based two-stage batch control technique was derived and employed to reduce the heavy computational demand in the original two-stage batch control technique. By accommodating the first result, a linear state space model for the controller design was identified between the lamp powers and the fourth power of wafer temperatures as inputs and outputs, respectively. The control system was applied to an experimental RTP equipment. As a consequence, great uniformity improvement could be attained over the entire time horizon compared to the original multi-loop PID control. In addition, controller implementation was standardized and facilitated by completely eliminating the tedious and lengthy control tuning trial.