• Journal of the Korean Society of Safety
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• v.25 no.6
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• pp.75-80
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• 2010

The present study presented the implementation of a remote control/supervision system for guard lamps used in public illumination with little endeavor by far for safe management, which makes possible to supervise the state and to control the functions remotely including electric safety elements. Especially, the developed system adopts the measurement algorithm for detecting resistive leakage current(Igr) flowing based on the phase difference checkable for sensing at a monitor, being allowable for monitoring at MMI and transmitter for data transmittance. To verify reliability about the algorithm to accurately detect Igr leakage current, the laboratory-based functional test was performed.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.05a
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• pp.301-304
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• 2002

This paper describes a design and fabrication of an electronic ballast for 70［W］ceramic discharge metal halide lamps. The proposed ballast is composed of a rectifier, an active PFC, a half-bridge inverter, a LC resonant circuit and a controller. The design also includes a specially designed time circuit which provides reignition of the lamp. Running frequency of the ballast is set at 45［KHz］to avoid acoustic-resonance and flicker. from the test results, input power factor and efficiency of the ballast were estimated 91［%] and 97.7［%］, respectively.

• Journal of Korean Elementary Science Education
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• v.18 no.1
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• pp.65-73
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• 1999

The purpose of this study is tile development of tile observation Assessment criteria that is used to assess manipulative skills in elementary science. The procedures of developing observation Assessment criteria are as follows. First, we investigated the actual condition about science process skills assessment with tile questionnaire. Second, we selected 7 experimental apparatus through the analysis of the science textbooks. The selected experimental apparatus are dropper, alcohol lamp, thermometer, test tube, filtering device, able balance, graduated cylinder Third, the observation Assessment criteria arc developed through tile analysis of the related experimental textbooks, the demonstrations, and the questionnaire, Forth, tile validity is verified by science education specialists and graduate students who major in science education. Fifth, the first jilter-rater agreement is investigated in the result of the field with observation criteria of which the validity was verified. The second inter-rater agreement is investigated through the revision and the addition of the criteria with the low agreement. In result, the jilter-rater agreement ranged from 0.86 to 0.98. One of the major problems in observation assessment is the rater's subjective viewpoint. So, this research shows a more specified scale and criteria for the assessment. This suggests that the observation Assessment criteria developed in tile study satisfies the high reliability and validity requirements. Considering the results, this criteria call be used effectively for assessing manipulative skills of elementary school students.

• Proceedings of the KIEE Conference
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• 2003.07c
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• pp.1840-1842
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• 2003

This paper describes an experiment of detecting a temperature and components of arc plasma of electrical circuit breaker with a spectroscopic system. The system includes an optical fiber, a monochromator which has three gratings from low to high resolution and ICCD of which time resolution is 50 ns. This system enables measuring a temperature and components of arc plasma of a circuit breaker which is generated and extinguished in a few ms. We use a Planck's law and Boltzmann Plot method for calculating a temperature of arc plasma. A Xenon lamp is used for calibrating the system and this is very important for calculating a temperature of arc plasma. In this study, Arc plasma of Ag and Cu contact was investigated and these represent the contact of low voltage and extra-ultra high voltage circuit breaker, respectively. 8 $kA_{rms}$ test current was applied with a capacitor bank.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 1997.11a
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• pp.289-296
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• 1997

This paper discribes an experimental explosion risk assessment study on refrigerators containing flammable hydrocarbon refrigerant. A refrigerator used in this study is a larder fridge type, 215 liter in volume. The hydrocarbon refrigerant used in the refrigerator is iso-butane(C$_4$H$_{10}$). For the explosion safety assessment of the refrigerator, temperature of compressor, cooling air circulation fan motor, defrost heater and inner lamp were measured during the operation. And to confirm the ignitablity of flammable gas by the electric spark of the switches of the refrigerator, ON-OFF test of all switches were conducted with compulsorily near the stoichiometric concentration atmosphere of iso-butane-air mixture. As the result of experiment above mentioned and another experiment for the explosion safety assessment, we can conclude that explosion hazard in connection with the use of hydrocarbon refrigerant was few.w.

• Smart Structures and Systems
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• v.32 no.2
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• pp.123-133
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• 2023

This paper proposes a thermography-based coating thickness estimation method for steel structures using model-agnostic meta-learning. In the proposed method, a halogen lamp generates heat energy on the coating surface of a steel structure, and the resulting heat responses are measured using an infrared (IR) camera. The measured heat responses are then analyzed using model-agnostic meta-learning to estimate the coating thickness, which is visualized throughout the inspection surface of the steel structure. Current coating thickness estimation methods rely on point measurement and their inspection area is limited to a single point, whereas the proposed method can inspect a larger area with higher accuracy. In contrast to previous ANN-based methods, which require a large amount of data for training and validation, the proposed method can estimate the coating thickness using only 10- pixel points for each material. In addition, the proposed model has broader applicability than previous methods, allowing it to be applied to various materials after meta-training. The performance of the proposed method was validated using laboratory-scale and field tests with different coating materials; the results demonstrated that the error of the proposed method was less than 5% when estimating coating thicknesses ranging from 40 to 500 ㎛.

• Advances in materials Research
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• v.13 no.1
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• pp.1-18
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• 2024

The present experimental investigation focuses on finding optimal parametric data-set of laser micro-drilling operation with minimum taper and Heat-affected zone during laser micro-drilling of Carbon Nanotube/Epoxy-based composite materials. Experiments have been conducted as per Box-Behnken design (BBD) techniques considering cutting speed, lamp current, pulse frequency and air pressure as input process parameters. Then, the relationship between control parameters and output responses is developed using second-order nonlinear regression models. The analysis of variance test has also been performed to check the adequacy of the developed mathematical model. Using the Response Surface Methodology (RSM) and an Accelerated particle swarm optimization (APSO) technique, optimum process parameters are evaluated and compared. Moreover, confirmation tests are conducted with the optimal parameter settings obtained from RSM and APSO and improvement in performance parameter is noticed in each case. The optimal process parameter setting obtained from predictive RSM based APSO techniques are speed=150 (m/s), current=22 (amp), pulse frequency (3 kHz), Air pressure (1 kg/cm²) for Taper and speed=150 (m/s), current=22 (amp), pulse frequency (3 kHz), air pressure (3 kg/cm²) for HAZ. From the confirmatory experimental result, it is observed that the APSO metaheuristic algorithm performs efficiently for optimizing the responses during laser micro-drilling process of nanocomposites both in individual and multi-objective optimization.

• Journal of the Korean Institute of Telematics and Electronics T
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• v.36T no.1
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• pp.51-57
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• 1999

This thesis is written about the Wired Logic Type Unit in developing equipment that the load is driven, that the interface unit connect with 1 Scan time to PO30 of operated PLC output contact with that a sensing signal of Temperature Sensor RSD Pt $100\Omega$ let generate the relay output of temperature controller and input the PLC. The PLC Test Kit in country that the PLC to be programmed at the PLC education place is able to drive the load, is done to do a education of PLC on status that interface process between PLC and load are disregarded. As Developing Kit for supplement this point, when the relay output of temperature controller to use Pt 100 of temperature sensor as mentioned on the former among every kinds of sensor feed back to the input of the PLC, as the equipment to act with real time system that the output contact of PLC operated to insert the WLTIJ among PC, PLC and the load, it can understand and see very easy the main principle of PLC use. The structure of WLTU to be a interface unit of load separated as to the point of contact and noncontact, sensor, indicating lamp and A contact and B contact that is belong to driving part, and a motor is belong to loading part.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.6
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• pp.83-88
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• 2010

In this paper, to propose a valid method solving a problem relevant to grounding from actual field data, the experimental results relevant to touch and step voltages and surface potential profiles measured around the real-sized and small-sized grounding electrode models were described. The ground surface potential profiles and dangerous voltages around the concrete pedestals employed in street facilities such as street lamps, traffic signal lamp and controllers as a case study were measured and discussed. The hemispherical cell with a diameter of 1,160[mm] was employed to simulate uniform soil. As a result, the results measured with the small-sized model were in reasonably agreement with the data obtained from the real-sized installation. It was found that the small-sized model test could be employed as a useful means evaluating the dangerous voltages around grounding electrodes installed at the inaccessible areas such as mountains, underground, underwater, and so on.

• Journal of Acupuncture Research
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• v.23 no.1
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• pp.95-103
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• 2006

Objectives : This study was to evaluate the clinical effectiveness of Bee Venom acupuncture therapy for acute ankle sprain. Methods : From September 1st, 2005 to December 31st, 2005, the 60 patients who had visited Conmaul oriental medical hospital with acute ankle sprain were sample into 2 groups for this study; one group for the bee-venom acupuncture therapy combined with needle acupuncture therapy and the other group for needle acupuncture therapy only at least 3 times respectively. Both group had been treated with same additional infrared lamp, physical therapy and ankle supporter during the whole treatment period. Among 60 patients, 20 participants satisfied the whole inclusion criteria. To estimate the efficacy of treatments, Numerical Rating System(NRS) and Ankle-Hindfoot Scale(AHS) were applied before 1st and 4th treatment. Each score results were analysed and compared by Mann-Whitney test and Wilcoxon signed rank test with the level of 5% significance. Result : The NRS score in bee-venom acupuncture therapy group was increased significantly and the AHS score in bee-venom therapy group was decreased significantly compared to each of single acupuncture therapy group(P<0.01). The score change comparisons between the two groups had no significance before and after the treatment. Conclusion : Both bee-venom acupuncture therapy and single acupuncture therapy were effective to treat the acute ankle sprain. but there were no significant data to prove that bee-venom acupuncture therapy is more effective than single acupuncture therapy.