• Proceedings of the KIEE Conference
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• 2001.10a
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• pp.200-204
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• 2001

A ZVZCS(Zero Voltage and Zero Current Switching) Three Level DC/DC Converter is presented to secondary auxiliary circuit. The new converter presented in this paper used a phase shift control with a flying capacitor in the primary side to achieve ZVS for the outer switch. A secondary auxiliary circuit, which consists of one small capacitor two small diode and one coupled inductor is added in the secondary to provides ZVZCS conditions to primary switches, ZVS for outer switches and ZCS for inner switches. Many advantages including simple circuit topology high efficiency, and low cost make the new converter attractive for high power applications. The principle of operation, feature and design considerations are illustrated and verified through the experiment with a 1kW 50kHz IGBT based experimental circuit.

• The Transactions of the Korean Institute of Power Electronics
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• v.4 no.6
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• pp.500-506
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• 1999

This paper presents the h밍h performance [GBT type auxiliary jXlWer supply designt.'Cl by new concept. For t the simplification and higher performance, the direct :3 level PWlVl inverter using the high capacity IGBT and t the 32bit DSP are adopted. The cost as well as bulk and weight is appreciably reduced about 40% lower than t those of conventional one. the electrical efficiency above 94~) o and the audible noise level is less than 65dB. In a addition, the TIID(Total lIannonic Distortion) factor is below 5% an이 the voltage fluctuation on a transient s state is below 10%.w 10%.

• Current Research on Agriculture and Life Sciences
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• v.32 no.4
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• pp.215-223
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• 2014

This study examines the contribution level of greenhouse gas(GHG) emission reduction and installation costs of renewable energy facilities. The GHG emission forecasts and industrial structures in the 16 regions of Korea are then analyzed to identify the proper supply of renewable energy sources for each region. The results show that water power is the most effective and efficient renewable energy source to reduce GHG emissions, followed by sunlight, wind power, geothermal heat, and solar heat, respectively. The 16 regions are then categorized into 4 groups based on their GHG emission forecast and industrial structure: high emission and manufacturing group, low emission and manufacturing group, low emission and service group, and high emission and service group. The proper supply of renewable energy sources for each group is then determined based on the contribution level and cost efficiency of GHG emission reduction.

• Korea Trade Review
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• v.44 no.1
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• pp.237-251
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• 2019

This paper seeks to recommend strategic policy options geared towards enhancing sophistication level of Ulsan City's major export industries in the Republic of Korea. Ulsan's major export industries, including shipbuilding, automobile and petrochemical industries, turn out to be based mostly on low to medium technology with low R&D intensity suggesting relatively low level of product sophistication. Using a recent Eurostat high-tech industry classification table which suggests 9 high-tech industries, the paper identifies Ulsan's chemical industry as the only RCA industry. Focusing on chemical industry products at HS 6-digit level, specific products are identified at the efficiency frontier for future policy considerations.

• Journal of the Korean Physical Society
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• v.80
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• pp.117-122
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• 2022

The Belle II detector at the SuperKEKB e⁺e^- collider in Japan is designed for precise measurements of weak interaction parameters and new physics beyond the Standard Model; therefore, it requires very high instantaneous luminosity. To handle such high luminosity, the level-1 trigger system in the Belle II experiment is designed to efficiently trigger events of interest with the highest efficiency. Among many sub-detectors, track reconstruction of charged particles is performed using information collected from the central drift chamber. Therefore, the central drift chamber-based trigger plays a central role in distinguishing specific types of physics based on fast track reconstruction. To improve the longitudinal position resolution of a track vertex and for the fine-tuning of trigger signal timing, the time of the collision, which we call event time, is necessary. We developed an event time finding algorithm using the wire hit time information obtained from the central drift chamber and validated our algorithm through Monte Carlo simulation.

• Asian-Australasian Journal of Animal Sciences
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• v.5 no.4
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• pp.605-610
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• 1992

Two experiments were conducted to investigate into the effects of replacing maize with a mixture of cassava root and leaf meal (CRLM) on the performance of broiler chickens. In experiment 1, CRLM replaced 50 or 100 percent of maize in the control diet. In experiment 2, the 100 percent CRLM based-diet was fortified at a further 3 percent level with coconut oil. A total of 180, one-day old Shaver Starbro chicks, raised up to 49 days of age, were used. There were no significant (p<0.05) differences in final body weights, feed intake and feed efficiency between the control group and the group fed the diet in which 50 percent of the maize was replaced with CRLM. At the 100 percent level of replacement of maize with CRLM, however, final body weights, feed efficiency and carcass yields, were significantly (p<0.05) reduced. Dressing percentage and feed intake were not affected (p>0.05) by level of substitution of maize with CRLM. In experiment 2, when the diet in which all of the maize was replaced with CRLM was fortified with coconut oil at an additional 3 percent level, broiler performance improved and equaled (p=0.05) that obtained on the control maize diet. It was concluded the CRLM can replace 50 percent of maize in broiler diet without adversely affecting performance. However, for the complete replacement of maize with CRLM, it is necessary to further supplement such a diet with a high energy density ingredient if broiler performance is to be maintained.

• Fisheries and Aquatic Sciences
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• v.18 no.3
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• pp.265-271
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• 2015

A feeding trial of four dietary protein levels (20, 30, 40, and 50%) and two lipid levels (7 and 14%) with a factorial design was conducted to determine the optimal dietary protein and lipid levels for juvenile Israeli carp Cyprinus carpio. Triplicate groups of fish (average body weight, $1.3{\pm}0.02g$) were fed the experimental diets for 9 weeks. Survival of fish was not affected by either dietary protein or dietary lipid level. Weight gain and feed efficiency increased as dietary protein levels increased up to 40 and 50%, respectively. Weight gain was higher in fish fed the high-lipid diets with 20 and 40% protein content. Feeding efficiency increased as the dietary lipid level increased for the 30, 40, and 50% protein diets. Daily feed intake decreased with increasing protein level and the minimum feed consumption was observed in fish fed the 50% protein diet with 14% lipid content. Moisture and lipid contents of the whole body were affected by both dietary protein and lipid levels. The crude lipid content of fish fed the 14% lipid diet was higher than that of fish fed the 7% lipid diet at each protein level. The results of this study indicate that a diet containing 40% protein with 14% lipid content is optimal for the growth and effective protein utilization of juvenile Israeli carp.

• Journal of Nutrition and Health
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• v.19 no.1
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• pp.16-22
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• 1986

This study was designed to investigate the nutritional effect of mugowrt powder supple mentation to rice diets with different protein levels. Thirty female albino rats weighing 39-43g were adopted for the feeding trial for 4 weeks. The different 5 kind of experimental diets were performed . Control diet was commercially available forage for rats, experimental diet (I-C) highly milled rice, (Ⅰ) highly milled rice 95% and mugwort powder 5%, (Ⅱ-C)highly milled rice 95% and milk casein 5%, and (Ⅱ) highly milled rice 90%, milk casein 5 % and mugwort powder 5%. Growth rate was remarkably high in the dietary group fed on highly milled rice supplemented with 5% mugwort powder (protein 8%) (P<0.05), but it showed the tendency to be rather low in the group fed on highly milled rice supplemented with 5% casein and 5% mugwort powder (protein 12%). Food efficiency as well as protein efficiency appeared similar to the growth rate. Hematodcrit level demonstrated the same tendency as growth rate, but hemoglobin content was observed to increase by diets supplemented with increasing amount of mugwort regardless of protein level. Each nutrient intake was increased by adding mugwort powder to diets after a week's feeding, but it was increased by 8% protein diet, and decreased by 12% protein diet in 3 weeks as well as 4 weeks after feeding . The absorption rate of carbohydrate and protein decreased by feeding mugwort supplemented diets regardless of protein level and feeding period, and that of lipid increased with 12% protein diet.

• Journal of Radiation Protection and Research
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• v.14 no.2
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• pp.51-62
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• 1989

The high efficiency moderated-type neutron spectrometer and doseequivalent counter were developed for the measurement of low level environmental neutrons. By using these detectors, the neutron energy spectra and dose equivalent rates due to skyshine effect were measured in the environment surrounding the accelerator facilities and also the altitude variation of cosmic ray neutrons in the aircraft flying over Japan.

• Journal of Food Hygiene and Safety
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• v.23 no.1
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• pp.80-84
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• 2008

Maximum level of hazardous chemicals in foods can be settled after overall investigation of toxicological database, the representative exposure assessment, risk level on the present exposure level, the need of maximum level establishment, making of maximum level scenario proposed under consumer protection and verification of contamination reduction method and review of application efficiency on maximum level for risk management. The maximum level should be needed when the risk value of specific chemical caused by food ingestion was high and chronic human exposure was predicted continuously unless the maximum level exists. The key role of the risk assessment is to improve the efficiency of the risk management to reduce the present risk level and make the risk management policy scientifically by setting the representative result of the risk assessment.