• Proceedings of the KIPE Conference
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• 2019.07a
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• pp.142-144
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• 2019

Nowadays, multi-MHz wireless power transfer (WPT) system has received a great concern of study due to its desirable characteristics such as user convenience, system compact and better safety as compared to the conventional DC-DC with cord. This paper presents a solution for WPT Lithium Batteries charger with Constant Current (CC) and Constant Voltage (CV) charging process. The proposed system consists of a high frequency class D power amplifier, a pair of PCB coil, transformable high-order resonant network and a full-bridge rectifier. The charger can be implemented CC /CV charging profile thanks to automatic reconfigurable resonant compensator. Therefore, the battery can be fully charged without the help of an additional DC/DC converter. The simulation and 50W-6.78-MHz hardware experimental results are presented to verify the feasibility of the proposed method and to evaluate the performance of the proposed wireless battery charger.

• Proceedings of the KIPE Conference
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• 2013.07a
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• pp.206-207
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• 2013

본 논문에서는 태양광 배터리 충전 시스템에서 충전 모드가 변환될 때 과도상태를 보상하기 위한 알고리즘을 제안한다. 제안하는 알고리즘은 기존의 정전류-정전압 충전 알고리즘을 기반으로 정전류 모드에서 정전압 모드로 변경될 때 과도상태를 보상하기 위한 최적의 제어기법을 추가함으로 기존 알고리즘보다 우수한 과도 특성을 갖는다. 본 논문은 3kW급 PSIM 시뮬레이션을 통해서 제안하는 충전제어 알고리즘의 우수한 제어특성을 검증하였다.

• Journal of Digital Contents Society
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• v.14 no.4
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• pp.529-536
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• 2013

Lack of proper amount of sun lights and wind strength which are major factors of solar power and wind power system may cause poor electric power generation and decrease the lifetime of batteries that are major energy saving units. Because the PCS, which is essential in solar and wind power system, for small power generation system has been rarely developed an efficient and stable PCS for small power generation system is highly required. In this paper, we design a new constant current/constant voltage type hybrid PCS by which stand alone/grid connected operation with commercial power system is available and implement the designed PCS as a protype for performance verification.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.10
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• pp.93-100
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• 2013

Generally, the conventional battery charging system using an analog method has the large, heavy hardware and low efficiency. Also, it has the disadvantage that it is necessary to replace the control circuit on the basis of the characteristic curve of the specific battery cell. The proposed programmable digital LLC resonant charging system use high efficiency control system(CC-CV), and has characteristic a small hardware and advantage that a digital programming of the voltage, current, and battery capacity characteristics can be flexible. The system proposed the use of Half-bridge LLC resonant converter is possible to improve efficiency and reduce switching losses by using ZVS topology. Further, a constant voltage - constant current(CC-CV) control algorithm apply to the charger which using a buck converter. The performance of the proposed system is demonstrated through experiments.

• IEMEK Journal of Embedded Systems and Applications
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• v.11 no.5
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• pp.305-312
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• 2016

Modern embedded systems are typically operated by the rechargeable batteries in our daily life. Since charge of batteries is considered as an time consuming task, there have been extensive efforts to manage the charge time from the perspective of materials, circuits, and systems. Estimation of battery charge time is one of the essential information to design the charge circuitry. A compact macro model for the constant-current and constant-voltage charge protocol was recently introduced, which gives us a quick estimation of charge time with similar shape to the famous Peukert's law for discharge time estimation. The CC-CV charging protocol is widely used for Lithium-based batteries and Lead-acid batteries. In this paper, we characterize the lead-acid battery by measurement to extract the model coefficients, which was not covered by the previous studies. By our proposed model, the key coefficient Kcc results in 1.18-1.31, which is little bit higher than that of Lithium batteries. The accuracy of our model is within the range of ${\pm}10%$ error, which is compatible with the other studies such as Peukert's law.

• Journal of Power Electronics
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• v.17 no.4
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• pp.1109-1116
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• 2017

Wireless power transfer (WPT) technology has the advantages of intelligence and facilitation. This paper designs a WPT system applied to battery charging and provides a strategy which switches from the constant current (CC) charging mode to constant voltage (CV) charging mode. The LCL-LCL topology is used to realize the CC output, while the LCL-S (series compensation) topology is used to realize the CV output. The main factor affecting the output characteristics is extracted by analyzing the two topologies above. Based on the main factor, this paper puts forward a modified way to design the system. In addition, on-line monitors for the battery and switches are placed at receiving side, which avoids the need for introducing an information interaction module into the system. Therefore, the complexity of the controlling system is reduced. Finally, simulation and experimental analyses are carried out to verify the correctness of the compound topologies.

• Food Science and Preservation
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• v.6 no.2
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• pp.200-205
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• 1999

This experiment was carried out to search mm reasonable and scientific method to distinguish Korean sesame with Chinese sesame. Sesame samples used in this study were Korean variety cultivated in Chochiwon City of Korea (KvKc), Chinese variety cultivated in Jilin Province of China (CvCc), Chinese variety cultivated in Chochiwon city of Korea (CvKc) and Korean variety cultivated in Jilin Province of China (KvCc). In volatile flavor components analysis, 41 component were identified from KvKc and 39 components from CvCc. Major flavor components were pyrazines and furans. Pyrazines compositions of KvKc and CvCc were 55.4% and 56.8%, respectively while furans compositions of KvKc and CvCc were 27.0% and 20.4%, respectively. Other flavor components pattern showed no difference. When the headspace volatiles of sesame oils were analyzed using Electronic Nose System and the obtained data were interpreted using statistical method of MANOVA and Discriminant analysis, characteristic patterns of sesame oil odors were different from each other according to variety as well as cultivated area. These results suggest that Korean sesame oils may be distinguished from Chinese sesame oils by using Electronic Nose System.

• Journal of Pharmacopuncture
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• v.20 no.2
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• pp.132-138
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• 2017

Objectives: We report the results of three case studies on the clinical efect of ascending kidney water and descending heart fre (AKDH) pharmacopuncture on patients with Hwa-Byung. Methods: Tis study involved three patients, all female, who had been admitted to a hospital of traditional Korean medicine and had been diagnosed as having Hwa-Byung by using the Hwa-Byung Structure Clinical Interview for DSM-IV. AKDH pharmacopuncture is administered by injecting pharmacopuncture at a specifc acupoint to change from a state of water-fre disharmony to one of water-fre harmony. For our three patients, Hwangyeonhaedoktang (黃連解毒湯) pharmacopuncture was injected at GB21 and GB20 on both sides; a total of 0.4 cc was injected, with 0.1 cc being injected at each point. Fel ursi, Bezora bovis and moschus (BUM) pharmacopuncture was injected at CV17, CV12, and CV6; a total of 0.15 cc was injected, with 0.05 cc being injected at each point. Treatment was done daily. Progress was evaluated using the Hwa-Byung diagnostic interview (HBDIS), beck depression inventory (BDI), and numeric rating scale (NRS) scores. Results: For the frst patient (case 1), after treatment, the HBDIS score was reduced from 44 to 30 points, the BDI score from 37 to 14, and the NRS score from 10 to 7. For the second patient (case 2), after treatment, the HBDIS score was reduced from 41 to 27 points, the BDI score from 13 to 7, and the NRS score from 10 to 5. For the third patient (case 3), after treatment, the HBDIS score was reduced from 42 to 28 points, the BDI score from 12 to 9, and the NRS score from 10 to 4. Conclusion: Ascending kidney water and descending heart fre pharmacopuncture treatment can be efective for improving ascending kidney water and descending heart fre energy and can be used to alleviate Hwa-Byung.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.23 no.2
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• pp.83-87
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• 2017

This study was conducted to determine types of oxygen transmission rate (OTR) films suitable for modified atmosphere (MA) storage treatment of strawberries (cv. 'Maehyang') for export and examination related changes in quality of strawberries during simulated shipping distribution conditions ($2^{\circ}C$ for $10days{\sim}8^{\circ}C$ for 11 days). Strawberries were packed by 1,300, 10,000, 20,000, and $30,000cc/m^2{\cdot}day{\cdot}atm$ OTR films for MA storage treatment and perforated film as the control for MAP. Fresh weight loss rate was less than 0.5% in OTR films except for the perforated film. Carbon dioxide and oxygen content in packages prevailed in permissible range for strawberries under recommended CA/MA conditions (i.e., $CO_2$: 15~20%, $O_2$: 5~10%) at 10,000 cc, 20,000 cc, and 30,000 cc OTR films. Ethylene content in OTR films did not reveal significant differences during storage. The 1,300 cc OTR film revealed highest off-flavor and lowest fungal incidence rate by sensory evaluation. The firmness, soluble solids, and visual quality were preserved the highest at 10,000 cc OTR film. In conclusion, 10,000 cc OTR film preserved the highest quality and extended shelf-life by 13 days if compared with conventional distribution conditions.

• Proceedings of the KIPE Conference
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• 2011.07a
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• pp.327-329
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• 2011

본 논문에서는 3.3kW급 차량탑재형 충전기에 적합한 공진형 컨버터의 최적설계기법을 제안한다. 주어진 배터리 충전 프로파일에 대하여 대표적인 4가지 공진형 컨버터를 각각 최적의 궤적에 따라 동작하도록 하는 설계기법을 제안한다. 또한 이 충전 궤적에 따른 각 컨버터의 도통전류, 턴오프전류 등의 비교를 통하여 최적의 컨버터를 제안하고 시작품으로 타당성을 검증한다.