• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 2000년도 THE THIRD INTERNATIONAL CONFERENCE ON AGRICULTURAL MACHINERY ENGINEERING. V.II
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• pp.378-387
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• 2000

A rice mill plant with a capacity of 2.5 ton/hr was constructed with automated facilities at Chonnam National University. A simulation model was developed with SLAM SYSTEM for evaluating and improving the rice mill plant. The developed model was validated in the views of hulling efficiency, milling efficiency, milled rice recovery, other materials produced, and bottlenecks in the processes. The results of hulling efficiency, milling efficiency, milled rice recovery in the simulation were, respectively, 81.1%, 89.5%, and 73.1%, while those of the actual mill plant were 81.5%, 90.2%, and 73.5%. The simulation results including the productivity of other materials(chaff, bran, broken rice, stone, etc) produced in the processes were almost similar with those of the actual process. In the simulation the bottlenecks were found out in the processes of separating brown rice and of sorting colored rice. These phenomenon also appeared in the actual process. It needed to increase the hourly capacity of the brown rice separator and the rice color sorter. As the developed model could well express the automated rice mill plant, it could be used for designing and improving rice mill plants. In addition, an alternative model needed to be developed for the system control more accurately and for increasing the rice quality.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2005년도 전력전자학술대회 논문집
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• pp.380-384
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• 2005

Plasma display panel (PDP) has a serious thermal problem, because the luminance efficiency of the conventional PDP is about 1.5 lm/W and it is less than $3{\sim}5$ lm/W of cathode ray tube (CRT). Thus there is a need for improving the luminance efficiency of the PDP There are several approaches to improve the luminance efficiency of the PDP and we adopt the driving PDP at high frequency range from 400 kHz up to over 700 kHz. Since a PDP is regarded as an equivalent inherent capacitance, many types of sustaining drivers have been proposed and widely used to recover the energy stored in the PDP. However, these circuits have some drawbacks for driving PDP at high frequency range. In this paper, we investigate the effect of the parasitic components of PDP itself and driver when the reactive energy of panel is recovered. Various drivers are classified and evaluated whether it is suitable for high frequency driver, and finally current-fed type with do input voltage biased is proposed. This driver overcomes the effect of parasitic component in panel and driver and fully achieves ZVS of all full-bridge switches and reduces the transition time of the panel polarity.

• 드라이브 ㆍ 컨트롤
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• 제11권2호
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• pp.16-21
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• 2014

The purpose of this paper is to construct a control algorithm for improving the driving efficiency of 4-wheel-drive in-wheel electric vehicles. The main parts of the vehicle were modeled and the input-output relations of signals were summarized using MATLAB/Simulink. A performance simulator for 4-wheel-drive in-wheel electric vehicles was developed based on the co-simulation environment with a commercial dynamic behavior analysis program called Carsim. Moreover, for improving the driving efficiency of vehicles, a torque distribution algorithm, which distributes the torque to the front and rear wheels, was included in the performance simulator. The effectiveness of the torque distribution algorithm was validated by the SOC simulation using the FTP-75 driving cycle.

• 한국초지조사료학회지
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• 제42권3호
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• pp.208-214
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• 2022

Drought stress is a condition that occurs frequently in the field, it reduces of the agricultural yield of field crops. The aim of the study was to screen drought-adapted genotype of Italian rye grass. The experiments were conducted between the two Italian ryegrass (Lolium multiflorum L.) cultivars viz. Hwasan (H) and Kowinearly (KE). The plants were exposed to drought for 14 days. The results suggest that the morphological traits and biomass yield of KE significantly affected by drought stress-induced oxidative stress as the hydrogen peroxide (H₂O₂) level was induced, while these parameters were unchanged or less affected in H. Furthermore, the cultivar H showed better adaptation by maintaining several physiological parameter including photosystem-II (Fv/Fm), water use efficiency (WUE) and relative water content (RWC%) level in response to drought stress. These results indicate that the cultivar H shows improved drought tolerance by generic variation, improving photosynthetic efficiency and reducing oxidative stress damages under drought stress. These findings can be useful to the breeder and farmer for improving drought tolerance in Italian rye grass through breeding programs.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.484.2-484.2
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• 2014

There are many efforts to improving the power conversion efficiencies (PCEs) of dye-sensitized solar cells (DSCs). Although DSCs have a low production cost, their low PCE and low thermal stability have limited commercial applications. This study describes the preparation of a novel multifunctional polymer gel electrolyte in which a cross-linking polymerization reaction is used to encapsulate $TiO_2$ nanoparticles toward improving the power conversion efficiency and long-term stability of a quasi-solid state DSC. A series of liquid junction dye-sensitized solar cells (DSCs) was fabricated based on polymer membrane encapsulated dye-sensitized $TiO_2$ nanoparticles, prepared using a surface-induced cross-linking polymerization reaction, to investigate the dependence of the solar cell performance on the encapsulating membrane layer thickness. The ion conductivity decreased as the membrane thickness increased; however, the long term-stability of the devices improved with increasing membrane thickness. Nanoparticles encapsulated in a thick membrane (ca. 37 nm), obtained using a 90 min polymerization time, exhibited excellent pore filling among $TiO_2$ particles. This nanoparticle layer was used to fabricate a thin-layered, quasi-solid state DSC. The thick membrane prevented short-circuit paths from forming between the counter and the $TiO_2$ electrode, thereby reducing the minimum necessary electrode separation distance. The quasi-solid state DSC yielded a high power conversion efficiency (7.6/8.1%) and excellent stability during heating at $65^{\circ}C$ over 30 days. These performance characteristics were superior to those obtained from a conventional DSC (7.5/3.5%) prepared using a $TiO_2$ active layer with the same thickness. The reduced electrode separation distance shortened the charge transport pathways, which compensated for the reduced ion conductivity in the polymer gel electrolyte. Excellent pore filling on the $TiO_2$ particles minimized the exposure of the dye to the liquid and reduced dye detachment.

• 신재생에너지
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• 제4권2호
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• pp.31-38
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• 2008

Using a surplus head in presented water supply pipes, we have studied to improve the operating efficiency of small hydro generator, which was chosen for a test model with 00 hydro power plant. With regard to power control and countermeasure of water hammer impact, Finally we have represented the optimal control method through the synthetical analysis of existing system symptoms, operation efficiency, the effect of water hammer impact and system configuration.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.1222-1225
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• 2008

The power efficiency of a full-color OLED display decreases with long-term operation because of the material characteristics. The lifetime of the OLED display also decreases as the power efficiency declines. Therefore, this work provides a novel color difference algorithm to improve the power consumption and extend the OLED lifetime.

• 한국전기전자재료학회논문지
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• 제17권12호
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• pp.1341-1346
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• 2004

The OLED research is gone for two directions. One is material development research, and another one is structural improvement part. All two are thing to heighten luminescence efficiency of OLED. n other to improve luminescence efficiency of OLED Electron - hole pairs must consist much more in the device Their profiles are sensitive to mobility velocity of electrons and holes. In this paper, we demonstrate the difference of velocity between hole and electron by experiments, and compare with a data of simulation and experiment changing hole carrier transport layer thickness, so we get the optimal we improve luminescence efficiency. We suggest improving the efficiency of OLEDS would be to balance the injection of electrons and holes into light emission layer of the device. And, we improve understanding of the various luminescence efficiency through experiments and numerical analysis of luminescence efficiency in variable hole carrier transport layer's thickness.

• International journal of advanced smart convergence
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• 제9권4호
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• pp.52-61
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• 2020

The AHP method was used in 30 provinces of China to construct the index system of creative space efficiency evaluation and determine the weight of each index. The fuzzy comprehensive evaluation method was further used to score the indexes at all levels, and then the total efficiency score was sorted. The purpose of this study is to adjust the regional layout of creative space reasonably and implement financial policies accurately through the evaluation of the efficiency of creative space. The results is ranking top in weight of several indicators, which include the number of incubated Startups, the number of innovation and entrepreneurship mentors, the survival rate of incubator, the innovative training activities, etc. It was also found that Beijing, Shanghai, Jiangsu, Guangdong and Zhejiang ranked first in the score of creative space efficiency. This study is meaningful in that it was In order to effectively solve the problem of the imbalance of the creative space efficiency in China's province, by coordinating the regional pattern, establishing a sound service system and improving the efficiency evaluation system.

• 한국정보통신학회논문지
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• 제9권2호
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• pp.422-427
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• 2005

본 논문에서는 무선 네트워크 장비에도 적용 가능한 WCDMA 중계기용 전력증폭기의 선형성 및 효율을 향상시키기 위한 도허티증폭기를 구현하였다. 입력 전력의 변화에 따라 고효율 전력증폭기를 구현하고자 능동 로드풀을 이용한 도허티 기술을 이용하고 기존의 증폭기의 낮은 효율 구간에서도 우수한 선형성과 고효율을 유지하도록 설계하였다. WCDMA 주파수 대역인 2.11$\~$2.17 CHz에서 CW 1-tone 실험 결과 치대 출력 전력 52.3 dBm에서 6dBm 백 오프 지점부터 50$\%$의 전력 부가 효율을 갖게 하여 기존의 AB급에 비해 13.3$\%$ 이상의 높은 효율을 가졌다. 또한 게이트 바이어스 조절을 통하여 선형성 개선의 최적 바이어스 점을 찾은 후 도허티증폭기에서는 4dB 이상의 IMD3가 개선됨을 알 수 있었다.