• The Transactions of the Korean Institute of Electrical Engineers B
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• v.51 no.3
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• pp.142-149
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• 2002

As is well-known, the maximum power point (MPP) of PV power generation system depends on array temperature and solar insolation, it is necessary to track MPP of solar array all the time. Among various MPP control algorithms, the constant voltage control method, the perturbation and observation (P&O) method and the incremental conductance method (IncCond) have drawn many attractions due to the usefulness of each system. In this parer, the effectiveness of above mentioned three different control algorithms are thoroughly investigated via simulations and preposed efficiency evaluation method on experiment. Both the steady-state and transient characteristics of each control algorithms along with measured efficiency are analyzed, respectively. Finally, a novel MPPT control algorithm combining the constant voltage control and IncCond method for low insolation condition is proposed to improve efficiency of the 3KW PV power generation system.

• Proceedings of the KIEE Conference
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• 2002.04a
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• pp.207-212
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• 2002

As is well-known, the maximum power point(MPP) of PV power generation system depends on array temperature and solar insolation, it is necessary to track MPP of solar array all the time. Among various MPP control algorithms, the constant voltage control method, the perturbation and observation(P&O) method and the incremental conductance method(IncCond) have drawn many attractions due to the usefulness of each system. In this paper, the effectiveness of above mentioned three different control algorithms are thoroughly investigated via simulations and proposed efficiency evaluation method on experiment. Both the steady-state and transient characteristics of each control algorithms along with measured efficiency are analyzed, respectively. Finally, a novel MPPT control algorithm combining the constant voltage control and IncCond method for low insolation condition is proposed to improve efficiency of the 3KW PV power generation system.

• Proceedings of the KIPE Conference
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• 2012.07a
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• pp.248-249
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• 2012

PV 어레이에 부분적으로 음영이 발생하면 그 P-V 특성은 여러 개의 MPP를 보인다. 이런 상황에서는 global MPP를 찾아내기 위한 특수한 기법이 요구된다. 본 논문에서는 기존에 제안된, 부분 음영 조건 발생 시 global MPP를 찾아내는 MPPT 기법을 개선하고 실험을 통하여 유효성을 검증한다.

• Proceedings of the KIPE Conference
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• 2015.07a
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• pp.375-376
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• 2015

태양광 시스템은 낮 시간 동안에만 사용할 수 있기 때문에 사용시간이 제한적이다. 이 제한적인 시간 내에 최대의 효율을 발휘하기 위해서 태양광 시스템은 주로 최대전력지점 추종(MPPT) 방법을 사용한다. 결국 MPPT 방법에 따라서 전체 시스템의 효율이 영향을 받을 수 있다. 본 논문은 황금분할법으로 최대전력지점(MPP)을 추종하는 새로운 MPPT 알고리즘을 제안한다. 제안방법의 성능은 결정형 PV 패널 MSX120을 이용하여 기존의 MPPT방법인 P&O 방법을 제안방법과 비교하며, 제안방법의 성능의 검증은 기존방법과 시스템의 효율 및 MPP를 추종하는 속도를 비교하여 평가하였다. 그 결과 제안방법의 효율 및 MPP추종속도가 개선됨을 확인할 수 있었다.

• Journal of Bio-Environment Control
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• v.12 no.2
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• pp.77-82
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• 2003

The effect of the particle size of perlite and irrigation amount on the growth, root activity and mineral competition of tomato was investigated in a recycling system. The particle sizes used were small (SPP, øl∼2 mm), medium (MPP, ø2∼3 mm), (LPP. ø4∼5 mm). Plant height, fresh weight and dry weight of tomato at the earlier growth stage were good at 3.0 L/day in MPP and LPP, but these were not significantly affected by irrigation amount in MPP, Fruit number, weight and yield increased at 1.5 L/day in SPP and 3.0 L/day at MPP or LPP, Deformed fruits tended to increase at higher irrigation amounts regardless of particle size. Root activity increased with increasing particle size with higher irrigation amount during early stage after transplanting, but remarkably decreased at 3.0 L/day in SPP as compared with the others at 100 days. Mineral contents of plants after harvest were higher at MPP and LPP than SPP, but were highest at 3.0 L/day in LPP. In conclusion, it was regarded that tomato growth in a recycling system was optimal at MPP or LPP with irrigation amount of B.0 L/day.

• Journal of Aquaculture
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• v.10 no.3
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• pp.255-260
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• 1997

In order to investigate the effects of phosphorus and iron levels in the diets containing fish meal as only protein source on the growth, feed conversion, body composition and blood characteristics of juvenile Korean rockfish, either graded monobasic potassium phosphate (MPP) of 1% (MPP-1), 2% (MPP-2), 3% (MPP-3) and 4% (MPP-4), or Fe-citrate (FC) of 0.022% (FC-1), 0.044% (FC-2), 0.066% (FC-3) and 0.088% (FC-4) was added to fish meal-based diet (MMP-0 or FC-0), respectively. Duplicate groups of 40 fish weighing 7g were fed the diets for 21 weeks. Weight gain, feed efficiency and nutrient retention of fish fed diets with different MPP levels were not significantly different (P>0.05). Lipid content of whole body decreased with an increase in dietary MMP (P<0.05). No significant differences were found in the Ht, Hb, total protein, or total glucose in serum among diets containing different MMP levels (P>0.05). Weight gain of fish fed the FC-0, FC-1 adn FC-3 diets was significantly higher than that of FC-4 diet (P>0.05), whereas feed efficiency, nutrient retention, hematological values (Ht, Hb, total protein, and total glucose), and whole body composition were not affected by dietary FC levels (P>0.05). The present results revealed that phosphate or iron supplementation to the diet containing 65% fish meal for juvenile Koran rockfish was not necessary.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.3
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• pp.569-575
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• 2020

Recently, research on renewable energy technologies has come into the spotlight due to rising concerns over the depletion of fossil fuels and greenhouse gas emissions. Demand for portable electronic and wearable devices is increasing, and electronic devices are becoming smaller. Energy harvesting is a technology for overcoming limitations such as battery size and usage time. In this paper, the V-I characteristic curve and internal resistance of thermal electric devices were analyzed, and MPPT control methods were compared. The Perturbation and Observation (P&O) control method is economically inefficient because two sensors are required to measure the voltage and current of a Thermoelectric Generator(TEG). Therefore, this paper proposes a new MPPT control method that tracks MPP using only one sensor for the regulation of the output voltage. The proposed MPPT control method uses the relationship between the output voltage of the load and the duty ratio. Control is done by periodically sampling the output voltage of the DC-DC converter to increase or decrease the duty ratio to find the optimal duty ratio and maintain the MPP. A DC-DC converter was designed using a cascaded boost-buck converter, which has a two-switch topology. The proposed MPPT control method was verified by simulations using PSIM, and the results show that a voltage, current, and power of V=4.2 V, I=2.5 A, and P=10.5 W were obtained at the MPP from the V-I characteristic curve of the TEG.

• The Journal of the Acoustical Society of Korea
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• v.39 no.4
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• pp.270-278
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• 2020

In this paper, sound transmission of Micro-Perforated Plates (MPPs) installed in an impedance tube with a circular cross-section is described using an analytic method. Vibration of the plates is expressed in terms of an infinite series of modal functions, where modal function in the radial direction is given by the Bessel function. Under the plane wave assumption, a low frequency approximation is derived, and a formula for the sound transmission coefficient of multi-layered MPPs is presented using the transfer matrix method. The Sound Transmission Losses (STLs) of single and double MPPs are computed using the proposed method and compared with those done by the Finite Element Method (FEM), which shows an excellent agreement. As the perforation increases, the STL is degraded, since the STL becomes dominated by the perforation ratio rather than by vibration of the plate. The STL shows dips at natural frequencies as well as at the mass-spring-mass resonance frequency. The proposed model for the STL prediction in this study can be applied to an arbitrary number of MPPs, where each MPP may or may not have a perforation.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.05a
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• pp.111-112
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• 2006

This paper a new method which applies a genetic algorithm for determining which sectionalizing switch to operate in order to solve the distribution system loss minimization re-configuration problem. In addition, the proposed method introduces a ultra efficient MPP tracking in a solar power generation system.

• Bulletin of the Korean Chemical Society
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• v.24 no.10
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• pp.1521-1524
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• 2003