• Proceedings of the KIEE Conference
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• 2009.04a
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• pp.183-185
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• 2009

In this thesis, output voltage, current and power of solar module were classified by irradiation and module temperature from data of overall operating characteristics collected for one year in order to manage efficient photovoltaic generation system and deliver maximum power. In addition, from these data, correlations between irradiation, module temperature of photovoltaic cell and amount of power given by photovoltaic cell was quantitatively examined to deduce optimization of the design and construction of photovoltaic generation system. The results of this thesis can be summarized as follows. As I-Y characteristics according to a temperature range of 10$\sim$50[], the area of I-V characteristics were increased with an increase in temperature. Since this area corresponds to the power, output power is thought to have increased with temperature.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.349-350
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• 2008

Average throughput estimation of EV-DO forward link is implemented on the basis of the serving coverage area per sector instead of time consuming and complicated Monte Carlo simulation. For the implementation of this analysis function in cell planning tool, $CellTREK^{(R)}$, developed by KT, both SNR vs. DRC mapping table and receiver sensitivity are suggested as the satisfying criteria to be satisfied above each threshold level simultaneously.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.445-446
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• 2008

With the semiconductor industry evolving into the deep sub-micron (DSM) era, the crosstalk effects on interconnect lines of a chip have increasingly caused a major bottleneck for design closure. In this paper, we propose an effective design guide line to reduce cell area overhead without crosstalk noise violations by using crosstalk prevention flow with clock shielding.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.31 no.2
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• pp.70-76
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• 1999

This study was to measure the potential of nonwoody fibrous material, kenaf. Whole stalk of kenaf, Hibiscus cannabinus was separated by two parts of bast and core portion, and cooked separately by alkaline method. Morphological characteristic was evaluated using confocal laser scanning microscope (CLSM) and fiber quality analyzer(FQA). The strength properties of handsheets, made by different mixing ration between kenaf base and core fibers, were measured. Cross-sectional area of bast fibers was smaller than that of core fibers, but the bast fibers had a thick cell wall and narrow lumen area. Bast fibers were longer in length than core fibers. Core fibers had thin cell walls, broad lumen areas, and short lengths, and they had collapsed shape even in water. These characteristics of core fibers affected strength properties of handsheet positively. When the amount of core fibers increased, the strength properties of handsheet were increased. When the amount of bast fibers increased, the handsheet had rougher surface and higher air permeability.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.460-460
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• 2014

Organic photovoltaic cells (OPV) have been extensively studied due to their unique properties such as flexibility, light-weight, easy processability, cost-effectiveness, and being environmental friendly. These advantages make them an attractive candidate for application in various novel fields and promising development with new features. Photovoltaic cell-integrated textiles have greatly attractive features as a power source for the smart textile solutions, and OPV is most ideal form factor due to advantage of flexibility. In this study, we develop a textile-based OPV through various experimental methods and we suggest the direction for the design of the photovoltaic textile. We used a textile electrode and tried to various layouts for textile-based OPV. Finally, we determined the contact area by using Hertzian theory for the calculation of power conversion efficiency (PCE). Based on the results of calculation, the short circuit current density, Isc, was $13.11mA/cm^2$ under AM 1.5condition and the PCE was around 2.5%.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.53 no.9
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• pp.657-662
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• 2004

The low-power design of the digital hearing aid is indispensable to achieve the compact portable device with long battery duration. In this paper, new low-power adaptive filter structure is proposed based on distributed arithmetic(DA). By modifying the DA technique, the proposed decimation filter structure can significantly reduce the power consumption and implementation area. Through Verilog-HDL coding, cell occupation of the proposed structure is reduced to 33.49% in comparison with that of the conventional multiplier structure. Since Verilog-HDL simulation processing time of the two structures are same, it is assumed that the power consumption or implementation area is proportional to the cell occupation in the simulation.

• Journal of Hydrogen and New Energy
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• v.15 no.4
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• pp.291-300
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• 2004

Performance of PEMFC is affected by many factors such as that of MEA, configuration of flow field, operating conditions, humidification, cooling and so on. In this study, in order to improve the performance of fuel cell, a small area fuel cell stack was made and its performance was tested under various operating conditions. Stack consists of 3 single PEM fuel cells. Channel is serpentine type and the active area of the electrode is $50cm^2$. The test results show that the peak power is 60W at $70^\circ{C}$ of stack temperature with humidification condition.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.13-14
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• 2006

In this paper, an efficient butterfly structure for Radix-4 FFT algorithm using DA(Distributed Arithmetic) is proposed. It is shown that DA can be efficiently used in twiddle factor calculation of the Radix-4 FFT algorithm. The Verilog-HDL coding results for the proposed DA butterfly structure show 61.02% cell area reduction comparison with those of the conventional multiplier butterfly structure. Furthermore, the 64-point Radix-4 pipeline structure using the proposed butterfly and delay commutators is compared with other conventional structures. Implementation coding results show 46.1% cell area reduction.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.30A no.11
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• pp.132-139
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• 1993

This paper presents a new performance-driven multi-levelizer which transforms a two-level description into a boolean network of the multilevel structure satisfied with user's costraints, such as chip area, the number of wires and literals, maximum delay, function level, fanin, fanout, etc.. The performance of circuits is estimated by reference to the informations in cell library through the cell mapping phase, and multi-levelization of circuits is constructed by the decomposition using the kernel and factoring concepts. Here, the saving cost of a common subexpression is defined to the sum of area and delay saved, when it is substituted. The experiments with MCNC benchmarks show the efficiency of the proposed method.

• Animal cells and systems
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• v.4 no.4
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• pp.315-318
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• 2000

Structure of the skin in amphibious fish, Periophthalmus modestus, was described in relation to cutaneous respiration. The epidermis has no gland cell. The epidermis consists of three regions: outermost layer of one to five layers of flattened epithelial cells, middle layer of swollen epithelial cells instead of glandular cells and stratum germinativum of cuboidal cells. There are numerous blood capillaries in the outermost layer of the epidermis and diffusion distance between the blood of capillaries and the epidermis is about 1.4 Um. The middle layer of the epidermis appears to be a web-like structure due to the swollen epithelial cells. The stratum germinativum has a well-developed lymphatic space containing lymphocytes. There are numerous blood capillaries and elliptical area with acid mucopolysaccharides in stratum laxum of the dermis. The skin of Periophthalmus modestus may be an accessory respiratory organ for oxygen uptake during terrestrial or aquatic life.