• YAKHAK HOEJI
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• v.34 no.3
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• pp.161-165
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• 1990

An automated, simple, and reliable method was developed for determining in vitro drug release rate from transdermal delivery dosage forms. The patch is held in position in the heating block by sandwiching it between the middle plate and the bottom plate of diffusion cell. The dissolution profile of the commercially available transdermal scopolamine patch was determined over a 72-h period, and the results were compared with those obtained with other methods; paddle-over-disk method, reciprocating method, and diffusion cell method. It was demonstrated that the flow-through method is equivalent in terms of release rate profile and accumulated released drug amount over the lifetime of the dosage form tested. Also this method is simple, reliable and reproducible. Therefore, this technique can be used in a quality control for assuring product uniformity.

• Bulletin of the Korean Chemical Society
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• v.27 no.4
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• pp.519-523
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• 2006

Poly(dimethyl siloxane) (PDMS) has been employed as a microchip material for DNA separation in microfluidic condition. Different sieving molecules such as cellulose derivatives having glucose building block (methyl cellulose (MC), hydroxyethyl cellulose (HEC), and hydroxypropyl methyl cellulose (HPMC)) and polyethylene oxide (PEO) having linear (ring-opened ethylene oxide) unit were used and their performance was compared in terms of separation efficiency and resolution. In general, PEO showed better separation performance than cellulose derivatives probably due to the nature of linear shape polymer conformation. It was possible to perform at least 15 consecutive running with 1.2% PEO at the electric field strength around 200 V/cm. Fast analysis of the standard $\Phi$X 174 RF DNA/Hae III (less than 130s) was obtained with the number of the theoretical plate around 250,000/m. Our PMDS microchip was applied to the measurement of CAG repeat number, which is related to male infertile disease.

• Journal of Electrical Engineering and information Science
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• v.2 no.6
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• pp.48-55
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• 1997

Advances in VLSI technology have brought us completely new design principles for the high-performance switching fabrics including ATM switches. From a practical point of view, port scalability of ATM switches emerges as an important issue while complexity and performance of the switches have been major issues in the switch design. In this paper, we propose a cost-effective approach to modular ATM switch design which provides the good scalability. Taking advantages of both time-division and space-division switch architectures, we propose a practically implementable large scale ATM switch architecture. We present a scalable shared buffer type switch for a building block and its expansion method. In our design, a large scale ATM switch is realized by interconnecting the proposed shared buffer switches in three stages. We also present an efficient control mechanism of the shared buffers, synchronization method for the switches in each stage, and a flow control between stages. It is believed that the proposed approach will have a significant impact on both improving the ATM switch performance and enhancing the scalability of the switch with a new cost-effective scheme for handling the traffic congestion. We show that the proposed ATM switch provides an excellent performance and that its cell delay characteristic is comparable to output queueing which provides the best performance in cell delay among known approaches.

• Bulletin of the Korean Chemical Society
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• v.26 no.10
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• pp.1539-1542
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• 2005

We have introduced polyelectrolyte micro-patterning technique employing agarose plane stamp and a hard substrate having microscale features on its surface. With this method, chemically micropatterned surfaces with both positive and negative functionalities were successfully embedded in well-defined microstructures, and selective impartment of charge functionalities was confirmed by patterning bead bearing surface charge. Furthermore, this technique allows highly sensitive immobilization of protein onto targeted surface simply by endowing functionalities, which extends the potential of its use as a tool for high-throughput protein microarray and proteomics. Because plane agarose stamp is free of structures on its surface, there is no concern for pattern collapse, and the combination of agarose plane stamp with patterned substrate is more suited for selective protein patterning compared with adopting surface-patterned agarose stamp with flat substrate. Our technique using agarose plane stamp and a substrate having microscale features on its surface suggests a range of possible applications, including the micropatterning of biofunctionalized copolymer having polyelectrolyte block, immobilization of micro- and nanoparticle with biofunctionalities such as biotin and streptavidine, and establishing optoelectronic microstructures with micro-beads on various surfaces.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.366-370
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• 2003

This paper is on weighted model reduction using structurally balanced truncation. For a given weighted(single or double-sided) transfer function, a state space realization with the linear fractional transformation form is obtained. Then we prove that two block diagonal LMI(linear matrix inequality) solutions always exist, and it is possible to get a reduced order model with guaranteed stability and a priori error bound. Finally, two examples are used to show the validity of proposed weighted reduction method, and the method is compared with other existing methods.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.277-279
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• 2004

In this paper, we propose an channel estimation method for Multi-Input Multi-Output-Orthogonal frequency Division Multiplexing (MIMO-OFDM). The proposed method estimates uniquely all channel frequency responses needed in space-frequency block coded OFDM systems using "comb-type" pilot symbols. To reduce the computational complexity of the proposed method, least square(LS) and linear minimum mean square error(LMMSE) are used in the frequency-domain. The performance of the proposed approach is evaluated by computer simulation for rayleigh fading channel.

• Proceedings of the Optical Society of Korea Conference
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• 1990.02a
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• pp.227-231
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• 1990

A SiO2/Si concave diffraction grating(period: 1.3${\mu}{\textrm}{m}$) for the angular dispersive element of WDM was fabricated by sandwiching the SiO2/Si plane diffraction grating between a slab waveguide and a cylindrical concave block. Using this concave grating and input/output fiber, and wavelength division demultiplexer was composed. The demultiplexer has five channels, the insertion loss of 30dB, the wavelength spacing per channel of 7nm and crosstalk of-15dB.

• ETRI Journal
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• v.33 no.1
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• pp.140-143
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• 2011

Recent test data compression techniques raise concerns regarding power dissipation and compression efficiency. This letter proposes a new test data compression scheme, twin symbol encoding, that supports block division skills that can reduce hardware overhead. Our experimental results show that the proposed technique achieves both a high compression ratio and low-power dissipation. Therefore, the proposed scheme is an attractive solution for efficient test data compression.

• Proceedings of the Korean Statistical Society Conference
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• 2004.11a
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• pp.313-317
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• 2004

Confounded row-column designs for factorial experiments are studied in this paper. The Designs, thus, have factorial balance with respect to estimable main effects and interactions. John and Lewis (1983) considered generalized cycle row=column designs for factorial experiments. A simple method of constructing confounded designs using the classical method of confounding for block designs is described in this paper

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.201-202
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• 2008

In this paper, an efficient frequency offset compensation design for OFDM(Orthogonal Frequency Division Multiplexing) is proposed. The conventional CORDIC(COordinate Rotation Digital Computer) algorithm for frequency offset compensation utilizes CORDIC hardware and complex multiplier. But, proposed structure utilizes only one CORDIC hardware.