• ETRI Journal
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• v.20 no.1
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• pp.16-27
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• 1998

In this paper, we consider the acquisition performance of an IS-95 reverse link access channel slot as a function of system design parameters such as postdetection integration length and the number of access channel message block repetitons. The uncertainty region of the reverse link spreading codes compared to that of forward link is very small, since the uncertainty region of the reverse link is determined by a cell radius. Thus, the parallel acquisiton technique in the reverse link is more efficient than a serial acquisition technique in terms of implementation and of acquisition time. The parallel acquisition is achieved by a bank of N parallel I/Q noncoherent correlator are analyzed for band-limited noise and the Rayleigh fast fading channel. The detection probability is derived for multiple correct code-phase offsets and multipath fading. The probability of no message error is derived when rake combining, access channel message block combining, and Viterbi decoding are applied. Numerical results provide the acquisition performance for system design parameters such as postdetection integration length and number of access channel message block repetitions in case of a random access on a mobile station.

• Transactions of the Korean hydrogen and new energy society
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• v.28 no.5
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• pp.465-470
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• 2017

Sulfonated fluorinated block copolymers having diphenyl units were mixed with the sulfonated cationic conductive polymers at an optimum mixing ratio to form hybrid membranes for fuel cells and their characteristics were studied. 2D and 3D AFM topology analysis confirmed that the number of hydrophilic units in the hybrid membrane was improved. Through the FE-SEM, the microstructure of the hybrid membrane implied hydrogen bonding and pi-pi interactions, and EDAX confirmed carbon, oxygen, sulfur, and fluorine. The thermogravimetric analysis showed that the hybrid membrane was thermally stable and the hydrophilicity of the hybrid membrane was increased by the contact angle of water droplets. As a result, it was confirmed that the cation conductivity increased by a factor of 1.8 times as the number of acidic domains in the hybrid film increased.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.5
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• pp.1107-1115
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• 1997

In this paper, we propose an error concealment method to recovre damaged block-based image coding schemes. Channel errors during transmission of image data such as bit errors or cell loss result in damaged image blocks in the reconstructed images. To recover damaged blocks is to estimate them using the correctly received or undamaged neighborhood information. In the proposed method, an overcomplete basis for a large block containing a damaged block at its center is introduced and damaged blocks are recovered by sequentially projecting the known neighborhood information onto the overcomplete basis function. Computer simulations show that the proposed algorithm outperforms the conventional method in subjectie recovery qualities as well as objective ones.

• The Korean Journal of Physiology and Pharmacology
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• v.9 no.6
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• pp.353-361
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• 2005

The interaction of cyclosporine A (CsA), an immunosuppressant, with rat brain Kv1.5 (Kv1.5) channels, which were stably expressed in Chinese hamster ovary cells, was investigated using the whole-cell patch-clamp technique. CsA reversibly blocked Kv1.5 currents at +50 mV in a reversible concentrationdependent manner with an apparent $IC_{50}$ of 1.0μM. Other calcineurin inhibitors (cypermethrin, autoinhibitory peptide) had no effect on Kv1.5 and did not prevent the inhibitory effect of CsA. Fast application of CsA led to a rapid and reversible block of Kv1.5, and the onset time constants of the CsA-induced block were decreased in a concentration-dependent manner. The CsA-induced block of Kv1.5 channels was voltage-dependent, with a steep increase over the voltage range of channel opening. However, the block exhibited voltage independence over the voltage range in which channels were fully activated. The rate constants for association and dissociation of CsA were $7.0{\mu}M{-1}s^{-1}$ and $8.1s^{-1}$, respectively. CsA slowed the deactivation time course, resulting in a tail crossover phenomenon. Block of Kv1.5 by CsA was use-dependent. CsA also blocked Kv1.3 currents at +50 mV in a reversible concentration-dependent manner with an apparent $IC_{50}$ of $1.1{\mu}M$. The same effects of CsA on Kv1.3 were also observed in excised inside-out patches when applied to the internal surface of the membrane. The present results suggest that CsA acts directly on Kv1.5 currents as an open-channel blocker, independently of the effects of CsA on calcineurin activity.

• Clinical and Experimental Reproductive Medicine
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• v.21 no.1
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• pp.77-81
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• 1994

To improve in vitro embryonic cell development, this study was desigend to culture in vitro fertilized early embryos of mouse in two different systems; conditioned medium alone and ampullary cells co-culture. Thirty two of 83 embryos(38.6%) were blocked in the 2 cell stage by co-culture, as compared to forty of 42 embryos(95.2%) in control group for 24hours culture. And all the embryonic cells cultured for conditioned medium alone were blocked for 48 hours culture. Twenty seven of 46 embryos (58.7 %) which overcome culture block in 2 cell stage by cocultured were developed morular and expanded blastocyst, and ninteen of 46 embryos(26.1 %) underwent hatching for 96 hours culture. The cellular fragmented rates for embryo were 26.2% in medium alone; 10 fragmented blastomere were graded mild status and 1 fragmented blastomere in severe status. On the other hand, the fragmented rate for 48 hours co-cultured were 15.7%03/83); 8 fragmented embryos were graded mild status, moderate status in 3 fragmented embryos and severe in 2 fragmented embryos respectively. In conclusion, the co-culture of embryos with ampullary cells is good to improve quality of embryos and overcome of culture block as well as development of cell cleavage.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.4
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• pp.1431-1437
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• 2012

The growth of many breast tumors is stimulated by IGF-1, which activates signal transduction pathways inducing cell proliferation. $ER{\alpha}$ is important in this process. The aim of the study was to investigate relationships in vitro among inhibitory effects of luteolin on the growth of MCF-7 cells, IGF-1 pathway and $ER{\alpha}$. Our results showed that luteolin could effectively block IGF-l-stimulated MCF-7 cell proliferation in a dose- and time-dependent manner and block cell cycle progression and induce apoptosis evidenced by the flow cytometric detection of sub-G1DNA content. Luteolin markedly decreased IGF-l-dependent IGF-IR and Akt phosphorylation without affecting Erk1/2 phosphorylation. Further experiments pointed out that $ER{\alpha}$ was directly involved in IGF-l induced cell growth inhibitory effects of luteolin, which significantly decreased $ER{\alpha}$ expression. Knockdown of $ER{\alpha}$ in MCF-7 cells by an $ER{\alpha}$-specific siRNA decreased the IGF-l induced cell growth inhibitory effects of luteolin. $ER{\alpha}$ is thus a possible target of luteolin. These findings indicate that the inhibitory effect of luteolin on the growth of MCF-7 cells is via inhibiting IGF-l mediated PI3K-Akt pathway dependent of $ER{\alpha}$ expression.

• Composites Research
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• v.37 no.1
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• pp.7-14
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• 2024

Due to the structural characteristic of a double roller, the double roller can have various deformation behaviors depending on a gap block design, even if dimensions and loading conditions for the double roller are the same. Based on this feature, we propose a strategy for designing the gap block of the carbon-fiber reinforced plastic (CFRP) double roller to minimize defects (e.g., sagging and wrinkling), which can be raised during the product conveying process, with the pursue of the lightweight design. In the suggested strategy, analysis cases are first selected by considering main design parameters and engineering tolerances of the gap block, and then deformation behaviors of these selected cases are extracted using the finite element method (FEM). Here, to obtain the optimal gap block parameters that satisfy the purpose of this study, deformation deviations in the contact area are calculated and compared using the extracted deformation behaviors. Note that the contact area in this work is located between the product and the roller. As a result, through the design method of the gap block proposed in this work, it is possible to construct the CFRP double roller that can significantly decrease the defects without changing the overall sizes of the roller. A detailed method is suggested herein, and the results are evaluated in a numerical way.

• KSBB Journal
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• v.22 no.5
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• pp.282-287
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• 2007

The antiviral mechanism of KT5720 is known to inhibit the cAMP-dependent protein kinase (PKA), on the VSV infection in BHK-21 cell cultures. The virus inducted CPE (cell rounding) was almost completely suppressed by KT5720 at 5 uM. The inhibitor, however, did not affect the replication of the virus and the synthesis of viral macromolecules. Immunological studies showed the viral matrix (M) protein displayed intimate association with the cytoskeletal components and probably the cell rounding. KT5720, did not block the cytoskeletal disruption, while the cell rounding was suppressed. These observations suggest that the interaction between the viral M protein and the cytoskeletal components may not be enough to cause the morphological change of the cell. And, the KT5720-sensitive function may be involved in developing the VSV-induced CPE, but not essential for the virus replications.

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.1199-1200
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• 2006

In this paper, I try to measure the electrical characteristics of PV cell for lanterns with solar simulator and simulated with PC1D software. I keep my eye on the characteristics variation of PV cell as a temperature change. Therefore, I try to increase a temperature of controlled block from $10^{\circ}C$ to $50^{\circ}C$ while measuring the PV cell. As a result, A variation caused by voltage have an effect on the efficacy of PV cell. Hence, it is an important variable when a designer plan to make a solar cell for lanterns.

• Journal of Power System Engineering
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• v.4 no.4
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• pp.92-98
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• 2000

Modern manufacturing systems should cope with the frequent changes in a product model and disturbances in manufacturing process. The control system of such systems must cover a constant adaptation and high flexibility. Holonic Flexible Manufacturing Cell(HFMC) is introduced to handle these issues more successfully. It is based on the concept of autonomous co-operating agent, called 'Holon', which is a building block of a manufacturing system for transforming, transporting, storing and/or validating information and physical objects. In this paper the basic structure of the HFMC is represented by using Unified Modeling Language and Open architecture cell controller is developed for effective integration components of a manufacturing system. Also a new control model, called MuLOM(Multi-Layered Operation Model), is suggested to represent the control behaviour for a holonic flexible manufacturing cell control system.