• BMB Reports
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• v.29 no.2
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• pp.175-179
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• 1996

Viral surface proteins are known to play an essential role in attachment of the virus particle to the host cell membrane. In case of the hepatitis B virus (HBV) several reports have described potential receptors on the target cell side, but no definite receptor protein has been isolated yet. As for the viral side, it has been suggested that the preS region of the envelope protein, especially the preS1 region, is involved in binding of HBV to the host cell. In this study, preS1 region was recombinantly expressed in the form of a maltose binding protein (MBP) fusion protein and used to identify and visualize the expression of putative HBV receptor(s) on the host cell. Using laser scanned confocal microscopy and by FACS analysis, MBP-preS1 proteins were shown to bind to the human hepatoma cell line HepG2 in a receptor-ligand specific manner. The binding kinetic of MBP-preS1 to its cellular receptor was shown to be temperature and time dependent. In cells permeabilized with Triton X-100 and treated with the fusion protein, a specific staining of the nuclear membrane could be observed. To determine the precise location of the receptor binding site within the preS1 region, several short overlapping peptides from this region were synthesized and used in a competition assay. In this way the receptor binding epitope in preS1 was revealed to be amino acid residues 27 to 51, which is in agreement with previous reports. These results confirm the significance of the preS1 region in virus attachment in general, and suggest an internalization pathway mediated by direct attachment of the viral particle to the target cell membrane.

• Korean Journal of Crystallography
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• v.4 no.1
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• pp.6-10
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• 1993

11 β ,17 β -dihydroxy-9a-fluoro-l7a-methyl androst-4-en-3-one (Fluoxymesterone), CgoH29 FO,, orthorhombic, P2,2,2,, a=13.468(5) A, b= 19.554 (2)A, c=6.578(9)A, a=b=r=90˚, A (CuKa)=1.5406 A , Dm=1.289cm-3, Dc=1.299cm-3 and Z=4 at T=298k. The structure was solved by direct method using seminvariants of ggg Parity group and refined by the full-matrix least-square method, resulting model with reliability factor R=0.069 for 1098 unique reflection over 3σ . Ring A is an 1β-2a-half chair, 5 ring has a highly symmetrical chair conformation, C ring is in a distorted chair conformation and D ring is a 13aenveLope conformation. In the crystal structure, the molecules are packed with a hydrogen bond of 011-H23‥‥03(0.5+x, 1.5-y, 1.0-z) [1.94(9) A of H‥‥0.2.786(9)A of 0‥‥0 and 165(8) ˚ of

• The Korean Journal of Zoology
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• v.29 no.2
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• pp.121-140
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• 1986

The spermiogenesis of Cipangopaludina chinensis malleata began with the changes of nucleus and cytoplasm. The chromatin in the nucleus began to stack and condense around perinuclear envelope. Axonema (doublet microtubules of 9+2) appeared in the cytoplasm. After this process, the cytoplasm was protruded and the bell-shaped nucleus was located on protruding part of it. The electron dense masses were distributed throughout cytoplasm and lysed or secreted by exocytosis of lysosomal vacuoles. Especially, some mitochondria were migrated by the doublet microtubules of axonema toward nucleus. The axoneme was enclosed by electron dense materials after exocytosis of unnecessary materials for the tail formation. The electron dense masses were released and migrated into the each part through microtubules or axonemal doublet microtubules as the granular particles. These granular particles were containing glycogen. Ultimately, the condensed head developed into helical and neck region into cylindrical shape respectively. The mitochondria which have regular lamellar layers at cross axis became to middle piece, and then spermatozoon was completely matured. Thus, these phenomena showed special processes in spermiogenesis, those were as follows; chromatin in the head was condensed, the head was changed into helical shape, and cytoplasmic materials are migrated and transferred into the each part in the tail by mitochondria and microtubules.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.5
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• pp.510-518
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• 2010

In this paper, the designed and implemented results of CFL linearization chip which can be used in mobile radio and TRS terminal of UHF band(380~910 MHz), using $0.6\;{\mu}m$ BiCMOS process based on Si, are shown. As gain control circuits for modifying transmit power are inserted not only in feedback path but also in forward path, the stability of CFL is maintained. And, DC-offset correction function of S/H structure, which is suitable for walkie-talkie PTT operation and is easily implemented, is realized. The performance test results of transmitter show that the regulation of FCC emission mask at PEP 3 W(34.8 dBm) is satisfied when the CQPSK modulated signal is fed and more than 30 dBc improvement of 3rd order IMD is achieved when two-tone signal is inputted.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.9
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• pp.2009-2019
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• 2013

In this paper, we propose an automatic modulation recognition algorithm based on cyclic moment and new modified cumulant for analog and digital modulation signals. It is noteworthy that each modulated signal has different cycle frequency characteristics according to its order of cyclic moment. By means of this characteristics as classification features, various modulated signals can be efficiently classified. Also, to identify modulated signals having the same cycle frequency characteristics, we take advantage of the additional classification factors such as variations of envelope and phase as well as modified cumulant. The proposed algorithm was evaluated by considering the number of symbols, SNR, and frequency offset. In the simulation condition where the number of gathered symbols was about 819, and SNR and frequency offset were above 10dB and below 25%, respectively, the average accuracy of the proposed algorithm was more than 95%.

• Journal of the Korean Institute of Educational Facilities
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• v.2 no.2
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• pp.17-25
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• 1995

Because of energy crisis and environment pollution, we have become more conscious of the need to conserve heat in buildings. In response to this need. new requirements have been developed for insulation and other matters relating to energy consumption. Among others, more promising is to use the energy that is all around us in the dynamic forces of nature:the wind, tides, waves, rivers, geothermal hot spots, and the sun. The problem is that we have not been forced to find the technological means to convert these natural energies into usable forms because it has been too easy simply to dig or pump our energy out of the ground. Now, the problem is not a shortage of energy itself, but a shortage of technology for converting the energy that lies aoo around us into usable forms. Energy-conversion technology is the real issue, and solar energy is one of the brightest and most promising frontiers in energy conversion. All buildings are wrapped in a skin. Generally skins protect the person in stay from rain, wind, dust, noise, cold, hot etc.. However, there are some skins that provide energy from given environment into the building. Out of aoo, transparent insulation material is one of these materials that most effectively satisfies this kind of envelope function. Since, there are no research on transparent insulation in Korea, it has been studied very actively in Europe and in America. Thus, in this thesis, we will theoratically study and analyze how the heat flows through a trans arrent insulated opaque wall of a school building in Korea. It will be an important information for the effective using guidelines of transparent insulation materials in Korea.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.3C
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• pp.83-91
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• 2005

We analyze the performance of an adaptive hybrid search code acquisition algorithm for direct-sequence code division multiple access (DS-CDMA) systems under slowly-moving mobile environments. The code acquisition algorithm is designed to provide the desired feature of constant false alarm rate (CFAR) to cope with nonstationarity of the interference in CDMA forward links. An analytical expression for the mean acquisition time is first derived and the probabilities of detection, miss, and false alarm are then obtained for frequency-selective Rayleigh fading environments. The fading envelope of a received signal is assumed to be constant over the duration of post-detection integration (PDI), considering slow fading environments. Finally, the performance of the designed code acquisition algorithm shall be evaluated numerically to examine the effect of some design parameters such as the sub-window size, size of the PDI, decision threshold, and so on, considering cdma2000 environments.

• The KIPS Transactions:PartB
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• v.10B no.4
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• pp.429-442
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• 2003

In this paper, we describe an address image recognition system for automatic processing of standard- size letter mail. The inputs to the system are gray-level mail piece images and the outputs are delivery point codes with which a delivery sequence of carrier can be generated. The system includes five main modules; destination address block location, text line separation, character segmentation, character recognition and finally address interpretation. The destination address block is extracted on the basis of experimental knowledge and the line separation and character segmentation is done through the analysis of connected components and vortical runs. For recognizing characters, we developed MLP-based recognizers and dynamical programming technique for interpretation. Since each module has been implemented in an independent way, the system has a benefit that the optimization of each module is relatively easy. We have done the experiment with live mail piece images directly sampled from mail sorting machine in Yuseong post office. The experimental results prove the feasibility of our system.

• Journal of the Korean Society for Advanced Composite Structures
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• v.4 no.2
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• pp.15-24
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• 2013

This project is mainly related to evaluation of total energy consumption of low energy house, the exterior envelope of which was wholly composed of structural insulated panels(SIP). The U-value of applied SIP was in the range of 0.189 to $0.269W/m^2{\cdot}K$ and the U-value of pair glass from 0.78 to $1.298W/m^2{\cdot}K$ was applied for window dependent to its function respectively. For comparison of total energy performance, the energy simulation for pilot house was performed to compare with the control house having insulation criteria of Korean building regulation in 2009. Based on simulation of dynamic energy performance, the pilot house saved 48.3% of annual energy consumption while the control house in 2009 consumed as 85.7GJ/y. In case of heating, the result showed that the energy saving ratio amounted to 76.7%. For $CO_2$ emission, the pilot house diminished approximately 35.4% from $6,208.4kgCO_2$ to $4,009.2kgCO_2$. In payback period to early investment, it was analyzed the pilot house took 7.8 years, when the low energy house built by other insulation method with same thermal perfusion took 11.5 years. From this result, it is considered that the SIP is more effective, economic to Green Home application.

• The Journal of Korean Physical Therapy
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• v.9 no.1
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• pp.59-70
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• 1997

The ability of neurotropic alpha herpesviruses to replicate within synaptically linked neurons has made these pathogens valuable tools for transneuronal analysis. Recent studies suggest that unique gene products expressed by genetically engineered strains of virus may permit the use of multiple strains in complex tracing paradigms. In the present study we have examined the invasiveness of two genetically engineered strains of the swine pathogen known as pseudorabies virus(PRV). The two strains were isogenic with the attenuated Bartha strain of PRV; in one strain a lacZ reporter gene was inserted into the gC locus (PRV-BaBlu; $4.75\times10^8pfu/ml$) contrained a PRV envelope glycoprotein gene that was absent in PRV-BaBlu. Simultaneous or temporally separated sequential injection of $4\mu\ell$ of each strain into the ventral wall of the stomach produced a predictale course of retrograde synaptic infection. The results were as follows: 1. PRV-BaBlu and PRV-D infected the dorsal motor nucleus of vagus nerve(DMV) and paraventricular nucleus(PVN). 2. Invasion and replication of PRV-D occured at a faster rate than the parental strain or PRV-BaBlu. 3. PRV-D was much more virulent than PRV-BaBlu or the parental strain. 4. Co-injection of PRV-D and PRV-BaBlu produced an infection that was more virulent than that produced by the parental strain (PRV-Bartha), 5. Neurons in DMV were permissive to co-infection with PRV-D and PRV-BaBlu when they were injected simultaneously into the same site. 6. Replication of PRV-BaBlu was compromised by prior infection of the same circuit with PRV-D. 7. Prior infection of neurons with PRV-D maked them resistant to infection with PRV-BaBlu.