• International journal of advanced smart convergence
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• v.11 no.4
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• pp.41-46
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• 2022

This study is a Ku-band array antenna for the manufacture of low-orbit satellite communication terminals, designed to have miniaturization, high gain, and wide beam width. The transmission of low-orbit satellite communication has a right-rotating circularly polarized wave, and the reception has a left-rotating circularly polarized wave. The 4×8 array antenna was separated for transmission and reception, and it was combined with the RF circuit part of the transmitter and receiver, and was terminated in the form of a waveguide for RF signal impedance matching in the form of a transition from the microstrip line to the waveguide. The 30° beam width of the receiver maximum gain of 19 dBi and the 29° beam width of the transmitter maximum gain of 18 dBi are shown. Through this antenna configuration, the system was configured to suit the low-orbit satellite transmission/reception characteristics.

• Journal of the Korean Association of Geographic Information Studies
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• v.11 no.4
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• pp.1-9
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• 2008

It is restricted on CPU ability, memory, display size and networking to process GIS data on ubiquitous-based terminal. For that reason, we tried to improve the cadastral electronic file to solve these problems in this paper. The format of old cadastral electronic files is not efficient because it is made of file structure. So, it has inconvenience to let us read whole file, displaying on the screen and connecting to geographic objects by adding index file like database for connecting to geographic object and displaying on the screen. The file size was decreased to 27.6% of original file size through converting format.

• Journal of Photoscience
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• v.5 no.2
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• pp.73-81
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• 1998

Light signals constitute major factors in regulating gene expression and morphogenesis in plants and fungi. Phytochrome A and B were well characterized red and far-red light receptors in plants. Red light signals increased the phosphorylation of 18 kDa protein, which was identified to be nucleoside diphosphate (NDP) kinase. The NDP kinase catalyzed autophosphorylation and had a protein kinase activity similar to MAP (mitogen activated protein) kinase. As candidates for blue light photoreceptors, cDNAs for CRY1 and CRY2 were isolated. The N-teminal regions of these proteins showed a high hornology to DNA photolyase. The 120 kDa protein first detected in Pisurn sativurn, which showed blue light induced phosphorylation was also detected in Arabidopsis thaliana. The 120 kDa protein was encoded by the nphl gene, which regulated positive phototropism of the plant. In Neurospora crassa, blue light irradiation of the membrane fraction prepared from roycelia stimulated the phosphorylation of the 15 kDa protein, which was also identifmd to be an NDP kinase. Recent progress in understanding early events in light signal transduction mainly in Pisum sativum Alaska, Arabidopsis thaliana and Neurospora crassa was summarized.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.2
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• pp.375-382
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• 1996

In this paper, aneffective method for computing source to terminal reliability of network by decomposition is described. A graph is modeled after a network, and decomposed into two subgraphs. A logic product term of one subgraph is computed, and a graph of the other subgraphs is made according to the event representing the logic product term, and it's logic product term is compted. By multiplying the logic product term of one subgraph by that of the other subgraphs, a method for computing the source to terminal reliability is proposed. the time complexity for computing all the logic product terms of one subgraph is the product of copies of the number of edges in the subgraph of 2, and that of the other subgraph is the number of edges multiplied by the number of logic product terms. This method requires less computation time than that not by decomposition.

• Journal of Service Research and Studies
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• v.4 no.1
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• pp.61-70
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• 2014

We are being developed many applicaton of wireless mobile computing system environment with development of wireless internet technology and teminal eqipment. Lately, Modern Society increase terror of infant children and weak peoples. This study suggested missing child prevention and protection of infant children. When happened an emergency of missing child has risen, we suggest missing child prevention system. This system find position of missing child in fast time. We analysis and design and constructed missing child prevention system by bluetooth and GPS of wireless mobile environment.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 1999.10a
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• pp.333-344
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• 1999

Currently many studies on the unmanned gantry crane for the automated container terminal are accomplished. This is needed for the development of large scale, automation, high speed, unmanned system and information system in port facility. In order to do efficient container handling job in port yard, the automated handling system is well adapted to the job environments and all-season weather, In order to realize the automatic and unmanned system for container handling job, the required functions and main structure system are studied. The major problems of operation of the conventional gantry crane are that the vibration of gantry structure body is occurred by operation and that high-speed and precision position-velocity control and the capability to dope to the external disturbances caused by the wind, rain, fog and job environments. In this paper, the fundamental study for establishment of the concept and the dynamic modelling of the major sub system of the unmanned gantry crane is presented. These studies are useful for design and manufacturing of the new concept model of the unmanned gantry crane for efficient operation of the automated container terminal.

• Journal of the Korean Vacuum Society
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• v.6 no.2
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• pp.151-158
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• 1997

Nitrogen incorporated diamond-like carbon films were deposited by r.f. glow discharge of mixtures of benzene and ammonia gases. Mechanical properties, composition and atomic bond structure were investigated when the fraction of ammonia increases from 0 to 0.79 and the negative self bias voltage of cathode from 100 to 900 V. Both the residual compressive stress and the hardness decrease from 1.7 to 1.0 GPa and from 2750Kgf/$\textrm{mm}^2$ to 1700Kgf/$\textrm{mm}^2$, respectively. In addition to hydrogen, triply bonded nitrogens also play a role of teminal sites of the three dimensional atomic bond network. By considering the hydrogen concentration and the nitrogen bond characteristics, it can be shown that the mechanical properties of the films are determined by the content of three dimensional inter-links of $sp^2$ clusters. Although the mechanical properties are affected by the nitrogen addition, its depedence on the negative bias voltage is qualitatively identical to that of pure diamond-like carbon films.

• Proceedings of the Korea Society of Environmental Biology Conference
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• 2002.11a
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• pp.33-37
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• 2002

The present was performed to identify the effects of tributyltin (TBT) in the immature mice testes. 3-week-old male ICR mice were orally administrated on one time basis of TBT dose of O (Vehicle control, VC), 25 (TBT 25 mg/kg, T$_{25}$ ), 50 (TBT 50 mg/kg, T$_{50}$ ), 100 (TBT 100 mg/kg, T$_{100}$ ) mg/kg per each one. After 3 days the time treated of TBT, mice were sacrified and wighted body, testis, epididymis, seminal vesicle, vas deferens, and prostate. As the result of weighing, wights of each oragan and gonad index were tendency decresed in comparing groups of TBT treated with that (C) of unteated (p <0.05). As the result of examination of steroid hormones in the immature male mice, The concentrations of serum and intratesticular testosterone were significatly increased rather than the control group. But concentrations of estradiol were decresed objectly. A group of the highest change of concentrations of steroid hormones is T$_{100}$ . The high dose group, T$_{100}$ , was decreased all of concentrations of steroid hormones rather than those of T$^{25}$ . The result of observation with histological changes in testis showed a tendency for innercellular wall to increase damage and extinction in seminiferous tubles. As the result of investigation apoptotic cell numbers in the testis using teminal deoxy-nucleotidyl transferase -mediated dUTP-digoxygenin nick end-labeling immunohistochemical straia, The ratio of Apoptic cells significantly was incensed in depending on treatment of TBT does. In conclusion, these results shows that TBT triggers apoptosis on reproductive cell in testis and changes level of concentrations of steroid hormones in the immature male mice , as endocrine disruptors (EDs).

• Korean Chemical Engineering Research
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• v.46 no.4
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• pp.669-675
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• 2008

Carbon black has been widely used in composites, tonor resin, and ink materials. Since carbon black readily agglomerates, it is important to disperse carbon black in real applications. Aiming to improve dispersion stability, carbon black was chemically oxidized to possess hydroxyl groups using a phase transfer catalyst at room temperature. The modified carbon black (CB-OH) was grafted by a silane coupling agent, p-methylacryloxypropyltrimethoxysilane, to carry teminal vinyl groups. The modified carbon black was subsequently used in miniemulsion polymerization to achieve encapsulted core-shell structure. Finally, well-encapsulated carbon black by polymer was obtained in the size range of 100-500 nm. Throughout the polymerization, the effects of surface modification, types of monomers, initiators, and emulsifiers were investigated.

• Biomolecules & Therapeutics
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• v.19 no.3
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• pp.348-356
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• 2011

Liriope platyphylla is a medical herb that has long been used in Korea and China to treat cough, sputum, neurodigenerative disorders, obesity and diabetes. The aims of this study were to study the antidiabetic effects of the aqueous extract of L. platyphylla (AEtLP) through pancreatic and extrapancreatic actions. AEtLP were orally administrated to ICR mice once a day for 7 days. Of three different concentrations of AEtLP, only 10% AEtLP were low toxic to liver, based on body weight and serum biochemical analyses. However, 10% AEtLP-treated mice displayed signifi cant reduction of the glucose concentration and increased insulin concentration; no changes were noted using 5% and 15% AEtLP. Also, the increase of glucose transporter (Glut)-1 expression in liver was dependent on the concentration of AEtLP, and was regulated by the phosphorylation of Akt. The lowest expression of Glut-3 was observed in 15% AEtLP treated mice, followed by 10% AEtLP- and 5% AEtLP-treated mice. This pattern of Glut-3 expression was roughly in accord with the phosphorylation of c-Jun N-teminal kinase (JNK) in the mitogen-activated protein kinase (MAPK) pathway. Furthermore, a signifi cant rise of the superoxide dismutase activity (SOD) was detected in AEtLP-treated mice. The fi ndings suggest that AEtLP should be considered as a diabetes therapeutic candidate to induce insulin secretion from pancreatic ${\beta}$-cells and glucose uptake in liver cells.