• Journal of the Korean Institute of Telematics and Electronics A
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• v.31A no.4
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• pp.21-29
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• 1994

Three protocols based on the slotted Aloha technique are proposed for very high-speed optical fiber local area networks using wavelength division multiplexing (WDM) passive star topology and the throughputs and delays are derived. For getting a high probability in successful transmission of control packets determining the transmission of a data packet, we adopt control mini slot groups in these protocols. The retransmission probability is also considered in analysis. Both throughput and delay of three protocols are compared and analyzed by varying the number of control solt groups, the retransmission probability the length of a data packet and the number of channels. The numerical analysis shows that the proposed protocols adopted the control slot groups give the increase of throughput and the decrease of delay.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.9 no.5
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• pp.34-39
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• 2010

The characteristic evaluation of an aluminium filler tube for automotive is presented in this paper. The material of filler tube was used AL3003 aluminium. In characteristic evaluation of an aluminium filler, we measured the corrosion, chemical resistance, weight, leak, welding strength, exciting endurance, and the solt spray test etc.. It has been shown that the weight decreased approximately 61% in aluminum filler tube developed comparing with steel filler tube. As the characteristic evaluation on the manufactured aluminium filler it was enough satisfied to use at the automotive filler tube.

• Proceedings of the KIEE Conference
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• 1996.11a
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• pp.32-35
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• 1996

This paper analyzes characteristics of PMLSM using 3 dimensional equivalent magnetic circuit network method (3-D EMC). PMLSM of which the effective electric-airgap is not only very large, but also the width is finite width lateral edges has much leakage flux. Therefore, 2-D analysis method cannot consider it so carefully that 3-D analysis method must required. 3-D EMC which will be used for analysis of PMLSM performs modeling of it including solt and teeth structure, uses the magnetic motive force of stator winding and permanent magnet as source. and calculates magnetic flux density and force considering nonlinear characteristics of materials. we verified analysis validity by comparing simulation results with expermental results.

• Journal of Marine Bioscience and Biotechnology
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• v.15 no.2
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• pp.90-95
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• 2023

This study aimed to develop low-salt seasoned Gim (김) with new functionality to meet the diversification of the export market and consumer demand for Gim, which is one of the four major seafood products in Chungcheongnam-do province. Spirulina, a microalgae containing essential amino acids, vitamins, and minerals, is known to have antioxidant components such as phycocyanin. Therefore, to determine the suitability of spirulina as a seasoning material, we conducted seaweed. It can be used as a substitute for seasoning salt in the development of low-salt seasoned laver with enhanced functionality.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.9
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• pp.830-837
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• 2015

Space debris has been a major issue recently for the space-active nations because its growing population is expected to increase the collision risk with operational satellites. Radar and electro-optical system has been used for space debris surveillance, which may cause unnecessary anti-collision manoeuvers due to their low tracking accuracy. So an additional tracking system is required to improve the predicted orbit accuracy and then to jude the anti-collision maneouvers more efficiently. The laser tracking system has been considered as an alternative to decrease these unnecessary manoeuvers. Korea Astronomy and Space Science Institute has been developing a space object laser tracking system which is capable of laser tracking for satellites with retro-reflectors and for space debris using high power laser, and satellite imaging using adaptive optics. In this study, the tracking capability is analyzed for space debris using high power laser based on link budget, false alarm probability and signal detection probability.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.1B
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• pp.1-7
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• 2004

Increase of internet users and new type of applied traffic such as game, news, distributed computing, online image conference, and real time audio and video have leaded to demand for more bandwidth for each application. This algorithm represents a complex optical exchanger having typical wavelength switching function and time-slotted transmission function. Performance assessment of the proposed OXC (Optical Cross connect) sttucture defines LFS (Limit Frame Size) and VFS (Variable Frame Size) for classification by packet type and calculates the channel effect and loss probability depending the demanded bandwidth by access node increase. Optical exchanger in this type of structure can guarantee future network expansion as well as decrease of frame collision resulted from node increase.

• Journal of Nutrition and Health
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• v.29 no.10
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• pp.1080-1086
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• 1996

The purpose of this study was to determine the effects of taurine supplementation on the hepatic lipid peroxidation, activiteis of defense enzymes and membrane stability during rat hepatocarcinogenesis. Hepatocarcinogenesis was induced by Solt & Farber modification. Lipid peroxide contents of carcinogen treated group which was not supplemented with taurine were lower than those of control group. This might be that peroxide is decreased because of the activation of detoxifing enzyme. Glutathione S-transferase(GST) activites of carcinogen treated groups were significantly (p<0.05) increased compared to those of control groups. The GST activities of group supplemented with taurine before treatment of carcinogen and during the all period of experiment were only less increased. In carcinogen treated groups, glutathione peroxidase(GPx) activites of groups supplemented with taurine were higher than those of non supplemented group. By carcinogen treatemtn, glucose 6-phosphatase(G6Pase) activites, index of membrane stability were decreased, but in carcinogen treated groups supplemented with taurine, they were less decreased. These results suggest that taurine supplementation seems to inhibit lipid peroxidation, to change the activities of defense enzymes and to prevent to membrane disintegration during chemically induced hepatocarcinogenesis.

• The korean journal of orthodontics
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• v.23 no.2 s.41
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• pp.283-294
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• 1993

The friction of orthodontic appliances is recogonized to be detrimental to tooth movement. The purpose of this study was to determine the magnitude of frictional force changes between bracket$(018'\times025'\;solt)$ and orthodontic wires(stainless steel, cobalt-chromium, and $\beta-titanium$, $017'\times0.25'$ rectangular) with time. The wire was secured in the bracket slot with a elastomeric ligature. Frictional forces were measured by universal testing machine. The following conclusions were obtained. 1. The frictional forces under dry condition were greater than those in saliva. 2. The frictional forces produced by cobalt-chromium wire were less than those generated by stainless steel and $\beta-titanium$ wire. 3. The frictional forces increased progressively with time, and the amount of increase on first two weeks was greater than on last two weeks. 4. The change of frictional force under dry condition was greater than in artificial saliva.

• Geotechnical Engineering
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• v.10 no.3
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• pp.97-110
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• 1994

Interaction between an unlined tunnel may cause a serious stability both the tunnel and the overlying and unli Red tunnel interaction meta study on the three dimensional bets a three dimensional elasto plastic the program, a wide range of blur puter analysis such as stress distr menu and tunnel deformation were footing and unlined tunnel. The yes traces the ultimate bearing capacity only on the tunnel size and location revealed is that an unlined tunnel under a square footing is subjected to three dimensional stress pattern along the tunnel axis, and that the magnitudes of stresses in the foundation soil and around tunnel perimeter are considerably smaller when loaded with a square than with a strip footings and the difference varies with the location and the type of stress. It is also revealed that the footing failure mechanism varies with the degree of footing and tunnel interaction.

• Magazine of the Korean Society of Agricultural Engineers
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• v.34 no.E
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• pp.30-44
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• 1992

A modification of the TEACH-like computer program based on the k-$\varepsilon$ turbulence transport was applied for predicting air mixing patterns and temperature distributions in a rectangular, slot-ventilated enclosure having obstructions ; a rectangular obstacle with heat flux, solid walls separates the passage and the pig pens, and purlins beneath the ceiling. Air flow patterns were calculated for the cases with and without the purlin, extending 300mm beneath the ceiling. Comparisons of prediction data of Randall & Battams(1976) showed air flow pattern predicted well for the case without the purlin. Heat was accumulated at the corner of the left side of the solid wall and the right-upper region of the simulated pigs. However the air distribution pattern was completely different from data for the case with the purlin. The deviation from the observation may be attributed to the difference of the geometric configuation. Exploring the cause of the deviation should be conducted in a further study. Temperature stratification was also observed due to incomplete mixing. The obstruction in the route of the inlet air jet at inlet should be avoided since most of kinetic energy dissipates at the abstacle duet to impingement.