• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.2
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• pp.170-177
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• 2003

This study is to analyze the influence of the Tsushima Warm Current (TWC) on the variation of sound speed in the southern part of the East Sea. Sound speed is calculated by method of Chen and Millero (1977:, based on the CTD data measured in June of 1996. Sound speed in the central part of the TWC is about $45ms^{-1}$ more fast than that in the other regions without the TWC. Sound speed minimum layer (SML) in the TWC region exists between loom and 341 m, while it exists between 260m and 290m in the non-TWC region. SML distributes along the path of TWC over continental shelf in the coastal waters of Japan.

• 유체기계공업학회:학술대회논문집
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• 2004.12a
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• pp.473-478
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• 2004

This work presents the Thermal Hydraulic analysis has been performed for a 19-pin wire-spacer fuel assembly using three-dimensional Reynolds-averaged Navier-Stokes equations. SST model is used as a turbulence closure. The whole fuel assembly has been analyzed for one period of the wire-spacer using periodic boundary condition at inlet and outlet of the calculation domain. The overall results far a preliminary calculation show a good agreement with the experimental observations. It has been found that the major unidirectional flows are the axial velocity in sub-channels and the peripheral sweeping flows and the velocities are found to be following a cyclic path of period equal to the wire-wrap pitch. The temperature is found to be maximum in the central region and also, there exist a radial temperature gradient between the fuel rods. The major advantage of performing this kind of analysis is the prediction of thermal-hydraulic behavior of a fuel assembly with much ease.

• Proceedings of the Korea Society for Simulation Conference
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• 2005.05a
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• pp.139-143
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• 2005

The P2P is a network environment supporting data exchange which is directly connected peers without limit of existing server-client and intervening central server for resource or offered service with each peer. JXTA is a representative of P2P system. JXTA is a typical distributed computing model that proposed by Sun Microsystems. JXTA that doesn't require centralized services or resources is adaptable in extreme changes of network organization. MANET(Mobile Ad Hoc Network) is a representative wireless network that is composed of mobile nodes without infrastructure. So MANET establishes the path for the communication of each peers and maintains the newest routing information by exchanging routing information. In this paper, we propose a technique of JXTAMAUET which implements JXTA which is the P2P network system from the wireless network which is becoming the foundation of ubiquitous computing. For the performance evaluation of the JXTAMANET, we use simulation.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.14 no.24
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• pp.169-177
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• 1991

The Existing Protect schedulings are mathematical nodes upon which probability control is based. In fact, under the mechatronics environment in the new product design and development, statistical information is very poor or sometimes non-existent. Probabilistic PERT/CPM methods are not always satisfying because those methods suppose that it is possible to apply central- limit theorem and there exists a critical path which is much mart critical than all the other paths. Fuzzy project scheduling is possibility based scheduling. For this reason, the Fuzzy Project Scheduling essential to design, development and control the new product under the mechatranics environment. This paper deals with a modeling on the project scheduling which use fuzzy set theory. Fuzzy concepts in the project scheduling are shown to be very useful and easy to work with in the R & D system.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2009.05a
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• pp.277-280
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• 2009

In this paper, the method to apply the RFID technology to schools will be presented in order to effectively integrate and manage various assets in school. The proposed system may be seemed to be very useful of individual school to grasp the status of their assets and also the central government to control and manage the assets scattered far and wide around the country. We also propose the OSN/PMS server based on EPC global standard could be appropriate especially in schools. In addition the proposed system can acquire simultaneously the information from several RFID readers at real time so that it is possible and easy to track the position, the path of moving and the status of assets in the school. To show the usefulness of the proposed system, the prototype of the system has been implemented and conducted. The proposed system seems to be applicable to various fields such as factories, farms, or homes as well as school.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.17 no.2
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• pp.65-74
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• 2021

This study aims to assess the effect of postulated seismic loads on the structural integrity of a spent nuclear fuel dry storage facility. Firstly, three-dimensional modal and response spectrum analyses were carried out. With regard to the latter analysis, the effect of incident angles against two horizontal and one vertical response spectra was also considered. Results showed that even though two critical locations were predicted at the longitudinal axis central part of upper flow path as well as the end discontinuity part of upper and lower flow paths connector, their maximum principal stress values were less than the tensile strength. Moreover, since the influence of vertical angle was 87% higher than that of horizontal angle in particular, which should be carefully handled to demonstrate integrity of the facility.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.6
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• pp.135-141
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• 1997

Low velocity impact test and compressive residual strength test after impact were performed by using Hercules AS4/3501-6[45/0/-45/90]$_{2s}$ laminated plate to investigate the low velocity impact damage behavior and the post-impact strength degradation on orthotropic composite laminate plate. Due to the lateral impact losd, the load path showed "" shape according to the laminate central deflection. Damage in a laminate occurs by inclined matrix crack at the damage initiation load stage and vertical matrix crack, occurs on the outer surface. Evaluating the compressive residual strength after the low velocty impact test, it could be found that there is a transient range where the compressive residual strength drop suddenly in the initial damage which is in the matrix crack range and the initial delamination area. is in the matrix crack range and the initial delamination area.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.25 no.1
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• pp.15-28
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• 1992

Temporal variations of the path of the East Korea Warm Current(EKWC) which flows northward along the east coast of Korea were analysed to investigate whether the EKWC directly influences the existence of the so-called Warm Core in the Ulreung basin. From the 13 years(1975-1987) data of the Fisheries Research and Development Agency(FRDA), the $10^{\circ}C$ isotherm at the 100m depth and the depth of $2^{\circ}C$ isotherm and the temperature field at the 200m depth were used for identification of the path and the central position of the Warm Core. Sea surface winds computed from the surface pressure charts gave the monthly-averaged wind stress curl over the East Sea which was used for determination of the Sverdrup transport. And the mass transport stream functions were computed by use of the Sverdrup balance. The variations of the path show that the EKWC does not always have a fixed path and fluctuates with time. And the existence of the Warm Core is independent upon the presence of the EKWC even when the EKWC doesn't flow northward along the east coast of Korea. In view of the mass transport stream functions, the influences of the sea surface winds on the branching of the Tsushima Warm Currents and the presence of the EKWC were investigated. The presence of the EKWC may be hindered by the southward flow driven by the sea surface winds when the Tsushima currents are rather weak. A very weak correlation exists between the north-south component of the Sverdrup transport and the position of the Warm Core. However, a small but significant part of the southward transport across the latitudinal line of $38^{\circ}N$ indicates that cold water from the northern part of the East Sea may be driven and be forced to flow beneath the permanent thermocline in such a way that the thermal structure of the Warm Core and its position might be changed.

• Korean Journal of Medicinal Crop Science
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• v.12 no.1
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• pp.17-23
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• 2004

This study was carried out to obtain the basic information on mating parents and selection for high yielding safflower breeding. Thirty nine world safflower lines, which had collected from 13 countries of origjn, were evaluated for major agronomic characters, correlation and path-coefficients. The results obtained were summarized as follows. Days to flowers ranged from 83 days to 100 days. Days to flower of most foreign lines were later than that of domestic lines. Plant height ranged from 75 cm to 162 cm. The plant height and stem diameter of most foreign lines were higher than those of domestic lines. The leaf number and size of domestic lines were much more than those of foreign lines. The total branch numbers of foreign lines were more than domestic lines. Particularly, the number of third branch ranged from 0 to 25 and there were none in domestic lines. The number of corolla of foreign lines was much more than that of domestic lines. The yield of foreign lines collected from Central Asia and United States of America were more than any others. Significantly positive correlations were observed between yield and days to flower, stem diameter, the number of branch and the number of corolla. In the analysis of path-coefficient, the highest direct effects on yield was the number of corolla followed by the number of total branch, whereas those of the number of second branch and stem diameter were negative.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.66 no.4
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• pp.411-418
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• 2021

The yield potential of sesame depends on genetic factor, environmental factor, genetic × environmental interaction, as well as agronomic factors such as sowing date, planting density or seed rate for sowing. The main aim of this study was to analyze the effects of different sowing dates on the yield-related traits and total seed weight of sesame. The analysis of variance revealed that different sowing dates affected sesame yield-related traits such as plant height, number of branch per plant, number of capsule per plant, 1,000-seed weight, and total seed weight. Early or late sowing date showed negative effect of yield-related sesame traits and total seed weight. Optimum sowing date for sesame in the middle region of Korean peninsula was May 10^th, in which total seed yield recorded 90 kg per 10 are. Path-coefficient analysis revealed that the number of capsule per plant and plant height were major factors that affected the total seed weight of sesame across different sowing dates.