• Journal of The Korean Astronomical Society
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• v.38 no.2
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• pp.135-140
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• 2005

This paper summarizes the recent progress made by our group at Seoul National University on studies of the evolution and formation of distant galaxies. Various research projects are currently underway, which include: (i) the number density of distant early-type galaxies (z < 1); (ii) the optical-NIR color gradient of nearby early-type galaxies; (iii) J - K-selected Extremely Red Objects (EROs) in field (CDF-S) and the cluster environment; and (iv) the Lyman-break galaxies in the Spitzer First Look Survey (FLS) field. These works will constrain the mass evolution and the star formation history of galaxies in different environments, and the results will serve as useful contraints on galaxy formation models.

• Journal of Digital Convergence
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• v.4 no.1
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• pp.31-41
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• 2006

This article introduces developing trends of an 'Ubiquitous Interface' as an access method for use of various network resources, such as public wireless networks and un-licensed wireless networks in ubiquitous sensor network environments, without troublesome settings or operations by users. 'Ubiquitous Interface' is a relatively wide sense meaning not only physical interface of specified device or between processors, but anything method for access USN. These 'Ubiquitous Interface' able to provide seamless services that adapt autonomously to the user's movements and changes in the state of wireless resources. Recently, strongly recommended current technologies are RFID, NFC, Multi-mode mobile terminal, UMA mobile terminal and Wearable computer as a future ubiquitous interface. These technologies are have to have flexibility and multiple physical communication channels for seamless service hand over and serve easy connection at huge USN to user. Also, they have to must have flexible software structure. Finally, through the 'Ubiquitous Interface', we will be experience of seamless communication and realize a real liberty of communication.

• Journal of Korean Institute of Industrial Engineers
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• v.23 no.4
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• pp.741-754
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• 1997

Code matrix is the matrix of which on element and its neighbors are arranged to have a code value. The code matrix was originally designed by the author for developing a vision system but has not been theoretically studied. In this paper some theoretical properties of the code matrix are investigated. The studied characteristics of the code matrix are useful for not only understanding the matrix itself but efficiently restructuring the matrix. A number of transformation functions, which enable the matrix to have different shape, are thus developed based on the investigated properties. The transformation functions are then applied to build a perfectly and uniformly structured square code matrix, which is proven useful in on image processing example. The study in this paper is expected to serve a theoretical background for the application of the code matrix in many areas.

• Proceedings of the KIEE Conference
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• 1991.11a
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• pp.336-338
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• 1991

Effects of $Nb_2O_5$ addition ranged from 0.0 to 0.75(wt%) on the microstructure and electrical porperties of PZT ceramics have been investigated. The Pb vacancy concentration increases with increasing NbO content. However, the experimental results show the resistivity increases with increasing $Nb^{5+}$ content. This behavior can be explained as a compensation effect and $Nb^{5+}$ can serve as a donar and contribute electrons to the conduction process. According to the law of mass action, this result may reduce the total charge carrier:thus the resistivity increase with NbO content in PZT.

• Asia pacific journal of information systems
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• v.7 no.3
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• pp.109-124
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• 1997

Pricing information services, where congestion can threaten the efficient operation of information systems, has been studied in economics and information systems literature, Recent explosion of the Internet ana proliferation of multimedia content over the Internet have rekindled the research interest in designing pricing schedules for differentiated information services, In order for the information system to effectively serve users having heterogeneous needs, pricing rules for discriminated services should be considered. At the same time, when individual users' interest does not align with that of the organization that individual users belong to, organization-wide pricing policy should be devised to improve the value of the services rendered by the system. This paper, using a priority queuing model, addresses the need for such on incentive-compatible pricing for different information services.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.231-233
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• 2004

Queuing is waiting lines which play routing service when packet entered. Queuing is decide how and whom is going to provide priority service. This is kind of first in first out(FIFO) or weighted fair queuing(WFQ) method. In this study, UDP design using WFQ way to serve to provide service evenly and rapidly in network. Also in actuality internet, datagram analyzed by packet captured. Queuing services through the requesting port number, input, output, output queuing creation & delete, message request by internet control message protocol(ICMP). Queuing designed in control block module, input queues, input/output module composition. In conclusion, I have confirm queuing result of WFQ method by the datagram information analyzed.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.9
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• pp.1535-1542
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• 2007

HTS (High Temperature Superconducting) Power devices has the several useful characteristics from the technical and economical viewpoint. Possible application to the utility industry have been widely discussed in various research projects. For the successful introduction of HTS power devices into power system, establishing a proper R&D and marketing strategies through estimating the future market size are necessary. However, quantitative estimates of how well HTS power devices will serve their markets have been lacking. In this paper, we propose a estimation methodology of future market size for HTS power divices such as cable, transformer, generator, and motor, and also evaluate the future international and domestic market size by using proposed methodology.

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.186-189
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• 2003

Helicobacter pylori is the etiologic agent of human gastritis and peptic ulceration and produces urease as the major protein component on its surface. H. pylori urease is known to serve as a potent immunogen as well as major virulence factor. In order to express the recombinant urease in tobacco plants, a DNA fragment containing the minimal H. pylori urease gene cluster was subcloned into a plant expression vector. The recombinant vector was transformed to tobacco plants. The integration of the recombinant plasmids into tobacco chromosomal genome was verified by genomic PCR. Expression to mRNA was confirmed by Northern blot analysis, and expression to recombinant urease protein was observed by Western blot analysis. These results showed that the recombinant urease can be produced in tobacco plants and will be tested for immune response to use as an edible vaccine.

• Journal of Korea Port Economic Association
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• v.20 no.2
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• pp.101-130
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• 2004

Such Hinterland in New Busan-Jinhae Port are so placed as to do harm to their surrounding residential areas due to traffic, noise and dirt, etc. according to the current plan. So they are likely to fail to serve as harbors and residential districts. Because this is responsible for a conflict between harbors and urban functions, plans for the use of such areas should be well planned enough to achieve win-win results by getting rid of a conflict between the harbors and urban functions by creating manufactural and industrial complexes and green parks close to harbor logistics, by consolidating the functions of the cities through exchanges, commercial business and educational facilities and by adding comfort facilities at the hinterland of Ungdong and Myeongji.

• Journal of Korea Port Economic Association
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• v.20 no.2
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• pp.19-33
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• 2004

Recognizing that the main container ports' status is gradually inclining, the Japanese government is driving forward the super hub port project. This project has three goals, unifying Japanese ports separating nationally, diminishing the port costs by 30 percents less than the current port costs of their competitors, and cutting down the lead time of processing import-export freight into 24 hours, Singaporean level. The project will work to some extent, if succeeding, but the effect is doubtful if it will be the fundamental solution of Japanese ports' crisis. I wrote this paper since I thought that this Japanese policy would serve as a good reference of Korea, which had two container ports system and its prospect was not good through the fact that the Busan ports' rank of dealing with containers fell down to the fifth in 2003.