• Journal of the Semiconductor & Display Technology
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• v.12 no.2
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• pp.79-84
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• 2013

Nanoimprint lithography (NIL) is the next generation photolithography process in which the photoresist is dispensed onto the substrate in its liquid form and then imprinted and cured into a desired pattern instead of using traditional optical system. There have been considerable attentions on NIL due to its potential abilities that enable cost-effective and high-throughput nanofabrication to the display device and semiconductor industry. Although one of the current major research trends of NIL is large-area patterning, the technical difficulties to keep the uniformity of the residual layer become severer as the imprinting area increases more and more. In this paper, with the rolling type imprinting process, a mold, placed upon the $2^{nd}$ generation TFT-LCD glass sized substrate($370{\times}470mm^2$), is rolled by a rubber roller to achieve a uniform residual layer. The prediction of residual layer thickness of the photoresist by rolling of the rubber roller is crucial to design the rolling type imprinting process, determine the rubber roller operation conditions-mpressing force & feeding speed, operate smoothly the following etching process, and so forth. First, using the elasticity theory of contact problem and the empirical equation of rubber hardness, the contact length between rubber roller and mold is calculated with consideration of the shape and hardness of rubber roller and the pressing force to rubber roller. Next, using the squeeze flow theory to photoresist flow, the residual layer thickness of the photoresist is calculated with information of the viscosity and initial layer thickness of photoresist, the shape of mold pattern, feeding speed of rubber roller, and the contact length between rubber roller and mold previously calculated. Last, the effects of rubber roller operation conditions, impressing force & feeding speed, on the residual layer thickness are analyzed with consideration of the shape and hardness of rubber roller.

• The KIPS Transactions:PartC
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• v.10C no.7
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• pp.943-954
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• 2003

The mobile telecommunication system has been growing exponentially after 1990s due to the high population in a city and the growth of mobile user. In this time, the current mobile system mainly concentrates on the voice communication. However, in the next generation, mobile users want to get very diverse services via mobile terminal such as the Internet access, web access, multimedia communication, and etc. For this reason, the next generation system, such as the UMTS (Universal Mobile Telecommunication Services) system, has to support the packet data service and it will play the major role in the system. By the way, since the Web service is based on TCP, most of the Internet traffic TCP traffic. Therefore, efficient transmission of TCP traffic will take very important role in the performance of packet data service. There are many researches about improving TCP performance over wireless network. In those schemes, the UMTS system adapts the link layer retransmission scheme. However, there are rarely studies about the exact performance of the link layer retransmission scheme in the face of dynamic changes of wireless environment over the UMTS system. The dynamic changes of wireless environment, such as wireless bandwidth, can degrade TCP performance directly. So, in this paper, we simulate and analyze the TCP performance in the UMTS system with dynamic wireless environments. Then, we propose a simple scheme for minimizing TCP performance degradation. As a result of simulation, we can find that when wireless environment is changed dynamically, the probability of TCP timeout is increased, and the TCP performance is degraded very much. In this situation, the proposed simple scheme shows good performance. It saves wireless resources and reduces the degradation of TCP performance without large overhead of the base station.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1586-1589
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• 2005

GUMF (Global User Management Framework) that is proposed in this research can be applied to next generation network such as BcN (Broadband convergence Network), it is QoS guaranteed security framework for user that can solve present Internet's security vulnerability. GUMF offers anonymity for user of service and use the user's real-name or ID for management of service and it is technology that can realize secure QoS. GUMF needs management framework, UMS (User Management System), VNC (Virtual Network Controller) etc. UMS consists of root UMS in country dimension and Local UMS in each site dimension. VNC is network security equipment including VPN, QoS and security functions etc., and it achieves the QoSS (Quality of Security Service) and CLS(Communication Level Switching) functions. GUMF can offer safety in bandwidth consumption attacks such as worm propagation and DoS/DDoS, IP spoofing attack, and current most attack such as abusing of private information because it can offer the different QoS guaranteed network according to user's grades. User's grades are divided by 4 levels from Level 0 to Level 3, and user's security service level is decided according to level of the private information. Level 3 users that offer bio-information can receive secure network service that privacy is guaranteed. Therefore, GUMF that is proposed in this research can offer profit model to ISP and NSP, and can be utilized by strategy for secure u-Korea realization.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.10a
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• pp.328-330
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• 2022

Currently, the Metaverse is introduced in various fields, and a virtual convergence economy that uses NFTs for content or item transactions is expected to develop into a 'metaverse environment'. The 'metaverse environment' will lead the changes in our society in the future and it will be fused with AI, big data, cloud, IoT, block chain, and next-generation network technology. However, personal information, device information, and behavior information provided by Metaverse users to use the service are subject to major attacks. Therefore, in order to provide a safe environment for users to use and to expand the business base of related companies, building a public-private cooperation system and developing a security guide are the leading tasks. Therefore, in this study, we compare and analyze metaverse features and technologies, and examine possible security threats and countermeasures.

• Journal of Advanced Navigation Technology
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• v.19 no.5
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• pp.345-353
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• 2015

In this paper, we proposed an information fusion method for enhancement of automatic dependent surveillance - broadcast (ADS-B) system which is one of the next generation navigation system. Although ADS-B provides better performance than traditional radar, ADS-B still has error due to dependence of global navigation satellite system (GNSS) information. In this paper, we improved the ADS-B performance using information fusion of multilateration (MLAT) and wide area multilateration (WAM). Information fusion provides accurate data compared to original data. Mostly, information fusion methods use Kalman filter or IMM(interacting multiple model) filter as a subfilter. However, we used Robust IMM filter as a subfilter to improve the aircraft tracking performance. Also, we use actual ADS-B data not virtual data to increase reliability of our information fusion method.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.12C
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• pp.1181-1185
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• 2005

A combining of MIMO signal processing with OFDM is regarded as a promising solution of enhancing the performance of next generation wireless system. Therefore, in this paper, an OFDM-based wireless system employing layered space-time architecture is considered for a high-rate transmission. In the MIMO-OFDM system, we evaluate the PAR performance using the SLM approaches. The investigated SLM scheme for MIMO-OFDM signals selects the transmitted sequence with lowest average PAR over all transmitting antennas and retrieves the side information very accurately at the expense of a slight degradation of the PAR performance. The low probability of false side information can improve the overall detection performance of the MIMO-OFDM system with erroneous side information compared to the ordinary SLM approache, respectively. Also, we provide closed form of the average BER performance in MIMO-OFDM system using analytic approach.

• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.751-756
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• 2002

Since the operation of the first satellite-based navigation services, satellite positioning has played an increasing role in both surveying and navigation, and has become an indispensable tool for precise relative positioning. However, in some situations, e.g. at a low angle of elevation, the use of satellites for navigation is seriously restricted because obstacles like buildings and mountains can block signals. As a mean to resolve this problem, the quasi-zenith satellite system has been proposed as a next-generation satellite navigation system. Quasi-zenith satellite is a system which simultaneously deploys several satellites in a quasi-zenith geostationary orbit so that one of the satellites always stay close to the zenith if viewed from a specific point on the ground of East Asia. Thus, if a position measurement function compatible with GPS is installed in the quasi-zenith and stationary satellites, and these satellites are utilized together with the GPS, four satellites can be accessed simultaneously nearly all day long and a substantial improvement in position measurement, especially in metropolitan areas, can be achieved. The purpose of this paper is to evaluate the effectiveness of quasi-zenith satellite system on positioning accuracy improvement through simulation by using precise orbital information of the satellites and a three-Dimensional digital map. Through this simulation system, it is possible to calculate the number of simultaneously visible satellites and available area of the positioning without the need of actual observation.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.913-918
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• 2008

When developing railway vehicle system, investigation of the dynamical stability is essential as a virtual prototyping process. Not only the verification using the commercial analysis tools, systematic analysis using customized tools is also necessary, because these can give other points of view in stability, which is sometimes unable to evaluate in the former one. As a solver platform for customization, it is important to derive basic theory about flexible bodies and build flexible structure, which enables easy module insertion of user-created functions. In the paper, a flexible dynamic analysis system is developed, using absolute cartesian coordinate, modal coordinate and absolute nodal coordinate. Each coordinate system is verified by respective examples for every system. This solver system will play an important role for building the basic platform for analysis system, keeping pace with the concurrent development of the modules, such as wheel-contact force, constraints and user-defined force modules. Using the information from the analysis, the evaluation of the dynamic behavior of the train and its stability analysis will be available.

• Journal of Korea Spatial Information System Society
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• v.11 no.1
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• pp.1-8
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• 2009

The u-GIS national land information providing technology is the technology which maximizes the application of u- GIS data through the national land information platform technique of the next generation web and provides a user with the on-demand national land information in the ubiquitous environment. Recently, as the environment emphasizing the web as a platform 'Web 2.0' emerges, the where 2.0 which is paradigm is diffused in the spatial information area. And the Geo-spatial Web technology develops in a center. Moreover, it is changed to the open platform of the user participation trend. And the consumer of the geo-spatial information is changed to the end-user center from the public institution. The geo-spatial technique is technologically faced with the new challenge. In this paper, we analyze the technical tendency about a paradigm, And we present the u-GIS national land information platform technique, the u-GIS national land information visualization technology, the u-GIS national land information GeoDRM integrative technique, and the u-GIS national land information mobile application technology as the essential elemental technology for overcoming this.

• Journal of Life Science
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• v.33 no.8
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• pp.623-631
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• 2023

This study was conducted to develop microsatellite markers in Parapristipoma trilineatum using next-generation sequencing. A total of 402,244,934 reads were generated on the Illumina Hiseq X Ten System, yielding 60,738,985,034 bp of sequences. The de novo assembly resulted in 1,320,995 contigs. A total of 952,326 contigs (0.016%) including 151 microsatellite loci were derived from the 1,320,995 contigs longer than 640 bp. A total of 34 primer sets were designed from the 151 microsatellite loci. As a result, 15 microsatellite loci were chosen and used for assuming population genetic parameters in the wild and farmed populations. The mean number of effective alleles was 12, ranging from 6 to 25. The observed heterozygosity (H_O) and the expected heterozygosity (H_E) ranged between 0.530 and 0.873, with an average of 0.750, and from 0.647 to 0.895, with an average of 0.793, respectively. According to these results, the developed set of 15 microsatellite markers is expected to be useful for the analysis of genetic characteristics in the population of P. trilineatum in Korea. There are requirements now for further genetic information, fishery resource management, breeding guidelines, support with the selection of breeds and studies on the effects of release, all of which will improve species conservation, and through future research, we aim to offer genetic foundational data with that goal.