• 한국경영과학회지
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• 제33권3호
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• pp.43-58
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• 2008

In this paper, we have presented a dynamic, predictive location update scheme that takes into account each user's mobility patterns. A user's past movement history is used to create two-dimensional transition probability matrix which makes use of two directional consecutive location areas. A mobile terminal utilizes the transition probability to develop a predictive path which consists of several predictive nodes and then the location update is saved as long as a mobile user follows the predictive path. Using continuous-time Markov chain, cost functions of location update and paging are derived and it is shown that the number of predictive nodes can be determined optimally. To evaluate the proposed scheme, simulations are designed and the numerical analysis is carried out. The numerical analysis features user's mobility patterns and regularity, call arrival rates, and cost ratio of location update to paging. Results show that the proposed scheme gives lower total location management cost, compared to the other location update schemes.

• 한국컴퓨터정보학회논문지
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• 제9권4호
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• pp.167-172
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• 2004

IETF에서 제안한 Mobile IP는 효율적이나, 이동 호스트들이 어느 특정한 지역 내에서 많은 움직임을 가지면서 통신할 경우 비효율적인 면이 있다. 이는 이동 호스트를 등록하고 인터넷 환경 하에서 보안된 경로를 설정하며 이 경로에 데이터를 전송하는 데 많은 지연을 유발하기 때문이며, 이동 호스트들이 어느 특정한 지역 내에서 잦은 이동성을 갖는 경우, 이러한 비 효율성은 더 심각해진다고 할 수 있다. 따라서 본 논문에서는 특정지역 내의 이동성 관리에 있어서 위와 같은 문제점을 보완하기 위한 방법의 하나로 경계 라우터와 포인터 포워딩 및 캐시 방법을 결합한 Anchor 체인 방법에 의한 Anchor 외부 에이전트를 사용한 방법을 제안한다.

• 한국자동차공학회논문집
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• 제9권1호
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• pp.205-215
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• 2001

In this study, modeling and analysis procedure for the dynamic analysis of a high mobility tracked vehicle system were studied. The vehicle model used in this investigation is assumed to be consist of two kinematically decoupled subsystems. The chassis subsystem consists of chassis frame, sprocket, support rollers, road wheels, idler wheel, road wheel arms and idle wheel arm, while the track subsystem is represented as a closed kinematic chain consisting of track links and end connectors interconnected by revolute joints with bushing. Nonlinear contact force module describing the interaction between track link, and sprocket, idler wheel, road wheel, support roller, ground was used. The effects of road wheel arms and idler wheel arm due to tension adjuster are also considered.

• 공업화학
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• 제10권5호
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• pp.743-747
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• 1999

비상용성인 polystyrene(PS)와 polymethacrylate(PMA)의 블렌드에서 분자간 수소결합이 가능하도록 구성고분자를 변성하였다. 공중합을 통해 hydroxystyrene 함량이 몰분율로 각각 7%, 10%, 18% 도입된 poly(styrene-co-4-hydroxystyrene) (modified polystyrene, MPS)을 합성하여 블렌드의 상용성 변화를 살펴보았다. 또한 PMA의 측쇄의 크기가 분자간 수소결합 형성에 미치는 영향을 조사하기 위하여 각각 methyl기, butyl기, hexyl기, ethylhexyl기의 측쇄를 갖는 PMA를 선정하였다. 그 결과 수산기의 함량이 증가함에 따라 분자간 수소결합 형성이 증가하였다. PMA의 측쇄의 크기에 따라 수소결합 형성 정도가 영향을 받아 상용성에 큰 차이가 나타남을 온도변화에 따른 상변화 거동을 통하여 확인하였다. 측쇄의 크기가 증가됨에 따라 입체장애 효과와 증가된 사슬의 운동성 때문에 분자간 수소결합의 형성 및 수소 결합력은 크게 감소하였다.

• Journal of Information Technology Applications and Management
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• 제21권4호
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• pp.225-245
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• 2014

ICT based convergence application is one of the most prevalent industrial issue these days. Despite of criticalness and potential economic opportunities of the ICT based convergence, theoretical research to analyze the feasibility and estimate the economic impact of the application is rather limited. This paper is intended to fill this research gap. In this respect, we develop theoretical framework to quantitatively estimate the differential benefits of convergent applications, which necessarily include underling ICT technology's contribution attributes extractions, and resulting value increments engendered from user's process effectiveness when ICT based service application is adopted. The research model to assess the differential value of the ICT based service application is developed, grounded on theoretical framework of TPC (Technology-to-performance chain) and contingency fit theories. Scenario based survey method is adopted, and SmartPLS 2.0. is used for statistical analysis of the structural equation model using 312 questionnaire. Valid statistical results are presented to provide useful insight.

• 전자공학회논문지A
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• 제28A권11호
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• pp.910-914
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• 1991

This paper describes the improvement of frequency characteristic of crystal oscillator I.C using Ti-Salicide. The characteristics of transistor(drive current) using Ti-Salicide process are better than Poly-Si process, because the mobility. To know frequency characteristic of oscillator I.C, the simulation is performed using inverter buffer chain of Fan-out 10 TTL. Its result shows at once the generation of normal clock pulse in input signal and the improvement of rising and falling time.

• BMB Reports
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• 제41권5호
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• pp.394-399
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• 2008

Multiple sequence alignments of the Bombyx mori fibroin light chain gene (fib-L) from hybrids and from Chinese and Japanese strains demonstrated that 51.6% of the fib-L third intron is conserved. One of these conserved segments, 41 bp long, contains the sequence CGTTATTATACATATT, which is duplicated in the B. mori Nd-$s^D$ mutant. In the present work, electrophoretic mobility assays and computational analyses revealed a major peak of intrinsic bent DNA within the segment that undergoes breakage in the previously-described Nd-$s^D$ mutation. This result suggested that this intrinsically-curved region might mediate DNA cleavage and enhance recombination events in the third intron of the Bombyx mori fib-L gene.

• Elastomers and Composites
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• 제57권1호
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• pp.13-19
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• 2022

Polycarbonate diol-based waterborne polyurethane (WPU) was prepared by prepolymer mixing process. The prepolymer mixture contained the polycarbonate diol, isophorone diisocyanate (IPDI), dimethylol propionic acid, triethylamine, and ethylenediamine (EDA). The NCO/OH ratio in the prepolymer was adjusted by controlling the molar ratio of IPDI, and its effects on the properties of WPU were studied. The structure of WPU was characterized by fourier transform infrared spectroscopy. The average particle size increased and viscosity decreased with increasing NCO/OH ratio and EDA content in WPU. The reduced phase separation between soft and hard segments increased glass transition temperature. The reduction in the thermal decomposition temperature could be attributed to the low bond energy of urethane and urea groups, which constituted the hard segment. Additionally, the polyurethane chain mobility was restricted, elongation decreased, and tensile strength increased. The hydrogen bond between the hard segments formed a dense structure that hindered water absorption.

• The Korean Journal of Physiology and Pharmacology
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• 제8권2호
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• pp.83-88
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• 2004

The purpose of this study was to provide a basis for studying the molecular mechanism of pharmacological action of chlorhexidine digluconate. Large unilamellar vesicles (OPGTL) were prepared with total lipids extracted from cultured Porphyromonas gingivalis outer membranes (OPG). The anthroyloxy probes were located at a graded series of depths inside a membrane, depending on its substitution position (n) in the aliphatic chain. Fluorescence polarization of n-(9-anthroyloxy)stearic acid was used to examine effects of chlorhexidine digluconate on differential rotational mobility, while changing the probes' substitution position (n) in the membrane phospholipids aliphatic chain. Magnitude of the rotational mobility of the intact six membrane components differed depending on the substitution position in the descending order of 16-(9-anthroyloxy)palmitic acid (16-AP), 12, 9, 6, 3 and 2-(9-anthroyloxy)stearic acid (12-AS, 9-AS, 6-AS, 3-AS and 2-AS). Chlorhexidine digluconate increased in a dose-dependent manner the rate of rotational mobility of hydrocarbon interior of the OPGTL prepared with total lipids extracted from cultured OPG, but decreased the mobility of membrane interface of the OPGTL. Disordering or ordering effects of chlorhexidine digluconate on membrane lipids may be responsible for some, but not all of its bacteriostatic and bactericidal actions.

• 한국통신학회논문지
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• 제29권10A호
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• pp.1131-1138
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• 2004

IP 기반의 이동 통신망에서는 사용자들에게 연속적인 이동성을 제공하기 위해서 여러 이동성 에이젼트가 사용된다. 대규모 모바일 IP 시스템의 경우 이러한 에이젼트의 확장성과 규모성이 중요한 문제가 될 수 있다. 모바일 Ipv6에서의 시그널링 부하와 핸드오프 지연 시간을 줄이기 위해서 제안된 계층적 모바일 Ipv6에서는 MAP이라고 하는 지역 홈 에이젼트를 사용하여 위치 등록을 지역적으로 처리 가능하도록 한다. 하지만 한 지역 내에서의 움직임이 많은 경우 이러한 MAP이 성능상의 병목 지점이 될 수 있다. 이는 MAP이 시그널링 트래픽 뿐만이 아니라 이동 단말기에게 전달되는 데이터 트래픽에 대한 터널링 기능도 담당하기 때문이다. 따라서 보다 안정적인 서비스를 위해서는 이러한 MAP에서 서비스 받는 단말기의 수를 제한할 필요가 있다. 본 논문에서는 기존의 무선망 자원 할당에서 사용되던 수락 제어 기법과 SMR (Session-to-Mobility Ratio)에 기반한 교체 기법을 이용하여 MAP의 부하를 효과적으로 제어할 수 있는 적응형 부하 제어 기법을 제안한다. 성능 분석을 위해서 제안한 기법을 마르코브 체인을 통해 모델링하여 핸드오프 이동 단말기 봉쇄 확률과 새 이동 단말기 봉쇄 확률을 분석하였다. 그 결과 제안한 기법은 두 봉쇄 확률을 아주 낮은 수준으로 낮출 수 있다는 것을 알 수 있었다.