• 대한수학회보
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• 제43권2호
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• pp.443-459
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• 2006

The prey-predator system with a single cross-diffusion pressure is known to possess a local solution with the maximal existence time $T\;{\leq}\;{\infty}$. By obtaining the bounds of $W\array_2^1$-norms of the local solution independent of T we establish the global existence of the solution. And the long-time behaviors of the global solution are analyzed when the diffusion rates $d_1\;and\;d_2$ are sufficiently large.

• 대한수학회논문집
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• 제29권4호
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• pp.505-518
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• 2014

Considered here is the first initial boundary value problem for the two-dimensional g-Navier-Stokes equations in bounded domains. We first study the long-time behavior of strong solutions to the problem in term of the existence of a global attractor and global stability of a unique stationary solution. Then we study the long-time finite dimensional approximation of the strong solutions.

• 제어로봇시스템학회논문지
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• 제13권3호
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• pp.187-191
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• 2007

We analyze the stability property of a class of nonlinear time-delay systems. We show that the state variable is bounded both below and above, and the lower and upper bounds of the state are obtained in terms of a system parameter by using the comparison lemma. We establish a time-delay independent sufficient condition for the global asymptotic stability by employing a Lyapunov-Krasovskii functional obtained from a change of the state variable. The simulation results illustrate the validity of the sufficient condition for the global asymptotic stability.

• 제어로봇시스템학회논문지
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• 제14권6호
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• pp.554-557
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• 2008

We analyze the stability property of a class of nonlinear time-delay systems with time-varying delays. We present a time-delay independent sufficient condition for the global asymptotic stability. In order to prove the sufficient condition, we exploit the inherent property of the considered systems instead of applying the Krasovskii or Razumikhin stability theory that may cause the mathematical difficulty of analysis. We prove the sufficient condition by constructing two sequences that represent the lower and upper bound variations of system state in time, and showing the two sequences converge to an identical point, which is the equilibrium point of the system. The simulation results illustrate the validity of the sufficient condition for the global asymptotic stability.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume II
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• pp.993-996
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• 2006

NOAA operational bulk SST product (Reynolds et al, 2002) is very popular global SST data sets and is extensively used for various studies. However, the original time resolution is weekly and relatively large. On the other hand, there exist many new global SST data sets at present. In this study, we compare many global SST data sets including NOAA operational bulk SST product, CAOS OI SST product, Microwave Optimum Interpolation (MWOI) SST, Real Time Global (RTG) SST and JMA merged satellite and in situ Global Daily (MGD) SST.

• Journal of electromagnetic engineering and science
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• 제8권2호
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• pp.84-89
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• 2008

In a wireless channel above microwave frequency, rain attenuation is very important. In order to predict rain attenuation, 1-min. rain rate distribution is required. This paper discusses appropriate conversion methods to estimate 1-minute rain rate from that of other integration time. Based on the measurement data filed in ITU-R WP3J including ETRI data for 6 consecutive years, distributions of rain rate with 1-, 5-, 10-, 20-, 30-minute integration time were analyzed, both on the global and regional basis, and the parametric relationship between the statistical characteristics of 1-minute and other measurement data were investigated to deduce the conversion methods. It is shown that the global model works good with good accuracy for 5-, 10-, 20-min integration time, and the global model is also applicable globally with good accuracy for 5-, 10-, 20-min integration time. The global conversion model was adopted last year as an ITU-R document for new recommendation. The regional conversion model would also be very useful for locations of similar climatic zone.

• 통상정보연구
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• 제8권1호
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• pp.325-336
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• 2006

This paper examines the global supply chain management strategy and business performance of Doolee Vision Co. Ltd.. Based on the analysis of eighty-seven cases, the following results were found. First, it was found that just-in-time of GSCM strategy of firm have a positive influences on the business performance in transformation sector. Second, just-in-time of GSCM strategy of firm have a positive influences on the business performance in custody sector. Third, just-in-time of GSCM strategy of firm have a positive influences on the business performance in order response and support sector. Forth, just-in-time of GSCM strategy of firm have a positive influences on the business performance in customs sector. Fifth, just-in-time of GSCM strategy of firm have a positive influences on the business performance in customer service sector. However, several limitations, such as measurement for intra-industry homogeneity, measurement for flexibility of global supply chain management strategy, and measurement for business performance of global supply chain management, that make the preceding conclusions be considered preliminary.

• 동국한의학연구소논문집
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• 제7권2호
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• pp.149-154
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• 1999

생쥐의 전뇌허혈(全腦虛血) 모델에서 potassium cyanide 유발(誘發) 혼수시간(昏睡時間) 및 생존시간(生存時間), 감압성(減壓性) 무효소(無酵素) 부하시(負荷時) 생존시간(生存時間)을 측정(測定)하여 전뇌처혈시(全腦處血時) 뇌순환대사(腦循環代謝) 개선(改善) 효과(效果)를 관찰(觀察)하였다. KCN 유발(誘發) 혼수시간(昏睡時間)의 단축(短縮), 치사양(致死量)의 KCN에 대한 생존시간(生存時間)의 연장(延長), 감압(減壓)에 의한 무산소(無酸素) 부하시(負荷時) 생존시간(生存時間)의 연장(延長) 효과(效果)가 나타났다.

• Journal of Information Display
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• 제10권4호
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• pp.188-194
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• 2009

Conventional stereoscopic (3D) displays using binocular parallax generate unnatural conflicts between convergence and accommodation. These conflicts can affect the observer's ability to fuse binocular images and may cause visual fatigue. In this study, time series changes in visual fatigue and depth sensation when viewing stereoscopic images with changing parallax were examined. In particular, the physiological changes, including the subjective symptoms of visual fatigue, when viewing five parallax conditions, were examined. Then a comparative analysis of the 2D and 3D conditions was performed based on the visual function. To obtain data regarding the visual function, the time series changes in the spontaneous-blinking rate before and during the viewing of 3D images were measured. The time series change results suggest that 2D and 3D images cause significantly different types of visual fatigue over the range of binocular disparity.

• 대한수학회지
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• 제48권2호
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• pp.223-240
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• 2011

In this paper, the problem on periodic solutions of the bidirectional associative memory neural networks with both periodic coefficients and periodic time-varying delays is discussed. By using degree theory, inequality technique and Lyapunov functional, we establish the existence, uniqueness, and global asymptotic stability of a periodic solution. The obtained results of stability are less restrictive than previously known criteria, and the hypotheses for the boundedness and monotonicity on the activation functions are removed.