• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.12 no.6
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• pp.865-870
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• 2001

In this paper, we analyse the effect of phase noise from PLL frequency synthesizer on 64 QAM when detecting corrupted signals. To predict the phase noise of an oscillator very accurately, we assume that the oscillator is linearly time-varying when the input impulsive current to the oscillator is small. The performance of the detector which detects the corrupted signal by oscillator phase noise is compared with that when the detector is only affected by AWGN and then analyse how much the phase noise degrades the system performance for 64 QAM.

• Journal of Institute of Control, Robotics and Systems
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• v.5 no.5
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• pp.521-528
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• 1999

The nth-order, scalar, linear time-varying (LTV) systems can be dealt with operators on a differential ring. Using this differential algebraic structure and a classical result on differential operator factorizaitons developed by Floquet, a novel eigenstructure(eigenvalues, eigenvectors) concepts for linear time0varying systems are proposed. In this paper, Necessary and sufficient conditions for the existence of well-defined(free of finite-time singularities) SD- and PD- spectra for SPDOs with complex- and real-valued coefficients are also presented. Three numerical examples are presented to illustrate the proposed concepts.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2000.05a
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• pp.217-221
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• 2000

In this paper, we analyze the effect of phase noise from PLL frequency synthesizer on 64QAM when detecting the corrupted signals. To predict the phase noise of oscillator very accurately, we considered that oscillator has the linearly time-varying nature when the input impulsive torrent to oscillator is small. The performance which detects the corrupted signal by oscillator phase noise is compared with only affected by AWCN and then analyze how much it degrade system performance for 64QAM.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.27.3-27
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• 2001

In this paper, a robust receding horizon controller for uncertain linear time-varying systems is presented in the dynamic output-feedback form. The existing output-feedback receding horizon controller in the literature is composed of a state observer and a static controller associated with the observer states (similar to LQC control), where the fundamental assumption is that the state observer will supply the exact states as time goes up. The performance of those controllers may be much degraded and even the closed-loop stability may not be guaranteed when the system suffers from disturbances and uncertainties or is time-varying. The proposed controller, which is not necessary to have the state-observer, overcomes such difficulties. Using matrix inequality conditions on the terminal weighting matrix, the closed-loop system stability is guaranteed. Numerical examples are ...

• Proceedings of the KIEE Conference
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• 2002.11c
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• pp.54-57
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• 2002

In this paper model reference adaptive control (MRAC) of linear time-varying(LTV) systems is considered. MRAC for a linear time invariant(LTI) system does not assure the boundedness of the output and parameter estimation errors in the presence of time variations of the parameters. However, changing the adaptive laws such as use of $\sigma$-modification can result in the boundedness of the output and parameter estimation errors[5]. Together with the $\sigma$-modification in the adaptive law, we also modify the control law by adding an additional term to the standard control law. The additional term leads to smaller bounds of the output and parameter estimation errors when compared to the case where only the standard control law is applied.

• Proceedings of the KIEE Conference
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• 2007.10a
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• pp.219-220
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• 2007

Image plane상에서의 목표의 크기, 시선각 (Line-of-Sight angle) 및 관측자의 상태 정보 등을 이용하여 목표의 상태를 추정한다. 표적 모델을 Linear Time Varying(LTV) system처럼 다룰 수 있음을 밝히고, 이를 이용하여 가관측성(observability)이 성립하는 조건을 구하고 Kalman filter를 이용하여 비선형 추정기를 설계한다. 그리고 등가속도 표적 추정, 미사일의 정지 표적 공격 등의 모의실험에 적용해 본다.

• Proceedings of the Safety Management and Science Conference
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• 2007.04a
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• pp.21-26
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• 2007

Kaplan & Norton introduce the BSC in early 1990s. after introducing the Balanced scorecard, The Balanced scorecard has been evolved in various function. In the various functional Balanced scorecard, this paper focuses on the logistics BSC, and the decision the weights of Key Performance Indicators. In this paper, a combination of Balanced scorecard and AHP-LTV based approach proposed multi-criteria provides a more accurate representation of the problem for measuring company.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.11a
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• pp.182-183
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• 2019

The amount of multi-aged housing more than 15 years since the completion has increased, and the real estate market caused by apartment remodeling has also increased. The domestic mortgage loan regulation on relocation expense caused by remodeling apply to same limit as that for mortgage loan newly-built apartment. The excessive government housing regulation could be an obstacle for the occupants residential stability of remodeling apartment. To suggest methods for government housing regulation of residential mortgage loan related to remodeling, examples for mortgage loan regulation and mortgage products were studied and compared. It is pointed out that regulation on occupants relocation expense caused by remodeling has to be relaxed and mortgage product development are needed to boost remodeling project.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.10
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• pp.401-409
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• 2018

This paper presents means of reducing noise in NSD using path control methods for Light Tactical Vehicles (LTV). NSD is applied to the rear axle of LTVs for enhancing mobility. NSD can improve mobility of vehicles with a high locking ratio but causes noise under certain conditions due to its mechanical structure. This noise results from contact between gears due to the differential role of NSD. The noise affects users, so users have continually requested noise reductions. Though the noise doesn't affect product performance and durability, and satisfies the National Defense's noise condition standards, users request for noise reduction is the focus of this research. Eliminating the source of sound for LTVs is realistically limited, so this research applies a path control method to reduce noise by controlling the path which transmits the noise. This study improves the structural delivery system and examines methods of reducing noise in LTV systems.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.9
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• pp.4514-4523
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• 2013

Currently the number of unsold housing is rapid increasing over again in the Seoul Metropolitan area. So this research analyzed effective and possible solutions focus on the potential customers and professionals. There was a research method setting up alternative solutions from the existing researches and the other suggestions though FGI (Focus Group Interview) by professionals. And then it investigated the efficient ways to resolve those problems through Conjoint Analysis. According to the result of this paper, firstly the customers considered 'financial supports', 'self-rescue efforts for construction companies' and 'taxation support' than the other. On the other hand, professionals evaluated 'publicly purchased housing' and 'new housing policies' were more essential solutions besides, both of them recognized the importance of ;financial support'. Secondly there were some ideas that it was necessary to more less control LTV (Loan to Value ratio) and DIT ( Debt to Income) and the LH (Korea Land and Housing Corporation) buy unsold housing. Finally the government and housing association had to manage and intervene the supply of housing within metropolitan area and restrict to building new properties and the construction companies actively provide less strict standard terms and conditions in contract for purchasing housing for instance, the decline of housing sale price or interest-free and so on.