• Title/Summary/Keyword: Reduced

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Generalized singular perturbation approximation preserving positive real property of discrete system (이산시스템의 positive real 특성을 유지하는 일반화된 특이 섭동 근사화)

  • 오도창;김재권;방경호;박홍배
    • Journal of the Korean Institute of Telematics and Electronics S
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    • v.34S no.9
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    • pp.50-59
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    • 1997
  • This paper is on the generalized singular perturbation approximation (GSPA) preserving the discrete positive real property. We transform the discrete positive real(PR) system into a stochastically banlanced system and get the reduced order discrete system from the GSPA of the full order stochastically balanced system. eSPECIALLY, WHEN THE FREE PARAMETER OF THE gspa IS .+-.1, we show that the reduced order discrete system retains stability, minimality, and positive real and stochstically balancing properties. And we derived the .inf.-norm error bound with the reduced order discrete strictly positive real(SPR) system by the proposed method. Finally, we give an example to ascertain the properties of the proposed reduced order discrete system and to compare with the conventional methods.

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Reduced-State MLSD Based on Volterra Kernels for Square-Law Detected Multipath Channels

  • Ha, Young-Sun;Chung, Won-Zoo
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.5 no.12
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    • pp.2315-2325
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    • 2011
  • We propose a novel reduced-state maximum-likelihood sequence detection (MLSD) structure using the Viterbi algorithm based on the second-order Volterra kernel modeling nonlinear distortion due to square law detection of multipath channels commonly occurring in chromatic dispersion (CD) or polarization mode dispersion (PMD) in optical communication systems. While all existing MLSD methods for square-law detection receivers are based on direct computation of branch metrics, the proposed algorithm provides an efficient and structured way to implement reduced-state MLSD with almost the same complexity of a MLSD for linear channels. As a result, the proposed algorithm reduces the number of parameters to be estimated and the complexity of computation.

Properties of Reduced Polyacrylonitrile Nano Fiber (I) (폴리아크릴로니트릴 나노섬유의 환원 및 특성 (I))

  • Choi Chang-Nam;Park Won-Kyu;Lee Woong-Eui
    • Textile Coloration and Finishing
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    • v.18 no.2 s.87
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    • pp.1-7
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    • 2006
  • In order to prepare PAN nano fiber web, PAN/DMF solution was prepared and electrospun. The diameter of fiber was depended on the polymer concentration (7.5-15wt%) and the applied voltage (10-16kV). The average diameter of fiber increased with an increase of the polymer concentration and decreased with the applied voltage. At 7.5wt% concentration, many beads were found. So, we prepared a nano PAN fiber by electrospinning at concentration of 10wt% and 16kV. PAN fibers were reduced with litium aluminium hydride and the dyeability to acid dye was checked. The reduced nano PAN fiber showed much better dyeability compared with the reduced ordinary PAN fiber. It was considered that the increase of specific surface area have an important role in dyeing with acid dye.

A Study on the Allergenicity of Milk Protein (우유 단백질의 Allergenicity에 관한 연구)

  • 정은자
    • The Korean Journal of Food And Nutrition
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    • v.8 no.2
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    • pp.79-87
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    • 1995
  • It is generally known that the protein of talk has allergenicity and the allerenicity Induces allergic diseases. Finding methods to reduce the allergenicity of the food and develop methods to make low allergic food is the purpose of this study. For this study, 1 tried various experimental methods : heat treatment, irradation with ultraviolet and microwaves treatment with polyphosphate, enzyme hydrolysis and PCA inhibition test using guinea pigs and degrees of hydrolysis. The results obtained are as follows. Heat treatment reduced allergenicity of milk protein. The higher the heat, the better the effect. Irradiating with ultraviolet and microwave increased both the degree of protein hydrolysis and PCA inhibition reduced the allergenicity. Ultraviolet was more effective than microwaves on milk protein. Enzyme treatment increased the degree of hydrolysis and PCA inhibition, and reduced allergenicity considerably. Neutrase was more effective than alcalase on milk protein. Adding Polyphosphate did not induced protein hydrolysis, but increased PCA inhibition and reduced allergenicity.

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Study on the efficient dynamic system condensation (동적 해석의 효율적 축소 기법에 관한 연구)

  • Baek, Sung-Min;Cho, Meang-Hyo
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2007.04a
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    • pp.631-636
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    • 2007
  • Eigenvalue reduction schemes approximate the lower eigenmodes that represent the global behavior of the structures. In the, we proposed a two-level condensation scheme(TLCS) for the construction of a reduced system. In first step, the of candidate elements by energy estimation, Rayleigh quotient, through Ritz vector calculation, and next, the primary degrees of freedom is selected by sequential elimination from the degrees of freedom connected the candidate elements in the first step. In the present study, we propose TLCS combined with iterative improved reduced system(IIRS) to increase accuracy of higher modes intermediate range. Also, it possible to control the accuracy of the eigenvalues and eigenmodes of the reduced system. Numerical examples demonstrate performance of proposed method.

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A Low Power SDRAM Output Buffer with Minimized Power Line Noise and Feedthrough Current (최소화된 Power line noise와 Feedthrough current를 갖는 저 전력 SDRAM Output Buffer)

  • Ryu, Jae-Hui
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.39 no.8
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    • pp.42-45
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    • 2002
  • A low power SDRAM output buffer with reduced power line noise and feedthrough current is presented. In multi I/O SDRAM output buffer, feedthrough current as well as the corresponding power dissipation are reduced utilizing proposed undershoot protection circuits. Ground bounce is minimized by the pull down driver using intelligent feedback scheme. Ground bounce noise is reduced by 66.3% and instantaneous and average power are reduced by 27.5% and 11.4%, respectively.

Size and Harmonic Reduced Wilkinson Balun Using Parallel Coupled Line with Open Stub

  • Lee, Won-Kyun;Hwang, Hee-Yong
    • Journal of electromagnetic engineering and science
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    • v.14 no.4
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    • pp.387-392
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    • 2014
  • In this paper, a size-reduced Wilkinson balun with wide harmonic-suppressed band is presented. An accurate analysis of the parallel coupled line with an open stub (PCL-OS) is carried out. The PCL-OS structure shows excellent low pass filter and harmonic-suppression characteristics, which is useful for designing a low pass filter unit cell (LUC) with a reduced size. The designed Wilkinson balun at a 2.45 GHz center frequency not only shows an excellent harmonic suppression including the 5th harmonics up to 14 GHz over 15 dB, but it also has an area reduced to 48% of the conventional one.

Simple Design of Sand Drains Considering Smear Effect (교란효과를 고려한 샌드 드레인의 약식설계)

  • 유영삼;정충기
    • Geotechnical Engineering
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    • v.10 no.3
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    • pp.33-40
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    • 1994
  • The effects of smear and well resistance should be taken into account for the design of sand drains. Practically, simple design, which employs the method using 112 reduced diameter of drains or assuming the coefficient of consolidation in horizontal direction equals to that in vertical direction, based on the theory neglecting these effects, has been used. In this study, the reliability of existing simple design methods as well as the influences of smear and well resistance was investigated with the equations proposed by Hansbo and Onoue. It is shown that the consolidation time is chiefly governed by the effect of smear for drains with highly permeable sands. For general soil condition and placing type of sand drain, consolidation time is underestimated for simple design wi어. 1/2 reduced diameter of drains, and it is overestimated for that with the assumption that the coefficient of consolidation in horizontal direction equals to that in vertical direction. Through the investigations on different reduced diameter, it was shown that simple design with 1/4 reduced diameter of drains yielded the reliable results with errors less than 6%.

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A novel ZVS interleaved totem-pole PFC converter with reduced circulating current and diode reverse recovery current (순환전류와 다이오드 역회복 전류가 작은 인터리빙 방식의 새로운 ZVS 토템폴 PFC 컨버터)

  • ;Choe, U-Jin
    • Proceedings of the KIPE Conference
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    • 2018.07a
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    • pp.189-191
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    • 2018
  • This paper introduces a novel ZVS interleaved totem-pole PFC with the reduced circulating current and the reverse recovery current of the diodes. With the help of a simple auxiliary inductor, both ZVS turn-on of the main switches and soft turn-off of the body diodes can be achieved. In the proposed totem-pole PFC topology since the switching losses and the reverse recovery losses can be significantly reduced, the typical Si MOSFETs can be employed. In addition the circulating current is reduced by adjusting the switching frequency. The proposed PFC topology can be a low cost solution to achieve high efficiency in high power PFC applications. The validity and the feasibility of the proposed topology is verified by the experimental results with a 3.3kW interleaved totem-pole PFC converter.

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A Reduced Equivalent 5 conductors Modeling of the Catenary System (전차선로 시스템의 5 도체 등가 축약 모델링)

  • 이한민;오광해;이장무;창상훈;장길수;권세혁
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.52 no.12
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    • pp.684-690
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    • 2003
  • This paper estimates line constants of equivalent five-conductors model using the reduced equivalent method. Actually, the catenary system is considered by the equivalent five-conductors model in the electrical aspect. Therefore, we should compose the catenary system of the equivalent five-conductors model, then the line constants of this equivalent five-conductors model are calculated. This paper shows the reducing process about the real system of the field by using the proposed theory. Also the line constants of reduced system are provided in this paper.