• 한국통신학회논문지
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• 제36권6C호
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• pp.384-390
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• 2011

The paper derives formulas for the mean-squared error distortion and resulting signal-to-noise (SNR) ratio of a fixed-rate scalar quantizer designed optimally in the minimum mean-squared error sense for a Gaussian density with the standard deviation ${\sigma}_q$ when it is mismatched to a Laplacian density with the standard deviation ${\sigma}_q$. The SNR formulas, based on the key parameter and Bennett's integral, are found accurate for a wide range of $p\({\equiv}\frac{\sigma_p}{\sigma_q}\){\geqq}0.25$. Also an upper bound to the SNR is derived, which becomes tighter with increasing rate R and indicates that the SNR behaves asymptotically as $\frac{20\sqrt{3{\ln}2}}{{\rho}{\ln}10}\;{\sqrt{R}}$ dB.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제14권3호
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• pp.171-180
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• 2014

In this paper, a multiple sliding surface (MSS) controller for a twin rotor multi-input-multioutput system (TRMS) with mismatched model uncertainties is proposed. The nonlinear terms in the model are regarded as model uncertainties, which do not satisfy the standard matching condition, and an MSS control technique is adopted to overcome them. In order to control the position of the TRMS, the system dynamics are pseudo-decomposed into horizontal and vertical subsystems, and two MSSs are separately designed for each subsystem. The stability of the TRMS with the proposed controller is guaranteed by the Lyapunov stability theory. Some simulation results are given to verify the proposed scheme, and the real time performances of the TRMS with the MSS controller show the effectiveness of the proposed controller.

• 한국통신학회논문지
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• 제21권7호
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• pp.1803-1813
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• 1996

This paper describes an automatic threshold decision using a maximum mismatched correlation value in the direct sequence spread spectrum (DS-SS) system. For received PN codes with different single-to-noise ratio (SNR), this scheme is able to detect a desired threshold value in the search mode, i.e. a maximum mismstched correlation value, so that value is utilized as a threshold for the verification mode. Performance of the proposed scheme in both the additive white gaussian noise (AWGN) and frequency-selective Rayleigh fading channels is analyzed through the Monte Carlo simulation. And hardware implementation of this scheme using a DSP processor is demonstrated. The proposed acquisition shceme is compared to the conventional constant threshold (CT) scheme, and significant improvement of performance is shown. Analysis of system performance in the verification mode is presented, and key quantities such as the false alarm probability and the detection probability are derived in a AWGN channel.

• 제어로봇시스템학회논문지
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• 제12권6호
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• pp.524-529
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• 2006

In this paper, we propose a method to design variable structure systems with sliding sector for multi-input multi-output systems with mismatched uncertainties in the state matrix. For the uncertain systems we define sliding sectors within which a norm of the state decreases with zero input despite of mismatched uncertainties. Using the notion of the sliding sector we give simple design algorithms of variable structure control laws that can reduce the chattering. Finally, we give a design example in order to show the effectiveness of our method.

• Journal of Power Electronics
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• 제19권6호
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• pp.1575-1581
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• 2019

Due to the mismatched line impedance among distributed generation units (DGs) and uncontrolled harmonic current, the droop controller has a number of problems such as inaccurate reactive power sharing and voltage distortion at the point of common coupling (PCC). To solve these problems, this paper proposes a resistive-capacitive virtual impedance control method. The proposed control method modifies the DG output impedance at the fundamental and harmonic frequencies to compensate the mismatched line impedance among DGs and to regulate the harmonic current. Finally, reactive power sharing is accurately achieved, and the PCC voltage distortion is compensated. In addition, adaptively controlling the virtual impedance guarantees compensation performance in spite of load changes. The effectiveness of the proposed control method was verified by experimental results.

• Journal of Chest Surgery
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• 제57권2호
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• pp.217-219
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• 2024

Matching for the rhesus (Rh) blood group is currently not taken into account in the organ allocation system. However, in Rh-mismatched transplantation, the primary concern is the potential for RhD-negative recipients to develop sensitization and produce anti-D antibodies if they receive a transfusion of RhD-positive blood. It is estimated that over 80% of RhD-negative recipients may experience Rh allosensitization when exposed to RhD-positive blood, although this occurrence is less common in recipients of solid organs. In theory, RhD-negative recipients who receive organs from RhD-positive donors are at risk of alloimmunization and the production of anti-D antibodies, which could complicate future blood product transfusions. However, our understanding of the impact of donor-recipient Rh mismatch on transplant outcomes, particularly in heart transplantation, is limited. We report a case of successful Rh-mismatched heart transplantation, which was effectively managed through the use of preoperative RhD immunoglobulin and plasmapheresis.

• 한국정보통신학회논문지
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• 제21권6호
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• pp.1203-1211
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• 2017

본 논문은 유연관절로봇의 추종성능과 정합과 비정합 외란 모두에 대한 강인성을 향상시키기 위한 강인한 제어기를 제안한다. 제안된 제어기는 백스테핑 외란관측기(DOB), 수동성기반 제어기(PBC)와 적분슬라이딩모드 제어기(ISMC)가 백스테핑기법 형태로 구성되어 있다. 백스테핑 DOB는 링크측의 비정합 외란을 고려하는데 사용되며 모터측의 기준입력을 제공하는 역할을 한다. IDA-PBC는 모터측의 추종제어를 수행하며 적분슬라이딩모드제어와 결합될 때 공칭제어기의 역할을 하며 전체 공칭제어시스템의 안정도를 보장받도록 한다. 반면에 적분슬라이딩모드제어는 정합조건을 만족시키는 모터측의 외란의 영향을 제거하는데 사용된다. 링크측의 제어기를 설계하는데 있어서는 PD타입의 임피던스제어기와 DOB가 결합됨으로써 강인한 제어특성과 함께 모터측의 기준입력에 적합한 연속적인 입력의 제공이 가능하도록 하였다.

• Childhood Kidney Diseases
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• 제6권1호
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• pp.120-122
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• 2002

IgA신병증으로 말기 신부전에 도달한 B형 혈액형의 9세 남아가 O형 혈액형의 아버지로부터 신이식을 시행받았다. 환아는 16개월 간 복막 투석 중이었으며 이전에 수혈받은 병력은 없었다. 이식 9일째 혈관내 용혈이 발견되었으며 항 B 항체 형성이 확인되었다. 저자들은 공여자의 신장과 함께 이동한 림프구가 일으킨 자가 면역 용혈성 빈혈로 진단하고 사이클로스포린 투여를 중단하였다. 용혈성 빈혈은 회복되었으나 이식 18일째 이식 신 기능 저하가 발견되어 이식 신생검을 시행하여 급성 거부를 확인하고 스테로이드 충격 요법을 시행하였다. 저자들은 ABO 부적합 신이식 후 발생한 용혈성 빈혈 1례를 겅험하여 보고하는 바이다.

• Archives of Reconstructive Microsurgery
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• 제18권1호
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• pp.9-15
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• 2009

Whether a seven days course of anti-${\alpha}{\beta}$-T cell receptor-antibody (${\alpha}{\beta}$-TCRmAb) combined with FK506 therapy promotes survival of limb allografts in fully MHC-mismatched combination (Brown Norway $\rightarrow$ Lewis) was examined. Eight animals received 250 ${\mu}g$/kg/day of ${\alpha}{\beta}$-TCRmAb for 7 days and 2 mg/kg/day of FK506 postoperatively (Combination therapy group). Eight animals had FK506 only (Mono-therapy group) and five animals did not have treatment (Control group). Clinical signs of early rejection with edema or erythema in the skin occurred at an average of 8.6${\pm}$1.5 days postoperatively in Control group and 59.0${\pm}$8.3 days in Mono-therapy group, both of which proceeded to irreversible rejection with necrosis of the epidermis and finally mummification. In Combination therapy group, all animals showed evidence of early rejection at an average of 56.8${\pm}$12.6 days postoperatively, however, in 4 of 8 limbs, early rejection resolved without any treatment and limbs survived >1 year. At 9 months postoperatively, donor skin grafts were accepted and third-party skin grafts were rejected by all four survivors, demonstrating donor-specific tolerance. Little or no detectable chimerism was observed in any of the 4 surviving animals at one-year postoperatively. Combination therapy of ${\alpha}{\beta}$-TCRmAb and FK506 resulted in long-term survival in fully MHC-mismatched limb transplants.

• 대한조선학회 특별논문집
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• 대한조선학회 2011년도 특별논문집
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• pp.32-35
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• 2011

Template has been widely used for hull forming process in most of shipyards. It is used to estimate the curvature of deformed shape in comparison with design shape. SHI (Samsung Heavy Industry) had used AutoKon system for ship manufacturing design in the past. The AutoKon used the global coordinate system of ship (frame, water line and so on) to create template data. It brought the mismatched angles between templates and a curved shell plate. The mismatched angle is measured by forming worker to place template on shell forming stage. However, the mismatched angle is difficult to place template with exactly required angle because the shell plates have various curvature and size. It causes incorrect shape of formed shell plates. The attached angle of template should be 90 degree to place template easily on forming shell plates. Currently, SHI has been applied GSCAD for ship manufacturing design process which is 3D solid modeling system. The GSCAD is the rule-based system which can automate 3D modeling and control the manufacturing data by rule. The rule can easily provide methods to create and automate template object with regular attached angle in comparison with AutoKon system. Therefore, SHI developed new template rule which it can automatically create template object with regular attached angle in GSCAD.