• 제목/요약/키워드: SOF

검색결과 177건 처리시간 0.022초

상수 출력궤환 선형 시스템의 안정화 및 $H_\infty$ 제어기 설계 (Stabilization and $H_\infty$ control of linear systems with static output feedback)

  • 김형진;김명순;김진훈
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 A
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    • pp.111-114
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    • 2003
  • In this paper, we consider the stabilization and $H_\infty$ control of linear systems with static output feedback control. The static output feedback control represents the simplest closed-loop control that can be realized in practice, and, moreover, it is less expensive to be implemented and is more reliable. In spite of its advantages, it is one of the open problems which is not sloved analytically or numerically yet. After decompose the closed-loop system into feedback form, by adopting the small gain theorem, we obtain a sufficient condition for stabilization and a sufficient condition for It control expressed as linear matrix inequalites. Finally, we show the usefulness of our results by a numerical example.

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The Effect of Biodiesel and Ultra Low Sulfur Diesel Fuels on Emissions in 11,000 cc Heavy-Duty Diesel Engine

  • Baik, Doo-Sung;Han, Young-Chool
    • Journal of Mechanical Science and Technology
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    • 제19권3호
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    • pp.870-876
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    • 2005
  • It seems very difficult to comply with upcoming stringent emission standards in vehicles. To develop low emission engines, better quality of automotive fuels must be achieved. Since sulfur contents in diesel fuels are transformed to sulfate-laden particulate matters as a catalyst is applied, it is necessary to provide low sulfur fuels before any Pt-based oxidation catalysts are applied. In general, flash point, distillation $90\%$ and cetane index are improved but viscosity can be worse in the process of desulfurization of diesel fuel. Excessive reduction of sulfur may cause to degrade viscosity of fuels and engine performance in fuel injection systems. This research focused on the performance of an 11,000 cc diesel engine and emission characteristics by the introduction of ULSD, bio-diesel and a diesel oxidation catalyst, where the bio-diesel was used to improve viscosity of fuels in fuel injection systems as fuel additives or alternative fuels.

소형디젤기관에서 황함유량에 따른 SOx 및 PM저감에 관한 실험적 연구 (An Experimental Study on SOx and PM Reduction by Sulfur Content in Light Duty Diesel Engine)

  • 한영출;오용석
    • 한국대기환경학회지
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    • 제14권4호
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    • pp.387-392
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    • 1998
  • Recently, among after-treatment devices which have high possibility of utility, diesel oxidation catalyst (DOC) is concerned over the world. DOC oxidizes pollutants by means of activate-reaction during by -passing in the catalyst, in doing so, conversion efficiency of PM, CO and HC is high, and this device does not have an effect on engine performance because back pressure is not nearly increased. But, as a small amount of sulfur content in fuel is oxidized, it makes sulfate, which is absorbed on the surface of catalyst. So, in this study, the experiment is carried out by means of using ordinary fuel (0.1wt%) and low sulfur fuel (0.05wt%) with DOC, and the emission gas of diesel engine is measured.

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디젤기관에서 산화촉매장치에 의한 배기가스 저감에 관한 이론적 연구 (A Theoretical Study on Exhaust Gas Reduction by Oxidation Catalyst in Diesel Engine)

  • 한영출;김종춘;김태섭
    • 한국자동차공학회논문집
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    • 제5권4호
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    • pp.179-189
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    • 1997
  • Among aftertreatment devices which reduce exhaust gas of diesel engine, diesel oxidation catalyst(DOC) with high reduction efficiency for gaseous matter and particulate matter is now studied actively. In this study, a transient one-dimensional model developed to simulate the thermal and conversion characteristics of adiabatic monolithic converters operating under warm up conditions is presented. This model takes into account the gas solid heat and mass transfer, axial heat conduction, chemical reactions and the related heat release. The model has been used to analyze the transient response of an axisymmetric catalytic converter during a warm-up as a function of catalyst design parameters and operation conditions in order to observe their effects on the lightoff behaviour. The experimental test was carried out 2400 cc light diesel engine with DOC.

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Perceived Subjective Features of Software Components: Consumer Behavior in a Software Component Market

  • Lee, Jang-Hyuk;Hong, Se-Joon;Sawng, Yeong-Wha;Kim, Ju-Seong
    • ETRI Journal
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    • 제31권3호
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    • pp.304-314
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    • 2009
  • Component-based software reuse has been generally regarded as a promising approach to improving software productivity and quality within software development. However, progress in component-based software reuse has been slower than expected. Much of the software reuse literature points to the lack of software components that can maximize users' benefits as the most important source of the slow progress. Considering that the underlying processes behind component-based software reuse are strikingly similar to commercial software marketing, this paper attempts to identify the aspects of software components that consumers value and to establish relationships between the identified aspects and consumer behavior in the software component market. More specifically, this paper focuses on the perceived subjective features of software components. This study was conducted in a web-based artificial market environment called "SofTrade."

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승차감 향상과 차량 전복 방지를 위한 능동 롤 제어기의 성능 비교 (Comparison among Active Roll Controllers for Rollover Prevention and Ride Comfort Enhancement)

  • 임성진
    • 제어로봇시스템학회논문지
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    • 제20권8호
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    • pp.828-834
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    • 2014
  • This paper presents a comparison among three types of approaches to an ARC (Active Roll Control) with an AARB(Active Anti-Roll Bar) for a vehicle system. Lateral acceleration and road profile are considered as disturbance. The ARC is designed with an LQ SOF (Linear Quadratic Static Output Feedback) control, $H_{\infty}$ control and SMC (Sliding Mode Control). These approaches are compared in terms of rollover prevention and ride comfort. For comparison, Bode plot analysis based on linear model and frequency response analysis based on CarSim simulation are performed.

저전력 소모와 테스트 용이성을 고려한 회로 설계 (A study on low power and design-for-testability technique of digital IC)

  • 이종원;손윤식;정정화;임인칠
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 1998년도 하계종합학술대회논문집
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    • pp.875-878
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    • 1998
  • In this thesis, we present efficient techniques to reduce the switching activity in a CMOS combinational logic network based on local logic transforms. But this techniques is not appropriate in the view of testability because of deteriorating the random pattern testability of a circuit. This thesis proposes a circuit design method having two operation modes. For the sake of power dissipation(normal operation mode), a gate output switches as rarely as possible, implying highly skewed signal probabilities for 1 or 0. On the other hand, at test mode, signals have probabilities of being 1 or 0 approaching 0.5, so it is possible to exact both stuck-at faults on the wire. Therefore, the goals of synthesis for low power and random pattern testability are achieved. The hardware overhead sof proposed design method are only one primary input for mode selection and AND/OR gate for each redundant connection.

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광 솔리톤 전송 시스템에 있어서 최대치 추적에 의한 상호 작용력 분석 (Interaction force analysis by peak value tracking in optical soliton transmission system)

  • 변승우;송재원
    • 전자공학회논문지A
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    • 제33A권7호
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    • pp.15-22
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    • 1996
  • In the soliton transmission system for a long-length and high bit rate data transmission systme using the nonlinear/dispersive optical fibers, the improtant problem is the loss characteristics and is the limited transmission rate by interaction forces. In this paper, It is explained the reasons of moved time position for the soliton peak value due to interaction force sof adjacent solitons. And for the analysis of interaction force affection level in the losslessmedia, we define the percent parameter of error rate due to the interaction forces and propose the optimum time distance of adjacent solitons by peak value tracking methods. With the results, initial percent of error is approximately 50% when itme difference between adjacent solitons is 5 times of funddametnal soliton pulse width. And it is confirmed that maximum transmission length of th esolitons is approximately 38 times of fundamental soliton period, which the maximum allowable percoent of error is 50%.

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굴곡 및 굴절형 터널 내의 전파 전파의 전송 효율에 관한 연구 (A study on the transmission efficiency of electromagnetic wave propagation in tunnels with bend and fold)

  • 김기래;한경구
    • 전자공학회논문지A
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    • 제33A권12호
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    • pp.25-32
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    • 1996
  • This paper is concenred with a finite volume time domain (FVTD) method for the analyses of transmission efficiency of electromagnetic wave propagation in tunnels with bend and fold. This method is gased on the volume integratio sof the maxwell's equation with respected to arbitrary shaped small polyhedron cells. The advantages of the present mehtod are that the algorithm is very simple since the coordinate system is restricted only to the cartesian, and so the arbitrary shaped boundaries can easily be dealt with since the fields at every center point of the cells are assigned in an average fashion.

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Characteristics of Radiation-Resistant Real-Time Neutron Monitor for Accelerator-Based BNCT

  • Nakamura, Takemi;Sakasai, Kaoru;Nakashima, Hiroshi;Takamiya, Koichi;Kumada, Hiroaki
    • Journal of Radiation Protection and Research
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    • 제41권2호
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    • pp.105-109
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    • 2016
  • Background: For an accelerator-based BNCT, we have fabricated a new detector consisting of quartz optical fibers that have excellent radiation-resistant characteristics. Materials and Methods: The developed detectors were irradiated at Kyoto University Research Reactor. Results and Discussion: The experimental results showed that the new detector had good output linearity for the neutron intensity, and the response of the new detector did not decrease during the irradiation. Conclusion: The new detector consisting of quartz optical fibers can be applied to measurement of neutron field of an accelerator-based BNCT.