• 제목/요약/키워드: Simultaneous Stabilization

검색결과 60건 처리시간 0.02초

수동화 기법에 의한 비정방 선형 시스템의 강인 제어기 설계 (Robust Controller Design for Non-square Linear Systems Using a Passivation Approach)

  • 손영익
    • 제어로봇시스템학회논문지
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    • 제8권11호
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    • pp.907-915
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    • 2002
  • We present a state-space approach to design a passivity-based dynamic output feedback control of a finite collection of non-square linear systems. We first determine a squaring gain matrix and an additional dynamics that is connected to the systems in a feedforward way, then a static passivating (i.e. rendering passive) control law is designed. Consequently, the actual feedback controller will be the static control law combined with the feedforward dynamics. A necessary and sufficient condition for the existence of the parallel feedfornward compensator (PFC) is given by the static output feedback fomulation, which enables to utilize linear matrix inequality (LMI). The effectiveness of the proposed method is illustrated by some examples including the systems which can be stabilized by the proprotional-derivative (PD) control law.

점성토 연약지반에서의 다중 동시주입 컴팩션 그라우팅 공법 적용성 연구 (Study on Applicability of Simultaneous Multiple Compaction Grouting Method in Soft Clay Ground)

  • 이효범;정현석;정의엽;최항석
    • 대한토목학회논문집
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    • 제39권6호
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    • pp.779-788
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    • 2019
  • 컴팩션 그라우팅 공법, 일명 CGS (Compaction Grouting System) 공법은 저유동성 그라우트재의 주입을 통해 주변 지반을 압밀·다짐하여 원지반의 물성 향상은 물론 지중 그라우트 구근체의 형성을 통해 복합지반 거동을 기대함으로써 지반을 개량하는 공법이다. 그러나 기존 컴팩션 그라우팅 공법에 사용되는 펌프는 한 번에 여러 공을 동시에 주입하기 어려워 시공 물량이 많아 신속함이 요구되는 공사 시에 시공 효율성 확보가 어려웠다. 따라서 본 논문에서는 3공까지 동시주입이 가능한 다중 동시주입 컴팩션 그라우팅 공법을 개발하여 현장시험을 통해 지반 보강효과의 적용성을 평가하였다. 현장시험은 점성토 연약지반에 단일공과 3공 삼각 배열로 각각 시험시공하고 그라우팅 주입 전·후 표준관입시험(SPT)을 수행하여 그 결과를 비교·분석하였다. 최종적으로 점성토 연약지반에서 다중 동시주입 컴팩션 그라우팅 공법의 적용 시, 요구되는 적정 동시주입 이격거리와 충분한 지반 안정화 시간 확보의 중요성에 대해 제언하였다.

Design of Fault Diagnostic and Fault Tolerant System for Induction Motors with Redundant Controller Area Network

  • 홍원표;윤충섭;김동화
    • 한국조명전기설비학회:학술대회논문집
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    • 한국조명전기설비학회 2004년도 학술대회 논문집
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    • pp.371-374
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    • 2004
  • Induction motors are a critical component of many industrial processes and are frequently integrated in commercially available equipment. Safety, reliability, efficiency, and performance are some of the major concerns of induction motor applications. Preventive maintenance of induction motors has been a topic great interest to industry because of their wide range application of industry. Since the use of mechanical sensors, such as vibration probes, strain gauges, and accelerometers is often impractical, the motor current signature analysis (MACA) techniques have gained murk popularity as diagnostic tool. Fault tolerant control (FTC) strives to make the system stable and retain acceptable performance under the system faults. All present FTC method can be classified into two groups. The first group is based on fault detection and diagnostics (FDD). The second group is independent of FDD and includes methods such as integrity control, reliable stabilization and simultaneous stabilization. This paper presents the fundamental FDD-based FTC methods, which are capable of on-line detection and diagnose of the induction motors. Therefore, our group has developed the embedded distributed fault tolerant and fault diagnosis system for industrial motor. This paper presents its architecture. These mechanisms are based on two 32-bit DSPs and each TMS320F2407 DSP module is checking stator current, voltage, temperatures, vibration and speed of the motor. The DSPs share information from each sensor or DSP through DPRAM with hardware implemented semaphore. And it communicates the motor status through field bus (CAN, RS485). From the designed system, we get primitive sensors data for the case of normal condition and two abnormal conditions of 3 phase induction motor control system is implemented. This paper is the first step to drive multi-motors with serial communication which can satisfy the real time operation using CAN protocol.

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DSP 마이크로컨트롤러를 사용한 CAN 네트워크 기반 유도전동기고장진단 시스템 설계 (Design of Network-Based Induction Motors Fault Diagnosis System Using Redundant DSP Microcontroller with Integrated CAN Module)

  • 윤충섭;홍원표
    • 조명전기설비학회논문지
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    • 제19권5호
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    • pp.80-86
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    • 2005
  • 유도전동기는 프로세스산업과 다른 산업분야에 광범위하게 적용되는 매우 중요한 기기이다. 프랜트를 운전함에 있어서 이의 신뢰성, 효율 및 성능은 매우 중요한 관심사항이다. 특히 유도전동기의 고장을 미리 검출하여 진단하고 고장 아래에서도 시스템이 안전하고 신뢰성 있는 성능을 가질 수 있는 고장허용제어의 실현이 매우 중요하다. 따라서 본 논문에서는 고정자전류신호 검출과 디지털 신호 프로세싱에 의한 효과적인 유도전동기의 베어링 고장검출 및 진단 기반을 가진 고장허용제어 시스템을 구축하였다. 또한 모타 고장허용제어에 기본이 되는 제어 하드웨어 구조를 제시하였으며 실험을 통하여 이 시스템의 실시간 데이터 취득 성능을 확인하였다.

목질 재료의 자기가수분해 및 효소당화에 관한 연구 (IV) - Laccase 및 Cellulase의 동시 이용 가능성 - (Autohydrolysis and Enzymatic Saccharification of Lignocellulosic Materials (IV) - Simultaneous Utilization of Laccase and Cellulase -)

  • 조남석;임창숙;이재성
    • Journal of the Korean Wood Science and Technology
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    • 제17권3호
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    • pp.52-60
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    • 1989
  • This study was carried out to know the possibility of simultaneous utilization of laccase from white-rot fungus with cellulase on enzymatic hydrolysis of cellulosic substrate from autohydrolyzed oak wood. Laccases from 3 white-rot fungi, Pleurotus ostreatus. Ganoderma lucidum, and Phanerochaete chrysosporium, were isolated, purified and measured their activities. The highest activity was shown in Pleurotus ostreatus and the lowest in Phanerochaete chrysosporium. Laccase from Pleurotus ostreatus has optimum pH of 5.94, Km value of 3.209 mM and appeared to be stable at relatively wide pH range, 4.7-8.72. Temperature stability showed that 60% activity was preserved after 40 minutes at $50^{\circ}C$. Laccase from Ganoderma lucidum reached to the maximum activity during 15-20 day incubation. This enzyme has optimum pH of 6.45, Km value of 6.71 mM and pH range of 5.0-9.0 for stabilization. 95% activity was preserved at $30^{\circ}C$ and 58% activity at $50^{\circ}C$. Concerned to the enzymatic hydrolysis of cellulosic substrate with both enzymes, cellulase and laccase, simultaneously, mixed culture filtrates and mycellium extracts were shown higher hydrolysis rates than those of Trichoderma viride. There were no significant differences in the extent of hydrolysis among various mixed culture filtrates and mycellium extracts.

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수도권 매립지에서 침출수-가스의 동시 유동 해석을 위한 전산 모델링 연구 (The Numerical Modeling Study for the Simultaneous Flow of Leachate and LFG in Kimpo Landfill)

  • 성원모;박용찬;이광희
    • 대한지하수환경학회지
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    • 제6권2호
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    • pp.101-106
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    • 1999
  • 쓰레기의 단순 매립은 주변 환경에 대해 고려하지 않고 이루어지기 때문에 침출수에 의해서 지하수와 토양이 오염되고 매립가스에 의해서 악취 및 대기오염을 발생시킨다. 본 연구에서는 김포매립지의 침출수 수위저감과 매립가스의 포집 및 제어에 관한 연구를 수행하기 위해 다차원 2상 천이유동 유한차분 전산 모델을 활용하여 침출수와 매립가스의 동시 유동 해석을 시도하였다. 이 전산해석에서는 매립지 상부는 가스 생성량의 58%가 대기로 발산되며. 지하함앙율은 연평균 강수량의 12%로 가정하였다. 이외의 모든 자료들도 1995년 3단 매립 시점의 자료를 이용하였다. 전산 해석결과 매립지 중앙에 위치한 지점에서 수두의 최대값은 26 m$H_2O$(2.52 atm)로 나타났으며. 수평관의 설치는 매립지의 안정화 시점을 앞당기는데 중요한 역할을 한다는 것을 알 수 있었다. 수도권 매립지에서 3단 매립이란 가정과 낮은 지하 함양율을 적용하였음에도 40년이 경과되는 시점에서 침출수는 15.l$\times$$10^{6}$ ㎥, 매립가스는 5.85$\times$$10^{9}$ ㎥ 의 엄청난 양이 누적 생산되었다.

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질소희석이 부상된 수소 난류확산화염의 화염안정성에 미치는 영향 (Nitrogen Dilution Effects on Liftoff Flame Stability in Non-premixed Turbulent Hydrogen Jet with Coaxial Air)

  • 오정석;윤영빈
    • 한국추진공학회:학술대회논문집
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    • 한국추진공학회 2008년도 제31회 추계학술대회논문집
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    • pp.393-396
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    • 2008
  • 질소 희석 가스가 수소화염의 화염안정성에 미치는 영향을 실험적으로 연구하였다. 연료는 수소이며 수소화염을 부상시키기 위하여 동축공기를 사용하였다. 이때 수소의 속도는 200 m/s이고 동축공기의 속도는 16 m/s로 고정하였다. 질소 희석 가스는 연료 공급라인에 주입되었으며 전체 연료 부피의 0$\sim$20%까지 주입하였다. 화염구조분석을 위하여 PIV/OH PLIF 동시측정 기법을 사용하였다. 수소 난류 확산화염 화염안정성 실험을 통하여 질소 가스 주입에 따라 부상화염 높이는 증가하였으며, 난류 화염 전파속도는 감소하였다. 그리고 난류 화염전파속도는 난류강도의 함수로 표현될 수 있었다.

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실질금리 결정모형에서의 구조변화분석 (Structural Change Analysis in a Real Interest Rate Model)

  • 전덕빈;박대근
    • 경영과학
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    • 제18권1호
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    • pp.119-133
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    • 2001
  • It is important to find the equilibrium level of real interest rate for it affects real and financial sector of economy. However, it is difficult to find the equilibrium level because like the most macroeconomic model the real interest model has parameter instability problem caused by structural change and it is supported by various theories and definitions. Hence, in order to cover these problems structural change detection model of real interest rate is developed to combine the real interest rate equilibrium model and the procedure to detect structural change points. 3 equations are established to find various effects of other interest-related macroeconomic variables and from each equation, structural changes are found. Those structural change points are consistent with common expectation. Oil Crisis (December, 1987), the starting point of Economic Stabilization Policy (January, 1982), the starting point of capital liberalization (January, 1988), the starting and finishing points of Interest deregulation (January, 1992 and December, 1994), Foreign Exchange Crisis (December, 1977) are detected as important points. From the equation of fisher and real effects, real interest rate level is estimated as 4.09% (October, 1988) and dependent on the underlying model, it is estimated as 0%∼13.56% (October, 1988), so it varies so much. It is expected that this result is connected to the large scale simultaneous equations to detect the parameter instability in real time, so induces the flexible economic policies.

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미만성 척수 경막외 농양을 동반한 화농성 척추염 - 증 례 보 고 - (Pyogenic Spondylitis with Diffuse Spinal Epidural Abscess - A Case Report -)

  • 김훈;김성민;정대진;심영보;박용기;최선길
    • Journal of Korean Neurosurgical Society
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    • 제29권8호
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    • pp.1074-1079
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    • 2000
  • We report a case of pyogenic spondylitis on L2 and L3 with diffuse epidural abscess up to T4 to L3 and large psoas abscess. A forty-nine-year old male was presented with progressive back pain, left flank pain and ab-dominal distention, weakness of the both legs and voiding and defecation difficulty during last 2 months. Initially multiple coronal hemilaminectomies from T4 to T12 were done for the treatment of diffuse thoracic epidural ab-scess. Then second operation via left retroperitoneal approach was performed for lumbar spondylitis and psoas abscess on third day after initial operation. After removal and curettage of pyogenic psoas and epidural abscess and spondylitis (L2-L3), iliac bone grafting with Keneda instrumentation from L1 to L4 was done simultaneously. Postoperative course has been unevenful without recurrent infection. The literature on diffuse epidural and large psoas abscess with pyogenic spondylitis are reviewed and instrumentation for stabilization of pyogenic spondylitis is also discussed.

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지하수의 라듐/라돈 동시측정을 위한 백그라운드 감마선 제어

  • 이길용;윤윤열;조수영;김용제
    • 한국지하수토양환경학회:학술대회논문집
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    • 한국지하수토양환경학회 2005년도 총회 및 춘계학술발표회
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    • pp.308-311
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    • 2005
  • [ $^{222}Rn\;and\;^{226}Ra$ ] in groundwater were determined simultaneously using a gamma-spectroscopy. A nitrogen flushing equipment has been used for elimination and stabilization of high and unstable background activity due to the radon and its progenies in counting shield and room. The aim of present work was to control the background activity for simultaneous measurement of radium$(^{226}Ra)$ and radon$(^{222}Rn)$ in groundwater using a gamma-spectrometry. Background activity was about 1.0dps and the standard deviation was about 50%, The background activity could be minimized using nitrogen flushing equipment in the range of 0.1 to 0.5 and the RSD was about 5% at the experimental condition. The detection limit of $^{222}Rn\;and\;^{226}Ra$ in groundwater was 0.5dps/L in the background control method. In most groundwater used in the work, radon activity was more than the detection limit. However, radium activity in some groundwater was less than the detection limit. If the low level radium in groundwater must be measured, preconcentration process such as concentration should be performed before measuring the groundwater.

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