불확실한 시변 파라메터를 갖는 선형시스템의 고장검출 시스템 설계

류석환 대구대학교 2005 대구대학교 학술논문집 Vol.1 No.1

본 연구에서는 시변 파라메터 불확실성을 갖는 선형시스템의 고장검출 시스템 설계를 다룬다. 고장 검출 시스템은 플랜트의 입력과 출력으로부터 오차신호를 발생시키기 위하여 불확실성을 갖는 플랜트의 동적 방정식을 왼쪽 소인수 분해를 이용한다. 이 오차신호로부터 효과적으로 제어시스템의 센서나 액츄에이터의 고장을 실시간으로 검출하기 위하여 고장검출 필터를 설계한다. 본 연구에서 제시한 방법의 효용성을 보여주기 위해서 원자력 발전소의 증기발생기 수위제어시스템에 본 연구의 결과를 적용하여 컴퓨터 모의실험을 수행한다. This paper deals with a fault detection system design for linear systems with uncertain time varying parameters. In order to generate a residual signal, we use a left coprime factorization of the plant dynamic equation with uncertainties. We also design a fault detection filter to effectively detect the fault occurences of the control systems. From the filtered output of the residual signal generator, we can detect sensor or actuator faults effectively. A simulation study with nuclear steam generator level control system shows that the presented method can detect the sensor fault or actuator fault effectively.

韓國의 産業災害補償制度에 關한 小考

崔晳煥 明知大學校 行政學會 1985 명지행정 Vol.5 No.-

단백뇨를 보이는 사구체 질환 및 당뇨병성 신병증에서의 Lp(a)

권태환,김준홍,조성,김석재,김용림,조동규,백미영 경북대학교 병원 1998 경북대학교병원의학연구소논문집 Vol.2 No.1

Background: Recently there has been evidences that serum Lp(a), an independent risk factor to atherosclerotic cardiovascular diseases, were increased in proteinuric disorders such as nephrotic syndrome and diabetic nephropathy. Methods: We intended to search of altered concentrations of Lp(a) in proteinuric disorder measuring serum Lp(a) concentrations with ELISA in 44 glomerulonephritic patients(25 nephrotic syndrome(NS), 19 non-nephrotic range proteinuric glomerulonephritis(GN), 25 diabetic nephropathy patients(DN), and 31 healthy controls(HC). Also, we compared Lp(a) concentration between glomerulonephritis patients and diabetic nephropathy patients with proteinuria of similar degree. Results: 1) There were significantly increased levels of total choesterol, triglyceride, and LDL-cholesterol in Ns compared to GN, DN, HC. 2) There were significantly increased concentrations of serum Lp(a) in NS compared to HC, but no signiicant difference in serum Lp(a) among NS, GN, and DN. 3) There was no significant difference in serum Lp(a) concentrations between NS & DN with 24 hour urine protein greater than 3.0g. 4) There was no significant difference in serum Lp(a) concentration between GN with 24 hour urine protein greater than 0.5g and less than 1.5g and DN with proteinuria of simial degree. 5) In glomerulonephritis patients, there was negative correlation between serum Lp(a) concentration and serum albumin level but correlation with 24 hour urinary protein, total cholesterol, Ldl-cholesterol, and HDL-cholesterol was not shown. In diabetic nephropathy, there was no significant correlation among serum Lp(a) concentration and all parameters including serum albumin, 24 hour urinary protein, and other lipid profiles. Conclusion: The present study confirmed that patients with nephrotic syndrome of diverse etiologies have makedly increased plasma level of Lp(a), in conjunction with other lipid abnormalities. However, this study shows no difference in Lp(a) concentrations between diabetic nephropathy and glomerulonephritis with similar degree of proteinuria.

제어 입력에 시간 지연을 갖는 선형 시스템의 견실한 H∞ 제어기 설계

류석환,김홍락 대구대학교 과학기술연구소 1997 科學技術硏究 Vol.4 No.1

In this paper, a solution of the H∞ control problem for linear uncertain systems with input time delay is presented. An H∞ norm bounded condition is obtained as a sufficient condition for linear uncertain systems with input time delay. Based upon this sufficient condition, a robust H∞ controller design method which involves the solutions of linear matrix inequalities is developed. A numerical example is solved in order to illustrate the efficacy of the suggested design method.

체적제어를 이용한 신뢰성 기반 위상 최적화

박재용,황승민,임민규,오영규,박재용,한석영 한국공작기계학회 2009 한국공작기계학회 춘계학술대회논문집 Vol.2009 No.-

This paper presents a reliability-based topology optimization (RBTO) using bi-directional evolutionary structural optimization (BESO). An actual design involves uncertain conditions such as material property, operational load and dimensional variation. Deterministic topology optimization (DTO) is obtained without considering of uncertainties related to the uncertainty parameters. However, the RBTO can consider the uncertainty variables because it has the probabilistic constraints. In this paper, the reliability index approach (RIA) is adopted to evaluate the probabilistic constraint. RBTO based on BESO starting from various design domains produces a similar optimal topology each other. Numerical examples are presented to compare the DTO with the RBTO.

불확실한 파라미터와 유연한 관절을 갖는 로보트 매니퓰레이터를 위한 견실한 비선형 제어

이희영,류석환 대구대학교 과학기술연구소 1994 科學技術硏究 Vol.1 No.-

In this paper, a robust controller design problem for robot manipulators with parameter uncertainty and flexible joints is considered. The system dynamics of the robot manipulator is expressed as a nonlinear singularly perturbed system. Based on the singular perturbation theory, a robust slow control law is developed such that the control law stabilizes the slow subsystem for allowable parameter uncertainty. Based on this slow control law, a corrective control law is synthesized using the integral manifold theory. In order to demonstrate the efficacy of the proposed controller, computer simulation is performed for a robot

Benzoate, m-Toluate, Phenol의 Pseudomonas putida에 의한 생분해

김장규,김석형,김태환,이대광,김남기 成均館大學校 科學技術硏究所 1993 論文集 Vol.44 No.1

It this study, basic data were obtained for the treatment of industrial waste water which includes aromatic compounds. Substrate concentrations used were 100ppm, 500ppm, and 1,000pprn and initial pH's were pH6, pH7, and pH8 in order to obtain the optimum conditions for treating benzoate, m-toluate, and phenol by Pseudomonas putida(KCTC 1644). Durations were 20hrs for 100ppm, 40hrs for 500ppm, and 60hrs for 1,000ppm before the static growth of Pseudomonas putida. 100% of 100ppm benzoate(0.31g cell/1) was biodegraded at pH6, pH7, and pH8 before 20hrs, 52.8% of 500ppm at pH8 in 40hrs, and 27.9% of 1,000ppm at pH8 in 60hrs. The best initial pH was pH8 for the biodegradation and the growth of Pseudomonas putida in benzoate medium. For m-toluate, the best initial pH was also pH8. At this pH, 40.6% of 10Dppm(0.31 cell/1), 21.9% of 500ppm, and 14.1% of 1,000ppm m-toluate were biodegraded respectively in limited time. But for phenol, the best initial pH was pH7. At this point, 9.8% of 100ppm(0.218 cell/1), 7.1% of 500ppm, and 4.7% of 1,000ppm phenol were biodegraded respectively. Therefore, the best carbon source in this experiment was benzoate. Pseudomonas putida was also able to biodegrade m-cresol, p-hydroxybenzoic acid, and benzaldehyde.

Phage Ф FSV가 Lactobacillus casei의 증식에 미치는 영향

김경태,이정준,서인영,나석환,백영진 한국산업미생물학회 1991 한국미생물·생명공학회지 Vol.19 No.2

Phage Φ FSV가 유산종균의 배양에 미치는 영향을 조사하기 위하여 prophage Φ FSV를 보유한 L. casei YIT 9018 균주나 prophage cured strain인 L. casei HYM 1213 균주에 phage Φ FSV(Lac S21)나 wild type phage Φ J-1(Lac J-1)을 임의의 농도로 각각 감염시켜 이들 균주의 증식을 비교하였다. Lac S21 phage를 L. casei YIT 9018 균주에 감염시켰을 경우, 초기 감염농도가 6.0×10 exp(6) pfu/㎖ 미만인 시료에서는 균주의 성장 및 유산생성능이 정상적이었으며, 오히려 phage수는 감소하였다. 그러나 L. casei HYM 1213균주는 Lac S21 phage에도 민감하게 반응하여, 감염된 균주는 감염시킨 농도에 상관없이 모두 2일균에서 phage가 10^9∼10^10 pfu/㎖로 급격히 증가하였으며, 계속 배양함에도 phage는 감소되지 않고 6일균에서 10^7∼10^9 pfu/㎖로 유지되었고, 이로 인하여 유산균은 정상 발효를 못하였다. 따라서 phage Φ FSV는 모균주인 L. casei YIT 9018 균주에는 어떠한 영향도 미치지 못하고, 오히려 prophage cured strains에는 민감하게 작용하여 비정상 발효를 유도함을 알 수 있었다. 또한, Lac J-1 phage는 prophage Φ FSW를 보유한 L. casei YIT 9018 균주와 prophage cured strain인 L. casei HYM 1213 균주에 모두 민감하게 감염되어 phage의 농도가 급증하고, 이로 인해 균주의 이상발효를 야기시켰다. In order to study effect of the phage Φ FSV on the growth of lactic acid bacteria, Lactobacillus casei YIT 9018 (wild type strain with prophage) or L. casei HYM 1213 (prophage cured strain) was infected with various concentrations of phage Φ FSV (called Lac S21) or wild type virulent phage (called Lac J-1). When L. casei YIT 9018 was infected with Lac S21 under the concentration of 6.0×10 exp(6) pfu/㎖, the growth and lactic acid production of the strain were normal and the number of phages decreased. But L. casei HYM 1213 was susceptible to Lac S21. Regardless of the concentration of the phage infection, the number of phages increased rapidly into 10^9 to 10^10 pfu/㎖ at 2 day cultures and was maintained 10^7 to 10^9 pfu/㎖ phages until 6 day cultures. The lactic acid production of L_n casei HYM 1213 infected with Lac S21 was abnormal. Therefore, phage Φ FSV had an evil effect on growth of L. casei HYM 1213, but not L. casei YIT 9018. On the other hand Lac J-1 caused abnormal fermentation to either L. casei YIT 9018 or L. casei HYM 1213.

자율 이동 로봇의 경로계획과 주행

곽상필,최병재,류석환 대구대학교 2005 대구대학교 학술논문집 Vol.1 No.1

자율 이동 로봇의 경로계획과 주행에 관한 연구가 널리 진행되고 있다. 자율 이동 로봇은 주어진 환경에서 효율적인 주행을 하기 위하여 환경 지도를 구성하고, 이를 기반으로 목표 지점에 대한 효율적인 광역 주행 경로를 계산하게 되고, 계산된 광역 경로를 주행하여 목표 지점에 이르게 된다. 본 논문에서는 퍼지 환경 지도를 제안하고, 퍼지 환경 지도로부터 최단시간 광역 경로 계산 알고리즘을 소개하며, 주행 제어를 위한 퍼지 논리 제어기를 제안한다. There are many researches about the path planning and navigation of autonomous mobile robots. In this paper we present a fuzzy logic based environment map and navigation system. Firstly we introduce grid based method and topological method for an environment map and propose a fuzzy environment map. And then we design a fuzzy logic system for navigation of the autonomous mobile robot.

A Fault Detection System Design for Uncertain Fuzzy Systems

Seog-Hwan Yoo,Byung-Jae Choi 한국지능시스템학회 2006 INTERNATIONAL JOURNAL of FUZZY LOGIC and INTELLIGE Vol.6 No.1