Model Following Control System을 이용한 퍼지 적응制御

장기효,박재호 동의공업대학 2001 論文集 Vol.27 No.1

An adaptive fuzzy control with using Model Following Control system is proposed, in this paper, which can compensate disturbances in much shorter than model reference adaptive control system. A discrete DC servomotor control system is designed as the model following control system. In addition, adaptive fuzzy system is included for compensation of disturbances. Adaptive fuzzy control system equipped with a training algorithm, where the fuzzy logic system is constructed from a collection of fuzzy IF-THEN rules, and the training algorithm adjusts the parameter of fuzzy system based on numerical input-output pairs. The Adaptive fuzzy control is then to find a method of adjusting the fuzzy rule-base parameter for the controller when the characteristics of the process and its parameter changing unpredictably. The performance of the proposed control system is analyzed by computer simulation for model and plant. Excellent agreements have been the results and theorical ones.

건조 담체 고정화 Zymomonas mobilis 세포의 oxidoreductase 활성도

장기효,이제혁,전억한 경희대학교 유전공학연구소 1991 遺傳工學論文集 Vol.3 No.-

박테리아인 Zymomonas mobilis는 glucose와 fructose를 각각 gluconic acid와 sorbitol으로 동시전환할 수 있다. Glucose fructose oxidoreductase에 의하여 glucose의 산화와 fructose의 환원이 일어난다. 균체를 cationic detergent인 CATB(cethyltrimethylammoniumbromide)로 처리하여서 투과성을 높인 후에 glutaraldehyde로 crosslinking 하였던 결과, 균체에서의 glucose-fructose oxidoreduc-tase의 유출이 감소되었으며 고정화균체의 안정성이 증가하였다. 투과성을 증가시킨 균체를 K-carra-geenan으로 고정화하여서 연속공정을 실시한 결과 효소의 안정성이 30일 이상 지속되었다. Kcarrageenan으로 고정화한 균체를 건조시 beads의 견고성과 저장성의 향상이 나타났다. 건조된 Kcarrageenan 담체의 V_(max)값은 39C와 pH6.2에서 free cells의 거의 절반값을 나타내었다. 연속공정에서 회석비율 0.1h^(-1)일때 wet beads와 건조 beads에서의 sorbitol 생산성은 각각 3.2∼3.5, 2.85∼2.9(g/l-h)를 나타내었다. The bacterium Zymumonas mobilis is able to convert glucose and fructose to gluconic acid and sorbitol simultaneously. The enzyme complex, which is responsible for glucose oxidation and fructose reduction, has been described as glucose-fructose oxidoreductase. After treatment of the cells with cationic detergent CTAB(Cetyltrimethylammoniumbromide) for permeabilization, the cells were treated with glutaraldehyde in order to crosslink enzymes. Glutaraldehyde treatment of the permeabilized cells could improve the stability of the system by decreasing the loss of glucose-fructose oxidoreductase. The methods of glutaraldehyde cross-linking of enzymes in CTAB treated cells immobilized in K-carrageenan showed a stable ability of enzymes in CTAB treated cells oxidoreductase for 30 days of process. K-carrageenan beads entrapped with permeabilized cells were dried to improve bead rigidity and storage stability. The value of V_(max) for the dry K-carrageenan beads was found to a 1/2 of that of free cells. It was shown that the productivities of the continuous process with wet K-carrageenan beads and dry beads at dilution rate 0.1h^(-1) were 3.2-3.5 g/l-h and 2.85-2.9 g/l-h, respectively.

Model 追從 制御系를 이용한 堅實한 Fuzzy 制御

장기효,박재호 동의공업대학 1999 論文集 Vol.25 No.1

Robust control has been the purview of quantitative linear control techniques for a long time, while qualitative, symbolic control has been deemed to be more suitable to obtaining complex control objectives that require only low output precision. Since the dynamic response trajectory of a traditional fuzzy controller can not be quantitatively controlled, a Robust fuzzy control with model following controller is proposed in this paper. In the proposed controller, an output feedback linear model following control is designed first according to the roughly estimated plant model to let its response follow the out put generated by a reference model. Then a model following error driven control signal is synthesized such that good model following characteristics can be preserved at various operation conditions. The proposed controller is applied to the speed control of a servomotor. Dynamic signal analysis of model following behavior is made and the procedure for constructing the control algorithms is described detailedly. The performance of the drive and the effectiveness of the proposed controller are demonstrated by some simulation results.

건조 고정화 Zymomonas mobilis에 의한 sorbitol 생산

장기효,박철진,전억한 慶熙大學校 大學院 院友會 1992 高凰論集 Vol.11 No.-

The purpose of this study is to develop a continuous process for sorbitol production using dried Zymomonas mobilis immobilized in K-carrageenan. The methods of glutaraldehyde cross-linking of enzymes in CTAB(cetyltrimetylammoniumbromide) treated cells immobilized in K-carrageenan showed a stability for the production of sorbitol for 30 days of operation K-carrageenan beads entrapping permeabilized cells were dried to improve bead rigidity and storage stability. A semi-batch process with dry beads was carried out and only a small loss of enzyme activity(less than 8%) was observed during 72h. The value of Vmax for the dry K-carrageenan beads was found to be one half of that for free cells. It was shown that the productivities of the continuous process with wet K-carrageenan beads and dry beads at a dilution rate 0.1h^-1 were 3.4g/L and 2.88g/L-h respectively.

Model 추종형 Servo Controller에 의한 위치제어계의 설계

장기효,하홍곤,홍창희 한국통신학회 1991 韓國通信學會論文誌 Vol.16 No.1

In this paper the design and construction of discrete model following servo dontroller on the position control system is proposed. The operational time delay of the plant in the controller which is proposed, is considered and the system which is added by the integral compensation in first order difference equation is constructed. By applying the optimal regulator method to the system, the method which find the optimal state feedback gain is developed theoretically. The output of a model which is correspond to a DC Servo motor follow quickly the speed response of a DC Servo motor and the velocity error in ansteady-state is reduced in zero and the position response is controlled correctly, the performance of the controller is contoller is confirmed by Computer Simulation.

A mixture of poly-γ-glutamic acid and levan ameliorates obesity in high fat diet-induced mice

장기효,김미자 한국식품과학회 2022 Food Science and Biotechnology Vol.31 No.3

Anti-obesity effects of a mixture of poly-c-glu- tamic acid (c-PGA) and levan (PL, 6:4 w/w) were evalu- ated using C57BL/6 mouse models including normal diet (G1), normal diet containing 5% of PL (G2), high-fat diet (HFD) (G3), HFD with 3% of PL (G4), and HFD with 5% of PL (G5) and followed by breeding 12 weeks. After 12 weeks, the content of epididymal fat and the size of fat cell for test animals were significantly decreased by com- paring G3 (p \ 0.05). Similarily, contents of serum triglyceride, total cholesterol, LDL cholesterol, insulin and leptin in G5 were significantly decreased than G3. Fat accumulations and inflammatory degrees within liver and fat cells were also decreased in the G5 than G3. In addition 5% PL diet might not have any problems causing liver damages. Conclusively, a mixture of c-PGA and levan could help to improve obesity and dyslipidemia due to high-fat meals.

견실성 향상을 위한 직류서어보모터의 가속도제어

장기효,홍창희 한국통신학회 1990 韓國通信學會論文誌 Vol.15 No.3

직류 서어보 모터는 속도 및 위치제어계에서 성능이 뛰어나므로 위치제어계로 많이 사용하고 있지만 불확실한 외란이나 부하 Torque 변동들이 직류서어보 모터의 위치제어계에서 발생할 때 정상상태 혹은 과도상태 오차가 발생한다. 본 논문에서는 이 오차를 가속도 제어법을 통해서 감소시키는 견실성이 높은 제어법을 제안하고 컴퓨터 시뮤레이션을 통해서 가속도 제어기법의 유효성을 확인하였다. DC servo motor has been often used as the position control system, because the performance is excellent on the velocity and position control system. When the unknow disturbance and accessible load torque are imposed on the position control of DC servo motor, this system has the steady and/or transient state error. In this paper, a new method which has high stiffness for reducing the error is proposed. This error will be reduced by acceleration control. The effectiveness of the acceleration control is confirmed by using computer simulation.

Effects of Dietary Fructan on Cecal Enzyme Activities in Rats

장기효,Soon Ah Kang,Uckhan Chun 한국생물공학회 2005 Biotechnology and Bioprocess Engineering Vol.10 No.6

In this study, we have attempted to determine the effects of dietary fructose polymers (fructan), high molecular-weight β-(2,6)-linked levan, and low-molecular-weight β-(2,1)-linked inulin, on two intestinal enzymes (β-glucuronidase and β-glucosidase). As a preliminary experiment, when intestinal microflora were cultured in anaerobic media harboring levan or its oligosaccharides, bacterial cell growth was observed in the levanoligosaccharide-supplemented media, but not in the levan-supplemented media, indicating that levan’s size is important for the utilization by intestinal bacteria of levan as an energy source. In our animal study, the intake of a levan-rich diet was determined to significantly attenuate the activity of the harmful enzyme β-glucuronidase, but did not affect the activity of β-glucosidase.

식이 레반과 이눌린이 흰쥐의 장내 유산균 성장 및 장내환경에 미치는 영향

장기효(Jang Ki Hyo),강순아(Kang Soon Ah),조윤희(Cho Yunhi),김윤영(Kim Yun Young),이윤정(Lee Yun Jung),홍경희(Hong Kyunghee),장은경(Jang Eun-Kyung),김철호(Kim Chul Ho),조여원(Choue Ryowon) 韓國營養學會 2002 Journal of Nutrition and Health Vol.35 No.9

청국장 점질물의 3T3-L1 지방세포 분화 억제 효과

장기효(Ki-Hyo Jang),김민아(Min-Ah Kim),나하균(Ha Gyoon Na),유상권(SangGuan You),김지은(Ji-Eun Kim),김미자(Mi-Ja Kim) 한국식품영양과학회 2022 한국식품영양과학회지 Vol.51 No.11

청국장의 점질물은 일반적으로 레반과 γ-PGA로 구성되어 있다. 본 연구는 청국장으로부터 분리된 레반과 γ-PGA가 3T3-L1 전지방 세포주의 지방세포 분화에 미치는 영향을 조사하기 위해 수행되었다. 청국장 점질물 유래 γ-PGA와 레반을 점질물 구성 비율인 6:4로 혼합한 점질물(PL64)을 200 μg/mL 농도로 처리할 경우 대조군에 비해 23.7% 유의적으로 지방축적이 감소함을 확인할 수 있었다. 그뿐만 아니라 PL64의 처리는 pparγ, c/ebpα, srebp-1c, ap2, fas, acc1, cd36를 포함한 지방축적 관련 유전자의 발현을 감소시켰다. 또한 PPARγ, C/EBPα, SREBP-1C, AP2, FAS, SCD1의 지방축적 관련 단백질 발현이 감소한 것을 관찰할 수 있었다. 따라서 청국장 점질물인 PL64는 3T3-L1 전지방 세포주의 지방세포 분화와 관련된 유전자와 단백질의 발현을 감소시킴으로써 지방축적을 억제하는 것으로 나타났다. 이와 같은 결과로 청국장 점질물은 지방축적 관련 유전자와 단백질을 하향 조절함으로써 항비만 기능성 물질로 활용 가능함을 확인할 수 있었다. Cheonggukjang mucoid is typically composed of levan and polygamma glutamate (γ-PGA). In this study, we investigated the effect of levan and γ-PGA isolated from Cheonggukjang on the differentiation of 3T3-L1 preadipocytes. At 200 μg/mL PL 64 [γ-PGA : levan (6:4)] significantly inhibited triglyceride accumulation in adipocytes by 23.7% compared to untreated adipocytes (P<0.05). PL64 treatment reduced the expressions of fat accumulation-related genes, including peroxisome proliferator-activated receptor γ (pparγ), CCAAT-enhancer-binding protein α (c/ebpα), sterol regulatory element-binding protein-1c (srebp-1c), adipocyte protein 2 (ap2), fatty acid synthase (fas), acetyl-CoA carboxylase 1, and cluster of differentiation 36. In addition, PL64 reduced the protein levels of PPARγ, C/EBPα, SREBP-1C, AP2, FAS, and SCD1. These results show PL64 suppresses fat accumulation in vitro by down-regulating the expressions of adipogenesis-related genes and proteins. Consequently, this study shows that Cheonggukjang mucoid could be used as a potent anti-obesity functional substance that down-regulates fat accumulation-related genes and proteins.