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Stability of Linear Dynamical Systems with Fuzzy Parameters

2008 Fifth International Conference on Fuzzy Systems and Knowledge Discovery, 2008

... Stability of Linear Dynamical Systems with Fuzzy Parameters. Author: Le Hung Lan, Published i... more

Evolutionary optimization of a fed-batch penicillin fermentation process

2010 International Symposium on Computer, Communication, Control and Automation (3CA), 2010

This paper presents a genetic algorithms approach for the optimization of a fed-batch penicillin ... more This paper presents a genetic algorithms approach for the optimization of a fed-batch penicillin fermentation process. A customized float-encoding genetic algorithm is developed and implemented to a benchmark fed-batch penicillin fermentation process. Off-line optimization of the initial conditions and set points are carried out in two stages for a single variable and multiple variables. Further investigations with online optimization have been carried out to demonstrate that the yield can be significantly improved with an optimal feed rate profile. The results have shown that the proposed approaches can be successfully applied to optimization problems of fed-batch fermentation to improve the operation of such processes.

format_quoteOffline optimization improved penicillin yield from 106.03g to higher levels by optimizing four key variables: substrate concentration, initial biomass, and others.format_quote

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Aggregation stability of multiple agents with fuzzy attraction and repulsion forces

2013 18th International Conference on Methods & Models in Automation & Robotics (MMAR), 2013

ABSTRACT The swarm behaviors of multi agent is a popular topic and has significant interest and a... more ABSTRACT The swarm behaviors of multi agent is a popular topic and has significant interest and application in industrial engineering, such as multi-robot team and autonomous air vehicle. Many studies have been done on modeling and describing swarm aggregation as well as analyzing its stability properties. This study provides a novel contribution by using Fuzzy Logic and simple Mamdani rules for constructing the attraction/repulsion function. It shows that the agents of multi-agents in indirect communications network will asymptotically form a cohesive cluster in predicted bounded region. A numerical simulation is also given to illustrate the theoretical results.

Specific inhibition of gene expression and transactivation functions of hepatitis B virus X protein and c-myc by small interfering RNAs

FEBS Letters, 2004

With a view to developing therapeutic strategies against hepatocellular carcinoma (HCC), we have ... more With a view to developing therapeutic strategies against hepatocellular carcinoma (HCC), we have recently shown that co-expression of c-myc and the X protein of hepatitis B virus (HBx) resulted in the development of HCC in the X-myc transgenic mice [Lakhtakia et al., J. Gastroenterol. Hepatol. 18 (2003) 80^91]. We now show in cell culture-based studies that small interfering RNA (siRNA) corresponding to HBx and cmyc can regulate expression and transactivation of the target genes. Expression vectors for small hairpin RNAs (shRNAs) against two di¡erent regions each of the HBx and c-myc open reading frames were constructed and their regulatory e¡ects were investigated in COS-1 cells. A dose-dependent speci¢c inhibition in the expression levels of HBx and c-myc was observed with individual shRNAs. Further, the recombinantly expressed shRNAs also blocked the transactivation functions of their cognate genes. Though each shRNA worked at a di¡erent e⁄ciency, the inhibitory e¡ects with two di¡erent shRNAs were cumulative. These results appear promising for developing a siRNA-based therapy for HCC.

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Antisense regulation of expression and transactivation functions of the tumorigenic HBx and c-myc genes

Biochemical and Biophysical Research Communications, 2006

Earlier we have shown that the X-myc transgenic mice develop hepatocellular carcinoma (HCC) due t... more Earlier we have shown that the X-myc transgenic mice develop hepatocellular carcinoma (HCC) due to co-expression of c-Myc and HBx protein of hepatitis B virus [R. Lakhtakia, V. Kumar, H. Reddi, M. Mathur, S. Dattagupta, S.K. Panda, Hepatocellular carcinoma in a hepatitis B 'x' transgenic mouse model: a sequential pathological evaluation. J. Gastroenterol. Hepatol. 18 (2003) 80-91]. With the aim to develop therapeutic strategies for HCC, we constructed several mono-and bicistronic antisense recombinants against HBx and c-myc genes to regulate their expression as well as transactivation function in a human hepatoma cell line. A dose-dependent inhibition in the expression levels of HBx and c-Myc was observed with monocistronic constructs. Likewise, the bicistronic recombinants also blocked the expression as well as transactivation functions of cognate genes with equal efficacy. Further, expression of the constituent genes from the X-myc transgene could also be inhibited by these antisense constructs in cell culture. Thus, our study points towards clinical implications of antisense regulation of tumor-promoting genes in the management of HCC.

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Construction of the Value Sets for Interval Transfer Functions and Their Application to Robust Control Problems

Automation and Remote Control, 1994

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