FEEDBACK CONTROL OF THE CHEMOTHERAPY OF HIV

2000 ◽  
Vol 10 (09) ◽  
pp. 2207-2219 ◽  
Author(s):  
JOSE ALVAREZ-RAMIREZ ◽  
MONICA MERAZ ◽  
JORGE X. VELASCO-HERNANDEZ
Keyword(s):  
Human Immunodeficiency Virus ◽  
Immune System ◽  
Feedback Control ◽  
Numerical Simulations ◽  
Control Strategy ◽  
Early Treatment ◽  
Viral Production ◽  
Hiv Dynamics ◽  
Immunodeficiency Virus ◽  
Feedback Control Strategy

Using a model which describes the interaction of the immune system with the human immunodeficiency virus (HIV), we introduce a feedback control strategy of chemotherapy in an early treatment setting, where the control represents the percentage of effect chemotherapy has on the viral production. We seek to regulate the viral count by manipulating the percentage of effect chemotherapy has on the viral production. We show via numerical simulations that the proposed feedback control strategy can handle strong uncertainties in the HIV dynamics induced by imperfect modeling and sampled/delayed cell measurements.

scholarly journals Theoretical Study and Optimization of the Biochemical Reaction Process by Means of Feedback Control Strategy

2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Kaibiao Sun ◽  
Andrzej Kasperski ◽  
Yuan Tian
Keyword(s):  
Mathematical Model ◽  
Feedback Control ◽  
Theoretical Analysis ◽  
Numerical Simulations ◽  
Control Strategy ◽  
Theoretical Study ◽  
Biomass Productivity ◽  
Reaction Process ◽  
Biochemical Reaction ◽  
Feedback Control Strategy

The aim of this work is to present a theoretical analysis and optimization of a biochemical reaction process by means of feedback control strategy. To begin with, a mathematical model of the biochemical reaction process with feedback control is formulated. Then, based on the formulated model, the analysis of system's dynamics is presented. The optimization of the bioprocess is carried out, in order to achieve maximal biomass productivity. It is shown that during the optimization, the bioprocess with impulse effects loses the possibility of synchronization and strives for a simple continuous bioprocess. The analytical results presented in the work are validated by numerical simulations for the Tessier kinetics model.

scholarly journals Simulation and feedback control of the Ahmed body flow exhibiting symmetry breaking behaviour

2017 ◽  
Vol 817 ◽  
Author(s):  
O. Evstafyeva ◽  
A. S. Morgans ◽  
L. Dalla Longa
Keyword(s):  
Reynolds Number ◽  
Feedback Control ◽  
Symmetry Breaking ◽  
Numerical Simulations ◽  
Control Strategy ◽  
Low Reynolds Number ◽  
Reynolds Numbers ◽  
Low Reynolds ◽  
Feedback Control Strategy ◽  
Ahmed Body

The present work considers the low-Reynolds-number wake flow behind a squareback Ahmed body, in close proximity to a ground. At low Reynolds numbers such wakes are known to undergo a series of bifurcations to a state that breaks reflectional symmetry. The symmetry breaking of the wake also persists at turbulent high Reynolds numbers, where it manifests as bi-modal behaviour with random switching between the asymmetric states. Thus far, it has only been possible to study the low-Reynolds-number sequence of bifurcations experimentally and mathematically. The present work presents the first numerical simulations capturing the sequence of symmetry breaking bifurcations that occur. A study of how the wake topology changes throughout suggests that interaction between the closer top/bottom pair of parallel shear layers can only dominate once there is sufficient underbody flow. When this occurs, the two main vortex structures in the wake switch from being horizontally to vertically aligned. A linear feedback control strategy, designed to attenuate base pressure force fluctuations, is then implemented. This causes an accompanying reduction in drag and re-symmetrisation of the wake. Analysis using the dynamic mode decomposition confirms that the wake shedding mode is re-symmetrised. This work motivates future attempts to capture wake symmetry breaking and bi-modality in numerical simulations, and application of a promising feedback control strategy at higher, turbulent Reynolds numbers.

scholarly journals An Optimal Feedback Control Strategy for Nonlinear, Distributed-Parameter Processes

Processes ◽  
2019 ◽  
Vol 7 (10) ◽  
pp. 758 ◽  
Author(s):  
Debaprasad Dutta ◽  
Simant Ranjan Upreti
Keyword(s):  
Feedback Control ◽  
Oil Recovery ◽  
Control Strategy ◽  
Moving Boundary ◽  
State Feedback Control ◽  
Optimal Feedback Control ◽  
Distributed Parameter ◽  
Optimal State ◽  
Non Linear ◽  
Feedback Control Strategy

In this work, an optimal state feedback control strategy is proposed for non-linear, distributed-parameter processes. For different values of a given parameter susceptible to upsets, the strategy involves off-line computation of a repository of optimal open-loop states and gains needed for the feedback adjustment of control. A gain is determined by minimizing the perturbation of the objective functional about the new optimal state and control corresponding to a process upset. When an upset is encountered in a running process, the repository is utilized to obtain the control adjustment required to steer the process to the new optimal state. The strategy is successfully applied to a highly non-linear, gas-based heavy oil recovery process controlled by the gas temperature with the state depending non-linearly on time and two spatial directions inside a moving boundary, and subject to pressure upsets. The results demonstrate that when the process has a pressure upset, the proposed strategy is able to determine control adjustments with negligible time delays and to navigate the process to the new optimal state.

scholarly journals Recent advances in understanding HIV evolution

F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 597 ◽  
Author(s):  
Sophie M. Andrews ◽  
Sarah Rowland-Jones
Keyword(s):  
Human Immunodeficiency Virus ◽  
Immune System ◽  
Reverse Transcriptase ◽  
Viral Diversity ◽  
Recent Advances ◽  
Technological Advances ◽  
Generation Times ◽  
Immunodeficiency Virus ◽  
Shed Light ◽  
Hiv Evolution

The human immunodeficiency virus (HIV) evolves rapidly owing to the combined activity of error-prone reverse transcriptase, recombination, and short generation times, leading to extensive viral diversity both within and between hosts. This diversity is a major contributing factor in the failure of the immune system to eradicate the virus and has important implications for the development of suitable drugs and vaccines to combat infection. This review will discuss the recent technological advances that have shed light on HIV evolution and will summarise emerging concepts in this field.

scholarly journals Development Model of Family Empowerment and Peer Group Support in Independence of Caring on Indonesian’s Migrant Worker (TKI) Infected by HIV

Jurnal NERS ◽  
2016 ◽  
Vol 10 (2) ◽  
pp. 265 ◽  
Author(s):  
Nursalam Nursalam ◽  
Ah. Yusuf ◽  
Ika Yuni Widyawati ◽  
Candra Panji Asmoro
Keyword(s):  
Human Immunodeficiency Virus ◽  
Immune System ◽  
Peer Support ◽  
Migrant Workers ◽  
Peer Group ◽  
Group Support ◽  
Family Empowerment ◽  
Immunodeficiency Virus ◽  
The Family ◽  
Work Abroad

Introduction: Human Immunodeficiency Virus (HIV) is a retrovirus that infects cells of the immune system, destroying or damaging the function of cells of the immune system. This makes the immune system becomes weaker, and people become more liable to infection. A lot of new detected HIV transmission source comes from former workers who work abroad. The challenge in dealing the number of transmission performed comprehensive care of patients and their family empowerment and peer support groups. The aimed of this study was to develop the ability of a family of Indonesian Workers who are infected with HIV and Peer Support Group in independence of care. Methods: This study was used an explanatory design and quasy-experimental. Population in this study were the closest family who care for patients infected with HIV during work abroad as migrant workers in East Java. Samples were selected using simple random sampling technique. The independent variable was the peer group and family support, the dependent variable is the level of independence of care on the respondent. Data were collected using a questionnaire that has been tested for validity and reliability and results were tested using the Wilcoxon Signed Rank Test with alpha ≤0.05. Results: The results showed that this method can improve the independence of the family of the HIV-infected client care during labor as migrant workers abroad with a significance value of p=0.004. Conclusion: Empowerment of family and peer group support can be used to increase the independence of families and patients in the treatment of HIV-infected patients during work abroad as migrant workers. Future studies are expected to use a larger sample.Keywords: empowerment of the family, peer group support, independence treatment, TKI (Indonesian Labor), Human Immunodeficiency Virus (HIV)

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