A new mathematical model is developed to represent the interaction between healthy and cancer cel... more A new mathematical model is developed to represent the interaction between healthy and cancer cells in the human body, focusing on the role of input on the dynamics of the cancer model. For this purpose, the effect of input on the dynamics of a system is investigated. The question is whether an input implemented only for a limited duration can change the characteristics of a dynamic system such that the behavior of the free system, after eliminating the input, differs from that before acting the input? It is shown that nonlinearity is a necessary condition for a system in order that its dynamical properties change due to a limited duration acted input. According to the results, the accelerated fractionation is the best protocol. Also, after removing the radiotherapy the patient becomes healthy and the cancer do not relapse due to change in the dynamics of the cancer. So, the present analysis suggests that a proper treatment method should change the dynamics of the cancer instead of only reducing the population of cancer cells.
In this paper, a new mathematical model is developed to represent the interaction between healthy... more In this paper, a new mathematical model is developed to represent the interaction between healthy and cancer cells in the human body, focusing on the role of input on the dynamics of the cancer. Therefore, the effect of input, acted in limited duration, on the dynamics of a system is investigated. It is shown that nonlinearity is a necessary condition for a system in order that its dynamical properties change due to a limited time acted input. Then, based on this new approach, the best radiotherapy protocol is extracted. For this purpose, three aspects of constant radiation are considered. In this study we display consequences for protocols applied, taking into account the sort of fractionation, the dose per fraction, treatment time and the total dose. The simulations were performed with the aim of determining which protocol has minor damage in patients exposed to radiation. In other words, which protocol has the lowest fraction of normal cell kill (FN) and shorter time for the tumor removal. According to the results, the accelerated fractionation is the best protocol. Also, after removing the radiotherapy the patient become healthy and the cancer do not relapse due to change in the dynamics of the cancer. So, the present analysis suggests that a proper treatment method should change the dynamics of the cancer instead of only reducing the population of cancer cells.
Permanent change in the dynamic characteristics of a system, by exerting an input in a finite dur... more Permanent change in the dynamic characteristics of a system, by exerting an input in a finite duration, is a very interesting and challenging topic in control engineering. We show that if an input affect on the parameters of the system instead of its states and change them, it can alter the dynamics of the system even after its elimination. Then, the application of this subject is used in cancer modeling and dynamic analysis. In this paper, a novel mathematical model is developed for tumor–immune system with positive immune response, focusing on the role of external inputs in the progression of cancer which is not considered yet. We also conducted an investigation in to the effects of input on a dynamic system, and provide a comprehensive discussion of how cancer has variable behavior patterns throughout the lives of patients. The behavior of the cancer (with inputs) is studied using the trajectory patterns and stability analysis. We show that Hopf bifurcation may occur due to change in the normal rate of changing of ECs into the tumor site caused by external inputs. Therefore, the present analysis suggests that a proper treatment method should change the dynamics of the cancer instead of only reducing the population of cancer cells.
The most straightforward method for heart beat estimation is R-peak detection based on an electro... more The most straightforward method for heart beat estimation is R-peak detection based on an electrocardiogram (ECG) signal. Current R-peak detection methods do not work properly when the ECG signal is contaminated or missing, which leads to the incorrect estimation of the heart rate. This raises the need for reliable algorithms which can locate heart beats in continuous long-term multimodal data, allowing robust analysis.In this paper, three peak detectors are evaluated for heart beat detection using various cardiovascular signals. One of the peak detectors is a new general peak detector (GPD) algorithm which is applicable on ECG and other pulsatile signals to compensate for the limitation of QRS detection. This peak detector algorithm is adaptive and independently finds amplitude characteristics for every recording, while not tuned for ECG or other pulsatile signals. Three strategies, which are different disciplines of detectors, are then proposed while the fusion method remains the ...
Australasian Physical & Engineering Sciences in Medicine, 2015
The purpose of this study is to provide a new method for detecting fetal QRS complexes from non-i... more The purpose of this study is to provide a new method for detecting fetal QRS complexes from non-invasive fetal electrocardiogram (fECG) signal. Despite most of the current fECG processing methods which are based on separation of fECG from maternal ECG (mECG), in this study, fetal heart rate (FHR) can be extracted with high accuracy without separation of fECG from mECG. Furthermore, in this new approach thoracic channels are not necessary. These two aspects have reduced the required computational operations. Consequently, the proposed approach can be efficiently applied to different real-time healthcare and medical devices. In this work, a new method is presented for selecting the best channel which carries strongest fECG. Each channel is scored based on two criteria of noise distribution and good fetal heartbeat visibility. Another important aspect of this study is the simultaneous and combinatorial use of available fECG channels via the priority given by their scores. A combination of geometric features and wavelet-based techniques was adopted to extract FHR. Based on fetal geometric features, fECG signals were divided into three categories, and different strategies were employed to analyze each category. The method was validated using three datasets including Noninvasive fetal ECG database, DaISy and PhysioNet/Computing in Cardiology Challenge 2013. Finally, the obtained results were compared with other studies. The adopted strategies such as multi-resolution analysis, not separating fECG and mECG, intelligent channels scoring and using them simultaneously are the factors that caused the promising performance of the method.
Indian Journal of Science and Technology, May 20, 2015
In Wireless Sensor Networks (WSNs), signals are used as channels for communicating data. Wireless... more In Wireless Sensor Networks (WSNs), signals are used as channels for communicating data. Wireless channels are inherently insecure; hence, the vulnerability of signals to external destructive factors and to the interference of intruders can result in the production of errors in data to be transferred. On the other hand, in as much as wireless sensors have limited energy, optimal consumption of energy for enhancing network lifetime is of high significance. In this paper, a protocol based on block-level retransmission and network-coding has been proposed which is intended to optimize error recovery in sensor networks. This protocol takes the parameters of reliability and energy consumption into account. In this protocol, data frames are divided into blocks and in the case of error occurrence, the total frame need not to be transferred since only the error containing block is retransferred using the network coding technique. This procedure minimizes the number of transfer and reception in the nodes. Consequently, energy consumption is reduced. The simulation results revealed that utilizing the networking coding technique in the proposed method results in reliability enhancement. Thus, the simulation results indicate that the proposed method leads to higher reliability and lower energy consumption than the LIERMO method.
... SUBMAXIMAL ISOKINETIC CONTRACTIONS SHOJA ALDIN SSAD,JAMSHIDI AA,GHAFARI ALI The purpose of th... more ... SUBMAXIMAL ISOKINETIC CONTRACTIONS SHOJA ALDIN SSAD,JAMSHIDI AA,GHAFARI ALI The purpose of this study was to investigate the effect of massage on the knee extensor muscles fatigue following sub maximal is kinetic contractions. Ten male games players (age ...
International Journal of Environmental Science and Technology, 2014
ABSTRACT An oxidized mesoporous carbon material, modified with tetraethylenepentamine, has been d... more ABSTRACT An oxidized mesoporous carbon material, modified with tetraethylenepentamine, has been developed as a highly efficient adsorbent for hexavalent chromium. Influence of parameters such as adsorbent dose (0.1–0.8 g L−1) solution pH (1–9), contact time, and initial concentration (100–1,000 mg L−1) on adsorption capacity has been investigated and optimized. The sorption equilibrium was reached within 60 min. The structural order and textural properties of the synthesized material were studied by X-ray diffraction, scanning electron microscopy, Fourier transform infrared, and nitrogen adsorption–desorption analysis. The experimental results were analyzed by the Langmuir and Freundlich isotherms. The maximum adsorption capacity of 510 mg g−1 at an initial concentration of 1,000 mg L−1 is well predicted by the Freundlich isotherm. The kinetic analysis indicated that the adsorption process was successfully fitted with the pseudo-first-order kinetic model. Compared to other adsorbents reported in the literature, the modified nanoporous carbon material prepared in this study is found to be highly efficient adsorbent for the removal of hexavalent chromium from wastewater.
Abstract In a hybrid vehicle with dual power systems such as internal combustion engines working... more Abstract In a hybrid vehicle with dual power systems such as internal combustion engines working with conventional fuels and electric motors, each system has specific operational characteristics and requirements which these have to be matched with each other and at the same time ...
A new mathematical model is developed to represent the interaction between healthy and cancer cel... more A new mathematical model is developed to represent the interaction between healthy and cancer cells in the human body, focusing on the role of input on the dynamics of the cancer model. For this purpose, the effect of input on the dynamics of a system is investigated. The question is whether an input implemented only for a limited duration can change the characteristics of a dynamic system such that the behavior of the free system, after eliminating the input, differs from that before acting the input? It is shown that nonlinearity is a necessary condition for a system in order that its dynamical properties change due to a limited duration acted input. According to the results, the accelerated fractionation is the best protocol. Also, after removing the radiotherapy the patient becomes healthy and the cancer do not relapse due to change in the dynamics of the cancer. So, the present analysis suggests that a proper treatment method should change the dynamics of the cancer instead of only reducing the population of cancer cells.
In this paper, a new mathematical model is developed to represent the interaction between healthy... more In this paper, a new mathematical model is developed to represent the interaction between healthy and cancer cells in the human body, focusing on the role of input on the dynamics of the cancer. Therefore, the effect of input, acted in limited duration, on the dynamics of a system is investigated. It is shown that nonlinearity is a necessary condition for a system in order that its dynamical properties change due to a limited time acted input. Then, based on this new approach, the best radiotherapy protocol is extracted. For this purpose, three aspects of constant radiation are considered. In this study we display consequences for protocols applied, taking into account the sort of fractionation, the dose per fraction, treatment time and the total dose. The simulations were performed with the aim of determining which protocol has minor damage in patients exposed to radiation. In other words, which protocol has the lowest fraction of normal cell kill (FN) and shorter time for the tumor removal. According to the results, the accelerated fractionation is the best protocol. Also, after removing the radiotherapy the patient become healthy and the cancer do not relapse due to change in the dynamics of the cancer. So, the present analysis suggests that a proper treatment method should change the dynamics of the cancer instead of only reducing the population of cancer cells.
Permanent change in the dynamic characteristics of a system, by exerting an input in a finite dur... more Permanent change in the dynamic characteristics of a system, by exerting an input in a finite duration, is a very interesting and challenging topic in control engineering. We show that if an input affect on the parameters of the system instead of its states and change them, it can alter the dynamics of the system even after its elimination. Then, the application of this subject is used in cancer modeling and dynamic analysis. In this paper, a novel mathematical model is developed for tumor–immune system with positive immune response, focusing on the role of external inputs in the progression of cancer which is not considered yet. We also conducted an investigation in to the effects of input on a dynamic system, and provide a comprehensive discussion of how cancer has variable behavior patterns throughout the lives of patients. The behavior of the cancer (with inputs) is studied using the trajectory patterns and stability analysis. We show that Hopf bifurcation may occur due to change in the normal rate of changing of ECs into the tumor site caused by external inputs. Therefore, the present analysis suggests that a proper treatment method should change the dynamics of the cancer instead of only reducing the population of cancer cells.
The most straightforward method for heart beat estimation is R-peak detection based on an electro... more The most straightforward method for heart beat estimation is R-peak detection based on an electrocardiogram (ECG) signal. Current R-peak detection methods do not work properly when the ECG signal is contaminated or missing, which leads to the incorrect estimation of the heart rate. This raises the need for reliable algorithms which can locate heart beats in continuous long-term multimodal data, allowing robust analysis.In this paper, three peak detectors are evaluated for heart beat detection using various cardiovascular signals. One of the peak detectors is a new general peak detector (GPD) algorithm which is applicable on ECG and other pulsatile signals to compensate for the limitation of QRS detection. This peak detector algorithm is adaptive and independently finds amplitude characteristics for every recording, while not tuned for ECG or other pulsatile signals. Three strategies, which are different disciplines of detectors, are then proposed while the fusion method remains the ...
Australasian Physical & Engineering Sciences in Medicine, 2015
The purpose of this study is to provide a new method for detecting fetal QRS complexes from non-i... more The purpose of this study is to provide a new method for detecting fetal QRS complexes from non-invasive fetal electrocardiogram (fECG) signal. Despite most of the current fECG processing methods which are based on separation of fECG from maternal ECG (mECG), in this study, fetal heart rate (FHR) can be extracted with high accuracy without separation of fECG from mECG. Furthermore, in this new approach thoracic channels are not necessary. These two aspects have reduced the required computational operations. Consequently, the proposed approach can be efficiently applied to different real-time healthcare and medical devices. In this work, a new method is presented for selecting the best channel which carries strongest fECG. Each channel is scored based on two criteria of noise distribution and good fetal heartbeat visibility. Another important aspect of this study is the simultaneous and combinatorial use of available fECG channels via the priority given by their scores. A combination of geometric features and wavelet-based techniques was adopted to extract FHR. Based on fetal geometric features, fECG signals were divided into three categories, and different strategies were employed to analyze each category. The method was validated using three datasets including Noninvasive fetal ECG database, DaISy and PhysioNet/Computing in Cardiology Challenge 2013. Finally, the obtained results were compared with other studies. The adopted strategies such as multi-resolution analysis, not separating fECG and mECG, intelligent channels scoring and using them simultaneously are the factors that caused the promising performance of the method.
Indian Journal of Science and Technology, May 20, 2015
In Wireless Sensor Networks (WSNs), signals are used as channels for communicating data. Wireless... more In Wireless Sensor Networks (WSNs), signals are used as channels for communicating data. Wireless channels are inherently insecure; hence, the vulnerability of signals to external destructive factors and to the interference of intruders can result in the production of errors in data to be transferred. On the other hand, in as much as wireless sensors have limited energy, optimal consumption of energy for enhancing network lifetime is of high significance. In this paper, a protocol based on block-level retransmission and network-coding has been proposed which is intended to optimize error recovery in sensor networks. This protocol takes the parameters of reliability and energy consumption into account. In this protocol, data frames are divided into blocks and in the case of error occurrence, the total frame need not to be transferred since only the error containing block is retransferred using the network coding technique. This procedure minimizes the number of transfer and reception in the nodes. Consequently, energy consumption is reduced. The simulation results revealed that utilizing the networking coding technique in the proposed method results in reliability enhancement. Thus, the simulation results indicate that the proposed method leads to higher reliability and lower energy consumption than the LIERMO method.
... SUBMAXIMAL ISOKINETIC CONTRACTIONS SHOJA ALDIN SSAD,JAMSHIDI AA,GHAFARI ALI The purpose of th... more ... SUBMAXIMAL ISOKINETIC CONTRACTIONS SHOJA ALDIN SSAD,JAMSHIDI AA,GHAFARI ALI The purpose of this study was to investigate the effect of massage on the knee extensor muscles fatigue following sub maximal is kinetic contractions. Ten male games players (age ...
International Journal of Environmental Science and Technology, 2014
ABSTRACT An oxidized mesoporous carbon material, modified with tetraethylenepentamine, has been d... more ABSTRACT An oxidized mesoporous carbon material, modified with tetraethylenepentamine, has been developed as a highly efficient adsorbent for hexavalent chromium. Influence of parameters such as adsorbent dose (0.1–0.8 g L−1) solution pH (1–9), contact time, and initial concentration (100–1,000 mg L−1) on adsorption capacity has been investigated and optimized. The sorption equilibrium was reached within 60 min. The structural order and textural properties of the synthesized material were studied by X-ray diffraction, scanning electron microscopy, Fourier transform infrared, and nitrogen adsorption–desorption analysis. The experimental results were analyzed by the Langmuir and Freundlich isotherms. The maximum adsorption capacity of 510 mg g−1 at an initial concentration of 1,000 mg L−1 is well predicted by the Freundlich isotherm. The kinetic analysis indicated that the adsorption process was successfully fitted with the pseudo-first-order kinetic model. Compared to other adsorbents reported in the literature, the modified nanoporous carbon material prepared in this study is found to be highly efficient adsorbent for the removal of hexavalent chromium from wastewater.
Abstract In a hybrid vehicle with dual power systems such as internal combustion engines working... more Abstract In a hybrid vehicle with dual power systems such as internal combustion engines working with conventional fuels and electric motors, each system has specific operational characteristics and requirements which these have to be matched with each other and at the same time ...
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Papers by Ali Ghaffari