Bhuwan Mohan Karan

Birla Institute of Technology, Mesra, Rānchī, State of Jharkhand, India

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Publications (18)10.94 Total impact

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    ABSTRACT: The present work is concerned to model the molecular signalling pathway for vasodilation and to predict the resting young human forearm blood flow under heat stress. The mechanistic electronic modelling technique has been designed and implemented using MULTISIM 8.0 and an assumption of 1V/ degrees C for prediction of forearm blood flow and the digital logic has been used to design the molecular signalling pathway for vasodilation. The minimum forearm blood flow has been observed at 35 degrees C (0 ml 100 ml(-1)min(-1)) and the maximum at 42 degrees C (18.7 ml 100 ml(-1)min(-1)) environmental temperature with respect to the base value of 2 ml 100 ml(-1)min(-1). This model may also enable to identify many therapeutic targets that can be used in the treatment of inflammations and disorders due to heat-related illnesses.
    Computers in biology and medicine 05/2010; 40(5):533-42. · 1.27 Impact Factor
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    ABSTRACT: Continuous wavelet transform (CWT) method has been applied to capture localized time-frequency in-formation of rat electroencephalogram (EEG) in dif-ferent vigilance states and analyze alterations in transients during awake, slow wave sleep (SWS), and rapid eye movement (REM) sleep stages due to ex-posure to high environmental heat. Rats were divided in three group (i) acute heat stress-subjected to a sin-gle exposure for four hours in the Biological Oxygen Demand (BOD) incubator at 38C; (ii) chronic heat stress-exposed for 21 days daily for one hour in the incubator at 38C, and (iii) handling control groups. After two hours long EEG recordings from young healthy rats, EEG data representing three sleep states was visually selected and further subdivided into 2 seconds long epoch. Powers of wavelet spectra corresponding to delta, theta, alpha, and beta bands at all scales and locations were computed and varia-tion in their states investigated. The wavelet analysis of EEG signals following exposure to high environ-mental heat revealed that powers of subband fre-quencies vary with time unlike Fourier technique. Changes in higher frequency components (beta) were significant in all sleep-wake states following both acute and chronic heat stress conditions. Percentage power of different components of the four bands was always found to be varying at different intervals of time in the same signal of analysis.
    Journal of biomedical science and engineering 01/2010; 334056:405-414. · 0.27 Impact Factor
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    Priyam Amrita, B. M. Karan, Sahoo G
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    ABSTRACT: This paper presents a probabilistic approach for DNA sequence analysis. A DNA sequence consists of an arrangement of the four nucleotides A, C, T and G and different representation schemes are presented according to a probability measure associated with them. There are different ways that probability can be associated with the DNA sequence: one way is when the probability of an occurrence of a letter does not depend on the previous one (termed as unsuccessive probability) and in another scheme the probability of occurrence of a letter depends on its previous letter (termed as successive probability). Further, based on these probability measures graphical representations of the schemes are also presented. Using the diagram probability measure one can easily calculate an associated probability measure which can serve as a parameter to check how close is a new sequence to already existing ones.
    International Journal of Computer Science and Information Security. 01/2010;
  • Priyam Amrita, B. M. Karan, G. Sahoo
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    ABSTRACT: This paper presents a probabilistic approach for DNA sequence analysis. A DNA sequence consists of an arrangement of the four nucleotides A, C, T and G. There are various representation schemes for a DNA sequence. This paper uses a representation scheme in which the probability of a symbol depends only on the occurrence of the previous symbol. This type of model is defined by two parameters, a set of states Q, which emit symbols and a set of transitions between the states. Each transition has an associated transition probability, aij, which represents the conditional probability of going to state j in the next step, given that the current state is i. Further, the paper combines the different types of classification classes using a Fuzzy composition relation. Finally a log-odd ratio is used for deciding to which class the given sequence belongs to.
    International Journal of Computer Science and Information Security. 01/2010;
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    ABSTRACT: Heat stress is known to induce high mortality rate due to multi-system illness, which demands urgent attention to reduce the fatality rate in such patients. Further, for the diagnosis and supportive therapy, one needs to define the severity of heat stress that can be distinguished as mild, intermediate and severe. The objective of this work is to develop an automated unsupervised artificial system to analyze the clinical outcomes of different levels of heat related illnesses. The Kohonen neural network program written in C++, which has seven normalized values of different clinical symptoms between 0–1 fed to the input layer of the network with 50 Kohonen output neurons, has been presented. The optimized initializing parameters such as neighborhood size and learning rate was set to 50 and 0.7, respectively, to simulate the network for 10million iterations. The network was found smartly distinguishing all 51 patterns to three different states of heat illnesses. With the advent of these findings, it can be concluded that the Kohonen neural network can be used for automated classification of the severity of heat stress and other related psycho-patho-physiological disorders. However, to replace the expert clinicians with such type of smart diagnostic tool, extensive work is required to optimize the system with variety of known and hidden clinical and pathological parameters.
    Journal of Clinical Monitoring and Computing 11/2008; 22(6):425-430. · 0.71 Impact Factor
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    ABSTRACT: Many mathematical models of thermoregulation in humans have been developed, so far. These models appeared to be very useful tools for studying temperature regulation in humans under adverse environmental conditions. However, no one discussed the heat transfer characteristics of denervated subjects. Thus, the present study is concerned with aspects of the passive system for denervated subjects: (1) modeling the human body extremities (2) modeling heat transport mechanism within the body and at its periphery. The present model was simulated using the software (Wintherm 8.0, Thermoanalytics, USA) for different body segments to predict the heat flow between body core and skin surface with changes in environmental temperature with fixed relative humidity and wind velocity. The simulated model for comparative study of internal temperature distribution of hand, arm, leg and feet segments yielded remarkably good results and observed to be in trends with previously cited work under ambient environmental condition and at controlled room temperature. Models could be used to measure the temperature distribution in human limbs during local hyperthermia and to investigate the interaction between limbs and the thermal environment.
    Journal of Medical Systems 09/2008; 32(4):283-90. · 1.78 Impact Factor
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    ABSTRACT: The thermoregulatory control of human skin blood flow is vital to maintain the body heat storage during challenges of thermal homeostasis under heat stress. Whenever thermal homeostasis disturbed, the heat load exceeds heat dissipation capacity, which alters the cutaneous vascular responses along with other body physiological variables. Whole body skin blood flow has been calculated from the forearm blood flow. Present model has been designed using electronics circuit simulator (Multisim 8.0, National Instruments, USA), is to execute a series of predictive equations for early prediction of physiological parameters of young nude subjects during resting condition at various level of dry heat stress under almost still air to avoid causalities associated with hot environmental. The users can execute the model by changing the environmental temperature in degrees C and exposure time in minutes. The model would be able to predict and detect the changes in human vascular responses along with other physiological parameters and from this predicted values heat related-illness symptoms can be inferred.
    Journal of Medical Systems 05/2008; 32(2):167-76. · 1.78 Impact Factor
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    ABSTRACT: We are introducing in this paper a digital-analog hybrid model approach for the study of a complete gene regulatory network; the heat shock response (HSR) network of eukaryotes. HSR is a crucial and widely studied cellular phenomenon occurring due to various stresses on the cell, and is characterised by the induction of heat shock genes resulting in the production of heat shock proteins (HSPs) which restores cellular homeostasis by maintaining protein integrity. We are proposing a model which incorporates simple digital and analog components which mimic the functioning of biological molecules involved in HSR and model their dynamics and behaviour. The simulation result of the circuit for the production of HSP70 has been found to be consistent with published experimental results. The qualitative behaviour of the HSR is expressed through a truth table. Through this novel approach, the authors have tried to develop a level of understanding of the interactions of the parts of the HSR system and of this system as a whole.
    Computer Methods and Programs in Biomedicine 05/2008; 90(1):17-24. · 1.56 Impact Factor
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    ABSTRACT: Exertional heat illness is primarily a multi-system disorder results from the combined effect of exertional and thermoregulation stress. The severity of exertional heat illness can be classified as mild, intermediate and severe from non-specific symptoms like thirst, myalgia, poor concentration, hysteria, vomiting, weakness, cramps, impaired judgement, headache, diarrhea, fatigue, hyperventilation, anxiety, and nausea to more severe symptoms like exertional dehydration, heat cramps, heat exhaustion, heat injury, heatstroke, rhabdomyolysis, and acute renal failure. At its early stage, it is quite difficult to find out the severity of disease with manual screening because of overlapping of symptoms. Therefore, one need to classify automatically the disease based on symptoms. The 7:10:1 backpropagation artificial neural network model has been used to predict the clinical outcome from the symptoms that are routinely available to clinicians. The model has found to be effective in differentiating the different stages of exertional heat-illness with an overall performance of 100%.
    Journal of Medical Systems 01/2008; 31(6):547-50. · 1.78 Impact Factor
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    ABSTRACT: Sliding Mode Control (SMC) is an appropriate robust control method for a specific class of nonlinear systems. SMC is recently used in control of switch mode power supplies as against different control algorithms like PID control, current programmed control etc. In this paper Fuzzy Sliding Mode Like Control (FSMLC) is build through fuzzy knowledge base which has advantage of still higher robustness. FSMLC is further modified by adding additional boundary layer in the phase plane to avoid drastic changes in the control variable. It is implemented in real time using TMS320LF2407A Digital Signal Processor (DSP) as against the conventional microprocessor implementations through lookup tables. Experimental results are in accordance with the simulated results carried out in Matlab Simulink. The comparison of the FSMLC is shown with conventional PID controller and SMC.
    Control and Intelligent Systems 01/2008; 36(3).
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    KESHRI R., S. G. KADWANE, B. M. KARAN
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    ABSTRACT: With the increasing use of electronic equipments, the problem of low power factor and input current harmonics associated with AC to DC conversion stage has been a matter of concern for all. Passive PFC methods have certain disadvantages against active PFC methods, which use high frequency converters to provide high power factor with negligible harmonics. In the present work neural network based intelligent controller is proposed for active power factor correction and voltage regulation using Zeta converter for dc-to-dc conversion stage. The proposed model is simulated using PSIM and MATLAB. Neural Network is trained offline using current-mode-controller with PI controllers. This considerably improves the startup response (after training) and reduces the harmonics which intern improves the power factor.
    IEEE Region 10 Colloquium and Third IEEE Conference on Industrial and Information System 2008; 01/2008
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    ABSTRACT: The thermoregulatory control of human skin blood flow is vital to maintain the body heat storage during challenges of thermal homeostasis under heat stress. Whenever thermal homeostasis disturbed, the heat load exceeds heat dissipation capacity, which alters the cutaneous vascular responses along with other body physiological variables. Whole body skin blood flow has been calculated from the forearm blood flow. Present model has been designed using electronics circuit simulator (Multisim 8.0, National Instruments, USA), is to execute a series of predictive equations for early prediction of physiological parameters of young nude subjects during resting condition at various level of dry heat stress under almost still air to avoid causalities associated with hot environmental. The users can execute the model by changing the environmental temperature in °C and exposure time in minutes. The model would be able to predict and detect the changes in human vascular responses along with other physiological parameters and from this predicted values heat related-illness symptoms can be inferred.
    Journal of Medical Systems 01/2008; 32:167-176. · 1.78 Impact Factor
  • A.K. Jha, K.H. Babu, B.M. Karan
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    ABSTRACT: In this paper, a new parallel-connected single phase power factor correction (PFC) topology using flyback converter in parallel with forward converter is proposed to improve the input power factor with simultaneously output voltage regulation taking consideration of current harmonic norms. Paralleling of converter modules is a well-known technique that is often used in medium-power applications to achieve the desired output power by using smaller size of high frequency transformers and inductors. The proposed approach offers cost effective, compact and efficient AC-DC converter by the use of parallel power processing. Forward converter primarily regulates output voltage with fast dynamic response and it acts as master which processes 60% of the power. Flyback converter with AC/DC PFC stage regulates input current shaping and PFC, and processes the remaining 40% of the power as a slave. This paper presents a design example and circuit analysis for 300 W power supply. A parallel-connected interleaved structure offers smaller passive components, less loss even in continuous conduction inductor current mode, and reduced volt-ampere rating of DC/DC stage converter. MATLAB/Simulink is used for implementation and simulation results show the performance improvement.
    Power Electronics, Drives and Energy Systems, 2006. PEDES '06. International Conference on; 01/2007
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    S G Kadwane, A Kumar, B M Karan
    01/2007;
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    ABSTRACT: This paper deals with real time DC motor speed control, using the low-cost new generation TMS320LF2407A digital signal processor. A PID controller is designed using MATLAB functions to generate a set of coefficients associated with the desired controller characteristics. The controller coefficients are then discretised and included in an assembly language or C program that implements the PID controller. Code composer studio is used to load and run the PID controller to achieve real time control. Furthermore, the PID parameters can be adjusted while the motor is running, so that the online adjustment is achieved. Speed control is investigated on a DC motor with speed feedback. According to the error in speed, followed by PID action DSP processor changes the duty cycle of the PWM, which is given as the input to the buck converter. Results show the improvement of system outputs as expected with a PID controller, with actual system outputs matching theoretical calculations. Since cascaded buck converter is having the added advantage over DAC that it can be principally extended for motors of higher ratings only by changing the component values of buck converter
    Industrial Electronics and Applications, 2006 1ST IEEE Conference on; 06/2006
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    ABSTRACT: Buck converter is highly nonlinear system because of its inherent switching. When a buck converter is cascaded with DC servomotor for controlling the speed, conventional design approach (like PID, deadbeat...) for speed control can not be applied. This paper proposes design of fuzzy PI like controller for speed control of small DC servo motor cascaded with buck converter. The proposed fuzzy logic controller is first programmed in C language and results are compared with fuzzy inference system (FIS) editor in Matlab. This C program is then executed in code composer studio (CCS) for real time implementation on DSP processor TMS320LF2407A. Cascaded buck converter has an added advantage over digital to analog converters, that, it can be principally extended for motors of higher ratings only by changing the component values of buck converter.
    01/2006;
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    ABSTRACT: Abstract Fuzzy Sliding Mode ,like Control (FSMC) is an appropriate robust control method for a specific class of nonlinear systems that provides higher robustness as compared,to conventional ,sliding mode ,control. The main,problem ,in implementing ,a FSMC is how ,to select the shape of membership ,functions, more precisely to select the optimum,width for bases of the triangles. This paper deals with Genetic tuned Fuzzy Sliding Mode like Control (GFSMC) applied to buck converter. The membership,functions are tuned offline byGenetic,Algorithm and Simulation model ,of buck converter is developed. GFSMC is implemented on the prototype of buck converter through TMS320LF2407A Digital signal processor ,and ,improvements ,in the results are clearly shown Keywords Sliding mode control, Fuzzy control, Real time systems, Robust control Converters, Stability analysis, Genetic Algorithm.
    01/2006;
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    ABSTRACT: Dynamic programming is a form of recursion in which intermediate results are saved in a matrix where they can be refereed to later by the program. The paper aims at presenting the calculation of the edit distance between two given strings which includes a cost factor for the different edit operations like copy, insert and delete. The method used in this paper is a form of dynamic programming which includes the formation of a recurrence relation which is then used to represent the problem in a tabular form. In the next step the table is used to trace back to get the possible combinations of edit operations and the one which involves the least cost can be considered the appropriate one.