Wyniki wyszukiwania - Biblioteka Nauki

1

Assessment of energy balance against the nutritional status of women carriers in the brickfields of West Bengal

100%

Bandyopadhyay B. , Sen D.

International Journal of Occupational Safety and Ergonomics

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2016

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tom Vol. 22, No. 3

399--404

EN

The Indian brick industry is an unorganized sector in which large numbers of migrant women workers are employed. A survey was conducted on 62 women workers working in different brickfields of West Bengal to assess their physiological workload, nutritional profile, total energy expenditure and energy balance. Energy intake was calculated using physiological fuel values of carbohydrate, fat and protein. From the results it is seen that 13% of the sample population falls under severe (grade III) chronic energy deficiency. The average daily consumption of the workers was comparatively lower than their daily energy expenditure, considering the nature of the job which falls under heavy to extremely heavy categories. This negative energy balance is effectively observed in the nutritional anthropometry data. Thus, an immediate ergonomics intervention with better nutrition should be implemented to improve the health status of the workers so they can safely continue to work for a longer period.

2

An improvement in stable Pade approximation using constrained minimization

100%

Bandyopadhyay B. , Singare P. S.

Systems Science

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2006

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tom Vol. 32, no 2

5-17

EN

In this paper, an improvement in Pade approximation is proposed to reduce the order of a linear-time-invariant higher order stable system, using the Hermite-Biehler stability theorem. Two free parameters are introduced in the denominator polynomial of the reduced model. It will be shown that for any positive values of these two parameters, the resulting reduced model will be stable. The numerator polynomial and these two parameters are obtained by matching time moments. In this proposed algorithm, the reduced model matches (r + 2) time moments exactly while (r + 3)-th moment is matched approximately. The proposed method is illustrated by two numerical examples.

3

Discrete time sliding mode control using multirate output feedback with chattering elimination

100%

Bandyopadhyay B. , Thakar V. K.

Systems Science

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2005

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tom Vol. 31, no 4

49-61

EN

This paper presents a inultirate output feedback based sliding mode control algorithm which eliminates the chattering. The proposed algorithm uses the output samples for the switching function evaluation and sliding mode control computation. The control is based on the reaching law approach and drives the system trajectory to sliding manifold in finite time. The control law obtained has two parts, nonlinear and linear. The nonlinear part brings the trajectory in the vicinity of the sliding manifold and linear control guarantees that the sliding manifold is readied in one step and thereafter the motion of the system confines to the manifold. The proposed algorithm does not require knowledge of the complete state vector. As in many practical situations, all the states are not available for mcasurement: the proposed algorithm gives better choice for obtaining similar result. The algorithm is applied to a dc motor system with position measurement only.

4

Design of output feedback compensator for smart structure model via reduced order model

80%

Umapathy M. , Bandyopadhyay B. , Unbehauen H.

Systems Science

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2002

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tom Vol. 28, nr 4

61-84

EN

A method of designing an output feedback compensator for vibration control of a flexible smart cantilever beam based on its reduced order model is presented. By retaining the first two vibration modes the state space model is obtained from a smart structure Finite Element Model (FEM). A reduced order model is obtained by retaining the first vibration mode. It has been shown that an output feedback compensator can be obtained for the smart structure model from the state feedback gains designed from its reduced order model. It has also been shown that if the compensator is placed in the closed loop with the higher order system, it guarantees the closed loop stability. As the states are not needed for feedback, the method is simple and can be easily implemented.

5

Discrete output feedback sliding mode control of second order systems - a moving switching line approach.

80%

Chakravarthini M. , Saaj C. M. , Bandyopadhyay B.

Systems Science

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2001

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tom Vol. 27, nr 3

5-21

EN

The sliding mode control systems (SMCS) for which the switching variable is designed independent of the initial conditions are known to be sensitive to parameter variations and extraneous disturbances during the reaching phase. For second order systems this drawback is eliminated by using the moving switching line technique where the switching line is initially designed to pass the initial conditions and is subsequently moved towards a predetermined switching line. In this paper, we make use of the above idea of moving switching line together with the reaching law approach to design a discrete output feedback sliding mode control. The main contributions of this work are such that we do not require to use system states as it makes use of only the output samples for designing the controller. and by using the moving switching line a low sensitivity system is obtained through shortening the reaching phase. Simulation results show that the fast output sampling feedback guarantees sliding motion similar to that obtained using state feedback.

6

Robust variable structure model following controller for load frequency control

80%

Patre B. M. , Bandyopadhyay B. , Unbehauen H.

Systems Science

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2002

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tom Vol. 28, nr 4

43-59

EN

A systematic procedure for design of variable structure model following load frequency controller for a single-area power system has been presented. The variable structure model following control (VSMFC) technique presented in this paper not only guarantees invariance to a class of parameter variations and disturbances but also possesses other attractive features of variable structure systems (VSS) such as robustness to unknown disturbances, simplicity in design, and reduced order dynamics when in sliding mode. The simulation results of the variable structure model following control strategy to load frequency control are presented by changing all parameters by 30% to 50% from their nominal values. These results show that systems performance is robust to parameter variations and disturbances.

7

Robust multirate output feedback sliding mode controller for sensorless induction motor

80%

Abera A. , Bandyopadhyay B. , Agarwal V.

Systems Science

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2006

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tom Vol. 32, no 1

57-69

EN

In this paper, the design of sensorless induction motor speed controller using the concept of multirate output feedback discrete-time sliding mode control technique is proposed. The nonlinear model of the motor is linearized at its operating point and the multirate output feedback discrete time sliding mode control using output samples is designed and the same is applied to nonlinear model of the motor at its operating (equilibrium) point. This method does not require the complete states of the system for feedback and is easily implementable.