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Wireless capsule endoscopy (WCE) is used to diagnose lesions in the gastrointestinal (GI) tract. The physicians require to know the exact position of the lesions which can be performed by localizing the WCE in the GI tract. In this paper,... more
Wireless capsule endoscopy (WCE) is used to diagnose lesions in the gastrointestinal (GI) tract. The physicians require to know the exact position of the lesions which can be performed by localizing the WCE in the GI tract. In this paper, we propose ultra-wideband (UWB) path loss-based WCE localization and compute the Cramer–Rao lower bound (CRLB) to evaluate the accuracy bounds of localization in the small intestine. First, we propose the estimation of smoothed path loss by minimizing the path loss deviations caused by shadow fading effects of body tissues. Then, the estimated path loss is used to estimate the degree of path loss and to compute the weight of the sensor’s positions. Finally, we propose the smoothed path loss degree-based weighted centroid localization (SPLD-WCL) algorithm to estimate the location of the WCE. We simulate the proposed SPLD-WCL algorithm and verify the accuracy by comparing it to the computed CRLB. The proposed SPLD-WCL localization algorithm shows a s...
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In this paper transmit power and bits/channel allocation of the opportunistic users are jointly optimized in a multiple user OFDM cognitive radio network for up-link inheriting M-ary QAM scheme. Here, optimization refers to minimization... more
In this paper transmit power and bits/channel allocation of the opportunistic users are jointly optimized in a multiple user OFDM cognitive radio network for up-link inheriting M-ary QAM scheme. Here, optimization refers to minimization of transmit power and maximization of bits/channel per user. Bit Error Rate threshold and minimum requirement of bits/channel are considered as the quality of service (QoS) of this system. Effects of this allocation strategy on efficiencies from different aspects of the system are also canvassed.
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Wireless video capsule endoscopes (VCEs) are used to diagnose intestinal abnormalities. By accurate localization of the VCE, proper diagnosis of the lesions are possible. In this letter, we propose path loss degree based weighted centroid... more
Wireless video capsule endoscopes (VCEs) are used to diagnose intestinal abnormalities. By accurate localization of the VCE, proper diagnosis of the lesions are possible. In this letter, we propose path loss degree based weighted centroid localization (WCL) for VCE. The main challenge in path loss based VCE localization is the random deviation in the measured path loss caused by shadowing and multi-path propagation due to non-homogeneous medium. To address the randomness issue, we model the expected path loss using linear least square (LLS) method in the experimental phase. Then, we apply local polynomial least square method to estimate the path loss in the test phase. Finally, we propose path loss degree based WCL to estimate the coordinate position of the capsule. We simulate the proposed algorithm and visualize the results using a 3D simulation platform developed in MATLAB. We verify the accuracy of our proposed algorithm using different performance metrics and observe significant improvement over the literature without any prior precise knowledge of channel parameters or distance.
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Department of Electrical and Electronic Engineering, Bangladesh University of Engineering and Technology, Dhaka-1000, Bangladesh ... ABSTRACT This paper illustrates the superiority of using time-frequency varying averaging factor to... more
Department of Electrical and Electronic Engineering, Bangladesh University of Engineering and Technology, Dhaka-1000, Bangladesh ... ABSTRACT This paper illustrates the superiority of using time-frequency varying averaging factor to estimate the a priori SNR far
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This paper investigates an optimal allocation of transmit power and bits/subchannel for OFDM-based downlink CR system. The aim is to construct an optimization framework for OFDM-based downlink CR system that jointly maximizes the... more
This paper investigates an optimal allocation of transmit power and bits/subchannel for OFDM-based downlink CR system. The aim is to construct an optimization framework for OFDM-based downlink CR system that jointly maximizes the bits/subchannel and minimizes its transmit power while maintaining quality of service (QoS) and total transmit power limit. The measures for QoS include bit error rate (BER) and minimum rate requirement. Numerical results reveal the performance of the proposed scheme. Equivalence between power consumption-bits/subchannel trade-off and EE-SE trade-off of the system is also studied.
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Accurate localization of Wireless video capsule endoscope (VCE) is a crucial requirement for proper diagnosis of intestinal abnormalities. A major challenge in RF based localization is the shadow fading and multi-path propagation effects... more
Accurate localization of Wireless video capsule endoscope (VCE) is a crucial requirement for proper diagnosis of intestinal abnormalities. A major challenge in RF based localization is the shadow fading and multi-path propagation effects of non-homogeneous medium of human body which causes high random deviations in the measured path loss resulting in high localization error. To address the randomness issue of the scattered path loss, we propose Savitzky-Golay filtering to estimate the smoothed path loss. Then we estimate the positions of the moving capsule using weighted centroid localization (WCL) algorithm by finding the weighted average of the sensor's position. We compute the weight of the sensor receivers position using degree based estimated smoothed path loss. Finally, we propose two position bounds on the estimated positions to improve the accuracy of localization and verify the accuracy using different performance metrics. To validate our proposed algorithm, we develop a simulation platform using MATLAB and observe significant improvement over the literature using our proposed position bounded smoothed path loss based WCL without any prior knowledge of channel parameters or distance.
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... Lutfa Akter, Balasubramaniam Natarajan and Caterina Scoglio WiCom Group, Department of Electrical & Computer Engineering Kansas State University, Manhattan, Kansas 66506-5204, Telephone:(785) 532-4664, Email: lutfa@ksu.edu,... more
... Lutfa Akter, Balasubramaniam Natarajan and Caterina Scoglio WiCom Group, Department of Electrical & Computer Engineering Kansas State University, Manhattan, Kansas 66506-5204, Telephone:(785) 532-4664, Email: lutfa@ksu.edu, bala@ksu.edu, caterina@ksu.edu ...
Research Interests: Computer Science, Networks, Markov Processes, Resource sharing, Cognitive radio, and 12 moreKalman Filter, Quality of Service, Political processes modeling and forecasting, Primary User, Optical network, Spectrum, Wavelength Division Multiplexing, Upper Bound, Optimal Design, Cognitive Radio Network, MODELING AND FORECASTING, and Continuous Time Markov Chain (CTMC)
Speech enhancement is increasingly becoming an important topic of research due to the use of automatic speech process-ing systems in a variety of real world applications. Speech degraded by background noise adversely affects the... more
Speech enhancement is increasingly becoming an important topic of research due to the use of automatic speech process-ing systems in a variety of real world applications. Speech degraded by background noise adversely affects the perfor-mances of speech recognition and ...
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In this paper, we propose distance and path loss based weighted centroid localization (WCL) algorithms for video capsule endoscope (VCE) using the received signal strength indicator (RSSI). We evaluate the performance of both algorithms... more
In this paper, we propose distance and path loss based weighted centroid localization (WCL) algorithms for video capsule endoscope (VCE) using the received signal strength indicator (RSSI). We evaluate the performance of both algorithms considering real channel characteristics of human body. One of the major challenge in RSSI based VCE localization is the shadow fading and multi-path propagation effects of non-homogeneous medium of human body for which the measured RSSI is highly random resulting in high localization error. Again, due to the complex environment of experiment, accurate estimation of the channel parameters is quite difficult. We evaluate the performance of both algorithms in presence of randomness in path loss and estimation errors in channel parameters. To address the randomness issue, we estimate the smoothed path loss using moving averaging filter. Then, we introduce 10–50% errors in channel parameters to analyze the performance of both algorithms. We develop a sim...
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Different models apropos of image processing has been approbated for the application of face recognition over twenty years and more. Our proposed algorithm in this paper is a double layer process. Here the holistic approach is used to a... more
Different models apropos of image processing has been approbated for the application of face recognition over twenty years and more. Our proposed algorithm in this paper is a double layer process. Here the holistic approach is used to a certain extent to quantify the feature vectors such as median and standard deviation derived from a set of images for training and the same method is applied for finding out the feature vectors of test images and then matching those vectors, the recognized class of test image is calculated. This is to be known as the primary class and the first layer of the process and then the test image is rotated at various angles and matched against the other pre-defined training images of the derived primary class. If the number of matched pixel intensities exceeds an empirical threshold value for any of those matching the primary class is declared as the ultimate class otherwise invalid class is defined. This is the second layer of the process. An important feature of this proposed method is that though the higher rate of detection of the right class of face may not be possible over a large set of images as training set due to the variation of pose and illumination intensity, the eradication of declaring the wrong class will certainly be prevented to a certain extent by making the result invalid. This feature is very much appropriate and apposite in some real life applications where the security issue is highly concerned so that not even a single person recognized due to the erroneous result can pass through while considering the speed of the process being slow. Using our algorithm, we have found that the process efficiency of correct image class detection is 90% where 60 images from ORL database is taken into consideration for the face recognition process.
Research Interests: Mathematics and IEEE
We propose scattered path loss based weighted centroid localization (WCL) algorithm for wireless video capsule endoscope (VCE). The main challenge in this approach is the random deviation in the measured received signal strength indicator... more
We propose scattered path loss based weighted centroid localization (WCL) algorithm for wireless video capsule endoscope (VCE). The main challenge in this approach is the random deviation in the measured received signal strength indicator (RSSI) caused by multipath propagation and shadowing effects of human body channel which in turn increases the localization error. To address this issue, we propose local parameter dependent path loss representation in the training phase and apply adaptive least square error (LSE) method to extract the parameters. Then, in the test phase, we estimate distance using the extracted parameters and the randomly scattered path loss. The position of capsule is estimated using non-degree based WCL followed by a calibration process. We propose suboptimal method of estimating the calibration coefficient and also compute the optimal value of coefficient analytically to set the benchmark. We develop a simulation platform using MATLAB to present the results and...
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This paper investigates an optimal allocation of transmit power for uplink cognitive OFDMA system. The aim is to construct two optimization frameworks namely, framework-I and II for uplink cognitive OFDMA system that minimizes it’s... more
This paper investigates an optimal allocation of transmit power for uplink cognitive OFDMA system. The aim is to construct two optimization frameworks namely, framework-I and II for uplink cognitive OFDMA system that minimizes it’s transmit power while maintaining Quality of Service (QoS). The measures for QoS include SNR threshold for framework-I whereas, for framework-II, it is measured by minimum rate requirement (bits/sec/Hz) to obtain a certain bit error rate (BER). Simulation results reveal the effectiveness of the proposed frameworks. Additionally, for framework-I, effects of different SNR threshold and users’ power budget are observed on the allocation of transmit power. Whereas, for framework-II, effects of different target BER, users’ power budget and minimum rate requirement are observed on the allocation of transmit power. Results are also compared with the results obtained from conventional capacity maximization based resource allocation approaches in terms of allocated...
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Research Interests: Distributed Computing, Service Quality, Resource Allocation, Optimization, Computer Communications, and 8 moreQuality of Service, Bit Error Rate, Resource Management, Boolean Satisfiability, Electrical And Electronic Engineering, Cognitive Radio Network, Signal to Interference Plus Noise Ratio (SINR, and Channel Allocation
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ABSTRACT In this paper, we study a resource allocation problem, specifically allocation of power and rate (modulation order) to secondary users in a competitive cognitive radio network (CRN). In a competitive CRN, multiple secondary users... more
ABSTRACT In this paper, we study a resource allocation problem, specifically allocation of power and rate (modulation order) to secondary users in a competitive cognitive radio network (CRN). In a competitive CRN, multiple secondary users share a single channel and multiple channels are simultaneously used by a single secondary user (SU) to satisfy their rate requirements [1]. In such an environment, we compute optimal power and rate distribution choices that each secondary user needs to make in order to maintain their quality of service (QoS). Our measures for QoS include bit error rate (BER) and minimum rate requirement. We consider M-ary amplitude shift keying (M-ary ASK) modulation scheme and following the concept in [1], we work on transforming the BER constraint into a convex constraint in order to guarantee optimality of the resulting solutions. Simulation results demonstrate that optimal transmit power follows “reverse water filling” process and rate allocation follows signal to interference plus noise ratio (SINR).
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ABSTRACT In this work we have theoretically analysed a bi-layer waveguide placing a magnetic metamaterial on Double Positive (DPS) material and then implemented the waveguide as substrate for microstrip patch antenna and achieved 30% size... more
ABSTRACT In this work we have theoretically analysed a bi-layer waveguide placing a magnetic metamaterial on Double Positive (DPS) material and then implemented the waveguide as substrate for microstrip patch antenna and achieved 30% size reduction. This patch antenna operates at three different bands and the radiation gain at each band is quite high with a moderate bandwidth of each band. These bands have potential applications in WLAN and WiMAX devices. Flexibility for band tuning is possible in this antenna.
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ABSTRACT In this paper we have proposed a new hybrid metamaterial structure. This structure behaves as Frequency Selective Surface (FSS) and shows some Photonic Band Gap (PBG). Under two different excitation conditions once it behaves as... more
ABSTRACT In this paper we have proposed a new hybrid metamaterial structure. This structure behaves as Frequency Selective Surface (FSS) and shows some Photonic Band Gap (PBG). Under two different excitation conditions once it behaves as Epsilon Negative (ENG) and then Mu Negative (MNG) material at different bands. Each Electric and Magnetic resonance has been explained from surface current point of view. For a certain excitation two consecutive Lorentz shape electrical resonances happened within about 8GHz frequency difference. This is the effect of hybrid structure. For each excitation there is an electrical resonance at a fixed frequency band.
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We consider a multichannel cognitive radio network where multiple secondary users (SUs) share a single channel and where multiple channels are simultaneously used by a single SU to satisfy their rate requirements. We attempt to evaluate... more
We consider a multichannel cognitive radio network where multiple secondary users (SUs) share a single channel and where multiple channels are simultaneously used by a single SU to satisfy their rate requirements. We attempt to evaluate the optimal power and rate distribution choices that each SU has to make to maintain their quality of service (QoS). Our measures for QoS