Cooperative MAC design for Ad Hoc wireless networks

Cooperative diversity is proposed to combat the detrimental effects of channel fading. In this thesis, we investigate the effectiveness of cooperative diversity in interference limited ad hoc networks. The throughput performance of ad hoc networks that employ cooperative diversity techniques is examined. The negative effects of relay transmission blocking and extra time delay due to using the relay node, on the network throughput are investigated. We show that cooperative diversity based ad hoc networks inherits relay blocking problem which causes net network throughput degradation. To solve the relay blocking problem, we propose a new cooperative medium-access-control (MAC) protocol where each relay is equipped with directive antennas and the transmitter-relay-receiver transmission mode is designed using two frequency channels. Furthermore, we discuss the throughput performance considering single and multiple relay scenarios and analyze the effect of interference on the throughput. Then we investigate the throughput performance of the proposed cooperative MAC protocol in the presence of position estimation errors. In the literature, a perfect position estimation of all nodes is commonly assumed. Here, we focus on the throughput performance of the cooperative network when taking into consideration the effect of directional-of-arrival (DOA) error caused by imperfect global-positioning system (GPS) position estimation. Our results show that using adaptive antennas at the relay becomes advantageous when the DOA error is less than 20 degrees. We noted that increasing the number of antennas (at the relay station) can improve the throughput performance but, on the other hand, the effect of node position error becomes more substantial

Enhancing GI Cancer Radiation Therapy: Advanced Organ Segmentation with ResECA-U-Net Model

This research introduces a pioneering solution to the challenges posed by gastrointestinal tract (GI) cancer in radiation therapy, focusing on the imperative task of precise organ segmentation for minimizing radiation-induced damage. GI imaging has historically used manual demarcation, which is laborious and uncomfortable for patients. We address this by introducing the ResECA-U-Net deep learning model, a novel combination of the U-Net and ResNet34 architectures. Furthermore, we further augment its functionality by incorporating the Efficient Channel Attention (ECA-Net) methodology. By utilizing data from the UW-Madison Carbone Cancer Center, we carefully investigate several image processing techniques designed to capture critical local characteristics. With its foundation in computer vision concepts, the ResECA-U-Net model is excellent at extracting fine details from GI images. Sophisticated metrics such as intersection over union (IoU) and the dice coefficient are used to evaluate performance. Our study's outcomes demonstrate the effectiveness of the suggested method, yielding an impressive 96.27% Dice coefficient and 91.48% IoU. These results highlight the significant contribution that our strategy has made to the advancement of cancer therapy. Beyond its scientific merits, this work has the potential to significantly enhance cancer patients' quality of life and provide better long-term outcomes. Our work is a significant step towards automating and optimizing the segmentation process, which can potentially change how GI cancer is treated completely. Doi: 10.28991/ESJ-2024-08-03-012 Full Text: PD

bbOCR: An Open-source Multi-domain OCR Pipeline for Bengali Documents

Despite the existence of numerous Optical Character Recognition (OCR) tools, the lack of comprehensive open-source systems hampers the progress of document digitization in various low-resource languages, including Bengali. Low-resource languages, especially those with an alphasyllabary writing system, suffer from the lack of large-scale datasets for various document OCR components such as word-level OCR, document layout extraction, and distortion correction; which are available as individual modules in high-resource languages. In this paper, we introduce Bengali$.$AI-BRACU-OCR (bbOCR): an open-source scalable document OCR system that can reconstruct Bengali documents into a structured searchable digitized format that leverages a novel Bengali text recognition model and two novel synthetic datasets. We present extensive component-level and system-level evaluation: both use a novel diversified evaluation dataset and comprehensive evaluation metrics. Our extensive evaluation suggests that our proposed solution is preferable over the current state-of-the-art Bengali OCR systems. The source codes and datasets are available here: https://bengaliai.github.io/bbocr

An efficient one dimensional parabolic equation solver using parallel computing

This paper will discuss the heat equation or as known as parabolic equation by Jacobi, Gauss Seidel and Alternating Direct Implicit (ADI) methods with the implementation of parallel computing on it. The numerical method is emphasized as platform to discretize the one dimensional heat equation. The result of three types of numerical methods will be presented graphically. The parallel algorithm is used to solve the one dimensional parabolic equation. Parallel Virtual Machine (PVM) is used in support of the communication among all microprocessors of Parallel Computing System. PVM is a software system that enables a collection of heterogeneous computers to be used as coherent and flexible concurrent computational resource. The numerical results and how fast of the convergence by Jacobi, Gauss-Seidel, and ADI will be evaluated, which are the main effort of this paper in order to fabricate an efficient One Dimensional Parabolic Equation Solver (ODPES). This new well-organized ODPES technique will enhance the research and analysis procedure of many engineering and mathematic fields

One-dimensional finite element discretization of crack propagation through parallel computation

In this study, a new approach of the application of finite element method is presented, to solve the initial stages of crack propagation problems which mean the deformation due to the stress and strain of a material. In early applications of the finite element method for the analysis of crack propagation, the crack-tip motion was modelled by discontinuous jumps. We have implemented one dimensional finite element discretization to solve crack propagation problem. The parallel algorithm with parallel computer system has been used in order to perform the computational analysis of finite element for this study. Parallel Virtual Machine (PVM) has been used as a message passing software with Parallel Computer System. The result of this study will be useful in the mathematics and engineering fields. In mathematics, the research will widen the application of finite elements in solving the engineering science problems

A case study : 2D Vs 3D parallel differential equation toward tumor cell detection on multi-core parallel computing atmosphere

This study thrashes out some of the visualisation and computational challenges encountered in the field of neuroscience. With the intention to address such computational challenges; we recognised the particular significance of the iterative solvers and parallel algorithms on Multi-Core parallel computing atmosphere. In order to detect tumour cells, 2D and 3D Partial Differential Equations (PDE) are considered and compared by using Multi-Core parallel computing atmosphere with visualisation, communication and data analysis. The performance analysis of Multi-Core computing is presented in provisions of speedup, efficiency, effectiveness and temporal performance where the use of 2D and 3D PDEs and parallel algorithms was found to give in remarkable results

A review of the parallel algorithms for solving multidimensional PDE problems

This review study gives a widespread overview of the solutions of several engineering problems based on some multidimensional partial differential equations like parabolic, hyperbolic, elliptic, AGE, IADE equations. Different analytical methods of treatment as well as those of numerical methods are presented in this paper. Finally some evaluation phases of several experiments in order to solve some current engineering problems and recommendations are demonstrate