Browsing by Author "Islam, Maheen"

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A DYNAMIC LOAD BALANCING APPROACH FOR SOLUTION ADAPTIVE FINITE ELEMENT GRAPH APPLICATIONS ON DISTRIBUTED SYSTEMS
(Daffodil International University, 2008-01-01) Islam, Maheen; Kabir, Upama
Load balancing is the key to the efficient operation of distributed systems. To efficiently utilize computing resources provided by distributed systems, an underlying Dynamic load balancing (DLB) scheme must address both heterogeneous and dynamic features of distributed systems. In this paper, a DLB scheme for Solution Adaptive Finite Element Graph Applications on distributed systems is proposed. Experiments show that by using the proposed distributed DLB scheme which considers the heterogeneous and dynamic features of distributed systems, the execution time and the number of process migration is close to using Condensed Binary Tree Load Balancing (CBTLB) scheme which does not consider the heterogeneous and dynamic features of distributed systems.
A New Load Balancing Method Based on Dynamic Cluster Construction for Solution-Adaptive Finite Element Graphs on Distributed Memory Multicomputers
(East West University, 1/1/2008) Islam, Maheen; Kabir, Upama; Kamal, Mossadek Hossain
To solve the load imbalance problem of a solution-adaptive finite element application program on a distributed memory multicomputer, the load of s refined finite element graph can be redistributed, based on the current load of each processor. For this purpose a load-balancing algorithm can be applied to balance the computational load of each processor. In this paper, a distributed methods for load balancing is proposed, which is based on the global load balancing information and current load distribution of the system. A simulation model has been developed to computre the performance of the proposed methods with previously stated methods like Maximum cost spanning tree Load-Balancing (MCSTLB) method, binary tree load balancing (BTLB) method and condensed binary tree load balancing (CBTLB) method. Two criteria, the execution time and the number of process migration required by different load balancing methods have been used for performance evaluation. The experimental result shows that the execution time and the number of process migration required by the proposed method is better than that of existing methods.
Dynamic Traffic Engineering for high-Throughput Data Delivery III Wireless Mesh Networks
(© University of Dhaka, 2025-05-27) Islam, Maheen
Dynamic traffic engineering for high-throughput data delivery in wireless mesh networks
(University of Dhaka, 2018-04-08) Islam, Maheen
Wireless Mesh Network (WMN) has recently been emerged as a promising technology for wireless Internet infrastructure development because of its low cost, ease of deployment and installation facilities. The increasing number of users and diversi ed application usages as well as the incorporation of sensors and Internet of Things (IoT) devices with the WMNs have caused exponential growth in traffic ows. This increased volume of traffic causes congestion in the network and degrades application throughput, reliability and delay performances. Therefore, providing satisfactory network performance using the limited bandwidth resources, has emerged as a challenging problem. Our endeavour in this dissertation is to address high-throughput data delivery chal- lenges in WMNs. Many state-of-the-art works address ow performance improvements in WMNs in many ways, ranging from routing, scheduling, channel allocation to rate control. However, none of these approaches merely addresses the instantaneous network conditions and sudden surge of huge data traffic from diverse user applications, that cause network to become congested. To optimize network performance, a dynamic traffic engi- neering mechanism requires to consider underlying network topology, available resources and traffic demand. Furthermore, traffic forwarding should act upon network dynamics, e.g., link error, link failure, neighborhood interference, path congestion, etc. Considering the aforementioned issues, in this thesis, we rst develop an optimization framework for Dynamic Traffic Engineering, namely O-DTE, assuming that xed channels are allocated to different links. O-DTE aims to minimize neighborhood interference and backlogged traffic, and explores the least congested next-hop nodes so that the overall throughput of the network is maximized. The O-DTE belongs to mixed integer nonlinear programming (MINLP) problem and involves both combinatorial and continuous constraints, making it an NP-hard problem. A greedy heuristic alternate solution G-DTE is then developed that produces near-optimal results. Motivated by the enhanced capacity offered by dynamic channel allocation in WMNs, the second part of our thesis focus on developing a joint link-channel selection and power allocation optimization framework (OLCP), which follows hop-by-hop traffic splitting approach and exploits single-hop information to forward traffic over least-congested and minimally-interfered link-channel pairs, which in turn improves spatial reuse and thus helps to improve overall network throughput. As nding a real-time solution of OLCP is intractable in a typical mesh router, we develop a greedy heuristic solution for the problem, GLCP, to achieve a sub-optimal solution. Recently, cognitive radio (CR) enabled mesh routers have proven to mitigate spec- trum scarcity by opportunistic licensed spectrum utilization. Thus, to boost up flow throughput in Cognitive Radio Wireless Mesh Network (CR-WMNs), we present a cen- tralized optimization framework, called COTE, in the third part of this dissertation. The COTE aims at maximizing aggregated network throughput by selecting an optimal set of link-channel pairs, power allocation over those and fair traffic splitting after considering channel idle probability, link interference and path congestion. Further, a centralized Suboptimal Traffic Engineering (SOTE) solution is proposed by employing Lagrangian dual decomposition to the COTE problem, to ensure a resolution in polynomial time. Finally, a Distributed Greedy Traffic Engineering (DGTE) method is proposed to ensure fast convergence to the dynamic changing network behavior and to improve scalability. The effectiveness of our proposed dynamic traffic engineering methods are evaluated via ns-3 simulations. The simulation results demonstrate that the proposed solutions outperform the state-of-the-art works in terms of throughput, delay, reliability, fairness and convergence cost.
Surface Plasmon Resonance Based Titanium Coated Biosensor for Cancer Cell Detection
(IEEE Photonics Journal, 2019-06-26) Jabin, Md. Asaduzzaman; Ahmed, Kawsar; Rana, Md. Juwel; Paul, Bikash Kumar; Islam, Maheen; Vigneswaran, Dhasarathan; Uddin, Muhammad Shahin
A new optimized bowl-shaped mono-core surface plasmon resonance based cancer sensor is proposed for the rapid detection of different types of cancer affected cell. By considering the refractive index of each individual cancer contaminated cell with respect to their normal cell, some major optical parameters variation are observed. Moreover, the cancerous cell concentration is considered at 80% in liquid form and the detection method is finite element method with 2 100 390 mesh elements. The variation of spectrum shift is obtained by plasmonic band gap between the silica and cancer cell part which is separated by a thin (35 nm) titanium film coating. The proposed sensor depicts a high birefringence of 0.04 with a maximum coupling length of 66 μm. However, the proposed structure provides an optimum wavelength sensitivity level between about 10 000 nm/RIU and 17 500 with a resolution of the sensor between 1.5 × 10−2 and 9.33 × 10−3 RIU. Also, the transmittance variance of the cancerous cell ranges from almost 3300 to 6100 dB/RIU and the amplitude sensitivity ranges nearly between −340 and −420 RIU−1 for different cancer cells in major polarization mode with the maximum detection limit of 0.025. Besides, the overall sensitivity performance is measured with respect to their normal cells which can be better than any other prior structures that have already proposed.