Browsing by Author "Das, Bimal Chandra"

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A COMPARATIVE STUDY OF THE METHODS OF SOLVING NON-LINEAR PROGRAMMING PROBLEM
(Daffodil International University, 2009-01-01) Das, Bimal Chandra
The work present in this paper is based on a comparative study of the methods of solving Non-linear programming (NLP) problem. We know that Kuhn-Tucker condition method is an efficient method of solving Non-linear programming problem. By using Kuhn-Tucker conditions the quadratic programming (QP) problem reduced to form of Linear programming(LP) problem, so practically simplex type algorithm can be used to solve the quadratic programming problem (Wolfe’s Algorithm).We have arranged the materials of this paper in following way. Fist we discuss about non-linear programming problems. In second step we discuss Kuhn- Tucker condition method of solving NLP problems. Finally we compare the solution obtained by Kuhn- Tucker condition method with other methods. For problem so consider we use MATLAB programming to graph the constraints for obtaining feasible region. Also we plot the objective functions for determining optimum points and compare the solution thus obtained with exact solutions.
A Cost-effective Counterfeiting Prevention Method Using Hashing, Qr Code, and Website
(Intelektual Pustaka Media Utama (IPMU), 2024-07-15) Hossain, Monir; Begum, Momotaz; Das, Bimal Chandra; Uddin, Jia
In this paper, we proposed a cost-effective software method to prevent counterfeiting where we used a website, quick-response (QR) code, and hashing. At the early stage of the product, the system will create a unique ID and a password with a random password generator for all products. Then, the password hash would be stored along with the ID in the database. At the same time, the password would be converted into a QR code for each product. The manufacturer will collect the QR code and ID and attach them to the product. When consumers attempt to verify the product, they will enter the website provided by the manufacturer and scan the QR code. After applying the same hash used before, the code will be checked on the database. After a successful check, the product entity will be destroyed and the life of the product ends. This paper contains flowcharts, figures, cost estimation, and a detailed explanation of the system. As it only requires domain hosting, thus the fixed cost of the system is so lower to bear for small enterprises also. We built a similar system using PHP, HTML, JavaScript for websites, and MYSQL for databases.
An Improved Kohonen Self-organizing Map Clustering Algorithm for High-dimensional Data Sets
(Indonesian Journal of Electrical Engineering and Computer Science, 2021) Begum, Momotaz; Das, Bimal Chandra; Hossain, Md. Zakir; Saha, Antu; Papry, Khaleda Akther
Manipulating high-dimensional data is a major research challenge in the ﬁeld of computer science in recent years. To classify this data, a lot of clustering algorithms have already been proposed. Kohonen self-organizing map (KSOM) is one of them. However, this algorithm has some drawbacks like overlapping clusters and non-linear separability problems. Therefore, in this paper, we propose an improved KSOM (I-KSOM) to reduce the problems that measures distances among objects using EISEN Cosine correlation formula. So far as we know, no previous work has used EISEN Cosine correlation distance measurements to classify high-dimensional data sets. To the robustness of the proposed KSOM, we carry out the experiments on several popular datasets like Iris, Seeds, Glass, Vertebral column, and Wisconsin breast cancer data sets. Our proposed algorithm shows better result compared to the existing original KSOM and another modiﬁed KSOM in terms of predictive performance with topographic and quantization error.
Approach to Problem of Minimizing Network Power Consumption Based on Robust Optimization
(International Journal of Communication Systems, 2019-01-08) Das, Bimal Chandra; Takahashi, Satoshi; Oki, Eiji; Muramatsu, Masakazu
In this paper, a green and robust optimization model is introduced to minimize network power consumption, which allows fluctuations of traffic demands between source‐destination pairs in the network. Our model is based on the green hose model, where the traffic is bounded by just total outgoing and incoming amount at each node. In addition to the green hose model, we use the ellipsoidal uncertainty set to allow a different type of fluctuations in traffic demands. Here, the total amount of squared errors in traffic demands is bounded by a constant which controls the total admissible fluctuations over the network. Applying the conic duality, we formulate our model in the form of mixed‐integer second order cone programming (MISOCP) problem. Furthermore, we establish a relationship between our model and the green hose model with bound of link traffic (HLT) model, an developed version of the hose model known as the HLT. Numerical results demonstrate that each of the MISOCP problems can be solved to its optimality in a reasonable time by a general MISOCP solver, and that the proposed model has different tendency in performance with the green hose and green HLT models
Approach to problem of minimizing network power consumption based on robust optimization
(2019-01-08) Das, Bimal Chandra; Takahashi, Satoshi; Oki, Eiji; Muramatsu, Masakazu
In this paper, a green and robust optimization model is introduced to minimize network power consumption, which allows fluctuations of traffic demands between source‐destination pairs in the network. Our model is based on the green hose model, where the traffic is bounded by just total outgoing and incoming amount at each node. In addition to the green hose model, we use the ellipsoidal uncertainty set to allow a different type of fluctuations in traffic demands. Here, the total amount of squared errors in traffic demands is bounded by a constant which controls the total admissible fluctuations over the network. Applying the conic duality, we formulate our model in the form of mixed‐integer second order cone programming (MISOCP) problem. Furthermore, we establish a relationship between our model and the green hose model with bound of link traffic (HLT) model, an developed version of the hose model known as the HLT. Numerical results demonstrate that each of the MISOCP problems can be solved to its optimality in a reasonable time by a general MISOCP solver, and that the proposed model has different tendency in performance with the green hose and green HLT models
Conic Programming Approach to Reduce Congestion Ratio in Communications Network
(Lecture Notes of the Institute for Computer Sciences, Social-Informatics and Telecommunications Engineering, Springer, Cham, 2020-07-30) Das, Bimal Chandra; Begum, Momotaz; Uddin, Mohammad Monir; Rahman, Md. Mosfiqur
These researches introduce a robust optimization model to reduce the congestion ratio in communications network considering uncertainty in the traffic demands. The propose formulation is depended on a model called the pipe model. Network traffic demand is fixed in the pipe model and most of the previous researches consider traffic fluctuation locally. Our proposed model can deal with fluctuation in the traffic demands and considers this fluctuation all over the network. We formulate the robust optimization model in the form of second-order cone programming (SOCP) problem which is tractable by optimization software. The numerical experiments determine the efficiency of our model in terms of reducing the congestion ratio compared to the others model.
EFFECT OF GRAPHICAL METHOD FOR SOLVING MATHEMATICAL PROGRAMMING PROBLEM
(Daffodil International University, 2010-01-01) Das, Bimal Chandra
In this paper, a computer implementation on the effect of graphical method for solving mathematical programming problem using MATLAB programming has been developed. To take any decision, for programming problems we use most modern scientific method based on computer implementation. Here it has been shown that by graphical method using MATLAB programming from all kinds of programming problem, we can determine a particular plan of action from amongst several alternatives in very short time.
Effect of Transportation Problem in Business and Economic Sector
(Daffodil International University, 2012-07) Das, Bimal Chandra
. Transportation Problem Transportation problem is one of the sub-class of Linear Programming (L.P) problems in which the objective is to transport various amount of a homogeneous commodity, that are initially stored at various origins, to different destinations in such a way that the total transportation cost is minimum. _Its major application yin solving problems involving several product sources and several destinations of products, this type of problem is frequently called the Transportation Problem (T.P).
Exact Solution for the Tzitzeica-Dodd-Bullough Equation and Dodd-Bullough-Mikhailov Equation
(Daffodil International University, 2014-07-01) Hossain, Mohammad Raquibul; Rahman, Md. Mijanoor; Das, Bimal Chandra
Analytical technique Tanh method is applied in this work for finding solution of two nonlinear partial differential equations (NLPDEs) named as Tzitzeica-Dodd-Bullough (TDB) equation and Dodd-Bullough-Mikhailov (DBM) equation which contain exponential terms.
First-Principles Quantum Treatment of Electron-Phonon Interactions in Thin-Film Nanodevices
(Scopus, 22-11-09) Hafiz, Md. Samzid Bin; Khosru, Quazi Deen Mohd; Begum, Momotaz; Das, Bimal Chandra
Electron–phonon interactions play a crucial role in nano-electronic device performance. As the accurate calculation of these interactions requires huge computational resources, reduction of this burden without losing accuracy poses an important challenge. Here, we investigate the electron–phonon interactions of nano-devices using two first-principles-based methods in numerically efficient manners. The first method is the Lowest Order Approximation (LOA) version of the computationally burdensome self-consistent Born approximation method. The LOA method incorporates the effect of each phonon mode on the electronic current perturbatively. In this work, we theoretically resolve the discrepancy between two conventional approaches of direct LOA calculation. To validate the correct approach, we compared its output with a completely different method (second method) named Special Thermal Displacement (STD) method. The STD method uses non-interacting transport calculation of the displaced atomic configuration of a device. We apply both methods to two thin-film nanodevices: 2D silicon junctionless FET and n-i-n FET. Both methods justify each other by providing similar results and exhibiting important quantum phenomena, such as phonon-assisted subthreshold swing degradation and tunneling.
Green Hose-Rectangle Model Approach for Power Efficient Communication Networks
(Scopus, 2021) Das, Bimal Chandra; Miah, Md. Waliur Rahman; Chakraborty, Narayan Ranjan; Hafiz, Md. Samzid Bin; Begum, Momotaz
Power efficiency of computer networks is an important issue for green computing. Currently available models such as the green pipe model minimizes the power consumption in the networks only for traffic demands which is fixed beforehand. In practice, the ongoing traffic demands can fluctuate due to different reasons, which the green pipe model cannot handle. On the contrary, some other existing models such as the green hose model can deal with traffic fluctuations, however with much lower power efficiency compared with the green pipe model. This research presents a robust green hose rectangle (green HR) model that employs the advantages of the mentioned both kinds of models. In one hand, our proposed model improves the power efficiency, on the other hand, allows the traffic demands to fluctuate within some acceptable range. In our model, we use an uncertainty set which is the intersection of the rectangle and hose uncertainty sets to allow errors and traffic fluctuations. Our model is tractable by modern optimization software within a reasonable time although it is in the form of mixed-integer linear programming (MILP) problem. Our experiments show some promising results. The efficiency of our proposed model is improved in terms of power savings, number of deactivating links, and computation time when compared with the green hose model.
Green Networking Approach Using Conic Optimization
(Springer, 2024-10-15) Das, Bimal Chandra; Haque, Shahina; Jahan, Nusrat; Begum, Momotaz
This study introduces a mixed integer second order cone programming (MISOCP) model called the green Ellipsoid model for power saving in communication networks. The goal of this research is to optimize power consumption in communication networks by applying the conic optimization technique which is an emerging branch of research. The consumed power in communication networks is minimized considering network data variation using robust optimization. We apply the ellipsoidal uncertainty set to grant a variation in the network data and presented the model in the form of MISOCP. To scale down the total energy utilization in the network, the study proposes shutting down some unnecessary links throughout the entire network. By identifying and deactivating these redundant or unused links, the overall power consumption is reduced. Based on the numerical results obtained, the proposed green Ellipsoid model demonstrates the ability to save consumed power in comparison to the existing green Hose approach. The results indicate that the green Ellipsoid model exceeds the green Hose approach in terms of power savings. This suggests that the introduced model is more adequate in optimizing power utilization and achieving energy efficiency in the communication networks. An additional advantage of the green Ellipsoid model is its ability to accommodate data variation across the network through a single parameter. Acknowledging that MISOCP is a known NP-hard problem, the study also proposes an improved method to minimize computation time. This is achieved by leveraging optimization software tools that make the model tractable. By utilizing these tools, the presented model can be efficiently solved within an acceptable time.
Robust SOCP Model for Business Production Mix Problems
(Daffodil International University, 2022-01-12) Das, Bimal Chandra; Nur-E-Mostafa, Md.
In this work, a robust optimization model for business production mix problem is introduced to minimize the production cost. We apply conic programming technique to the original production cost minimization problem and formulate the model in the form of second-order cone programming (SOCP) problem which is an emerging branch in current research. For decision taking, optimization plays the crucial role. In robust optimization, we have to optimize a problem where some data are not provided directly but it is declared that the data are contained in a predefined set. Minimizing the production cost for production business is a big interest to maximize the profit. In this research, we propose a robust optimization model for production in business which minimizes the production cost maintaining the quality of product. To formulate the propose model, we use conic programming technique considering the worst-case in the ratio of ingredients in product materials and introduce the model in the form of second-order cone programming (SOCP) problem. So far we studied, this is the first time application of conic programming in minimization of production cost problems. The proposed robust model is presented as an alternative option to minimize the production cost maintaining the quality of product rather than the optimal value of the problem. Of course, the proposed model can minimize the production cost compared to the original problem since it is more robust.