M.Sc. Engg.
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Item A Comparative Study on Fecal Sludge Management in Three Municipalities of Bangladesh(Khulna University of Engineering & Technology (KUET), Khulna, Bangladesh, 2016-10) Islam, Md.Sahidul; Hassan, Prof. Dr. Khondoker MahbubThe sanitation needs of 2.7 billion people worldwide are served by onsite sanitation technologies, and that number is expected to grow to 5 billion by 2030. Bangladesh provides a striking example of progress to meet the Millennium Development Goal (MDG) - 7 to halve, by 2015, the “proportion of urban population with access to improved sanitation”. Open defecation has been reduced to only 1%, a milestone change from 42% in 2003. But the increase in fixed-place defecation has created an urgent need for Fecal Sludge Management (FSM) in the cities of Bangladesh, where most human waste is dumped untreated into waterways or onto marginal land, harming the health of the country’s poorest. The draft national regulatory framework identifies municipalities as responsible for FSM. This research was carried out in Khulna City Corporation, Kushtia Municipality and Jhenaidah Municipality. The study involved data collection, field visits, fecal sludge sampling and laboratory analysis, investigation on emptying, treatment and disposal services. Khulna City Corporation (KCC) covers an area of 45.65 km2 with tax-payee holdings of 66,257 of population 15,00,689. Manual sweepers are providing emptying services. KCC is providing both manual (by boggy) and mechanical emptying (vacutug) services since ten years. But there was no designated disposal site and the septage/fecal sludge was disposed here and there specially in drains which ultimately flows to river. 84% of the septic tanks have no soak wells and is connected directly to drains. Besides, City Corporation, Community Development Committee (CDC) have three smaller (1m3) vacutugs and those are much popular in services. Annual fecal sludge generation was estimated to be around 7,10,000 m3. Recently, KCC has started to construct a fecal sludge treatment plant (FTP) with financial assistance from Bill & Melinda Gates Foundation (BMGF). Kushtia Municipality is a class “A” municipality and recently been extended to total land area of 42.79 sq.km with population 3,75,149. In this municipality, 68% septic tanks have no soak well and are connected to drains. Fecal sludge generation was estimated to be around 104,581 m3/year. In this municipality, vacutug services have been launched since ten years. They have a treatment plant with two drying beds and coco-peat filter and compost is being produced here. Recently, the emptying demand has been increased tremendously, but capacity of the treatment plant is less. Thus, another FTP is under planning to meet the additional demands for FSM. Jhenaidah municipality is a small town of 32.42 Sq.km with 1,57,822 population. About 80% of the septic tanks have soak wells. Annual fecal sludge (FS) generation was estimated to be around 58,705 m3. A constructed wetland was built by the Department of Public Health Engineering (DPHE) in 2012 and handed over to the municipality for field operation and maintenance (O & M) using two vacutugs. But the municipality didn’t have any experience for the O & M of those and eventually left unused. Characterization of FS has been done for three municipalities. Experiments have been performed for sixteen wastewater quality parameters for each FS sample such as solids concentration, chemical oxygen demand (COD), biochemical oxygen demand (BOD5), nutrients, pathogens, etc. The Solid contents in Fecal Sludge of these three towns varied between 3% to 6%. The range of COD concentrations were 7600-9600 mg/L. BOD5 concentrations were 819-1662 mg/L while the acceptable limit for disposal into inland water bodies is only 40 mg/L (ECR, 1997). Thus, it’s a big challenge to reduce the BOD5 in fecal sludge treatment plant for its ultimate disposal. Based on the entire value chain of FSM in three municipalities, proposals have been suggested for the overall improvement. There are 38.3%, 46% and 54.5% of pit toilets in Khulna, Kushtia and Jhenaidah, respectively. Placement of water seal, Y-junction of pit toilets and proper maintenance of the toilets can keep the toilets hygienic and improved. In Khulna and Kushtia municipalities, around 84% and 68% of septic tanks, respectively are connected to drains and thus stringent regulatory enforcement seemed imperative for its control and revision following Bangladesh National Building Code (BNBC). Manual emptiers can be registered by Municipal Authority so that only they can provide the services ensuring health and safety. Small devices such as Gulper and Diaphragm-Pump for emptying, Excrevator/Augur for extracting the hard solids from bottom of septic tanks, promotion and encouragement of local manufacturing process of Vacutugs, provision of secondary transfer station (STS), FSM as market based solution, simple treatment technology, raising Social Awareness, addressing Health and Safety issues, etc. have been proposed for the improvement of fecal sludge management in the study areas.Item A Multi-Objective Genetic Algorithm with Fuzzy Relational Clustering for Automatic Data Clustering(Khulna University of Engineering & Technology (KUET), Khulna, Bangladesh., 2016-12) Kundu, Animesh; Shill, Dr. Pintu Chandra.A Fuzzy relational clustering algorithm (FRC) based on multi-objective nondominated Sorting genetic algorithm (NSGA-II) called FRC-NSGA-II is proposed for automatic data clustering. A given data set is spontaneously promoted into an optimal number of groups in a precise fuzzy partition through the fuzzy relational clustering algorithm, FRC. FRC operates on a similarity square matrix which is generated by comparing the pair wise similarities between data points. Multi objective NSGA-II is employed to search for appropriate number of partitions for different cluster shapes. Moreover, two well-known cluster validity indices, compactness and separation, are optimized concurrently through multi-objective NSGA-II where compactness indicates variation between data within a cluster and separation means quantifying the separation between different clusters. Real encoding schema is used for variable length NSGA-II chromosomes representing the variable number of clusters. The simulation result on benchmark data sets exhibits that the proposed method gives promising results in the complex, overlapped, high-dimensional non-gene and gene expression data sets and it has better capability of determining well-separated, hyper spherical and overlapping clusters compared with other existing clustering algorithms.Item A New Approach to Design Microstrip Low Pass Filter(Khulna University of Engineering & Technology (KUET), Khulna, Bangladesh., 2015-07) Rafiquzzaman, G. M.; Mollah, Prof. Dr. Mohammad NurunnabiWith the emergence of novel wireless technologies, the demands for larger bandwidth, high efficiency and high capacity RF and microwave devices have been growing tremendously. The recent implementations in solid state and semiconductor materials give us hope for future applications. It should be remarked that although many of the ideas could have been proposed much earlier, it is only recently that they were identified or demonstrated due to various technological advances. The electromagnetic bandgap (EBG) is introduced to improve the performances of existing RF active and passive devices. Electromagnetic Band Gap (EBG) structures produced a wide variety of design alternatives for researchers working in the area of microwave and photonics. The focus is now towards on finding real applications combined with detailed modeling. Due to the incredible potential of EBGs, there are huge applications in which they can be used. New companies have also started to exploit the commercial potential of this technology. This thesis describes the planar EBG structures in the forms of conventional circular and rectangular photonic bandgaps (PBGs) and dumbbell shaped defected ground structures (DGSs). Novel PBGs in the form of non-uniform Binomial and Chebyshev distributions of unit PBG cells have been proposed. This novel PBGSs contains fewer ripples with lesser height or ripple free passband and wide stopband properties, which are very useful to suppress higher order harmonics in the lowpass filters (LPF). The dumbbell shaped DGSs study has been described with the gap width and length and the size of dumbbell slots. Some novel designs have been proposed such as; non-uniform dumbbell shaped DGSs with Binomial and Chebyshev distribution, hybrid dumbbell shaped DGS and PBGS and modified hybrid dumbbell shaped DGS and PBGS configurations. The novel designs perform better than the conventional DGSs reported in the literature. The DGSs yield perfect LPF responses with negligible passband ripples and extremely wide stopband. In this thesis, we have investigated on uniform circular, rectangular and dumbbell shaped DGS structures with different filling factor (FF). Therefore, FF is not a single valued parameter. In our study, we have defined the FF as the ratio of central dumbbell shaped DGS element and inter-element spacing. And then for the better performance, we have focused on different Binomially and Chebyshev distributed dumbbell shaped DGSs. This research conveys the performance of low pass filter using those distributions at about 4 GHz cutoff frequency. These distributions remove the unwanted insertion loss in the band rejection region. Sufficient explanations have been provided to validate the total research works in the thesis. Finally, comparing the insertion loss (IL) and return loss (RL) performances of the LPFs with binomially and Chebyshev distributed dumbbell shaped DGSs and hybrid DGSs. Binomially distributed DGSs and hybrid DGSs provide improved performance than conventional PBGSs and Chebyshev distributed dumbbell shaped DGSs in terms of suppression of the ripple in the passband and return and insertion-loss bandwidths.Item A New Approach to Grow High Quality Bulk lnxGa1-xAs Crystal by Multi-component Zone Melting Method(Khulna University of Engineering & Technology (KUET), Khulna, Bangladesh., 2005-12) Rahman, Mohammad Shaifur; Islam, Dr. Md. RafiqulAn analytical study has been carried out to grow high-quality bulk InGaAs crystals by the two-step multi-component zone melting (MCZM) method. Characterization of bulk InGaAs crystal grown by the two-step MCZM method has confirmed the existence of large amount of strain of the order of 10 in bulk InGaAs crystal due to approximately exponential variation of composition from 0.06 to 0.29 in the first step growth process of the two-step MCZM technique. From the experimental evidence, it has been confirmed that the composition-dependent strain is associated with the breakage issue in the MCZM grown crystals. Using an axially symmetrical strain model, the quantitative amount of strains and their distributions have been studied for various compositional profiles including the currently used profile. In addition, the spatial variations of strain components for various compositional profiles have been analyzed using the twodimensional strain maps. The strain values and their distributions corresponding to the various compositional profiles have been compared and a suitable compositional profile has been proposed to grow compositionally homogeneous high quality bulk InGaAs crystals using the MCZM method. Further, from the dependency of the strain values with the crystal length and diameter, the possibility of the growth of large-size crystals has been investigated. It has also been studied that the proposed compositional profile allows achieving the growth parameters easily for the two-step MCZM growth process.Item A Precise Evolutionary Approach to Solve Multivariable Functional Optimization(Khulna University of Engineering & Technology (KUET), Khulna, Bangladesh., 2011-06) Islam, Md. Robiul; Akhand, Dr. Muhammad Aminul Haque.Mankind has been facing optimization problems throughout history and making the great efforts to solve them. Optimization problems, in simple terms, are to find the best or close to the best solutions to the problems. The task of optimization in solving engineering problems is also crucial and the biologically motivated computing techniques have waxed and waned over the period of time. Evolutionary approach is a common technique that uses natural phenomena like biological genes, population, mating etc., to solve optimization problems. In an evolutionary approach a population of solution is maintained and tries to improve the solutions for better performance as better fitted species survive. Among several different methods of evolutionary approach Genetic Algorithm (GA) is the most popular due to its simplicity. Genetic Algorithm is a stochastic search and optimization method imitating the metaphor of natural biological evolution. It works on the population of individuals instead of single solution. Although GA draws attention for functional optimization, it may search same point again due to its probabilistic operations that hinder its performance. Generally, GAs are time-consuming in computing due to the large number of fitness function evaluations required and the implementation of many operators and parameters, but sometimes they cannot produce the desired results. it is always challenging for GA for functional optimization to achieve optimal solution in acceptable time. In this thesis, we make a novel approach of standard Genetic Algorithm (sGA) that minimizes the shortcomings of sGA. The proposed method is called Precise Genetic Algorithm (PGA). The primary motivation for the proposed PGA is to ensure the successive convergence in optimization problems to reach optimal solution with a minimal time. PGA searches the target space efficiently and it shows several potential advantages over the conventional GA for solving both single and multivariable functional problems. We have shown that the proposed method reveals the good performance in the context of the quality and the time needed to reach the optimal solutions compared to sGA.Item A Scalable Storage System For Structured Data(Khulna University of Engineering & Technology (KUET), Khulna, Bangladesh, 2017-12) Omar, Mehnuma Tabassum; Hasan, Dr. K. M. AzharulArray based storage system is a key choice of many featured applications such as Scientific, engineering, and financial computing applications; for their easy maintenance. However, the lack of scalability of the conventional approaches degrades with the Dynamic size of data sets as they entail reallocation in order to preserve expanded data Velocity. To maintain the velocity of data, the storage system must be scalable enough by Allowing subjective expansion on the boundary of array dimension. Again, for an array based storage system, if the number of dimension and length of each dimension of the Array is very high then the required address space overflows and hence it is impossible to Allocate such a big array. We demonstrate a dynamic scalable array storage scheme Namely Scalable Array Indexing (SAl) that can be an efficient choice of large volume Dynamic data management by removing the problems of the existing ones. The SAl converts an n dimensional array to 2 dimensions. Traditionally, the dynamic array models need indices for each dimensions. Since, SAl is a 2 dimensional dynamic model it reduces the index overhead significantly and compromises relatively faster data accessing. We also propose another scalable structure based on the SAl scheme to increase storage utilization. We named the structure as Segment based Scalable Array Indexing (SSAI). Using our SSAI structure, we also offer an efficient encoding with good comparison ratio and range of usability. All the operations are presented with sufficient theoretical analysis and experimental resultsItem A Study on Big Data Management Strategy Using Fog Computing(Khulna University of Engineering & Technology (KUET), Khulna, Bangladesh, 2018-11) Islam, Tajul; Hashem, Prof. Dr. M.M.A.In modern ages, data is increasing day by day using internet of things for various purposes. Data intensive analysis is the major challenge because of the ubiquitous deployment of various kinds of sensors. Traditional cloud computing infrastructure is not enough for processing these large amount, variety or velocity of data that means big data. Traditional cloud computing structure is geographically centralized. Balancing load for big data is a crucial issue. A preprocessing stage is necessary to handle these big data for real time service oriented application. In this thesis, a big data management strategy is proposed using a preprocessing stage that is fog computing. Providing real time services from cloud is too many time consuming for big data. Here, Fog Computing plays a vital role. The maximum functions of processing data are implemented outside of cloud in the case of Fog Computing and one thing considered in Fog Computing is that here memory of fog devices is very little. So, a well-organized communication system is needed for data processing. Here, in this work an affordable, robust and secure power supply or third party memory management has been suggested which is Smart Grid and Smart Local Grid. The smart grid and smart local grid or third party memory management support the customer's real time services using fog infrastructure. In this work a hierarchical architecture has been proposed for creating well-organized communication system for data processing in the case of smart grid and smart local grid or third party memory management using fog infrastructure or nodes. For task scheduling of nodes in case of fog infrastructure queue based scheduling technique is used. In this work, an effective result for big data management and providing real time services has been found. Here, different parameters such as network latency, throughput have been used for measuring performance in real time services. The overall network latency is minimized and throughput is increased in case of fog computing.Item A Study on Knowledge Extraction from Official Bangla Documents(Khulna University of Engineering & Technology (KUET), Khulna, Bangladesh, 2018-12) Gope, Monika; Hashem, Prof. Dr. M.M.A.Bangla is the seventh largest spoken language in the world. However, the information searching in the digital Bangla papers is a tiresome job as its ends up with incorrect and a very few information. It is difficult because wide computational resources for Bangla are very limited. It is literally infeasible to list and analyze the Bangla data manually. Several approaches for identifying and extracting tables, figures, emotion, reviews, and algorithms have been done in English. Furthermore, knowledge extraction in Bangla documents for emotion or opinion detection and sentence extraction for summarization have been explored. However, they do not provide enough textual information for the user for Bangla text content. In this work, we proposed a domain specific composite approaches to find out the agendas, and its decisions from the minutes of meeting of academic council of Khulna University of Engineering & Technology (KUET) with Query-based features, Content-based features, Context-based features and Semantic features. We also demonstrated the techniques to categorize the knowledge where a single query is given by the user and displayed the result sequentially by date. All the operations are presented with sufficient theoretical analysis and experimental results.Item A Study on Rule Based Reporting Systems(Khulna University of Engineering & Technology (KUET), Khulna, Bangladesh, 2018-12) Das, Prodip Kumer; Hashem, Prof. Dr. M.M.A.Government enacts rules & regulations. People are bound to follow those rules and regulations in their everyday life. Human brains do the computation for generating conclusions to take decisions on different circumstances applying those rules. A Human being does not need any external rule reasoner. However, nowadays data is generated by different automated systems, and inserted, updated, deleted in different database design formats. So, the decision-making becomes difficult by generating required conclusions from large repositories of data having multiple formats. Therefore, artificial intelligence in form of the Rule Based System can help to mitigate this problem by analyzing the conclusions from the given facts. But, the existing Rule Based Systems processes the adverse events from only one data sources at a single time and manually generates the facts. In this circumstance, the study proposes an automated Rule Based System, which is capable of generating conclusions as output for the given input queries. The study results in a database independent Rule Based method with dynamic predicate generation & translation for analyzing the stored adverse events from multiple databases by applying the predefined set of rules and regulations. The formal rules are generated using Defeasible Logic (DL) to efficiently handle the logic-based implementation of the proposed methodology. In addition, the proposed system includes SPINdle rule engine to generate required conclusions by loading the formal rules that are generated using the DL. The resulting Rule Based Reporting System (RuleRS) integrates simultaneous reasoning generation from the adverse events along with the existing Rule Based Systems to get the argumentation from multiple relational databases. It also supports the easy integration of additional data sources for generating assumptions. The output is sent to the I/O section for showing the generated reports. The study also conducted an empirical evaluation for the single sources (i.e., FAERS & ChildSafe database separately) and proposed RuleRS in reasoning simultaneously from multiple sources of data (i.e., FAERS & ChildSafe database concurrently). The evaluation result is promising to integrate the developed system with the existing RuleRS.Item A Study on Sectionalizing and Coordination of Protective Devices and Voltage Drop Compensation of Rural Distribution System(Bangladesh Institute of Technology (BIT), Khulna, Bangladesh., 2002-05) Das, Santosh Kumar; Ghosh, Prof. Dr. Bashudeb ChandraMethodologies are presented in this thesis to study the coordination among the protective devices and voltage drops at different points of a radial distribution system. Maximum and Minimum values of currents due to different types of faults occurring at various points of the distribution system are calculated. The inverse time relays and fuses are modeled by nonlinear time current relations. The definite time relays are modeled by constraint conditions. Impedance model for the radial distribution system is considered to find the fault currents. The effectiveness of the protection scheme is studied using different sets of minimum and maximum values of fault currents for all concerned fuses and relays acting as primary and backup protective devices. In the case of any miscoordination or improper coordination the CT plug multiplier setting and relay time dial setting are proposed to adjust. The optimal coordination of the radial distribution system is calTied out using two- phase technique. In phase I, the constraints for protecting the lines and equipment of the distribution system for primary and back up protection is tested for feasibility of the constraint conditions for protection. In this phase the relay and fuse time-current characteristic curves arc superimposed to visualize and ensure coordination graphically. Phase II endeavors to find out the optimal settings of relays to ensure minimum power interruption. Voltage drops under specified loading at different points are calculated to have an idea about the condition of power at different distribution points of the feeder. As case study, the radial distribution feeders of the Topshidanga 33/11 KV S/S and the Baganchra 33/11 KV S/S, under Jessore PBS-I, a project of Rural Electrification Board is considered for study on sectionalizing and coordination of protective devices and voltage drop compensation. The proposed methodology is tested in a Pentium III PC-based digital computer environment.Item A Study on Secure Outsourcing of Large Scale Computations to Cloud(Khulna University of Engineering & Technology (KUET), Khulna, Bangladesh, 2018-11) Ferdush, Jannatul; Hashem, Prof. Dr. M.M.A.At present, cloud computing has become the most prominent field for the clients which make them relax to outsource their expensive computations. Based on a pay-per-use model, a client without enough computational power can easily outsource large scale computational tasks to a cloud. But this relaxation also brings some anxious like as data confidentiality, storage overhead and trustworthiness of cloud and so on. To relief from these threats, a perfect cloud outsourcing protocol is needed. A cloud outsourcing system is perfect if it can minimize the client’s overhead as well as it has trust. So, the problem is how a client can send his overload task to cloud by privacy preserving and verifiable way. Since mathematical computations always have contribution on various scientific and engineering tasks, we are motivated to design a secure, efficient and verifiable cloud outsourcing protocol for some large-scale mathematical computations such as lyapunov equation, linear regression. Lyapunov equation needs for stability analysis. It is applied to the power system analysis also. To solve it by cloud, we use affine transformation that actually transfers the problem linearly. These transformation computes in a such way that from transferred result original result can be found. Linear regression is studied for with constrained and without constrained. Unconstrained linear regression that is studied here in two ways. First of all, it is studied by hiding its dimension and then transferred the problem by random permutation. Because of increasing dimension, efficiency of this method is decreasing but increased security. It is the trade off between efficiency and security. Second, for transforming it, we use the idea of chaotic map and frobenius matrix. Chaotic map is one of the most used random number generation algorithms and it has some advantages using frobenius matrix over diagonal matrix. At last, constrained linear regression outsourcing is done by affine mapping like as lyapunov equation. Actually, We proposed protocols for outsourcing these problems and studied these protocols in a privacy preserving, efficient and verifiable way. Real cloud is also invoked and a comparison between real and simulation cloud is also showed. Theoretical and experimental results confirm the effectiveness and efficiency of our protocols.Item A Study on the Comparison between HTML5 and OpenGL in Rendering Fractal Tree(Khulna University of Engineering & Technology (KUET), Khulna, Bangladesh, 2019-03) Khan, Mehbuba Zerin; Hashem, Prof. Dr. M.M.A.This is the era of web applications as for each desktop application, there is a corresponding web application being developed. Each web application consists of interactive graphical user interface and some of them requires in-browser rendering. In this period, it’s high time to study the abilities of modern-day web applications on handling graphical operations. As both HTML5 and OpenGL are strong tools for graphical operation and both depicts rendering capabilities on different platforms, in this project, they have been compared thoroughly. To measure the effectiveness and compare the results from HTML5 and OpenGL, Fractals are considered to be drawn on web platform and on desktop graphical program. In this project, A simple HTML5 web page is implemented along with a C++ based command line program is also implemented to render fractal trees. HTML5 and OpenGL both performed significantly well in case of rendering fractal trees where HTML5 fell a little bit short in case of rendering time in case of large number of iterations. As the number of iterations increased rapidly, the rendering time required by the HTML5 increased but it performed on par with OpenGL in rendering quality.Item A Study on the Effect of Seam, Color and Boundary Priors on Salient Region Detection(Khulna University of Engineering & Technology (KUET), Khulna, Bangladesh, 2019-12) Islam, Aminul; Ahsan, Prof. Dr. Sk. Md. MasudulBeing the best creation of almighty Allah, human beings have the ability to analyse a visual scenario. They not only see an image, but can judge the importance of different parts of a visual area. They can easily differentiate a running car from its background, can tell the color of different objects in an image and can focus attention to some important parts of a visible scene. The value of this visual power of human is easily understood if one thinks about these. Achieving this wonderful human quality using machine is one of the most precious goals of today’s scientific researches. With the continuous advancement of imaging technologies, more and more visual data are being collected all over the world. But, a major portion of these data are left unprocessed. Image processing is used to process these types of visual data. For all image processing techniques, the initial goal is to find some target region for extracting information from the image. Saliency detection is the technique of computationally finding important regions of an image. It is usually done using the contrast information present in an image. Seam map is the combination of cumulative summation of energy values from different directions. In this thesis, a combined method is proposed which uses seam importance map along with boundary aware color importance map. Color importance map is the weighted average of different color channels of Lab color space. Some intermediate combinations which are closer to the proposed optimized version but differ in the optimization technique are also presented in this thesis. Several standard benchmark datasets including the famous MSRA 10k and ECSSD datasets are used to evaluate performance of the suggested method. The proposed saliency model has been compared with several state of the art methods for each dataset. The qualitative and quantitative results from those omparisons make things easier to understand. Besides that, comparison with those state of the art techniques and precision recall curves and F-beta values found from the experiments on several datasets prove the superiority of the proposed method. This robust saliency model can improve almost all types of vision related applications including object detection, robotics, medical image analysis, content aware image resizing etc. In this research, the proposed architecture of saliency detection technique has been applied into a simple implementation of pedestrian detection. Its application has significantly improved the result of pedestrian detection in terms of performance and accuracy.Item A Technique for Assuring Secrecy and Lossless Properties of Digital Image(Khulna University of Engineering & Technology (KUET), Khulna, Bangladesh, 2020-09) Tanveer, Md. Siddiqur Rahman; Alam, Prof. Dr. Kazi Md. RokibulDue to various disease diagnosis, the volume of medical data is rising fast. Also, for telemedicine, while medical image transmits over the public network, the distortion of pixels may cause erroneous disease diagnosis. Here, encryption of the image by multiple chaos-based schemes along with DNA cryptography can be a safeguard. As chaotic schemes are very sensitive to the initial conditions, a small difference in the initial conditions yields entirely uncorrelated sequences that assure the strength of encryption. To get high randomness, several DNA encoding and computing rules are deployed. This thesis proposes a multi-stage chaotic encryption technique for the medical image through Logistic map along with Lorenz attractor and DNA cryptography, where both schemes possess the most significant value of control parameters. Thus, their consecutive deployment generates colossal chaotic sequences that ensure the robustness of the proposed technique. At first, the usage of the Logistic map with SHA-256 hash value generates a chaotic sequence that converts the plain medical image into a confusing image. Now, this sequence is used to create a confusion key to encrypt this blur image. Later on, to overcome the limitations of DNA computing rules and to get high randomness, encode this blur image and Lorenz attractor based key according to DNA encoding rules. These rules are determined randomly from eight encoding rules. Then, execute DNA operations between encoded blur image and Lorenz key using the four DNA computing rules and these rules are also determined by chaotic logistic sequence. Thus, the ultimate cipher is generated. Then, to approve the potency of the cipher, a randomness test according to NIST, security and statistical analyses and comparisons are performed.Item A Technique for DNA Cryptography Based on Dynamic Mechanisms(Khulna University of Engineering & Technology (KUET), Khulna, Bangladesh, 2018-09) Biswas, Md. Rafiul; Alam, Prof. Dr. Kazi Md. RokibulThis thesis proposes a dynamic technique for DNA cryptography based on dynamic sequence table and dynamic DNA encoding mechanisms along with an asymmetric cryptosystem. The main focusing area of the thesis is to deploy a completely dynamic approach which includes generating dynamic sequence table to produce ciphertext, dividing the ciphertext into a number of chunks, applying public key to encrypt each chunk and finally dynamic DNA encoding is used to merge the chunk of each ciphertext. Firstly, the plaintext is transformed into its corresponding DNA bases. Secondly, ASCII characters are randomly assigned to each sequence of DNA bases in the dynamic sequence table. Herein, the position of the DNA bases changes dynamically through iteration process. The generated ciphertext is divided into a fixed sized of chunks and to encrypt each chunk an symmetric cryptosystem is employed. Dynamic DNA encoding is formed using adequate random strings and efficient mathematical series and it is used to set how much random strings will be taken to merge all the ciphertext of chunks together. The usage of dynamic sequence table, public key cryptography, random string and dynamic DNA encoding altogether enhance the secrecy of data. According to the National Institute of Standards and Technology (NIST), an empirical test is performed to analyze the randomness of the ciphertext. Finally the encryption and decryption time is compared between the proposed technique and other existing techniques.Item A Voting Scheme Based on Revised-SVRM and Confirmation Numbers(Khulna University of Engineering & Technology (KUET), Khulna, Bangladesh, 2019-02) Rahman, S. M. Saifur; Alam, Prof. Dr. Kazi Md. RokibulThis thesis improves the performance of the revised-simplified verifiable re-encryption mixnet (R-SVRM) based e-voting scheme by introducing confirmation numbers (𝐶𝑁s) that are used in the 𝐶𝑁 based e-voting scheme. Although 𝐶𝑁 based and R-SVRM based schemes had made e-voting schemes more practical by excluding zero knowledge proof (ZKP) that requires large volume of computations, still they are not efficient enough. Namely, the 𝐶𝑁 based scheme adopts RSA encryption functions that are not probabilistic or commutative, therefore to satisfy essential requirements of elections, extra random factors are necessary for individual votes, election authorities must sign on votes and they must keep encryption keys as their secrets. On the other hand, although the R-SVRM based scheme uses ElGamal encryption functions that are probabilistic and commutative, vote forms in it is complicated, i.e. vote forms consist of at least 3 items and they include information about candidates as exponents. The improved scheme simplifies vote forms by exploiting 𝐶𝑁s, and extensively reduces the number of operations required for individual votes. Also, the scheme successfully satisfies all essential requirements of e-voting systems, i.e. it is endowed with features about privacy, robustness, accuracy, incoercibility and fairness as 𝐶𝑁 based and RSVRM based schemes are.Item Air Quality Assessment of Cement Manufacturing Process: A Case Study in Khulna City(Khulna University of Engineering & Technology (KUET), Khulna, Bangladesh, 2017-04) Alam, Zerin Binte; Mohiuddin, Dr. Kazi ABMAir pollution has deleterious impacts on human health and environment. Industrial sector has always led to increase the immense challenge of controlling this atmospheric pollution. Cement industry is one of the potential anthropogenic sources of air pollution and gradual substitution of traditional building patterns by modern high-rise ones has pushed up the use of cement in Bangladesh. It may cause an alteration on the air quality of Bangladesh in near future until any initiatives taken. Therefore, this study has made an attempt to determine the contribution level of a sampled cement manufacturing factory (CMF) on human health. With this consequence, this study has estimated the emission of air pollutant’s by emission factor method, characterized existed materials by different micro analysis such as XRF, particle size analysis SEM-EDS, XRD, and FTIR to correlate them with the health risk exposure. In addition it has also assessed occupational health risks at sampled CMF. The results of XRF analysis showed that the oxides such as CaO, SiO2, Al2O3, MgO, SO3, K2O, Na2O, and Fe2O3 are available in raw materials, products and by-products of CMF. SEM micrographs have evidently shown the existence of fine particles (Item Air Quality Modeling and Health Risk Assessment of Air Pollutants Generating from Khulna Power Plant(Khulna University of Engineering & Technology (KUET), Khulna, Bangladesh, 2016-05) Alam, Salma; Mohiuddin, Dr. Kazi ABMClean air is seriously affected by the atmospheric emissions generating from industrial sectors. Power plants contribute significantly among these emissions of air pollutants. This study describes the air pollutants emission from Khulna Power Company Limited (KPCL), the distribution of emitted pollutants with time and space, the contribution of power plant emission to the ambient air, and finally the estimation of health risk. This Study reveals that KPCL (225 MW power generation capacity) using Heavy Fuel Oil (HFO) that contains C (83.42%), H (10.02%), S (0.7%), O (0.05%) and N (0.1%) by weight and the chemical formula of HFO was derived as C2230H3211S7N2.5O. The energy content of HFO was determined 17.76 MJ/kg and it contains Amino (-NH), Hydroxyl (-OH) and Aliphatic Carbon (-CH), Esters (S-OR) and Sulphate (S=O) bonds. The atmospheric emission from KPCL Power plants was estimated as 197.4 t/yr of SO2, 84 t/yr of NOX, 9 t/yr of CO, 12.46 t/yr of PM10, 9.30 t/yr of PM2.5 and 2.7 kg/yr of Lead compounds. The dominant air pollutants from KPCL were found SO2 (62.04%) and NOx (26.35%). This study also shows that the dispersion of air pollutants from KPCL during September month mostly travelled towards the northern direction in a long distance (>300 km) covering the area of Jessore, Chuadanga, magura, Jhenaidah in Khulna division; Pabna, Shirazgonj, Bogra in Rajshahi division and in some cases dispersed over Dinazpur, Rangpur, Thakurgaon in Rangpur division. During the period of November 2014 to February 2015 the plume travelled long distance of more than 200km covering the area of Mongla, Bagerhat Shundarbans, Potuakhali, Borguna, Gopalgonj, Pirozpur and over Bay of Bengal. Plume also travel over Sundarbans about one- fourth (4 months) period of a year. Back trajectory of long range transport showed that air pollutants from India, Bhutan and Nepal were also contributed to the airshed of Khulna city. Due to the location Himalayan Mountains the massive air pollution of china seems not transported to Khulna airshed. Air Quality Index (AQI) results showed that during the September 2013the AQI for SO2 (15) and NOX (21) indicating the ‘good’ category (1-50) which pose little or no short term health risk. During this month comparing with the available local air quality monitoring station data, it was found that 18.5% of total ambient SO2 and 12.36% of total ambient NOX contributed by KPCL emission respectively. From dispersion modeling of November 2014 to February 2015, it was found that, 2km surrounding area of KPCL is mostly affected by SO2 and NOX. Average concentrations of SO2in that area were 7.04μg/m3 in November 2104, 7.7μg/m3 in December 2014, 6.62μg/m3 in January 2015 and 7.92μg/m3and the average concentrations of NOX were 2.94μg/m3 in November 2014, 3.13μg/m3 in December 2014, 2.81μg/m3 in January 2015 and 3.42μg/m3 in February 2015. Due to the exposure of SO2 and NOX in this area the DALYs for chronic respiratory disease obtained 0.15 and for cardiovascular disease it was obtained 0.35 per 10 Lac which indicates that 10 Lac inhabitants surrounding the KPCL area will lose their life expectancy by 128 days due to cardiovascular disease and 55 days due to chronic respiratory disease.Item An Approach for the Selection and Evaluation of Integrated Municipal Solid Waste Management in Bangladesh(Khulna University of Engineering & Technology (KUET), Khulna, Bangladesh., 2006-11) Chowdhury, Md. Khaled Hassan; Alamgir, Prof. Dr. Muhammed; 2006Bangladesh, one of the Least Developed Asian Countries is facing very complicated situations for the management of vast quantities of municipal solid waste (MSW) generated by urban communities. Due to the absence of an integrated system there are many loop holes and constraints in the existing waste management practice, which ultimately fails to improve the overall system. This study provides information about the present situation of MSW and its characteristics, management practices and limitations in the six city corporations of Bangladesh, namely Dhaka, Chittagong, Khulna, Rajshahi, Barisal and Syihet. The key issues needs to be addressed for an efficient waste management system and the limitations of the present system are also identified and illustrated here explicitly. For an integrated management of MSW, the study discuss several options such as cost benefit analysis, life cycle analysis and multicriteria decision analysis (MCDA) and propose a spreadsheet tool for an integrated management system based on the MCDA. The tool is suggested for the verification of suitability and sustainability of the adopted approach. The proposed approach is based on series of spread sheets of waste system components such as contain & collect, sort & recovery, transfer & treat and dispose & make safe, and aspects of evaluation such as source & streams, cost & return, health & environment and community & structures. The spreadsheet can be used in two ways῾WasteCheck’—where the body of the table is used to highlight the most significant questions and ῾WasteCase’—where the body of the table is used to highlight the most pertinent answers relating to the ῾usiness and sustainability’ justification. The selection and evaluation tools is then adopted theoretically for a case study city, Khulna, the third largest city of Bangladesh, to check its sustainability based on local needs and associated aspects. New terminology WastePoint for on-site disposal facility. WasteNode for waste transfer facility, StrategicSite for ultimate disposal facility is adopted in the study for better understanding and clarity. As the six study cities show a remarkable degree of similarity with respect to financial aspects, technical aspects and human resources development,the selection and evaluation approach can be easily extendable for other city corporations of Bangladesh as well.Item An Approach to Ensure the Secrecy of Scene Images(Khulna University of Engineering & Technology (KUET), Khulna, Bangladesh, 2018-07) Mondal, Arindom; Alam, Prof. Dr. Kazi Md. RokibulThis thesis proposes a multi-stage encryption technique to enhance the level of secrecy of image to facilitate its secure transmission through the public network. A vast number of researches have been done on image secrecy. The existing image encryption techniques like visual cryptography (VC), steganography, and watermarking etc. while are applied individually; usually they cannot provide unbreakable secrecy. Through combining several separate techniques, a hybrid multi-stage encryption technique is proposed in this thesis, which provides nearly unbreakable image secrecy, while the encryption/decryption time remains almost the same of the exiting techniques. The technique consecutively exploits VC, steganography and one time pad (OTP). At first it encrypts the input image using VC, i.e., splits the pixels of the input image into multiple shares to make it unpredictable. Then after the pixel to binary conversion within each share, the exploitation of steganography detects the least significant bits (LSBs) from each chunk within each share. At last, OTP encryption technique is applied on LSBs along with randomly generated OTP secret key to generate the ultimate cipher image. Besides, prior to sending the OTP key to the receiver, first it is converted from binary to integer and then an asymmetric cryptosystem is applied to encrypt it and thereby the key is delivered securely. Finally, the outcome, the time requirement of encryption and decryption, the security and statistical analyses of the proposed technique are evaluated and compared with existing techniques.