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11th graduation ceremony of MIST held
(The Financial Express, 2013-03-13) The Financial Express
5th International Conference on Electrical Engineering and Information & Communication Technology (ICEEICT 2021)
(DEPARTMENT OF ELECTRICAL, ELECTRONIC AND COMMUNICATION ENGINEERING, 2021-11)
A BRIEF INTERPRETATION OF ACCIDENTS IN BANGLADESH INLAND RIVER ROUTES: (An Approach from Practical Point of View)
(R&D Wing, MIST, 2015-03) Rabiul Islam, Major Muhammad PhD; Rashid, Cdr Kaosar (E), psc, BN
Inland river transportation, the safest form of transportation in developed countries is the agent of catastrophe in Bangladesh, a developing country. Over the past decades there have been a number of launch (passenger ferry) accidents in which several thousand people met watery graves. Literature review shows that analyses were carried out mostly from the viewpoint of academic research. To enlighten the roles of professionals like Naval Architects and Law Enforcing Agencies, the reasons behind the accidents in Bangladesh Inland Waterways have been simplified and the nature of actions required for preventing the accidents have been identified from practical point of view. Data analysis of major accidents shows that prevention of passenger vessels’ accident will drastically reduce the number of casualties in Bangladesh Inland Waterways where the two repeatedly reported causes of accidents are overloading and inclement weather. Vessels of length around 40 meters are more accident prone in inclement weather. Analysis shows that consideration of overloading condition in design will have no effect in practical scenario and consideration of higher wind pressure in design is not feasible from the socio-economical aspect of Bangladesh. Role of proper design and construction has been identified by dividing the accidental phenomenon into two phases, capsizing and sinking of vessels.
A COMPARATIVE ANALYSIS OF AHP, ISM AND MICMAC METHODS IN FINDING THE MOST SIGNIFICANT BARRIERS OF PHARMACEUTICAL SUPPLY CHAIN MANAGEMENT IN BANGLADESH
(2019-12) Mimi, Afsana Akter; Faiza, Fahmida
A supply chain is a network between a company and its suppliers to produce and distribute a specific product to the final buyer. This network includes different activities, people, entities, information and resources. Among all the supply chains, pharmaceutical supply chain is one of the most complex supply chains, which is focused in this research. This analysis indicates the problems or barriers which mostly affects achieving the goal in pharmaceutical supply chain in a developing country like Bangladesh. The pharmaceutical industry is a growing sector in Bangladesh as the country produce medicine for local markets as well as for the international markets. So, for a better performance the barriers in this sector needs to be identified, and as well as their impact should also be measured. The company‟s most priority should be delivering of medicines as a strategic product. Pharmaceutical companies are the most important player of the drug supply chain, which is a subject to many risks. These risks or barriers interrupt the quality and quantity of supply of medicines and their delivery at the correct manner. All these problems in this Pharmaceutical Supply Chain (PSC) system of Bangladesh need a proper analysis and identification of the most significant barrier. Considering these facts of PSC in Bangladesh we approached a few local and multinational companies in Bangladesh and conducted the expert opinion for identifying the main barrier. Firstly, the analysis was done on the basis of existed literature review. For the proper identification and analysis we chose some methodologies and conducted results of finding the major barrier from each which is the main objective of this analysis. The identification of barriers is desired to enhance the performance of the industry. This study identifies 26 barriers under 5 major criteria of Bangladesh pharmaceutical supply chain through existed literature review as well as from the expert opinion in the practical field. The methodologies applied for the identification here are- AHP, ISM and MICMAC method. The results conducted from the literature review and industrial survey indicates that shipping problem in Chittagong port and lack of government support in this case have the most significant impact on the whole process in the context of Bangladesh pharmaceutical supply chain.
A COMPARATIVE STUDY OF AERODYNAMIC CHARACTERISTICS OF NACA 0015 AND NACA 4415 AIRFOILS AT VARIOUS REYNOLDS NUMBER
(2023-02) MAZUMDER, MD.HASIB MAHMUD; CHOWDHURY, PAVEL; SHAHRIAR, SADIK
The shape of an airfoil is paramount to its aerodynamic characteristics. In many applications, the streamlined shape has proven to be the most effective geometry shape. Airfoils are employed in aircraft wings, tails, and other control surfaces, wind turbines, boats, and ships, among other things. The current study compares the numerical aerodynamic performance of two regularly used airfoils, NACA 0015 and NACA 4415. The study is to evaluate the performance of these airfoils in terms of lift, drag, and lift to drag ratio at various angles of attack using wind tunnel experiments and computational fluid dynamics (CFD) simulations. These two airfoils were evaluated in a subsonic wind tunnel at Reynolds numbers ranging from 1×105 to 3.5×105. The NACA 0015 and NACA 4415 were tested from 0° to 18° angle of attack with a 2° interval. The conventional Sparlat-Allamaras model is used in the computational procedure. The outcome demonstrates a similarity between experimental and CFD results. The lift and drag curves for both profiles follow the same pattern. The optimum angle of attack for both airfoils is 14 degrees. However, the experimental results show that drag is greater, particularly at higher angles of attack. Both airfoils are thick, which adds structural integrity to the blades at the expense of increased drag. Furthermore, it has been shown that symmetric airfoils offer no lift at 0° AOA, making them extremely useful in control surface applications, whereas cambered airfoils provide higher lift, which is beneficial for devices requiring more lift, such as wind turbines.
A COMPARATIVE STUDY ON CONSTRUCTION COST OF A DUAL FRAMING REINFORCED CONCRETE (IMRF) STRUCTURAL SYSTEM IN DIFFERENT SEISMIC ZONES OF BANGLADESH
(DEPARTMENT OF CIVIL ENGINEERING, 2019-09) HOSSANIN, MD. EMDAD
Bangladesh is an earthquake prone country as it lies along the border of the Eurasian and Indo-Australian plates, where earthquakes of comparatively uniform intensity are generated at regular intervals. This increase in earthquake activity is an indication of fresh tectonic activity or propagation of fractures from the adjacent seismic zones. In the light of these after various researches upgraded BNBC 2015 has been divided Bangladesh into four seismic zones, namely Zone - 4, Zone - 3, Zone - 2, Zone - 1 being the most severed to least respectively. The occurrence of earthquakes in an earthquake prone region cannot be prevented. So it is suggested to follow seismic code in order to reduce the loss of life. The present study is aimed to find out the variation of material costing for two (80 feet and 150 feet height) buildings in four seismic zones of Bangladesh. Framing systems of these two building are considered as dual system reinforced concrete. Earthquake and other load are considered as per BNBC 2015. Constant wind load is considered for these building analyses. Analyses of these building are carried out by using ETABS 2016. Structural design and seismic detailing of various structural elements are done based on as per BNBC 2015. Detail structural drawings are prepared for these buildings to comparisons of material cost. Comparative study has been carried on required materials cost for these building (beams, columns and shear walls) among four seismic zones. Average reinforcement, required of these structural elements (beams, columns and shears walls) been calculated separately for four seismic zones of Bangladesh. It is found that average reinforcements required per square feet of 150 feet height building are 1.63 kg, 1.87 kg, 2.08 kg and 2.35 kg in Zone -1, Zone -2, Zone -3 and Zone - 4, respectively. On the other hand 1.44 kg, 1.61 kg, 1.76 kg and 2.09 kg reinforcements are required for square feet of 80 feet height building in Zone -1, Zone - 2 , Zone - 3 and Zone - 4, respectively.
A COMPREHENSIVE DESIGN AND CONSTRUCTION OF COCONUT OIL EXTRACTION MACHINE AND ANALYSIS OF COCONUT OIL
(2015-06-23) Hasan Kawser, Mahmudul; Kabir, Humayun; Premadasa, Flt. Lt. GDP; Nayeem, Nazratun
Coconut oil is very familiar and useful for human civilization. Now-a-days many coconut oil extraction procedures are used. All these process are adapted in large industries. In this project the main concern was to produce coconut oil by using simple extraction process and ensure its perfect quality. In modern coconut oil extraction machine, only copra is used to produce oil, but in this machine, all kinds of coconut can be used to produce oil except baby coconut. In this thesis paper, the design procedure, production process and quality of the coconut oil are described clearly. The construction of coconut oil extraction machine is very simple, small in size and low cost. It is made of stainless steel, mild steel bar and plain sheet. Coconut meat is used as a raw material. In every process coconut meat is heated inside the machine. But here in this machine moisture of coconut meat is removed by using direct sunlight. That is why the nutrition value of produced coconut oil is better. Applications of coconut oil are versatile. It is used for cooking, health care, direct fuel mixed with diesel and producing biofuel. It is also used as a lubricant in the textile industry. Special feature of this extracting machine is that anyone can operate and produce coconut oil easily by this machine. The paper also contains a comparison study of exhaust gases produced by using pure diesel and 15% coconut oil mixed with diesel.
A Cost Effective Regression Testing Approach for Web Application
(Department of Computer Science and Engineering, Military Institute of Science and Technology, 2012-12) Nahar Jesy, Sumsun; Raihan Majumder, Md.; Arifur Rahman, Md.
Regression testing is an expensive testing procedure utilized to validate modiﬁed software. Duringregressiontesting,amodiﬁedsystemisretestedusingtheexistingtestsuite. Because the size of the test suite may be very large, testers are interested in detecting faults in the systemasearlyaspossibleduringtheretestingprocess. Regressiontestselectiontechniques attempt to reduce the cost of regression testing by selecting a subset of a program’s existing testsuite. Inthispaperwehavebrieﬂydiscussedtwooftheselectiontechniquesandchoose the safe algorithm technique. The previous researches indicate that safe regression test selectioncanbecost-effective,butthatitscostsandbeneﬁtsvarywidelybasedonanumberof factors. Inordertocarrythroughtheregressiontestingquicklyandeffectively,wehaveproposed a regression testing approach from a large test suite using hybrid technique based on safeselectionalgorithmandprioritizationbasedoncostcriterion. Weexaminedsomeprioritizationstrategiesanddevelopourproposedalgorithmtoimprovetherateoffaultdetection for web applications. We propose a new hybrid regression testing approach that select less test cases and then prioritize them according to their cost, so that the regression testing for web application become more time effective and less expensive.
A Critical Assessment of Graceful Graphs and Trees: Study and Development of New Approaches
(Department of Computer Science and Engineering, Military Institute of Science and Technology, 2014-12) Abdul Kader, Mohammad; Manjur, Sharmin; Manzur Ankon, Md. Tasnim
AgraphGisgracefulifitssetofverticesisdenotedbytheset{0,1,...,m}andthe set of edges is denoted by {1,2,...,m}, such that all edges are labeled uniquely and accordingtothedifferenceofthelabelsoftheverticesconnectingit. Asimplenotation to be mentioned that all the vertices will have unique labels, and so will the edges. The idea of graceful labeling came to being from Ringel’s conjecture(see chapter 1). The conjecture introduced in 1963, established the open problem of graceful labeling. Any graphthatcanbelabeledgracefullysuggeststhattheclassofthegraphimpliesRingel’s conjecture. Over the years many people worked on this conjecture and found out many classesofgracefultreesandgraph. SuchgracefulclassesoftreesandgraphsarePathor Chain, Caterpillar, Extended caterpillar, super caterpillar, Star, Olive tree, Banana tree, Lobstar, product tree Cyle wheel, Crown graph etc. A C4 graph is a cycle consisting of four vertices. The C4 graph is graceful. However, graphs formed by multiple number of C4 cycles in them were yet to be studied. Another type of graph is a star. A star S1, nisacentervertexconnectedwithnleaves. Astarisalsoclassiﬁedasatree,according to the deﬁnition. It has been proved earlier that all stars are graceful. The purpose of this paper was to study and develop procedures to gracefully labeled graphs formed by thecombinationofmultiple C4 cyclesandthecombinationofmultiplestars. Ageneral procedure was developed for each of the three classes, proved to be graceful, through thispaper. Furtherresearchwasconductedonﬁndingmorevarietiesofsuchgraphsand the results were discussed. The result of the research proposes an open problem about aclassofgraphswhichpartiallysupportsRingel’sconjecture. Thepaperhighlightsthe classes of graphs and trees that were previously proved to be graceful.
A Crowdsourced Approach for Supply Chain Network Optimization Using Hub and Spoke Model
(2019-12) Sarwar, Md. Azim; Humayra, Israt; Sadman, Navid Anas
This study aims to identify and analyze an optimized & efficient supply chain network solved with hub and spoke model using a crowdsourced approach. The main focus of the resulting supply chain is to minimize the total transportation cost and analyze how crowdsourcing affects the whole chain. Hub and spoke distribution paradigm are a form of transport topology optimization in which traffic planners organize routes as a series of "spokes" that connect outlying points to a central "hub". The supply chain network includes a number of manufacturers, suppliers, distributer locations and demand points which need to be located not just randomly but as a result of careful calculation to minimize the overall cost and increase the supply chain surplus. The hub and spoke model is an excellent approach to make the whole system more robust and agile by receiving products from many different origins, consolidating the products, and sending them directly to destinations. Crowdsourcing is the process of obtaining ideas, services or information by soliciting feedback from a large group of people. Here in this report, the effects of crowdsourcing on the supply chain is emphasized by using a linear programming model in MATLAB. The result is evaluated and analyzed for further improvement and practical use.
A Feasibility Study of Solar-Wind Hybrid System in Urban Area of Bangladesh
(Military Institute of Science and Technology, 2014-12) Shueb Al Hasan, Capt; Nurul Islam, Md.; Akter, Faisal
Utilization of renewable energy resources have been the most important and prospective field to seek new energy sources to meet up the increasing demand in power all over the world specially in a developing country like Bangladesh. Among the renewable resources, wind and solar being the most popular ones due to abundant ease of accessibility and convertibility to the electricity. The paper presents the next generation of power energy systems where generation will not be dependent on fossil fuel, using solar and wind energy systems. The thesis is emphasized on the feasibility study of hybrid energy system (comprising solar and wind) from literature followed by evaluation of performance through simulation. The primary focus of this study is to develop a dynamic model for a small standalone hybrid power generation system for the urban as well as coastal areas and compare their performance. For designing and studying the feasibility of the system, software named ‘HOMER’ was used. HOMER software has been used for analyzing the performance of the system. Different performance analysis includes feasibility, sensitivity, cost and sustainability were measured using the software. Our designed solar wind hybrid power system capacity is 650 Watts. It is proposed as the model with LED lights and limited fans which are considered as domestic load. It is found that the proposed system reduces CO2 emission.
A GIS BASED DRASTIC MODEL FOR ASSESSING GROUNDWATER VULNERABILITY IN TONGI, GAZIPUR DISTRICT OF BANGLADESH
(2024-03) RAHMAN, MD. MAHMUDUR; REZA, SYED AHNAF
Groundwater resources in Tongi are currently threatened by many garments, dyeing, paper and pulp, wood, tannery, dairy, poultry, fishery, chemical and textile industries. Many of these industries release untreated heavy metals, solid and liquid wastes consisting of cadmium (Cd), chromium (Cr), and lead (Pb), threatening water resources. A model-based groundwater pollution risk assessment was conducted to address these issues. The most sophisticated among the vulnerability assessment techniques is the GIS-based DRASTIC model. The model considers parameters like depth to the water table, net recharge, aquifer and soil media and hydraulic conductivity, which were collected from Bangladesh Water Development Board (BWDB), Geological Survey of Bangladesh (GSB). This study determined the net recharge from specific yield using bore log data and water table fluctuation. The average net recharge has been calculated as 359 mm/year and varied from 105 to 614 mm/year. Determination of the DRASTIC index involves multiplying each parameter weight by its site rating and summing up the total. The higher index values symbolise a greater risk of GW pollution or greater aquifer vulnerability. Finally, for the year 2013 and 2019, two groundwater vulnerability map were developed for each year for the study area using the DRASTIC Index and GIS mapping. One of the maps was developed following typical DRASTIC weightage suggested in the model and the other map was developed by modifynig weightage for the study area. In 2013, the DRASTIC index values vary from 104 to 156 according to model suggested weightage and it was reclassified into two groups of moderate, and highly vulnerable zones. About 21% of the area is highly vulnerable and 79% area is moderately vulnerable to groundwater contamination. On the other hand, modified weightage DRASTIC index values vary between 113 and 183 and it was reclassified into two groups of moderate and high vulnerable zones. About 3.5% area is moderately vulnerable, 96.5% area is highly vulnerable. In 2019, the DRASTIC index values vary from 91 to 137 according to model suggested weightage. The whole study area is susceptible to moderate vulnerablility to groundwater contamination. On the other hand, modified weightage DRASTIC index values vary between 95 and 164 and it was reclassified into two groups of moderate and high vulnerable zones. About 20.6% area is moderately vulnerable, 79.4% area is highly vulnerable. The modified weightage map has more vulnerbility compared to typical map. Thus, the model provides important information that could be useful to city planners and decision-makers for the establishment of ETPs and putting restrictions on further industrialisation in the vulnerable zones.
A Molecular Dynamics Study of Mechanical Properties of PLA-CNT Nanocomposite
(2019-12) Rahman, Md. Sohanoor; Parvez, Mohammad Rokibul Hasan; Jitu, Md. Mahedi Khan
This thesis contains a non-destructive process of determining structural and mechanical properties of a promising composite material named PLA-CNT. Polylactic Acid (PLA) is widely used in 3D printing (additive manufacturing) technology and biomedical industry. In order to perform molecular dynamics simulation PLA is modeled and packed in Materials Studio software package and validated in terms of Young’s modulus against mechanical testing value found in published literature of Kamthai and Magaraphan (2016). This PLA model is incorporated with CNT reinforcement and undergone molecular dynamics simulation of uniaxial tensile deformation through LAMMPS software package. Simulation resulted in significant improvement of mechanical properties such as Young’s modulus, tensile strength in PLA-CNT composite over PLA. Thus, enhanced mechanical property of raw material will result in similar enhancement in printed model.
A Neural Network Based Software Defect Prediction Approach Using SMOTE and Noise Filtering-CLNI
(Research and Development Wing, MIST, 2025-12-30) Ashfaque, Ahmmed Bin; Sattar, Abdus; Jahan, Hosney; Akhtaruzzaman, M.; Nur, Fernaz Narin
Software defects can cause significant loss and system failures in software development life cycle. Software Defect Prediction (SDP) is a vital step for ensuring the quality of software. Till now, a number of machine learning models have been proposed to predict potential defects and make the software more reliable. However, SDP models suffer from the problem of imbalanced dataset, resulting in poor prediction accuracy. To mitigate this, issue several data balancing techniques, i.e., over sampling, under sampling etc. have been proposed to balance the dataset. In some cases, the data balancing methods may further introduce noisy and mislabeled samples in the dataset. To deal with these issues, in this paper, we propose a neural network based approach that combines the oversampling technique Synthetic Minority Oversampling Technique (SMOTE) with the noise filtering technique Class Level Noise Identification (CLNI). Here, we applied three different CLNI methods which are Edited Nearest Neighbor (ENN), Repeated ENN (RENN) and All-KNN. Our aim is to make the dataset clean, balanced and efficient by combining SMOTE with CLNI. In addition, we applied a number of feature selection methods to identify the most important features, further contributing towards achieving better prediction accuracy. To evaluate the effectiveness of the proposed model, we conduct experiments on several benchmark datasets (MC1, PC1, PC2, PC3 and PC4) obtained from NASA MDP and (ML, LC and JDT) AEEEM repository. The experimental results have been evaluated and compared in terms of accuracy, precision, recall and AUC-ROC curve. The experimental results demonstrated that our proposed approach has achieved up to 98% accuracy and outperformed state-of- the-art approaches.
A New Algorithm for Solution of System of Linear Equations
(Department of Computer Science and Engineering, Military Institute of Science and Technology, 2012-12) Iftekharul Hoque, Md.; Nur-E-Areﬁn, Md.; Saiful Ahmad, Md
Systemsoflinearequationsareusedinavarietyofﬁelds. Thecanonicalproblemofsolving a system of linear equations arises in numerous contexts in information theory, communication theory, and related ﬁelds. This thesis is aimed at analyzing the available methods for solving a system of linear equations of the form n x n. Using a couple of iterative and/or direct methods, implement a program for these methods that could be run for different dimension size n of system of linear equation . At the end, a graph can be plotted with time taken for execution of a method considered V/s dimension size n. In this contribution, we develop a solution that does not involve direct matrix inversion. The iterative nature of our approachallowsforadistributedmessage-passingimplementationofthesolutionalgorithm. We present test results which show that our solver achieves good results, both in terms of numerical accuracy as well as computing time. Furthermore, even very large systems (n≤ 1000) can be solved given a cluster with sufﬁcient resources. We also address some properties of the algorithm, including convergence, exactness, its complexity order and relation to classical solution methods.
A New Algorithm for Solution of System of Linear Equations
(Military Institute of Science and Technology, 2012-12) Maowa, Jannatul; Kabir, Sraboni; Khosru, Ibn Md. Abu Saleh
Systems of linear equations are used in a variety of fields. The canonical problem of solving a system of linear equations arises in numerous contexts in information theory, communication theory, and related fields. This thesis is aimed at analyzing the available methods for solving a system of linear equations of the form n x n. Using a couple of iterative and/or direct methods, implement a program for these methods that could be run for different dimension size n of system of linear equation . At the end, a graph can be plotted with time taken for execution of a method considered V/s dimension size n. In this contribution, we develop a solution that does not involve direct matrix inversion. The iterative nature of our approach allows for a distributed message-passing implementation of the solution algorithm. We present test results which show that our solver achieves good results, both in terms of numerical accuracy as well as computing time. Furthermore, even very large systems (n 1000) can be solved given a cluster with sufficient resources. We also address some properties of the algorithm, including convergence, exactness, its complexity order and relation to classical solution methods.
A NEW APPROACH FOR CALCULATING TRANSMISSION RELIABILITY MARGIN
(DEPARTMENT OF ELECTRICAL, ELECTRONIC AND COMMUNICATION ENGINEERING, 2020-12) Nadia, Awatif
The basic function of an electric power system is to satisfy the system load requirements as economically as possible and with a reasonable assurance of continuity and quality. Therefore, it is essential to maintain the reliability of the electric grid under all situations. Reliability is a time varying function. It is the probability of a system performing its purpose adequately for the period intended under the operating conditions encountered. Under specified system conditions, how reliably power can be transferred from one network zone to another through all the network transmission lines which interconnect the electric systems is known as transfer capability. During any occurrence of uncertainties such as: change in load, line impedances, voltage magnitudes, customer demands etc. in the network, power transfer can’t be ceased, so to transfer power productively during these unpredictable condition one needs to enumerate transmission reliability margin (TRM). Available transfer capability (ATC) is the additional amount of power that may flow across the interface. It can also become a useful indicator for the operator to indicate the amount by which the inter area power transfers can be increased without jeopardizing system security. To ensure effective power transfer over the transmission lines during the occurrence of uncertainties an accurate estimation of TRM is required. In this work, a new technique has been proposed for calculating TRM by using AC, DC, and DCQ load flow method considering sensitivity to load, line admittances and voltage parameter. The TRM estimation is incorporated with the ATC since when the amount of power transfer is increased in the transmission network it needs to estimate that the system would be secured under a reasonable range of uncertainty. The proposed technique is used for IEEE 6 bus test system and is done for Normal distribution. The results are compared with previous results for validation.
A Novel Approach to Detect Cardiac Arrhythmia Based on Continuous Wavelet Transform and Convolutional Neural Network
(Research and Development Wing, MIST, 2022-12) Mohonta, Shadhon Chandra; Firoj Ali, Md.
Electrocardiogram (ECG) signal is informative as well as non-invasive clinical tool to diagnose cardiac diseases of human heart. However, the diagnosis requires professionals’ clarification and is also time-consuming. To make the diagnosis proficient, a novel convolutional neural network (CNN) has been proposed for automatic arrhythmia detection. In this work, the ECG data collected from the MIT-BIH database have been preprocessed, and segmented in short ECG segments of 60 s. Then, all these segments have been transformed into scalogram images obtained from time-frequency analysis using continuous wavelet transform (CWT). Finally, these scalogram images have been exploited as an input for our designed CNN classifier to classify cardiac arrhythmia. In this approach, the overall accuracy, sensitivity, and specificity are 99.39%, 98.79%, and 100% respectively. Proposed CNN model has significant advantages, and it can be used to differentiate the healthy and arrhythmic patients effectively.
A P-Median Closed Loop Model Using Tabu Search for Health Care Supply in Bangladesh
(2019-12) Roy, Sayantee; Shawon, Mohammad Ferdous Hasan; Safa, Zareen Tasnim
Healthcare supply chain management involves obtaining resources, managing supplies, and delivering goods and services to providers and patients. It is responsible for stocking organizations with the products providers need and managing inventory. This thesis aims to identify and analyses a closed loop medical supply chain which is sustainable and effective with p-median multi-echelon approach. The study is inaugurated only focusing on the heath-care supply chain model. This leads us to design a closed loop multi echelon model. In this process the model is more effective and viable by considering the reverse flow of material while allocating the location of distribution centers and facility location. The p-median model is based upon the assumption that each demand can be served by its closest facility. A multi-echelon system is one that relies heavily on layers of suppliers distributed across multiple distribution centers and that is based on outsourced manufacturing. In this model, p-facilities are to be placed to minimize the (demand- weighted) average distance between a demand node and the location in which a facility was placed. This serves as an approximation to total delivery cost. There are no capacity constraints at the facilities. Adding the Travelling Salesman Problem (TSP) a feasible closed loop model is developed for finding out the shortest path for delivering medicines and returning expired ones to the factory and dispose it with their conventional method to save environment. The main objective of this system is to minimize the cost and distance, maximize the profit developing a sustainable model which will increase customer response. The presented model and analysis are the results of an experiment of the supply chain network of the platform toward engaging in Mirpur area with the location of corresponding factory of a specific pharmaceuticals company. This analysis is solved using TabuSearch algorithm in MATLAB. The result is compared to develop a feasible closed loop model for health care supply. The result is evaluated and analyzed for further improvement and practical use by using different algorithm and coding method.
A Parametric Optimization of Selective Laser Sintering Process to Increase Process Efficiency
(2019-12) Karim, Mehrab; Hassan, Jakir; Ahmed, Kazi Arman
Selective laser sintering (SLS) is a powder-based layer-additive manufacturing process generally meant for rapid prototyping and rapid tooling. Laser beams either in continuous or pulse mode are used as a heat source for scanning and joining powders in predetermined sizes and shapes of layers. The geometry of the scanned layers corresponds to the various cross sections of the computer-aided design (CAD) models or stereo lithography (STL) files of the object. Selective laser sintering has been used to make models for design testing, patterns for investment casting, and small lots of functional parts. But with SLS, it is sometimes difficult to achieve the best quality in appearance with the best mechanical properties and it is time consuming and inefficient too. So, it is important to obtain a better understanding of the relationship between powder properties, fabrication parameters in the SLS process, and the parts produced using this process. So, this thesis aims to find the optimum quality and better efficiency by setting these parameters differently according to powder properties and requirements of application. It is therefore required to optimize the relationship between the fabrication parameters and powder properties. This thesis aims to relate fabrication parameters with powder properties and they are: laser power ratio, layer thickness, grain size etc. In this thesis, optimization tool has been used to obtain suitable fabrication parameters to satisfy the demands of specific applications. Finally, the research direction is therefore a means of balancing in-process parameters with post-process parameters in order to meet the requirements for good overall quality components and better efficiency with minimum time and effort.