Browsing by Author "Mostafizur Rahman, Md."

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Community Based Help Desk
(Daffodil International University, 2019-08-06) Mostafizur Rahman, Md.; Rana, Md. Masud; Siddik, Shak. Md. Tuhin
A community-based help desk is a web-based learning method and strategy that engages with learning, Learners collaborate with each other and work together to solve problems, complete a task, or create something special. In this project we strive to create a global community for any kind of human benefit. This study aims to explore the possibility of using web application techniques to build predictive models of performance in collaborative induction tasks. As per the general education system of the country, we have lacked some concentration in our class session. Our system can help those students get a clearer idea of subjective knowledge. We have explored how to improve communication skills through this application. The results show that such features have some potential to effectively predict performance in these typical functions.
Development & application of a multi-mode transportation model for distribution of imported foodgrains in Bangladesh
(Department of Industrial and Production Engineering, BUET, 1988-10) Mostafizur Rahman, Md.; Anwarul Haque, Dr. A. F. M.
The method of distribution of imported foodgrains in • Bangladesh has so long been based entirely upon traditional pratices. No scientific technique has ever been applied to evolve the least cost distribution network. In the present work after having studied & analysed the existing foodgrains movement programme and the transport infrastructure a modified transportation model including a transshipment model has been developed for distributing imported foodgrains by diff-. erent modes to various districts at an optimal cost. The models considered the various factors such as constraints due to 11mited capacities and requirements of the sources and destinations respectively, capacities of the different modes of transportation, their availabilities in different seasons of the year etc. The two models described above were applied to identify the least-cost route for the distribution of imported foodgrains in year 1986. From the output of the result, the monthly schedules of distribution have been prepared. The modified transportation model has been found to provide better result than that obtained by the current traditional practices. The costs of transportation of foodgrains for the year 1986 are Tk. 64,87,62,202 and Tk. 58,17,28,243 by the existing movement programme and the developed transportation respectively. model xii When the total supply of foodgrains exceeds the total demand, the developed transshipment model provides better result than that obtained by the transportation model. The costs of transportation for the month of May 1986, are Tk. 13,91,96,690 and Tk.12,57,37,000 by the transportation model and the transshipment respectively. The present work identified some planning and operational weaknesses in the present system of movement programme. To overcome these deficiencies, a set of recommendations has been suggested. It is expected that if the current movement programme is properly redesigned incorporating the above models then the leastcost route for the transportation of imported foodgrains may be evolved.
Evaluation of Ullapara pourashava master plan considering climate change induced flood
(Department of Urban and Regional Planning, 2015-01) Mostafizur Rahman, Md.; Islam, Dr. Ishrat
Bangladesh is one of the most flood prone countries in the world. A number of research works have identified that the monsoon flood scenario will be aggravated with climate change context in Bangladesh. In 2008, Local Government Engineering Department (LGED) has started to prepare master plan (2011-2031) for 223 Pourashavas in Bangladesh. It is evident from the Terms of Reference (ToR) of the project that it did not consider future climate induced flood scenario which poses a question towards the sustainability of the plan in a flood prone country like Bangladesh. Ullapara Pourashava of Sirajganj district has been selected as a study area to conduct the research. Due to its geo-physical settings this area is most vulnerable to flood and future climate change induced flood will worsen the scenario. The study aims to evaluate the Pourashava Master Plan in the light of climate change induced flood and suggests adaptation strategies in the face of climate change induced flood. The methodology of the study follows GIS based flood exposure analysis of selected infrastructure. Considering the data availability, climate change induced flood for the year 2040 has been used for flood exposure analysis. Based on the exposure analysis the infrastructure plan has been evaluated. These infrastructures include transport and communication infrastructure, educational infrastructure, health infrastructure, and other community facilities. It is evident from the study that infrastructure in Ullapara Pourashava would be highly exposed to climate change induced flood for longer duration. The duration of inundation may stay up to 19 days where about 90.14% land of the whole Pourashava would be exposed to more than 1m inundation level due to climate change. The study also finds that about 33.99% Pucca road will be exposed to 1.5-2m inundation level; proposed one bus terminal would be exposed to 2.5-3.0m inundation level; seven primary school, six secondary school and four colleges would be highly exposed to 2.0-2.50m inundation level; four health facilities would be exposed to 1.0-2.0m inundation level due to future climate change. The study finds that in 2007 flood the physical damage of roads, hospitals, Police Station and Fire service was equivalent to about 8.57 crore Tk. The study also finds that about 17,251 students were in problems to access the educational institutions; about 26,550 patients were in problem to access the health facilities; about 18,180 business men were in trouble with their business due to inundation of road. It is evident that newly proposed infrastructure including educational infrastructure and different urban facilities like community center, waste disposal site will also be highly exposed to future climate change induced flood. This inundation scenario for long duration will lead to dysfunction of concerned infrastructure and, in turn, undermines the stability of a socio-economic system of Ullapara Pourashava. In such a context this study suggests adaptation strategies to cope with the climate change induced flood. To devise adaptation strategies, expert opinions were taken from various organizations. This study suggests that integrated landuse planning, land zoning, height enhancement, relocation, climate proofing material; construction of floodwall may be the adaptation strategies for infrastructure to tackle with climate change induced flood in Ullapara Pourashava. The study suggests some structural interventions to adapt with climate change induced flood. The total cost of proposed intervention will be about 29.04 crore Tk. Based on the expert opinions, literature review and researcher’s own judgments this study argues that climate change adaptation can only be adequately addressed if action is taken at all levels of government: international, national, regional, and local. Hence the study emphasizes to adopt multi-level governance approach for infrastructure planning to face the challenges of climate change.
Mental task classification utilizing interchannel relationship of eeg signal based on wavelet and empirical mode decompostition
(Department of Electrical and Electronic Engineering (EEE), BUET, 2017-10-07) Mostafizur Rahman, Md.; Shaikh Anowarul Fattah, Dr.
In view of recent increase of brain computer interface (BCI) based applications, the importance of efficient classification of various mental tasks has increased prodi-giously now-a-days. For effective classification purpose, efficient feature extraction scheme is necessary. Most of the reported algorithms are performed on the EEG signals or the processed EEG signals taken from various channels while the inter-channel relationship has not been utilized. Depending on the nature of the mental tasks, different spatial locations of brain become more actuated compare to other locations. It is expected that the correlation obtained from different combination of channels will be different for different mental tasks which can be exploited to extract distinctive feature. To corroborate this idea, in the proposed method, a feature extraction scheme based on cross-correlation among data (or decomposed data) obtained from various channels is proposed. Instead of directly utilizing EEG signal, various decomposition techniques, such as empirical mode decomposition (EMD), spectral band division, wavelet decomposition (WD) and wavelet packet decomposition (WPD) are employed on a test EEG signal obtained from a channel. Different well defined narrow frequency bands, corresponding to state of vigilance, are also investigated for feature extraction. Since EEG is a non-stationary signal, EMD, WD and WPD have the potential to perform better than the conventional time-frequency analysis method. Correlation coefficients are extracted from inter-channel pre-processed EEG signal. At the same time, different statistical features of decomposed EEG signals are also obtained. Finally, the feature matrix is formed utilizing inter-channel features and intra-channel features (statistical features) of the decomposed EEG signals. Different kernels of support vector machine (SVM) clas-sifier are used to carry out classification result. For the purpose of demonstrating classification performance, ten different combinations of five different mental tasks, namely geometrical figure rotation, mathematical multiplication, mental letter com-posing, visual counting, base-line resting obtained from a publicly available dataset are utilized. It is found that the proposed scheme can classify mental tasks with a very high level of accuracy compared to some existing methods.
Modeling flood inudation of the Jamuna river
(Department of Water Resources Engineering (WRE), 2015-03) Mostafizur Rahman, Md.; Ali, Dr. Mohammad Mostafa
Bangladesh lies at the con uence of worlds three major rivers, namely the Ganges, the Jamuna and the Meghna. In Bangladesh, normally four types of ood expressly river ood, ash ood, tidal ood and storm surge ood appear. The Jamuna River is most vulnerable to river ood. As a low lying country, ood occurs repeatedly in Bangladesh and cause tremendous losses in terms of property and life, particularly in the low land areas. At least 20 % areas are ooded every year and in case of severe ood 68 % areas are inundated. Therefore, the study is carried out to develop oodplain extend maps and inundation maps of the Jamuna River. The present study also deals the ood pattern change with time and impact of levee on ood inundation area. One dimensional hydraulic model HEC-RAS with HEC-GeoRAS interface in co-ordination with ArcView is applied for the analysis. The bathymetric data collected from Institute of Water Modelling (IWM) is used for river grid generation. The collecting DEM from NASA is resampled into 10 10 m res- olution. The bathymetric grid has been merged with the topographic DEM to produce the complete DEM of the river. Using this complete DEM, required data sets such as stream centerline, banks, ow paths and cross sections are prepared in HEC-GeoRAS pre-processing option, which are nally imported in HEC-RAS. In HEC-RAS, bound- ary conditions for upstream and downstream are de ned by discharge and water level data respectively. After boundary condition setup, the model calibration and valida- tion are performed using known hydrological data collected from BWDB. Performance of the HEC-RAS models are evaluated using standard and widely used indicators. The coe cient of determination (R2) has been found as 0.985, 0.977, 0.821 and 0.811 for steady calibration, steady validation, unsteady calibration and unsteady validation re- spectively. The NSE values have been found greater than 0.60 for both calibration and validation. After calibration and validation ood inundation and ood hazard map are generated using post-processing of HEC-GeoRAS . The results of ood frequency analysis by Log Normal method showed discharges of 65772, 76871, 83519, 91299, 96703 and 101790 m3/sec for 2, 5, 10, 25, 50 and 100-year return periods oods, where Log Normal method is best tted among the using other methods and used in modeling. The percentages of area inundated by 2, 5, 10, 25, 50 and 100-year return periods oods are 38.28, 46.10, 51.14, 54.63, 56.89 and 59.19% respectively. The ood inundation area increase with the increase of return period. It followed into the log curve y = 249:84ln(x) + 1789:3. The classi cation of ood depth area showed most of the ooding area had water depth between 1.2 m to 3.6 m. The assessment of the ood inundated area showed that 41.99% and 30.83% area are of high hazard and very high hazard respectively for the 100-year return period ood. The ood inundation area's changing pattern with time are studied by ve years unsteady simulation ow data at Bahadurabad station. From unsteady simulation, an empirical equation is developed between water level and ood inundation area. The empirical equation is y = 4:77x2 􀀀 138:76x + 1008:30. The levee has impact on ood inundation area. The ood inundation areas decrease with rise of levee elevation . For the 100 year return period, if levee elevation is raised up to 2.13 m from existing levee elevation, then ood inundation land area decreased from 59.19% to 40%. No land will be inundated, if the levee elevation raised up to 2.56 m. Thus, nding of the study may help in planning and management of ood plain area of the Jamuna River to mitigate future probable disaster through technical approach. Finding of the study may also help to determine suitability of building ood control structure like embankment, detention ponds for prevention purposes. The automated oodplain mapping and analysis using these tools provide more e cient, e ective and standardized results and saves time and resources. In future study, this model results can be compared with the studies with SOBEK or HEC-RAS (1D/2D) model results. Flood risk maps, others structures like ood control dam, reservoir impact on ood can be studied in future studies.
Performance of natural fiber reinforced soil blocks for earthen houses
(Department of Civil Engineering, 2010-06) Mostafizur Rahman, Md.; Shariful Islam, Dr. Mohammad
Soil-fibre matrix has been used for centuries for earthen house construction. The reason for using fibre might be for imparting ductility and other strength properties to the built structure. In this research work, performance of natural fibre (i.e., jute and straw) reinforced soil for earthquake resistant earthen house construction has been investigated. Cylindrical and block specimens were prepared with and without fibre reinforcement. Uniaxial compression tests were conducted on dried specimens. Shear strength of bond mortar was also tested for block-mortar specimen. Earthen block-mortar system was prepared by pressing the dried blocks against mortar with or without jute and straw fibre. Effect of soil composition on shrinkage behavior was studied. Capacity of fibre for shrinkage control was monitored. The contribution of fibre reinforcement towards the enhancement of strength control properties was also investigated. Test results of strength properties were compared for both unreinforced and reinforced (i.e., jute and straw fibre reinforced) soil. It was found that soil composition played the main role over the shrinkage behavior of earthen wall elements (i.e., block and mortar). Furthermore, it was observed that addition of jute fibre (2% by weight and 3 cm long) could effectively control the shrinkage crack of block and mortar. The same amount of jute fibre mixed soil proved its effectiveness over straw (1.5% by weight and 3 cm long) reinforced soil in improving strength and deformation properties of block and block- mortar. The test results revealed that earthquake resistance of earthen houses could be increased by the addition of jute fibre in both block and mortar. Based on the investigation, simple construction guidelines for jute fibre reinforced earthen house construction have also been presented.
Study of the effect of temperature on failure behaviour of locality manufactured PVC pipes
(Department of Mechanical Engineering, 1992-10) Mostafizur Rahman, Md.; Mandal, Dr.A.C.
An experimental investigation of the effect of testing temperature on the internal pressure sustaining capacity of locally manufactured polyvinyl chloride (PVC) pipes is presented in this thesis. An experimental set-up consisting of a constant temperature bath, temperature control devices and a pressurizing device is designed, fabricated and installed for the investigation. It is observed from the experimental results that there is significant effect of temperature on the mean failure pressure characteristics of the PVC pipes. With the increase of the temperature, the failure pressure decreases remarkably. For a wide range of temperature, from 10°C to 50°C, the experimental investigation is carried out. At each temperature, a reasonable number of samples .for the study is considered and the mean failure pressure is calculated. An empirical relation between mean failure pressure and temperature is also introduced. Two types of failures such as brittle failure and ductile failure are observed in the study. At low temperature failure of pipes occurs with almost no swelling of the pipe due to their brittle nature,. while as the temperature rises, the ductility of pipe material rises and the failure of pipes occurs with swelling effect. The calculated values of mean hoop stress obtained from the experimental data for the PVCpipes are shown with the available results of hoop stress for high density polyethylene ( HDPE ) pipes.