Browsing by Author "Rahman, Md. Saidur"

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Assessing the Performance of a Hybrid Geolocation Algorithm Integrating FP and TOA Techniques Across Diverse Environmental Conditions
(Tuijin Jishu/Journal of Propulsion Technology, 2023-10-30) Kabir, Md. Humayun; Kabir, Md. Alomgir; Ahmmed, Rubab; Rahman, Md. Saidur
This paper presents a validation study of indoor geolocation accuracies using a hybrid approach that combines fingerprinting (FP) and time of arrival (TOA) techniques. The investigation focuses on three dense environments, examining the influence of furniture density and multipath components on geolocation accuracy, particularly in non-line-of-sight (NLOS) scenarios. The results indicate that geolocation performance improves in denser environments with higher furniture density due to increased multipath components. Additionally, optimizing the hybrid method with a polygon size of 50 cm and sampling rate of 80 GHz leads to further accuracy enhancements. These findings underscore the significance of furniture density and demonstrate the effectiveness of the hybrid method in addressing NLOS challenges. The research contributes to the advancement of indoor geolocation techniques and provides valuable insights for designing precise indoor positioning systems across various applications.
Convergent Effect of Work Family Conflict on Job Satisfaction of commercial Banks Employees in Bangladesh: does gender role moderate the effect?
(2020-02-19) Uddin, Mohammad Jamal; Rahman, Mohammad Mizanur; Rahman, Md. Saidur
Work and family are two domains of extraordinary importance in the lives of the most men and women in our society. Today's highly demanding nature of work and family has given rise to conflicting relations. The present study has explored the effect of Woprk-family Conflict (W-FC) on employee's job satisfaction of commercial banks in Bangladesh. Convenience sampling method has been used for this research. A sample of 216 respondents from different commercial banks in Bangladesh has drowned and used in the study. Different statistical measures such as descriptive statistics, zero-order correlation, Confirmatory Factor Analysis and multiple regression analysis have been used to explore the convergent effect of WFC /FWC on the job satisfaction and other research observations.
Difficulties teachers and students face in EFL/ESL listening classroom at secondary level education in Bangladesh
(BRAC University, 2014-04) Rahman, Md. Saidur
Listening comprehension is the primary channel of learning a language. This study tried to find out the difficulties/problems face both the teachers and the students in terms of listening skill in the classroom at Secondary level Education in Bangladesh. At secondary level education CLT (Communicative Language Teaching) approach is introduced and the students and teachers are asked to practice all four skills equally to develop their communicative skill. But only speaking, writing and reading skills are given maximum importance. The teachers are avoiding teaching listening skill to the students. The study focused on teachers and students problems in terms of teaching and learning listening skill in the classroom. Five research questions were developed to find out the problems. Sufficient data and information were collected from teachers’ and students’ opinions through questionnaire, FGD and class observation. Both the teachers and the students of Non Government Secondary high schools took part in this study. After collecting the data, it was analyzed and the findings came. The study discovered some reasons that were helpful to find out the answers of the problems. Based on the findings, conclusions and recommendations were made.
Recruitment and selection process at J & L Fashion Ltd.
(BRAC University, 5/18/2016) Rahman, Md. Saidur; Chowdhury, Noman Hossain
As a part of my MBA academic requirement, I have joined J & L Fashion Ltd, a established company in Dhaka in their three months internship program. Based on my internship experience, I have prepared an internship report on the “Recruitment and Selection Practices of J & L Fashion Ltd”. I was assigned to the HR department of J & L Fashion Ltdas an intern under direct supervision of the Executive Director of the company. Recruitment and Selection in J & L Fashion Ltd is an integral part of the organization. The HR department of J & L Fashion Ltd strives to execute the HR functions of the organization effectively and optimally. In this report I have briefly provided the overview of the company. Then I have outlined the HR functions and practices of the company. Next I have discussed in detail my internship activities in J & L Fashion Ltd. I have tried to effectively integrate the knowledge that I gained through my course works with my work as an intern in the company. In the final part of the internship report, I provided some recommendations, which in my opinion would help improve the employee perception of the company if implemented.
Robocars for Shortest Track Finding and Transmitting
(East West University, 9/16/2018) Ara, Ismat; Sumon, Md Ibrahim; Rahman, Md. Saidur
Robocars can reduce human efforts in packet routing management problems in many industries including airport and postal packet services. Large airports and postal departments need many such Robocars to carry their packet properly. Central server-based system can be used to monitor or suggests optimum paths to the Robocars from source to destination. However, central system damage will crash or fail the whole system. The problem even becomes more challenging when the Robocars are autonomously carry information and suggest others the optimum path to choose the destination from their own experience. We built two (2) such Robocars, those are capable to find shortest track and transmit the path to other Robocar. Our Robocars apply optimum and shortest path by applying shortest path algorithm. We fixed seven (7) different paths in a maze of a Robocar. The Robocar traverses all seven (7) paths and then find an optimum path among them (lower cost) to reach from source to destination. After reaching destination, it transmits his experience (the shortest path) to its neighbor Robocars. Other Robocars will follow the given direction to reach the destination. Our Robocars are implemented in a static 4x4 maze environment and communicate themselves using Bluetooth technology, and successfully traverse source to destination using optimum path.
Solar powered traffic sensitive automated LED street lighting system
(BRAC University, 2012-12) Ahmed, Sanjana; Tasneem, Nisat; Rahman, Md. Saidur; Zenan, Ahmed Hosne; Rahman, Md Mosaddequr
Production and use of photovoltaic cells to generate electricity is an increasingly popular resource solution in Bangladesh currently. The focus of this project is to make the most efficient use of the energy received from the sun to power street lights in the city. Solar Panels mounted on the street lamps will collect the energy from the sun during day time, driving the LED lamps at night. The system we would be designing includes operation in the main streets of the major cities of Bangladesh which is to be equipped with solar powered street lamps effective in regulating the amount of load voltage depending on the intensity of traffic present. The project is about developing and fabricating the circuit that can charge the lead acid battery during day time by using solar energy as the source. The process, like most other photovoltaic systems theses days, would require the use of a micro-controller, namely PIC16F877A, to control many of the circuit functionalists including switching, controlling driver circuit, and integrating sensor output etc. The preferred lighting source is LED considering its photo-metrics such as efficacy, life span, cost, efficiency and power consumption. Since DC supply is being used, a DC-to-DC converter is employed to implement the LED. Traffic detection will be done through the concept of ultrasonic sensing using the Ping Sensor. In different seasons, the sun is incident on the earth’s surface and thereby on the solar panels in different angles. Thus a mounting angle for the panels has also been determined which will allow optimum efficiency for all four seasons of the year.
Solvent Extraction of Mn(II), Ni(II) and Zn(II) by Cyanex 272: Equilibrium and Kinetic Studies
(University of Rajshahi, 2010-06) Rahman, Md. Saidur; Biswas, Ramjit Kumar
The solvent extraction systems: Mn(II)-SO, -Ac Cyanex 272-kerosene, Ni(II)- SO4-Ac Cyanex 272-kerosene and Zn(II)-SO4 Cyanex 272-kerosene have been thoroughly investigated from equilibrium and kinetic point of views. From the dependence of extraction ratio (at constant equilibrium values of other parameters) on various parametric concentrations, the equations for extraction ratios have been derived at 303 K as: log Dmn=-6.17+2 pHm) + log [H2Azam)-log (1 + 1.9 [SO"]) log Di-11.16+2 pH)+ log [H2A2)-log (1+ 6.92 [SO."])-log [Ac"]; at [H2A2]) <0.05 kmol/m log DN-11.56+2 pH)+3 log [H2A2km)-log (1+6.92 [SO, D)-log [Ac]; at [H2A2 >0.10 kmol/m log Dzn --3.11+2 pH)+ log [H2A2])-log (1+2 [SO,"]); at [H2A2] (en) <0.05 kmol/m3 log "Dzn -2.08 +2 pH() +2 log [H2A2](o)-log (1+2 [SO"]); at [H2A2]()>0.10 kmol/m where, the first terms on the right hand sides represent the logarithmic values of extraction equilibrium constants (Kex). The equilibrium extraction reactions in low concentration regions of extractant are suggested as M(II) + H2A2(0) [MA2](0) + 2 H; but disolvated and monosolvated species are extracted in the cases of Ni(II) and Zn(II), respectively, at high concentration regions of Cyanex 272 (H2A2). The extraction processes are found to be endothermic. The maximum loading capacities of the extractant are found to be 9.52 g Mn(II), 21.28 g Ni(II) and 11.5 g Zn(II) per 100 g extractant. The extracted species are strippable by dilute H2SO4, HNO3 and HCl solutions. In kinetics of forward extractions of the selected divalent metal ions by Cyanex 272, the rates have been measured the single falling drop technique at various extraction parametric concentrations in order to determine the orders of reaction with respect to various concentration terms and also to evaluate the log kr values. Rates have measured at various temperatures to determine E., AH* and AS* values at various parametric conditions for all systems under consideration. The rates of forward extractions of Mn(II), Ni(II) and Zn(II) at 303 K can be expressed respectively as: log F-3.6+ log [Mn(II)] +0.5 log [H2A2]()-log (1+ 105 [H])-log (1+1.58[SO"]) log Fr=-3.7+ log [Ni(11)] +0.5 log [H2A2](o)-log (1+ 10635 [H])-log (1+6.3[SO, ])-log (1 +0.55 [Ac"] log Fr=-8.4 + log [Zn(II)-log [H])+0.5 log [H2A2])+ log (1+ 1.07 [H2A]()) where, Fr represents flux of metal transfer from one phase to another and defined as rate per unit interfacial area. From the rate equations, the mechanisms of extractions are given. Invariably in all cases under investigation, the attachment of the first monomeric anion of the extractant (A') to the metal ion is the rate controlling (M2++ A slow [MA]'); which has been supported by high activation energy (>48 kJ/mol). However, in certain parametric conditions diffusions rather the chemical reaction stated become rate controlling, which is supported by low activation energy. In case of Ni(II) extraction, at high concentration region of extractant, the reaction: Ni2++ HA2 (int) → [NIHA2] becomes rate controlling. The highly negative AS* values in all cases suggest the chemical rate determining step occurs via SNo2 mechanism. The kinetics of stripping of metal ions from highly metal ion loaded organic phases by sulphuric acid solutions have been investigated by the single falling drop technique to derive respective stripping rate equations at 303 K. The stripping rate equations derived for stripping of Mn(II), Ni(II) and Zn(II), respectively, are: log F1 = -4.88 + log [MnA2])- 0.5 log (1+0.002 [H]') + log (1 +5.129 [SO,")) log F-4.35+ log [Ni-H2A2 complex])-log (1 + 1042 [H])-log ([H2A2])+2.5 [H2A2])+ log (1+6 [SO, ])+ log (1 + 3.2 [Ac']) log F-5.24+ log [Zn-HA, complex]) + log [H]-0.5 log [H2A2]) + log (1 +1.5 log [SO."]) The rate equations have been analyzed to give stripping mechanisms. It is found that the dissociation of second anion ligand from [MA2](o) is rate determining which occurs in the bulk aqueous phase (MA slow M2++ A), which is, supported by high Eq. values. This mechanism is valid for Mn(II) and Zn(II) covering all concentration region of free extractant in the organic phase; and also for Ni(II) in low concentration region of extractant, but at its high concentration region, the dissociation of dimeric anion (HA2) from [Ni(HA2)2. H2A2] (0) appears as rate determining. However, low E, value suggests this step occurs via SN2 mechanism. The extraction equilibrium constants (Ke) for Mn(II) and Zn(II) derived from equilibrium studies are matchable to those from respective kinetic studies (Kex = kr/k). But in the case of Ni(II), a deviation by a factor of 10 is obtained, which may be attributed to the loss buffer action resulting the change of interfacial pH. The possibilities of separations of the metal ions under consideration from their mixtures by Cyanex 272 have been theoretically evaluated and it has been shown that the mutual almost complete separation of this metal ion by single or by at least two stage extractions by Cyanex 272 solution in kerosene is possible.
Successful diagnosis and treatment of feline infectious peritonitis in a household cat with remdesivir
(Chattogram Veterinary and Animal Sciences University Khulshi, Chattogram-4225, Bangladesh, 2022-11) Rahman, Md. Saidur
Domestic and wild cats alike may be exposed to the virus that causes Feline Infectious Peritonitis, or FIP. Chini, an 11-month-old, 3.8-kilogram domestic male longhair crossbreed, presented to the Teaching and Training Pet Hospital and Research Center (TTPHRC) in Purbachal, Dhaka, with a 21-day treatment history of stress, lacrimation, conjunctivitis, anorexia, weight loss, and recurring fever. Total protein (TP), albumin, bilirubin, SGPT, SGOT, and alkaline phosphatase (ALP) were measured after a blood sample was collected from the patient. The patient had an X-ray as well as an ultrasound to check on his kidney, chest, and abdominal structure. Serum total protein and albumin-globulin (AG) ratio was low, and the cat tested positive for FIP Ab, confirming that the animal had non-effusive feline infectious peritonitis based on the clinical history and symptoms. FIP has always been thought of being a deadly disease. Considering the recent COVID-19 epidemic, scientists have been more interested in the pathogenesis and potential therapies for coronaviruses. As a useful side result, we now have a cure for FIP that is widely available. A household cat at TTPHRC with FIP Ab rapid test confirmed non-effusive FIP was successfully treated with remdesivir (10mg/kg body wt. daily for 84 days), and the disease was cured.
The study of the beneficial effects of pet ownership on some aspects of human well-being and behaviors
(Chattogram Veterinary & Animal Sciences University, 2022-09) Rahman, Md. Saidur
There is a long history of anecdotal and observational evidence of the mutual benefits of the pet ownership. The present research examined links between attachment to pets and physical and psychological well-being in different populations. To analyze the bonding between pets and human in relation to well-being in Dhaka city, Bangladesh, 82 data from 15th February to 15th March were collected and evaluated. Among them, small number pets reared by young owner (9.76%), medium number by old category owner (18.29%) and large number by middle aged owner (71.95%). 52.44% owners were female and 47.56% were male. Maximum 58.54% owners were married, 34.15% were unmarried and rest 7.32% were divorced. Highest 56.10% owners do not have any kids, 21.95% owners have only one (1) kid, 17.07% owners have two (2) kids and only 4.88% owners have three (3) kids. Regarding employment status of owners, 65.85% owners were employed and 34.15% were unemployed. 70.73% owners lived in a joint family and other 29.27% owners separately. 62.20% owners have experienced for short period pet ownership where 37.80% owners have long period pet ownership. 65.85% owners reared pets as companion and hobby purposes, 28.05% owners have pets for breeding purposes and only 6.10% owners use pets for security purposes. 41.46% owners have given their statement that there was not any effect on reduction of chronic diseases or mental state due to having pets, 9.76% owners found reduction of high pressure, diabetes and heart disease due to pet ownership and maximum 48.78% owners reduced anger, depression, loneliness and restlessness for rearing pets. 20.73% owners were exposed some disease conditions like ring worm, asthma, and allergic reaction duo to having pets in their house and rest 79.27% owners did not have exposed any problems for pet ownership. The results provide evidence that pet acquisition may have positive effects on human health and behaviors, and that in some cases these effects are relatively long term.