Fuzzy Logic Controller for Parallel Plug-in Hybrid Vehicle

Hybrid electric vehicles combine two methods for propelling a vehicle. In a parallel hybrid vehicle, the two propulsion methods work in parallel to meet the total power demand. Among different combination of power sources, internal combustion engine and electric motor drive system are the most popular because of their availability and controllability. Plug-in hybrid vehicle is the latest version in hybrid vehicle family. In plug-in hybrid vehicle, battery is directly recharged from the electrical power grid and it can be used for a long distance with higher efficiency. Most of the hybrid vehicles on the road are parallel in nature and battery is recharged directly by the engine. If it is possible to convert existing hybrid vehicle into plug-in hybrid vehicle, it will lead to significant improvements in fuel economy and emissions.In this thesis, two fuzzy logic controllers have been developed for the energy management system of the hybrid vehicle. For the first controller, it is assumed that the vehicle will work like a plug-in hybrid vehicle. For the second controller it is assumed that the battery will always recharged by the engine. It is found that with the help of developed fuzzy logic controller, the plug-in hybrid vehicle can run up to 200 miles with high efficiency. Both controllers are developed and their performance is tested on the highly reliable vehicle modeling and simulation software AUTONOMIE. The main objective of developing the controllers is increasing the fuel economy of the vehicle. The results from the both developed controllers are compared with the default controller in AUTONOMIE in order to show performance improvements

Changes in the menstrual hygiene management facilities and usage among Bangladeshi school girls and its effect on school absenteeism from 2014 to 2018

Background The lack of menstrual hygiene management (MHM) information and facilities in schools is a major contributor to adolescent girls’ school absenteeism in low- and middle-income countries like Bangladesh. Objectives This paper examines the changes over time in school MHM facilities, knowledge and perceptions among adolescent girls, in relation to school absenteeism between 2014 and 2018 in Bangladesh. Methods We examined changes in MHM and school absenteeism among schoolgirls using nationally representative data from the Bangladesh National Hygiene Baseline Survey 2014 and National Hygiene Survey 2018. Given the repetitive nature of our data and its clustering within participants, our method included performing descriptive analysis, bivariate analysis, and multivariate Generalised Estimating Equation (GEE) modelling to analyse these changes. Results Results showed that adolescent girls’ menstruation-related absenteeism decreased between 2014 and 2018. Percentage of adolescents who missed school decreased from 25% to 14% (PD: −11; CI: −16 to −6.1), while the average number of missed days reduced from 2.8 to 2.5 (PD: −0.33; CI: −0.57 to −0.10). In the GEE model, we found that living in rural areas (coef: −5.6; CI: −10.06 to −1.14), parental restrictions on going outside (coef: 4.47; CI: 0.75 to 8.2), education levels of girls (coef: −9.48; CI: −14.17 to −4.79), girl’s belief that menstruation affects school performance (coef: 23.32; CI: 19.71 to 26.93), and using old cloths (coef: −4.2; CI: −7.6 to −0.79) were significantly associated with higher absenteeism. However, participant’s age, type of school, knowledge of menstruation before menarche, receiving information regarding MHM, separate place for changing absorbents, and separate latrine and urine facility were not significantly associated with the changes in absenteeism over time. Conclusion This paper emphasised the associations between changes in school absenteeism, parental restrictions on students, students’ education levels, and menstruation-related misperceptions. Ongoing research, policy reviews, and targeted interventions to improve MHM perceptions among girls are required to provide long-term benefits for adolescent girls in Bangladesh

Design and implementation of potentiometer-based nonlinear transducer emulator

This work attempts to design and implement in hardware a transducer with a nonlinear response using potentiometer. Potentiometer is regarded as a linear transducer, while a the response of a nonlinear transducer can be treated as a concatenation of linear segments made out of the response curve of an actual nonlinear transducer at the points of inflections being exhibited by the nonlinear curve. Each straight line segment is characterized by its slope and a constant, called the y-intercept, which is ultimately realized by a corresponding electronic circuit. The complete circuit diagram is made of three stages: (i) the input stage for range selection, (ii) a digital logic to make appropriate selection, (iii) a conditioning circuit for realizing a given straight-line segment identified by its relevant slope and reference voltage. The simulation of the circuit is carried using MULTISIM, and the designed circuit is afterward tested to verify that variations of the input voltage give us an output voltage very close to the response pattern envisaged in the analytical stage of the design. The utility of this work lies in its applications in emulating purpose built transducers that could be used to nicely emulate a transducer in a real world system that is to be controlled by a programmable digital system