219 research outputs found
The Effect of Quantitative Easing on the Financial Market in Canada
This empirical study examines the effects of quantitative easing (QE) on the Canadian financial market. Specifically, the study focuses on the Bank of Canada\u27s Government of Canada Bond Purchase Program (GBPP), conducted during COVID-19 between 2020 and 2022. I use two analytical methods, e.g., event study and time series analysis, to quantify the impact of the Bank of Canada\u27s large asset purchases on the 10-year government bond yield\u27s term premium. The results indicate that the Bank of Canada\u27s $260 billion asset purchases in 2020 would reduce the 10-year term premium by 34 basis points, which suggests the significant impact of quantitative easing on the term premium. Furthermore, the study finds that QE has a portfolio balance effect by reducing the yields on other non-government assets. The findings of this study constitute a significant contribution to the current discourse regarding the use of QE as a monetary policy tool and have implications for future policy decisions related to monetary policy in the Canadian economy
Modeling The Interactions Between Turbulence And Radiation In Oxy-Combustion Flames
In order to accurately estimate radiative heat transfer in turbulent combustion systems, one needs to take into account the non-linear interactions between the temporally fluctuating species and temperature variables and the radiation field. Simply employing time-averaged values of these variables in the radiation calculations to estimate absorption and emission (as is commonly done in the modeling community) can result in gross errors in the estimation of the radiative fluxes. Therefore, models that account for these Turbulence-Radiation Interactions (TRI) have been proposed in the literature to improve the fidelity of the radiative transfer calculations. TRI models accomplish this by computing appropriate time-averaged representations of the absorption and emission terms by taking into consideration the interactions and relationships between these terms and the fluctuating species and temperature fields. However, knowledge of the specie and temperature fluctuation statistics is key to developing these TRI relationships.
In this thesis, statistical analysis of high-fidelity experimental measurements in five oxy-fuel flames with fuel jet Reynolds numbers ranging from 12,000 to 18,000 and fuel compositions in the range (50% H2-50% CH4 to 40% H2-60%CH4) were first carried out to formulate TRI models of absorption and emission. Statistical analysis of the measurements showed that in spite of the high concentrations of the radiatively participating gases in these flames, the temporal variations in the absorption field were determined to be insignificant. However, strong fluctuations in the emission field were observed and was found to correlate well with the root-mean-square of temperature.
Next, a TRI model for emission based on this experimentally observed correlation was implemented as a User-Defined Function (UDF) in the computation fluid dynamic code ANSYS FLUENT. Time-averaged simulations of the five flames were then carried out to examine the impact of the new TRI model on the radiation field. Turbulence was modeled employing the realizable k-epsilon model and non-adiabatic mixture fraction relationships were employed to represent the chemistry. The radiative properties of the mixture were determined employing a weighted-sum-of-gray gases model developed at the University of North Dakota. The predicted temperature and CO2 mole fractions agreed well with the experimental measurements suggesting the adequacy of our modeling procedure. The radiant fraction in these flames without accounting for the effects of TRI was 8%. However, including the TRI model predicted a radiant fraction of 16% as a result of significant enhancement in the emission term. Therefore, numerical simulations that do not adequately account for the TRI effects in these flames can significantly under-estimate the resulting wall radiative fluxes. Further, despite the absence of fluctuations in the absorption term, the magnitude of the absorption term was nearly equal to that of the emission term across all flames. This also indicates that the “optically thin” radiation approximation (which neglects absorption) that has traditionally been employed to simulate similar laboratory flames can again result in a significant over-estimation of the radiative fluxes. Finally, our preliminary calculations indicate that despite the importance of TRI models for wall radiative flux estimations, the impact of their inclusion on the flame temperature and specie field predictions was negligible
Towards an integrated pollution management approach for the Buriganga River in Bangladesh
Water pollution management in the Buriganga River, which encompasses the south-western periphery of the capital city Dhaka, has been a major concern for the Government of Bangladesh at least for the last two decades. Several policies based on direct regulatory measures have been adopted by the government in different times to address this issue. In spite of this, no significant improvement in the river water quality has been achieved. In addition, an updated, detailed and systematic analysis of water quality along the full length of the river has not been conducted for some time. Hence, this research aimed to postulate a new management system to control pollution in the Buriganga River based on a recently conducted qualitative and quantitative assessment of river water and wastewater that are discharged into the river. The study also aimed to evaluate the existing system for river pollution control and to determine the economic costs that are likely to result under alternative policy instruments for pollution mitigation, such as, uniform reduction, uniform taxes and tradable permit system. In the study, a conceptual framework was recommended for an integrated pollution management approach in the Buriganga River. The river water quality was found to be unacceptable (as per the standards set by the Department of Environment in Bangladesh) for the parameters such as dissolved oxygen (DO), biochemical oxygen demand on five days (BOD5), chemical oxygen demand (COD), ammonia-nitrogen (NH3-N) and chromium (Cr) during both dry (low flow condition) and wet (high flow condition) seasons and for electrical conductivity in water (ECw) during only dry season. For the river water, the average concentration of DO ranges between 0.9 mg/L in dry and 2.8 mg/L in wet season, BOD5 between 34.5 mg/L in dry and 2.5 mg/L in wet season, COD between 60.1 mg/L in dry and 17.2 mg/L in wet season, ECw between 661 µS/cm in dry and 83 µS/cm in wet season, NH3-N between 4.1 mg/L in dry and 3.3 mg/L in wet season, Cr between 0.06 mg/L in dry and 0.07 mg/L in wet season. Temperature, pH, phosphate-phosphorus (PO4-P) and lead (Pb) were found within the DOE acceptable limits in both dry and wet seasons. Moreover, along the length of the river, relatively higher ambient concentration of BOD5, COD, NH3-N and Cr was observed at Kholamora station for both dry and wet seasons compared to four other selected stations (receptor points) along the river. The study established that the water of the Buriganga River is polluted by a combination of wastewater from both municipal and industrial sources, located within its basin area, which are discharged through three main drainage channels. The wastewater was found hypoxic to anoxic in most cases associated with very high concentration of BOD5, COD, ECw, Cr and NH3-N compared to the guidelines. For the incoming wastewater, the minimum and the maximum average concentration (including three major discharge points) of BOD5 ranges between 251.0 to 1003.4 mg/L, COD between 378.9 to 1261.1 mg/L, ECw between 458.9 to 3939.3 µS/cm, Cr between 0.02 to 13.3 mg/L and NH3-N between 4.1 to 83.5 mg/L throughout the year. The average BOD5 pollution loading rates for the three major discharge points at Rayerbazar sluice gate, Shahidnagar drainage outlet and Pagla Sewage Treatment Plant (PSTP) effluent outfall were estimated as 83, 71 and 32 tons/day respectively. The study identified that the existing command and control (CAC) based regulatory approaches to pollution management for the Buriganga River are not functioning effectively. The compliance and enforcement of these regulatory measures are not satisfactory, which contributes to continuing pollution problems. The present pollution control measures do not provide any economic incentives for pollution prevention and adoption of new technologies. Despite the provisions made within the national policies, no specific role has been outlined to ensure the effective contribution of Non-Government Organisations/Community Based Organisations for pollution control. However, the current study found that the local community is willing, and has the potential, to directly participate in the pollution control process of this river. The research used a spreadsheet based decision support tool in order to conduct a simulation exercise for evaluating the economic efficiency of the several alternative pollution abatement policies, while meeting specific water quality targets. The method generated empirical estimates on costs of BOD5 reduction from three major discharge points in the Buriganga River using three alternative policies. The results from the simulation exercise showed that application of the approaches based on economic incentives (uniform tax or tradable permit system) could achieve significant cost savings (up to about 50 per cent) for BOD5 pollution control in the Buriganga River in contrast to the CAC based approach (uniform reduction system). Further, considering the prerequisites for the tradable permit system and the marginal difference of economic benefit to be gained from this system compared to the uniform tax system, it is recommended that at this stage the uniform pollution tax system with revenue recycling should be considered as an effective alternative policy for water quality improvement in the Buriganga River. Finally, through this interdisciplinary study a conceptual framework of an integrated pollution management system for the Buriganga River was developed taking into account the state of water quality, the weaknesses encountered in the present system, the empirical evidence of the potential benefits from economic incentive based approaches to regulating pollution and from the experiences of river pollution management in other countries. The integrated management framework was recommended by combining appropriate pollution control instruments which encourages coordination of different stakeholders, public participation and application of economic incentive based measures. The proposed new approaches (economic incentive and community involvement) do not replace the present regulatory measures (particularly the ambient water quality standards) but they rather complement them. The research also proposed a set of policy initiatives that should be implemented within the integrated management framework. It would necessitate legislative changes to incorporate a legal basis for pollution taxing. The legal reform should incorporate the scope to vary the emission tax rate from time to tome and/or to impose strict regulations in short notice in case of emergency situation. In this context, legal agreements between polluters and regulatory authorities could be formed in order to ensure the proper collection of pollution taxes. The study also suggested the strengthening of organisational capacity at the cost of aborting the involvement of multiple government authorities, in favour of a single authority that would be invested with full power and responsibility for pollution control in the Buriganga River. Hence it was recommended that a Buriganga River Management Authority be established, to work under the supervision of the Ministry of Environment and Forests (MOEF). This agency could be assigned with legislative power and would hold sole responsibility to manage and coordinate all activities related to pollution control and conservation of the Buriganga River. Moreover, the study noted the significant positive contributions of community participation and commitments towards managing the pollution problem of the Buriganga River and the catalytic role it could play. With this end in view, the proposed integrated approach recommended formulating a standard procedure and guideline for water quality monitoring by community groups to ensure ease and efficiency of their work. In addition, necessary training programs should be directed by experts in the field to equip in the community for this purpose. Giving the community a responsible role in monitoring and recording failures and improvements could provide the necessary focus of attention and impetus required to resolve the Buriganga River pollution problem. Application of economic incentive based instruments and continual disclosure of information were also recommended in the study. The study concluded that a sustainable pollution management system for the Buriganga River could be achieved by bringing together all the stakeholders concerned at a local level and by applying appropriate pollution control measures along with the suggested set of policies
Applying Data Augmentation to Handwritten Arabic Numeral Recognition Using Deep Learning Neural Networks
Handwritten character recognition has been the center of research and a
benchmark problem in the sector of pattern recognition and artificial
intelligence, and it continues to be a challenging research topic. Due to its
enormous application many works have been done in this field focusing on
different languages. Arabic, being a diversified language has a huge scope of
research with potential challenges. A convolutional neural network model for
recognizing handwritten numerals in Arabic language is proposed in this paper,
where the dataset is subject to various augmentation in order to add robustness
needed for deep learning approach. The proposed method is empowered by the
presence of dropout regularization to do away with the problem of data
overfitting. Moreover, suitable change is introduced in activation function to
overcome the problem of vanishing gradient. With these modifications, the
proposed system achieves an accuracy of 99.4\% which performs better than every
previous work on the dataset.Comment: 5 pages, 6 figures, 3 table
The Role Of Bangladesh As A Coastal State In Preventing Marine Plastic Pollution From Land-Based Sources
Marine Plastic Pollution from land-based sources is posing a serious threat to the marine environment. This thesis aims to examine the international laws and national laws of Bangladesh regarding plastic pollution from land-based sources
Time- and frequency-asynchronous aloha for ultra narrowband communications
A low-power wide-area network (LPWAN) is a family of wireless access technologies which consume low power and cover wide areas. They are designed to operate in both licensed and unlicensed frequency bands. Among different low-power wide-area network (LPWAN) technolo-gies, long range (LoRa), Sigfox, and Narrowband Internet of Things (NB-IoT) are leading in IoT deployment in large-scale. However, Sigfox and LoRa both have advantages in terms of battery lifetime, production cost and capacity whereas lower latency and better quality of service are of-fered by Narrowband Internet of Things (NB-IoT) operating licensed cellular frequency bands. The two main approaches for reaching wide coverage with low transmission power are (i) spread spectrum, used by LoRa, and (ii) ultra-narrow band (UNB) which is used by Sigfox.
This thesis work focuses on the random-access schemes for UNB based IoT networks mainly. Due to issues related to receiver synchronization, two-dimensional time-frequency ran-dom access protocol is a particularly interesting choice for UNB transmission schemes. Howev-er, UNB possess also some major constraints regarding connectivity, throughput, noise cancel-lation and so.
This thesis work investigates UNB-based LPWAN uplink scenarios. The throughput perfor-mance of Time Frequency Asynchronous ALOHA (TFAA) is evaluated using MATLAB simula-tions. The main parameters include the interference threshold which depends on the robust-ness of the modulation and coding scheme, propagation exponent, distance range of the IoT devices and system load. Normalized throughput and collision probability are evaluated through simulations for different combinations of these parameters. We demonstrate that, using repeti-tions of the data packets results in a higher normalized throughput. The repetition scheme is designed in such a way that another user's packets may collide only with one of the target packets repetitions. The power levels as well as distances of a user’s all repetitions are consid-ered same. By using repetitions, reducing the distance range, and increasing the interference threshold, the normalized throughput can be maximized
Two-Dimensional Nanomaterials and Nanocomposites for Sensing, Separation, and Energy Applications
Two-dimension (2D) nanomaterials have gained popularity for the last few decades due to their excellent mechanical, electrical and thermal properties. These unique properties of 2D nanomaterials can be exploited in various applications specially in sensor, energy, and separation devices. In this study, the sensing and energy generation performance of PVDF/PAni fiber mat systems made by the forcespinning method with and without graphene coating. The graphene-coated nanocomposites show an average output voltage of 75 mV (peak-to-peak) which is 300% higher compared to bare fiber mats and an output current of 24 mA (peak-to-peak) by gentle finger pressing. Moreover, the graphene-coated PVDF/PAni was investigated as a promising system for temperature (5 times better sensitivity), vibration (2 times better voltage generation), and airflow sensing. The graphene-coated composite has been further investigated as a water tide energy harvesting piezoelectric nanogenerator, the system generates ~ 40 mV for a synthetic ocean wave with a flow rate of 30 mL/min. Additionally, fabricated a low-cost, single-step, sophisticated graphene-enhanced elastomeric nanocomposite sensor for multifunctional usage by using a batch mixer. This nanocomposite ink was then fabricated into flexible keypad & forecepad and separation devices. Furthermore, the study also showed the enhanced battery performance of chemical vapor deposited pyrolytic carbon coatings on nanoparticles and nanofibers
Bank size, relationship lending and SME financing: Evidence from Bangladesh
This paper examines the effect of bank size on relationship lending and how relationship lending can affect credit availability, interest rates and collateral to SMEs in the context of Bangladesh. Our empirical results suggest that SMEs with a long-term relationship with small banks have more access to finance than from large banks. However, we did not find any evidence that long-term relationship with small banks can reduce interest rates or collateral requirements for SMEs. We find evidence though that a stronger and much more exclusive relationship with a small bank can reduce the interest rates for SMEs. This mixed evidence suggests that small banks do not have full comparative advantage in processing soft information, but large banks in Bangladesh may have different lending techniques to extend loans to SMEs with similar interest rates and collateral requirements as like as small banks. Furthermore, we find evidence that small banks are giving priority to both long-term relationship and collateral requirement for SME credit risk than large banks. © Ashiqur Rahman, M. Twyeafur Rahman, Aleksandr Kljucnikov, 2016
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