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13 results on '"Alam, S. B."'

3. Nuclear data adjustment using Bayesian inference, diagnostics for model fit and influence of model parameters

Author

Kumar D., Alam S. B., Sjöstrand H., Palau J.M., and De Saint Jean C.

Subjects
Physics, QC1-999
Abstract

The mathematical models used for nuclear data evaluations contain a large number of theoretical parameters that are usually uncertain. These parameters can be calibrated (or improved) by the information collected from integral/differential experiments. The Bayesian inference technique is used to utilize measurements for data assimilation. The Bayesian approximation is based on the least-square or Monte-Carlo approaches. In this process, the model parameters are optimized. In the adjustment process, it is essential to include the analysis related to the influence of model parameters on the adjusted data. In this work, some statistical indicators such as the concept of Cook’s distance; Akaike, Bayesian and deviance information criteria; effective degrees of freedom are developed within the CONRAD platform. Further, these indicators are applied to a test case of 155Gd to evaluate and compare the influence of resonance parameters.

Published
2020
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4. Influence of nuclear data parameters on integral experiment assimilation using Cook’s distance

Author

Kumar D., Alam S. B., Sjöstrand H., Palau J. M., and De Saint Jean C.

Subjects
Physics, QC1-999
Abstract

Nuclear data used in designing of various nuclear applications (e.g., core design of reactors) is improved by using integral experiments. To utilize the past critical experimental data to the reactor design work, a typical procedure for the nuclear data adjustment is based on the Bayesian theory (least-square technique or Monte-Carlo). In this method, the nuclear data parameters are optimized by the inclusion of the experimental information using a Bayesian inference. The selection of integral experiments is based on the availability of well-documented specifications and experimental data. Data points with large uncertainties or large residuals (outliers) may affect the accuracy of the adjustment. Hence, in the adjustment process, it is very important to study the influence of experiments as well as of the prior nuclear data on the adjusted results. In this work, the influence of each individual reaction (related to nuclear data) is analyzed using the concept of Cook’s distance. First, JEZEBEL (Pu239, Pu240 and Pu241) integral experiment is considered for data assimilation and then the transposition of results on ASTRID fast reactor concept is discussed.

Published
2019
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7. Uncertainty Quantification and Robust Optimization in Engineering

Author

Kumar, Dinesh, Alam, S. B., Vucinic, Dean, Lacor, C., Kumar, Dinesh, Alam, S. B., Vucinic, Dean, and Lacor, C.

Abstract

The application and use of engineering components such as engines, wings, or complete airplanes are all subject to uncertainties, either of operational nature (variations in speed, angle of attack, pressure, etc) or of geometrical nature (manufacturing tolerances or uncertainties due to wearing). These uncertainties can have an important effect on the performance (output) of these components. The effect of these uncertain parameters should be quantified and included in the final solution to assure and improve the quality of the results. Polynomial chaos is a recent methodology to account for uncertainties that can be described by a distribution function. The method allows to obtain the distribution of the output for given input distributions. Over the last decade, with increasing computational resources and hardware power, design optimization is receiving more and more interest in aeronautical applications. Due to the uncertainties in a design process, the objective is also uncertain. Robust optimization is an extension of conventional optimization where uncertainties are also included in the design procedure. Using polynomial chaos expansion, the uncertain objective can be characterized by its mean and its variance. Therefore, it becomes a multi-objective problem and gradient based optimization requires the gradient of both quantities. These gradients can be obtained from the polynomial chaos expansion of the gradient of the objective. In this chapter, first, a brief introduction to polynomial chaos approach for uncertainty quantification is provided. Further its formulation with adjoint methods is described for gradient based robust optimization. The approach is applied to the optimal shape design of a transonic airfoil under uncertainties.

Published
2020
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8. Nuclear data adjustment using Bayesian inference, diagnostics for model fit and influence of model parameters

Author

Kumar, Dinesh, Alam, S. B., Sjöstrand, Henrik, Palau, J. M., De Saint Jean, C., Kumar, Dinesh, Alam, S. B., Sjöstrand, Henrik, Palau, J. M., and De Saint Jean, C.

Abstract

The mathematical models used for nuclear data evaluations contain a large number of theoretical parameters that are usually uncertain. These parameters can be calibrated (or improved) by the information collected from integral/differential experiments. The Bayesian inference technique is used to utilize measurements for data assimilation. The Bayesian approximation is based on the least-square or Monte-Carlo approaches. In this process, the model parameters are optimized In the adjustment process, it is essential to include the analysis related to the influence of model parameters on the adjusted data. In this work, some statistical indicators such as the concept of Cook's distance; Akaike, Bayesian and deviance information criteria; effective degrees of freedom are developed within the CONRAD platform. Further, these indicators are applied to a test case of Gd-155 to evaluate and compare the influence of resonance parameters.

Published
2020
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9. Agribusiness of poultry and poultry products in Bangladesh

Author

Alam, S. B. and Azad, M. A. K.

Subjects
Poultry products, Bangladesh, Livestock Production/Industries, Agribusiness, health care economics and organizations, Poultry
Abstract

The present research has been undertaken to study the agribusiness of poultry with the following objectives: to study the market structure and distribution system of important inputs used in poultry farms; to estimate the cost, return and profitability of broiler and layer farms; to examine the existing marketing system and estimate the cost, margin and profit of traders involved in the marketing chain; and to suggest some policy measures for sustained development of poultry industry. According to farm owners the Aratdars were mainly responsible for different crisis in poultry sector. Eighty two Aratdars in Tejgaon area control the whole poultry business in Dhaka. The government has no control over them. They fix price according to their will. The Aratdars reputed the farm owners'. complain. They stated that they earned only Tk. 5 as profit from selling 100 eggs.The farm owner association reported that there is no appropriate government policy for poultry industry.

Published
2005
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13. Therapeutic Potentials of Syzygium fruticosum Fruit (Seed) Reflected into an Array of Pharmacological Assays and Prospective Receptors-Mediated Pathways

Author

Kamrul Hasan Chowdhury, Mahfuz Ahmed Sakib, Adnan, Jannatul Nasma Rupa Moni, Seema Binte Alam, Syed Al Jawad Sayem, Ahm Khurshid Alam, A. S. M. Ali Reza, Imtiazul Kabir, Abu Montakim Tareq, Mst. Samima Nasrin, Atiar Rahman, Raffaele Capasso, Dong Ha Cho, Ki Kwang Oh, Moni, J. N. R., Adnan, M., Tareq, A. M., Kabir, M. I., Reza, A. S. M. A., Nasrin, M. S., Chowdhury, K. H., Sayem, S. A. J., Rahman, M. A., Alam, A. H. M. K., Alam, S. B., Sakib, M. A., Oh, K. K., Cho, D. H., and Capasso, R.

Subjects
Elevated plus maze, computational studies, and computational studies, Syzygium fruticosum, Computational studie, Ethyl acetate, Pharmacology, Article, General Biochemistry, Genetics and Molecular Biology, Open field, law.invention, chemistry.chemical_compound, Neuropharmacology, In vivo, law, lcsh:Science, GC‐MS, Receptor, Ecology, Evolution, Behavior and Systematics, Paleontology, Analgesic and anti‐inflammatory, In vitro, analgesic and anti-inflammatory, chemistry, Space and Planetary Science, lcsh:Q, GC-MS, Thrombolytic, Phytotherapy, Behavioural despair test
Abstract

Syzygium fruticosum (SF), a valuable Bangladeshi fruit, is considered an alternative therapeutic agent. Mainly, seeds are used as nutritional phytotherapy to ease physical and mental status by preventing chronic diseases. Here, we scrutinized theS. fruticosum seed’s fundamental importance in traditional medicine by following an integrated approach combining in vivo, in vitro,and in silico studies. The SF was fractionated with different solvents, and the ethyl acetate fraction of SF (EaF-SF) was further studied. Mice treated with EaF-SF (200 and 400 mg/kg) manifested anxiolysis evidenced by higher exploration in elevated plus maze and hole board tests. Similarly, a dose-dependent drop of immobility time in a forced swimming test ensured significant anti-depressant activity. Moreover, higher dose treatment exposed reduced exploratory behaviour resembling decreased movement and prolonged sleeping latency with a quick onset of sleepduring the open field and thiopental-induced sleeping tests, respectively. Inparallel, EaF-SF significantly (p &lt, 0.001) and dose-dependently suppressed aceticacid and formalin-induced pain in mice. Also, a noteworthy anti-inflammatoryactivity and a substantial (p &lt, 0.01) clot lysis activity (thrombolytic) was observed. Gas chromatography-mass spectrometry (GC–MS) analysis resulted in 49 bioactive compounds. Among them, 12 bioactive compounds with Lipinski’s rule and safety confirmation showed strong bindingaffinity (molecular docking) against the receptors of each model used. Toconclude, the S. fruticosum seed isa prospective source of health-promotingeffects that can be an excellent candidate for preventing degenerative diseases.

Published
2021
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