Dhaka University Journal of Science最新文献_第3页

Characteristics of General Linear Group of Order 2 as Lie Group and Lie Algebra 一般2阶线性群作为李群的特征与李代数

Dhaka University Journal of Science Pub Date : 2023-05-29 DOI: 10.3329/dujs.v71i1.65277

Md Shapan Miah, Khondokar M. Ahmed, S. Nasrin

引用次数: 0

An Integrated Forecasting Technique with Modified Weight Measurement 修正权值的综合预测技术

Dhaka University Journal of Science Pub Date : 2023-05-29 DOI: 10.3329/dujs.v71i1.65270

M. B. Hasan, M. Asadujjaman, M. H. Haque

引用次数: 0

Analyzing Business Strategies of a Company in Bangladesh by Comparing Three Rigorous Forecasting Techniques 通过比较三种严格的预测技术分析孟加拉国一家公司的商业战略

Dhaka University Journal of Science Pub Date : 2023-05-29 DOI: 10.3329/dujs.v71i1.65269

M. B. Hasan, M. Asadujjamanand, M. Haque

{"title":"Analyzing Business Strategies of a Company in Bangladesh by Comparing Three Rigorous Forecasting Techniques","authors":"M. B. Hasan, M. Asadujjamanand, M. Haque","doi":"10.3329/dujs.v71i1.65269","DOIUrl":"https://doi.org/10.3329/dujs.v71i1.65269","url":null,"abstract":"Business organizations in Bangladesh are basically running their business through intuition based forecasting. But it is crucial to anticipate the near future as accurate as possible to make the business profitable. This helps the manager of a business organization to plan their resources properly and as a result the organization can minimize its cost and maximize profit. In this research paper, we will analyze the business strategies of a company in Bangladesh by comparing the results obtained from three different rigorous forecasting techniques such as Holt’s method, Holt-Winter’s method and Autoregressive Integrated Moving Average (ARIMA) method so that the business organization can select proper forecasting technique to run their business. For this, we will first illustrate and analyze basics of forecasting and time series analysis, usual forecasting methods, some rigorous methods e.g., Holt’s method, Winter’s method and Autoregressive Integrated Moving Average (ARIMA) models. We will carry out our analysis and calculation by using Microsoft Excel, statistical data analysis tool R and MATHEMATICA.\u0000Dhaka Univ. J. Sci. 71(1): 26-35, 2023 (Jan)","PeriodicalId":11280,"journal":{"name":"Dhaka University Journal of Science","volume":"81 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79317769","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Evaluating the Accuracy of Chebyshev’s Inequality for Probability Calculation: A Simulation Study 评价切比雪夫不等式在概率计算中的准确性:模拟研究

Dhaka University Journal of Science Pub Date : 2023-05-29 DOI: 10.3329/dujs.v71i1.65276

Tasmiah Afrin Emma, A. Sajib, Sabina Sharmin

{"title":"Evaluating the Accuracy of Chebyshev’s Inequality for Probability Calculation: A Simulation Study","authors":"Tasmiah Afrin Emma, A. Sajib, Sabina Sharmin","doi":"10.3329/dujs.v71i1.65276","DOIUrl":"https://doi.org/10.3329/dujs.v71i1.65276","url":null,"abstract":"This paper aims to evaluate the accuracy of probability calculation using Chebyshev’s inequality based on simulation study. We consider symmetric (Normal (3,1.52 ), Laplace (3, 2 ) Beta (7.7 ) t5) positively skewed, negatively skewed (5 χ2, Beta (3, 8 ) Gamma (5,1)), (Beta (7, 2)), Exponential (5) and Uniform (0, 1 ) distributions, fx(x) in our simulation study to measure the performance of Chebyshev’s inequality. We then calculate Pr (μ − kσ ≤ X ≤ μ + kσ ) for ~ ( ) X X f x , μ = E ( X ) and σ 2 =Var ( X ), and compare this with the approximated probability obtained from Chebyshev’s inequality to measure the accuracy of Chebyshev’s inequality. From our simulation study, it is observed that loss due to using Chebyshev’s inequality for probability calculation is the least and the maximum when fx(x) is the Exponential and the Beta (symmetric) distributions, respectively for k ≥ 2.5. Moreover, the value of Pr (μ − kσ ≤ X ≤ μ + kσ ) calculated using Chebyshev’s inequality is underapproximated for all the probability distributions considered in the study.\u0000Dhaka Univ. J. Sci. 71(1): 76-81, 2023 (Jan)","PeriodicalId":11280,"journal":{"name":"Dhaka University Journal of Science","volume":"157 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74179807","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

ZnO-Cu2O Composites for Photocatalytical Removal of Methylene Blue from Aqueous Solution under Visible Light ZnO-Cu2O复合材料在可见光下光催化去除水溶液中的亚甲基蓝

Dhaka University Journal of Science Pub Date : 2023-05-29 DOI: 10.3329/dujs.v71i1.65271

N. Akter, Mahbuba Zaman, M. Rahman, M. Hossain

{"title":"ZnO-Cu2O Composites for Photocatalytical Removal of Methylene Blue from Aqueous Solution under Visible Light","authors":"N. Akter, Mahbuba Zaman, M. Rahman, M. Hossain","doi":"10.3329/dujs.v71i1.65271","DOIUrl":"https://doi.org/10.3329/dujs.v71i1.65271","url":null,"abstract":"ZnO-Cu2O composites were prepared by precipitation technique followed by calcination. The prepared composite was characterized by scanning electron microscopy (SEM), energy dispersion X-ray (EDX), Fourier transform infra-red (FT-IR) and X-ray diffraction (XRD). Band gap energy of the composite was determined by UV-visible reflectance measurement. The absorption range of the ZnO-Cu2O composite was shifted to the visible region due to the doping of Cu2O. SEM image represented that composite nanoparticle was smaller in size compared to the pure ZnO. The EDX spectral analysis showed that no elements other than Zn, Cu and O were present in the sample. XRD showed that ZnO-Cu2O composite was made of hexagonal ZnO and cubic Cu2O. The photocatalytic activity of ZnO-Cu2O composite was studied by degrading MB under different experimental conditions. The molar ratios of the composites, amount of the composite, initial concentration of dyes were varied to optimize the conditions for degradation. The experimental result was compared with those of commercial ZnO. It was found that the ZnO-Cu2O composite is a better photocatalyst than ZnO under visible light.\u0000Dhaka Univ. J. Sci. 71(1): 42-48, 2023 (Jan)","PeriodicalId":11280,"journal":{"name":"Dhaka University Journal of Science","volume":"12 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89876245","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Integrated Study of CO2 Sequestration and CO2-EOR in Oil Reservoir by Compositional Simulation 基于组分模拟的油藏CO2固存与CO2提高采收率综合研究

Dhaka University Journal of Science Pub Date : 2022-12-18 DOI: 10.3329/dujs.v70i2.62602

Mohammad Amirul Islam, A. Woobaidullah

{"title":"Integrated Study of CO2 Sequestration and CO2-EOR in Oil Reservoir by Compositional Simulation","authors":"Mohammad Amirul Islam, A. Woobaidullah","doi":"10.3329/dujs.v70i2.62602","DOIUrl":"https://doi.org/10.3329/dujs.v70i2.62602","url":null,"abstract":"Now researchers are performing extensive research work to increase the oil and gas production to meet increasing energy demand and to reduce the CO2concentration from atmosphere to reduce global worming.This study is an effort to increase oil production by CO2-EOR from an oil reservoir in Surma basin and to evaluate the oil reservoir as a candidate of CO2 sequestration. The oil reservoir rock is Bhuban sandstone and fluid is heavy oil. High salinity water is also present in the oil reservoir. A compositional reservoir simulation model has been developed for this study. Geo-cellular 3D reservoir grid structure has been constructed by block centered geometry. Reservoir rock properties such as porosity, absolute permeability and net to gross ratio have been modeled using rock properties of Bhuban sandstone. Reservoir oil composition has been determined from liquid chromatograph. Thermodynamic properties of pure components in reservoir oil have been included in the compositional reservoir simulation model. The reservoir has been developed by four CO2 injection wells arranged at the periphery of the reservoir and one oil production well kept at the center of the reservoir. The optimum CO2 injection rate is 500 MSCF/D at pressure 3100 psi by a single well and optimum oil production rate is 4900 STB/D.\u0000Dhaka Univ. J. Sci. 70(2): 23-28, 2022 (July)","PeriodicalId":11280,"journal":{"name":"Dhaka University Journal of Science","volume":"80 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86892290","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Forecasting the Growth Rate of GDP and its Indicators Remittance and Labor Force Participation of Bangladesh using VECM and ARIMA Models 利用VECM和ARIMA模型预测孟加拉国GDP增长率及其指标汇款和劳动力参与率

Dhaka University Journal of Science Pub Date : 2022-12-18 DOI: 10.3329/dujs.v70i2.62605

Akash Saha, Murshida Khanam

{"title":"Forecasting the Growth Rate of GDP and its Indicators Remittance and Labor Force Participation of Bangladesh using VECM and ARIMA Models","authors":"Akash Saha, Murshida Khanam","doi":"10.3329/dujs.v70i2.62605","DOIUrl":"https://doi.org/10.3329/dujs.v70i2.62605","url":null,"abstract":"The present study used VECM model and ARIMA model for modeling the growth rate of GDP, Remittances and total Labor Force Participation. All of the data of this study are collected from the World Bank Database with indicators as the time series variable from 1999 to 2020. The stationarity of the time series variables has been tested by the Augmented Dickey-Fuller test and investigated that they become stationary at first difference. The lag selection criteria has been applied to find out the no. of lags needed to be included in the model. Lag 2 has been selected for this study. VEC model has been applied in the time series data. Also the ARIMA model imposed on these time series variables. These two models have been used for forecasting. Among the predictions obtained by these two models the better one has been selected by using RMSE, MAPE and MAE. It has been found that for growth rate of GDP and total Labor Force Participation, the ARIMA model is more preferable but for Remittance, VECM is desirable. It has been found that the Remittance and Labor Force have significant positive impact on the growth of GDP. Also, a long run relationship has been found among the growth rate of GDP, Remittances and total Labor Force Participation.\u0000Dhaka Univ. J. Sci. 70(2): 42-47, 2022 (July)","PeriodicalId":11280,"journal":{"name":"Dhaka University Journal of Science","volume":"22 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83573008","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Estimation and Health Risk Assessment of Respirable Silica in the Ambient Particulate Matter of Dhaka City 达喀市环境颗粒物中可吸入二氧化硅的估算与健康风险评价

Dhaka University Journal of Science Pub Date : 2022-12-18 DOI: 10.3329/dujs.v70i2.62604

Mni Nahin, S. Nahian, MS Islam, Sayantee Roy, F. Jeba, A. Salam

{"title":"Estimation and Health Risk Assessment of Respirable Silica in the Ambient Particulate Matter of Dhaka City","authors":"Mni Nahin, S. Nahian, MS Islam, Sayantee Roy, F. Jeba, A. Salam","doi":"10.3329/dujs.v70i2.62604","DOIUrl":"https://doi.org/10.3329/dujs.v70i2.62604","url":null,"abstract":"A simple, rapid, and efficient spectrophotometric method was developed for the quantification of respirable crystalline silica (SiO2) in atmospheric particulate matter (PM). The PM samples were collected for 24 hours from two different locations at the University of Dhaka (Mukarram Hussain Khundker Building-MHK and Teacher Student Centre-TSC) using a low-volume air sampler from September to December 2021. The extraction of PM loaded filters followed by filtration resulted in a clear solution. Using UV-visible spectroscopy, the concentration of silica in the filtrate was evaluated by treating the filtrate with molybdate-3 reagent and an amino acid suspension. The average PM-bound silica concentrations at MHK and TSC were 7.72 and 33.86 μgm-3 respectively. Compared to MHK, the silica content in the ambient atmosphere of TSC was four times higher, owing to extensive metro-rail construction work at TSC. The contribution of silica to PM was 3.47% (Site 1) and 5.15% (Site 2). The Hazard Quotient (HQ) was used to characterize the non-cancer risk posed by respirable silica. TSC recorded a high value of 12.87 for the hazard quotient of respirable silica compared to 2.57 for MHK indicating that the exposed inhabitants may have adverse noncancer health impacts. Carcinogenic risk assessment of silica showed that 1 in 341 individuals at MHK and 1 in 78 individuals at TSC could get cancer in their lifetime. This is the first study that demonstrated the high level of PM-bound respirable silica severely degraded air quality as well as potential human health in Dhaka.\u0000Dhaka Univ. J. Sci. 70(2): 35-41, 2022 (July)","PeriodicalId":11280,"journal":{"name":"Dhaka University Journal of Science","volume":"96 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80567031","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Analysis of Fats and Fatty Acids in Several Bakery Cookies of Bangladesh 孟加拉国几种烘焙饼干中脂肪和脂肪酸的分析

Dhaka University Journal of Science Pub Date : 2022-12-18 DOI: 10.3329/dujs.v70i2.62607

Shahnaz Akhtar Nishat, Supath Xavier Besra, M. Shoeb, A. Sultana

{"title":"Analysis of Fats and Fatty Acids in Several Bakery Cookies of Bangladesh","authors":"Shahnaz Akhtar Nishat, Supath Xavier Besra, M. Shoeb, A. Sultana","doi":"10.3329/dujs.v70i2.62607","DOIUrl":"https://doi.org/10.3329/dujs.v70i2.62607","url":null,"abstract":"Cookie is one of the most common baked goods consumed by people throughout the globe including in Bangladesh. Cookies have a considerable amount of fats, despite not being considered as fatty foods by consumers. Since cookies are eaten by individuals of all ages and socioeconomic groups, an experimental investigation was conducted to evaluate the quality and quantity of the fat fraction of bakery cookies available in Dhaka. Ten different bakery cookies (5 savory and 5 sweet) from five different manufacturers were collected from several local supermarkets of Dhaka and analyzed to study the total fat contents, relative fatty acids compositions, moisture and ash contents. Extraction of fat from cookie samples was done using n-hexane. The fatty acid compositions of the samples were determined by gas-liquid chromatograph equipped with flame ionization detector. The results showed the total fat content to be ranged from 16.13-26.84 g/100g of cookies. The fatty acid composition exhibited that the relative percentage of saturated fatty acids (SFA), monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA) were in the range of 7.76-78.20, 9.66-79.56 and 0.38-9.64%, respectively. The major FAs were found to be palmitic acid (C16:0), palmitoleic acid (C16:1), stearic acid (C18:0), oleic acid (C18:1) and linoleic acid (C18:2). The moisture and ash contents in the samples were found in the range of 0.79-4.80 and 0.73-4.23%, respectively.\u0000Dhaka Univ. J. Sci. 70(2): 53-58, 2022 (July)","PeriodicalId":11280,"journal":{"name":"Dhaka University Journal of Science","volume":"18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89662560","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Impact of Migration on the Utilization of Antenatal Care Services among Women of Urban Slums in Bangladesh 移民对孟加拉国城市贫民窟妇女利用产前保健服务的影响

Dhaka University Journal of Science Pub Date : 2022-12-18 DOI: 10.3329/dujs.v70i2.62599

Ummay Nayeema Islam, Farzana Afroz

{"title":"Impact of Migration on the Utilization of Antenatal Care Services among Women of Urban Slums in Bangladesh","authors":"Ummay Nayeema Islam, Farzana Afroz","doi":"10.3329/dujs.v70i2.62599","DOIUrl":"https://doi.org/10.3329/dujs.v70i2.62599","url":null,"abstract":"Mothers living in urban slums in Bangladesh get far less access to maternal and child health care services which may lead to mortality or serious morbidity to mothers as well as newborns. Lack of antennal care (ANC) is closely linked to poor pregnancy outcomes including low birth weight, preterm births or infant mortality. However, exposure to migration makes the situation worse in terms of attending urban community health care facilities among women in slums. Since the effect of migration on the usage of antenatal care services in slums has remained an under studied area, this paper aims to examine the adjusted effect of migration on perceiving adequate ANC. Data from the second round of Bangladesh Urban Health Survey conducted in 2013 have been used for this study. A well fitted binary logistic model resulted in lower odds of receiving complete ANC among recently migrated women in slums (AOR=0.602, 95% CI=0.43-0.85). Therefore, further emphasis should be given to increase awareness about antenatal care services among women who are recently migrated to urban slums in Bangladesh.\u0000Dhaka Univ. J. Sci. 70(2): 8-14, 2022 (July)","PeriodicalId":11280,"journal":{"name":"Dhaka University Journal of Science","volume":"14 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87439845","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0