首页 > 最新文献

Dhaka University Journal of Science最新文献

英文 中文
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
Pub Date : 2023-05-29 DOI: 10.3329/dujs.v71i1.65277
Md Shapan Miah, Khondokar M. Ahmed, S. Nasrin
The main target of this article is to study about Lie Groups, Lie Algebras. This article will enrich our knowledge about Algebraic properties of manifolds, how Lie Groups and Lie Algebras are working with their properties. Finally, we have discussed an example by showing all the properties of Lie Algebra,Lie Groups for a special Group and a Theorem has established.Dhaka Univ. J. Sci. 71(1): 82-86, 2023 (Jan) 
本文的主要目的是研究李群、李代数。本文将丰富我们关于流形的代数性质,李群和李代数如何处理它们的性质的知识。最后,我们讨论了一个例子,给出了李代数的所有性质,一个特殊群的李群,并建立了一个定理。达卡大学学报(自然科学版),71(1):82- 86,2023 (1)
{"title":"Characteristics of General Linear Group of Order 2 as Lie Group and Lie Algebra","authors":"Md Shapan Miah, Khondokar M. Ahmed, S. Nasrin","doi":"10.3329/dujs.v71i1.65277","DOIUrl":"https://doi.org/10.3329/dujs.v71i1.65277","url":null,"abstract":"The main target of this article is to study about Lie Groups, Lie Algebras. This article will enrich our knowledge about Algebraic properties of manifolds, how Lie Groups and Lie Algebras are working with their properties. Finally, we have discussed an example by showing all the properties of Lie Algebra,Lie Groups for a special Group and a Theorem has established.\u0000Dhaka Univ. J. Sci. 71(1): 82-86, 2023 (Jan) ","PeriodicalId":11280,"journal":{"name":"Dhaka University Journal of Science","volume":"97 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74558986","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
An Integrated Forecasting Technique with Modified Weight Measurement 修正权值的综合预测技术
Pub Date : 2023-05-29 DOI: 10.3329/dujs.v71i1.65270
M. B. Hasan, M. Asadujjaman, M. H. Haque
Forecasting has long been part of our life since early of the history of human being. In the middle of 20th century forecasting becomes a part of every business and financial sectors. Nowadays every successful firm has to make its own forecasts with an acceptable error as there is no chance of zero error. The situation becomes more complicated if the observed data is more diverted from the existing pattern. In such situation it becomes more difficult to fit it into a suitable forecasting model.Then it requires to combine several forecasts to reach a better forecast.In this paper, we willdevelop a sophisticated forecasting technique bycombining the weighted average method with Linear Programming (LP) model by developing an alternative technique to calculate the weights. We will carry out our analysis by using Microsoft Excel, statistical data analysis tool R and MATHEMATICA. We will demonstrate our model by numerical examples.Dhaka Univ. J. Sci. 71(1): 36-41, 2023 (Jan)
从人类历史的早期开始,预测就一直是我们生活的一部分。在20世纪中期,预测成为每个商业和金融部门的一部分。如今,每个成功的公司都必须在可接受的误差范围内做出自己的预测,因为不可能零误差。如果观测到的数据更多地偏离现有模式,情况就会变得更加复杂。在这种情况下,将其拟合到合适的预测模型中变得更加困难。然后,它需要将几个预测结合起来,以达到更好的预测。在本文中,我们将通过开发一种计算权重的替代技术,将加权平均方法与线性规划(LP)模型相结合,开发一种复杂的预测技术。我们将使用Microsoft Excel,统计数据分析工具R和MATHEMATICA进行分析。我们将用数值例子来证明我们的模型。达卡大学学报(自然科学版),71(1):36-41,2023 (1)
{"title":"An Integrated Forecasting Technique with Modified Weight Measurement","authors":"M. B. Hasan, M. Asadujjaman, M. H. Haque","doi":"10.3329/dujs.v71i1.65270","DOIUrl":"https://doi.org/10.3329/dujs.v71i1.65270","url":null,"abstract":"Forecasting has long been part of our life since early of the history of human being. In the middle of 20th century forecasting becomes a part of every business and financial sectors. Nowadays every successful firm has to make its own forecasts with an acceptable error as there is no chance of zero error. The situation becomes more complicated if the observed data is more diverted from the existing pattern. In such situation it becomes more difficult to fit it into a suitable forecasting model.Then it requires to combine several forecasts to reach a better forecast.In this paper, we willdevelop a sophisticated forecasting technique bycombining the weighted average method with Linear Programming (LP) model by developing an alternative technique to calculate the weights. We will carry out our analysis by using Microsoft Excel, statistical data analysis tool R and MATHEMATICA. We will demonstrate our model by numerical examples.\u0000Dhaka Univ. J. Sci. 71(1): 36-41, 2023 (Jan)","PeriodicalId":11280,"journal":{"name":"Dhaka University Journal of Science","volume":"32 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87432579","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
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
Pub Date : 2023-05-29 DOI: 10.3329/dujs.v71i1.65269
M. B. Hasan, M. Asadujjamanand, M. Haque
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.Dhaka Univ. J. Sci. 71(1): 26-35, 2023 (Jan)
孟加拉国的商业组织基本上是通过基于直觉的预测来经营业务的。但关键是要尽可能准确地预测不久的将来,使企业盈利。这有助于商业组织的管理者正确规划他们的资源,从而使组织的成本最小化,利润最大化。在这篇研究论文中,我们将通过比较三种不同的严格预测技术如霍尔特方法,霍尔特-温特方法和自回归综合移动平均(ARIMA)方法获得的结果来分析孟加拉国一家公司的商业战略,以便商业组织可以选择适当的预测技术来经营他们的业务。为此,我们将首先说明和分析预测和时间序列分析的基础知识,常用的预测方法,一些严格的方法,如Holt方法,Winter方法和自回归综合移动平均(ARIMA)模型。我们将使用Microsoft Excel,统计数据分析工具R和MATHEMATICA进行分析和计算。达卡大学学报(自然科学版),71(1):26- 35,2023 (1)
{"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
Pub Date : 2023-05-29 DOI: 10.3329/dujs.v71i1.65276
Tasmiah Afrin Emma, A. Sajib, Sabina Sharmin
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.Dhaka Univ. J. Sci. 71(1): 76-81, 2023 (Jan)
本文旨在通过仿真研究,评价利用切比雪夫不等式进行概率计算的准确性。在我们的模拟研究中,我们考虑对称(Normal(3,1.52),拉普拉斯(3,2)Beta (7.7) t5)正偏态,负偏态(5 χ2, Beta (3,8) Gamma (5,1)), (Beta(7,2)),指数(5)和均匀(0,1)分布,fx(x)来衡量Chebyshev不等式的性能。然后我们计算了~ ()X X f X, μ = E (X)和σ 2 =Var (X)的Pr (μ−kσ≤X≤μ + kσ),并将其与由Chebyshev不等式得到的近似概率进行比较,以衡量Chebyshev不等式的精度。从我们的模拟研究中可以观察到,当k≥2.5时,fx(x)为指数分布和Beta(对称)分布时,使用Chebyshev不等式进行概率计算的损失分别最小和最大。此外,用Chebyshev不等式计算的Pr (μ−kσ≤X≤μ + kσ)的值对于研究中考虑的所有概率分布都是过近似值。达卡大学学报(自然科学版),71(1):76- 81,2023 (1)
{"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
Pub Date : 2023-05-29 DOI: 10.3329/dujs.v71i1.65271
N. Akter, Mahbuba Zaman, M. Rahman, M. Hossain
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.Dhaka Univ. J. Sci. 71(1): 42-48, 2023 (Jan)
采用沉淀焙烧法制备了ZnO-Cu2O复合材料。采用扫描电镜(SEM)、能量色散x射线(EDX)、傅里叶变换红外(FT-IR)和x射线衍射(XRD)对所制备的复合材料进行了表征。通过紫外-可见反射率测量确定了复合材料的带隙能。由于Cu2O的掺杂,ZnO-Cu2O复合材料的吸收范围向可见光区偏移。SEM图像表明,复合纳米颗粒的尺寸比纯ZnO小。EDX光谱分析表明,样品中除Zn、Cu和O外不存在其他元素。XRD结果表明,ZnO-Cu2O复合材料由六方ZnO和立方Cu2O组成。通过在不同的实验条件下降解MB,研究了ZnO-Cu2O复合材料的光催化活性。通过改变复合材料的摩尔比、复合材料的用量、染料的初始浓度来优化降解条件。实验结果与工业氧化锌进行了比较。结果表明,ZnO- cu2o复合材料在可见光下是比ZnO更好的光催化剂。达卡大学学报(自然科学版),71(1):42- 48,2023 (1)
{"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
Pub Date : 2022-12-18 DOI: 10.3329/dujs.v70i2.62602
Mohammad Amirul Islam, A. Woobaidullah
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.Dhaka Univ. J. Sci. 70(2): 23-28, 2022 (July)
目前,研究人员正在开展广泛的研究工作,以增加石油和天然气产量,以满足日益增长的能源需求,并减少大气中的二氧化碳浓度,以减少全球变暖。本研究旨在通过CO2- eor提高Surma盆地某油藏的产油量,并评估该油藏作为CO2封存的候选油藏。储层岩石为布班砂岩,流体为稠油。油藏中也存在高矿化度水。为此,建立了储层模拟模型。采用块心几何构造了三维地元胞储层网格结构。利用布班砂岩的岩石性质对储层岩石的孔隙度、绝对渗透率和净总比等进行了建模。用液相色谱仪测定了储层油的成分。储层油中纯组分的热力学性质已纳入储层成分模拟模型。通过在储层外围布置4口注二氧化碳井和在储层中心保留1口采油井对储层进行开发。在3100 psi压力下,单井的最佳CO2注入速率为500 MSCF/D,最佳产油量为4900 STB/D。达卡大学学报(自然科学版),70(2):23- 28,2022 (7)
{"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
Pub Date : 2022-12-18 DOI: 10.3329/dujs.v70i2.62605
Akash Saha, Murshida Khanam
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.Dhaka Univ. J. Sci. 70(2): 42-47, 2022 (July)
本研究采用VECM模型和ARIMA模型对GDP增长率、汇款和总劳动力参与率进行建模。本研究的所有数据均来自世界银行数据库,以指标为时间序列变量,时间跨度为1999 - 2020年。用增广Dickey-Fuller检验检验了时间序列变量的平稳性,并研究了它们在一差时变得平稳性。应用滞后选择准则来找出不存在的问题。需要在模型中包含延迟。本研究选择Lag 2。将VEC模型应用于时间序列数据。还有ARIMA模型对这些时间序列变量的作用。这两个模型已被用于预测。利用RMSE、MAPE和MAE等方法对两种模型的预测结果进行了分析,选出了较好的预测结果。研究发现,对于GDP增长率和总劳动力参与率,ARIMA模型更可取,而对于汇款,VECM模型更可取。研究发现,汇款和劳动力对GDP增长有显著的正向影响。此外,国内生产总值增长率、汇款和总劳动力参与率之间存在长期关系。达卡大学学报(自然科学版),70(2):42-47,2022 (7)
{"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
Pub Date : 2022-12-18 DOI: 10.3329/dujs.v70i2.62604
Mni Nahin, S. Nahian, MS Islam, Sayantee Roy, F. Jeba, A. Salam
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.Dhaka Univ. J. Sci. 70(2): 35-41, 2022 (July)
建立了一种简单、快速、高效的分光光度法测定大气颗粒物(PM)中可呼吸性结晶二氧化硅(SiO2)的方法。从2021年9月至12月,使用小容量空气采样器在达卡大学(Mukarram Hussain Khundker Building-MHK和师生中心tsc)的两个不同地点采集了24小时的PM样本。提取PM负载过滤器,然后过滤,得到清澈的溶液。采用紫外可见光谱法,用钼酸盐-3试剂和氨基酸悬浮液处理滤液,测定了滤液中二氧化硅的浓度。MHK和TSC中pm结合二氧化硅的平均浓度分别为7.72和33.86 μgm-3。与MHK相比,TSC周围大气中的二氧化硅含量高出四倍,这是由于TSC大量的地铁建设工作。二氧化硅对PM的贡献分别为3.47%(站点1)和5.15%(站点2)。采用危害系数(HQ)表征可吸入二氧化硅的非癌风险。TSC记录的可吸入二氧化硅危险系数高达12.87,而MHK的危险系数为2.57,表明暴露的居民可能对非癌症健康产生不利影响。对二氧化硅的致癌风险评估显示,MHK的341人中有1人,TSC的78人中有1人一生中可能患癌。这是第一个证明达卡高水平的与pm结合的可吸入二氧化硅严重降低空气质量以及潜在的人类健康的研究。达卡大学学报(自然科学版),70(2):35- 41,2022 (7)
{"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
Pub Date : 2022-12-18 DOI: 10.3329/dujs.v70i2.62607
Shahnaz Akhtar Nishat, Supath Xavier Besra, M. Shoeb, A. Sultana
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.Dhaka Univ. J. Sci. 70(2): 53-58, 2022 (July)
饼干是包括孟加拉国在内的世界各地人们最常见的烘焙食品之一。饼干含有相当多的脂肪,尽管消费者不认为它是高脂肪食品。由于所有年龄和社会经济群体的人都吃饼干,因此进行了一项实验调查,以评估达卡面包店饼干中脂肪部分的质量和数量。从达卡的几家当地超市中收集了来自五个不同制造商的10种不同的烘焙饼干(5种咸味饼干和5种甜味饼干),并对其总脂肪含量、相对脂肪酸组成、水分和灰分含量进行了分析。用正己烷从饼干样品中提取脂肪。采用配备火焰电离检测器的气液色谱法测定样品的脂肪酸组成。结果显示,每100克饼干的总脂肪含量为16.13-26.84克。脂肪酸组成表明,饱和脂肪酸(SFA)、单不饱和脂肪酸(MUFA)和多不饱和脂肪酸(PUFA)的相对比例分别为7.76 ~ 78.20%、9.66 ~ 79.56和0.38 ~ 9.64%。主要脂肪酸为棕榈酸(C16:0)、棕榈油酸(C16:1)、硬脂酸(C18:0)、油酸(C18:1)和亚油酸(C18:2)。样品的水分和灰分含量分别为0.79 ~ 4.80和0.73 ~ 4.23%。达卡大学学报(自然科学版),70(2):53-58,2022 (7)
{"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
Pub Date : 2022-12-18 DOI: 10.3329/dujs.v70i2.62599
Ummay Nayeema Islam, Farzana Afroz
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.Dhaka Univ. J. Sci. 70(2): 8-14, 2022 (July)
生活在孟加拉国城市贫民窟的母亲获得妇幼保健服务的机会要少得多,这可能导致母亲和新生儿死亡或严重发病。缺乏产前护理与不良妊娠结局(包括低出生体重、早产或婴儿死亡)密切相关。然而,由于受到移徙的影响,贫民窟妇女在城市社区保健设施就诊的情况更糟。由于移民对贫民窟产前保健服务使用的影响仍然是一个研究不足的领域,本文旨在研究移民对感知适当ANC的调整影响。本研究使用了2013年进行的第二轮孟加拉国城市健康调查的数据。拟合良好的二元logistic模型显示,最近移民的贫民窟妇女接受完全ANC的几率较低(AOR=0.602, 95% CI=0.43-0.85)。因此,应进一步强调提高最近移徙到孟加拉国城市贫民窟的妇女对产前保健服务的认识。达卡大学学报(自然科学版),70(2):8- 14,2022 (7)
{"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
期刊
Dhaka University Journal of Science
全部 Acc. Chem. Res. ACS Applied Bio Materials ACS Appl. Electron. Mater. ACS Appl. Energy Mater. ACS Appl. Mater. Interfaces ACS Appl. Nano Mater. ACS Appl. Polym. Mater. ACS BIOMATER-SCI ENG ACS Catal. ACS Cent. Sci. ACS Chem. Biol. ACS Chemical Health & Safety ACS Chem. Neurosci. ACS Comb. Sci. ACS Earth Space Chem. ACS Energy Lett. ACS Infect. Dis. ACS Macro Lett. ACS Mater. Lett. ACS Med. Chem. Lett. ACS Nano ACS Omega ACS Photonics ACS Sens. ACS Sustainable Chem. Eng. ACS Synth. Biol. Anal. Chem. BIOCHEMISTRY-US Bioconjugate Chem. BIOMACROMOLECULES Chem. Res. Toxicol. Chem. Rev. Chem. Mater. CRYST GROWTH DES ENERG FUEL Environ. Sci. Technol. Environ. Sci. Technol. Lett. Eur. J. Inorg. Chem. IND ENG CHEM RES Inorg. Chem. J. Agric. Food. Chem. J. Chem. Eng. Data J. Chem. Educ. J. Chem. Inf. Model. J. Chem. Theory Comput. J. Med. Chem. J. Nat. Prod. J PROTEOME RES J. Am. Chem. Soc. LANGMUIR MACROMOLECULES Mol. Pharmaceutics Nano Lett. Org. Lett. ORG PROCESS RES DEV ORGANOMETALLICS J. Org. Chem. J. Phys. Chem. J. Phys. Chem. A J. Phys. Chem. B J. Phys. Chem. C J. Phys. Chem. Lett. Analyst Anal. Methods Biomater. Sci. Catal. Sci. Technol. Chem. Commun. Chem. Soc. Rev. CHEM EDUC RES PRACT CRYSTENGCOMM Dalton Trans. Energy Environ. Sci. ENVIRON SCI-NANO ENVIRON SCI-PROC IMP ENVIRON SCI-WAT RES Faraday Discuss. Food Funct. Green Chem. Inorg. Chem. Front. Integr. Biol. J. Anal. At. Spectrom. J. Mater. Chem. A J. Mater. Chem. B J. Mater. Chem. C Lab Chip Mater. Chem. Front. Mater. Horiz. MEDCHEMCOMM Metallomics Mol. Biosyst. Mol. Syst. Des. Eng. Nanoscale Nanoscale Horiz. Nat. Prod. Rep. New J. Chem. Org. Biomol. Chem. Org. Chem. Front. PHOTOCH PHOTOBIO SCI PCCP Polym. Chem.
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
0
微信
客服QQ
Book学术公众号 扫码关注我们
反馈
×
意见反馈
请填写您的意见或建议
请填写您的手机或邮箱
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
现在去查看 取消
×
提示
确定
Book学术官方微信
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术
文献互助 智能选刊 最新文献 互助须知 联系我们:info@booksci.cn
Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。
Copyright © 2023 Book学术 All rights reserved.
ghs 京公网安备 11010802042870号 京ICP备2023020795号-1