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Financial Innovation 2017年第1期3卷 238-256页

作者： S.m.Abdullah Salina Siddiqua muhammad Shahadat hossain Siddiquee Nazmul hossain Department of Economics University of DhakaDhakaBangladesh Department of Development Studies University of DhakaDhakaBangladesh University of manchester ManchesterUK

Background:modeling exchange rate volatility has remained crucially important because of its diverse *** study aimed to address the issue of error distribution assumption in modeling and forecasting exchange rate volatility between the Bangladeshi taka(BDT)and the US dollar($).methods:Using daily exchange rates for 7 years(January 1,2008,to April 30,2015),this study attempted to model dynamics following generalized autoregressive conditional heteroscedastic(GARCH),asymmetric power ARCH(APARCH),exponential generalized autoregressive conditional heteroscedstic(EGARCH),threshold generalized autoregressive conditional heteroscedstic(TGARCH),and integrated generalized autoregressive conditional heteroscedstic(IGARCH)processes under both normal and Student’s t-distribution assumptions for *** and Conclusions:It was found that,in contrast with the normal distribution,the application of Student’s t-distribution for errors helped the models satisfy the diagnostic tests and show improved forecasting *** such error distribution for out-of-sample volatility forecasting,AR(2)–GARCH(1,1)is considered the best.

关键词： Exchange rate Volatility ARCH GARCH Student’s t Error distribution

Proposal for dispersion compensating square-lattice photonic crystal fiber

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Optoelectronics Letters 2021年第3期17卷 160-164页

作者： Ashraful hossain Howlader md.Sherajul Islam S.m.A.Razzak Department of Electrical and Electronic Engineering Rajshahi University of Engineering and TechnologyRajshahi 6204Bangladesh Department of Electrical and Electronic Engineering Khulna University of Engineering and TechnologyKhulna 9203Bangladesh Department of Electrical and Electronic Engineering Bangabandhu Sheikh Mujibur Rahman Science and Technology UniversityGopalganj 8100Bangladesh

A dispersion-compensating square-lattice photonic crystal fiber for broadband compensation which covers the S, C and L communication bands, i.e. wavelength ranging from 1 460 nm to 1 625 nm is proposed in this paper. Theoretically, it is shown a negative dispersion coefficient of about-595 ps/(nm·km) to-1 288 ps/(nm·km) over S to L bands and-975 ps/(nm·km) at the operating wavelength 1 550 nm. The relative dispersion slope is perfectly matched to that of conventional single-mode fiber of about 0.003 6 nm^(-1). Besides the proposed photonic crystal fiber shows the large nonlinear coefficient of 61.88 W/km at the operating wavelength of 1 550 nm. moreover, the variation of structural parameters is also studied and discussed here.

关键词： fiber dispersion crystal

Shifting cultivation effects on creek water quality around Barkal Upazila in Chittagong Hill Tracts,Bangladesh

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Journal of Forestry Research 2012年第4期23卷 623-630页

作者： Shyamal Karmakar S.m.Sirajul Haque m.mozaffar hossain Sohag miah Institute of Forestry and Environmental Sciences University of ChittagongChittagong 4331Bangladesh

Abstract： We report the effects of shifting cultivation on water quality in 16 creeks investigated once in 2007 and twice in 2008 in 16 apparently similar small neighboring watersheds, each of 3 to 5 ha, at four locations around Barkal sub-district under Rangamati District of Chittagong Hill Tracts in Bangladesh. Concentrations of 5042- and K＋, and pH in creek water were lower, and NO3-N and Na＋ concentrations were higher in shifting-cultivation land compared to land with either plantation or natu- ral forest or a combination of these cover types. Shifting cultivation effects on some water quality parameters were not significant due to change in land cover of the watershed between two sampling periods either through introduction of planted tree species or naturally regenerated vegetation. Conductivity and concentrations of HCO3- PO43-, Ca2-- and mg2＋ in creek water showed no definite trend between shifting cultivation and the other land cover types. At one area near the Forest Range Office of Barkal, creek water pH was 5.8 under land cover with a com- bination of shifting cultivation and plantation. At this area Na~ concentra- tion in shitting-cultivation land ranged from 32.33 to 33.00 mg-L＂ and in vegetated area from 25.00 to 30.50 mg.L-1 in 2007. At another area, Chaliatali Chara, SO42 concentration in a shifting-cultivation watershed ranged from 4.46 to 10.51 mg-L-1, lower than in a vegetated watershed that ranged from 11.69 to 19.98 mg.L-1 in 2007. S042-concentration in this shifting-cultivation area ranged from 1.28 to 1.37 mg.L^-1 and in the vegetated area from 1.37 to 3.50 mg-L^-1 in 2008.

关键词： Shifting cultivation Creek water quality Chittagong Hill Tracts Riparian vegetation Land cover Bangladesh

Water quality of Kaptai reservoir in Chittagong Hill Tracts of Bangladesh

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Journal of Forestry Research 2011年第1期22卷 87-92页

作者： Shyamal Karmakar S. m. Sirajul Haque m. mozaffar hossain m. Shafiq Institute of Forestry and Environmental Sciences University of Chittagong Chittagong Bangladesh 4331 Department of Soil Science University of Chittagong Chittagong Bangladesh 4331

A study was conducted in Kaptai reservoir, one of the largest man-made freshwater lakes of South-east Asia, to determine present status of water quality and its suitability for fishing and other uses. Water samplings were from middle part of the reservoir at 0.2 and 0.8 fractional depths at five different locations from upstream to downstream viz. Burburichara, maichchari, Subolong, Basanthakum, and Rangamati. Water analyses show that concentrations of NO3-N, K＋ and total P, and suspended solid at all the sampling stations were beyond the recommended values for fish culture. Concentrations of Na^＋, Ca^2＋, mg^2＋, SO4^2-, Cl^-, total dissolved solid （TDS）, dissolved oxygen （DO） and chemical oxygen demand （COD） were within the standards for aquaculture. Concentrations of NO3-N, SO4^2-, K＋ and total P showed no definite trend with depths, locations as well as rainy and dry seasons. Water pH, conductivity, Na^＋ and HCO3- contents were lower in rainy season, and DO and COD higher at almost all the locations in both the depths, compared with dry season. Total solids and concentrations of TDS, DO, COD, Ca^2＋, mg^2＋ and Na^＋ were higher in upstream and decreased gradually towards downstream in the reservoir. Concentrations of DO and Ca2＋ and pH were higher and mg2＋ less at 0.2-fractional depth than those at 0.8-fractional depth at almost all the locations. The reservoir is in mesotrophic condition containing high concentration of NO3-N and total P, in alarming status with the presence of excessive suspended solids from urban pollution around the town. It is necessary to adopt measures for protecting water quality in the reservoir due to such deteriorations.

关键词： Karnaphuli river lake water quality Chittagong Hill Tract

Thermoluminescence Response of Germanium-Doped Optical Fibers to X-Ray Irradiation

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Chinese Physics Letters 2012年第7期29卷 284-286页

作者： m.A.Saeed N.A.Fauzia I.hossain A.T.Ramli B.A.Tahir Department of Physics Universiti Teknologi MalaysiaSkudai-81310JohorMalaysia Department of Physics College of Sciences and ArtsKing Abdulaziz UniversityRabigh 21911P.O.Box No.344KSA

We present the characteristics of the thermoluminescence (TL) response of Ge-doped optical fibers with various energies and exposures of photon *** investigate the Ge-doped SiO2 as an efficient TL material,the TL responses are compared with commercially available standard TLD100 *** Ge-doped optical fiber and TLD100 are placed in gelatin capsules and irradiated with x-ray using a Toshiba model KXO-15R x-ray *** Ge-doped fiber and TLD-100 show linear response as a function of current and time using x-ray photon of energy 60,80 and *** irradiated with 60,80 and l00kV x-ray energy at various currents (mA ),tube distance (cm) and exposure time (second) ranges,TLD100 media provide a TL yield up to two times that of Ge-doped *** energy response of the Ge-doped fibers is linear and similar over the 60-l00 kVenergy range,and its sensitivity is 0.39±0.05 of the TLD100 *** glow curves of TLD 100 and doped optical fiber are also compared.

关键词： fiber fibers photon

Fog-Based Secure Framework for Personal Health Records Systems

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Computers, materials & Continua 2021年第2期66卷 1937-1948页

作者： Lewis Nkenyereye S.m.Riazul Islam mahmud hossain mAbdullah-Al-Wadud Atif Alamri Department of Computer&Information Security Sejong UniversitySeoul05006Korea Department of Computer Science and Engineering Sejong UniversitySeoul05006Korea Department of Computer Science University of Alabama at BirminghamBirminghamAL35294USA Department of Software Engineering King Saud UniversityRiyadh11543Saudi Arabia

The rapid development of personal health records(PHR)systems enables an individual to collect,create,store and share his PHR to authorized *** care systems within the smart city environment require a patient to share his PRH data with a multitude of institutions’repositories located in the *** cloud computing paradigm cannot meet such a massive transformative healthcare systems due to drawbacks including network latency,scalability and *** computing relieves the load of conventional cloud computing by availing intermediate fog nodes between the end users and the remote *** a massive demand of PHR data within a ubiquitous smart city,we propose a secure and fog assisted framework for PHR systems to address security,access control and privacy *** under a fog-based architecture,the proposed framework makes use of efficient key exchange protocol coupled with ciphertext attribute based encryption(CP-ABE)to guarantee confidentiality and fine-grained access control within the system *** also make use of digital signature combined with CP-ABE to ensure the system authentication and users *** provide the analysis of the proposed framework in terms of security and performance.

关键词： Fog computing personal health records ciphertext attribute based encryption secure communications

Effect of substrate miscut on the electron mobility in InSb(001) structures on Ge and Ge-on-insulator substrates

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Chinese Science Bulletin 2014年第4期59卷 369-373页

作者： m.C.Debnath T.D.mishima m.B.Santos K.hossain omer L. Dodge Department of Physics and Astronomy and Center for Semiconductor Physics in Nanostructures University of Oklahoma Amethyst Research Inc.

InSb epilayers and InSb/Al0.20In0.80Sb quantum wells were grown on Ge(001)substrates and Ge-on-insulator(GeOI)-on-Si(001)substrates by molecular beam *** on both on-axis and 4°-off-axis substrate orientations was ***-phase domains were formed when InSb films were grown on on-axis substrates,but suppressed significantly by the use of 4°-off-axis *** off-axis substrates also reduced the densities of micro-twin defects and threading *** defect reduction resulted in an increase in the room-temperature electron mobility from 37,000 to 59,000 cm2/Vs in 4.0-lm-thick InSb epilayers and from 10,000 to20,000 cm2/Vs in 25-nm-thick InSb quantum wells on Ge(001)and GeOI-on-Si(001)substrates.

关键词：电子迁移率 InSb 基板绝缘体 Ge 硅(001) 薄膜生长结构

The ASEAN experience of the purchasing power parity theory

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Financial Innovation 2018年第1期4卷 333-343页

作者： S.m.Woahid murad mohammad Amzad hossain Department of Economics Noakhali Science and Technology UniversityNoakhali 3814Bangladesh Department of Economics Jahangirnagar UniversitySavarDhaka 1342Bangladesh

We used panel data analysis to evaluate the relative purchasing power parity(PPP)hypothesis of the ten ASEAN member countries between 1973 and *** incorporated the cross-sectionally augmented panel unit root test as proposed by Pesaran(J Appl Econ 22:265-312,2007).For panel cointegration analysis,we employed the four error-correction-based Westerlund(Oxf Bull Econ Stat 69:709-748,2007)panel cointegration *** Westerlund(Oxf Bull Econ Stat 69:709-748,2007)tests are general enough to permit a large degree of heterogeneity,both in the long-run cointegrating relationship and in the short-run dynamics,and dependence within as well as across the cross-sectional *** check the robustness of the results,we further estimated the cointegration test excluding Indonesia and *** findings support our initial ***,all the results overwhelmingly support the relative PPP ***,the monetary authority would be able to implement a self-regulating monetary *** would also be able to control the exchange rates.

关键词： Purchasing power parity Panel unit root test Panel cointegration test ASEAN countries

Influences of Biochar and Biochar-mineral Complex on mycorrhizal Colonisation and Nutrition of Wheat and Sorghum

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Pedosphere 2015年第5期25卷 686-695页

作者： Paul BLACKWELL Stephen JOSEPH Paul mUNROE hossain m.ANAWAR Paul STORER Robert J.GILKES Zakaria m.SOLAImAN Department of Agriculture and Food Western Australia Geraldton Regional Office School of materials Science and Engineering University of New South WalesSydney Discipline of Chemistry University of Newcastle University of Wollongong School of Earth and Environment and UWA Institute of Agriculture The University of Western Australia Australian mineral Fertilisers Pty Ltd. Soil Biology and molecular Ecology Group School of Earth and Environment and UWA Institute of AgricultureThe University of Western Australia

The high price of synthetic fertilisers and the price barrier for biochar as a soil amendment have encouraged the exploration of using biochar in fertiliser replacement formulations. Biochars coupled with fertilisers can be applied at lower application rates to achieve benefits in plant growth and nutrition, as well as soil biological fertility. It is necessary to evaluate the use of biochar as a fertiliser substitute. Therefore, this study investigated the comparative influences of biochars, including Acacia saligna （AS）, Simcoa jarrah （S J） and Wundowie jarrah （W J）, mineral fertiliser with microbes （mF ＋ m）, biochar-mineral complex （BmC） and their combination on mycorrhizal colonisation, growth and nutrition of wheat in a glasshouse experiment and sorghum in field conditions. BmC ＋ mF ＋ m treatment produced higher mycorrhizal colonisation than mF ＋ m alone, indicating that BmC had a significant role in increasing mycorrhizal colonisation. SJ （treated with acetic acid） and mF ＋ m treatments, as well as AS ＋ mF ＋ m application, showed similar effects on mycorrhizal colonisation, but lower colonisation than the BmC ＋ mF ＋ m treatment. Ovcrall~ the BmC ＋ mF ＋ m treatment supported the maximum shoot, root and total plant dry weight followed by AS ＋ mF ＋ m and WJ ＋ mF ＋ m. The mF ＋ m treatment had the maximum shoot N and K concentrations, while BmC ＋ mF ＋ m application had the maximum shoot P concentration. AS ＋ mF -4- m and WJ ＋ mF ＋ m treatments supported the maximum N uptake by wheat shoots, while BmC ＋ mF ＋ m supported the maximum P uptake. The results showed that biochars and BmCs could increase mycorrhizal colonisation, plant growth and nutrient uptake of wheat, particularly N, P, K, S and Zn. The field experiment confirmed that BmC application at a rate of 300 kg ha-1 could increase the yield of irrigated sorghum on a loam soil and provide better applied P use efficiency compared to a water-soluble fertiliser alone. These results indicated that biochar-based fer

关键词： carbon sequestration nutrient uptake P use efficiency soil biological fertility wheat production

A Historical Perspective on Development of Systems Engineering Discipline:A Review and Analysis

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Journal of Systems Science and Systems Engineering 2020年第1期29卷 1-35页

作者： Niamat Ullah Ibne hossain Raed m.Jaradat michael A.Hamilton Charles B.Keating Simon R.Goerger Department of Industrial and Systems Engineering Mississippi State UniversityPO Box 9542Mississippi State 39762USA Department of Industrial and Systems Engineering Mississippi State UniversityPO Box 9542Mississippi State39762USA Institute for Systems Engineering Research(ISER) Mississippi State University 3909 Halls Ferry RdVicksburgMS 39180 Department of Engineering management&Systems Engineering Old Dominion UniversityNorfolkVA 23529 eInstitute for Systems Engineering Research(ISER) U.S Army Engineer Research Development Center(ERDC)3909 Halls Ferry RdVicksburgMS 39180

Since its inception,Systems Engineering(SE)has developed as a distinctive discipline,and there has been significant progress in this field in the past two *** to other engineering disciplines,SE is not affirmed by a set of underlying fundamental propositions,instead it has emerged as a set of best practices to deal with intricacies stemming from the stochastic nature of engineering complex systems and addressing their *** the existing methodologies and paradigms(dominant patterns of thought and concepts)of SE are very diverse and somewhat *** appears to create some confusion regarding the design,deployment,operation,and application of *** purpose of this paper is 1)to delineate the development of SE from 1926-2017 based on insights derived from a histogram analysis,2)to discuss the different paradigms and school of thoughts related to SE,3)to derive a set of fundamental attributes of SE using advanced coding techniques and analysis,and 4)to present a newly developed instrument that could assess the performance of systems *** than Two hundred and fifty different sources have been reviewed in this research in order to demonstrate the development trajectory of the SE discipline based on the frequency of publication.

关键词： Systems Engineering(SE) history development systems engineering attributes performance measures