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Elastic Optimization for Stragglers in Edge Federated Learning

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Big Data Mining and Analytics 2023年第4期6卷 404-420页

作者： Khadija Sultana khandakar Ahmed Bruce Gu Hua Wang Institute for Sustainable Industries and Liveable Cities(ISILC) Victoria UniversityMelbourne 3011Australia Intelligent Technology Innovation Lab(ITIL) Institute for Sustainable Industries and Liveable Cities(ISILC)Victoria UniversityMelbourne 3011Australia. Shandong Computer Science Center(National Supercomputer Center) Jinan 250101China

To fully exploit enormous data generated by intelligent devices in edge computing,edge federated learning(EFL)is envisioned as a promising *** distributed collaborative training in EFL deals with delay and privacy issues compared to traditional centralized model ***,the existence of straggling devices,responding slow to servers,degrades model *** consider data heterogeneity from two aspects:high dimensional data generated at edge devices where the number of features is greater than that of observations and the heterogeneity caused by partial device *** large number of features,computation overhead on the devices increases,causing edge devices to become *** incorporation of partial training results causes gradients to be diverged which further exaggerates when more training is performed to reach local *** this paper,we introduce elastic optimization methods for stragglers due to data heterogeneity in edge federated ***,we define the problem of stragglers in ***,we formulate an optimization problem to be solved at edge *** customize a benchmark algorithm,FedAvg,to obtain a new elastic optimization algorithm(FedEN)which is applied in local training of edge *** mitigates stragglers by having a balance between lasso and ridge penalization thereby generating sparse model updates and enforcing parameters as close as to local *** have evaluated the proposed model on MNIST and CIFAR-10 *** experiments demonstrate that our approach improves run time training performance by achieving average accuracy with less communication *** results confirm the improved performance of our approach over benchmark algorithms.

关键词： edge computing federated learning distributed machine learning regularization stragglers

Impact of Nitrogen, Phosphorus and Potassium on Brown Planthopper and Tolerance of Its Host Rice Plants

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Rice science 2016年第3期23卷 119-131页

作者： Md Mamunur RASHID Mahbuba JAHAN khandakar Shariful ISLAM Plant Physiology Division Bangladesh Rice Research Institute Department of Entomology Bangladesh Agricultural University

The brown planthopper(BPH),Nilaparvata lugens(St?l),appeared as a devastating pest of rice in Asia. Experiments were conducted to study the effects of three nutrients,nitrogen(N),phosphorus(P) and potassium(K),on BPH and its host rice plants. Biochemical constituents of BPH and rice plants with varying nutrient levels at different growth stages,and changes in relative water content(RWC) of rice plants were determined in the laboratory. Feeding of BPH and the tolerance of rice plants to BPH with different nutrient levels were determined in the nethouse. Concentrations of N and P were found much higher in the BPH body than in its host rice plants,and this elemental mismatch is an inherent constraint on meeting nutritional requirements of BPH. Nitrogen was found as a more limiting element for BPH than other nutrients in rice plants. Application of N fertilizers to the rice plants increased the N concentrations both in rice plants and BPH while application of P and K fertilizers increased their concentrations in plant tissues only but not in BPH. Nitrogen application also increased the level of soluble proteins and decreased silicon content in rice plants,which resulted in increased feeding of BPH with sharp reduction of RWC in rice plants ultimately caused susceptible to the pest. P fertilization increased the concentration of P in rice plant tissues but not changed N,K,Si,free sugar and soluble protein contents,which indicated little importance of P to the feeding of BPH and tolerance of plant against BPH. K fertilization increased K content but reduced N,Si,free sugar and soluble protein contents in the plant tissues which resulted in the minimum reduction of RWC in rice plants after BPH feeding,thereby contributed to higher tolerance of rice plants to brown planthopper.

关键词： Nilaparvata lugens relative water content host tolerance nitrogen phosphorus potassium rice nutrient subsidy

Effect of shifting cultivation on soil physical and chemical properties in Bandarban hill district, Bangladesh

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Journal of Forestry Research 2013年第4期24卷 791-795页

作者： khandakar Showkat Osman M.Jashimuddin S.M.Sirajul Haque Sohag Miah Institute of Forestry and Environmental Sciences University of Chittagong

This study reports the effects of shifting cultivation at slashing stage on soil physicochemical properties at Bandarban Sadar Upazila in Chittagong Hill Tracts of Bangladesh. At this initial stage of shifting cultivation no general trend was found for moisture content, maximum water holding capacity, field capacity, dry and moist bulk density, parti- cle density for some chemical properties between shifting cultivated land and forest having similar soil texture. Organic matter was significantly 0.05） lower in 1-year and 3-year shifting cultivated lands and higher in 2-year shifting cultivation than in adjacent natural forest. Significant differences were also found for total N, exchangeable Ca, Mg and K and in CEC as well as for available P. Slashed area showed higher soil pH. Deterioration in land quality starts from burning of slashing materials and continues through subsequent stages of shifting cultivation.

关键词： Chittagong Hill Tracts natural forest shifting cultivation soil properties

Development of New Submergence Tolerant Rice Variety for Bangladesh Using Marker-Assisted Backcrossing

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Rice science 2015年第1期22卷 16-26页

作者： khandakar Md IFTEKHARUDDAULA Helal Uddin AHMED Sharmistha GHOSAL Zakiah Rahman MONI Al AMIN Md Shamsher ALI Plant Breeding Division Bangladesh Rice Research Institute

Submergence tolerant high yielding rice variety was developed using BR11 as a recipient parent applying foreground, phenotypic and background selection approaches. Recombinant selection was found essential to minimize linkage drag by BC2F2 generation. Without recombinant selection, the introgression size in the backcross recombinant lines （BRLs） was approximately 15 Mb on the carrier chromosome. The BRLs were found submergence tolerance compared to the check varieties under complete submergence for two weeks at Bangladesh Rice Research Institute, and produced higher yield compared to the isogenic Subl-line under controlled submerged condition. The BRL IR85260-66-654-Gaz2 was released as BRRI dhan52 in 2010, which was the first high yielding submergence tolerant variety in Bangladesh. BRRI dhan52 produced grain yield ranging from 4.2 to 5.2 t/hm2 under different flash flood prone areas of Bangladesh in three consecutive seasons. The study demonstrated the efficiency of recombinant selection and better adaptability of the newly released submergence tolerant high yielding variety in flash flood prone different areas of the country with respect to submergence tolerance and yield potential.

关键词： backcross recombinant line marker-assisted backcrossing recombinant selection rice submergence tolerance

Flexural Strength and Load-Deflection Behaviour of Hybrid Thermoset Composites of Wood and Canola Biopolymers

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Advanced Fiber Materials 2021年第5期3卷 331-346页

作者： Ikra Iftekhar Shuvo Md.Saiful Hoque Md.Shadhin Lovely K.M.khandakar University of Alberta EdmontonCanada University of Manitoba WinnipegCanada

The study aims to incorporate cellulosic canola(Brassica napus L.)biopolymers with wood biomass to increase flexural strength more than wood fraction alone.A facile fabrication process-at ambient temperature-is employed for ease of producing two different sets of bio-composites utilizing unsaturated polyester resin:pristine composite structures of 100%wood and hybrid composite structures of a canola-wood *** curing process is accompanied by methyl ethyl ketone peroxide(MEKP).Besides the lightweight feature,the hybrid composite structures exhibit maximum flexural strength up to 59.6 and 89.58 MPa at 2.5 and 5%fibre polymer fraction,outperforming the pristine wood composites(49.25 MPa).Also,the bending behaviours of the composite structures are illustrated by the load-deflection curves and the associated SEM micrographs display their fractured and debonded surface at the *** novel canola fibre benefits from its inherent hollow architecture,facilitating an excellent strength to weight ratio for the thermoset ***,canola displays a fibre diameter and density of 79.80(±41.31)μm and 1.34(±0.0014)g/cc,contributing effectively towards the flexure performance and high packing *** breaking tenacity(13.31±4.59 g-force/tex)and tensile strength(174.93±60.29)of canola fibres are comparable to other bast *** synergy among fibre diameters,density and break-ing tenacity creates a good interphase to successfully transfer the external compressive load from the resin matrix to the ***,the two-parameter Weibull distribution model is applied for predicting the failure and reliability probability of composite specimens against a wide range of compressive ***,prioritized SWOT factors have been summa-rized associated with the prospects and key challenges of canola biopolymers-an attempt to strategize the planning and decision-making process for a potential business *** introduction of canola into the pla

关键词： Flexural strength Load-deflection Fibre Composite Weibull distribution

Reduced tillage with residue retention improves soil labile carbon pools and carbon lability and management indices in a seven-year trial with wheat-mung bean-rice rotation

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Pedosphere 2022年第6期32卷 916-927页

作者： Rafeza BEGUM Mohammad M.R.JAHANGIR Mohammad JAHIRUDDIN Mohammad Rafiqul ISLAM Shaikh M.BOKHTIAR khandakar R.ISLAM Department of Soil Science Bangladesh Agricultural UniversityMymensingh 2202(Bangladesh) Soil Resource Development Institute Dhaka 1215(Bangladesh) South Asian Association for Regional Cooperation(SAARC)Agriculture Center Dhaka 1215(Bangladesh) The Ohio State University Columbus OH 43235(USA)

Soil total organic carbon(TOC)is a composite indicator of soil quality with implications for crop production and the regulation of soil ecosystem *** reports on the dynamics of TOC as a consequence of soil management practices in subtropical climatic conditions,where microbial carbon(C)loss is high,are very *** objective of our study was to evaluate the impact of seven years of continuous tillage and residue management on soil TOC dynamics(quantitative and qualitative)with respect to lability and stratification under an annual wheat-mung bean-rice cropping *** soil samples were collected at 0-15 and 15-30 cm depths from a three-replicate split-plot experiment with tillage treatment as the main plots and crop residue levels as the *** tillage treatments included conventional tillage(CT)and strip tillage(ST).Residue levels were high residue level(HR),30%of the plant height,and low residue level(LR),15%.In addition to TOC,soil samples were analyzed for particulate organic C(POC),permanganate oxidizable C(POXC),basal respiration(BR),specific maintenance respiration rate(qCO_(2)),microbial biomass C(MBC),potentially mineralizable C(PMC),and TOC lability and management *** ST treatment significantly increased the TOC and labile C pools at both depths compared with the CT treatment,with the effect being more pronounced in the surface *** HR treatment increased TOC and labile C pools compared with the LR *** ST+HR treatment showed significant increases in MBC,metabolic quotient(qR),C pool index(CPI),C lability index(CL_(I)),and C management index(CMI),indicating improved and efficient soil biological activities in such systems compared with the CT ***,the stratification values,a measure of soil quality improvement,for POC and MBC were>2,indicating improved soil quality in the ST+HR treatment compared with the CT *** ST+HR treatment not only significantly increased the contents o

关键词： basal respiration carbon management index carbon stratification particulate organic carbon permanganate oxidizable carbon total organic carbon

Ecological fitness of brown planthopper, Nilaparvata lugens (Stål), to rice nutrient management

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Ecological Processes 2017年第1期6卷 149-158页

作者： Md.Mamunur Rashid Mahbuba Jahan khandakar S.Islam Md.Abdul Latif Plant Physiology Division Bangladesh Rice Research Institute(BRRI)Gazipur 1701Bangladesh Department of Entomology Bangladesh Agricultural UniversityMymensingh 2202Bangladesh Plant Pathology Division Bangladesh Rice Research Institute(BRRI)Gazipur 1701Bangladesh

Introduction:The brown planthopper(BPH),Nilaparvata lugens(Stål)(Hemiptera:Delphacidae),is a notorious insect pest of *** supplementation can alter plant biochemical compositions which may indirectly affect on ecological fitness parameters of its insect ***,few findings are available on nutrient-induced ecological fitness of BPH and relationship of BPH fitness parameters with its host rice plant biochemical ***:We studied the main and interaction effects of nitrogen(N),phosphorus(P),and potassium(K)inputs on BPH fitness,as measured by the following variables:nymph survival,nymphal duration,adult body weight,and its *** planthopper fitness parameters were regressed as function of rice plant(Oryza sativa)biochemical composition.A completely randomized design with four replications in a factorial scheme was used considering N,P,and K levels as ***:Nitrogen application to the host rice plants provided greater survival and enhanced body weight of *** nymphal duration was found to decrease with N subsidy that caused shorter generation time of *** compounds N and soluble protein(SP),total free sugar(TFS),and silicon(Si)content in rice plant tissue correlated strongly with all fitness traits of ***,SP,and TFS associated positively with BPH survival and body weight,while negatively with nymphal *** contrast,Si had negative correlation with BPH survival and body weight,but positive with nymphal *** supplementation to host plant contributed to increase BPH body *** of P with all parameters of BPH were weak except body weight which was highly significant and *** between N and P inputs demonstrated significant effect on BPH body *** of K had no significant effect on BPH survival and *** analysis did not detect significant relationship of BPH fitness parameters with plant tissue content of ***:The res

关键词： Nilaparvata lugens Nutrient management Survival Nymphal duration Body weight

Comparative investigation of the free radical scavenging potential and anticancer property of Diospyros blancoi(Ebenaceae)

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Asian Pacific Journal of Tropical Biomedicine 2016年第5期6卷 410-417页

作者： Muhammad Ali Khan Mahbubur Rahman Nazmul Sardar Saiful Islam Arman Badrul Islam Jahangir Alam khandakar Mamunur Rashid Golam Sadik AHM Khurshid Alam Department of Pharmacy Bangabandhu Sheikh Mujibur Rahman Science and Technology University Department of Pharmacy University of Rajshahi Drugs and Toxins Research Division Bangladesh Council of Scientific and Industrial Research Product Development and Validation Department Square Pharmaceutical Limited Laboratory of Genetics Graduate School of BiostudiesKyoto University

Objective: To investigate the comparative effects of Diospyros blancoi(Ebenaceae)leaves(DBL), root bark(DBRB) and stem bark(DBSB) on free radicals and ***: The polyphenol contents, antioxidant and free radical scavenging properties were determined using standard spectrophotometric methods. Cytotoxicity and anticancer activities were performed on brine shrimp nauplii and Ehrlich ascite carcinoma cells, ***: Among the extracts, DBSB showed the highest total antioxidant capacity and reducing capacity on ferrous ion. Based on 1,1-diphenyl-2-picrylhydrazyl and hydroxyl radical scavenging activities, DBSB showed(95.760 ± 0.343)% and(67.460 ± 2.641)%scavenging with IC50of(3.10 ± 0.17) and(50.00 ± 3.11) mg/m L, respectively. The IC50 values of standard butylated hydroxytoluene and catechin(CA) for 1,1-diphenyl-2-picrylhydrazyl and hydroxyl radicals were(8.50 ± 0.25) and(75.00 ± 0.14) mg/m L,respectively suggesting that DBSB had a significant(P DBRB > CA > ***, the phenolic [(139.91 ± 3.924) mg gallic acid equivalent/g] and flavonoid contents[(412.00 ± 16.70) mg catechin equivalent/g)] of DBSB were higher than that of other extracts. In addition, the DBSB showed the moderate cytotoxic and anticancer ***: Our results indicate that Diospyros blancoi stem bark had the significant highest antioxidant and free radical scavenging properties as well as moderate anticancer ***, we assume that the anticancer activity of this plant can be, at least in part, attributed to its content in phenolic compounds as well as its significant free radical scavenging properties.

关键词： Diospyros blancoi Free radicals Polyphenols Antioxidant Cytotoxicity Anticancer

Morphological and Genetical Variability among Rhizoctonia solani Isolates Causing Sheath Blight Disease of Rice

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Rice science 2016年第1期23卷 42-50页

作者： Zakiah Rahman MONI Md Ansar ALI Md Shahidul ALAM Md Asif RAHMAN Md Rejwan BHUIYAN Md Salim MIAN khandakar Md IFTEKHARUDDAULA Md Abdul LATIF Mohammad Ashik Iqbal KHAN Plant Breeding Division Bangladesh Rice Research Institute Director Research Bangladesh Rice Research Institute Department of Botany Rajshahi University Department of Genetics and Plant Breeding Bangabandhu Sheikh Mujibur Rahman Agricultural University Plant Pathology Division Bangladesh Rice Research Institute

Eighteen isolates of Rhizoctonia solani collected from infected rice plants in four different locations of Bangladesh were studied by using morphological characters and molecular markers. Anastomosis study with a reference isolate confirmed that all the isolates belonged to R. solani. Significant variation was observed in sclerotial size, shape and distribution. Un-weighted pair group method with arithmetic mean dendrogram constructed based on the Gower＇s general similarity coefficient showed that these isolates were grouped into four clusters at the 0.68 similarity coefficent according to morphological characters. Cluster I was a major cluster consisting of 13 isolates, while clusters Ⅱ to Ⅳ consisted of 1 or 2 isolates. Analyses by variable number of tandem repeat and amplified fragment length polymorphism markers showed that the isolates were grouped into five and three clusters at a similarity coefficient of 0.64 and 0.69, respectively. Although most of the variability was found between isolates from different regions as expected, significant variation was observed within the isolates collected from similar agro-ecological regions. Our results suggest the presence of different races of R. solani within the same local geographic regions.

关键词： rice Rhizoctonia solani fungal variability molecular marker morphological character