检索结果-南通市图书馆

Analysis of Dynamic Virtual Private Networks Resource Allocation Schemes

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Communications, Network and System Sciences 2018年第4期11卷 53-67页

作者： Chinenye ajibo augustine Chukwukaelo Osuizugbe Anthony Chinaeke Ogbuka Maryrose Nwafor Chukwudi Ikechukwu Ani Cosmas Department of Electronic Engineering University of Nigeria Nsukka Nigeria Department of Electrical and Electronics Engineering Federal Polytechnic Bida Nigeria

The need for high performance resource allocation schemes for Virtual Private Networks (VPNs) has led to the proliferation of algorithms for VPN resource allocation. It was found that most works on VPN resource allocation focused either on admission control or link reservation on the network. Also, review of relevant literatures has revealed the need for a resource allocation/scheduling scheme whose algorithm will be able to allocate bandwidth and memory resources to different VPNS sharing the same link to the network service provider. Resources should be allocated in such a manner that utilization is optimal while VPN endpoints or customers receive services that do not undermine the service-level agreement (SLA) with the service provider. MATLAB Simulink was used to design a simulation model for analysing the VPN access network obtaining and comparing results for the link bandwidth utilization, buffer memory utilization and packet loss rate performances of the RDVNP (Robust Dynamic Virtual Network Provisioning) algorithm against the DWARF-Net (Dynamic bandwidth Allocation and guarantee on Resource Fairness) algorithm. From the results obtained, DWARF-Net algorithm’s performance was better than the RDVNP’s algorithm in almost all parameters tested on. On bandwidth utilization, DWARF-Net had an average channel utilization of 61.23% against RDVNP’s 48.28%, on buffer utilization 42% for DWARF-Net, 41% for RDVNP and average loss rate average of 1 Packet/second for DWARF-Net against 20 Packets/second for RDVNP. From the simulation analysis and result of this work, DWARF-Net is recommended as an optimal performing algorithm for VPN resource allocation.

关键词： ATM DWARF-Net MPLS RDVNP VPN

A single micro-LED manipulation system based on micro-gripper

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nanotechnology and Precision Engineering 2024年第2期7卷 45-52页

作者： Jie Bai Pingjuan Niu Erdan Gu Jianming Li Clarence augustine TH Tee School of Mechanical Engineering Tiangong University School of Electronic and Information Engineering Tiangong University Institute of Photonics University of Strathclyde Tianjin Key Laboratory of Micro Low Gravity Environment Simulation Technology Tianjin Aerospace Electromechanical Equipment Research Institute Department of Electrical and Information Engineering School of Physics and Electrical Information EngineeringZhejiang Normal University

Micro-LEDs(μLEDs) have advantages in terms of brightness, power consumption, and response speed. In addition, they can also be used as micro-sensors implanted in the body via flexible electronic skin. One of the key techniques involved in the fabrication of μLED-based devices is transfer printing. Although numerous methods have been proposed for transfer printing, improving the yield of μLED arrays is still a formidable task. In this paper, we propose a novel method for improving the yield of μLED arrays transferred by the stamping method, using an innovative design of piezoelectrically driven asymmetric micro-gripper. Traditional grippers are too large to manipulate μLEDs, and therefore two micro-sized cantilevers are added at the gripper tips. A μLED manipulation system is constructed based on the micro-gripper together with a three-dimensional positioning system. Experimental results using this system show that it can be used successfully to manipulate μLED arrays.

关键词： Micro-gripper Micro-LED Transfer printing Manipulation

A critical literature review of security and privacy in smart home healthcare schemes adopting IoT&blockchain:Problems,challenges and solutions

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Blockchain(Research and Applications) 2024年第2期5卷 13-61页

作者： Olusogo Popoola Marcos Rodrigues Jims Marchang Alex Shenfield augustine Ikpehai Jumoke Popoola Department of Computing Sheffield Hallam UniversitySheffieldS11WBUK Department of Engineering and Math Sheffield Hallam UniversitySheffieldS11WBUK

Protecting private data in smart homes,a popular Internet-of-Things(IoT)application,remains a significant data security and privacy challenge due to the large-scale development and distributed nature of IoT ***,smart healthcare has leveraged smart home systems,thereby compounding security concerns in terms of the confidentiality of sensitive and private data and by extension the privacy of the data ***,proof-of-authority(PoA)-based blockchain distributed ledger technology(DLT)has emerged as a promising solution for protecting private data from indiscriminate use and thereby preserving the privacy of individuals residing in IoT-enabled smart *** review elicits some concerns,issues,and problems that have hindered the adoption of blockchain and IoT(BCoT)in some domains and suggests requisite solutions using the aging-in-place *** issues with BCoT were examined as well as the combined challenges BCoT can pose when utilised for security *** study discusses recent findings,opportunities,and barriers,and provides recommendations that could facilitate the continuous growth of blockchain applications in ***,the study explored the potential of using a PoA-based permission blockchain with an applicable consent-based privacy model for decision-making in the information disclosure process,including the use of publisher-subscriber contracts for fine-grained access control to ensure secure data processing and sharing,as well as ethical trust in personal information disclosure,as a solution *** proposed authorisation framework could guarantee data ownership,conditional access management,scalable and tamper-proof data storage,and a more resilient system against threat models such as interception and insider attacks.

关键词： IoT Smart home healthcare PoA-based permissioned blockchain Authorisation framework Fine-grained access control Interception Privacy model Consent

Effects of crop residues for animal consumption and soil enhancement on the electricity generation potential of residues:A case study of Sawla-Tuna-Kalba district,Ghana

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Agricultural and Biological Engineering 2024年第4期17卷 276-287页

作者： augustine Awaafo Edward A.Awafo Meisam Mahdavi David Vera Gilbert Ayine Akolgo Emmanuel Amankwah Francisco Jurado Department of Electrical Engineering University of JaénLinares 23700JaénSpain Department of Computer and Electrical Engineering University of Energy and Natural ResourcesSunyani P.O.Box 214Ghana Department of Agricultural and Bioresources Engineering University of Energy and Natural ResourcesSunyani P.O.Box 214Ghana

Many studies have estimated the potential of crop residues for energy generation globally and recognized its great potential,especially in rural areas where on-grid electricity is ***,crop residues have other equally important uses as animal feed and as mulch for soil enhancement,especially in rural farming ***,most of the known studies have neglected the estimation of the quantity of crop residues that will be required for feeding animals and also for the enhancement of soil through mulching in their energy potential estimation from crop *** these two important uses can lead to the over-exploitation of the residues for energy generation at the expense of conservation agriculture practices as well as depriving animals of quality feed which can lead to low crop yield and animal production,with the ability to cause hunger and *** study has assessed the potential of electricity generation from agricultural residues in the Sawla-Tuna-Kalba district of Ghana using gasification technology,taking cognizance of the proportion of residues needed for animal consumption and soil *** results of the study indicate that out of the 207646.22 t of residues that can be generated from maize,yam,cassava,millet,sorghum,and groundnut,26830.36 t(representing 13%)will be required by sheep,goats,and cows for consumption,and 13936.17 t(representing 7%)will be required for mulching soils where the crops are ***,it was found that a total of 592.17 MW∙h of electricity can be generated from crop residues without animal consumption and soil enhancement needs,while 461.89 MW∙h could be generated from the residues,considering animal feed and soil *** study has indicated that it is not enough to consider soil enhancement and animal feeding in agricultural biomass power generation through recovery factors without the exact quantification of residues required for these purposes since this can lead to a vi

关键词： animal feed crop residue electricity generation soil enhancement

Investigation of Groundwater Quality with Borehole Depth in the Basin Granitoids of the Ashanti Region of Ghana

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Water Resource and Protection 2024年第5期16卷 381-394页

作者： Bernard Ofosu augustine Kofi Asante Festus Anane Mensah Umar-Farouk Usman Naa Korkoi Ayeh Geotechnical and Materials Engineering Division CSIR-Building and Road Research Institute Kumasi Ghana

The dependence of groundwater quality on borehole depth is usually debatable in groundwater studies, especially in complex geological formations where aquifer characteristics vary spatially with depth. This study therefore seeks to investigate the relationship between borehole depth and groundwater quality across the granitoid aquifers within the Birimian Supergroup in the Ashanti Region. Physicochemical analysis records of groundwater quality data were collected from 23 boreholes of public and private institutions in the Ashanti Region of Ghana, and the parametric values of iron, fluoride, total hardness, pH, nitrate, and nitrite were used to study the groundwater quality-depth relationship. The results showed that the depth-to-groundwater quality indicated a marginal increase in water quality in the range of 30 to 50 m, which is mathematically represented by the low-value correlation coefficient (r2 = 0.026). A relatively significant increase occurs in the depth range of 50 to 80 m, which is given by a correlation coefficient of r2 = 0.298. The mean percent parameter compatibility was 74%, 82%, 89%, and 97% at 50, 60, 70, and 80 m depths, respectively. The variations in groundwater quality per depth ratio ranged from 1.48, 1.37, 1.27, and 1.21 for 50, 60, 70, and 80 m depth, respectively. The recommended minimum borehole depth for excellent groundwater quality is suggested with a compatibility per meter depth ratio of 1.37. This results in a range between 50 and 70 m as the most desirable drilling depth for excellent groundwater quality within the granitoids of the Birimian Supergroup of the Ashanti Region in Ghana.

关键词： Groundwater Quality Borehole Depth Birimian Supergroup Granitoid Aquifers Ashanti Region

Genetic and Agronomic Parameter Estimates of Growth, Yield and Related Traits of Maize (Zea mays L.) under Different Rates of Nitrogen Fertilization

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

American Journal of Plant Sciences 2024年第4期15卷 274-291页

作者： Prince Emmanuel Norman Lansana Kamara Aloysius Beah Kelvin Sahr Gborie Francess Sia Saquee Sheku Alfred Kanu Fayia augustine Kassoh Yvonne Sylvia Gloria Ethel Norman Abdul Salaam Kargbo Sierra Leone Agricultural Research Institute (SLARI) Freetown Sierra Leone School of Agriculture Njala University Njala Campus Njala Sierra Leone School of Natural Resources Management Njala University Njala Campus Njala Sierra Leone Department of Agro Biotechnology Institute of Agriculture RUDN University Moscow Russia Faculty of Development Agriculture & Natural Resources Management Eastern Technical University of Sierra Leone Kenema Sierra Leone

This study evaluated the genetic and agronomic parameter estimates of maize under different nitrogen rates. The trial was established at the Njala Agricultural Research Centre experimental site during 2021 and 2022 in a split block design with three maize varieties (IWCD2, 2009EVDT, and DMR-ESR-Yellow) and seven nitrogen (0, 30, 60, 90, 120, 150 and 180 kg∙N∙ha−1) rates. Findings showed that cob diameter and anthesis silking time (ASI) had intermediate heritability, ASI had high genetic advance, ASI and grain yield had high genotypic coefficient of variation (GCV), while traits with high phenotypic coefficient of variation (PCV) were plant height, ASI, grain yield, number of kernel per cob, number of kernel rows, ear length, and ear height. The PCV values were higher than GCV, indicating the influence of the environment in the studied traits. Nitrogen rates and variety significantly (p −1 plots exhibiting the lowest and highest grain yields of 1238 kg∙ha−1 and 2098 kg∙ha−1, respectively. Variety and nitrogen effects on partial factor productivity (PFPN), agronomic efficiency (AEN), net returns (NR), value cost ratio (VCR) and marginal return (MR) indicated that these parameters were significantly affected (p N (41.3 kg grain kg−1∙N) and AEN (29.4 kg grain kg−1∙N) were obtained in the 30 kg∙N∙ha−1 plots, while the highest VCR (2.8) and MR (SLL 1.8 SLL−1 spent on N) were obtained in the 180 kg∙N∙ha−1. The significant influence of variety and nitrogen on traits suggests that increasing yields and maximizing profits require use of appropriate nitrogen fe

关键词： Nitrogen Rates Genetic and Agronomic Estimates Introduced Genotypes Grain Yield Zea mays

Retinoblastoma: The Situation in Burkina Faso over Ten Years

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Open Journal of Ophthalmology 2024年第3期14卷 175-195页

作者： Amadou Ouattara Anicet Corneille Beremwidougou Paté Sankara Mariam Traore Dolo Tierinyê Armand Meda Windinmanégdé Pierre Djiguimde Rolande Kabore Chantal Gabrielle Bouda Gertrude augustine Meda Hien Jerome Sanou Jean Wenceslas Diallo Ahgbatouhabeba Zabsonre Ahnoux Ophthalmology Department Regional University Hospital of Ouahigouya Ouahigouya Burkina Faso Regional University Hospital of Ouahigouya Ouahigouya Burkina Faso National Center for the Fight against Blindness Ouagadougou Burkina Faso University Hospital of Sour Sanou Bobo-Dioulasso Burkina Faso Nouna District Hospital Nouna Burkina Faso University Hospital of Bogodogo Ouagadougou Burkina Faso University Hospital of Yalgado Ouedraogo Ouagadougou Burkina Faso

Context: In Burkina Faso, there is only one retinoblastoma treatment center located in the capital. Nowadays, the treatment of retinoblastoma has benefited from the contribution of scientific progress. Objective: The aim was to take stock of the situation of retinoblastoma in the pediatric oncology department from January 1, 2010 to December 31, 2019. Materials and Methods: This was a descriptive cross-sectional study with retrospective data collection over a 10-year period, based on records of patients admitted to pediatric oncology department of CHU-YO. Data were analysed using CS Pro version 7.2 software. Categorical variables were compared using Pearsons Chi-square test at the 5% significance level. Overall survival was estimated using the Kaplan-Meier method. Operational definitions were used for lost to follow-up, consultation and diagnosis delays. Results: We collected a total of 204 cases in 10 years, i.e. an annual average of 20.4 cases/year. The mean age at diagnosis was 37.5 months for unilateral cases and 26.4 months for bilateral cases. Male predominance was noted, with a sex ratio of 1.31. The majority of patients came from disadvantaged backgrounds (72% farming fathers and 91% housewives). Clinically, leukocoria and exophthalmos were the main presenting features. The average time to consultation was long (8.73 months) and unilateral localization was predominantly unilateral at 77%. In terms of treatment, 102 patients were eligible for curative treatment and 80 for palliative treatment. The prognosis was poor, with 41% death and numerous cases of lost to follow-up (18%). Overall survival was estimated at 32%. The factor associated with the lethality of retiniblastoma was the extension of the tumor to other organs. Conclusion: Recognition of the early clinical signs of retinoblastoma can anticipate the occurrence of this cancer. Health professionals should be encouraged to perform the Buckner test every time they come into contact with children aged 0 t

关键词： Retinoblastoma Prognosis Pediatric Oncology CHU-YO Burkina Faso

Rare earth nanostructures based on PrO_x/CNT composites as potential electrodes for an asymmetric pseudocapacitor cell

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Rare Earths 2020年第6期38卷 625-632页

作者： Anjali Paravannoor Chippy Alphons augustine N.Ponpandian School of Chemical Sciences Swami Anandatheertha CampusKannur University.Edat P 0KeralaIndia Department of Nanoscience and Technology Bharathiar UniversityCoimbatoreTamil NaduIndia

Rare earth metal oxides have been widely used as pseudocapacitor electrodes owing to their unique physical and electronic *** present paper reports the synthesis and pseudocapacitor applications of praseodymium oxides,owing to their unique physical ***/unzipped carbonnanotubes were synthesized following a hydrothermal *** morphological as well as electrochemical analyses were performed to elucidate how the unique properties of PrOx affect the charge storage *** emphasis was given on the effect of anion intercalation due to the surface oxygen vacancies in PrOx which would contribute towards the pseudocapacitive energy *** intercalation was exploited for the first time in fluorite crystals for fast energy storage and a specific capacitance value as high as 1099 F/g was obtained with the *** asymmetric supercapacitor prototype was also fabricated with a V2 O5/graphene counter electrode and the energy and power density values obtained are as high as 52.08 Wh/kg and 2.9 kW/kg,respectively.

关键词： PrO_x Carbon nanotubes Supercapacitor Anion intercalation Graphene Rare earths

On the Lorentz factor of superluminal sources

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2013年第5期13卷 509-516页

作者： Chika Christian Onuchukwu augustine A. Ubachukwu Department of Industrial Physics Anambra State University Uli Department of Physics and Astronomy University of Nigeria Nsukka

We investigate the properties of features seen within superluminal sources often referred to as components. Our result indicates a fairly strong correlation of r ～ 0.5 for quasars, r ～ 0.4 for galaxies and r ～ 0.7 for BL Lac objects in our sam- ple between component sizes and distances from the stationary core. The assumption of free adiabatic expanding plasma enables us to constrain the Lorentz factor for su- perluminal sources. Our estimated Lorentz factor of y ～ 9-13 for quasars, 7 ～ 7-11 for galaxies and y～ 4 - 9 for BL Lac objects indicates that BL Lacs have the lowest range of Lorentz factors.

关键词： galaxies: general -- galaxies: active -- galaxies: jets -- methods: ana-lytical -- methods: statistical -- methods: data analysis