650 research outputs found
Exploiting peer group concept for adaptive and highly available services
This paper presents a prototype for redundant, highly available and fault
tolerant peer to peer framework for data management. Peer to peer computing is
gaining importance due to its flexible organization, lack of central authority,
distribution of functionality to participating nodes and ability to utilize
unused computational resources. Emergence of GRID computing has provided much
needed infrastructure and administrative domain for peer to peer computing. The
components of this framework exploit peer group concept to scope service and
information search, arrange services and information in a coherent manner,
provide selective redundancy and ensure availability in face of failure and
high load conditions. A prototype system has been implemented using JXTA peer
to peer technology and XML is used for service description and interfaces,
allowing peers to communicate with services implemented in various platforms
including web services and JINI services. It utilizes code mobility to achieve
role interchange among services and ensure dynamic group membership. Security
is ensured by using Public Key Infrastructure (PKI) to implement group level
security policies for membership and service access.Comment: The Paper Consists of 5 pages, 6 figures submitted in Computing in
High Energy and Nuclear Physics, 24-28 March 2003 La Jolla California. CHEP0
Library Leadersâ Attitude towards User Care in University Libraries of Khyber Pakhtunkhwa and Islamabad
The goal of this research was to look at the attitudes of library leadersâ towards user care in university libraries of Khyber Pakhtunkhwa and Islamabad. This study was conducted utilizing a quantitative research methodology that included a survey approach and a questionnaire. The data were collected from all library leadersâ working in the universities/ degree awarding institutions of Khyber Pakhtunkhwa and Islamabad recognized by Higher Education Commission of Pakistan. Both descriptive as wells as inferential statistics were applied to analyze data using SPSS. The results revealed that the library leaders had an overall positive attitude towards user care. There were no statistically significant differences in the library leadersâ attitude based on types of university, number of employees in libraries, year of establishment of university, library working days in a week, and library timing respectively. Conversely, there were statistically significant mean differences in library leadersâ attitude towards user care based on geographical locations of university and gender of the respondents. The results provided a pragmatic insight into the user-centred approaches for managing customer (user) relationship for marketing of library resources and services. This research also had an important contribution to the existing literature on relationship marketing in general and user relationship management in particular as only a few such studies appeared so far
Reliability and Validity of Scales Assessing Anxiety Associated with Information Related Tasks: A Systematic Review
This research carried out a systematic review of the evidence of reliability and validity of scales available in studies reporting surveys of individuals to assess anxiety associated with information related tasks such as library anxiety, information seeking anxiety, and information anxiety. A systematic search using keywords âlibrary anxietyâ, âinformation anxietyâ, \u27information seeking anxiety\u27, and \u27information seeking\u27 AND \u27anxiety\u27 was carried in Web of Science, Scopus, LISA, and LISTA to identify the relevant literature. This review included those studies reporting the use of any scale assessing information related anxiety, and published in the English language, and included all type of documents (e.g. journal articles, conference papers, book chapters, thesis/dissertations, reports). The two-phase screening process, title/abstract screening, and full-text screening resulted in 85 eligible studies reviewed in this paper. The data extracted from each eligible study included author names, year of publication, scale title, type of constructed assessed, sample characteristics, number of items in the scale, types of reliability and validity reported. The results revealed that most of the empirical studies did not report the reliability and validity of scales used for data collection. Eight instruments assessing information related anxieties were identified. These scales were heterogeneous in the number of statements and subscales and homogenous in the type of scale options. An internal consistency coefficient such as Cronbach\u27s alpha was the widely used reliability measure. Face validity, content validity, and construct validity either through exploratory factor analysis or confirmatory factor analysis were the most used validity measures. These results quite had serious implications on the inferences drawn by the practitioners and researchers based on the results of existing studies. The use of good-quality measures for assessing information related anxieties needs to be promoted not only by academicians but also by journal referees and editors. This review would be a worthy contribution in the existing research on information related anxieties as no such study appeared so far in this area
Effects of Wet Separated and High Speed Milling Fly Ash Added in High Volume to Cementitious Materials
In this research high speed milling was carried out on particles of brown coal raw fly ash, on second layer, and on third layer particles obtained from wet separation of brown coal raw fly ash. Due to milling process, median particle size d50 of raw fly ash, second layer, and third layer reduced by 46 %, 23 %, and 77 %, densities reduced by 11 %, 17 %, and 8 % respectively. Due to milling process, formation of agglomerations was observed, the standard deviation of the chemical composition of each element from the mean value reduced. After milling, high volume cementitious paste mixes were prepared with 60 % cement replacement. Due to the milling process the increase in compressive strength at 28 and 90 days was observed for raw fly ash is 59 % and 16 %, for second layer is 12 % and 15 %, for third layer and milled third layer is 78 % and 75 %. Flexural strength testing showed that due to the milling process the deflections at maximum loads have reduced considerably leading to brittle behavior of milled cementitious specimens. The testing for Mercury Intrusion Porosimetry showed that the cementitious specimens of third layer have maximum concentration of large capillary pores between 0.05 and 10 ”m, whereas, all others have maximum concentration of medium capillary pores between 0.01 and 0.05 ”m. Autogenous shrinkage of cementitious specimens was measured for first sixteen hours after mixing which showed that the second layer particles have the least shrinkage as compared to all other specimens
Radiative Darcy-Forchheimer Micropler Bödewadt flow of CNTs with viscous dissipation effect
[EN] This article aims at the examination of the three-dimensional micropolar nanofluids of single and multi-walled carbon nanotubes (CNTs) dissolved in water and gasoline liquids for the first time reported to the case of so-called classical Bodewadt flow, which occurs when a fluid rotates at an adequate great distance out of a static disk. The static disk is then stretched linearly in the radial direction. The Darcy-Forchheimer porous media are also taken into account. Energy equation is investigated in existence of convection and radiation. The effect of viscous dissipation is also taken into account. The flow field equations are converted from PDEs to ODEs using appropriate transformation. The implementation of the bvp4c technique (Shooting scheme) is used to construct solutions to these ODEs. In addition to Nusselt number, skin friction, axial velocity, radial velocity, tangential velocity, micro-rotational velocities and fluid temperature are all investigated using physical factors. The finding indicates that the volume fraction enhanced, the micro-rotational velocities enhances. The tabulation outcomes indicates that the skin friction declined for escalating values of porosity parameter and volume fraction, while Nusselt number show opposite behavior. It has been also discovered that the effect of multiple-walled CNTs is quite effective than that of single-walled CNTs. When compared to water-based fluids, gasoline oil also displays an overarching trend.Project financed by Lucian Blag a University of Sibiu through research grant LBUS-IRG-2022-08.Shah, Z.; Rooman, M.; Asif Jan, M.; Vrinceanu, N.; Deebani, W.; Shutaywi, M.; Ferråndiz Bou, S. (2022). Radiative Darcy-Forchheimer Micropler Bödewadt flow of CNTs with viscous dissipation effect. Journal of Petroleum Science and Engineering. 217:1-11. https://doi.org/10.1016/j.petrol.2022.11085711121
Hybrid adaptive evolutionary algorithm based on decomposition
The performance of search operators varies across the different stages of the search/optimization process of evolutionary algorithms (EAs). In general, a single search operator may not do well in all these stages when dealing with different optimization and search problems. To mitigate this, adaptive search operator schemes have been introduced. The idea is that when a search operator hits a difficult patch (under-performs) in the search space, the EA scheme âreactsâ to that by potentially calling upon a different search operator. Hence, several multiple-search operator schemes have been proposed and employed within EA. In this paper, a hybrid adaptive evolutionary algorithm based on decomposition (HAEA/D) that employs four different crossover operators is suggested. Its performance has been evaluated on the well-known IEEE CECâ09 test instances. HAEA/D has generated promising results which compare well against several well-known algorithms including MOEA/D, on a number of metrics such as the inverted generational distance (IGD), the hyper-volume, the Gamma and Delta functions. These results are included and discussed in this paper
Novel MLR-RF-Based Geospatial Techniques: A Comparison with OK
Geostatistical estimation methods rely on experimental variograms that are mostly erratic, leading to subjective model fitting and assuming normal distribution during conditional simula-tions. In contrast, Machine Learning Algorithms (MLA) are (1) free of such limitations, (2) can in-corporate information from multiple sources and therefore emerge with increasing interest in real-time resource estimation and automation. However, MLAs need to be explored for robust learning of phenomena, better accuracy, and computational efficiency. This paper compares MLAs, i.e., Multiple Linear Regression (MLR) and Random Forest (RF), with Ordinary Kriging (OK). The techniques were applied to the publicly available Walkerlake dataset, while the exhaustive Walker Lake dataset was validated. The results of MLR were significant (p \u3c 10 Ă 10â5), with correlation coeffi-cients of 0.81 (R-square = 0.65) compared to 0.79 (R-square = 0.62) from the RF and OK methods. Additionally, MLR was automated (free from an intermediary step of variogram modelling as in OK), produced unbiased estimates, identified key samples representing different zones, and had higher computational efficiency
PHURIE : hurricane intensity estimation from infrared satellite imagery using machine learning
Automated prediction of hurricane intensity from satellite infrared imagery is a challenging problem with implications in weather forecasting and disaster planning. In this work, a novel machine learning-based method for estimation of intensity or maximum sustained wind speed of tropical cyclones over their life cycle is presented. The approach is based on a support vector regression model over novel statistical features of infrared images of a hurricane. Specifically, the features characterize the degree of uniformity in various temperature bands of a hurricane. Performance of several machine learning methods such as ordinary least squares regression, backpropagation neural networks and XGBoost regression has been compared using these features under different experimental setups for the task. Kernelized support vector regression resulted in the lowest prediction error between true and predicted hurricane intensities (approximately 10 knots or 18.5 km/h), which is better than previously proposed techniques and comparable to SATCON consensus. The performance of the proposed scheme has also been analyzed with respect to errors in annotation of center of the hurricane and aircraft reconnaissance data. The source code and webserver implementation of the proposed method called PHURIE (PIEAS HURricane Intensity Estimator) is available at the URL: http://faculty.pieas.edu.pk/fayyaz/software.html#PHURIE
Experimental validation of bulk-graphene as a thermoelectric generator
Quest for alternate energy sources is the core of most of the research activities these days. No matter how small or large amount of energy can be produced by utilizing the non-conventional techniques and sources, every bit of innovation can reshape the future of energy. In this work, experimental analysis of the thermoelectric (TE) properties of bulk-graphene in the temperature range of (303 to 363) K is presented. Graphene powder was pressed to form a pellet which was used to fabricate the TE device. The effects of temperature on the Seebeck coefficient, electrical and thermal conductivities, and the dimensionless figure of merit (FOM) were measured. The increasing value of the Seebeck coefficient (thermopower) with temperature is indicant of the metallic behavior. Additionally, the observed thermopower (TEP) is positive, which shows that the majority charge carriers are holes and peaked to a value of 56 ÎŒV K-1 at 363 K. The thermopower of the pellet is four times larger than the previously reported values for single layer graphene (SLG) and few layer graphene (FLG). In addition to this, low values of the thermal conductivity were observed for the pellet which is one of the requirements of a good TE material. Besides this, an upward trend is observed with increasing temperature for FOM, which attains a peak value of 0.0016 at 363 K, which is almost ten times that of the previously reported values
A sensor placement approach using multi-objective hypergraph particle swarm optimization to improve effectiveness of structural health monitoring systems
In this paper, a novel Multi-Objective Hypergraph Particle Swarm Optimization (MOHGPSO) algorithm for structural health monitoring (SHM) systems is considered. This algorithm autonomously identifies the most relevant sensor placements in a combined fitness function without artificial intervention. The approach utilizes six established Optimal Sensor Placement (OSP) methods to generate a Pareto front, which is systematically analyzed and archived through Grey Relational Analysis (GRA) and Fuzzy Decision Making (FDM). This comprehensive analysis demonstrates the proposed approachâs superior performance in determining sensor placements, showcasing its adaptability to structural changes, enhancement of durability, and effective management of the life cycle of structures. Overall, this paper makes a significant contribution to engineering by leveraging advancements in sensor and information technologies to ensure essential infrastructure safety through SHM systems
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