1,488,584 research outputs found

    Discovering the Impact of Knowledge in Recommender Systems: A Comparative Study

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    Recommender systems engage user profiles and appropriate filtering techniques to assist users in finding more relevant information over the large volume of information. User profiles play an important role in the success of recommendation process since they model and represent the actual user needs. However, a comprehensive literature review of recommender systems has demonstrated no concrete study on the role and impact of knowledge in user profiling and filtering approache. In this paper, we review the most prominent recommender systems in the literature and examine the impression of knowledge extracted from different sources. We then come up with this finding that semantic information from the user context has substantial impact on the performance of knowledge based recommender systems. Finally, some new clues for improvement the knowledge-based profiles have been proposed.Comment: 14 pages, 3 tables; International Journal of Computer Science & Engineering Survey (IJCSES) Vol.2, No.3, August 201

    Mathematical modeling and operational optimization of ultrafiltration membrane processes

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    A utilização de processos de membrana em Engenharia Ambiental tem expandido de forma significativa nos últimos anos e, tendo em vista a importância da possibilidade de otimização da sua operação com vistas à produção máxima de permeado em função do tempo, este trabalho teve por objetivo definir uma técnica de otimização da operação de sistemas de ultrafiltração mediante o estudo de ciclos de operação e lavagem. Os ensaios experimentais foram efetuados tendo-se empregado duas membranas de ultrafiltração com diferentes pesos moleculares de corte e, com base nos resultados experimentais, foi possível a proposição de um modelo matemático que permitiu a otimização da operação de sistemas de ultrafiltração, o que possibilitou o aumento da produção do volume de permeado em cerca de 14%.The utilization of membrane processes in Environmental Engineering has expanded significantly in the last few years. This paper had the primary objective of defining an optimization technique for ultrafiltration (UF) membrane operation by studying UF membrane operation and backwashing cycles. The main importance of UF operation optimization is to maximize permeation production as a function of time. Experimental tests were conducted with two UF membranes with different molecular weight cutoff. The experimental results led to the proposition of a mathematical model for the optimization of UF systems; such optimization conducted in practice to an increase of 14% in the permeate volume production.Veolia Water Systems Brasi

    The Nimbus 6 data catalog, volume 12: Data orbits 9227 through 10043

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    Nimbus 6 was successfully launched from the Western Test Range, Vandenberg Air Force Base, California at 08 hr. 12 min. 00 sec. GMT on 12 June 1975. The orbit was nearly circular at 1093 x 1105 km. Satellite operations from launch through 14 July (orbit 425) consisted of engineering evaluation of all spacecraft systems. As a result of that effort, data reception, accountability and processing were intermittent during that period. This volume reflects the operational changes that occurred to each individual subsystem on a bi-monthly basis. Also this volume incorporates significant findings and various subsystem summaries as detailed by the respective experimenter. During orbit 9793 (12 June 1977) Nimbus 6 successfully completed two years of operations

    Simulations on Consumer Tests: A Perspective for Driver Assistance Systems

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    This article discusses new challenges for series development regarding the vehicle safety that arise from the recently published AEB test protocol by the consumer-test-organisation EuroNCAP for driver assistance systems [6]. The tests from the test protocol are of great significance for an OEM that sells millions of cars each year, due to the fact that a positive rating of the vehicle-under-test (VUT) in safety relevant aspects is important for the reputation of a car manufacturer. The further intensification and aggravation of the test requirements for those systems is one of the challenges, that has to be mastered in order to continuously make significant contributions to safety for high-volume cars. Therefore, it is to be shown how a simulation approach may support the development process, especially with tolerance analysis. This article discusses the current stage of work, steps that are planned for the future and results that can be expected at the end of such an analysis.Comment: 6 pages, 5 figure, Proceedings of International Workshop on Engineering Simulations for Cyber-Physical Systems (ES4CPS '14

    Envirnonmental Standards for Northern Regions: A Symposium

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    Symposium was held June 13-14, 1974 in Anchorage, Alaska.The environmental standards for water, air, and land are of prime importance to all members of the northern community. Many of the ecological systems are easily disrupted. Some of the systems are extremely stable. Although the volume of scientific and engineering research on various aspects of the total environment is expanding rapidly it appears that those studying the conditions that exist and those setting the standards for these areas seldom, if ever, communicate. Due to the increased attention being paid to the meaning and impact of regulations, the sponsors of this symposium proposed an opportunity for open discussion of the issues. The program was designed to address the full range of environmental situations. The principal objectives of this symposium were: 1. to review environmental standards and regulations 2. to identify environmental problem areas 3. to examine the adequacy, pertinence, enforcement, and effectiveness of environmental control in the North. While these objectives could not be completely satisfied by this meeting, doors were opened; participants discussed issues brought forth; and progress was made toward a better understanding of needed environmental standards for northern regions.Financial support for this symposium was provided by the University of Alaska - Division of Statewide Services, Program of Environmental Quality Engineering, and the Institute of Water Resources. These organizations are acknowledged for their participation

    spinfortec2022 : Tagungsband zum 14. Symposium der Sektion Sportinformatik und Sporttechnologie der Deutschen Vereinigung für Sportwissenschaft (dvs), Chemnitz 29. - 30. September 2022

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    Dieser Tagungsband enthält die Beiträge aller Vorträge und Posterpräsentationen des 14. Symposiums der Sektion Sportinformatik und Sporttechnologie der Deutschen Vereinigung für Sportwissenschaft (dvs) an der Technischen Universität Chemnitz (29.-30. September 2022). Mit dem Ziel, das Forschungsfeld der Sportinformatik und Sporttechnologie voranzubringen, wurden knapp 20 vierseitige Beiträge eingereicht und in den Sessions Informations- und Feedbacksysteme im Sport, Digitale Bewegung: Datenerfassung, Analyse und Algorithmen sowie Sportgeräteentwicklung: Materialien, Konstruktion, Tests vorgestellt.This conference volume contains the contributions of all oral and poster presentations of the 14th Symposium of the Section Sport Informatics and Engineering of the German Association for Sport Science (dvs) at Chemnitz University of Technology (September 29-30, 2022). With the goal of advancing the research field of sports informatics and sports technology, nearly 20 four-page papers were submitted and presented in the sessions Information and Feedback Systems in Sport, Digital Movement: Data Acquisition, Analysis and Algorithms, and Sports Equipment Development: Materials, Construction, Testing

    Some engineering properties of three selected groundnut (Arachis hypogaea L.) varieties cultivated in Nigeria

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    The importance of engineering properties on agricultural materials in determining the parameters for agricultural produce processing and equipment design and development cannot be over emphasized. Knowledge of these properties is necessary for the design of various separating, handling, storage and drying systems. Three varieties of groundnuts commonly cultivated in Nigeria were identified, selected and procured. They were: Samnut 10, Samnut 14 and Samnut 18. The aim of the study was to investigate varietal differences for seed weight, average length, thickness, width, geometric mean diameter, degree of sphericity, volume, true densities, surface area, aspect ratio and hydration capacity of the three selected groundnut pods and kernels at 8% moisture content. The average properties of pods for the selected varieties were found to be pod mass of 1.62 g, 1.31 g, 1.40 g; volume of 5.53 ml, 4.35 ml, 4.94 ml; geometric mean diameter of 18.1 mm, 16.43 mm, 17.90 mm; surface area of 10.37 cm², 8.50 cm², 10.08 cm²; sphericity of 0.56 %, 0.64 %, 0.60 %; aspect ratio of 28.26, 38.76, 39.41 and a hydration capacity of 0.36, 0.49, 0.70 g/pod for Samnut 10, Samnut 14, and Samnut 18, respectively. The respective values of the kernels for these varieties were determined to be kernel mass of 0.52 g, 0.47 g, 0.57 g; volume of 0.74 cm³, 0.57 cm³, 0.70 cm³; geometric mean diameter of 5.05 mm, 4.47 mm, 5.02 mm; surface area of 0.42 cm², 0.53 cm², 0.41 cm²; sphericity of 0.35, 0.39, 0.35; aspect ratio of 62.18, 69.90, 60.77 and a hydration capacity of 0.30, 0.17, 0.28 g/kernel. Correlation coefficient (r) was used to determine the degree of association between different parameters. The results of this study showed that each of these varieties has different physical properties and thus require careful study for successful design and development of optimal processing equipment

    Estimating geometrical and mechanical REV based on synthetic rock mass models at Brunswick Mine

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    This paper uses a case study from Brunswick Mine in Canada to determine a representative elementary volume (REV) of a jointed rock mass in the vicinity of important underground infrastructure. The equivalent geometrical and mechanical property REV sizes were determined based on fracture systems modeling and numerical experiments on a synthetic rock mass. Structural data collected in massive sulphides were used to generate a large fracture system model (FSM), 40 m×40 m×40 m. This FSM was validated and subsequently sampled to procure 40 cubic specimens with a height to width ratio of 2 based on sample width from 0.05 to 10 m. The specimens were introduced into a 3D particle flow code (PFC3D) model to create synthetic rock mass (SRM) samples. The geometrical REV of the rock mass was determined based on the number of fractures in each sampled volume (P30) and the volumetric fracture intensity (P32) of the samples. The mechanical REV was estimated based on the uniaxial compressive strength (UCS) and elastic modulus (E) of the synthetic rock mass samples. The REV size of the rock mass was determined based on a series of statistical tests. The T-test was used to assess whether the means of the samples were statistically different from each other and the F-test to compare the calculated variance. Finally, the coefficient of variation, for the synthetic rock mass geometrical and mechanical properties, was plotted against sample size. For this particular site the estimated geometrical REV size of the rock mass was 3.5 m×3.5 m×7 m, while the mechanical property REV size was 7 m×7 m×14 m. Consequently, for engineering purposes the largest volume (7 m×7 m×14 m) can be considered as the REV size for this rock mass
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