2,673 research outputs found
Content-Aware DataGuides for Indexing Large Collections of XML Documents
XML is well-suited for modelling structured data with
textual content. However, most indexing approaches perform
structure and content matching independently, combining
the retrieved path and keyword occurrences in a third
step. This paper shows that retrieval in XML documents can
be accelerated significantly by processing text and structure
simultaneously during all retrieval phases. To this end,
the Content-Aware DataGuide (CADG) enhances the wellknown
DataGuide with (1) simultaneous keyword and path
matching and (2) a precomputed content/structure join. Extensive
experiments prove the CADG to be 50-90% faster
than the DataGuide for various sorts of query and document,
including difficult cases such as poorly structured
queries and recursive document paths. A new query classification
scheme identifies precise query characteristics with
a predominant influence on the performance of the individual
indices. The experiments show that the CADG is applicable
to many real-world applications, in particular large
collections of heterogeneously structured XML documents
The Effects Of Unannounced Quizzes On Student Performance: Further Evidence
This study explores the impact of unannounced quizzes on studentsâ performance on Quantitative Analysis examinations by comparing course sections with unannounced quizzes to sections with announced quizzes. The difference in academic performance between students with unannounced quizzes and students with announced quizzes was examined in this study. Test scores for the first and second semesters were compared between the students with unannounced quizzes and students with announced quizzes. A significant difference was found in academic performance between the group with unannounced quizzes and group with announced quizzes. The group with unannounced quizzes showed better performance than the control group with announced quizzes. Therefore, this study demonstrates that an unannounced quiz is more effective than announced quiz in Quantitative Analysis Performance
Refugees: the âOtherâ Human face, and the âotherâ academics, an African and Personal Experience
For many centuries, refugees have continued to move from one country to another, pushed away from their homes for many different reasons. This often results in aimless journeys around the world as they change into homeless wanderers. Wars, political conflicts, ideological differences, social rejections, natural disasters, and socio-economic failures are the main reasons, pushing thousands in different ways toward the unknown. If immigrants are indeed observed all over the world, the case of African refugees is very much outstanding. The Middle Passage shipped many Africans to the Americas during the slave trade era, and many still leave the continent today and go to all parts of the world. Immigration statistics project no change in this trend in the near future. This paper covers the main reasons for the African massive exodus towards overpopulated continents. It also expands on the conditions these generally unwanted immigrants face in hostile hosting countries, while offering a set of examples where good hearts and minds have facilitated both social insertion and human communications. The Scholar at Risk Network represents an exceptionally good example, and illustrates the author's personal example as an academic "other". Finally, the paper proposes what countries all around the world could do together to avoid large human flows
Does Smaller Class Size Affect Students Performance In Basic Statistics Class? An Empirical Study
The objective of this study was to determine whether smaller class size, defined as fewer than 20 students in Business Statistics class influence grades earned in the course. The investigator hypothesized that there is a positive relationship between class size and performance, which is measured by grade earned in the course. The study revealed a positive relationship between performance and class size. The results also indicated that the groups that were in the smaller classes performed better on tests than the control groups that were in the larger classes. Furthermore, the study revealed that although there was a positive correlation between performance and class size, simply reducing class size does not guarantee significant increases in performance for all students
Do Learning & Teaching Styles Affect Students Performance? An Empirical Study
The ways in which students normally obtain, retain, and get back information are defined as the studentsâ learning style.  Mismatches often occur between the learning styles of students in a Basic Statistics class and the teaching style of the instructor, with adverse effects on the quality of the studentsâ learning and on their attitudes toward the class and the subject.  The purpose of this study was to determine whether or not congruency of learning and teaching styles improve studentsâ performance in my Basic Statistics class
Euler buckling instability and enhanced current blockade in suspended single-electron transistors
Single-electron transistors embedded in a suspended nanobeam or carbon
nanotube may exhibit effects originating from the coupling of the electronic
degrees of freedom to the mechanical oscillations of the suspended structure.
Here, we investigate theoretically the consequences of a capacitive
electromechanical interaction when the supporting beam is brought close to the
Euler buckling instability by a lateral compressive strain. Our central result
is that the low-bias current blockade, originating from the electromechanical
coupling for the classical resonator, is strongly enhanced near the Euler
instability. We predict that the bias voltage below which transport is blocked
increases by orders of magnitude for typical parameters. This mechanism may
make the otherwise elusive classical current blockade experimentally
observable.Comment: 15 pages, 10 figures, 1 table; published versio
Pheromone deposition/updating strategy in a network: using ant colony optimization (ACO) approach
The study and understanding of the social behavior of insects has contributed to the definition of some algorithms that are capable of solving several types of optimization problems. The most important and challenging problems that the ants encounters when routing through a network arc, is their ability to searching for the path with a shorter length as well as to minimize the total cost incurred in the process of routing through the network. In this paper, we introduced some features to the existing Ant Colony Optimization (ACO) algorithm to help tackle this problem. First, we defined two kinds of pheromone and then we also defined three kinds of heuristic information to guide the searching direction of ants for this bi-criteria problem. Each of the ants uses the heuristic types and the pheromone types in each iteration based on the probability, controlled by two parameters. These two parameters are adaptively adjusted in the process of the algorithm. Second, we used the information of the partial solutions to modify the bias of ants so that inferior choices will be ignored. Finally, we tested the performance of the experimental results of the algorithm in an application under different Deadline constraints and the performance of the algorithm prove to be more promising, for it outperformed the performance of most of the algorithm we downloaded on line.Keywords: Ant Colony Optimization algorithm, Pheromone Deposition, Pheromone Updating strategy, Cost Minimization, Network Routing, Optimization problem.
Packets routing and bandwidth sensing in a network traffic: Ant colony optimization tactic.
Packets routing and bandwidth sensing in a network platform remains an integral part of the study of signal flow.The algorithm to route packets in a network link called the AntNet algorithm was inspired by the behavior of real ant colonies. At each node in the network, a forward ant deposits some amount of pheromones at different links that responds to the nodeâs queue length. In this paper, we propose the inclusion of the computation of paths to adapt with the Depth Search Ant Explorer Network (DS-ANTENet) algorithm for discrete problems as an IP based mechanism. This method is tested and the efficiency is compared to the original AntNet algorithm and the Link-State algorithm to check the transmission of computing traffic flows between the nodes. We then made comparison with the algorithms proposed in the literature. The protocols were sorted out in terms of average number of lost packets ranging from the higher priority queue to the lower priority queue which then resulted to the fact that; First, AntNetBW (loss ratios reduction of 9.6% when compared to the AntNet and the Link-State algorithm respectively. Secondly, SANTENetBW (loss ratios reduction of 8.3% and 36.7% when compared to the AntNet and the Link-State algorithm respectively. Finally, DS-ANTENet (loss ratios reduction 0.7% and 33.2% when compared to the AntNet and the Link- State algorithm respectively.Keywords: Packets Routing, Bandwidth Sensing, Network Traffic, Ant Colony Optimization Algorithm, AntNe
Relationship of Time and Learning Retention
This study explores the degree to which students’ understanding, or knowledge, may deteriorate over time. Our specific focus was examining the importance of course sequencing in a curriculum. We measured student performance in quantitative business courses and found that, over time, the correlation between students’ performance in those courses declined significantly. We further found that that decline was not linear
Métodos de captura, contenção e fixação de transmissores VHF em caititus (Tayassu tajacu).
O objetivo do trabalho foi descrever metodologias para a captura, contenção e marcação de caititus. A captura foi realizada de duas formas: com laço e com armadilhas; os mĂ©todos de contenção considerados foram: fĂsico e quĂmico; transmissores de VHF foram afixados aos animais para monitoramento apĂłs captura utilizando colar de couro, colar de aço revestido ou brinco. As armadilhas medindo 1,5m x 0,8m x 0,6m, foram instaladas em locais com indĂcios da presença da espĂ©cie, durante a estação seca no Pantanal da NhecolĂąndia. Ăgua em reservatĂłrios plĂĄsticos nivelados Ă superfĂcie do solo (25 litros) e pequenas quantidades de mandioca foram utilizadas como atrativo. As armadilhas instaladas nas condiçÔes descritas mostraram-se eficientes para atração e captura de animais da espĂ©cie. Embora o mĂ©todo do laço tenha se mostrado eficiente, seu uso certamente compromete o bem estar dos animais manejados, devido Ă presença de cĂŁes. Quando houve apenas a contenção fĂsica dos animais a mortalidade pĂłs-captura foi menor. Dentre as opçÔes testadas para anexar transmissores aos animais, o colar confeccionado manualmente utilizando sola de couro foi a mais viĂĄvel
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