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Reston, VA, United States

Evjen S.,Applied Information Sciences
Library and Information Science Research

In terms of political perceptions, library building projects appear to be similar across different contexts. Qualitative interviews with local politicians were employed to examine attitudes towards public libraries and library development in three cities building new central libraries: Aarhus, Denmark; Birmingham, UK; and Oslo, Norway. Applying an institutional perspective, the analysis focuses on norms, legitimization, and organizational change. Findings show shared views on the role and mission of the library. The informants primarily pointed to citizens' democratic rights and their country's democratic tradition when legitimizing public funding for libraries in general. However, argumentation for local library building projects was connected to city development and the desire to portray a city as oriented towards knowledge and culture. © 2015 Elsevier Inc. Source

Orvatinia M.,Applied Information Sciences | Heydarianasl M.,Bushehr Azad University
Sensors and Actuators, A: Physical

A novel method for detection of continuous infrared (IR) radiation by pyroelectric detectors was presented. In this method, instead of conventional modulation of IR radiation by mechanical parts, which are complicated and unreliable, the temperature of the detector is modulated by thermoelectric cooler to activate it. With this new method, the main inherent limitation for application of these detectors is expected to be eliminated. An equivalent electrical circuit was proposed to simulate the thermal and electrical behavior of the detector. A prototype sensor was fabricated and its transient responses to different level of IR radiations were recorded. The model-based calculations were fitted to the measured data, and the fitting parameters were considered as model parameters. Good agreement between experimental data and analytical calculations confirmed the validity of the model. It was also demonstrated that, the application of this method increases the detection speed of the sensor. Improved speed is more than three orders of magnitude better than the other type of thermal detectors. © 2011 Elsevier B.V. All rights reserved. Source

Mohammad A.H.,Applied Information Sciences | Zitar R.A.,New York Institute of Technology
Applied Soft Computing Journal

Spam is a serious universal problem which causes problems for almost all computer users. This issue not only affects normal users of the internet, but also causes a big problem for companies and organizations since it costs a huge amount of money in lost productivity, wasting users' time and network bandwidth. There are many studies on spam indicates that spam costs organizations billions of dollars yearly. This work presents a lot of modification on a machine learning method inspired by the human immune system called artificial immune system (AIS) which is a new emerging method that still needs more investigations and demonstrations. Core modifications were applied on the standard AIS with the aid of the Genetic Algorithm (GA). Also Artificial Neural Network (ANN) for spam detection is applied in a new manner. SpamAssassin corpus is used in all our simulations. In standard AIS several user defined parameters are used such as culling of old lymphocytes. Genetic optimized AIS is used to present culling time instead of using user defined value. Also, a new idea to check antibodies in AIS is introduced. This would make the system able to accept types of messages that were previously considered as spam. The idea is accomplished by introducing a new issue which we call "rebuild time". Moreover, an adaptive weighting of lymphocytes is used to modify selection opportunities for different gene fragments. In this work also, core modifications on ANN neurons are applied; these modifications allow neurons to be changed over time replacing useless layers. This approach is called Continuous Learning Approach Artificial Neural Network, CLA-ANN. The final results are compared and analyzed. Results show that both systems, optimized spam detection using GA and spam detection using ANN, achieved promising scores comparable to standard AIS and other known methods. © 2011 Elsevier B.V. Source

Arike Y.,Applied Information Sciences
Letters in Mathematical Physics

We show that the space of logarithmic intertwining operators among logarithmic modules for a vertex operator algebra is isomorphic to the space of 3-point conformal blocks over the projective line. This can be viewed as a generalization of Zhu's result for ordinary intertwining operators among ordinary modules. © 2012 Springer. Source

Mimouni A.,Universite Ibn Khaldoun | Rachidi F.,Ecole Polytechnique Federale de Lausanne | Rubinstein M.,Applied Information Sciences
IEEE Transactions on Electromagnetic Compatibility

We present an analysis of the nearby electromagnetic fields generated by lightning discharges in the presence of a horizontally stratified, two-layer ground. To the best of our knowledge, this is the first time the effect of ground stratification on underground fields generated by lightning is analyzed. The analysis is performed by solving Maxwell's equations using the finite-difference time-domain technique. The return stroke channel is modeled using the modified transmission line model with exponential decay. The effect of the soil stratification on both above-ground fields and the fields penetrating into the ground is illustrated and discussed for two different cases characterized, respectively, by an upper layer more conductive than the lower level, and vice versa. The analysis was carried out for close distances (10 m-100 m from the channel). It is shown that, for these distances, the ground stratification does not significantly affect the electromagnetic fields above the ground. The above-ground vertical electric field and the azimuthal component of the magnetic field can be calculated assuming the ground as a perfectly conducting plane. The above-ground horizontal electric field is essentially determined by the characteristics of the conductive layer and it can be computed considering a homogeneous ground characterized by the conductive layer conductivity as long as the depth of the upper layer remains below 10 m or so. In general, the fields penetrating into the ground are markedly affected by the soil stratification. The electromagnetic field components inside the stratified soil are generally characterized by faster rise times compared to those of the field components in the case of a homogeneous ground with the upper layer characteristics. The peak value of the horizontal electric field is found to be very sensitive to the ground stratification. The horizontal electric field peak decreases considerably in the presence of a lower layer of higher conductivity. On the other hand, the presence of a lower layer with lower conductivity results in an increase of the peak value of the underground horizontal electric field. © 1964-2012 IEEE. Source

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