Physical Sciences and Mathematics Commons^™

Leading Firms As Knowledge Gatekeepers In A Networked Environment, Deogratias Harorimana Mr

Dr Deogratias Harorimana

This chapter introduces the role of the knowledge gatekeeper as a mechanism by which knowledge is created and transferred in a networked environment. Knowledge creation and transfer are essential for building a knowledge based economy. The chapter considers obstacles that inhibit this process and argues that leading firms create a shared socio-cultural context that enables the condivision of tacit meanings and codification of knowledge. Leading firms act as gatekeepers of knowledge through the creation of shared virtual platforms. There will be a leading firm that connects several networks of clients and suppliers may not interact directly with one another, but …

Homogeneous Dbd In N2: 1) Lif, Talif And Electrical Measurements, N. Gherardi, Et. Es-Sebbar, C. Sarra-Bourret, N. Naudé, F. Massines

Dr. Et-touhami Es-sebbar

In this paper we compare two different discharges that can be obtained in a DBD configuration, that is to say the filamentary discharge (usual regime in atmospheric DBD) with the Atmospheric Pressure Townsend Discharge (APTD), which is a homogeneous regime obtained in nitrogen atmosphere. The aim is to help in the understanding of the processes which control the transition from one regime to the other. To do so, the discharge is characterized through electrical measurements, coupled with optical diagnostics among which Laser Induced Fluorescence (LIF) for radical density measurements. The influence of the addition of small quantities of additives on …

Active Species Generation Of Homogeneous Dbd In N2: Experiment And Modelling, N. Gherardi, Et. Es-Sebbar, C. Sarra-Bourret, N. Naudé, F. Massines, D. Tzyganov, P. Ségur, S. Pancheshnyi

Dr. Et-touhami Es-sebbar

No abstract provided.

A Heuristic Scheduling Scheme In Multiuser Ofdma Networks, Zheng Sun, Zhiqiang He, Ruochen Wang, Kai Niu

Zheng Sun

Conventional heterogeneous-traffic scheduling schemes utilize zero-delay constraint for real-time services, which aims to minimize the average packet delay among real-time users. However, in light or moderate load networks this strategy is unnecessary and leads to low data throughput for non-real-time users. In this paper, we propose a heuristic scheduling scheme to solve this problem. The scheme measures and assigns scheduling priorities to both real-time and non-real-time users, and schedules the radio resources for the two user classes simultaneously. Simulation results show that the proposed scheme efficiently handles the heterogeneous-traffic scheduling with diverse QoS requirements and alleviates the unfairness between real-time …

Using Bayesian Networks For Candidate Generation In Consistency-Based Diagnosis, Sriram Narasimhan, Ole J. Mengshoel

Ole J Mengshoel

Consistency-based diagnosis relies on the computation of discrepancies between model predictions and sensor observations. The traditional assumption that these discrepancies can be detected accurately (by means of thresholding for example) is in many cases reasonable and leads to strong performance. However, in situations of substantial uncertainty (due, for example, to sensor noise or model abstraction), more robust schemes need to be designed to make a binary decision on whether predictions are consistent with observations or not. However, if an accurate binary decision is not made, there are risks of occurrence of false alarms and missed alarms. Moreover when multiple sensors …

The Dependence Of Measured Modulation Error Ratio On Phase Noise, Ron D. Katznelson

Ron D. Katznelson

This paper reviews the algorithms used by Vector Signal Analyzers to measure Modulation Error Ratio (MER) and derives the explicit functional dependence of measured MER on phase noise of digital transmitters. The modulation error model is introduced and the analytical expression for key estimated parameters required to obtain MER measure are derived. The essential elements of algorithms employed by MER measurement instruments to estimate amplitude scale, frequency offset, and initial phase intercept and the resulting MER are identified. The frequency response of the effective phase-noise rejection filtering action associated with a given measurement epoch is derived. It is shown that …

Investigation Of Stun Guns As Intentional Electromagnetic Interference (Emi) Sources, George H. Baker, Ryan C. Tuttle

George H Baker

Determined malefactors have demonstrated the use of common systems as effective weapons against civilian infrastructures, e.g. commercial jetliners used as kinetic weapons and cell phones used to trigger explosive devices. This undergraduate research project investigated the possibility of using readily available stun gun devices for electro-magnetic interference with or disruption of personal computers. At present, the system effects of high power electromagnetic sources are well recognized by world scientific and military communities. Former CIA Director John Deutch has said that, "the electron is the ultimate precision-guided weapon."1 There has been much research on the deleterious effects of pulsed voltages and …

Investigation Of Stun Guns As Intentional Electromagnetic Interference (Emi) Sources, George H. Baker, Ryan C. Tuttle

George H Baker

Because the operation and control of most critical infrastructures are highly dependent on electronics, it is important to understand the vulnerability of those electronics to intentional electromagnetic interference (EMI). The possibility of interference using readily available consumer devices is a particular concern. We investigated the feasibility and effectiveness of using compact stun guns to intentionally interfere with electronic systems. Test articles included individual computers and computers networked through a central hub. 60KV and 600KV devices were used in the experiments. Results indicate that stun guns are effective in disabling digital electronic systems.

Surface Ion-Electron Recombination As The Main Source Of Atoms In Flowing N2 Dbd, D. Tsyganov, Et. Es-Sebbar, S. Pancheshnyi, N. Gherardi, P. Ségur, F. Massines

Dr. Et-touhami Es-sebbar

No abstract provided.

Talif Quantification Of Nitrogen Atoms Applied To Experimental Simulation Of Titan’S Atmosphere, Et. Es-Sebbar, Y. Benilan, E. Arzoumanian, M.-C. Gazeau

Dr. Et-touhami Es-sebbar

No abstract provided.

S.E.T.U.P., A New Program Of Representative Simulations Of Titan’S Atmosphere: Current Status, M-C. Gazeau, E. Arzoumanian, Y. Benilan, Et. Es-Sebbar, A. Jolly, S. Perrier, C. Romanzin

Dr. Et-touhami Es-sebbar

No abstract provided.

Modeling Of Fermentation Processes Using Online Kernel Learning Algorithm, Yi Liu

Dr. Yi Liu

No abstract provided.

Adaptive Control Of A Class Of Nonlinear Discrete-Time Systems With Online Kernel Learning, Yi Liu

Dr. Yi Liu

No abstract provided.

Report Of The Commission To Assess The Threat To The United States From Emp Attack: Critical National Infrastructures, William R. Graham

George H Baker

The physical and social fabric of the United States is sustained by a system of systems; a complex and dynamic network of interlocking and interdependent infrastructures (“critical national infrastructures”) whose harmonious functioning enables the myriad actions, transactions, and information flow that undergird the orderly conduct of civil society in this country. The vulnerability of these frastructures to threats — deliberate, accidental, and acts of nature — is the focus of greatly heightened concern in the current era, a process accelerated by the events of 9/11 and recent hurricanes, including Katrina and Rita. This report presents the results of the Commission’s …

Comparison Of Townsend Dielectric Barrier Discharge In N2, N2/O2 And N2/N2o: Behavior And Density Of Radicals, F. Massines, Et. Es-Sebbar, N. Gherardi, N. Naudé, D. Tsyganov, P. Ségur, S. Pancheshnyi

Dr. Et-touhami Es-sebbar

No abstract provided.

Criteria On Utility Designing Of Convex Optimization In Fdma Networks, Zheng Sun, Wenjun Xu, Zhiqiang He, Kai Niu

Zheng Sun

In this paper, we investigate the network utility maximization problem in FDMA systems. We summarize with a suite of criteria on designing utility functions so as to achieve the global optimization convex. After proposing the general form of the utility functions, we present examples of commonly used utility function forms that are consistent with the criteria proposed in this paper, which include the well-known proportional fairness function and the sigmoidal-like functions. In the second part of this paper, we use numerical results to demonstrate a case study based on the criteria mentioned above, which deals with the subcarrier scheduling problem …

Understanding The Role Of Noise In Stochastic Local Search: Analysis And Experiments, Ole J. Mengshoel

Ole J Mengshoel

Stochastic local search (SLS) algorithms have recently been proven to be among the best approaches to solving computationally hard problems. SLS algorithms typically have a number of parameters, optimized empirically, that characterize and determine their performance. In this article, we focus on the noise parameter. The theoretical foundation of SLS, including an understanding of how to the optimal noise varies with problem difficulty, is lagging compared to the strong empirical results obtained using these algorithms. A purely empirical approach to understanding and optimizing SLS noise, as problem instances vary, can be very computationally intensive. To complement existing experimental results, we …

Proceedings From Scientific Conference On Green Energy And It, Dr. Erik Dahlquist

Dr. Erik Dahlquist

This conference is part of the annual Energitinget, a national arena for energy in Sweden, with some 2500 participants. The focus with this session is to give a forum for researchers to present scientific results, and also to discuss these with other researchers. It contains papers in the area of Energy and IT as well as Green energy generally

Laboratory Experiments As Support To The Built Up Of Titan’S Theoretical Models And Interpretation Of Cassini-Huygens Data, M-C. Gazeau, Y Benilan, Et. Es-Sebbar, T. Ferradaz, E. Hébrard, A. Jolly, F. Raulin, C. Romanzin, J-C. Guillemin, C. Berteloite, A. Canosa, S. D. Le Picard, Ian R. Sims

Dr. Et-touhami Es-sebbar

No abstract provided.

Sensor Validation Using Bayesian Networks, Ole J. Mengshoel, Adnan Darwiche, Serdar Uckun

Ole J Mengshoel

One of NASA’s key mission requirements is robust state estimation. Sensing, using a wide range of sensors and sensor fusion approaches, plays a central role in robust state estimation, and there is a need to diagnose sensor failure as well as component failure. Sensor validation techniques address this problem: given a vector of sensor readings, decide whether sensors have failed, therefore producing bad data. We take in this paper a probabilistic approach, using Bayesian networks, to diagnosis and sensor validation, and investigate several relevant but slightly different Bayesian network queries. We emphasize that onboard inference can be performed on a …

Charge Transfer Mechanisms In Electrospinning, Jonathan J. Stanger

Jonathan J Stanger

Electrospinning is a method of producing nano structured material from a polymer solution or melt using high strength electric fields. It is a process that has yet to find extensive industrial application yet shows promise if obstacles such as low rate of production overcome perhaps by more complete theoretical modelling. This work examines the effects of adding an ionic salt to a solution of poly(vinyl alcohol) in water. The direct effect was an increase the charge density and electric current. It was found that an increase in charge density decreases the mass deposition rate and forms a thinner initial jet. …

Use Of Modeling And Simulation In Pulp And, Dr. Erik Dahlquist

Dr. Erik Dahlquist

The book is a handbook for operators and process engineers in primarily pulp and paper industry, but also other process industries about how to utilise simulation as a tool for enhanced process operations. The book has been written as part of a EU COST action on Process Simulation, with 14 countries and 50 researchers and process industry representatives involved.

Cascading Infrastructure Failures: Avoidance And Response, George H. Baker, Cheryl J. Elliott

George H Baker

No critical infrastructure is self-sufficient. The complexity inherent in the interdependent nature of infrastructure systems complicates planning and preparedness for system failures. Recent wide-scale disruption of infrastructure on the Gulf Coast due to weather, and in the Northeast due to electric power network failures, dramatically illustrate the problems associated with mitigating cascading effects and responding to cascading infrastructure failures once they have occurred.

The major challenge associated with preparedness for cascading failures is that they transcend system, corporate, and political boundaries and necessitate coordination among multiple, disparate experts and authorities. This symposium brought together concerned communities including government and industry …

Diagnosing Faults In Electrical Power Systems Of Spacecraft And Aircraft, Ole J. Mengshoel, Adnan Darwichse, Keith Cascio, Mark Chavira, Scott Poll, Serdar Uckun

Ole J Mengshoel

Electrical power systems play a critical role in spacecraft and aircraft. This paper discusses our development of a diagnostic capability for an electrical power system testbed, ADAPT, using probalistic techniques. In the context of ADAPT, we present two challenges, regarding modelling and real-time performance, often encountered in real-world diagnostic applications. To meet the modelling challenge, we discuss our novel high-level specification language which supports auto-generation of Bayesian networks. To meet the real-time challenge, we compile Bayesian networks intro arithmetic circuits. Arithmetic circuits typically have small footprints and are optimized for the real-time avionics systems found in spacecraft and aircraft. Using …

The Crowding Approach To Niching In Genetic Algorithms, Ole J. Mengshoel, David E. Goldberg

Ole J Mengshoel

A wide range of niching techniques have been investigated in evolutionary and genetic algorithms. In this article, we focus on niching using crowding techniques in the context of what we call local tournament algorithms. In addition to deterministic and probabilistic crowding, the family of local tournament algorithms includes the Metropolis algorithm, simulated annealing, restricted tournament selection, and parallel recombinative simulated annealing. We describe an algorithmic and analytical framework which is applicable to a wide range of crowding algorithms. As an example of utilizing this framework, we present and analyze the probabilistic crowding niching algorithm. Like the closely related deterministic crowding …