2,174 research outputs found
Three-Level Laser Dynamics with the Atoms Pumped by Electron Bombardment
We analyze the quantum properties of the light generated by a three-level
laser with a closed cavity and coupled to a vacuum reservoir. The three-level
atoms available in the cavity are pumped from the bottom to the top level by
means of electron bombardment and we carry out our analysis by putting the
noise operators associated with the vacuum reservoir in normal order. The
maximum quadrature squeezing of the light generated by the laser, operating far
below threshold, is found to be 50% below the coherent-state level. We have
also established that the quadrature squeezing of the output light is equal to
that of the cavity light and has the same value in any frequency interval. This
implies that the quadrature squeezing of the laser light is an intrinsic
property of the individual photons.Comment: 14 pages, 1 figure; a revised version of arXiv: 1105.1438v
Two-Level Laser Dynamics with a Noiseless Vacuum Reservoir
We analyze the quantum properties of the light generated by a two-level laser
in which the two-level atoms available in a closed cavity are pumped to the
upper level by means of electron bombardment. We consider the case in which the
two-level laser is coupled to a vacuum reservoir via a single-port mirror and
seek to carry out our analysis by putting the noise operators associated with
the vacuum reservoir in normal order. It is found that the two-level laser
generates coherent light when operating well above threshold and chaotic light
when operating at threshold. Moreover, we have established that a large part of
the total mean photon number is confined in a relatively small frequency
interval.Comment: 11 pages, 1 figure; this is a revised version of a paper published in
Opt. Commun. (284, 1357, 2011). arXiv admin note: text overlap with
arXiv:1105.143
Dynamic Motion Modelling for Legged Robots
An accurate motion model is an important component in modern-day robotic
systems, but building such a model for a complex system often requires an
appreciable amount of manual effort. In this paper we present a motion model
representation, the Dynamic Gaussian Mixture Model (DGMM), that alleviates the
need to manually design the form of a motion model, and provides a direct means
of incorporating auxiliary sensory data into the model. This representation and
its accompanying algorithms are validated experimentally using an 8-legged
kinematically complex robot, as well as a standard benchmark dataset. The
presented method not only learns the robot's motion model, but also improves
the model's accuracy by incorporating information about the terrain surrounding
the robot
Efficient Data Mining Algorithm Network Intrusion Detection System for Masked Feature Intrusions
Most researches have been conducted to develop models, algorithms and systems to detect intrusions. However, they are not plausible as intruders began to attack systems by masking their features. While researches continued to various techniques to overcome these challenges, little attention was given to use data mining techniques, for development of intrusion detection. Recently there has been much interest in applying data mining to computer network intrusion detection, specifically as intruders began to cheat by masking some detection features to attack systems. This work is an attempt to propose a model that works based on semi-supervised collective classification algorithm. For this study, data mining algorithms were first selected based on efficiency and accessibility criteria. An experiment was conducted using real .arff dataset to develop the model. The result shows that meta.Filtered Collective Classifier is appropriate to detect intrusions with hidden features, which scored the best classification accuracy of 96.2%
Toolbox value creation final report (WP-101)
This document contains the deliverables of TransForum project WP-101, Toolbox Value Creation. Its contents allow users to use a summary analysis toolbox made for charting and improving value chains in the areas of People, Planet and Profit. Features of the toolbox are: Guidance in organizing a quick scan and change process. Create summary graphic overview of the materials balance of a production network. Model People and Planet and Profit separately but in conjunction. Allow flexible inclusion or omission of actors, processes and products. Analyze value of improvements
Assessment of the Prevalence of Good Governance In The Public Sector: the Case of Public Institutions in Debre Birhan Town
Having seen its desperate importance and the great efforts of the government in achieving good
governance, this study stands to assess governance in public institutions making its topic ‘an
assessment of the prevalence of good governance in public institutions.’
The main objective of the study is assessing how far good governance is prevalent in public
sector institutions and the research was conducted on 11 public institutions purposefully selected
in Debre Birhan town. The study employed qualitative research methodology and data was
collected through questionnaire method and the data obtained both from public institution
employees and service users together with the information obtained through interview from
selected officials. The descriptive analysis made revealed that institutions are on the way striving
to achieve governance practically in their institutions. Based on the analysis conducted using five
core elements of good governance namely accountability, transparency, equity and equality,
effectiveness and efficiency and participation different achievements and failures were observed.
Frameworks and mechanisms for good governance implementation are found ready. The
necessity of engaging the society in full scale participation, the need for trainings, workshop,
seminars, on good governance, increasing implementing capacity of the institutions, the
necessity of using different mass medias including the regional mass medias for good
governance issues , struggling against corruptions are recommended for the failures in public
institutions in their run forward to achieve good governance
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