A Survey on Service Creation by End Users

We conducted a survey on end users' willingness and capability to create their desired communication services. The survey is based on the graphical service creation tool we implemented for the Language for End System Services (LESS). We call the tool CUTE, which stands for Columbia University Telecommunication service Editor. This report demonstrates our survey result and shows that relatively inexperienced users are willing and capable to create their desired communication services, and CUTE fits their needs

Service Learning in Internet Telephony

Internet telephony can introduce many novel communication services, however, novelty puts learning burden on users. It will be a great help to users if their desired services can be created automatically. We developed an intelligent communication service creation environment which can handle automatic service creation by learning from users' daily communication behaviors. The service creation environment models communication services as decision trees and uses the Incremental Tree Induction (ITI) algorithm for decision tree learning. We use Language for End System Services (LESS) scripts to represent learned results and implemented a simulation environment to verify the learning algorithm. We also noticed that when users get their desired services, they may not be aware of unexpected behaviors that the serivces could introduce, for example, mistakenly rejecting expected calls. In this paper, we also did a comprehensive analysis on communication service fail-safe handling and propose several approaches to create fail-safe services

Modelling and Linear Control of a Buoyancy-Driven Airship

International audienceWe describe the modelling and control of a newkind airship which is propelled by buoyancy. Based on the Newton-Euler equations and Kirchhoff equations, and referred to the models of underwater gliders and aircraft, a 6DOF nonlinear mathematical model of a buoyancy-driven airship is derived, with features distributed internal mass, and no thrust, elevators and rudders. The attitudes are controlled by the motion of internal mass. The performances of the airship are studied in the vertical plane. A linear feedback controller is derived for the nonlinear model. The results of simulation display robustness properties of the controllers to disturbances

VoIP-based Air Traffic Controller Training

Extending VoIP beyond the Internet telephony, we propose a case study of applying the technology outside of its intended domain, to solve a real-world problem. This work is an attempt to understand an analog hardwired communication system of the U.S. Federal Aviation Administration (FAA), and effectively translate it into a generic, standards-based VoIP system that runs on their existing data network. We develop insights into the air traffic training and weigh on the design choices for building a soft real-time data communication system. We also share our real-world deployment and maintenance experiences, as the FAA Academy has been successfully using this VoIP system in five training rooms since 2006 to train the future air traffic controllers of the U.S. and the world

Modélisation et Commande d’un Dirigeable Propulsé par la Force de Flottabilité

A new concept of airship without thrust, elevator or rudder is considered in this thesis. It is actuatedby a moving mass and a mass-adjustable internal air bladder. This results into the motion ofthe center of gravity and the change of the net lift. The development of this concept of airship ismotivated by energy saving. An eight degrees-of-freedom complete nonlinear mathematical model ofthis airship is derived through the Newton-Euler approach. The interconnection between the airship’srigid body and the moveable mass is clearly presented. The dynamics in the longitudinal plane is analyzedand controlled through a LQR method, an input-output feedback linearization, and the maximalfeedback linearization with internal stability. Thanks to maximal feedback linearization, an efficientnonlinear control is derived. In this process, modelling, analysis, and control are solved for specialcases of the airship, which become gradually closer to the most general model. The most constrainedspecial case reduces to a two degree-of-freedom system. It is shown that the basic properties of thistwo DOF mechanical system remain instrumental for the analysis and synthesis of advanced airshipmodels. These properties are far from being obvious from the most complex model. Through a singularperturbation approach, the superposition of the two control actions in the longitudinal plane andin the lateral plane is shown to achieve the control of the dynamics in three dimension.Un nouveau concept de dirigeable est considéré dans cette thèse. Une commande non linéaire est mise en oeuvre, fondée sur la linéarisation maximale de la dynamique

Programmable Conference Server

Conferencing services for Internet telephony and multimedia can be enhanced by the integration of other Internet services, such as instant messaging, presence notification, directory lookups, location sensing, email and web. These services require a service programming architecture that can easily incorporate new Internet services into the existing conferencing functionalities, such as voice-enabled conference control. W3C has defined the Call Control eXtensible Markup Language (CCXML), along with its VoiceXML, for telephony call control services in a point-to-point call. However, it cannot handle other Internet service events such as presence enabled conferences. In this paper, we propose an architecture combining VoiceXML with our Language for End System Services (LESS) and the Common Gateway Interface (CGI) for multi-party conference service programming that integrates existing Internet services. VoiceXML provides the voice interface to LESS and CGI scripts. Our architecture enables many novel services such as conference setup based on participant location and presence status. We give some examples of the new services and describe our on-going implementation

Nonlinear Control of a Buoyancy Driven Airship

International audienceThe control of a new kind of airship is presented. By restricting its flight to a vertical plane, the athematical model is reduced. The simplified model is proved to be minimum phase, and a nonlinear controller based on inputoutput linearization is designed. Since the performance of the controller is significantly impacted by the choice of parameters, simulations of three different pole placement strategies are presented. The nonlinear controller shows better performances than a linear LQR controller when the initial condition is significantly away from the desired equilibrium

6-Oxo-5-[(trifluoro­meth­yl)sulfon­yl]-1,2,4a,5,6,11b-hexa­hydro-1,3-dioxolo[4,5-j]phenanthridin-2-yl benzoate

In the title compound, C22H16F3NO7S, the two benzene rings are almost perpendicular, the dihedral angle between their mean planes being 87.1 (1)°. The terminal O atom of the benzoate moiety is disordered over two positions with site occupancies of 0.244 (15) and 0.756 (15). The crystal structure is stablized by two types of weak inter­molecular C—H⋯O hydrogen bonds