50 research outputs found
Tracking Performance of the Scintillating Fiber Detector in the K2K Experiment
The K2K long-baseline neutrino oscillation experiment uses a Scintillating
Fiber Detector (SciFi) to reconstruct charged particles produced in neutrino
interactions in the near detector. We describe the track reconstruction
algorithm and the performance of the SciFi after three years of operation.Comment: 24pages,18 figures, and 1 table. Preprint submitted to NI
A review on system architectures for sensor fusion applications
Abstract. In the literature there exist many proposed architectures for sensor fusion applications. This paper briefly reviews some of the most common approaches, i. e., the JDL fusion architecture, the Waterfall model, the Intelligence cycle, the Boyd loop, the LAAS architecture, the Omnibus model, Mr. Fusion, the DFuse framework, and the Time-Triggered Sensor Fusion Model, and categorizes them into abstract models, generic and rigid architectures. While an abstract model does not guide the designer in the concrete implementation, the generic architectures provide a generic design but leave open several design decisions regarding operating system, hardware, communication system, or database system. Rigid architectures specify at least some of these aspects and therefore provide existing hardware designs, tools, and source code at the cost of flexibility.
Localized Ensemble Kalman Dynamic Data Assimilation for Atmospheric Chemistry
The task of providing an optimal analysis of the state of the atmosphere requires the development of dynamic data-driven systems (DDDAS) that efficiently integrate the observational data and the models. Data assimilation, the dynamic incorporation of additional data into an executing application, is an essential DDDAS concept with wide applicability. In this paper we discuss practical aspects of nonlinear ensemble Kalman data assimilation applied to atmospheric chemical transport models. We highlight the challenges encountered in this approach such as filter divergence and spurious corrections, and propose solutions to overcome them, such as background covariance inflation and filter localization. The predictability is further improved by including model parameters in the assimilation process. Results for a large scale simulation of air pollution in North-East United States illustrate the potential of nonlinear ensemble techniques to assimilate chemical observations
Localized Ensemble Kalman Dynamic Data Assimilation for Atmospheric Chemistry
The task of providing an optimal analysis of the state of the atmosphere requires the development of dynamic data-driven systems (DDDAS) that efficiently integrate the observational data and the models. Data assimilation, the dynamic incorporation of additional data into an executing application, is an essential DDDAS concept with wide applicability. In this paper we discuss practical aspects of nonlinear ensemble Kalman data assimilation applied to atmospheric chemical transport models. We highlight the challenges encountered in this approach such as filter divergence and spurious corrections, and propose solutions to overcome them, such as background covariance inflation and filter localization. The predictability is further improved by including model parameters in the assimilation process. Results for a large scale simulation of air pollution in North-East United States illustrate the potential of nonlinear ensemble techniques to assimilate chemical observations
Um sistema de controle da produção para a manufatura celular parte I: sistema de apoio à decisão para a elaboração do programa mestre de produção A production control system to the cellular manufacturing part I: decision support system for elaborating the master production scheduling
Este artigo e mais o artigo Parte II (Emissão de Ordens e Programação de Operações) fazem parte de um trabalho que visa integrar todas as atividades de programação da produção dentro do contexto de um Sistema de Controle da Produção, concebido para operar na manufatura celular semi-repetitiva. Para deixarmos claro o que entendemos por manufatura celular semi-repetitiva fazemos uma classificação dos sistemas de produção e uma taxonomia da manufatura celular. O sistema proposto foi concebido e implementado computacionalmente em 3 módulos (nível de produto final, de componentes e de operações). O primeiro é tratado neste artigo (Parte I), enquanto que outros dois módulos são tratados no outro artigo (Parte II).<br>This paper and that of Part II (ordering system and operations scheduling) aims to integrate all production scheduling activities in a semi-repetitive cellular manufacturing environment. With the aim of clarifying what we mean by semi-repetitive cellular manufacturing, we have made a production systems classification and a cellular manufacturing taxonomy. The proposed system was conceptualized and computationally implemented in three modules (product, component and operation levels). The first level is treated in this paper and the other two are treated in the Part II
Convex Cones, Lyapunov Functions, and the Stability of Switched Linear Systems
Recent research on switched and hybrid systems has resulted
in a renewed interest in determining conditions for the existence of a
common quadratic Lyapunov function for a finite number of stable LTI
systems. While efficient numerical solutions to this problem have existed
for some time, compact analytical conditions for determining whether or
not such a function exists for a finite number of systems have yet to be
obtained. In this paper we present a geometric approach to this problem.
By making a simplifying assumption we obtain a compact time-domain
condition for the existence of such a function for a pair of LTI systems.
We show a number of new and classical Lyapunov results can be obtained
using our framework. In particular, we demonstrate that our results can
be used to obtain compact time-domain versions of the SISO Kalman-
Yacubovich-Popov lemma, the Circle Criterion, and stability multiplier
criteria. Finally, we conclude by posing a number of open questions that
arise as a result of our approach