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991.
Nicolás Peña David Scarlatti Aníbal Ollero 《Journal of Intelligent and Robotic Systems》2009,54(1-3):39-59
The System Wide Information Management (SWIM) approach has been conceived to overcome the capacity and flexibility limitations of the current ATM systems. On the other hand the commercial applications of Unmanned Aerial Vehicles (UAVs) require the integration of these vehicles in the ATM. From this perspective, the unavoidable modernization of the ATM is seen as an opportunity to integrate the UAVs with the rest of the air traffic. This paper is devoted to study the feasibility and impact of the aggregation of UAVs on the future ATM supported by a SWIM inspired architecture. Departing from the existing technical documents that describe the fundamentals of SWIM we have explored the compatibility with a potential UAVs integration and also explored how the UAVs could help to improve the future ATM system. We will use the weather application as an example in both cases. 相似文献
992.
Donato Di Paola David Naso Biagio Turchiano Grazia Cicirelli Arcangelo Distante 《Journal of Intelligent and Robotic Systems》2009,56(5):513-541
This paper focuses on the control system for an autonomous robot for the surveillance of indoor environments. Our approach
proposes a matrix-based formalism which allows us to merge in a single framework discrete-event supervisory control, conflict
resolution and reactive control. As a consequence, the robot is able to autonomously handle high level tasks as well as low-level
behaviors, solving control and decision-making issues simultaneously. Moreover, the matrix-based controller is modular and
can be easily reconfigured if mission characteristics or robot hardware configuration change. An illustrative example and
a report on experimental investigations are provided to illustrate the main features of the proposed approach. 相似文献
993.
Detection of sulfur dioxide (SO2) at high temperature (600–750 °C) in the presence of some interferents found in combustion exhausts (NO2, NO, CO2, CO, and hydrocarbon (C3H6)) is described. The detection scheme involves use of a catalytic filter in front of a non-Nernstian (mixed-potential) sensing element. The catalytic filter was a Ni:Cr powder bed operating at 850 °C, and the sensing elements were pairs of platinum (Pt) and oxide (Ba-promoted copper chromite ((Ba,Cu)xCryOz) or Sr-modified lanthanum ferrite (LSF)) electrodes on yttria-stabilized zirconia. The Ni:Cr powder bed was capable of reducing the sensing element response to NO2, NO, CO, and C3H6, but the presence of NO2 or NO (“NOx”, at 100 ppm by volume) still interfered with the SO2 response of the Pt–(Ba,Cu)xCryOz sensing element at 600 °C, causing approximately a 7 mV (20%) reduction in the response to 120 ppm SO2 and a response equivalent to about 20 ppm SO2 in the absence of SO2. The Pt–LSF sensing element, operated at 750 °C, did not suffer from this NOx interference but at the cost of a reduced SO2 response magnitude (120 ppm SO2 yielded 10 mV, in contrast to 30 mV for the Pt-(Ba,Cu)xCryOz sensing element). The powder bed and Pt–LSF sensing element were operated continuously over approximately 350 h, and the response to SO2 drifted downward by about 7%, with most of this change occurring during the initial 100 h of operation. 相似文献
994.
David Longinotti 《Minds and Machines》2009,19(4):495-506
Computationalism, a specie of functionalism, posits that a mental state like pain is realized by a ‘core’ computational state
within a particular causal network of such states. This entails that what is realized by the core state is contingent on events
remote in space and time, which puts computationalism at odds with the locality principle of physics. If computationalism
is amended to respect locality, then it posits that a type of phenomenal experience is determined by a single type of computational
state. But a computational state, considered by itself, is of no determinate type—it has no particular symbolic content, since
it could be embedded in any of an infinite number of algorithms. Hence, if locality is respected, then the type of experience
that is realized by a computational state, or whether any experience at all is realized, is under-determined by the computational
nature of the state. Accordingly, Block’s absent and inverted qualia arguments against functionalism find support in the locality
principle of physics. If computationalism denies locality to avoid this problem, then it cannot be considered a physicalist
theory since it would entail a commitment to phenomena, like teleological causation and action-at-a-distance, that have long
been rejected by modern science. The remaining theoretical alternative is to accept the locality principle for macro events
and deny that formal, computational operations are sufficient to realize a phenomenal mental state. 相似文献
995.
A formalism to describe design patterns based on role concepts 总被引:1,自引:0,他引:1
996.
Magnetic materials used in cored microinductors to supersede ferrite in the 0.5-10 MHz frequency range are investigated in
this article. The performance of electrodeposited nickel–iron, cobalt–iron–copper alloys and the commercial alloy Vitrovac
6025 have been assessed through their inclusion within a custom-made solenoid microinductor. Although the present inductor
achieves 77% power efficiency at 500 KHz for 24.7 W/cm3 power density, an optimized process predicts a power efficiency of
97% for 30.83 W/cm3 power density. The main issues regarding microinductor design and performance are discussed. 相似文献
997.
A six-degree-of-freedom slider dynamic simulator is developed to analyze the slider’s motion in the vertical, pitch, roll, yaw, length and width directions. The modified time-dependent Reynolds equation is used to model the air bearing and a new second order slip model is used for a bounded contact air bearing pressure. The simulator considers the air bearing shear acting on the air bearing surface and the slider–disk contact and adhesion. Simulation results are analyzed for the effects of the disk surface micro-waviness and roughness, skew angle, slider–disk friction and micro-trailing pad width on the vertical bouncing, down-track and off-track vibrations of a micro-trailing pad partial contact slider. 相似文献
998.
David Basin Manuel Clavel Jürgen Doser Marina Egea 《Information and Software Technology》2009,51(5):815-831
We have previously proposed SecureUML, an expressive UML-based language for constructing security-design models, which are models that combine design specifications for distributed systems with specifications of their security policies. Here, we show how to automate the analysis of such models in a semantically precise and meaningful way. In our approach, models are formalized together with scenarios that represent possible run-time instances. Queries about properties of the security policy modeled are expressed as formulas in UML’s Object Constraint Language. The policy may include both declarative aspects, i.e., static access-control information such as the assignment of users and permissions to roles, and programmatic aspects, which depend on dynamic information, namely the satisfaction of authorization constraints in a given scenario. We show how such properties can be evaluated, completely automatically, in the context of the metamodel of the security-design language. We demonstrate, through examples, that this approach can be used to formalize and check non-trivial security properties. The approach has been implemented in the SecureMOVA tool and all of the examples presented have been checked using this tool. 相似文献
999.
Previous research has identified user concerns about biometric authentication technology, but most of this research has been
conducted in European contexts. There is a lack of research that has investigated attitudes towards biometric technology in
other cultures. To address this issue, data from India, South Africa and the United Kingdom were collected and compared. Cross-cultural
attitudinal differences were seen, with Indian respondents viewing biometrics most positively while respondents from the United
Kingdom were the least likely to have a positive opinion about biometrics. Multiple barriers to the acceptance of biometric
technology were identified with data security and health and safety fears having the greatest overall impact on respondents’
attitudes towards biometrics. The results of this investigation are discussed with reference to Hofstede’s cultural dimensions
and theories of technology acceptance. It is argued that contextual issues specific to each country provide a better explanation
of the results than existing theories based on Hofstede’s model. We conclude that cultural differences have an impact on the
way biometric systems will be used and argue that these factors should be taken into account during the design and implementation
of biometric systems. 相似文献
1000.
Juan Gabriel Brida David Matesanz Gómez Wiston Adrián Risso 《Expert systems with applications》2009,36(4):7721-7728
In this paper we introduce a new method to describe dynamical patterns of the real exchange rate co-movements time series and to analyze contagion in currency crisis. The method combines the tools of symbolic time series analysis with the nearest neighbor single linkage clustering algorithm. Data symbolization allows us obtaining a metric distance between two different time series that is used to construct an ultrametric distance. By analyzing the data of various countries, we derive a hierarchical organization, constructing minimal-spanning and hierarchical trees. From these trees we detect different clusters of countries according to their proximity. We show that this methodology permits us to construct a structural and dynamic topology that is useful to study interdependence and contagion effects among financial time series. 相似文献