به نام خدا
Title: Path Planning and Ground Control Station Simulator for UAV
Authors: Alain AJAMI, JeanFrancois BALMAT, JeanPaul GAUTHIER, Thibault MAILLOT
Abstract: In this paper we present a Universal and Interoper-able Ground Control Station (UIGCS) simulator for fixed androtary wing Unmanned Aerial Vehicles (UAVs), and all types ofpayloads. One of the major constraints is to operate and man-age multiple legacy and future UAVs, taking into account thecompliance with NATO Combined/Joint Services OperationalEnvironment (STANAG 4586). Another purpose of the station isto assign the UAV a certain degree of autonomy, via autonomousplanification/replanification strategies. The paper is organizedas follows.In Section 2, we describe the non-linear models of the fixed androtary wing UAVs that we use in the simulator.In Section 3, we describe the simulator architecture, which isbased upon interacting modules programmed independently.This simulator is linked with an open source flight simulator, tosimulate the video flow and the moving target in 3D. To concludethis part, we tackle briefly the problem of the Matlab/Simulinksoftware connection (used to model the UAV_s dynamic) with thesimulation of the virtual environment.Section 5 deals with the control module of a flight path of theUAV. The control system is divided into four distinct hierarchicallayers: flight path, navigation controller, autopilot and flightcontrol surfaces controller.In the Section 6, we focus on the trajectory planifica-tion/replanification question for fixed wing UAV. Indeed, one ofthe goals of this work is to increase the autonomy of the UAV. Wepropose two types of algorithms, based upon 1) the methods ofthe tangent and 2) an original Lyapunov-type method. Thesealgorithms allow either to join a fixed pattern or to track amoving target.Finally, Section 7 presents simulation results obtained on oursimulator, concerning a rather complicated scenario of mission.
Publish Year: 2013
Published in: Aerospace - IEEE
Number of Pages: 13
موضوع: مهندسی هوافضا
ایران سای – مرجع مقالات علمی فنی مهندسی
حامی دانش بومی ایرانیان
به نام خدا
Title: The role of the atmosphere in the provision of ecosystem services
Authors: Ellen J. Cooter, Anne Rea, Randy Bruins, Donna Schwede, Robin Dennis
Abstract: Solving the environmental problems that we are facing today requires holistic approaches to analysis and decision making that include social and economic aspects. The concept of ecosystem services, defined as the benefits people obtain from ecosystems, is one potential tool to perform such assessments. The objective of this paper is to demonstrate the need for an integrated approach that explicitly includes the contribution of atmospheric processes and functions to the quantification of air–ecosystem services. First, final and intermediate air–ecosystem services are defined. Next, an ecological production function for clean and clear air is described, and its numerical counterpart (the Community Multiscale Air Quality model) is introduced. An illustrative numerical example is developed that simulates potential changes in air–ecosystem services associated with the conversion of evergreen forest land in Mississippi, Alabama and Georgia to commercial crop land. This one-atmosphere approach captures a broad range of service increases and decreases. Results for the forest to cropland conversion scenario suggest that although such change could lead to increased biomass (food) production services, there could also be coincident, seasonally variable decreases in clean and clear air–ecosystem services (i.e., increased levels of ozone and particulate matter) associated with increased fertilizer application. Metrics that support the quantification of these regional air–ecosystem changes require regional ecosystem production functions that fully integrate biotic as well as abiotic components of terrestrial ecosystems, and do so on finer temporal scales than are used for the assessment of most ecosystem services.
Publish Year: 2013
Published in: Science of The Total Environment - Science Direct
Number of Pages: 12
موضوع: حفاظت از محیط زیست
ایران سای – مرجع مقالات علمی فنی مهندسی
حامی دانش بومی ایرانیان
به نام خدا
Title: Construction of fuzzy ontologies from fuzzy XML models
Authors: Fu Zhang, Z.M. Ma, Li Yan
Abstract: The success and proliferation of the Semantic Web depends heavily on construction of Web ontologies. However, classical ontology construction approaches are not sufficient for handling imprecise and uncertain information that is commonly found in many application domains. Therefore, great efforts on construction of fuzzy ontologies have been made in recent years. In particular, XML is imposing itself as a standard for representing and exchanging information on the Web, topics related to the modeling of fuzzy data have become very interesting in the XML data context. Therefore, constructing fuzzy ontologies from fuzzy XML data resources may make the existing fuzzy XML data upgrade to Semantic Web contents, and the constructed fuzzy ontologies may be useful for improving some fuzzy XML applications.This paper proposes a formal approach and an automated tool for constructing fuzzy ontologies from fuzzy XML data resources. Firstly, we propose a formal definition of fuzzy XML models (including the document structure fuzzy DTDs and the document content fuzzy XML documents). On this basis, we propose a formal approach for constructing fuzzy ontologies from fuzzy XML models, i.e., transforming a fuzzy XML model (including fuzzy DTD and fuzzy XML document) into a fuzzy ontology. Also, we give the proof of correctness of the construction approach, and provide a detailed construction example. Furthermore, we implement a prototype tool called FXML2FOnto, which can automatically construct fuzzy ontologies from fuzzy XML models. Finally, in order to show that the constructed fuzzy ontologies may be useful for improving some fuzzy XML applications, we focus on investigating how to reason on fuzzy XML models (e.g., conformance, inclusion, and equivalence) based on the constructed fuzzy ontologies, and it turns out that the reasoning tasks of fuzzy XML models can be checked by means of the reasoning mechanism of fuzzy ontologies.
Publish Year: 2013
Published in: Knowledge-Based Systems - Science Direct
Number of Pages: 20
موضوع: XML، فازی
ایران سای – مرجع مقالات علمی فنی مهندسی
حامی دانش بومی ایرانیان
به نام خدا
Title: Structure learning for belief rule base expert system: A comparative study
Authors: Leilei Chang, Yu Zhou, Jiang Jiang, Mengjun Li, Xiaohang Zhang
Abstract: The Belief Rule Base (BRB) is an expert system which can handle both qualitative and quantitative information. One of the applications of the BRB is the Rule-base Inference Methodology using the Evidential Reasoning approach (RIMER). Using the BRB, RIMER can handle different types of information under uncertainty. However, there is a combinatorial explosion problem when there are too many attributes and/or too many alternatives for each attribute in the BRB. Most current approaches are designed to reduce the number of the alternatives for each attribute, where the rules are derived from physical systems and redundant in numbers. However, these approaches are not applicable when the rules are given by experts and the BRB should not be oversized. A structure learning approach is proposed using Grey Target (GT), Multidimensional Scaling (MDS), Isomap and Principle Component Analysis (PCA) respectively, named as GT–RIMER, MDS–RIMER, Isomap–RIMER and PCA–RIMER. A case is studied to evaluate the overall capability of an Armored System of Systems. The efficiency of the proposed approach is validated by the case study results: the BRB is downsized using any of the four techniques, and PCA–RIMER has shown excellent performance. Furthermore, the robustness of PCA–RIMER is further verified under different conditions with varied number of attributes.
Publish Year: 2013
Published in: Knowledge-Based Systems - Science Direct
Number of Pages: 14
موضوع: سیستمهای خبره
ایران سای – مرجع مقالات علمی فنی مهندسی
حامی دانش بومی ایرانیان
به نام خدا
Title: Engineering Mathematics: The Odd Order Theorem Proof
Authors: Georges Gonthier
Abstract: Even with the assistance of computer tools, the formalized description and verification of research-level mathematics remains a daunting task, not least because of the talent with which mathematicians combine diverse theories to achieve their ends. By combining tools and techniques from type theory, language design, and software engineering we have managed to capture enough of these practices to formalize the proof of the Odd Order theorem, a landmark result in Group Theory.
Publish Year: 2013
Published in: ACM-SIGPLAN-SIGACT
Number of Pages: 2
موضوع: ریاضی مهندسی
ایران سای – مرجع مقالات علمی فنی مهندسی
حامی دانش بومی ایرانیان