In this paper, a modified receding horizon guidance law (MRHG) is proposed which can be a proper guidance law when the accurate time-to-go is available only for a short time before the final time. In the proposed MRHG...
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In this paper, a modified receding horizon guidance law (MRHG) is proposed which can be a proper guidance law when the accurate time-to-go is available only for a short time before the final time. In the proposed MRHG, RHG is used before the accurate time-to-go is available and after that, OGL is used until the missile intercepts the target using the accurate time-to-go given for a short time. The proposed MRHG makes the lateral miss distance (MD) below the pre-described value before the accurate time-to-go is available and makes the terminal MD zero using the accurate time-to-go even in the presence of target maneuvers and an initial relative normal velocity between the target and the missile. Through simulation, the performance of MRHG is illusrtated in terms of the terminal MD the lateral MD and the missile normal acceleration.
The scientific approach toward ecological risk assessment (ERA) has advanced greatly during the 1990s. This growth has been accompanied by the development of ERA guidance by USEPA Headquarters, individual USEPA Region...
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The scientific approach toward ecological risk assessment (ERA) has advanced greatly during the 1990s. This growth has been accompanied by the development of ERA guidance by USEPA Headquarters, individual USEPA Regions, state environmental agencies, as well as international agencies. This compilation of ERA guidance and procedural documents identifies many of the existing ERA reference materials from the regulatory and/or governmental agency arena. In addition, this compilation provides annotations pertaining to the focus of each reviewed document, and compares/contrasts the approaches presented in the documents. As such, the evaluation provides insight into some of the qualities and levels of detail provided by each document. Examples of documents which are highlighted include recently published USEPA's "Guidelines for Ecological Risk Assessment;" USEPA's "Ecological Risk Assessment guidance for Superfund;" the U.S. Army's "Procedural Guidelines for Ecological Risk Assessments;" and Environment Canada's "Ecological Risk Assessments Under the Canadian Environmental Protection Act."
In order to achieve a new minimum energy interception of an arbitrarily maneuvering vehicle a nonlinear modal is first approximated by a series of local linear models using an on-line linearizing method for some state...
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In order to achieve a new minimum energy interception of an arbitrarily maneuvering vehicle a nonlinear modal is first approximated by a series of local linear models using an on-line linearizing method for some state variables, and then from the derived local linear models a new optimal strategy is developed using the receding horizon concept and associated techniques. That evader maneuvering in a small scope can be dealt with by the correspoding local linear model, and its maneuverring in a large scope is handled by model switching among a series of local linear models. Simulation results show that tile system designed in this way can intercept a randomly maneuvering evader.
Considering the nonlinear model between a realistic missile and an aircraft in three-dimensions, one minimun energy guidance law is obtained. By employing the linearizing method, an efficient and robust guidance law f...
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Considering the nonlinear model between a realistic missile and an aircraft in three-dimensions, one minimun energy guidance law is obtained. By employing the linearizing method, an efficient and robust guidance law for intercepting randomly maneuvering evader is derived. A new approach to pursuit-evasion problem in two-dimensions and three-dimensions is provided, which can deal with the randomly maneuvering evader in time. Numerical simulations denote that the system designed by this method can cut down the miss distance remarkably.
We present a guidance system for blind people exploring tactile graphics. The system is composed of a new device using 8 vibrating elements to output directional information and a guidance software controlling the dev...
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ISBN:
(纸本)9781581130201
We present a guidance system for blind people exploring tactile graphics. The system is composed of a new device using 8 vibrating elements to output directional information and a guidance software controlling the device. The evaluation of the system is also described.
Active components are starting to become accepted within railway vehicle suspension systems which have been exclusively mechanical since railways began in the 1800s. At the moment these are principally being applied i...
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Active components are starting to become accepted within railway vehicle suspension systems which have been exclusively mechanical since railways began in the 1800s. At the moment these are principally being applied in tilting trains, but opportunities which arise from applying control systems engineering to railway suspensions extend much further, and this is the first of two articles which explore such possibilities. Part 1 concentrates on control approaches which are mainly concerned with passenger comfort-active tilting technology which enables trains to go faster around curves without passengers experiencing the higher curving accelerations, and active secondary suspensions which also improve the essential ride quality on straight track.
Laminin-1 is a glycoprotein found in the basement membrane of many tissues. In the cerebellum of rodents, it has also been localized along Bergmann glial fibers, where it is thought to be involved in promoting granule...
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A technique has been developed to localise the path of an ultrasound pulse, launched from a transmitting transducer and travelling within a scattering medium, utilising a separate receiving transducer to detect off-ax...
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A technique has been developed to localise the path of an ultrasound pulse, launched from a transmitting transducer and travelling within a scattering medium, utilising a separate receiving transducer to detect off-axis scattered energy. The operation of the two transducers enables a locus of the sites of detected signals, across a range of angles, to be generated. Two different mathematical approaches were investigated for the analysis of these data, and their relative success quantified. It was found that it was possible to determine the parameters defining the orientation of the beam, by fitting the data to an appropriately formed equation. A clinical application of the technique would be the visualisation of a therapeutic beam, operating initially at relatively low intensity, on a B-mode image. This would enable accurate positioning of its focus in the region of interest, prior to the application of therapeutic intensity levels and the formation of lesions. Similarly, a guidance system for the insertion of a biopsy needle into soft tissues could be developed with this technique and a low intensity path-finding beam. (C) 1999 Elsevier Science B.V. All rights reserved.
Enterprise Knowledge Development (EKD) is a method for reasoning on change in organisations. It tackles different aspects of organisations: who does what, how and why. Applying EKD is an iterative, non-linear and guid...
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Enterprise Knowledge Development (EKD) is a method for reasoning on change in organisations. It tackles different aspects of organisations: who does what, how and why. Applying EKD is an iterative, non-linear and guided process. guidance is based on a decision making pattern that promotes a situation and decision-oriented view. The claim is that EKD engineers are repeatedly faced with situations that need them to make decisions. Thanks to the use of the decision making pattern together with domain specific, EKD specific or generic knowledge, the Ego process systematically provides guidance. Generic guidance is the default option that includes the co-operative aspects of decision making. (C) 1999 Elsevier Science B.V. All rights reserved.
Electrodynamic systems (EDS's) for maglev have an advantage over electromagnetic systems (EMS's) in that the stability is built into the system. EDS's induce the currents used for levitation and guidance, ...
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Electrodynamic systems (EDS's) for maglev have an advantage over electromagnetic systems (EMS's) in that the stability is built into the system. EDS's induce the currents used for levitation and guidance, while EMS's impose those currents with controlled feedback, The movement of a magnet over properly designed EDS coils results in forces to keep the system fixed in the lowest energy or null flux spot. In the past such systems have been examined through two-dimensional boundary element techniques [1], [2], An approximation to the full three-dimensional time harmonic problem is obtained through Laplace transform theory after using boundary element methods to predict the mutual coupling of the magnets with the track coils. The analytic solution offers helpful design and operation guidelines.
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