Although invented over 40 years ago and studied by many researchers, Rotman lenses have not seen widespread use in military or commercial applications. This may be due in large part to their time-consuming and tedious...
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ISBN:
(纸本)9781424420414
Although invented over 40 years ago and studied by many researchers, Rotman lenses have not seen widespread use in military or commercial applications. This may be due in large part to their time-consuming and tedious implementation. In this paper, we suggest tools to semi-automate and speed up the Rotman lens design process, allowing researchers to rapidly iterate designs or produce studies that span multiple design parameters. As guidance for the analysis of these lenses, we describe methods for measuring or simulating insertion loss and beam efficiency of the entire lens. These are real-world characteristics that must be assessed and optimized if Rotman lenses are to contend with other phase-shifting devices for military or commercial use.
Complex dialogs with comprehensive underlying data models are gaining increasing importance in todaypsilas Web applications. This in turn accelerates the need for highly dynamic dialogs offering guidance to the users ...
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ISBN:
(纸本)9780769532615;9780769534206
Complex dialogs with comprehensive underlying data models are gaining increasing importance in todaypsilas Web applications. This in turn accelerates the need for highly dynamic dialogs offering guidance to the users and reducing cognitive overload. Beyond that, requirements from the fields of Web accessibility, platform-independence and Web service integration arise. Considering the resulting complexity, a systematic engineering approach becomes important. Besides addressing the specific characteristics of these dialogs, key success factors from a communication perspective like strong user involvement and clear business objectives must be taken into account. To this end, we present an evolutionary, extensible approach for the model-driven construction of advanced dialogs which is based on a Domain-specific Language (DSL). We introduce a modeling notation based on Petri net constructs and XForms as well as a supporting Web-based editor, both focusing on simplicity and fostering communications. The technical framework allows for quick prototyping and flexible changes. In conclusion, complex, device-independent dialogs with rich behavior and appearance can be constructed and evolved with intense stakeholder collaboration.
We propose a generally applicable method for the tracking of ground vehicles by aerial vehicles. The method does not require any modifications to the guidance and control of the UAV. It only requires the capability to...
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ISBN:
(纸本)9781424420780
We propose a generally applicable method for the tracking of ground vehicles by aerial vehicles. The method does not require any modifications to the guidance and control of the UAV. It only requires the capability to follow waypoint commands. Sensing of ground vehicle position with significant time delays is assumed. The delays model the time of image processing, and the communication delays involved in sending data to a ground station, performing the computations and receiving the results on the UAV. Variants of the method have been tested successfully on the field and may see widespread deployment.
Whilst the argument for equivalent levels of rigour being applied to Safety and Human Computer Interaction (HCI) in defence, is generally well recognised, it is the authors opinion and experience that this is rarely t...
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Whilst the argument for equivalent levels of rigour being applied to Safety and Human Computer Interaction (HCI) in defence, is generally well recognised, it is the authors opinion and experience that this is rarely the case and this could be due to the lack of guidance and collaboration between HCI and Safety guidance and communities. This paper will compare the confidence levels defined in Def Stan 00-56, Issue 4 [3] along with the equivalent Safety Integrity Levels (SILs) in IEC 61508 [2] and discuss the need for the consideration of HCI issues within the confidence levels commensurate with the level of safety risk within the defence domain.
The purposes of this article are twofold. First, it considers the policy links between guidance and lifelong learning, highlighting in particular the implications of findings from a recent study by the Organisation fo...
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The purposes of this article are twofold. First, it considers the policy links between guidance and lifelong learning, highlighting in particular the implications of findings from a recent study by the Organisation for Economic Co-operation and Development (OECD). Secondly, it critically compares two approaches to workplace guidance about education and training, drawing upon evaluations of various initiatives organized by trade unions and employers in Denmark and the UK. These evaluations are based on qualitative data collected from in-depth interviews with those responsible for organizing and giving the guidance, as well as those who received it. Five interviews were conducted with recipients of guidance in each country, either face-to-face or by telephone, using a semi-structured interview schedule. The conclusions suggest some issues that need to be addressed by guidance practitioners and policy makers, including employers and trade unions.
Scientists in the pharmaceutical industry have ready access to samples from animal toxicology studies carefully designed to test the safety characteristics of a steady pipeline of agents advancing toward clinical test...
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Scientists in the pharmaceutical industry have ready access to samples from animal toxicology studies carefully designed to test the safety characteristics of a steady pipeline of agents advancing toward clinical testing. Applications of toxicogenomics to the evaluation of compounds could best be realized if this promising technology could be implemented in these studies fully anchored in the traditional study end points currently used to characterize phenotypic outcome and to support the safe conduct of clinical testing. Regulatory authorities worldwide have declared their support for toxicogenomics and related technological tools to positively impact drug development, and guidance has been published. However, applications of exploratory “omics” technologies to compounds undergoing safety testing remain inhibited due to two core data submission responsibility implications and ambiguities: (1) constraints arising from continual literature surveillance and data reanalysis burdens, under the shadow of looming subsequent reporting requirements to regulatory authorities as gene expression end points loosely linked to safety gain attention in the published literature, and (2) ambiguities in interpretation of validation stature remain between exploratory, probable valid, and known valid safety biomarkers. A proposal is offered to address these regulatory implementation barriers to open access for exploring this technology in prospective drug development animal toxicology studies. less
GNC algorithms are evolved from linear optimal control theory. This approach accommodates simple target maneuvers;however, these approaches lack robustness when advanced threats with intelligent target maneuvers are e...
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ISBN:
(纸本)0819457981
GNC algorithms are evolved from linear optimal control theory. This approach accommodates simple target maneuvers;however, these approaches lack robustness when advanced threats with intelligent target maneuvers are encountered. Kalman filters (KF) and Extended Kalman filters (EKF) require a priori defined models or equations of motion for objects being observed. Data Modeling autonomously assesses physical characteristics of a tracked object from only its measured motion. Estimates of object's mass, equivalent area, and probable control feedback loop parameters are obtained. These equations become state and process models for Kalman filters.
In this paper, the decision parts of a launch rocket—guidance law (GL) and autopilot—are discussed. In the controller design, the differential geometry and sliding mode control are employed. In addition to the indiv...
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In this paper, the decision parts of a launch rocket—guidance law (GL) and autopilot—are discussed. In the controller design, the differential geometry and sliding mode control are employed. In addition to the individual GL and autopilot system, stability of the integrated guidance/autopilot (G/A) system are discussed. Finally, various simulations are demonstrated to examine the feasibility and performance of the rocket's integrated G/A system.
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