Sensor systems based on capacitive or inductive measurement principles usually require sophisticated analog and digital signal processing. Particularly in automotive applications, a high degree of integration with as ...
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ISBN:
(纸本)0780366468
Sensor systems based on capacitive or inductive measurement principles usually require sophisticated analog and digital signal processing. Particularly in automotive applications, a high degree of integration with as few external components as possible is desirable. We describe the design of an integrated angular speed sensor system based on a carrier frequency approach. To optimize the performance, we combined a synchronous demodulation strategy with an external resonance filter serving as clock reference and noise protection. the filter was extended by an additional lowpass easing implementation of the demodulator and compensating for internal signal delays. For system simulation, a simple analytical model based on Fourier synthesis was found to be superior to a conventional SPICE simulation.
the field of applications for smart structures based on piezoelectric devices is manifold. An advantage of this technology is that one can construct spatially distributed devices. this fact requires special control te...
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the field of applications for smart structures based on piezoelectric devices is manifold. An advantage of this technology is that one can construct spatially distributed devices. this fact requires special control techniques to use the additional freedom for the design of the overall system. the structures under consideration are composite beams and plates consisting of a large number of thin layers of laminae with and without piezoelectric properties that can be well described by Lagrangian systems. Furthermore, there exists a wide range of controller design methods. To apply this machinery, one has to derive the potentials and energy functions related to the piezoelectric structures, which is a laborious task for more complex structures. But this task can be perfectly performed by a computer algebra system. therefore, this contribution deals withthe application of the Lagrangian formalism to the modeling and design of smart piezoelectric structures, and the implementation of the proposed approach in a computer algebra system.
this study investigates the varying-order analysis based on mechanism, and realizes it in dynamic signal processing of rotary machinery. Firstly, the synthetic signatures consisting of fixed-order, varying-order compo...
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this study investigates the varying-order analysis based on mechanism, and realizes it in dynamic signal processing of rotary machinery. Firstly, the synthetic signatures consisting of fixed-order, varying-order components and resonance-related ones as well are designed to validate the developed computation schemes. Secondly, this work takes an electrical scooter as a test bench, which some experiments have been conducted on. the noise and vibration signatures are measured and processed to characterize different spectral components and identify their sources. Some of the annoying ones belong to fixed order (e.g., gear whine noise), varying order (e.g., CVT-belt noise) and structure resonance (e.g., the structure-borne noise originated from the CVT housing). therefore, the concerned noise/vibration can subsequently be coped with via machine component modification.
Sensor systems based on capacitive or inductive measurement principles usually require sophisticated analog and digital signal processing. Particularly in automotive applications, a high degree of integration with as ...
详细信息
ISBN:
(纸本)0780366468
Sensor systems based on capacitive or inductive measurement principles usually require sophisticated analog and digital signal processing. Particularly in automotive applications, a high degree of integration with as few external components as possible is desirable. We describe the design of an integrated angular speed sensor system based on a carrier frequency approach. To optimize the performance, we combined a synchronous demodulation strategy with an external resonance filter serving as clock reference and noise protection. the filter was extended by an additional low-pass easing implementation of the demodulator and compensating for internal signal delays. For system simulation, a simple analytical model based on Fourier synthesis was found to be superior to a conventional SPICE simulation.
Many boundaries impede the flow of authorization information, forcing applications that span those boundaries into hop-by-hop approaches to authorization. We present a unified approach to authorization. Our approach a...
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Many boundaries impede the flow of authorization information, forcing applications that span those boundaries into hop-by-hop approaches to authorization. We present a unified approach to authorization. Our approach allows applications that span administrative, network, abstraction, and protocol boundaries to understand the end-to-end authority that justifies any given request. the resulting distributed systems are more secure and easier to audit. We describe boundaries that can interfere with end-to-end authorization, and outline our unified approach. We describe the system we built and the applications we adapted to use our unified authorization system, and measure its costs. We conclude that our system is a practical approach to the desirable goal of end-to-end authorization.
the proceedings contain 24 papers. the topics discussed include: policies for dynamic clock scheduling;towards higher disk head utilization: extracting free bandwidth from busy disk drives;checking system rules using ...
the proceedings contain 24 papers. the topics discussed include: policies for dynamic clock scheduling;towards higher disk head utilization: extracting free bandwidth from busy disk drives;checking system rules using system-specific, programmer-written compiler extensions;a low-overhead high-performance unified buffer management scheme that exploits sequential and looping references;how to build a trusted database system on untrusted storage;taming the memory hogs: using compiler-inserted releases to manage physical memory intelligently;latency management in storage systems;surplus fair scheduling: a proportional-share CPU scheduling algorithm for symmetric multiprocessors;DEVIL: an IDL for hardware programming;performance-driven processor allocation;end-to-end authorization;system support for bandwidth management and content adaptation in internet applications;operating system management of MEMS-based storage devices;trading capacity for performance in a disk array;exploring failure transparency and the limits of generic recovery;proactive recovery in a byzantine-fault-tolerant system;and design and evaluation of a continuous consistency model for replicated services.
the tradeoffs between consistency, performance, and availability are well understood. Traditionally, however, designers of replicated systems have been forced to choose from either strong consistency guarantees or non...
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the tradeoffs between consistency, performance, and availability are well understood. Traditionally, however, designers of replicated systems have been forced to choose from either strong consistency guarantees or none at all. this paper explores the semantic space between traditional strong and optimistic consistency models for replicated services. We argue that an important class of applications can tolerate relaxed consistency, but benefit from bounding the maximum rate of inconsistent access in an application-specific manner. thus, we develop a set of metrics, Numerical Error, Order Error, and Staleness, to capture the consistency spectrum. We then present the design and implementation of TACT, a middleware layer that enforces arbitrary consistency bounds among replicas using these metrics. Finally, we show that three replicated applications demonstrate significant semantic and performance benefits from using our framework.
Opendesign is an open user-configurable project environment that supports distributed collaborative design and execution on the Internet. the environment is created by configuring a generic client for a specific proje...
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ISBN:
(纸本)0769508014
Opendesign is an open user-configurable project environment that supports distributed collaborative design and execution on the Internet. the environment is created by configuring a generic client for a specific project. this is in contrast to an implementation of a project-specific client-server architecture. this paper introduces the Opendesign environment in the context of a design process and project-specific tasks. An Opendesign task is defined as execution of one or more CAD point tools, whereas a task flow is a dependency graph of tasks and/or other task flows. Challenges arise when, within a single project, (1) tasks must be executed on remote hosts under different file systems, (2) data must be accessed, moved, modified, and archived with consistency, (3) tasks and task flows are assigned to more than one designer, and (4) designers are physically dispersed. In collaboration with peer institutions, a number of demo design projects demonstrate the features and the opportunities withthe Opendesign environment.
three-dimensional maps ale fundamental tools for presenting, exploring, cmd manipulating geo data. this paper describes multiresolution concepts for 3D maps and their texture-based design. In our approach, 3D maps are...
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ISBN:
(纸本)0769506437
three-dimensional maps ale fundamental tools for presenting, exploring, cmd manipulating geo data. this paper describes multiresolution concepts for 3D maps and their texture-based design. In our approach, 3D maps are based on a hybrid, multiresolution terrain model composed of data sets having different topological structure, for example a coarse regular grid combined with by, triangulated microstructures. Any number of texture layers can be associated,viththe terrain model. For each texture layer;the multiresolution structure builds a texture tree which is linked to geometry patches of the multiresolution terrain model. the terrain model together with multiple texture layers can be rendered in real-time, in particular if multitexturing is available. Texture layers can be combined by high-level operations such as blending and masking and can he rebuilt at run-time. this mechanism simplifies the implementation of visual exploration tools and of procedural, automated map designs. 3D maps facilitate the visual simulation of environmental issues in spatial support systems virtual,reality applications, real-time GIS, and interactive cartography.
the requirements for this processor were established using the experience of the hardware and software designers in the APL Space Department. the use of commercial hardware and software products, combined with an erro...
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the requirements for this processor were established using the experience of the hardware and software designers in the APL Space Department. the use of commercial hardware and software products, combined with an error- and fault-tolerant architecture, resulted in a low-cost design without adversely affecting overall reliability. the processor's architecture and mechanical design, and hardware and software test and validation methods are described.
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