Time-of-arrival (TOA) estimator design for impulse radio ultra-wideband (IR-UWB) ranging demands high sampling rate high resolution ADC, which is difficult to implement. Some tradeoffs can be made such as limiting amp...
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Time-of-arrival (TOA) estimator design for impulse radio ultra-wideband (IR-UWB) ranging demands high sampling rate high resolution ADC, which is difficult to implement. Some tradeoffs can be made such as limiting amplitude resolution. In this paper, we propose a two-step threshold selection TOA estimator using a two-bit ADC. the quantization threshold of ADC is set as the coarse threshold to distinguish between noise samples (NS) and signal samples (SS). Training-based Decision-Vector (DV) maximum likelihood (ML) estimation and the closed-form expression of early detection probability are presented. Based on early detection control, a simple but effective criteria to determine the fine threshold is proposed. the effects on the performance of training sequence length and coarse threshold, as well as fine threshold are simulated. It is also demonstrated that the proposed method is superior to conventional ED methods via simulation.
Moving object database is the core technology for location-based services (LBS), permitting users to pose spatial queries about the environment around them. We introduce a sensor-based LBS approach that is more econom...
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Moving object database is the core technology for location-based services (LBS), permitting users to pose spatial queries about the environment around them. We introduce a sensor-based LBS approach that is more economical and scalable for large-scale deployments supporting a large user community. We discuss this framework in the context of k-nearest-neighbor queries. We present simulation results and efficiency analysis to show the effectiveness of the proposed technique.
Efficient traffic control systems are required in towns and cities around the world. As the number of vehicles increase, and new infrastructure is less viable;high levels of mobility become essential. this work propos...
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ISBN:
(纸本)9788988678251
Efficient traffic control systems are required in towns and cities around the world. As the number of vehicles increase, and new infrastructure is less viable;high levels of mobility become essential. this work proposes a strategy for Intelligent Transportation Systems (ITS), in particular for the task of adaptive signal management. this approach is based on Complex Event Processing (CEP). Event processing provides fast assessment of the situation, due to its inherent capabilities for pattern detection and information composition. this work proposes an architectural model based on the concept of event processing networks. Our model is specifically designed to derive events obtained from loop detectors and compose enhanced signal timings, representing accurately the requirements of the roadway for signal management.
Intelligent Environments on varying scales and for different purposes are slowly becoming a reality. In the near future, global smart world infrastructures will become a commodity that will support various activities ...
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Embedded control systems in automobiles are typically implemented by a set of tasks deployed on multiple Electronic control Units (ECUs) communicating via one or more buses like CAN or FlexRay. In the case of safety-c...
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ISBN:
(纸本)9781605589046
Embedded control systems in automobiles are typically implemented by a set of tasks deployed on multiple Electronic control Units (ECUs) communicating via one or more buses like CAN or FlexRay. In the case of safety-critical systems, there are hard real-time bounds on the (i) response times of tasks/messages, and (ii) end-to-end latencies of certain task/message chains. these depend on various factors like the number of tasks (and messages) involved in the processing (and communication) sequence, parameters of these tasks/messages, scheduling policies, communication protocols, clock drifts, etc. Moreover, since the data transfer among tasks/messages is typically via asynchronous buffers that are overwritable and sticky, multiple semantics are possible for end-to-end latency. Hence, precise estimation of response times and end-to-end latencies in embedded systems is a non-trivial problem. In this paper, we propose a model-checking based technique to compute worst-case response times and end-to-end latencies. We consider a distributed system made of preemptively scheduled tasks and non-preemptively scheduled messages. Given a chain in the system, we estimate two different end-to-end latencies -LIFO and LILO- which are important in automotive domain. From a system description, we automatically synthesize a formal model based on a discrete event simulation formalism called Calendar Automata. It is then model-checked to compute response times and end-to-end latencies. Our technique is more scalable than the existing formal methods based techniques. We have illustrated this technique on reasonably large case-studies from the automotive domain.
Wireless sensor network (WSN)becomes a research hotspot of structural health monitoring(SHM) withthe characteristics such as convenience for remote monitoring, good fault-tolerant ability, easiness of system maintena...
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Wireless sensor network (WSN)becomes a research hotspot of structural health monitoring(SHM) withthe characteristics such as convenience for remote monitoring, good fault-tolerant ability, easiness of system maintenance ,etc. In this paper, a WSN for bridge SHM is designed and deployment on the ZhengDian viaduct in Wuhan. In this deployment, 20 wireless nodes are distributed over the main span, collecting the ambient vibrations at *** collected data agrees withtheoretical models and previous studies of the bridge.
this paper proposes an effective framework to boost the efficiency of covariance matching. In this framework, covariance matrices are used to match object in complex environment by fusing multiple features. then, Gene...
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this paper proposes an effective framework to boost the efficiency of covariance matching. In this framework, covariance matrices are used to match object in complex environment by fusing multiple features. then, Genetic Algorithm (GA) is employed to improve the processing speed of covariance matching. To take advantage of the property of GA for the optimization in large search spaces to covariance matching, a fitness function is designed using the distances between the covariance matrices of model and candidate regions. Experimental results show that the proposed approach can improve the processing speed of covariance matching observably. the computing speed of the proposed method is at least 7 times than that of exhaustive searching.
Spectrogram is a main analysis method of audio signals and other similar quasi - stationary ones and produces a time-frequency portrait of a signal. this paper researches correspondence between important time-frequenc...
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Spectrogram is a main analysis method of audio signals and other similar quasi - stationary ones and produces a time-frequency portrait of a signal. this paper researches correspondence between important time-frequency structures and music representations of vocal performance, aiming at providing quantitative analysis and objective information description of the subjective perception of specific voice techniques. Experiments and vocal music examples reveal and indicate that spectrogram is a powerful tool for aiding the study, comprehension, and interpretation of musical expression.
Self-organization in learning systems refers to the ability of the system to adapt and respond data as it is presented without outside intervention. the ability to self-organize is desirable and is critical in realizi...
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this paper describes the design of simulation software and control system for mechanism with hybrid kinematic structure (HKS) called trivariant which were realized on the workplace of authors. Designed simulation soft...
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this paper describes the design of simulation software and control system for mechanism with hybrid kinematic structure (HKS) called trivariant which were realized on the workplace of authors. Designed simulation software allows the movement simulation of HKS as a machine tool with five degrees of freedom (DOF) or as a robot with six DOF. Both modifications can be simulated in manual or in automatic mode too. For the calculation of joint coordinates was necessary to create the mathematical model of mechanism. Simulation software was designed in programming language Delphi with support of OpenGL library. the control system for trivariant is based on standard PC which is connected to the mechanism by communication module. For practical functional verification of simulation SW and control system was built a real prototype.
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