The paper is concerned with the problem of tracking a manoeuvring target. The error monitoring and recovery technique of the perception net is utilised to improve the tracking performance for a highly manoeuvring targ...
详细信息
The paper is concerned with the problem of tracking a manoeuvring target. The error monitoring and recovery technique of the perception net is utilised to improve the tracking performance for a highly manoeuvring target. The interacting multiple model (IMM) filter is well known as being the most cost-effective hybrid-state estimation sch.me. Both the detection of a manoeuvring target and the compensation of the estimated state can be achieved by employing a properly implemented error monitoring and recovery technique. IMM and full IMMPDA filters which employ an error monitoring and recovery technique show a better tracking performance compared with the conventional IMM and IMMPDA filters for a highly manoeuvring target, even in a clutter environment. They also reduce the peak values of the estimation errors when manoeuvring starts and finishes. The effectiveness of the proposed method is validated through simulations by comparing it with a conventional IMM filter. A similar evaluation is performed for a conventional IMMPDA filter.
In contrast to sequential computation, concurrent computation gives rise to parallel events. Efforts to translate the history of concurrent computations into sequential event traces result in the potential uncertainty...
详细信息
In contrast to sequential computation, concurrent computation gives rise to parallel events. Efforts to translate the history of concurrent computations into sequential event traces result in the potential uncertainty of the observed order of these events. Loosely coupled distributed systems complicate this uncertainty even further by introducing the element of multiple imperfect observers of these parallel events. Properties of such systems are difficult to reason about and, in some cases, attempts to prove safety or liveness lead to ambiguities. The authors present a survey of challenges of reasoning about properties of concurrent systems. They then propose a new approach, view-centric reasoning, that avoids the problem of translating concurrency into a sequential representation. Finally, they demonstrate the usefulness of view-centric reasoning as a framework for disambiguating the meaning of Tuple Space predicate operations, versions of which exist commercially in IBM's T Spaces and Sun's JavaSpaces.
Signal subspace methods in DOA estimation for wideband sources require preprocessing to find initial values which are close enough to the true values or to convert sensor outputs into desired forms. The preprocessing ...
详细信息
Signal subspace methods in DOA estimation for wideband sources require preprocessing to find initial values which are close enough to the true values or to convert sensor outputs into desired forms. The preprocessing procedure should be carefully done lest it introduce some distortion. Failure to find proper initial values may prevent convergence of the estimator or cause biases in the estimator. The proposed method detects uncorrelated wideband sources using the signal subspace and the noise subspace of decomposed wideband signals. It does not require any initial values. The only preprocessing is narrowband decomposition of the sensor output which is very common in other wideband methods. computer simulation showed that the proposed method has less bias and comparable variance than CSSM with small focussing errors.
We describe a property-based test generation procedure for synchronous sequential circuits. Several techniques are used to generate test sequences that achieve high fault coverages at low computational complexity. The...
详细信息
We describe a property-based test generation procedure for synchronous sequential circuits. Several techniques are used to generate test sequences that achieve high fault coverages at low computational complexity. These include the use of static test compaction, input vector holding with optimal numbers of hold cycles, input vector perturbation, and identification of subsequences that are useful in extending the test sequence. Experimental results presented demonstrate that the proposed procedure achieves fault coverages which are in all cases the same or higher than those achieved by existing procedures.
A short monopole antenna top-loaded with a one-point-open rectangular wire loop is investigated. The antenna is located on an infinite ground plane. The return loss characteristics are calculated by the method of mome...
A short monopole antenna top-loaded with a one-point-open rectangular wire loop is investigated. The antenna is located on an infinite ground plane. The return loss characteristics are calculated by the method of moments with respect to the size of the loop, the height of the monopole, the position of the open point on the loop and the connecting position of the monopole with the loop. The return loss becomes -15dB that is a big improvement from -3dB without the open point. The return loss bandwidth ( less than or equal -10dB) is 8%. The maximum gain in the horizontal direction becomes 6.63dBi with an open point from 5.24dBi without it.
The Design of Experiment approach (DoE) and an elec.romagnetic full-wave solver are combined in a single algorithm in order to produce parametric model of planar microwave and millimeter wave components. The DoE is a ...
详细信息
The Design of Experiment approach (DoE) and an elec.romagnetic full-wave solver are combined in a single algorithm in order to produce parametric model of planar microwave and millimeter wave components. The DoE is a technique normally used to improve a process or a system and is here applied for conducting an elec.romagnetic analysis in which parameter levels, as geometrical dimensions, are made vary and the corresponding changes on the output are recorded. The results are then statistically processed by the Analysis of Variance (ANOVA) for determining which parameters or their combination is more significant. The elec.romagnetic analysis performed in time-domain by means of a Transmission Line Matrix (TLM) method provides a very broadband characterization. The given structure is simulated for each of the possible combination obtained from changing each parameter between two levels while keeping all the others constant. Once the parameters have been identified multiple linear regression (MLR) approach is applied to develop the model. This algorithm is here tested on two different test structures, as a microstrip patch antenna on teflon substrate and a coplanar waveguide bend on silicon substrate. The accuracy analysis complete the algorithm description by giving an estimation of the model error.
Thin films of low molecular weight elec.roluminescence (EL) materials, Alq3 (aluminum tirs-8-hydoroxyquinline), TPD (N, N′-diphenyl-N, N′-bis (3methylphenyl)-(1, 1′-biphenyle)-4, 4′-diamine) were deposited by puls...
详细信息
Thin films of low molecular weight elec.roluminescence (EL) materials, Alq3 (aluminum tirs-8-hydoroxyquinline), TPD (N, N′-diphenyl-N, N′-bis (3methylphenyl)-(1, 1′-biphenyle)-4, 4′-diamine) were deposited by pulsed laser ablation (PLA) method using KrF excimer laser and Nd: YAG laser. Optical absorption property, surface morphology and photoluminescence of the films were investigated. Alq3 films by Nd:YAG laser show slight absorption at around 400 nm, and TPD films by either KrF laser or Nd:YAG laser showed absorption at 320 nm and 360 nm. It was found that TPD thin films for EL devices can be deposited by PLA method usig Nd:YAG laser.
A technique known as digital predistortion (DPD) is the subject of much current research and is being contemplated for the next generation of RF power amplifiers. DPD has the capability of linearizing the overall ampl...
详细信息
A technique known as digital predistortion (DPD) is the subject of much current research and is being contemplated for the next generation of RF power amplifiers. DPD has the capability of linearizing the overall amplifier response and is a cost effective technique for applications requiring wideband operation with low out-of-band spurious emissions, also known as "spectral regrowth." Estimation of the DPD parameters is hampered by the presence of measurement noise at the output of the amplifier, even though this noise is not actually transmitted on air. The end effect of the noise is to degrade the DPD performance, leading to higher spectral regrowth. This paper shows that a major cause of this degradation can be attributed to coefficient bias induced by measurement noise in a nonlinear model. Two techniques are proposed for mitigating these effects. One uses a specially designed periodic training signal with frame averaging, and the other uses forward estimation followed by off-line noiseless inverse estimation. Simulations show that spectral regrowth reductions in excess of 10 dB are possible using these techniques.
In this paper, we present an automatic multi-cue video segmentation sch.me based on clustering and change detection. The k-means algorithm is employed to partition an image into a set of homogenous regions. The purpos...
详细信息
ISBN:
(纸本)2726112420
In this paper, we present an automatic multi-cue video segmentation sch.me based on clustering and change detection. The k-means algorithm is employed to partition an image into a set of homogenous regions. The purpose of change detection is to localize moving objects in a video sequence. The proposed change detection technique is based on the F test and block-based motion estimation. The results from the clustering-based spatial segmenter and the change detector are analyzed to segment the foreground objects. The performance of the segmentation sch.me is illustrated by simulations carried out on standard video sequences.
We develop a labelled tableaux system for the modal logic KD45 ni-j extended with epistemic notions. This logic characterises a particular type of interpreted systems used to represent and reason about states of corre...
详细信息
ISBN:
(纸本)9783540206460
We develop a labelled tableaux system for the modal logic KD45 ni-j extended with epistemic notions. This logic characterises a particular type of interpreted systems used to represent and reason about states of correct and incorrect functioning behaviour of the agents in a system, and of the system as a whole. The resulting tableaux system provides a simple decision procedure for the logic. We discuss these issues and we illustrate them with the help of simple examples.
暂无评论