Extended Objects Research Articles

Touchscreen Surface Based on Interaction of Ultrasonic Guided Waves With a Contact Impedance

In this paper, a touchscreen device is proposed, based on guided-wave reflection and transmission induced by the presence of an object. The principle uses the advantages of other acoustic wave devices in terms of simplicity and applicability to any thin surface but is not subject to classical drawbacks (single touch, sensitivity to scratches or contaminant, and impossibility to follow motion of contact point). The theoretical interaction of guided waves with contact impedance is first derived in order to define the requirements of the sensor in terms of frequency range, mode, sensor type and location, and embedded electronics. Design criteria and experimental validation on a small prototype ( $200 \times 250$ mm) are proposed to demonstrate the potential of the approach for simple, robust, and reliable contact detection of pointlike or extended objects for consumer electronics or biomedical applications.

Improved Multi-Bernoulli Filter for Extended Stealth Targets Tracking Based on Sub-Random Matrices

In this paper, we address a radar detection and tracking of multi-stealth targets. Multi-Bernoulli filter is a provable optimal Bayes approach of multi-target filtering and shows excellent performance over the other filters. The original multi-Bernoulli filters rely on the assumption that the interest targets are point source objects. Normally, in realistic scenarios, the point source assumption is not suitable for estimating the extent stealth targets (ESTs) scenarios. Recently, the random matrices approach has been proposed for ellipsoidal extended object tracking by additional state variables. In multiple EST scenarios, although the extension ellipsoid is efficient, it may not be accurate enough because of lacking useful information, such as size, shape, and orientation. To this point, we introduce a non-ellipsoidal EST composed of multiple ellipsoidal sub-objects, and each one is represented by a random matrix. Based on such models, a multi-Bernoulli filter is used to estimate kinematic states and extensions of sub-objects for each EST. However, in multiple EST scenarios, the detection profile is prior unknown due to fluctuation of EST parameters. The parameter, such as detection probability, is of critical importance in this extended filter. To tackle these problems, a beta Gaussian inverse Wishart implementation is proposed to estimate the EST extent augment with unknown detection probability and kinematic state. The results show that the proposed filter has more accurate cardinality estimation and smaller optimal sub-pattern assignment errors than the recently extended probability hypothesis density (PHD) and cardinalized PHD filters.

Sparse Representation Based Binary Hypothesis Model for Hyperspectral Image Classification

The sparse representation based classifier (SRC) and its kernel version (KSRC) have been employed for hyperspectral image (HSI) classification. However, the state-of-the-art SRC often aims at extended surface objects with linear mixture in smooth scene and assumes that the number of classes is given. Considering the small target with complex background, a sparse representation based binary hypothesis (SRBBH) model is established in this paper. In this model, a query pixel is represented in two ways, which are, respectively, by background dictionary and by union dictionary. The background dictionary is composed of samples selected from the local dual concentric window centered at the query pixel. Thus, for each pixel the classification issue becomes an adaptive multiclass classification problem, where only the number of desired classes is required. Furthermore, the kernel method is employed to improve the interclass separability. In kernel space, the coding vector is obtained by using kernel-based orthogonal matching pursuit (KOMP) algorithm. Then the query pixel can be labeled by the characteristics of the coding vectors. Instead of directly using the reconstruction residuals, the different impacts the background dictionary and union dictionary have on reconstruction are used for validation and classification. It enhances the discrimination and hence improves the performance.

Detection of simply shaped objects on stationary images of an underlying surface by an interpreter/operator and by a computer vision system

Mathematical expressions were obtained for the probabilities of Type I and Type II errors when an interpreter/operator and a computer vision system search for axially symmetric and extended objects superimposed on an underlying surface, as a function of the noise correlation function, the ratio of object size to the correlation radius of the background, and the signal-to-noise ratio. Based on the results of a comparison of the potential approaches for addressing issues relating to detection of these objects, we propose an integrated system designed to improve the decision-making reliability.

Bipolar H II regions – Morphology and star formation in their vicinity

Our goal is to identify bipolar HII regions and to understand their morphology, their evolution, and the role they play in the formation of new generations of stars. We use the Spitzer and Herschel Hi-GAL surveys to identify bipolar HII regions. We search for their exciting star(s) and estimate their distances using near-IR data. Dense clumps are detected using Herschel-SPIRE data. MALT90 observations allow us to ascertain their association with the central HII region. We identify Class 0/I YSOs using their Spitzer and Herschel-PACS emissions. These methods will be applied to the entire sample of candidate bipolar HII regions. This paper focuses on two bipolar HII regions, one interesting in terms of its morphology, G319.88$+$00.79, and one in terms of its star formation, G010.32$-$00.15. Their exciting clusters are identified and their photometric distances estimated to be 2.6 kpc and 1.75 kpc, respectively. We suggest that these regions formed in dense and flat structures that contain filaments. They have a central ionized region and ionized lobes perpendicular to the parental cloud. The remains of the parental cloud appear as dense (more than 10^4 per cm^3) and cold (14-17 K) condensations. The dust in the PDR is warm (19-25 K). Dense massive clumps are present around the central ionized region. G010.32-00.14 is especially remarkable because five clumps of several hundred solar masses surround the central HII region; their peak column density is a few 10^23 per cm^2, and the mean density in their central regions reaches several 10^5 per cm^3. Four of them contain at least one massive YSO; these clumps also contain extended green objects and Class II methanol masers. This morphology suggests that the formation of a second generation of massive stars has been triggered by the central bipolar HII region. It occurs in the compressed material of the parental cloud.

A phase-diversity speckle experimental system for one meter-scale ground-based telescope

Phase-diversity (PD) is the least square adaptive-filter of the imaging system based on wave optics theory. It can use unknown extended object as the observation object to collect two or more images whose wave-front diversities are known and fixed. According to the images, the wave-front of the optical system can be calculated by PD, and simultaneously the estimation of ideal image for the observation object can be obtained. Phase-diverse speckle (PDS) technique extends PD by using a series of short-expose frames as the input. In this paper, we designed PDS experiment on a 1.23m telescope and successfully got clear restored images of space objects. Under the observation condition that the atmospheric coherent length was not more than 8cm at 500nm wavelength in Changchun city, we replaced the deformable mirror with a plane mirror in adaptive optical system and separately used the moon and Polaris as the observation objects. For Polaris, the FWHW reduced from 20.6 to 5.3 (in pixel), which decreased about 74%. The experimental results demonstrate that PDS algorithm can be used on one meter-scale telescope in practical observation.

A molecular line study towards massive extended green object clumps in the southern sky: chemical properties

We present a molecular line study towards 31 extended green object (EGO) clumps in the southern sky using data from MALT90 (Millimetre Astronomy Legacy Team 90 GHz). According to previous multiwavelength observations, we divide our sample into two groups: massive young stellar objects (MYSOs) and HII regions. Our results seem to support that N2H+ and C2H emissions mainly come from the gas inside quiescent clumps. In addition, we also find that the [N2H+]/[H13CO+] and [C2H]/[H13CO+] relative abundance ratios decrease from MYSOs to HII regions. These results suggest depletion of N2H+ and C2H in the late stages of massive-star formation, probably caused by the formation of HII regions inside. N2H+ and C2H might be used as chemical clocks for massive-star formation by comparing with other molecules such as H13CO+ and HC3N.

Non-extremal branes

We prove that for arbitrary black brane solutions of generic Supergravities there is an adapted system of variables in which the equations of motion are exactly invariant under electric–magnetic duality, i.e. the interchange of a given extended object by its electromagnetic dual. We obtain thus a procedure to automatically construct the electromagnetic dual of a given brane without needing to solve any further equation. We apply this procedure to construct the non-extremal (p,q)-string of Type-IIB String Theory (new in the literature), explicitly showing how the dual (p,q)-five-brane automatically arises in this construction. In addition, we prove that the system of variables used is suitable for a generic characterization of every double-extremal Supergravity brane solution, which we perform in full generality.

New nonparametric statistical test for problems with three samples, which is more effective than the Whitney test

A new nonparametric statistical test for testing the hypothesis of homogeneity of three samples against an alternative hypothesis, which implies that random variables of one of these samples tend to be stochastically greater than random variables of each of the other two samples separately, is proposed. The known Whitney test is equivalent to a particular case of the new test. Application of these tests in a real difficult problem of detection of a specified extended object in a noisy image in a situation with possible appearance of another “interfering” object of a greater size is considered.

CDW and Similarity of the Mott Insulator-to-Metal Transition in Cuprates with the Gas-to-Liquid-Liquid Transition in Supercooled Water

New advances in X-ray diffraction, extended X-ray absorption fine structure (EXAFS), and X-ray absorption near edge structure (XANES) using synchrotron radiation have now provided compelling evidence for a short-range charge density wave phase (CDW) called striped phase in the CuO2 plane of all cuprate high-temperature superconductors. The CDW is associated with a bond order wave (BOW) and an orbital density wave (ODW) forming nanoscale puddles which coexist with superconducting puddles below T c . The electronic CDW crystalline phase occurs around the hole doping 0.125 between the Mott charge transfer insulator and the 2D metal. The Van der Waals (VdW) theoretical model for a liquid of anisotropic extended objects proposed for supercooled water is used to describe the following: (a) the underdoped regime as a first spinodal regime of a “slightly doped charge transfer Mott insulator puddles coexisting with the striped polaronic CDW puddles;nd (b) the optimum doping regime as a second spinodal regime where striped polaronic CDW puddles coexist with the normal 2D metal puddles. This complex phase separation with three competing phases depends on the strength of the anisotropic electron-phonon interaction that favours the formation striped polaronic CDW phase.

基于区域特征匹配的扩展目标高精度跟踪

基于区域特征匹配的扩展目标高精度跟踪

Star formation associated with a large-scale infrared bubble

Using the data from the Galactic Ring Survey (GRS) and Galactic Legacy Infrared Mid-Plane Survey Extraordinaire (GLIMPSE), we performed a study for a large-scale infrared bubble with a size of about 16 pc at a distance of 2.0 kpc. We present the 12CO J=1-0, 13CO J=1-0 and C18O J=1-0 observations of HII region G53.54-0.01 (Sh2-82) obtained at the the Purple Mountain Observation (PMO) 13.7 m radio telescope to investigate the detailed distribution of associated molecular material. The large-scale infrared bubble shows a half-shell morphology at 8 um. H II regions G53.54-0.01, G53.64+0.24, and G54.09-0.06 are situated on the bubble. Comparing the radio recombination line velocities and associated 13CO J=1-0 components of the three H II regions, we found that the 8 um emission associated with H II region G53.54-0.01 should belong to the foreground emission, and only overlap with the large-scale infrared bubble in the line of sight. Three extended green objects (EGOs, the candidate massive young stellar objects), as well as three H II regions and two small-scale bubbles are found located in the G54.09-0.06 complex, indicating an active massive star-forming region. C18O J=1-0 emission presents four cloud clumps on the northeastern border of H II region G53.54-0.01. Via comparing the spectral profiles of 12CO J=1-0, 13CO J=1-0, and C18O J=1-0 peak at each clump, we found the collected gas in the three clumps, except for the clump coincided with a massive YSO (IRAS 19282+1814). Using the evolutive model of H II region, we derived that the age of H II region G53.54-0.01 is 1.5*10^6 yr. The significant enhancement of several Class I and Class II YSOs around G53.54-0.01 indicates the presence of some recently formed stars, which may be triggered by this H II region through the collect and collapse (CC) process.

Metric-independent measures for supersymmetric extended object theories on curved backgrounds

For Green–Schwarz superstring σ-model on curved backgrounds, we introduce a non-metric measure Φ≡ϵijϵIJ(∂iφI)(∂jφJ) with two scalars φI(I=1,2) used in ‘Two-Measure Theory’ (TMT). As in the flat-background case, the string tension T=(2πα′)−1 emerges as an integration constant for the Ai-field equation. This mechanism is further generalized to supermembrane theory, and to super-p-brane theory, both on general curved backgrounds. This shows the universal applications of dynamical measure of TMT to general supersymmetric extended objects on general curved backgrounds.

Investigation ofQ-tubes stability using the piecewise parabolic potential

We analyze the classical stability of Q-tubes --- charged extended objects in $(3+1)$-dimensional complex scalar field theory. Explicit solutions were found analytically in the piecewise parabolic potential. Our choice of potential allows us to construct a powerful method of stability investigation. We check that in the case of the zero winding number $n=0$, the previously known stability condition $\partial^2E/\partial Q^2<0$ for Q-balls is fulfilled. However, in the case $n\geq 1$, we find a continuous family of instabilities. Our result has an analogy with the theory of superconductivity of the second type, in which the vortex with $n>1$ becomes unstable towards the decay into the $n$ vortices with the single winding number.

The search for faint radio supernova remnants in the outer Galaxy: five new discoveries

High resolution and sensitivity large-scale radio surveys of the Milky Way are critical in the discovery of very low surface brightness supernova remnants (SNRs), which may constitute a significant portion of the Galactic SNRs still unaccounted for (ostensibly the Missing SNR problem). The overall purpose here is to present the results of a systematic, deep data-mining of the Canadian Galactic Plane Survey (CGPS) for faint, extended non-thermal and polarized emission structures that are likely the shells of uncatalogued supernova remnants. We examine 5$\times$5 degree mosaics from the entire 1420 MHz continuum and polarization dataset of the CGPS after removing unresolved point sources and subsequently smoothing them. Newly revealed extended emission objects are compared to similarly-prepared CGPS 408 MHz continuum mosaics, as well as to source-removed mosaics from various existing radio surveys at 4.8 GHz, 2.7 GHz, and 327 MHz, to identify candidates with non-thermal emission characteristics. We integrate flux densities at each frequency to characterise the radio spectra behaviour of these candidates. We further look for mid- and high-frequency (1420 MHz, 4.8 GHz) ordered polarized emission from the limb brightened shell-like continuum features that the candidates sport. Finally, we use IR and optical maps to provide additional backing evidence. Here we present evidence that five new objects, identified as filling all or some of the criteria above, are strong candidates for new SNRs. These five are designated by their Galactic coordinate names G108.5+11.0, G128.5+2.6, G149.5+3.2, G150.8+3.8, and G160.1$-$1.1. These discoveries represent a significant increase in the number of SNRs known in the outer Galaxy second quadrant of longitude (90$^{\circ} \leq \ell \leq $180$^{\circ}$).

FLECHAS – A new échelle spectrograph at the University Observatory Jena

AbstractThe new échelle spectrograph FLECHAS (Fibre Linked ECHelle Astronomical Spectrograph) is in operation at the Nasmyth‐focus of the 0.9 m telescope of the University Observatory Jena. FLECHAS is equipped with a sensitive back‐illuminated and midband coated CCD‐detector, as well as with a calibration unit for flatfield and wavelength‐calibration. The spectrograph covers the spectral range between about 3900 and 8100 Å and exhibits a resolving power of R ∼ 9300. In this article all technical characteristics of FLECHAS are described and examples of the first astronomical observations obtained with the new instrument in July 2013 at the University Observatory Jena are presented, among them the first light spectra taken with FLECHAS, simultaneous imaging and spectroscopic observations, the determination of the detection limit of the instrument, the spectroscopy of stars of different spectral types and of faint extended objects, as well as the Li‐line detection in the spectra of young solar‐like stars. (© 2014 WILEY‐VCH Verlag GmbH &amp; Co. KGaA, Weinheim)

Tracking of Maneuvering Non-Ellipsoidal Extended Object or Target Group Using Random Matrix

For non-ellipsoidal extended object and group target tracking (NEOT and NGTT), using a random matrix to simplify the extension as an ellipsoid, although efficient, may not be accurate enough because of the loss of useful information in shape and orientation. In view of this, we model a non-ellipsoidal extended object or target group as a combination of multiple ellipsoidal sub-objects, each represented by a random matrix. Different sub-objects are distinguished by different dynamic models. Based on such models, a Bayesian approach is proposed to estimate the kinematic states and the extensions of the sub-objects. For maneuvering NEOT and NGTT, a multiple-model approach is proposed. The overall maneuver model is combined with the sub-object models to describe the common and the individual motions of the sub-objects. Three simplifications of the approach are presented. Two scenarios for maneuvering and nonmaneuvering NEOT and NGTT are simulated. The results demonstrate the effectiveness of the proposed modeling and estimation approach.

Automated generation of mission reliability simulation model for space tracking, telemetry and control system by extensible markup language and extended object-oriented Petri net

To evaluate and optimize the space tracking, telemetry and command system design, it is important to perform mission reliability analysis of tracking, telemetry and command system. Considering the complexity of tracking, telemetry and command system configuration and mission process, it is nearly infeasible to model and analyze the system by manual work. For accuracy and efficiency reasons, system designers need to have an integrated set of methods and tools for modeling specifications and performing reliability analysis. This article presents an XML-based (extensible markup language–based) schema named reliability modeling language to formally represent data and information, which are necessary for building the mission reliability model of tracking, telemetry and command system. To facilitate the evaluation of mission reliability measures, we propose the improved extended object–oriented Petri net formalism, which is an extension of object-oriented Petri net to perform mission reliability simulation and analysis. The standard descriptive model in reliability modeling language can be automatically and directly transformed into an extended object–oriented Petri net model by applying model transformation rules and algorithm. The proposed approach is illustrated and validated by examples, which consider the complex situation such as component phase dependence, non-exponential failure rate, instantaneous repair as well as different work start and end time. The simulation results show a good approximation compared with the results of analytical models.

Random Set Methods: Estimation of Multiple Extended Objects

Random set-based methods have provided a rigorous Bayesian framework and have been used extensively in the last decade for point object estimation. In this article, we emphasize that the same methodology offers an equally powerful approach to estimation of so-called extended objects, i.e., objects that result in multiple detections on the sensor side. Building upon the analogy between Bayesian state estimation of a single object and random finite set (RFS) estimation for multiple objects, we give a tutorial on random set methods with an emphasis on multiple-extended-object estimation. The capabilities are illustrated on a simple yet insightful real-life example with laser range data containing several occlusions.

High precision localization for profiled extended object based on GHT

A high precision localization scheme for profiled extended objects based-on Generalized Hough Transform (GHT) is proposed. The proposed localization scheme utilizes the edge points’ gratitude orientations of profiled extended objects to build an R-table in frame t-1. When frame t is coming, we search the R-table according to the pre-computed edge points’ gratitude orientations of profiled extended objects in current frame, generating an accumulator array. The coordination corresponding to the accumulator's peak value is regarded as coarse localization point in current frame. Then, a relaxation iteration method is proposed to refine the coarse localization point to obtain a sub-pixel localization point. Numerical experiments show that the localization scheme has following characteristics: high-precision and stability. Furthermore, we present the results of our work which involves investigation of the performance evaluation for the proposed localization scheme.