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One of the most significant advantages of multiple frequencies is that it can improve the success rate of ambiguity resolution, such as the three-frequency carrier ambiguity resolution (TCAR) method. So far, the global BeiDou-3 navigation satellite system already provides four frequencies. Hence, we systematically study the models and methods of four-frequency carrier ambiguity resolution (FCAR) by using real BeiDou-3 data. First, the models of four-frequency linear combinations are given, and the optimal linear combinations are found out based on certain optimal criteria. Second, two typical methods, including geometry-free and geometry-based methods, are studied. In the end, the real BeiDou-3 data are used to evaluate the performance of the FCAR method, where two strategies, i.e., single-epoch and multi-epoch solutions, are both applied. The results indicate that the FCAR method can offer more high-quality virtual signals in quantity and quality than the TCAR method. By using the real BeiDou-3 data with different lengths ranging from 4.9 m to 61.6 km, three high-quality and independent signals can fix the ambiguities instantaneously with an approximately 100% success rate. Then the fourth independent signal can be fixed with high efficiency and success rate. Therefore, the FCAR method is promising in large-scale real-time precise positioning, where the successful ambiguity resolution may take tens of minutes to hours.

The research conducted in this work, was aimed at finding conditions that suppress the influence of the magnetic field on zero drift in Zeeman four-frequency and quasi-four-frequency laser gyroscopes. We determined the optimal areas within the gain contour in the active medium. During operation in those areas the maximum suppression of the influence of the magnetic field on the drift of the gyroscope is provided. A gyroscope control system that switches gyroscope to the regime of minimum magnetic sensitivity has been created. We obtained weakening of the effect of the magnetic field on zero drift by more than three orders of magnitude.

This work proposes a compact 5G reconfigurable antenna for four frequency bands (2GHz, 2.45 GHz, 3.1 GHz and 3.4 GHz), where the frequency selectivity is provided through a lumped element switch. The compact size (37x35x1.6 mm3) of the proposed monopole antenna is designed on a FR-4 substrate with 4.3 relative permittivity. With the provision of frequency selectivity through switches, the designed antenna can operate in various configurations such as single band frequency mode, i.e. WLAN applications at 2.45 GHz (2.34-2.93 GHz) or at 3.1 GHz (2.81-3.77 GHz). In dual band frequency mode, the antenna is designed to support both 2GHz (1.95-2.14GHz) and 3.4GHz (3.14-3.82) bands, which is verified through simulation results in CST Microwave Studio. The proposed design allows the antenna to operate as an omnidirectional antenna with fractional bandwidth (>10%), efficiency (>85 %), gain (>1.5 dB) and VSWR (

The fourth signal of BDS (BeiDou Navigation System) allows for measurements on frequency S. To take advantage of this new signal, an investigation has been carried out on the models and characteris...

Intelligibility of four-band speech stimuli was investigated (n = 18), such that only one of the frequency bands was preserved, whereas other bands were locally time-reversed (segment duration: 75–300 ms), or vice versa. Intelligibility was best retained (82% at 75 ms) when the second lowest band (540–1700 Hz) was preserved. When the same band was degraded, the largest drop (10% at 300 ms) occurred. The lowest and second highest bands contributed similarly less strongly to intelligibility. The highest frequency band contributed least. A close connection between the second lowest frequency band and sonority was suggested.

The brightness temperature (TB) data of the Moon acquired by the microwave radiometer (MRM) on-board the Chinese Chang’e-2 (CE-2) lunar probe are valuable and comprehensive data, which can be helpful in studying the physical properties of the lunar regolith, such as thickness, physical temperature, and dielectric constant. To construct the accurate and high-resolution lunar TB model with the TB data obtained by the MRM on-board CE-2, 2401 tracks of the original TB data are quantized by using the hour angle processing, and the hierarchical MK splines function (HMKSF) method is presented, which uses a hierarchy of coarse-to-fine control lattices to generate a sequence of TB model functions. The TB model constructor is the sum of the TB model functions derived at each level of the hierarchy. In addition, the lunar TB models with a resolution of $0.5 {^{\circ }} \times 0.5 {^{\circ }}$ in all four frequency channels are constructed for both the daytime and the nighttime. The obtained models show rich information, e.g., the global distribution of TB over the lunar surface, the effect of frequency on the TB model.

Five van der Pol oscillators connected into a ring have been investigated numerically. We have considered different types of coupling: dissipative and active, as well as dissipative and active with a single coupling sign reversal. Bifurcations observed upon a transition from a five- to four-frequency torus have been investigated. The possibility of quasi-periodic Hopf bifurcation in this system has been established.

We consider the nonlinear derivative Schrodinger equation with a quintic nonlinearity, on the one dimensional torus. We exhibit that the nonlinear dynamic properties consist of four frequency modes initially excited, whose frequencies include the resonant clusters and phase matched resonant interactions of nonlinearities. This phenomena arrests energy transfers between low and high modes, which are quantified by a growth in the Sobolev norm., Comment: 28 pages

We have examined a sample of 13 sub-Eddington supermassive black holes hosted by galaxies spanning a variety of morphological classifications to further understand the empirical fundamental plane of black hole activity. This plane describes black holes from stellar-mass to supermassive and relates the mass of an accreting black hole and its radio and X-ray luminosities. A key factor in studying the fundamental plane is the turnover frequency, the frequency at which the radio continuum emission becomes optically thin. We measured this turnover frequency using new VLA observations combined, when necessary, with archival Chandra observations. Radio observations are in the range of 5--40 GHz across four frequency bands in B-configuration, giving high spatial resolution to focus on the core emission. We use Markov Chain Monte Carlo methods to fit the continuum emission in order to find the turnover frequency. After testing for correlations, the turnover frequency does not display a significant dependence on either mass or mass accretion rate, indicating that more complicated physics than simple scaling and optical depth effects are at play, as has been suggested by recent theoretical work., Comment: 10 pages, 4 figures, 2 tables, accepted for publication in ApJ

This paper studies the effect of antenna polarization on measurement uncertainty of a multi-band body-worn distributed exposure meter (BWDM). The BWDM is a device for assessing electromagnetic fields in real environments accurately. The BWDM consists of 8 nodes and is calibrated on the body for simultaneous measurement of the incident power density in four frequency bands. Each node contains an antenna that can have two potential antenna polarizations.The BWDM is calibrated on four human subjects in an anechoic chamber to determine its measurement uncertainty in terms of 68% confidence interval (CI68) of the on-body antenna aperture. The results show that using a fixed polarization of the antennas on body can lead to a different CI68 up to maximum 4.9 dB when worn by another person which is still 9.6 dB lower than the measurement uncertainty of commercial exposure meters.

Context. In the previous decade, two new classes of fast radio transients were detected: the Galactic, rotating radio transients (RRATs) and the extragalactic fast radio bursts (FRBs). If the detectable emission of these objects extends to lower radio frequencies, the LOw Frequency ARray (LOFAR) is ideally suited to seek and localize these transients at frequencies of 10–250 MHz. This is due to LOFAR’s sensitivity, diverse beamform capabilities, and transient buffers for the individual elements that allow post-event imaging of events, potentially at arcsecond resolution. Aims. Our aim is to identify and localize pulses at frequencies below 250 MHz and, in the case of nondetections, derive upper limits on the sky and volume rates of FRBs. Methods. A real-time search program for fast radio transients is installed on the LOFAR systems which runs commensally with other observations, and uses the wide incoherent LOFAR beam (11.25 deg2 at 150 MHz). Buffered data from hundreds of dipoles are used to reconstruct the direction and polarization information of the event, and to distinguish between celestial, terrestrial, and instrumental origins. Results. Observations were taken covering either the frequency range 119–151 MHz or in four frequency bands, each of 2 MHz in width, centered at 124, 149, 156, and 185 MHz. A first pilot survey covered a range of dispersion measures (DM) below 120 pc cm−3, focusing on Galactic sources, and resulted in an upper limit on the transient rate at LOFAR frequencies of less than 1500 events per sky per day above a fluency of 1.6 kJy ms for an 8-ms pulse. A second pilot survey covered a range of DMs below 500 pc cm−3, focusing on extragalactic sources to about 1 Gpc, and resulted in an upper limit of 1400 events per sky per day above a fluency of 6.0 kJy ms for an 8-ms pulse. Using a model for the distance-DM relationship, this equates to an upper limit of 134 events per Gpc3 per day.

In this article, compact quad-band cylindrical dielectric resonator antenna (CDRA) with complementary C-shaped defected ground structure (DGS) is examined. The proposed antenna design is excited by annular shape microstrip line. Annular shape microstrip line, at center position and shifted from center position, are used to generate HE12δ and HE11δ mode in CDRA at 12.1 GHz and 11.6 GHz, respectively. Complementary C-shaped DGS is used to make proposed antenna design compact (approximately half the resonant frequency of CDRA mode). Archetype of antenna structure has been fabricated and experimentally tested. The proposed antenna operates in four frequency bands 3.21–3.63 GHz; 4.83–6.78 GHz; 7.25–7.77 GHz, and 11.76–12.45 GHz with a fractional bandwidth of 14.36%, 23.14%, 3.68%, and 1.88%, respectively. The proposed antenna design is applicable for WLAN (5.2/5.8 GHz) and WiMAX (3.5/5.5 GHz) bands. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:611–615, 2016

Multiplexing metasurfaces have drawn great interest from the microwave to optical regimes. However, previous works often encounter the restriction of insufficient independence and deficient interference suppression among different channels. Herein, a metasurface platform featuring a dual-wavelength and dual-polarization multiplexing operation is proposed for highly decorrelated and completely independent manipulation of four frequency and polarization states. As illustrative examples, two paradigms of a multiplexing holographic metasurface in which four channels can respond independently without conjugate images are presented, and the measurement results not only validate the feasibility but also exhibit excellent imaging efficiency. The proposed metasurface may thus boost more complex and versatile multi-functional devices.

In this paper, a tuneable rectangular microstrip patch antenna (MPA) is simulated and optimized to operate in four frequency bands of the next generation of wireless communication systems. The proposed design incorporates a copper radiating patch with four implanted graphene strips for tuning purposes. The reconfigurable surface impedance of graphene can easily be altered by applying a DC voltage bias directly to the graphene strips, allowing the operating frequency of the antenna to be tuned as desired. The capability of the applied voltage to tune the operating frequency band of the proposed antenna is studied via computer simulation technology (CST) microwave studio (MWS). Frequency selective surfaces (FSSs) are introduced in order to improve the radiation parameters of the antenna. The operating frequency band of the tuneable rectangular MPA increases directly as the applied DC voltage bias is increased. Based on the simulation results, a tuneable rectangular MPA placed between two FSSs is proposed for fifth-generation applications.

In the above article [1] , in the left column of the first page, the statement “Thus, the cycle slip detection and repair (CDR) is critical to high-precision GNSS positioning [1] –[4]” in the introduction is corrected as “Thus, the cycle slip detection and repair (CDR) is critical to high-precision GNSS positioning [1] –[4], [36] .”

A meandered square patch antenna is proposed and developed for multiband operation. By rotating a 60 mm x 60 mm square patch by 45° in the X-Y plane and using a coaxial feed, a circularly polarized antenna has been obtained. It is designed on an FR-4 substrate of height $\mathbf{h}=1.6$ mm. The proposed antenna operates in four frequency bands with resonances at 594 MHz, 888 MHz, 1380 MHz and 2046 MHz and return loss of −16.61 dB, −21.57 dB, −32.68 dB and −32.54 dB have been obtained at their respective frequencies. The antenna thus finds applications in the lower UHF Band, S-Band as well as UHF RFID applications. An axial ratio bandwidth of 228 MHz has been achieved.

The Fourier spectrum of the $\gamma$-Dor variable KIC 5608334 shows remarkable frequency groups at $\sim$3, $\sim$6, $\sim$9, and 11--12\,d$^{-1}$. We explain the four frequency groups as prograde sectoral g modes in a rapidly rotating star. Frequencies of intermediate-to-high radial order prograde sectoral g modes in a rapidly rotating star are proportional to $|m|$ (i.e., $\nu \propto |m|$) in the co-rotating frame as well as in the inertial frame. This property is consistent with the frequency groups of KIC 5608334 as well as the period vs. period-spacing relation present within each frequency group, if we assume a rotation frequency of $2.2$\,d$^{-1}$, and that each frequency group consists of prograde sectoral g modes of $|m| = 1, 2, 3,$ and 4, respectively. In addition, these modes naturally satisfy near-resonance conditions $\nu_i\approx\nu_j+\nu_k$ with $m_i=m_j+m_k$. We even find exact resonance frequency conditions (within the precise measurement uncertainties) in many cases, which correspond to combination frequencies., Comment: 12 pages, 10 figures; accepted for publication in MNRAS

The design of a four-band slot antenna for the global positioning system (GPS), worldwide interoperability for microwave access (WiMAX), and wireless area network (WLAN) is presented. The antenna consists of a rectangular slot with an area of ${\mathbf{0}}.{\mathbf{37}}{\lambda _g} \times {\mathbf{0}}.{\mathbf{14}}{\lambda _g} = {\mathbf{48}} \times {\mathbf{18}}\;{\bf m}{{\bf m}^{\mathbf{2}}}$ (where ${\lambda _g}$ is the guide wavelength), a $T$ -shaped feed patch, an inverted $T$ -shaped stub, and two $E$ -shaped stubs to generate four frequency bands. The radiating portion and total size of the antenna are less than those of the tri-band antennas studied in literature. Parametric study on the parameters for setting the four frequency bands is presented and hence the methodology of using the design for other frequency bands is proposed. The multiband slot antenna is studied and designed using computer simulation. For verification of simulation results, the antenna is fabricated and measured. The simulated and measured return losses, radiation patterns, realized peak gains, and efficiencies of the antenna are presented. Measured results show that the antenna can be designed to cover the frequency bands from 1.575 to 1.665 GHz for the GPS system, 2.4–2.545 GHz for the IEEE 802.11b&g WLAN systems, 3.27–3.97 GHz for the WiMAX system, and 5.17–5.93 GHz for the IEEE 802.11a WLAN system. The effects of the feeding cable used in measurement and of the cover are also investigated.

A new quad band quadrature branch line coupler (BLC) has been presented in this paper. The proposed BLC has been designed with the help of the T shaped coupled line sections, quad band impedance inverter. The BLC has been designed using Advanced Design System (ADS) software for f 1 = 0.66 GHz, f 2 = 1.52 GHz, f 3 = 2.57 GHz and f 4 = 3.44 GHz operating frequencies. The Rogers 5870 substrate has been selected for the BLC design. The BLC's S-parameters characteristics including insertion loss, isolation loss, quadrature phase and equal power division have been achieved with 0.58 dB maximum amplitude imbalance and 4.33° maximum phase deviation while preserved the

Millimeter wave (mmWave) communication has been a key technology for the fifth generation (5G) wireless communications. There have been various mmWave channel measurements. However, many measurements in the literature are conducted with different configurations, which may have large impacts on the propagation channel characteristics, and make the comparison of propagation channel characteristics for different mmWave bands impossible. In this paper, we carry out channel measurements at 11, 16, 28, and 38 GHz bands in an indoor environment using a vector network analyzer (VNA). The space-alternating generalized expectation-maximization (SAGE) algorithm is used to obtain the multipath component (MPC) parameters including three dimensional (3D) angular domain information. The propagation characteristics like average power delay profile (APDP), power azimuth profile (PAP), power elevation profile (PEP), root mean square (RMS) delay spread (DS), and azimuth and elevation angular spread (AS) are shown and compared for the four frequency bands. The results show similar properties for different bands and indicate the possibility of the derivation of a unified channel model framework for 10-40 GHz bands.

We investigate the electromagnetic wave behavior and its characterization using collective variables technique. Second-order dispersion, first- and second-order nonlinearities, which strongly act in a left-handed nonlinear transmission line with series varactor diodes, are taken into account. Four frequency ranges have been found. The first one gives the so-called energetic soliton due to a perfect combination of second-order dispersion and first-order nonlinearity. The second frequency range presents a dispersive soliton leading to the collapse of the electromagnetic wave at the third frequency range. But the fourth one shows physical conditions which are able to provoke the appearance of wave trains generation with some particular waves, the rogue waves. Moreover, we demonstrate that the number of rogue waves increases with frequency. The soliton, thereafter, gains a relative stability when second-order nonlinearity comes into play with some specific values in the fourth frequency range. Furthermore, th...

The frequency stabilization error is an important error for four frequency differential laser gyro (FFDLG). The first kind of dispersion equalization technology (FKDET) can minimize the frequency stabilization sensitivity of FFDLG essentially. From the independent dual-gyro approximation model, the principle and physical picture of FKDET are analyzed. Basing on the analysis, the calibration algorithm is put forward. At last the experimental system is set up. Experimental results show that the frequency stabilization sensitivity of FFDLG can be reduced more than 300 times by using FKDET. The startup and long term drift are also decreased of 0.00396 and 0.00152 respectively. Under temperature environment between −40 °C ∼ 60 C, the drift difference is reduced at least 0.6 by using FKDET. Therefore, FKDET is helpful to improve the performance of FFDLG for practical engineering application.

A linear-to-circular polarization conversion transmitter is proposed using 3 × 3 periodic metallic strips, which are twisted 900 in the upper and bottom layers. The metallic strips are printed on both sides of the dielectric substrate that are subjected to enhance the axial ratio bandwidth at resonance frequencies. The proposed structure is excited by a normal incident of x-linearly polarized wave, after transmission, it decomposed into two orthogonal linear components through structure have equal magnitudes and 900 phase difference between them. Numerical simulation results indicate that the incident x-polarized wave converts into a right handed circularly polarized (RHCP) wave at 12.0 GHz - 14.59 GHz and left handed circularly polarized waves (LHCP) are achieved at 14.83 GHz - 15.63 GHz, 15.80 GHz -16.51 GHz and 17.13 GHz - 18 GHz, respectively. The accumulative axial ratio of Txx, Txy 33.06% is obtained at four frequency wide bands. The measured results are in very good agreements to numerical simulation results.

A double layer frequency selective surface (DFSS) composed of modified square loop, cross dipole, and Jerusalem cross loop patch elements is presented to obtain angle and polarization insensitivity and a broad bandwidth. The presented DFSS reflects the X- and K-band signals, while allowing the C- and Ku-band signals to pass through. In this design, a four-band FSS (including band-stop FSS and band-pass FSS) with a broad bandwidth is obtained by controlling the thickness of the air foam between the FSS layers. An equivalent circuit model is developed to provide insight into the response of the DFSS. Experimental verifications are carried out. The computed results agree well with the measured ones. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2153–2157, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27007

This paper presents an enhanced Quadri-band microstrip patch antenna, using defective slots in the ground plane, designed to operate in the millimeter wave band, formulated using cavity model and simulated by an EM-simulator, based on finite element method: HFSSv15 (High Frequency Structure Simulator). The proposed antenna incorporates two symmetric patterns of “U” shaped slots with an “I” shaped slot engraved in the middle of the ground plane. The resulting antenna has four frequency bands; the first resonant frequency is located in the Ka band, at about 27Ghz, the second at nearly 35Ghz, the third at 41Ghz and the last one at 51GHz. Those resonant frequencies could be shifted by tuning the slots dimensions introduced if the ground plane of the proposed antenna .

A methodology for quantitative, directional validation of a long-term wave model hindcast is described and applied. Buoy observations are used as ground truth and the method does not require the application of a parametric model or data-adaptive method to the observations. Four frequency ranges, relative to the peak frequency, are considered. The validation of the hindcast does not suggest any systematic bias in predictions of directional spreading at or above the spectral peak. Idealized simulations are presented to aid in the interpretation of results.

This paper studies the application of vector tracking algorithm in GPS and BDS receiver with the high speed. Firstly, it proposes an architecture of GNSS receiver with four frequency. Secondly, it expounds transfer and measurement equation of vector tracking navigation filter. Then it briefly compares and analyzes performance and positioning accuracy of four frequency vector GNSS receiver with normal GPS receiver within a simulant scenarios of first cosmic velocity scenarios, and results show that the vector tracking technology has obvious advantages and applications for ground in this complex environment.

We investigate how the imprint of Faraday rotation on radio spectra can be used to determine the geometry of radio sources and the strength and structure of the surrounding magnetic fields. We model spectra of Stokes Q and U for frequencies between 200 MHz and 10 GHz for Faraday screens with large-scale or small-scale magnetic fields external to the source. These sources can be uniform or 2D Gaussians on the sky with transverse linear gradients in rotation measure (RM), or cylinders or spheroids with an azimuthal magnetic field. At high frequencies the spectra of all these models can be approximated by the spectrum of a Gaussian source; this is independent of whether the magnetic field is large-scale or small-scale. A sinc spectrum in polarized flux density is not a unique signature of a volume where synchrotron emission and Faraday rotation are mixed. A turbulent Faraday screen with a large field coherence length produces a spectrum which is similar to the spectrum of a partial coverage model. At low and intermediate frequencies, such a Faraday screen produces a significantly higher polarized signal than the depolarization model by Burn, as shown by a random walk model of the polarization vectors. We calculate RM spectra for four frequency windows. Sources are strongly depolarized at low frequencies, but RMs can be determined accurately if the sensitivity of the observations is sufficient. Finally, we show that RM spectra can be used to differentiate between turbulent foreground models and partial coverage models., 20 pages, 15 figures. Accepted for publication in MNRAS

Based on a developed and experimentally tested model, self-oscillatory lasing regimes have been studied for a Class A four-frequency gas ring laser with linear coupling of elliptically polarized counter-propagating waves. In the self-oscillatory regime, switching of the intensities, polarization states, and phase differences of the counter-propagating waves is observed, and also a polarization-phase dynamics effect involving displacement of the intensity switching point (with respect to detuning), due to the phase shift as a result of an ellipticity different from zero.

We consider a lossless one-dimensional nonlinear discrete bi-inductance electrical transmission line made of $N$ identical unit cells. When lattice effects are considered, we use the reductive perturbation method in the semidiscrete limit to show that the dynamics of modulated waves can be modeled by the classical nonlinear Schr\"odinger (CNLS) equation, which describes the modulational instability and the propagation of bright and dark solitons on a continuous-wave background. Our theoretical analysis based on the CNLS equation predicts either two or four frequency regions with different behavior concerning the modulational instability of a plane wave. With the help of the analytical solutions of the CNLS equation, we investigate analytically the effects of the linear capacitance ${C}_{S}$ on the dynamics of matter-wave solitons in the network. Our results reveal that the linear parameter ${C}_{S}$ can be used to manipulate the motion of bright, dark, and kink soliton in the network.

The four-frequency autocorrelation function (ACF) of the polarization-mode-dispersion (PMD) vector in optical fibers is obtained. The derivation of this function is part of a general effort aimed at understanding the complex behavior of the PMD vector as a stochastic process in frequency. The four-frequency ACF is also used for assessing the possibility of improving measurements of the mean differential group delay (DGD) by processing information regarding the measured correlations between the PMD vector at various frequencies. By manipulating the four-frequency ACF, the ACF of the square modulus of the PMD derivative is obtained and it is rigorously shown that DGD measurements that exploit this quantity are characterized by a 20% improvement in measurement accuracy.

This paper presents the complex permittivity of a number of liquids measured using waveguide transmission-line techniques. These liquids are measured over four frequency ranges: 8–12.4 GHz, 12.4–18 GHz, 18–26.5 GHz, and 26.5–40 GHz (or at the X, Ku, K, and Ka bands). The measured results of liquids are discussed and compared with results in the literature and the calculated data using Debye's method. Finally, statistical values such as the means and standard deviations, and the percentages of permittivity errors are computed for the consideration of data spread and error estimation. All of the possible sources of errors are also discussed with regard to improvements and developments of measurements in the near future. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 275–281, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21326

The local field potential (LFP) is a population measure of neuronal activity complementary to spike trains. Whereas the response properties of the spiking activity in the visual cortex have been characterized extensively, the responses of the LFP have not been well explored. No coherent picture exists about which frequency ranges exhibit feature tuning or show stimulus locked activity. Addressing this, we recorded LFP in the primary visual cortex of alert cats and calculated the tuning indices for orientation, spatial and temporal frequency. Furthermore, we quantified the locking of the power in different LFP frequency bands to the velocity profile of artificial and natural stimuli. We found that the LFP in alert animals is well tuned with similar specificity to orientation, spatial frequency and temporal frequency. Tuning to these features is most prominent in two frequency bands (8-23 Hz and 39-109 Hz). In two complementary frequency bands (23-39 Hz and above 109 Hz) the dynamics of the LFP power is locked tightly to the temporal structure of the stimulus. This locking is furthermore independent of the spatial structure of the stimulus. Together these four frequency bands cover the whole frequency range investigated. In contrast to previous studies, which often reported correlates of visual processing only in a limited frequency range of the LFP, the present results suggest that the entire frequency range of the LFP can be assigned a role in visual processing.

Optical solitons which remain radiationless in spite of having wavenumbers immersed in the spectrum of linear waves are rather unusual. This article shows that moving solitons of this type are solutions of an extended NLS equation with third and fourth-order dispersion, and a quintic nonlinearity. The mechanism which prevents the emission of radiation in these solitons is presented. The radiation emitted when these solitons are perturbed is also studied. This radiation exhibits four propagating fronts, and the velocities of these fronts are calculated and explained.

In order to establish a quantitative detection method for appearance in epileptic discharges (EDs), we propose using the model parameters in a Duffing oscillator, which is a nonlinear mathematical model. Extracting four frequency bands of delta, theta, alpha and beta waves from the time history of the electrocorticogram (ECoG) obtained from rats with induced EDs, we applied a sweep window to the time history for each band. So as to fit the equation for the Duffing oscillator to the time history of the ECoG, we used the least square method to determine the model parameters expressing characteristics of ECoG. The Duffing oscillator has three kinds of vibrational parameters and four kinds of parameters about the amplitude for the driving force with two predominant frequencies contained in ECoG. In order to examine the appearance time of the EDs and the change of ECoG characteristics, we determined the model parameters for each sweep window. When epilepsy occurs, we found that the amount of the parameters related to “conservation”, “dissipation” and “input quantities” increases. On the other hand, the parameter value corresponding to nonlinearity tends to decrease. It is found that the proposed method by the model parameters of the Duffing oscillator can be used in quantitative detection for EDs.Copyright © 2014 by ASME

The Cosmology Large Angular Scale Surveyor (CLASS) is an experiment to measure the signature of a gravita-tional-wave background from inflation in the polarization of the cosmic microwave background (CMB). CLASS is a multi-frequency array of four telescopes operating from a high-altitude site in the Atacama Desert in Chile. CLASS will survey 70\% of the sky in four frequency bands centered at 38, 93, 148, and 217 GHz, which are chosen to straddle the Galactic-foreground minimum while avoiding strong atmospheric emission lines. This broad frequency coverage ensures that CLASS can distinguish Galactic emission from the CMB. The sky fraction of the CLASS survey will allow the full shape of the primordial B-mode power spectrum to be characterized, including the signal from reionization at low $\ell$. Its unique combination of large sky coverage, control of systematic errors, and high sensitivity will allow CLASS to measure or place upper limits on the tensor-to-scalar ratio at a level of $r=0.01$ and make a cosmic-variance-limited measurement of the optical depth to the surface of last scattering, $\tau$., Comment: 23 pages, 10 figures, Presented at SPIE Astronomical Telescopes and Instrumentation 2014: Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy VII. To be published in Proceedings of SPIE Volume 9153

In this paper we present a new sample of 87 Compact Steep Spectrum radio sources (CSS) with flux density0.8 Jy at 0.4 GHz. This sample has been selected from the B3-VLA sample with the aid of new VLA observations at 4.9 and 8.5 GHz which allowed to clean an earlier selection based on VLA 1.5 GHz data. Redshifts, either spectroscopic or photometric, are known for 62% of the sources. About 75% of the sources are resolved or slightly resolved in the new observations. The range of measured linear sizes is from 20 h 1 kpc (selection upper limit) down to0.5 h 1 kpc, which corresponds to our resolution limit. The Largest Linear Size (LLS) distribution is well represented by the power law dN=d(LLS) / LLS 0:6 , consistent with earlier results. The majority of the radio sources smaller than 0.5 h 1 kpc shows a marked spectral flattening at low frequencies. The four frequency spectra computed in the range 0.4{8.5 GHz display a signicant steepening at high frequencies in the largest majority of cases. A considerable fraction of source components are polarized, with median values of their fractional polarization6% and4% at 8.5 and 4.9 GHz respectively.

We studied the generation and propagation of high-frequency (above 1 Hz) S-wave energy from the 1995 Hyogo-Ken Nanbu (Kobe), Japan, earthquake (MW 6.9) by analyzing seismogram envelopes of the mainshock and aftershocks. We first investigated the propagation characteristics of high-frequency S-wave energy in the heterogeneous lithosphere around the source region. By applying the multiple lapse time window analysis method to aftershock records, we estimated two parameters that quantitatively characterize the heterogeneity of the medium: the total scattering coefficient and the intrinsic absorption of the medium for S waves. Observed envelopes of aftershocks were well reproduced by the envelope Green functions synthesized based on the radiative transfer theory with the obtained parameters. Next, we applied the envelope inversion method to 13 strong-motion records of the mainshock. We divided the mainshock fault plane of 49 × 21 km into 21 subfaults of 7 × 7 km square and estimated the spatial distribution of the high-frequency energy radiation on that plane. The average constant rupture velocity and the duration of energy radiation for each subfault were determined by grid searching to be 3.0 km/sec and 5.0 sec, respectively. Energy radiated from the whole fault plane was estimated as 4.9 × 1014 J for 1 to 2 Hz, 3.3 × 1014 J for 2 to 4 Hz, 1.5 × 1014 J for 4 to 8 Hz, 8.9 × 1012 J for 8 to 16 Hz, and 9.8 × 1014 J in all four frequency bands. We found that strong energy was mainly radiated from three regions on the mainshock fault plane: around the initial rupture point, near the surface at Awaji Island, and a shallow portion beneath Kobe. We interpret that energetic portions were associated with rupture acceleration, a fault surface break, and rupture termination, respectively.