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Nowadays, there is a trend to employ adaptive solutions in mobile communication. The adaptive transmission systems seem to answer the need for highly reliable communication that serves high data rates. For efficient adaptive transmission, the future Channel State Information (CSI) has to be known. The various prediction methods can be applied to estimate the future CSI. However, each method has its bottlenecks. The task is even more challenging while considering the future 5G/6G communication where the employment of sub-6 GHz and millimetre waves (mmWaves) in narrow-band, wide-band and ultra-wide-band transmission is considered. Thus, author describes the differences between sub-6 GHz/mmWave and narrow-band/wide-band/ultrawide- band channel prediction, provide a comprehensive overview of available prediction methods, discuss its performance and analyse the opportunity to use them in sub-6 GHz and mmWave systems. We select Long Short-Term Memory Recurrent Neural Network (RNN) as the most promising technique for future CSI prediction and propose optimising two of its parameters - the number of input features, which was not yet considered as an opportunity to improve the performance of CSI prediction, and the number of hidden layers. [ABSTRACT FROM AUTHOR]

Independent component analysis (ICA) has been used for data mining in many branches of science. In beam physics, ICA can be applied to analyze turn-by-turn beam position monitor data of beam motion. The narrow-band filtering of ICA provides us methods to identify and extract information on the linear betatron and synchrotron motion, effects of wake fields, etc. We show that the ICA is also a powerful tool to measure nonlinear magnetic field in accelerators. Numerical simulations are used to demonstrate the ability to obtain sextupole strengths at high precision. The methods can be extended to other higher order multipoles. [ABSTRACT FROM AUTHOR]

Background and Aim: The Japan narrow‐band imaging (NBI) Expert Team (JNET) was organized to unify four previous magnifying NBI classifications (the Sano, Hiroshima, Showa, and Jikei classifications). The JNET working group created criteria (referred to as the NBI scale) for evaluation of vessel pattern (VP) and surface pattern (SP). We conducted a multicenter validation study of the NBI scale to develop the JNET classification of colorectal lesions. Methods: Twenty‐five expert JNET colonoscopists read 100 still NBI images with and without magnification on the web to evaluate the NBI findings and necessity of the each criterion for the final diagnosis. Results: Surface pattern in magnifying NBI images was necessary for diagnosis of polyps in more than 60% of cases, whereas VP was required in around 90%. Univariate/multivariate analysis of candidate findings in the NBI scale identified three for type 2B (variable caliber of vessels, irregular distribution of vessels, and irregular or obscure surface pattern), and three for type 3 (loose vessel area, interruption of thick vessel, and amorphous areas of surface pattern). Evaluation of the diagnostic performance for these three findings in combination showed that the sensitivity for types 2B and 3 was highest (44.9% and 54.7%, respectively), and that the specificity for type 3 was acceptable (97.4%) when any one of the three findings was evident. We found that the macroscopic type (polypoid or non‐polypoid) had a minor influence on the key diagnostic performance for types 2B and 3. Conclusion: Based on the present data, we reached a consensus for developing the JNET classification. [ABSTRACT FROM AUTHOR]

Incidents of pedestrian-induced large lateral vibrations of footbridges reveal the occurrence of an instability-type phenomenon in pedestrian-induced vibration. However, the mechanism involved has yet to be clearly explained. In this work, a novel model for predicting the lateral vibration of footbridges is proposed. Under an algebraic framework of nonlinear stochastic vibration, the narrow-band vibration caused by the pedestrian intra-subject randomness and the phase lag between the footbridge motion and the pedestrian load are considered. The critical condition that triggers the large lateral vibration of the footbridge is identified using the stochastic averaging method and the concept of stability based on the Lyapunov exponent. The validity of the proposed method is confirmed through case studies of three bridges. Through a parametric analysis, the effects of several crucial parameters on the stability/instability of vibration are discussed. Finally, conclusions are drawn regarding insights that can be useful to the future designs of footbridges. [ABSTRACT FROM AUTHOR]

Narrow-band imaging (NBI) is an optical technique enhancing mucosal vasculature. The aim of this study is to assess the effectiveness of rigid NBI endoscopy in the early detection of second primaries or local recurrences after treatment for oral (OSCC) and oropharyngeal squamous cell carcinoma (OPSCC), its advantage over standard white-light (WL) endoscopy, and the influence of previous radiotherapy, the learning curve, and lesion site. Between January 2013 and June 2015, 195 patients treated for OSCC or OPSCC with surgery alone (group A) or radiotherapy with or without surgery and/or chemotherapy (group B) underwent additional follow-up assessments using NBI. Sensitivity, specificity, positive/negative predictive values (PPV and NPV), and accuracy for detecting second primaries or local recurrences were calculated for patients with at least two NBI assessments. The effect of previous radiotherapy was determined by test of proportions and that of the learning curve and lesion site with Fisher's exact test. 138/195 patients were included in the analysis. NBI sensitivity, specificity, PPV, NPV, and accuracy for groups A and B were 89.5 vs 100%, 85.2 vs 81.5%, 65.4 vs 69.7%, 96.3 vs 100%, and 86.3 vs 87%, respectively. The diagnostic gain of NBI was 88.2% in group A and 69.6% in group B. The learning curve was the main source of false positives ( p = 0.025), whereas radiotherapy and lesion site were uninfluential ( p = NS). NBI appears useful for follow-up after treatment for OSCC or OPSCC, its performance being affected only by the learning curve and not by previous treatment or lesion site. [ABSTRACT FROM AUTHOR]

In this study, an expendable current profiler sensor is developed to satisfy the actual requirements of an expendable current profiler for measuring electric fields induced by ocean currents. The electric field induced by ocean currents is an important process variable for investigating the motion characteristics of ocean currents; however, accurate measurement thereof is affected by various factors. Amplitude modulation is used to modulate the measured signals into narrow-band, single-frequency signals, thereby reducing the noise level of the sensor when measuring the electric field induced by ocean currents and for extracting ocean current signals in the nanovolt range under high background noise. In this study, front-end weak signal processing circuits are designed, strong interfering signals induced by the descent of the expendable current profiler probe are partially offset by a compensation circuit for the in-phase electric field component, and useful signals are extracted using a filter circuit. System on a programmable chip technology is used for the digital processing module of the expendable current profiler probe, thereby achieving rapid development, rapid optimization, and software/hardware integration of the digital processing module, as well as enhancing the overall performance of the system. In addition, dynamic data transmission technology using an enameled wire with a diameter of 0.1 mm and a length of 2 km is developed to achieve dynamic data transmission requirements for the expendable current profiler surface float. Finally, the ocean current electric field data and ocean temperature data are acquired through experiments. [ABSTRACT FROM AUTHOR]

The uniaxial strain of quasi-one-dimensional conductor whiskers of orthorhombic TaS at a strain higher than ε ~ 0.8% leads to a sharp increase in the coherence of the properties of a charge density wave (CDW), which manifests itself in its motion in fields higher than threshold field E . During uniaxial elongation, TaS is shown to exhibit the following unusual properties even in weak fields: Peierls transition temperature T depends nonmonotonically on ε, one-dimensional fluctuations weaken near T , and the coherence length of a charge density increases at T < T . Investigations in fields higher than E show that the ultracoherent properties of CDW exist in a wide temperature range and are retained when temperature increases up to T . These properties of CDW make it possible to observe a sharp increase in E near T and an almost jumplike increase in E at T < 90 K. The increase in E at T is explained by a decrease in the coherence volume of CDW because of a fluctuational suppression of the Peierls gap. [ABSTRACT FROM AUTHOR]

Enlightened by ASTFA method, adaptive sparsest narrow-band decomposition (ASNBD) method is proposed in this paper. In ASNBD method, an optimized filter must be established at first. The parameters of the filter are determined by solving a nonlinear optimization problem. A regulated differential operator is used as the objective function so that each component is constrained to be a local narrow-band signal. Afterwards, the signal is filtered by the optimized filter to generate an intrinsic narrow-band component (INBC). ASNBD is proposed aiming at solving the problems existed in ASTFA. Gauss-Newton type method, which is applied to solve the optimization problem in ASTFA, is irreplaceable and very sensitive to initial values. However, more appropriate optimization method such as genetic algorithm (GA) can be utilized to solve the optimization problem in ASNBD. Meanwhile, compared with ASTFA, the decomposition results generated by ASNBD have better physical meaning by constraining the components to be local narrow-band signals. Comparisons are made between ASNBD, ASTFA and EMD by analyzing simulation and experimental signals. The results indicate that ASNBD method is superior to the other two methods in generating more accurate components from noise signal, restraining the boundary effect, possessing better orthogonality and diagnosing rolling element bearing fault. [ABSTRACT FROM AUTHOR]

Ultrawideband (UWB) communication channels cause pulse distortion and result in many multipath components arriving at the receiver in clusters. In this paper, the effects of lossy dielectric walls on UWB pulses are analyzed. The frequency-dependent parameters of commonly used building materials are used to analyze the effects of multiple reflections and transmissions, material distortion, and interpulse interference on the UWB pulse waveform. The possibility of polarization-dependent distortion is discussed. Various thicknesses of walls and angles of incidence are considered. The distortion due to each effect is quantified in terms of maximum correlation coefficients (MCCs). The overall effect of the wall is modeled as a tapped-delay-line filter based on the MCC. The results are used to specify the multicluster structure of UWB channel models for indoor communication. [ABSTRACT FROM PUBLISHER]

Inspired by track-before-detection technology in radar, a novel time-frequency transform, namely polynomial chirping Fourier transform (PCFT), is exploited to extract components from noisy multicomponent signal. The PCFT combines advantages of Fourier transform and polynomial chirplet transform to accumulate component energy along a polynomial chirping curve in the time-frequency plane. The particle swarm optimization algorithm is employed to search optimal polynomial parameters with which the PCFT will achieve a most concentrated energy ridge in the time-frequency plane for the target component. The component can be well separated in the polynomial chirping Fourier domain with a narrow-band filter and then reconstructed by inverse PCFT. Furthermore, an iterative procedure, involving parameter estimation, PCFT, filtering and recovery, is introduced to extract components from a noisy multicomponent signal successively. The Simulations and experiments show that the proposed method has better performance in component extraction from noisy multicomponent signal as well as provides more time-frequency details about the analyzed signal than conventional methods. [ABSTRACT FROM AUTHOR]

Narrow-band terahertz emission from coherently excited spin precession in metallic ferrimagnetic Mn3-xGa Heusler alloy nanofilms has been observed. The efficiency of the emission, per nanometer film thickness, is comparable or higher than that of classical laser-driven terahertz sources based on optical rectification. The center frequency of the emission from the films can be tuned precisely via the film composition in the range of 0.20–0.35 THz, making this type of metallic film a candidate for efficient on-chip terahertz emitters. Terahertz emission spectroscopy is furthermore shown to be a sensitive probe of magnetic properties of ultra-thin films. [ABSTRACT FROM AUTHOR]

The features of forming output radiation in a powerful monopulse single-frequency side diode-pumped laser operating in external narrow-band signal seeding mode were investigated. The monopulse single-frequency laser was fabricated of a YAG:Nd active element excited by three laser diode matrices. A compact continuous-wave YAG:Nd-laser with longitudinal diode pumping served as the seeding laser. It was shown experimentally that the transition of the monopulse laser from multimode to single-frequency lasing with a spectral line width of about 54 MHz (0.2 pm) occurs at seeding-laser radiation power P ≈ 0.14 mW (radiation intensity of 1.8·10 W/cm). Increasing the seeding-laser power over P does not lead to a noticeable change of the output characteristics of the monopulse laser for a given pump level (above the threshold). If the pump power varies from 1.5 to 3.0 kW, the P value is not changed but the energy of the output pulses of single-frequency monopulse generation increases to 40 MJ. The low level of the external narrow-band seeding signal allows us to consider the single-frequency low-power semiconductor laser as a promising source of the seeding signal. [ABSTRACT FROM AUTHOR]

Background: Magnifying endoscopy (ME) with narrow-band imaging (NBI) can visualize a white opaque substance (WOS) in gastric epithelial neoplasms, gastric intestinal metaplasias, and colorectal epithelial neoplasms. Histological examination showed the WOS to be lipid droplets accumulated in the epithelium. The white appearance of colorectal hyperplastic polyps suggests that they may contain WOS, but this has not been investigated as yet. Aims: The purpose of this study was to determine whether WOS is present in colorectal hyperplastic polyps. Methods: We retrospectively evaluated endoscopic images of 26 consecutive lesions investigated by ME with NBI and subsequently endoscopically resected and confirmed to be hyperplastic polyps. Results: WOS was present in 21 of the 26 colorectal hyperplastic polyps (80.8%) based on the findings of ME with NBI. Adipophilin was present in 24 of the 26 colorectal hyperplastic polyps (92.3%). Conclusions: This study is the first to demonstrate that WOS (i.e. lipid droplets) accumulates in the epithelium of colorectal hyperplastic polyps. [ABSTRACT FROM AUTHOR]

Background: The "resect and discard" strategy is beneficial for cost savings on screening and surveillance colonoscopy, but it has the risk to discard lesions with advanced histology or small invasive cancer (small advanced lesion; SALs). The aim of this study was to prove the principle of new "resect and discard" strategy with consideration for SALs using magnifying narrow-band imaging (M-NBI).Methods: Patients undergoing colonoscopy at a tertiary center were involved in this prospective trial. For each detected polyp <10 mm, optical diagnosis (OD) and virtual management ("leave in situ", "discard" or "send for pathology") were independently made using non-magnifying NBI (N-NBI) and M-NBI, and next surveillance interval were predicted. Histological and optical diagnosis results of all polyps were compared.Results: While the management could be decided in 82% of polyps smaller than 10 mm, 24/31 (77%) SALs including two small invasive cancers were not discarded based on OD using M-NBI. The sensitivity [90% confidence interval (CI)] of M-NBI for SALs was 0.77 (0.61-0.89). The risk for discarding SALs using N-NBI was significantly higher than that using M-NBI (53 vs. 23%, p = 0.02). The diagnostic accuracy (95% CI) of M-NBI in distinguishing neoplastic from non-neoplastic lesions [0.88 (0.86-0.90)] was significantly better than that of N-NBI [0.84 (0.82-0.87)] (p = 0.005).Conclusions: The results of our study indicated that our "resect and discard" strategy using M-NBI could work to reduce the risk for discarding SALs including small invasive cancer (UMIN-CTR, UMIN000003740). [ABSTRACT FROM AUTHOR]

The hearing sensitivity of a 2-yr-old male harbor porpoise was measured using a standard psycho-acoustic technique under low ambient noise conditions. Auditory sensitivity was measured for narrow-band 1 s sweeps (center frequencies: 0.125-150 kHz). The audiogram was U-shaped; range of best hearing (within 10 dB of maximum sensitivity) was from 13 to ~140 kHz. Maximum sensitivity (threshold: ~39 dB re 1 µPa) occurred at 125 kHz at the peak frequency of echolocation pulses produced by harbor porpoises. Reduced sensitivity occurred at 32 and 63 kHz. Sensitivity fell by ~10 dB per octave below 16 kHz and declined sharply above 125 kHz. Apart from this individual's ca. 10 dB higher sensitivity at 0.250 kHz, ca. 10 dB lower sensitivity at 32 kHz, and ca. 59 dB lower sensitivity at 150 kHz, his audiogram is similar to that of two harbor porpoises tested previously with a similar psycho-acoustic technique. [ABSTRACT FROM AUTHOR]

Antenna tuning is a very promising technique to cope with the expansion of the mobile communication frequency spectrum. Tunable antennas can address a wide range of operating frequencies, while being highly integrated. In particular, high-Q antennas (also named narrow-band antennas) are very compact, thus are good candidates to be embedded on fourth generation handsets. This study focuses on 'high-Q' tunable antennas and contributes with a characterisation of their loss mechanism, which is a major parameter in link-budget calculations. This study shows, through an example, that the tuner loss is not sufficient to explain the total loss of tunable antennas. It is found that thermal loss -because of the metal conductivity of the antenna itself - plays a major role in the loss mechanism of narrow-band tunable antennas. The investigated high-Q planar inverted F antenna designs exhibit a significant thermal loss; at 1400 MHz nearly 2 dB are lost solely because of the copper conductivity. Thermal loss poses a limitation to achievable performance of tunable antennas and to antenna miniaturisation. [ABSTRACT FROM AUTHOR]

ABSTRACT In this article, a new type of microstrip vias-free balanced-to-balanced diplexer suitable for narrow-band applications is presented. The structure of the balanced diplexer is based on two balanced bandpass filters designed for f1=1.1 GHz and f2=1.8 GHz and two transmission lines used to satisfy the open circuit conditions required in the diplexer's design. This diplexer exhibits good common-mode rejection ratio better than 40 dB at the passbands. The attenuation is better than 35 dB at the rejection bands. The isolation between output ports is better than 50 dB. Simulated and experimental results are compared with good agreement. The diplexer is easy of fabricate and integrate with others planar balanced devices. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:567-570, 2015 [ABSTRACT FROM AUTHOR]

Background: Curative treatment of patients with gastric cancer requires reliable detection of early gastric cancer. Magnifying endoscopy with narrow-band imaging (M-NBI) is useful for the accurate preoperative diagnosis of early gastric cancer. However, the role of M-NBI in screening endoscopy has not been established. The aims of this study were to determine the feasibility and limitations of M-NBI in screening endoscopy. Methods: We conducted a multicenter prospective uncontrolled trial of patients undergoing routine screening endoscopy patients. We determined the diagnostic accuracy, sensitivity and specificity of M-NBI according to the degree of certainty and need for biopsy, as assessed using the VS (vessel plus surface) classification system. We analyzed the endoscopic and histopathological characteristics of both false negative and false positive high confidence M-NBI diagnoses. We then developed a provisional diagnostic strategy based on the diagnostic performance and limitations identified in this study. Results: A total of 1097 patients were enrolled in the study. We analyzed 371 detected lesions (20 cancers and 351 non-cancers). The accuracy, sensitivity and specificity of high confidence M-NBI diagnoses were 98.1, 85.7 and 99.4 %, respectively. The false negative case was a pale mucosal lesion with tissue diagnosis of signet-ring cell carcinoma. Exclusion of pale mucosal lesions increased the accuracy, sensitivity and specificity of high confidence M-NBI diagnoses to 99.4, 100 and 99.4 %, respectively. We therefore propose a practical strategy targeting non-pale mucosal lesions. Conclusions: With a refined strategy considering its limitations, M-NBI can act as an 'optical biopsy' in screening endoscopies. [ABSTRACT FROM AUTHOR]

A finite-difference based numerical method for the simulation of multiphase incompressible flows is presented. The proposed algorithm adapts the gradient-augmented level set method of Nave et al. [25] for use in multiphase fluid simulations by interpolating the fluid velocity and introducing a simple reinitialization procedure. The method is carried out only along a narrow band surrounding the interface, reducing computational effort while preserving the advantages of the gradient-augmented method. Numerical results show excellent agreement with an analytical solution and available experimental data. A new experimental benchmark is introduced, using data gathered in a wedge-driven wave tank. In addition to the optimally local advection scheme and sub-grid resolution afforded by the new method, numerical comparisons with the standard level set method reveal superior volume conservation. [ABSTRACT FROM AUTHOR]

The mitigation of narrow-band interference (NBI) is an appealing topic in the synthetic aperture radar (SAR) community. It is an underdetermined single-channel separation problem. This paper proposes a method for NBI mitigation using the independent subspace analysis. First, each single pulse is transformed onto a manifold time-frequency distribution by the short-time Fourier transform (STFT). Then, the singular value analysis is carried out to extract the prominent features corresponding to the NBIs. Next, independent component analysis is employed to obtain statistically independent basis components. Furthermore, the independent subspaces corresponding to NBI are reconstructed and subtracted from the raw signal space. The signal with NBI mitigated is resynthesized by inverse STFT. Finally, after processing all the pulses, a well-focused SAR imagery is obtained by a conventional imaging algorithm. Experimental results of simulated and measured data have demonstrated the effectiveness of the proposed method. [ABSTRACT FROM PUBLISHER]

The nonclassical photon pair, generated via a parametric process, is naturally endowed with a specific form of frequency-time quantum correlations. Here, we report complete control of frequency-time quantum correlations of narrow-band biphotons generated via spontaneous four-wave mixing in a cold atomic ensemble. We have experimentally confirmed the generation of frequency-anticorrelated, frequency-correlated, and frequency-uncorrelated narrow-band biphoton states, as well as verifying the strong nonclassicality of the correlations. Our work opens up new possibilities for engineering narrow-band entangled photons for various quantum optical and quantum information applications. [ABSTRACT FROM AUTHOR]

ABSTRACT A meandered substrate integrated waveguide (SIW) has been proposed for the frequency scanning array that has potential application of the low cost 24-GHz Doppler radar system. All radiating slots are connected in series using a short circuit ended SIW; therefore, its radiation beam can be steered with frequency. The modified antenna with meandering structure is proposed to enhance the scanning range. The physical slot spacing is kept at about half free space waveguide, whereas the electrical spacing is about 540° at the center frequency of 24 GHz. A broadside radiation is achieved at 24-GHz frequency and a ±30° continuous scanning range is experimentally confirmed with the frequency band from 23 to 25 GHz. Another antenna with center frequency of 77 GHz is designed and tested. It also achieves a ±30° continuous scanning range with the frequency band from 75 to 79 GHz. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1478-1483, 2014 [ABSTRACT FROM AUTHOR]

ABSTRACT A novel single-feed circularly polarized microstrip antenna with compact size is proposed for indoor wireless local area network (WLAN) applications. The antenna structure consists of eight slits which are introduced at the boundary and the corners in the radiating square patch with a cross-slot at the center. The proposed antenna shows a compactness of 42% compared with the conventional circularly polarized antenna design at indoor WLAN frequency band. It is found that the resonance frequency of the proposed structure is highly depending on length and width of cross-slot and corner slit for entire band of circular polarization. The 3 dB axial ratio bandwidth of the proposed antenna is 1.9%. Proposed structure is fabricated on the FR-4 epoxy substrate and fed by a single coaxial probe. Measured results show a good agreement with the simulated results. Antenna shows stable radiation characteristics for the entire operating band. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1313-1317, 2014 [ABSTRACT FROM AUTHOR]

In this paper, we propose a low-complexity blind carrier frequency offset (CFO) estimation scheme for constant modulus (CM)-signaling-based orthogonal frequency-division multiplexing (OFDM) systems. Provided that the channel can be assumed to be slowly time-varying, subcarriers having the same indexes in two consecutive OFDM symbols will experience nearly the same channel effect. This assumption enables us to derive a cost function that is determined by the sum of the products of the signal amplitudes on each pair of equivalent subcarriers from two successive OFDM symbols. The maximization process of this cost function makes it possible to find an appropriate estimate of the CFO. Over frequency-selective Rayleigh fading channels, the proposed CFO estimation method provides improved performance over existing techniques. Moreover, in the context of narrow-band noise and signal gain variations, the simulations demonstrate the robustness and immunity of our scheme. [ABSTRACT FROM PUBLISHER]

Peak filtering methods are commonly used in track-following control of hard disk drives (HDDs) to suppress narrow-band disturbances around a specific frequency. When there are significant plant dynamics within the bandwidth of the filter, the closed-loop system is prone to be unstable due to the lightly damped poles of the filter, as well as lightly damped poles of the plant. On the other hand, settling response of such peak filters during shock disturbances is slow, and increases tremendously with decreasing damping ratios. In this article, we present a novel design of peak filters with improved transient responses using a phase scheduling method in addition to varying gain and damping ratio. By doing so, the stability margin of the closed-loop systems during both transient stage and steady-state stage will be improved. The effectiveness of the proposed methodology is verified with extensive simulations and the proposed method is then applied in an integrative servo analysis platform to carry out a scaling exercise to evaluate and predict servo performance to support 10 Terabits/in2. [ABSTRACT FROM AUTHOR]

A planar generator based on a free-electron maser (FEM generator) is developed employing a relativistic sheet electron beam (0.8 MeV/1 kA/4 μs) formed by an ELMI accelerator. A hybrid two-mirror resonator consisting of a two-dimensional upstream and a one-dimensional downstream Bragg reflectors is used as the electrodynamic system. The use of two-dimensional distributed feedback implemented in the upstream Bragg structure has made it possible to achieve stable well reproducible single mode generation regime with transverse dimensions of the system of ∼25 × 2.5 wavelengths. Experiments carried out at a frequency of 75 GHz have yielded narrow-band radiation with spectrum width of ∼20 MHz in pulses with a duration of ∼100-200 ns and power of 30-50 MW. [ABSTRACT FROM AUTHOR]

This paper presents a low-cost hyperspectral measurement setup in a new application based on fluorescence detection in the visible (Vis) wavelength range. The aim of the setup is to take hyperspectral fluorescence images of viscous materials. Based on these images, fluorescent and non-fluorescent impurities in the viscous materials can be detected. For the illumination of the measurement object, a narrow-band high-power light-emitting diode (LED) with a center wavelength of 370 nm was used. The low-cost acquisition unit for the imaging consists of a linear variable filter (LVF) and a complementary metal oxide semiconductor (CMOS) 2D sensor array. The translucent wavelength range of the LVF is from 400 nm to 700 nm. For the confirmation of the concept, static measurements of fluorescent viscous materials with a non-fluorescent impurity have been performed and analyzed. With the presented setup, measurement surfaces in the micrometer range can be provided. The measureable minimum particle size of the impurities is in the nanometer range. The recording rate for the measurements depends on the exposure time of the used CMOS 2D sensor array and has been found to be in the microsecond range. [ABSTRACT FROM AUTHOR]

Fundamental bandwidth limitations on the design of ultra high frequency (UHF) radio frequency identification (RFID) tags are investigated. This study was conducted by considering the optimum equivalent-circuit network necessary for bandwidth broadening in single resonant UHF-RFID tags with conjugate matching. This equivalent-circuit network is simply a parallel combination of an inductor and a resistor cascaded to the UHF-RFID chip. Bandwidth optimisation of the resulting network is validated by means of the Bode criterion. According to this analysis, a broadband UHF-RFID tag prototype able to operate worldwide is designed and fabricated. In order to reduce tag size and cost, the external matching network is omitted in the reported implementation. The measured read ranges are above 5 m within the whole UHF-RFID frequency band (840- 960 MHz), with a peak value of 9 m at 870 MHz. [ABSTRACT FROM AUTHOR]

The estimation of the directions of arrival (DoAs) of narrow-band signals impinging on a linear antenna array is addressed within the Bayesian compressive sensing (BCS) framework. Unlike several state-of-the-art approaches, the voltages at the output of the receiving sensors are directly used to determine the DoAs of the signals thus avoiding the computation of the correlation matrix. Towards this end, the estimation problem is properly formulated to enforce the sparsity of the solution in the linear relationships between output voltages (i.e., the problem data) and the unknown DoAs. Customized implementations exploiting the measurements collected at a unique time instant (single-snapshot) and multiple time instants (multiple-snapshots) are presented and discussed. The effectiveness of the proposed approaches is assessed through an extensive numerical analysis addressing different scenarios, signal configurations, and noise conditions. Comparisons with state-of-the-art methods are reported, as well. [ABSTRACT FROM PUBLISHER]

Abstract: In this paper a second iteration Sierpinski carpet fractal shape UWB antenna with hexagonal boundary is presented. The antenna covers the frequency band from 3GHz to 12GHz (VSWR≤2). The proposed antenna has the capability to reject 5.15–5.825GHz band assigned for IEEE802.11a and HIPERLAN/2 which is achieved by embedding a ‘Y’ shaped slot in the radiator that extends to the central conductor of the CPW feed as well. A fabricated prototype is developed where the simulation and experimental results are in good agreement. Measured peak antenna gain varies from 1.25dBi to 6dBi within the band. The proposed antenna has a compact size of 33mm×32mm that includes the substrate around the radiating element. Time domain characteristic reveal that the antenna is non-dispersive with a variation of measured group delay within 0.5ns over the entire band. [Copyright &y& Elsevier]

This article presents a novel interdigital capacitor resonator (ICR), which has a high spurious frequency and compact size. A six-pole high-temperature superconducting (HTS) bandpass filter (BPF) has been designed and fabricated with this ICR on a double-sided MgO-based YBCO thin film. Measurement at cryogenic temperature shows a fractional bandwidth of 0.4%, and an ultra high spurious passband at about 4.1 f0. Moreover, the measurement shows a good agreement with simulation in wideband response. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:443-447, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27324 [ABSTRACT FROM AUTHOR]

A novel discrete model (D model) is presented describing nonlinear wave interactions in systems with small and moderate nonlinearity under narrow frequency band excitation. It integrates in a single theoretical frame two mechanisms of energy transport between modes, namely, intermittency and energy cascade, and gives the conditions under which each regime will take place. Conditions for the formation of a cascade, cascade direction, conditions for cascade termination, etc., are given and depend strongly on the choice of excitation parameters. The energy spectra of a cascade may be computed, yielding discrete and continuous energy spectra. The model does not require statistical assumptions, as all effects are derived from the interaction of distinct modes. In the example givenÂ--surface water waves with dispersion function Ï%² = gk and small nonlinearityÂ--the D model predicts asymmetrical growth of side-bands for Benjamin-Feir instability, while the transition from discrete to continuous energy spectrum, excitation parameters properly chosen, yields the saturated Phillips' power spectrum ~g²Ï%-5. The D model can be applied to the experimental and theoretical study of numerous wave systems appearing in hydrodynamics, nonlinear optics, electrodynamics, plasma, convection theory, etc. [ABSTRACT FROM AUTHOR]

The diagnosis of early gastric cancer by magnifying endoscopy with NBI is based on two components: microvascular pattern and mucosal pattern.Mucosal patterns are characterized by a whitish edge, which has been named the white zone. Some cancerous areas showing a distinct white zone form clear mucosal patterns, whereas others showing a nondistinct white zone do not form mucosal patterns. The aim of the present study was to clarify the histological differences between these two types of area. In transverse sections of gastric epithelium, the lengths of intervening parts in areas showing a distinct white zone, a nondistinct white zone, and an invisible white zone were measured, and the depths of the crypts in these three types of area were also measured. The intervening parts in areas with a nondistinct or invisible white zone were shorter than those in areas with a distinct white zone (P < 0.05), and the crypts in the former areas were shallower than those in the latter (P < 0.01). Areas in which the intervening part were long and the crypts deep tended to show a distinct white zone, whereas areas with short intervening parts or shallow crypts tended to show a nondistinct or non-visible white zone. [ABSTRACT FROM AUTHOR]

Aim. To compare narrowband imaging (NBI) and autofluorescence imaging (AFI) endoscopic visualization for identifying superficial esophageal squamous cell carcinoma (SCC). Methods. Twenty-four patients with superficial esophageal carcinomas diagnosed at previous hospitals were enrolled in this study. Lesions were initially detected using white-light endoscopy and then observed with both NBI and AFI. Endoscopic images documented each method, and three endoscopists experienced in esophageal imaging retrospectively reviewed respective images of histologically confirmed esophageal SCCs. Images were assessed for quality in identifying superficial SCCs and rated as excellent, fair, or poor by the three reviewers with interobserver agreement calculated using kappa (?) statistics. Results. Thirty-one lesions histologically confirmed as superficial esophageal SCCs were detected in 24 patients. NBI images of 27 lesions (87%) were rated as excellent, three as fair, and one as poor compared to AFI images of 19 lesions (61%) rated as excellent, 10 as fair and two as poor (P < 0.05). Moderate interobserver agreement (? = 0.42, 95% CI 0.24-0.60) resulted in NBI while fair agreement (? = 0.35, 95% CI 0.18-0.51) was achieved using AFI. Conclusion. NBImay be more effective than AFI for visualization of esophageal SCC. [ABSTRACT FROM AUTHOR]

Narrow band imaging (NBI), in conjunction with magnifying endoscopy (ME), has arisen more and more attention in the area of advanced endoscopy. By enhancing the mucosal microvascular architecture and surface pattern, it is feasible to use ME-NBI to identify subtle changes associated with gastric inflammation, atrophy, intestinal metaplasia, and early gastric cancer. The new technique thus plays a valuable role in therapeutic decision-making, endoscopic treatment process, postoperative evaluation, and follow-up examination. To date, many criteria or evaluation method of ME-NBI has been proposed. This paper aims to summarize the various diagnosing classifications and the current clinical applications of ME-NBI in the stomach. [ABSTRACT FROM AUTHOR]

Although magnifying chromoendoscopy had been a reliable diagnostic tool, narrow-band imaging (NBI) has been developed in Japan since 1999 and has now replaced the major role of chromoendoscopy because of its convenience and simplicity. In this paper, we principally describe the efficacy of magnifying chromoendoscopy and magnifying colonoscopy with NBI for detection, histological prediction, estimation of the depth of early colorectal cancer, and future prospects. Although some meta-analyses have concluded that NBI is not superior to white light imaging for detection of adenomatous polyps in screening colonoscopy, NBI with magnification colonoscopy is useful for histological prediction, or for estimating the depth of invasion. To standardize these diagnostic strategies, we will focus on the NBI International Colorectal Endoscopic (NICE) classification proposed for use by endoscopists with or without a magnifying endoscope. However, more prospective research is needed to prove that this classification can be applied with satisfactory availability, feasibility, and reliability. In the future, NBI might contribute to the evaluation of real-time histological prediction during colonoscopy, which has substantial benefits for both reducing the risk of polypectomy and saving the cost of histological evaluation by resecting and discarding diminutive adenomatous polyps (resect and discard strategy). [ABSTRACT FROM AUTHOR]

The gravitational-wave (GW) sky may include nearby pointlike sources as well as stochastic backgrounds. We perform two directional searches for persistent GWs using data from the LIGO S5 science run: one optimized for pointlike sources and one for arbitrary extended sources. Finding no evidence to support the detection of GWs, we present 90% confidence level (C.L.) upper-limit maps of GW strain power with typical values between 2 - 20 x 10-50 strain² Hz-1 and 5 - 35 x 10-49 strain² Hz-1 sr-1 for pointlike and extended sources, respectively. The latter result is the first of its kind. We also set 90% C.L. limits on the narrow-band root-mean-square GW strain from interesting targets including Sco X-1, SN 1987A and the Galactic center as low as ≈ 7 x 10-25 in the most sensitive frequency range near 160 Hz. [ABSTRACT FROM AUTHOR]

A geometrical theory is proposed for depolarization in narrow-band fixed-to-mobile (F2M) and mobile-to-mobile (M2M) wireless channels. This novel theory is used to reveal the origin of channel depolarization and to provide a mechanism for computing cross-polarization discrimination (XPD). Based on the superposition of polarization components on conservation-of-polarization planes, a new 3-D geometry-based reference model is proposed for XPD in narrow-band F2M and M2M wireless channels. This purely theoretical approach is used to derive the XPD without the aid of measurement data or its approximation. The geometrical theory and reference model provide a relationship between channel depolarization or XPD and channel modeling factors such as the distance between the transmitter (Tx) and the receiver (Rx), the azimuth/elevation angles of arrival and departure, and the distribution of scatterers around the Tx and/or the Rx. Our geometry-based XPD model shows good agreement with previously reported empirical results from other authors and provides insight on the detailed behavior observed in their XPD measurements. [ABSTRACT FROM PUBLISHER]

Background: Various methods are reported as aids to cecal intubation for cases in which colonoscopy is difficult. This study aimed to investigate prospectively whether a gastroscope with magnification function, narrow-band imaging (NBI), and a soft black hood can aid insertion in cases of difficult colonoscopy and facilitate both accurate diagnosis and safe treatment. Methods: This prospective study recruited 177 patients. All were examined with a magnifying gastroscope. A commercially available soft black hood was attached to the gastroscope during insertion and magnification. Difficult colonoscopy was anticipated before colonoscopy in cases of patients with at least one of the following factors: low BMI (<20 kg/m), adhesion due to previous surgery, or previous colonoscopy that could not reach to the cecum. The success rate and duration of cecal intubation then were assessed. All detected lesions were evaluated by magnifying NBI and then classified as non-neoplastic or neoplastic for endoscopic diagnosis. Subsequently, all the lesions were removed and examined histologically for comparison. Results: The overall success rate of cecal intubation was 100% (177/177), and the mean time taken to reach the cecum was 5.9 min. A total of 156 lesions were detected endoscopically, and the overall diagnostic accuracy of NBI with magnification was 98.7%. No associated complications occurred. Conclusion: Magnifying gastroscopy using a soft black hood and NBI is useful for cecal intubation in cases wherein colonoscopy is difficult, facilitating accurate diagnosis and safe treatment. [ABSTRACT FROM AUTHOR]

The popular algorithms for wideband source localization pass the data through a bank of narrowband filters, and use the narrowband signal model for subsequent processing of the filter-bank output. This requires a large time window over which the data must be collected. We propose a new low-rank signal model, which does not rely on the narrowband signal model. In this way we can avoid narrowband filtering. The model is applicable to arbitrary array geometries, and is useful in both far-field and near-field problems. A subspace algorithm for source localization using the new model is proposed, which requires significantly smaller time window to yield reliable results. [ABSTRACT FROM PUBLISHER]

We present a photometric study of UGC 4599, a low-luminosity galaxy superficially resembling Hoag's Object in that on sky survey images it appears to be a complete ring surrounding a roundish core. The nature of the outer ring of Hoag-type galaxies is still debated and may be related either to slow secular evolution or to environmental processes, such as galaxy-galaxy interactions. As the nearest of its kind, UGC 4599 is a perfect target for a detailed study of the peculiar structure of this type of objects. Surface photometry of the central body of the ring and the ring itself was performed using GALEX, Sloan Digital Sky Survey (SDSS) and Two Micron All Sky Survey (2MASS) photometric data available online. To identify bright clumps across the ring that could be H regions associated with the ring we obtained images of UGC 4599 at the Wise Observatory through U-, B- and R-band and narrow-band rest-frame Hα filters. Although classified in HyperLEDA as S0 with an external ring, we show that in UGC 4599 (a) the nearly round central body follows well an light profile almost all the way to the centre, (b) the isophotes are strongly twisted with a sharp transition at a radius of arcsec, (c) the blue ring seems to have reached near-equilibrium configuration with the central body, (d) the ring is actually composed of a one-and-a-half turn spiral feature and (e) one side of the spiral shows conspicuous star formation in the form of at least nine H regions, revealed by their Hα emission. Based on the photometric data, together with H information from the literature, we characterize UGC 4599 as an elliptical-like object surrounded by a luminous ring and a massive, extremely extended H disc. Given its observed properties, we rule out UGC 4599 as representing a late phase in barred early-type galaxies evolution. We discuss the origin of UGC 4599 and conclude that this galaxy could be the result of a major interaction between two gas-rich spiral galaxies that took place at least 5 Gyr ago. However, deep optical imaging and a detailed stellar population analysis are required to determine whether the large gas reservoir could have been accreted directly from the intergalactic medium on to a pre-existing elliptical galaxy in the early Universe. A detailed kinematical study will shed light on the exact nature of the central body and the ring of UGC 4599. [ABSTRACT FROM AUTHOR]

Several previous studies have identified narrow-band imaging (NBI) with magnification as being useful in evaluating early colorectal cancer invasion depth, but comparative diagnostic accuracy of invasion depth between pit pattern analysis using magnifying chromoendoscopy and NBI remains unclear. The aim of this retrospective study was to compare NBI and pit pattern analysis using magnifying chromoendoscopy in estimating early colorectal cancer invasion depth and to assess interobserver agreement. We analyzed a total of 72 early colorectal cancers in 72 patients fulfilling the inclusion criteria. Each lesion image was subsequently reviewed by two experienced colonoscopists (A, B) and then classified clinically based on invasive/non-invasive pattern and Sano's capillary pattern classification with a five-point scale of confidence. In terms of diagnostic accuracy with confidence for A and B, the areas under the receiver operating characteristics curve were 0.84 and 0.81 for pit pattern analysis and 0.82 and 0.79 for NBI, respectively. Interobserver agreement for the diagnosis of submucosal deep (>1000 µm) invasion was evaluated for both modalities and indicated substantial agreement with pit pattern analysis (κ = 0.63) and moderate agreement with NBI (κ = 0.44). Estimating invasion depth of early colorectal cancer using NBI appeared to have been comparable to pit pattern analysis, but there was greater interobserver variability using NBI. [ABSTRACT FROM AUTHOR]

This paper constitutes a major attempt to associate tympanic deflections with the mechanoreceptor organ location in an acoustic insect. The New Zealand tree weta (Hemideina thoracica) has tympanal ears located on each of the prothoracic tibiae. The tympana exhibit a sclerotized oval plate, membranous processes bulging out from the tibial cuticle and many loosely suspended ripples. We used microscanning laser Doppler vibrometry to determine how such a tympanal membrane vibrates in response to sound and whether the sclerotized region plays a role in hearing. The tympanum displays a single resonance at the calling frequency of the male, an unusual example of an insect tympana acting as a narrow bandpass filter. Both tympana resonate in phase with the stimulus and with each other. Histological sections show that the tympanal area is divided into two distinct regions, as in other ensiferans. An oval plate lies in the middle of a thickened region and is surrounded by a transparent and uniformly thin region. It is hinged dorsally to the tympanal rim and thus resembles the model of a 'hinged flap'. The thickened region appears to act as a damping mass on the oscillation of the thin region, and vibration displacement is reduced in this area. The thinner area vibrates with higher amplitude, inducing mechanical pressure on the dorsal area adjacent to the crista acustica. We present a new model showing how the thickened region might confer a mechanical gain onto the activation of the crista acustica sensory neurons during the sound-induced oscillations. [ABSTRACT FROM AUTHOR]

We have used Hα narrow-band imaging to search for star-forming satellite galaxies around 143 luminous spiral galaxies, with the goal of quantifying the frequency of occurrence of satellites resembling the Magellanic Clouds, around galaxies comparable to the Milky Way. For two-thirds of the central galaxies, no star-forming satellites are found, down to luminosities and star formation rates well below those of the Magellanic Clouds. A total of 62 satellites are found, associated with 47 of the central galaxies searched. The R-band magnitude difference between central galaxies and their satellites has a median value of 4.6 mag and a maximum value of 10.2 mag. The mean projected separation of the satellites from their central galaxies is 81 kpc, or 98 kpc for systems beyond 30 Mpc. Thus, star-forming satellites are quite rare, and the Milky Way is unusual both for the luminosity and the proximity of its two brightest satellites. We also find that the Clouds themselves are unusual in that they appear to form a bound binary pair; such close satellite pairs, of any luminosity, are also extremely rare in our survey. [ABSTRACT FROM AUTHOR]

Abstract: A new line intensity distribution function is introduced in order to improve the accuracy of statistical narrow-band (SNB) models in the Doppler line broadening regime and in a wide temperature range. This distribution function generalizes the Malkmus distribution through a parameter enabling to adjust the contribution of small line intensities. This new model is shown to enhance significantly SNB accuracy for CO2 uniform column radiation, especially at low temperatures. For non-uniform columns, Lindquist–Simmons type approximations are derived for this new intensity distribution. Their results are in much closer agreement with line by line results than Curtis–Godson approximation ones when steep temperature gradients are considered. [ABSTRACT FROM AUTHOR]

Abstract: The aim of this study was to investigate the functionality of cochlear active mechanisms in normal-hearing subjects affected by Williams syndrome (WS). Transient evoked otoacoustic emissions (TEOAEs) were recorded in a group of young WS subjects and a group of typically developing control subjects, all having normal-hearing thresholds and normal middle-ear functionality. We also analysed the narrow-band frequency components of TEOAEs, extracted from the broad-band TEOAE recordings by using a time–frequency analysis algorithm based on the Wavelet transform. We observed that TEOAEs and the frequency components extracted from TEOAEs measured in WS subjects had significantly lower energy compared to the controls. Also, the narrow-band frequency components of TEOAEs measured in WS subjects had slightly increased latency compared to the controls. Overall, results would suggest a subtle (i.e., sub-clinical) dysfunction of the cochlear active mechanisms in WS subjects with otherwise normal hearing. Also, results point out the relevance of using otoacoustic emissions in the audiological evaluation and monitoring of WS subjects to early identify possible subtle auditory dysfunctions, before the onset of mild or moderate hearing loss that could exacerbate language or cognitive impairments associated with WS. [Copyright &y& Elsevier]

This study focuses on the narrow-band radar imaging for high-speed spinning targets. Based on the time–frequency characteristic of the echoed signal, a novel coherent spectrogram redistribution method, coherent single range Doppler interferometry (CSRDI), is proposed, which is capable of generating high-resolution imagery by applying a phase matched processing. Furthermore, the approach performs well at low signal-to-noise ratio. The spinning rate error is also taken into consideration and an estimation approach based on the focal entropy is proposed. The validity is confirmed by real data and numerical simulations. [ABSTRACT FROM AUTHOR]

Formulas are derived for computing performance gain that is achieved by coherent integration over noncoherent integration in detection schemes based on polyphase fast Fourier transform (FFT) and FFT filter banks. Numerical computation of the processing gain is then discussed. The crucial role that is played by window energy normalization in detection performance comparisons, which has never been recognized in the literature, is emphasized and analyzed. The numerical results provided for typical implementation parameters are useful for making appropriate tradeoffs in the design of solutions for practical signal detection problems. [ABSTRACT FROM AUTHOR]