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Wide color gamut display has become a new generation of display technology because of its good color saturation. However, the low quantum efficiency and wide half peak width of narrow‐band green phosphors are still the main barriers in their development and application. This work addresses these challenges by using Mn2+ as the luminescent center and constructing efficient Eu2+ → Mn2+ energy transfer in Na2MgAl10O17 (NMAO) matrix. The NMAO:0.15Eu2+, 0.30Mn2+ phosphor presents a single‐band emission peaking at 513 nm with a full width at half maximum (FWHM) of only 33 nm under the excitation of 365 nm LED chip. In addition, under the excitation wavelength of 365 nm, the energy transfer efficiency reaches 74%. Compared with the NMAO:0.30Mn2+, the intensity of the NMAO:0.15Eu2+, 0.30Mn2+ increases by 5.5 times and the internal quantum efficiency is up to 61.82%. A white LED device with the CIE coordinates of (0.2871, 0.3472) and a color gamut area of 94% NTSC has been assembled successfully by combining 365 nm LED chips with NMAO:0.15Eu2+, 0.30Mn2+, BaMgAl10O17:Eu2+, and K2SiF6:Mn4+ as green, blue, and red component. This work enriches the relevant content of Mn2+‐doped phosphors and provides a constructive insight into improving luminescent performance through energy transfer. [ABSTRACT FROM AUTHOR]

Electrofluorochromic (EFC) materials and devices with controllable fluorescence properties show great application potential in advanced anticounterfeiting, information storage and display. However, the low color purity caused by the broad emission spectra and underperforming switching time of the existing EFC materials limit their application. Through biomimetic exploration and the study of reversible electrochemical responsive coordination reactions, boron–nitrogen embedded polyaromatics (B,N‐PAHs) with narrow‐band emission and high color purity have been successfully integrated into EFC systems, which also help to better understand the role of boron in biological activity. The EFC device achieve good performance containing quenching efficiency greater than 90% within short switching time (ton: 0.6 s, toff: 2.4 s), and nearly no performance change after 200 cycles test. Three primary color (red, green, and blue) EFC devices are successfully prepared. In addition, new phenomena are obtained and discussed in this biomimetic exploration of related boron reactions. The success and harvest of this exploration are expected to provide new ideas for optimizing properties and broadening applications of EFC materials. Moreover, it may provide ideas and reference significance for further exploring and understanding the function of boron compounds in biological systems. [ABSTRACT FROM AUTHOR]

Summary: The proposed antenna is a small wideband monopole with wideband circular polarization using heterogeneous bidirectional recurrent neural network for both narrow and wide band applications (NWB‐MAD‐HBRNN). The electromagnetic structure is designed, fabricated, and simulated with 1 mm thickness on FR4 substrate material along dielectric constant 4.3. The proposed antenna includes 4.3–8.85 GHz for ultrawideband applications; it contains reconfigurable narrow band for L‐band 1.27 GHz, LTE, and ultrawideband applications. To enhance the antenna impedance bandwidth (BW) along axial ratio bandwidth (ARBW), a slit is etched at the antenna patch, a rectangular stub is inserted into the ground plane, and semicircular stub is added to the top of antenna feed line. The better agreement is observed in the measured and simulated gain performance of 4.8 dB for LTE band applications. The proposed NWB‐MAD‐HBRNN design provides 13.50%, 18.91%, and 22.58% higher bandwidth and 18.36%, 20.38%, and 27.58% lower return loss than the existing designs, such as bio‐inspired wideband antenna for wireless applications based on perturbation technique (BWA‐WA‐PA), a compact circularly polarized modified printed monopole antenna for wireless applications (CCP‐MPMA‐WA), and new multiband monopole antenna for certain broadband wireless applications along wireless personal communications (PA‐MMA‐BWA), respectively. [ABSTRACT FROM AUTHOR]

Abstract Electrofluorochromic (EFC) materials and devices with controllable fluorescence properties show great application potential in advanced anticounterfeiting, information storage and display. However, the low color purity caused by the broad emission spectra and underperforming switching time of the existing EFC materials limit their application. Through biomimetic exploration and the study of reversible electrochemical responsive coordination reactions, boron–nitrogen embedded polyaromatics (B,N‐PAHs) with narrow‐band emission and high color purity have been successfully integrated into EFC systems, which also help to better understand the role of boron in biological activity. The EFC device achieve good performance containing quenching efficiency greater than 90% within short switching time (ton: 0.6 s, toff: 2.4 s), and nearly no performance change after 200 cycles test. Three primary color (red, green, and blue) EFC devices are successfully prepared. In addition, new phenomena are obtained and discussed in this biomimetic exploration of related boron reactions. The success and harvest of this exploration are expected to provide new ideas for optimizing properties and broadening applications of EFC materials. Moreover, it may provide ideas and reference significance for further exploring and understanding the function of boron compounds in biological systems.

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Using characteristic mode analysis (CMA), a pair of ultra-wideband (UWB) and narrow band antennas is made. The Multiple Input Multiple Output (MIMO) configuration incorporates a circular monopole to attain UWB functionality, while an umbrella-shaped element generates the narrowband operation. The two radiators are symmetrically positioned to accomplish space diversity. Distinct sizes of small electromagnetic band gap cells separate the two radiators. The MIMO structure has dimensions of 40×40×1.6 mm3 (0.32λo×0.32λo×0.12 λo) and improved isolation is accomplished by adding a T-shaped stub to the ground plane. The exceptional bandwidth of 11.6 GHz offered by the Circular-pot UWB antenna covers a frequency range from 2.4 GHz to 14 GHz. The antenna demonstrates favorable MIMO performance, featuring a gain of 4.9dBi, isolation exceeding 23 dB. The diversity characteristics encompass an enveloped correlation coefficient (ECC) of under 0.0012, a diversity gain (DG) approaching 10 dB, a channel capacity loss of 0.28 b/s/Hz, and a mean effective gain (MEG) measuring -3.3 dB. A favorable agreement between the tested and simulated results.

In order to improve the efficiency of particle-based fluid surface reconstruction, this paper proposed a perspective-grid-based adaptive narrow-band surface particle extraction method. Compared with the object-space-based method, this scheme adaptively extracted the surface particles closest to the viewpoint within the frustum according to the particle density, dispersion coefficient, so that the number of surface particles and memory consumption were related to the visible surface area, rather than the entire fluid surface or simulation domain. In addition, this paper presented an adaptive thickness estimation method based on particle density by taking advantage of the arrangement of perspective grids along the view. Experiments show that this scheme effectively reduces surface particles by 40% to 76% and memory overhead by 30% to 50%,solves the problems of surface particle redundancy and holes, and quickly obtains thickness information at a lower cost. This scheme brings significant performance improvement for surface reconstruction and rendering, and can better handle the surface reconstruction and rendering of large-scale particle sets. [ABSTRACT FROM AUTHOR]

Narrow-band deep-blue organic light-emitting diodes (OLEDs) have played a key role in the field of high-quality full-color displays. However, because of the considerable challenges of inherent band gaps, unbalanced carrier injection and the lack of molecular structures, narrow-band deep-blue emitters develop slowly compared with red- and green-emitting materials. Encouragingly, with the continuous efforts of scientists in recent years, great progress has been made in the molecule design and material synthesis of highly efficient narrow-band deep-blue emitters. The typical deep-blue emitters which exhibit narrow emission with a full width at half maximum of < 50 nm are summarized in this article. They are divided into the three categories: fluorescence, phosphorescence and thermally activated delayed fluorescence. The methods of molecular design for realizing narrow-band deep-blue emission are described in detail and future research directions are also discussed in this article. [ABSTRACT FROM AUTHOR]

There are very few results in the literature on spectral content of seismic ground displacement; nonetheless, these results are singular as most of the spectral content is limited to a very narrow low frequency band, contrary to ground acceleration. These few spectral characterizations have been obtained, expectedly, by means of power spectral or Fourier analyses of ground displacement records, only. As these records are not as reliable as ground acceleration records, the existence of a clear predominant frequency in ground displacement warrants confirmation through a different procedure. We propose a corroboration method of this highly narrow-band characteristic that is based on the more dependable acceleration signal, rather than on the same ground displacement record that is the subject of study. Specifically, displacement response spectra are analyzed (which rely on acceleration records) to verify previously observed neat predominant frequencies in ground displacement, which is a novelty. [ABSTRACT FROM AUTHOR]

Plasmonic metal nanostructures have promising applications in biosensing due to their ability to facilitate light–matter interaction. However, the damping of noble metal leads to a wide full width at half maximum (FWHM) spectrum which restricts sensing capabilities. Herein, we present a novel non-full-metal nanostructure sensor, namely indium tin oxide (ITO)–Au nanodisk arrays consisting of periodic arrays of ITO nanodisk arrays and a continuous gold substrate. A narrow-band spectral feature under normal incidence emerges in the visible region, corresponding to the mode-coupling of surface plasmon modes, which are excited by lattice resonance at metal interfaces with magnetic resonance mode. The FWHM of our proposed nanostructure is barely 14 nm, which is one fifth of that of full-metal nanodisk arrays, and effectively improves the sensing performance. Furthermore, the thickness variation of nanodisks hardly affects the sensing performance of this ITO-based nanostructure, ensuring excellent tolerance during preparation. We fabricate the sensor ship using template transfer and vacuum deposition techniques to achieve large-area and low-cost nanostructure preparation. The sensing performance is used to detect immunoglobulin G (IgG) protein molecules, promoting the widespread application of plasmonic nanostructures in label-free biomedical studies and point-of-care diagnostics. The introduction of dielectric materials effectively reduces FWHM, but sacrifices sensitivity. Therefore, utilizing structural configurations or introducing other materials to generate mode-coupling and hybridization is an effective way to provide local field enhancement and effective regulation. [ABSTRACT FROM AUTHOR]

Accurate stratospheric temperature observations are crucial for weather forecasts and climate change studies. This paper discusses a precise measurement method for the stratospheric temperature profile using narrow bands with ultra-high spectral resolution from nadir-viewing satellites. First, the CO2 absorption band around 15 μm is selected as the major sounding source by the calculation and analysis of the temperature Jacobian and the atmospheric molecular spectra. Next, the influence of spectral resolution, spectral range and instrumental noise on the sounding capability is analyzed, and the sounding feasibility of the single spectral band and multiple spectral bands is discussed under the condition that the spaceborne long-wave infrared space heterodyne spectrometer (SHS) is selected as suggested sounder onboard the satellite. Finally, the optimal joint-sounding scheme of narrow bands is proposed. The temperature retrieval and validation show that the joint-sounding of two discontinuous narrow bands can realize the high precision measurement of the stratospheric temperature profile for the given spectral resolution, spectral range, and instrumental noise. When the sounder adopts two narrow bands (the regions of 666.87–676.44 cm−1 and 683.58–693.15 cm−1) and a spectral resolution of 0.03 cm−1, the retrieval accuracy (RMSE) is about 0.9 K over a pressure range of 200 to 0.7 hPa (11.5–50 km). This study will provide technical preparation for high-precision and low-cost satellite sounder design for stratospheric temperature observations. [ABSTRACT FROM AUTHOR]

This paper proposes a quad-band graphene-based terahertz (THz) metamaterial perfect absorber for refractive index sensing. This proposed absorber consists of concentric hexagon-shaped rings on top of a thin graphene sheet and is numerically simulated using the Finite Integration Technique (FIT) and achieves four absorption peaks, i.e., 94.86%, 99.13%, 98%, and 99.37% at 2.9626 THz, 3.1576 THz, 3.4891 THz, and 3.9259 THz, respectively, at Fermi energy of 0.2 eV. In addition to this, this absorber is insensitive to the polarization of the incident wave. This proposed absorber can be used as a refractive index sensor to detect several chemicals whose refractive index varies from n = 1.33 to 1.54 with a sensitivity of 1.42 THz/RIU, 1.54 THz/RIU, 1.68 THz/RIU, and 1.90 THz/RIU where RIU stands for refractive index unit. By varying an external DC-bias voltage which changes the Fermi energy of the graphene layer, the absorption spectra of the proposed absorber can be adjusted. So, the Fermi energy of thin graphene sheet has been varied, and it is observed that the resonance frequency varied linearly with the refractive index, particularly at Fermi energy of 0.4 eV. The FoM (figure of merit) and Q-factor of four absorption peaks of this proposed absorber can reach 110.95, 117.25, 85.96, and 97.2 and 231.45, 239.21, 178.015, and 200.30, respectively, at the Fermi level of 0.2 eV. The geometrical parametric analysis has been carried out at the Fermi energy level of 0.4 eV to justify the choice of the design parameters. This proposed absorber finds applications in terahertz sensing and imaging. [ABSTRACT FROM AUTHOR]

Wide color gamut display has become a new generation of display technology because of its good color saturation. However, the low quantum efficiency and wide half peak width of narrow-band green phosphors are still the main barriers in their development and application. This work addresses these challenges by using Mn 2+ as the luminescent center and constructing efficient Eu 2+  → Mn 2+ energy transfer in Na 2 MgAl 10 O 17 (NMAO) matrix. The NMAO:0.15Eu 2+ , 0.30Mn 2+ phosphor presents a single-band emission peaking at 513 nm with a full width at half maximum (FWHM) of only 33 nm under the excitation of 365 nm LED chip. In addition, under the excitation wavelength of 365 nm, the energy transfer efficiency reaches 74%. Compared with the NMAO:0.30Mn 2+ , the intensity of the NMAO:0.15Eu 2+ , 0.30Mn 2+ increases by 5.5 times and the internal quantum efficiency is up to 61.82%. A white LED device with the CIE coordinates of (0.2871, 0.3472) and a color gamut area of 94% NTSC has been assembled successfully by combining 365 nm LED chips with NMAO:0.15Eu 2+ , 0.30Mn 2+ , BaMgAl 10 O 17 :Eu 2+ , and K 2 SiF 6 :Mn 4+ as green, blue, and red component. This work enriches the relevant content of Mn 2+ -doped phosphors and provides a constructive insight into improving luminescent performance through energy transfer., (© 2024 John Wiley & Sons Ltd.)

There are very few results in the literature on spectral content of seismic ground displacement; nonetheless, these results are singular as most of the spectral content is limited to a very narrow low frequency band, contrary to ground acceleration. These few spectral characterizations have been obtained, expectedly, by means of power spectral or Fourier analyses of ground displacement records, only. As these records are not as reliable as ground acceleration records, the existence of a clear predominant frequency in ground displacement warrants confirmation through a different procedure. We propose a corroboration method of this highly narrow-band characteristic that is based on the more dependable acceleration signal, rather than on the same ground displacement record that is the subject of study. Specifically, displacement response spectra are analyzed (which rely on acceleration records) to verify previously observed neat predominant frequencies in ground displacement, which is a novelty.

Plasmonic metal nanostructures have promising applications in biosensing due to their ability to facilitate light–matter interaction. However, the damping of noble metal leads to a wide full width at half maximum (FWHM) spectrum which restricts sensing capabilities. Herein, we present a novel non-full-metal nanostructure sensor, namely indium tin oxide (ITO)–Au nanodisk arrays consisting of periodic arrays of ITO nanodisk arrays and a continuous gold substrate. A narrow-band spectral feature under normal incidence emerges in the visible region, corresponding to the mode-coupling of surface plasmon modes, which are excited by lattice resonance at metal interfaces with magnetic resonance mode. The FWHM of our proposed nanostructure is barely 14 nm, which is one fifth of that of full-metal nanodisk arrays, and effectively improves the sensing performance. Furthermore, the thickness variation of nanodisks hardly affects the sensing performance of this ITO-based nanostructure, ensuring excellent tolerance during preparation. We fabricate the sensor ship using template transfer and vacuum deposition techniques to achieve large-area and low-cost nanostructure preparation. The sensing performance is used to detect immunoglobulin G (IgG) protein molecules, promoting the widespread application of plasmonic nanostructures in label-free biomedical studies and point-of-care diagnostics. The introduction of dielectric materials effectively reduces FWHM, but sacrifices sensitivity. Therefore, utilizing structural configurations or introducing other materials to generate mode-coupling and hybridization is an effective way to provide local field enhancement and effective regulation.

Advances in visualization technologies have made it possible to detect non-muscle-invasive bladder cancer (NMIBC), which is difficult to identify with conventional white-light imaging (WLI). Among these technologies, narrow-band imaging (NBI) emphasizes capillaries on the mucosal surface by narrowing WLI to two wavelengths. NBI is significantly more sensitive than WLI for detection of cancer lesions, and thus is useful for the diagnosis of NMIBC. Moreover, several meta-analyses have shown that transurethral resection of NMIBC under NBI (NBI-TUR) significantly reduces postoperative recurrence, compared to TUR under WLI (WLI-TUR). However, some cancer lesions remain difficult to detect with NBI, and there is a need for a flexible treatment strategy that includes the addition of other appropriate treatment methods after understanding the limitations of NBI. Despite these limitations, NBI is attractive in clinical practice because it does not require special pretreatment, there are no concerns about side effects from the administration of a photosensitizing agent, and there is no need for complicated perioperative management. This is ideal for obtaining optimal results in facilities in which time and resources are limited. Thus, NBI is a natural choice for NMIBC with regard to provision of care with maximum benefit in certain medical environments. [ABSTRACT FROM AUTHOR]

The Common Spatial Pattern (CSP) algorithm is the most widely used method for decoding Electroencephalography (EEG) signals from motor imagery (MI) paradigm. However, due to the inter-subject variability, the CSP algorithm heavily relies on the selection of filter bands and extensive analytical processing time required to build an effective model, which has been a challenge in current research. In this paper, we propose a narrow filter bank CSP (NFBCSP) algorithm, which automatically determines the optimal narrow band for two-class motor imagery by band search tree, and a high-performance classification model dedicated to each subject can be obtained in a short time for online processing or further offline analysis. The optimal narrow band is combined with the CSP algorithm to extract the dynamic features in the EEG signals. For the multi-class motor imagery task, it is first transformed into multiple One-Versus-Rest (OVR) tasks and determines the corresponding optimal narrow bands. After extracting the features of each optimal narrow band separately, the Deep Convolutional Neural Network (DCNN) is used for the fusion of band features and classification of multi-class motor imagery. Finally, we verified our method using two different motor imagery datasets, the BCI-VR dataset with two classes of motor imagery and the BCI Competition IV dataset 2a with four classes of motor imagery. The experimental results show that the proposed method achieves an average classification accuracy of 86.43% for the two-class motor imagery task, and 76.87% for the four-class motor imagery task, which outperforms other recent methods. [ABSTRACT FROM AUTHOR]

This paper presents a novel pipeline that improves the efficiency of narrowband surface reconstruction for particle-based fluids. Different from previous narrow band methods, we only construct the scalar field in the outer surface region. A method with robust criteria for detecting the outer surface vertices of the scalar field is then proposed to eliminate the redundant inner vertices, leading to a significant reduction in the computational complexity and memory consumption. The presented pipeline is fully parallel with a parallel compact memory scheme to avoid race conditions. Several experiments are conducted to compare our present method with the state-of-the-art approach, and the results indicate that our method saves nearly half of the computing time and ten percent of the memory consumption. [Display omitted] [ABSTRACT FROM AUTHOR]

IOT is a new web sample based on the fact that there are many things and entities other than humans that can connect to the Internet. This fact means that machines or things can automatically interconnected without the need of interacting with humans and thus become the most important entities that create Internet data. In this article, we first examine the challenges of IOT. Then we introduce features of NB- IOT through browsing current international studies on NB- IOT technology in which, we focus on basic theories and key technologies , such as the connection number analysis theory, the theory of delay analysis, the coating increase mechanism , low energy consumption technology, and the connection of the relationship between signaling and data .Then we compare some functions of NB- IOT and other wireless telecommunication technologies in terms of latency, security, availability, data transfer speed, energy consumption, spectral efficiency, and coverage area . Finally, we review and summarize NB- IOT security requirements that should be solved immediately. These topics are provided to overview NB- IOT which can offer a complete familiarity with this area.

Accurate stratospheric temperature observations are crucial for weather forecasts and climate change studies. This paper discusses a precise measurement method for the stratospheric temperature profile using narrow bands with ultra-high spectral resolution from nadir-viewing satellites. First, the CO2 absorption band around 15 μm is selected as the major sounding source by the calculation and analysis of the temperature Jacobian and the atmospheric molecular spectra. Next, the influence of spectral resolution, spectral range and instrumental noise on the sounding capability is analyzed, and the sounding feasibility of the single spectral band and multiple spectral bands is discussed under the condition that the spaceborne long-wave infrared space heterodyne spectrometer (SHS) is selected as suggested sounder onboard the satellite. Finally, the optimal joint-sounding scheme of narrow bands is proposed. The temperature retrieval and validation show that the joint-sounding of two discontinuous narrow bands can realize the high precision measurement of the stratospheric temperature profile for the given spectral resolution, spectral range, and instrumental noise. When the sounder adopts two narrow bands (the regions of 666.87–676.44 cm−1 and 683.58–693.15 cm−1) and a spectral resolution of 0.03 cm−1, the retrieval accuracy (RMSE) is about 0.9 K over a pressure range of 200 to 0.7 hPa (11.5–50 km). This study will provide technical preparation for high-precision and low-cost satellite sounder design for stratospheric temperature observations.

Introduction: Narrow-band (NB) ultraviolet B (UVB) phototherapy has been shown to halt disease progression in vitiligo, but whether there is any difference in the response to NB-UVB seen in patients with progressive vitiligo versus non-progressive vitiligo has not been evaluated. Objectives: To evaluate the effect of NB-UVB on progressive versus non-progressive non-segmental vitiligo. Study Design: Prospective observational comparative study. Duration: April 2016-November 2017. Methods: Adult patients having non-segmental vitiligo involving 2-50% body surface area were divided into two subsets; patients developing >5 lesions in the last 1 month or >15 lesions in the last 3 months (progressive vitiligo, Group I) and patients with static disease for the last 6 months (non-progressive vitiligo, Group II). Both groups were treated with NB-UVB for 6 months (26 weeks) cumulatively and its efficacy in halting disease progression, re-pigmentation, side effects and psychosocial impact were evaluated. Results: Nineteen out of 24 patients with progressive vitiligo had arrest of disease progression. Rest five patients developed lesions at a slower pace. Group II had earlier onset of re-pigmentation, while Group I had more NB-UVB fluence (34.73 J/cm2 vs 25.2 J/cm2, P value = 0.034), more time for the fluence to be fixed (P value = 0.001) and more pruritus (P value = 0.001). Conclusions: NB-UVB has the potential to halt disease progression in some patients with progressive vitiligo; but is associated with more total NB-UVB fluence and time taken for fixing it. Progressive vitiligo patients have more pruritus as compared to patients with non-progressive vitiligo. [ABSTRACT FROM AUTHOR]

This article describes a quad-band frequency tunable antenna for 5G applications that operates in the sub-6 GHz frequency range. On the top side, a stubloaded square patch is printed on an inexpensive glass epoxy substrate, and on the opposite side, a C-shaped slot embedded into the partial ground plane. To achieve frequency reconfigurability with a consistent radiation pattern, the C-shaped slot and matching stub are used. The antenna is electronically frequency tunable by placing two positive intrinsic negative diodes (PIN) in the C-shaped slot and one PIN diode between the stub and feed line. The frequency is tunable between one ultra-wideband (UWB) and three communication bands based on the switching conditions of the PIN diodes. The proposed configuration is small, with a substrate dimension of 25×25×1 mm³. The antenna was fabricated, tested and found measurements result back up the simulation; it can switch between UWB (3.31.0-6.03 GHz) and three communication modes (3.31-4.32, 3.78-4.98, 4.98-5.96 GHz). The antenna has peak gains of 1.91, 1.86, 2.0 and 2.0 dB, and radiation efficiencies of 80, 78, 83 and 86%, respectively, in the four frequency bands. The developed antenna is ideally suited for multi-functional wireless systems and cognitive radio applications since it covers the frequency bands below 6 GHz and is tunable between wide and narrow bands. [ABSTRACT FROM AUTHOR]

An activator's selective occupation of a host is of great significance for designing high-quality white light-emitting diodes (w-LEDs) phosphors, while achieving a full-spectrum single-phase white light emission phosphor is challenging. For developing high-performance and green-emitting phosphors with narrow bands used for backlight display, a series of Na 2 Mg 1-x Al 10 O 17 :xMn2+ (NMAO:xMn2+) phosphors with high Mn2+ concentration were synthesized. The NMAO:0.65Mn2+ green phosphor exhibits an ultra-narrow band green emission with full width at half maximum (FWHM) about 27 nm and peak position at 513 nm when excited by the blue light with wavelength of 450 nm. The NMAO:0.65Mn2+ not only has a super narrow band which is narrower than β -SiAlON:Eu2+ (FWHM ∼ 55 nm) but also shows an exceptional thermal stability performance (77% peak intensity @423 K). A w-LED device was assembled with NMAO:0.65Mn2+, a blue GaInN chip and K 2 SiF 6 :Mn4+ phosphors, which represents a wide color-gamut of 112% National Television System Committee (NTSC) standard under the current of 50 mA. These results demonstrate the NMAO:0.65Mn2+ has potential superiority in application of backlight display. • A narrow-band green Na 2 MgAl 10 O 17 :Mn2+ phosphor was prepared by solid state method. • Na 2 Mg 0.35 Al 10 O 17 :0.65Mn2+ shows emission peaked at 513 nm and the FWHM of 27 nm. • Na 2 Mg 0.35 Al 10 O 17 :0.65Mn2+ shows good thermal stability with 77%@423 K. • A w-LED device with wide color-gamut of 112% NTSC was fabricated. [ABSTRACT FROM AUTHOR]

In this brief, a new approach based on quality factor technique is proposed to design narrower band matching networks. The main idea is to use one series and one parallel lossless one-port LC network between generator and load resistances. In the proposed approach, it is not necessary to use a high quality factor value to get narrower band, it is enough to use the quality factor value defined by generator and load resistances. After explaining the rationale of the new approach, an example is given to compare the performances of the proposed and existing methods in the literature. [ABSTRACT FROM AUTHOR]

OBJECTIVES: This study aims at comparing the tone-burst (TB) and narrow-band (NB) CE-chirp stimuli in terms of amplitude, latency, and interaural asymmetry ratio (IAR) in ocular vestibular evoked myogenic potentials (oVEMP). MATERIALS and METHODS: In this prospective study, we enrolled 60 healthy subjects (27 men, 33 women) with a mean age of 25.83 (range, 18-48) years. Otological examination was normal in all the subjects. The subjects did not have any otological disease. All the subjects underwent oVEMP testing. We used 500 Hz TB stimulus and 500 Hz NB CE-chirp stimulus in random order. oVEMP test was performed at 100 dB normalized hearing level. P1 latency, N1 latency, and P1N1 amplitude were measured for each ear and stimulus, and IAR was calculated. RESULTS: Ocular VEMPs were obtained from all the subjects for both the stimuli. P1 and N1 latencies were significantly shorter in chirp stimulus than in TB stimulus for both the sides (p<0.0001). P1 and N1 amplitudes were significantly higher for chirp stimulus than for TB stimulus for both the sides (p<0.0001). There was no significant difference between the ears in IAR between the 2 types of stimuli. CONCLUSION: Narrow-band CE-chirp stimulus is an effective stimulus to evoke oVEMP with higher amplitudes and shortened latencies. [ABSTRACT FROM AUTHOR]

A narrow‐band bandpass filter (BPF) based on parallel coupled lines and shorted stubs with very wide upper stopband has been presented. The transmission coefficient and reflection coefficient of the proposed BPF are straightforwardly derived via the input impedances using odd‐ and even‐mode analysis method. The calculation results illustrate that two narrow passbands with very high frequency ratio of the upper‐band to lower‐band center frequencies can be realized, which is significantly suitable to design a narrow‐band BPF with very wide upper stopband. To verify the proposed design idea, a narrow‐band BPF example was designed and experimentally characterized, whose measured in‐band return loss is >30 dB with center frequency at 1.76 GHz. The measured upper stopband is up to 14.34 GHz with the rejection levels of over 20 dB. [ABSTRACT FROM AUTHOR]

We present a novel surface reconstruction pipeline that significantly improves reconstructing efficiency while preserves high-quality details for particle-based liquid simulation. Our surface reconstruction algorithm is a sort of completely parallel narrow band method. At the beginning of reconstruction, we develop a spatial hashing grid-based strategy to identify surface particles, which is much more precise and simpler than the smoothed color field. Consequently, those precise surface particles ensure accurate extraction of scalar field in the narrow band around surface without any redundancy, which brings great performance improvement for subsequent reconstruction stages. Furthermore, in order to obtain a better computation performance, we carefully analyze the potential race conditions and conditional branches of each reconstruction step between parallel threads and come up with a completely parallel reconstruction method combined with the exclusive prefix sum algorithm. Our method is pretty straightforward to implement. Experimental results demonstrate that our method runs up to dozen times faster than the state-of-the-art of narrow band-based fluid surface reconstruction, especially for large-scale particle-based fluid. [ABSTRACT FROM AUTHOR]

Deformable isosurfaces, implemented with level-set methods, have demonstrated a great potential in visualization and computer graphics for applications such as segmentation, surface processing, and physically-based modeling. Their usefulness has been limited, however, by their high computational cost and reliance on significant parameter tuning. This paper presents a solution to these challenges by describing graphics processor (GPU) based algorithms for solving and visualizing level-set solutions at interactive rates. The proposed solution is based on a new, streaming implementation of the narrow-band algorithm. The new algorithm packs the level-set isosurface data into 2D texture memory via a multi-dimensional virtual memory system. As the level-set moves, this texture-based representation is dynamically updated via a novel GPU-to-CPU message passing scheme. By integrating the level-set solver with a real-time volume renderer, a user can visualize and intuitively steer the level-set surface as it evolves. We demonstrate the capabilities of this technology for interactive volume segmentation and visualization.

Deformable isosurfaces, implemented with level-set methods, have demonstrated a great potential in visualization for applications such as segmentation, surface processing, and surface reconstruction. Their usefulness has been limited, however, by two problems. First, 3D level sets are relatively slow to compute. Second, their formulation usually entails several free parameters that can be difficult to tune correctly for specific applications. The second problem is compounded by the first. This paper presents a solution to these challenges by describing graphics processor (GPU) based algorithms for solving and visualizing level-set solutions at interactive rates. Our efficient GPU-based solution relies on packing the level-set isosurface data into a dynamic, sparse texture format. As the level set moves, this sparse data structure is updated via a novel GPU to CPU message passing scheme. When the level-set solver is integrated with a real-time volume renderer operating on the same packed format, a user can visualize and steer the deformable level-set surface as it evolves. In addition, the resulting isosurface can serve as a region-of-interest specifier for the volume renderer. This paper demonstrates the capabilities of this technology for interactive volume visualization and segmentation.

Busbar distribution system is used as a modular infrastructure to carry electrical energy in low voltage grid. Due to the widespread usage in industrial areas, the power line communication possibilities should be investigated in terms of smart grid concept. This paper addresses modeling of the busbar distribution system as a transmission line and gives some suggestions on the link performance for narrowband power line communication for the first time in literature. Firstly, S-parameters of different current level busbars were measured up to 500 kHz for all possible two-port signal paths. The utilization of the frequency-dependent model was proposed to extract transmission line characteristics to eliminate the unwanted measurement effects. Particle swarm algorithm was used to optimize the model parameters with a good agreement between measured and simulated S-parameters. Additionally, link performance of busbar distribution system as a power line communication channel at 3 kHz-148.5 kHz band was examined for frequency shift keying and phase shift keying modulations under different network configurations such as varying busbar type, the line length between transmitter and receiver, branch number, and terminating load impedance. Obtained results were presented as bit-error-rate vs. signal to noise ratio graphs.

Medical image segmentation is one of the most challenging tasks in medical image analysis and widely developed for many clinical applications. While deep learning-based approaches have achieved impressive performance in semantic segmentation, they are limited to pixel-wise settings with imbalanced-class data problems and weak boundary object segmentation in medical images. In this paper, we tackle those limitations by developing a new two-branch deep network architecture which takes both higher level features and lower level features into account. The first branch extracts higher level feature as region information by a common encoder-decoder network structure such as Unet and FCN, whereas the second branch focuses on lower level features as support information around the boundary and processes in parallel to the first branch. Our key contribution is the second branch named Narrow Band Active Contour (NB-AC) attention model which treats the object contour as a hyperplane and all data inside a narrow band as support information that influences the position and orientation of the hyperplane. Our proposed NB-AC attention model incorporates the contour length with the region energy involving a fixed-width band around the curve or surface. The proposed network loss contains two fitting terms: (i) a high level feature (i.e., region) fitting term from the first branch; (ii) a lower level feature (i.e., contour) fitting term from the second branch including the (ii1) length of the object contour and (ii2) regional energy functional formed by the homogeneity criterion of both the inner band and outer band neighboring the evolving curve or surface. The proposed NB-AC loss can be incorporated into both 2D and 3D deep network architectures. The proposed network has been evaluated on different challenging medical image datasets, including DRIVE, iSeg17, MRBrainS18 and Brats18. The experimental results have shown that the proposed NB-AC loss outperforms other mainstream loss functions: Cross Entropy, Dice, Focal on two common segmentation frameworks Unet and FCN. Our 3D network which is built upon the proposed NB-AC loss and 3DUnet framework achieved state-of-the-art results on multiple volumetric datasets.

In this letter, a wide-angle narrowband leaky-wave antenna (LWA) based on substrate integrated waveguide-spoof surface plasmon polariton (SIW-SSPP) structure is proposed. Periodic slots are etched on both the top and bottom surfaces of SIW to introduce an SSPP mode. The periodic slots on the top surface are sinusoidally modulated to realize bidirectional LWA radiation. The problem of open stopband is solved by the asymmetrical design of the top and bottom slots. Thus, a wide bidirectional scanning range from −60° to +63° is achieved. Besides, the relative bandwidth of the fabricated antenna is reduced to only 9% by introducing the slow-wave effect of SSPP. It means the proposed antenna has a large scanning rate, or equivalently beam scanning range/bandwidth ratio. [ABSTRACT FROM AUTHOR]

In this article, a narrow and a wide band high gain antenna with improved front to back ratio using highly reflecting surface are proposed. A highly reflecting compact ultrathin metasurface (MS) of thickness 0.0134 λ with >90% reflection band of 1.42 GHz from 4.55 to 5.97 GHz is designed. The open air field Fabry–Perot cavity resonator antenna is designed by placing this MS over a microstrip patch antenna radiator first and next on standard wide band C‐band wave guide port radiator at an optimum height to get narrow and wide enhanced gain band width, respectively. The proposed antennas are fabricated and measured experimentally. A low profile narrow band FPC antenna with measured broad side gain enhancement of 8.54 dB having maximum measured gain of 16.5 dBi at 5.3 GHz is designed first. Next, a wide band FPC antenna having broad side measured enhanced gain band width of >1 GHz from 4.75 GHz to about 6.00 GHz with maximum gain enhancement of 8.32 dB with maximum measured gain of 17.85 dBi at 5.30 GHz is observed. A wide improved front to back ratio (FBR) band of 1 GHz with maximum FBR of 39.5 dB at 5.30 GHz is presented. This antenna can be used for 5G long range services. [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract Herein, we present a simple strategy to enhance the stability of water-sensitive SrLiAl 3 N 4 :Eu2+ phosphor through embedding the phosphor particles into low-melting Sn-P-F-O glass using phosphor-in-glass (PiG) approach. After being immersed in water for 96 h, the emission intensity of the SrLiAl 3 N 4 :Eu2+-PiG sample was maintained at 80% of its pristine intensity, indicating the moisture-resistance property of SrLiAl 3 N 4 :Eu2+ was significantly enhanced. Employing the narrow-band red-emitting SrLiAl 3 N 4 :Eu2+-PiG sample and a blue COB (chip-on-board), a plant growing LED device was fabricated. The emission spectrum of the device matches well with the absorption of Chlorophyl (a and b) in plants, indicating the as-prepared SrLiAl 3 N 4 :Eu2+-PiG are suitable to be applied in plant lighting field. We believe that this simple method reported in this communication can be easily expanded to other water-sensitive luminescence materials. [ABSTRACT FROM AUTHOR]

Narrowband-Internet of Things (NB-IoT) displays high-quality connectivity underpinned by fifth-generation (5G) networks to cover a wide array of IoT applications. The devices’ development and integration into different smart systems require permanent control, supervision, and the study of power consumption models to determine the performance of the network topology and allow for the measurement of the efficiency of the network topology’s application. This paper reports on an architecture and open-sourced simulation that was developed to study NB-IoT in Device-to-Device (D2D) mode, which includes the Physical (PHY), network, and application layers, as well as a queuing model, the model for uplink and downlink delays, the throughput, the overall NB-IoT D2D network performance, and the energy consumption based on the Low Energy Adaptive Clustering Hierarchy (LEACH) protocol. Our results prove that the suggested framework contributes to a reduction in power consumption, a minimization of queuing delays, a decrease in communication cost, a reduction in inter-cluster collisions, and the prevention of attacks from malicious nodes. Consequently, the framework manages the battery’s State of Charge (SOC), improves the battery’s State of Health (SOH), and maximizes the whole network lifetime. The proposed framework, the code of which has been open-sourced, can be effectively used for scientific research and development purposes to evaluate different parameters and improve the planning of NB-IoT networks.

Designing various nanostructures to achieve narrowband light reflection resonances is desirable for optical sensing applications. In this work, we theoretically demonstrate two narrowband light reflection resonances resulting from the excitations of the zero-order transverse magnetic (TM) and transverse electric (TE) waveguide modes, in a waveguide structure consisting of an Au sphere array on an indium tin oxide (ITO) spacer on a silica (SiO2) substrate. The positions of the light reflection resonances can be tuned easily, by varying the array periods of gold (Au) spheres or by changing the thickness of the ITO film. More importantly, the light reflection resonances have a very narrow bandwidth, the full width at half maximum (FWHM) of which can be reduced to only several nanometers for the zero-order TM and TE waveguide modes. The conventionally defined performance parameters of sensors, sensitivity (S) and figure of merit (FOM), have quite high values of about 80 nm/RIU and 32, respectively, in the visible wavelength range.

Spectral imaging is a promising technique for detecting the quality of rice seeds. However, the high cost of the system has limited it to more practical applications. The study was aimed to develop a low-cost narrow band multispectral imaging system for detecting rice false smut (RFS) in rice seeds. Two different cultivars of rice seeds were artificially inoculated with RFS. Results have demonstrated that spectral features at 460, 520, 660, 740, 850, and 940 nm were well linked to the RFS. It achieved an overall accuracy of 98.7% with a false negative rate of 3.2% for Zheliang, and 91.4% with 6.7% for Xiushui, respectively, using the least squares-support vector machine. Moreover, the robustness of the model was validated through transferring the model of Zheliang to Xiushui with the overall accuracy of 90.3% and false negative rate of 7.8%. These results demonstrate the feasibility of the developed system for RFS identification with a low detecting cost.