Lobe Of Pattern Research Articles

Motion corrected MRI differentiates male and female human brain growth trajectories from mid-gestation

It is of considerable scientific, medical, and societal interest to understand the developmental origins of differences between male and female brains. Here we report the use of advances in MR imaging and analysis to accurately measure global, lobe and millimetre scale growth trajectory patterns over 18 gestational weeks in normal pregnancies with repeated measures. Statistical modelling of absolute growth trajectories revealed underlying differences in many measures, potentially reflecting overall body size differences. However, models of relative growth accounting for global measures revealed a complex temporal form, with strikingly similar cortical development in males and females at lobe scales. In contrast, local cortical growth patterns and larger scale white matter volume and surface measures differed significantly between male and female. Many proportional differences were maintained during neurogenesis and over 18 weeks of growth. These indicate sex related sculpting of neuroanatomy begins early in development, before cortical folding, potentially influencing postnatal development.

3D sedimentary architecture showing the inception of an Ice Age

Northeast Atlantic climate shifted into the Quaternary Ice Age around 2.6 M yr ago. Until now, however, the detailed changes associated with this inception of an Ice Age have remained obscure. New high-quality three-dimensional seismic data reveal a detailed geological record of buried surfaces, landforms and sedimentary architecture over vast parts of the Norwegian North Sea. Here, we show the sequence of near-coast geological events spanning the Northeast Atlantic inception of an Ice Age. We identify the location of immediate pre-glacial fluvially derived sandy systems where rivers from the Norwegian mainland built marine deltas. The stratigraphic position of a large submarine channel, formed by enhanced meltwater from initial build-up of local glaciers, is also shown. Finally, we document the transition to full ice-sheet growth over Scandinavia from the ice sheet’s earliest position to the later pattern of debris-flow lobes reaching the present-day shelf edge.

New records of the genus Bryobia (Acari: Tetranychidae) from Syria with description of a new species

Three species of Tetranychidae belonging to the genus Bryobia were collected from Latakia governorate, Syria in 2019: Bryobia (Allobia) syriensis n. sp. collected from Salvia verbenaca L., is described; Bryobia (Allobia) nikitensis and Bryobia (Bryobia) gigas collected from S. verbenaca and from soil litter, respectively, are reported. New observations of Bryobia specimens previously reported from the same governorate during 2014-2016 revealed that specimens of Bryobia (Bryobia) watersi were misidentified as Bryobia (Bryobia) graminum and Bryobia (Bryobia) kissophila. Among them, we found two aberrant females bearing three propodosomal lobes. By analogy, we discussed the cases of the trilobed species, Bryobia bakeri and Bryobia aegyptiacus, and concluded that they could be teratological forms of quadrilobed Bryobia species rather than species with a particular pattern of propodosomal lobes.

Discrete noise control of cooling fan module: Stator and rotor interaction

With the development of automobile industry and the continuous demand for driving comfort, discrete noise level of the automobile cooling fan module (CFM) should be controlled. In this study, a non-uniform rotor blade design is developed, and the methods for predicting discrete noise are theoretically expounded using a simplified model. The lobe modes of the stator and rotor interaction (SRI) and their influence on the sound power of orders are evaluated. Using above methods, a specific discrete noise control method is proposed for a CFM with seven rotor-blades (RBs) and eight stator-vanes (SVs). Subsequently, on combination with numerical simulation, the pulsation characteristics of the RBs and SVs with non-uniform circumferential distribution in free air are analyzed. From the results, the pulsation sources of discrete components and the SRI mechanisms are examined. Finally, samples are fabricated to analyze the discrete characteristics of the CFM acoustic spectrum through acoustic experiments to verify the effectiveness and applicability of present methods. It is shown that the circumferential non-uniform design changes distribution characteristics of the pulsating force on the RB and SV surfaces as well as the SRI lobe pattern, which greatly affects the amplitude distribution of discrete components in the CFM acoustic spectrum. This method can effectively and quickly predict and control discrete noise in the early stages of CFM design.

Interferometric Microwave Radar With a Feedforward Neural Network for Vehicle Speed-Over-Ground Estimation

A novel approach to measuring the ground speed of autonomous vehicles using interferometric radar is presented. Using a microwave radar with interferometric processing and a feedforward neural network with local regression, high-accuracy velocity estimation is achieved with a downward-facing radar that, unlike forward-looking Doppler radars, can be protected from road debris and is, furthermore, unaffected by wheel slip and requires no external inputs, such as Global Navigation Satellite Systems (GNSS). A 16.9-GHz active interferometric array generates a grating lobe pattern and as the ground passes through the pattern, the range of frequencies over which the response is distributed increases proportionally with the ground velocity. We implement a feedforward neural network to estimate the velocity based on the interferometer's frequency response. The estimator achieved a root-mean-squared error of 0.138 (m/s), equivalent to that of the forward-looking Doppler radars.

Doppler Shifting Technique for Generating Multi-Frames of Video SAR via Sub-Aperture Signal Processing

The signal processing technologies of synthetic aperture radar (SAR) have been vastly studied as diverse measurement modes for various applications. One of the technologies is Video-SAR (ViSAR). It is a land-imaging mode where a sequence of images is continuously formed on the spotlight mode. We propose a new signal processing method to generate the multi-frames of ViSAR using Doppler shifting technique via sub-aperture processing. The method is based on our designed wide-angle antenna, which is a corrugated horn shape with low side lobe and Gaussian beam pattern. This wide-angle antenna receives a wide Doppler band along the azimuth direction. Based on the characteristics of the antenna, we separate the wide Doppler band into each chirp pulse signal. Each of these separated signals has a different center time. Through each chirp pulse signal in Doppler domain, the proposed method generates each frame of video at a high frame rate. The proposed ViSAR processing can show high efficiency with low computation and without a fixed coordinate system. Moreover, it can also visualize a wider area on stripmap mode than the conventional ViSAR mode, and can derive the video results based on Range Doppler Algorithm (RDA). These advantages can lead to reduce economic costs and simplify the operating ViSAR system. We have performed the practical experiments using X-band chirp pulse SAR system mounted on an airplane to verify the proposed method.

Individual horizontal array elements as windows to estimating ship radiated noise signature lobing patterns

A horizontal hydrophone array is typically beamformed to produce the directivity required to produce array gain and determine bearing to a contact of interest. For ships passing near an array each omnidirectional hydrophone also provides a number of discrete “look windows” at the ship from a range of received angles. By assembling similar look window angles and applying a propagation model to estimate transmission loss, a partial lobing pattern for the ship's radiated noise signature can be estimated. A 48-element bottom-mounted hydrophone array in the Canadian Arctic provides an opportunity to test this approach in a low ambient noise environment with a variety of passing ships.

Beamforming with semi-coprime arrays.

A semi-coprime array (SCA) interleaves two undersampled uniform linear arrays (ULAs) and a Q-element standard ULA. The undersampling factors of the first two arrays are QM and QN, respectively, where M and N are coprime. The resulting non-ULA is highly sparse. Taking the minimum of the absolute values of the conventional beampatterns of the three arrays results in a beampattern that is free of grating lobes. A SCA requires fewer sensors than other popular sparse arrays such as coprime arrays, nested arrays, and minimum redundant arrays for a given aperture. Also, a SCA exhibits better side lobe patterns than other sparse arrays. This means that a SCA is better able to mask signals away from the look direction and detect weak sources in the presence of strong interferers. In this paper, the author explores the direction of arrival estimation with the SCA. The results illustrate the SCA's ability to reduce the number of sensors and decrease system cost and complexity in various signal processing applications.

Liquid Crystal-Based Wideband Reconfigurable Leaky Wave X-Band Antenna

In this paper, a pattern and frequency reconfigurable leaky wave X-band antenna based on liquid crystal is designed. The frequency sweep characteristics of traditional leaky wave antennas are replaced by electrical properties of liquid crystal materials. Through the liquid crystal tuning, the main lobe pattern is deflected by 25 degrees at a frequency shift of 1GHz, where the liquid crystal tuning is saturated at 20V bias voltage. The relative frequency reconfigurable bandwidth is 19%, the relative pattern reconfigurable bandwidth is 9.3% and the maximum gain is 10dBi. Moreover, the pattern and frequency response are well preserved during the tuning.

Angle Estimation Using Wideband Frequency Modulation and an Active Distributed Array

A new method of target angle estimation, which leverages wideband waveforms and a distributed array receiver, is presented. The distributed array receiver generates a grating lobe pattern, the spatially distributed phase of which changes as a function of frequency. By implementing a wideband linear frequency modulated waveform, a phase response manifests in the distributed array receiver output, whose instantaneous frequency is proportional to the angle of the object. The receiver frequency response is derived, and the angle estimation approach is experimentally demonstrated. A 4.8-GHz distributed array radar was implemented with a receiver baseline of $19.36\lambda $ using a waveform modulated over 2 GHz of bandwidth. Measurements with a single-point target were conducted, and the measured frequency responses show the expected correspondence to the angle of the target with an average error of 2.8° (0.049 rad) and a standard deviation of 1.8° (0.031 rad).

Ear lobe rotation flap for the reconstruction of full-thickness defects of the middle third of the auricle

The authors propose a novel surgical technique for reconstruction of full-thickness defects of the middle portion of the auricle including the helix and the antihelix up to the neighboring portion of the concha and sparing the whole of the ear lobe. It is a single-stage procedure that is indicated when a large, redundant, and pendulous earlobe exists as typically occurs in the elderly patient. The earlobe is rotated into the full-thickness ear defect and fits as an inlay between two cartilaginous stumps. The ear lobe presents two anatomical patterns: the pendulous or free one, with the ear lobe lying free from the cheek, and the non-pendulous or attached one, where the ear lobe is attached to the cheek. Donor site deformity is therefore limited to the conversion of a pendulous ear lobe pattern into an attached one. Surgery may be scheduled in an outpatient basis as the procedure is easy to plan, is fast to perform, and is carried out under local anesthesia. Level of Evidence: Level IV, therapeutic study.

A new species of Stilestrongylus (Nematoda, Heligmonellidae) from the Atlantic Forest of Misiones, Argentina, parasitic in Euryoryzomys russatus (Cricetidae, Sigmodontinae).

A new species of Heligmonellidae (Trichostrongylina, Heligmosomoidea), Stilestrongylus kaaguyporai n. sp. is described from the small intestine of Euryoryzomys russatus (Rodentia, Cricetidae, Sigmodontinae) from the Argentine Atlantic Forest, in the Misiones province. The new species was found at Campo Anexo Manuel Belgrano, Reserva de Vida Silvestre Urugua-í and Parque Provincial Urugua-í, with a prevalence of 73% in 15 hosts examined. Stilestrongylus includes 24 Neotropical species, all parasitic in rodents, mostly Sigmodontinae. Stilestrongylus kaaguyporai n. sp. can be differentiated from its congeners by the following characters: caudal bursa dissymmetrical with right lobe larger and pattern of type1-4 in both lobes, rays 6 not forming a lateral trident with rays 4 and 5, rays 8 with dissymmetrical pathway, genital cone hypertrophied with a conspicuous hood-like projection and females with a marked dorso-ventral torsion of the posterior end. This report is the second record of a Stilestrongylus species in E. russatus, increasing to nine the number of parasitic species known from this host.

Transport properties of a quantum dot and a quantum ring in series

The decoherence mechanism of an electron interferometer is studied by using a serial quantum dot and ring device. By coupling a quantum dot to a quantum ring (closed-loop electron interferometer), we were able to observe both Coulomb oscillations and Aharonov-Bohm interference simultaneously. The coupled device behaves like an ordinary double quantum dot at zero magnetic field while the conductance of the Coulomb blockade peak is modulated by the electron interference at finite magnetic fields. By injecting one electron at a time (by exploiting the sequential tunneling of a quantum dot) into the interferometer, we were able to study the visibility of the electron interference at non-zero bias voltage. The visibility was found to decay rapidly as the electron energy was increased, which was consistent with the recently reported result for an electron interferometer. However, the lobe pattern and the sudden phase jump became less prominent. These results imply that the lobe pattern and the phase jump in an electron interferometer may be due to electron interactions inside the interferometer, as is predicted by the theory.

Hardware-in-the-loop experiment of turning

A hardware-in-the-loop (HIL) experimental setup is presented to analyze the stability of turning process. In our test rig, the dummy workpiece in the spindle can be excited in radial direction by an electromagnetic contactless actuator. This actuator is utilized to emulate the contact (cutting) force that acts originally between the tool and workpiece in case of a real process. In the HIL test, the displacement of the dummy workpiece is measured with the help of an optical sensor. A high performance real target computer is used to calculate the theoretical cutting force based on the present and past values of the relative displacements of the dummy workpiece. For the sake of simplicity, linear cutting force characteristics is implemented together with the emulated surface regeneration effect. In the HIL test, the loss of linear stability is detected for various real spindle speeds and virtual depth of cut, namely, the theoretically predicted pattern of the instability lobes is verified.

Autogenic controls on hybrid bed distribution in submarine lobe complexes

Hybrid beds, the deposits of sediment gravity flows that show evidence for more than one flow regime (turbulent, transitional and/or laminar), have been recognized as important components of submarine lobe deposits. A wide range of hybrid bed types have been documented, however, quantitative analysis of the stratigraphic and geographic distribution of these enigmatic bed types is rare. Here, extensive exposures integrated with research borehole data from Unit A of the Laingsburg Formation and Fan 4 of the Skoorsteenberg Formation, Ecca Group, South Africa, provide the opportunity to examine geographical and stratigraphic patterns over a range of hierarchical scales.For this purpose, >23,000 individual beds have been evaluated for deposit type and bed thickness. On average, hybrid beds make up < 5% of all events and <10% of the cumulative thickness. Lobe complex 1 (LC1) of Fan 4,Skoorsteenberg Formation, preserves a prominent geographical trend of hybrid beds becoming more prevalent towards the frontal fringes of a lobe complex (up to 33.2% of beds), whereas their proportion in proximal and medial lobe complex settings is <10%.Data from Unit A, Laingsburg Formation, show hybrid beds are less common in the basal (A.1) and top (A.6) subunits compared to A.2-A.5 in both core data sets. The bases and tops of some lobe complexes (A.2, A.3 and A.5.7) are observed to be slightly enriched in hybrid beds, whereas others (A.5.1, A.5.5 and A.6.1) show no hybrid beds in their bases, which does not conform to expected allogenically-driven distributions that predict more hybrid beds during the initiation of lobe complexes. Instead, the occurrence and distribution of hybrid beds in lobe complexes are interpreted to be controlled by autogenic processes, including flow transformation processes on the basin-floor meaning enrichment in frontal lobe fringe settings. Therefore, the 1D distribution of hybrid beds in lobe complexes reflects the dominant stacking pattern of lobes within a lobe complex, with enrichment at the base and top of lobe complexes due to overall progradational to retrogradational stacking patterns. Individual lobes show a wide range of hybrid bed distributions, due to stacking patterns of the component lobe elements. These findings highlight the importance of autogenic processes rather than allogenic controls in the distribution of hybrid beds, which has implications for reservoir evaluation and the assessment of lobe stacking patterns in 1D core data sets.

Main Beam Controlling Planar Antenna Array Design and Synthesis for Square Kilometre Array and Satellite Applications

Antenna arrays are currently being used for ultra sensitive radio observations in the project called Square Kilometre Array (SKA). In this paper, a planar array has been proposed to match high spatial resolution and high sensitivity requirements of the SKA, and satellite applications. The proposed design offers a well-controlled and elliptically shaped main beam. In addition, optimized thinned configuration provides minimum side lobe peaks and high directivity by applying modified binary Genetic Algorithm (GA). Design-induced modification in GA with a double-stage uniform crossover operation has been proposed. Array factor, forming the cost function with the constraint of uniform side lobe pattern, has been derived. At first, the design has been examined for side lobe peaks, side lobe pattern, and directivity in the orthogonal planes (φ = 0 and φ = π/2). For direction-specific optimization, design offers a directivity of 32 dB and a peak side lobe level of −25 dB. A comprehensive investigation involving optimization in all the planes (φ from 0 to π) has been carried out, giving a side lobe peak of −20 dB and a directivity of 30 dB. The achievable 3-dB beam width is 0.088, evidently fulfilling the high-resolution requirement of SKA applications. A performance comparison with several state-of-the-art synthesis methods shows that the proposed design in combination with the modified heuristic approach can provide high directivity and low beam width, well-controlled main beam, and a radiation pattern with quite competitive side lobe peaks.

Mechanism of nanosecond laser drilling process of 4H-SiC for through substrate vias

Role of optical parameters on nanosecond laser drilling of 4H-SiC was experimentally studied. Using ns pulsed Nd:YAG laser, parametric studies on effects of wavelength (1064 nm or 532 nm), beam profile (Gaussian or Bessel), and ambient condition (air or water) were conducted. The wavelengths which have large optical penetration depth were selected as wavefront has to propagate through materials to generate Bessel beam. The experimental results showed that carbonization of SiC surface accelerates thermal ablation of the materials with fluence under the lattice melting threshold. Especially, pattern of side lobes with small fluence was formed by irradiation of Bessel beam. The pattern disturbed penetration of wavefronts through materials. Implementation of water environment was not effective to suppress carbonization and had slight effect on improvement of drilling quality. For this reason, deep drilling with small entrance was not achieved using Bessel beam. Irradiation of 1064 nm Gaussian beam with large fluence led to formation of critical amount of re-solidified silicon due to the large optical penetration depth. Carbonization and silicon formation had a significant effect on unique fluence dependence of drilling depth. Absorption mechanism was studied as well to discuss effect of wavelength on processing characteristics.

Radiation Performance Characteristic Optimization of Time-Modulated Circular Antenna Arrays

ABSTRACTIn this paper, memetic flower pollination algorithm (MFPA) is proposed for solving the optimal synthesis of time-modulated half symmetric circular antenna array (TMHSCAA) and time-modulated asymmetric circular antenna array (TMASCAA) by controlling the switching time sequence and the excitation phase of each element time intervals and phases. Current excitation and inter-element spacing of each element are kept uniform. A unique cost function has been formulated for both the case studies. Several low-side lobe patterns synthesized from TMHSCAA and TMASCAA have been compared with those of the conventional circular array. A 20- and 36-element TMHSCAA and TMASCAA have been taken as examples. Furthermore, a novel six-ring time-modulated concentric hexagonal antenna array (TMCHAA) design has been considered to check superiority of the MFPA. The cost function has been designed for the concurrent improvement of side lobe level (SLL) and directivity in the new geometry of TMCHAA by an appropriate fine-tuning of the switching time succession and the inter-element separation of the hexagonal ring. Numerical results show that TMHSCAA, TMASCAA, and TMCHAA can be successfully used for the synthesis of low SLLs even if the amplitude excitations and inter-element spacing are uniform. Statistical analysis is also carried out to ensure that the results are significant in terms of the statistics. The results show that MFPA can exhibit a better performance than the other algorithms like real-coded genetic algorithm, particle swarm optimization, and differential evolution for the antenna array synthesis examples.

Synthesizing Asymmetric Side Lobe Pattern with Steered Nulling in Nonuniformly Excited Linear Arrays by Controlling Edge Elements

In radar antennas, asymmetric side lobes are useful, where undesired signals such as noise and ground clutter should be minimized. Also, for practical implementation, the feeding network of such antennas should be efficiently designed. In this paper, a simple analytical method for synthesizing asymmetric side lobe pattern with a wide-angle steered null in the nonuniformly excited linear arrays is presented. In this method, the difference in the side lobe levels on both sides of the main beam is achieved by varying just the phase excitations of the two-edge elements. The major novelty of this paper lies in the fact that the required asymmetric side lobe pattern can be achieved by changing a single phase shifter resulting in a simple feeding network.

Variante cambial en tallos de Ipomoea (Convolvulaceae) nativas de Argentina.

Ipomoea es un género diversificado y complejo, compuesto por herbáceas, lianas y enredaderas leñosas, y un pequeño grupo de arbustos y árboles. Llama la atención que todas las especies estudiadas anteriormente presentaron diferentes tipos de variante cambial en sus tallos, independientemente del modo de vida, excepto dos taxones con crecimiento secundario normal, una liana y un árbol. Por ello, en el presente trabajo se planteó el estudio de tres enredaderas nativas de Argentina, Ipomoea cairica, I. purpurea e I. rubriflora, y de I. carnea ssp. fistulosa, árbol con crecimientonormal, con el fin de comparar el desarrollo de sus tallos y aportar datos de interés para dilucidar sus relaciones filogenéticas. Las cuatro especies estudiadas presentaron igual ontogenia y anatomía desus tallos con crecimiento primario, lo que apoyaría sus estrechas relaciones filogenéticas. Por otro lado, las enredaderas presentaron sólo dos tipos de variante cambial, el patrón lobado y el de cámbiumsupernumerario. Se puede inferir que en Ipomoea el tipo de crecimiento secundario, así como los tipos de variante cambial, no estarían directamente relacionados con el hábito; sin embargo, otras características del leño pueden ponerse a consideración como la proporción de tejido parenquimático y características de los vasos.