Cosine Phase Research Articles

A novel device placement approach based on position-aware subgraph neural networks

Coping with the growing demand for data and parameters in complex neural network (NN) models of contemporary times typically involves distributing them across multiple devices, giving rise to the device placement problem. Several widely adopted solutions to this challenge leverage graph embedding schemes. However, the current graph embedding models employed for device placement suffer from several limitations, such as being highly time-consuming in the search for optimal parallelization strategies and yielding suboptimal parallel results. In this paper, we develop a novel graph embedding approach CP-GNNAK for efficient device placement. CP-GNNAK mainly depends on an efficient subgraph-based node embedding strategy, namely GNN as kernel, and a novel cosine phase position embedding scheme. CP-GNNAK goes beyond encoding only the immediate neighbors by deriving the representation of each node from the encoding of a surrounding subgraph. This expanded approach significantly enhances the efficiency of device placement through the integration of subgraph sampling strategies. Additionally, the cosine phase position embedding not only considers the positional information between nodes but also captures the directional information underlying the nodes. This adds richness to the node embeddings and improves the performance of device placement. The experimental results clearly indicate that the CP-GNNAK model achieves the state-of-the-art device placement results. Specifically, the experimental results reveal a remarkable 13.77% improvement in runtime when employing CP-GNNAK compared to Placeto. CP-GNNAK also outperforms GraphSAGE by 7.36% and P-GNN by 0.94%. Turning to computation time, CP-GNNAK exhibits a substantial speedup of 3.40× over Placeto, 3.87× over GraphSAGE, and 3.20× over P-GNN.

Generation of ultra-long optical needles with dual-ring cosine filter

Combining the advantages of phase and amplitude modulation, we designed a dual-ring cosine filter which was consisted by an inner and outer ring, and the two rings have different number of paired cosine phase. Using the dual-ring cosine filter, ultra-long longitudinally polarized optical needles were obtained by tight focusing radially polarized Bessel-Gaussian beams with a single lens system. The obtained optical needles have a depth of focus of 268λ, lateral full width of 0.37λ at half height, the beam quality of 94%, and axial uniformity of 95%. In addition, we found that the depth of focus of obtained optical needles can be further stretched and the lateral dimension can be further compressed by increasing the number of paired cosine phase. The ultra-long optical needles were appropriately applied in the fields of optical beam lithography, laser direct writing, particle acceleration, and optical trapping.

Tight Focusing of a higher order Radially Polarized sinh-Gaussian beam Transmitting through Cosine Phase Plate

Tight Focusing of a higher order Radially Polarized sinh-Gaussian beam Transmitting through Cosine Phase Plate

Phase control scheme of the coherent beam combining system for generating perfect vectorial vortex beams assisted by a Dammann vortex grating.

Based on Dammann vortex grating and adaptive gain stochastic parallel gradient descent algorithm, we theoretically proposed a phase control technology scheme of the coherent beam combining system for generating perfect vectorial vortex beams (VVBs). The simulated results demonstrate that the discrete phase locking for different types of VVBs (including vortex beams, vector beams, and generalized VVBs) can be successfully realized. The intensity distributions, polarization orientation, Pancharatnam phases, and beam widths of different |Hm,n〉 states with the obtained discrete phase distribution further prove that the generated beams are perfect VVBs. Subsequently, the phase aberration residual for different VVBs is evaluated using the normalized phase cosine distance function, and their values range from 0.01 to 0.08, which indicates the obtained discrete phase distribution is close to the ideal phase distribution. In addition, benefitting from the high bandwidth of involved devices in the proposed scheme, the influence of dynamic phase noise can be negligible. The proposed method could be beneficial to realize and switch flexible perfect VVBs in further applications.

The vortex cosine-gaussian beam in strongly nonlocal nonlinear media

Different cosine phase factors n can make the vortex cosine-Gaussian beam(VCGB) exhibit a multi-ring structure. When the number of vortex points of the VCGB was 1, the analytical expression of the orbital angular momentum was the Dawson integral function. By the split-step Fourier method, the propagation of a VCGB in nonlocalized medium was numerically simulated. It was found that when the vortex point was asymmetric with respect to the origin, the energy flow distribution of the VCGB was asymmetric. The center of mass is move with the transmission of the beam in nonlocal medium, resulting in oblique transmission. If the sign in front of the imaginary part of the vortex point changes, the rotation direction of the soliton changes. When two VCGBs were transmitted in nonlocalized medium, they can be intertwined or transmitted in serpentine shapes. Therefore, the beam information can be encoded by changing the phase factor and the number of vortex points. The beam transmission path in the nonlocal medium can be controlled by changing the vortex position.

Evaluation of Mathematical Models for Teaching Precision in the Framework of Big Data

With the continuous development and application of data computing in the whole society in the construction of digital campus and intelligent campus of each higher education institution. In the environment of education, universities use these data well, which not only affects the orderly operation of higher education but also will become an inexhaustible power to help higher education promote the reform and innovation of education and teaching system. In this paper, we focus on the teaching operation and students’ independent learning by taking students’ evaluation data and students’ online learning data of Y school as the research objects. We conducted a preliminary analysis and transformation of students’ evaluation data of a university, eliminated the abnormal evaluation data by using the improved cosine phase dissimilarity algorithm, standardized the evaluation data by using the normalization method, and used the traditional K -modes algorithm. Based on these three problems, the traditional K -modes algorithm was improved in three aspects, including the determination of the number of clustering families, the determination of the measurement of clustering distances, and the experimental results showed that the improved algorithm was more reasonable and effective.

Deep Learning Piston Aberration Control of Fiber Laser Phased Array By Spiral Phase Modulation

The stochastic parallel gradient descent (SPGD) algorithm is usually employed as the control strategy for phase-locking in fiber laser phased array systems. However, the convergence speed of the SPGD algorithm will slow down as the number of array elements increases. To improve the control bandwidth, the convolutional neural network is introduced to quickly calculate the initial piston aberration in a single step. In addition, the irrationality of the commonly used Mean Square Error (MSE) evaluation function in existing convolutional neural networks is analyzed. A new evaluation function NPCD (Normalized Phase Cosine Distance) is proposed to improve the accuracy of the neural networks. The results show that the piston aberration residual is 0.005 and the power in the bucket (PIB) is 0.993 after accurate preliminary compensation, which means that the system directly enters the co-phase state. We also demonstrate the robustness and scalability by adding additional disturbance and expanding the scale of the array.

Homodyne interferometry using a phase rotator for calibration of sine-cosine phase detection of a 70GHz probe beam through a plasma.

Homodyne interferometry using a motorized phase rotator for calibration of sine-cosine detection of the phase shift of a 70 GHz probe beam through a plasma has been developed. Four interferometers based on this interferometry have been installed on the low aspect ratio torus experiment (LATE) device with four horizontal probe beams on the mid-plane, which has measured the line-integrated electron densities with a time resolution of 10 μs and a resolution of line-integrated density of 5 × 1015m-2.

In-Phase and Quadrature-Phase Sinusoidal Signal Generation Using DDS Technique

In-phase and quadrature-phase (IQ) sinusoidal signals are used as bases functions in many phase modulation schemes in communication systems. Generating such signals in engineering education laboratories without higher-end signal generators is quite challenging. Most of the time, the IQ signals used in undergraduate engineering education laboratories are in audio frequency range that is used to demonstrate or experiment with various phase modulation schemes. This paper presents a method to generate IQ sinusoids in the audio frequency range using direct digital synthesis technique. The system developed is simulated using MathWorks® Simulink and implemented on commonly available Xilinx’s® Spartan 6 FPGA. The system designed is capable of producing phase correct sine and cosine waves having frequencies between 1 Hz and 20 kHz.

Color-encoded single-shot computer-generated Moir\xe9 profilometry

A color-encoded single-shot computer-generated Moiré profilometry (CSCGMP) is proposed. Two sinusoidal gratings with a π phase difference are encoded in red and blue channels respectively to combine a composite color grating. While this composite color grating is projected onto the measured object, the corresponding color deformed pattern can be captured. So two deformed patterns with a π phase difference are separated from its red and blue components respectively. After normalization and subtraction, the AC component of both separated deformed patterns can be extracted. If this AC component respectively multiplied by the two AC components of fringe patterns of reference plane with a π/2 phase difference prepared and saved on the computer in advance, two computer-generated Moiré fringes just respectively standing for sine and cosine of phase which is modulated by the height of the object relative to the reference plane are figured out. So the 3D shape of the measured object can be reconstructed with normal computer-generated Moiré profilometry. Both simulation and experimental results show the feasibility and validity of the proposed method. It has potential in real-time 3D measurement due to its single-shot feature.

Focusing pattern of cosh-Gaussian beam with polarization mixing cosine phase modulation.

Based on the vector diffraction theory, this paper focuses on the focusing pattern of cosh-Gaussian beams with polarization mixing cosine phase modulation and discusses the focused optical intensity under different parameters in detail. The results that show by adjusting the polarization parameter C, a tunable focal shift and a continuous shifting of focus on both directions of the optical axis can be achieved and the component that dominates the intensity distribution of the total field can be changed. When the tunable parameter D is positive, the optical chain with tunable length can be structured by increasing D. When D is negative, there will appear one special optical trap focus mode by which the number of optical traps can be changed by tailoring D. When the phase modulation parameter m increases, the focal pattern will wholly enlarge and stretch along the radial direction, changing from two intensity peaks to six optical chains. By increasing the decentered parameter β, the shape of the light intensity distribution in the focusing region can be remarkably adjusted. Besides, by combining the theories and analyzing the field patterns in the transverse plane, there is an electric field intensity dependence on the azimuthal angle φ. Those novel findings may be helpful in the applications such as optical manipulation, optical focusing, and imaging.

Cluster Analysis of Lithology Grouping Trends using Principal Component Spectral Analysis and Complex Seismic Attributes

Cluster analysis is used to determine possible lithology groupings on the basis of information from seismic data. Specifically, k-means is used in the cluster analysis of different lithologies. The data center is determined randomly and updated through an iterative process (unsupervised). The cluster analysis process involves combinations of complex seismic attributes and spectral decomposition as inputs. The complex seismic attributes are reflection strength and cosine phase. Reflection strength clearly describes the lithology boundary while the cosine phase describes the lithologies. Spectral decomposition is used to detect the presence of channels. The resolution of seismic data generally reaches 90 Hz. Spectral decomposition can produce outputs with up to 1 Hz intervals. The spectral components are correlated and repeated. To reduce the repetition of spectral data and increase the trend within the data, we use principal component spectral analysis. We apply and validate the workflow using the seismic data volume acquired over Boonsville, Texas, USA. The results of the cluster analysis method show good consistency with existing lithological maps interpreted from well data correlations.

Tectono-stratigraphic evolution of a cretaceous intracontinental rift: Example from Rio do Peixe Basin, north-eastern Brazil

The Rio do Peixe Basin is part of a set of aborted rifts with NE-SW trend along the NE region of Brazil. This axis was originated in response to the stress caused by the fragmentation of Pangea during the Mesozoic, and effectively installed during the Cretaceous event that defined the Brazilian equatorial margin. The detailed structural framework allowed the recognition of the Brejo das Freiras fault zone which presents NE-SW trend and, locally, ENE-WSW. This fault zone, strongly influenced by the basement fabric, deformed the layers and originated drag folds, fault-bending folds, and fault-propagation gentle folds. The half-graben fault margin developed alluvial fans, triggered by tectonic activity and geologically instantaneous creation of accommodation space. At the central portion it predominates a lacustrine sedimentation, while fluvial systems are responsible for carrying sedimentary supply from the flexural margin towards the depocenter. Since tectonics controls sedimentation on rifts, the tectonic systems tracts correspond to an arrangement of contemporaneous depositional systems associated with basin evolutional stages. In the syn-rift sequence, corresponding to Rio do Peixe Group nine stratigraphic units were recognized, bounded by flooding surfaces and drowning unconformities which record cycles of expansion and contraction of the lacustrine system. The tectonic systems tracts related to the initial stages of the rift installation were identified, followed by moments of high and low tectonic activity. The seismic and the well data support both the tectono-sedimentary evolution of the Brejo das Freiras Sub-Basin and the seismic-stratigraphic model proposed in this work. Different correlations between accommodation and sedimentation along a half-graben basin are expected in moments of tectonic activity and quiescence. The use of seismic attributes and filters improved the visualization and extraction of geological features, in both, structural (using pseudo-relief and curvature attributes) and stratigraphic interpretations (RMS amplitude and cosine phase). The understanding of spatial and temporal distribution of depositional systems responsible for a basin filling allows predicting potential petroleum systems.

Ultrahigh-resolution seismic enhancement. The use of colored inversion and seismic attributes on sub-bottom profiler data

Companies perform acoustic surveys before installing any submarine infrastructures in the seafloor, like new wells, pipelines, manifolds, cables, or wind farms. These surveys provide high-detailed geological information about the seabed and the first one hundred meters underneath the seafloor to subsea engineers and geologists. The prime use of this information by marine geologists is in geohazards analysis. The industry always used the sub-bottom profiler data in a fast-track way, not using its full capacity of geological representation. This contribution wants to magnify the potential of the sub-bottom profiler and define it as an ultrahigh-resolution seismic method. Sub-bottom profiler data assists numerical geotechnical analysis, and despite the scaling difference, can be the initial values when modeling velocity, sedimentary layers, and the continuities of geological faults. To support it, we present some established procedures from multichannel seismic, like classical seismic attributes applied to sub-bottom data. We computed envelope, instantaneous phase, instantaneous frequency, the cosine of phase, RMS, and TecVA on it. In a seismic line acquired in South Atlantic with a sub-bottom profiler, and one geological sample drilled from the seabed and profiled with a multi-sensor core logger. We applied for the first time the colored inversion technique to enlarge the spectrum of the ultrahigh-resolution seismic, increasing the low frequencies content. The new seismic spectrum enhances geological features providing better results than obtained with the raw seismic waveform and the seismic envelope attribute provided by most sub-bottom systems. While the raw seismic waveform has more vertical resolution with more reflectors in the same vertical unit, the envelope attribute has higher amplitude values. The result achieved with colored inversion has both the vertical resolution of the seismic waveform and the amplitude intensity of the envelope attribute.

An Unsupervised Generative Neural Approach for InSAR Phase Filtering and Coherence Estimation

Phase filtering and pixel quality (coherence) estimation is critical in producing Digital Elevation Models (DEMs) from Interferometric Synthetic Aperture Radar (InSAR) images, as it removes spatial inconsistencies (residues) and immensely improves the subsequent unwrapping. Large amount of InSAR data facilitates Wide Area Monitoring (WAM) over geographical regions. Advances in parallel computing have accelerated Convolutional Neural Networks (CNNs), giving them advantages over human performance on visual pattern recognition, which makes CNNs a good choice for WAM. Nevertheless, this research is largely unexplored. We thus propose "GenInSAR", a CNN-based generative model for joint phase filtering and coherence estimation, that directly learns the InSAR data distribution. GenInSAR's unsupervised training on satellite and simulated noisy InSAR images outperforms other five related methods in total residue reduction (over 16.5% better on average) with less over-smoothing/artefacts around branch cuts. GenInSAR's Phase, and Coherence Root-Mean-Squared-Error and Phase Cosine Error have average improvements of 0.54, 0.07, and 0.05 respectively compared to the related methods.

Seismic attributes and analogs to characterize a large fold in the Taranaki Basin

The Taranaki Basin lies in the western portion of New Zealand, onshore and offshore. It is a Cretaceous rift basin that is filled with up to approximately 10 km thick deposits from marine to deepwater depositional environments from the Cretaceous (approximately 93 ma) to the Neogene (approximately 15 ma). This basin underwent important tectonic events that resulted in large-scale features such as faults and folds and the deposition of turbidites such as channels and channel belts. These features easily are recognizable in seismic data. When analyzing the offshore 3D Pipeline data set, we recognized a peculiar fault-like feature with large-scale dimensions (approximately 15 km long and approximately 1 km wide) within the sequence. The alignment was perpendicular to the direction of deposition in the basin (southeast–northwest) as identified by previous studies and subparallel to the main structures in the area (southwest–northeast). We interpreted the seismic character of the funny-looking thing (FLT) likely as (1) a fault, (2) a fold, or (3) a large channel belt within the basin. We use seismic attributes such as coherence (Sobel filter), dip, cosine of phase, and curvature to characterize this feature geomorphologically. The geologic background of the area and analog settings aided in understanding and distinguishing the nature of this large structure. Monocline examples in seismic data are rare to find, and we want to show how to avoid misinterpretations. Geological feature: Fault-bend fold or large-amplitude fold (possibly monocline) Seismic appearance: Large, discontinuous, high-variance feature Alternative interpretations: Fault, fold Features with a similar appearance: Fault, fold, wide straight channel belt (time or horizon slice) Formation: Rift sequence of the Taranaki Basin Age: Eocene Location: Taranaki Basin, Western offshore New Zealand Seismic data: Provided by New Zealand Petroleum and Minerals Contributors: Karelia La Marca, Heather Bedle, Jerson Tellez; School of Geosciences; University of Oklahoma, Norman, OK, USA Analysis tool: 3D reflection seismic, geometric seismic attributes

Effects of a navigation spoofing signal on a receiver loop and a UAV spoofing approach

A civil navigation signal is vulnerable to interference and tampering owing to its open interface and low signal power. We focus on navigation spoofing. First, using a piecewise function, we quantitatively analyze the effects of the navigation spoofing signal on the receiver tracking loop. For a phase-locked loop, the spoofing signal extends the pull-in range of the discriminator. The autocorrelation gain of the spoofing signal has a different effect on the slope of the discriminator, depending on whether the discriminator is related to the signal amplitude. For the delay-locked loop, taking the non-coherent early minus late power method as an example, the unlocking condition and interval are analyzed quantitatively using the spoofing amplitude gain and the initial phase cosine of the spoofing and authentic carriers. A carrier frequency difference between the spoofing signal and authentic signal causes a phase jump and attenuation of the amplitude gain. Second, in luring an unmanned aerial vehicle (UAV) to a designated location, we assume a UAV model and provide a spoofing strategy. Experimental results show that it is feasible to lure a civilian quadrotor UAV to a designated location about 50 m from where the UAV believes it is located.

Focal Hole Shifting of Azimuthally Polarized Sinh Gaussian Beam using Cosine Phase Filter

Focal Hole Shifting of Azimuthally Polarized Sinh Gaussian Beam using Cosine Phase Filter

Assessing the Impact of a Heated Basement on Groundwater Temperatures in Bratislava, Slovakia.

Groundwater temperature is a useful hydrogeological parameter that is easy to measure and can provide much insight into groundwater flow systems, but can be difficult to interpret. For measuring temperature directly in the ground, dedicated specifically designed monitoring wells are recommended since conventional groundwater wells are not optimal for temperature monitoring. Multilevel monitoring of groundwater temperature is required to identify contributions of different possible heat inputs (sources) on measured temperature signals. Interpreting temperature data as a cosine function, including period, average temperature, amplitude, and phase offset, is helpful. Amplitude dampening and increasing phase shift with distance from a boundary can be used for estimation of transport parameters. Temperature measurements at different depths can be used for evaluation of unknown parameters of analytical functions by optimization of regression fits in Python. These estimated parameters can be used to calculate temperatures at known water table depths which can be applied as a fixed transient boundary condition in MT3DMS to overcome the limitations of MT3DMS heat transport modeling in the unsaturated zone. In this study, temperature monitoring and modeling was used to evaluate the influence of a department store's heated basement foundation on groundwater temperature within a green space (city park), with the main outcome that 17 years after construction, the department store foundation has increased the mean groundwater temperature by 3.2 °C. Heat input evaluated by the MT3DMS model varied from 0.1W/m2 at a distance of 100 m up to 12 W/m2 next to the building.

Intensity maxima position shift of spirally polarized hollow Gaussian beam with radial cosine phase modulation

The intensity maxima position shift and the focal pattern evolution principle of spirally polarized hollow Gaussian beams (HGBs), with radial cosine phase wavefront modulation, are researched by the vector diffraction theory with Debye approximation. Significant intensity maxima position shift and focal pattern transformation of spirally polarized HGBs were found by changing the value of the spiral parameter, phase parameter or beam order. The spiral parameter contributes considerably to focal splitting, the phase parameter contributes to the intensity maxima position shift, and the beam order induces a sharper radial focal pattern. When the phase parameter equals 1, the intensity maxima position shift curves dependent on spiral parameter are initially smooth, then they begin to oscillate, and their vertical coordinates gradually increase. When the phase parameter equals 2, the intensity maxima position shift curves are initially smooth, then they begin to oscillate across the focal plane along the propagation direction with increasing amplitude. The spiral parameter, phase parameter and beam order greatly affect the intensity distribution, with the appearance of many novel focal patterns in evolution process, including intensity bowl, spheroidal shell and intensity ring. Spirally polarized HGBs with radial cosine phase modulation may be applied widely in optical manipulation, particle limitation systems, laser surface modification and laser direct writing techniques.