Imaging diffraction points using the local image matrices generated in prestack migration

Geophysics ◽  
2010 ◽  
Vol 75 (1) ◽  
pp. S1-S9 ◽  
Author(s):  
Xiaosan Zhu ◽  
Ru-Shan Wu
Keyword(s):  
Singular Values ◽  
Linear Distribution ◽  
Prestack Migration ◽  
Secondary Sources ◽  
Potential Applications ◽  
Geological Discontinuities ◽  
Entire Matrix ◽  
The Difference ◽  
Seismic Images ◽  
Local Image

Energy-angle distributions in the local image matrix, which is a function of local incident and receiving angles at a subsurface point, are different for a planar reflector and a diffraction point. The former exhibits a linear distribution along a certain dip direction, whereas the latter shows a scattered distribution in the entire matrix. Therefore, the singular values of the local image matrix in the local angle domain indicate the energy distribution along different dip directions. The difference between the auto- and crosscorrelation coefficients of the sets of singular values between adjacent image points can be used to distinguish these two types of targets and obtain prestack images which contain only diffraction points. Using three synthetic examples, we found that the method can effectively image diffraction points. Seismic images of diffraction points may provide important information about geological discontinuities and diffraction points can be taken as secondary sources for potential applications in imaging subsalt structures which are poorly illuminated by primary waves.

FG-LiquID

2021 ◽  
Vol 5 (3) ◽  
pp. 1-27
Author(s):  
Yumeng Liang ◽  
Anfu Zhou ◽  
Huanhuan Zhang ◽  
Xinzhe Wen ◽  
Huadong Ma
Keyword(s):  
Alcohol Concentration ◽  
Coarse Grained ◽  
Robust Identification ◽  
Fine Grained ◽  
Fresh Milk ◽  
Average Accuracy ◽  
Coarse Grained Material ◽  
Potential Applications ◽  
Fine Grained Material ◽  
The Difference

Contact-less liquid identification via wireless sensing has diverse potential applications in our daily life, such as identifying alcohol content in liquids, distinguishing spoiled and fresh milk, and even detecting water contamination. Recent works have verified the feasibility of utilizing mmWave radar to perform coarse-grained material identification, e.g., discriminating liquid and carpet. However, they do not fully exploit the sensing limits of mmWave in terms of fine-grained material classification. In this paper, we propose FG-LiquID, an accurate and robust system for fine-grained liquid identification. To achieve the desired fine granularity, FG-LiquID first focuses on the small but informative region of the mmWave spectrum, so as to extract the most discriminative features of liquids. Then we design a novel neural network, which uncovers and leverages the hidden signal patterns across multiple antennas on mmWave sensors. In this way, FG-LiquID learns to calibrate signals and finally eliminate the adverse effect of location interference caused by minor displacement/rotation of the liquid container, which ensures robust identification towards daily usage scenarios. Extensive experimental results using a custom-build prototype demonstrate that FG-LiquID can accurately distinguish 30 different liquids with an average accuracy of 97%, under 5 different scenarios. More importantly, it can discriminate quite similar liquids, such as liquors with the difference of only 1% alcohol concentration by volume.

scholarly journals Linear traveltime perturbation interpolation: a novel method to compute 3-D traveltimes

2015 ◽  
Vol 203 (1) ◽  
pp. 548-552 ◽  
Author(s):  
Jianzhong Zhang ◽  
Junjie Shi ◽  
Lin-Ping Song ◽  
Hua-wei Zhou
Keyword(s):  
Seismic Waves ◽  
Homogeneous Medium ◽  
Cell Boundary ◽  
Routine Method ◽  
Bilinear Interpolation ◽  
Linear Distribution ◽  
Heterogeneous Model ◽  
Computational Errors ◽  
Novel Method ◽  
The Difference

Abstract The linear traveltime interpolation has been a routine method to compute first arrivals of seismic waves and trace rays in complex media. The method assumes that traveltimes follow a linear distribution on each boundary of cells. The linearity assumption of traveltimes facilitates the numerical implementation but its violation may result in large computational errors. In this paper, we propose a new way to mitigate the potential shortcoming hidden in the linear traveltime interpolation. We use the vertex traveltimes in a calculated cell to introduce an equivalent homogeneous medium that is specific to the cell boundary from a source. Therefore, we can decompose the traveltime at a point on the cell boundary into two parts: (1) a reference traveltime propagating in the equivalent homogeneous medium and (2) a perturbation traveltime that is defined as the difference between the original and reference traveltimes. We now treat that the traveltime perturbation is linear along each boundary of cells instead of the traveltime. With the new assumption, we carry out the bilinear interpolation over traveltime perturbation to complete traveltime computation in a 3-D heterogeneous model. The numerical experiments show that the new method, the linear traveltime perturbation interpolation, is able to achieve much higher accuracy than that based on the linear traveltime interpolation.

Anatomy of a Natural Sunlight Driven CdS/CoTiO3/ZnO Ternary Photocatalyst for Efficient Optical Properties and Removal of Reactive Orange 30

2021 ◽  
Vol 25 (8) ◽  
pp. 100-109
Author(s):  
G. Divya ◽  
D. Sakthi ◽  
A. Priyadharsan ◽  
S. Boobas ◽  
S. Sivakumar
Keyword(s):  
Electron Transfer ◽  
Photocatalytic Activity ◽  
Potential Gradient ◽  
Spatial Separation ◽  
Morphological Properties ◽  
Photoexcited Electron ◽  
Visible Absorption ◽  
Potential Applications ◽  
The Difference ◽  
Reactive Orange

ZnO as a promising photocatalyst has gained much attention for the removal of organic pollutants from water. However, the main drawbacks of the relatively low photocatalytic activity and high recombination rate of photoexcited electron-hole pairs restrict its potential applications. Promoting the spatial separation of photoexcited charge carriers is of paramount significance for photocatalysis because the difference in the band positions makes the potential gradient at the composite boundary. In this work, binary CdS/ZnO and CoTiO3/ZnO are first prepared by dispersion method and then decorated with ZnO particles to construct CdS/CoTiO3/ZnO ternary composites. For this reason, the CdS/CoTiO3/ZnO ternary composites was effectively designed and analyzed for the crystalline structure, light absorption, photoexcitation behavior and surface morphological properties by X-ray diffraction, diffuse reflectance UV/visible absorption spectroscopy, photoluminescence spectroscopy and scanning electron micrograph respectively. The photocatalytic activity was examined by degradation of the dye solution spectrophotometrically. The results of photocatalytic degradation indicated that the CdS/CoTiO3/ZnO ternary composites are much higher than those of bare CdS, CoTiO3, ZnO and any binary composites such as CoTiO3/ZnO and ZnO/CdS. The enhanced activity could be attributed to the drop electron transfer from CdS to ZnO to CoTiO3 through the interfacial potential gradient in the ternary hybrid conduction bands. The enhanced electron transfer of CdS/CoTiO3/ZnO ternary composites was also applicable to degrade other reactive dyes.

Jio-Bharti Airtel Data War and Strategy

2018 ◽  
pp. 171-179
Author(s):  
Anil Kumar ◽  
Mohan Balaji ◽  
Ujjwal Krishna ◽  
Mohit Yadav
Keyword(s):  
Quality Of Service ◽  
Regulatory Authority ◽  
The Other ◽  
Complete Understanding ◽  
Secondary Sources ◽  
The Difference

The chapter examines various viewpoints in regards to Reliance Jio and Bharti Airtel. This includes the entry of Jio in the telecom space along with the difference in the market Jio bought right after its introduction of the services for public. The focus area for the research has been the secondary sources. A complete understanding of both these companies has been taken into account for this study to pick up the points that both Jio and Bharti have been lacking upon and areas in which one has surpassed the other by attracting a new set of consumers into their family. The chapter as recorded by the facts presented through the Telecom Regulatory Authority of India Analytics Portal witnessed that Jio proved to have an upper hand in terms of the quality of service, which included data speed and tariffs. The other side of the story shows Bharti Airtel's lack of dominance in 4G experience delivery after Jio's entrance.

Substrate Polarity Effects on the Interface Electronic Structure in Organic Light Emitting Diodes

2016 ◽  
Vol 852 ◽  
pp. 746-749
Author(s):  
Huang Tian ◽  
Xin Zhao ◽  
Qiang Zhang ◽  
Huai Xin Wei
Keyword(s):  
Electronic Structure ◽  
Performance Enhancement ◽  
Open Circuit ◽  
Organic Electronic Devices ◽  
Light Emitting ◽  
Organic Layers ◽  
Interface Dipole ◽  
Potential Applications ◽  
The Difference ◽  
Polarity Effects

Organic layers deposited on various polarity substrates and the electronic structures of (PTCDA/TiOPc) on hydrophobic and hydrophilic substrates have been studied by ultraviolet photoemission spectroscopy. The difference between work function and polarity of the substrates induce the formation of an interface dipole with corresponding shift in the relative position of molecular levels across the interface. While the vacuum level and open circuit voltage show vastly difference respectively, the barrier between anode-organic or organic-cathode also changes from 0.75eV to 1.13eV or 0.35eV to 0.65eV. The results show the possibility of tuning the electronic structure by the modification of substrate and potential applications on performance enhancement in organic electronic devices.

scholarly journals Co-occurrence Retrieval: A Flexible Framework for Lexical Distributional Similarity

2005 ◽  
Vol 31 (4) ◽  
pp. 439-475 ◽  
Author(s):  
Julie Weeds ◽  
David Weir
Keyword(s):  
Language Processing ◽  
Similarity Measures ◽  
Document Retrieval ◽  
Wide Range ◽  
Distributional Similarity ◽  
Potential Applications ◽  
The Difference ◽  
Occurrence Type ◽  
Definition Of ◽  
Relationship Of

Techniques that exploit knowledge of distributional similarity between words have been proposed in many areas of Natural Language Processing. For example, in language modeling, the sparse data problem can be alleviated by estimating the probabilities of unseen co-occurrences of events from the probabilities of seen co-occurrences of similar events. In other applications, distributional similarity is taken to be an approximation to semantic similarity. However, due to the wide range of potential applications and the lack of a strict definition of the concept of distributional similarity, many methods of calculating distributional similarity have been proposed or adopted. In this work, a flexible, parameterized framework for calculating distributional similarity is proposed. Within this framework, the problem of finding distributionally similar words is cast as one of co-occurrence retrieval (CR) for which precision and recall can be measured by analogy with the way they are measured in document retrieval. As will be shown, a number of popular existing measures of distributional similarity are simulated with parameter settings within the CR framework. In this article, the CR framework is then used to systematically investigate three fundamental questions concerning distributional similarity. First, is the relationship of lexical similarity necessarily symmetric, or are there advantages to be gained from considering it as an asymmetric relationship? Second, are some co-occurrences inherently more salient than others in the calculation of distributional similarity? Third, is it necessary to consider the difference in the extent to which each word occurs in each co-occurrence type? Two application-based tasks are used for evaluation: automatic thesaurus generation and pseudo-disambiguation. It is possible to achieve significantly better results on both these tasks by varying the parameters within the CR framework rather than using other existing distributional similarity measures; it will also be shown that any single unparameterized measure is unlikely to be able to do better on both tasks. This is due to an inherent asymmetry in lexical substitutability and therefore also in lexical distributional similarity.

scholarly journals On the Concepts of the “Family” and the “Household” in the Political Theory of Jean Bodin

2019 ◽  
Vol 18 (4) ◽  
pp. 130-148
Author(s):  
Gulnara Bayazitova
Keyword(s):  
Political Theory ◽  
The Political ◽  
Ancient Rome ◽  
The Public ◽  
Secondary Sources ◽  
Jean Bodin ◽  
The Family ◽  
History Of ◽  
The Difference ◽  
The Republic

The article examines the tradition of formation of the concepts “family” (famille) and “household” (ménage) in the political theory of the French lawyer, Jean Bodin. The article looks into different editions of Six Books of the Commonwealthto explore the connotations of the key concepts and the meaning that Bodin ascribed to them. As secondary sources, Bodin uses the works by Xenophon, Aristotle, Apuleus, and Marcus Junianus Justin, as well as the Corpus Juris Civilis. Bodin examines three different traditions, those of Ancient Greece, Ancient Hebrew, and Ancient Rome. Each of these traditions has its own history of the concepts of the “family” and of the “household”. Bodin refers to ancient traditions for polemics, but eventually offers his own understanding, not only of the concepts of “famille” and “ménage”, but also of the term «République», defined as the Republic, a term that (with some reservations) refers to the modern notion of state. The very fact that these concepts are being used signifies the division of the political space into the spheres of the private and the public. Furthermore, the concepts of the “family” and of the “household” are key to understand the essence of sovereignty as the supreme authority in the Republic. The author concludes that the difference between Bodin’s concepts of the “family” and the “household” lies not only in the possession of property and its legal manifestation, but also in the fact that the “household” is seen by Bodin as the basis of the Republic, the first step in the system of subordination to the authority.

scholarly journals Advances and Physicochemical Property Investigations by Methylene Chain Length of Perovskite-type Layer Crystals [NH3(CH2)nNH3]CdCl4 (n=2, 3, and 4)

2021 ◽  
Author(s):  
Ae Ran Lim
Keyword(s):  
Molecular Dynamics ◽  
Structural Characteristics ◽  
Mas Nmr ◽  
X Ray Diffraction ◽  
Thermal Stabilities ◽  
Type Layer ◽  
Phase Transition Temperatures ◽  
Potential Applications ◽  
The Difference ◽  
Perovskite Type

Abstract Hybrid perovskites have potential applications in several electrochemical devices such as supercapacitors, batteries, and fuel cells. However, despite various potential applications, there have been limited studies on compounds containing Cd. Therefore, in this study, the structures and phase transition temperatures TC of organic–inorganic perovskite [NH3(CH2)nNH3]CdCl4 (n=2, 3, and 4) were confirmed by X-ray diffraction and DSC experiments. The thermal stabilities obtained by TGA and DTA results were considered as a function of the length n of the CH2 groups in the cation. In addition, structural characteristics and molecular dynamics of the cation and anion near TC were studied by 1H MAS NMR, 13C MAS NMR, 14N static NMR, and 113Cd MAS NMR experiments. From these results, regardless of whether n is even or odd, the differences in thermal and physical properties were minimal. Rather, the difference in molecular motion relative to the length of the cation was seen only at higher temperatures. These results provide insights into the thermal stability and molecular dynamics of [NH3(CH2)nNH3]CdCl4 crystals and are expected to facilitate potential applications.

scholarly journals Differential Networks for Visual Question Answering

2019 ◽  
Vol 33 ◽  
pp. 8997-9004 ◽  
Author(s):  
Chenfei Wu ◽  
Jinlai Liu ◽  
Xiaojie Wang ◽  
Ruifan Li
Keyword(s):  
Question Answering ◽  
Image Feature ◽  
Visual Question Answering ◽  
Key Points ◽  
Potential Applications ◽  
Observation Noise ◽  
The Difference ◽  
Difference Operation ◽  
Novel Model ◽  
Differential Networks

The task of Visual Question Answering (VQA) has emerged in recent years for its potential applications. To address the VQA task, the model should fuse feature elements from both images and questions efficiently. Existing models fuse image feature element vi and question feature element qi directly, such as an element product viqi. Those solutions largely ignore the following two key points: 1) Whether vi and qi are in the same space. 2) How to reduce the observation noises in vi and qi. We argue that two differences between those two feature elements themselves, like (vi − vj) and (qi −qj), are more probably in the same space. And the difference operation would be beneficial to reduce observation noise. To achieve this, we first propose Differential Networks (DN), a novel plug-and-play module which enables differences between pair-wise feature elements. With the tool of DN, we then propose DN based Fusion (DF), a novel model for VQA task. We achieve state-of-the-art results on four publicly available datasets. Ablation studies also show the effectiveness of difference operations in DF model.

The magneto-seismic method in geoscience

2021 ◽  
Vol 40 (3) ◽  
pp. 194-201
Author(s):  
Qiuzi Li ◽  
Harry W. Deckman ◽  
Deniz Ertaş ◽  
Lang Feng
Keyword(s):  
Magnetic Field ◽  
Seismic Response ◽  
Seismic Waves ◽  
Signal To Noise Ratio ◽  
Cross Product ◽  
Seismic Effect ◽  
Sound Waves ◽  
Current Dipole ◽  
Potential Applications ◽  
The Difference

Key concepts and potential applications associated with a phenomenon hitherto unexplored by the geoscience community, which we have named the magneto-seismic effect, are introduced. The method is based on the simple principle that when an electric charge moves in the presence of an external magnetic field, the charge carrier experiences an instantaneous force, which is equal to the vector cross product of the current it carries and the magnetic field that is present. This “Lorentz force” can create both compressional and shear sound waves in electrical conductors by passing an alternating current through them via an electromagnetic source. In laboratory settings, this magneto-seismic effect can produce readily detectable rock frame displacements. This opens up the possibility of developing new experimental methods to interrogate elastic and poroelastic response of rocks in a broad frequency range from subhertz to megahertz, potentially closing the frequency gap between traditional ultrasonic characterization and properties of interest in the seismic frequency band. In exploration settings, electric current dipole/bipole sources, or novel rotating magnetic dipole sources, can be used to generate electric currents at depth. These currents produce seismic waves at interfaces (or boundaries) where conductivity abruptly changes. The amplitude and propagation directions of these generated seismic waves depend on the relative orientation of the interfaces (or boundaries) with respect to the earth's magnetic field. These seismic waves can then be recorded by receivers at the surface and, in principle, might be processed to yield a resistivity map with seismic resolution. It is shown that processing to obtain a signal from deep targets is significantly limited by seismic background noise. However, an acceptable signal-to-noise ratio might be achieved for shallower targets. The difference between the magneto-seismic response and the previously well-studied electro-seismic response will be discussed.

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