Development Of Data Processing Methods Research Articles

Molecular Characterization of Hydrocarbons in Petroleum by Ultrahigh-Resolution Mass Spectrometry

The progress in ultrahigh-resolution mass spectrometry (UHRMS) and related technologies has significantly promoted the development of petroleomics. The study of petroleomics has greatly broadened our knowledge of the composition of petroleum at the molecular level, especially heavy fractions that cannot be analyzed by gas chromatography (GC)-based methods. To date, heteroatom-containing (O, N, S, and metal atoms) compounds in petroleum have been studied extensively by UHRMS. Nevertheless, the main components of petroleum, hydrocarbon compounds, have remained out of reach of petroleomics characterization for a long time because they are too difficult to be softly and efficiently ionized for UHRMS analysis. It is undoubtedly the case that petroleum hydrocarbons should not be the missing part of petroleomics characterization since they play important roles not only as feeding pools for various high value-added petroleum products but also as critical biomarkers for geochemistry studies. Here, the most recent breakthroughs in petroleomics characterization of hydrocarbon compounds using UHRMS rather than conventional methods have been reviewed. Innovations of soft ionization methods can transform non-polar hydrocarbon molecules into molecular ions or quasi-molecular ions that are reachable for UHRMS without fragmentation. The development of data processing methods has assisted the decoding of the complicated UHRMS data to visualize the molecular composition and structure of hydrocarbon compounds. These advances make it possible to see the whole picture of petroleum compositions, from light distillation fractions to heavy distillation fractions, and from small volatile molecules to large non-volatile ones. The applications of UHRMS-based methods for petroleomics characterization of hydrocarbon compounds in crude oils and various petroleum samples including fuel oil, slurry, and even asphaltene have made a great contribution to petrochemistry and geochemistry studies, especially in the fields of molecular refining and biomarker discovery.

Basic Principles of Secure Information Systems

The relevance of the work lies in the fact that the pace of development of the field of information security does not correspond to progress in the development of data processing methods, resulting in a serious lack of practical knowledge of the subject area, which prevents the creation of conditions for secure recording, processing and storage of data. In the process of writing the article, modern methods and principles of ensuring information security, including a mandatory approach, were studied, and a brief description of software products supporting this approach was given. The mandatory method of information protection implies granting access rights to certain actions in accordance with the user’s status. Such actions can be, for example, writing, reading and changing data. Examples of user statuses are ‘administrator’ and ‘reader’, where the administrator, as a rule, is provided with the entire list of available actions, and the reader is provided with only a minimum, sufficient for familiarization activities. In its architecture, the mandatory approach often contains tools for conducting cluster analysis. Cluster analysis can be used both to carry out work on risk analysis and assessment, and to determine the degree of protection of an object. In any case, when building a cluster, it should be taken into account that some levels of protection may be represented by more objects than others. There are software products on the information security market that allow the use of a mandatory method of ensuring information security. One of the striking examples is the PostgreSQL database management system, which has an apparatus of labels assigned according to the user’s level of rights: the higher the level of rights, the higher the access level.

A mathematical theory of computational resolution limit in multi-dimensional spaces * *Hai Zhang was partially supported by Hong Kong RGC grant GRF 16305419.

Resolving a linear combination of point sources from their Fourier data in a bounded domain is a fundamental problem in imaging and signal processing. With incomplete Fourier data and inevitable noise in the measurement, there is a fundamental limit on the separation distance between the point sources that can be resolved. This is the so-called resolution limit problem. Characterization of this resolution limit is still a long-standing puzzle despite the prevalent use of the classical Rayleigh limit. It is well-known that the Rayleigh limit is heuristic and its drawbacks become prominent when dealing with data that is subjected to elaborated processing, as is what modern computational imaging methods do. Therefore, a more precise characterization of the resolution limit becomes increasingly necessary with the development of data processing methods. For this purpose, we developed a theory of ‘computational resolution limit’ for both the number detection problem and the support recovery problem in one dimension in (Liu and Zhang 2019 arXiv:1912.05430; Liu and Zhang 2021 IEEE Trans. Inf. Theory 67 4812–27). In this paper, we extend the theory from dimension one to multiple dimensions. More precisely, we define and quantitatively characterize the ‘computational resolution limit’ for the number detection problem and the support recovery problem respectively in general multi-dimensional spaces. Our results indicate that there exists a phase transition phenomenon regarding the super-resolution factor and the signal-to-noise ratio in each of the two recovery problems. Our main results are obtained by using a projection strategy. Finally, to verify the theory, we propose deterministic projection-based algorithms for the number detection problem and the support recovery problem respectively. The numerical results in dimensions two and three confirm the phase transition phenomenons.

Synthetic Data in Quantitative Scanning Probe Microscopy.

Synthetic data are of increasing importance in nanometrology. They can be used for development of data processing methods, analysis of uncertainties and estimation of various measurement artefacts. In this paper we review methods used for their generation and the applications of synthetic data in scanning probe microscopy, focusing on their principles, performance, and applicability. We illustrate the benefits of using synthetic data on different tasks related to development of better scanning approaches and related to estimation of reliability of data processing methods. We demonstrate how the synthetic data can be used to analyse systematic errors that are common to scanning probe microscopy methods, either related to the measurement principle or to the typical data processing paths.

Point spread function estimation for wide field small aperture telescopes with deep neural networks and calibration data

ABSTRACT The point spread function (PSF) reflects states of a telescope and plays an important role in the development of data-processing methods, such as PSF-based astrometry, photometry, and image restoration. However, for wide field small aperture telescopes (WFSATs), estimating PSF in any position of the whole field of view is hard, because aberrations induced by the optical system are quite complex and the signal-to-noise ratio of star images is often too low for PSF estimation. In this paper, we further develop our deep neural network (DNN)-based PSF modelling method and show its applications in PSF estimation. During the telescope alignment and testing stage, our method collects system calibration data through modification of optical elements within engineering tolerances (tilting and decentring). Then, we use these data to train a DNN (Tel–Net). After training, the Tel–Net can estimate PSF in any field of view from several discretely sampled star images. We use both simulated and experimental data to test performance of our method. The results show that the Tel–Net can successfully reconstruct PSFs of WFSATs of any states and in any positions of the field of view (FoV). Its results are significantly more precise than results obtained by the compared classic method – inverse distance weight interpolation. Our method provides foundations for developing deep neural network-based data-processing methods for WFSATs, which require strong prior information of PSFs.

Development of data processing methods in time-resolved Laue photocrystallography

Development of data processing methods in time-resolved Laue photocrystallography

The Status and Progress of Thermal Analysis Kinetics

Thermal analysis kinetics has been applied rapidly in recent decades. Thermal analysis technology is widely used in various fields under the commercialization of analyser. In this paper, the thermal analysis dynamics equation, the application development of thermal analysis technology and the development of data processing method are introduced in this paper, and the research of thermal analysis dynamics is described. And the prospect of the research direction is also put forward.

Research progress in Asia on methods of processing laser-induced breakdown spectroscopy data

Laser-induced breakdown spectroscopy (LIBS) has attracted much attention in terms of both scientific research and industrial application. An important branch of LIBS research in Asia, the development of data processing methods for LIBS, is reviewed. First, the basic principle of LIBS and the characteristics of spectral data are briefly introduced. Next, two aspects of research on and problems with data processing methods are described: i) the basic principles of data preprocessing methods are elaborated in detail on the basis of the characteristics of spectral data; ii) the performance of data analysis methods in qualitative and quantitative analysis of LIBS is described. Finally, a direction for future development of data processing methods for LIBS is also proposed.

Finite‐Difference Modelling of Rayleigh Surface Wave in Elastic MEDIA

AbstractTo study the generation mechanism and propagation rule of Rayleigh surface waves, and to accelerate the corresponding development of data processing method, the paper applies the finite‐difference method with staggered grids to simulate full‐wave‐fields, including both Rayleigh surface wave and body waves, in shallow isotropic media based on elastic wave equations. Meanwhile, a variable coefficient absorbing boundary condition, which makes the treatment of boundary condition more simplified and more effective, is developed. Furthermore, a method to process angle points is also proposed. Simulations have been done for continuous and stratified media which are common in the field of engineering survey, and more realistic seismograms are obtained. According to the synthetic records, the condition of Rayleigh surface wave excitation is investigated, and the influence of the depth of epicenter on the energy of surface wave is discussed.

Fast static correction methods for high-frequency multichannel marine seismic reflection data: A high-resolution seismic study of channel-levee systems on the Bengal Fan

Very high-frequency marine multichannel seismic reflection data generated by small-volume air- or waterguns allow detailed, high-resolution studies of sedimentary structures of the order of one to few metres wavelength. The high-frequency content, however, requires (1) a very exact knowledge of the source and receiver positions, and (2) the development of data processing methods which take this exact geometry into account. Static corrections are crucial for the quality of very high-frequency stacked data because static shifts caused by variations of the source and streamer depths are of the order of half to one dominant wavelength, so that they can lead to destructive interference during stacking of CDP sorted traces. As common surface-consistent residual static correction methods developed for land seismic data require fixed shot and receiver locations two simple and fast techniques have been developed for marine seismic data with moving sources and receivers to correct such static shifts. The first method – called CDP static correction method – is based on a simultaneous recording of Parasound sediment echosounder and multichannel seismic reflection data. It compares the depth information derived from the first arrivals of both data sets to calculate static correction time shifts for each seismic channel relative to the Parasound water depths. The second method – called average static correction method – utilises the fact that the streamer depth is mainly controlled by bird units, which keep the streamer in a predefined depth at certain increments but do not prevent the streamer from being slightly buoyant in-between. In case of calm weather conditions these streamer bendings mainly contribute to the overall static time shifts, whereas depth variations of the source are negligible. Hence, mean static correction time shifts are calculated for each channel by averaging the depth values determined at each geophone group position for several subsequent shots. Application of both methods to data of a high-resolution seismic survey of channel-levee systems on the Bengal Fan shows that the quality of the stacked section can be improved significantly compared to stacking results achieved without preceding static corrections. The optimised records show sedimentary features in great detail, that are not visible without static corrections. Limitations only result from the sea floor topography. The CDP static correction method generally provides more coherent reflections than the average static correction method but can only be applied in areas with rather flat sea floor, where no diffraction hyperbolae occur. In contrast, the average static correction method can also be used in regions with rough morphology, but the coherency of reflections is slightly reduced compared to the results of the CDP static correction method.

Study of the high‐frequency spectrum of the anomalous gravity potential

The analysis of the high‐frequency spectrum of the anomalous gravity potential is important for a number of current and emerging technologies in geodesy and geophysics. Among them is the precise determination of deflections of the vertical by inertial techniques, the development of data processing methods in airborne gradiometry, and the signal extraction methods for airborne gravimetry. The spectral information required can be obtained by analyzing dense gravity data by fast Fourier transform techniques. An attempt has been made to use available data files in Canada for this purpose. The data consisted of a rather uniform set of (5 arc min × 5 arc min) point anomalies in most of the continental areas of Canada and four sets of point gravity anomalies with an average data spacing of about 1 km in areas of limited extent. The analysis showed that the gravity spectrum has to be resolved to about degree and order 7000, i.e., to a point spacing of about 3 km, to resolve the gravity anomalies to 1 mGal. Thus a similar data spacing would be required in airborne gradiometry and gravimetry in order to get an equivalent resolution. The derived spectrum was used to determine suitable degree variance models and covariance functions for the above applications. The spectrum estimated from the 5 arc min × 5 arc min gravity anomalies covering the nonmountainous areas of Canada indicates that the degree variances of the anomalous potential decay as ℓ−3.6. This means that a number of currently used covariance models do not agree with the results of this analysis. A discussion on the choice of a more adequate model concludes the paper.

The development of data analysis systems for bubble chambers, for spark chambers and for counter experiments

Work done on bubble chamber data processing methods in the past two years is reviewed. It includes improvements to the now standard methods, development of new measuring devices, and progress on completely automatic systems. Most projects for automatic processing of spark chamber pictures take the most recent bubble chamber analysis techniques as their starting point, but several methods to determine spark positions without the use of film are reviewed in relation to their possible use in an automatic data analysis system. Development of data processing methods for counter experiments has shown two main features since 1980: (1) construction and use of a variety of digital data- handling systems, and (2) use of digital computers on-line to control data flow, to do a certain amount of processing during an experiment, and to carry out checks on the operation of the equipment. (A.G.W.)