MUSTANG: Multi-sample spatial transcriptomics data analysis with cross-sample transcriptional similarity guidance
Not Available
Niyakan, Seyednami (ORCID:0000000193282489)↗
Engineering topics
Wu, Ling
Publications and source records attributed to Wu, Ling.
Power system disturbance localization using recurrence quantification analysis and minimum-volume-enclosing ellipsoid
A method for determining a location of a disturbance in a power system is provided. The method includes receiving data from a plurality of sensors distributed across the power system; performing a recurrence quantification analysis on the received data to identify a predetermined number of sensors, from the plurality of sensors, that are closest to the disturbance; constructing a plurality of minimum-volume-enclosing ellipsoids based on and enclosing the data received from the identified sensors; extracting one or more parameters from the plurality of minimum-volume-enclosing ellipsoids; inputting the one or more parameters into a multivariate-random-forest regression algorithm to determine the location of the disturbance and a power mismatch corresponding to the disturbance; and presenting, on one or more display units, the determined location of the disturbance and the determined power mismatch.
Cui, Yi↗
Power system disturbance location determination based on rate of change of frequency
A method for determining a location of a disturbance in a power system is provided. The method includes receiving data from a plurality of sensors distributed across the power system; determining, with one or more processors, for each sensor, an extremum of the data corresponding to the sensor; interpolating, with the one or more processors, the extrema; and presenting, on one or more display units, a location corresponding to a global maximum of the interpolated extrema as the location of the disturbance. The method may further include, if a difference between the largest extremum and each of remaining extremum is greater than a predetermined threshold, skipping the interpolating step and the presenting step, and presenting a location of the sensor corresponding to the largest extremum as the location of the disturbance.
You, Shutang↗
Impact of the Measurement Errors on Synchrophasor-Based WAMS Applications
Not Available
42 ENGINEERING↗
Multiple Linear Regression Based Disturbance Magnitude Estimations for Bulk Power Systems
Sudden trips of generation or large system load threaten bulk power systems (BPSs) secure and reliable operations. With the increasing deployment of Phasor Measurements Units (PMUs), system operators are thrilled to receive instant notifications of sudden disturbances and be aware of where, when, and what type of disturbances the system is experiencing. The amount of power imbalance is one of the fundamental information of the interests of both system operators and academic researchers. The PMU-based applications estimate the magnitude by interpreting the dynamic frequency responses immediately after a disturbance occurrence. However, the accuracy of the traditional method is unsatisfying because it oversimplifies the relation between the imbalance magnitude and the frequency response. This paper proposes to estimate the magnitudes of power imbalances based on multiple linear regression. It considers several other system and environmental factors and identifies those factors strongly associated with the disturbance magnitude. The approach is applied to actual generation trip events happened in two of the main power grids in North America. Compared with the traditional method, the proposed approach demonstrates improved accuracy.
Wu, Ling↗
HOXC10 promotes gastric cancer cell invasion and migration via regulation of the NF-κB pathway
Homeobox gene C10 (HOXC10), known to regulate cell differentiation and proliferation, is upregulated in gastric cancer (GC). The mechanism underlying HOXC10 involvement in GC metastasis is unclear. Herein, we found that HOXC10 is overexpressed in GC relative to normal controls. In the 73 GC patients tissue microarrays (TMA) tested, HOXC10 expression was closely related with tumor-node-metastasis (TNM) stage, lymph node metastasis, and distant metastasis. HOXC10 overexpression tended to associate with low 5-year cumulative survival. Cox regression analysis identified HOXC10 as an independent prognostic factor for poor patient survival. HOXC10 promoted GC cell invasion and migration, regulated the expression of activated ATM and markers of NF-κB signaling. HOXC10 may promote invasion and migration of GC by regulating ATM/NF-κB signaling pathway. HOXC10 should be explored as a clinical marker of GC prognosis.
60 APPLIED LIFE SCIENCES↗
Recent application examples of FNET/GridEye
As a pilot wide-area monitoring system (WAMS), FNET/GridEye monitors the bulk power systems using a network of GPS-synchronized sensors and a wide variety of FNET/GridEye applications have been spawned in the past years. In this paper, following a brief description of the FNET/GridEye historical developments, several recent examples of FNET/GridEye applications are introduced.
Liu, Yong↗
Inter‐area oscillation statistical analysis of the U.S. Eastern interconnection
Although extensive studies have been conducted on inter‐area oscillation detection and analysis by using phasor measurement data, few have focused on inter‐area oscillation statistics due to the lack of considerably long‐term and high‐resolution recorded data. A preliminary statistical analysis on the inter‐area oscillations that occurred in the U.S. Eastern interconnection from 2010 to 2015 is presented. These oscillation events were captured and recorded by the wide‐area frequency monitoring network FNET/GridEye. Oscillation occurrence, dominant frequency, damping ratio and oscillation excitation types are investigated to explore the statistical characteristics of the detected inter‐area oscillations. The results from this paper will provide valuable information for system operators and planners regarding network operation and future grid development.
Cui, Yi↗
Disturbance location determination based on electromechanical wave propagation in FNET/GridEye: a distribution‐level wide‐area measurement system
This study presents a method to locate power system disturbances using wide‐area synchropahsor measurements. The merits of the proposed method include robustness and ease of visualisation. In addition, the proposed method facilitates the calculation of electromechanical wave propagation speed distribution. Examples of locating the disturbance and generating the propagation speed distribution are demonstrated using the FNET/GridEye system, a distribution‐level wide‐area measurement system. Without losing generality, the proposed method can be implemented in any other wide‐area measurement system.
You, Shutang↗
Impact of High PV Penetration on the Inter-AreaOscillations in the U.S. Eastern Interconnection
Explore the source record for details and available documents.
Wu, Ling↗
A Distribution Level Wide Area Monitoring System for the Electric Power Grid–FNET/GridEye
The wide area monitoring system (WAMS) is considered a pivotal component of future electric power grids. As a pilot WAMS that has been operated for more than a decade, the frequency monitoring network FNET/GridEye makes use of hundreds of global positioning system-synchronized phasor measurement sensors to capture the increasingly complicated grid behaviors across the interconnected power systems. In this paper, the FNET/GridEye system is overviewed and its operation experiences in electric power grid wide area monitoring are presented. Particularly, the implementation of a number of data analytics applications will be discussed in details. FNET/GridEye lays a firm foundation for the later WAMS operation in the electric power industry.
24 POWER TRANSMISSION AND DISTRIBUTION↗
A Novel Method for Phasor Measurement Unit Sampling Time Error Compensation
This paper focuses on a novel method for successive approximation register analog to digital converter control in synchronized phasor measurement units (PMUs). To compensate for the sampling time error caused by the division remainder between the desirable sampling rate and the oscillator frequency, a variable sampling interval control method is presented by interlacing two integers under a proposed criterion. The frequency of the onboard oscillator is monitored in real-time using the pulse per second (PPS) timing reference from global positioning system. The sampling control is adaptively adjusted each second according to the latest estimated oscillator frequency. The “saw tooth” in phasor angle error and DC offset and spikes in frequency error can be effectively eliminated by applying the proposed method. The simulation and experiment results validate the effectiveness and accuracy of the proposed method, which is believed to be able to greatly improve the performance of PPS-disciplined synchronous sampling methods in PMUs.
24 POWER TRANSMISSION AND DISTRIBUTION↗
Plasmon-induced charge separation at two-dimensional gold semishell arrays on SiO{sub 2}@TiO{sub 2} colloidal crystals
Photoelectrodes based on plasmonic Au semishell (or halfshell) arrays are developed. A colloidal crystal consisting of SiO{sub 2}@TiO{sub 2} core-shell particles is prepared on a TiO{sub 2}-coated transparent electrode. A Au semishell (or halfshell) array is deposited by sputtering or evaporation on the colloidal crystal. An electrode with the semishell (or halfshell) array exhibits negative photopotential shifts and anodic photocurrents under visible light at 500-800 nm wavelengths in an aqueous electrolyte containing an electron donor. In particular, hydroquinone and ethanol are good electron donors. The photocurrents can be explained in terms of plasmon-induced charge separation at the Au-TiO{sub 2} interface.
36 MATERIALS SCIENCE↗
Impact of Measurement Error on Synchrophasor Applications
Phasor measurement units (PMUs), a type of synchrophasor, are powerful diagnostic tools that can help avert catastrophic failures in the power grid. Because of this, PMU measurement errors are particularly worrisome. This report examines the internal and external factors contributing to PMU phase angle and frequency measurement errors and gives a reasonable explanation for them. It also analyzes the impact of those measurement errors on several synchrophasor applications: event location detection, oscillation detection, islanding detection, and dynamic line rating. The primary finding is that dynamic line rating is more likely to be influenced by measurement error. Other findings include the possibility of reporting nonoscillatory activity as an oscillation as the result of error, failing to detect oscillations submerged by error, and the unlikely impact of error on event location and islanding detection.
24 POWER TRANSMISSION AND DISTRIBUTION↗
Lanthanide stannate pyrochlores Ln{sub 2}Sn{sub 2}O{sub 7} (Ln = Nd, Sm, Eu, Gd, Er, Yb) nanocrystals: Synthesis, characterization, and photocatalytic properties
Highlights: • Ln{sub 2}Sn{sub 2}O{sub 7} (Ln = Nd, Sm, Eu, Gd, Er, Yb) are synthesized by hydrothermal method. • Light absorption edge shows red shift with decreasing Ln{sup 3+} radius from Nd{sup 3+} to Yb{sup 3+}. • Ln{sub 2}Sn{sub 2}O{sub 7} shows increasing photocatalytic activity with the decease of Ln{sup 3+} radius. • Electronic configuration reaches 4f{sup 14} under light irradiation may decrease photocatalytic activity. • Hydroxyl radicals are detected to be the major reactive species. - Abstract: A series of lanthanide stannate pyrochlores Ln{sub 2}Sn{sub 2}O{sub 7} (Ln = Nd, Sm, Eu, Gd, Er, Yb) nanocrystals have been successfully synthesized via a facile hydrothermal route. With the decrease of Ln{sup 3+} radius, the light absorption edge of the as-prepared Ln{sub 2}Sn{sub 2}O{sub 7} shows a red shift from Nd{sup 3+} to Yb{sup 3+}. Their photocatalytic activities are found to be improved with the decrease of Ln{sup 3+} radius. However, the photocatalytic activity of Yb{sub 2}Sn{sub 2}O{sub 7} is a little lower than Er{sub 2}Sn{sub 2}O{sub 7}, although the Yb{sup 3+} radius is smaller than Er{sup 3+}, which may be attributed to the full-filled electronic configuration (4f{sup 14}) of surface Yb{sup 2+} intermediates (formed by Yb{sup 3+} trapping a photo-excited electron). The crystallite size and surface area play the most important role in determining the activities. Furthermore, hydroxyl radicals are detected to be the major reactive species during the photo-degradation process. Our findings provide insights in the fabrication of highly efficient stannate photocatalysts, thus enlarging the family of photocatalysts available.
36 MATERIALS SCIENCE↗
Effects of the solvent on the structure, morphology and photocatalytic properties of Bi{sub 2}MoO{sub 6} in the solvothermal process
Graphical abstract: Various nanostructure Bi{sub 2}MoO{sub 6} photocatalysts have been prepared by a solvothermal process via simply altering the used solvent. It is revealed that the type of solvents has a strong influence on the morphology of Bi{sub 2}MoO{sub 6}. This could be understood in terms of the reaction media effect on the crystal growth. The photocatalytic experiments for the decomposition of RhB demonstrate that the samples prepared by different solvents show different photocatalytic activity. The highest photocatalytic activity is obtained by the sample with glycol as solvent. Highlights: ► The used solvent in the synthesis can affect the morphology and size of Bi{sub 2}MoO{sub 6}. ► Different solvent in the reaction leads to different surface area and pore size. ► The highest photocatalytic activity is obtained by the sample prepared in glycol. ► The high activity is mainly due to the large surface area and small particle size. - Abstract: Visible-light-driven photocatalyst Bi{sub 2}MoO{sub 6} was prepared by a solvothermal process with different kinds of solvent including water, isopropanol and ethylene glycol. The obtained samples were characterized by X-ray diffraction technique, N{sub 2}-sorption, UV–vis diffuse reflectance spectra, transmission electron microscopy and Fourier transform infrared spectroscopy. The results revealed that the type of solvent has a strong influence on the morphologies and physico-chemical properties of Bi{sub 2}MoO{sub 6}. Meanwhile, the formation mechanism of Bi{sub 2}MoO{sub 6} with various morphologies was discussed. The photocatalytic activities of Bi{sub 2}MoO{sub 6} photocatalysts were evaluated by the decomposition of rhodamine B (RhB) under visible light irradiation (λ > 420 nm). It was found that the sample prepared with glycol as solvent showed the best performance in the photodegradation of RhB under visible light irradiation. This could be ascribed to the large surface area, unique morphology and small particle size.
36 MATERIALS SCIENCE↗