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Ma, Jin

Publications and source records attributed to Ma, Jin.

Coarse-to-fine Task-driven Inpainting for Geoscience Images

The processing and recognition of geoscience images have wide applications. Most of existing researches focus on understanding the high-quality geoscience images by assuming that all the images are clear. However, in many real-world cases, the geoscience images might contain occlusions during the image acquisition. This problem actually implies the image inpainting problem in computer vision and multimedia. As far as we know, all the existing image inpainting algorithms learn to repair the occluded regions for a better visualization quality, they are excellent for natural images but not good enough for geoscience images, and they never consider the following geoscience task when developing inpainting methods. Here, this paper aims to repair the occluded regions for a better geoscience task performance and advanced visualization quality simultaneously, without changing the current deployed deep learning based geoscience models. Because of the complex context of geoscience images, we propose a coarse-to-fine encoder-decoder network with the help of designed coarse-to-fine adversarial context discriminators to reconstruct the occluded image regions. Due to the limited data of geoscience images, we propose a MaskMix based data augmentation method, which augments inpainting masks instead of augmenting original images, to exploit the limited geoscience image data. The experimental results on three public geoscience datasets for remote sensing scene recognition, cross-view geolocation and semantic segmentation tasks respectively show the effectiveness and accuracy of the proposed method. The code is available at: https://github.com/HMS97/Task-driven-Inpainting.

97 MATHEMATICS AND COMPUTING↗

Multi-Stage Stochastic Programming to Joint Economic Dispatch for Energy and Reserve With Uncertain Renewable Energy

To address the uncertain renewable energy in the day-ahead optimal dispatch of energy and reserve, a multi-stage stochastic programming model is established in this paper to minimize the expected total costs. The uncertainties over the multiple stages are characterized by a scenario tree and the optimal dispatch scheme is cast as a decision tree which guarantees the flexibility to decide the reasonable outputs of generation and the adequate reserves accounting for different realizations of renewable energy. Most importantly, to deal with the “Curse of Dimensionality” of stochastic programming, stochastic dual dynamic programming (SDDP) is employed, which decomposes the original problem into several sub-problems according to the stages. Specifically, the SDDP algorithm performs forward pass and backward pass repeatedly until the convergence criterion is satisfied. At each iteration, the original problem is approximated by creating a linear piecewise function. Besides, an improved convergence criterion is adopted to narrow the optimization gaps. The results on the IEEE 118-bus system and real-life provincial power grid show the effectiveness of the proposed model and method.

economic dispatch↗

Characterization of niobium-doped titania epitaxial films deposited by metalorganic chemical vapor deposition

Highlights: • The undoped and Nb-doped TiO{sub 2} films were deposited on SrTiO{sub 3} (100) substrates. • The epitaxial growth relationship between TiO{sub 2} film and the substrate was confirmed. • The microstructures of the films were explored. • The electrical and optical properties of the films were revealed. - Abstract: Titania (TiO{sub 2}) films with different niobium (Nb) doping concentrations were deposited on SrTiO{sub 3} (STO) (100) substrates by metalorganic chemical vapor deposition (MOCVD). The crystal structures, surface morphologies, electrical and optical properties of the Nb-doped TiO{sub 2} (TiO{sub 2}:Nb) films varying with Nb content were investigated. The single crystal TiO{sub 2} films with anatase structure were obtained at low Nb doping levels. The highest Hall mobility of the prepared films reached as high as 16.50 cm{sup 2} V{sup −1} s{sup −1}. The lowest resistivity of 5.75 × 10{sup −2} Ω cm with a Hall mobility of 7.40 cm{sup 2} V{sup −1} s{sup −1} and a carrier concentration of 1.47 × 10{sup 19} cm{sup −3} were obtained from the 1.20% Nb-doped TiO{sub 2} film. This resistivity was about 6 orders of magnitude lower than the undoped TiO{sub 2} film. Moreover, all the deposited films exhibited high average transmittances of over 88% in the visible wavelength range.

36 MATERIALS SCIENCE↗

A Stochastic Maximum Principle for General Mean-Field Systems

In this paper we study the optimal control problem for a class of general mean-field stochastic differential equations, in which the coefficients depend, nonlinearly, on both the state process as well as of its law. In particular, we assume that the control set is a general open set that is not necessary convex, and the coefficients are only continuous on the control variable without any further regularity or convexity. We validate the approach of Peng (SIAM J Control Optim 2(4):966–979, 1990) by considering the second order variational equations and the corresponding second order adjoint process in this setting, and we extend the Stochastic Maximum Principle of Buckdahn et al. (Appl Math Optim 64(2):197–216, 2011) to this general case.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗

Influence of Al content on the properties of ternary Al{sub 2x}In{sub 2−2x}O{sub 3} alloy films prepared on YSZ (1 1 1) substrates by MOCVD

Highlights: • Al{sub 2x}In{sub 2−2x}O{sub 3} films were prepared on the Y-stabilized ZrO{sub 2} (1 1 1) substrates by MOCVD at 700 °C. • A phase transition from the bixbyite In{sub 2}O{sub 3} structure to the amorphous structure was observed. • The lowest resistivity of 4.7 × 10{sup −3} Ω cm was obtained for the Al{sub 0.4}In{sub 1.6}O{sub 3} film. • Tunable optical band gap from 3.7 to 4.8 eV was obtained. - Abstract: The ternary Al{sub 2x}In{sub 2−2x}O{sub 3} films with different Al contents of x [Al/(Al + In) atomic ratio] have been fabricated on the Y-stabilized ZrO{sub 2} (1 1 1) substrates by metal organic chemical vapor deposition at 700 °C. The structural, electrical and optical properties of the films as a result of different Al contents (x = 0.1–0.9) were investigated in detail. With the increase of Al content from 10% to 90%, a phase transition from the bixbyite In{sub 2}O{sub 3} structure with a single orientation along (1 1 1) to the amorphous structure was observed. The minimum resistivity of 4.7 × 10{sup −3} Ω cm, a carrier concentration of 1.4 × 10{sup 20} cm{sup −3} and a Hall mobility of 9.8 cm{sup 2} v{sup −1} s{sup −1} were obtained for the sample with x = 0.2. The average transmittances for the Al{sub 2x}In{sub 2−2x}O{sub 3} films in the visible range were all over 78% and the optical band gap of the films could be tuned from 3.7 to 4.8 eV.

36 MATERIALS SCIENCE↗

Preparation and characterization of Al{sub 2x}In{sub 2−2x}O{sub 3} films deposited on MgO (1 0 0) by MOCVD

Highlights: • Ternary Al{sub 2x}In{sub 2−2x}O{sub 3} alloy films were deposited on MgO (1 0 0) by MOCVD. • The microstructure of the Al{sub 2x}In{sub 2−2x}O{sub 3} films were studied upon HRTEM. • Al{sub 2x}In{sub 2−2x}O{sub 3} alloy films exhibited great optical transparency in the visible wavelength range. • The band gap of the Al{sub 2x}In{sub 2−2x}O{sub 3} films can be modulated by controlling the Al contents in the samples. - Abstract: The ternary Al{sub 2x}In{sub 2−2x}O{sub 3} films with different compositions x[Al/(Al + In) atomic ratio] have been fabricated on the MgO (1 0 0) substrates by the metal organic chemical vapor deposition (MOCVD) method. The influence of different Al contents on the structural, optical and electrical properties of Al{sub 2x}In{sub 2−2x}O{sub 3} films has been studied. The structural studies reveal a change from single crystalline structure of cubic In{sub 2}O{sub 3} to amorphous as the Al content increases. The average transmittances of all samples in the visible range are over 80%. The optical band gap is observed to increase monotonically from 3.67 to 5.38 eV as the Al content increases from 0.1 to 0.9.

36 MATERIALS SCIENCE↗

Epitaxial growth of SnO{sub 2} films on 6H-SiC (0 0 0 1) by MOCVD

Highlights: Black-Right-Pointing-Pointer Heteroepitaxial SnO{sub 2} films have been successfully deposited on 6H-SiC (0 0 0 1) substrates. Black-Right-Pointing-Pointer We propose a growth model that SnO{sub 2} films consist of three domains with equivalent in-plane orientations. Black-Right-Pointing-Pointer The electrical properties of SnO{sub 2} films are in consistent with the structure analysis. -- Abstract: SnO{sub 2} films have been deposited on 6H-SiC (0 0 0 1) substrates by metalorganic chemical vapor deposition in the temperature range 500-750 Degree-Sign C. X-ray diffraction analysis showed that all the films were highly (1 0 0) oriented with the tetragonal rutile structure. Based on the structure analysis, we propose a growth model that SnO{sub 2} films consist of three variant structures with equivalent in-plane orientations. The in-plane orientation relationship between SnO{sub 2} and 6H-SiC was determined to be SnO{sub 2} [0 1 0]//SiC <101{sup Macron }0> and SnO{sub 2} [0 0 1]//SiC <12{sup Macron }10>. As the substrate temperature increased from 500 to 750 Degree-Sign C, the carrier concentration decreased from 1.1 Multiplication-Sign 10{sup 20} to 1.6 Multiplication-Sign 10{sup 18} cm{sup -3} while the resistivity increased from 0.01 to 0.57 {Omega} cm.

36 MATERIALS SCIENCE↗

Microemulsion-assisted solvothermal synthesis of Nd{sub 2}(CO{sub 3}){sub 3}.8H{sub 2}O microstructures

Research highlights: {yields} Pyramid-like and spherical Nd{sub 2}(CO{sub 3}){sub 3}.8H{sub 2}O microstructures were synthesized using a microemulsion-assisted solvothermal method with precise control of the reaction time and reaction temperature. {yields} The obtained products were characterized by X-ray diffraction (XRD), differential scanning calorimetry and thermal gravimetric analysis (DSC-TGA), scanning electron microscope (SEM), transmission electron microscope (TEM) and electron diffraction (ED). {yields} The increase in size of pyramid-like Nd{sub 2}(CO{sub 3}){sub 3}.8H{sub 2}O microstructures with increasing reaction time was attributed to the typical Ostwald ripening process, while the increase in size of spherical Nd{sub 2}(CO{sub 3}){sub 3}.8H{sub 2}O microstructures with increasing reaction temperature was explained by the increasing collision probability of microemulsion droplets. -- Abstract: Microstructures of Nd{sub 2}(CO{sub 3}){sub 3}.8H{sub 2}O with various morphological structures and sizes were successfully synthesized using the microemulsion-assisted solvothermal method. The obtained products were characterized by X-ray diffraction (XRD), differential scanning calorimetry and thermal gravimetric analysis (DSC-TGA), scanning electron microscope (SEM), transmission electron microscope (TEM) and electron diffraction (ED). The results showed that pyramid-like and spherical Nd{sub 2}(CO{sub 3}){sub 3}.8H{sub 2}O microstructures were synthesized depending on the reaction time and reaction temperature. Moreover, the reaction time and temperature also played important roles in controlling the morphologies and sizes of the resulting Nd{sub 2}(CO{sub 3}){sub 3}.8H{sub 2}O microstructures.

36 MATERIALS SCIENCE↗

Alterations in Vasoreactivity of Femoral Artery Induced by Hindlimb Unweighting are Related to the Changes of Contractile Protein in Rats

Responses of endothelium removed femoral arterial rings to vasoactive compounds were examined in vitro, and the expression of Myosin and Actin of femoral artery were observed by Western Blotting and Immunohistochemistry in hndlimb unweighting rats and control rats. The results showed that contractile responses of femoral arterial rings evoked by Phenylephrine, Endothelin-1, Vasopressin, KCl, Ca(2+) and Ca(2+) ionophore A23187 were decreased in hindlimb unweighting rats as compared with that of controls. But vasoddatory responses induced by SNPand cGMP were not different between groups. No significant differences have been found in expressions of Calponin, Myosin, Actin, and the ratio of MHC SM1/SM2 between the two groups, but expression of alpha-SM-Actin decreased in hindlimb unweighting rats. The data indicated that the diminished contractile responsiveness probably result from altered contractile apparatus, especially the contractile proteins.

Ma, Jin↗

Effects of simulated microgravity on arterial nitric oxide synthase and nitrate and nitrite content

The aim of the present work was to investigate the alterations in nitric oxide synthase (NOS) expression and nitrate and nitrite (NOx) content of different arteries from simulated microgravity rats. Male Wistar rats were randomly assigned to either a control group or simulated microgravity group. For simulating microgravity, animals were subjected to hindlimb unweighting (HU) for 20 days. Different arterial tissues were removed for determination of NOS expression and NOx. Western blotting was used to measure endothelial NOS (eNOS) and inducible NOS (iNOS) protein content. Total concentrations of NOx, stable metabolites of nitric oxide, were determined by the chemiluminescence method. Compared with controls, isolated vessels from simulated microgravity rats showed a significant increase in both eNOS and iNOS expression in carotid arteries and thoracic aorta and a significant decrease in eNOS and iNOS expression of mesenteric arteries. The eNOS and iNOS content of cerebral arteries, as well as that of femoral arteries, showed no differences between the two groups. Concerning NOx, vessels from HU rats showed an increase in cerebral arteries, a decrease in mesenteric arteries, and no change in carotid artery, femoral artery and thoracic aorta. These data indicated that there were differential alterations in NOS expression and NOx of different arteries after hindlimb unweighting. We suggest that these changes might represent both localized adaptations to differential body fluid redistribution and other factors independent of hemodynamic shifts during simulated microgravity.

Non-NASA Center↗