Andrey N. Kuznetsov

Mechanical properties of thermomechanically treated Ti-rich γ+α2 titanium aluminide alloys

Abstract Tensile mechanical properties of Ti-rich γ+α 2 titanium aluminide alloys, Ti-45.2Al-3.5(Nb,Cr,B) and Ti-44.2Al-3(Nb,Cr,B), have been investigated in thermomechanically treated fine-grained and lamellar conditions. These alloys exhibited excellent superplastic properties in the fine-grained condition, high strength coupled with high ductility at elevated temperatures, reasonable ductility and fracture toughness at room temperature in the lamellar condition.

Pollination of Vietnamese Aspidistra xuansonensis (Asparagaceae) by female Cecidomyiidi flies: Larvae of pollinator feed on fertile pollen in anthers of anthetic bisexual flowers

UNLABELLED • PREMISE OF THE STUDY Aspidistra is a species-rich, herbaceous monocot genus of tropical Southeast Asia. Most species are recently discovered and apparently endangered, though virtually nothing is known about their biology. Species of the genus are primarily distinguished using flower morphology, which is enormously diverse. However, the pollination process has not been directly observed in the center of diversity of the genus (N Vietnam and S China). Indirect and partly direct data on the only widely cultivated species of the genus (A. elatior) placed it among angiosperms with the most unusual pollination biology, though these data are highly controversial, suggesting pollen transfer by mollusks, crustaceans, flies, or possibly tiny soil invertebrates such as collembolans.• METHODS Pollination of Aspidistra xuansonensis in the center of diversity of the genus was studied using visual observations and videos and light and scanning electron microscopy investigation of flowers and their pollinators. Pollinators and their larvae were molecularly barcoded.• KEY RESULTS Aspidistra xuansonensis is pollinated by female cecidomyiid flies (gall midges). They oviposit on anthers, and larvae develop among the pollen mass. Molecular barcoding proved taxonomic identity of the larvae and the flies. The larvae neither damage floral parts nor cause gall formation, but feed on pollen grains by sucking out their content. The larvae move out of the flowers before decomposition starts. Carebara ants steal developing larvae from flowers but do not contribute to pollination.• CONCLUSIONS More than one kind of myiophily is present in Aspidistra. Brood site pollination was documented for the first time in Aspidistra. The pollination system of A. xuansonensis differs from other kinds of brood site pollination in the exit of the larvae prior to the decomposition of floral parts.

Aspidistra cylindrica (Asparagaceae), a New Species from Southern Vietnam

Abstract Aspidistra cylindrica, a new species from southern Vietnam (Kon Tum province), is described and illustrated. The new species possesses a unique combination of cylindrical shape of pistil and shoot system with foliage leaves crowded in groups and not divided into petiole and lamina. Aspidistra cylindrica resembles A. muricata but differs in longer leaves, shorter and wider perigone, shorter pistil, shape and colour of perigone lobes, anther position, and stigma shape. The conservation status of A. cylindrica is assessed. A key for species of Aspidistra in southern Vietnam is provided.

A Copy-Move Detection Algorithm Using Binary Gradient Contours

Nowadays copy-move attack is one of the most obvious ways of digital image forgery in order to hide the information contained in images. Copy-move process consists of copying the fragment from one place of an image, changing it and pasting it to another place of the same image. However, only a few existing studies reached high detection accuracy for a narrow range of transform parameters. In this paper, we propose a copy-move detection algorithm that uses features based on binary gradient contours that are robust to contrast enhancement, additive noise and JPEG compression. The proposed solution showed high detection accuracy and the results are supported by conducted experiments for wide ranges of transform parameters. A comparison of features based on binary gradient contours and based on various forms of local binary patterns showed a significant 20–30 % difference in detection accuracy, corresponding to an improvement with the proposed solution.

Jasminanthes tuyetanhiae (Apocynaceae, Asclepiadoideae), a New Species from Vietnam, and J. pilosa New for Vietnam

Jasminanthes tuyetanhiae T.B. Tran & Rodda (Apocynaceae, Asclepiadoideae) is described as a new species from Vietnam. It differs from the morphologically similar J. chunii by its shorter peduncles and by the triangular-ovate calyx lobes. Jasminanthes pilosa, earlier known from China and Thailand, is lectotypified and newly recorded for the flora of Vietnam, fully described and for the first time colour photographs are provided. An appendix with key characters for the separation of all seven Jasminanthes species as well as the key to the species of Jasminanthes are included.

Satellite Image Forgery Detection Based on Buildings Shadows Analysis

Satellite images are to be effectively protected nowadays. There are a lot of ways of changing image content to hide important information: resampling, copy-move, object replacement and other attacks. When these changes are applied to satellite data inclination angles of shadows can be also changed. We propose a new method for satellite image forgery detection based on the analysis of high buildings shadows inclination angles on high resolution snapshots (0.5 m and less). In the proposed solution, the shadows are detected using Canny edge detector with further edge tracing. The comparison of both edge detection methods is presented in the experiments section. The next step is shadows inclination angles estimation using special model-oriented descriptors. The experiments show high accuracy of changed areas detection.

Using Efficient Linear Local Features in the Copy-Move Forgery Detection Task

Digital images are often used to prove some facts or events, but nobody can guarantee their originality. More often we can see in TV news, that some satellite imagery evidences were received to show what has happened. However, we cannot be sure, that these data were not changed by some hackers. In this paper we propose a new algorithm for detection of the most frequently used attack plain copy-move. The algorithm is based on a hash value calculation in a sliding window mode. The hash function is constructed using efficient linear local features that were developed by coauthor V. Myasnikov in 2010. Finally, we present results of conducted experiments and comparison with existing solutions, as well as recommendations for the use of the proposed approach. The main advantage of the proposed solution is 99.95% precision of copy-move blocks detection comparing with existing approaches. Another impact is that it can be easily used for large satellite image analysis as well as ordinary digital images processing because of low computational complexity.

An evaluation of popular hyperspectral images classification approaches

This work is devoted to the problem of the best hyperspectral images classification algorithm selection. The following algorithms are used for comparison: decision tree using full cross-validation; decision tree C 4.5; Bayesian classifier; maximum-likelihood method; MSE minimization classifier, including a special case – classification by conjugation; spectral angle classifier (for empirical mean and nearest neighbor), spectral mismatch classifier and support vector machine (SVM). There are used AVIRIS and SpecTIR hyperspectral images to conduct experiments.

Remote Sensing Data Verification Using Model-Oriented Descriptors

This paper presents a solution of remote sensing data verification problem. Remote sensing data includes digital image data and metadata, which contains parameters of satellite image shooting process (Sun and satellite azimuth and elevation angles, shooting time, etc.). The solution is based on the analysis of special numerical characteristics, which directly depend on the shooting parameters: sun position, satellite position and orientation. We propose two fully automatic algorithms for remote sensing data analysis and decision-making based on data compatibility: the first one uses vector data of the shooting territory, the second doesn’t.