178 research outputs found
Streaming phishing scam detection method on Ethereum
Phishing is a widespread scam activity on Ethereum, causing huge financial
losses to victims. Most existing phishing scam detection methods abstract
accounts on Ethereum as nodes and transactions as edges, then use manual
statistics of static node features to obtain node embedding and finally
identify phishing scams through classification models. However, these methods
can not dynamically learn new Ethereum transactions. Since the phishing scams
finished in a short time, a method that can detect phishing scams in real-time
is needed. In this paper, we propose a streaming phishing scam detection
method. To achieve streaming detection and capture the dynamic changes of
Ethereum transactions, we first abstract transactions into edge features
instead of node features, and then design a broadcast mechanism and a storage
module, which integrate historical transaction information and neighbor
transaction information to strengthen the node embedding. Finally, the node
embedding can be learned from the storage module and the previous node
embedding. Experimental results show that our method achieves decent
performance on the Ethereum phishing scam detection task
MSAT: Matrix stability analysis tool for shock-capturing schemes
The simulation of supersonic or hypersonic flows often suffers from numerical
shock instabilities if the flow field contains strong shocks, limiting the
further application of shock-capturing schemes. In this paper, we develop the
unified matrix stability analysis method for schemes with three-point stencils
and present MSAT, an open-source tool to quantitatively analyze the shock
instability problem. Based on the finite-volume approach on the structured
grid, MSAT can be employed to investigate the mechanism of the shock
instability problem, evaluate the robustness of numerical schemes, and then
help to develop robust schemes. Also, MSAT has the ability to analyze the
practical simulation of supersonic or hypersonic flows, evaluate whether it
will suffer from shock instabilities, and then assist in selecting appropriate
numerical schemes accordingly. As a result, MSAT is a helpful tool that can
investigate the shock instability problem and help to cure it.Comment: 18 pages, 6 figure
Efficient and Accurate Arbitrary-Shaped Text Detection with Pixel Aggregation Network
Scene text detection, an important step of scene text reading systems, has
witnessed rapid development with convolutional neural networks. Nonetheless,
two main challenges still exist and hamper its deployment to real-world
applications. The first problem is the trade-off between speed and accuracy.
The second one is to model the arbitrary-shaped text instance. Recently, some
methods have been proposed to tackle arbitrary-shaped text detection, but they
rarely take the speed of the entire pipeline into consideration, which may fall
short in practical applications.In this paper, we propose an efficient and
accurate arbitrary-shaped text detector, termed Pixel Aggregation Network
(PAN), which is equipped with a low computational-cost segmentation head and a
learnable post-processing. More specifically, the segmentation head is made up
of Feature Pyramid Enhancement Module (FPEM) and Feature Fusion Module (FFM).
FPEM is a cascadable U-shaped module, which can introduce multi-level
information to guide the better segmentation. FFM can gather the features given
by the FPEMs of different depths into a final feature for segmentation. The
learnable post-processing is implemented by Pixel Aggregation (PA), which can
precisely aggregate text pixels by predicted similarity vectors. Experiments on
several standard benchmarks validate the superiority of the proposed PAN. It is
worth noting that our method can achieve a competitive F-measure of 79.9% at
84.2 FPS on CTW1500.Comment: Accept by ICCV 201
Role of Modified Atmosphere in Pest Control and Mechanism of Its Effect on Insects
Pests not only attack field crops during the growing season, but also damage grains and other food products stored in granaries. Modified or controlled atmospheres (MAs or CAs) with higher or lower concentrations of atmospheric gases, mainly oxygen (O2), carbon dioxide (CO2), ozone (O3), and nitric oxide (NO), provide a cost-effective method to kill target pests and protect stored products. In this review, the most recent discoveries in the field of MAs are discussed, with a focus on pest control as well as current MA technologies. Although MAs have been used for more than 30 years in pest control and play a role in storage pest management, the specific mechanisms by which insects are affected by and adapt to low O2 (hypoxia) and high carbon CO2 (hypercapnia) are not completely understood. Insect tolerance to hypoxia/anoxia and hypercapnia involves a decrease in aerobic metabolism, including decreased NADPH enzyme activity, and subsequently, decreases in glutathione production and catalase, superoxide dismutase, glutathione-S-transferase, and glutathione peroxidase activities, as well as increases in carboxyl esterase and phosphatase activities. In addition, hypoxia induces energy and nutrient production, and in adapted insects, glycolysis and pyruvate carboxylase fluxes are downregulated, accompanied with O2 consumption and acetate production. Consequently, genes encoding various signal transduction pathway components, including epidermal growth factor, insulin, Notch, and Toll/Imd signaling, are downregulated. We review the changes in insect energy and nutrient sources, metabolic enzymes, and molecular pathways in response to modified O2, CO2, NO, and O3 concentrations, as well as the role of MAs in pest control. This knowledge will be useful for applying MAs in combination with temperature control for pest control in stored food products
Characteristics of buried paleo-channels in the Western South Yellow Sea during the Late Last Glaciation
Istraživanja o evoluciji paleolitskih korita u obalnim područjima važna su za konstrukcije podmorskog inženjerstva i za otkrivanje promjena u globalnom paleolitskom okruženju. Stoga je za istraživanje značajki paleo-korita tijekom kasnog posljednjeg ledenog doba u zapadnom Južnom Žutom moru primijenjena digitalna metoda analize terena i ArcGis funkcija porijekla rijeke, analizirani su plitki stratigrafski seizmički profili visoke rezolucije i osnovni podaci, a rabljene su empirijske formule rijeke za određivanje riječnih svojstava i struktura. Rezultati pokazuju da je drevni riječni sustav tijekom kasnog posljednjeg ledenog doba grebena Južnog Žutog mora podijeljen na paleo-Žutu (Huanghe) i paleo-Yangtze (Changjiang) rijeku. Paleo-korita blizu 33°N pripadaju paleo-Yangtze rijeci i uglavnom teku od istoka do sjeveroistoka. Paleo-korita oko 35°N i 123,5°E dio su paleo-Žute rijeke. U usporedbi s paleo-Žutom rijekom, paleo-Yangtze rijeka inklinira horizontalnom premiještanju, ima veću prodornu moć i veću količinu vode. Na temelju metode širine nagiba sustav paleo-Žute rijeke može se smatrati uglavnom krivudavim dok je sustav paleo-Yangtze rijeke uglavnom sustav račvaste (braided) rijeke. Pronađene su značajne razlike između paleo-Yangtze rijeke i paleo-Žute rijeke. Značajke podzemnih paleo-korita tijekom kasnog posljednjeg ledenog doba mogu biti korisne u predviđanju popratne moguće opasnosti kod podvodnih konstrukcija i otkrivanju promjena paleookruženja u grebenu Južnog Žutog mora.Studies on the evolution of paleo-channels in coastal areas are important for submarine engineering construction and to reveal changes in the global paleoenvironment. Thus, to explore the characteristics of paleo-channels during the late Last Glaciation in the western South Yellow Sea, digital terrain analysis method and ArcGis river extraction function were employed, high-resolution shallow stratigraphic seismic profiles and core data were analysed, and river empirical formulas were used to determine river properties and river patterns. Results indicate that the ancient river system during the late Last Glaciation of the South Yellow Sea shelf is divided into paleo-Yellow (Huanghe) and paleo-Yangtze (Changjiang) Rivers. The paleo-channels near 33°N belong to the paleo-Yangtze River, and generally flow from east to northeast. The paleo-channels around 35°N and 123,5°E are part of the paleo-Yellow River. Compared with the paleo-Yellow River, the paleo-Yangtze River is prone to horizontal migration and has higher penetration depths and discharge. Based on the slope-width method, the paleo-Yellow River system can be considered mainly as a meandering river, whereas the paleo-Yangtze River system is largely a braided river. Remarkable differences are found between the paleo-Yangtze River and the paleo-Yellow River. The characteristics of buried paleo-channels during the late Last Glaciation can be useful in predicting the incident potential hazard of submarine engineering and in revealing the paleoenvironment changes in the South Yellow Sea shelf
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