Search

Binary Code Similarity Detection (BCSD) is a fundamental binary analysis technique in the area of software security. Recently, advanced deep learning algorithms are integrated into BCSD platforms to achieve superior performance on well-known benchmarks. However, real-world large programs embed more complex diversities due to different compilers, various optimization levels, multiple architectures and even obfuscations. Existing BCSD solutions suffer from low accuracy issues in such complicated real-world application scenarios. In this paper, we propose BinCola, a novel Transformer-based dual diversity-sensitive contrastive learning framework that comprehensively considers the diversity of compiler options and candidate functions in the real-world application scenarios and employs the attention mechanism to fuse multi-granularity function features for enhancing generality and scalability. BinCola simultaneously compares multiple candidate functions across various compilation option scenarios to learn the differences caused by distinct compiler options and different candidate functions. We evaluate BinCola's performance in a variety of ways, including binary similarity detection and real-world vulnerability search in multiple application scenarios. The results demonstrate that BinCola achieves superior performance compared to state-of-the-art (SOTA) methods, with improvements of 2.80%, 33.62%, 22.41%, and 34.25% in cross-architecture, cross-optimization level, cross-compiler, and cross-obfuscation scenarios, respectively.

Given a target binary function, the binary code search retrieves top-K similar functions in the repository, and similar functions represent that they are compiled from the same source codes. Searching binary code is particularly challenging due to large variations of compiler tool-chains and options and CPU architectures, as well as thousands of binary codes. Furthermore, there are some pivotal issues in current binary code search schemes, including inaccurate text-based or token-based analysis, slow graph matching, or complex deep learning processes. In this paper, we present an unsupervised tensor embedding scheme, Codee, to carry out code search efficiently and accurately at the binary function level. First, we use an NLP-based neural network to generate the semantic-aware token embedding. Second, we propose an efficient basic block embedding generation algorithm based on the network representation learning model. We learn both the semantic information of instructions and the control flow structural information to generate the basic block embedding. Then we use all basic block embeddings in a function to obtain a variable-length function feature vector. Third, we build a tensor to generate function embeddings based on the tensor singular value decomposition, which compresses the variable-length vectors into short fixed-length vectors to facilitate efficient search afterward. We further propose a dynamic tensor compression algorithm to incrementally update the function embedding database. Finally, we use the local sensitive hash method to find the top-$K$K similar matching functions in the repository. Compared with state-of-the-art cross-optimization-level code search schemes, such as Asm2Vec and DeepBinDiff, our scheme achieves higher average search accuracy, shorter feature vectors, and faster feature generation performance using four datasets, OpenSSL, Coreutils, libgmp and libcurl. Compared with other cross-platform and cross-optimization-level code search schemes, such as Gemini, Safe, the average recall of our method also outperforms others.

Errors in elucidating the structures of four natural classes of prenylated aromatic compounds with 2,3-epoxy, 2,3-dihydroxy, and cyclization with an ortho-phenolic hydroxyl to give a pyran or furan ring moiety are frequent and inevitable. Based on rigorous literature research and a series of chemical transformation experiments, a rule for the rapid determination of these four classes of prenylated derivates based on 13C NMR data was formulated, and 57 corrections featuring these fragments were accordingly reported.

Twelve hitherto unknown tandem prenylated p-hydroxybenzoic acid derivatives, namely, oberoniamyosurusins A–L, together with five known derivatives, were isolated from an EtOH extract of the whole parts of the plant Oberonia myosurus. Compounds 10, 13, and 17exhibited moderate inhibitory activity against Staphylococcus aureussubsp. aureusATCC29213 with MIC50values ranging from 7.6 to 23 μg/mL. To determine the biosynthetic pathway of this class of tandem prenyl-substituted compounds, the full-length transcriptome of O. myosuruswas sequenced, yielding 19.09 Gb of clean data and 10 949 nonredundant sequences. Two isoforms of p-hydroxybenzoic acid prenyltransferases were annotated and functionally characterized as the enzymes that might be involved in the biosynthesis of nervogenic acid (13) in Pichia pastoris.

The first total synthesis of gastrodinol, an unprecedented poly-p-cresol-substituted natural product with a rearranged and reconstructed C ring moiety, is reported. Our synthesis features a convergent fragment approach. The Sonogashira coupling reaction forges the two segments together to furnish the conjugated ene–yne. Photocatalytic 6π electrocyclization followed by spontaneous aromatization is used to construct the tetrasubstituted B ring at the late stage. Further study shows that gastrodinol exhibits significant cytotoxic activity against five human cancer cell lines in vitro(IC502.5–3.8 μM).

Airborne LIDAR can flexibly obtain point cloud data with three-dimensional structural information, which can improve its effectiveness of automatic target recognition in the complex environment. Compared with 2D information, 3D information performs better in separating objects and background. However, an aircraft platform can have a negative influence on LIDAR obtained data because of various flight attitudes, flight heights and atmospheric disturbances. A structure of global feature based 3D automatic target recognition method for airborne LIDAR is proposed, which is composed of offline phase and online phase. The performance of four global feature descriptors is compared. Considering the summed volume region (SVR) discrepancy in real objects, SVR selection is added into the pre-processing operations to eliminate mismatching clusters compared with the interested target. Highly reliable simulated data are obtained under various sensor’s altitudes, detection distances and atmospheric disturbances. The final experiments results show that the added step increases the recognition rate by above 2.4% and decreases the execution time by about 33%.

To explore whether volumetric acquisition of histogram analysis of apparent diffusion coefficient (ADC) maps could quantify liver fibrosis stages. 84 patients underwent MRI exams including DWI before surgery or liver biopsy were included. Histogram analysis of whole liver ADC maps were performed and parameters including ADC mean, ADC median, ADC skewness, ADC kurtosis, ADC standard deviation (SD), ADC 5th, 10th, 25th, 75th, 90th and 95th percentiles were calculated. The correlations between different histopathologic grades and histogram analysis parameters were determined. For the significant parameters, receiver operating characteristics (ROC) analyses were further established to evaluate the potential diagnostic performance for differentiating liver fibrosis stages. The ADC mean and ADC median, ADC SD, ADC5th, 10th, 25th, 75th, 90th and 95th percentile were significantly lower with the increasing grade of liver fibrosis (rho: from − 0.580 to − 0.230). ADC skewness and ADC kurtosis were significantly higher with the increasing grade of liver fibrosis (rho: 0.243, 0.347, respectively). Areas under the ROC curve (AUC) of ADC mean and ADC 75th percentile for identification liver fibrosis (F1–F4), moderate to advanced liver fibrosis (F2–F4), advanced liver fibrosis (F3–F4), cirrhosis (F4) were 0.87, 0.83, 0.82, 0.76 and 0.88, 0.82, 0.80, 0.74, respectively. Histogram analysis of volumetric acquisition of liver ADC maps has a potential value for quantifying liver fibrosis grades.

Today search engines are tightly coupled with social networks, and present users with a double-edged sword: they are able to acquire information interesting to users but are also capable of spreading viruses introduced by hackers. It is challenging to characterize how a search engine spreads viruses, since the search engine serves as a virtual virus pool and creates propagation paths over the underlying network structure. In this paper, we quantitatively analyze virus propagation effects and the stability of the virus propagation process in the presence of a search engine. First, although social networks have a community structure that impedes virus propagation, we find that a search engine generates a propagation wormhole. Second, we propose an epidemic feedback model and quantitatively analyze propagation effects based on a model employing four metrics: infection density, the propagation wormhole effect, the epidemic threshold, and the basic reproduction number. Third, we verify our analyses on four real-world data sets and two simulated data sets. Moreover, we prove that the proposed model has the property of partial stability. Evaluation results show that, compared the cases without a search engine, virus propagation with the search engine has a higher infection density, shorter network diameter, greater propagation velocity, lower epidemic threshold, and larger basic reproduction number.

Increased mean kurtosis value and the presence of irregular circumferential enhancement were independent risk factors for predicting microvascular invasion of hepatocellular carcinoma.

Six hitherto unknown prenylated 2-phenoxychromones, epimedonin G (1), 7-O-methylepimedonin G (2), and epimedonins H–K (3–6), and two new prenylflavonoids, epimedonin L (7) and 3″-O-desmethylspinorhamnoside (8), were isolated from an ethanol extract of the aerial parts of Epimedium brevicornum. Their structures were established on the basis of spectroscopic data interpretation. Compound 7exhibited cytotoxic activity when evaluated against four human cancer cell lines (HL-60, A-549, MCF-7, and SW-480), with IC50values of <10 μM. In addition, the structures of epimedonins A and B (9a, 10a), recently isolated from E. koreanum, were corrected by reanalysis of the published NMR data.

The fractional-order chaotic systems have more complex dynamic characteristics than the integer order chaotic systems, which can more reflect the physical properties of the actual system and more practical values, whereas it is difficult to control the synchronisation for fractional chaotic systems. Chaotic system identification is the basis of chaos control and performance analysis. In order to identify the parameters of the chaotic systems with time delay, a novel particle swarm optimisation with increasing inertia weight is proposed and then the issue is settled by solving an optimisation problem. The identification of parameters mainly includes the system order, the time delay parameter and the coefficient parameters. An estimation-correction algorithm based on linear interpolation method is used to solve the fractional-order delay differential equation. The Mackey-Glass chaotic system is conducted and comparisons with other two widely used particle swarm optimisations and the differential evolution algorithm indicate the effectiveness of the proposed method and an improvement in identification accuracy as well as convergence speed.

The embrittlement of nickel-based structural alloys by fission-produced tellurium (Te) is a major challenge for molten salt reactors (MSR). In this study, the effects of thermal exposure time on tellurium diffusion in a candidate MSR structural alloy (Ni–16Mo–7Cr–4Fe) and the consequent mechanical property degradation of the alloy were investigated through surrogate diffusion experiments at 700 °C. The results show that some tellurium reacted with the alloy to form tellurides on the surface, while some tellurium diffused into the alloy along grain boundaries. Ni3Te2and CrTe were the most stable reaction products at the tested temperature, and the formation of CrTe on the surface induced the Cr depletion at grain boundaries of the alloy. The diffusion depth of Te increased gradually with thermal exposure time, and the diffusion rate kept stable within the test duration of up to 3000 h. The Te diffusion in the alloy caused the embrittlement of grain boundaries, inducing crack formation and strength degradation in tensile test at room temperature.

Four hitherto unknown polysubstituted isoflavonoids, including three isoflavans: 7,4′-dihydroxy-8,2′,3′-trimethoxyisoflavan (1), 7,2′,4′-trihydroxy-8,3′-dimethoxyisoflavan (2), and 7,2′,4′-trihydroxy-5-methoxyisoflavan (3), and one prenylated isoflavone cudraisoflavone M (4) were isolated from the ethanol extracts of Spatholobus suberectus(for 1and 2), Flemingia macrophylla(for 3), and Cudrania cochinchinensis(for 4), respectively. Their structures were established on the basis of extensive spectroscopic analysis. Compounds 1and 4exhibited weak cytotoxic activity against five human cancer cell lines (HL-60, A-549, SMMC-7721, MCF-7, and SW-480).

Four hitherto unknown prenylated isoflavonoids, named derrisisoflavones H–K (1–4) and one new isoflavan, namely 6-hydroxyisosativan (5), were isolated from the ethanol extract of Derrisrobusta. Their structures were elucidated on the basis of extensive spectroscopic studies. To our knowledge, derrisisoflavones J (3) and K (4) are the first examples of hydroxyethylated isoflavonoid.

Network structures and human behaviors are considered as two important factors in virus defense currently. However, due to ignorance of network security, normal users usually take simple activities, such as reinstalling computer system, or using the computer recovery system to clear virus. How system recovery influences virus spreading is not taken into consideration currently. In this paper, a new virus propagation model considering the system recovery is proposed first, and then in its steady-state analysis, the virus propagation steady time and steady states are deduced. Experiment results show that models considering system recovery can effectively restrain virus propagation. Furthermore, algorithm with system recovery in BA scale-free network is proposed. Simulation result turns out that target immunization strategy with system recovery works better than traditional ones in BA network.

Four hitherto unknown 6a,11b-dihydroxypterocarpans, namely pterocarpadiols A–D (1–4), were isolated from the ethanol extract of the twigs and leaves of Derris robusta. Their structures were elucidated on the basis of extensive spectroscopic analysis. Pterocarpadiols A–D are a kind of very rare 6a,11b-dihydroxypterocarpans, and their presence as markers may be helpful in chemotaxonomical classification.

Two hitherto unknown lanostane-type triterpenoids, namely scillascillol (1) and scillascillone (2), and a hitherto unknown norlanostane-triterpene glycoside, namely scillascilloside B-1 (3), were isolated from the ethanol extract of the whole plants of Scilla scilloides. Their structures were elucidated on the basis of extensive spectroscopic studies. In addition, the structure of drimiopsin D (6a) has been revised as 2,5-dimethoxy-8-methyl-1,3,6-trihydroxyxanthone (6) by reanalysis of the spectroscopic data.

Fatigue is a major cause of failure in marine structures resulting from random wave and wind loading. A nonlinear ultrasound method for fatigue evaluation which uses interaction of two non-collinear nonlinear ultrasonic waves with quadratic nonlinearity is investigated in this paper. A hyperbolic system of conservation laws is applied here and a semi-discrete central scheme is used to solve the numerical problem. The numerical results prove that a resonant wave can be generated by two primary waves with certain resonant conditions. Features of the resonant wave are analyzed both in the time and frequency domains, and several regularities are found on intensity distribution of the resonant wave in two-dimensional domain.

In this paper, we will select and use stepper motor which is comparatively important and widely used in ships for the study. Through the study, we can propose a method that we can use the synchronous repeater compass for the high-precision digital conversion, and then statistics will be put into SCM AT89C52 with the simple handling of circuit conversion, thus, we can take a series of processes, such as data processing, initial value setting, directional displaying and serial port outputting. Foremost, the precision of this converting circuit can reach 0.1°that can ensure the numbers continuously change behind the decimal point one digit. So it is not only inexpensive, but also flexible and convenient in use.

Due to the enormous harm of virus propagation, research regarding virus immunizations still absolutely necessary. In comparison to current researches, a new virus immunization method the hierarchical virus immunization method (HVIM) for community networks is proposed. Based on the virus transmission dynamic model Susceptible-Infectious-Removed and Susceptible-Removed (SIRSR), HVIM considered the influence of external factors on the spread of viruses and only needs a portion of the network structure to be able to carry out immunization. Another pro for HVIM is that it is scalable and suitable for parallel computing which is a requirement in the big data era. Finally, a simulation dataset and a real dataset were used to run experiments, and the results of simulation showed that HVIM obviously is superior to others on the aspect of immunity.

The paper introduces a kind of inverse distance weighted interpolation theoretical derivation and its solving way. The basic principle of this method is that to use known information limited data were interpolated to the unknown information for point, through the obtained interpolation point value to calculate the new interpolation point value. Thus, it is solved that the problem that limited number of temperature points can not be comprehensive description of temperature field, and the method is applied in the process of solving the unknown temperature points in the two dimensional temperature field. The characteristics of this method are simple, practical, less amount of calculation.

Based on the basic principles and influencing factors of analyzing routes design, this paper establishes a novel mathematical model for optimal control of routes design with the help of optimization theory. On the condition of satisfying its constraints, the article applies genetic algorithm to process algorithms implementation on the established routes design model. It also further illustrates the feasibility and practicality of routes design model in maritime practice by verification.

The surface of hot rolled ribbed steel bar after remained-heat-treatment process readily corrodes and rusts on store and transportation process due to falling off of the surface of its oxide layer in the steel production. By studying different cooling intensity having what effect on rebar structure, mechanical property and the thickness and component of surface oxide layer, this paper analyses the influence factor of strengthening mechanism and anti-corrosion on the surface oxide layer of hot rolled ribbed steel bars (HRB). The result indicates that there is a certain extent improvement on the bar’s yield strength and strength of extension after remained heat treatment, and that this change in large size bar is more distinct than which in small size’s. The most distinct strengthening effect happens in a temperature on cooling table about 720°C. Above 820°C —the temperature on cooling table, all metallographic structure consist of ferrite and pearlite (F+P); under 725°C, the sclerotic structure like bainite appears. With the temperature on cooling table arising, surface oxide layer thickens. In low temperature on cooling table, the sample integrates with matrix comparatively closely and has relatively better anti-corrode property.

SAT (Separating Axis Theorem) is an algorithm applied in two-dimensional games of collision detection in the convex polygon. This paper applied SAT algorithm into video monitoring at intersections to detect the vehicles collision incidents. Established separation axis to extracted vehicles and projected the target vehicles into separation axis. Through comparing the scalar value in separation axis to determine whether the target vehicles collision. It's proved that the method is effective by using Matlab software to the simulation test in this algorithm.

Through interaction with online consumers, e-commerce websites can gather data reflecting consumer preferences. The available data on consumer preferences together with sophisticated analytical tools enables companies’ increases in profit through optimization of prices. We consider a class of models of consumer purchasing behavior, each of which affected the data on a consumer’s requirements and budget constraint to subsequent purchasing tendencies. We can study for the multi-product pricing problem based on the max budgets of consumers, and a customer data-oriented multi-product pricing model is presented. Proposed models were solved through genetic algorithms. Optimal solution of the given examples shows that this model is effective for enterprises.

This paper introduce the necessity of the construction of offshore wind power projects, analysis of the impact on the marine transport of offshore wind power project after completion, and then use the fuzzy comprehensive evaluation method to carry out a comprehensive assessment of offshore wind power projects, by identifying risk assessment index system, establish model for risk assessment, the final task is use the model to evaluate the navigation safety of an offshore wind power project.

With the widely acception of extended producer responsibility system, reverse logistics has attracted more and more attention. For manufacturers, reverse logistics activities is not inseparable to the general forward logistics, and they constitute the closed-loop supply chain. Decision makers of enterprises need to control the new products inventory and the recovered materials inventory to make the enterprises get the maximum profit.In this paper,the inventory characteristics under the closed-loop supply chain be analyzed and a inventory model for a single repair period, many production period is proposed .On condition that the number of recovery is controlled by the recycling price and is equal in different cycles,the recovered products can be sold as new.A economic production quantity and recycling price can be solved to make the total cost of a single cycle lowest ,which provides a basis for business decisions.

In this study, canola oil triglycerides have been successfully transformed into canola oil-based polyisocyanates via thiol-ene click reaction and Curtius rearrangement reaction sequently. The synthesis method is non-phosgene and green. The structure of these novel diisocyanates was confirmed through Fourier transform infrared spectroscopy (FT-IR) and proton nuclear magnetic resonance (NMR). The result shows that the goal product has been produce successfully.

In this paper, two processes for V-Ti magnetite smelting were introduced, the processes respectively are the conventional blast furnace-BOF process and the high-profile rotary hearth furnace direct reduction technology. The two kinds of processes were introduced briefly, and the problems of the two processes in the production of V-Ti magnetite were analysed. The blast furnace-BOF process with the relatively perfect, large output, high energy efficiency can't make full use of Ti in the mineral resources, in this way, the resource was wasted and the environmental were polluted, and the existence of Ti in slag can also bring a series of problems in blast furnace production. Rotary hearth furnace direct reduction technology has the advantages of high reduction temperature, low product price, flexible selection for raw materials and reducing agent, while the large scale of equipment brings a series of problems to the production and design.

Steel slag is hydraulic cementing material, which is mainly applicable approach to the production of cement, admixture of high performance concrete, road engineering. But as a result of hydration expansion of the free calcium oxide and free magnesium oxide and dicalcium silicate morphological changes which is contained in slag cause poor stability of steel slag used in engineering, the steel slag utilization is very low. Therefore, the key technology of steel slag treatment process is to improve the stability of steel slag. Steel slag is alkaline slag, with lower temperature, the viscosity increases sharply, the liquidity variation, it is one of the important factors affect the steel slag processing, According to the need for different liquidity of steel slag to choose the corresponding steel slag treatment technology. Tank-type hot disintegrating, Rotary cylinder technology processing available to small particle size, good steel slag separation, active promotion of slags, conducive to the comprehensive utilization of steel slag.