Dependency Graph Research Articles

Unapređenje tehnološke opreme drona za uzorkovanje vode - projektovanje i modelovanje

One of the modern problems in the field of ecology is the creation of environmentally friendly equipment for monitoring the state of various reservoirs by taking water for further laboratory analysis. Water quality monitoring is needed to record changes in water quality over time, as well as to detect contamination from storm water runoff, which may contain microorganisms, minerals, debris, and fuel residues. One of the promising ways to solve this problem is using drones to collect hydro-chemical data on the spot and take water samples from freshwater environments. This approach makes it possible to perform the aspects of biological and physical-chemical water sampling that are necessary for implementing large-scale water sampling programs and makes these programs more efficient, safe, and economically profitable. However, in modern times, the use of drones for water quality monitoring is held back by a number of important limitations, namely the low level of objective sampling and the relatively small volume of water samples. The article proposes a fundamentally new design of the technological equipment of a drone for taking water samples, namely a new design of a bathometer - a device for taking water samples and installing them on the Cardan suspension. These structural differences ensure the orientation of the bathometer only under the influence of gravitational force, which in turn significantly increases the objectivity of water sampling. The article also provides kinematic and dynamic models of the bathometer's movement on the Cardan suspension rings. It presents the modeling results in the form of graphical and analytical dependencies of kinematic analysis, which constitutes the scientific aspect of the problem. The main motivation of the conducted research is the creation of environmentally friendly equipment in the form of an unmanned aerial vehicle, which is designed to increase the objectivity of water sampling.

Determination of the maximum mechanical stresses in the insulating material around a defect with a high dielectric permittivity in an electrostatic field

Introduction. All insulating macrohomogeneous solid materials change shape under the influence of an electric field. Problem. The presence of minor defects changes the distribution of an electric field and causes a significant concentration of mechanical stresses in a given section of the material, which, under certain circumstances, can cause partial or complete destruction of this material. Goal. The purpose of the work is to determine maximum mechanical stresses according to the von Mises criterion in insulating materials around defects with ionized air and water in an electrostatic field. Also, to analyze the influence of the following parameters on the indicated stresses: the location of the defect, the orientation angle of the semi-major axis of the defect cross-section, the ratio of semi-major and semi-minor axes, elastic and dielectric properties of the insulating material and the defect. Methodology. The study is based on the interrelated equations of electrostatics and structural mechanics for an isotropic piecewise homogeneous medium. The solution of these equations is obtained by the finite element method. Results. Graphs of dependences of maximum mechanical stresses on the ratio of semi-major and semi-minor axes of the ellipsoidal cross-section of the defect have been obtained. The minimum ratio of the greatest stresses in the insulating materials around the surface cracks and pores for ionized air has been 9.3 times for the maximum ratio of major and minor semi-axes of the cross-section of the defect considered in the work, which is 10. For a water defect, the similar ratio has been 2...5.6 times, increasing when the relative dielectric permittivity of the insulating material changes from 7 to 2. When Young’s modulus of the insulating material increases from 1 MPa to 100 GPa, the angles of the inclination of the linearized dependences of maximum mechanical stresses around bounded pores with ionized air (water) to the axis of the ratio of major and minor semi-axes of the defect cross-section have been increased by 35.9° (58.0°) and 18.6° (20.1°) at orientations of major semi-axes at angles of 0° and 45°, respectively. Originality. The numerical-field mathematical two-dimensional model has been developed for the first time, which consists of sequentially solved equations of electrostatics and structural mechanics, for the determination of the distribution of mechanical stresses in an insulating material with a liquid or gaseous defect. It has been established for the first time that the ratio of the elastic properties of the insulating material and the defect determines the angle of the inclination of the linearized dependence of the maximum mechanical stress to the axis of the ratio of major and minor semi-axes of the defect cross-section. Practical value. The types of defects that contribute to the aging of insulation materials under the combined action of an electric field and a stress field to the greatest extent have been established.

Artificial neural network with dynamic synapse model

The purpose of this study is to develop and investigate a new short-term memory model based on an artificial neural network without short-term memory effect and a dynamic short-term memory model with astrocytic modulation. Methods. The artificial neural network is represented by a classical convolutional neural network that does not have short-term memory. Short-term memory is modeled in our hybrid model using the Tsodyks-Markram model, which is a system of third-order ordinary differential equations. Astrocyte dynamics is modeled by a mean field model of gliotransmitter concentration. Results. A new hybrid short-term memory model was developed and investigated using a convolutional neural network and a dynamic synapse model for an image recognition problem. Graphs of dependence of accuracy and error on the number of epochs for the presented model are given. The sensitivity metric of image recognition d-prime has been introduced. The developed model was compared with the recurrent neural network and the configuration of the new model without taking into account astrocytic modulation. A comparative table has been constructed showing the best recognition accuracy for the introduced model. Conclusion. As a result of the study, the possibility of combining an artificial neural network and a dynamic model that expands its functionality is shown. Comparison of the proposed model with short-term memory using a convolutional neural network and a dynamic synapse model with astrocytic modulation with a recurrent network showed the effectiveness of the proposed approach in simulating short-term memory.

U-DepPLLaMA: Universal Dependency Parsing via Auto-regressive Large Language Models

This paper investigates the rapidly advancing domain of Large Language Models (LLMs) and their growing potential in various fields. A central focus is the exploration of LLMs, e.g., LLaMA, as powerful tools for modeling and representing linguistic information, especially in the realm of syntax. We aim to evaluate the ability of these models to encode syntactic information, especially when explicitly supplied, through fine-tuning processes. Traditionally, Dependency Parsing has relied on specific techniques and dedicated architectures. Our research shifts this approach, conceptualizing it as a sequence-to-sequence task where Language Models interpret and transform syntax into bracketed structures that reflect dependency graphs. We introduce U-DepPLLaMA (Universal Dependency Parsing via auto-regressive LLMs based on LLaMA), a novel architecture optimized for multilingual, end-to-end Dependency Parsing. Our experimental evaluation, across 50 datasets in 26 languages from the Universal Dependency Treebank, shows that LLMs can be effectively trained for dependency parsing without the need for task-specific architectures. The results are on par with current state-of-the-art methods and demonstrate resilience across varying sentence complexities and lengths.

Identifying Hate Speech Through Syntax Dependency Graph Convolution and Sentiment Knowledge Transfer

Identifying Hate Speech Through Syntax Dependency Graph Convolution and Sentiment Knowledge Transfer

Enhancing Security Patch Identification by Capturing Structures in Commits

With the rapid increasing number of open source software (OSS), the majority of the software vulnerabilities in the open source components are fixed silently, which leads to the deployed software that integrated them being unable to get a timely update. Hence, it is critical to design a security patch identification system to ensure the security of the utilized software. However, most of the existing works for security patch identification just consider the changed code and the commit message of a commit as a flat sequence of tokens with simple neural networks to learn its semantics, while the structure information is ignored. To address these limitations, in this paper, we propose our well-designed approach E-SPI, which extracts the structure information hidden in a commit for effective identification. Specifically, it consists of the code change encoder to extract the syntactic of the changed code with the BiLSTM to learn the code representation and the message encoder to construct the dependency graph for the commit message with the graph neural network (GNN) to learn the message representation. We further enhance the code change encoder by embedding contextual information related to the changed code. To demonstrate the effectiveness of our approach, we conduct the extensive experiments against six state-of-the-art approaches on the existing dataset and from the real deployment environment. The experimental results confirm that our approach can significantly outperform current state-of-the-art baselines.

МАТЕМАТИЧНЕ МОДЕЛЮВАННЯ СИМЕТРИЧНОЇ КРАЙОВОЇ ЗАДАЧІ ДЛЯ ПОСЛАБЛЕНОГО НАСКРІЗНИМ ОТВОРОМ ШАРУ З ПОКРИТИМИ ДІАФРАГМОЮ ТОРЦЯМИ

The paper presents a new mathematical model for the solution of a static symmetric boundary-value problem for a layer weakened by a through hole with ends covered with a diaphragm. A new method based on a system of three singular integral equations has been developed and tested numerically. As a result of a high-precision numerical study, it was found that with an increase in the thickness of the layer, an increase in the relative circumferential stress occurs. With a decrease in one of the radii of the elliptical hole, an increase in the relative circumferential stress is also observed. The paper presents the respective dependency graphs. Keywords: three-dimensional boundary-value problems, singular integral equations, numerical experiment, static stretching–compression, a through hole.

Особенности формования и трансформации максимального стока реки Миус

Purpose: to study the features of the formation and transformation of the maximum river runoff based on empirical data. Materials and methods. The series of observations of water levels and flows in two existing gauging stations Kuibyshevo (hydrological station 1) and Matveev Kurgan (hydrological station 2) with a duration of 51 years, were used as source materials. Statistical and theoretical methods were used as information processing methods, including system analysis and hydrological and geographical generalizations. Results and discussions. A study consisting of four stages: analysis of hydrographic characteristics, construction of dependency graphs of maximum flow rates Q = f(H), analysis of hydrological series and calculated data, was carried out. As a result of the analysis of hydrographic characteristics, a significant difference in the average heights of the watershed area and the bed slope was revealed. When comparing the maximum parameters by year, it was revealed that the maximum level recorded at the gauging station does not correspond to the maximum flow rate: at the hydrological station 1, the maximum water level was observed in 1979 and corresponded to 2 % availability, while the same year discharge of 151 cubic m/s corresponded to 6 % availability, the highest discharge was recorded in 1970 and was higher by 30 cubic m/s, the water level corresponded to 4 % availability and was lower by 0.49 m; at hydrological station 2, the maximum water level was recorded in 1985 with a flow rate of 202 cubic m/s, corresponding to 6 % probability, the maximum flow rate was observed in 1964 at a water level 0.38 m below the maximum, which corresponds to 12 % availability. Conclusions. The materials presented in the article confirm that the use of the coefficients of variation and asymmetry of one gauging station for the long-term average values of another gauging station is not entirely correct, despite the fact that they are located on the same river at a fairly close distance.

Search and Retrieval in Semantic-Structural Representations of Novel Malware

In this study, we present a novel representation for binary programs which captures semantic similarity and structural properties. This representation enables the search and retrieval of binary executable programs based on their similarity of behavioral properties. The proposed representation is composed in a bottom-up approach: we begin by extracting data dependency graphs (DDG), which are representative of both program structure and operational semantics. We then encode each program as a set of graph hashes representing isomorphic uniqueness, a method we have labeled DDG Fingerprinting. We present experimental results of search using k-Nearest Neighbors in a metric space constructed from a set of binary executables. Searches in the dataset are based on the operational semantics of specific malware examples By quantifying behavioral similarity we show that we can recognize patterns of operation in novel malware with functionality not previously identified. We show in addition that the associated metric space allows an adjustable level of resolution. Resolution of the features may be decreased for breadth of search and retrieval, or as the search space is reduced, the resolution may be increased for accuracy and fine-grained analysis of malware behavior. This allows for explainability in the interpretation of fine-grained analysis.

A review on graph representation for object-oriented programming

Relationships and connections between entities are typically represented by graphs, a fundamental data structure in computer science. A graph illustrates the control flow among statements within a program, whereas a dependence graph delineates the interrelationships among various objects within it. The object-oriented paradigm introduces numerous innovative concepts, including encapsulation, inheritance, polymorphism, and dynamic binding. A complete object-oriented graph representation entails structuring and conceptualizing a graph based on the principles of object-oriented programming (OOP). Several models have been suggested previously designed to depict the diverse features of object-oriented programming. This study distinguishes between partial and fully object-oriented graph representations. It also analyses the fully object-oriented graph representation models.

IC‐GraF: An Improved Clustering with Graph‐Embedding‐Based Features for Software Defect Prediction

Software defect prediction (SDP) has been a prominent area of research in software engineering. Previous SDP methods often struggled in industrial applications, primarily due to the need for sufficient historical data. Thus, clustering‐based unsupervised defect prediction (CUDP) and cross‐project defect prediction (CPDP) emerged to address this challenge. However, the former exhibited limitations in capturing semantic and structural features, while the latter encountered constraints due to differences in data distribution across projects. Therefore, we introduce a novel framework called improved clustering with graph‐embedding‐based features (IC‐GraF) for SDP without the reliance on historical data. First, a preprocessing operation is performed to extract program dependence graphs (PDGs) and mark distinct dependency relationships within them. Second, the improved deep graph infomax (IDGI) model, an extension of the DGI model specifically for SDP, is designed to generate graph‐level representations of PDGs. Finally, a heuristic‐based k‐means clustering algorithm is employed to classify the features generated by IDGI. To validate the efficacy of IC‐GraF, we conduct experiments based on 24 releases of the PROMISE dataset, using F‐measure and G‐measure as evaluation criteria. The findings indicate that IC‐GraF achieves 5.0%−42.7% higher F‐measure, 5%−39.4% higher G‐measure, and 2.5%−11.4% higher AUC over existing CUDP methods. Even when compared with eight supervised learning‐based SDP methods, IC‐GraF maintains a superior competitive edge.

Learning conditional dependence graph for concepts via matrix normal graphical model

Learning conditional dependence graph for concepts via matrix normal graphical model

PBDG: a malicious code detection method based on precise behaviour dependency graph

PBDG: a malicious code detection method based on precise behaviour dependency graph

The effect of phosphorus content in copper alloys used for crystallisers of continuous casting machines

One of the key elements defining the technical level and operational capabilities of continuous casting machines (CCM) is the complex of physico-mechanical properties of copper or copper alloys used in its production. The paper provides a comprehensive assessment of the possibility of obtaining high-quality copper plates for CCBC crystallizers based on domestic technologies and equipment using refined copper. Special attention was paid to the need to optimize the chemical composition of the copper alloy within a narrower range of chemical element values. The analysis of the research shows that currently used copper alloys for CCM crystallizer manufacturing have a wide range of fluctuations in the main operational properties, namely thermal conductivity (260-390 W/(m·K)) and solidification temperature (250-700 °C). However, most of the alloys used have narrower fluctuation limits for acceptable values, constituting 340-390 W/(m·K) for thermal conductivity and 300-370 °C for solidification temperature, significantly depending on the impurity content in the copper alloy. Generalizing graphical dependencies, it should be assumed that the rational phosphorus content in the alloy is in the range of 40-120 ppm. In this case, the thermal conductivity of the alloy will be in the range of 370-400 W/(m·K), the solidification temperature will be 410-440 °C, and the recrystallization start temperature will be 370-400 °C. Moreover, such a phosphorus content interval is technologically feasible to maintain during billet casting. It is also shown that normalization annealing after cold deformation in the temperature range of 320-350 °C is capable of increasing the thermal conductivity of the alloy by 1-2 %. As a result of the conducted research, optimal limits of phosphorus content in fire-refined copper were established, ensuring the level of its physico-mechanical properties not lower than the indicators characteristic of alloys obtained from cathode copper. However, besides phosphorus, other alloy impurities, the content of which differs from the values characteristic of alloys obtained from cathode copper, may affect the properties of the material made from refined copper. Therefore, further research will focus on studying their complex impact on the physico-mechanical properties of refined alloys.

«Золотой век» геологии и организация морских геологоразведочных работ в СССР

The features of the organization of geological exploration (GE) in the USSR at government and legislative levels in the “Golden Age of Geology” 1955-1985 are considered. The main achievements of the USSR are noted, including the discovery of the giant West Siberian oil and gas province and a large raw material base for the oil and gas industry on the shelf of the Western Arctic. The graphical dependences of the shares of Russia, the USSR-CIS and the Yamal-Nenets Autonomous District in the world volume of oil and gas production for the period 1900-2022 are presented. The necessity for a radical increase in the volume of GE from state budget funds is substantiated. It is recommended to revive the fund for the reproduction of the country's mineral resource base.

Cercetări privind stabilirea unor legături dintre compoziția și procesul de structurare a fructelor-snack-uri

The article presents the experimental work results analysis concerning the study of structuring of fruit puree with different content of insoluble solids. Structuring has been carried out in the process of puree dehydration to different values of water activity, which are in the range of 0.38-0.78. Correlations between water activity (aw) and moisture content, and dependences between aw and insoluble solids content have been established for the studied products of different quality. Graphical dependences of the quality organoleptic evaluation on water activity, the content of water-insoluble solids (Inap) and alcohol-insoluble solids (Inal) have been presented for the structured purees. The most favorable ranges of aw, Inap, Inal for fruit puree structuring have been determined.

The influence of anisotropic properties of the under-rail base on the track dynamic settlement

The article presents the results of a study of the anisotropy of the under-rail base on the dynamic settlement of sections of transitional stiffness reinforced with bottomless boxes. It is proposed to model the railway track by flat elements, each of which is represented by an anisotropic plate resting on a deformable base with its own deformability parameters. Three main directions of change in the mechanical and geometric characteristics of the structure are identified: horizontal directions along the rail strands, transverse directions along the sleepers, and vertical directions down from the level of the rail head. Setting boundary conditions for individual fragments of the track structure and varying the anisotropy coefficients allows to achieve a good correspondence between the real railway track structure and its mathematical model. Graphical dependencies for the vertical displacement of points on the median surface of a flat element modeling a segment of a railway track were constructed and analyzed based on the results of determining the frequencies of natural oscillations.

Exhaust device braid transmission pattern changes in the driven branch

The article presents the results of an analysis of the pattern of voltage changes in the driven branch of transmission by a braid with a variable gear ratio using the analytical method. A system of differential equations is obtained that describes the movement of the belt drive rollers. Based on the numerical solution of the problem, the laws were obtained changes in braid voltage in the driven transmission branch. Graphical dependences of the change in the maximum voltage value in the driven branch on the values of the pre-tension of the transmission band have been constructed. The parameters of the belt drive are justified.

ПОБУДОВА МАТЕМАТИЧНОЇ МОДЕЛІ ПОДАЧІ ТЕХНОЛОГІЧНОЇ МАСИ В МОЛОТАРКУ ЗЕРНОЗБИРАЛЬНОГО КОМБАЙНА

Purpose of the research: to develop and research a multifactorial mathematical model of the feed of the grain harvester, taking into account several factors that influence the formation of its value. Methods and materials. The development of a mathematical model of the grain loss indicator was carried out using mathematical modeling methods; its assessment was performed using Fisher’s test. The study of the supply of technological mass was carried out at the multifactorial level depending on the technical parameters and technological modes of the harvester systems and the characteristics of the technological culture. Multifactorial experimental studies of the technological mass supply indicator were carried out during the operation of the combine in the direct combine mode. 14 combines of the same type with a drum-type thresher were included in the experiment. Results. Based on the results of the obtained statistical data analysis, it was concluded that an increase in the width of the thresher, the area of the straw shaker, the energy supply of the combine, the width of the grain header, the grain yield of the technological crop and the working speed contribute to the increase in the supply of bread mass to the thresher of the combine. A multifactorial mathematical model of the technological mass supply indicator was developed. Based on the obtained mathematical model, graphical dependences of the feed rate on the width of the harvester’s grip, the grain yield of the ear crop and the width of the thresher were developed, which determine the technological mode of operation of the combine - the supply of bread mass to threshing. Their use makes it possible to choose the necessary working speed of the combine for the thresher of specific parameters, in order to form a flow of technological mass of the required productivity - feed into the thresher. When working in the same conditions (on the same field), the productivity of combines will be determined by the amount of bread mass supplied to the combine, which is determined by the harvester, thresher, and the working speed of movement during the execution of the technological process. Conclusions. It has been established that the technological throughput capacity of the thresher for threshing bread mass is determined by its technical parameters. The use of a thresher with a significant diameter of the threshing drum (along with correspondingly increased other parameters of the threshing system) contributes to the productivity of passing/feeding and technological processing in the threshing-separating system, which serves to increase the supply of bread mass to the threshing machine and the ability of the combine to work in the mode of design productivity. It is advisable to use graphic models of the feed indicator when choosing the technological mode of the combined harvester - working speed, depending on its design productivity, the width of the harvester’s grip, and the grain yield of ear crops. Keywords: grain harvester, drum-type thresher, feed of bread mass, grain threshing, grain harvester.

Theoretical substantiation of the device parameters for drying the green mass of essential oil crops in a vacuum drum dryer

Purpose. To substantiate theoretically the main structural parameters of the device for drying the green mass of essential oil crops in a vacuum. Methods. In the process of theoretical substantiation of the device for drying the green mass of essential oil crops in a vacuum drum dryer, the methods of technical analysis of the movement of the green mass along the blades and the inner surface of the drying drum, planimetry, and trigonometry were used. The dependencies for calculating the design parameters of the device were derived on the basis on algebraic methods. The analysis of the formulas was based on graphical dependencies constructed on their basis. Results. A preliminary experiment using straw mass on the SVB-10 vacuum drum dryer found that a grass bundle is formed in one complete rotation, the central part of which is difficult to dry. To prevent the formation of the grass tourniquet, it was proposed to use L-shaped blades attached to the inner surface of the drum. It was found that to ensure the turning of the green mass and the rational use of the drying drum space, the height of the blade should be equal the length of the L-shaped blade visor. Dependencies have been developed to calculate the angle between the canopy and the blade, the condition for the blade height, their rational number, and the maximum portion mass of green mass that can be loaded into the developed device. A general view of the device for drying green mass of essential oil crops in a vacuum drum dryer was also proposed. Conclusions. Due to the large internal friction angle and low thermal conductivity, it is advisable to use a drying drum with L-shaped blades attached to the inner surface of the drum, with the height of the blade equal to the length of the canopy. The use of L-shaped blades ensures uniform mixing of the green mass of essential oil crops during the rotation of the drying drum and prevents the formation of a harness. The number of blades, their geometric dimensions depend on the radius of the drying drum, the friction angle of the green mass of essential oil crops on the metal surface, the permissible technological gap, and the specified weight of the portion loaded into the vacuum drum dryer. Keywords: green mass of essential oil crops, vacuum, L-shaped paddle, vacuum drum dryer, drying drum, canopy, herbal bundle, drying, friction angle.