scholarly journals Hydrogeological processes and phenomena and assessment of their danger

2021 ◽  
Vol 937 (3) ◽  
pp. 032018
Author(s):  
D Moiseev ◽  
L Gorina ◽  
V Romanovsky ◽  
K Valeeva ◽  
O Gorbunova
Keyword(s):  
Physical State ◽  
Negative Impact ◽  
Climatic Factors ◽  
Structural Parameters ◽  
Natural Processes ◽  
Geological Conditions ◽  
Complex Engineering ◽  
Hazard Level ◽  
The Stability ◽  
Negative Factors

Abstract In modern complex engineering-geological conditions of cities, the growth and scale of development of dangerous natural processes and phenomena can be traced. In many ways, the reasons for this are not only technogenic load on the soil, but also changes in climatic factors. Buildings and objects exposed to hazardous factors of hydrogeological processes are becoming increasingly vulnerable to their impact, which can lead to catastrophic consequences. One of the main conditions for increasing the stability of objects is the adaptation of existing methods or approaches to assessing natural hazards that have a negative impact on the physical state of such objects. The authors of the article propose an adaptation of the international INFORM approach in order to assess the hazard level of natural processes and phenomena in built-up areas. The task is also to develop a methodology for assessing the physical state of objects exposed to such processes and phenomena. To solve this problem, the study examines the practical aspects of applying the principles of the Weber-Fechner law in determining the state of the structural parameters of buildings that are under the influence of negative factors of hazardous natural processes and phenomena. The study is based on the principle of changing the category of the physical state of objects from changes in the level of exposure to hazardous factors of natural processes and phenomena.

scholarly journals Analysis and Modeling of the Negative Impact of Virtual Reality

2021 ◽  
Vol 2096 (1) ◽  
pp. 012033
Author(s):  
N Vehteva ◽  
A Nazarova ◽  
E Surkova
Keyword(s):  
Mathematical Model ◽  
Virtual Reality ◽  
Focus Group ◽  
Motion Sickness ◽  
Physical State ◽  
Negative Impact ◽  
Negative Effects ◽  
Virtual Training ◽  
Virtual Objects ◽  
Negative Factors

Abstract During the use of virtual training complexes for the training of specialists in the engineering, chemical, mining industries, in the course of numerous studies, the negative impact of virtual reality on the physical state of a person is noted. These include various types of motion sickness, dizziness, nausea, disorientation in space. Therefore, an actual task is researching of causes and the degree of influence of negative factors using virtual reality technologies. To track negative effects, an algorithm for analyzing user’s state has been developed, which allows collect data of person’s state during the interacting with virtual reality. The algorithm allows fixing quantitative and qualitative metrics. Calculation of metrics is formalized in a mathematical model of process of the virtual reality influence on a person. Algorithm and model are tested on example of an exercise on moving simple virtual objects, data is obtained on a focus group of young specialists. Dynamics of changing quantitative and qualitative metrics is evaluated; it received an idea of degree of influence of negative effects on studying process.

Engineering-Geological Studies Of The Territory, Soils Of Foundation And Foundations Of The Architectural Monument Of The "Melnikov’s House" In Moscow

2019 ◽  
pp. 41-51
Keyword(s):  
Working Condition ◽  
Overlying Water ◽  
North East ◽  
The North ◽  
Geological Processes ◽  
Architectural Monument ◽  
Geological Conditions ◽  
Zone Of Influence ◽  
Complex Engineering ◽  
Building Engineering

On the basis of engineering and design surveys of the building, engineering-geological and geophysical studies of the soils of the territory conducted by the article authors, as well as with due regard for the results of studies conducted on this territory by other authors, the features of the foundations, soils of their foundation and engineering-geological conditions of the territory of the Melnikov House are established. It is shown that the Melnikov house is located under complex engineering-geological conditions on the territory of high geological risk, in the zone of influence of tectonic disturbance. To the North of the area there is a zone of intersection of the observed disturbance with a larger disturbance that can have an impact on geological processes. To the North-East of the site of the Melnikov House, a sharp immersion of the roof of carbon deposits was revealed. It promotes groundwater seepage into limestone of the carbonate strata from overlying water-bearing sands and activation of processes of suffusion removal and sinkhole phenomena of the soil. The surveyed area is assessed as potentially karst-hazardous and adjacent to it from the North-East territory as karst-dangerous. In this regard any construction on the adjacent territory can provoke activation of sinkhole phenomena on the surface. The foundations of the building are basically in working condition. Existing defects can be eliminated during repair. The foundation soils mainly have sufficient bearing capacity. Areas of the base with bulk soil can be reinforced. However, when developing a project for the reconstruction of the building and its territory, it should be taken into account that the design of the Melnikov House does not provide for its operation on the loads at the formation of sinkholes.

Political aspects of security of the European Union Member States

2020 ◽  
pp. 97-105
Author(s):  
Aleksandra Kusztykiewicz-Fedurek
Keyword(s):  
European Union ◽  
Negative Impact ◽  
The European Union ◽  
Member States ◽  
Eu Member States ◽  
Political Security ◽  
New Institutions ◽  
The Stability ◽  
Key Aspects ◽  
The Eu

Political security is very often considered through the prism of individual states. In the scholar literature in-depth analyses of this kind of security are rarely encountered in the context of international entities that these countries integrate. The purpose of this article is to draw attention to key aspects of political security in the European Union (EU) Member States. The EU as a supranational organisation, gathering Member States first, ensures the stability of the EU as a whole, and secondly, it ensures that Member States respect common values and principles. Additionally, the EU institutions focus on ensuring the proper functioning of the Eurozone (also called officially “euro area” in EU regulations). Actions that may have a negative impact on the level of the EU’s political security include the boycott of establishing new institutions conducive to the peaceful coexistence and development of states. These threats seem to have a significant impact on the situation in the EU in the face of the proposed (and not accepted by Member States not belonging to the Eurogroup) Eurozone reforms concerning, inter alia, appointment of the Minister of Economy and Finance and the creation of a new institution - the European Monetary Fund.

Slope Stability Analysis under the Condition of Seepage

2012 ◽  
Vol 204-208 ◽  
pp. 241-245
Author(s):  
Yang Jin
Keyword(s):  
Finite Element Method ◽  
Shear Strength ◽  
Slope Stability ◽  
Negative Impact ◽  
Strength Reduction ◽  
Soil Slope ◽  
Failure State ◽  
Calculation Results ◽  
The Stability ◽  
Shear Strength Reduction

The stability of soil slope under seepage is calculated and analyzed by using finite element method based on the technique of shear strength reduction. When the condition of seepage or not is considered respectively, the critical failure state of slopes and corresponding safety coefficients can be determined by the numerical analysis and calculation. Besides, through analyzing and comparing the calculation results, it shows that seepage has a negative impact on slope stability.

scholarly journals Analysis of the influence of asymmetric geological conditions on stability of high arch dam

2021 ◽  
Vol 28 (1) ◽  
pp. 426-436
Author(s):  
Zelin Ding ◽  
Xuanyi Zhu ◽  
Hongyang Zhang ◽  
Hanlin Ban ◽  
Yuan Chen
Keyword(s):  
Safety Factor ◽  
Negative Impact ◽  
Decisive Role ◽  
Arch Dam ◽  
Test Method ◽  
Stable Operation ◽  
High Arch Dam ◽  
Reinforcement Scheme ◽  
Structural Plane ◽  
Geological Conditions

Abstract Geological conditions play a decisive role in the stability of arch dam engineering, and the asymmetric geological conditions of the abutment have a very negative impact on the safety of the arch dam. This article takes Lizhou arch dam as the research object, and determines that the arch dam is preliminarily affected by the geological asymmetric characteristics. Through the geomechanical model test method, the overload failure test of the Lizhou arch dam was carried out, and the resistance body, the instability deformation of the structural plane of the two dam abutments, and the influence of each structural plane on the dam body are obtained, and the safety factor is determined. According to the test results under the condition of asymmetric foundation of arch dam, for the structural plane which affects the geological asymmetry of the arch dam, the corresponding reinforcement measures are carried out. The feasibility of the reinforcement scheme is verified by the finite element method, and the safety factor after reinforcement is obtained. According to the results, it is suggested that some engineering measures can be taken to reduce the geological asymmetry between the two banks and ensure the safe and stable operation of the arch dam in the future.

scholarly journals Study on instability failure mode and monitoring early warning standard of surrounding rock in fully weathered argillaceous sandstone section of large section tunnel

2019 ◽  
Vol 136 ◽  
pp. 04023
Author(s):  
Ming Zhao ◽  
Ke Li ◽  
Hong Yan Guo ◽  
KaiCheng Hua
Keyword(s):  
Limit State ◽  
Stable State ◽  
Simulation Software ◽  
Surrounding Rock ◽  
Large Section ◽  
Rock Stability ◽  
Geological Conditions ◽  
Construction Step ◽  
The Face ◽  
The Stability

Based on the special geological conditions of a tunnel in Qingyuan section of Huizhou-Zhanzhou Expressway, FLAC3d numerical simulation software is used to simulate the rheological properties and instability of surrounding rock in large-section fully weathered sandstone section, and the stability and loss of surrounding rock are analyzed. The deformation of the dome and the face at steady state is analyzed. It is found that: 1) when the surrounding rock is in a stable state, the deformation curve of the dome is smooth. When the surrounding rock of the face is unstable, the front of the face appears ahead. Deformation should be first strengthened on the surrounding rock in front of the face. 2) The arched foot is an important part of the instability of the surrounding rock. In order to prevent the expansion of the collapsed part, the arched part should be reinforced. 3) In order to obtain the limit state of surrounding rock stability, the strength of surrounding rock is reduced, and the strength reduction coefficient corresponding to the displacement sudden point is taken as the safety factor of rock stability around the hole, and the stability safety coefficients of surrounding rock of each construction step are greater than 1.2. 4) The dynamic standard values of deformation control in the whole construction stage are obtained by analyzing the deformation curves of each data monitoring point with time in the corresponding time period of each construction step.

scholarly journals Reliable Learning with PDE-Based CNNs and DenseNets for Detecting COVID-19, Pneumonia, and Tuberculosis from Chest X-Ray Images

Mathematics ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 434
Author(s):  
Anca Nicoleta Marginean ◽  
Delia Doris Muntean ◽  
George Adrian Muntean ◽  
Adelina Priscu ◽  
Adrian Groza ◽  
...  
Keyword(s):  
Transfer Learning ◽  
Negative Impact ◽  
X Ray ◽  
Domain Specific ◽  
Direct Training ◽  
Public Data ◽  
Normal Chest ◽  
Chest X Ray ◽  
The Stability ◽  
Definition Of

It has recently been shown that the interpretation by partial differential equations (PDEs) of a class of convolutional neural networks (CNNs) supports definition of architectures such as parabolic and hyperbolic networks. These networks have provable properties regarding the stability against the perturbations of the input features. Aiming for robustness, we tackle the problem of detecting changes in chest X-ray images that may be suggestive of COVID-19 with parabolic and hyperbolic CNNs and with domain-specific transfer learning. To this end, we compile public data on patients diagnosed with COVID-19, pneumonia, and tuberculosis, along with normal chest X-ray images. The negative impact of the small number of COVID-19 images is reduced by applying transfer learning in several ways. For the parabolic and hyperbolic networks, we pretrain the networks on normal and pneumonia images and further use the obtained weights as the initializers for the networks to discriminate between COVID-19, pneumonia, tuberculosis, and normal aspects. For DenseNets, we apply transfer learning twice. First, the ImageNet pretrained weights are used to train on the CheXpert dataset, which includes 14 common radiological observations (e.g., lung opacity, cardiomegaly, fracture, support devices). Then, the weights are used to initialize the network which detects COVID-19 and the three other classes. The resulting networks are compared in terms of how well they adapt to the small number of COVID-19 images. According to our quantitative and qualitative analysis, the resulting networks are more reliable compared to those obtained by direct training on the targeted dataset.

Numerical and Experimental Approaches to Investigate the Stability of a Motorcycle Vehicle

2006 ◽  
Author(s):  
Federico Cheli ◽  
Marco Bocciolone ◽  
Marco Pezzola ◽  
Elisabetta Leo
Keyword(s):  
Degrees Of Freedom ◽  
Structural Parameters ◽  
Experimental Tests ◽  
Roll Angle ◽  
Longitudinal Motion ◽  
Reference Trajectory ◽  
Steering Angle ◽  
Steady State Condition ◽  
The Stability ◽  
Linearized Model

The study of motorcycle’s stability is an important task for the passenger’s safety. The range of frequencies involved for the handling stability is lower than 10 Hz. A numerical model was developed to access the stability of a motorcycle vehicle in this frequency range. The stability is analysed using a linearized model around the straight steady state condition. In this condition, the vehicle’s vertical and longitudinal motion are decoupled, hence the model has only four degrees of freedom (steering angle, yaw angle, roll angle and lateral translation), while longitudinal motion is imposed. The stability was studied increasing the longitudinal speed. The input of the model can be either a driver input manoeuvre (roll angle) or a transversal component of road input able to excite the vibration modes. The driver is introduced in the model as a steering torque that allows the vehicle to follow a reference trajectory. To validate the model, experimental tests were done. To excite the vehicle modes, the driver input was not taken into account considering both the danger for the driver and the repeatability of the manoeuvre. Two different vehicle configurations were tested: vehicle 1 is a motorcycle [7] and vehicle 2 is a scooter. Through the use of the validated model, a sensitivity analysis was done changing structural (for example normal trail, steering angle, mass) and non structural parameters (for example longitudinal speed).

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