Research on Evolution Characteristics of Shale Crack Based on Simultaneous Monitoring of Multi-Parameters

Meso-crack evolution mechanism of shale is a key factor affecting the mechanical properties of shale. In order to explore evolution laws of cracks in shale during loading, a meso-crack monitoring system, loading test equipment and an automatic ultrasonic data acquisition system were set up. On this basis, a set of experimental apparatus simultaneous monitoring multi-parameters of shale micro-crack was designed, and destruction experiments of shale samples with different bedding angles were carried out to find out evolution characteristics of cracks. The results show the following: (1) The designed apparatus can monitor ultrasonic, mechanical and video information simultaneously of crack evolution in the entire process of shale destruction under load to provide information for analyzing acoustic and mechanical characteristic responses of crack propagation at key time nodes. (2) With an increase in load, shale will undergo four stages of destruction: crack initiation, propagation, penetration and overall failure. In the course of these stages, acoustic characteristics and mechanical characteristics are in good agreement, which proves the validity of predicting rock mechanical parameters with acoustic data. (3) During the loading process of shale, the main amplitude of acoustic wave is more sensitive than mechanical parameters to the change of rock cracks. Research results have important theoretical reference value for evaluating wall stability of shale gas horizontal well with ultrasonic data.

An analysis of YouTube videos on oral hygiene practices during coronavirus disease 2019 pandemic

Objectives: The objectives of the study were to examine the usefulness and content of YouTube videos regarding additional oral hygiene practices that need to be taken during the coronavirus disease 2019 (COVID-19) pandemic. Materials and Methods: A search of YouTube videos was performed using the terms “oral health,” “dental hygiene,” “oral health child” and “dental hygiene child” in combination with “COVID-19”. When analyzing each video, the descriptive characteristics such as title, country of origin, date of upload, duration of the video, the number of views, comments, likes, and dislikes were recorded. The quality of the videos were assessed through indices: Video ınformation and quality ındex (VIQI), modified DISCERN, and global quality score (GQS). The content quality score of the videos was examined. Results: The majority of the analyzed videos were uploaded by health-care professionals (67%). About 40% of the videos were slightly useful, and 6% were useful. There was no statistically significant correlation between the source of upload and GQS, VIQI, total content, or modified DISCERN scores (P > 0.05). Highly-watched videos appeared to have a higher total content, VIQI, Modified DISCERN, and GQI scores than poorly-watched videos, but this difference was not statistically significant (P > 0.05). Conclusion: YouTube videos related to oral hygiene practices during COVID-19 pandemic were a limited source for children. Oral health-care professionals and organizations should play an active important role for providing educative oral hygiene-related information on YouTube videos.

INFORMATION REPRODUCTION SYSTEMS IN INFORMATION BUSINESS LOGISTICS

The article considers the fundamentals of the information reproduction systems formation in the optoelectronic element base for information logistics systems. The use of optoelectronic elements for information processing has been considered, namely discrete optoelectronic digital systems, analog systems, optical memory systems, optical systems of input-output of information in computers, systems based on fiber devices of neuristor type. It is emphasized that modern logistics is impossible without the active use of information technology. The functions of information support of managerial influences can be performed by information technologies used today in logistics. To perform the tasks of financial flow management, these technologies can be supplemented by modules of eye-processing of the information. Logic-clock quantron automatic devices based on optocouplers are suitable for creating parallel information operating environments, which is a universal means of converting and presenting information. This approach leads to the creation of matrix-type devices that are able not only to receive information but also to process it. One of the promising areas of use of optoelectronic matrix systems is the creation of flat operating screens for parallel reception and display of information. The paper presents the classification of operating screens according to such features as: the principle of displaying information, the type of input information, the type of output information, the method of image formation, the number of consumers of the information. The analysis of electric circuit diagram of modern LED matrix video screens, in particular of a typesetting-modular design has been presented. A comparison of the forms of organization of matrix video screens is made, and it is emphasized that the most economical in terms of the number of memory trigger elements per one LED of the display cell is a video information system based on the structure of the third group video screen. The structure of the video information system is optimized according to the criterion of optimality – the maximum image quality on the matrix screen and the minimum screen complexity, which is determined by the circuit features of the microelectronic circuits.

ASSESSMENT OF THE QUALITY OF RADIO COMMUNICATION CHANNELS OF UNMANNED AERIAL SURVEILLANCE SYSTEMS

Unmanned aerial vehicles (UAVs) allow effective solving the problems of reconnaissance, relaying information on targets to means of fire destruction and striking on any type of object. However, there are many problematic issues regarding the creation of a communication system for remote control of UAV of medium and long range, obtaining video information about reconnaissance objects in real time. The methods allow to estimate the value of the deviation of the carrier frequency of the transmitter of the radio communication channel of unmanned aerial system (UAS) in the normal mode of its operation from the value of the prototype stated by the Developer based on the instrumental measurement of the average or assigned frequency of modulated radio emission. The purpose of the article is to consider the methods, technical means and conditions of instrumental evaluation of the radio emission frequency of UAV‟s radio channels transmitters by means of radio frequency control. This technique defines a set of procedures and rules for instrumental evaluation (measurement) of radio frequency of UAVs prototypes radio transmitters by means of radio frequency control in order to verify compliance of its parameters with the requirements of technical conditions or specifications for experimental aircraft.

Efficiency of spatially recursive algorithms for transmitting images of marine vessels

На современном этапе развития интеллектуальных морских технологий необходимо включить в состав видеосистемы обработки изображений две подсистемы передачи видеоинформации морских сюжетов. Во первых на основе спектрального преобразования сигналов из пространственной области в частотную для оперативной доставки видеоинформации, полученной с различных камер подводного и надводного наблюдения. Во вторых, на основе пространственных методов обработки, без перехода в спектральную область сигнала для передачи выделенных ключевых точек объектов на изображениях. При этом важнейшая особенность этих подсистем заключается в улучшении информационных показателей качества морских видеосистем автоматизированной обработкой видеоинформации: точность визуальных данных, битовая скорость передачи по каналам связи и вычислительная сложность алгоритмов анализа и передачи видеоинформации. В предлагаемом исследовании приводятся алгоритмы спектральной и пространственной обработки видеоинформации, проведена оценка эффективности алгоритмов обработки изображений. А также отражены результаты моделирования алгоритмов и сравнительная оценка информационных показателей интеллектуальных морских видеосистем: точность, битовая скорость и вычислительная сложность видеосистем обработки морских изображений. At the present stage of the development of intelligent marine technologies, it is necessary to include two subsystems for the transmission of video information of marine scenes in the video image processing system: 1) based on the spectral conversion of signals from the spatial domain to the frequency domain for the rapid delivery of video information obtained from various underwater and surface surveillance cameras; 2) based on spatial processing methods without switching to the spectral domain of the signal to transmit selected key points of objects in the images. At the same time, the most important feature of these subsystems is to improve the information quality indicators of marine video systems by automated processing of video information: the accuracy of visual data, the bit rate of transmission over communication channels and the computational complexity of algorithms for analyzing and transmitting video information. The proposed study provides algorithms for spectral and spatial processing of video information. The results of algorithm modeling and comparative evaluation of information indicators of intelligent marine video systems are also presented: accuracy, bit rate and computational complexity of marine image processing video systems.

Changing maladaptive beliefs among individuals with coronary heart disease using video information

Many individuals with coronary heart disease (CHD) have maladaptive beliefs which might increase anxiety and depression. This study investigates the impact of using video information to convey facts and correct misconceptions about CHD in individuals. 150 individuals with CHD were assigned to either the control group or one of two experimental groups. The participants completed the York Cardiac Beliefs Questionnaire in the baseline measure immediately after first viewing the video (time 1), and after viewing the video for six times within two weeks (time 2). The Beck Anxiety Inventory and Beck Depression Inventory II were completed in the baseline and at time 2. Multiple repeated measures anova shows that after the intervention, participants’ maladaptive beliefs, anxiety and depression were reduced in both experimental groups. Yet, it did not happen in the control group. It indicates that the video information corrects maladaptive beliefs, and reduces anxiety and depression levels in individuals with CHD.

Метод непрямого приховування інформації в процесі стиснення відеозображень

It is substantiated that steganographic systems should be used to ensure the protection of special information resources in conditions of its prompt delivery. Here, steganographic technologies are an integral part of complex information protection systems. Simultaneously, for steganographic systems, there is a contradiction between the density of embedded data and level of information compaction of video container (level of reduction of volume bit volume of compact presented video image concerning bit volume of an initial video image). It leads to the fact that under the conditions of the required quality (reliability) of digital video information, the bit rate level of the covert channel is insufficient. Consequently, the scientific-applied problem concerns the necessity to increase the integrity (the level of correspondence of the hidden information before its embedding in a video container and after its extraction) and bit rate of the hidden channel of special information transmission. It is relevant. The solution of the described problem in the field of application of steganographic transformations can be realized based on the application of two different approaches. The first approach is based on methods of direct message embedding. But this approach is characterized by introducing distortions in the video images used as a container. Therefore, changes in structural and statistical patterns in the syntactic description of the video container happen. It reduces the potential for video container compaction. The second approach to creating steganographic transformation methods is based on information hiding using indirect embedding technique. Here, the embedding process exploits the functional dependency between the elements of the video container and the elements of the embedded message. Setting a specific dependency between the elements in the video container corresponds to the embedded element with a value of "0" or "1". However, the existing indirect steganographic transformation methods have a disadvantage. It consists of an insufficient value of embedded data density. To eliminate these disadvantages, it is proposed to develop an approach that allows using not only psychovisual but also structural redundancy of video container for concealment. Therefore, the research objective of this paper is to develop a method for indirect information withholding in the video container compression process to increase the bit rate of the hidden message channel. In the process of research, a steganographic multiagent system is constructed, which allows embedding hidden message elements without loss of information based on the indirect approach by modifying the active bases of the multiagent basis considering their uncertainty. To select transformants (data sets) as containers for information embedding, the requirement of the existence of a base system with all active bases is taken into account. The number of embedded bits of the hidden message is equal to the number of active bases in the base system of the multiadic space. Because of the made experiments, the following results have been received: in the process of embedding messages based on the created method distortions in a video container is not brought; for the created method the additional increase in the hidden channel bit rate in average 5 … 7 times are reached.

Augmented Reality in Online Teacher Traning for Digital Competence

The article presents an approach applied in the online training of pre-service teachers to acquire digital competence. The content of the concept of ‘digital competence’ in its sustainable and variable component is clarified. The understanding of ‘augmented reality’ to e-learning objects is presented. Two forms of ‘augmented reality’ have been proposed to visualize video information to a clarified concept. The first one is presented via a QR code for quick access and applicable for mobile learning. The other is provided by icons and is applicable to e-learning with a computer. It is believed that ‘augmented reality’ can differentiate students’ online learning according to the field-dependent and field-independent cognitive style and their preferences on the use of different digital learning devices.