bluuebunny/crossref_metadata_2025 huggingface dataset:
A study on the repeated practice experiences of servant leadership for the hotel workers: Based on the grounded theory
Authors:   The Tourism Sciences Society Of Korea, Jin Jin-Hee , Cho Min-ho
Published: June 2023

The purpose of this study is to derive a theory that can improve the basis for understanding the repeated practice experiences of servant leadership for hotel workers. In order to achieve the purpose of this study, the research questions are 1) what are the stages in which hotel workers practice servant leadership? 2) what kind of problems do hotel workers face when they practice servant leadership? 3) in what stages do hotel workers practice servant leadership again when it is not successful? The data collection was conducted through in-depth interviews with 10 hotel workers who practice servant leadership and data analysis was conducted according to the procedures of open coding, analysis elaboration, and theory integration. The results of the analysis were as follows: 1) 86 concepts, 24 sub-categories, and 9 categories were derived through open coding. 2) in the analysis elaboration, a relationship model was constructed between the interest stage, preparation stage, practice stage, conviction stage, belief stage, conflict stage, reflection stage, recovery stage, and resolution stage as categories. 3) in the theory integration, the core category was composed of ‘realization of servant leadership through repeated efforts to convey warmth to subordinates’, and a grounded theory was created by integrating the core category and other categories. Therefore, this study contributes to the advancement of servant leadership research and suggests how to practice servant leadership repeatedly in the hotel industry.
Burdur Gölü’nde uzun dönemli kıyı çizgisi değişimleri ve iklim ilişkisi: Zamansal-mekânsal eğilimler ve tahminler
Authors: ALEVKAYALI Çağan , ATAYETER Yıldırım , YAYLA Onur , BİLGİN Tuğçe , AKPINAR Hasan
Published: June 2023

Burdur Gölü, Türkiye’nin güneyinde Toros Dağları kuşağının batısında Göller yöresi olarak adlandırılan bölgede yer alan pek çok türe ev sahipliği yapan önemli sulak alanlarından biridir. Burdur Gölü kapsamında yürütülen birçok çalışmada göl aynasının son yıllarda hızlı bir daralma eğilimi içerisinde olduğu ifade edilmektedir. Bu çalışmanın amacı Burdur Gölü su yüzey alanındaki mekânsal değişimleri (1986-2022) ortaya koymak ve Burdur Gölü Havzasında uzun yıllık iklim kayıtlarındaki (1940-2021) eğilimlerin mevcut kayıtlar üzerinden incelenerek göl aynasının gelecekteki durumu hakkında tahminler yürütmektir. Bu amaçla iklim parametrelerindeki tahminler Mann-Kendall Eğilim testi ile iklim parametrelerinin 10 yıllık tahmini değerleri SARIMA yönteminden yararlanılarak gerçekleştirilmiştir. Burdur Gölü kıyı değişimleri ve bu değişimlere yönelik tahmin uygulamaları da DSAS aracı ile gerçekleştirilmiştir. Burdur Gölü’ne en yakın meteoroloji istasyona ait aylık ve yıllık veriler incelendiğinde yıllık ve aylık yağış miktarında istatistiksel olarak anlamlı eğilimler belirlenmemiştir. Diğer yandan aylık ve yıllık maksimum sıcaklık verilerinde anlamlı artış eğilimi test edilmiştir. İklim parametreleri kapsamında SARIMA yöntemi ile yapılan tahminlerde aylık maksimum ve aylık ortalama sıcaklıklarda 10 yıl ileride yaklaşık 1 C0’lik artış olacağı öngörülmüştür. Burdur Gölü kıyı çizgisi değişimleri ile yapılan analizlere göre su yüzey alanındaki daralmanın 10 yıl sonra bugünkü ayna alanının 17 km2 daha daralacağı tahmin edilmektedir. Bu çalışmada göl yüzeyindeki daralmanın devam edeceği ve iklim değişikliğinin bir geri besleme mekanizması oluşturarak bu değişimi hızlandıracağı çıkarımına varılmıştır.
Analytical model of equal-channel angular pressing of titanium sponge
Authors:   Ural Federal University named after the first President of Russia B.N. Yeltsin, Ekaterinburg, Russian Federation, Berezin Ivan ,   Guide Systems LLC, Ekaterinburg, Russian Federation, Zalazinsky Alexander ,   Institute of Engineering Science, Ural Branch of the Russian Academy of Science, Ekaterinburg, Russian Federation, Kryuchkov Denis ,   Institute of Engineering Science, Ural Branch of the Russian Academy of Science, Ekaterinburg, Russian Federation
Published: June 2023

Introduction. The use of equal-channel angular pressing (ECAP) of metal powder makes it possible to obtain practically non-porous blanks with high hardness, with a high level of accumulated deformation and with the formation of an ultra-fine-grained structure. A relevant issue for the study of the semi-continuous ECAP process remains a reliable assessment of the energy-power parameters of the process and the prediction of the porosity of compressed materials. This, in turn, is due to the need to develop sufficiently accurate, reliable and simple mathematical models for practical application. The purpose of the work is to develop an analytical model of the process of equal-channel angular pressing of porous material. Powdered screening of spongy titanium of the TG-100 brand was selected as a model of the material for the study. The object of the study is the process of semi-continuous equal-channel angular pressing of axisymmetric porous briquette of titanium sponge in the channel of the mold. It is assumed that the ECAP uses a punch to create back pressure. For the solution, a process scheme, a statically permissible load scheme on a layer of intense deformation and a kinematically permissible flow scheme of a plastically compressible medium in a layer are determined. A system of equations is constructed in accordance with the accepted schemes. The equation power balance is applied. The analytical equation is solved by the method of successive approximations. Finite element simulation of the porous titanium ECAP process was carried out at the angles of intersection of the mold channels at 45°, 50°, 55° and 60°. Results and Discussion. The porosity of the blank is determined at different stages of the ECAP process. A diagram of the change in pressure on the punch using the analytical solution and finite element simulation is obtained. It is revealed that the results of the analytical solution are consistent with the data of the finite element simulation. The highest stress level occurs in the process of equal-channel angular pressing at α = 45°, however, the distribution of relative density over the cross section is most uniform. The maximum value of the pressure on the working punch decreases with an increase in the angle α. Rational technological parameters of pressing porous blanks should provide the maximum permissible pressure on the deforming tool. From this condition, in each specific ECAP process, it is possible to determine the optimal angle value from the analytical solution.
Structure and properties of low carbon steel after plasma-jet hard-facing of boron-containing coating
Authors:   Irkutsk National Research Technical University, Russian Federation, Balanovsky Andrey , Nguyen Van Vinh ,   Irkutsk National Research Technical University, Russian Federation, Astafieva Natalya ,   Irkutsk National Research Technical University, Russian Federation, Gusev Ruslan ,   Irkutsk National Research Technical University, Russian Federation
Published: June 2023

Introduction. One of the effective thermochemical methods for increasing the hardness of steel is boronizing by diffusion of boron atoms into the steel surface at high temperatures. As a result of boronizing, coatings are formed on the steel surface, consisting of columnar crystals of FeB and Fe2B. The volume fraction of phases and the thickness of the coatings depend on the heating temperature and the chemical composition of the base material and the saturating medium. The main disadvantage of these boronized layers is its high brittleness. Boronizing by plasma heating is one of the alternatives to the diffusion boronizing process to minimize the brittleness of the boronized layer. The purpose of the work: to form boride coatings on low-carbon steel using plasma-jet hard-facing. The research methods are: determination of the content of chemical elements using an electron probe micro-analyzer, metallographic studies, analysis of the phase composition of the boronized layer, as well as measurement of the microhardness of the coating after plasma-jet hard-facing. In this work boronized layers obtained on low-carbon steel 20 by plasma-jet hard-facing of a boron-containing coating are studied. Powdered amorphous boron was used as an alloying element. The parameter varied during plasma-jet hard-facing process is the current strength (120 A, 140 A and 160 A). Results and discussions. Based on the studies performed, it is found that it is possible to form boronized layers on the steel surface using plasma-jet hard-facing method. It is noted that the surface layer of the coating of the 1st and 2nd specimens after plasma-jet hard-facing has a heterogeneous structure, consisting of rows of different zones. The first zone has a hypereutectic structure, which consists of primary borides FeB and Fe2B, located in the eutectic, consisting of Fe2B and α-Fe. The second zone above the boundary with the base metal is represented by eutectic colonies composed of Fe2B and α-Fe. The third specimen is characterized by a hypoeutectic structure consisting of boride eutectic and primary dendrites of the α-solid solution of boron in iron. The maximum hardness is fixed on the surface of the first specimen and is 1,575 HV. The depth of the hardened layer increases with increasing current, but the hardness value and boron content decrease after treatment. The slight hardness gradient observed over the depth of the coating, as well as the gradual decrease in hardness due to the presence of the transition zone, are considered favorable for good adhesion of the boronized layer to the surface of the base material.
Doğallık ve Yapaylık Sınırında Bio-Konstrüktif Sanat
Authors: BALKAN Gokhan
Published: June 2023

Bio-teknolojik yöntemler medeniyetin gelişiminde etken ve belirleyici olmuşlardır. Tohum ıslahı, mayalama, aşılama ve benzeri doğal tekniklerin yerini günümüzde laboratuvar ortamında geliştirilen ve canlı dokunun yetiştirildiği, yapılandırıldığı veya manipüle edildiği sentetik teknikler almaktadır. Bio-teknoloji ana başlığı altında yer alan moleküler biyoloji, nanoteknoloji, genetik mühendisliği ile transjenik ve benzeri çalışmalar tekil organizmanın yapısal düzenlenmesi veya yetiştirilmesinden başlayarak toplumsal sistemin tümel varlığının belirlenmesine açılan geniş bir spektrumda işlerler. Benzer şekilde ‘Bio-konstrüksiyon’ kavramının kapsamı da canlı dokunun işlenmesi veya yetiştirilmesinden başlayarak gezegenimize ait tüm canlılığın yapısal dönüşümüne kadar uzanır. Bu bağlamda Bio-konstrüktif sanat da yapısal manipülasyona tabi olan canlılığın ete kemiğe bürünen gerçekliği olarak makalede irdelenmekte ve anlamlandırılmaktadır. Bio-konstrüktif sanat bir medyum olarak bio-teknolojilerin kullanıldığı sembolik anlatılardan ziyade canlı dokunun gerçek anlamı ile yaratıldığı, işlendiği, genetik yapısı ile oynandığı uygulamalar ve performanslar olmaktadır. Hümanist, toplumsal yerleşik sistemlerin bio-teknolojik müdahaleler ile başkalaşması, diğer bir deyişle ‘bios’ ve ‘zoe’ ayrımının gün geçtikçe zorlaşması, insansonrası durumun gerçekliğini söz konusu eder. Makale seçili çalışmalar üzerinden bio-konstrüktif sanat edimini tanımlarken, insansonrası durumun niteliği ve bio-konstrüksiyon ile ilişkisi hakkında geliştirilen yaklaşımları da çözümler.
Regional mineral and raw material bases as a key factor in the development of Ukraine during the war and post-war periods
Authors:   Taras Shevchenko National University of Kyiv, Kyiv, Ukraine, Vyzhva S. , Kurylo M. ,   Taras Shevchenko National University of Kyiv, Kyiv, Ukraine, Virshilo I. ,   Taras Shevchenko National University of Kyiv, Kyiv, Ukraine
Published: June 2023

In the study, an analysis of the regional components of the mineral and raw material base of Ukraine was carried out, and its structure was determined. Regions were analyzed according to a number of basic characteristics: the intensity of subsoil use, minerals production, the level of geological study, the level of industrial development of explored mineral reserves, and the presence of strategically important minerals. It was determined that the main disadvantage of individual regional components of the mineral raw material base is the uneven distribution of reserves and inferred resources, as well as the asymmetric distribution of consumers of mineral raw materials. The changes in the regional structure of the mineral and raw material base of Ukraine were analyzed and directions for their optimization were determined in order to achieve balanced indicators of development. The results indicate significant differences in the structure of the mineral base of individual regions. The number of mineral deposits varies significantly – from ≈100 to ≈700, exploited deposits – from 35 to ≈300. The average values of these indicators in Ukraine are 348 and 130 objects. The average rate of objects involved in industrial development by region is 37%. Characteristics such as the structure of explored reserves by type of minerals and the size and quality of reserves are determined. In order to provide the regions with construction materials and fuel resources in a timely and continuous manner, an up-to-date reassessment of the regional mineral and raw material bases is necessary, taking into account the damages and violations that occurred as a result of military operations, and with the assessment of modern needs and opportunities of the damaged infrastructure.
Design and Development of High-Performance Heat Exchangers for Aerospace Applications
Authors: Bangari Raghubeer Singh
Published: June 2023

When two bodies have different temperatures, heat, a type of energy, is transmitted between them. While weight and volume restrictions are either unchanged or even decreasing, thermal management requirements in the realm of aircraft applications are rising. Aerospace systems frequently have high heat flux requirements and necessitate small, light equipment that can function in environments with little or no air pressure. Efficient heat transfer is essential in these systems.Conduction, convection, and radiation are the three main ways in which heat transmission can take place. Understanding the fundamental mechanics of thermal convection and radiation in space applications remains a problem, despite the extensive experimentation and computational techniques used to govern heat transfer in aerospace systems.The heat exchanger, which is a crucial part of thermal management and is important in aeronautical systems, is one example. Heat exchangers are necessary for maintaining the ideal operating temperatures because they make the transfer of heat between fluids possible. This study examines a number of common uses for heat exchangers in aerospace systems and provides several hypothetical designs that have been used or may be useful in the field.Aerospace systems may effectively control and manage heat by using efficient heat exchanger designs, resulting in maximum performance and dependability. To advance thermal management skills in the sector, cutting-edge heat exchanger ideas that are specifically suited to the needs of aerospace applications must be created.
Investigation of Computational Topology for Data Analysis and Visualization Applications
Authors: K. Robin
Published: June 2023

In a variety of disciplines, from biology and physics to computer science and the social sciences, computational topology has become a potent tool for data analysis and visualisation. This study explores computational topology's uses in data analysis and visualisation, showing its potential for revealing hidden structures and patterns in large, complicated datasets.The paper starts out by giving a general introduction of computational topology and outlining its core ideas and methods. The use of it for extracting important information from big, high-dimensional datasets is then explored in relation to data analysis. Computational topology allows for the discovery of topological properties such as holes, voids, and connection patterns by modelling data as topological structures, such as simplicial complexes or persistent homology diagrams.The study also explores the function of computational topology in data visualisation, highlighting its capacity to offer clear and insightful visual representations of challenging datasets. Computational topology enables the construction of simpler and aesthetically pleasing representations while preserving the fundamental topological properties of the data through methods like topological simplification and dimensionality reduction.The usefulness of computational topology in several application domains, such as genomics, image analysis, and network analysis, is demonstrated through a number of case studies. These instances show how computational topology can improve activities like data exploration, clustering, classification, and anomaly detection, resulting in fresh perceptions and learnings.This study emphasises the enormous potential of computational topology for applications in data processing and visualisation. Computational topology provides a new perspective that complements current approaches by utilising the inherent geometric and topological properties of data. This allows researchers and practitioners to better understand complex datasets and make decisions based on the knowledge gleaned from them.
Impact of Hardware Distortion Correlation on Massive MIMO
Authors: Chauhan Rahul
Published: June 2023

Massive MIMO has grow to be a not unusualplace buzzword withinside the improvement of wi- fi cell verbal exchange systems. It's one of the technology which can be promising lately to remedy the hassle of devilish records business. It improves spectral performance of the verbal exchange machine through attaining devilish array benefit and multiplexing benefit. Massive MIMO is an prolonged model of MIMO (further than one enter, further than one affair) wherein the variety of antennas employed in base station are big( variety of 50- one hundred antennas). These array of antennas talk with multitudinous variety of unattached terminal person outfit. still, this period faces a numerous troubles which can be important. One of those problems is impairments which can be attack at the bottom station receiver. When big variety of antennas are used at BS, the general price of attack along with analog- to- virtual mills, amplifiersetc. Used at the bottom station receiver will increase and consequently to be suitable to drop price the affable this is attack reduced. This goods in nonlinearity in attack which distorts the enter signal. We want to probe whether or not this distortion is linked or uncorrelated amongst antennas, and if linked its effect at the spectral performance of the machine. The distortion ultimate of the antennas wishes to be analyzed. In this paper analyze this trouble is completed through us. The distortion in sure conditions may be approached still every now and also want to be taken into consideration for overall performance evaluation to get right goods. In our paper we show that the attack distortion correlation gift among the antennas indeed supposing taken into consideration for evaluation has negligible effect at the overall performance of big MIMO.
An Analysis of Reversible Data Hiding Techniques in Images
Authors: Gupta Richa
Published: June 2023

The reversible data- hiding fashion conceals some sensitive information in an image for secure communication. Only an authorised party may decrypt the concealed communication and recreate the cover image. The strategies put forth by different experimenters haven't yet been suitable to reflect a picture with a high embedding rate and advanced reconstructed image quality. In this exploration, certain significant reversible data- caching strategies are addressed and a system is proposed that can enhance the quality of the reconstructed image, the embedding capacity, and the denoising of the image. This approach can offer a secret data transfer that's further authentic, private, and dependable. Keywords: Embedding rate, Encryption, Prediction error, PSNR, Reversible data-hiding, Steganography
Machine Learning-Based Rainfall Prediction: A Comprehensive Review
Authors: Sahoo Ashok Kumar
Published: June 2023

Several industries, including agriculture, water resource management, disaster preparedness, and urban planning, depend heavily on rainfall forecasting. Traditional approaches for predicting rainfall rely on numerical simulations and statistical models, which frequently have accuracy and computing efficiency issues. Growing interest has been shown in using machine learning (ML) algorithms to enhance rainfall prediction as a result of recent developments in ML approaches. In-depth analysis of the methodology, difficulties, and potential applications of machine learning in rainfall prediction is provided in this work.
A Healthcare System for Cardiac Disease Diagnosis Using Distributed Computing
Authors: Garg Navin
Published: June 2023

The sector of health care makes extensive use of cloud computing and wireless devices that are based on the internet of things.  These kinds of wireless and wearable sensors are being used to monitor patients who are at risk for developing chronic diseases. This not only shields patients from attacks that come out of the blue but also makes it easier for them to monitor their treatment regimen. However, the quantity of data acquired from numerous sensors is substantial, and if the data is kept in a centralised location, there is a possibility that the power supply will fail. As a result, in this paper, we suggest the creation of a technology called Smart Fog, which is capable of edge-fog computing and would be able to detect and diagnose heart patients at an early stage. It is anticipated that the overall efficacy of the system would improve as a result of the implementation of the suggested model, which is founded on the concepts of distributed computing and deep learning. With the application of the distributed computing approach, the risk associated with a single point of failure would be eliminated, and in addition, a less amount of data would be required to transfer the information between the cloud and the sensors.
Anomalous Behavior Detection in ATM using Artificial Intelligence
Authors: Jain Abhishek
Published: June 2023

This paper proposes a new supervised algorithm for detecting abnormal events in confined areas such as ATM rooms and server rooms. The objective of this work is to establish a robust technical foundation that supports a secure and convenient social infrastructure, with abnormal behavior detection using image processing being one of the key technologies. Abnormal behavior detection involves creating a model based on normal behavior data and identifying any behavior that deviates from this model as abnormal. However, collecting comprehensive abnormal behavior data in advance can be challenging. Therefore, the ability to detect abnormalities using a model built solely on normal behavior data is highly valuable for practical implementation.  This proposed work presents examples of abnormal behavior detection using image processing techniques applied to ATM surveillance videos. Additionally, typical examples of abnormal behavior detection through motion image processing are demonstrated. Furthermore, our approach enhances system security by verifying the identity of the cardholder during ATM transactions. The combination of image processing algorithms and supervised learning enables effective identification of abnormal events, contributing to a more secure and reliable social infrastructure.
PHYSICAL PROPERTIES OF GEOPOLYMERS MADE FROM MINERAL WASTE
Authors: Noviks Gotfrīds
Published: June 2023

Geopolymer is an alumino-silicon gel consisting of tetrahedral SiO 4 and AlO 4 sections, polycondensed in a spatial structure as a result of the reaction between aluminosilicates and an alkaline activator.The report is a part of the complex research plan for geopolymers, in which information is given about the experimental results in the preparation of geopolymers from natural and man-made mineral components characteristic of Latvia (clay, sand, wood ash, brick waste).The aim of the study was to find out the dependence of the geopolymer formation process on the composition of the reacting components at constant exposure factors. Sodium alkali  solution and sodium silicate was used in the experiments. The raw materials used are red and gray clay, sand, wood ash.The composition of the clay, ash and sand composition was changed with an interval of twenty percent. The obtained geopolymer samples were subjected to physical and technical tests. The compositions that are perspective in terms of properties in the studied modes of exposure have been determined.
OPPORTUNITIES AND CHALLENGES IN MODELING AN ENVIRONMENTAL MANAGEMENT SYSTEM
Authors: Chipriyanova Galina , Marinova Miglena
Published: June 2023

The business ecosystem provides full integration of economic and environmental objectives. Every company, including those from the Bulgarian mining industry, implements specific actions, mechanisms, innovations for environmental management. The aim of the present study is to analyse the relationship between the economic and non-economic priorities of enterprises of the mining industry, especially now in the context of solving the global problem of transformation towards sustainable development. The following research tasks have to be settled for reaching the above-mentioned goal: 1. to analyze the influence of modern technologies, the remote control of machines underground, including remote control and self-learning drones in underground mines on the optimization and improvement of work processes and the protection of a cleaner environment; 2. to focus on some relevant aspects of green transformation of the mining industry, incl. in the development of environmental, social and new management models as a factor for successful business; 3. to research the impact of the initiated cycle of interest rate tightening on the implementation of the planned activities for environmental management of the mining industry. In the course of the study shall be justified the thesis that the future of the mining industry in Bulgaria is digital, green and sustainable. The methodology of structured interview was used. The sample was formed by the method of random non-recurrent selection. For the purposes of the research, we have carried out analysis of the whole assessment of the favourable opportunities and potential risks, as well as the strengths and weaknesses of the new model for an environmental management system. The results of the research are expressed in establishing the trend for digitalization and innovation, tracking the importance of environmental management and protection.
FUZZY RELATIONS BASED INTELLIGENT INFORMATION RETRIEVAL FOR DIGITAL LIBRARY USERS
Authors: Rakhmatullaev Marat , Normatov Sherbek , Bekkamov Fayzi
Published: June 2023

It is known that today information and library systems are one of the main sources of information needs of the population and have many users. Information and library systems have a large amount of valuable information resources and information retrieval services have been established to allow users to find the necessary literature. We know that search engines take requests and return results they think are relevant. As a result, the user again faces the problem of finding what he needs among the many sources of information provided.Today, a number of information systems effectively use recommendation systems based on artificial intelligence to recommend objects. In information and library systems, high efficiency can be achieved by identifying the information needs of users and recommending relevant literature.To do this, it is necessary to determine the information needs of library users by analyzing information about their age, interests, level of knowledge in a particular area, previous requests, professions, etc. By introducing recommender systems into library information systems, it is possible to facilitate the work of librarians, increase speed and accuracy finding the necessary source of information, increase the efficiency of management and the level of satisfaction of the information needs of the population.The article proposes a fuzzy model for solving the problem of assessing the needs of users of information and library systems and recommending relevant literature to them.
PROPERTY INSURANCE DECISION-MAKING ON THE BASIS OF UTILITY FUNCTIONS
Authors: Uzhga-Rebrov Oleg , Kuleshova Galina
Published: June 2023

Property and other valuables insurance is widespread all over the world. An insurance company assumes the risk of damage or total destruction of the insured property. When this kind of damage or destruction is established, the company pays its client compensation (insurance premium) up to the amount specified in the insurance contract. For his part, the insured must pay a certain amount to the firm for the provision of insurance services. In any property insurance process, the question arises as to whether it is appropriate to insure the property for the price offered by the firm. The paper considers an approach to solving this problem based on expected utility theory.
ALGORITHM FOR OPTIMIZATION OF IDLE TOOL MOVES WHEN MILLING COMPLEX SURFACES ON A TRIAXIAL CNC MILLING MACHINE
Authors: Salapateva Silviya , Chetrokov Iliya , Stefanov Bano
Published: June 2023

The idle running times of the working units of a machine tool are the sum of the idle running times for the tool change and for changing the section uder treatment. The time, spent on idle running is the extra machining time. A large number of milling cutters are used for purely mechanical machining of details with complex surfaces and for a significant number of machined sections, where the complex surface is broken as a rule. This leads to an increase in the extra time for treatment. Reducing the auxiliary time in machining the parts will significantly increase the productivity of the actual milling process. When modeling the process of machining details with complex surfaces on triaxial milling machines, the optimization of the sequence of moves will allow to reduce the idle running time by up to 50% without causing deterioration in the quality of the surface layer.
INCREASING THE QUALITY OF FORMING OF SPINNING DETAILS OF ALUMINUM ALLOYS BY CONTROLLING THE RESIDUAL STRESSES IN THEIR SURFACE LAYER
Authors: Leonov Dimilyan , Lengerov Angel , Krumov Kalin , Metev Hristo
Published: June 2023

In the article are analyzed the effect of technological modes and processing parameters on the stress of spinning (cold flow turning) details of aluminum alloys. Аs the object of the study was used a detail of aluminum alloy AMg5, obtained after 3-stage spinning with intermediate heat treatments between the stages. As a control criterion was used non-destructive resistive electro contact method, based on the correlation between the integral electric and mechanical characteristics of metals and alloys – specific conductivity or electrical resistivity within the h-layer of the metal and the amount of deformation in the crystal lattice of the material due to the residual stresses.
WORKING REGIMES FOR FRICTION STIR PROCESSING OF ALUMINIUM ALLOY A6061
Authors: Kondoff Christo , Mikhov Rossen , Kirilov Leoneed , Zaekova Radostina , Tashev Plamen
Published: June 2023

Friction Stir Processing (FSP) is a method for solid-state processing, in which a rotating tool is moved onto the material surface to modify the microstructure and thus obtain improved properties of the material surface. We study the effects of FSP on aluminium alloy A6061-T651 using a tool made at the Institute of Metal Science, Equipment, and Technologies with Centre for Hydro- and Aerodynamics (IMSETCHA) of the Bulgarian Academy of Sciences. The tool has a threaded pin with three flutes and a concave shoulder. Optimal process parameters should always be chosen for the treatment of new materials and when a new instrument is used in order to achieve target properties of processed zone. The appropriate properties, like strength, hardness, corrosion resistance, etc. require process parameters that are correctly configured. The most influential parameters on friction stir processing are direction of rotation of the tool, rotation speed, and traverse speed of the processing. In this paper, we investigate the properties of the processed zone for a total of 16 regimes: 4 rotation speeds (900, 1100, 1300, 1500 rpm) and 4 traverse speeds (15, 30, 45, 60 mm/min) using counterclockwise rotation, comparing the results with a previous study using clockwise rotation. Metallographic inquiry, hardness and tribological tests are used to estimate the stirred zone quality.
COMPARATIVE ANALYSIS OF METHODS FOR MEASURING LASER POWER
Authors: Karadzhov Tsanko , Lazov Lyubomir
Published: June 2023

The application of lasers in many fields of technology and medicine is constantly increasing. This causes the development of new physical methods and principles for correct measurement of power, energy, and other parameters of laser sources. In most cases, the correct measurement of the laser power is important because the quality of the processes in which laser sources are used depends on it. In the paper, a comparative analysis of the existing methods for measuring the power and energy of laser radiation of diverse types of laser sources is made. This research aims to help users of laser equipment to choose the right measurement method depending on the laser source.
OPTICAL GEOMETRIC DESIGN OF SMALL MODULAR CYLINDRICAL GEARS WITH ASYMMETRIC PROFILE
Authors: Cvetanov Genadi , Karadzhov Tsanko
Published: June 2023

The article presents specific practical solutions for optimal geometric design of evolvental cylindrical gears with an asymmetric profile of cogs in the context of the basic principle of cog interlocking. In order to achieve unknown until now quality indicators, constructions with a minimum number of cogs and a maximum angle of interlocking are shown, which allow for the production of off-polar gears and significantly increase the gear ratio of the differential and planetary mechanisms. In the process of determining the geometrical parameters of the cogwheels of the gear, the “classical approach” is used by analogy with the parameters of the instrument, necessary for the production of the small-module cogwheels of the gear.
COMPARISON OF POTENTIAL ROAD ACCIDENT DETECTION ALGORITHMS FOR MODERN MACHINE VISION SYSTEM
Authors: Byzkrovnyi Oleksandr , Smelyakov Kyrylo , Chupryna Anastasiya , Savulioniene Loreta , Sakalys Paulius
Published: June 2023

Nowadays the robotics is relevant development industry. Robots are becoming more sophisticated, and this requires more sophisticated technologies. One of them is robot vision. This is needed for robots which communicate with the environment using vision instead of a batch of sensors. These data are utilized to analyze the situation at hand and develop a real-time action plan for the given scenario. This article explores the most suitable algorithm for detecting potential road accidents, specifically focusing on the scenario of turning left across one or more oncoming lanes. The selection of the optimal algorithm is based on a comparative analysis of evaluation and testing results, including metrics such as maximum frames per second for video processing during detection using robot’s hardware. The study categorises potential accidents into two classes: danger and not-danger. The Yolov7 and Detectron2 algorithms are compared, and the article aims to create simple models with the potential for future refinement. Also, this article provides conclusions and recommendations regarding the practical implementation of the proposed models and algorithm.
Artificial Intelligence and Human-Induced Seismicity: Initial Observations of ChatGPT
Authors: Wilson Miles P. , Foulger Gillian R. , Wilkinson Maxwell W. , Gluyas Jon G. , Mhana Najwa , Tezel Timur
Published: June 2023

Freely available artificial intelligence (AI) tools, such as the Chat Generative Pre-trained Transformer (ChatGPT), offer an alternative method to online search engines for scientific results and opinions to be automatically collated into concise summary prose. We applied this approach to human-induced seismicity by asking ChatGPT common, earthquake-related questions before asking questions about natural, induced, and debated earthquakes. ChatGPT provided rudimentary descriptive distinction between natural and induced seismicity, and for clear-cut cases of each type provided a response giving the scientific consensus. For debated cases, a natural origin was implied by responses focusing on fault rupture and tectonic setting. The inclusion of the word “induced” in the question phrasing led to discussion on possible induced origins, but not all response information was consistent with our knowledge of the scientific literature. ChatGPT did not provide an answer to a case more recent than its training data. For most questions, ChatGPT tended to include irrelevant information to increase response length. Online AI tools could become a mainstream technology, particularly for nonspecialists, to obtain concise summaries of published science. However, it is important to recognize the limitations of the current technologies, particularly sensitivity to question wording and inability to correctly reference scientific material, especially where a definitive answer does not yet exist to the question asked.
The triggering of aftershocks by the free oscillations of the earth
Authors: Kamal  , Mansinha L.
Published: June 2023

Analysis of the Loma Prieta aftershock sequence (mainshock: 18 October 1989) shows periodicities at the periods of two normal modes 0S2 and 0T2. About 10% of the small aftershocks in the fault zone are triggered by these two modes during the 6 days following the mainshock.
Low-velocity fault-zone guided waves: Numerical investigations of trapping efficiency
Authors: Li Yong-Gang , Vidale John E.
Published: June 2023

Recent observations have shown that shear waves trapped within low-velocity fault zones may be the most sensitive measure of fault-zone structure (Li et al., 1994a, 1994b). Finite-difference simulations demonstrate the effects of several types of complexity on observations of fault-zone trapped waves. Overlying sediments with a thickness more than one or two fault-zone widths and fault-zone step-overs more than one or two fault widths disrupt the wave guide. Fault kinks and changes in fault-zone width with depth leave readily observable trapped waves. We also demonstrate the effects of decreased trapped wave excitation with increasing hypocentral offset from the fault and the effects of varying the contrast between the velocity in the fault zone and surrounding hard rock. Careful field studies may provide dramatic improvements in our knowledge of fault-zone structure.
Source parameters of the damaging Cornwall-Massena earthquake of 1944 from regional waveforms
Authors: Bent Allison L.
Published: June 2023

The Cornwall-Massena earthquake (MW 5.8) of 5 September 1944 was one of the most damaging earthquakes in Canadian history. Its epicenter, near the Canada-United States border and the southern end of the Western Quebec seismic zone, lies within a heavily populated region, rendering this earthquake significant for regional seismic hazard analysis. The reappearance of a seismogram collection from the 1940s previously unavailable to (recent) researchers helps provide new insight into this earthquake. Waveforms recorded at regional distances indicate that this was a mid-crustal (20-km deep) oblique thrust event (strike 313°, dip 70°, rake 52°). Either nodal plane is a plausible fault plane in terms of the local and regional seismotectonics—one is more consistent with the seismicity pattern and the other with the mapped faults. The mechanism is similar to those determined for many smaller and more recent events in the Western Quebec seismic zone and is consistent with the regional stress field. The low value of a previously determined mb (4.6) relative to the moment magnitude is at least partially a result of the P-wave radiation pattern and the distribution of stations used to calculate mb. Previously calculated values for MS range from 5.1 to 5.6. While the larger number is more consistent with the MW determined in this study, the reason for the large variation in MS values has not yet been fully explained.
Deformation rates across the Placerita (NorthridgeMw= 6.7 aftershock zone) and Hopper Canyon segments of the western transverse ranges deformation belt
Authors: Huftile Gary J. , Yeats Robert S.
Published: June 2023

Aftershocks of the 1994 Northridge (Mw = 6.7) earthquake provide insights into the geometry of the seismic source faults in the San Fernando Valley and the east Ventura Basin and allow the calculation of deformation rates for the region. The Northridge thrust and Santa Susana faults dip in opposite directions, with the Northridge thrust entirely beneath the Santa Susana fault. These opposing reverse faults interact, resulting in a folded active Santa Susana fault and uplift in the footwall block of that reverse fault.

Two balanced cross sections suggest thick-skinned deformation of the western Transverse Ranges. The western section, across the Modelo lobe segment of the north-dipping San Cayetano fault and the easternmost surface trace of the south-dipping Oak Ridge fault, is west of any aftershocks of the Northridge earthquake and has been termed the Hopper Canyon segment of the deformation belt. Structural modeling predicts a dip of 46° S on the Oak Ridge fault at seismogenic depths. Horizontal shortening rates are calculated by adding the products of the dip-slip displacements and the cosines of the dips of both faults. The eastern cross section shows the Northridge mainshock, with a 45° south-dipping nodal plane at a depth of 18 km. Aftershocks reach a depth of 20 km. In a thin-skinned paradigm, a hinge should occur at the surface near the Santa Monica Mountains due to rocks moving from a decollement at the brittle-plastic transition and changing dip as they move up the ramp. No hinge of that magnitude occurs there. Calculation of horizontal short-ening rates across this part of the western Transverse Ranges must take into account the displacement on both the Northridge thrust (eastern extension of the Oak Ridge fault) and the Santa Susana fault (Placerita segment).

Horizontal shortening rates are 8.2 ± 2.4 mm/yr across the Modelo lobe segment of the San Cayetano fault and the Oak Ridge fault and 5.7 ± 2.5 mm/yr across the Northridge thrust and the Santa Susana fault. These rates are consistent with those based on tectonic geodesy using GPS. Dip-slip displacement rates on the faults are 1.7 mm/yr for the Northridge thrust since 2.3 Ma, 4.1 ± 0.4 mm/yr for the Oak Ridge fault since 500 ka, 5.9+3.9/−3.8 mm/yr for the Santa Susana fault since 600 to 2300 ka, and 7.4 ± 3.0 mm/yr for the Modelo lobe segment of the San Cayetano fault since 500 ka. This indicates that the slip rates on the north-dipping, the eastern San Cayetano, and the Santa Susana faults are comparable, but the slip rate on the south-dipping faults decreases eastward; the slip rate on the Oak Ridge fault in the Ventura basin is more than double that of the Northridge thrust.
Localized amplification of seismic waves and correlation with damage due to the Northridge earthquake: Evidence for focusing in Santa Monica
Authors: Gao S. , Liu H. , Davis P. M. , Knopoff L.
Published: June 2023

The analysis of seismograms from 32 aftershocks recorded by 98 seismic stations installed after the Northridge earthquake in the San Fernando Valley, the Santa Monica Mountains, and Santa Monica, California, indicates that the enhanced damage in Santa Monica is explained in the main by focusing due to a lens structure at a depth of several kilometers beneath the surface and having a finite lateral extent. The diagnosis was made from the observation of late-arriving S phases with large amplitudes, localized in the zones of large damage. The azimuths and angles of incidence of the seismic rays that give rise to the greatest focusing effects correspond to radiation that would have emerged from the lower part of the rupture surface of the mainshock. Thus the focusing and, hence, the large damage in Santa Monica were highly dependent on the location of the Northridge event, and an earthquake of similar size, located as little as one source dimension away, would not be likely to repeat this pattern. We show from coda wave analysis that the influence of surface geology as well as site effects on damage in Santa Monica is significantly smaller than are the focusing effects.
Qualitative Meta-analysis on Family Caregiving Experiences for Terminally Ill Cancer Patients in Korea
Authors:   Research Institute For Life And Culture Sogang University, Oh Eun Sun , Kim Hyoung Suk
Published: June 2023

In this study, a qualitative meta-analysis was conducted to comprehensively examine the experiences of family caregiving for terminally ill cancer patients in Korea. To this end, data were collected from papers published in Korea on the topic of family caregiving experiences for terminally ill cancer patients. A total of seven articles were selected according to selection and exclusion criteria and a qualitative meta-analysis was conducted. As a result, five themes in family caregiving were identified: (1) Difficulties in choosing and deciding, (2) coping with life-altering pain, (3) caregiving for the patient, (4) care received by the family caregiver, and (5) ambivalent change Based on the results of this study, the perspectives of nurses on the categories of “ Difficulties in choosing and deciding” and “coping with life-altering pain” were discussed as categories that require assistance for families experiencing difficulties.
Development of Web-based 2013 Curriculum Learning Set Compiler Apps for Teachers in Vocational High Schools
Authors: Setiani Asih , Patmanthara Syaad , Herwanto Heru Wahyu , Wu Kai-Lun
Published: June 2023

The curriculum is a set of plans and arrangements regarding the objectives, content and learning materials, and methods used as guidelines for the implementation of teaching and learning activities. Permendikbud 22/2016 stated that every teacher in the education unit was obliged to prepare a complete and systematic learning plan. So, every teacher was obliged to make a comprehensive and systematic learning plan, but what was currently being done to make it needed to be typed again or only copy-paste. Based on the research results on teachers at SMKN 1 Banyuwangi, the teachers wanted a dynamic application to facilitate teachers in preparing learning tools effectively and efficiently. Based on the problem, a solution was needed to assist teachers in compiling syllabus and lesson plans. This research and development aimed to design, develop, test the feasibility, and implement a website-based application for the learning set compiler to facilitate vocational school teachers. The research and development model used was the development model. It is consisted of: (1) Analysis, (2) Design, (3) Code (4) Test. This application also applied a text mining algorithm to analyze basic competencies with active verbs. Fifty teachers of SMKN 1 Banyuwangi conducted the feasibility test and implementation of this research and development. The validation tests that software experts have carried out obtained a percentage of 100 percent. Based on these data results, the application of the learning device compiler is declared to be very valid and can be tested. Tests by users, both functionality and usability of the application, resulted in a score of 99.83 percent and 91.11 percent, respectively. The results showed that the application of learning tools was considered good, so the Vocational High School teachers can use it to compile learning sets effectively and efficiently