bluuebunny/crossref_metadata_2025 huggingface dataset:
Parametric modeling of radio engineering devices at the stage of system design
Authors:   State University of Telecommunications, Zhukova О. R.
Published: September 2023

System design provides for solving the task of comparative analysis and choosing the best option for constructing a radio engineering device. Its main result should be a structural diagram of the product and an assessment of the effectiveness of its implementation. The number of possible structural options for their implementation is limited when designing radio engineering devices of a certain class, so the search for the best option is mainly determined by the costs of its implementation, provided that the requirements of the technical specifications are fully satisfied. The main way to reduce the costs of developing devices is to use high-availability modules as much as possible in the designed product, which means electronic modules that have passed certain stages of development or have at least working design documentation. Then, the task of system design is reduced to solving the task of covering the given structures of high-availability modules, and the efficiency of its solution depends to a large extent on the number of possible alternatives. The methodology of using parametric modeling to determine the best option of construction of a radio engineering device (system) is considered. It is proposed to use an information approach to assess the degree of coincidence of the parametric models of highavailability modules with the values of parameters specified in the technical specifications while maintaining a given level of reliability. The degree of coincidence is evaluated by three criteria: informativeness, adequacy, and accuracy. It is shown that the considered methodology makes it possible to solve the parametric synthesis task of the effective structure of a radio engineering device while maintaining its specified reliability. The resulting options are highly reliable because the cost estimation is performed by real developers. As information on the actual costs for possible modifications of high-availability modules is accumulated, the preliminary cost estimation procedure can be automated.
St. Cyprian of Moscow and the "Mitya's case"
Authors: Красноперов Д. В. иер.
Published: September 2023

В данной научной статье будет рассмотрено участие святителя Киприана в «деле Митяя». Рассматривается процесс борьбы за московский престол различных партий. Показывается, что святитель Киприан, который придёт к власти в конечном счёте, не позволит князю Дмитрию Донскому воплотить в реальность свой церковно-политический курс. Константинопольский Собор 1380 года утвердит Пимена митрополитом Киевским, а рукоположение свт. Киприана при жизни свт. Алексия Московского будет рассматриваться как неканонический акт. Так как осуждение свт. Киприана было осуществлено заочно, он оставался пребывать как действующий митрополит Литовский и Малоросский. После смерти свт. Киприана эти территории перейдут в юрисдикцию митр. Пимена.

In this scientific article, the participation of St. Cyprian in the "Mitya's case" will be considered. The process of the struggle for the Moscow throne of various parties is considered. It is shown that St. Cyprian, who will eventually come to power, will not allow Prince Dmitry Donskoy to make his church-political course a reality. The Council of Constantinople in 1380 will confirm Pimen as Metropolitan of Kiev, and the ordination of svt. Cyprian during the life of svt. Alexia of Moscow will be uncanonical. Since the condemnation of svt. Cyprian was executed in absentia, he remained as the acting Metropolitan of Lithuania and Little Russia. After the death of svt. Cyprian these territories will pass into the jurisdiction of the Mitr. Pimena
The Moral State of the Students of Theological Schools in the Beginning of the XX Century in the Diaries of Archbishop Nikon (Rozhdestvensky) Authors
Authors: Асеев Викторин иером.
Published: September 2023

В статье рассматриваются свидетельства дневниковых записей Преосвященного Никона (Рождественского) о нравственном состоянии учащихся в церковно-приходских школах, духовных семинариях и Академиях в начале XX века. Владыка был всерьез обеспокоен упадком веры и нравственности среди воспитанников духовных школ и будущих пастырей Церкви. Пророчески осознавая последствия такого религиозного охлаждения, архиепископ Никон не только критиковал образовательный процесс в Русской Церкви, но и направлял все свои усилия и способности к исправлению назревших проблем.

The article examines evidence from the diary entries of His Grace Nikon (Rozhdestvensky) about the moral state of students in parochial schools, theological seminaries and Academies at the beginning of the 20th century. Vladyka was seriously concerned about the decline in faith and morality among the students of theological schools and future pastors of the Church. Prophetically realizing the consequences of such religious cooling, Archbishop Nikon not only criticized the educational process in the Russian Church, but also directed all his efforts and abilities towards correcting urgent problems.
The Program of Deradicalization of Islamists “Operation Safe Corridor” in Nigeria: Evaluation by Contemporary African Scholars
Authors: Nefliasheva Naima A.
Published: September 2023

The problem of deradicalization programs for Islamists in Nigeria has taken an important place in the studies of the modern African scholars. The article is devoted to the study of the works of contemporary African authors related to the Operation Safe Corridor program. The authors of the works selected for analysis note that the state’s forceful responses and military operations should coexist with the concept and practices of “soft power”. Scholars argue that the Operation Safe Corridor program has structural flaws. These, according to the authors, include the predominant role of the military in program management; non-transparency of program management for society; amnesty for former terrorists without justice. One of the key problems of the program is the reintegration of the former fighters into local communities. The lack of mechanisms to ensure the involvement of public and religious community leaders in the development of a deradicalization program often undermines the goals of the program. The economic dimension of the program, according to scientists, is very important. There are risks for former terrorists returning to the terrorist group due to economic problems, poverty and unemployment.
Maternal Serum Zinc level in pregnant women with second trimester induced abortion with anencephalic fetus
Authors: Shalal .Maad M. , Al-Bassam Anwar N. , Alwan Buthaina A.
Published: September 2023

Background: Neural tube defects (NTD) are group of heterogeneous and complex congenital anomalies of the CNS. Commonly included in this group anencephaly, spina bifida andencephaloceles. Anencephaly is the most severe defect; it is always lethal and results in stillbirth or early neonatal demise, is characterized by absence of the brain and cranium above the base of the skull and orbitsObjective: The objective of this study is to assess the relationship between maternal serum zinc level and anencephaly occurrence in women with second -trimester induced abortion due to anencephalic fetus.Study design and setting: This study is a case- control study, carried out in Baghdad teaching hospital throughout the period between November 2008- November 2009.Patients and method: This study involves 33 pregnant women whose pregnancies were terminated for anencephaly in the second-trimester that was diagnosed by ultrasound the control group consisted of 66 matched to demographic and obstetrical characteristics and had normal ultrasonographic findings in second-trimester with documented normal fetal outcome. Zinc level determination was made using flame atomic absorption spectrophotometer (AAS).Results: Medication consumption during the first trimester of pregnancy has a significant relation with the occurrence of NTDs with a p – value = 0.027. Low serum Zinc level was found in 18 (54.5%) of the cases and 5 (7.6%) of the controls with p- value = 0.0001. There was a highly significant relationship between the presence of NTDs and low serumzinc level.Conclusions: In this study there was a significant association between NTDs and low serum zinc levels, adding to the evidence about the importance of nutritional and maternal health factors in the etiology of this disease.
A Transmission-Reflection Photoelastic Combined Technique for Internal Stress Analysis of Inorganic Flexible Electronic Bilayer Structures
Authors: He Quanyan , Du Yitao , Zhang Lanxin , Wang Miaojing , Wang Zong , He Saisai , Qiu Wei
Published: September 2023

In recent years, inorganic flexible electronics technology has been widely researched as a promising field that enables semiconductor devices to combine excellent electrical and flexible properties for various electronic applications. However, rigid semiconductor materials are susceptible to fracture during service, leading to functional failure. Therefore, mechanical reliability testing is essential for these devices. Digital photoelasticity is one of the techniques that can be used for stress analysis of semiconductor materials, which is a non-destructive, full-field, real-time experimental method based on photoelasticity. In this paper, a transmission-reflection photoelastic combined technique is proposed for internal stress analysis of inorganic flexible electronic bilayer structures. This technique can achieve non-contact, in-situ, parallel measurement of internal stress fields. A transmission-reflection photoelastic bidirectional combined experimental system is developed. A photoelastic parameter extraction technique for stress decoupling of bilayer structures is introduced. An experimental study on the quantitative characterization of the internal stress field of each layer is conducted for a typical class of inorganic flexible electronic bilayer structures.
Parameter Optimisation of Rolling Bearing Finite Element Simulation Model Based on Actual Vibration Response
Authors: Gong Xiaoyun , Feng Kunpeng , Li Bangshuai , Fei Heyong , Du Wenliao , Hao Mengxuan
Published: September 2023

In order to reduce the difference of the vibration response between the finite element simulation model and the actual physical model, the parameter modification method for the finite element simulation model of rolling bearings is proposed. Firstly, the finite element simulation models of normal bearings with different clearances are created, and their vibration responses are obtained. Secondly, a joint credibility analysis method based on kurtosis and margin factors is proposed, and the optimal bearing clearance is obtained. Finally, a bearing fault simulation model is established based on optimizing the bearing clearance. The results show that the matching degree between the simulated vibration response and the actual vibration response has been improved.
Air Dynamic Stability of Airfoils in Lift-Type Vertical Axis Wind Turbine by Measuring Turbulence
Authors: Qian Zhong , Li Jinyi , Xia Guanben , Xia Jianping , Kang Xuhong , Wang Jian , Zhang Wendong , Guo Tong , Yang Yanan , Wang Yujie , Cao Yang
Published: September 2023

Stability might be the other important target besides power efficiency. At this work, we focus on examining air dynamic stability of vertical axis wind turbine (VAWT). While our aim is on stability, we will consider it in instability aspect, specifically by measuring turbulence. The quantities are including turbulence kinetic energy, intensity, dissipation and production. Three representative airfoils have been selected, which are NACA0012, NACA23012 and NACA2412. The turbulence generated around these airfoils would be compared at different stages of running, at TSR of 0, 2, 5 and 7. Every position of the airfoil is taken into account, 360 degrees with interval of 5. Here we will apply static analysis instead of transient one because we attempt to eliminate some other effect of air flow in the meantime acquiring higher computation accuracy. At first, we would scrutinize some fundamental principles of turbulence theory. The theory is based on the structure of statistics. Unfolded, there is the kinetic energy equation that leads to the basic quantities mentioned above. Each quantity has certain meaning and role in turbulence. Then we will resent the computation method and results.
A Genetic Algorithm-Based Method for Smooth Modeling of Blade Surfaces
Authors: Zhao Xi
Published: September 2023

To further optimize the quality of the blade surface model, a fairing modeling method of blade surface based on a genetic algorithm is proposed. According to the NURBS curve and surface modeling principle, the fairing criterion of minimum strain energy and curvature change rate is established. Then the spline interpolation value points are optimized by the genetic algorithm and compared with the B-spline curve. The value points are modeled by NX. The blade surface is smooth, the curve curvature changes evenly, the strain energy is small, and there are no singular points and redundant inflection points.
Yaw Stability Control of High-Clearance Sprayer Driven by Hub Motor
Authors: Wang Weijun , Liu Zefeng , Zhang Zhanyu , Qiu Yuanyuan , Song Xiyan , Feng Jing’an , Wang Yuzhong , Liu Xiangdong
Published: September 2023

Based on the active torque distribution of hub motor, the stability of agricultural vehicles with high clearance spray can be controlled. The seven degree of freedom model of the chassis of the high clearance spray, the tire model and the simplified degree of freedom model of the spray are established. With two important indicators reflecting the stability of the high clearance spray as state variables, The yaw High clearance spray stability controller based on model prediction design control; Simulate and analyze using Matlab/Simulink under sinusoidal operating conditions of a stable speed of 20 km/h and steering wheel angle. Two important indicators reflecting the stability of the high clearance spray, namely yaw rate and sideslip angle of the center of mass, were controlled. The simulation results show that, compared with no control,the model predictive control reduced the absolute average error of the two important indicators reflecting the stability of the high clearance spray by 45% and 30%, respectively, and effectively improved the working stability of the spray.
Experimental Study on the Construction Site of the Subgrade of the Engineering Waste Soft Soil Solidified Material
Authors: Yuan Yunguang , Jiang Pan
Published: September 2023

In order to solve the problems of the shortage of waste slag resources, the difficulty of Engineering abandoned earthwork and the outward transportation of bored pile mud, and realize the resource utilization of Engineering abandoned earthwork and mud, five processes are used for field comparative tests, and the research on the replacement of traditional waste slag as subgrade filler by cushion cap excavation earthwork and bored pile mud solidified material is carried out. The results show that inorganic materials with a mix ratio of 3% cement + 1% mineral powder + 5% lime are selected as the main curing materials. Under the condition that the amount of solidified material remains unchanged, the water stability of solidified backfill subgrade is better than that of the one-time lime mixing method by using the secondary lime mixing and the sludge soil site solidification construction technology without strong mixing head. The application of this technology can effectively solve the problem of shortage of slag supply, reduce environmental pollution and save construction costs on the premise of ensuring the use function of the road.
Analysis of Surrounding Rock Disturbance in Shallow Buried Double-Side Biased Small Clear Distance Tunnel
Authors: Hu Yu , Wang Genzhong , Zhou Min , Hu Wangjin , Gao Wenxue
Published: September 2023

In order to explore the surrounding rock disturbance in the shallow buried double-sided biased small clear distance tunneling process, relying on a national highway project, the finite element Midas Gts Nx was used to conduct numerical simulation analysis of the tunnel construction process, in order to analyse the law of surrounding rock stress and strain in the shallow buried double-sided biased small clear distance tunneling process. The results show that the subsidence shape of surface slope develops from “V” shape to “W” shape, and the vertical horizontal displacement shape of septal rock changes from “V” shape to “W” shape. The surrounding rock produced a certain amount of uplift halfway up the mountain. When the rear tunnel is driven, the centre of gravity of the septum rocks migrates towards the rear tunnel side, which reduces the stress of the surrounding rock at the front tunnel and is conducive to the stability of the front tunnel structure. The stress increase of the middle barrier rock at the arch foot is obvious and it has the characteristic of through-through. The stress of the structure at the tunnel wall foot should be monitored emphatically during construction. When the rear tunnel is driven, the plastic zone of surrounding rock appears on the diagonal of the septum rock, and the safety factor of surrounding rock is increased and the speed is reduced. Numerical simulation can provide theoretical guidance for field monitoring and measurement.
Finite Element Analysis of Negative Skin Friction of Collapsible Loess Foundation Group Piles
Authors: Tian Wang , Zhang Yanjie
Published: September 2023

Based on the parameter changes of strong collapsible loess in Xi’an before and after humidification, a finite element model of pile group was established, and the pile group effect and negative skin friction characteristics of pile foundation after loess collapse caused by the rise of groundwater table were analyzed. The results show that the effect of pile diameter change on negative skin friction is not obvious, and with the increase of pile diameter, negative skin friction has a weak tendency to decrease. The pile group effection has a significant weakening effect on the negative skin friction, and the pile group effect weakens as the pile spacing increases, and when the pile spacing exceeds six times the pile diameter, this effect is minimal. When the pile spacing is six times the diameter, the total negative skin friction of the edge pile in the group pile is very close to that of the single pile. The axial force have a strong correlation with the friction resistance of the pile side, from the top of the pile downward, the friction resistance changes from negative to positive at the neutral point, while the axial force of the pile body has a vertex at the neutral point. In addition, due to the weight of the cushion cap, not only the neutral surface depth ratio is reduced, but also the axial force of the pile group increases.
Research on Formation Reinforcement Materials and Its Application During Shield Chamber Opening
Authors: Sun Shicheng
Published: September 2023

A grouting material composed of water glass and phosphoric acid was proposed aimed to the formation reinforcement problem during shield chamber opening. Then the gelation time of the material and the interfacial shear strength between the solidified grouting material and metal was analyzed. Finally the grouting material was applied in practical engineering. The test results show that when the pH value of phosphoric acid is constant, the gelation time of the mixture of phosphoric acid and water glass gradually decreases as the Baume degree of water glass increases. When the Baume degree of water glass is the same, as the pH value of phosphoric acid decreases, the gelation time of the mixture of phosphoric acid and water glass gradually increases. As the Baume degree of water glass increases, the interfacial shear strength between the solidified grouting material and metal gradually increases. Under the same concentration of water glass, the lower the pH value of phosphoric acid, the smaller interfacial shear strength between the solidified grouting material and metal.
Performances of a Top-Down Deep Excavation and Its Surroundings in Shanghai Soft Clay
Authors: Huang Kaiyong , Wei Xiang , Liang Zhirong
Published: September 2023

The project of Emergency Treatment Complex Building in Shanghai Tenth People’s Hospital is presented in this paper to illustrate the behaviors of the two-floor top-down excavation and its complicated surroundings in Shanghai soft clay. In order to restrict excavation deformations and expand construction site, the two layers of permanent floor slabs were adopted as horizontal supporting systems and the B0 slab was meanwhile exploited as working place and traffic passageway. Before construction, numerical simulations were conducted to predict the responses of the pile walls and the structure slabs. Based on the calculation results and monitoring data, it can be concluded that buildings without piles have significant impacts on the wall deflections while those with piles hardly influence the ground movements during excavation. Furthermore, the magnitude of displacements is related to the length of side and the construction loads around excavation. Buildings subside larger as their distances to excavation get closer. Settlements of buildings without piles are much more remarkable than those with piles.
Three-Dimensional Numerical Analysis of Basal Heave Stability and Influencing Factors of Circular Foundation Pit Supported by Diaphragm Wall
Authors: Zhang Jun , Zhou Rui , Liu Yinqi
Published: September 2023

Circular underground continuous walls are widely used in deep and large excavation projects. The tensile stability is the main reason for the loss of strength and failure of continuous underground walls. A three-dimensional numerical analysis is conducted on the stability of a continuous wall bottom tube supporting a circular base hole using the strength attenuation method. Firstly, based on the foundation pit anchored by the Wuhan Yanglao Bridge as the engineering background, a finite element symmetrical axis was formed, which was created on the basis of the software PLAXIS. By reducing the shear force of the soil at the bottom of the hole, the shape of the sliding surface and the safety factor of the foundation were discussed, and stability failed. Then use FLAC 3D software to create a three-dimensional digital model. The following conclusion is drawn by changing the inner diameter of the foundation pit, the depth, thickness, and stiffness buried in the continuous underground wall. The thickness and stiffness of the lining, as well as the internal friction angle and soil adhesion. The tensile durability of circular continuous wall base holes is affected by the omnidirectional impact—safety factor obtained by the element method. The symmetry limit of the axis is higher than the safety factor given by two-dimensional plane analysis. As the inner diameter of the hole increases and the embedding depth, pad stiffness, internal friction, and adhesive force increase. Low sensitivity to changes in lining thickness and wall thickness. When using the strength attenuation method for finite element analysis Axisymmetric continuous wall base hole, circular guide, loss stability mainly due to the infiltration of plastic area, and soil at the bottom of the turn hole. The displacement of various feature points can serve as auxiliary guidelines.
Research on Static and Dynamic Model Updating Method Based on Field Test Data
Authors: Yu Ganglong , Li Songhui , Wang Xianzuo , Wu Shuang
Published: September 2023

In order to make the bridge finite element model more accurately and effectively reflect the state of the real bridge, this paper uses the dynamic response of the on-site structural vibration frequency and static load and strain, and proposes a method of combining static and dynamic forces to construct the objective function for optimal analysis. The finite element model of the approach structure of the Yihe Super Bridge has been corrected. By using the “ANOVA” method to find out the significant parameters, and then according to the actual situation of the project, the elastic modulus of concrete, the thickness of the bridge deck pavement, the concrete bulk density and the moment of inertia of the beam section are selected as the parameters to be corrected for the structure.
Seismic Analysis of Low-Rise Structures with Friction Dampers
Authors: Wu Xiangxiang , Li Yang , Zhou Dawei
Published: September 2023

With the issuance of Shanghai Technical Standard for Energy dissipation, Vibration reduction and Isolation of Buildings (DG/TJ08-2326) in 2020, the requirements on structural seismic performance are stricter for eight-categorized important buildings. One category of building is low-rise kindergarten buildings. To illustrate the function of friction damper in low-rise building, 18 friction dampers are applied in a 4-story kindergarten building and nonlinear seismic analysis is performed. The analysis is done with seismic input of small, moderate and large seismic input. The analysis results show that the friction dampers can dissipate significant energy in moderate and large seismic input. With the contribution of friction dampers, the structural response can meet the requirements in Shanghai technical standard.
Distributed Optical Fiber Intelligent Technology Risk Prediction Technology for Dam Structure Cracking
Authors: Zhang Qing , Liu Hua , Zhao Qiangzheng , Wang Junyong
Published: September 2023

As an important facility for the safe operation of the reservoir, the dam is the key structure to ensure the normal operation of the reservoir. However, due to the influence of construction and environment, the dam is easy to appear hot and cold deformation, resulting in the cracking of the dam structure and other problems. Therefore, how to adopt effective methods to effectively monitor the dam structure deformation risk has become the main way to identify the dam structure safety. Optical fiber intelligent technology is an effective way to monitor the deformation of dam structure. The intelligent learning and fitting prediction of dam structure deformation and displacement can realize the risk prediction of dam structure deformation and cracking through intelligent methods. At the same time, combined with the conclusion of risk prediction, corresponding measures are formulated to ensure the safe operation of the dam. The results show that the distributed optical fiber technology can effectively obtain the deformation and displacement of the dam structure, and can be timely fed back to the monitoring and control center in real time. Meanwhile, artificial intelligence method (Gaussian process regression analysis) can be used to fit the deformation and displacement data collected. This method can effectively predict the structural deformation of levees and has strong feasibility.
Preparation and Performance of Mineral Admixture Concrete with Nano-Modified Fly Ash
Authors: Sun Yihan , Zheng Longqing , Chen Longjie , Chi Fengxia , Hu Zhi
Published: September 2023

Based on the brief analysis and summary of previous research achievements, this paper put forward a method to improve the durability of medium-low-strength concrete (such as concrete used for bridge substructures). The performance including strength, chloride ion penetration resistance, sulfate corrosion resistance, anti-permeability, and frost resistance grade of such concrete with nano-modified fly ash was investigated. The results showed that when the dosing of modified fly ash was 6%, the compressive strength of 28 days was increased by 19.0% and the permeability coefficient of chloride ion was decreased by 79.9%, and the impermeability grade reached P10. With the increase of a single amount of nano-modified fly ash, the improvement of cement concrete performance is more obvious.
Study on the Performance of Nanoparticle Synergistic Stabilization of Anti-Icing Emulsified Asphalt
Authors: Zhu Jie , Huang Jiacong , Li Meixuan , Yin Yanqiong , Lai Yuepiao , Wei Xuzhou , Huang Xiaojun
Published: September 2023

To develop the potential of solid particles to maintain the storage stability of salt- and ice-resistant emulsified asphalt, nano-SiO2 and nano-CaCO3 without surface modification are mixed with emulsified asphalt with different antifreeze content. Through 10d delamination rate and 5d storage stability test, we studied the influence of two materials on the stability of salt-storage emulsified asphalt. The results show that the delamination settlement rate of salt-storage emulsified asphalt slows down with the increase of nano-CaCO3 content, and first slows down and then accelerates with the increase of nano-SiO2 content. The ability of nano-CaCO3 to reduce the delamination sedimentation rate is higher than that of nano-SiO2 at the same dosage. With the increase of nano CaCO3 content, the 5d storage stability of lotion increases. Within 0.4% content, the storage stability of lotion increases greatly, and then the increase gradually decreases. Nano-CaCO3 is more suitable as an additive stabilizer.
Finite Element Analysis of Axial Pressure of Rectangular Steel Pipe Coal Gangue Concrete Medium Length Column
Authors: Zhang Yuzhuo , Huang Yimeng , Wang Huju
Published: September 2023

In order to study the axial compression performance of rectangular steel pipe coal gangue concrete medium-length columns. ABAQUS was used to establish the finite element model to investigate the influence law of different parameter changes on the axial load bearing capacity of the specimen. It is found that the yield strength of steel and compressive strength of concrete are the key influencing factors of axial load bearing capacity, and the results show that the members mixed with coarse aggregates of coal gangue or after upgrading the slenderness ratio still have high load bearing capacity and can meet the project use conditions.
Study on Mechanical Properties of 6063 Aluminum Alloy Tube with Defects Under Impact Load
Authors: Jiang Yantao , Li Shiqi , Lai Yongcheng , Wang Peiding
Published: September 2023

When aluminum alloy tube have defects, they may be damaged by lateral impact in practical applications. Based on the general finite element analysis software, the dynamic analysis and performance research on lateral impact of aluminum alloy tube with and without defects with different diameter to thickness ratios and impact velocities were conducted in this paper. The results show that aluminum alloy tube with defects have weak impact resistance and are prone to local damage. Reducing the diameter to thickness ratio of aluminum alloy tube can improve the impact resistance of the structure; when the impact speed is the same, due to large tensile deformation at the midspan defect, energy is locally absorbed by the defect, and the maximum midspan displacement of the tube with defects is smaller than that of the tube without defects; The larger the impact velocity is, the tube with and without defect reaches the mid-span displacement peak at the same time, but the displacement of the tube with defect enters the stable stage faster.
Experimental Study on Mechanical Properties of Polyvinyl Alcohol Fiber Barite Concrete After High Temperature
Authors: Liu Caishan , Chen Zhenfu , Wu Dan , Tao Qiuwang , Xie Liping
Published: September 2023

In order to study the mechanical properties of barite concrete (BC) after high temperature, this experiment tested and analyzed the mass loss, compressive strength and splitting tensile strength of barite concrete at different polyvinyl alcohol fiber volume admixture (0, 0.1%, 0.2% and 0.3%) and different temperatures (25, 105, 200, 300 and 400 °C). The results indicated that the mass loss of barite concrete specimens increased with the increase of temperature. Its compressive strength and splitting tensile strength both gradually decreased. The admixture of polyvinyl alcohol fiber could improve the compressive strength and splitting tensile strength of barite concrete, among which the effect on the splitting tensile strength of specimens was greater. Among them, when the volume content of polyvinyl alcohol fiber is 0.2%, the improvement effect of barite concrete at high temperature is the best.
Prediction and Analysis of Advance Rate Based on an Improved Deep Learning Method
Authors: Li Xiangyang , Zhang Ye
Published: September 2023

The advance rate is the key parameter of shield machine tunneling. The prediction of the advance rate plays an important role in improving the efficiency of shield machine tunneling. In this paper, three deep learning models based on RNN, LSTM and GRU are proposed to predict the advance rate of shield machine tunneling, and a bidirectional deep network is designed to construct sequence timing features. At the same time, the CNN model is used to extract sequence information of monitoring data, and the Attention mechanism is coupled to realize the weighted calculation of important information of data sequence. Finally, a shield machine advance rate prediction method based on improved deep learning model is established. The research results show that the improved model can achieve a better prediction effect. The research result can provide support for EPB construction.
The “Africa Rising”: An Empirical Analysis of the Determinants of Per-Capita Growth
Authors: Scalamonti Francesco
Published: September 2023

In developing economies, the race toward inclusive development has prompted researchers to reconsider the drivers of growth in view of achieving the Sustainable Development Goals (SDGs). This study aims to explore the determinants of African growth after analysing reference literature to select the explanatory variables.

The paper aims to identify the robust drivers of growth of 54 African countries over the period 2010-2019, where the data source is more complete. As a data source, the main international organisations (UN, WB, IMF) have been considered.

We employ a system dynamic panel estimator (GMM-sys) without and with added exogenous regressors for the robustness check. As far as we know, we have not found any studies analysing the determinants of growth in a panel of 54 African countries and/or using GMM estimators with data referring to the last decade. We have used the real per-capita GDP as a dependent variable.

Our findings indicate that in addition to the initial conditions of the per-capita GDP, the natural resource rent with one order of lags has emerged as significant and with a negative sign, crowding out the per-capita GDP. On the other hand, the government expenditure with one order of lags is also confirmed as significant with a positive sign, while the terms-of-trade has emerged as not significant, after the robustness check with the instrumental variables. We conclude that institutional and business environments are particularly important in explaining African growth.
Why Existence? The Question is the Answer
Authors: Drob Sanford
Published: September 2023

The riddle of existence is approached through an analysis of the meaning and existential significance of the question, “Why is there something rather than nothing?” It is argued that this question asks for both a _reason_ and a _cause_ for existence and must (as Plato suggested) involve an appeal to something “beyond existence.” It is further argued that values are objective and (like logic and mathematics) pre-exist the cosmos. It is then demonstrated that values are the only “beyond-existent” that can provide _both a reason and cause for existence_. The author thus suggests that a “quest” for value gives rise to all existence, and that this quest is both linguistically and existentially expressed in the question “Why is there something rather than nothing?” As such, this question, as per the dictum of the 16th century Kabbalist Shimon Labis, is its own answer, answering itself without leaving anything to be explained.
The edge rings of compact graphs
Authors: Wang Zexin , Lu Dancheng
Published: September 2023

We define a simple graph as compact if it lacks even cycles and satisfies the odd-cycle condition. Our focus is on classifying all compact graphs and examining the characteristics of their edge rings. Let \(G\) be a compact graph and \(\mathbb{K}[G]\) be its edge ring. Specifically, we demonstrate that the Cohen-Macaulay type and the projective dimension of \(\mathbb{K}[G]\) are both equal to the number of induced cycles of \(G\) minus one and that the regularity of \(\mathbb{K}[G]\) is equal to the matching number of \(G_{0}\). Here, \(G_{0}\) is obtained from \(G\) by removing the vertices of degree one successively, resulting in a graph where every vertex has a degree greater than \(1\).
Методичні підходи, реалізовані у підручнику з математики для учнів 6 класів (за підручником «Математика. 6 клас» Світлани Скворцової та Катерини Нєдялкової)
Authors: Скворцова Світлана , Нєдялкова Катерина
Published: September 2023

У статті презентовано методичні підходи, реалізовані у підручнику з математики Світлани Скворцової та Катерини Нєдялкової для учнів 6 класів закладів загальної середньої освіти. Підручник у двох частинах структуровано за розділами; зміст розділів розгортається через систему уроків, кожен із яких розкриває певну тему. У такий спосіб реалізовано авторську динаміку подання змісту через нарощування рівня складності, тобто відтворюється рух по спіралі. Розділи завершуються рубриками «Перевіряємо свої досягнення» – аналогом діагностичної роботи, і «Навчальний проєкт», на який відведено окремий урок. Автори розгортають зміст матеріалу з урахуванням психолого-педагогічних засад навчання математики, зважаючи на особливості дітей цифрового покоління, зокрема на кліповість їхнього мислення. Навчальний матеріал подається невеличкими порціями, нові змістові одиниці «вплетені» у зміст дослідницьких завдань, що забезпечує навчання через дослідження за відсутності теоретичних параграфів. Натомість теоретична інформація узагальнена та структурована у вигляді таблиць, пам’яток, блок-схем. Тренувальні завдання диференційовано за трьома рівнями складності. Задачний матеріал, у поєднанні з теоретичним підґрунтям, забезпечують формування предметної математичної і ключових компетентностей, що своєю чергою реалізує інтегрований підхід. Проєктне навчання втілюється через виконання школярами проєктів різної тематики: «Поглиначи часу», «Волонтерська діяльність», «Подорож річками України», «Український борщ», «Золотий перетин», «Подорож повітряним океаном», «Зелений одяг планети», «Світ професій і математика». Інновацією підручника є оновлені сюжети задач, у яких ураховано досягнення науки й техніки – сонячна та вітряна генерація електрики, електричні таксі, дрони, швидкісні потяги тощо. Також за рахунок сюжетів задач активно формується екологічна та культурна компетентність, підприємливість та фінансова грамотність. Отже, підручник створено на засадах Концепції Нової української школи.
Застосування ментальних карт як засобу візуалізації та категоризації понять на заняттях медичної біології
Authors: Гавриленко Ксенія , Приходько Олександр , Шеметенко Олександра
Published: September 2023

У статті описано особливості використання ментальних карт як засобу візуалізації та категоризації інформації у закладі вищої медичної освіти на заняттях медичної біології. Наведено аналіз останніх досліджень та публікацій щодо застосування ментальних карт у закладах освіти на різних рівнях, включаючи дошкільну, початкову, середню та вищу освіту. Авторами обґрунтовано основні переваги застосування ментальних карт на заняттях з природничих дисциплін, зокрема, медичної біології та запропоновано варіанти застосування ментальних карт у професійній діяльності викладача. Наведені деякі платформи та сервіси, які використовуються для створення інтелектуальних карт онлайн. На прикладі конкретних тем показаний алгоритм розробки ментальних карт та особливості їх використання на практичних та лекційних заняттях і при підготовці студентів до інтегрованого тестового іспиту КРОК, а також обґрунтовано доцільність використання інтерактивної дошки Miro для проведення занять. Встановлено, що застосування ментальних карт на заняттях медичної біології є сьогодні актуальним, оскільки цей метод дає можливість візуалізувати та систематизувати складну інформацію про біологічні процеси і встановити зв’язки між попередніми та майбутніми темами, що дозволяє студентам засвоїти великі об’єми інформацію та засвоїти її цілком, а не фрагментарно.
Проблема управління шкільною освітою у науковому полі Норвегії
Authors: Максименко Оксана
Published: September 2023

Стаття присвячена висвітленню питання управління шкільною освітою у науковому полі Норвегії, засновуючись на прикладі досвіду наукової роботи Університету Осло. Визначаючись провідною рушійною силою змін функціонування освіти загалом та її шкільної ланки зокрема, управління покликано реалізовуватися у державі у межах шкільних спільнот задля виконання своєї суспільної, освітньої, реформативної та трансформаційної місій, вибудовуючись з урахуванням особливих реалій країни Норвегії.Встановлено, що наукове поле дослідження проблеми управління шкільною освітою сформоване у вимір, який поєднав площини наукового простору країни, європейського та глобалізованого наукового досвіду. Практично така схема наукового пошуку працює, базуючись на поєднанні досліджень засобами різноманітних проєктів, поєднуюючи проєкти на здобуття ступеня, та міжнародних мереж, у межах яких відбувається робота щодо напрямів вивчення та розробки проблем управління шкільною освітою.З’ясовано, що для цілісного вивчення питання управління шкільною освітою та за багатовимірності досліджуваних контекстів використовується перелік інструментів, а саме: теоретико-методологічні підходи (історичний, соціокультурний, прогнозування, моделювання, міждисциплінарний, багаторівневий, крос-контекстний аналіз тощо) та методи (порівняльного аналізу, кейсів, аналізу інформаційних джерел та контекстів, екстраполяції тощо), що дозволяє виявити особливості досліджуваного феномену у Норвегії та зарубіжжі.Проведений аналіз проблематики досліджень управління шкільною освітою Норвегії дозволив виявити основні напрями, які тісно взаємопов’язані та взаємовпливові: реформування шкільної освіти у напрямку демократичних змін включно, освітнє управління (підпорядкування та співробітництво), вдосконалення навчальних планів, підзвітність, лідерство.Зроблено висновок, що управління шкільною освітою позиціонується у країні, як і у Європі, як нове державне управління через реформування та модернізацію з обов’язковою вихідною позицією – урахуванням існуючих відмінностей у національних контекстах для подальших успішних трансформацій. Враховуючи особливості внутрішніх потреб, основними напрямами нового державного управління означені: навчальні плани та освітні реформи, управління та підзвітність, лідерство та просування знань, що розробляється у тематиці дослідницької діяльності у наковому полі країни.
Testing Environmental Kuznets Curve Hypothesis in Somalia: Empirical Evidence from ARDL Technique
Authors: Hussein Hassan Abdikadir , Warsame Abdimalik Ali
Published: September 2023

Economic growth is typically attributed as the fundamental cause of environmental problems due to higher production which generates more pollution. The EKC hypothesis is used to test the link between economic growth and environmental pollution. In this regard, this study aims to ascertain the validity of the EKC hypothesis in Somalia using time series data spanning between 1989 to 2020. The autoregressive distributed lag (ARDL) technique is applied to verify the presence of EKC and integrations between the sampled variables. According to the empirical result, it was revealed that all the regressors are statistically significant except trade openness. Agriculture production and squared economic growth are negatively related to environmental pollution whereas economic growth significantly impedes environmental quality in Somalia. Hence, an inverted U-shaped relation between growth and pollution has been found confirming the EKC hypothesis. In contrast, both economic growth and squared growth Granger cause environmental pollution but not vice versa. Policymakers should develop environmental policies to help reduce pollution emissions in order to achieve economic sustainability in the country by promoting and investing in cleaner energy resources to improve Somalia’s economy's overall energy efficiency.
Predictors of Statistics Anxiety Among Graduate Students in Saudi Arabia
Authors:   ,   Andrews University, Abdulghani Rabab
Published: September 2023

Problem The problem addressed in this study is the anxiety experienced by graduate students toward statistics courses, which often causes students to delay taking statistics courses until the end of their program. Students believe that statistics courses are not essential and are the greatest obstacles to obtaining their degree. Previous theoretical models have focused on predicting student performance in statistics. However, this study aims to identify specific factors that could decrease student statistics anxiety and enhance positive attitudes and self-efficacy toward statistics. The study developed a conceptual model to predict statistics anxiety among graduate students in educational and social science majors in Saudi Arabia, which should improve the quality of statistics education in higher education. Method A cross-sectional non-experimental survey design was employed to collect data during the Spring of 2022 from 356 graduate students in Saudi Arabia. Participants completed a self-report survey measuring their (a) demographic information, (b) statistics anxiety (SAS), (c) attitudes toward statistics (SATS), and (d) current statistics selfefficacy (CSSE). The dependent variable was statistics anxiety, while the independent variables were previous statistics experience, attitudes toward statistics, and statistics self-efficacy. Data analyses included descriptive statistics and structural equation modeling (SEM) to evaluate the relationship among the study variables, while a multigroup analysis was used to examine gender differences in the study model. Results The study indicated that the participants reported a moderate level of statistics anxiety and positive attitudes toward statistics, and a low to moderate level of statistics self-efficacy. Results also found that attitudes toward statistics were negatively associated with statistics anxiety, but previous statistics experience positively predicted attitudes toward statistics and current statistics self-efficacy. Mediation analysis revealed that attitudes toward statistics significantly mediated the relationship between previous statistics experience and statistics anxiety. A multi-group analysis showed that the research model was equally applicable to males and females and no significant gender differences were observed at the individual path level. Conclusions The present study investigated the relationship among previous statistics experience, attitudes toward statistics, statistics self-efficacy, and statistics anxiety among graduate students in Saudi Arabia. The findings suggest that positive previous statistics experience and attitudes toward statistics can account for reducing students’ statistics anxiety. Results have important implications for educators and counselors who work with students experiencing statistics anxiety, such as promising positive attitudes toward statistics and enhancing students’ experience with mathematics and statistics.