Oumaima Mikram, Abdelmajid Abouloifa, Ibtissam Lachkar
et al.
The widespread adoption of nonlinear loads in industry has introduced significant power quality issues in electric power distribution grids. The integration of these nonlinear loads has led to the proliferation of serious power quality problems such as the generation of harmonics and reactive power that negatively impact the quality and stability of the electrical grid. In addition to eliminating current harmonics, a shunt active power filter (APF) can also provide reactive power compensation. By dynamically adjusting the reactive power injection, these APFs can improve the power factor of the system and maintain the desired voltage regulation. The proposed control leverages the differential flatness property of the SAPF system, allowing for exact linearization and simplified tracking control without requiring complex modulation techniques. In this paper, a flatness-based control scheme is proposed for a three-phase three-level Neutral Point Clamped (NPC) APF. The main objectives of this work are twofold. The first objective is to mitigate current harmonics and compensate the reactive power drawn by nonlinear loads. The second objective focuses on maintaining a stable DC-link capacitor voltage of the active power filter (APF). To meet these requirements, a cascaded control structure is used, where the external loop regulates the DC-link voltage, while the inner loop is responsible for harmonic current compensation. The effectiveness of the proposed control strategy is validated through simulation results obtained using the MATLAB/Simulink R2024a environment.
Based on the innovative mode driven by “data + artificial intelligence”, in this study, three methods, namely Gaussian noise (GAUSS Noise), the Generative Adversarial Network (GAN), and the optimized Generative Adversarial Network (GANPro), are adopted to expand and enhance the collected dataset of element contents and the hardness of the AlCoCrCuFeNi high-entropy alloy. Bayesian optimization with grid search is used to determine the optimal combination of hyperparameters, and two interpretability methods, SHAP and permutation importance, are employed to further explore the relationship between the element features of high-entropy alloys and hardness. The results show that the optimal data augmentation method is Gaussian noise enhancement; its accuracy reaches 97.4% under the addition of medium noise (σ = 0.003), and an optimal performance prediction model based on the existing dataset is finally constructed. Through the interpretability method, it is found that the contributions of Al and Ni are the most prominent. When the Al content exceeds 0.18 mol, it has a positive promoting effect on hardness, while Ni and Cu exhibit a critical effect of promotion–inhibition near 0.175 mol and 0.14 mol, respectively, revealing the nonlinear regulation law of element contents. This study solves the problem of revealing the mutual relationship between the element contents and hardness of high-entropy alloys in the case of a lack of alloy data and provides theoretical guidance for further improving the performance of high-entropy alloys.
B4C/TC4 titanium matrix composites are fabricated by laser-directed energy deposition（L-DED） to investigate the effect of B4C content on the microstructure and mechanical properties of the deposited layers. The results indicate that during the deposited process，B4C reacts in-situ with the TC4 matrix，generating TiC and TiB reinforcement phases. With the addition of B4C content，the hardness of the composites increases significantly，while the plasticity decreases accordingly. When the mass fraction of B4C is 0.2%，the precipitated phases of TiC and TiB exhibit the most uniform distribution. At this point，the composite achieves the highest strength while still maintaining good plasticity，demonstrating the optimal comprehensive mechanical properties. This performance optimization is mainly attributed to the synergistic effect of multiple strengthening mechanisms，including the load transfer effect of TiB phases with a high aspect ratio，the pinning effect of precipitated phases on grain boundaries and the resulting grain refinement.
Disasters that occur in Indonesia lead to financial loss. One approach to mitigating the financial impact is through the utilization of natural disaster insurance. Although natural disasters occur with a relatively small frequency, the associated losses are substantial. Insurance companies need to carefully consider the characteristics of natural disaster data, as these events can lead to significant claims and potentially result in the bankruptcy of insurance companies. Insurance companies can reduce the risk of bankruptcy by transferring some risk to reinsurance companies. In this paper, the disaster reinsurance premium is determined by considering both the mortality and economic risks using the peaks over threshold (POT) model under the standard deviation principle. The Poisson, generalized Pareto, and lognormal distributions are used to determine the premium, with parameters estimated using the maximum likelihood method. A simulation analysis is conducted using synthetic data generated with RStudio software, which includes the frequency of floods per year over 20 years, as well as the number of deaths and the number of houses damaged in each flood event. The threshold is determined using the percentage method, where 10% of the data is considered extreme values. The POT model is applied to various retention cases. The simulation results show that the risk of the number of damaged houses has a greater impact on the premium amount that the insurance company must pay to the reinsurance company than the risk of the number of deaths. Additionally, cases with retention values below the threshold result in the highest reinsurance premiums, while cases with retention values above the threshold result in the lowest reinsurance premiums. This paper also shows that the reinsurance premium changes almost linearly with the increase in the extreme value percentage. This study is among the first to apply the peaks over threshold model in combination with multiple distributions for reinsurance premium estimation in the Indonesian context. The findings provide new insights into the sensitivity of reinsurance premiums to damage thresholds and retention levels, offering a practical tool for insurers in disaster-prone regions.
Abstract To leverage advancements in machine learning for metallic materials design and property prediction, it is crucial to develop a data-reduced representation of metal microstructures that surpasses the limitations of current physics-based discrete microstructure descriptors. This need is particularly relevant for metallic materials processed through additive manufacturing, which exhibit complex hierarchical microstructures that cannot be adequately described using the conventional metrics typically applied to wrought materials. Furthermore, capturing the spatial heterogeneity of microstructures at the different scales is necessary within such framework to accurately predict their properties. To address these challenges, we propose the physical spatial mapping of metal diffraction latent space features. This approach integrates (i) point diffraction data encoding via variational autoencoders or contrastive learning and (ii) the physical mapping of the encoded values. Together, these steps offer a method to comprehensively describe metal microstructures. We demonstrate this approach on a wrought and additively manufactured alloy, showing that it effectively encodes microstructural information and enables direct identification of microstructural heterogeneity not directly possible by physics-based models. This data-reduced microstructure representation opens the application of machine learning models in accelerating metallic material design and accurately predicting their properties.
Materials of engineering and construction. Mechanics of materials, Computer software
All optical soliton communication is a new generation of ultra-long distance and ultra-high speed optical fiber communication technology. Optical cavity solitons (CSs), whose pulse property is unique, have shown great potentials in optical soliton communication systems. Here, a theoretical model of nonlinear fiber resonator for CS generation is proposed. The effect of pump laser and resonant cavity parameters on the CS pulse performance is detailedly investigated and deeply analysed. Furthermore, the synergistic effect of continuous wave (CW) pump laser power and pump pulse peak power, and the synergistic effect of dispersion condition, fiber nonlinear coefficient and fiber length on the generation and property of CS pulse are respectively discussed and summarized. Finally, the launch conditions and parameter variation tolerances of cavity soliton in nonlinear fiber resonant cavity have been successfully generalized. These results can provide important instruction to the experimental generation and optimization of CS pulse.
A Nemzeti Média- és Hírközlési Hatóság 2023 januárjában „Szabadság és biztonság a digitalizálódó világban” címmel közzétett aktuális stratégiája értelmében a hatóság egyebek között a digitális szolgáltatásokról, valamint a digitális piacokról szóló európai uniós rendeletek alkalmazásából eredő és azokat kiegészítő hazai szabályozási igények vizsgálatát, szabályozási javaslatok előkészítésének szabályozási és szakértői támogatását határozta meg egyik kiemelt feladataként. A Gazdasági Versenyhivatal 2023 márciusában tagságot nyert abban a magas szintű nemzetközi munkacsoportban, amely az Európai Bizottságot segíti a digitális piacokról szóló rendelet szabályainak betartatásában. A jelen tanulmány a Nemzeti Média- és Hírközlési Hatóság, a Gazdasági Versenyhivatal és egyéb érintett hazai döntéshozók, ágazati szereplők stratégiájához és feladatköreik ellátásához oly módon kíván szakmai támogatást nyújtani, hogy részletesen bemutatja a német jogrendszerben körvonalazódó változásokat, gyakorlatokat a digitális szolgáltatásokról és a digitális piacokról szóló jogi aktusokkal kapcsolatban. A kutatást a német piac mérete és az ebből fakadó számos jogeset indokolja. Fontos tényező továbbá, hogy a német társadalom hagyományosan érzékeny az adatvédelem, a média és a demokrácia, továbbá a fenntartható gazdaság közötti kapcsolatokra, így a digitális szolgáltatásokról és a digitális piacokról szóló rendeletek végrehajtása során sok impulzusra számíthatunk Németország részéről, amely – a kevés ilyen tagállam egyikeként – már az uniós jogalkotást megelőzve, saját nemzeti jogszabályokban foglalt versenyjogi vagy médiaszabályozási eszközökkel beavatkozott a digitális piacok folyamataiba.
Since the Lorenz chaotic system was discovered in 1963, the construction of chaotic systems with complex dynamics has been a research hotspot in the field of chaos. Recently, memristive Hopfield neural networks (MHNNs) offer great potential in the design of complex, chaotic systems because of their special network structures, hyperbolic tangent activation function, and memory property. Many chaotic systems based on MHNNs have been proposed and exhibit various complex dynamical behaviors, including hyperchaos, coexisting attractors, multistability, extreme multistability, multi-scroll attractors, multi-structure attractors, and initial-offset coexisting behaviors. A comprehensive review of the MHNN-based chaotic systems has become an urgent requirement. In this review, we first briefly introduce the basic knowledge of the Hopfiled neural network, memristor, and chaotic dynamics. Then, different modeling methods of the MHNN-based chaotic systems are analyzed and discussed. Concurrently, the pioneering works and some recent important papers related to MHNN-based chaotic systems are reviewed in detail. Finally, we survey the progress of MHNN-based chaotic systems for application in various scenarios. Some open problems and visions for the future in this field are presented. We attempt to provide a reference and a resource for both chaos researchers and those outside the field who hope to apply chaotic systems in a particular application.
This paper presents a novel design for uplift piles incorporating a composite-anchor system. The composite-anchor system consists of steel strands, a non-expansion grouting body, and a high-strength steel pile. The aim of this design is to enhance the mechanical performance, durability, and economic efficiency of uplift piles. To evaluate the performance of the new pile, three sets of full-scale load tests were conducted, focusing on their in situ capacity, deformation, and stress characteristics. Despite a significantly lower reinforcement ratio of 0.75% compared to conventional piles with a ratio of 3.84%, the new uplift piles exhibit an exceptional uplift bearing performance. The utilization of the lateral friction resistance of the lower pile body is significantly improved, leading to enhanced load distribution and stress transfer mechanisms. Furthermore, a numerical model was developed and validated against the experimental results, demonstrating its reliability in simulating the bearing characteristics of the new uplift piles. The multi-interface design of the composite-anchor system ensures the efficient transmission of internal forces induced by external uplift loads, resulting in an improved stress state within the pile body. Moreover, the multi-layer structure of the composite main bar enhances the durability of the uplift piles. In comparison to conventional piles, the new uplift pile design offers substantial advantages, including an 80% reduction in reinforcement ratio, a 65% reduction in reinforcement cage welding, a cost reduction of approximately 30%, and a shortened construction time by around 20%. These findings highlight the potential of the new composite-anchor-pile design to revolutionize the field of uplift pile applications, offering improved efficiency and effectiveness.
Mohammad Nazmul Hasan, Jianglei Chen, Huaiwen Wang
et al.
<i>Cyp2c70</i> knockout mice lack the enzyme that produces muricholic acids and show a “human-like” hydrophobic bile acid pool-induced hepatobiliary injury. In this study, we investigated the potential anti-cholestasis effect of glycine-conjugated β muricholic acid (G-β-MCA) in male <i>Cyp2c70</i> KO mice based on its hydrophilic physiochemical property and signaling property as an farnesoid X receptor (FXR) antagonist. Our results showed that G-β-MCA treatment for 5 weeks alleviated ductular reaction and liver fibrosis and improved gut barrier function. Analysis of bile acid metabolism suggested that exogenously administered G-β-MCA was poorly absorbed in the small intestine and mostly deconjugated in the large intestine and converted to taurine-conjugated MCA (T-MCA) in the liver, leading to T-MCA enrichment in the bile and small intestine. These changes decreased the biliary and intestine bile acid hydrophobicity index. Furthermore, G-β-MCA treatment decreased intestine bile acid absorption via unknown mechanisms, resulting in increased fecal bile acid excretion and a reduction in total bile acid pool size. In conclusion, G-β-MCA treatment reduces the bile acid pool size and hydrophobicity and improves liver fibrosis and gut barrier function in <i>Cyp2c70</i> KO mice.
Maritime search and rescue (SAR) plays a very important role in emergency waterway traffic situations, which is supposed to trigger severe personal casualties and property loss in maritime traffic accidents. The study aims to exploit an optimal allocation strategy with limited SAR resources deployed at navigation-constrained coastal islands. The study formulates the problem of SAR resource allocation in coastal areas into a non-linear optimization model. We explore the optimal solution for the SAR resource allocation problem under constraints of different ship and aircraft base station settings with the help of an enhanced particle swarm optimization (EPSO) model. Experimental results suggest that the proposed EPSO model can reasonably allocate the maritime rescue resources with a large coverage area and low time cost. The particle swarm optimization and genetic algorithm are further implemented for the purpose of model performance comparison. The research findings can help maritime traffic regulation departments to make more reasonable decisions for establishing SAR base stations.
Mortgage rights are regulated in Law Number four of 1996 concerning Mortgage Rights on Land and Objects Related to Land, hereinafter abbreviated as UUHT. With a variety of options 13/pdt.bth/2021/pn/tjk where the land due to the marriage is used as collateral for the rights of borrowing and borrowing through the husband and spouse as guarantors. election No.13/pdt.bth/2021/pn/tjk. The approach used in this study is empirical through interviews with judges at the Tanjung Karang District Court. Land rights that can be encumbered with Borrowing Rights consist of: Ownership Rights, Cultivation Rights, Building Use Rights, and Land Use Rights on state land which in accordance with the legal guidelines and guidelines of the winner must be registered and according to their nature can be transferred. Flats that stand on Ownership Rights, Building Use Rights and Use Rights granted through the state. Because one of the parties,namely Edwin Bunyamin Pohar,was not drawn as a party in the a quo rebuttal case,the rebuttal of the rebuttal as a rebuttal is lacking because not all parties in the main case are parties in the a quo rebuttal case, so the rebuttal of the rebuttal must be declared no acceptable (Niet Onvankelijke Verklaard).
Osvrt na knjigu Poreklo porodice, privatne svojine i države Fridriha Engelsa (Friedrich Engels.1884. The Origin of the Family, Private Property and the State. New York: Pathfinder Press, 180 p.)
Bolin Li,1 Chunyan Liu,2,3 Ze-hui Fang,4 Ying Cao,4 Zheng Zhou,3 Haiyan Lu2 1Hebei Key Laboratory of Stomatology, Hebei Clinical Research Center for Oral Diseases, School & Hospital of Stomatology, Hebei Medical University, Shijiazhuang 050017, People’s Republic of China; 2Department of Orthodontics, Hebei Key Laboratory of Stomatology, Hebei Clinical Research Center for Oral Diseases, School & Hospital of Stomatology, Hebei Medical University, Shijiazhuang 050017, People’s Republic of China; 3School of Dentistry, University of Detroit Mercy, Detroit, Michigan 48208, USA; 4School & Hospital of Stomatology, Anhui Medical University, Hefei 230032, People’s Republic of ChinaCorrespondence: Zheng ZhouSchool of Dentistry, University of Detroit Mercy, 2700 Martin Luther King Jr. Blvd, Detroit, Michigan 48208, USATel +1-313-494-6667Fax +1-313-494-6666Email zhouzh1@udmercy.eduHaiyan LuDepartment of Orthodontics, Hebei Key Laboratory of Stomatology, Hebei Clinical Research Center for Oral Diseases, School & Hospital of Stomatology, Hebei Medical University, 383 Zhongshan East Road, Shijiazhuang, Hebei 050017, People’s Republic of ChinaTel/Fax +86 311-86265748Email luhaiyan67@163.comBackground: Dentin hypersensitivity (DH) is a common dental clinical condition presented with a short and sharp pain in response to physical and chemical stimuli. Currently no treatment regimen demonstrates long-lasting efficacy in treating DH, and unesthetic yellow tooth color is a concern to many patients with DH.Aim: To develop a bi-functional material which can occlude dentinal tubules in-depth and remineralize dentin for long-lasting protection of the dentin–pulp complex from stimuli and bleach the tooth at the same time.Methods: A mixture containing CaO, H3PO4, polyethylene glycol and H2O2 at a specific ratio was mechanically ground using a planetary ball. The mineralizing complex paste was characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Dentin was exposed to the synthesized paste for 8 h and 24 h in vitro. The mineralizing property was evaluated using SEM and microhardness tests. Red tea-stained tooth slices were exposed to the synthesized paste for 8 h and 24 h in vitro. The bleaching effect was characterized by a spectrophotometer.Results: The complex paste had very a fine texture, was injectable, and had a gel-like property with 2.6 (mass/volume) % H2O2 concentration. The X-ray diffraction pattern showed that the inorganic phase was mainly monetite (CaHPO4). The mineralizing complex paste induced the growth of inorganic crystals on the dentin surface and in-depth occlusion of dentin tubules by up to 80 μm. The regenerated crystals were integrated into the dentin tissue on the dentin surface and the wall of dentinal tubules with a microhardness of up to 126 MPa (versus 137 Mpa for dentin). The paste also bleached the stained dental slices.Conclusion: The mineralizing complex paste is a promising innovative material for efficient DH management by remineralizing dentin and in-depth occlusion of dentin tubules, as well as tooth bleaching.Keywords: dentin hypersensitivity, remineralization, tooth whitening, planetary ball mill
The study is devoted to providing new facts to support the influence of culture on the development of the country. We tried to interpret the phenomenon of eco-nomic growth through non-economic factors such as institutions, technology (in-novation), trust, culture, values. There is no single decisive factor of economic growth, it is always a set of unities. It is assumed that cultural values and eco-nomic performance in a country have a two-way relationship. Cultural values determine the social direction and complement the traditional factors of economic growth. Moreover, at the same time, they change under the influence of socio-economic development. A comparative analysis of different cultures requires identifying universal characteristics and grouping countries according to these characteristics. Categories of universal culture are the informal rules that underlie any social organization and form the basis of social relations. The categories of property rights, income distribution, competition, and environmental protection are among the main issues of society's existence and development. These catego-ries relate to economic values, the economic interests of the country. Values and attitudes largely determine the direction and rate of economic growth and, at the same time, are influenced by ideology, religion, and political regime. The purpose of this article is to determine the interdependence of society's values and its eco-nomic development. The main economic values are private property, competi-tion, and profit. It is possible to explore these categories of economic values through an analysis of data from the World Values Survey (WVS). Research methods. Regression is useful to test the relationship between economic values and well-being on the example of 36 countries. The initial data are economic val-ues statistics WVS (Greif, Mokyr, 2016) and GDP per capita, World Bank (GDP per capita (current US$)). The regression model includes independent (values) and dependent (GDP per capita) variables. Result. The study examined attitudes to private property, competition and environmental protection in European countries. A positive correlation was found between attitudes towards private property and well-being, between economic growth and environmental goals. The findings confirm the correlation between culture, values and economic growth. At the same time, there is no noticeable correlation between attitudes toward compe-tition and income levels. Institutional factors are assumed to have a particular influence on competition values.
Koh-ichi Sugimoto, Sho-hei Sato, Junya Kobayashi
et al.
In this study, the effects of Cr and Mo additions on mechanical properties of hot-forged medium carbon TRIP-aided bainitic ferrite (TBF) steel were investigated. If 0.5%Cr was added to the base steel with a chemical composition of 0.4%C, 1.5%Si, 1.5%Mn, 0.5%Al, and 0.05%Nb in mass%, the developed steel achieved the best combination of strength and total elongation. The best combination of strength and impact toughness was attained by multiple additions of 0.5%Cr and 0.2%Mo to the base steel. The excellent combination of strength and impact toughness substantially exceeded those of quenched and tempered JIS-SCM420 and 440 steels, although it was as high as those of 0.2%C TBF steels with 1.0%Cr and 0.2%Mo. The good impact toughness was mainly caused by uniform fine bainitic ferrite matrix structure and a large amount of metastable retained austenite.