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In this work, an improved moth-flame optimization algorithm is proposed to alleviate the problems of premature convergence and convergence to local minima. From the perspective of diversity, an inertia weight of diversity feedback control is introduced in the moth-flame optimization to balance the algorithm's exploitation and global search abilities. Furthermore, a small probability mutation after the position update stage is added to improve the optimization performance. The performance of the proposed algorithm is extensively evaluated on a suite of CEC'2014 series benchmark functions and four constrained engineering optimization problems. The results of the proposed algorithm are compared with the ones of other improved algorithms presented in literatures. It is observed that the proposed method has a superior performance to improve the convergence ability of the algorithm. In addition, the proposed algorithm assists in escaping the local minima. [ABSTRACT FROM AUTHOR]

Crowdfunding which is raising small amounts of resources – mainly financial – from many people in order to collect huge sums for a particular purpose has been practiced by some societies over years. The practice of crowdfunding today makes the use of different kinds of platforms necessary. This paper presents a survey of 18 observations and one in-depth case study of WhatsApp groups in Tanzania where WhatsApp social media has been used mainly between 2018 and 2019 as a platform for crowdfunding. The paper is mainly informed by secondary data. It identifies purposes of the observed crowdfunding, number of individuals involved in each round of crowdfunding per group, total amounts of funds raised per group per round of crowdfunding, maximum and minimum amounts contributed per group as well as average contribution per contributor in a round of crowdfunding. [ABSTRACT FROM AUTHOR]

Sigmund's 2001 educational paper with a self-contained 99-line MATLAB code had far-reaching impact to teaching and research of topology optimization. This brief note aims to close the gaps on self-contained content desirable for classroom teaching. The goal is to add clarity to the theoretical foundation, and to enable students' learning of the complete iterative optimization solution with minimum additional effort. [ABSTRACT FROM AUTHOR]

This paper develops a unified and structured solution framework for the minimum spanning tree (MST) problem and its variants (e.g., constrained MST problem and inverse MST problem) on networks with fuzzy link weights. It is applicable to any additive decision criterion under fuzziness (e.g., expected value, value at risk, and conditional value at risk), for generalized cases that the link weights may be represented by arbitrary types of fuzzy variables. It also applies to the entropy criterion while the link weights are continuous fuzzy variables. Following the optimality conditions of the fuzzy MST under different decision criteria proved first in this paper, it is shown that the MST problem and its variants on a fuzzy network can be converted into equivalent deterministic counterparts on their corresponding crisp networks. Consequently, these problems can be effectively solved via their deterministic counterparts without fuzzy simulation, and meanwhile, the performance of the trees under a specified criterion is precisely measured. The accuracy and efficiency are both significantly improved compared with other fuzzy simulation-based approaches. Numerical examples illustrate the superiority of the proposed solution framework. Furthermore, some new theoretical conclusions on the MST problem under fuzziness are also presented. [ABSTRACT FROM AUTHOR]

In order to eliminate the voltage imbalance among battery cells when they are connected in series, the paper proposes a double-layer E-structure (DLE) equalizer based on bidirectional buck–boost converters, which has the advantage of quick equalization speed and can be applied to arbitrary number batteries. Furthermore, a novel two-stage equalization control strategy is proposed for the DLE equalizer to decrease maximum voltage gap between the maximum and minimum voltage cells. The paper analyses the working principle of proposed equalizer in detail and describes the detailed design of the control strategy and implement process. Simulation and experiment results show that the proposed equalizer can improve equalization performance of battery cells compared with adjacent cell-to-cell (AC2C) equalizer. [ABSTRACT FROM AUTHOR]

Though the curriculum reform movement that began in 1989 has had a significant impact on calculus pedagogy and content (Windham, 2008), the question remains to what extent reform-based calculus textbooks reflect these reforms. This paper explores this question by analyzing the mathematical content and pedagogical approach of the chapter on functions in Hughes-Hallett et al.'s (2018) reform-based college textbook Calculus: Single and Multivariable (CS&M). To conduct this analysis, the paper first synthesizes Hwang et al.'s (2021) framework for analyzing mathematics textbooks along with Sood and Jitendra's (2007) framework for comparing traditional and reform-based mathematics textbooks. The paper then applies the synthesized frameworks to identify elements of reform from the big ideas, contextual features, mediated scaffolding, problem solving activities, and STEM integration found in the CS&M chapter. The results suggest that, although the chapter integrates many reform-based principles, there may be scope for further integration. Such efforts, however, may be constrained by influential stakeholders. [ABSTRACT FROM AUTHOR]

In the present paper we give a short proof of a result of Zaks, Frostig and Levikson [2006] on the solution of an optimization problem which is related to the problem of optimal pricing of a heterogeneous portfolio. [ABSTRACT FROM AUTHOR]

Consider a massive random access scenario in which a small set of $k$ active users out of a large number of $n$ potential users need to be scheduled in $b\ge k$ slots. What is the minimum common feedback to the users needed to ensure that scheduling is collision-free? Instead of a naive scheme of listing the indices of the $k$ active users in the order in which they should transmit, at a cost of $k\log (n)$ bits, this paper shows that for the case of $b=k$ , the rate of the minimum fixed-length common feedback code scales only as $k \log (e)$ bits, plus an additive term that scales in $n$ as $\Theta (\log \log (n))$ for fixed $k$. If a variable-length code can be used, assuming uniform activity among the users, the minimum average common feedback rate still requires $k \log (e)$ bits, but the dependence on $n$ can be reduced to $O(1)$. When $b>k$ , the number of feedback bits needed for collision-free scheduling can be significantly further reduced. Moreover, a similar scaling on the minimum feedback rate is derived for the case of scheduling $m$ users per slot, when $k \le mb$. The problem of constructing a minimum collision-free feedback scheduling code is connected to that of constructing a perfect hashing family, which allows practical feedback scheduling codes to be constructed from perfect hashing algorithms. [ABSTRACT FROM AUTHOR]

Purpose: This paper aims to focus on addressing endogeneity using instrument-free methods. The authors discuss some extensions to well-known techniques. Design/methodology/approach: This paper discusses some attractive methods to address endogeneity without the need for instruments. The methods are labeled are "harmless" in the sense that instruments are not needed and the distributional assumptions are kept to a minimum or they are replaced by more flexible semi-parametric assumptions. Findings: Using a hospitality application, the authors provide evidence about the effectiveness of these techniques and provide directions for their implementation. Research limitations/implications: Finding valid instruments has always been a key challenge for researchers in the field. This paper discusses and introduces methods that free researchers from the need to find instruments. Originality/value: The paper discusses techniques that are introduced from the first time in the tourism literature. [ABSTRACT FROM AUTHOR]

A lookback option is a maturity option that pays off based on the maximum or minimum stock price over the life of the option. This paper investigates the problem of pricing a lookback option based on the uncertain mean-reverting currency model and designs the algorithms to calculate the formulations. Furthermore, discussions about parameters and results are drawn in the paper. [ABSTRACT FROM AUTHOR]

Geological sampling data often need to be regionally segmented to mark blocks with different geological properties in mathematical geosciences. This paper uses the directed graph model of graph theory to model sampling data and calculate the segmentation of the directed graph by the improved maximum flow minimum cut (max-flow min-cut) algorithm. The proposed energy expressions reflect the continuity of geological properties and the smoothness of segmentation boundaries. A major advantage of this method is that it allows geological experts to share prior knowledge regarding the partitioning of a mineralization area as the seeds of the directed graph. Incorporating this knowledge in the segmentation result via a very intuitive and simple outline operation greatly improves the interactivity and editability of the algorithm. For the integrity of the process framework, this paper also proposes incorporating the characteristic scale of the Hilbert–Huang transformation (HHT) framework as the characteristic parameter to calculate the initial seed, which can achieve automatic regional segmentation. [ABSTRACT FROM AUTHOR]

Path Planning is critical for a mobile robot (MR) to navigate safely towards its target position, without collision with the surrounding obstacles. There are many aspects that need to be considered in path planning; computation time, path smoothness, and path length. The Artificial Potential Field (APF) approach is popular for solving the path planning problem. It is a unique approach that has a simple computation model, which makes it a good choice for real-time and dynamic environments. The principle of the APF approach is based on attracting the MR to its target position and repelling it away from obstacles. The APF approach has some inherent limitations, such as local minima and path oscillations in narrow passages. This paper reviews the traditional APF approach and several modified versions that aimed to overcome these limitations. A brief comparison is made to give an overview of the performance of each modified version. In addition, the main advantages and disadvantages are discussed to highlight the parameters affecting the performance of the modified methods. [ABSTRACT FROM AUTHOR]

INTRODUCTION: Against the background of the new period of casting souls in Civics, empowering reforms, and strengthening foundations through cooperation, it is necessary to put the educational concepts and strategies of the Party and the government into practice in the process of deepening the educational reform of Civics and Politics courses. OBJECTIVES: This paper starts from the practical feasibility of the work and the conditions of the course design, with clear objectives, optimizing the teaching content, innovating and improving the teaching mode, and gradually forming effective strategies and methods of educational thought and policy. METHODS: This work examines and synthesizes the challenges and strategies of ideological and political education reform in the contemporary era, employing fuzzy theory and algorithmic approaches. RESULTS: It is concluded that the reform of the ideological and political curriculum is not only suitable for the development of students but also for the development of an era. Therefore, it is necessary to retain the content of all new textbooks, pay attention to the inclusion of ideological and political content in all textbooks, and ensure that there are scientifically sound and appropriate teaching materials for all teaching materials in order to contribute to the development of curriculum ideology and politics effectively. CONCLUSION: In the implementation process, it is necessary to improve the comprehensive quality of ideological and political course teaching, establish a sound ideological and political teaching system, and set up a comprehensive construction and educational collaboration mechanism. A multifactor ideological and political learning platform has been created to promote closer integration and interaction between theoretical learning and value orientation. [ABSTRACT FROM AUTHOR]

As part of a departmental reform project, a large University converted a "Precalculus College Mathematics" lecture-based course for 97 students into an active learning flipped classroom for first-year engineering students. The curriculum was designed specifically to provide applications of pre-calculus in various engineering subjects. This paper outlines the course evolution, design features, ongoing adjustments made to the course, and quantitative data from the common examination and course evaluations to support the instructional design. The paper concludes with a reflection on which aspects of the learning environment helped facilitate successful learning and guidance for future implementations of a large-scale flipped undergraduate mathematics classroom. [ABSTRACT FROM AUTHOR]

In this paper we define a new operator J for the study of Δ u + f (u) = 0 , x ∈ R N , N > 2. Using J we can easily see some qualitative properties of the solutions, for example we can determine the values where u changes sign, has a local maxima or minima, or changes concavity. We also use this functional to construct, for any k ∈ N , nonlinearities f such that this problem has at least two bound state solutions that change sign j times, for j = 0 , 1 , ... , k − 1. And another f such that this problem has a unique ground state solution, and at least two bound state solutions that change sign one time. [ABSTRACT FROM AUTHOR]

This paper is a generalization of two of our preceding papers which considered, among other things, a version of the solution with a minimum and a maximum number of atoms in the spatial configurations 1+2+3. Some results of these works, pertaining to probabilistic transitions of atoms from one configuration to another, follow from the results of the given paper as a special case. [ABSTRACT FROM AUTHOR]

The lightning search algorithm (LSA) is a novel meta-heuristic optimization method, which is proposed in 2015 to solve constraint optimization problems. This paper presents a comprehensive survey of the applications, variants, and results of the so-called LSA. In LSA, the best-obtained solution is defined to improve the effectiveness of the fitness function through the optimization process by finding the minimum or maximum costs to solve a specific problem. Meta-heuristics have grown the focus of researches in the optimization domain, because of the foundation of decision-making and assessment in addressing various optimization problems. A review of LSA variants is displayed in this paper, such as the basic, binary, modification, hybridization, improved, and others. Moreover, the classes of the LSA's applications include the benchmark functions, machine learning applications, network applications, engineering applications, and others. Finally, the results of the LSA is compared with other optimization algorithms published in the literature. Presenting a survey and reviewing the LSA applications is the chief aim of this survey paper. [ABSTRACT FROM AUTHOR]

The paper presents trends for three categories of variables: average annual, average maximum and average minimum air temperatures. Data was provided by the meteorological yearbooks of the Republic Hydrometeorological Service of Serbia. The main goal of this paper is to detect possible temperature trends in Central Serbia. The trend equation, trend magnitude, and Mann-Kendall non-parametric test were used in the analysis of climate parameters. The used statistical methods were supplemented by GIS numerical analysis, which aimed to analyze the spatial distribution of isotherms from 1949 to 2018. The obtained results indicate that out of the 72 analyzed time series, an increase in air temperature is dominant in 61 time series, while 11 time series show no changes. The highest increase was recorded in the average maximum time series (4.2 °C), followed by an increase of 3.5°C in average maximum air temperatures. The highest increase in the average annual time-series was 3.0 °C. The lowest increases in air temperature were recorded in the average minimum time series (0.1 and 0.2 °C). In two average minimum time series a decrease in average air temperatures was identified (-0.6 and -0.4 °C. The application of GIS tools indicates the existence of interregional differences in the arrangement of isotherms, leaded by the orography of the terrain. In the spatial distribution of the analyzed variables, "poles of heat" and "poles of cold" stand out, and the influence of the urban heat island is evident (especially in the case of the urban agglomeration of Belgrade). The manifested spatial patterns of air temperature need to be further examined and the correlation with possible causes need to be determined. For these reasons, the paper provides a solid basis for studying the climate of this area in the future, as it provides insight into climate dynamics over the past decades. [ABSTRACT FROM AUTHOR]

Concerns about ethical issues in ICTD/ICT4D research have been growing in recent years, alongside calls to agree minimum ethical standards. This paper reflects on the three-year participatory process, co-facilitated by the authors, that has led to collective agreement on such a set of minimum ethical standards for ICTD/ICT4D research. The standards have been published (at ) under a Creative Commons licence, and are open for further comment. The current version has been endorsed by the ICTD conference series, and there is ongoing dialogue about their implementation by other conferences, journals, and funding bodies. While the standards themselves are a collective effort, in this paper the facilitators lay out their own specific thinking and approach to the co-production process that they designed and facilitated. It considers the successes, potential for further improvement, as well as critical features underpinning the standards' legitimacy. These reflections may help guide other research communities interested in such participatory self-regulation processes. [ABSTRACT FROM AUTHOR]

In this paper, to keep the researchers interested in nature-inspired algorithms and optimization problems, a comprehensive survey of the group search optimizer (GSO) algorithm is introduced with detailed discussions. GSO is a nature-inspired optimization algorithm introduced by He et al. (IEEE Trans Evol Comput 13:973–990, 2009) to solve several different optimization problems. It is inspired by animal searching behavior in real life. This survey focuses on the applications of the GSO algorithm and its variants and results from the year of its suggestion (2009) to now (2020). GSO algorithm is used to discover the best solution over a set of candidate solution to solve any optimization problem by determining the minimum or maximum objective function for a specific problem. Meta-heuristic optimizations, nature-inspired algorithms, have become an interesting area because of their rule in solving various decision-making problems. The general procedures of the GSO algorithm are explained alongside with the algorithm variants such as basic versions, discrete versions, and modified versions. Moreover, the applications of the GSO algorithm are given in detail such as benchmark function, classification, networking, engineering, and other problems. Finally, according to the analyzed papers published in the literature by the all publishers such as IEEE, Elsevier, and Springer, the GSO algorithm is mostly used in solving various optimization problems. In addition, it got comparative and promising results compared to other similar published optimization algorithm. [ABSTRACT FROM AUTHOR]

Consider a configuration of points comprising a point q and a set of concyclic points R that are all a given distance r from q in the Euclidean plane. In this paper, we investigate the relationship between the length of a minimum Steiner tree (MStT) on R∪{q}$R\cup \lbrace q\rbrace$ and a minimum spanning tree on R. We show that if the degree of q in the MStT is 1, then the difference between these two lengths is at least (2−3)r$(2-\sqrt {3})r$, and that this lower bound is tight. This bound can be applied as part of an efficient algorithm to find the solution to the prize‐collecting Euclidean Steiner tree problem, as outlined in an earlier paper. [ABSTRACT FROM AUTHOR]

There has been much increased interest in the academic and industrial research communities on vehicular ad-hoc networks (VANETs). In this paper, we present an analytical model to study the end-to-end delay in a one-way VANET. This paper proposes an analytical formula for the end-to-end delay probability distribution. Using the derived probability distribution, the probability that the end-to-end delay is lower than a given threshold may be calculated. In addition, one can straightforwardly study the impact of parameters such as wireless communication range, vehicular densities, distance between source the destination, and minimum and maximum vehicle speeds on the end-to-end delay. This can help to better understand data dissemination in VANETs. Moreover, closed forms for lower and upper bounds on the end-to-end delay probability distribution are obtained. Extensive simulation results demonstrate the accuracy of our analysis. [ABSTRACT FROM AUTHOR]

In particular, we are interested in answering the questions as follows. Whether is it a good choice to collaborate? Under what conditions, collaboration is a good choice? Inspired by the society of animals, this paper studies collaborative robots via simulations using a case study of the coalition formation of robots in order to detect and capture intrusions in a curved loop. Our simulation results confirm the theoretical findings. Furthermore, we study more complicated scenarios that involve more complex coalition formations with more robots in order to extend the results of theoretical studies. We found the factors that affect the coalition behaviors of the robots, and we also found the maximum and minimum intruders. [ABSTRACT FROM AUTHOR]

This paper first theoretically simulates the change trend of Metal reflectance with various thicknesses of IZO and MoNbOxNy, and then experimentally produces an ultra‐low‐reflective Metal film layer: 60nm IZO + 45nm MoNbOxNy, with a reflectance of 4.97%. Furthermore, the reflectance uniformity is very excellent, the maximum & minimum values within the range of the average value ± 0.50%. Subsequently, this paper performed performance tests on IZO/MoNbOxNy Metal samples. The results are as follows: ① The reflectance in the whole band of 380nm ~ 780nm is stable, all within the range of 5% ~ 7%; ② Each film layer is well crystallized, and there is no abnormality in the microscopic morphology; ③ The adhesion is good; ④ The invisible performance Level is improved from Level 5 to Level 3. The indicators meet the requirements of the TP industry and can be used to make ultra‐low reflection and good invisible touch panels. [ABSTRACT FROM AUTHOR]

Diamond‐like carbon (DLC) coatings were indented 3000 to 15 000 times cyclically using a Si3N4 sphere having a diameter of 10 mm under a normal load of approximately 107 N. DLC coatings were prepared by unbalanced magnetron (UBM) sputtering under substrate bias voltage of −200 on a heat‐treated and polished JIS SCM 415 substrates. SEM images and the energy dispersive X‐ray spectrometry (EDX) results of the indented impressions showed that a Cr/C layer or substrate surface partially revealed on the impressions. In order to estimate structural alterations in DLC coatings after cyclic indentations, Raman spectroscopy were performed on the impressions. Relationships between Raman parameters such as the intensity ratio I(D)/I(G) of the disorder peak around 1350 cm−1 and the graphitic peak around 1580 cm−1 and full width of half maximum of the G peak (FWHM(G)) were estimated with the Raman spectroscopy on the impressions. Enclosed area by maximum and minimum of I(D)/I(G) and FWHM(G) was defined as "Safety Zone" in this paper, and it can be used to determine integrity of DLC coatings. [ABSTRACT FROM AUTHOR]

1) The problem this paper is going to solve is how to determine the optimal number of dimension when using dimensionality reduction methods, and in this paper, we mainly use local linear embedding (LLE) method as example. 2) The solution proposed is on the condition of the parameter k in LLE is set in advance. Firstly, we select the parameter k , and compute the distance matrix of each feature in the source data and in the data after dimensionality reduction. Then, we use the Log-Euclidean metric to compute the divergence of the distance matrix between the features in the original data and in the low-dimensional data. Finally, the optimal low dimension is determined by the minimum Log-Euclidean metric. 3) The performances are verified by a public dataset and a handwritten digit dataset experiments and the results show that the dimension found by the method is better than other dimension number when classifying the dataset. [ABSTRACT FROM AUTHOR]

Due to complicated manufacturing processes and inherent dispersions of constituents, uncertainty is unavoidably existing in mechanical properties, including strength, of composite laminates which can be described as random or interval variables. Considering the multivariable and hybrid uncertainty, the hybrid reliability evaluation of composite laminates is quite an important problem. The objective of this paper is to construct a reliability evaluation method to evaluate hybrid reliability of composite laminates accurately and efficiently. The existence of interval variables produced a limit-state strip formed by minimum and maximum limit state function (LSF). Combining first-order reliability method (FORM) and univariate method, the paper developed a strategy to search the most probable point (MPP) of minimum and maximum LSF. In the process of MPP searching, the univariate function of interval variables is constructed by Legendre orthogonal polynomials and the least-square fitting method. Then, the minimum and maximum LSF are constructed at MPP in a similar way with interval variables which can ensure the accuracy of LSF approximation. Furthermore, Monte–Carlo simulation can be utilized to calculate interval of failure probability. Finally, the results of examples verified the accuracy and efficiency of the constructed model. [ABSTRACT FROM AUTHOR]

In previous papers, it was shown that in a quasi-spherical Szekeres (QSS) metric, impulses of gamma radiation can arise that have several properties in common with the observed gamma-ray bursts. This happens when the bang-time function tB(r) has a gate-shaped hump around the origin of the QSS region. The gamma rays arise along two preferred directions of the QSS geometry (coincident with dipole extrema when axially symmetric, otherwise unrelated). In these directions, the rays of the relic radiation are blueshifted rather than redshifted. The blueshift is generated in a thin region between the Big Bang (BB) and the extremum-redshift hypersurface (ERH). However, the Szekeres models can describe the real Universe only forward in time from the last-scattering hypersurface (LSH) because the matter in them has zero pressure. The ERH is tangent to the BB at the origin, so in a neighbourhood thereof the ERH lies earlier than the LSH and no blueshift is generated in the physical region. The question thus arose whether the BB and ERH can be "unglued" if the QSS region has no origin, but the areal radius function Φ has a local maximum or minimum somewhere. In the present paper, it is demonstrated that this is indeed the case. If the hump in tB(r) is centred around the minimum of Φ, then the BB and ERH in general do not coincide there and a stronger blueshift is generated on rays passing nearby. It follows that a lower and narrower hump on the BB set can generate sufficient blueshift to move the initial frequencies of the relic radiation to the gamma range. These facts are demonstrated by numerical calculations in an explicit example of a QSS region. [ABSTRACT FROM AUTHOR]

Emergency vehicle (EV) plays an important role in evacuations or rescues when emergencies occur. To insure that an EV can transfer people in danger to emergency shelters or medical assistance organizations as soon as possible, EV signal preemption (EVSP) strategy is usually adopted. After EV has passed through the intersection, traffic signal has to transfer back to normal signal timing scheme. This paper focuses on the control strategy of EV signal transitioning from EVSP back to normal operation. Considering both efficiency and fairness, the maximum vehicles passing through in per unit time during the transition period and the minimum difference between the maximum and the minimum queue length after transition are selected as objectives, and a multi-objective optimization model is presented. A nondominated sorting genetic algorithm II (NSGA-II) is designed to solve the optimization model and unique encoding and decoding methods are presented. The established model and designed algorithm are verified and the control effect is analyzed. Simulation results indicate that by adopting the control strategy obtained by the presented model, the number of vehicles passing through in per unit time during the transition period is increased and the difference of vehicle length in different directions is reduced significantly, from which we can conclude that the control method proposed in this paper has good performance. [ABSTRACT FROM AUTHOR]

While solving the optimization problems of complex functions, particle swarm optimization (PSO) would be easy to fall into trap in the local optimum. Besides that, it has slow convergence speed and poor accuracy during the late evolutionary period. So a SA-PSO algorithm would be proposed in this paper. Classically, the probability to accept bad solutions is high at the beginning. It allows the SA algorithm to escape from local minimum. As the result of that, the improved algorithm, combined SA with PSO, would be given in this paper. The given algorithm owned the abilities of both increasing the diversity of particle swarm and jumping out of the local optimum. In this paper, several classic unimodal/multimodal functions were used to simulate the SA-PSO algorithm. The results illustrated that SA-PSO had a stronger ability to avoid prematurity and get rid of local optimum. Compared with traditional PSO, the SA-PSO has improvement over effectiveness and accuracy to some extent. And it has competitive potential for solving other complicated optimization problems. [ABSTRACT FROM AUTHOR]

The objective of this paper is to extract concave and convex feature regions via segmenting surface mesh of a mechanical part whose surface geometry exhibits drastic variations and concave-convex features are equally important when modeling. Referring to the original approach based on the minima rule (MR) in cognitive science, we have created a revised minima rule (RMR) and presented an improved approach based on RMR in the paper. Using the logarithmic function in terms of the minimum curvatures that are normalized by the expectation and the standard deviation on the vertices of the mesh, we determined the solution formulas for the feature vertices according to RMR. Because only a small range of the threshold parameters was selected from in the determined formulas, an iterative process was implemented to realize the automatic selection of thresholds. Finally according to the obtained feature vertices, the feature edges and facets were obtained by growing neighbors. The improved approach overcomes the inherent inadequacies of the original approach for our objective in the paper, realizes full automation without setting parameters, and obtains better results compared with the latest conventional approaches. We demonstrated the feasibility and superiority of our approach by performing certain experimental comparisons. [ABSTRACT FROM AUTHOR]

In this paper, we prove the asymptotic growth rate of the summatory function of the pairwise maxima of the generalized divisor function d k (n), for a fixed positive integer k ≥ 2. This result generalizes previous results of Kátai, Erdős and Hall on the local behaviour of divisor function on short intervals. [ABSTRACT FROM AUTHOR]

Some recent papers relate the criticality of complex systems to their maximal capacity of information processing. In the present paper, we consider high dimensional point processes, known as age-dependent Hawkes processes, which have been used to model spiking neural networks. Using mean-field approximation, the response of the network to a stimulus is computed and we provide a notion of stimulus sensitivity. It appears that the maximal sensitivity is achieved in the sub-critical regime, yet almost critical for a range of biologically relevant parameters. [ABSTRACT FROM AUTHOR]

We study the following fractional Schrödinger equation where . Under some conditions on , we show that the problem has a family of solutions concentrating at any finite given local minima of provided that . All decay rates of are admissible. Especially, can be compactly supported. Different from the local case or the case of single-peak solutions, the nonlocal effect of the operator makes the peaks of the candidate solutions affect mutually, which causes more difficulties in finding solutions with multiple bumps. The methods in this paper are penalized technique and variational method. We study the following fractional Schrödinger equation \begin{equation*} \label{eq0.1} \varepsilon^{2s}(-\Delta)^s u + V(x)u = f(u), \,\,x\in\mathbb{R}^N, \end{equation*} where . Under some conditions on , we show that the problem has a family of solutions concentrating at any finite given local minima of provided that . All decay rates of are admissible. Especially, can be compactly supported. Different from the local case or the case of single-peak solutions, the nonlocal effect of the operator makes the peaks of the candidate solutions affect mutually, which causes more difficulties in finding solutions with multiple bumps. The methods in this paper are penalized technique and variational method. [ABSTRACT FROM AUTHOR]

A theoretical model is developed to determine simultaneously and in different ways thermal diffusivity and thermal conductivity of thin layers. This is done by using the accurate expression of the temperature distribution derived from the parabolic heat equation when the front surface of the thin layer is excited by a periodic heat flux, while the rear surface is maintained at one of three different types of boundary conditions: modulated periodic heat flux, modulated temperature, or constant temperature. Our approach exploits the modulation frequencies at which the normalized front surface temperature reaches its first maximum and first minimum. It is shown that (i) these characteristic frequencies can be used to obtain the thermal diffusivity of the finite layer under three different types of boundary conditions. (ii) The ratio between the values of the maxima and minima of the temperature can be utilized to determine the thermal conductivity of the finite layer. These two thermal properties are sensitive to the nature of the boundary conditions as well as the modulation frequency of the heat excitation. This paper provides a theoretical basis for the determination of the thermal diffusivity and thermal conductivity of the finite layer using laser-based heating photothermal techniques. [ABSTRACT FROM AUTHOR]

Machine learning (ML) methods are proliferating in scientific research. However, the adoption of these methods has been accompanied by failures of validity, reproducibility, and generalizability. These failures can hinder scientific progress, lead to false consensus around invalid claims, and undermine the credibility of ML-based science. ML methods are often applied and fail in similar ways across disciplines. Motivated by this observation, our goal is to provide clear recommendations for conducting and reporting ML-based science. Drawing from an extensive review of past literature, we present the REFORMS checklist (recommendations for machine-learning-based science). It consists of 32 questions and a paired set of guidelines. REFORMS was developed on the basis of a consensus of 19 researchers across computer science, data science, mathematics, social sciences, and biomedical sciences. REFORMS can serve as a resource for researchers when designing and implementing a study, for referees when reviewing papers, and for journals when enforcing standards for transparency and reproducibility. [ABSTRACT FROM AUTHOR]

In this research paper, a well‐performing solar pump at the minimum cost of project life is designed and installed. Initially, the capacity of submersible pumps and discharge have been determined based on the water requirement of the crop and the size of the field. The total number of solar panels, inverter size, and motor pump system have been designed based on the law of conservation of energy. The two optimization techniques genetic algorithm (GA) and response surface methodology (RSM) have been used for analyzing the pump performance parameters and total cost. The GA tool has been used to determine the optimum tilt angle on which responses namely solar flux, solar panel efficiency, exergy, and pump efficiency should be maximum. Moreover, the performance of the solar pump at the optimum tilt angle has been compared with the 28° fixed tilt angle (latitute of location). For the experimental study solar pump experimental setup of 5 hp power has been installed in Faculty of Engineering and Technology, MJP Rohilkhand University at 28.36°N, 79.43°E. The total cost of the solar pump has been optimized with the help of RSM based on the discharge and head of the solar pump. The new optimization approach reduced the levelized cost of electricity (LCOE) from 0.041 to 0.035 $/kWh and the payback period is reduced from 4 to 3 years. The annual increment in average solar flux and overall efficiency has been recorded to be from 606 to 697 W/m2 and 11% to 14% respectively. [ABSTRACT FROM AUTHOR]

This is the first paper dealing with the study of minimum and maximum principle sufficiency properties for nonsmooth variational inequalities by using gap functions in the setting of Hadamard manifolds. We also provide some characterizations of these two sufficiency properties. We conclude the paper with a discussion of the error bounds for nonsmooth variational inequalities in the setting of Hadamard manifolds. [ABSTRACT FROM AUTHOR]

Recently, fresh agricultural cold-chain logistics have been greatly developed with the increasing needs of people's life. Reducing costs of cold-chain distribution has become the main object of loss control in logistics enterprises. The objective of this research is to find a set of optimal routes that minimize the total loss, including fuel cost, refrigeration cost, soft time window penalty cost, and cargo damage cost over transit time. In this paper, the definition and model construction of vehicle routing problem (VRP) with multiobjective minimum lost are introduced first. Then, an ant colony optimization (ACO) algorithm combined with Pareto local search (PLS) is put forward to solve the minimum loss model. In order to avoid the influence of complex road conditions during distribution, the distance matrix and the transit time matrix are both derived from the recommended navigation road based on E-map API. At last, a compare experiment between the traditional method and our proposed method is performed. The results indicate that our method has strong applicability and potential advantages in cold-chain logistic and has important practical significance and application value. [ABSTRACT FROM AUTHOR]

In this paper, we extend the Zipf distribution by means of the Randomly Stopped Extreme mechanism; we establish the conditions under which the maximum and minimum families of distributions intersect in the original family; and we demonstrate how to generate data from the extended family using any Zipf random number generator. We study in detail the particular cases of geometric and positive Poisson stopping distributions, showing that, in log-log scale, the extended models allow for top-concavity (top-convexity) while maintaining linearity in the tail. We prove the suitability of the models presented, by fitting the degree sequences in a collaboration and a protein-protein interaction networks. The proposed models not only give a good fit, but they also allow for extracting interesting insights related to the data generation mechanism. [ABSTRACT FROM AUTHOR]

Grinding is one of the important machining processes that are widely applied in precision manufacturing. In the beginning, studies mostly focused on dry machining. In time, emerging technologies have led to change in the development of the machining process. New techniques and tools have been developed over the last decade that has brought the process to an advanced place. At first, flood cooling has removed the burning problems in the grinding process. After that, a new technique was developed which is known as minimum quantity lubrication (MQL). This technique is a recognized opportunity to eliminate environmental concerns. This paper reviews some of the common as well as advanced MQL systems specifically used in grinding operations. The effect of MQL and other cutting parameters on cutting forces, surface roughness of the machined workpiece, tool wear, temperature, specific cutting energy, and residual stress is outlined. This paper also addressees the recent trend of cooling systems in the grinding process. After reading this research paper, one can easily get an overview of the previously conducted research to find the output parameter trends in MQL condition. The reader can infer from this paper in which direction the development trend in grinding is in the machining process. [ABSTRACT FROM AUTHOR]

Summary: The losses and efficiency of a modular multilevel converter (MMC) are strongly linked to the switching frequency, component selection, and the choice of internal control structures such as the circulating current control and sub‐module (SM) capacitor voltage balancing algorithm. Equally, the structure of the SM impacts the overall converter operation and the efficiency of the conversion system. However, consideration for the impact of converter operating points on the overall system efficiency is required in order to derive a complete picture. Thus, this paper presents a comprehensive evaluation of the impact of inverter/rectifier operation and power factor on the losses of the different SMs in an MMC with a particular focus on SMs and operational limits for high‐voltage DC transmission systems. Considering 27 different SM topologies, it is demonstrated that due to the voltage balancing requirements, the inverter or rectifier operation modes of the converter and the power factor, influence the average losses of SMs and also the maximum and minimum losses within a fundamental period. [ABSTRACT FROM AUTHOR]

In most studies of hydraulic simulation of water distribution systems (WDS), the uncertain input parameters such as nodal demands, pipe roughness coefficients, pipe diameters, water levels in reservoirs, and pump characteristics usually are considered to be fuzzy, with triangular distribution membership functions. In this paper, pipe roughness coefficients were considered to be fuzzy parameters affecting pipe flows and nodal pressures due to their significant effects on hydraulic simulation, and trapezoid distribution membership functions instead of triangular distribution membership functions were considered for pipe roughness coefficients. At each α -cut level of roughness coefficients, a genetic algorithm (GA) was applied to obtain the minimum and maximum pipe flows and nodal pressures. The proposed method was applied to four networks to analyze the fuzziness of pipe flows and nodal pressures based on two parameters, dispersion degree and relative flat line rate. This study will help in the fuzziness analysis of hydraulic simulation results in WDS under uncertain pipe roughness coefficients. [ABSTRACT FROM AUTHOR]

In this paper, we obtain bounds for the extreme entries of the principal eigenvector of a hypergraph; these bounds are computed using the spectral radius and some classical parameters such as maximum and minimum degree. We also study inequalities involving the ratio and difference between the two extreme entries of this vector. [ABSTRACT FROM AUTHOR]