Concept Of Point Research Articles

Effect of thermodynamic-dynamic parameters on the oscillation and performance of a free piston Stirling engine

This paper presents an analysis of the oscillation and parametric performance of a gamma-type free piston Stirling engine using a thermodynamic-dynamic nonlinear model. Firstly, the concept of oscillation and impact cylinder points is defined and a method for determining the stable oscillation zone of the free piston Stirling engine is proposed. Besides, the effects of various thermodynamic parameters on the system’s performance, such as charging pressure, hot-end and cold-end temperatures, and dynamic parameters (such as the masses and spring stiffness of the displacer and piston), are investigated. The oscillation zone takes on a “V” shape when the piston and displacer masses or stiffness, and hot-end temperature and displacer stiffness, are varied. Finally, the output power and operating frequency of the impact cylinder line are determined. The results show that maximum output power and operating frequency of 75.36 W at 58.21 Hz or 76.73 W at 58.61 Hz are achieved at the “V” bottom when either the piston and displacer masses are adjusted or their stiffness properties are varied. Additionally, consistent output power and operating frequency of 125.35 W and 75.08 Hz, and 104.63 W and 68.59 Hz, are obtained regardless of changes in both displacer mass and stiffness.

Kontrastujące style metamorficznych i metasomatycznych złóż kamieni szlachetnych w Cabo Delgado w północnym Mozambiku

From a conceptual point of view, in some ruby and garnet deposits of the Lalamo Supergroup – Cabo Delgado Nappes Complex, Northern Mozambique – the structural control of the primary mineralization seems to be spatially and geochemically related to the genesis of calcsilicate rocks, also with gemstones. Two main locations, with contrasting paragenesis, were studied in detail – Miteda area and Micute to N’Djekwa sector. Structural and paragenetic analysis, departing from high-resolution cartography, fabric microanalysis, SEM microscopy and mineral identification by X-ray diffractometry, were used with a major incidence in outcrops and small-scale mine diggings. Regional Neoproterozoic formations, especially its metacarbonate members, host Mg, B - rich skarns, bearing dravite and B-Mg-calc-silicate gemstones, especially in Micute and N’Djekwa area. Following the composition of the probable lithological precursor, these minerals, consistently, reveal a geochemical Mg - B signature that could have been inherited from an evaporite type ancestor, inter-stratified with carbonate rocks in the protolithic Lalamo sequence. The focus of hydrothermal circulation in multistage shear zones is invoked as the main pathway to interpret the complex mineralization observed in Miteda. In this case, the structure of a corundum + garnet major spot is coherent with a pull-a- part dilation associated with sinistral shear. There is a relation between red color saturation of ruby and the content of Cr in corundum. Cr can be leached from the meta-ultramafic host-rocks as a byproduct of desilication. Calcsilicate metasomatism could trigger Si sequester, producing metamorphic desilicated fluids. The focus of hydrothermal circulation in shear zones is invoked as the main pathway for the entrapment of metamorphic and metasomatic gem deposits. These occur in corridors of anomalous host-lithologies and vein swarms where peraluminous paragenesis are located inside highly modified meta-ultramafic or metacarbonate rocks. Skarn like lithologies result from reaction with a sedimentary carbonate protolith and gem deposition is mainly metasomatic. Veining affecting metaultramafic sequences of amphibolitic to granulitic facies show occasional, metasomatically affected, eclogite. For the contrasting styles of deposits represented in Micute – N’Djekwa and in Miteda, although the corresponding paragenesis are separated in space, their deposition can be situated in a conceptual model characterized by a geochemical interdependency and time proximity.

An Application of φ-Metric and Related Best Proximity Point Results Generalizing Wardowski’s Fixed Point Theorem

Abstract In this article, an application of φ-metric is given via a geometrical example to show how it can help to measure distance for non-planar surfaces where the classical metric becomes incapable. We also introduce the concept of best proximity point and proximal contraction for a class of mappings in a φ-metric space and prove a best proximity point theorem for such class of contraction mappings from which the famous “Wardowski’s fixed point theorem” can be deduced as a particular case. To support our theorem, we provide an example in which Wardowski’s metric fixed point theorem cannot be applied.

Reliability Assessment for a Stochastic Air Transport Network with Multiple Demands

Air transport networks play a significant role in the modern tourism industry, and their operational performance and stability can be measured by reliability analysis. This study, from the perspective of a travel agency, attempts to assess the reliability of a stochastic air transport network (SATN) by considering multiple passenger demands generated by both the starting airport and several connection airports. The SATN is modeled as a stochastic flow network comprised of several nodes and arcs where nodes represent airports, and arcs represent flights connecting two airports. Each flight is associated with a predetermined stochastic capacity following a specific probability distribution, departure time, arrival time, and discount fare. Accordingly, network reliability refers to the probability that the network can successfully transport passengers from their respective source airports to the destination airport within the given travel time and travel cost limit. An algorithm in terms of the concept of lower boundary point is developed to compute network reliability. Furthermore, a simple example and a case study are presented to demonstrate the proposed reliability method and the managerial implications of reliability for travel agencies.

Bi-modal COVID-19 transmission with Caputo fractional derivative using statistical epidemic cases

The progression of the still ongoing COVID-19 epidemic must be studied in the world of differential operators other than those specified with integer-order temporal derivatives, according to ongoing scientific studies in the fields of fractional calculus, mathematical modeling, and epidemiology. Infectious diseases leave behind a historical footprint because of their long memory. With this in mind, the article below makes an effort to probe an epidemiological model using a Caputo differential operator with a singular kernel of power-law type. The ability of the Caputo operator to capture the evolution of complicated phenomena has been demonstrated in a number of studies, prompting us to conduct the analysis presented here. The analysis contains solid reasons while using the fractional operator for the COVID-19 epidemiological paradigm and presents the fixed point concept for the existence and uniqueness of its solutions. Hyers–Ulam–Rassias stability aids in finding model equilibrium, and the nonlinear least squares method yields the unknown parameters that also include the model’s fractional order. The actual cases of the infection support the superiority of the Caputo concept with evidence of smaller residuals. The numerical simulations are run to see how varying important parameters affect the disease’s spread.

Research on Innovative Paths of Brand Marketing in the New Consumption Era from the Perspective of Brand Touchpoints

The purpose of this paper is to explore the innovative path of brand marketing in the new consumption era, and to analyze and look forward to its future development trend. Firstly, through literature review, this paper summarizes the characteristics and trends of the new consumption era, the concept and significance of brand touch points, and the challenges and opportunities faced by brand marketing in this context. Secondly, the paper classifies and characterizes brand touch points, and focuses on the analysis of consumers' brand touch preferences and their influence on consumer decision making in the new consumption era. Then, the innovation path in brand marketing is discussed, including innovation strategies based on digital technology, social media, cross-border cooperation and user generated content. Finally, combining the influence of intelligent technology, consumer behavior change and new technology and new media on brand touch points, the paper makes an in-depth analysis of the future development trend of brand marketing in the new consumption era, and puts forward corresponding conclusions and suggestions. The purpose of this study is to provide effective guidance for brand marketers to meet the challenges of the new consumption era and achieve sustained brand growth and development.

Integrating worthiness with leader identity development for college students.

While leader identity development (LID) and meaning making are interwoven and essential for student development, little research has explicitly explored their intersection. In this article, we briefly summarize the work of two research projects that explored the intersection of LID and meaning making, including a review of the findings that "worthiness" is a central component of the LID process among college students. Next, we propose an Input-Process-Worthiness-Outcome model for LID that highlights the centrality of worthiness, conceptualizing inputs as developmental experiences; processes as meaning making, and outcomes as personal development. Finally, we close with a review of the scholarship behind the concept of worthiness and point out future research directions that require exploration regarding worthiness in LID, particularly among college students.

Skyline query under multidimensional incomplete data based on classification tree

A method for skyline query of multidimensional incomplete data based on a classification tree has been proposed to address the problem of a large amount of useless data in existing skyline queries with multidimensional incomplete data, which leads to low query efficiency and algorithm performance. This method consists of two main parts. The first part is the proposed incomplete data weighted classification tree algorithm. In the first part, an incomplete data weighted classification tree is proposed, and the incomplete data set is classified using this tree. The data classified in the first part serves as the basis for the second step of the query. The second part proposes a skyline query algorithm for multidimensional incomplete data. The concept of optimal virtual points has been recently introduced, effectively reducing the number of comparisons of a large amount of data, thereby improving the query efficiency for incomplete data. Theoretical research and experimental analysis have shown that the proposed method can perform skyline queries for multidimensional incomplete data well, with high query efficiency and accuracy of the algorithm.

A multi-objective particle swarm optimization based on local ideal points

Numerous multi-objective evolutionary algorithms have recently been proposed for the leader selection or archive maintenance process via using reference sets. Despite the potential of this strategy has been demonstrated in the existing literatures, a significant drawback is that this methodology requires additional parameters or predefined reference points, which leads to increasing the complexity in real-world applications and reducing the versatility in addressing various optimization challenges. Novel to this study, a new convergence contribution (CC) evaluator without extra parameters and predefined reference points is presented for convergence evaluation, where the inspiration is drawn from the concept of an ideal point on a Pareto front and the divide-and-conquer technique. Specifically, the local ideal points are introduced in this paper by dynamically fabricating from the approximate Pareto front. Furthermore, the CC evaluator and parallel cell distance (PCD) are cooperatively integrated into a multi-objective particle swarm optimization (MOPSO/CP) to enhance both the global best solution selection and archive maintenance strategies. Comparative experiments on 21 benchmark test functions exhibited that the performances in terms of inverted generational distance and hypervolume of the proposed MOPSO/CP was the best among those of the chosen competitive algorithms. The significant role of the cooperative mechanism and the CC evaluator is further verified by ablation studies. The superiority of the designed algorithm against its competitors is unequivocally highlighted by the experimental results.

Power equalization and optimization of photovoltaic module based on forward-flyback converter

This paper focuses on enhancing the energy extraction efficiency of photovoltaic (PV) modules through the use of a straightforward power converter and control algorithm. This research delves into the electrical characteristics of PV modules, explaining the concepts of global maximum power point, and local maximum power points. By integrating maximum power point tracking algorithms and differential power processing technology, an innovative scheme for power equalization and optimization of PV modules is introduced. The scheme is based on a single-switch multi-winding forward-flyback converter. Using the STP-340-72-Vfh-type PV module as a case study, a simulation model is developed with PLECS simulation software. The simulations cover 30 different irradiance scenarios. The findings illustrate the effectiveness of the proposed PV module power optimization system in achieving maximum power output under different irradiance conditions, achieving an average efficiency of 94.61%. This efficiency rate is 13.95% greater than that of existing global maximum power tracking schemes.

Identification of the continuum field structure at multiple scale levels.

For continuum fields such as turbulence, analyses of the field structure offer insights into their kinematic and dynamic properties. To ensure the analyses are quantitative rather than merely illustrative, two conditions are essential: space-filling and structure quantification. A pertinent example is the dissipation element (DE) structure, which is however susceptible to noisy interference, rendering it inefficient for extracting the large-scale features of the field. In this study, the multi-level DE structure is proposed based on the multi-level extremal point concept. At a given scale level, the entire field can be decomposed into the corresponding space-filling and non-overlapping DEs, each characterized by its length scale l and the scalar difference Δϕ between its two extremal points. We will first elaborate on the fundamental principles of this method. Results from an artificially constructed two-scale field indicate that the decomposed units adequately represent the geometry of the original field. In examining the fractal Brownian motion, a structure function equivalent ⟨Δϕ|l⟩ and an energy spectrum equivalent are introduced. The scaling relation derived from ⟨Δϕ|l⟩ corresponds with the Hurst number. Furthermore, the multi-level DE structure distinctly reveals the two different inertial ranges in two-dimensional turbulence. Overall, this novel structure identification approach holds significant potential for complex analyses concerning the field geometry.

PECULIARITIES OF THE REPRESENTATION OF MORAL AND ETHICAL NORMS IN THE WORKS OF A. SEIDIMBEK

It is known that the spiritual nature of the Kazakh people, which characterizes its spiritual culture, is passed on from generation to generation through the cumulative function of language. This article presents the moral and ethical principles of spiritual culture - the spirit of the people, achievements in the world of the mind, cumulative activities that are passed on from generation to generation. The main direction of our research is to consider the features of the representation of moral and ethical forms in spiritual culture. This message clearly examines the nature of artistic concept in spiritual culture and its relationship with rituals, which need to be studied from a conceptual point of view. As basic research material, we focus on the works of the ethnographer A. Seidimbek, as well as on the peculiarities of the representation of the concepts of “superstition” and “forbidden”, which form a cultural unity in the concepts of the Kazakh people. According to this goal, the study of the mentioned concepts in the scholar’s literary texts in the continuity of language and culture indicates their linguistic representation of the social life and spiritual culture of the nation. The fact that moral and ethical units are reflected in artistic and poetic texts as representatives of an artistic concept is formulated using methods of comparison, modeling and codification in an anthropocentric direction. The results of research work in this direction help to determine the purpose and significance of the system of traditions, rituals and customs in the culture of the people, how they are reflected in the thoughts, feelings and actions of a native speaker; the purpose and significance of traditions and lifestyles, moral and ethical norms (state) of property. It is assumed that, like general folk knowledge, superstition can beseen as a fusion of rational and irrational principles, as well as the result of a syncretic unity. Information about the nature of the connection between understanding the ethnic language and moral and ethical norms, the linguistic picture-image (picture) in rituals as a whole is divided into several layers, and also that the moral and ethical layers in these layers differ in chronological (diachronological) characteristics, which reflected in the words of rituals. Like popular knowledge, superstition is defined as the intersection of rational and irrational principles, as well as the result of syncretic unity. Mental ideas about a person in the cognitive space of ethnocultural names of the Kazakh language, Professor A. Seіdimbek determined that the works represent national and cultural characteristics. The representation of moral and ethical values as a spiritual treasure, a continuation of a person’s past life and present existence in the future is presented with evidence based on the works of A. Seіdimbek.

Some fixed point theorems in C*-algebra valued partial metric spaces

In this present paper, we introduce the concept of ψ-fixed point and we give some fixed point results on C*-algebra valued metric spaces. Then, we deduce analogous results on C*-algebra valued partial metric spaces.

A Data Mining Method for Constitutive Model of Hard Brittle Coal

Data mining is an effective way to solve various types of complex nonlinear problems. And the anisotropy of the mechanical characteristics of coal is a typical nonlinear problem. Hard coal seam are usually characterized by brittleness, which makes them difficult to be crushed efficiently. It is important to improve the efficiency of hard coal crushing by the brittleness characterization method of hard coal is clarified. So the constitutive model and damage mechanism of hard brittle coal was studied in this paper. Damage model of hard brittle coal based on Weibull distribution was established. The damage transition point concept was proposed based on the deformation stage characteristics of hard brittle coal. And effective damage intervals for hard brittle coals can be determined based on the damage transition point. Uniaxial compression experiments of hard brittle coal were simulated using EDEM. The characterization of the effect of discrete elemental eigenstructural parameters on the brittleness of coal was analyzed. And quantitative relationships between shear modulus and brittleness, brittleness and damage transition point were fitted by Matlab. A discrete elemental constitutive model for hard brittle coals was obtained. Finally, the correctness of discrete elemental constitutive model was verified by comparing uniaxial compression experiments with other specimens. The results of this paper were expected to provide a theoretical basis for the crushing technology of hard brittle coal. And the numerical theoretical basis for data mining of the intrinsic model of hard and brittle coal was provided.

Proximitization: Opportunities for manipulating correlations in hybrid organic/2D materials

Van der Waals layered and 2D materials constitute an extraordinary playground for condensed matter physics, since the strong confinement of wavefunctions to two dimensions supports a diverse set of correlated phenomena. By creating carefully designed heterostructures, these can be readily manipulated. In this Perspective, we advance the viewpoint that heterostructures from these materials with thin layers of organic molecules offer an opportunity for creating and manipulating the correlated degrees of freedom in unprecedented ways. We briefly survey what has been accomplished thus far, including proposed mechanisms, before concentrating on unique opportunities offered by the vast selection of available organic molecules. We further introduce the notion of “proximitization” in combination with symmetry breaking as a fertile and potentially unifying conceptual vantage point from which to consider opportunities for tailoring correlations in van der Waals layered materials.

Advanced Deep-Plane Rhytidectomy: Advantages for Neck Treatment and Volumization of the Midface.

The aged neck is the most common motivator for patients seeking facial rejuvenation. Unlike the deflated midface, surgical treatment is still the gold standard for optimal outcomes. It is our view that the majority etiology of both the aged neck and deflated midface is gravity's effects on the superficial soft tissue envelope, leading to soft tissue redundancy. It is also our view that the deep-plane rhytidectomy is supported by anatomy, embryology, and clinical evidence as the best methodology to treat soft tissue redundancy without producing the aesthetic and longevity issues associated with superficial musculoaponeurotic system techniques. As one of the early pioneers in deep-plane rhytidectomy, the lead author will define contemporary advances in deep-plane technique such as dissection entry point, flap design, and flap fixation concepts that allow aggressive approach to treating both the aged neck and deflated midface.

The virtual pivot point concept improves predictions of ground reaction forces.

Ground reaction forces (GRFs) are essential for the analysis of human movement. To measure GRFs, 3D force plates that are fixed to the floor are used with large measuring ranges, excellent accuracy and high sample frequency. For less dynamic movements, like walking or squatting, portable 3D force plates are used, while if just the vertical component of the GRFs is of interest, pressure plates or in-shoe pressure measurements are often preferred. In many cases, however, it is impossible to measure 3D GRFs, e.g., during athletic competitions, at work or everyday life. It is still challenging to predict the horizontal components of the GRFs from kinematics using biomechanical models. The virtual pivot point (VPP) concept states that measured GRFs during walking intercept in a point located above the center of mass, while during running, the GRFs cross each other at a point below the center of mass. In the present study, this concept is used to compare predicted GRFs from measured kinematics with measured 3D-GRFs, not only during walking but also during more static movements like squatting and inline lunge. To predict the GRFs a full-body biomechanical model was used while gradually changing the positions of the VPP. It is shown that an optimal VPP improves the prediction of GRFs not only for walking but also for inline lunge and squats.

Fragment velocity distribution formula of the thin-walled structure subjected to two-line asymmetrically initiated explosion

The thin-walled structure enveloping an explosive charge makes an ammunition warhead. Numerous studies have been conducted on the structural dynamics of the center-initiated charge explosion, including the casing fragmentation behavior and the fragment velocity distribution. Although adopting asymmetrical initiation could enhance the casing fragment velocity and energy utilization, the fragment velocity distribution of a two-line asymmetrically initiated warhead has rarely been studied and few formulae exist. However, the velocity distribution formula is valuable and necessary in the rapid design and lethality evaluation of warheads. Based on the concepts of the stationary point and local charge ratio of the Gurney equation, this work establishes a new velocity distribution formula for the two-line asymmetrically initiated warhead. An asymmetrical ratio function of the stationary point is first proposed for the two-line initiation and validated against the verified numerical modeling. Thereafter, to solve the undetermined parameters of the asymmetrical ratio function, it is discovered that there exists an overlapping effect for fragments at angles of 45° and 135° of the asymmetrical two-line initiation of a 90° central angle. Finally, to validate the entire mathematical model, experiments are conducted using X-ray photography. The mathematical model agrees strongly with the experimental results. This work could offer a solid reference for the rapid design and lethality evaluation of warheads.

Gaining deep leverage? Reflecting and shaping real-world lab impacts through leverage points

Real-world laboratories (RwLs) are gaining further traction as a means to achieve systemic impacts towards sustainability transformation. To guide the analysis of intended impacts, we introduce the concept of leverage points, discerning where, how, and to what end RwLs intervene in systems. Building on conceptual reasoning, we further develop our argument by exploring two RwL cases. Examining RwLs through the lens of the leverage points opens the way for a balanced and comprehensive approach to systemic experimentation. We invite RwL researchers and practitioners to further advance RwLs’ transformative capacity by targeting the design and emerging direction of a system, contributing to a culture of sustainability.

When to Talk and When to Keep It to yourself? Strategies for Legitimating Managerial Intuitions in An Organisational Context

The purpose of this study is to explore the strategies deployed by managers in organisations to legitimate their intuitions. Managerial practice is a continual process of emergence and integration of problems and projects, and by which managers navigate a complex world. To do so, they rely partly on their intuitions, whose effectiveness has largely been demonstrated in the literature. However, the rational model is still considered the optimal cognition and decision-making process in organisations. The persistence of the myth of rationality compels managers to deploy strategies to legitimate their intuitions. But these strategies are poorly understood. The aim of this study therefore was to describe them. For this purpose, we collected 191 accounts of episodes where managers legitimated their intuitions. Our analysis of these accounts revealed seven intuition legitimation strategies. Some of these strategies had not previously been identified in the institutional literature (personalisation, transparency, exploration and compound strategy). For others which had already been partly described (rationalisation, manipulation and relational strategy), we show that managers deploy new modes. These results contribute to the knowledge of legitimation strategies from a conceptual point of view. They also shed some light on the mistrust of intuition that still prevails in organisations, despite its importance.