Analytical Definition Research Articles

Tasks with parameters: a digitized approach

Technological and methodological aspects of using freeware software, such as GeoGebra, Wolfram|Alpha, Maxima, SageMath and GRAN1, for solving tasks with parameters, are presented in the article. Criteria were defined for selection of computer mathematics system (CMS) to solve tasks with parameters, including plotting a graph of a function given in explicit and implicit forms, using a parameter in a function’s analytical definition, and automatically changing the graph of a function depending on the parameter value; ability to changing the parameter step change; plotting of a tangent and a normal to a curve at a point; ability to change the scale; determination of the coordinates of the intersection of graphs of functions; obtaining an analytical solution. In the article, some examples were presented for graphic and analytical tasks that used CMS parameters. GRAN1 and GeoGebra are recommended to use for plotting and analyzing of the graphs

Parametrical synthesis of various radio devices with the set quantity of identical cascades of type «the nonlinear part – the mixed two-port network»

Background. Presence of possibility of analytical definition of a part of parametres of various radio devices, optimum by criterion of maintenance of preset values of modules and phases of transfer functions on necessary quantity of frequencies, considerably reduces time of numerical optimisation of other part of parametres by criterion of formation demanded frequency response and phase response in a strip of frequencies. Till now such problems dared concerning radio devices only with one cascade of type «a nonlinear part - the coordination the device» or «the coordination the device – a nonlinear part». In quality «the coordination devices were used the jet, resistive, complex or mixed two-port networks. The problem of multicascade radio devices with jet two-port networks is solved also. Change of basis for the coordination two-port networks and a place of inclusion of a nonlinear part leads to change of area of a physical realizability. Aim. Working out of algorithms of parametrical synthesis of radio devices with any quantity of identical and unequal cascades of type «a nonlinear part ‑the coordination the mixed two-port network» by criterion of maintenance of the set frequency characteristics. Nonlinear parts are presented in the form of a nonlinear element and parallel either consecutive on a current or pressure of a feedback. Methods. The theory of two-port networks, matrix algebra, a decomposition method, a method of synthesis of actuation microwave devices, numerical methods of optimisation. Results. In interests of achievement of the specified purpose systems of the algebraic equations are generated and solved. Models of optimum two-port networks in the form of mathematical expressions for definition of interrelations between elements of their classical matrix of transfer and for search of dependences of mixed of two-poles from frequency are received. It is shown, that at certain parities between quantity of cascades and values of resistance of a source of a signal and loading of the one-cascade radio device frequency characteristics of one-cascade and multicascade radio devices appear identical or similar. Such schemes are named by equivalent. Conclusion. The comparative analysis of theoretical results (frequency response and phase response radio devices, value of parametres), received by mathematical modelling in system MathCad, and the experimental results received by схемотехнического of modelling in systems OrCad and MicroCap, shows their satisfactory coincidence.

Evaluation of a standard analytical model and definition of efficiency metrics for lunar and planetary excavation

To sustainably live on and explore the lunar and other planetary surfaces, in situ regolith will need to be used for resource extraction and infrastructure development. To evaluate and ensure such safety and efficiency of excavation operations in variable, site-specific regolith terranes with given equipment designs, reliable computational models are necessary. The work here evaluates the accuracy and reliability of a standard, well-established excavation force prediction model using published data from a previous planetary excavation experimental study and establishes efficiency metrics for force reduced excavation as a proof-of-concept. It is shown that the established excavation force prediction model is not able to simulate planetary excavation mechanics sufficiently and hence more advanced models of lunar and planetary excavation are needed to enable safer, faster, and more economical resource acquisition hardware development. The case study of the efficiency metrics being applied to the published data shows informative trends that can be used in future excavation hardware and tool path optimizations. These are recommended for use in future planetary excavation modeling and planning workflows.

The Generic Failure of Lower-Semicontinuity for the Linear Distortion Functional

AbstractWe consider the convexity properties of distortion functionals, particularly the linear distortion, defined for homeomorphisms of domains in Euclidean n-spaces, $$n\ge 3$$ n ≥ 3 . The inner and outer distortion functionals are lower semi-continuous in all dimensions and so for the curve modulus or analytic definitions of quasiconformality it ifollows that if $$ \{ f_{n} \}_{n=1}^{\infty } $$ { f n } n = 1 ∞ is a sequence of K-quasiconformal mappings (here K depends on the particular distortion functional but is the same for every element of the sequence) which converges locally uniformly to a mapping f, then this limit function is also K-quasiconformal. Despite a widespread belief that this was also true for the geometric definition of quasiconformality (defined through the linear distortion $$H({f_{n}})$$ H ( f n ) ), T. Iwaniec gave a specific and surprising example to show that the linear distortion functional is not always lower-semicontinuous on uniformly converging sequences of quasiconformal mappings. Here we show that this failure of lower-semicontinuity is common, perhaps generic in the sense that under mild restrictions on a quasiconformal f, there is a sequence $$ \{f_{n} \}_{n=1}^{\infty } $$ { f n } n = 1 ∞ with $$ {f_{n}}\rightarrow {f}$$ f n → f locally uniformly and with $$\limsup _{n\rightarrow \infty } H( {f_{n}})<H( {f})$$ lim sup n → ∞ H ( f n ) < H ( f ) . Our main result shows this is true for affine mappings. Addressing conjectures of Gehring and Iwaniec we show the jump up in the limit can be arbitrarily large and give conjecturally sharp bounds: for each $$\alpha <\sqrt{2}$$ α < 2 there is $${f_{n}}\rightarrow {f}$$ f n → f locally uniformly with f affine and $$\begin{aligned} \alpha \; \limsup _{n\rightarrow \infty } H( {f_{n}}) < H( {f}) \end{aligned}$$ α lim sup n → ∞ H ( f n ) < H ( f ) We conjecture $$\sqrt{2}$$ 2 to be best possible.

Parametrical synthesis of various radio devices with the set quantity of identical cascades of type «the nonlinear part – the resistive two-port network»

Background. Presence of possibility of analytical definition of a part of parametres of various radio devices, optimum by criterion of maintenance of preset values of modules and phases of transfer functions on necessary quantity of frequencies, considerably reduces time of numerical optimisation of other part of parametres by criterion of formation demanded PFC and FFC in a strip of frequencies. Till now such problems dared concerning radio devices only with one cascade of type «a nonlinear part – the coordination the device» or «the coordination the device – a nonlinear part». In quality согласующего devices were used the jet, resistive, complex or mixed two-port networks. The problem of multicascade radio devices with jet two-port networks is solved also. Change of basis for the coordination two-port networks and a place of inclusion of a nonlinear part leads to change of area of a physical realizability. Aim. Working out of algorithms of parametrical synthesis of radio devices with any quantity of identical and unequal cascades of type «a nonlinear part -the coordination the resistive two-port network» by criterion of maintenance of the set frequency characteristics. Nonlinear parts are presented in the form of a nonlinear element and parallel either consecutive on a current or pressure of a feedback. Methods. The theory of two-port networks, matrix algebra, a decomposition method, a method of synthesis of actuation devices microwave, numerical methods of optimisation. Results. In interests of achievement of the specified purpose systems of the algebraic equations are generated and solved. Models of optimum two-port networks in the form of mathematical expressions for definition of interrelations between elements of their classical matrix of transfer and for search of dependences of resistance of two-poles from frequency are received. It is shown, that at certain parities between quantity of cascades and values of resistance of a source of a signal and loading of the one-cascade radio device frequency characteristics of one-cascade and multicascade radio devices appear identical or similar. Such schemes are named by equivalent. Conclusion. The comparative analysis of theoretical results (PFC and FFC radio devices, value of parametres), received by mathematical modelling in system MathCad, and the experimental results received by circuit engineering modelling in systems OrCad and MicroCap, shows their satisfactory coincidence.

What Is Colonialism? The Dual Claims of a Twentieth-Century Political Category

Although a master category of contemporary social and political thought, the conceptual import of colonialism has long been contested. Turning to the political thought of Jawaharlal Nehru, this article reconstructs the surprising, and often surreptitious, intellectual transformations that rendered colonialism into a generic name for European rule over Asia and Africa. It demonstrates how the dual claims of colonialism—a historical reference for the global event of European expansion and a threadbare analytical definition for a particular form of rule—generated a powerful framework in the anticolonial age. While the expanded juridical uses of colonialism in the Cold War era undermined its historical claims, the priority would reverse with its postcolonial re-signification as a shorthand for studying the paradoxes of global modernity. Reframing these debates, this article argues that reflexive navigation between the dual claims of colonialism is key to a capacious appreciation of its historical and normative contentions.

Can failure be useful in policymaking? The case of EU equal pay policy

Although equal pay for equal work between women and men is a founding principle of the European Union, enshrined in the Treaties since 1957, the gender pay gap stands at 12.7 per cent in 2021 and has only changed minimally for two decades. This article explores a policymaking paradox: the EU equal pay policy seems unaffected by failure, on the contrary, failure seems to contribute to the legitimisation of the policy. The article asks how and why a policy implementation failure framing has been developed in the field of EU equal pay promotion? What is the political function of this framing and what is its impact on the EU policymaking process? Over the years, the EU equal pay policy has been associated with a repeated experience of implementation failure. This failure framing has been particularly present in the debates over the implementation of the 2006 Recast Directive, especially since this frame has been impelled by the quantitative and symbolic strength of the gender pay gap’s percentage. The article shows that this framing performed important functions. From a policymaking perspective, the implementation failure framing allowed the gender equality policy community to keep the issue firmly on the EU agenda and to ride out the dismantling storm. The article also shows that the analytical definition of what constitutes a policy failure should be more nuanced. To conclude, the article asks if this type of failure framing can continue to produce results in an increasingly polarised context such as that of gender equality.

Parametrical synthesis of various radio devices with the set quantity of cascades of type «the mixed two-port network – nonlinear part»

Background. Presence of possibility of analytical definition of a part of parametres of various radio devices, optimum by criterion of maintenance of preset values of modules and phases of transfer functions on necessary quantity of frequencies, considerably reduces time of numerical optimisation of other part of parametres by criterion of formation demanded PFC and FFC in a strip of frequencies. Till now such problems dared concerning radio devices only with one cascade of type «a nonlinear part - the coordination the device» or «the coordination the device - a nonlinear part». In quality coordination devices were used the jet, resistive, complex or mixed two-port networks. The problem of multicascade radio devices with jet two-port networks is solved also. Change of basis for the coordination two-port networks and a place of inclusion of a nonlinear part leads to change of area of a physical realizability.
 Aim. Working out of algorithms of parametrical synthesis of radio devices with any quantity of identical and unequal cascades of type «the coordination the mixed two-port network – a nonlinear part» by criterion of maintenance of the set frequency characteristics. Nonlinear parts are presented in the form of a nonlinear element and parallel either consecutive on a current or pressure of a feedback.
 Methods. The theory of two-port networks, matrix algebra, a decomposition method, a method of synthesis of actuation microwave devices, numerical methods of optimisation.
 Results. In interests of achievement of the specified purpose systems of the algebraic equations are generated and solved. Models of optimum two-port networks in the form of mathematical expressions for definition of interrelations between elements of their classical matrix of transfer and for search of dependences of mixed of two-poles from frequency are received. It is shown, that at certain parities between quantity of identical cascades and values of resistance of a source of a signal and loading of the one-cascade radio device frequency characteristics of one-cascade and multicascade radio devices appear identical or similar. Such schemes are named by equivalent. Use of unequal cascades leads to substantial growth of a working strip of frequencies.
 Conclusion. The comparative analysis of theoretical results (PFC and FFC radio devices, value of parametres), received by mathematical modelling in system «MathCad», and the experimental results received by scheme modelling in systems «OrCad» and «MicroCap», shows their satisfactory coincidence.

Prevention of brittle failure for steel connections utilizing special devices

The present paper proposes the use of a special design procedure devoted to the prevention of brittle failure for welded steel connections. In particular, reference is made to steel frame structures made up of beam elements with I-shaped cross-sections where the connections between columns and beams are usually welded and/or bolted. The proposed new design procedure consists of four subsequent analysis steps; it is based on the identification and analytical definition of new appropriate brittle safe domains defined in the N,V,M space and on the use of suitably designed devices (LRPD), recently proposed by the authors, belonging to the class of the RBS connections. The latter are able to impose prefixed values of internal forces on selected beam element cross-sections, avoiding any modification of the elastic stiffness features of the involved beam. The main novelties of the present study consist in the introduction of new brittle safe domains for I-shaped cross-sections, in the specialization of the LRPD optimal design to the present context and in the definition of a special design strategy which allows to contextually obtain structures safe from the risk of brittle failure as well as being able to dissipate an appropriate amount of plastic strain energy. The numerical application, devoted to plane steel frames, confirms the sound reliability of the procedure and the great flexibility of the utilized LRPDs.

A unified analytical disk cam profile generation methodology using the Instantaneous Center of Rotation for educational purpose

Cam design is a fundamental part of the Mechanism and Machine Theory (MMT) and is included in the vast majority of MMT books. Cam profile design is usually determined with graphical and analytical methods. Graphical methods are didactically very successful to introduce the theory of cam profile generation in a simple way. In turn, analytical methods allow computer implementations of cam profile generation in order to reproduce it accurately. Most modern MMT books describe analytical methods using geometric equations and envelope theory. However, the analytical profile definition depends on the specific type of follower and there is a lack of a general formulation. This work presents a unified and general analytical formulation for the disk cam profile determination. Based on the Instantaneous Center of Rotation and the kinematic inversion, the formulation provides analytical expressions of the cam profile and is applicable to any type of follower. Thus, the unified formulation can be used in forthcoming books on this discipline.

A finite element model for investigating the influence of keel design and position on unicompartmental knee replacement cementless tibial component fixation

ObjectivesThe cementless Oxford Unicompartmental Knee Replacement (OUKR) tibial component relies on an interference fit to achieve initial fixation. The behaviour at the implant-bone interface is not fully understood and hence modelling of implants using Finite Element (FE) software is challenging. With a goal of exploring alternative implant designs with lower fracture risk and adequate fixation, this study aims to investigate whether optimisation of FE model parameters could accurately reproduce experimental results of a pull-out test which assesses fixation. Materials and methodsFinite element models of implants with three methods of fixation (standard keel, small keel, and peg) in a bone analogue foam block were created, in which implants were modelled using an analytical rigid definition and the foam block was modelled as a homogenous linear isotropic material. The total interference and elastic slip were varied in these models and optimised by comparing simulated and experimental results of pull-out tests for two (standard and peg) implant geometries. Then the optimised interference and elastic slip were validated by comparing simulated and experimental data of a third (small keel) implant geometry. ResultsThe optimisation of parameters established an interference of 0.16 mm and an elastic slip of 0.20 mm as most suitable for modelling the experimental force–displacement plots during pull-out. This combination of parameters accurately reproduced the experimental results of the small keel geometry. The maximum pull-out forces from the FE models were consistent with experimental data for each implant design. ConclusionsThis study shows that experimental pull-out tests can be accurately modelled using adjusted interference values and non-linear friction and outlines a method for determining these parameters. This study demonstrates that complex problems in modelling implant behaviour can be addressed with relatively simple models. This can potentially lead to the development of implants with reduced risk of failure.

What the Milan conference has taught us about analytical performance specification model definition and measurand allocation.

Analytical performance specifications (APS) represent the criteria that specify the quality required for laboratory test information to satisfy clinical needs. In 2014 the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) considered timely to update the topic of APS by organizing a conference in Milan in which some strategic concepts were proposed. Here I summarize the essential points representing the EFLM Strategic Conference heritage and discuss the approaches that will permit us to become more concrete, including roles and main actions expected from each of involved stakeholders for contributing a quantum leap forward in the way of practicality of Milan consensus about APS.

Методы предметной аналитики в высшем образовании как факторы формирования компетенций профессорско-преподавательского состава

The subject of the study is the mechanisms of applying the methods of subject analysis in the higher education system of Russia in the context of the digitalization of the economy. World experience has shown that information technology contributes to progress in various fields, including the substantive analysis of economic processes. The use of digital innovation tools is an important factor in improving the educational process, forming the competencies of the teaching staff and ensuring the global competitiveness of Russian higher education, taking into account Vladimir Putin's Messages to the Federal Assembly dated February 29, 2024. The purpose of the work is to identify the main directions and methods of subject analysis as a driver for the formation of an analytical approach to decision—making that contribute to the successful work of university graduates in the field of industrial policy implementation; expansion of reproductive processes; development of the sphere of servants, trade and other areas of professional activity in the digital environment of reproductive processes. The definition of subject analytics is given. The methods of systematization of information are considered. It is concluded that the key methods of subject analysis have a universal character, which includes determining the purpose of obtaining the necessary data, their list, scope of application; data collection and purification; their visualization and quantitative analysis. The expansion of students' practical work in the digital environment and their acquisition of subject analysis competencies within the framework of educational programs of higher education in Russia is an important area of academic work directly related to the ability to correctly use information, analytical tools and methods in order to solve important problems of economic development of the Russian Federation.

Developing an Analytical Definition of Cybercrime

Developing an Analytical Definition of Cybercrime

Intradialytic Hypotension and Mortality in Adolescents and Young Adults With Kidney Failure Receiving Maintenance Hemodialysis

Rationale & ObjectiveIntradialytic hypotension is associated with mortality in adults with kidney failure requiring hemodialysis; however, large-scale pediatric studies are lacking. Moreover, there is no evidence-based consensus definition of intradialytic hypotension in the pediatric literature. We aimed to examine the association of commonly used definitions of intradialytic hypotension with mortality in adolescents and young adults. Study DesignRetrospective observational cohort study. Setting& Participants: 1,199 adolescents and young adults (n=320, ages 10-18 years and n= 879, ages 19-21 years) who initiated hemodialysis at a large dialysis organization. ExposuresDifferent definitions of intradialytic hypotension. Outcome2-year all-cause mortality. Analytical ApproachSeveral definitions of intradialytic hypotension were selected a priori based on a literature review. Patients were classified as having intradialytic hypotension if it was present in at least 30% of hemodialysis treatments during the first 90 days after dialysis initiation. Cox proportional hazards regression was used to test whether intradialytic hypotension associated with 2-year all-cause mortality. ResultsOver a 2 year follow up period, 54 (4.5%) patients died. Dependent on its definition, intradialytic hypotension was present in 2.9% to 61.1% of patients. After multivariable adjustment for sociodemographic and clinical characteristics, we found no association of intradialytic hypotension with mortality. Results were consistent across subgroups stratified by age (<18 and 19-21 years old) and pre-dialysis systolic blood pressure (<120, 120-150, >150 mmHg). We also examined intradialytic hypotension as occurring in <5%, 5-29%, 30-50%, and >50% of baseline treatments, and did not find a dose-response association with mortality (p value > 0.05). LimitationsDue to low event rates, our current sample size may have been too small to detect a difference in mortality. ConclusionsOur study found that intradialytic hypotension was not associated with mortality in adolescents and young adults.

From book to bedside? A critical perspective on the debate about "translational bioethics".

The concept of "translational bioethics" has received considerable attention in recent years. Most publications draw an analogy to translational medicine and describe bioethical research that aims at implementing and evaluating ethical interventions. However, current accounts of translational bioethics are often rather vague and seem to differ with regard to conceptual and methodological assumptions. It is not clear and scarcely analyzed what exactly "translation" in the field of bioethics means, in particular regarding goals and processes so that it is justified to appeal to translational medicine. In this article, we thus explore possible analogies and disanalogies between translational medicine and translational bioethics to establish whether the often occurring reference to concepts of translational medicine in the field of bioethics can be justified by substantial analogies. We will first provide an account of different models of translational medicine. In a second step, we will propose an analytic definition that explicitly articulates the essential characteristics of "translational research" irrespective of the research field (i.e., biomedicine, bioethics). Subsequently, we will explore whether and in how far general characteristics and phases of translational research in medicine can be applied to translational research in bioethics. Based on our analyses, we will come to the skeptical conclusion that at present there are considerable conceptual disanalogies and unsolved conceptual problems that disallow using "translational bioethics" in a meaningful analogy to respective accounts in biomedicine. Nevertheless, we will demonstrate that some insights gained by the conceptual accounts of translational medicine can contribute to advance current research activities in bioethics.

Analytic Osculating Frozen Orbits Under Perturbation

This work provides a set of closed-form analytical expressions to define osculating frozen orbits under the perturbation effects of the oblateness of the main celestial body. To this end, an analytical perturbation method based on osculating elements is proposed to characterize, define, and study the three existing families of frozen orbits in closed form: the two families of frozen orbits close to the critical inclination and the family of frozen orbits appearing at low eccentricity values. As such, this work aims to complement other analytical approaches based on mean elements by providing an alternative methodology based on the more natural osculating elements that is able to generate closed-form expressions for all known frozen conditions in the main satellite problem. Additionally, this work includes the first- and second-order approximate solutions of the proposed perturbation method, including their applications to the analytical definition of frozen orbits, repeating ground-track orbits, and sun-synchronous orbits under this perturbation. Examples of applications are also provided to show the expected error performance of the proposed approach.

Extinction and attenuation by voids in absorbing host media.

Extinction and attenuation by particles in an absorbing host have suffered a long-lasting controversy, which has impeded the physical insights on the radiative transfer in the voids dispersed composite. In this paper, we outline the existing extinction definitions, including an equivalence theorem neglecting the host absorption, the near-field analytical definition neglecting the far-field effects, and the operational way which simulates the actual detector readings. It is shown that, under the independent scattering approximation, the generalized operational definition is equivalent to a recent effective medium method according to the rigorous theory of multiple scattering. Using this generalized extinction, we show the important influences of the host absorption on the void extinction. Specifically, at the void resonance, the extinction cross sections of the small voids can be positive, zero, and even negative, which is regulated quantitively by host absorption. Considering the voids in SiC or Ag, the intriguing properties are verified through the attenuation coefficient calculated by the Maxwell-Garnett effective medium theory. In contrast, the equivalent theorem cannot describe any void resonance structures in the absorbing media. Also, the near-field definition fails to generate negative extinction and cannot thus describe the diminished total absorption by the voids. Our results might provide a better understanding of complex scattering theory in absorbing media.

Continuity and Change in Islamic Religious Authority

This article aims to elaborate on the debate surrounding continuity and change in Islamic religious authority. The discussion begins by establishing a framework for understanding the analytical definition of authority before delving into the dimensions that experience continuity and change. Arendt defines authority as a relationship, signifying a connection to a specific discursive tradition, knowledge, and history. Additionally, it involves a relationship with others who may recognize, accept, or contest this connection. Building upon Arendt’s definition, the article deconstructs the nature of this relationship, emphasizing three constitutive elements: the notion of a past, the connection to the foundational past, and the ability to convey and enhance that model. This includes the augmentation of the foundational past and the ability to elicit obedience without resorting to coercion. What sets authority apart is its unique capacity to foster obedience through a relationship, free from coercion. To identify the constituents of authority, the article explores the question of continuity and change in a more productive manner by focusing on each of its three constitutive elements.

Analytical determination of eclipse entry and exit points considering a conical shadow and oblate Earth

This paper presents a new analytical procedure to model the umbra generated during an eclipse considering an oblate ellipsoid of rotation as occulting body and a conical shadow. The method is based on purely geometrical considerations and results in the analytical definition of the entry and exit points from the conical shadow starting from the knowledge of the Sun position vector, the occulting body position vector and the orbital elements of the spacecraft orbiting the occulting body. The conical shadow also permits analytical definition of the entry and exit points of the penumbra region, which cannot be defined by using the classic cylindrical approach. Some numerical applications are proposed to test the effectiveness of the analytical formulations and to check the error in the prediction of the time spent in the shadow by the satellite. Finally, a discussion between the new conical shadow model and the classic cylindrical eclipse is carried out to see the improvements introduced by the refined geometry and the effects on space missions focusing on the cumulative error when multiple revolutions are considered.