Using Spline Functions for the Shape Description of the Surface of Shell Structures

2014 ◽  
Vol 13 (1) ◽  
Author(s):  
Grzegorz Lenda
Keyword(s):  
Point Of View ◽  
Shell Structures ◽  
Shape Description ◽  
Basic Parameters ◽  
Point Set ◽  
The One ◽  
Half Axis ◽  
The Given ◽  
The Ideal

AbstractThe assessment of the cover shape of shell structures makes an important issue both from the point of view of safety, as well as functionality of the construction. The most numerous group among this type of constructions are objects having the shape of a quadric (cooling towers, tanks with gas and liquids, radio-telescope dishes etc.). The material from observation of these objects (point sets), collected during periodic measurements is usually converted into a continuous form in the process of approximation, with the use of the quadric surface. The created models, are then applied in the assessment of the deformation of surface in the given period of time. Such a procedure has, however, some significant limitations. The approximation with the use of quadrics, allows the determination of basic dimensions and location of the construction, however it results in ideal objects, not providing any information on local surface deformations. They can only be defined by comparison of the model with the point set of observations. If the periodic measurements are carried out in independent, separate points, then it will be impossible to define the existing deformations directly. The second problem results from the one-equation character of the ideal approximation model. Real deformations of the object change its basic parameters, inter alia the lengths of half-axis of main quadrics. The third problem appears when the construction is not a quadric; no information on the equation describing its shape is available either. Accepting wrong kind of approximation function, causes the creation of a model of large deviations from the observed points.All the mentioned above inconveniences can be avoided by applying splines to the shape description of the surface of shell structures. The use of the function of this type, however, comes across other types of limitations. This study deals with the above subject, presenting several methods allowing the increase of accuracy and decrease of the time of the modelling with the splines.

Improving the accuracy of the synthesis of the amplitude-phase distribution in an antenna array with an arbitrary geometry

2021 ◽  
Author(s):  
D.D. Gabrielyan ◽  
Dan.S. Fedorov ◽  
Den.S. Fedorov
Keyword(s):  
Antenna Arrays ◽  
Phase Distribution ◽  
Problem Statement ◽  
Arbitrary Geometry ◽  
Radiating Element ◽  
Path Measurement ◽  
The One ◽  
The Given ◽  
Single Approach

Problem statement. One of the constructing antenna arrays (AA) topic is related to the determination of complex amplitudes at the input of the antenna-feeder path, which, taking into account the distortions introduced by the its, ensure the formation of an amplitude-phase distribution (APD), in which the formed DP differed minimally from the set one. The statement of the problem assumes the known number and coordinates of the location of the emitters, the DP of the radiating element in the composition of the radiating opening, a given radiation pattern. It is required to form an APD in a given opening of the AA, which ensures the formation of a DP that has a minimum deviation from the specified one. To solve the problem, the following algorithm is proposed: determination of the APD at the input of the antenna-feeder path, which ensures the formation of a given DP in the absence of distortions introduced by the antenna-feeder path; measurement for the selected directions of the generated DP with the selected APD in the presence of APD distortions introduced by the antenna-feeder path; formation of a refined APD that ensures the fulfillment of required condition in the presence of distortions introduced by the antenna-feeder path of the AA. Objective. Minimize the root-mean-square deviation of the generated PD from the one specified for the AP with the opening of an arbitrary geometry. Results. The results obtained showed: The formulation of the problem of synthesis of the APD allows us to consider, within the framework of a single approach, AA with different geometries, including AA with a non-planar radiating opening, no restrictions are imposed on the shape of the boundary, and linear (quasi-ring) AA, the emitters of which are located along an arbitrary mane. Using the proposed algorithm for the synthesis of APD, which includes three main stages: the formation of APD for a given DP; measurement of complex values of the generated DP; refinement of the APD by determining the corrections while minimizing the standard deviation (SD) between the specified and formed at the first stage of the DP, allows us to form an APD that provides a minimum SD between the specified and formed DP. The performed studies have shown that when choosing the number of angular directions in each plane, comparable to the number of emitters in this plane, there is a large difference between the given and formed DP. When the number of angular directions for measuring the DP is approximately three times greater than the number of emitters in a given plane, the SD between the specified and formed DP is close to the minimum value and practically does not change with further increase.

Integration of one-dimensional equations of motions

2020 ◽  
pp. 79-90
Author(s):  
Gleb L. Kotkin ◽  
Valeriy G. Serbo
Keyword(s):  
Potential Energy ◽  
Field Change ◽  
One Dimensional ◽  
System A ◽  
Small Correction ◽  
The Law ◽  
The One ◽  
The Given ◽  
Equations Of Motions

If the potential energy is independent of time, the energy of the system remains constant during the motion of a closed system. A system with one degree of freedom allows for the determination of the law of motion in quadrature. In this chapter, the authors consider motion of the particles in the one-dimensional fields. They discuss also how the law and the period of a particle moving in the potential field change due to adding to the given field a small correction.

From spatial value to panopticon: study of organizational changes in riverside areas in Poznań

2020 ◽  
Vol 33 (7) ◽  
pp. 1297-1312
Author(s):  
Przemysław Wechta
Keyword(s):  
Urban Space ◽  
Research Study ◽  
Low Cost ◽  
Point Of View ◽  
Organizational Changes ◽  
Government Officials ◽  
Content Type ◽  
Community Resistance ◽  
The One

PurposeThe aim of the article is to analyze the process of creating spatial value. The object of the analysis concerns the riverside areas of the city of Poznan. The study focuses on spontaneous practices that are outside the legal regulations, thanks to less-visited places which have gained popularity among residents and disciplinary techniques introduced by government officials in response to such activities.Design/methodology/approachAt the theoretical level, the study is primarily based on Florian Znaniecki's spatial value concept and Michel Foucault's concept of power. The empirical research study includes quantitative (questionnaire-based interviews) and qualitative methods (expert interviews and content analysis).FindingsIdentification of the method of creating spatial value which does not require direct financial outlays; determination of disciplinary techniques used by government officials ultimately led to a reduction in the spatial value.Originality/valueThe article reveals the hidden mechanisms of functioning of the authority that defends itself against the reduction of its powers. It is an alternate way of analyzing and interpreting organizational changes in urban space to the one promoted by the Poznan authorities. The results can be used in various ways. Researchers representing the critical trend of urban research can interpret the process of creating spatial value by residents in terms of community, resistance and alternates to the actions of the authorities. From this point of view, the research study is interventional and exposing in nature. On the other hand, for city decision makers allowing the possibility to consume alcohol in a given area can be an effective, low-cost way of revitalizing it. Research can also be useful in assessing the effectiveness of particular disciplinary techniques by public officers.

Integration of one-dimensional equations of motion

2020 ◽  
pp. 3-5
Author(s):  
Gleb L. Kotkin ◽  
Valeriy G. Serbo
Keyword(s):  
Potential Energy ◽  
Equations Of Motion ◽  
Field Change ◽  
One Dimensional ◽  
System A ◽  
Small Correction ◽  
The Law ◽  
The One ◽  
The Given

If the potential energy is independent of time, the energy of the system remains constant during the motion of a closed system. A system with one degree of freedom allows for the determination of the law of motion in quadrature. In this chapter, the authors consider motion of the particles in the one-dimensional fields. They discuss also how the law and the period of a particle moving in the potential field change due to adding to the given field a small correction.

scholarly journals XVII. On the double tangents of a curve of the fourth order

1861 ◽  
Vol 151 ◽  
pp. 357-362 ◽  
Keyword(s):  
Fourth Order ◽  
Plane Curve ◽  
Original Form ◽  
Quartic Curve ◽  
Cubic Curve ◽  
Seventh Order ◽  
The One ◽  
The Given ◽  
In Virtue Of

The present memoir is intended to be supplementary to that "On the Double Tangents of a Plane Curve.” I take the opportunity of correcting an error which I have there allen into, and which is rather a misleading one, viz., the emanants U 1 , U 2 ,.. were numerically determined in such manner as to became equal to U on putting ( x 1 , y 1 , z 1 ) equal to ( x, y, z ); the numerical determination should have been (and in the latter part of the memoir is assumed to be) such as to render H 1 , H 2 , &c. equal to H, on making the substitution in question; that is, in the place of the formulæ U 1 = 1/ n ( x 1 ∂ x + y 1 ∂ y + z 1 ∂ z ) 2 U, U 2 = 1/ n ( n -1)( x 1 ∂ x + y 1 ∂ y + z 1 ∂ z ) 2 U, &c., here ought to have been U 1 = 1/( n - 2)( x 1 ∂ x + y 1 ∂ y + z 1 ∂ z )U, U 2 = 1/( n - 2)( n - 3) ( x 1 ∂ x + y 1 ∂ y + z 1 ∂ z ) 2 U, &c. The points of contact of the double tangents of the curve of the fourth order or quartic U = 0, are given as the intersections of the curve with a curve of the fourteenth order II = 0; the last-mentioned curve is not absolutely determinate, since instead of II = 0, we may, it Is clear, write II + MU = 0, where M is an arbitrary function of the seventh order. I have in the memoir spoken of Hesse’s original form (say II 1 = 0) of the curve of the fourteenth order obtained by him in 1850, and of his transformed form (say II 2 = 0) obtained in 1856. The method in the memoir itself (Mr. Salmon’s method) gives, in the case in question of a quartic curve, a third form, say II 3 = 0. It appears by his paper “On the Determination of the Points of Contact of Double Tangents to an Algebraic Curve,” that Mr. Salmon has verified by algebraic transformations the equivalence of the last-mentioned form with those of Hesse; but the process is not given. The object of the present memoir is to demonstrate the equivalence in question, viz. that of the equation II 3 = 0 with the one or other of the equations II 1 = 0, II 2 = 0, in virtue of the equation U = 0. The transformation depends, 1st, on a theorem used by Hesse for the deduction of his second form II 2 = 0 from the original form II 1 = 0, which theorem is given in his paper “Transformation der Gleichung der Curven 14ten Grades welche eine gegebene Curve 4ten Grades in den Berührungspuncten ihrer Doppeltangenten schneiden,” Crelle , t. lii. pp. 97-103 (1856), containing the transformation in question; I prove this theorem in a different and (as it appears to me) more simple maimer; 2nd, on a theorem relating to a cubic curve proved incidentally in my memoir“ On the Conic of Five-pointic Contactat any point of a Plane Curve”, the cubic curve being in the present case any first emanant of the given quartic curve: the demonstration occupies only a single paragraph, and it is here reproduced; and I reproduce also Hesse’s demonstration of the equivalence of the two forms II 1 = 0 and II 2 = 0.

Two Kinds of Soft Facts

2018 ◽  
Vol 95 (1) ◽  
pp. 34-53 ◽  
Author(s):  
Ciro De Florio ◽  
Aldo Frigerio
Keyword(s):  
Point Of View ◽  
The Other ◽  
Future Contingents ◽  
The Past ◽  
Other Hand ◽  
Divine Knowledge ◽  
Soft Fact ◽  
The One ◽  
Definition Of

The concept of soft facts is crucial for the Ockhamistic analysis of the divine knowledge of future contingents; moreover, this notion is important in itself because it concerns the structure of the facts that depend—in some sense—on other future facts. However, the debate on soft facts is often flawed by the unaware use of two different notions of soft facts. The facts of the first kind are supervenient on temporal facts: By bringing about a temporal fact, the agent can bring about these facts. However, on the one hand, the determination of the existence of these facts does not affect the past; on the other hand, assimilating divine knowledge into this kind of facts does not help the Ockhamist. The authors will argue that, to vindicate Ockhamism, another definition of “soft fact” is necessary, which turns out to be much more demanding from a metaphysical point of view.

scholarly journals The comparison of deciduous teeth eruption pattern in small gestational age (SGA) and appropriate gestational age (AGA) children

2010 ◽  
Vol 22 (2) ◽  
Author(s):  
Irawati Kirana ◽  
Roosje Rosita Oewen ◽  
Williyanti Soewondo
Keyword(s):  
Gestational Age ◽  
First Trimester ◽  
Point Of View ◽  
Deciduous Teeth ◽  
Cross Sectional ◽  
Intrauterine Growth ◽  
First Trimester Of Pregnancy ◽  
Cross Sectional Design ◽  
The Given

Introduction: Small Gestational Age (SGA) children is defined as infant whose birth’s weight was below the tenth percentile intrauterine growth and development curve of Lubchenco. There are two types of SGA children, namely symmetrycal SGA (the disturbance occurred in the first trimester of pregnancy) and asymmetrical SGA (the disturbance occured in second and third trimesters of pregnancy). The aim of this research was to obtain the deciduous teeth eruption patterns in symmetrical and asymmetrical of SGA children, based on baby teeth that  have erupted the eruption of primary teeth. Methods: The research design was descriptive and analytical, with cross-sectional design and using the given sample size. The sample were 28 SGA children aged 1-4 years and 33 Appropriate Gestational Age (AGA) children. Determination of SGA children based on Ponderal Index. Eruptive stage was determined by Nola Modification Scoring by the score between 0-4. (Score (0) for tooth that have not erupted; (1) tooth emerge, (2) ⅓ crown  erupted tooth, (3) ½ crown erupted tooth, (4) full crown tooth. Results: The results showed, that there were differences in the pattern of deciduous teeth eruption based on teeth eruption stages that have been erupted. Eruption pattern of SGA children deciduous teeth were slower than the eruption pattern of AGA children deciduous teeth. Conclusion: Different patterns of deciduous teeth eruption in symmetrical SGA children and asymmetrical SGA children were showed. Viewed from the stand point of view the stage of teeth eruption, the deciduous teeth eruption pattern of symmetrical SGA children was slower than the asymmetrical SGA children.

Increase of Accuracy of Well Bottom Position Determination by Minimization of Seismic Vibration Finding Errors

2014 ◽  
Vol 682 ◽  
pp. 154-159
Author(s):  
G. Tsvetkov ◽  
V. Kostitsyn
Keyword(s):  
Total Force ◽  
Axially Symmetric ◽  
Transverse Waves ◽  
Bottom Position ◽  
Seismic Surveying ◽  
Seismic Vibrations ◽  
The Given ◽  
The Ideal

In the given work, on the basis of the carried out researches at the decision of seismic surveying tasks an attempt on advancement of methods and means of excitation of elastic vibrations by the generator of seismic vibrations (GSV) is made. The geometry of the real GSV differs from the ideal axially symmetric form resulting in deviations of parameters of geometry of mass (deviations of the centre of mass, main central axes of inertia), and is a consequence of the static and dynamic disbalance.The character of forces and moments acting on the GSV, as a whole and on separate units, depends on quality of the law of change of total force of resistance of escapement and return of plunger; dynamic loads resuling in occurrence of transverse waves at excitation of seismic vibrations deterioting the accuracy of determination of well bottom position are formed.

scholarly journals The risky temptation of wanting to be the Legislator of the Language

2021 ◽  
pp. 85-107
Author(s):  
Silvia Niccolai
Keyword(s):  
Point Of View ◽  
Legal Positivism ◽  
The Other ◽  
Language And Thought ◽  
Open Texture ◽  
Living Together ◽  
History Of ◽  
History Of Law ◽  
The One ◽  
The Ideal

Criticizing the modern, rationalistic temptation to legislate on language, this article argues that issues of 'political correctness' are an aspect of the eternal problem of definitions in law. This problem has in its turn profound connections, on the one hand, with the need, entirely human, for a correct (not one-sided or arbitrary) relationship with reality; and, on the other hand, with the insidious attempt –  which is all the same typically human – to deny reality, with its conflicts and ambiguities, and to replace it with a false,  less challenging reality of 'objective' certainties. In law, the problem of definitions has historically followed many and different itineraries; this article briefly traces some, trying to show that the ideal of an objective definition – an ideal epitomized in the 'norm' idealized by legal positivism – has always co-existed, in the legal experience, with the different ideal of a subjective definition (dialectical, controversial, negative, refutative), of which the ancient maxims of equity, the regulae iuris, offer a model. The problem of legal definitions in law is then a matter of forms of reason that confront each other throughout the history of law, the one investing on a calculating and instrumental rationality, the other relying on a more porous and flexible reason. In the legacy of this second point of view – which, the article maintains, has more than one analogy with the paths of contemporary Feminist 'Radical' Thought – antidotes can be found to the temptation to legislate on language, which is risky. If objectivity tries to suppress subjectivity, in fact, this is in the name of the illusion, that problems that trouble the human conditions can be fixed, defined, solved once and for all. It is instead the open texture of these problems, which cannot be defined once and for all, that encourages the work of language and thought. And these latter are the resources for a living together really capable of freedom and equality, of change and future.

scholarly journals Gender Dynamics in Islamic Law Perspective: Descriptive Study in Idaman Village, Banten

SIASAT ◽  
2021 ◽  
Vol 6 (1) ◽  
pp. 73-81
Author(s):  
Tolkah Tolkah
Keyword(s):  
Islamic Law ◽  
Point Of View ◽  
Dark Side ◽  
Gender Dynamics ◽  
Gender Status ◽  
The Status ◽  
The Village ◽  
Descriptive Method ◽  
The Ideal

Gender differences and cultural structures in the ideal village area classify the status of men and women. Islamic law has a different point of view in seeing gender status in Indonesian society. This study looks at the dynamics of gender in the village of ideal banten from the perspective of Islamic law. This study used a descriptive method with a qualitative approach, while the determination of the informants was purposvie sampling by considering traditional leaders, village heads and communities and finally data collection through primary and secondary. The results showed that gender dynamics inequality as a problem in the Islamic world, as well as the dark side of masculine-related behaviors cannot only be approached through the perspective of women alone. 

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