scholarly journals XXI. On skew surfaces, otherwise scrolls

1863 ◽  
Vol 153 ◽  
pp. 453-483 ◽  
Keyword(s):  
Three Dimensions ◽  
Linear Functions ◽  
Ruled Surfaces ◽  
Nodal Curves ◽  
Nodal Curve ◽  
Double Points ◽  
The Subject ◽  
Line Meeting

It may be convenient to mention at the outset that, in the paper “On the Theory of Skew Surfaces”, I pointed out that upon any skew surface of the order n there is a singular (or nodal) curve meeting each generating line in ( n -2) points, and that the class of the circumscribed cone (or, what is the same thing, the class of the surface) is equal to the order n of the surface. In the paper “On a Class of Ruled Surfaces”, Dr. Salmon considered the surface generated by a line which meets three curves of the orders m , n , p respectively : such surface is there shown to be of the order =2 mnp ; and it is noticed that there are upon it a certain number of double right lines (nodal gene­rators); to determine the number of these, it was necessary to consider the skew surface generated by a line meeting a given right line and a given curve of the order m twice; and the order of such surface is found to be =½ m ( m —1)+ h , where h is the number of apparent double points of the curve. The theory is somewhat further developed in Dr. Salmon’s memoir “On the Degree of a Surface reciprocal to a given one”, where certain minor limits are given for the orders of the nodal curves on the skew surface generated by a line meeting a given right line and two curves of the orders m and n and respectively, and on that generated by a line meeting a given right line and a curve of the order m twice. And in the same memoir the author considers the skew surface generated by a line the equations whereof are ( a , ..)( t , 1) m =0 ( a' , ..)( t , 1) n =0, where a , .. a' , .. are any linear functions of the coordinates, and t is an arbitrary para­meter. And the same theories are reproduced in the ‘Treatise on the Analytic Geo­metry of Three Dimensions’ §. I will also, though it is less closely connected with the subject of the present memoir, refer to a paper by M. Chasles, “Description des Courbes à double courbure de tous les ordres sur les surfaces réglées du troisiѐme et du quatriѐme ordre”||.

scholarly journals Sustainability Requirements of Digital Twin-Based Systems: A Meta Systematic Literature Review

2021 ◽  
Vol 11 (12) ◽  
pp. 5519
Author(s):  
Rui Carvalho ◽  
Alberto Rodrigues da Silva
Keyword(s):  
Life Cycle ◽  
Literature Review ◽  
Systematic Literature Review ◽  
Environmental Sustainability ◽  
Product Life Cycle ◽  
Data Communication ◽  
Three Dimensions ◽  
Digital Twin ◽  
The Subject ◽  
Reducing Costs

Sustainable development was defined by the UN in 1987 as development that meets the needs of the present without compromising the ability of future generations to meet their own needs, and this is a core concept in this paper. This work acknowledges the three dimensions of sustainability, i.e., economic, social, and environmental, but its focus is on this last one. A digital twin (DT) is frequently described as a physical entity with a virtual counterpart, and the data, connections between the two, implying the existence of connectors and blocks for efficient and effective data communication. This paper provides a meta systematic literature review (SLR) (i.e., an SLR of SLRs) regarding the sustainability requirements of DT-based systems. Numerous papers on the subject of DT were also selected because they cited the analyzed SLRs and were considered relevant to the purposes of this research. From the selection and analysis of 29 papers, several limitations and challenges were identified: the perceived benefits of DTs are not clearly understood; DTs across the product life cycle or the DT life cycle are not sufficiently studied; it is not clear how DTs can contribute to reducing costs or supporting decision-making; technical implementation of DTs must be improved and better integrated in the context of the IoT; the level of fidelity of DTs is not entirely evaluated in terms of their parameters, accuracy, and level of abstraction; and the ownership of data stored within DTs should be better understood. Furthermore, from our research, it was not possible to find a paper discussing DTs only in regard to environmental sustainability.

scholarly journals EXTENSIONS AND RANK-2 VECTOR BUNDLES ON IRREDUCIBLE NODAL CURVES

2005 ◽  
Vol 16 (10) ◽  
pp. 1081-1118
Author(s):  
D. ARCARA
Keyword(s):  
Moduli Space ◽  
Vector Bundles ◽  
Rational Map ◽  
Nodal Curves ◽  
Nodal Curve ◽  
Stable Vector Bundles ◽  
Rank 2 ◽  
Rank 2 Vector Bundles

We generalize Bertram's work on rank two vector bundles to an irreducible projective nodal curve C. We use the natural rational map [Formula: see text] defined by [Formula: see text] to study a compactification [Formula: see text] of the moduli space [Formula: see text] of semi-stable vector bundles of rank 2 and determinant L on C. In particular, we resolve the indeterminancy of ϕL in the case deg L = 3,4 via a sequence of three blow-ups with smooth centers.

scholarly journals The Role of Empathy in Health and Social Care Professionals

Healthcare ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 26 ◽  
Author(s):  
Maria Moudatsou ◽  
Areti Stavropoulou ◽  
Anastas Philalithis ◽  
Sofia Koukouli
Keyword(s):  
Undergraduate Students ◽  
Health Professionals ◽  
Social Care ◽  
Academic Culture ◽  
Three Dimensions ◽  
Number Of Patients ◽  
Health And Social Care ◽  
Current Article ◽  
The Subject

The current article is an integrative and analytical literature review on the concept and meaning of empathy in health and social care professionals. Empathy, i.e., the ability to understand the personal experience of the patient without bonding with them, constitutes an important communication skill for a health professional, one that includes three dimensions: the emotional, cognitive, and behavioral. It has been proven that health professionals with high levels of empathy operate more efficiently as to the fulfillment of their role in eliciting therapeutic change. The empathetic professional comprehends the needs of the health care users, as the latter feel safe to express the thoughts and problems that concern them. Although the importance of empathy is undeniable, a significantly high percentage of health professionals seem to find it difficult to adopt a model of empathetic communication in their everyday practice. Some of the factors that negatively influence the development of empathy are the high number of patients that professionals have to manage, the lack of adequate time, the focus on therapy within the existing academic culture, but also the lack of education in empathy. Developing empathetic skills should not only be the underlying objective in the teaching process of health and social care undergraduate students, but also the subject of the lifelong and continuous education of professionals.

Kinematic Analysis of Spherical Four-Bar Linkages via the Inflection Cubic and Thales Ellipse

2015 ◽  
Author(s):  
Giorgio Figliolini ◽  
Jorge Angeles
Keyword(s):  
Special Interest ◽  
Kinematic Analysis ◽  
Vector Fields ◽  
Three Dimensions ◽  
Unique Point ◽  
Planar Case ◽  
Acceleration Vector ◽  
The Subject ◽  
Four Bar Linkage ◽  
Spherical Motion

The subject of this paper is the formulation of a specific algorithm for the kinematic analysis of spherical four-bar linkages via the inflection spherical cubic and spherical Thales ellipse by devoting particular attention to the crossed four-bar linkage (anti-parallelogram). Moreover, both the inflection and the elliptic cones, which represent the equivalent of the Bresse cylinders of the planar case in three-dimensions, are obtained by showing the particular properties of the spherical motion in terms of the curvature of a coupler curve and both the velocity and acceleration vector fields. Of special interest are also the cases in which the three acceleration poles coincide at one unique point or in two plus one, which depends on the intersections of two spherical curves of third and second degree.

Bisecant curves of ruled surfaces

1933 ◽  
Vol 29 (3) ◽  
pp. 382-388
Author(s):  
W. G. Welchman
Keyword(s):  
Ruled Surface ◽  
Ruled Surfaces ◽  
Normal Space ◽  
Double Points ◽  
Image Position

The bisecant curves of a ruled surface, that is to say the curves on the surface which meet each generator in two points, are fundamental in the consideration of the normal space of the ruled surface. It is well known that if is a bisecant curve of order ν and genus π on a ruled surface of order N and genus P, thenprovided that the curve has no double points which count twice as intersections of a generator of the ruled surface.

Small-scale magnetic fields in turbulence: Saffman's approximation revisited

1980 ◽  
Vol 99 (3) ◽  
pp. 481-493
Author(s):  
Ralph Baierlein
Keyword(s):  
Magnetic Field ◽  
Numerical Evaluation ◽  
Two Dimensions ◽  
Three Dimensions ◽  
Small Scale ◽  
Fluid Element ◽  
Relative Time ◽  
Fourier Decomposition ◽  
The Subject ◽  
The Magnetic Field

The subject is the small-scale structure of a magnetic field in a turbulent conducting fluid, ‘small scale’ meaning lengths much smaller than the characteristic dissipative length of the turbulence. Philip Saffman developed an approximation to describe this structure and its evolution in time. Its usefulness invites a closer examination of the approximation itself and an attempt to place sharper limits on the numerical parameters that appear in the approximate correlation functions, topics to which the present paper is addressed.A Lagrangian approach is taken, wherein one makes a Fourier decomposition of the magnetic field in a neighbourhood that follows a fluid element. If one construes the viscous-convective range narrowly, by ignoring magnetic dissipation entirely, then results for a magnetic field in two dimensions are consistent with Saffman's approximation, but in three dimensions no steady state could be found. Thus, in three dimensions, turbulent amplification seems to be more effective than Saffman's approximation implies. The cause seems to be a matter of geometry, not of correlation times or relative time scales.Strictly-outward spectral transfer is a characteristic of Saffman's approximation, and this may be an accurate description only when dissipation suppresses the contributions from inwardly directed spectral transfer. In the spectral region where dominance passes from convection to dissipation, one can generate expressions for the parameters that arise in Saffman's approximation. Their numerical evaluation by computer simulation may enable one to sharpen the limits that Saffman had already set for those parameters.

Evaluation of a leadership and intrapersonal development subject for university students in Hong Kong: findings based on 2 years

2016 ◽  
Vol 15 (1) ◽  
Author(s):  
Daniel T.L. Shek ◽  
Lu Yu ◽  
Xiaoqin Zhu
Keyword(s):  
Hong Kong ◽  
General Education ◽  
Course Evaluation ◽  
Three Dimensions ◽  
Positive Development ◽  
Final Grade ◽  
Significant Relationships ◽  
Teacher Attributes ◽  
Feedback Questionnaire ◽  
The Subject

AbstractThe present study aimed to examine the effectiveness of a general education subject entitled “Tomorrow’s Leaders” using the Student Feedback Questionnaire (SFQ) and student final grades in the subject in 2012/2013 and 2013/2014 academic years at The Hong Kong Polytechnic University. A total of 1406 and 1283 students in 2012/2013 and 2013/2014 academic years, respectively, completed the online SFQ. Results revealed that despite a slight decrease in student ratings in the second year, students generally expressed positive perceptions of the subject over 2 years regarding subject attributes, teacher attributes, and subject benefits. Results also showed consistent faculty differences in students’ satisfaction across 2 years. Students in the Faculty of Applied Science and Textiles and the Faculty of Engineering had more positive evaluations for the subject compared with students from the Faculty of Construction and Environment. Significant relationships amongst the three dimensions of course evaluation as well as between course evaluation and students’ final grade in the subject were also observed. Students’ perception of teacher attributes was a significant predictor for their final grade. The present study demonstrates the favorable effects of the subject on students’ positive development over time.

scholarly journals I. On skew surfaces, otherwise scrolls

1863 ◽  
Vol 12 ◽  
pp. 446-448
Keyword(s):  
Ruled Surfaces ◽  
Nodal Curve

It may be convenient to mention at the outset that in the paper “On the Theory of Skew Surfaces,” Camb. and Dubl. Math. Journ. vol. vi. pp. 171-173 (1852), I pointed out that upon any skew surface of the order n there is a singular (or nodal) curve meeting each generating line in ( n — 2) points, and that the class of the circumscribed cone, or what is the same thing, the class of the surface, is equal to the order n of the surface. In the paper “On a Class of Ruled Surfaces,” Camb. and Dubl. Math. Journ. vol. viii. pp. 45, 46 (1853), Dr. Salmon considered the surface generated by a line which meets three curves of the orders m, n, p respectively.

scholarly journals إشكالية تعيلم اللغة العربية في المؤسسات التربوية الإسلامية في إندونيسيا

Abjadia ◽  
2019 ◽  
Vol 3 (2) ◽  
pp. 147
Author(s):  
Mardhiya Agustina
Keyword(s):  
Language Learning ◽  
National Curriculum ◽  
Arabic Language ◽  
Three Dimensions ◽  
Islamic Education ◽  
Educational Institutions ◽  
Human Beings ◽  
Library Research ◽  
The Subject ◽  
Subject Material

<p dir="RTL">التعليم في الإسلام يشمل جميع أبعاد حياة المسلم. إما الأبعاد الإلهية تتعلق بالله، أو الأبعاد الإنسانية المتعلقة بالناس، والأبعاد الكونية المرتبطة بالكون. وبالتالي فإن مادة التربية في الإسلام هي أيضا واسعة جدا تشمل جميع الأبعاد الثلاثة ، وهي بصفة عامة مواد العقيدة والعبادة والأخلاق واللغة والأدب والعلوم والتكنولوجيا. التعليم الإسلامي مصدره بالكامل يستند إلى القرآن والسنة. وبالنظر إلى أن المصدر الرئيسي هو القرآن والسنة ، فإن اللغة العربية تعلمها وفهمها هو ضروري  لأنها اللغة المستخدمة في كلا المصدرين. اللغة العربية في إندونيسيا كأكبر دولة إسلامية في العالم، هي واحدة من المواد اللازمة في المناهج الدراسية للمؤسسات التربوية الإسلامية الحكومية ، في حين أن  في المؤسسات التربوية العامة هي مواد اختيارية. ولكن بطبيعة الحال في عملية تعليم اللغة العربية واجهت العقبات والصعوبات بالإضافة إلى التحديات ، حيث اللغة العربية هي لغة أجنبية لشعوب إندونيسيا. الإشكاليات والتحديات التي تواجه المؤسسات التربوية الإسلامية في إندونيسيا متنوعة إلى حد كبير، ولكن في الواقع لا تزال هناك أوجه تشابه في  المشاكل والتحديات المواجهة بين المؤسسات التعليمية مع بعضها البعض ، بحيث يمكن تجميعها في عدة نقاط رئيسية على النحو التالي: (1) الإشكاليات السياسية؛ (2) الإشكاليات الاجتماعية. (3) الإشكاليات المنهجية. لكن على الرغم من العديد من التحديات والعقبات التي تواجهها ، إلا أن كل ذلك يمكن أن يكون فرصة لتطوير تعليم اللغة العربية في المؤسسات التربوية الإسلامية في إندونيسيا.</p><p>Education in Islam covers the entire dimension of a Muslim's life. Bothdimensions ilahiyyahrelate to their relationship to God, or the dimensions of insaniyyah in relation to other human beings, as well as the dimensions of kauniyyah in relation to the universe. So the educational material in Islam is also very broadly covering the three dimensions, which are largely the subject of Aqidah, Ibadah, Morals, Languages and Literature, Science and Technology. Islamic education is entirely sourced and based on the Qur'an and the Sunnah. Given that its main source is the Qur'an and the Sunnah, then a necessity to study and understand the language used by both sources is Arabic. In Indonesia as the world's largest Muslim population, Arabic is one of the mandatory subject material in the national curriculum for Islamic education institutions, while for public education institutions as the subject matter of choice. But of course in the course of learning it encounters obstacles and difficulties as well as challenges, where Arabic is a foreign language morning Indonesian people. This research is a library research (Library Research) that is equipped with data from the field. The data collected are from the literature or from the informants related to this theme. The author describes the data through the deskreptive method and then draws conclusions that the undertaking is done objectively and systematically. The results show that the obstacles and challenges faced by Islamic educational institutions in Indonesia are quite diverse, but they still have similarities between one institution and another, so they can be grouped into the following major points: (1) politically problematic ; (2) problematic in sociological terms; (3) problematic in terms of methodology. But despite the many challenges and obstacles faced, but all of that can be an opportunity to develop Arabic language learning at Islamic educational institutions in Indonesia.</p>

scholarly journals Organizational commitment, job satisfaction and their possible influences on intent to turnover

2018 ◽  
Vol 25 (1) ◽  
pp. 84-101 ◽  
Author(s):  
Carolina Machado Dias Ramalho Luz ◽  
Sílvio Luiz de Paula ◽  
Lúcia Maria Barbosa de Oliveira
Keyword(s):  
Job Satisfaction ◽  
Organizational Commitment ◽  
Single Case ◽  
Three Dimensions ◽  
Advanced Technology ◽  
Intent To Turnover ◽  
Content Type ◽  
The Public ◽  
The Subject

Purpose The purpose of this paper is to investigate the extent to which the organizational commitment and job satisfaction influence intent to turnover. Design/methodology/approach Following a quantitative approach regarding methodological aspects of this research, a case study was carried out in a company of information technology and communication located in Porto Digital, in the Northeast of Brazil. A data collection technique with 172 forms, a self-administered form with 18 closed questions with a Likert-type scale and an open questionnaire were used. In this analysis, Statistical Package for the Social Sciences (SPSS) software was used as the technique; besides the descriptive statistics, a correlation was made between dependent variables (intention of rotation) and independent variables (affective, normative, instrumental and work satisfaction). The level of organizational commitment in its three dimensions (affective, normative and instrumental), the job satisfaction in its five dimensions (satisfaction with nature of the task, with leadership, with colleagues, with salary and promotions) and the level of intent to turnover from the respondents were investigated. Findings The results suggest that affective and normative commitments and satisfaction with pay, satisfaction with promotions and satisfaction with the nature of the work are correlated with the intention of negative turnover significantly. Among the demographic factors, only the age showed a negative correlation with intent to turnover. By performing multiple regression analysis, we identified that the variables that most impacted the turnover intention are affective commitment, satisfaction with salary and normative commitment. The qualitative portion of this study was accomplished through a content analysis of the open question of the form. Finally, one of the main considerations is the findings that revealed variables other than those adopted in the study, which influence the permanence of the respondents. Research limitations/implications Among the limitations of the research a single case study is highlighted that replicates the experience in other ICT companies to verify if the results found are similar in other organizations and in other segments. The findings direct the construction and validation of new scales, the creation of qualitative protocols to identify the variables that influence the retention of a specific group of individuals to serve as a guide for the elaboration of a questionnaire, as well as creation of surveys of longitudinal nature to correlate the data of intention of rotation with the effective turnover. Practical implications Based on the results, organizations can reduce voluntary evasion by adjusting actions, policies and practices, directing those responsible for People Management to attract and retain good employees. It should be emphasized that voluntary turnover should be treated as one of the management indicators of greater relevance by organizations, representing a thermometer of all human capital management. Social implications The monitoring of employment and unemployment levels is part of the public policy agenda for generating employment and income in Brazil. For organizations, employee turnover can and should be managed and monitored so that appropriate levels are found and their consequences are minimized through effective solutions. The results are important both for technology-based organizations and for all stakeholders interested in the subject as the public power. Originality/value Although in the international literature turnover is a topic of study for many years, in the Brazilian context, there is a shortage of research on the subject, specifically in the sector of advanced technology where there is a great lack of skilled labor, a fierce competition and where to keep employees standard high becomes a survival factor. This study may contribute to the exploration in the local literature, as it will help locate the academy on the Brazilian reality and open the doors to new research works on turnover and its possible correlations with other variables besides organizational commitment and job satisfaction.

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