To see the other types of publications on this topic, follow the link: Circle.
Journal articles on the topic 'Circle'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Circle.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Shemyakina, E. "Pencils of circles with a straight line and circle as the basic elements." Differential Geometry of Manifolds of Figures, no. 50 (2019): 169–76. http://dx.doi.org/10.5922/0321-4796-2019-50-19.
Full textAbstract:
Pencils of circles with are a straight line and a circle as the basic elements are investigated. Three cases of arrangement of a basic straight line and a circle are considered: when the straight line does not intersect a circle, when the straight line and a circle have one generic point, and when the straight line intersects a circle in two points. A parameter is entered and the equations of new pencils of circles are registered. By means of mathematical manipulations the obtained equations are given to the initial equation of a circle. Different values are attached to the parameter and the circles belonging to new pencils are constructed. Based on the obtained graphs it is concluded that the pencil with not intersecting basic straight line and a circle forms a hyperbolic pencil of circles, a pencil with a basic straight line and a circle having one generic point forms a parabolic pencil, and a pencil with the intersecting basic straight line and a circle forms an elliptic pencil.
2
Shulman, Gordon L. "Attentional Modulation of Size Contrast." Quarterly Journal of Experimental Psychology Section A 45, no. 4 (November 1992): 529–46. http://dx.doi.org/10.1080/14640749208401332.
Full textAbstract:
A test circle surrounded by smaller context circles appears larger if presented in isolation, whereas a test circle surrounded by large context circles is seen as smaller than in isolation. Two experiments are reported indicating that this phenomenon, the Ebbinghaus illusion, depends on whether subjects are attending to the context circles. Subjects first saw a reference circle and then a briefly presented (150 msec) test circle. Their task was to determine whether the test circle was larger or smaller than the reference. The test circle was surrounded by smaller context circles of one colour arrayed along a horizontal axis centred on the test, and larger context circles of a different colour arrayed along a vertical axis centred on the test. Subjects judged both the size of the test and the colours of either the small or large context circles. Perceived test size changed systematically, depending on which context circles were task-relevant.
3
Adam, Everett E. "Quality Circle Performance." Journal of Management 17, no. 1 (March 1991): 25–39. http://dx.doi.org/10.1177/014920639101700103.
Full textAbstract:
Quality circle advocates suggest a wide array of positive results when this participation technique is used. This study explores the importance of company, employee group (circle or non-circle), and time as well as their interactions. Assessment of circle performance was measured by employee attitudes, actual performance, and facilitator perception. This study did not support small group behavior and group dynamics research, as well as quality circle case study reports, that suggest attitudes will improve when quality circles are formed and will remain improved over time. Actual performance indicated cost savings and perceived circle success in three of the four circles, even though neither attitudes nor quality significantly improved over time.
4
Hu, Ying Lu, Wang Bin, Jian Hua Sun, Zhen Guo Song, Zhi Ming Song, Hong Wei Li, and Yan Xin Fu. "The Effect of Laser Processing Area on Nested-Circle Drilling Method." Advanced Materials Research 1082 (December 2014): 133–37. http://dx.doi.org/10.4028/www.scientific.net/amr.1082.133.
Full textAbstract:
A laser drilling technique named the nested-circle method is introduced in this work, in the respect of short-pulse laser processing.it is found that, as the power increases, the depth to diameter ratio of the hole will increase and the minimum number of circles can be set drilled hole reliably is reduced. Further studies have been carried out on the effect of the number of circles in the nested-circle method. Keys of settings the nested-circle method parameters—Outer circle diameter ‘D1’, Inner circle diameter ‘D2’, The Number of circles ‘R’—have been found out.
5
KIM, DONGUK, DEOK-SOO KIM, and KOKICHI SUGIHARA. "EUCLIDEAN VORONOI DIAGRAM FOR CIRCLES IN A CIRCLE." International Journal of Computational Geometry & Applications 15, no. 02 (April 2005): 209–28. http://dx.doi.org/10.1142/s021819590500166x.
Full textAbstract:
Presented in this paper is an algorithm to compute a Euclidean Voronoi diagram for circles contained in a large circle. The radii of circles are not necessarily equal and no circle inside the large circle wholly contains another circle. The proposed algorithm uses the ordinary point Voronoi diagram for the centers of inner circles as a seed. Then, we apply a series of edge-flip operations to the seed topology to obtain the correct topology for the desired one. Lastly, the equations of edges are represented in a rational quadratic Bézier curve form.
6
Calvo, R., A. Arteaga, and R. Domingo. "A comparison of fitting criteria for circle arc measurement applications." IOP Conference Series: Materials Science and Engineering 1193, no. 1 (October 1, 2021): 012073. http://dx.doi.org/10.1088/1757-899x/1193/1/012073.
Full textAbstract:
Abstract Measuring circular shape is a main task of dimensional metrology, characterized by circle diameter and its roundness, both for full circles and circle arcs. Point coordinates allows measuring both arcs and full circle, by fitting to substitution geometry, in many cases by least-squares criteria and fitting. Nevertheless, circle shape can be also characterized by the minimum zone, minimum circumscribed and maximum inscribed circles. This research presents a systematic experimental analysis of results of normal distributed points around the substitution circle through simulation, for different circle arc angles to the full circle and for the four mentioned fitting criteria. The results show the influence of arc angle in the variability of the results across criteria and the different behaviour depending on the arc amplitude. The results confirm the good stability and behaviour of least squares and minimum zone criteria, while warns the use of minimum circumscribed and maximum inscribed circles over half circumference. Experimental regression facilitates estimation of the minimum zone criteria from the least squares fitting that are independently verified with literature datasets with good results.
7
Mendoza, Jess, Cecilia Genuino, and Maria Elizabeth De Luna. "Verb Complementation in News Headlines by the Inner, Outer, and Expanding Circles." International Journal of Language and Literary Studies 1, no. 3 (December 21, 2019): 43–59. http://dx.doi.org/10.36892/ijlls.v1i3.55.
Full textAbstract:
The English language has survived the pangs of giving birth to its variations commonly called as World Englishes. Though there are many “Englishes” in the globe today, they do have similarities and differences which are manifested in the different styles employed by writers around the world. In this regard, the study aimed to analyze the structure of verb phrases in news headlines of the different countries in Kachru’s three concentric circles leading to the identification of types of verbs used. This is done to give fresher ideas into the style of headline writing by understanding what types of verbs are used by the writers from the inner, outer, and expanding circles. Using Brinton, L and Brinton, D’s (2010) structure of verb complementation, the researchers analyzed five news headlines per circle which served as their corpus in identifying the complements present in the verb phrases. This, furthermore, led to the following results: a) inner and outer circles mostly use monotransitive verbs, b) outer circle is characterized by its use of copulative verbs, inner circle by its usage of intransitive verb, and the expanding circle by its usage of prepositional and ditransitive verbs c) expanding and inner circles use diprepositional verbs while outer circle does not, d) the expanding and outer circles both use complex transitive, e) the expanding circle exhibits the characteristics of both inner and outer circles, and f) the circles overlap each other.
8
Aeunah, Een, Abdul Aziz, Caecilia Jilia Joe, and Cut Dihe Zayhaqqi Ali. "ANALYSIS OF STUDENTS' DIFFICULTIES IN LEARNING MATHEMATICS OF CIRCLE GEOMETRY IN FOURTH GRADE ELEMENTARY SCHOOL." ROMEO REVIEW OF MULTIDISCIPLINARY EDUCATION CULTURE AND PEDAGOGY 2, no. 3 (June 16, 2023): 155–59. http://dx.doi.org/10.55047/romeo.v2i3.751.
Full textAbstract:
The present study endeavors to comprehensively examine the obstacles faced by elementary school students when attempting to grasp fundamental mathematical concepts pertaining to circles. Specifically focusing on Grade 4 students at SDN Cipondoh 2, Tangerang City. The primary objective is to shed light on the difficulties encountered by students in three core areas: calculating circle area and circumference, understanding the complex concept of π (pi), and accurately sketching circles utilizing a compass. Various tools are employed to scrutinize the obstacles students encounter, including tasks such as calculating circle area and circumference, comprehending the intricate π (pi) concept, and accurately sketching circles using a compass. The findings indicate that students encounter hurdles in computing circle area and circumference due to the need to understand underlying formulas and calculation procedures. Additionally, comprehending the π (pi) concept presents a notable challenge in circle calculations. Moreover, students struggle with precise and symmetrical circle drawing using a compass. The research outcomes provide valuable insights for formulating effective pedagogical strategies to help students overcome challenges in comprehending and applying circle geometry principles.
9
A. Al-Mutairi, Mohammad. "Kachru’s Three Concentric Circles Model of English Language: An Overview of Criticism & the Place of Kuwait in it." English Language Teaching 13, no. 1 (December 13, 2019): 85. http://dx.doi.org/10.5539/elt.v13n1p85.
Full textAbstract:
This paper attempts to examine in a descriptive way the pioneering model of “World Englishes” proposed by Kachru in the mid-1980s that allocates the presence of English into three concentric circles: The Inner Circle, the Outer Circle, and the Expanding Circle. The Inner Circle presents the countries where English is used as a native language and as a first language among people. These countries include the USA, the UK, Canada, Australia, and New Zealand. The Outer Circle includes countries that have old historical British colonial relations and where English is commonly used in social life or the government sectors. Most of the countries that belong to this circle are former colonies of the British Empire, such as India, Malaysia, Singapore, Ghana, Kenya, and others. The usage of English in these countries is similar to what is known as English as a second language. The third circle, The Expanding Circle, includes countries that introduce English as a foreign language in schools and universities, mostly for communicating in English with the Inner and Outer Circles. Such countries include Turkey, Saudi Arabia, The Emirates, Japan, China, Korea, and others.
Since its first introduction in 1985, Kachru's Three Concentric Circles Model of English Language has occasioned a great debate. Many linguists considered it one of the most influential models for understanding the use of English in different countries. Some, on the other hand, including Kachru himself, criticized the model for its oversimplification and the unclear membership to the circles. In addition to an overview of criticism on Kachru's model based on different studies, this paper tries to locate the place of ELT in Kuwait among the three circles.
10
WANG, LIANG, HONGXUN YAO, and H. D. CHENG. "EFFECTIVE AND AUTOMATIC CALIBRATION USING CONCENTRIC CIRCLES." International Journal of Pattern Recognition and Artificial Intelligence 22, no. 07 (November 2008): 1379–401. http://dx.doi.org/10.1142/s0218001408006831.
Full textAbstract:
In this paper, we present an effective, flexible and completely automated camera calibration approach using only one pair of concentric circles. This approach utilizes the characteristics of concentric circles' tangent lines to locate the center of these circles, and finds the geometric constraints for calibration based on the orthogonality formed by a point on the circle and the two intersected points of the circle with the line through the center of the circle. The entire process requires no conic equation fitting and no metric measurement of the test pattern, which is very flexible to implement.
11
Lis, Artur. "ECONOMIC AND UNIQUE WOMEN. RURAL HOUSE WHEELS IN THE LAW." Roczniki Administracji i Prawa 2, no. XXII (June 30, 2022): 343–54. http://dx.doi.org/10.5604/01.3001.0016.0989.
Full textAbstract:
The review article was devoted to the publication by Grzegorz Krawiec entitled „The act on rural housewives’ circles. Comment”. On the basis of the Act on Rural Housewives’ Circles of November 9, 2018, a separate organizational formula was created for KGW, which are voluntary, independent and self-governing social organizations of rural residents. Based on the previously applicable legal regulations, KGW could be established within agricultural circles as their independent units. They could also function in the form of associations. An important statutory solution is to grant KGW a legal personality, which allows them to run a business on their own account and benefit from financial support from public funds. KGW operates on the basis of the adopted statute, which specifies in particular: the name and seat of the circle, the objective and territorial scope of the circle’s activities, goals and tasks of the circle and the means of their implementation, the method of acquiring and losing membership, the assets of the circle and the method of administering these assets, the way of representing the circle. outside, the rights and obligations of members, the bodies of the circle and their powers, the conditions for adopting and valid resolutions of the bodies of the circle, the procedure for changing the statute and liquidating the circle.
12
BABAEI, Ali. "The Boiling Circle, the Rotating Circle (Two kinds of symbols of the Circle in Islamic Tradition)." WISDOM 18, no. 2 (June 25, 2021): 162–75. http://dx.doi.org/10.24234/wisdom.v18i2.484.
Full textAbstract:
In theological sources, many symbols are used to explain the transcendent truths of existence. Among the shapes, the circle has the most use of a symbol which is important for Religious, philosophers, and mystics. However, what is refer mostly to the shape of a circle is the rotation of a circular line that begins at a point on a surface and ends at the same point; then, the most superficial and intermediate symbols of facts are explained with it. Contrary, the present article proposes a novel way of drawing a circle, and with this approach, examines some philosophical concepts. We call this drawing "Boiling Circle", because, the rays are coming out boiling from the center. We also have analyzed and introduced a unique example of a mystical-philosophical-religious Architectural building, during which a circular spring has been built. Its water comes out boiling of the center and fills the five circles within itself and twelve eyes around it. This article begins with the drawing of a boiling circle, continues with explaining the philosophical symbols of the boiling circle and boiling spring according to Islamic mysticism, and ends with comparing and expressing the differences between the symbols of the two circles.
13
Garrett, Michael Tlanusta, J. T. Garrett, and Dale Brotherton. "Inner Circle/Outer Circle: A Group Technique Based on Native American Healing Circles." Journal for Specialists in Group Work 26, no. 1 (March 1, 2001): 17–30. http://dx.doi.org/10.1080/01933920108413775.
Full text
14
Ou, Yun, Honggui Deng, Yang Liu, Zeyu Zhang, Xusheng Ruan, Qiguo Xu, and Chengzuo Peng. "A Fast Circle Detection Algorithm Based on Information Compression." Sensors 22, no. 19 (September 25, 2022): 7267. http://dx.doi.org/10.3390/s22197267.
Full textAbstract:
Circle detection is a fundamental problem in computer vision. However, conventional circle detection algorithms are usually time-consuming and sensitive to noise. In order to solve these shortcomings, we propose a fast circle detection algorithm based on information compression. First, we introduce the idea of information compression, which compresses the circular information on the image into a small number of points while removing some of the noise through sharpness estimation and orientation filtering. Then, the circle parameters stored in the information point are obtained by the average sampling algorithm with a time complexity of O(1) to obtain candidate circles. Finally, we set different constraints on the complete circle and the defective circle according to the sampling results and find the true circle from the candidate circles. The experimental results on the three datasets show that our method can compress the circular information in the image into 1% of the information points, and compared to RHT, RCD, Jiang, Wang and CACD, Precision, Recall, Time and F-measure are greatly improved.
15
Umbetov, N. "Demonstration of Common Elements of Involution on a Simple Example." Geometry & Graphics 10, no. 2 (October 10, 2022): 27–34. http://dx.doi.org/10.12737/2308-4898-2022-10-2-27-34.
Full textAbstract:
The involution of projective rows with a common support, its geometric interpretation are considered. Taking the special case of the geometric interpretation of involution, the problem of constructing harmonically conjugate points is solved for given initial conditions, when one circle and a radical axis of this circle with a bundle of corresponding circles with a common radical axis are given. A proposal is given on the existence of a single circle in a bundle, the diametrical points of which on the lines of centers make up a harmonic four with diametral points of a given circle. It is shown that using the diametrical points of a given circle and points P, Q of the radical axis in elliptical involution, you can build double points X, Y and the radical axis of the PQ of circles in hyperbolic involution. And the tangent from the vertical diammetral point of the circle w1 to the circle passing through double points of hyperbolic involution - there is a point P(Q) of the radical axis of elliptical involution. The indicated properties make it possible to carry out a mutual transition from one involution to another. It was established that the diagonals of the quadrangles obtained when crossing all the circles of the bundle, orthogonal to the two given in elliptical involution, intersect in the center of the radical axis of the given circles in hyperbolic involution, and the diagonals of the quadrangles of all circles of the beam in hyperbolic involution are intersected in the center of the radical axis of the given circles in elliptical Involution.
The geometric place (GP) of each point of the harmonic four is constructed. In this case, the geometric place a pair of harmonic four in an elliptic involution turns out to be an ellipse that has a common tangent at points P with the circle of double points of the hyperbolic involution. And the GP pairs of the harmonic four for hyperbolic involution are two branches of the hyperbola that pass through the centers of the circles that define the elliptical involution.
16
Orsel, Cansu, and Fatih Yavuz. "A Comparative study on English language teaching to young learners around the world." Contemporary Educational Researches Journal 7, no. 3 (November 10, 2017): 114–18. http://dx.doi.org/10.18844/cerj.v7i3.2656.
Full textAbstract:
Usage of the English language as Lingua Franca has caused an increasing demand on the English Language Teaching (ELT) in early childhood and according to Braj Kachru’s Three Circles Model of World Englishes as the Inner Circle, the Outer Circle, and the Expanding Circle the approaches to the Young Learners dramatically differs. Besides the features of English as a global language and the nature of early language learning, this paper also focuses on the comparison of the three different examples from the Three Circles Model of World Englishes. They are compared in terms of techniques that are used and the approaches to the Young Learners. The examples taken are from the official websites of the three countries from the Inner Circle, Outer Circle, and the Expanding Circle; respectively, New Zealand’s Ministry of Education, Indian Ministry of Human Resource Development, and the Turkish Board of Education and Instruction.
Keywords: Young Learners, The World Englishes, Lingua Franca, Braj Kachru, English Language Teaching (ELT).
17
Brigner, Willard L. "The Geometric Illusion and Induced Differences in Perceived Time." Perceptual and Motor Skills 67, no. 2 (October 1988): 373–74. http://dx.doi.org/10.2466/pms.1988.67.2.373.
Full textAbstract:
Just as circle-size induces differences in the perceived extent of a line which interconnects the circles of the Baldwin illusion, it is demonstrated that circle-size induces differences in the perceived duration of a time interval which intervenes between circles of different sizes.
18
Suliano, Mufid Ramadhani. "Strategi Komunikasi Pemasaran E-Commerce Boogie.id Menggunakan IMC Model Dwi Sapta." Jurnal Komunikasi Global 9, no. 2 (December 25, 2020): 300–315. http://dx.doi.org/10.24815/jkg.v9i2.17270.
Full textAbstract:
Boogie awalnya sempat menjadi top brand di bidang perlengkapan outdoor, namun perlahan mulai meredup. Penelitian ini bertujuan untuk mendeskripsikan strategi komunikasi pemasaran Boogie.id menggunakan IMC model Dwi Sapta yang membahas tentang discovery circle, intent circle, dan strategy circle. Jenis penelitian pada penelitian ini adalah deskriptif kualitatif. Pengumpulan data pada penelitian ini dilakukan melalui wawancara semi terstruktur dengan lima orang marketing Boogie. Teknik analisis data dalam penelitian ini menggunakan teknik yang dikemukakan oleh Miles dan Huberman. Hasil penelitian pada discovery circle menunjukkan bahwa Boogie sudah melakukan market review, competitor review, dan consumer review. Pada intent circle, problem dari Boogie yaitu kurangnya brand awareness terutama dari kalangan milenial serta minimnya budget yang dimiliki sehingga pengembangan produk dan inovasi produk menjadi terhambat. Pada strategy circle, Boogie memiliki brand soul sebagai pelopor produk outdoor di Indonesia, serta memiliki produk yang berbeda dengan kompetitornya yaitu produk perahu karet dan produk water activities.Boogie was once a top brand for outdoor products, but now slowly starting to fade. This study aims to describe the marketing communication strategy of Boogie using the Dwi Sapta IMC model, including discovery circles, intent circles, and strategy circles. The research used a descriptive qualitative study. Data collection in this study was carried out through semistructured interviews with four marketing staff of Boogie. The data were analysed using the technique proposed by Miles and Huberman. The results of research in discovery circles showed that Boogie conducted market, competitor, and consumer reviews. For the intent circle, the problem from Boogie was the lack of brand awareness among young target consumers and lack of budget resulting in the hampered product development and product innovation. For the strategy circle, Boogie has a soul brand as a pioneer of outdoor products in Indonesia and has different products from its competitors, namely rubber boat products and water activities products.
19
Wang, Qi Kui, You Dong Chen, Wei Li, Tian Miao Wang, and Hong Xing Wei. "Loci Conversion and Corner Smoothing with PH Curves in CNC System." Key Engineering Materials 419-420 (October 2009): 161–64. http://dx.doi.org/10.4028/www.scientific.net/kem.419-420.161.
Full textAbstract:
Free-form surface interpolation functions give more advantages in machining than the traditional line and circle functions. A method is developed to convert lines and circles into Pythagorean-hodograph (PH) curves. In order to get smooth machining process the PH curve is used to replace the joints of the circular/linear elements by the connection situation. The slope of line is used to get the tangent vector in the line conversion. When converting a circle to a PH curve, points of the divided circle are introduced to compute the vectors. The methods of computing tangent vectors are proposed according to the slope of the line and the quadrant of the circle. The transformation errors from lines and circles to PH curves are computed. In the corner smoothing process the tangent vectors are computed by the connection between lines and circles. Replacement errors at the joints are computed for the use of PH curve. The results demonstrate the feasibility of the conversion from line and circle to PH curve. The PH curves at the joints of the circular and linear elements show continuous trajectory.
20
Dewangan, Mamta, and Vandana Agrawal. "EVOLUTION OF TEMPLE ELEVATIONAL FORM WITH SQUARE CIRCLE METHOD: LAKSHMAN TEMPLE IN SIRPUR." Architecture and Engineering 8, no. 2 (June 30, 2023): 3–13. http://dx.doi.org/10.23968/2500-0055-2023-8-2-3-13.
Full textAbstract:
One of the fundamental methods for shaping the constructional geometry of any building is the use of basic shapes: circles and squares. The circle represents vitality or energy, while the square represents strength. In world history, the concept of geometry traces its origins to construction in Egypt and Babylonia, where proportional systems were described through mathematical equations. They later became known as the Pythagorean Theorem, named after Pythagoras. In Ancient India, the concept of geometry starts with the construction of altars for Vedic sacrifices, as per the instructions of the Śulbasūtras. This involved creating circles and squares, converting squares to circles and vice versa, resulting in altars of various shapes and proportionate systems. The intersection of these basic shapes, the square and the circle, is the key to constructional building geometry. For instance, Vesica Piscis is a geometrical element derived from the circle-circle intersection. It has been applied by researchers to examine the geometry of both ancient and modern buildings. Similarly, the Square-Circle Sequence (SCS) is a method derived from the square-circle intersection. Gandotra (2011) used it to study the constructional geometry of the Hindu temples in North India (Nāgara temples). Meister (1985) also applied the square-circle intersection geometric constructional method to define the proportionate system of the Hindu temples in India. Finally, this study attempts to correlate these types of constructional geometry in the evolution of elevational form of Nāgara temples through Lakshman temple in Sirpur. It determines that the building’s elevational form may be derived from the basic shapes of the circle and the square.
21
Popescu, Iulian, Ludmila Sass, and Alina Elena Romanescu. "Rolling with and without Slipping, during Epicycloids Generation." Applied Mechanics and Materials 880 (March 2018): 63–68. http://dx.doi.org/10.4028/www.scientific.net/amm.880.63.
Full textAbstract:
The starting point consists in the modality to generate epicycloids when two external circles are considered. The mobile circle is rolling on the fix circle without slipping, such as two arcs belonging to these circles are equal. The specialty literature presents an example with a simple planetary gear in which the “satellite porting” arm provides the rolling of the mobile circle on the fix circle. Our original idea, not approached in the specialty literature, considers the rolling with slipping of the mobile circle on the fix circle. Instead of the gears providing the rolling without slipping, two wheels with smooth surfaces are used now. The case when the two involved arc are no longer equal is analysed. Between them appear either frictions generating braking or “skating like” rolling when the lubricant layer is too thick. An analysis of the theoretical case when the slipping has a sense opposite to that of a normal rolling is also performer. A significant class of curves was obtained. Some are even epicycloids obtained with slipping, with other parameters.
22
Robertus Daya. "ANALYSIS OF ABILITY IN UNDERSTANDING MATHEMATICS CONCEPTS ON THE CIRCULAR MATERIAL OF STUDENTS OF CLASS VIII OF SMP NEGERI 2 BAY IN THE 2020/2021 STUDY YEAR." AFORE : Jurnal Pendidikan Matematika 1, no. 2 (February 15, 2023): 148–55. http://dx.doi.org/10.57094/afore.v1i2.725.
Full textAbstract:
This research is motivated by the ability to understand students' mathematical concepts which are still in the low category. This study aims to 1) describe the ability to understand mathematical concepts in the circle material for class VIII students of SMP Negeri 2 Telukdalam, 2) describe the students' difficulties in solving questions about the ability to understand mathematical concepts in the circle material. This research uses a type of qualitative research with descriptive research methods. The informants in this study were all students of class VIII SMP Negeri 2 Telukdalam, namely 25 people. Data were analyzed by data reduction, data presentation and conclusion. Research data collection techniques through tests of ability to understand mathematical concepts and interviews. The research findings showed that students were unable to restate the circle concept, students were unable to classify objects according to the nature of the circle, students were unable to distinguish examples of circles and non-circles, students were unable to select and use procedures or operations (formulas) according to the circle concept, and students still unable to apply the circle concept in solving simple problems.
23
Cox, J., and B. G. Dale. "Quality Circle Members' Views on Quality Circles." Leadership & Organization Development Journal 6, no. 2 (February 1985): 20–23. http://dx.doi.org/10.1108/eb053574.
Full text
24
Jaeger, Ted, and Katherine Grasso. "Contour Lightness and Separation Effects in the Ebbinghaus Illusion." Perceptual and Motor Skills 76, no. 1 (February 1993): 255–58. http://dx.doi.org/10.2466/pms.1993.76.1.255.
Full textAbstract:
For 48 observers, the central circle of Ebbinghaus figures appeared smaller as the separation between it and the contextual circles increased. Lightness of the contours only affected the illusion when the contextual circles were large and located close to the central circle. An explanation incorporating size contrast and attraction between contours was offered.
25
Polster, B., and G. F. Steinke. "Cut and Paste in 2-Dimensional Projective Planes and Circle Planes." Canadian Mathematical Bulletin 38, no. 4 (December 1, 1995): 469–80. http://dx.doi.org/10.4153/cmb-1995-069-1.
Full textAbstract:
AbstractWe describe two methods to combine sets of lines of different 2-dimensional projective planes into line sets of new 2-dimensional projective planes. Using these methods we describe several ways in which sets of circles of different 2-dimensional circle planes can be combined into circle sets of new 2-dimensional circle planes.
26
Piggins, David, John A. Wilson, and James O. Robinson. "Stereokinetic Interaction Effects Involving Static and Slowly Moving Identical Figures." Perceptual and Motor Skills 83, no. 2 (October 1996): 387–400. http://dx.doi.org/10.2466/pms.1996.83.2.387.
Full textAbstract:
Here a new depth effect evoked by the spatial and temporal interaction in 2-D of a slowly moving circle (optimally at 0.6 rads/sec.) with an identical static circle is reported. Typically, respondents report that with increasing adjacency, commencing with separations of a few diameters, the moving circle appears in a different plane of depth to the static circle, it then usually appears to “dip” onto the static circle and after complete coincidence with it to rise away from it. This effect, together with a number of associated descriptions are commented upon, in addition to observations when viewing overlapped static circles and overlapped circles in motion, this latter stimulus condition evoking the stereokinetic effect. The authors have previously suggested that contour “sliding,” which simulates motion parallax, is the key to understanding stereokinesis. The stimulus conditions giving rise to this new effect directly simulate the motion parallax information present in a retinal image.
27
Nastro, Vincenzo, and Urbano Tancredi. "Great Circle Navigation with Vectorial Methods." Journal of Navigation 63, no. 3 (May 28, 2010): 557–63. http://dx.doi.org/10.1017/s0373463310000044.
Full textAbstract:
The present paper is concerned with the solution of a series of practical problems relevant to great circle navigation, including the determination of the true course at any point on the great circle route and the determination of the lateral deviation from a desired great circle route. Intersection between two great circles or between a great circle and a parallel is also analyzed. These problems are approached by means of vector analysis, which yields solutions in a very compact form that can be computed numerically in a very straightforward manner. This approach is thus particularly appealing for performing computer-aided great circle navigation.
28
Herlina, Iin, Agus Suryana, and Muhamad Azhar Alwahid. "Learning Design Cooperative Learning Inside-Outside Circle in Indonesian Language Lessons at Madrasah Ibtidaiyah: A Literature Review." Tarbiatuna: Journal of Islamic Education Studies 2, no. 2 (February 10, 2022): 168–94. http://dx.doi.org/10.47467/tarbiatuna.v2i2.1097.
Full textAbstract:
The writing of this article aims to find out the design of the inside-outside circle cooperative learning learning design, namely, 2. The advantage of the Inside Outside Circle technique is that there is a clear structure and allows students to share with different partners briefly and regularly. In addition, students work with fellow students in a cooperative atmosphere and have many opportunities to process information and improve communication skills. The steps for the design of the inside-outside circle cooperative learning technique in Indonesian lessons are that half of the students form a small circle facing out, the other half form a large circle facing in, students facing each other share information simultaneously, students who are in the outer circle rotate then share information with their (new) friends in front of them, and so on.This research method uses the library method by analyzing various books and journals related to the application of the Inside-Outside Circle cooperative learning technique. The conclusions concluded that: 1. learning techniques with the system of inner and outer circles (Inside-Outside Circle) where students share information with each other at the same time with different pairs briefly and regularly.2. The advantage of using the IOC method is that students will easily get different and varied information at the same time. Meanwhile, the steps for implementing the inside-outside circle cooperative learning design in Indonesian lessons are: as follows: 1) The first step, half the class stands in a small circle and faces out. 2) The second step, the other half of the class forms a circle outside the first circle and faces inward. 3) The third step, then two students in pairs from small and large circles share information. This information exchange can be done by all partners at the same time. 4) The fourth step, students in the small circle stay in place, while students in the large circle move one or two steps clockwise, so that each student gets a new partner. 5) The last step, it is the turn of students who are in the big circle to share information. And so on.
Keywords: cooperative learning, Inside Outside Circle, Indonesian Lesson, speaking skills
29
Kapranov, Oleksandr. "Modal Verbs in Research Article Abstracts in Applied Linguistics: Juxtaposing Discursive Practices of the Inner and Outer Circles of English." East-West Cultural Passage 22, no. 2 (December 1, 2022): 6–34. http://dx.doi.org/10.2478/ewcp-2022-0013.
Full textAbstract:
Abstract The article introduces and discusses a computer-assisted study that seeks to shed light on the frequency and use of the central modal verbs (can, could, may, might, must, shall, should, will, would) in research article (further: RA) abstracts in applied linguistics published in the Inner and Outer Circles of English, respectively. The study is informed by the construal of the Circles of English that are comprised of the Inner Circle, where English is spoken as the mother tongue (for example, the United Kingdom), the Outer Circle, where it is used as a second language in the former British colonies (for instance, Hong Kong, Malaysia, etc.), and the Expanding Circle (e.g., Japan), where English is spoken and taught as a foreign language (Kachru 48). In the construal of the Circles of English, the Outer Circle is regarded as a heterogeneous sociolinguistic space with fluid boundaries (Higgins 615) that affects the frequency and use of the central modal verbs in a variety of textual genres (Lee and Collins 501). Against this background, the study aims at identifying and analysing the frequency of the central modal verbs in a corpus of RA abstracts in applied linguistics published by international peer reviewed journals associated with the Outer Circle (one journal published in Hong Kong and one in Malaysia, respectively) and the Inner Circle of English (one journal published in the United Kingdom). The results of the quantitative analysis of the corpus indicate that the most frequent modal verbs in the entire corpus are can and may, which function as hedging devices in the journals that are associated with the Outer and Inner Circles of English, respectively. These findings are discussed in the article through the prism of the construal of the Circles of English.
30
Liebersohn, Yosef Z. "Crito's Social Circles in Plato's Crito." Classica et Mediaevalia 72 (April 27, 2023): 37–80. http://dx.doi.org/10.7146/classicaetmediaevalia.v72i.137098.
Full textAbstract:
In this paper I identify and discuss three different circles concerning Crito’s social relations: the internal circle of those who know him well; the external circle of those who are Crito’s fellow citizens but who do not know him well; and the third circle which is the polis with its laws. Crito uses – both consciously and unconsciously – different stratagems in dealing with these different circles. The speech of the Laws is Socrates’ attempt to allow Crito to see his actual behavior, as if reflected in a mirror. In fact Crito harms his friends, cheats his fellow citizens and destroys the polis.
31
Liu, Shengjun, Hongqian Guo, and Lihong Su. "Evaluation of Quality of Life in Urban Life Circles from a Composite Perspective of Subjective Needs and the Supply of Public Amenities: A Case Study of Changbai Island, Shenyang." Sustainability 15, no. 13 (June 26, 2023): 10095. http://dx.doi.org/10.3390/su151310095.
Full textAbstract:
Evaluating the quality of life in life circles is an important prerequisite for effective life circle governance. Most studies evaluate the quality of life in life circles from either the living environment or public amenity supply perspective, and few adopt a composite perspective of these. This study developed an index system for evaluating the quality of life in life circles from both these perspectives, based on data from Changbai Island, Shenyang. We measured the living environment, amenity service, and quality of life indexes of urban life circles and analysed the spatial relationship between the living environment and amenity services, as well as the spatial effect of public amenities on the quality of life in communities. The findings are summarised as follows: (1) Quality of life tends to decline radially from the east to surrounding areas; (2) Life circles in Changbai Island are arranged in the following descending order according to the quality of life: life circles IV and II (equal), life circle III, and life circle I; (3) Various types of public amenities produce differentiated effects on the quality of life in life circles; specifically, middle schools can significantly improve the quality of life in surrounding communities, whereas community hospitals, large supermarkets, and community shops can have adverse effects if they are extremely close to residential areas. Our findings provide empirical evidence for evaluating the quality of life in urban life circles, evaluating methodology, and referencing for life circle governance.
32
GDAWIEC, KRZYSZTOF. "STAR-SHAPED SET INVERSION FRACTALS." Fractals 22, no. 04 (November 12, 2014): 1450009. http://dx.doi.org/10.1142/s0218348x14500091.
Full textAbstract:
In the paper, we generalized the idea of circle inversion to star-shaped sets and used the generalized inversion to replace the circle inversion transformation in the algorithm for the generation of the circle inversion fractals. In this way, we obtained the star-shaped set inversion fractals. The examples that we have presented show that we were able to obtain very diverse fractal patterns by using the proposed extension and that these patterns are different from those obtained with the circle inversion method. Moreover, because circles are star-shaped sets, the proposed generalization allows us to deform the circle inversion fractals in a very easy and intuitive way.
33
Richter, Wolf-Dieter, and Vincent Wenzel. "Mysterious Circle Numbers.Does πp,q Approach πp When q Is Tending to p ?" Mathematics 7, no. 9 (September 5, 2019): 822. http://dx.doi.org/10.3390/math7090822.
Full textAbstract:
This paper aims to introduce a mathematical-philosophical type of question from the fascinating world of generalized circle numbers to the widest possible readership. We start with recalling well-known (in part from school) properties of the polygonal approximation of the common circle when approximating the famous circle number π by convergent sequences of upper and lower bounds being based upon the lengths of polygons. Next, we shortly refer to some results from the literature where suitably defined generalized circle numbers of l p - and l p , q -circles, π p and π p , q , respectively, are considered and turn afterwards over to the approximation of an l p -circle by a family of l p , q -circles with q converging to p, q → p . Then we ask whether or not there holds the continuity property π p , q → π p as q → p . The answer to this question leads us to the answer of the question stated in the paper’s title. Presenting here for illustration true paintings instead of strong technical or mathematical drawings intends both to stimulate opening heart and senses of the reader for recognizing generalized circles in his real life and to suggest the philosophical challenge of the consequences coming out from the demonstrated non-continuity property.
34
ANDRIEȘ, Vasile, and Valeria BOTEZATU. "The role and functionality of school circles in the view of the students." Univers Pedagogic 79, no. 3 (September 2023): 92–100. http://dx.doi.org/10.52387/1811-5470.2023.3.13.
Full textAbstract:
Extracurricular activities are carried out both within extracurricular institutions (art schools, music schools, creative centers, clubs) and within school institutions through student circles. The authors proposed to identify the students’ position regarding the functioning of school circles, externalizing a series of aspects, such as: the source of information about the existence of the circle; motivation for joining the circle; teacher-student relationship; the relationship between students; teaching methods; evaluation method; the skills developed within school circles.
35
Li, Shaodong, Zhijiang Du, Hongjian Yu, and Jiafu Yi. "A Robust Multi-Circle Detector Based on Horizontal and Vertical Search Analysis Fitting with Tangent Direction." International Journal of Pattern Recognition and Artificial Intelligence 33, no. 04 (March 19, 2019): 1954013. http://dx.doi.org/10.1142/s0218001419540132.
Full textAbstract:
In this paper, we propose an efficient Multi-Circle detector which follows the fixed search order. The method makes use of horizontal and vertical search to realize circle detection, which is named as HVCD. First, this method computes edge areas in a given image. The edge areas could be divided into some regions by means of region growing. Each of regions could be efficiently searched to achieve not only one-pixel wide edges but edge segments as well. Next, the candidate circles can be extracted from every edge segment. Finally, the circle candidates could be validated with the help of Helmholtz principle. Experimental results demonstrate that HVCD could effectively detect circles on synthetic and natural images on the one hand; on the other hand, HVCD here could solve the weakness in the process of circle Hough transform implementation and EDcircles implementation.
36
Kurniawan, Hasyim, Rio Moehkardi, and Nabila Muliawati. "REVISITING THE ENGLISH STATUS IN THE OUTER AND EXPANDING CIRCLES: INSIGHTS FROM GOOGLE STREET VIEW®." LLT Journal: A Journal on Language and Language Teaching 27, no. 1 (April 30, 2024): 461–97. http://dx.doi.org/10.24071/llt.v27i1.7659.
Full textAbstract:
Globalization and glocalization may affect the use of English in Kachru’s (1986) Outer Circle and Expanding Circle countries. This study revisits the status of English by observing its use in the commercial signboards in Malaysia (Petaling Street) and the Philippines (Colon Street), representing the Outer Circle, Thailand (Khao San Road), and Indonesia (Legian Street), representing the Expanding Circle. Using Google Street View®, 557 signages were screen-captured, and their brand names, information, and slogan parts were analyzed. The finding shows that English is predominant on almost all signboard parts on the four streets, showcasing its crucial role in building brand identity and efficacy for communicating with a wider market. Furthermore, linguistic strategies such as code-mixing are pervasive in both circles, indicating the norm-developing characteristic not only in the Outer but also in the Expanding Circle. Language regulation enforcement may affect the degree of visibility of English, but its prevalence remains high nonetheless. Overall, the traditional conception of these concentric circles needs to be reanalyzed and a more fluid model needs to be put forward.
37
Fujimuraa, Masayo. "The complex geometry of Blaschke products of degree 3 and associated ellipses." Filomat 31, no. 1 (2017): 61–68. http://dx.doi.org/10.2298/fil1701061f.
Full textAbstract:
A bicentric polygon is a polygon which has both an inscribed circle and a circumscribed one. For given two circles, the necessary and sufficient condition for existence of bicentric triangle for these two circles is known as Chapple?s formula or Euler?s theorem. As one of natural extensions of this formula, we characterize the inscribed ellipses of a triangle which is inscribed in the unit circle. We also discuss the condition for the ?circumscribed? ellipse of a triangle which is circumscribed about the unit circle. For the proof of these results, we use some geometrical properties of Blaschke products on the unit disk.
38
Haggarty, Alison, Audrey Henshall, Richard Grove, Trevor Cowie, Andrew Foxon, Roderick McCullagh, David Jordan, Brian Moffat, and Daragh Lehane-Magee. "Machrie Moor, Arran: recent excavations at two stone circles." Proceedings of the Society of Antiquaries of Scotland 121 (November 30, 1992): 51–94. http://dx.doi.org/10.9750/psas.121.51.94.
Full textAbstract:
Excavations at stone circles 1 and 11 on Machrie Moor revealed previous use of the land on which they were situated, with features dating back to the earlier Neolithic. The exact positions occupied by both circles were found to have been preceded by timber monuments, comprising several elements in the case of circle 1. Evidence for fenced land divisions and ard ploughing between the timber and stone phases was also recovered. Both stone circles contained a single inserted cremation deposit. Stone circle 1 had been dug into in 1861 by James Bryce but circle 11 was previously untouched, having been buried in peat. The ceramic assemblage, though not extensive, produced examples of pottery traditions spanning over a millennium. A catalogue of Neolithic pottery by Audrey Henshall is on microfiche.
39
Görög, Augustín. "Number of Points for Roundness Measurement - Measured Results Comparison." Research Papers Faculty of Materials Science and Technology Slovak University of Technology 19, no. 30 (January 1, 2011): 19–24. http://dx.doi.org/10.2478/v10186-010-0035-x.
Full textAbstract:
Number of Points for Roundness Measurement - Measured Results Comparison Paper deals with filtering roundness. It presents experimental results measured for roundness turning and cylindrical grinding. Roundness was measured using Prismo Navigator 5 coordinate measuring machine. Evaluation was done by four methods: Minimum zone reference circles (MZCI), Least squares reference circle (LSCI), Minimum circumscribed reference circle (MCCI) and Maximum inscribed reference circle (MICI). The filters used were: Gauss, Spline and no filter.
40
Kirkpatrick, Jamie B., Alistair Deane, and Jared Parry. "The dynamics of rush circles in subalpine grassland." Australian Journal of Botany 67, no. 4 (2019): 335. http://dx.doi.org/10.1071/bt18151.
Full textAbstract:
Geometric patterning in vegetation is often the result of cyclic succession, although circular forms sometimes result from the clonal growth of individual plants. We investigated whether cyclic succession or clonal growth created patterns in Poa subalpine grassland with rush (Empodisma minus) circles on the Central Plateau of Tasmania, Australia. We mapped change in the number, size and reflectance of the rush circles from 1953 to 2011 using aerial photographs, tested whether the circles occurred in distinct microenvironments, and whether the circles were likely to be individuals and determined whether the smallest circles were associated with disturbance. The number and area of circles increased with time. As circles became larger they became more reflective, evenly across their extent. The circles were associated with flatter patches in the plain. Surface soil characteristics did not differ between an exemplar circle and adjacent grassland. The Empodisma foliage in each circle tended to have colour consistently distinct from that of other circles in its vicinity, indicating that the circular form was a product of vegetative expansion of a single individual at a much more rapid velocity than the expansion of woody plant rings. The smaller circles were sometimes associated with frost-damaged Astelia alpina mounds, although far from confined to them. We did not find any instances of Empodisma circles <0.1 m in diameter. We deduced that the probability of establishment of new individuals of Empodisma in the grassland was extremely low, or depended on an infrequent disturbance. Although the increasing reflectance of circles with size and the lack of differentiation of soils between circle and grassland indicated the possibility of cyclic succession, the area covered by circles increased at the decadal time scale. The increases in circle coverage and number may have resulted from changes in climate and grazing regimes on the eastern Central Plateau since the 1940s.
41
Yershov, V. N., and A. A. Nemiro. "An Autocollimation Circle Reading System for the Infrared Meridian Instrument." Symposium - International Astronomical Union 166 (1995): 361. http://dx.doi.org/10.1017/s0074180900228441.
Full textAbstract:
A new autocollimation circle reading system is proposed for the reflector meridian circle (Nemiro and Streletsky, 1988). The instrument will be used for observations in the K-infrared waveband. Instead of the divided circle fixed to the instrument tube the new system has small spherical mirrors polished at the lateral surfaces of the primary mirror. The primary mirror is made from sitall and has an autocollimation system aimed at monitoring its optical axis position. The small spherical mirrors of the circle reading system link the circle readings with the primary's optical axis. The divided circles are fixed unmovable opposite to both lateral surfaces of the primary's optical block. Both surfaces have four spherical mirrors. The distance between the divided circles and the mirrors is equal to the mirrors' radii of curvature. The scales of each circle are illuminated from outside (where the measuring microscopes are placed). The mirrors form autocollimated images of the divisions at the plane of the divisions itself. Averaged coordinates of a division and its autocollimated image give the position of the mirror's optical center, and the semi-difference of the coordinates gives the angular position of the telescope. So, the measurements of the circle positions are differential ones, and any displacements of the microscope zero-points are not critical. The precision of measurements is estimated to be better then 0.05″ (random) and 0.005″ (systematical). The work was supported by the Russian Foundation of Fundamental Investigations (the project's code is 93-02-17095).
42
Zhou, Bing, and Yang He. "Fast Circle Detection Using Spatial Decomposition of Hough Transform." International Journal of Pattern Recognition and Artificial Intelligence 31, no. 03 (February 2017): 1755006. http://dx.doi.org/10.1142/s0218001417550060.
Full textAbstract:
Circles are important patterns in many automatic image inspection applications. The Hough Transform (HT) is a popular method for extracting shapes from original images. It was first introduced for the recognition of straight lines, and later extended to circles. The drawbacks of standard Hough Transform (SHT) for circle detection are the large computational and storage requirements. In this paper, we propose a modified HT called Vector Quantization of Hough Transform (VQHT) to detect circles more efficiently. The basic idea is to first decompose the edge image into many subimages by using Vector Quantization (VQ) algorithm based on their natural spatial relationships. The edge points resided in each subimage are considered as one circle candidate group. Then the VQHT algorithm is applied for fast circle detection. A new paradigm to store potential curve parameters is also proposed, which can exponentially reduce the storage space for HT algorithm. Experimental results show that the proposed algorithm can quickly and accurately detect multiple circles from the noisy background.
43
Arana Araya, Ignacio. "inner circle of presidents." Estudios Internacionales 55, no. 206 (December 28, 2023): 81–109. http://dx.doi.org/10.5354/0719-3769.2023.73188.
Full textAbstract:
Who belongs to the inner circle of presidents remains understudied. Preceding research has mostly focused on advisors and ministers separately, and has not integrated other groups who also influence presidents. I argue that families, advisors, and ministers are members of the inner circle of presidents and support the leaders’ affective, intellectual, and political needs, respectively. I also propose that the inner circle becomes more functional when its three component groups work with a clear division of labor, are diverse, and combine hierarchical and horizontal relations with presidents. Semi-structured interviews conducted with 24 former Latin American presidents support that inner circles are composed of family, advisors, and ministers, although more evidence is needed to assess what constitutes a functional inner circle.
44
Tarnai, Tibor, and Koji Miyazaki. "Circle Packings and the Sacred Lotus." Leonardo 36, no. 2 (April 2003): 145–50. http://dx.doi.org/10.1162/002409403321554215.
Full textAbstract:
How must n non-overlapping equal circles be packed in a given circle so that the diameter of the circles will be as large as possible? This paper presents an account of this problem and its putative solutions and related configurations in lotus receptacles, classical Japanese mathematics (wasan) and traditional Japanese design. Particular emphasis is placed on the connection between the conjectural solutions of this discrete geometrical problem and the fruit arrangements in the receptacles of lotuses, because in most cases the actual fruit arrangements are identical to the mathematical solutions. As the lotus is an important symbol in Buddhism and lotus decorations are quite common in Japanese Buddhist art, packings of circles in a circle have been represented in Japanese art for centuries.
45
Графский, O. Grafskiy, Пономарчук, and Yu Ponomarchuk. "On One Property of a Circle on the Coordinate Plane." Geometry & Graphics 5, no. 2 (July 4, 2017): 13–24. http://dx.doi.org/10.12737/article_5953f2af770c35.65774157.
Full textAbstract:
Descartes’ and Fermat's method allowed to define many geometrical forms, including circles, on the coordinate plane by means of the arithmetic equations and to make necessary analytical operations in order to solve many problems of theoretical and applied research in various scientific areas, for example. However, the equations of a circle and other conics in the majority of research topics are used in the subsequent analysis of applied problems, or for analytical confirmation of constructive solutions in geometrical research, according to Russian geometrician G. Monge and others, including. It is natural to consider a circle as a locus of points, equidistant from a given point — a center of the circle, with a constant distance R. There is another definition of a circle: a set of points from which a given segment is visible under constant directed angle. Besides, a circle is accepted to model the Euclid plane in the known scheme of non-Euclidean geometry of Cayley-Klein, it is the absolute which was given by A. Cayley for the first time in his memoirs. It is possible to list various applications of this geometrical form, especially for harmonism definition of the corresponding points, where the diametral opposite points of a circle are accepted as basic, and also for construction of involutive compliances. The construction of tangents to a circle can be considered as a classical example. Their constructive definition is simple, but also constructions on the basis of known projective geometry postulates are possible (a hexagon when modeling a series of the second order, Pascal's lines). These postulates can be applied to construction of tangents to a circle (to an ellipse and hyperboles to determination of imaginary points of intersection of a circle and a line. This paper considers the construction of tangents to a circle without the use of arches of auxiliary circles, which was applied in order to determine the imaginary points of intersection of a circle and a line (an axis of coordinates). Besides, various dependences of parameter p2, which is equal to the product of the values of the intersection points’ coordinates of a circle and coordinate axes, are analytically determined.
46
Brown, Matthew R. "Laguerre geometries and some connections to generalized quadrangles." Journal of the Australian Mathematical Society 83, no. 3 (December 2007): 335–56. http://dx.doi.org/10.1017/s1446788700037964.
Full textAbstract:
AbstractA Laguerre plane is a geometry of points, lines and circles where three pairwise non-collinear points lie on a unique circle, any line and circle meet uniquely and finally, given a circle C and a point Q not on it for each point P on C there is a unique circle on Q and touching C at P. We generalise to a Laguerre geometry where three pairwise non-collinear points lie on a constant number of circles. Examples and conditions on the parameters of a Laguerre geometry are given.A generalized quadrangle (GQ) is a point, line geometry in which for a non-incident point, line pair (P. m) there exists a unique point on m collinear with P. In certain cases we construct a Laguerre geometry from a GQ and conversely. Using Laguerre geometries we show that a GQ of order (s. s2) satisfying Property (G) at a pair of points is equivalent to a configuration of ovoids in three-dimensional projective space.
47
Im, HunTaek, and Eun-Sung Ko. "Analysis of the teaching content and teaching method for the area of a circle by elementary mathematics curriculum: from the 1st curriculum to the 2015 revised curriculum." Korean Association For Learner-Centered Curriculum And Instruction 22, no. 18 (September 30, 2022): 695–709. http://dx.doi.org/10.22251/jlcci.2022.22.18.695.
Full textAbstract:
Objectives In this study, the teaching content and teaching method of the circle area were analyzed in elementary mathematics textbooks from the 1st curriculum to the 2015 revised curriculum.
Methods In this study, in order to compare and analyze the teaching content and teaching method of the area of a circle presented in elementary mathematics textbooks from the 1st curriculum to the 2015 revised curriculum, based on previous studies, the analysis focus was focused on the teaching content of the area of the circle(a teaching of approximation of the area of a circle, a method of finding the area of a circle using circumscribed and inscribed polygons, a method of finding the area of a circle using unit area, a method of finding the area of a circle by rearranging the circles), the basic concept of measurement of the area of a circle and the method of calculating the area of a circle.
Results The presence or absence of an estimate of the area of a circle was different for each curriculum, and among the basic concepts of measuring the area of a circle, the concepts of division, practice, rearrangement, and arrangement structure were covered in all curriculums, but the concepts of unit repetition and approximation were different for each curriculum. In most curriculum, the area of a circle was calculated using the area of a rectangle.
Conclusions Regarding the teaching of the area of a circle, the focus of the discussion could be divided into three (approximate map of the area of a circle, a method of presenting the concept of measuring the area of a circle, and a method of calculating the area of a circle). Based on this, implications for the teaching of the area of the circle and the development of the next textbook were derived.
48
Graham, R. L., B. D. Lubachevsky, K. J. Nurmela, and P. R. J. Östergård. "Dense packings of congruent circles in a circle." Discrete Mathematics 181, no. 1-3 (February 1998): 139–54. http://dx.doi.org/10.1016/s0012-365x(97)00050-2.
Full text
49
Sal'kov, N. "About One Way of Forming Conics." Geometry & Graphics 10, no. 4 (March 13, 2023): 3–12. http://dx.doi.org/10.12737/2308-4898-2022-10-4-3-12.
Full textAbstract:
In the articles of the Geometry and Graphics magazine devoted to the properties of the Dupin cyclide, the construction of a conic – ellipse, hyperbola and parabola – using the properties of the cyclide was considered. At the same time, the center of the transformation was located on a straight line connecting the centers of the two base circles, and its location on such a straight line was negotiated separately and was located as the center of homology. To construct a parabola, it was necessary to take a straight line instead of the second circle, and the center of the transformation – the center of homology – had to be located at the intersection point of a straight line passing through the center of the first circle perpendicular to the second circle-a straight line with the first circle. Two different parabolas were obtained as a result of the transformation. In this paper, it is proved that if we take the center of correspondence that does not belong to a circle, we get other second–order curves - ellipses and hyperbolas. The construction of an ellipse is geometrically proved. To do this, the center of correspondence must lie on a straight line connecting the centers of the circles, but outside the actual circle. Several examples are considered. If the center of correspondence is inside the circle, we will have a hyperbola. Thus, having initially given only one con-figuration from a straight line and a circle, it is possible to obtain all conics: ellipses, parabolas, and hyperbolas, passing into one another. The proposed scheme for constructing conics can be used for computer drawing of all conics, which is more convenient than with the available options sewn into today's graphical drawing systems.
50
Debrecéni, Ondrej, Z. Janesová, Vladimir Zimmermann, and A. Copík. "Exploitation of the nurse cows for meat production on dairy farms: Ethological aspects." Biotehnologija u stocarstvu 24, no. 1-2 (2008): 17–24. http://dx.doi.org/10.2298/bah0802017d.
Full textAbstract:
The purpose of the study was to evaluate nurse cow's behavior during the calves rearing. The experimental group consisted of five Holstein - Friesian nurse cows. The experiment takes 10 weeks of each circle. The calves were allotted to the nurse cows immediately after calving in the first circles. In the first circle was used 1 own calf and 2 foster calves in comparison with the second circle where were 3 foster calves. The calves were with nurse cows in the separate 'habitual pen' during the first week of rearing. We made 24 hours lasting etiological observations. During etiological observation we evaluated the following activities: 'Lying', 'Eating', 'Standing', 'Walking', 'Drinking', 'Licking calf', 'Standing and bellowing', 'Smelling calf', 'Sucking' and 'Head knocking'. Our results show that the activity of 'standing and bellowing' did not occur in the first circle in comparison with the volume 57,40 minutes in the second circle. These findings indicate that the nurse cows have more willingly accepted the calves in the first circle.