Flat Circle Research Articles

Eksplorasi Etnomatematika pada Permainan Tradisional Congklak di Kelurahan Srengseng Sawah

Ethnomathematics contributes greatly to the improvement of mathematics learning, because it relates to students' experiences in everyday life that touches the realm of local cultural arts so that students become more understanding of the mathematical concepts explained. This study aims to explore the concept of mathematics in the traditional game of congklak in Srengseng Sawah Village. This research is a qualitative research with an ethnographic approach. The data collection techniques used are observation, interview and documentation. The instruments in this study were researchers, observation guidelines, interview guidelines and documentation. Based on the research analysis and discussion of the history and philosophy of the traditional game of congklak, mathematical concepts in the game of congklak such as the concept of flat shapes, namely semicircles, circles, rectangles and spatial shapes, namely half a ball; the concept of transformation in this case reflection / mirroring; the concept of arithmetic calculation operations including addition, subtraction, multiplication and division. The game also has cultural and philosophical values.

Experimental Investigation into the Failure Mechanisms of Fabric Membrane Materials with Defective Flat Round Cracks

The emphasis of this study is placed on the investigation into the failure mechanisms of the fabric membranes when exposed to such defective cracks. This experimental study investigates the initial crack of a flat circle and conducts a uniaxial shear test on the membrane materials. The deformation of the membrane materials is obtained through an optical non-contact scanner. Our study has been conducted to assess the crack propagation of fabric membrane materials at different angles. The relationships between crack width and stress together with stress and strain are also obtained. Based on the results, a mechanic of failure on the membrane was proposed. Moreover, new findings into the ductility and energy absorption of the fabric membrane materials have been established to inform the failure mechanisms.

Three-Dimensionally Printed Vaginal Rings: Perceptions of Women and Gynecologists in a Cross-Sectional Survey.

Three-dimensional printing technologies can be implemented for the fabrication of personalized vaginal rings (VRs) as an alternative approach to traditional manufacturing. Although several studies have demonstrated the potential of additive manufacturing, there is a lack of knowledge concerning the opinions of patients and clinicians. This study aimed to investigate the perception of women and gynecologists regarding VRs with personalized shapes. The devices were printed with different designs (traditional, "Y", "M", and flat circle) by Fused Deposition Modeling for a cross-sectional survey with 155 participants. Their anticipated opinion was assessed through a questionnaire after a visual/tactile analysis of the VRs. The findings revealed that most women would feel comfortable using some of the 3D-printed VR designs and demonstrated good acceptability for the traditional and two innovative designs. However, women presented multiple preferences when the actual geometry was assessed, which directly related to their age, previous use of the vaginal route, and perception of comfort. In turn, gynecologists favored prescribing traditional and flat circle designs. Overall, although there was a difference in the perception between women and gynecologists, they had a positive opinion of the 3D-printed VRs. Finally, the personalized VRs could lead to an increase in therapeutic adherence, by meeting women's preferences.

Experimental Study for Load-Settlement Behavior of Flat and Shell Footings on Sandy Silt Soil

Shell foundations are often used to raise the carrying capacity of a structure on weak soils. In cases where large superstructure loads must be transferred to poorer soils, shell foundations are more cost-effective than ordinary shallow foundations. Advances in the study and design of shell-type foundations have shown their superiority over traditional footings in poorer soils. The current study aims to investigate shell shape’s influence on ultimate load capacity. Seven footing types’ models were created along with an appropriate testing box. The soil needed for the study was from the region north of Mosul city, classified as silt with low plasticity (sandy silt) soil. A laboratory model experimentally determined the ultimate load capacities for inverted and upright conical, inverted and upright pyramid, and hemispherical shell foundations on silty soil. The achieved results were associated with those for conventional flat squares and circles. According to the findings, the “upright conical” shell footing has a load capacity of 12.7 kN, higher than the other foundations, and its efficiency was 51%. When comparing foundations, the “upright pyramidal” shell footing has better settling characteristics and a settlement factor of 0.017. As the shell factor decreases, the shell foundation begins to behave more like a flat foundation, which reduces the maximum load capacity of the shell foundation.

“Time is a Flat Circle”: The Naturalist Visual Aesthetic of Contemporary Television Crime Series

“Time is a Flat Circle”: The Naturalist Visual Aesthetic of Contemporary Television Crime Series

호서지역 청동기~초기철기시대 환호 검토

This paper attempts to classify the types of ring ditches from the Bronze Age to the Early Iron Age in the region called Hoseo today. In addition, it examines their features and how they have been changed.
 A total of five types are identified: Type Ⅰ, which has multiple rows, a flat irregular shape, and residential areas inside; Type Ⅱ, which has a single row, a flat circle or oval shape, and a vacant lot inside, but only a ring ditch is constructed; Type Ⅲ, also similar to Type Ⅱ, which is adjacent to residential space outside; Type Ⅳ, which has a single row, a flat oval shape, and including living relics inside; Type Ⅴ, similar to Type Ⅵ, but no relics existed inside the ring ditch.
 Type Ⅰ has separated residential groups according to ring ditch. Therefore, it could guess that it was a means that indicates hierarchies within a village. In terms of Type Ⅱ~Ⅴ, they are strongly considered ceremonial uses because of the following reasons. First of all, their ring ditches surround the top of the hill. Secondly, places separated by ring ditches are a vacant lot or have a few habitations found inside of them. The last one is the presence of entrances to them. Despite the types having a lot in common, they also show significant differences in the scale. The Type Ⅳ·Ⅴ seems that more labour was put into its construction because of its relatively large scale compared to the Type Ⅱ·Ⅲ. Furthermore, it is presumed that it played a role not only in the ceremony but also in making their community strengthen.
 When it comes to time, in the Hoseo area, Type Ⅰ first appeared in the early period of the Bronze Age, then followed by Type Ⅱ and Type Ⅲ. Afterwards, Type Ⅳ newly appeared in the latter period. Eventually, in the Early Iron Age, Type Ⅳ and Type Ⅴ coexisted, and Type Ⅱ·Ⅲ has not been longer identified.
 Since the result that estimated the scope of ritual ceremony illustrates that there are a number of remains in the visible areas of Type Ⅱ rather than Type Ⅲ, Type Ⅱ would have been a communal place that encompassed much more groups. Moreover, the number of remains in the visible areas is the same in the case of Type Ⅳ and Type Ⅴ in spite of their scale difference. It could lead to the possibility that Type Ⅳ, relatively large, did not cover the wider community. Thus, the Type Ⅳ could be the ring ditch managed by a similar scale of community to the Type Ⅴ.

PENGEMBANGAN PERANGKAT PEMBELAJARAN BERBASIS PENDEKATAN SAINTIFIK DENGAN MODEL DISCOVERY LEARNING PADA MATERI SEGIEMPAT DAN SEGITIGA KELAS VII SMP

Quadrilaterals and triangles are geometric materials that have many uses in everyday life. However, based on the data from Puspendik KEMENDIKBUD, only 36.68% of students answered the flat shape and circle area correctly, and 29.0%7 answered the question interpreting the combined area of the flat shape correctly. Learning tools take an important role in the learning process. Learning tools are one of the tools that teachers can use to help them achieve their learning goals. However, from the observation results at school, there is a discrepancy between the learning tools developed by the teacher and the learning process carried out in the classroom, and it is meaningful for the students to positively feel their concepts and knowledge. This research have purpose to advance learning device based on a scientific approach using a discovery learning model. This reserach uses the Plomp method, which consists of stages. (1) Preliminary phase which is analyze of needss, student, curriculumand concept), (2) Prototyping phase which is including design the product, self-evaluation, validation by expert, one on one evaluation, and small group Evaluation, (3) Evaluation Phase, which was performed in a large group (field test), but in this study only up to the small group evaluation phase. The result of this research was obtained from the results of interviews and surveys. The results of the analyze of the obtained data show that learning devices based on a scientific approach based on the developed discovery learning model are very effective at an average rate of 92.32% and very practical at a rate of 93.36% of students response. It also got average 86.61% for practical by teachers' responese. From this, we can conclude that the resulting learning tools are effective and practical.Keywords __ Discovery learning, Learning, Plomp, Scientific approach

Innovative impact testing machine for enhancing impact related research in Australia

This paper summarises the development of a state-of-art impact testing machine for simulating impacts such as vehicular crashes or debris impacts onto structures. The machine has a 200 kg pneumatically powered projectile which can travel horizontally within the barrel of the machine with a maximum velocity of 50 m/s to impact the target structure. The maximum kinetic energy that can be generated by the projectile is 125 kJ by using different combinations of mass and velocity. The diameter of the projectile is 214 mm, and its impacting face can be changed to different shapes, such as flat circle, flat square or an elliptical nose to suit different impact scenarios. An innovative braking mechanism incorporating a crush tube is attached within the barrel to ensure safety when the projectile fails to be restrained by the impact. The crush tube can absorb the maximum imparted by the moving projectile. An advanced data acquisition system is installed to collect quantitative and qualitative test data during a period of 50 ms to 1 s. Two high-speed digital image correlation (DIC) cameras are attached and synchronised with the operation of the impact testing machine to record the images at the rate of 50,000 frames per second. Outputs in terms of strains, deformations, accelerations of the target structure with a record of damage history can be analysed using this 3D DIC technique. The paper also briefly presents the first application of this machine for impact testing masonry wall structures.

Research on Characteristics of Electrostatic Wear-Site and Oil-Line Sensor with Theoretical and Comprehensive Analysis

As a unique monitoring technique, electrostatic monitoring has been proved to be effective on prognostics and health management of tribological system by using electrostatic sensors. Wear-site sensor (WSS) with a flat circle probe and oil-line sensor (OLS) with a ring probe are two typical sensor types for electrostatic monitoring. However, this developing technique has not been applied in actual industry manufacture so far due to the united characteristics on electrostatic sensors. This paper first presents the mathematical models of both WSS and OLS for theoretical simulation. Then a series of contrast analysis on sensor characteristics between WSS and OLS with varied sensor structure parameters are presented. The results show that the distributions of spatial sensitivity for WSS or OLS itself only are similar, while they are quite different between WSS and OLS. Both WSS and OLS are symmetrical and their distributions can be simplified in one phase for further investigations. The theoretical efficiency curves have close relationship between WSS and OLS. The investigations of sensor performances on characteristics and a presented unified three level system have offered a better electrostatic sensor application in future.

Twisted cohomological equations for translation flows

AbstractWe prove by methods of harmonic analysis a result on the existence of solutions for twisted cohomological equations on translation surfaces with loss of derivatives at most$3+$in Sobolev spaces. As a consequence we prove that product translation flows on (three-dimensional) translation manifolds which are products of a (higher-genus) translation surface with a (flat) circle are stable in the sense of A. Katok. In turn, our result on product flows implies a stability result of time-$\tau $maps of translation flows on translation surfaces.

FOUR-DIMENSIONAL BALL IN A GRAPHIC REPRESENTATION

The paper presents a method for geometric modelling of a four-dimensional ball. For this, the regularities of the change in the shape of the projections of simple geometric images of two-dimensional and three-dimensional spaces during rotation are considered. Rotations of a segment and a circle around an axis are considered; it is shown that during rotation the shape of their projections changes from the maximum value to the degenerate projection.
 It was found that the set of points of the degenerate projection belongs to the axis of rotation, and each n-dimensional geometric image during rotation forms a body of a higher dimension, that is, one that belongs to (n + 1) -dimensional space. Identified regularities are extended to the four-dimensional space in which the ball is placed. It is shown that the axis of rotation of the ball will be a degenerate projection in the form of a circle, and the ball, when rotating, changes its size from a volumetric object to a flat circle, then increases again, but in the other direction (that is, it turns out), and then in reverse order to its original position. This rotation is more like a deformation, and such a ball of four-dimensional space is a hypersphere. For geometric modelling of the hypersphere and the possibility of its projection image, the article uses the vector model proposed by P.V. Filippov. The coordinate system 0xyzt is defined. The algebraic equation of the hypersphere is given by analogy with the three-dimensional space along certain coordinates of the center a, b, c, d. A variant of hypersection at t = 0 is considered, which confirms by equations obtaining a two-dimensional ball of three-dimensional space, a point (a ball of zero radius), which coincides with the center of the ball, or an imaginary ball. For the variant t = d, the equation of a two-dimensional ball is obtained, in which the radius is equal to R and the coordinates of all points along the 0t axis are equal to d. The variant of hypersection t = k turned out to be interesting, in which the equation of a two-dimensional sphere was obtained, in which the coordinates of all points along the 0t axis are equal to k, and the radius is . Horizontal vector projections of hypersection are constructed for different values of k. It is concluded that the set of horizontal vector projections of hypersections at t = k defines an ellipse.

Thermo-Hydraulic Performance of U-Tube Borehole Heat Exchanger with Different Cross-Sections

For reducing the initial GSHP investment, the heat transfer efficiency of the borehole heat exchange (BHE) system can be enhanced to reduce the number or depth of drilling. This paper proposes a novel and simple BHE design by changing the cross-sectional shape of the U-tube to increase the heat transfer efficiency of BHEs. Specifically, in this study, we (1) verified the reliability of the three-dimensional numerical model based on the thermal response test (TRT) and (2) compared the inlet and outlet temperatures of the different U-tubes at 48 h under the premise of constant leg distance and fluid area. Referent to the circular tube, the increases in the heat exchange efficiencies of the curved oval tube, flat oval tube, semicircle tube, and sector tube were 13.0%, 19.1%, 9.4%, and 14.8%, respectively. (3) The heat flux heterogeneity of the tubes on the inlet and outlet sides of the BHE, in decreasing order, is flat oval, semicircle, curved oval, sector, and circle shapes. (4) The temperature heterogeneity of the borehole wall in the BHE in decreasing order is circle, sector, curved oval, flat oval, and semicircle shapes. (5) Under the premise of maximum leg distance, referent to the heat resistance of the tube with a circle shape at 48 h, the heat exchange efficiency of the curved oval, flat oval, semicircle, and sector tubes increased 12.6%, 17.7%, 10.3%, and 7.8%, respectively. (6) We found that the adjustments of the leg distance and the tube shape affect the heat resistance by about 25% and 12%, respectively. (7) The flat-oval-shaped tube at the maximum leg distance was found to be the best tube design for BHEs.

Quantitative Assessment of Cardiac Intercalated Disk Ultrastructure and Molecular Organization by Indirect Correlative Light and Electron Microscopy

The intercalated disk (ID) is a specialized structure that affords electrical (gap junctions) and mechanical (adherens junctions, desmosomes) coupling between cardiomyocytes. Previous research suggests that cardiac sodium channels (NaV1.5) enriched within ID nanodomains may play a key role in cell-to-cell electrical communication. Current models of cardiac conduction do not include the ID or at best, grossly oversimplify it to a uniform flat circle with homogeneous properties. Little experimental data is available to enable realistic in silico representation of the ID and its ion channels. We are using indirect correlative light and electron microscopy (iCLEM) to characterize the ultrastructure (TEM) and molecular organization (STORM) to characterize NaV1.5-rich ID nanodomains under baseline conditions and following acute (60 minutes) structural perturbation using adhesion inhibitor peptides that selectively disrupt different ID nanodomains. Preliminary results indicate that ∼50% of ID-localized NaV1.5 are located within gap junction-adjacent perinexi with another ∼35% being associated with mechanical junctions. Disrupting adhesion within ID nanodomains locally increases intermembrane spacing (electron microscopy), and leads to dynamic dispersal of NaV1.5 clusters (STORM single molecule localization microscopy). In contrast, the inwardly-rectifying potassium channel (Kir2.1) was evenly distributed between GJ- and MJ-associated ID nanodomains and did not undergo redistribution following adhesion inhibitor treatments. Junctional protein distributions were not affected by the peptide inhibitors. Functionally, these effects correlate with conduction slowing and increased arrhythmia vulnerability. Furthermore, the magnitude of functional impacts are likely determined by the amount of sodium channels contained within the nanodomains disrupted. We use these structural data to generate realistic finite-element meshes of ID nanodomain structure and probe their functional roles. This model could reveal previously unanticipated electrical signaling mechanisms at ID nanodomains.

Lighting the Tetraconch Church Of Bosra (Syria). Architecture And Suspending Devices

During the archaeological excavations of the Tetraconch Church of the Saints Sergios, Bacchos and Leontios in Bosra (Syria), collaboration between University of Bologna (Director Prof. R. Farioli Campanati, Responsible of excavation PhD G. Bucci) and DGAM Syria, Direction Générale des Antiquités et de Musée de Syrie, Bosra Department (Arch. Wafa. Al Oude and Fayez Al Douz) under the High Patronage of the Italian Foreign Ministry, we discovered many findings belonging to Late Antique suspending lights: polykandela, polyangistra and lychniai ualai. We collected a big bronze discs which bears a geometric decoration of interlacing flat circles with three holes for hanging suspending hooks, a decorative disc with cross, glass beakers, stems and suspending devices of different typologies, including chains, hooks, rings, bars. The chronology of our evidences is attested mainly between the sixth and the seventh century AD. Thanks to a peculiar documentation of the stratigraphic excavations, a detailed catalogation of the artefacts, and a wide research about suspending light devices between Late Antique and Middle Age in the Near East, following the indication of the iconographical support of the Syrian Floor Mosaics representations, we completed a reconstruction of the lighting system of the Tetraconch Church. Here we would like to introduce some unpublished findings and our last studies about suspending lights found in Bosra.

Student’s cognitive conflict form problem solving on mathematics

This study aims to describe the cognitive conflicts of male and female students in mathematical problems solving. This research is a qualitative research with a descriptive approach. Data collection methods include tests, interviews, and documentation. The subjects of this study were 1 male and 1 female student selected from 6 samples consisting of 3 male students and 3 female students using purposive sampling technique. Data analysis techniques used are data reduction, data presentation, and conclusion. The results of the study showed that students experienced cognitive conflict when solving the problem of constructing a flat circle. This is indicated by the attitude of doubt and anxiety experienced by students in answering questions. In addition, the occurrence of errors and misconceptions in students when solving problems where students can not distinguish the concept of circumference and broad concepts in the flat circle. Therefore, it is better that in the learning process students not only memorize formulas, but students must understand the concepts in depth. In addition, teachers also need to pay more attention to male students in the learning process because male students experience cognitive conflict more often than female students.

Evaluation of the singular integrals of the three-dimensional thermoelasticity

The article deals with the solving of the problem of coupled thermoelastic vibrations of massive bodies. Numerical solution is sought by the boundary integral equation method. The main attention is paid to the definition of singular parts of integrals i.e. to integration along those boundary elements on which the pole is located. Two approaches are proposed for evaluation of singular integrals. The first approach is based on the expansion of integral equations kernels in a power series. For the realization of this approach, compact expressions approximating all components of the kernels are obtained. The obtained expressions has weak or strong singularities when the distance between the source point and integration point goes to zero similar to the behaviour of the corresponding elastostatic expressions. Therefore, such expressions can be successfully used for singular integrals evaluation. A number of numerical experiments have been performed, which confirms the robustness of the approach in a wide frequency range and allows us to trace the dependence between the number of retained members and the accuracy of the calculations. The second approach is related to the analytical calculation of integrals over a flat circle with a centre at the pole. In this paper the exact formulas were obtained that allow us to compute effectively the corresponding integrals over the boundary elements on which the pole is located. Among other things, the obtained exact expressions prove the existence of corresponding singular integrals in the sense of the Cauchy principal value. As a matter of a fact the above relations form the main part of a numerical algorithm aimed at solving the problem of coupled three-dimensional harmonic thermoelastic vibrations of massive elements of constructions using the of boundary element method.

3D-PIC simulation of the electron beam interaction with modulated density plasma

In this paper, the three-dimensional(3D3V) numerical model is developed for the simulation of enhanced electromagnetic emission due to the beam injection into the modulated density plasma. The proposed model is fully kinetic and based on Particle-In-Cell method. The results of numerical experiments for different beam and plasma parameters are presented. Comparison of the radiation efficiency for the flat plasma layer and circle plasma column with different plasma density modulation amplitude are obtained. Numerical experiments have been performed using computer systems with parallel architecture.

Screening and identification of Lipase Producing Bacterium

55 samples from different regions were selected and screened by Rhodamine B flat transparent circle method to observe lipase producing effect, among which, LHY-1, identified as Serratia sp. has the characteristics of fast growth, high enzyme production and stable ability. The colony of this strain is white, the edge is smooth and tidy, the surface is moist, the cell is straight, rod-shaped, gram negative, 0.1-0.2 μm in diameter and, length 0.3-0.5 μm in length.

Growth characteristics and enzyme production optimization of lipase Producing Strain

55 samples from different regions were selected and screened by Rhodamine B flat transparent circle method to observe lipase producing effect, among which, LHY-1, identified as Serratia sp. has the characteristics of fast growth, high enzyme production and stable ability. The colony of this strain is white, the edge is smooth and tidy, the surface is moist, the cell is straight, rod-shaped, gram negative, 0.1-0.2 μm in diameter and, length 0.3-0.5 μm in length.

On powers of the Euler class for flat circle bundles

Apparently a lost theorem of Thurston [1] states that the cube of the Euler class [Formula: see text] is zero where [Formula: see text] is the analytic orientation preserving diffeomorphisms of the circle with the discrete topology. This is in contrast with Morita’s theorem [5] that the powers of the Euler class are nonzero in [Formula: see text] where [Formula: see text] is the orientation preserving [Formula: see text]-diffeomorphisms of the circle with the discrete topology. The purpose of this short note is to prove that the powers of the Euler class [Formula: see text] in fact are nonzero in cohomology with integer coefficients. We also give a short proof of Morita’s theorem [5].