Circle Method Research Articles

Online measurement method for roundness of large aluminum alloy ring based on laser ranging principle

Aluminum alloy rings are widely used in aerospace, energy, petrochemical, and equipment applications. The loss of roundness often occurs because of the weak rigidity and unstable plasticity of aluminum alloy rings. Therefore, an online measurement technique for the roundness of aluminum alloy rings is critical for ensuring the processing quality of aluminum alloy rings. In this paper, an online roundness measurement method based on the laser ranging principle and improved particle swarm optimization (IPSO) is proposed with the aid of the rotation of the ring during the rolling process. First, the distance from the outer surface of the ring to the laser rangefinder was measured using a triangular laser rangefinder with the help of the rotation of the ring in the rolling process. Second, the distance data were denoized using an improved Kalman filter algorithm to reduce the influence of random noise on the measurement results. Finally, the roundness and geometric center were evaluated using the IPSO algorithm combined with the minimum zone circle (MZC) method and compared with the results obtained using the standard particle swarm optimization (PSO) algorithm, genetic algorithm (GA), and least square (LS) algorithm. The experimental results show that the roundness measured by the IPSO algorithm is less than 0.06 mm, demonstrating better performance in the roundness evaluation. The measurement method for roundness proposed in this paper is suitable for the online evaluation of large aluminum alloy rings, avoiding the influence of ring size on roundness measurement.

A new circle method for measuring humeral torsion on MRI-scans less sensitive to Hill-Sachs lesions

ObjectivesThe literature on humeral torsion angles (retrotorsion) reveals great inconsistencies between methodology and values. Decreased retrotorsion was suspected to correlate with instability, but evidence is contradictory. The measurement according to the gold standard method of Bernageau and Godefroy (B&G) can be challenging especially in the presence of Hill-Sachs-lesions. Therefore, we have developed and evaluated a new measurement method for the humeral torsion angle on MRI-scans. Materials and MethodsThree investigators have measured 67 patients (35 with shoulder instability, 32 healthy) on axial MRIs with 603 measurements used for reliability calculation. The new Circle-method determines the retrotorsion by overlaying two circles on the transversal section of the humeral head. The first circle is adjusted congruent with the margin of the humeral head, whereas the second circle is adjusted to the greater tubercle. The line bisecting the centres of these circles is defined as the humeral head axis. This method was compared to B&G. ResultsThe mean retrotorsion angle of all patients was 25°± 25° (mean ± SD) with B&G, and 24° ± 27° with the Circle-method. Neither method revealed a significant difference between stable and unstable shoulders (p = 0.47). Of the 35 patients with unstable shoulders 21 (60%) presented Hill-Sachs lesions. No significant differences between patients with or without Hill-Sachs lesions (Circle-method: p = 0.61; B&G: p = 0.67). The reliability parameters for both methods were similar. ConclusionsThe new Circle-method is as precise as the method of B&G. It may yield more consistent values in cases with substantial Hill-Sachs-lesions. Our data do not suggest retrotorsion as a predictor of instability.

The Effect of Production Planning and Quality Control on The Final Product

The purpose of this study was to determine the quality of products in furniture manufacturing companies, in fact, there are always defective products in the production process in the field. In order to achieve a quality final result, continuous planning and control must be carried out using the Quality Control Circle method. The sample taken in this study is the monthly report data available at PT Hema Medhajaya for the 2017-2019 period with a total sample size of 36. The statistical method used is multiple linear regression with calculations through SPSS version 25. The results of this study show that Production Quality Planning has a coefficient value. β regression of -0.189 with a tcount of -23.988 and a significance level of 0.000 <0.05, it can be concluded that production quality planning has a negative and significant effect on the final product. And quality control has a positive and significant effect on the final product result marked with a significance level of 0.000 <0.05 and a regression coefficient value β2 of 2.493. the results of the simultaneous significance test (Test F) in this study. The results obtained are in the form of Fcount of 323,988 and a significance value of 0.000 <0.05. So it can be concluded that the variables of the Effect of Quality Planning and Quality Control together have a significant effect on the Final Production Result at the Furniture company at PT Hema Medhajaya.

Reducing the Rate of Unplanned Extubation of Venous Access in Perioperative Patients

Objective: To investigate the application effect of quality control circle activities in reducing the rate of unplanned extubation of venous access in perioperative patients. Methods: The quality control circle method was used to analyze the causes, identify the actual causes of unplanned out-of-control, take corresponding measures, formulate corresponding countermeasures, implement standardized management, and carry out continuous improvement. Results: Following the implementation of quality control circle activities, the rate of unplanned extubation of venous access in perioperative patients decreased from 27.35% before improvement to 3.42% after improvement. Conclusion: The use of quality control circle activities in the safety management of venous access in perioperative patients is conducive to reducing the rate of unplanned extubation of venous access in perioperative patients.

New accurate algorithms of circularity evaluation

The minimum circumscribed circle (MCC), maximum inscribed circle (MIC), and minimum zone circle (MZC) methods for circularity evaluation are difficult to execute due to the lack of specific rules in mathematics, especially the MZC. New accurate algorithms have been proposed to realize the MIC, MCC and MZC evaluation methods. First, the diameter criterion and acute triangle criterion of control points defining the MIC or MCC are presented. The definition of the crossing sector structure is introduced in the minimum zone criterion and transformed into an angular relationship of control points, making it easy to identify the MZC. Then the key points of the algorithms are presented in details including the initial circle or the initial region, centre moving direction, minimum step size and updating rules of control points. Flow charts are provided to make the algorithm producible. Finally, four cases are selected to demonstrate the advantages of the algorithms. The results show that the proposed MZC algorithm is more general than that in the published reference. Compared to the traditional ergodic searching algorithms, the efficiency of the new algorithm for the MIC, the MCC and the MZC evaluations of circularity can be improved by 100% when the point set increases to 100 and above.

Extraction of natural piperine crystals from black pepper with expanded graphite for thermal energy storage

Substantial research was done on the synthesis of piperine crystals (PC) from black pepper using expanding graphite (EG) as a promising organic phase change material (O-PCM). Researchers examined the chemical structure and thermal properties of the substance. Using the diffusion–exudation circle method, the PC/EG-blended PCM had the highest PC mass content, at 93.4 %. According to (DSC) study, the melting and crystallization temperatures are 135.6 °C and 117.4 °C, and their related latent energies are 283.14 KJ/kg and 192.45 KJ/kg. This finding implies that the material retains a respectable capacity for heat storage after being exposed to multiple heat patterns. Thermal storage/discharge studies revealed that the EG/PC material had much better heat storage/discharge ratios than the PC sample. At ambient circumstances, our findings indicated that the Herbal Piperine crystals/expandable graphite PCM was a superior thermal energy storage medium. The results demonstrated that the proposed hybrid composite can be considered as a potential solar energy storage material for a variety of applications, including thermal cooling of photovoltaic panels, automobiles, digital units, solar residential heating systems, and passive solar heating systems.

In-Situ Measurement and Slow-Tool-Servo Compensation Method of Roundness Error of a Precision Mandrel.

This paper describes a method for measuring and compensating the roundness error of a larger mandrel manufactured by an ultra-precision diamond-turning lathe aimed to obtain a calibration cylinder with a roundness of less than 0.1 μm. The diamond-turning machine has a cross-stacked hydrostatic guideway, produces a cutting depth and feed movement direction, and a dual-spindle system that is firmly connected to the bed. Due to the good repeatability of aerostatic spindles, only in situ rather than online real-time measurements are required. To this end, three high-precision capacitance displacement sensors were utilized to detect the cross-section of the workpiece and the time domain via the three-point error separation technique to separate the roundness error from the rotation motion error. The slow tool servo (STS) cutting technique was employed to compensate for the roundness error, which did not require extra axes, only the excellent dynamic response of the feed axis; hence, the servo control parameters could be suitably adjusted. The experimental results reveal that the low-order harmonic error, often caused by aerostatic spindles, is almost removed completely. For this particular lathe, the experiments indicate that about 60% of the rotational error motion is compensated, and the roundness error is reduced to less than 0.1 μm, which is evaluated by the least-squares circle method.

Multilingualism among children, age 7–12, typological representation and language use pattern in a medium-sized town in Norway

ABSTRACT This article examines multilingual language use in two groups of children, one group at a state school, and one at a private IB school. The IB school has earlier been assumed to reflect an ‘elite’ multilingualism. Three research questions are posed: to what extent is the children’s language use multilingual, what are their typological profiles, and are there any differences between the two groups in the language use patterns. The agency of the speaker is captured by self-reporting questionnaires. We use a method of circles in which the participant fills in the names and domains of the languages in use. The answers are registered according to three main dimensions: family, social interaction and media use. The study is exploratory and descriptive, and the results demonstrate that a large majority of the children at both schools used more than one language. The study is innovative in combining a sociolinguistic approach with language typology. Our results shed light on children’s dynamic and flexible language use, using languages from all of the world’s language families. We found similarities in the multilingualism of the two groups, and there was little to indicate that the IB pupils could be characterised as having an ‘elite’ multilingualism.

Working with mathematically gifted students

Working with gifted students is of special social interest. However, in the existing secondary education curricula, it is only declaratively mentioned and this important segment of the education system is completely neglected. That is why in this paper an attempt was made to develop a program for work with mathematically gifted students aged 17–18, that is, for the third year of secondary education, using the concentric circle method. This study uses a descriptive method and gives examples of contents for the curriculum for working with gifted students. Curriculum materials were prepared using the method of concentric circles, which means that some contents adopted in previous years at a certain level are extended and expanded. The study draws from resources from previous researchers and existing literature.
 Keywords: Concentric circle; curricula; gifted students; mathematics.

A Spatial Equilibrium Evaluation of Primary Education Services Based on Living Circle Models: A Case Study within the City of Zhangjiakou, Hebei Province, China

Primary education services are a key component of public infrastructure. These services exert significant impacts on public activity, sustainability, and healthy socio-economic development. This research applies the concept of a ‘living circle’ in order to evaluate the spatial equilibrium of education services in existing primary schools. This has enabled equilibrium planning schemes to be proposed for primary schools as well as the promotion and construction of livable and defensible living spaces. This area remains a key issue, however, one that urgently needs to be addressed in terms of the layout of public infrastructural services to facilitate livable living space construction. Thus, from the perspective of livable and defensible living space construction, the aim of this study was to construct a primary education equalization assessment method based on the walking living circle method. An equilibrium index was also designed based on the number of primary school students; this was then combined with the standard construction of new primary schools to optimize the spatial equilibrium of these education services. The city of Zhangjiakou City was then used as a case study; the spatial equilibrium of primary education services was evaluated across four living circle scenarios (i.e., 15 min, 20 min, 25 min, and 30 min). Results reveal that the city of Zhangjiakou currently offers dramatically spatially negative non-equilibrium primary education services (i.e., supply < demand) across four living circle scenarios, but most notably in rural areas away from urban areas and towns, especially in the counties of Shangyi, Chicheng, Chongli, Kangbao, and Guyuan. It is interesting to note that all living circle scenarios could enable positive non-equilibrium primary education services (i.e., supply > demand), mainly within the urban districts of Qiaodong, Xuanhua, Qiaoxi, Wanquan, and Xiahuayuan. It is also clear that equilibrium living circles are distributed across all counties. A spatial optimization proposal for primary school services should therefore be presented that alleviates the issues inherent to non-equilibrium primary education services. The results of this study offer a number of suggestions for education service optimization across the city of Zhangjiakou as well as for other cities in China. We also provide further scientific foundations for research on livable space and defensible unit construction as well as the spatial equilibrium evaluation of other public infrastructural service facilities

Qualitative Review of Academic Advising Perceptions: Some Students Satisfied and Need It, Some Don’t

The research presented experiences in seeking academic advising patterns that produce satisfaction, urgency, and students’ academic and personal development at a university in Bandung, Indonesia. Data were collected using the story circle method. Four questions, including the meaning of advising, memorable experiences, perception of the process and advisors, and student expectations, were asked to answer the two main research questions. The two main questions involved the meaning and benefits of advising and satisfaction. A total of 57 respondents divided into seven groups of story circles were selected as participants using a purposive sampling method. Data were analyzed using a hierarchical Cresswell approach, starting from transcription, coding, categorizing, and developing themes. The results show that some students are satisfied with academic advising, but others feel dissatisfied even though it is important. The results also show that most advisors have created meaningful and memorable stories supporting student academic achievement. However, the relationship between lecturers and undergraduates determines the satisfaction level. The managers suggest from the research that it is necessary to hold coaching and counseling, training for advisors, and set a minimum procedural standard, including equating online communication channels because it minimizes the inequality of students’ satisfaction.

Mastoid obliteration and external auditory canal reconstruction using 3D printed bioactive glass S53P4 /polycaprolactone scaffold loaded with bone morphogenetic protein-2: A simulation clinical study in rabbits.

IntroductionThe lack of good prosthetic materials and objective standards has limited the promotion of mastoid obliteration and external auditory canal reconstruction, and the quality of the surgery varies. In this study, bioactive glass S53P4 (S53P4), the most popular artificial prosthetic material, was modified and combined with polycaprolactone (PCL) and bone morphogenetic protein-2 (BMP-2) to produce an individualized biological scaffold using 3D printing technology to explore a better material and method for mastoid obliteration and external auditory canal reconstruction.Methods3D-printed S53P4/PCL scaffolds were fabricated from 3D reconstruction data of bone defect areas in New Zealand rabbits simulating “Canal Wall Down Mastoidectomy”. The water absorption, swelling rate, porosity, and Young's modulus of the scaffold were measured, and the morphology and pore size of the scaffold were observed using scanning electron microscopy. The cytotoxicity of the S53P4/PCL scaffolds was detected using the CCK8 assay, and the in vitro antibacterial activity of the S53P4/PCL scaffolds was detected using the inhibition circle method. The BMP-2-loaded S53P4/PCL scaffolds were prepared using the drop-in lyophilization method and implanted into animal models. The biocompatibility, osteogenic activity, and external auditory canal repair of the scaffolds were observed using endoscopy, micro-CT, and histological examination.ResultsThe S53P4/PCL scaffold was highly compatible with the defective area of the animal model, and its physicochemical properties met the requirements of bone tissue engineering. In vitro experiments showed that the S53P4/PCL scaffold was non-cytotoxic and exhibited better antibacterial activity than the same volume of the S53P4 powder. In vivo experiments showed that the S53P4/PCL scaffold had good biocompatibility and osteogenic activity, and could effectively repair bone defects and reconstruct the normal morphology of the external auditory canal in animal models. Furthermore, its osteogenic activity and repair ability were significantly improved after loading with BMP-2.ConclusionsThe 3D printed S53P4/PCL scaffold has great potential for clinical mastoid obliteration and external auditory canal reconstruction.

Vinogradov’s theorem with Fouvry–Iwaniec primes

We show that every sufficiently large $x\equiv 3(4)$ can be written as the sum of three primes, each of which is a sum of a square and a prime square. The main tools are a transference version of the circle method and various sieve related ideas.

The ternary Goldbach problem with two Piatetski–Shapiro primes and a prime with a missing digit

Let [Formula: see text] Let [Formula: see text], [Formula: see text] be fixed. Let also [Formula: see text]. We prove on assumption of the Generalized Riemann Hypothesis that each sufficiently large odd integer [Formula: see text] can be represented in the form [Formula: see text] where the [Formula: see text] are of the form [Formula: see text], [Formula: see text], for [Formula: see text] and the decimal expansion of [Formula: see text] does not contain the digit [Formula: see text]. The proof merges methods of Maynard from his paper on the infinitude of primes with restricted digits, results of Balog and Friedlander on Piatetski-Shapiro primes and the Hardy–Littlewood circle method in two variables. This is the first result on the ternary Goldbach problem with primes of mixed type which involves primes with missing digits.

Polynomial averages and pointwise ergodic theorems on nilpotent groups

We establish pointwise almost everywhere convergence for ergodic averages along polynomial sequences in nilpotent groups of step two of measure-preserving transformations on \(\sigma \)-finite measure spaces. We also establish corresponding maximal inequalities on \(L^p\) for \(1<p\le \infty \) and \(\rho \)-variational inequalities on \(L^2\) for \(2<\rho <\infty \). This gives an affirmative answer to the Furstenberg–Bergelson–Leibman conjecture in the linear case for all polynomial ergodic averages in discrete nilpotent groups of step two. Our proof is based on almost-orthogonality techniques that go far beyond Fourier transform tools, which are not available in the non-commutative, nilpotent setting. In particular, we develop what we call a nilpotent circle method that allows us to adapt some of the ideas of the classical circle method to the setting of nilpotent groups.

Combinatorial mutagenesis of Bacillus amyloliquefaciens for efficient production of protease

As an important industrial enzyme, protease is widely used in feed, food and other fields. At present, the insufficient protease activity obtained from microorganisms cannot meet the purpose of industrial production. In this study, Bacillus amyloliquefaciens with high protease production was screened from animal feces by plate transparent circle method. To improve the production of protease, atmospheric room temperature plasma (ARTP) mutagenesis was used in the first round, protease activity reached 315.0 U/mL. Then, to enhance production of protease, 60Co-γ irradiation was used for combined mutagenesis, leading to protease activity of B. amyloliquefaciens FMME ZK003 up to 355.0 U/mL. Furthermore, to realize the efficient production of protease, after optimization of fermentation conditions, protease activity was increased to 456.9 U/mL. Finally, protease activity of B. amyloliquefaciens FMME ZK003 reached 823.0 U/mL in a 5 L fermenter. These results indicate that B. amyloliquefaciens can efficiently produce protease, which provides a good foundation for the industrial production of protease.

Bio-accumulation effects of heavy metals Pb, Zn and Cd on Procecidochares utilis parasitism to Eupatorium adenophorum at Suzu metal mines, Yunnan

Procecidochares utilis is an obligatory parasitic insect to Eupatorium adenophorum. Both organisms have been spread to some metal mines areas. The objective of this study is to comprehend the trend of heavy metals transfer and the process of their bio-accumulation in the soil-E. adenophorum-P. utilis system and particularly their impact on the parasitic effect of P. utilis to E. adenophorum to reflect the impact of heavy metals on obligate parasitic insect and its host. Therefore, a detailed investigation was carried out at the Suzu Lead–Zinc Mine in Yunnan Province using the concentric circle's method. The results showed that the parasitic rate of P. utilis to a single plant and branch is positively correlated with distance. The metals content of the soil in E. adenophorum and P. utilis, decreased dramatically with an increase in distance away from the center of the mining area. From which is cleared that these metals could enter to E. adenophorum and P. utilis through the soil-E. adenophorum-P. utilis system which likely to affect its parasitic activities. In addition, the parasitic rate is impacted by per Zn content greatly, and the parasitic rate per plant is affected by Cd content enormously. This work could provide important basis of data for further understanding and clarifying the effects of bioaccumulation and heavy metals pollution on various aspects of the food chain. Simultaneously, it could clarify and simplify whether heavy metal contamination affects the parasitic behaviour of some obligatory parasitic insects.

Circle Method for Robust Estimation of Local Conduction Velocity High-Density Maps From Optical Mapping Data: Characterization of Radiofrequency Ablation Sites.

Conduction velocity (CV) slowing is associated with atrial fibrillation (AF) and reentrant ventricular tachycardia (VT). Clinical electroanatomical mapping systems used to localize AF or VT sources as ablation targets remain limited by the number of measuring electrodes and signal processing methods to generate high-density local activation time (LAT) and CV maps of heterogeneous atrial or trabeculated ventricular endocardium. The morphology and amplitude of bipolar electrograms depend on the direction of propagating electrical wavefront, making identification of low-amplitude signal sources commonly associated with fibrotic area difficulty. In comparison, unipolar electrograms are not sensitive to wavefront direction, but measurements are susceptible to distal activity. This study proposes a method for local CV calculation from optical mapping measurements, termed the circle method (CM). The local CV is obtained as a weighted sum of CV values calculated along different chords spanning a circle of predefined radius centered at a CV measurement location. As a distinct maximum in LAT differences is along the chord normal to the propagating wavefront, the method is adaptive to the propagating wavefront direction changes, suitable for electrical conductivity characterization of heterogeneous myocardium. In numerical simulations, CM was validated characterizing modeled ablated areas as zones of distinct CV slowing. Experimentally, CM was used to characterize lesions created by radiofrequency ablation (RFA) on isolated hearts of rats, guinea pig, and explanted human hearts. To infer the depth of RFA-created lesions, excitation light bands of different penetration depths were used, and a beat-to-beat CV difference analysis was performed to identify CV alternans. Despite being limited to laboratory research, studies based on CM with optical mapping may lead to new translational insights into better-guided ablation therapies.

Sums of triangular numbers and sums of squares

For non-negative integers a,b, and n, let N(a,b;n) be the number of representations of n as a sum of squares with coefficients 1 or 3 (a of ones and b of threes). Let N⁎(a,b;n) be the number of representations of n as a sum of odd squares with coefficients 1 or 3 (a of ones and b of threes). We have that N⁎(a,b;8n+a+3b) is the number of representations of n as a sum of triangular numbers with coefficients 1 or 3 (a of ones and b of threes). It is known that for a and b satisfying 1≤a+3b≤7, we haveN⁎(a,b;8n+a+3b)=22+(a4)+abN(a,b;8n+a+3b) and for a and b satisfying a+3b=8, we haveN⁎(a,b;8n+a+3b)=22+(a4)+ab(N(a,b;8n+a+3b)−N(a,b;(8n+a+3b)/4)). Such identities are not known for a+3b>8. In this paper, for general a and b with a+b even, we prove asymptotic equivalence of formulas similar to the above, as n→∞. One of our main results extends a theorem of Bateman, Datskovsky, and Knopp where the case b=0 and general a was considered. Our approach is different from Bateman-Datskovsky-Knopp's proof where the circle method and singular series were used. We achieve our results by explicitly computing the Eisenstein components of the generating functions of N⁎(a,b;8n+a+3b) and N(a,b;8n+a+3b). The method we use is robust and can be adapted in studying the asymptotics of other representation numbers with general coefficients.

Cost object determination training to support Go-Barber business innovation in Malang City

In order to save small business owners, accounting is one of the spearheads that plays a role in maintaining cost efficiency so that service prices can still compete with similar businesses, reducing waste (improvident). Innovation from permanent barber to Go-Barber is should be accompanied by a change in the method of determining the cost object in determining activity cost rates, with additional considerations for measuring services that generally have to pay attention to distance to customers, so that it has an impact on the emergence of variable costs as a basis determine the price of the service. The circle method is considered the right method because it is based on the characteristics of innovation that efforts to innovate will certainly not stop at a certain point, but will continue to evaluate and innovate in response to developments in the business environment. Measurement of the cost object is needed to determine the price of the service based on the basic tariff which will be multiplied by the activity. Identification of the right cost object will provide accuracy in determining the Cost of Goods Sold (COGS) which is of course a method in determining the price of services. Based on the results of training from business actors carried out by instructors/presenters, participants understand enough about how to identify and analyze activity costs to determine the selling price of Go-Barber services where previously there was no calculation method applied by Go-Barber.