Circle Line Research Articles

Evaluation of three acetabular measurement methods for total hip replacement in dogs.

To compare three measurement methods for acetabular sizing and evaluate the influence of osteoarthritis (OA) on the accuracy of measurements. Observational study. Radiographic images of 73 hip joints from 60 dogs with cementless cups. Radiographs were anonymized and measured independently by three observers. One observer measured 12 sets of radiographs three times. A best-fit acetabular circle (AC) and cranial-caudal acetabular line (AL) were measured on ventral-dorsal (VD) radiographic view and open leg lateral (OLL) view. A best-fit femoral head circle (FHC) was measured on VD, OLL, and craniocaudal horizontal beam (CCHB) views. Two observers scored the OA in each hip joint. Intra- and interobserver consistency and repeatability and bias relative to implanted cup size were calculated and analyzed. Intraobserver consistency and repeatability were excellent for all measurements. Interobserver consistency was excellent (ICC > 0.9) for ACVD and ACOLL and was good (0.75 < ICC ≤ 0.9) for all other methods. Bias was small for AC and AL measurements (range, -0.46 to 0.45 mm) and large for FHC measurements (-3.58 to -2.42 mm). OA score significantly influenced bias for all acetabular measurement methods (p < 0.05). All acetabular measurement methods were highly consistent within an observer. Interobserver consistency was highest for ACVD and ACOLL. FHC measurements underestimated cup size. Higher OA scores decreased the accuracy of all acetabular measurement methods. Superimposing a circle on the acetabulum seen on VD radiographic view accurately measures the acetabulum before cementless cup placement.

Comprehensive Geometric Parameterization and Computationally Eficient 3D Shape Matching Optimization of Realistic Stents

Abstract Flexible and compact shape representation schemes are essential for design optimization problems. Current shape representation schemes for coronary stent designs concern predominantly idealized or Independent Ring (IR) designs, which are outdated and only consider a small number of core design variables (such as strut width, height, and thickness) and ignore clinically critical characteristics such as the number of connectors. No reports exist on the geometry parameterization of the latest Helical Stents (HS) that have more complex designs than IR stents. Here, we present two new shape parameterization schemes to fully capture the 3D designs of contemporary IR and double-helix HS stents. We developed a 3D stent geometry builder based on 17 (IR) and 18 (HS) design variables, including strut width, thickness, height, number of connectors and rings, stent length, and strut centerline shape. The shape of the strut centerline was derived via a combination of NURBS, PARSEC, quarter circle, and straight line segments. Shape matching for complex 3D geometries, such as the contemporary stents within limited function evaluations, is not trivial and requires efficient parameterization and optimization algorithms. We used shape matching optimization with a limited function evaluation budget to test the proposed parameterization and two surrogate-assisted optimization algorithms relying on predictor believer and an expected improvement maximization formulation. The performance of these algorithms is objectively compared with a gradient-based optimization method to highlight their strengths. Our work paves the way for more realistic, full-fledged stent design optimization with structural and hemodynamic objectives in the future.

EMNet: An ensemble deep learning approach for geological condition detection in tunnel excavation

This paper established a novel ensemble deep learning method for the identification of the geological condition encountered during tunnel boring machine (TBM) operation. By integrating multiple MobileNet base models with information fusion through the Dempster-Shafer theory (DST), the proposed method is able to provide reliable identification of the geological condition based on the images of the excavated mucks on TBM’s conveyor belt. Shapley additive explanations (SHAP) analysis is further presented for model interpretation and understanding of the key features in the images. A case study using data collected from Singapore’s Circle Line 6 tunnel construction projects is conducted to verify the effectiveness of the proposed method. The results indicate that (1) The proposed method detects the encountered geological condition with high accuracy; (2) EMNet outperforms all the base MobileNet models; (3) SHAP analysis demonstrates that surface texture could be the key feature that assists the model for the classification. The developed method contributes to the state of knowledge in proposing a novel ensemble method for reliable image identification and the state of practice in proposing a useful tool to identify the encountered geological condition automatically.

Poster 156: Intraobserver and Interobserver Reliability in Glenoid Track Measurement

Objectives: The purpose of our study was to determine the accuracy and reliability of measuring on- and off-track lesions within our institution using the circle line method. Methods: Electronic medical records between 2009 and 2019 were reviewed for active-duty military personnel who underwent a Latarjet or had recurrent dislocations of the shoulder joint. Advanced imaging (CT and/or MRI) was reviewed for glenoid and humeral head bone loss; patients with both glenoid and humeral head bone loss were included in the study. Measurement of the Hill-Sachs lesion (HSL) was standardized prior to the start of the study and measured as described by Di Giacomo. Results: All surgeons completed the review of all 38 images for 2 measurements. Intraobserver reliability was shown to have moderate reliability amongst all reviewers (intraclass correlation coefficient [ICC] = 0.459; p &lt; 0.001). The kappa (κ) value for interobserver reliability amongst all reviewers was moderate for glenoid diameter (ICC = 0.567; 95% CI, 0.474-0.663), moderate for glenoid defect (ICC = 0.61; 95% CI, 0.517-0.702), poor for HSL (ICC = 0.328; 95% CI, 0.232-0.441), moderate for glenoid track (ICC = 0.668; 95% CI, 0.584-0.75) and fair for HSL on- and off-track assessment (κ = 0.267, p &lt; 0.001). Conclusions: The intraobserver reliability of measuring advanced imaging for shoulder instability using the circle line method is overall good; however, the interobserver reliability is moderate to poor.

Experience of Russian-Chinese industrial cooperation on the construction of the Moscow metro

The commissioning of the Big Circle Line in Moscow, some sections of which were laid jointly with Chinese underground builders, provided the first experience of interaction with foreign construction contractors on the Moscow Metro. The paper investigates this experience which is of value for the development of such works in the future. The analysis was carried out on the basis of scientific and technical documentation on certain facilities, the progress and results of construction and installation works, and information on other events. The paper describes the facilities where construction and installation works were carried out by joint efforts and shows the peculiarities of interaction between Russian and foreign (Chinese) metro builders on a number of sections of the Big Circle Line of the Moscow Metro. The achieved results are demonstrated by the example of individual underground stations. The study reveals the peculiarities of material and technical support of works on the sections constructed by Chinese construction contractors. The mutual exchange of experience, technologies, and work management practices along with the application of various tunnel boring machines from both countries (Russia and the PRC) has yielded fruitful results, demonstrated the possibility and efficiency of the direct engagement of foreign tunnel builders at Russian sites in close cooperation with their Russian counterparts, and revealed a scheme for rational division of labour, work management, and logistical support of works.

A Summative Assessment of the Pattern-Cutting Task in Laparoscopic Box Trainer using Color Tracking and Fuzzy Logic

In Minimally Invasive Surgery (MIS), surgeons should acquire many skills before carrying out a real operation. The Fundamentals of Laparoscopic Surgery (FLS) tasks are currently used as an assessment tool for laparoscopic skills. However, the current training methods still require the presence of an expert surgeon to assess the surgical dexterity of the trainee. This process is time-consuming and may lead to subjective assessment. This research aims to extend the application of image processing and analysis methods to detect and track the tips of the laparoscopic instruments and to localize the circle center to calculate the distance between the scissors' tips and the circle's center in each processed frame. The data obtained will feed the fuzzy system to assess the trainer’s performance with a processing speed of 4 frames per second. The proposed system can provide a final text report that lists an error counter value and the fuzzy assessment at each time slot of 0.29 s on average. Additionally, a BMP image that summarizes the tips of the scissors within the predefined circles during the test is created. Finally, a Canny edge detector is applied to detect whether any circle line was cut during the test. This work enables a summative assessment of the precision-cutting task without altering the original setup of the FLS box trainer. Additionally, this can expedite the development of surgery skills and assess the trainees’ performance using a single-input-single-output fuzzy logic system. The output of the fuzzy logic assessment is the performance evaluation for the surgeon, and it is quantified in percentages.

Tarefas com base na Fonotática para estimulação de consciência fonológica

The purpose of this paper is to present some fundamental phonotactic concepts and their importance in phonological awareness tasks in literacy. Only after the beginning of their schooling do children start to observe and notice the segmental elements of words. Furthermore, mastery of phonological awareness will determine children’s reading success in school, which in turn affects their proficiency in adulthood (BYRNE; LEDEZ, 1983). In this study, we present a playful way to explore the sonority scale perception with students through the recognition of geometric shapes (circle and straight line), according to the Sonority Syllable Model (SSM), proposed by Basbøll (2005). It is an alternative proposal to the phonotactic description and analysis that uses distinctive features in its sound organization. In our proposal, we use a phoneme-grapheme correspondence, but, as Basbøll (2005) suggests, we firstly establish which one is the prototypical syllable peak, i.e., main/central peak, in order to determine the implicational relations among the segment types. In addition, in a playful way to illustrate this relation, we make use of a set of concentric circles known as Euler’s diagram. This set of circles is a mathematical set used to demonstrate the intersection among elements. Lastly, we show how this adaptation may be used in a pedagogical practice with children and adults in the literacy stage.

Simplified equations for object trajectories in rotating space habitats and space juggling

Rotating space habitats provide artificial gravity as a physiological countermeasure for long-term space habitation, though the lived experience of a person in these habitats requires further investigation. Movement planning will require adaptation to the Coriolis and centrifugal forces. The multicultural arts of juggling may offer potential psycho-physiological countermeasures for some individuals and provide interesting insights into movement planning and arts in both microgravity and rotating habitats. Previously developed equations of motion for thrown objects in rotating habitats have not been centered within the lived rotating environment. Here, I show a set of simplified equations for object trajectories in rotating environments and their underlying mathematical framework. The full set of possible trajectories for objects thrown in rotating environments is provided and a simplified approach to the Coriolis and centrifugal force differential equation using complex algebra is demonstrated. Experimentation reported in this article was conducted on parabolic flights and an analog weightlessness and rotating apparatus. Near the surface of the Earth, thrown objects travel along parabolas. In rotating space environments, thrown objects will travel along a set of mathematical curves known as roulettes, created by a fixed circle and rolling line with generator point connected to the line. These roulette trajectories will be the everyday experience of every person living in a rotating space habitat, always.

Comparing explicit and implicit ensemble perception: 3 stimulus variables and 3 presentation modes

Visual scenes are too complex for one to immediately perceive all their details. As suggested by Gestalt psychologists, grouping similar scene elements and perceiving their summary statistics provides one shortcut for evaluating scene gist. Perceiving ensemble statistics overcomes processing, attention, and memory limits, facilitating higher-order scene understanding. Ensemble perception spans simple/complex dimensions (circle size, face emotion), including various statistics (mean, range), and inherently spans space and/or time, when sets are presented scattered across the visual scene, and/or sequentially in rapid series. Furthermore, ensemble perception occurs explicitly, when observers are asked to judge set mean, and also automatically/implicitly, when observers are engaged in an orthogonal task. We now study relationships among these ensemble-perception phenomena, testing explicit and implicit ensemble perception; for sets varying in circle size, line orientation, or disc brightness; and with spatial, temporal or spatio-temporal presentation. Following ensemble set presentation, observers were asked if a test image, or which of two test images, had been present in the set. Confirming previous results, responses reflected implicit mean perception, depending on test image distance from the mean, and on its being within or outside ensemble range. Subsequent experiments asked the same observers to explicitly judge whether test images were larger, more clockwise, or brighter than the set mean, or which of two test images was closer to the mean. Comparing implicit and explicit mean perception, we find that explicit ensemble averaging is more precise than implicit mean perception—for each ensemble variable and presentation mode. Implications are discussed regarding possible separate mechanisms for explicit versus implicit ensemble perception.

Modeling cascading failures of urban rail transit network based on passenger spatiotemporal heterogeneity

To explore and alleviate large-scale failures under urban rail transit network accidents, cascading failures are usually investigated integrating the network topology and passenger flow. However, the impacts of the heterogeneity of travel demand and its interactions with the spatiotemporal heterogeneity of rail passenger flow on cascading failures are still left unknown. In this study, the dynamic changes of origin-destination travel demand under failures, the time-delay of cascading failures and the interaction between these dynamic properties and spatiotemporal heterogeneity of passenger flow are modeled and explored in an improved disaster spread theory model. The approach is applied to Shanghai urban rail transit network under different attack scenarios. Results show that the scale of cascading failures on Shanghai urban rail transit network importantly depends on the ratio of passengers changing travel demand and time-delay of cascading failures. Besides, large in-flow of stations adjacent to the failed station would not only cause fast spread of cascading failures at the early stage but also result in many failed stations in the end. The heterogeneity of passenger flows in different directions on the network would reduce the scales of cascading failures. It is also found out that the circle line could obviously prevent the spread of cascading failures.

Completeness out of incompleteness: Inferences from regularities in imperfect information ensembles.

Handling imperfect information problems is fundamental to perception, learning, and decision-making. Ensemble perception may partially overcome imperfect information by providing global clues. However, if not all cluster elements are readily accessible, the observations required for computing statistics are incomplete. In this case, these elements' internal correlations (i.e., regularity) could serve as clues to elucidate the missing pieces. We thus investigated spatial regularity's role in ensemble perception under imperfect information situations created using partially occluded stimuli. In two experiments, we manipulated circle size (Experiment 1) and line orientation (Experiment 2) to linearly vary with its location; spatial regularity thus supplied clues for inferring information of the invisible parts. Participants estimated the mean of the targeted feature of the entire cluster, including visible and invisible parts. We observed robust biases toward the overall cluster in the estimations, implying the invisible parts were considered during ensemble perception. We proposed this effect could be understood as assessing evidence from visible parts to construct the missing parts. Experiment 3 employed a periodicity regularity to deter participants from using specific strategies, and consistent results were found. We then developed a generative model, the Regularity-Based Model, to simulate the inference process, which better captured the pattern of human outcomes than the comparative model. These findings indicate the visual system could use high-level structural information to infer scenes with incomplete information, thus producing more accurate ensemble representations. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

CT methods for measuring glenoid bone loss are inaccurate, and not reproducible or interchangeable.

Glenoid bone loss is a significant problem in the management of shoulder instability. The threshold at which the bone loss is considered "critical" requiring bony reconstruction has steadily dropped and is now approximately 15%. This necessitates accurate measurement in order that the correct operation is performed. CT scanning is the most commonly used modality and there are a number of techniques described to measure the bone loss however few have been validated. The aim of this study was to assess the accuracy of the most commonly used techniques for measuring glenoid bone loss on CT. Anatomically accurate models with known glenoid diameter and degree of bone loss were used to determine the mathematical and statistical accuracy of six of the most commonly described techniques (relative diameter, linear ipsilateral circle of best fit (COBF), linear contralateral COBF, Pico, Sugaya, and circle line methods). The models were prepared at 13.8%, 17.6%, and 22.9% bone loss. Sequential CT scans were taken and randomized. Blinded reviewers made repeated measurements using the different techniques with a threshold for theoretical bone grafting set at 15%. At 13.8%, only the Pico technique measured under the threshold. At 17.6% and 22.9% bone loss all techniques measured above the threshold. The Pico technique was 97.1% accurate, but had a high false-negative rate and poor sensitivity underestimating the need for grafting. The Sugaya technique had 100% specificity but 25% of the measurements were incorrectly above the threshold. A contralateral COBF underestimates the area by 16% and the diameter by 5 to 7%. No one method stands out as being truly accurate and clinicians need to be aware of the limitations of their chosen technique. They are not interchangeable, and caution must be used when reading the literature as comparisons are not reliable.

On spatial relations to the Euler-Savary formula

The Euler-Savary formula is a well-established relation with multiple interpretations. This formula is revisited and cast as a geared three-link spatial mechanism with uniform motion and gear rotation axes without axial pitch. Two versions of the spatial Euler-Savary formula emerge; the classical version that matches motion parallel to the ISA and a new version that matches motion perpendicular to the ISA akin to the planar scenario. These two versions are combined resulting in a circle line surface of moving axes together with a conjugate center line surface of stationary axes. These two surfaces define axis pairs used to match second-order axode motion. Also included are inflection surfaces as the spatial analog to the planar inflection circle. One of the inflection surfaces is contrasted with an invariant relative curvature surface. Subsequently, a ruled surface is presented to emulate the planar Bresse circle by combining two axes on the inflection surface to establish a third axis on a Bressesque surface. Lastly, an RSSR mechanism is presented by combining aspects of the invariant curvature surface and an R-R interpretation of the Euler-Savary formula.

Solver comparison for Poisson-like equations on tokamak geometries

The solution of Poisson-like equations defined on a complex geometry is required for gyrokinetic simulations, which are important for the modelling of plasma turbulence in nuclear fusion devices such as the ITER tokamak. In this paper, we compare three existing solvers finely tuned to solve this problem, in terms of the accuracy of the solution, and their computational efficiency. We also consider practical implementation aspects, including the parallel efficiency of the code, potentially enabling an integration of the solvers in a state-of-the-art first-principle gyrokinetic simulation framework. The first, the Spline FEM solver, uses C1 polar splines to construct a finite elements method which solves the equation on curvilinear coordinates. The resulting linear system is solved using a conjugate gradient method. The second, the GMGPolar solver, uses a symmetric finite difference method to discretise the differential equation. The resulting linear system is solved using a tailored geometric multigrid scheme, with a combination of zebra circle and radial line smoothers, together with an implicit extrapolation scheme. The third, the Embedded Boundary solver, uses a finite volumes method on Cartesian coordinates with an embedded boundary scheme. The resulting linear system is solved using a multigrid scheme. The Spline FEM solver is shown to be the most accurate. The GMGPolar solver is shown to use the least memory. The Embedded Boundary solver is shown to be the fastest in most cases. All three solvers are shown to be capable of solving the equation on a realistic non-analytical geometry. The Embedded Boundary solver is additionally used to attempt to solve an X-point geometry.

Teaching Models for Correct Rhombic Flaps.

The aim of this study was to introduce teaching models for correct rhombic flaps. For the line of maximal extensibility (LME) and flap design, surgical fabric (model 1), scored corrugated cardboard (model 2), and scored polyethylene sheet (model 3) were used. For choosing the correct flaps, a silicone face (model 4) was used. Seven participants in the Plastic Surgery Department were recruited for the workshop. In models 1 to 3, a 2-cm diameter circle and relaxed skin tension line were indicated. Participants were requested to design Limberg flaps. Each flap was elevated, transposed, and fixed with sutures (model 1) or cellophane tape (models 2 and 3). In model 4, a 1-cm diameter circle was indicated on the cheek. Participants were requested to design correct Limberg flaps. Although participants were not provided an article describing how to create correct Limberg flaps, they eventually created correct flaps through trial and error. Participants drew 2 parallel lines tangential to the defect and following the LME, perpendicular to the relaxed skin tension lines, which are the same as the scoring marks. They then drew 2 other sides of 2 possible parallelograms by tilting them medially and laterally with angles of 60 and 120 degrees each. Thus, 4 possible Limberg flaps to close the defect were drawn. Among the 8 possible flaps, 4 flaps that did not follow the LME were eliminated. Scored polyethylene sheet had the best extensibility and least distortion among the 3 models. Through this workshop, participants learned to design rhombic flaps correctly, using 2 parallel LMEs.

Hybrid Random Forest-Based Models for Earth Pressure Balance Tunneling-Induced Ground Settlement Prediction

Construction-induced ground settlement is a serious hazard in underground tunnel construction. Accurate ground settlement prediction has great significance in ensuring the surface building’s stability and human safety. To that end, 148 sets of data were collected from the Singapore Circle Line rail traffic project containing seven defining parameters to create a database for predicting ground settlement. These parameters are the tunnel depth (H), the tunnel advance rate (AR), the EPB earth pressure (EP), the mean SPTN value from the soil crown to the surface (Sm), the mean water content of the soil layer (MC), the mean modulus of elasticity of the soil layer (E), and the grout pressure used for injecting grout into the tail void (GP). Three hybrid models consisting of random forest (RF) and three types of meta-heuristics, Ant Lion Optimizier (ALO), Multi-Verse Optimizer (MVO), and Grasshopper Optimization Algorithm (GOA), were developed to predict ground settlement. Furthermore, the mean absolute error (MAE), the mean absolute percentage error (MAPE), the coefficient of determination (R2) and the root mean square error (RMSE) were used to assess predictive performance of the constructed models for predicting ground settlement. The evaluation results demonstrated that the GOA-RF with a population size of 10 has achieved the most outstanding predictive capability with the indices of MAE (Training set: 2.8224; Test set: 2.3507), MAPE (Training set: 40.5629; Test set: 38.5637), R2 (Training set: 0.9487; Test set: 0.9282), and RMSE (Training set: 4.93; Test set: 3.1576). Finally, the sensitivity analysis results indicated that MC, AR, Sm, and GP have a significant impact on ground settlement prediction based on the GOA-RF model.

Think Talk Write: Efforts to Improve Students’ Critical Thinking In A Rural School Environment

This study aims to explain the impact of learning model and gender on critical thinking skills of junior high school students in a rural school environment. The population used is the students of the State High School IX first semester who have acquired material on the Circles and Circle Line in Pringsewu Lampung District. Think Talk Write (TTW) is a learning model that is used with the type of descriptive research and experimental semu. Data analysis using two-way ANOVA assisted SPSS 25 with a significant scale of 0.05. After the treatment, the difference in critical thinking ability based on gender obtained a significance of 0,072 &gt; 0,05. The significance value of the learning model factor is 0,013 &lt; 0,05, while the significance rate of the interaction of the learning model with gender is 0,230 &gt; 0,05, so it does not give a difference to the ability to think critically. Therefore, this study indicates that only model factor influences the ability to think critically about geometry.

Comparative Analysis of the Capacity of a Metro Circle Line

Comparative Analysis of the Capacity of a Metro Circle Line

Tunnel depth effect to pile in Tunnel's influence zone

The increased population in urban areas resulted in high demand for public facilities; hence, tunnels became popular, especially in developed countries. However, tunnel activity may alter the original ground equilibrium, leading to a ground stress release. These may result in an adverse pile response and potential hazard to a nearby building structure. Previous research focuses on the tunnel-pile interaction but solely investigates in homogeneous soil formation. Therefore, this paper presents the tunnel-pile-ground interaction with various tunnel depths in multiple soil formations. A three-dimensional model was developed by using the finite element method of ABAQUS based on Circle Line Stage 3 (C852) projects in Singapore. The models were carried out in two stages: first, by investigating the tunnel-induced ground movements (free-field condition) and second, with the presence of a pile. The tunnel model depth varied at respective ratios of C/D of 1, 2, 3, and 4. The results show, with a low tunnel depth ratio, a high maximum ground settlement is obtained. The longitudinal settlement trough presents a smooth surface settlement curve for free-field conditions, but a chimney-like transition at the pile periphery for conditions with the pile. The ground settlement trough for tunnelling near to adjacent pile leads to a skewed maximum settlement towards the pile. A higher C/D ratio produced higher lateral stress induced on the pile but the opposite for a lower C/D ratio. Pile was significantly affected and shown by extensive lateral stress for the pile body that lies parallel to the tunnel depth.

Systematic solution for optimally energy-efficient turning radius for wheeled skid-steer rovers

A skid-steer rover’s power consumption is highly dependent on the turning radius of its path, with a point turn consuming much more power compared to straight line motion. As energy is the integration of instantaneous power over time, a trade-off between arcs’ turning radii and lengths should be made to minimize energy consumption. Because of the skid-steer rovers’ ability to do point turns the simplest and shortest way to traverse a distance between two points is by doing a point turn-line-point turn (PLP) maneuver. However, we show that wheeled skid-steer rovers there are scenarios where optimal Circle–Line–Circle (CLC) paths consume less energy than PLP paths. Therefore, the goal in this work is to find the best path from among CLC paths; Karush–Kuhn–Tucker (KKT) conditions are used to systematically obtain the optimally energy-efficient answer for the CLC paths. It is assumed that the rovers move forward on hard flat ground. For solving the problem, a new practical constraint constant-vc is suggested. In this paper, comparing the KKT conditions and experimental results reveals that the lowest total energy consumption for CLC paths with or without considering constant-vc constraint is obtained by selecting turning radii equal to R′ (the half of slip-track).