Discrepancies In Shape Research Articles

VISUALIZATION OF POLITICAL RELATIONS BY THE MEANS OF ARCHITECTURE

Problem setting. The architecture has the powerful potential of impact on political consciousness of citizens. This role is reinforced due to the development of high technologies, growing data streams, etc. The policy of national memory in Ukraine is the testimony of this phenomenon.Recent research and publications analysis. The researches, devoted to the relations between the architecture and politics, including the problem of human rights, are spread recently. The studying of architecture impact on formation of symbolic policy, are spread within Urban Studies. O. Hatherley, S. Low et al. study the impact of city squares on political communications. The significant contribution into study on impact of architecture on social relations was made by neuropsychologist C. Ellard. Some researchers have analyzed the political the political aspects of the government institutions architecture. N. Khoma develops the theoretical principles for political Urban Studies in Ukraine. However, there are the contradictions in national researches; they often pay attention only to reflection of tendencies for political development in architecture.Paper objective. The paper objective is to analyze the mutual impact of architecture and social political relations, in particular, architecture ability not only to reflect the tendencies in social political development but to impact on them.Paper main body. A symbol not only represents the social actuality, it is such actuality and it forms it within dynamic aspect. This stipulates not only the propagandist but social organizing functions of architecture. Hereby, the architectural objects produce the senses, which their creators have not anticipated. Moreover, they can change the symbolic load with time. The mechanism to form the actuality through symbolization is the embodiment of new sense into symbolic object by its consumer, and the discrepancies in perception relate to different social positioning of consumers. The theoretical substantiation of these phenomena is the concept by M. McLuhan, in particular, his principle according to which the medium is the message the medium is amputated from its creator. As a result of this, the architecture can refer to other actuality, namely to society with its range of persuasions, emotions, etc.The history of president’s residencies in Turkey is analyzed in the paper as the example for impact of form on development of political relations. Moving of the President to the new residence was preceded to constitutional implementation of president’s government. Place de la Concorde and Vendome Column in Paris were chosen as the example for change in information content of architectural objects. The authors explain the discrepancies in shapes for T. Shevchenko monuments in Ukraine with discrepancies in concepts of nation, which are defended by different regional communities in Ukraine.Conclusions of the research. The authors refer the perspectives for researches on role of architecture in formation ofpolitical relations to accumulation of actual material both as to symbolization of certain architectural elements and mechanisms to form the senses of architectural spaces.

In vivo enamel stripping: A macroscopic and microscopic analytical study

Interdental stripping is often used in orthodontics to correct discrepancies of tooth shape or size. However, this procedure involves significant risks for the enamel. The roughness of the enamel surface might depend on the instruments used; it can lead to the accumulation of cariogenic plaque and periodontal problems. The main objective of our study was to evaluate the enamel surface condition after interproximal stripping in the mouth, by comparing different manual and mechanized enamel reduction protocols; on the other hand, the topography of the stripped area was observed to specify its location on the stripped proximal surfaces. An in vivo study was carried out: interdental stripping was performed in the mouths of patients undergoing orthodontic treatment and on healthy teeth intended for extraction for orthodontic or periodontal reasons. The sample was divided into four groups: in group 1, the distal faces were stripped with conventional single-sided diamond abrasive strips and non-stripped mesial faces (control faces); in group 2: the distal faces were stripped with the manual ContacEZ IRP Kit (single-sided abrasive files of different grain sizes) and non-stripped mesial faces (control faces); in group 3: the faces were stripped with ContacEZ IRP diamond discs attached to a handpiece and the mesial faces were not stripped (control faces); in group 4: the distal faces were stripped with the Intensiv Ortho-Strips mechanized system and the mesial faces were not stripped (control faces). Our study showed that regardless of the type of stripping material used, the enamel surface showed some roughness with the presence of striations and grooves of different widths and depths. Our observations objectivised more regular and less roughened enamel surface conditions when using the Intensiv oscillating files. Manual instruments (abrasive strips and files) have shown rougher and more irregular surface conditions that may constitute a real risk of carious and periodontal disease. The macroscopic evaluation of the topography of the stripped area showed that there is great variability in the situation and extent of the stripped area in relation to several parameters. The current mechanized instruments (oscillating files) provide enamel stripping with more comfort for the patient and the practitioner, and seem to produce a more regular and less harmful surface condition for the tooth and periodontium.

Multi-sequence myocardium segmentation with cross-constrained shape and neural network-based initialization

For myocardial infarction (MI) patients, delayed enhancement (DE) and T2-weighted cardiovascular magnetic resonance imaging (CMR) can play significant roles in diagnosis, prognosis and therapeutic strategy evaluation. However, the non-rigid registration between different CMR sequences is particularly challenging and prevents the use of multi-sequence image analysis. In this article, we propose an approach for segmenting T2 and DE CMR simultaneously with cross-constrained shape and shape discrepancy compensation. A framework for the unified segmentation of multi-sequence images is built based on the coupled level set method. Additionally, a sparse representation-based shape model is optimized under the constraints from both sequences for complementary information sharing. Considering the myocardium shape discrepancy between the two sequences due to non-perfect registration, an error term is added to explicitly model this difference. The intensity feature is extracted with a Gaussian mixture model from each sequence. To obtain a fully automatic approach, the conditional generative adversarial network is adopted for initialization. The results are evaluated with T2 and DE images from 32 MI patients. A promising Dice similarity coefficient of the myocardium is achieved (84.97±4.15% for T2 and 78.13±6.22% for DE CMR). This approach is a pilot work toward automatic, multi-sequence CMR image analysis.

Biomechanical analysis of bone remodeling following mandibular reconstruction using fibula free flap

Whilst the newly established biomechanical conditions following mandibular reconstruction using fibula free flap can be a critical determinant for achieving favorable bone union, little has been known about their association in a time-dependent fashion. This study evaluated the bone healing/remodeling activity in reconstructed mandible and its influence on jaw biomechanics using CT data, and further quantified their correlation with mechanobiological responses through an in-silico approach. A 66-year-old male patient received mandibular reconstruction was studied. Post-operative CT scans were taken at 0, 4, 16 and 28 months. Longitudinal change of bone morphologies and mineral densities were measured at three bone union interfaces (two between the fibula and mandibular bones and one between the osteotomized fibulas) to investigate bone healing/remodeling events. Three-dimensional finite element models were created to quantify mechanobiological responses in the bone at these different time points. Bone mineral density increased rapidly along the bone interfaces over the first four months. Cortical bridging formed at the osteotomized interface earlier than the other two interfaces with larger shape discrepancy between fibula and mandibular bones. Bone morphology significantly affected mechanobiological responses in the osteotomized region (R2 > 0.77). The anatomic position and shape discrepancy at bone union affected the bone healing/remodeling process.

Neutron Spectroscopy for pulsed beams with frame overlap using a double time-of-flight technique

A new double time-of-flight (dTOF) neutron spectroscopy technique has been developed for pulsed broad spectrum sources with a duty cycle that results in frame overlap, where fast neutrons from a given pulse overtake slower neutrons from previous pulses. Using a tunable beam at the 88-Inch Cyclotron at Lawrence Berkeley National Laboratory, neutrons were produced via thick-target breakup of 16 MeV deuterons on a beryllium target in the cyclotron vault. The breakup spectral shape was deduced from a dTOF measurement using an array of EJ-309 organic liquid scintillators. Simulation of the neutron detection efficiency of the scintillator array was performed using both GEANT4 and MCNP6. The efficiency-corrected spectral shape was normalized using a foil activation technique to obtain the energy-dependent flux of the neutron beam at zero degrees with respect to the incoming deuteron beam. The dTOF neutron spectrum was compared to spectra obtained using HEPROW and GRAVEL pulse height spectrum unfolding techniques. While the unfolding and dTOF results exhibit some discrepancies in shape, the integrated flux values agree within two standard deviations. This method obviates neutron time-of-flight spectroscopy challenges posed by pulsed beams with frame overlap and opens new opportunities for pulsed white neutron source facilities.

Mobility control ability and stability investigation of nitrogen foam under high temperature and high salinity condition

The mobility disparity between oil and water accounted for the poor water swept efficiency. Previous research has testified that nitrogen foam can increase sweep area and control water and gas mobility. However, the former studies have largely covered the mobility control ability performance in some conventional reservoir rather than that under high temperature and high salinity. This paper presents the results of a laboratory study of nitrogen foam at the experimental condition (113 °C and 21.28 × 104 mg/L) on its mobility control ability investigation, including different gas-to-liquid ratio, injection rate and core permeability; additionally, a novel method on studying the stability of mobility control ability of foam was utilized. Nitrogen foam injection was conducted in core holder to investigate the shape discrepancy of each resistance factor and residual resistance curve. The results showed that the most moderate gas-to-liquid ratio and injection rate were 2:1 and 1 mL/min, respectively; foam performed more significant mobility control ability with the increase in permeability. After 5 days’ aging, nitrogen foam still got enough mobility control ability to block water channeling. The above results demonstrate that, under high temperature and high salinity condition, nitrogen foam still can act as a promising economical method for improving the mobility difference between water and oil by applying appropriate injection parameters.

Recovering the Market Risk Premium from Stock and Option Prices

We …nd that the estimation of the market expected return bene…ts signi…cantly from enriching the information set we use, with increasingly …ner detail regarding the shape of the physical and risk-neutral distributions and the shape discrepancy between the two. Assuming the existence of a monotonic projected pricing kernel we extend Duan and Zhang’s (2014) theoretical model to a general system of equations that relates physical cumulants of any order to risk-neutral ones through the projected relative risk aversion coe¢ cient. Using stock and option data from the S&P 500 index we employ our general speci…cation to estimate the ex-ante market risk premium for the period 2001-2010 in a monthly frequency. The empirical results strongly support our hypothesis both in a statistical sense and in the context of the present value identity that associates dividend-price ratio to expected returns and dividend growth rates.

An Improved Approach for 3D Hand Pose Estimation Based on a Single Depth Image and Haar Random Fores

A vision-based 3D tracking of articulated human hand is one of the major issues in the applications of human computer interactions and understanding the control of robot hand. This paper presents an improved approach for tracking and recovering the 3D position and orientation of a human hand using the Kinect sensor. The basic idea of the proposed method is to solve an optimization problem that minimizes the discrepancy in 3D shape between an actual hand observed by Kinect and a hypothesized 3D hand model. Since each of the 3D hand pose has 23 degrees of freedom, the hand articulation tracking needs computational excessive burden in minimizing the 3D shape discrepancy between an observed hand and a 3D hand model. For this, we first created a 3D hand model which represents the hand with 17 different parts. Secondly, Random Forest classifier was trained on the synthetic depth images generated by animating the developed 3D hand model, which was then used for Haar-like feature-based classification rather than performing per-pixel classification. Classification results were used for estimating the joint positions for the hand skeleton. Through the experiment, we were able to prove that the proposed method showed improvement rates in hand part recognition and a performance of 20-30 fps. The results confirmed its practical use in classifying hand area and successfully tracked and recovered the 3D hand pose in a real time fashion.

Resin composite build-ups for complementing multidisciplinary esthetic and functional dental treatments: a case report

Discrepancies in tooth shape and placement of the anterior teeth represent uncomfortable esthetic scenario for many patients. Even current composite resin proximal build-up is considered to be practical and conservative, in some cases, interdisciplinary approach with orthodontics optimize functional and esthetic results. This case report describes the management of a patient who complained of lack of anterior esthetic, which compromises her quality of life. The correct diagnosis and the treatment with interdisciplinary strategy are highlighted to offer a reliable and promissory treatment.Keywords: Composite resin; Diastema closure; Orthodontics

Modeling, Design, and Evaluation of a Parallel Robot for Cochlear Implant Surgery

Cochlear implant surgery is a procedure that requires delicate insertion of an electrode array into the inner ear. This paper reports the clinical motivation, design considerations, analysis, and design optimization of a new robot for electrode arrays insertion. This paper describes a new approach for coordinated insertion of perimodiolar electrode arrays in order to minimize shape discrepancy between the shape of the electrode array and the shape of the inner ear anatomy. A new design of a 3-degrees-of-freedom (DoF) parallel robot with wire-actuated prismatic legs is presented. The dimensional synthesis of the robot design was based on satisfying the accuracy, speed, system size, and workspace requirements. The robot prototype is validated experimentally to execute electrode insertions in plastic models of temporal bones.

Body shape expectations and self-ideal body shape discrepancy in women seeking bariatric surgery: a cross-sectional study.

BackgroundPostoperative body shape expectations (BSE) of bariatric surgery candidates remain relatively unexplored, and may have important implications for weight loss outcomes, treatment satisfaction, and education.MethodsThe ‘Silhouette Figure Rating Scale’ was administered to 69 consecutive female candidates. Self-perceived current and goal body shape and postoperative BSE in four categories; “dream, “happy”, “acceptable”, and “disappointed” were examined.ResultsThe mean age and BMI of the sample was 43.4 ± 8.9 years and 48.8 ± 7.0 kg/m2. Self-ideal body shape discrepancy of 4.1 ± 1.3 silhouettes was reported, indicating body image dissatisfaction. 53% incorrectly identified the silhouette associated with their actual BMI. Goal body shape (4.3 ± 0.8 silhouettes) corresponded to a BMI figure 23.1 kg/m2- 26.2 kg/m2. The postoperative “dream” (4.1 ± 1.0 silhouettes), “happy” (5.0 ± 0.8 silhouettes), “acceptable” (5.3 ± 1.0 silhouettes), and “disappointed” (6.9 ± 1.0 silhouettes) BSE corresponded to silhouettes that were thinner than the thinnest silhouette clinically expected based on a 56.1% excess weight loss 1-year after laparoscopic sleeve gastrectomy (LSG) or a 22.3% to 47.2% total body weight loss.ConclusionsWomen seeking bariatric surgery experience body image dissatisfaction and misperceive their actual body size. BSE do not correspond with evidence-based LSG weight loss outcomes.

Effect of skull contours on dose calculations in Gamma Knife Perfexion stereotactic radiosurgery

In treatment planning of Leksell Gamma Knife (LGK) radiosurgery, the skull geometry defined by generally dedicated scalar measurement has a crucial effect on dose calculation. The LGK Perfexion (PFX) unit is equipped with a cone‐shaped collimator divided into eight sectors, and its configuration is entirely different from previous model C. Beam delivery on the PFX is made by a combination of eight sectors, but it is also mechanically available from one sector with the remaining seven blocked. Hence the treatment time using one sector is more likely to be affected by discrepancies in the skull shape than that of all sectors. In addition, the latest version (Ver. 10.1.1) of the treatment planning system Leksell GammaPlan (LGP) includes a new function to directly generate head surface contouring from computed tomography (CT) images in conjunction with the Leksell skull frame. This paper evaluates change of treatment time induced by different skull models. A simple simulation using a uniform skull radius of 80 mm and anthropomorphic phantom was implemented in LGP to find the trend between dose and skull measuring error. To evaluate the clinical effect, we performed an interobserver comparison of ruler measurement for 41 patients, and compared instrumental and CT‐based contours for 23 patients. In the phantom simulation, treatment time errors were less than 2% when the difference was within 3 mm. In the clinical cases, the variability of treatment time induced by the differences in interobserver measurements was less than 0. 91%, on average. Additionally the difference between measured and CT‐based contours was good, with a difference of −0.16%±0.66% (mean ±1 standard deviation) on average and a maximum of 3.4%. Although the skull model created from CT images reduced the dosimetric uncertainty caused by different measurers, these results showed that even manual skull measurement could reproduce the skull shape close to that of a patient's head within an acceptable range.PACS number: 87.53.Ly

Traumatic occlusions: diagnosis and classification

Malocclusions are an abnormality in the relationship of teeth due to their position and/or a discrepancy in jaw length and shape. Malocclusions are significant in our domestic species as they are a potential source of damage to the oral tissues, a potential source of pain, and may inhibit the normal masticatory function. They therefore need to be identified early in life before significant complications arise. The first article in this two-part series will help the reader identify common abnormalities present, while the second article will offer a variety of treatment options that are available in order to produce a comfortable and functional occlusion.

Estimating nonrigid motion from inconsistent intensity with robust shape features

To develop a nonrigid motion estimation method that is robust to heterogeneous intensity inconsistencies amongst the image pairs or image sequence. Intensity and contrast variations, as in dynamic contrast enhanced magnetic resonance imaging, present a considerable challenge to registration methods based on general discrepancy metrics. In this study, the authors propose and validate a novel method that is robust to such variations by utilizing shape features. The geometry of interest (GOI) is represented with a flexible zero level set, segmented via well-behaved regularized optimization. The optimization energy drives the zero level set to high image gradient regions, and regularizes it with area and curvature priors. The resulting shape exhibits high consistency even in the presence of intensity or contrast variations. Subsequently, a multiscale nonrigid registration is performed to seek a regular deformation field that minimizes shape discrepancy in the vicinity of GOIs. To establish the working principle, realistic 2D and 3D images were subject to simulated nonrigid motion and synthetic intensity variations, so as to enable quantitative evaluation of registration performance. The proposed method was benchmarked against three alternative registration approaches, specifically, optical flow, B-spline based mutual information, and multimodality demons. When intensity consistency was satisfied, all methods had comparable registration accuracy for the GOIs. When intensities among registration pairs were inconsistent, however, the proposed method yielded pronounced improvement in registration accuracy, with an approximate fivefold reduction in mean absolute error (MAE = 2.25 mm, SD = 0.98 mm), compared to optical flow (MAE = 9.23 mm, SD = 5.36 mm), B-spline based mutual information (MAE = 9.57 mm, SD = 8.74 mm) and mutimodality demons (MAE = 10.07 mm, SD = 4.03 mm). Applying the proposed method on a real MR image sequence also provided qualitatively appealing results, demonstrating good feasibility and applicability of the proposed method. The authors have developed a novel method to estimate the nonrigid motion of GOIs in the presence of spatial intensity and contrast variations, taking advantage of robust shape features. Quantitative analysis and qualitative evaluation demonstrated good promise of the proposed method. Further clinical assessment and validation is being performed.

The Accuracy of Tooth Image Reconstruction from Spiral CT, Micro-CT, and Cone-Beam CT Scans

Objectives The aim of this study was to compare 3D accuracy of tooth image reconstruction from three kinds of CT scans using 3D superimpositional method. Methods 18 sound extracted human teeth were scanned by 3D optical system, spiral CT, micro-CT, and cone-beam CT scanner. The digital teeth images reconstructed from three kinds of CT scans were superimposed onto the standard image from optical scans respectively. Distribution patterns of shape discrepancy were presented using histogram, as well as showed in different colors on the superimposed imagines. The ratio of voluminal discrepancy versus the volume of the standard image (RVD/VS) was calculated and analyzed, using the matched-pair t-test and rank sum test. Results Compared with the standard tooth image, the average RVD/VS of digital teeth images by the micro-CT, cone-beam CT, spiral CT scans were 5.11%, 20.73%, 24.60% respectively, and there were statistically significant difference among the three kinds of CT scans (P<0.01). Significant difference were also found among the anterior teeth, bicuspids, and molars (P<0.01). Histogram gave the description about the counts and magnitude of the discrepancies. Marked by difference colors, the superimposed images could give visualized information about the magnitude and distribution patterns of discrepancies. Conclusions The digital teeth models reconstructed from the spiral CT, micro-CT, cone-beam CT images are inhomogeneous enlarged, compared with the original models. As the only realizable way to individualized FEM analysis, tooth modeling by CT scans needs more efforts and refinements to improve its accuracy.

Design of Underactuated Steerable Electrode Arrays for Optimal Insertions

This paper addresses the design of wire actuated steerable electrode arrays for optimal insertions in cochlear implant surgery. These underactuated electrode arrays are treated as continuum robots which have an embedded actuation strand inside their flexible medium. By pulling on the actuation strand, an electrode array assumes a minimum-energy shape. The problems of designing optimal actuation strand placement are addressed in this paper. Based on the elastic modeling of the steerable electrode arrays proposed in this paper, an analytical solution of the strand placement is solved to minimize the shape discrepancy between a bent electrode array and a given target curve defined by the anatomy. Using the solved strand placement inside the steerable electrode array, an optimized insertion path planning with robotic assistance is proposed to execute the insertion process. Later, an optimization algorithm is presented to minimize the shape discrepancy between an inserted electrode array and a given target curve during the whole insertion process. Simulations show a steerable electrode array bending using the elastic model and robot insertion path planning with optimized strand placement. Two experiments have been conducted to validate the elastic model and algorithms.

Explaining the Relationship Between Media Exposure and Early Adolescents’ Body Image Perceptions

In recent years, there has been a worldwide increase in the extent of overweight and obesity as well as other eating disorders, especially among youths. Alongside genetic and biological factors that can explain some aspects of these phenomena and the psychological outcomes associated with them, researchers attributed an important role to social and cultural factors, including the mass media. This study examined the relationship between media exposure and early adolescents’ body image. It applied social comparison theory to the study of favorite television characters, an original extension of past research on general social comparison processes. Specifically, the parasocial relationships and motivations for self-comparison with the characters were examined. Based on a survey among 391 seventh and eighth graders, the study found that media exposure negatively predicted body image both directly and through a mediation process involving parasocial relationships with favorite characters, motivations to self-compare, and engagement in social comparison with them. Further, social comparison with favorite characters was found to positively predict an actual/ideal body shape discrepancy which negatively predicted body image. The findings are discussed in light of theory, developmental considerations associated with this unique age group, past research, and educational and policy implications.

3D Accuracy of Deciduous Tooth Model Reconstructed from CBCT Scan

Objective To assess the three dimensional (3D) accuracy of deciduous tooth surface model reconstruction from cone-beam CT(CBCT) scans using image superimposition method. Methods 14 sound extracted human deciduous teeth were scanned by micro-CT and CBCT scanner. The digital tooth models reconstructed from CBCT scans were superimposed onto the standard model from micro-CT scans respectively. Distribution patterns of shape discrepancy were presented using histogram, as well as shown in different colors on the superimposed images. The voluminal discrepancy versus the volume of the standard image (RVD/VS) were calculated and analyzed, using t test. Results There was no statistically significant difference between deciduous anterior teeth and molars(P>0.05). The mean RVD/VS of digital tooth images obtained by CBCT scans was 3.932±4.038%, and significant difference were found (P<0.01), compared with the standard tooth model from micro-CT. Marked by different colors, the superimposed images could give visualized information on the dimensions and distribution patterns of discrepancies. Histogram gave the statistical description about the numbers and magnitude of the discrepancies. Conclusions The superimposition method and the concept of RVD/VS are recommended for 3D accuracy evaluation. CBCT is of high accuracy for tooth modeling and suits for clinical and research purpose.

A correction factor for ablation algorithms assuming deviations of Lambert-Beer’s law with a Gaussian-profile beam

In this work, we propose an adjustment factor to be considered in ablation algorithms used in refractive surgery. This adjustment factor takes into account potential deviations of Lambert-Beer’s law and the characteristics of a Gaussian-profile beam. To check whether the adjustment factor deduced is significant for visual function, we applied it to the paraxial Munnerlyn formula and found that it significantly influences the post-surgical corneal radius and p-factor. The use of the adjustment factor can help reduce the discrepancies in corneal shape between the real data and corneal shape expected when applying laser ablation algorithms.

Nonrigid 2D/3D Registration of Coronary Artery Models With Live Fluoroscopy for Guidance of Cardiac Interventions

A 2D/3D nonrigid registration method is proposed that brings a 3D centerline model of the coronary arteries into correspondence with bi-plane fluoroscopic angiograms. The registered model is overlaid on top of interventional angiograms to provide surgical assistance during image-guided chronic total occlusion procedures, thereby reducing the uncertainty inherent in 2D interventional images. The proposed methodology is divided into two parts: global structural alignment and local nonrigid registration. In both cases, vessel centerlines are automatically extracted from the 2D fluoroscopic images, and serve as the basis for the alignment and registration algorithms. In the first part, an energy minimization method is used to estimate a global affine transformation that aligns the centerline with the angiograms. The performance of nine general purpose optimizers has been assessed for this problem, and detailed results are presented. In the second part, a fully nonrigid registration method is proposed and used to compensate for any local shape discrepancy. This method is based on a variational framework, and uses a simultaneous matching and reconstruction process to compute a nonrigid registration. With a typical run time of less than 3 s, the algorithms are fast enough for interactive applications. Experiments on five different subjects are presented and show promising results.