Shape Configuration Research Articles

Rethinking handshape

Abstract Concerted attention in sign language linguistics has focused on finding ways to document signs. Until now, most notation systems rely on a complex plethora of symbols and are under-specific, to the extent that visual images are still the most widely accepted way of recording primary data. This paper presents a novel phonetic notation of handshape in a step towards deriving an International Phonetic Alphabet for sign languages, based on digit shape (configuration) and position in terms of reference coordinates, aiming at both readability and precision. It is sufficiently hybrid to allow for both accurate measurements and estimates of digit positions, thereby affording a way of representing handshapes suitable for lexicography, studying phonetic variation and avatar programming. Originally tailored to describe handshapes in South African Sign Language, it can also notate gestures. After discussing transcription methods and hand physiology, digit configurations are defined in terms of joint angles. Variations in configuration positions are then specified in terms of Cartesian reference coordinates.

Numerical Examination of Metamaterial Concentrator Design for High Efficient Thermal Energy Harvester

Nowadays, research on energy harvesting is highly interest to harvest more waste thermal energy which produced by any kind of thermal engine in our daily life. Thermal metamaterials, designed by transformation thermodynamics are artificial structure that can actively control heat flux at a continuum scale. However, right now the problem of using metamaterial on thermal harvesting is to know what is the best shape design, configuration, and best material to obtain highly efficient on thermal energy harvesting because of the number of research on this field is limited. Flower-shaped metamaterial thermal concentrator has developed and it showed that the design can performed well on directing heat flux to specific location. However, the Flower-shaped metamaterial design that has been conducted before not optimized yet. In the current paper, the numerical simulation and analysis for several metamaterial and shape construction variations were performed using Ansys Workbench™ to characterize the best configuration to optimizing flower-shaped thermal concentrator. A number of interesting numerical computation presented on this research manuscript including total heat flux, temperature distribution, and thermal concentrator efficiency on the surface of the constructed concentrator. The aim of this paper is to provide more reference on metamaterial design for thermal harvesting.

Properties of a magnetic concrete core transformer for application in wireless power transfer systems

A combination of ferrimagnetic and ferromagnetic inclusions were blended within a diamagnetic Portland cement matrix to increase bulk relative permeability for possible application in wireless power transfer. The objective of this study is to quantify the interactive flux exchange coupling between ferritic inclusions of different composition, shape, size, volume fraction, core geometry, and coil winding configuration. Cores made of cement mortar and various combinations of ferrimagnetic and ferromagnetic inclusions were cast and the permeability was quantified. A total of 21 different mix combinations were considered. ANOVA was used to assess the level of significance of each individual inclusion and their interaction with each other with respect to relative magnetic permeability. X-Ray diffraction, thermogravimetric analysis, and mechanical compression tests were also completed. The results suggest that powder and fibrous ferritic inclusions at a volume fraction greater than 10% can reduce flux leakage, reduce hysteresis core loss, and significantly increase relative permeability. A steel reinforced magnetic concrete CI core can achieve a peak flux of 100 mT and relative permeability of 28 when the cement matrix contains 20% volume fraction of ferritic fiber and powder inclusions.

Impact of source shape on pollutant dispersion in a street canyon in different thermal stabilities

In previous studies of pollutant dispersion around and inside urban street canyons, several kinds source shape assumptions were employed. However, the impact of source shape on pollutant transport in urban street canyon is barely concerned. As a determinant of pollutant distribution, the shape effects of pollutant source should be analyzed carefully. In this study, source shape effects on street canyon pollutant dispersion are investigated using computational fluid dynamics (CFD) approach based on an idealized street canyon model in different thermal stabilities. The line shape source, band shape source and surface shape source assumptions are adopted to represent the widely used source shape patterns. The prediction accuracy of this numerical model is validated against wind tunnel measurement and LES results and is proved to be acceptable. Numerical simulations are performed under neutral and unstable thermal stratifications. Pollutant distribution inside the street canyon and its variation with thermal stability are examined. The results demonstrate that pollutant source shape can significantly alter the distribution of pollutant concentration in the whole street canyon. The most uneven distribution occurs under the surface shape source condition, where more than 60% pollutant is located in the leeward wall zone, but only 19% pollutant is found in the windward wall zone. The surface source assumption contributes to more dispersed distribution. Moreover, different source shape assumptions lead to distinct characteristics of pollutant residue in the street canyon, especially in the near-ground-zone. Also, the variation of pollutant residue with the thermal stability is greatly influenced by the source shape configuration. The source shape effect should not be neglected in future street canyon environment studies. The new findings present in this study can improve the understanding of pollutant dispersion characteristics in urban street canyons, and benefit architects, city-planners and policy makers to achieve optimized solution for urban air pollution.

Finite element study of the effects of fragment shape and screw configuration on the mechanical behavior of tibial tubercle osteotomy.

Tibial tubercle osteotomy (TTO) is a surgical technique used in the management of severe fractures of the knee joint and revision total knee arthroplasty. Limited research discusses the performance of the osteotomy and fixation of the TTO with screws. Therefore, this study investigated the effects of fragment shape and screw configuration on the mechanical behavior in the fixation of the TTO using the finite element (FE) method. FE TTO models with three fragment shapes and three screw configurations were developed. The three fragment shapes were a step cut, bevel cut, and straight cut. The screw configurations were two parallel horizontal and downward screws and two trapezoidal screws. A 1654-N upward tension force was applied on the tibia tubercle, and the distal end of the tibia was completely fixed. The results indicated that the step cut resulted in higher stability than the bevel and straight cut, but the stress was higher as well. Among the screw configurations, two parallel downward screws resulted in the highest stability, given the same fragment shape. In the horizontal configuration, the step cut tibia developed the largest contact force to achieve stability of the bone fragment under loading. The fragment shape with a step cut and fixation with two parallel horizontal or downward screws are suggested for TTO, while the trapezoidal screw configuration is not suggested. Furthermore, the downward screw configuration is a suitable strategy to reduce bone stress.

Development of a Versatile, High-Performance Solid Oxide Fuel Cell Stack Technology

A high-performance solid oxide fuel cell (SOFC) stack technology is being developed, based on a design concept that incorporates prime-surface metallic interconnects with the versatility of stacking different types of single cells (sintered cells or metal-supported cells). A preliminary design of the prime-surface interconnect based on an egg-carton shape configuration has been advanced for this stack concept. Laboratory-scale prime-surface interconnects have successfully been fabricated by stamping and evaluated for mechanical loading, flow distribution and current collection properties. A process based on sputtering has been developed for fabricating supported thin-film (several micrometers thick) cells for this stack technology. Fabricated thin-film cells have shown desirable structural characteristics and exceptional performance on different fuels at reduced temperatures (550º-650ºC). Sputtered cells (with yttria stabilized zirconia (YSZ) for the electrolyte, gadolinia-doped ceria (GDC) for the electrolyte/cathode interlayer, nickel-YSZ for the anode and lanthanum strontium cobalt iron perovskite (LSCF)–YSZ for the cathode) have exhibited peak power densities of ~1.7 W/cm2 and ~2.1 W/cm2 with hydrogen fuel and air at operating temperatures of 600ºC and 650ºC, respectively.

Vein of Galen arteriovenous malformation: Unedited microneurosurgery

Background:Vein of Galen arteriovenous malformations (VGAVMs) are vascular malformations of the pineal region between a persistent embryological median prosencephalic vein of Markowski and the arterial choroidal system by a direct (mural type) or indirect (choroidal type) communication. Angiographic evaluation of VGAVMs usually describes a limbic arch between the anterior and posterior cerebral arteries throughout a pericallosal artery, and the classic “ε” shape configuration of the thalamostriate veins drainage into a subtemporal or a lateral mesencephalic vein due to the underdevelopment of the straight sinus, sigmoid sinus, and jugular bulbs. Moreover, falcine dural channels join the pouch of the malformation with the posterior third of the superior sagittal sinus and less frequently with the cavernous sinus, inferior petrosal sinus, and facial veins. At present, endovascular therapy is the standard management for these lesions. However, under failure of endovascular procedures such in this case, microsurgical management of VGAVMs under an experienced neurosurgical team might be paramount.Case Description:The patient with a choroidal type VGAVM and multiple failed endovascular procedures underwent sitting praying position and midline supracerebellar infratentorial approach. Strong retraction with stitches and proper hemostasis of a highly vascular dura was achieved after transverse sinus-based opening. Accurate microsurgical dissection between the superior cerebellar surface and the tentorium allowed a supracerebellar approach over the vermis and along the midline recognizing the venous pouch of the VGAVM instead of the absent straight sinus. Water dissection allowed us to differentiate the cleavage plane between the VGAVM and surrounding structures maintaining an impeccable surgical field as well. Under high microscopic magnification, arterial feeders of the malformation coming from the posterior cerebral artery were recognized. Intraoperative angiography and reevaluation of the preoperative imaging helped us to confirm a safety approach before coagulation and cut those vascular feeders. Throughout an open-close and short bursts bipolar coagulation techniques preventing attachment of conventional bipolar tips within the vascular structure and without permanent use of water irrigation, the vessels were carefully dissected, coagulated, and sectioned. Along with our experience, we believe that this standard coagulation technique applied in all vascular malformation surgeries is safe and effective. A remaining small plexiform malformation associated with the vein of Galen malformation was coagulated and isolated. A new intraoperative angiography determined complete microsurgical occlusion of the VGAVM. Careful homeostasis based on electrocoagulation and surgical was achieved. Finally, we performed a microsurgical wound closure as a conventional technique in Helsinki neurosurgery.Conclusion:This unedited video offers all detailed aspects that a neurosurgeon as the senior author JH considers essential when performing an efficient and safe surgery for a VGAVM.Videolink:http://surgicalneurologyint.com/videogallery/vein-of-galen-avm.

CẤU TRÚC VÀ HIỆU SUẤT ÂM CỦA ỐNG XẢ ĐỘNG CƠ DÙNG CHO MÁY VÀ THIẾT BỊ XÂY DỰNG

The main objective of the present work is to characterize numerically the link between the geometrical parameters and the functional noise reduction properties of typical engine exhaust mufflers for construction equipment and machinery. To this regard, the acoustical modeling of these devices is first presented using the finite element approach. Then, we investigate the effects of both the geometrical parameters and the shape configuration of some typical mufflers (e.g., chambered, turbo, reactive, absorptive…) on their sound transmission loss. In terms of acoustics, for a given total length (600 mm), mufflers show a better acoustic performance (up to 50 dB) with a high number of chambers/partitions or using absorbing layers, especially micro-perforated panel with hole size of 24 mm and its fraction 48% can improve the sound transmission loss up to 100 dB at low frequency less than 1 kHz. The obtained results show clearly that the noise reduction target could be successfully achieved over an individual octave band or the whole frequency range by tuning structures of appropriate engine exhaust mufflers.

Strategies for Predicting Centrifugal Pump Performance Characteristics by Validating Blade Shape Configurations. Introducing the Trojan Horse Method

Strategies for Predicting Centrifugal Pump Performance Characteristics by Validating Blade Shape Configurations. Introducing the Trojan Horse Method - written by J. C. Statharas , E. S. Valamontes , P. Filiousis published on 2019/06/14 download full article with reference data and citations

The assessment of shape configuration effect of CFRP strips on the lateral capacity of shear walls with different aspect ratios

ABSTRACTThe purpose of this study is to find the effect of shape configuration of carbon fibre reinforced polymer (CFRP) strips on the lateral capacity of shear walls. For this purpose, a model of shear wall strengthened with different layout configurations of CFRP was investigated by pushover analysis. All carbon fibres placed symmetrically on reinforced concrete (RC) walls, and any sliding effect of fibres on concrete was neglected. Also, the effect of change in the aspect ratio of the RC wall on CFRP strengthening pattern was studied. Throughout the study, the results of all CFRP configurations and the increase in lateral strength were compared. With an increase in the number of fibre layers on all specimens strengthened with CFRP, change in lateral strength and in the shear wall damage occurred. By all specimens’ comparison, the best fibre configuration in each h/L ratio was determined.Abbreviations: CDP: Concrete Damage Plasticity; CFRP: Carbon Fiber Reinforced Polymer; FRP: Fiber Reinforced Polymer; h/L: Height/Length; RC: Reinforced Concrete; 2D: Two Dimensional; 3D: Three Dimensional

Outline Shape Analysis on the Trochlear Constriction and Olecranon Fossa of the Humerus: Insights for Sex Estimation and a New Computational Tool.

Sex estimation through visual analysis of the distal humerus can contribute to establishing the biological profile of an unidentified skeletal individual. Using statistical shape modeling, the trochlear constriction open curves and olecranon fossa closed outlines of 151 humeri were digitized and analyzed. The shape configurations exhibited strikingly different degrees of sexual dimorphism when evaluated using linear discriminant analysis with leave-one-out cross-validation. The trochlear constriction performed poorly, correctly classifying 63.6% of the individuals. However, the olecranon fossa showed high sexual dimorphism, presenting a 94.0% accuracy. A simpler model using only two principal components was also generated. While the accuracy is slightly inferior (88.1%), it has the advantage of being constrained to bidimensional components that were translated into morphoscopic variables within a simulator interface. This allowed us to implement the method through a web application that does not require users to be trained in landmark digitization or have knowledge of geometric morphometrics.

A STOCHASTIC APPROACH TO AUTOMATED RECONSTRUCTION OF 3D MODELS OF INTERIOR SPACES FROM POINT CLOUDS

Abstract. Automated reconstruction of 3D interior models has recently been a topic of intensive research due to its wide range of applications in Architecture, Engineering, and Construction. However, generation of the 3D models from LiDAR data and/or RGB-D data is challenged by not only the complexity of building geometries, but also the presence of clutters and the inevitable defects of the input data. In this paper, we propose a stochastic approach for automatic reconstruction of 3D models of interior spaces from point clouds, which is applicable to both Manhattan and non-Manhattan world buildings. The building interior is first partitioned into a set of 3D shapes as an arrangement of permanent structures. An optimization process is then applied to search for the most probable model as the optimal configuration of the 3D shapes using the reversible jump Markov Chain Monte Carlo (rjMCMC) sampling with the Metropolis-Hastings algorithm. This optimization is not based only on the input data, but also takes into account the intermediate stages of the model during the modelling process. Consequently, it enhances the robustness of the proposed approach to inaccuracy and incompleteness of the point cloud. The feasibility of the proposed approach is evaluated on a synthetic and an ISPRS benchmark dataset.

Numerical investigation of highly unsteady accelerated/decelerated flows for blunt bodies experiencing impulsive motion

Scale-resolving simulations (SRSs) such as large-eddy simulation (LES) and hybrid LES/Reynolds-averaged Navier–Stokes are applied to analyze the unsteady characteristics of the drag and flow fields for blunt bodies subject to impulsive motion. These simulations reveal highly transient behaviors of the primary and secondary vortices triggered by inertial forces during impulsive motion. A distinctive characteristic of the transient drag, namely, the existence of a plateau region, induced by a circular cylinder during impulsive acceleration is also revealed. It is found that among the SRS methods, the LES one-equation eddy method is able to more precisely capture the intrinsic local pressure gradient arising from unsteadiness of the vortices together with the instantaneous vorticity magnitude. The secondary vortices created by inertial forces and shear stresses due to the impulsive motion and the interactions of these vortices with the primary vortices turn out to play a key role in the transient behaviors of the flow field and the drag. The mechanism causing the highly unsteady flow field and its relationship to the bluntness of the shape configuration are also explored using the LES one-equation eddy method. It is found from the range of retained local Cp values and the transient vorticity distribution along the cylinder surface that the mobility of the unsteady flow separation point depends on the bluntness of the configuration.

Effects of Peripheral Gradient of Color Saturation on the Feeling of Being Dazzled.

The feeling of being dazzled that is evoked by images consisting of an achromatic uniform center surrounded by regions with a luminance gradient was investigated. The effects of type of color saturation gradient in the peripheral region on the feeling of being dazzled were examined. Stimulus configuration was also varied. For the stimulus configuration of a disk-annulus, the feeling of being dazzled was lower for an increasing saturation gradient from the center to the periphery than for decreasing and no-saturation gradients when the center and the periphery maximum luminances were the same. This suggests that the presence of a chromaticity difference between the disk and the surrounding annulus strengthens the feeling of being dazzled. Similar results were obtained for the stimulus configuration of a star shape. For the stimulus configuration of a cross shape, quite different results were obtained; the chromaticity discontinuity had little or opposite effect. These results suggest that chromaticity border and stimulus configurations are factors in the feeling of being dazzled that is evoked by images with luminance gradient.

Identifying key landscape pattern indices influencing the ecological security of inland river basin: The middle and lower reaches of Shule River Basin as an example

Landscape pattern evolution leads to changes of landscape spatial structure, which are intuitively reflected in the changes of ecosystem structure and composition and finally affect ecological security. In this paper, we assessed the spatiotemporal variation of the ecological security and landscape pattern of the middle and lower reaches of Shule River Basin in 1987–2015. Further, we analyzed the correlation between the ecological security and landscape pattern of the study region and correlation coefficients were calculated. On this basis, the key landscape pattern indices influencing the ecological security of the study region were identified. This may provide useful information for ecological regulation and design. The results show that: (1) From 1987 to 2015, the ecological security in the middle and lower reaches of the Shule River Basin was of medium or low level, showing periodic “U” shaped fluctuations, and the fluctuation period was gradually shortened. In addition, there was an overall spatial pattern of “high ecological security in the west, middle and south and low ecological security in the east”. (2) The landscape pattern showed clear stage characteristics. The complexity of landscape pattern increased from 1987 to 1996 and decreased after 1996. (3) Landscape size, shape, quantity, type and spatial configuration had important impacts on ecological security and showed significant temporal variation. In a period when the influence of human activities was weak, ecological security was mainly related to landscape area indices. With increase in human activities, landscape shape, fragmentation and connectivity changed greatly, which led to changes in the structure and composition of ecosystem, thus finally affecting ecological security.

Elastic electron scattering off nuclei with shape coexistence

In this paper, the effects of shape coexistence on the resulting mixed configuration of the ground state are investigated by elastic electron scattering. The shape configurations of ground states are searched by the constraint relativistic mean-field (RMF) model. For nuclei with shape coexistence, the density distributions of the coexistence states are obtained from the mixing of different configurations. With the charge distributions, the Coulomb form factors of the coexistence states are calculated by the distorted wave Born approximation method. By comparing the of coexistence states with the of certain shape configurations, the phenomena of the shape coexistence can be analyzed by electron scattering.

Hydrodynamic evaluation of gas testing chamber: Simulation, experiment

Gas concentration measurements by means of metal oxide microsensors represent a promising issue due to several advantages (size, low cost, power consumption, reliability…). However, improvements are required to increase performances of complete experimental systems including microsensor and testing chamber at least. This paper deals with the study of different size and shape configurations of gas testing chamber, by coupling 3D unsteady modelling and experiments in the case of a SnO2 sensor with ethanol gas flow. The influence of the testing-chamber design on the gas flow hydrodynamics and on the system response is shown. A new 3D-printed prototype chamber (boat-shape design), as compared to the commonly used testing chamber (cross-shape design), leads to an increase of the dynamics, an enhancement of the gas concentration homogeneity and a significant reduction of flow recirculation and dead volumes. In this work we have shown that the optimization of the test chamber (volume and shape) makes it possible to get as close as possible to the real electrical characteristics of the sensor. Consequently thanks to these new achieved characteristics, the performances of the whole system are improved.

Experimental analysis of the influence of the voltage waveform on ozone generation efficiency

ABSTRACTAlthough the dielectric barrier discharge (DBD) has been widely considered and studied for ozone generation, only a few studies have examined the influence of the alternating voltage waveform on the ozone rate production. This paper analyses the influence of the voltage shape on the ozone concentration and the energy efficiency of a DBD cylindrical ozone generator. Three voltage signals were studied using a high-voltage amplifier: sinusoidal, triangular and rectangular signals with voltage values up to 8 kV and frequencies up to 1.1 kHz. The obtained results showed that the efficiency of the ozone generator depends strongly on the type of the voltage waveform. The maximum values of the energy efficiency and the ozone concentration were obtained with the triangular voltage signal. This wave shape configuration has been successfully used for discolouration of water contaminated by textile dye.

A High-Performance FIR filter Architecture for Reconfigurable Applications

Transpose form finite-impulse response (FIR) filters are characteristically pipelined and support multiple constant multiplications (MCM) procedure that results in significant saving of calculation. However, transpose form configuration does not specifically support the block performing not like direct-form configuration. In this paper, we investigate the possibility of realization of block FIR filter in transpose shape configuration for area-delay efficient realization of huge order FIR filters for both fixed applications. Based on a detailed computational investigation of transpose form configuration of FIR filter, we have derived a flow diagram for transpose shape block FIR filter with reduced register complexity. A detailed block formulation is detailed for transpose form FIR filter. We have inferred a general multiplier-based architecture for the proposed transpose form block filter for reconfigurable applications. A reduced-complex design using multiple constant multiplications scheme is also showed for block implementation of fixed FIR filters. The proposed architecture obtains less area, less delay and less power consumption compared with the existing architecture of direct form structure for medium or long filter lengths. For this project analysis for determining area, power and delay it uses Xilinx.

Parametric Approach for Multi-Objective Optimization for Daylighting and Energy Consumption in Early Stage Design of Office Tower in New Administrative Capital City of Egypt

In the last few years, great improvements have been achieved in building optimization methods. Mustapha Sadeghipour Roudasri and others found new tools ” Ladybug, Honeybee and Butterfly” which could gather many simulation engines and visualization tools ” Energyplus, OpenStudio, Radiance, Daysim, CFD, OpenFOAM, etc ”. Consequently, These simulation engines will integrate with parametric modeling in Grasshopper and multiobjective optimization through Octopus plug-in to form an early stage parametric optimization framework in one canvas. This paper aims at finding the suitable plane shape and building configurations for multi-objective optimization to the daylighting levels and energy consumption of office tower building in the new administrative capital city in Egypt through parametric based optimization method. One of the most commonly used plan shapes of these types of buildings was studied. This shape and many building configurations ”WWR, window material, wall material and shading devices” were parametrically modeled. These Parameters will form many tradeoffs which will be simulated and optimized by the previous framework. Spatial Daylight Autonomy ”SDA300/50%” is examined to optimize Daylighting while Energy Use Intensity ” EUI” is used for energy consumption optimization. Multi-Objective Optimization was performed by genetic algorithms via Octopus plug-in. The near optimum design for plan shape and building configuration to balance between daylighting and energy consumption is achieved and will be a reference model for office tower buildings in this zone in Egypt which is under rapid development. The framework used in this study will guide designers to find effective solutions for early-stage design of office building in one canvas without any conflict between several engines and scripts.