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The peripapillary retinal pigment epithelium-basement membrane (ppRPE/BM) layer angle was recently proposed as a potential index for estimating intracranial pressure noninvasively. However, the ppRPE/BM layer angle, measured from the optical coherence tomography (OCT) scans, varied across the radial directions of the optic disc. This made the ppRPE/BM layer angle difficult to be utilized in its full potential. In this study, we developed a mathematical model to quantify the ppRPE/BM layer angles across radial scans in relation to the ppRPE/BM 3D morphology in terms of its 3D angle and scanning tilt angles. Results showed that the variations of the ppRPE/BM layer angle across radial scans were well explained by its 3D angle and scanning tilt angles. The ppRPE/BM layer 3D angle was reversely fitted from the measured ppRPE/BM layer angles across radial directions with application to six eyes from four patients, who underwent medically necessary lumbar puncture. The fitted curve from our mathematical model matched well with the experimental measurements (R 2 > 0.9 in most cases). This further validated our mathematical model. The proposed model in this study has elucidated the variations of ppRPE/BM layer angle across 2D radial scans from the perspective of the ppRPE/BM layer 3D morphology. It is expected that the ppRPE/BM layer 3D angle developed in this study could be further exploited as a new biomarker for the optic disc.

We studied the three-dimensional (3-D) shape variations and symmetry of the lunate to evaluate whether a contralateral shape-based approach to design patient-specific implants for treatment of Kienböck’s disease is accurate. A 3-D statistical shape model of the lunate was built using the computed tomography scans of 54 lunate pairs and shape symmetry was evaluated based on an intraclass correlation analysis. The lunate shape was not bilaterally symmetrical in (1) the angle scaphoid surface – radius-ulna surface, (2) the dorsal side and the length of the side adjacent to the triquetrum, (3) the orientation of the volar surface, (4) the width of the side adjacent to the scaphoid, (5) the skewness in the coronal plane and (6) the curvature of bone articulating with the hamate and capitate. These findings suggest that using the contralateral lunate to design patient-specific lunate implants may not be as accurate as it is intended.

Effective exudate retention by dressings requires close and intimate dressing‐wound contact, immediately and continuously after the dressing application. Any dressing‐wound spaces may allow for build‐up of non‐retained fluids, causing exudate pooling which forms a favourable environment for pathogen growth. Maceration may follow if the pooled exudates spread to peri‐wound skin. Dressings with a claimed 3D‐shape‐conformation technology are commercially available; however, their effectiveness in minimising dressing‐wound gaps has never been scientifically investigated. We present a novel bioengineering methodology for testing the effectiveness of such 3D‐shape‐conformation dressings, using our recently reported robotic phantom system of a sacral pressure ulcer. By means of 3D laser scanning and bespoke software, we reconstructed dressing shapes after simulated use and calculated the goodness‐of‐fit between each dressing (swelled to near‐saturation) and the corresponding wound geometry. Two dressing sizes (10 × 10 cm and 12.5 × 12.5 cm) and two wound depths (2.5 or 2 cm) were considered. All the tested dressings were far from reaching good contact with the (simulated) wounds: Approximately one‐third of the wound volume and nearly half of the wound surface were not in contact with the swelled dressings. Our present findings question whether 3D‐shape‐conformation dressings are effective, by revealing their swelling behaviour which was previously unknown.

Three‐dimensional (3D) shape reconstruction of objects requires multiple scans and complex reconstruction algorithms. An alternative approach is to infer the 3D shape of an object from a single depth image (i.e. single depth view). This study presents such a 3D shape reconstructor based on U‐Net 3D‐convolutional neural network (3D‐CNN) with bottle‐neck skipped connection blocks (U‐Net BNSC 3D‐CNN) to infer the 3D shapes of objects from only a single depth view. The BNSC block is a fully convolutional block that uses skip connections to improve the performance of the sequential 3D‐convolutional layers of U‐Net. The primary advantage of U‐Net BNSC 3D‐CNN is improving the accuracy of shape reconstruction while reducing the computational load. The evaluation of the proposed U‐Net BNSC 3D‐CNN uses unseen views from trained and untrained objects with two public databases, ShapeNet and Grasp database. Our reconstructor achieves 72.17% and 69.97% accuracy in terms of the Jaccard similarity index for trained and untrained objects, respectively, with the ShapeNet database, whereas previous reconstructor based on 3D‐CNN achieves 66.43% and 58.35%. With Grasp database, our reconstructor achieves 87.03% and 85.35%, whereas 3D‐CNN 76.52% and 76.02%. Also, our U‐Net BNSC 3D‐CNN reduces the computational load of the standard 3D‐CNN reconstructor by 6.67% in the computation time and by 98.69% in the number of trainable parameters.

Speckle interferometry has long been used to measure the deformation of an object with a rough surface. Currently, it can be used to measure the shape of a three-dimensional microstructure by inten...

This article presents an optical technique for the three-dimensional (3D) shape inspection of micro-solder balls used in ball grid array (BGA) packaging, before attaching them to a board or film. This technique uses an optical source comprising spatially arranged light-emitting diodes (LEDs), and the results are derived based on the specular reflection characteristics of the BGA balls. A vision system is designed to acquire the reflected image from the micro-solder balls. For shape inspection, the locations of the LED point-light-source reflections are determined via image processing, and defects in 3D BGA shapes are detected using statistical information of the relative positions of multiple BGA balls captured in the images. Experiments were conducted to validate our proposed method, and the results revealed that it allows for simultaneous inspection of multiple BGA balls placed arbitrarily in a glass dish, without the need for precise ball-position control.

We use gravity, magnetic, seismic reflection, well, and outcrop data to determine the three-dimensional shape and structural features of south-central Alaska’s Susitna basin. This basin is located within the Aleutian-Alaskan convergent margin region and is expected to show effects of regional subduction zone processes. Aeromagnetic data, when filtered to highlight anomalies associated with sources within the upper few kilometers, show numerous linear northeast-trending highs and some linear north-trending highs. Comparisons to seismic reflection and well data show that these highs correspond to areas where late Paleocene to early Eocene volcanic layers have been locally uplifted due to folding and/or faulting. The combined magnetic and seismic reflection data suggest that the linear highs represent northeast-trending folds and north-striking faults. Several lines of evidence suggest that the northeast-trending folds formed during the middle Eocene to early Miocene and may have continued to be active in the Pliocene. The north-striking faults, which in some areas appear to cut the northeast-trending folds, show evidence of Neogene and probable modern movement. Gravity data facilitate estimates of the shape and depth of the basin. This was accomplished by separating the observed gravity anomaly into two components—one representing low-density sedimentary fill within the basin and one representing density heterogeneities within the underlying crystalline basement. We then used the basin anomaly, seismic reflection data, and well data to estimate the depth of the basin. Together, the magnetic, gravity, and reflection seismic analyses reveal an asymmetric basin comprising sedimentary rock over 4 km thick with steep, fault-bounded sides to the southwest, west, and north and a mostly gentle rise toward the east. Relations to the broader tectonic regime are suggested by fold axis orientations within the Susitna basin and neighboring Cook Inlet basin, which are roughly parallel to the easternmost part of the Alaska-Aleutian trench and associated Wadati-Benioff zone as it trends from northeast to north-northeast to northeast. An alignment between forearc basin folds and the subduction zone trench has been observed at other convergent margins, attributed to strain partitioning generated by regional rheologic variations that are associated with the subducting plate and arc magmatism. The asymmetric shape of the basin, especially its gentle rise to the east, may reflect uplift associated with flat-slab subduction of the Yakutat microplate, consistent with previous work that suggested Yakutat influence on the nearby Talkeetna Mountains and western Alaska Range. Yakutat subduction may also have contributed to Neogene and later reverse slip along north-striking faults within the Susitna basin.

Learning three-dimensional shape of geometry is important for improving students’ spatial abilities. However, the concept of three-dimensional shape is still considered as one of difficult subject matters for teacher to teach and for student to understand in Indonesia. Therefore, it is necessary to find an alternative way that can allow teachers and students to easily understand some concepts of geometry. In this research, we try to implement mobile-based augmented reality in presenting three-dimensional geometry materials to help teachers and students of junior high school in Bandung, Indonesia. The results show that by using mobile based augmented reality, teachers can teach three dimensional shape of geometry clearly and students could understand the concept of three-dimensional shape of geometry faster. In addition, students can learn the concept of geometry comprehensively through geometry objects that can be seen from all points of view and students' spatial activities are increased

Background Information on the three-dimensional (3D) shape of vertebral end plates is lacking. Previous studies have analyzed two-dimensional shape; however, 3D data are important because they may help improve our understanding of how differences in shape are related to age, gender, race, size, and other parameters, which may subsequently help improve device design for interbody prosthesis. Objective To study the 3D shape of lumbar vertebral end plates from normal adult lumbar spines and correlate them with age, gender, spinal/end plate level, end plate surface area, concave depth, and size. Methods An in vivo analysis was undertaken of lumbar vertebral end plate 3D shape. A total of 136 patients' computed tomography scans were used to create 3D models of the lumbar spine for each patient, which were subsequently analyzed. Results The shape of the superior end plates is different compared with inferior end plates. Across the lumbar spine (L1-S1), the shape of inferior end plates is similar; however, the shape of the superior end plate varies between spinal levels significantly. There was no clear relationship between age and principal component (PC) shapes but there was a strong correlation between end plate concave depth and end plate PC shape scores. Conclusions Future interbody (disc replacement and fusion) device designs could use the findings that inferior end plate shape is similar throughout the length of the lumbar spine, whereas superior end plate shape changes. Further, future implants could be level-specific because the present study shows that end plate shape varies through the length of the lumbar spine.

Background Existing clinical measures to describe foot morphology are limited in that they are commonly two-dimensional, low in resolution and accuracy, and do not accurately represent the multi-planar and complex changes during development across childhood. Using three-dimensional (3D) scanner technology provides the opportunity to understand more about morphological changes throughout childhood with higher resolution and potentially more relevant 3D shape measures. This is important to advance the prevailing arguments about the typical development of children’s feet and inform the development of appropriate clinical measures. 3D shape descriptors derived from 3D scanning can be used to quantify changes in shape at each point of the 3D surface. The aim of this study was to determine whether 3D shape descriptors derived from 3D scanning data can identify differences in foot morphology between children of different ages. Methods Fifteen children were recruited from three age groups (2, 5, and 7 years of age). Both feet were scanned in bipedal stance, using the Artec Eva (Artec Group, Luxembourg, Luxembourg) hand-held scanner. Three dimensional shape descriptors were extracted from the 3D scans of the right foot, to create histograms for each age group and heat maps of representative participants for comparison. Results There were changes to the dorsal, medial and lateral surfaces of the feet with age. The surfaces became less round along with an increase in indented areas. This is supported by the heat maps which demonstrated that the surfaces of the anatomical landmarks (e.g. the malleoli and navicular tuberosity) became more rounded and protruding, with indented surfaces appearing around these landmarks. On the plantar surface, the concavity of the midfoot was evident and this concavity extended into the midfoot from the medial aspect as age increased. Conclusions The findings of this study indicated that with increasing age the foot becomes thinner in 3D, with bony architecture emerging, and the medial longitudinal arch (MLA) increases in area and concavity. Three-dimensional shape descriptors have shown good potential for locating and quantifying changes in foot structure across childhood. Three-dimensional shape descriptor data will be beneficial for understanding more about foot development and quantifying changes over time.

Exiting strategies for 3D shape-changing structures are constrained by either the complicated fabrication process or the harsh demands of active materials. Facile preparation of 3D shape-changing structures with an extremely simple approach based on the elastomeric polymer still remains a challenging topic. Here, we report a fast digital patterning of surface topography of a single-layer elastomeric polymer toward 3D shape-changing structures. The surface topography features digitally engraved grooves by a laser engraver on a poly(dimethylsiloxane) (PDMS) sheet, which is surface oxidized by the UV-ozone treatment. The resulting engraved PDMS sheets exhibit programmable shape-changing behaviors to form various 3D structures under the action of organic solvent. Experimental and numerical studies reveal the fundamental aspects of surface topography-guided 3D shape-changing structures. Demonstrations of this concept in developing various complex 3D shape-changing structures illustrate the simplicity and effectiveness of our approach, thereby creating engineering opportunities in a wide range of applications such as actuators and soft robots.

Introduction: Myocardial collagen structure is a complex three dimensional (3D) hierarchy, organizing cardiomyocytes and providing structural integrity. Changes in collagen organization have a crucial role in cardiac remodeling. However, quantitative methods for the analysis of collagen structures are still lacking. Herein, we apply our collagen shape analysis framework to compare within-sheetlet collagen (both endomysial collagen surrounding myocytes and perimysial cords) against sheetlet-surface collagen (perimysial meshwork collagen deposited between sheetlets) in spontaneously hypertensive rats undergoing quinapril treatment. Hypothesis: The different functional properties of endomysial and perimysial meshwork collagen are linked to their structure and will have markedly different features quantifiable by 3D shape analysis. Methods: Rat myocardium was stained for collagen (picrosirius red), and the left ventricular free wall imaged using extended volume confocal microscopy (0.4 μm 3 voxel size). The 3D image volumes were segmented into within-sheetlet and sheetlet-surface regions. Shape analysis was performed using eigenanalysis of the inertia matrix to derive 3D morphological (elongation and flatness) parameters, characterizing the collagen shape in the two regions. Results: Shape analysis revealed marked differences between within-sheetlet and sheetlet-surface collagen organization. Long-term quinapril treatment resulted in notable differences in within-sheetlet collagen shape in rats at 14 months of age (mo) compared with 24 mo. At 14 mo, the within-sheetlet collagen is a mix of sheet-, ribbon-, and rod-like structures (elongation: 0.43, flatness: 0.05), but by 24 mo this has remodeled to predominately thin rod-like structures (elongation: 0.03, flatness: 0.35). The sheetlet-surface collagen consisted of thick sheet-like structures in both 14 and 24 mo rats (elongation: 0.83 vs 0.79, flatness: 0.13 vs 0.09). Conclusion: Shape analysis in 3D showed marked differences between within-sheetlet and sheetlet-surface collagen structure, as well as differences between early treatment and late treatment of diseased hearts.

In this research, we aim to develop a method to recognize three dimensional shape of stacked rubbles each by each for rubble withdrawal rescue robots. Shapes, masses, states of stacked rubbles and so on are various and unknown at disaster areas. Then, grasping positions on rubbles and ways to remove them have to be considered for not breaking down the stacked rubbles and falling them down on victims. Thus, it is necessary to recognize stacked rubble individually and to identify their features, such as shapes, masses, center of gravity positions and so on. In this paper, we propose a 3-D object shape recognition system with a RGB-D sensor and a 3-D reference marker. Moreover, we also propose an extraction method of rubbles using the SSD (Single Shot Multi Box Detector) of the AI (Artificial Intelligence). Experiments were performed to confirm the validity of the proposed method with our constructed prototype of a rescue robot. Through the experiments, it is shown that target stacked rubbles were recognized individually.

A three-dimensional shape design problem is studied in this work. The objective is to estimate the optimal boundary geometry of a conductive body for producing boundary isotherms and the te...

A three-dimensional (3D) shape measurement method based on binary fringe conventional projection is proposed. In traditional 3D shape measurement methods based on binary fringe projection, the binary fringe is used as an approximate sinusoidal fringe by defocusing projection or even directly used as an approximate sinusoidal fringe by nonlinear error suppression feature of large-step phase measuring profilometry (PMP). In the proposed method (Prop), neither defocusing projection is needed nor large-step PMP must be used. When the binary fringe is conventionally projected on the measured object, just by filtering operation in spatial frequency domain from the captured deformed pattern, the nearly unbroken sinusoidal deformed pattern can be extracted efficiently. While N ( N≥3) frames binary fringes with 1/ N period misalignment between each adjacent fringe are conventionally projected onto the measured object sequentially, the corresponding nearly unbroken N-step sinusoidal deformed patterns extracted from the N frames captured deformed patterns can be used to reconstruct the 3D shape of the measured object with N-step PMP algorithm. The experimental results show the feasibility and validity of the Prop. It is more flexible for its optional fringe period and optional phase-shifting steps. It has potential application in the real-time 3D shape measurement.

This paper studies a selection of fine sands, their particle shape and its effect on the plastic properties of mortars via the influence on the workability and packing of cementitious mixtures. Five sands from different sources were sampled, wet sieved, and classified into six size classes: 20 μm–75 μm, 75 μm–150 μm, 150 μm–300 μm, 300 μm–600 μm, 600 μm to 1.18 mm and 1.18 mm–2.36 mm. Particle shape was measured and various geometrical quantities were determined for particles of each class using a combination of X-ray microcomputed tomography (μCT) and spherical harmonic analysis. Specimen preparation, scanning method, minimum required number of particles in a representative sample, and shape histograms are all discussed, and used to classify and compare the shape of the particles of each material type and size class. This information is then used to establish a connection between sand particle shape and the wet packing density, the workability in the form of slump-flow, and the water demand in mortar mixtures.

We explored the pigeon's representation of the shape of simple three-dimensional objects (geons) rotated in depth (four views each of four geons). Pigeons assigned to the Categorization group had to respond differentially to images of four different geons-termed arch, barrel, brick, and wedge-based on their 3D shape, regardless of the orientation of the object. Pigeons assigned to the Pseudocategorization group had to respond differentially to the same objects based on groupings that did not correspond to object identity, which required the learning of local orientation-dependent features (e.g., a concave curve on top, or the position of an illumination hotspot). The Categorization group, which could employ object-identity representations, quickly achieved highly accurate responding. The Pseudocategorization group, however, failed to achieve reliable above-chance responding. In addition, the reaction times for the Categorization group were significantly shorter than for the Pseudocategorization group. These results indicate that pigeons show a strong, spontaneous tendency to categorize the shapes of different orientations in depth of the same 3D object as similar, if not equivalent; they do so despite the vast differences in image characteristics caused by the variations in orientations, even when such categorization is contrary to the reinforcement contingencies.

There have been active studies on optimized dithering techniques to improve 3D shape measurement quality with image sensor and defocusing projector. These techniques can be classified into intensity-based optimization technology and phase-based optimization technology. However, those phase-based optimization methods are sensitive to the amount of defocusing while intensity-based optimization methods cannot reduce phase errors efficiently. This paper presents an optimization framework. This framework combines structural similarity index measurement and intensity residual error optimization. By applying this optimization framework to patches and tiling the best patch, high quality fringe pattern can be generated for three-dimensional measurement. Both simulation and experimental results show that this proposed algorithm can achieve phase quality improvements and it is robust to various defocusing levels.

Temperature control, fertilization management, and long-day treatments are performed to achieve optimal strawberry (Fragaria × ananassa Duch.) growth control. To date, the efficiency of the control of these parameters relies on visual assessment by the producers who evaluate the plants' status, or on growth surveys performed weekly. Therefore, to perform stable advanced production control, even for less-experienced producers, it is necessary to monitor the growth data of the plant continuously. In this study, we acquired strawberry growth data such as plant height and leaf area using Kinect for Windows v1, a three-dimensional shape measurement instrument, and examined whether it could be used for cultivation management. Kinect accurately measured the height of the strawberry plant. The leaf area measured using Kinect was smaller than the actual measured value. Kinect and environmental measurement equipment that were set up in a large-scale horticultural facility detected variations in growth of strawberry plants and environment data. At each measured location, there was a difference in the amount of solar radiation, and differences in plant height and the layered structure of the leaf area were detected. The results indicate that Kinect can acquire information regarding strawberry growth that are necessary for environmental control over time and may detect variation in strawberry growth due to environmental differences in the greenhouse.

This paper presents a single-shot, 360-degree, and high-precision three-dimensional shape measurement for human heads based on digital image correlation and plane mirrors, which improves the matching speed of DIC by introducing multiple threads.

The 3D shape of steam chamber is an important parameter to judge the production and development status of SAGD and to optimize the design scheme. According to the geological conditions and seismic data of the Zhong 18 test area in Xinjiang Oilfield, it had studied the seismic forward reflection characteristics of the steam chamber and established the connection between the steam chamber and various seismic attributes. By combining logging, production performance, temperature and pressure monitoring, geological model and other data, it had eliminated the seismic abnormal response and reduced the multiple solutions of seismic interpretation. Finally it can realize the accurate description of 3D shape of the steam chamber. It can provide technical support for adjustment and deployment of shallow heavy oil SAGD development and optimization of development plan.

6 pags., 2 figs., 2 tabs., There have been many studies on lens properties in specific populations (e.g. in China, Europe, Singapore, etc.) some of which suggest there may be differences between populations. Differences could be caused by ethnic or environmental influences or experimental procedures. The purpose of this study is to evaluate if any differences exist between Indian and European populations in the central geometric and full shape properties of human lenses. Two custom-developed spectral domain optical coherence tomography systems were used to acquire the crystalline lens geometry: one in India (69 lenses from 59 donors) and the other in Spain (24 lenses from 19 donors). The steps for obtaining accurate 3-D models from optical coherence tomography raw images comprised of image segmentation, fan and optical distortion correction, tilt removal and registration. The outcome variables were lens equatorial diameter, lens thickness, anterior and posterior lens thicknesses and their ratio, central radius of curvature of the anterior and posterior lens surfaces, lens volume and lens surface area. A mixed effects model by maximum likelihood estimation was used to evaluate the effect of age, population and their interaction (age*population) on lens parameters. After adjusting for age, there were no population differences observed in anterior and posterior radii of curvature, equatorial diameter, lens thickness, anterior and posterior lens thicknesses and their ratio, volume and surface area (all p ≥ 0.08). There was also no effect of the interaction term on anterior and posterior radii of curvature, equatorial diameter, lens thickness, anterior and posterior lens thicknesses and their ratio, volume and surface area (all p ≥ 0.06). All central geometric and full shape parameters appeared to be comparable between the European and Indian populations. This is the first study to compare geometric and full shape lens parameters between different populations in vitro., This work was supported by the National Institutes of Health/National Eye Institute [Grants 2R01EY021834 and P30EY14801 (Center Grant)]; the Hyderabad Eye Research Foundation; Ministerio de Educacion y Ciencia, Spain (FIS2017- 84753-R), European Research Council (ERC-2018-AdG-833106) and IMCUSTOMEYE Ref. 779960 (H2020- ICT- 2017-1) to S. Marcos, and European Research Council (ERC) under European Union’s Horizon 2020 research and innovation programme H2020-MSCA COFUND-2015 FP-713694, MULTIPLY(AdC), CSIC ICoop Program, Florida Lions Eye Bank and the Beauty of Sight Foundation, an unrestricted grant from Research to Prevent Blindness to the Department of Ophthalmology, University of Miami and the Henri and Flore Lesieur Foundation (J-M. Parel).

Mineral dust shape and roughness are important for a multitude of processes; it is known for aspherical shape but the true measurements in three dimensions are rare. Atomic Force Microscope was used for determine both 3D shape and roughness for two dust which are commonly used in laboratory experiments – Arizona Test Dust (ATD) and Kaolinite. We determined both of them are rather flat and round; an oblate spheroid would be a good model. Loess Filter was used to smooth the particles' surface and correlation analysis was used to examine the surfaces' properties of the dust; we found no features under 100nm scales. Also, our particles' surface area result is very similar to BET surface area.

This paper reports three-dimensional shape restoration in the millimeter waves frequency region. A millimeter-wave sensors, consisting of aligned carbon nanotube film channels, serves as a non-destructive reflective monitoring system of multi-layered curvilinear objects. Also, a simple algorithm facilitates to estimate the distance of the target via analyzing the signals obtained by the scanners. The proposed method enriches millimeter-wave sensing and monitoring technologies, and is potentially applicable to the medical field, inline inspections of products, and non-destructive inspections.

Shape sensing, identifying the shape of the structure based on sensor, which was installed on the structure, is an important technology for structural health monitoring (SHM). It contributes monitoring the condition of the structure, feedback control, and fatigue estimation. By installing fiber-optic sensor on the structure like nerves, the deformed shape can be identified based on inverse finite element method (iFEM) from the measurement strain. The measurement error and the placement of fiber-optic sensor affect the result of shape sensing. Here we show the shape sensing of a bended stiffened panel in the simulation and verify the influence of the measurement error and the sensor placement. The deflection of the plate is identified with an error less than 1% of maximum deflection. The mean percent difference (MPD) calculated from the measurement strain giving Gaussian noise with a standard deviation of 5% of the maximum strain was 2.86%. Furthermore, with simple bending deformation, it was found that shape sensing can be performed with less sensor placement. Our results demonstrate that the realistic sensor performance and sensor placement enable shape sensing of local structure of ship structure such as stiffened panel.

Visual perception, receiving a two-dimensional (2D) visual input, often constructs the three-dimensional (3D) perceptual image. Although there are generally multiple structures in the external world that give an equivalent two-dimensional retinal image, the perceptual process naturally and easily infer only one 3D structure as the solution. However, the following problems are not obvious at all: what kind of structure can be obtained as a 3D perceptual image from certain 2D information, and why do we get a three-dimensional perceptual image instead of a two-dimensional one. In the present study, we investigate this problem by untangling the Necker cube phenomenon, and propose a novel theory of three-dimensional visual perception from the viewpoint of the efficiency of information coding. Among the possible structures that can yield the 2D retinal image of the Necker cube, the structure of the typical three-dimensional perceptual image of the Necker cube maximizes the symmetry (in group theory). This maximization of symmetry is characterized by the pairs of adjoint functors (in category theory). Therefore, according to this proposed theory, "the Necker cube" in the three-dimensional space is perceived as the most efficient encoding of the two-dimensional retinal image.

Three-dimensional (3D) shape measurement of fringe projection profilometry (FPP) with high speed and accuracy is required in many applications. The measurement speed of FPP system is mainly limited by the low frame rate of pattern projection. Although defocusing binary patterns can be used to increase the measurement speed greatly, it will decrease the measurement depth. To this end, a novel triangular pattern generation method is proposed in this paper. By designing and projecting binary strip patterns with focused projector, images of triangular patterns can be then acquired with high frame rate. Fast and accurate 3D shape measurement can be finally obtained by using phase-shifting triangular patterns. Compared with the traditional sinusoidal patterns, the proposed method can improve the projection rate more than 4 times. Moreover, the proposed method will not decrease the measurement depth. Experimental results are given to confirm the validity of the proposed method.

Applying active occupant engagement into a responsive facade concept leads us to a transition from the facade regulatory function to the interactive phase. The Interactive facade has the capacity for hierarchically filtering daylight and real-time control, and preventing daylight discomfort. This research applied the combination of qualitative and quantitative methods for studying innovative daylight guide systems functions, relation with building forms and development of kinetic facade forms as advanced real-time daylight control. Literature referred to the responsive modular elements which can be adapted to dynamic daylight by continuously changing facade configurations. In particular, parametric decentralized facade's apertures interact with sun radiation based on relationship between external environment, interior space and occupant position as well. In this study, we develop a kinetic interactive facade with the capability to be transformed based on dynamic daylight and occupant position (functional scenario based) in order to meet visual comfort. Also, daylight parametric simulation investigates visual comfort performance provided by the kinetic facade forms through climate based daylight metrics. The simulation results prove high performance of the kinetic interactive facades for improving visual comfort regarding the base case. In particular, the three dimensional shape changes facade provides more visual comfort improvement than the two dimensional shape changes one regarding UDI, Exceed UDI and DGP metrics. Also, the results refer to multifunctional aspects of the three dimensional shape changes facade, as an advanced interactive daylighting system, which has a capability to control solar radiation in the facade ambient environment for preventing thermal discomfort.

This paper presents three-dimensional shape optimization of claw-pole motors. The claw-pole shape is determined from the binary state of hexahedral cells. The cell states are optimized to maximize induced voltage and minimize the field current using micro-genetic algorithm. The optimization is successfully carried out without time-consuming mesh generation.

This work aims at creating a universal software package for the development and testing of triangulation methods using structured lighting for measuring the three-dimensional geometry of objects in difficult ambient lighting conditions. As a result, a software package meeting the stated requirements is created. Lighting is based on the Fong model. A method for preloading objects is implemented to optimize the operation of the software package. An accelerated method for creating shadow maps is proposed and implemented. The developed software package is shown to successfully perform all required functions.

In order to study the micromechanical properties of functional microwires in three-dimensional space morphology, a performance testing device for functional microwires in three-dimensional morphology combined load mode was designed. First, the microwire material is introduced into the three-dimensional weaving process, and the cubic B-spline function curve is used to fit the shape of the three-dimensional microwire, and then the spatial configuration of the microwire is constructed. Secondly, based on the three-dimensional morphology of the microwire, the function and principle of the microwire in the compound loading mode are analyzed, and a three-dimensional testing device for the microwire is designed. Finally, the key components of the designed device were analyzed through simulation, and the key components of the test device were all within their yield limits, which verified the rationality of the test device.

This paper describes a Multiangle Snowflake Imager (MSI) designed to capture the pseudo-three-dimensional (3D) shape and the fall velocity of individual snowflakes larger than 1.5 mm in size. Four height-offset line-image scanners estimate fall velocities and the four-angle silhouettes are used to reconstruct the 3D snowflake shapes. The 3D shape reconstruction is tested using reference objects (spheres, spheroids, cubes, and plates). The four-silhouette method of the MSI improves the representation of the particle shape and volume compared to two-silhouette methods, such as the two-dimensional video disdrometer (2DVD). The volume (equivolumetric diameters) of snowflakes estimated by the four-silhouette method is approximately 44% (13%) smaller than that estimated by the two-silhouette method. The ability of the imager to measure the fall velocity and particle size distributions based on the silhouette width and the equivolumetric diameter of 3D-shaped particles is verified via a comparison with the 2DVD in three snowfall events.