Pattern Size Research Articles

Imaging the pediatric retina: An overview.

Recent decade has seen a shift in the causes of childhood blinding diseases from anterior segment to retinal disease in both developed and developing countries. The common retinal disorders are retinopathy of prematurity and vitreoretinal infections in neonates, congenital anomalies in infants, and vascular retinopathies including type 1 diabetes, tumors, and inherited retinal diseases in children (up to 12 years). Retinal imaging helps in diagnosis, management, follow up and prognostication in all these disorders. These imaging modalities include fundus photography, fluorescein angiography, ultrasonography, retinal vascular and structural studies, and electrodiagnosis. Over the decades there has been tremendous advances both in design (compact, multifunctional, tele-consult capable) and technology (wide- and ultra-wide field and noninvasive retinal angiography). These new advances have application in most of the pediatric retinal diseases though at most times the designs of new devices have remained confined to use in adults. Poor patient cooperation and insufficient attention span in children demand careful crafting of the devices. The newer attempts of hand-held retinal diagnostic devices are welcome additions in this direction. While much has been done, there is still much to do in the coming years. One of the compelling and immediate needs is the pediatric version of optical coherence tomography angiography. These needs and demands would increase many folds in future. A sound policy could be the simultaneous development of adult and pediatric version of all ophthalmic diagnostic devices, coupled with capacity building of trained medical personnel.

Age-Dependence of the Peripheral Defocus of the Isolated Human Crystalline Lens.

PurposeTo characterize the peripheral defocus of isolated human crystalline lenses and its age dependence.MethodsData were acquired on 116 isolated lenses from 99 human eyes (age range, 0.03–61 years; postmortem time, 40.1 ± 21.4 hours). Lenses were placed in a custom-built combined laser ray tracing and optical coherence tomography system that measures the slopes of rays refracted through the lens for on-axis and off-axis incidence angles. Ray slopes were measured by recording spot patterns as a function of axial position with an imaging sensor mounted on a positioning stage below the tissue chamber. Delivery angles ranged from –30° to +30° in 5° increments using a 6 mm × 6 mm raster scan with 0.5-mm spacing. Lens power at each angle was calculated by finding the axial position that minimizes the root-mean-square size of the spot pattern formed by the 49 central rays, corresponding to a 3-mm zone on-axis. The age dependence of the on-axis and off-axis optical power and the relative peripheral defocus (difference between off-axis and on-axis power) of lenses were quantified.ResultsAt all angles, lens power decreased significantly with age. Lens power increased with increasing delivery angle for all lenses, corresponding to a shift toward myopic peripheral defocus. There was a statistically significant decrease in the lens peripheral defocus with age.ConclusionsThe isolated human lens power increases with increasing field angle. The lens relative peripheral defocus decreases with age, which may contribute to the age-related changes of ocular peripheral defocus during refractive development.

Distribution and Size of Crab (Portunus pelagicus) in Betahwalang Waters, Demak, Central JavaSex Ratio, Size Distribution and Length-Weight Relationship of Portunus pelagicus Linnaeus, 1758 (Malacostraca : Portunidae) in Betahwalang, Demak, Central Java

Blue Swimming Crab (P. pelagicus, Linnaeus, 1758) is the main fisheries product from Betahwalang peoples. Fishing activity of Blue Swimming Crab by the fisherman almost every day in Betahwalang waters. Distribution and body size data of Blue Swimming Crab can be used for sustain management reference. The purpose of this study was to determine distribution pattern and body size of Blue Swimming Crab, started from July to November 2018 in Betahwalang waters, Demak. The data analyze consist of sex ratio, carapace width distribution and relationship between carapace width and body weight. 11790 samples Blue Swimming crab from Betahwalang waters consist of 7070 female crabs and 4720 male crabs. The result showed that sex-ratio between male and female crabs are balanced (1.0:1.37), with the most female crabs found at July and August. Body size distribution of male and female crabs are dominated in class 103-111 mm carapace width. Male and female crabs have a positive allometric on growth parameters, that means growth of the body weight is faster than carapace width. The result showed that Blue Swimming Crab in Betahwalang waters are support for sustainable fisheries.

The effect of carbon fibre stitching on the tensile behaviour of secondary bonded single- and double-lap composite joints

This paper presents a novel stitching method for enhancing the mechanical properties of secondary-bonded CFRP single- and double-lap joints. In this approach, holes were drilled in the secondary bonded joints and carbon fibre threads were stitched through the joints. The vacuum resin infusion technique was then used to integrate the threads with the joints. The tensile properties of the stitched joints were measured and compared with those offered by traditional bonded (unstitched) joints in order to investigate the potential of the stitching method. The experimental results show that by using this stitching method, the ultimate tensile strength of the stitched single- and double-lap joints are respectively 200% and 130% greater than the corresponding conventional bonded joints.A three-dimensional finite element analysis (FEA) has been undertaken to predict the mechanical response of the stitched joints. The numerical analysis showed that the stiffness degradation at the end of overlap area is held back by the stitching fibres. Finally, the semi-empirical formulae has been developed to investigate the effect of hole pattern and thread size on the joint behaviour. Both the numerical and theoretical predictions are validated against the corresponding experimental results with good correlation.

The Fabrication of Wrinkle‐Free Graphene Patterns on Ge(110) Substrate

A thermal expansion mismatch is inevitable for graphene grown on various substrates by chemical vapor deposition, which leads to the formation of wrinkles during post‐growth cooling. Wrinkles can degrade the superior properties of graphene and increase device‐to‐device inconsistency. To address this issue, wrinkle‐free graphene patterns are grown on Ge(110) substrate with the assistance of 5 × 1016 cm−2 Si ion implantation. The experimental data show that the wrinkle‐free graphene can grow on unimplanted areas, whereas no graphene is synthesized on Si ion implanted areas. Further research shows that the wrinkle‐free nature of graphene is closely related to the compressive strain distribution in graphene. The compressive strain in graphene is increased to a significant extent with an increase in the size of graphene patterns. When the compressive strain energy exceeds the wrinkle‐formation barrier, wrinkles emerge on the graphene, and the compressive strain decreases as a consequence. This research may help to understand the formation mechanisms of graphene wrinkles and promote the growth of wrinkle‐free graphene.

3D interactive garment parametric pattern-making and linkage editing based on constrained contour lines

PurposeThe purpose of this paper is to propose an interactive 2D–3D garment parametric pattern-making and linkage editing scheme that integrates clothing design, simulation and interaction to design 3D garments and 2D patterns. The proposed scheme has the potential to satisfy the individual needs of fashion industry, such as precise fit evaluation of the garment, interactive style editing with ease allowance and constrained contour lines in fashion design.Design/methodology/approachThe authors first construct a parametric pattern-making model for flat pattern design corresponding to the body dimensions. Then, the designing 2D patterns are stitched on a virtual 3D mannequin by performing a virtual try-on. If the customer is unsatisfied after the virtual try-on, the adjustable parameters (appearance parameters and fit parameters) can be adjusted using the 2D–3D linkage editing with hierarchical constrained contour lines, and the fit evaluation tool interactively provides the feedback.FindingsThe authors observed that the usability and efficiency of the existing garment pattern-making method simplifies the garment pattern-making process. The authors utilize an interactive garment parametric flat pattern-making model to generate an individualized garment flat pattern that effectively adjust and realize the local editing of the garment pattern-making. The 2D–3D linkage editing is then employed, which alters the size and shape of garment pattern for a precise human model fit of the 3D garment using hierarchical constrained contour lines. Various instances have validated the effectiveness of the proposed scheme, which can increase the reusability of the existing garment styles and improve the efficiency of fashion design.Research limitations/implicationsFirst, the authors do not consider the garment pattern-making design of sophisticated styles. Second, the authors do not directly consider complex garment shapes such as wrinkles, folds, multi-layer models and fabric physical properties.Originality/valueThe authors propose a pattern adjustment scheme that uses the 3D virtual try-on technology to avoid repetitions of reality-based fit tests and garment sample making in the designing process of clothing products. The proposed scheme provides interactive selections of garment patterns and sizes and renders modification tools for 3D garment designing and 2D garment pattern-making. The authors present the 2D–3D interactive linkage editing scheme for a custom-fit garment pattern based on the hierarchical constraint contour lines. The spatial relationship among the human body, pattern pieces and 3D garment model is adequately expressed, and the final design result of the garment pattern is obtained by constraint solving. Meanwhile, the tightness tension of different parts of the 3D garment is analyzed, and the fit and comfort of the garment are quantitatively evaluated.

The effect of building geometry on the size of aeolian deposition patterns: Scale model experiments at the beach

In sandy environments, like the beach-dune system, buildings not only affect the airflow, but also the aeolian sediment transport in their surroundings. In this study, we determine how the horizontal size of sediment deposition patterns around buildings depends on the building's dimensions. Four one-day experiments were conducted at the beach using box-shaped scale models. We tested 32 building geometries, where scale model height, width and length ranged between 0.3 and 2.0 m. The deposition patterns were substantial in size: the total length and width of the deposition area were up to an order of magnitude larger than the horizontal building dimensions. It was found that the size of upwind and downwind deposition patterns depended more on the building width perpendicular to the wind direction (w), than on the building height (h). Building length had little influence. Especially the combined effect of w and h correlated well with horizontal deposition size. This is expressed in a new scaling length B for deposition around buildings, with B=w2/3·h1/3. As a first validation, the spatial dimensions of the initial deposition patterns observed around a scale model of 2.5 × 12 × 2.5 m, placed at the beach for five weeks, showed good agreement with those predicted based on B.

Utility of Microhemorrhage as a Diagnostic Tool in Distinguishing Vestibular Schwannomas from other Cerebellopontine Angle (CPA) Tumors.

Although a majority of tumors in the Cerebellopontine Angle (CPA) are vestibular schwannomas (VS), other masses can also be seen in the region and differentiation of various CPA tumors, particularly meningiomas can be difficult on imaging alone. Treatment options may vary based on specific pathology of the CPA tumor. In this study, the presence of microhemorrhage (MH) and other imaging features such as size of lesion, cystic features and pattern of IAC extension, were evaluated as a tool in distinguishing VS from other CPA masses. A review of CPA masses in the last 11years at our institution was performed. All the pathology proven tumors with at least 1 pre-operative MRI were considered for analysis. A T2* GRE or SWI sequence was used to assess presence of MH within the lesion. Pattern of IAC extension ('centric' versus 'eccentric') of tumor was also evaluated. A total of 147 patients were reviewed out of which 102 patients (with T2* GRE or SWI) were included for analysis of MH. 57 patients (56%) had VS as the final histopathological diagnosis and 45 patients (44%) had other types of tumor. A sensitivity of 82% and a specificity of 98% was noted for the presence of MH favoring the diagnosis of VS from other tumors (p < 0.001). All meningiomas with IAC extension (25/31) showed an 'eccentric' pattern of extension into the canal. Visualization of MH and pattern of IAC extension is useful in the differentiation of schwannomas from other CPA masses, particularly meningiomas.

Examining the determinants of freight transport emissions using a fleet segmentation approach

Concerns over transport energy consumption and greenhouse gas emissions have lately prompted significant attention towards vehicle ownership patterns and the distributional implications of climate mitigation policies. This paper contributes to freight transport literature by examining how establishments can be meaningfully grouped using their fleet ownership pattern (size and composition) and how these segments vary in their freight travel pattern and CO2 emission levels. The analysis performed using an establishment-based freight survey dataset from Kerala, a coastal state in India, revealed five latent classes of fleet ownership. The determinants of freight transport emissions and the gross emitters in fleet segments are presented subsequently by analyzing how the establishment-level characteristics (employment, business age, industry sector, value density, and relative location) explain the variation in CO2 emissions. The study findings offer insights for designing effective carbon policy instruments and incentive schemes to regulate the establishment-level freight travel pattern and control transport emissions.

Modeling and analysis of material anisotropy-topology effects of 3D cellular structures fabricated by powder bed fusion additive manufacturing

For lightweight cellular structures fabricated via powder bed fusion additive manufacturing (PBF-AM), both the material anisotropy and the cellular topology design are both important design factors. In this work, a direct stiffness matrix-based analytical modeling approach was employed for the evaluation of material anisotropy-topology effects on three representative 3D cellular structures (auxetic, BCC and octahedral). The established models were verified via experimentation with samples fabricated by EB-PBF using Ti6Al4V as material, using the material anisotropy information established experimentally using single struts with different build orientations (0°, 15°, 30°, 45°, 60°, 75° and 90°). The predicted mechanical properties of the Ti6Al4V cellular structures showed good agreement with experimental results. It was shown that both the strength and elastic modulus anisotropy of the materials affect the strength of the cellular structures, which must be determined based on the topology design. In addition, the material anisotropy-topology effects on cellular structures of varying cellular pattern sizes were also investigated in order to quantify the pattern size effects. It was found that the pattern size effects and the material anisotropy effects can be decoupled during the design of the mechanical properties of these cellular structures.

A Novel Kite Cross Hexagonal Search Algorithm for Fast Block Motion Estimation

The performance quality and searching speed of Block Matching (BM) algorithm are affected by shapes and sizes of the search patterns used in the algorithm. In this paper, Kite Cross Hexagonal Search (KCHS) is proposed. This algorithm uses different search patterns (kite, cross, and hexagonal) to search for the best Motion Vector (MV). In first step, KCHS uses cross search pattern. In second step, it uses one of kite search patterns (up, down, left, or right depending on the first step). In subsequent steps, it uses large/small Hexagonal Search (HS) patterns. This new algorithm is compared with several known fast block matching algorithms. Comparisons are based on search points and Peak Signal to Noise Ratio (PSNR). According to results obtained in this paper, KCHS needs less search time than others algorithms and gives very acceptable performance quality.

Experimental analysis of fluid displacement and viscous fingering instability in fractured porous medium: effect of injection rate

Viscous fingering instability has been studied empirically by miscible flow displacement. Despite numerous experimental studies, there is little information regarding the fractured porous medium. The tests have been conducted in a rectangular porous medium, and the fluid was driven in the longitudinal direction. The generated fingering patterns are demonstrated and discussed based on injection rate and fracture orientation. Three porous models with 0°, 45° and 90° fractures were used in order to study the effect of fracture orientation. Quantitative parameters of fingering instability, such as sweep efficiency, headway position, and breakthrough time, have been measured by image processing techniques using MATLAB. It is shown that by increasing the injection rate, the size of the finger patterns slightly increased. Moreover, the effects of fractures on displacement behaviors are shown and explained. According to the results, zero degree fracture altered the rate of sweep efficiency and tip position the more significantly than other fractures. Furthermore, it was observed that by changing the direction of fractures from parallel to perpendicular to the flow direction, the breakthrough time increased consequently.

Sidewall chemical analysis of plasma-etched nano-patterns using tilted X-ray photoelectron spectroscopy combined with in-situ ion sputtering

A novel experimental technique for sidewall analysis of plasma-etched nano-patterns using tilted X-ray photoelectron spectroscopy (XPS) combined with in-situ ion sputtering was investigated. Complete removal of the residue layer (on the mask surface) and the mask layer using in-situ ion sputtering in the XPS chamber was conducted to reveal the sidewall information of the plasma-etched hole in SiO2 in addition to the trench in Si, after anisotropic plasma etching. The influence of the measured profile depth changes after adjusting the take-off angle in the sidewall chemistry of the plasma-etched hole in SiO2 and the trench in Si was examined. To demonstrate the analysis results, the sidewall compositions of the plasma-etched hole in SiO2 with various oxygen contents in the plasma were comparatively analyzed using XPS and Auger electron spectroscopy. It was observed that fluorinated carbon polymer (C-Fx, x ≤ 3) and SixOy (x ≤ 2, y ≤ 3) residue layers were formed on the hole in SiO2 and trench in Si sidewalls after C4F8/CH2F2/O2/Ar and HBr/Cl2 plasma etching, respectively. Thus, changes in the chemical characteristics of these sidewall etching residues were realized, revealing their dependency on the pattern size and type, plasma gas chemistry, and mask material. In addition, effectiveness of the dry cleaning process was evaluated using the tilted XPS combined with in-situ Ar ion sputtering.

Effect on microstructure and plastic deformation behavior of a Zr-based amorphous alloy by cooling rate control

In this study, Zr41.2Ti13.8Cu12.5Ni10Be22.5 amorphous alloys samples with the same diameter (8 mm) were prepared by using self-designed molds (viz. refractory steel, pure graphite, and copper molds) with different cooling capacities. Moreover, by eliminating the size effect, the effect of the cooling rate on the microstructure and compression deformation behavior of Zr41.2Ti13.8Cu12.5Ni10Be22.5 amorphous alloys was investigated. Differentiation of the cooling curves revealed that the instantaneous cooling rates of the alloy melt at the glass transition temperature (Tg) are 45, 52, and 64 K·s―1 for refractory steel, pure graphite, and copper molds, respectively. X-ray diffraction, differential scanning calorimetry, and high-resolution transmission electron microscopy analysis revealed that with the decrease in the cooling rate, trace icosahedral-like atomic clusters and nanocrystals appear in local areas of the amorphous alloy and that the amount of free volume decreases with the increase in the amount of icosahedra-like atomic clusters and nanocrystals. Compression test results revealed that the elastic strain, yield strength, and compressive strength of the amorphous alloy marginally change with the decrease in the cooling rate, while the plastic strain gradually increases. By fitting, the effective size of the vein-like pattern was linearly related to the enthalpy released during structural relaxation and plastic strain, indicating that at a low cooling rate, the trace nanocrystals in the amorphous alloy could not effectively improve its plasticity and that the amount of free volume mainly affects its plasticity.

Correlation between Ultrasonic Features of Medullary Thyroid Carcinoma and Cervical Lymph Node Metastasis

The aim of this study was to investigate the factors that affect cervical lymph node metastasis (CLNM) in individuals with medullary thyroid carcinoma (MTC) in terms of ultrasonic characteristics and other parameters. Single-factor χ2 analysis showed that the ultrasonic characteristics of tumor size >10 mm, unclear boundary, irregular pattern and capsular invasion, as well as pre-operative calcitonin level >302.50 pg/mL (p < 0.001) and age ≤52.50 y (p = 0.036), were risk factors for CLNM in individuals with MTC. Multivariate logistic regression analysis showed that age ≤52.50 y (odds ratio = 3.796; 95% confidence interval, 1.010–14.259; p = 0.048), irregular pattern (odds ratio = 5.262; 95% confidence interval, 1.200–23.084; p = 0.028) and tumor size >10 mm (odds ratio = 7.789; 95% confidence interval, 1.123–54.005; p = 0.038) were independent risk factors for CLNM in individuals with MTC. Individuals with MTC aged ≤52.50 y with an irregular pattern and tumor size >10 mm were more likely to develop CLNM. In addition, those with a pre-operative calcitonin level >302.50 pg/mL were more likely to have CLNM.

A dielectric resonator based line stripe miniaturized ultra‐wideband antenna for fifth‐generation applications

SummaryThis work presents an original dielectric resonator based line stripe miniature ultra‐wideband (UWB) antenna for 5G applications. The length, width, and height of the designed antenna are 23, 15, and 1.605 mm, respectively. The projected antenna prototype is composed of a simple line structure‐based modified scattered patch and a rectangular ground plane consisting of a saw tooth orientation in the upper end. A number of rectangular resonators are placed on both sides of the patch and ground to optimize the desired results. This technique ensures the lower operating band and made a significant improvement of efficiency without compromising the antenna size. The proposed design obtained the range of frequency bandwidth from 3.55 to 4.2 GHz under the −10‐dB scale, which covers the lower fifth‐generation (5G) communication band offered by Federal Communications Commission (FCC). The moderate gain and more than 80% radiation efficiency at a resonant point with strong fidelity factor confirms the usability and lower signal distortion of the antenna. The design offers an omnidirectional radiation pattern with 90° elevated directivity for cross polarization. This proposed design is compact in size and can be integrated into limited space around microwave circuitry with low manufacturing cost. The performance parameters like operating bandwidth, antenna size, and area of application, dielectric constant, fractional bandwidth, and omnidirectional radiation pattern were proposed as a suitable candidate for 5G application.

Kinematic Fields Measurement during Orthogonal Cutting Using Digital Images Correlation: A Review

Understanding the mechanism of chip formation during orthogonal cutting requires a local measurement of the displacement and strain fields in the cutting zone. These measurements can then be used in order to enhance/validate numerical simulation of metal cutting or calibrate material behavior laws for a better prediction of the thermomechanical loads inside the cutting zone. Particle tracking to identify the strain localization that is exhibited in the Adiabatic Shear Band (ASB) is a challenging task. These local measurements can be determined by images post-processing while using the Digital Image Correlation (DIC) technique or analytical models using streamline models or by micro grid analysis. Recently, the use of the DIC technique is widely increased. Texture quality has been shown to be an important factor. Various techniques of surface preparation are then discussed and classified in terms of the created pattern size. Tools for texture analysis are presented. The technique suitability for the kinematic fields measurement while using the DIC technique during machining is discussed. Various optical systems of the literature employed in the context of kinematic fields measurement during machining are discussed in this paper. The recent advances on the design of optical systems are given. Finally, the results of kinematic fields measurement during machining metallic alloys are analyzed.

Electrically Conductive Micropatterned Polyaniline-Poly(ethylene glycol) Composite Hydrogel.

Hydrogel substrate-based micropatterns can be adjusted using the pattern shape and size, affecting cell behaviors such as proliferation and differentiation under various cellular environment parameters. An electrically conductive hydrogel pattern system mimics the native muscle tissue environment. In this study, we incorporated polyaniline (PANi) in a poly(ethylene glycol) (PEG) hydrogel matrix through UV-induced photolithography with photomasks, and electrically conductive hydrogel micropatterns were generated within a few seconds. The electrical conductance of the PANi/PEG hydrogel was 30.5 ± 0.5 mS/cm. C2C12 myoblasts were cultured on the resulting substrate, and the cells adhered selectively to the PANi/PEG hydrogel regions. Myogenic differentiation of the C2C12 cells was induced, and the alignment of myotubes was consistent with the arrangement of the line pattern. The expression of myosin heavy chain on the line pattern showed potential as a substrate for myogenic cell functionalization.

Effectiveness of Super-Resolution Technique on Vegetation Indices

The identification and interpretation of remote sensed (RS) objects in an image depend on how well the sensor captures the region. In rare cases, RS images may be vulnerable to a lack of interpretability issues in some parts of the image due to the sensor's limits and preprocessing techniques. Conventionally, the interpretation of the land cover pattern's shape and size is apparent when the distance between the sensor and object is closer to the visualization level of objects and viable with digital airborne imagery. In this paper, an integration of the Super-Resolution (SR) technique in the high-resolution imagery to achieve the closer visualization level for mapping the vegetation is proposed. This approach enables the higher interpretive potential to define the land pattern's shape and size with very high spatial resolution, closer proximity, detailed and distinguishable patterns. This approach helps to precisely predict the total vegetated study area for land use and land cover changes (LULCC) and chlorophyll-rich vegetation applications. The proposed algorithm is carried out in two phases. In the first phase, the SR technique applied test images are tested for vegetation detection and mapping the vegetation information in a region with fourteen vegetation indices. In the second phase, similar testing is done without applying SR for input test images. The experiment revealed that test images using the SR technique yielded higher average values of 5 percent and 1 percent for the Normalized Difference Vegetation Index (NDVI) and Fractional Vegetation Cover (FVC), respectively, as compared to images tested using the non-SR technique.

Localization of plastic deformation in stretching plates: effect of crystalline structure

The integration of the polycrystalline structure in the simulation of stretching plates, performed by the random generation of a grain aggregate and a set of lattice orientations, gives new insights into the phenomenon of plastic strain localization in the form of necking, albeit well predicted at the scale of continuum by instability analysis. A transition is displayed from initial grain scale heterogeneity, with some connection to crystal lattice orientation towards stress axes, to the onset of macroscopic localization patterns. Depending on the number of grains and on the stretching rate, it seems that a competition emerges between a “weakest link” process for which the final necks are located in places where initial deformation is high and an instable mode controlled process during which larger patterns emerge driving the location of the final necks. At high stretching rates, it seems that the second effect is enhanced with, accordingly, a pattern size almost insensitive to the grain size and a limited variability with the grain structure occurrence.