Row Of Points Research Articles

Experiment on the Uniformity of Internal Lighting in Zigzag Photovoltaic Greenhouses by Grating Plates

As one of the main projects of facility agriculture promotion, the PV (photovoltaic) greenhouse has the problems of PV power generation competing for light with crop production, strong indoor chiaroscuro, and uneven light distribution. The internal light uniformity is tested by a zigzag greenhouse model to compare the light transmission effects of different light-transmitting materials applied to PV greenhouses. Altogether, 20 line/inch 3 mm and 30 line/inch 3 mm, 40 line/inch 2 mm, 25 line/inch 4 mm grating plates and 2 mm and 3 mm thick ordinary glass were used as light-transmitting components, and the light intensity and light uniformity in the greenhouse were the measurement indicators. The results show that the use of grating plates as covering material can improve the light intensity at the intersection of light and dark, but the overall light transmittance is not as good as glass because it is plastic, which ages easily with low light transmittance. It can also improve the use of land under the shade of PV modules to provide a better growth environment for crops. The test results show that using grating plates can maximize the light intensity of the greenhouse and solve the problem of uneven distribution of light inside the greenhouse caused by obstruction of PV equipment and greenhouse framework. In sunny weather, the light intensity in three rows of the measurement points at the north side in the greenhouse is greater than 20,000 Lx, and the light environment in other areas is between 5000 Lx and 20,000 Lx, which is suitable for planting shade-loving crops.

Comparison of baseline drifts using three reflector blocks versus using a single reflector block for the calibration of wall-mounted Respiratory Gating for Scanner (RGSC) camera integrated with a CT.

The calibration of the Respiratory Gating for SCanner (RGSC) system is critical to achieve better and more stable accuracy. The current procedure for a wall-mounted RGSC system has a relatively large residual error. To compare the baseline drifts in the image acquisition of DIBH using three reflector blocks versus using a single reflector block in the calibration of a wall-mounted RGSC camera system. Varian provides a calibration plate with three rows of calibration points: each row is separated by 15cm longitudinally and by 10cm laterally. In Varian's single-block calibration method, the reflector block was first placed on the center point of the calibration plate and aligned with the scanner isocenter. The calibration took a picture of the block, then placed the block on the other eight points sequentially. In the proposed three-block method, we placed three reflector blocks on the center row, with the center block aligned with the isocenter, and we took a picture of the center block by manually blocking the other two blocks in calibration. By moving the couch longitudinally in or out 15cm, the calibration goes through all nine points. Monte Carlo simulation was done using Matlab to analyze the calibration matrix eigenvalue characteristics. For a typical scan length of 40cm of DIBH, the residual baseline drift in simulated DIBH is 0.02±0.03 versus 0.30±0.12cm for three-block calibration and single-block calibration, respectively. To achieve 0.5mm tolerance for the eigenvalue, the laser and reflector box should be within ±3mm uncertainties based on the eigenvalue simulation. Three-block calibration method effectively removes baseline drift caused by couch movement in DIBH/4D CT scan for the wall-mounted camera while the single-block calibration method still has significant residual baseline drift.

How farmland birds react to traffic noise?

The effect of vehicle noise on farmland birds living in the vicinity of very busy roads was investigated. The study was conducted on two plots of crop fields located near national roads Nr. 12 and 19, the most important trunk roads in Poland and the eastern part of the Europe. The results of the current study are of wide relevance because crop fields are the dominant landscape type in both Poland and Europe. The conservation of the animals, including birds, living in such habitats is a priority issue in view of the strong pressure from human activities and the intensification of agriculture. The fieldwork was carried out in monthly from April to June 2020 and included counting birds in three rows of listening-observation points situated at 50, 150 and 250 m from the roads. At each observation point, all farmland and meadow birds seen and heard during a five-minute period were recorded, as was the maximum ambient noise level during this time. With increasing distance from the roads, the level of noise decreased while the number of individual birds and observed species increased. Most of the birds recorded, like skylark, lapwing, whinchat, yellowhammer, meadow pipit, pheasant, and common quail, avoided the vicinity of the roads. In contrast, the abundant yellow wagtail appeared to be insensitive to traffic noise and was evenly distributed over the two study plots. The roads and their associated traffic noise had a negative impact over a distance of about 100 m. At that distance, noise levels above 53–60 dB led to sharp falls in bird densities. Bird mortality due to collisions with vehicles was low because noise combined with the lack of attractive roadside habitats effectively deterred birds from the vicinity of the roads.

Using Automated Seepage Meters to Quantify the Spatial Variability and Net Flux of Groundwater to a Stream

AbstractWe utilized 251 measurements from a recently developed automated seepage meter (ASM) in streambeds in the Nebraska Sand Hills, USA to investigate the small‐scale spatial variability of groundwater seepage flux (q) and the ability of the ASM to estimate mean q at larger scales. Small‐scale spatial variability of q was analyzed in five dense arrays, each covering an area of 13.5–28.0 m2 (169 total point measurements). Streambed vertical hydraulic conductivity (K) was also measured. Results provided: (a) high‐resolution contour plots of q and K, (b) anisotropic semi‐variograms demonstrating greater correlation scales of q and K along the stream length than across the stream width, and (c) the number of rows of points (perpendicular to streamflow) needed to represent the groundwater flux of areas up to 28.0 m2. The findings suggest that representative streambed measurements are best conducted perpendicular to streamflow to accommodate larger seepage flux heterogeneity in this direction and minimize sampling redundancy. To investigate the ASM's ability to produce accurate mean q at larger scales, seepage meters were deployed in four stream reaches (170–890 m), arranged in three to six transects (three to eight points each) per reach across the channel. In each reach, the mean seepage flux from ASMs was compared to the seepage flux from bromide tracer dilution. Agreement between the two methods indicates the viability of a modest number of seepage meter measurements to determine the overall groundwater flux to the stream and can guide sampling for solutes and environmental tracers.

The soil aggregate structure as a marker of the ecological niche of the micromollusc Vallonia pulchella

The article discusses the role of the soil aggregate structure in quantifying the marginality and specialisation axes of the ecological niche of the micromollusc Vallonia pulchella (Muller 1774) that inhabits technosols. The experimental polygon consisted of 105 samples located within 7 transects (15 samples each). The distance between rows of sampling points was 3 m. The average density of V. pulchella was 1393 ind.∙m–2. The soil aggregate fraction of 1–5 mm was found to be predominant within the technosol. The spatial variation of aggregate fractions was characterised by a moderate level of the spatial dependence. It was impossible to choose an adequate covariance model from among the traditional ones to interpolate the spatial variation of aggregate fractions, and only the Matérn model was best suited. The axis of marginality and specialisation of the V. pulchella ecological niche projected in soil aggregate fractions was significantly different from a random alternative. The ecological niche of the V. pulchella was presented by integral variables, such as the axis of marginality and specialisation, which were the basis to build a map of the spatial variation of the habitat suitability index. The marginality of the V. pulchella ecological niche correlates with soil penetration resistance indicators at depths ranging from 0–5 to 20–25 cm, soil humidity, acidity, and aeration. The specialisation correlates with the soil mechanical impedance at 25–35 cm, nitrogen content, and the soil acidity regime.

Determination of the through-plane profile of vanadium species in hydrated Nafion studied with micro X-ray absorption near-edge structure spectroscopy - proof of concept.

Vanadium-ion transport through the polymer membrane results in a significant decrease in the capacity of vanadium redox flow batteries. It is assumed that five vanadium species are involved in this process. Micro X-ray absorption near-edge structure spectroscopy (micro-XANES) is a potent method to study chemical reactions during vanadium transport inside the membrane. In this work, protocols for micro-XANES measurements were developed to enable through-plane characterization of the vanadium species in Nafion 117 on beamline P06 of the PETRA III synchrotron radiation facility (DESY, Hamburg, Germany). A Kapton tube diffusion cell with a diameter of 3 mm was constructed. The tube diameter was chosen in order to accommodate laminar flow for cryogenic cooling while allowing easy handling of the cell components by hand. A vertical step size of 2.5 µm and a horizontal step size of 5 µm provided sufficient resolution to resolve the profile and good statistics after summing up horizontal rows of scan points. The beam was confined in the horizontal plane to account for the waviness of the membrane. The diffusion of vanadium ions during measurement was inhibited by the cryogenic cooling. Vanadium oxidation, e.g. by water radiolysis (water percentage in the hydrated membrane ∼23 wt%), was mitigated by the cryogenic cooling and by minimizing the dwell time per pixel to 5 ms. Thus, the photo-induced oxidation of V3+ in the focused beam could be limited to 10%. In diffusion experiments, Nafion inside the diffusion cell was exposed on one side to V3+ electrolyte and on the other side to VO2+. The ions were allowed to diffuse across the through-plane orientation of the membrane during one of two short defrost times (200 s and 600 s). Subsequent micro-XANES measurements showed the formation of VO2+ from V3+ and VO2+ inside the water body of Nafion. This result proves the suitability of the experimental setup as a powerful tool for the determination of the profile of vanadium species in Nafion and other ionomeric membranes.

МОДЕЛИРОВАНИЕ РАБОЧИХ ПОВЕРХНОСТЕЙ ПРОМЫШЛЕННЫХ ИЗДЕЛИЙ НА ОСНОВЕ МАССИВА ТОЧЕК

The formation of a geometric model of a product according to a real physical sample requires the development of methods for modeling surfaces according to specified conditions. It is advisable to use such methods when modeling complex dynamic surfaces, which include surfaces whose functional purpose is to interact with the environment. When designing dynamic surfaces, it is necessary to ensure the laminar nature of the flow around them. When modeling surfaces based on a wireframe, the properties of surfaces are provided by the properties of its elements - flat and spatial curved lines. From a geometrical point of view, laminar flow can be achieved due to the regular change in curvature and torsion along the lines belonging to the surface. The article has developed a method for forming ruled frameworks of surfaces based on an array of points. From the original array of points, subsets are selected - point rows, on the basis of which linear elements of the surface frame are formed. The wireframe is based on a guideline family and a curved line generator family. Methods for the formation of linear elements of the frame with the provision of regular changes in geometric characteristics along the curve while monitoring the occurrence of singular points are proposed. The specified properties of the framing elements provide the required surface properties. The developed method was tested when modeling functional surfaces that limit the interscapular channel of a turbocharger impeller. Further development of the developed method is aimed at increasing its versatility and adaptability to the requirements of specific applied problems. This problem can be solved by increasing the conditions imposed on the bypass by increasing the number of shaping parameters. Key words: discretely represented curve, tangent, monotonic change of curvature, normal, radius of curvature, center of curvature.

Non-hyperoctahedral categories of two-colored partitions part I: new categories

Compact quantum groups can be studied by investigating their representation categories in analogy to the Schur–Weyl/Tannaka–Krein approach. For the special class of (unitary) “easy” quantum groups, these categories arise from a combinatorial structure: rows of two-colored points form the objects, partitions of two such rows the morphisms. Vertical/horizontal concatenation and reflection give composition, monoidal product and involution. Of the four possible classes {mathcal {O}}, {mathcal {B}}, {mathcal {S}} and {mathcal {H}} of such categories (inspired, respectively, by the classical orthogonal, bistochastic, symmetric and hyperoctahedral groups), we treat the first three—the non-hyperoctahedral ones. We introduce many new examples of such categories. They are defined in terms of subtle combinations of block size, coloring and non-crossing conditions. This article is part of an effort to classify all non-hyperoctahedral categories of two-colored partitions. It is purely combinatorial in nature. The quantum group aspects are left out.

Peridynamic modeling of composite laminates with material coupling and transverse shear deformation

This study presents a new state-based PeriDynamic (PD) model of a composite laminate with arbitrary laminate layup; it captures all types of material couplings in the presence of transverse shear deformation. It consists of normal and shear bonds instead of fiber and matrix bonds to allow arbitrary fiber orientations. Also, rotational degrees of freedom are included in the equilibrium equations in order to evaluate the transverse shear angle and curvature. Mindlin-Reissner plate theory, employed in this model, permits the use of existing composite constitutive law which leads to the coupling between different deformation modes. In addition, a quasi-local boundary condition applied only to the first row of material points avoids the approximation of nonlocal boundary values. The accuracy of this model is verified against benchmark solutions, and validated by comparison with experimental results.

Cyclic order: a geometric analysis

Concepts of order play an important role in many branches of mathematics. We start the article with an analysis of the notion of cyclic order in algebraic structures, which includes a characterization of cyclically ordered groups by cyclic cones and the introduction of the notion of a cyclically ordered field. We then study the role of cyclic order in the foundations of geometry. In Euclidean and in absolute geometry, order structures are introduced by linear orders (see Hilbert in Grundlagen der Geometrie, Teubner, Stuttgart, 1972; Coxeter in Introduction to geometry, Wiley, New York, 1961; Sperner in Beziehungen zwischen geometrischer und algebraischer Anordnung. Sitzungsberichte der Heidelberger Akademie der Wissenschaften, 1949; Bachmann in Aufbau der Geometrie aus dem Spiegelungsbegriff, Springer, Heidelberg, 1973; H Struve and R Struve in J Geom 105:419–447, 2014; R Struve in J Geom 106:551–570, 2015). This excludes elliptic geometry. We show that the notion of cyclic order (on pencils of lines) allows the introduction of order structures in a unified way (including the elliptic case) and corresponds on the algebraic side to a linear order of the associated coordinate field. In addition we prove that the three classical geometries (Euclidean, hyperbolic, and elliptic) over fields K of characteristic $$\ne 2$$ are orderable if and only if a separation relation on rows of collinear points and a separation relation on pencils of concurrent lines can be defined which are ‘compatible’. The article closes with a geometric interpretation of cyclically ordered fields as $$\hbox {Gau}\ss \hbox {ian}$$ coordinate fields of Euclidean Hilbert planes.

THE RESEARCH LAYOUT OF IMAGE CONTROL POINTS FOR 1:1000 B LEVEL DIGITAL ELEVATION MODEL PRODUCTION BASED ON UAV IN PLAIN AREA

Abstract. With the advent of the era of big data, traditional measurement techniques have been difficult to meet the information extraction required by contemporary measurement products, and light UAV （Unmanned Aerial Vehicles）was used to mapping is one of the development trends of aerial photogrammetry in China. When data is processed on aerial photography, the control points in the measurement area directly affect the accuracy of the later mapping results as the basis of mathematical calculation. However, the traditional aerial photogrammetry lays out the number of image control points according to a wide range of industry specifications, For example, lay Leveling control point at four corners + a row of elevation control points is lay at both ends of the area and lay Leveling control point at four corners + two vertical framed air routes at both ends of the zone (Zhang, J. Q., 2009),there are no specific method for the number of image control points to achieve a certain scale accuracy. As a result, there are too many or too few image control points in different topography and different scales. Measured by the error, image point density and reasonable layout of the data acquisition of the Trimble UX5 UAV, The causes of the errors are analyzed, and the precise data are obtained by comparing the experiments. Based on this, the relationship between changing the density of image control points and reasonable location is analyzed through the typical plain survey area of 0.718 km2. Designing four layout schemes of Image control points, taking the national standard as the standard, four groups of data are studied by comparing and analyzing GPS acquisition data with photogrammetry mapping data of Wuhan VISIONEK INC MapMatrix software. Through experimental analysis, the results show that the experimental data show that the light UAV can satisfy the production of 1:1000 B level digital elevation model in plain area when the image resolution is 350 dpi, the line height is controlled at 180 ± 10 m and the density of image control point is more than 9/km2. At the same time, this image control point layout method is used reasonably can reduce the workload of the field, improve work efficiency, and also help to speed up the calculation of huge amount of aerial survey data so as to produce high-precision digital products.

Adjustable temperature array for characterizing ecological and evolutionary effects on thermal physiology

Abstract To accurately characterize a species’ thermal niche and aid in predicting effects of climate change we must not only include information on thermal tolerances and physiological responses to changing temperatures, but also incorporate ecological effects and evolutionary processes that may shape a species’ niche. However, quickly and practically collecting data on key factors such as adaptation potential, behaviour, effects of species interactions, plasticity and thermal tolerances is logistically challenging. We have therefore created an adjustable temperature array (ATA) to assist with experimental ecology and evolution research. ATA’s are a row of independent temperature points controlled and set by the user and made from commercially available parts. This allows the user to create unique thermal landscapes relevant to their study organism(s) and question(s). Further, the option of using an enclosed cage allows the user to answer questions at the individual, population, or community level in the context of changing thermal environments. ATA’s are able to be user‐set to constant or dynamic temperature regimes and are designed for use on small animals (e.g. fruit flies, beetles, mosquitoes) or plants (e.g. germinating seeds). We have tested and confirmed the accuracy of the ATA to several thermal landscapes that would be useful for experimental ecology and evolution, including: (a) coarse resolution of a broad thermal niche ranging from 12° to 42°C in 2°C intervals (R2 = 0.998); (b) fine resolution of a narrow thermal niche ranging from 15° to 32°C in 1°C intervals (R2 = 0.997); (c) a pyramid‐shaped niche consisting of a gradient from 14° to 30°C in 2°C intervals (R2 = 0.997); and (d) a very narrow thermal niche with replicate thermal resources ranging from 26.5° to 34°C in 1.5°C intervals (R2 = 0.989). The equipment described here is an important tool for thermal niche studies and will aid in gathering information on effects of ecological and evolutionary processes to create a comprehensive picture of species responses to climate change.

GOLD APPLIQUES AFFIXED TO THE WOODEN BOWLS FROM THE PERESCHEPINE BURIAL GROUND NEAR BELSK

The article is devoted to the analysis of gold plaques on wooden vessels from the Pereshchepino cemetery near Belsk, which are among the brightest indicators of Scythian culture and mark the distribution of this category of funeral equipment in the Dnieper forest-steppe Left Bank in the middle — second half of the 5th century BC. Items considered are represented by several subject-stylistic groups, among which there are plaques decorated with geometric patterns (a double row of convex points), and plaques with various zoomorphic motifs (recumbent stag, head of a bird of prey). The images differ in local specificity and have an original interpretation of individual details. First of all, it concerns the motif of recumbent stag, which demonstrate iconographic dynamics and with the involvement of materials from neighboring territories indicate the formation in the «late» V — first decades of the 4th centuries BC a «forest-steppe» type of images of this animal. Objects of animal style from forest-steppe areas of Ukraine are an important component of the Scythian art of Eastern Europe and must be taken into account when analyzing the genesis of this phenomenon.

INTERPOLATION AND APPROXIMATION BY RATIONAL CURVES OF BEZIER AND NURBS-CURVES

Relevance. Rational Bezier curves and NURBS curves are widely used in modeling curvilinear objects due to the great flexibility and efficiency of the method. Therefore, it is relevant to develop an interpolation method and approximation by these curves of a discrete series of points both in the plane and in three-dimensional space. Method. The work is devoted to the development of a new approach to interpolation and approximations curve fitting, represented by a set of discrete points. The analytical description of the desired curve is implemented using a rational Bezier curve and a NURBS-curve. To solve this problem, two approaches are proposed. The first approach is that the weights of the points are set in advance and then the coordinates of the points of the interpolating or approximating rational Bezier curve as well as the NURBS-curve are calculated. The second approach is that the coordinates of the points are set in advance and then the weights of the control points of the Bezier curve as well as the NURBS-curve are calculated. At the beginning of the process, are set not only coordinates, but also parameters are set to a discrete row of points, that is, each point has the following definition: T (x, y, u) on the plane or T (x, y, z, u) in the three-dimensional space, where u - parameter. To solve the interpolation problem, a system of linear equations is created in which each equation reflects the equality between the analytical formula for a curve and a given point. Moreover, the number of interpolated points cannot be more than the order of the interpolating curve. Thus, we have a system of N linear equations, where N is the number of points equal to the number of points of the curve. Unknown are N control points of the desired curve. Moreover, in the first approach, the unknowns are coordinates of control points, and in the second weights of points.To solve the approximation problem, the Least Squares method is used. In the beginning, a sum of squared functional of the terms of the differences between the analytic formula of the curve and the coordinate of the given point is created. The optimization problem of minimizing this functional is solved. For this, a system of linear equations is created., each equation of which is a derivative of the functional with respect to a given parameter and equated to zero. In the first approach, the desired parameters are the coordinates of points, and in the second weights of points. Results.Two methods of interpolation and approximation of a point series by rational Bezier curves and NURBS-curves were developed. Conclusions. The test cases carried out using computer programs and visualization of results confirm the validity of the proposed methods.

111 10 Years of Clinical Experience Using Point of Care Non Cultured Autologous Skin Cell Suspension

Time to healing is a key driver of scar outcome in the repair of skin post burn injury. Autologous skin cell suspension has facilitated early intervention or wound healing in isolation in partial thickness injuries and in combination with traditional techniques in deeper injuries with limited donor sites. The aim of the presentation is the analysis of the impact of the introduction of cell based therapies into a clinical model of care in a health system providing burn care to a population of 2.5 million The data captured prospectively from the point of injury to the 1 year follow up was analysed retrospectively. A comprehensive data base has been well established to include the injury details, interventions and an outcome battery considering functional psychological and aesthetic outcomes at multiple time points. The data was subject to a data hack process followed by in-depth data analytics using 1.2 million rows of data points. In a 10 year period the cell based therapy technique was used in 3500 cases, 9% scar revision, 90% acute burn injury and 1% miscellaneous wounds. Of the cases requiring surgical intervention 12% received SSG alone, 48% SSG and cells and 40% cells alone. The use of cell therapies was associated with a reduction in the number of surgical procedures, with earlier intervention and reduction in time to healing and length of stay. When using a cumulative outcome index the intervention within 1 week of injury was associated with significant improvement at 3 months which was maintained at 1 year post injury. Cell based therapies are associated with earlier intervention and associated reduction in scarring and measurable improvement in outcomes. Since evolving from cultured epithelial autograft sheets to suspension in 1995 then onto non cultured skin cell suspension in 1998, the use of skin cell therapies has become integrated into the standard of care. The results need to be taken in the context of a comprehensive model of care which focuses on every intervention from the time of injury to optimise marginal gains along the clinical pathway.

Nowy skarb trzcinieckiego kręgu kulturowego z Brzegu, stan. 3, gm. Rzeczyca, pow. Tomaszów Mazowiecki, woj. łódzkie

The paper presents a newly discovered hoard of bronze ornaments, which was found in November 2014 in Brzeg,Rzeczyca commune, Tomaszow Mazowiecki district (Fig. 1). After the initial analysis of the artefacts included in thedeposit, it was found that there were 4 oval bronze plates with eyelet, decorated with two rows of ambient points embossedfrom the bottom, 35 pipe-shaped salta leone coils with a total length of 2,941 m and fragments of a pottery vessel inwhich the bronze ornaments were placed. The pot belongs to the G123 variant (Gorski 2007), with an underlined shoulderand a neck folded outwards, with a slightly thickened rounded/truncated edge, the bottom is not separated (Fig. 2: 1).Spectrometric analysis has shown that all artefacts belong to high-tin bronzes (Table 1). After conducting a formal analysis,mainly of the metal artefacts included in the hoard, and to a lesser extent taking into account the discovered vessel, thetime when the hoard from Brzeg was deposited, should be located in the BrD-HA1 phases, which corresponds to the rangeof 1350-1150 BC in absolute dating

Development of high-speed camera hardware and software package to evaluate real-time electric seed meter accuracy of a variable rate planter

Electric drive seed metering systems have become common for planting row-crop seed to accommodate increased machine size and planting speeds and to allow individual row unit-control that enable site-specific planting for spatially sensitive areas and contour farming. Seed singulation (a measurement of singulated seeds, misses, and multiples) is critical requirement when adopting high speed planting. However, current planting controllers fail to indicate whether singulation errors occurred due to operator-based behaviors such as speed changes, headland operation, point rows and contour farming at varying speed transitions (accelerations/decelerations). Therefore this study was conducted to understand a seed metering system’s ability to singulate seed under typical scenarios with specific objectives to (1) quantify electric seed metering accuracy using high-speed imaging and (2) identify machine operating states that impact seeding accuracy. A Horsch Maestro 24.30 planter was sent commands to plant at constant speeds of 7.2, 9.7, 12.0kph while accelerating/decelerating at 2.4 and 4.8kph/s from/to a stop and between speeds. The planter was sent commands to plant around contours at varying radii (20, 40, 80, 150m) at varying speeds (i.e., 0, 2.4, 4.8, 6.4, 7.2, 9.7, 12.1, 12.9, 14.5, 16.1kph). Simulations were conducted at two rates (44,550 and 89,110seedsha−1). A high-speed imaging system was developed using LabVIEW to record real-time seed meter singulation at 300frames/s by combining planting machine states with seed tube sensor data and vision based seed measurements to quantify single count seeds, misses, and multiples. When planting from 2.4kph to 16.1kph, results showed an average singulation of 98.45% where errors nearly doubled with fast accelerations and decelerations and abrupt changes such as a shift during headland turns. Overall, planting above 1250seeds per minute resulted in an increased number of singulation errors. The vision based measurements were within 0.8±0.2% of the commercial seed tube sensors. The seed per minute value which provided optimal seed singulation can be used as a control parameter by technology users and manufactures to select optimal operating parameters to achieve target singulation rates. The methodology provided optimal machine conditions and operator behaviors to achieve a target percent singulation by identifying scenarios which increase singulation by minimizing misses and multiples.

A near row matching approach to prediction of multiple precipitation crystallography of compound precipitates and its application to a Mg/Mg2Sn system

Sharp faceted interfaces are often observed between compound precipitates and matrix phases, which are remarkably different in their lattice parameters. Multiple orientation relationships (ORs) corresponding to various faceted interfaces tend to coexist in one alloy. A near row matching (NRM) approach is proposed for a systematic investigation of ORs corresponding to potential preferred interfaces. Unlike a common practice to search for misorientations corresponding to low sigma grain boundaries associated with matching periodicity in three dimensions (3D), this approach directly searches for ORs that permit local 2D periodic good matching structures in preferred interfaces. The calculation method consists of two simple steps to evaluate matching within and between rows of lattice points. The method has been applied to a Mg2Sn/Mg system. Ten of the forty-four predicted facets agree with the experimental observations, for the cases that the preferred facets can be described (approximately) by low index planes of the precipitates. The predictions can cover all known observations, if limited high index planes are included as candidates. Each observed facet is characterized with a periodic pattern of good matching sites (GMSs) in localized regions. NRM is a necessary condition for the existence of a periodic GMS pattern. The agreement between the calculation results and experimental results confirms the important role of periodic matching in the development of preferred interfaces and their corresponding ORs. It also demonstrates the usefulness of geometric matching study for quantitative predictions of potential preferred interfaces.

Image distortion correction for micromanipulation system based on SLM microscopic vision.

Stereo light microscope (SLM) simulates stereo imaging principle of human eyes. Microscopic vision system based on SLM has become an important visual tool for micro measurement, micromanipulation, and microinjection. We develop a micromanipulation system based on SLM and present an image distortion correction method. We mainly correct two kinds of image distortions: lateral and vertical distortion. Distortion correction consists of two steps. First, a linear fitting algorithm for each row or column of target points is developed, and the fitting errors are calculated. If the fitting errors are smaller than a given threshold, the linear fitting results are kept and used. Otherwise polynomial fitting procedure will be used. Second, the parallelism of straight lines is corrected. The results show that a line in world coordinate frame (WCF) is not necessarily a straight line in image coordinate frame (ICF), or two parallel lines in WCF may be not parallel in ICF. Distortion correction can restore the parallel and linear relationship. For distorted left and right images, the magnitude of distortion exceeds 6 pixels and 4 pixels in the horizontal direction, and 1.2 pixels and 1.7 pixels in the vertical direction, respectively. After corrected, for left and right image, distortion can be reduced to 0.8 pixels and 0.7 pixels in the horizontal direction, and 0.96 pixels and 1.3 pixels in the vertical direction, respectively. The results show that distortion parameters obtained from the proposed method can effectively correct distorted images.

Can local NURBS refinement be achieved by modifying only the user interface?

NURBS patches have a serious restriction: they are constrained to a strict rectangular topology. This means that a request to insert a single new control point will cause a row of control points to appear across the NURBS patch, a global refinement of control. We investigate a method that can hide unwanted control points from the user so that the user’s interaction is with local, rather than global, refinement. Our method requires only straightforward modification of the user interface and the data structures that represent the control mesh, making it simpler than alternatives that use hierarchical or T-constructions. Our results show that our method is effective in many cases but has limitations where inserting a single new control point in certain cases will still cause a cascade of new control points to appear across the NURBS patch.