Estimating the normal vector field on the boundary of discrete 3D objects is essential for rendering and image measurement problems. Most of the existing algorithms do not provide an accurate determination of the normal vector field for shapes that present edges. We propose here a new and simple computational method to obtain accurate results on all types of shapes whatever their degree of local convexity. The presented method is based on the analysis of the gradient vector field of the distance map of the object. Some results on simulated data and snow images from X-ray tomography are presented and discussed. Keywords: discrete geometry, distance map, normalvectors, snow.
The alignment of the contact normalvectors in the direction of the major principal stress as deformation progresses is in agreement with the findings reported by Fonseca et al. (2013, 2016), for which pure geometrical considerations were used to identify the contacts and the associate normalvectors. When comparing the results from the geometrical approach and the active contacts approach, the aspect worth mentioning is the very small number of vector with orientations closer to horizontal found in the latter. Despite the sands being different (Fonseca and co-authors used an intact locked sand), this observation seems to suggest that the contacts for which the normal vector is nearly horizontal are not transmitting stress.
from such segments. A data-driven approach is applied; no pre-defined building models are used. Figure 2 shows a general workflow of a developed methodology. First, points on bare earth and points with low height are filtered out. Second, a plane fitting to its neighbourhood and a corresponding normal vector are assigned to each point on artificial and natural objects. Based on similarity of normalvectors, points are divided to segments. Segments boundaries are geometrically linked together to form a roof outline. Finally, the outlines obtained are regularised. A detailed description of each processing step follows. The proposed method- ology and its implementation require setting of several parameters. Their values are in the current implementation set automatically depending on the point cloud density and type of urban area. The values were determined empirically and tested so that the algorithm was transferable among datasets with different densities and types of buildings.
Abstract: In plant research, there is a demand for non-destructive and non-invasive trait measurement methods for phenotyping that can be used to accurately analyze various aspects of plants, such as stem length, leaf area, and leaf inclination. In this study, a method for measuring the leaf geometric characteristics of poplar seedlings based on 3D visualization via the use of time-of-flight (ToF) and digital cameras was proposed. Firstly, the average distance density function method was applied to process outliers of leaves. Secondly, to improve the accuracy of data fitting, a specific method using the angle of adjacent two-point normalvectors was introduced to filter redundant data, kept essential sample values as the control points, and then used the control points to fit the leaf surface based on non-uniform rational B-splines (NURBS). At the same time, NURBS was used to fit the trunk according to its control points and an iterative method to fit the other branches. Finally, 3D visualization of poplar seedlings was achieved, and leaf traits, including leaf width, leaf length, leaf area, and leaf inclination angle, were calculated. To obtain accurate results, multiple experiments were conducted including assessments of poplar seedlings exhibiting normal growth and those grown under water shortage. The results of the proposed method were compared with the real values of the leaves. The RMSE for leaf width, leaf length, leaf area, and leaf angle were 0.18 cm, 0.21 cm, 1.14 cm 2 , and 1.97°, respectively. The results proved that this approach could be used to accurately measure the leaf characteristics of poplar seedlings via visualization.
Abstract: Point clouds with ever-increasing volume are regular data in 3D city modelling, in which building reconstruction is a significant part. The photogrammetric point cloud, generated from UAS (Unmanned Aerial System) imagery, is a novel type of data in building reconstruction. Its positive characteristics, alongside its challenging qualities, provoke discussions on this theme of research. In this paper, patch-wise detection of the points of window frames on facades and roofs are undertaken using this kind of data. A density-based multi-scale filter is devised in the feature space of normalvectors to globally handle the matter of high volume of data and to detect edges. Color information is employed for the downsized data to remove the inner clutter of the building. Perceptual organization directs the approach via grouping and the Gestalt principles, to segment the filtered point cloud and to later detect window patches. The evaluation of the approach displays a completeness of 95% and 92%, respectively, as well as a correctness of 95% and 96%, respectively, for the detection of rectangular and partially curved window frames in two big heterogeneous cluttered datasets. Moreover, most intrusions and protrusions cannot mislead the window detection approach. Several doors with glass parts and a number of parallel parts of the scaffolding are mistaken as windows when using the large-scale object detection approach due to their similar patterns with window frames. Sensitivity analysis of the input parameters demonstrates that the filter functionality depends on the radius of density calculation in the feature space. Furthermore, successfully employing the Gestalt principles in the detection of window frames is influenced by the width determination of window partitioning.
We present an interactive system for computer aided generation of line art drawings to illustrate 3D mod- els that are given as triangulated surfaces. In a pre- processing step an enhanced 2D view of the scene is computed by sampling for every pixel the shading, the normalvectors and the principal directions obtained from discrete curvature analysis. Then streamlines are traced in the 2D direction fields and are used to de- fine line strokes. In order to reduce noise artifacts the user may interactively select sparse reference lines and the system will automatically fill in additional strokes. By exploiting the special structure of the streamlines an intuitive and simple tone mapping algorithm can be derived to generate the final rendering.
substrates such as phosphatidylinositol 3-kinase (PI3K). In a human mast cell leukemia cell line HMC-1, c-kitR was found to be constitutively phosphorylated on tyrosine, activated, and associated with PI3K without the addition of SCF. The expression of SCF mRNA transcript in HMC-1 cells was not detectable by means of PCR after reverse transcription (RT-PCR) analysis, suggesting that the constitutive activation of c-kitR was ligand independent. Sequencing of whole coding region of c-kit cDNA revealed that c-kit genes of HMC-1 cells were composed of a normal, wild-type allele and a mutant allele with two point mutations resulting in intracellular amino acid substitutions of Gly-560 for Val and Val-816 for Asp. Amino acid sequences in the regions of the two mutations are completely conserved in all of mouse, rat, and human c-kit. In order to determine the causal role of these mutations in the constitutive activation, murine c-kit mutants encoding Gly-559 and/or Val-814,
This paper presents an extension of the standard approach used for bilingual lex- icon extraction from comparable corpora. We study of the ambiguity problem re- vealed by the seed bilingual dictionary used to translate context vectors. For this purpose, we augment the standard ap- proach by a Word Sense Disambiguation process relying on a WordNet-based se- mantic similarity measure. The aim of this process is to identify the translations that are more likely to give the best rep- resentation of words in the target lan- guage. On two specialized French-English comparable corpora, empirical experimen- tal results show that the proposed method consistently outperforms the standard ap- proach.
29 Consider the vector and the vector . Find the angles of each of these vectors with respect to the x-axis. Show that these two vectors are perpendicular to each other. Also show that the products of each vector’s corresponding x- and y-components add up to 0. Can you confirm that this is a pattern for all perpendicular vectors?
Here is the component normal to the sail and parallel to it, in the plane of the Sun vector. n ˆ ˆ t 0 is the lightness number at the beginning of the mission, 0 A m 0 : values of 0 , ranging from 0 (pure SEP) to 0.05 can be assumed for near- to mid-term technology . and m are the spacecraft mass at the beginning of the mission and at any given time, respectively. Note that, in the hybrid case, the spacecraft mass varies in general, due to the SEP propellant consumption, and so does the acceleration from the sail.
Purpose From the CentreVu Framework window you can access tools to view, modify, add, and delete ACD items in the CentreVu CMS database. You can use the Navigator to view or modify the properties of objects in your Call Center World, including renaming some types of objects. You can use the Vector Editor to create new vectors or edit existing ones, and you can use VDN Assignment Wizard to assign one or more VDN(s) to a vector. No matter which tool you use to select an operation, the way in which you perform the operation is the same.
. In order to facilitate the exchange of scaffold frag- ments in the expression cassette, AscI-NotI restriction sites were engineered just downstream of nucA (Fig. 1). To achieve this, an 800-bp fragment containing the nucA gene was PCR-amplified from pVE5524 using primers a and b (Table 2), digested with SalI-EcoRV and ligated into similarly digested pVE5524 and pVE5523, yielding pAW004 and pAW005. To facilitate detection of E. coli clones that harbor cipA fragments, a lacZ- a stuffer frag- ment was PCR-amplified from pUC19 using primers c and d, digested with AscI-NotI, and subsequently ligated into similarly cut pAW004 and pAW005, yielding pAW004Z and pAW005Z, respectively. Since L. lactis HtrA NZ9000 is resistant to erythromycin, the ery mar- ker of the pAW vectors was replaced with the cat gene from pSCNIII. The cat gene was PCR-amplified using primers e and f, digested with AflII and HpaI, and ligated into similarly digested pAW004Z and pAW005Z, yielding plasmids pAW004ZC and pAW005ZC, respectively. For inducible expression of the scaffolds, we replaced the P59 promoter with P nisA from pSIP502. The P nisA promoter
the N phase of the tetrapode, where an interdigitation of the laterally attached mesogenic units is present, it is possible that the major director may be tilted. In order to determine whether or not it is tilted, the dependence of the absorbance for the phenyl ring deformations band at 762 cm − 1 vs. the angle of oblique incidence is investigated. The absorbance of this band plotted by open symbols in Fig. 2(a) shows that the angular profile is symmetrical with respect to the maximum that is ob- served at normal incidence ( ∼ 90 ◦ ). This implies that the main director is directed along the z-axis. It seems that anisotropy in the tilt fluctuations originates from the shape of the platelet and not from the tilt of the director. If the dimensions a and c of the platelet are comparable to each other then the platelets align similarly to those of discotic molecules, i.e., edge-on lying along the rubbing direction. 17 It makes fluctuations in
Establishment of vector-transduced T-cell lines. Clones of PA317 ampho- tropic packaging cells producing each retroviral vector at high titer were derived essentially as described previously (23). In brief, retroviral vector plasmid DNA was transfected by using DOTAP transfection reagent (Boehringer Mannheim, Indianapolis, Ind.) into the PE501 ecotropic packaging cell line. The transfected PE501 cell pools were selected in 0.5 mg of active G418 (Geneticin; GIBCO/ BRL, Bethesda, Md.) per ml. Cell culture supernatants from the G418-resistant PE501 cell pool were used to transduce PA317 amphotropic packaging cells. The transduced PA317 cells were cloned with G418, and individual clones were expanded and screened for the production of high titers of vectors, assayed by transfer of neomycin resistance to 3T3 cells.
Abstract Viruses have become extensively studied over the decade not just for decoding their complex structures but also to understand disease pathways and for the treatment of various diseases as well. The advent of recombinant technology has allowed viruses to be used as vectors in gene therapy, which is the treating of diseases by inserting/deleting genes. One such virus which has risen to prominence because of its flexibility in terms of usage and its versatility in regard to organisms is the adenovirus. This review will elaborate the remarkable progress that has been made with these vectors in the past decade, shortcomings involved in the entire process as well as current biological strategies employed in utilizing adenovirus mediated gene therapy.
shows that the death rate of whitefly vectors, the infection rate for susceptible vectors, the number of vectors that can be supported and the rate of loss of infected cassava due to disease are the most sensitive parameters to the dynamics of cassava mosaic disease. Numerical simulation indicates that, cassava new infections increase as the number of vectors that can be supported increase and acquire cassava mosaic disease. It shows that if control measures are not considered, then the susceptible breed and cassava resistant breed will be wiped out after five and ten months respectively. To control the disease, farmers are encouraged to apply control strategies such as spraying of insecticide, using of vector-resistant varieties, phytosanitation which involve the removal of infected cassava plants from the farm, crop hygiene and the use of free stem cutting method.
PCA are also known as Karhunen Loeve expansion. It is a classical feature extraction and data representation technique widely used in the area of pattern recognition and computer vision . Tao et al. , used two-dimensional Principal Component Analysis, 2D-PCA on the palmprint image. In Wang , the 2D-PCA and two-dimensional Linear Discriminant Analysis (2D-LDA) are compared with its 1D-PCA and LDA. Wang  applies two-dimensional methods directly on the palmprint image rather than transforming it into one-dimensional image vectors. The two- dimensional method can achieve higher recognition rate instead of one-dimensional method.
vectors (Fig. 1A) are based on previously described vectors derived from the NL4-3 isolate of HIV-1 (7, 22). In the exper- iments described here, the portion of RT located between amino acids 14 and 427 of RT was derived from the BH10 isolate of HIV-1. The env and vpr genes and are inactivated in the vectors (7, 22); this limits the vectors to a single cycle of replication. Cotransfecting 293 cells (Fig. 1B) with vector DNA and the plasmid, pHCMV-g, that expresses the vesicular sto- matitis virus G envelope glycoprotein produced infectious viri- ons (1, 69). Forty-eight-hour supernatants were harvested and used to infect HOS cells. The murine heat-stable antigen gene (hsa) (64) is expressed from the nef reading frame of the vector. Infected cells were identified and enumerated by being labeled with anti-HSA and subjected to FACS. Viral titers were determined 48 h after infection.
The random vectors u and e are distributed as independent multivariate normal with zero mean vectors and covariance matrices given by σ u 2 Ω 1 and σ 2 I N respectively. Assuming that the random effects for the same area and different points in time can be modelled as a realisation of an AR(1) process, and the same process applies in all areas, the matrix Ω 1 is then