645 research outputs found
Modelling and Validation of Robot Manipulators
There are many methods to describe manipulator dynamics, the iterative Newton-Euler dynamic formulation and the Lagrange-Euler formulation are two of them. Between these two well known methods, the former has been regarded as computationally efficient, and the latter as understandable in representing manipulator dynamics. It is hard and dull to generate robot manipulator dynamic equations manually from either the iterative Newton-Euler dynamic formulation or the Lagrange-Euler formulation. Therefore, the two general programmes, which are based on these two formulations respectively and suited to rotary joint manipulators, have been written in REDUCE. After running the programmes, we find that the calculation time for generating the dynamic equations of a rotary joint manipulator by the programme based on the Lagrange-Euler formulation is much shorter than the one by the programme based on the other
SEGSys: A mapping system for segmentation analysis in energy
Customer segmentation analysis can give valuable insights into the energy
efficiency of residential buildings. This paper presents a mapping system,
SEGSys that enables segmentation analysis at the individual and the
neighborhood levels. SEGSys supports the online and offline classification of
customers based on their daily consumption patterns and consumption intensity.
It also supports the segmentation analysis according to the social
characteristics of customers of individual households or neighborhoods, as well
as spatial geometries. SEGSys uses a three-layer architecture to model the
segmentation system, including the data layer, the service layer, and the
presentation layer. The data layer models data into a star schema within a data
warehouse, the service layer provides data service through a RESTful interface,
and the presentation layer interacts with users through a visual map. This
paper showcases the system on the segmentation analysis using an electricity
consumption data set and validates the effectiveness of the system
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Quantifying Cerebellum Grey Matter and White Matter Perfusion Using Pulsed Arterial Spin Labeling
To facilitate quantification of cerebellum cerebral blood flow (CBF), studies were performed to systematically optimize arterial spin labeling (ASL) parameters for measuring cerebellum perfusion, segment cerebellum to obtain separate CBF values for grey matter (GM) and white matter (WM), and compare FAIR ASST to PICORE. Cerebellum GM and WM CBF were measured with optimized ASL parameters using FAIR ASST and PICORE in five subjects. Influence of volume averaging in voxels on cerebellar grey and white matter boundaries was minimized by high-probability threshold masks. Cerebellar CBF values determined by FAIR ASST were 43.8 ± 5.1 mL/100 g/min for GM and 27.6 ± 4.5 mL/100 g/min for WM. Quantitative perfusion studies indicated that CBF in cerebellum GM is 1.6 times greater than that in cerebellum WM. Compared to PICORE, FAIR ASST produced similar CBF estimations but less subtraction error and lower temporal, spatial, and intersubject variability. These are important advantages for detecting group and/or condition differences in CBF values
Innovation of Chinaâs Grass-Root Agricultural Extension Team With ICTs
Agricultural extension plays a very important role in the technology transformation. Many researchers are committed to innovate the agriculture extension system with ICTs and there has been a remarkable progress in the use of ICTs in agricultural extension. This paper gave a brief introduction about the chinese agricultural extension system and focused on improving the service capacity of the grass-root agricultural extension team with ICTs. Some experience from what we have done is shared and the problems we have encountered are also discussed
Composite metamaterials with dual-band magnetic resonances in the terahertz frequency regime
Composite metamaterials(CMMs) combining a subwavelength metallic hole array
(i.e. one-layer fishnet structure) and an array of split-ring resonators(SRRs)
on the same board are fabricated with gold films on silicon wafer. Transmission
measurements of the CMMs in the terahertz range have been performed. Dual-band
magnetic resonances, namely, a LC resonance at 4.40 THz and an additional
magnetic resonance at 8.64 THz originating from the antiparallel current in
wire pairs in the CMMs are observed when the electrical field polarization of
the incident light is parallel to the gap of the component SRR. The numerical
simulations agree well with the experimental results and further clarify the
nature of the dual-band magnetic resonances.Comment: 4 figures, 14 page
Surface plasmon polaritons assisted diffraction in periodic subwavelength holes of metal films with reduced interplane coupling
Metal films grown on Si wafer perforated with a periodic array of
subwavelength holes have been fabricated and anomalous enhanced transmission in
the mid-infrared regime has been observed. High order transmission peaks up to
Si(2,2) are clearly revealed due to the large dielectric constant contrast of
the dielectrics at the opposite interfaces. Si(1,1) peak splits at oblique
incidence both in TE and TM polarization, which confirms that anomalous
enhanced transmission is a surface plasmon polaritons (SPPs) assisted
diffraction phenomenon. Theoretical transmission spectra agree excellently with
the experimental results and confirm the role of SPPs diffraction by the
lattice.Comment: 4 pages, 5 figures, 26 reference
Multiple Positive Solutions to Multipoint Boundary Value Problem for a System of Second-Order Nonlinear Semipositone Differential Equations on Time Scales
We study a system of second-order dynamic equations on time scales (p1u1â)Î(t)-q1(t)u1(t)+λf1(t,u1(t),u2(t))=0,tâ(t1,tn),(p2u2â)Î(t)-q2(t)u2(t)+λf2(t,u1(t), u2(t))=0, satisfying four kinds of different multipoint boundary value conditions, fi is continuous and semipositone. We derive an interval of λ such that any λ lying in this interval, the semipositone coupled boundary value problem has multiple positive solutions. The arguments are based upon fixed-point theorems in a cone
Preparation of Crystalline Sn-Doped TiO 2
Sn-doped TiO2 nanoparticles were prepared by the vapor transport method of water molecules and characterized by XRD and XPS analyses. The TEM images indicated that as-prepared samples were highly dispersed nanoparticles with a small and uniform size below 20ânm, as it would effectively control the rate of hydrolysis of Ti4+ by adjusting the flow speed of water vapor. Meanwhile, the photocatalytic properties of Sn-doped TiO2 were tested, and the results showed that doping an appropriate amount of Tin would improve the photocatalytic activity of TiO2 by enhancing the separation rate of photogenerated electrons and holes on the surface of TiO2. In addition, the calcination temperature and Tin content had an important influence on the photocatalytic activity of TiO2. When the mix ratio of Sn:Ti reached 1%, and the nano-Sn-TiO2 sample was calcined at 400oC, it showed the best photocatalytic activity
Establishment of linkage phase, using Oxford Nanopore Technologies, for preimplantation genetic testing of Coffin-Lowry syndrome with a de novo RPS6KA3 mutation
Background: This study aimed to perform preimplantation genetic testing (PGT) for a female Coffin-Lowry Syndrome (CLS) patient with a de novo mutation (DNM) in RPS6KA3. It was challenging to establish the haplotype in this family because of the lack of information from affected family members. Hence, we explored a new and reliable strategy for the detection of the DNM in PGT, using Oxford Nanopore Technologies (ONT) and the MARSALA platform.Methods: We performed whole-exome sequencing (WES) on the proband and confirmed the pathogenic mutation by Sanger sequencing. The proband then underwent PGT to prevent the transmission of the pathogenic mutation to her offspring. We diverged from the conventional methods and used long-read sequencing (LRS) on the ONT platform to directly detect the mutation and nearby SNPs, for construction of the haplotype in the preclinical phase of PGT. In the clinical phase of embryo diagnosis, the MARSALA method was used to detect both the SNP-based haplotype and chromosome copy number variations (CNVs), in each blastocyst. Finally, a normal embryo was selected by comparison to the haplotype of the proband and transferred into the uterus. Sanger sequencing and karyotyping were performed by amniocentesis, at 17Â weeks of gestation, to confirm the accuracy of PGT.Results: Using WES, we found the novel, heterozygous, pathogenic c.1496delG (p.Gly499Valfs*25) mutation of RPS6KA3 in the proband. The SNP-based haplotype that was linked to the pathogenic mutation site was successfully established in the proband, without the need for other family members to be tested with ONT. Eight blastocysts were biopsied to perform PGT and were assessed with a haplotype linkage analysis (30 SNP sites selected), to give results that were consistent with direct mutation detection using Sanger sequencing. The results of PGT showed that three of the eight blastocysts were normal, without the DNM. Moreover, the patient had a successful pregnancy, after transfer of a normal blastocyst into the uterus, and delivered a healthy baby.Conclusion: The ONT platform, combined with the MARSALA method, can be used to perform PGT for DNM patients without the need for other samples as a reference
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