374 research outputs found

    Ferrofluid 3-D Gyroscope and Light Modulator.

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    Apparatus and methods for passing a focused laser beam through a thin ferrofluid cell creates a spatial distribution in the refractive index of the ferrofluid and generates a diffraction ring patterns. Using a pair of perpendicularly placed ferrofluid cells, two sets of diffraction ring patterns can be produced on two viewing screens. Deformations in the diffraction patterns due to an acceleration can be viewed on the screens, providing a ferrofluid accelerometer. By applying an electric or a magnetic field on a thin ferrofluid sample, the light passing through the sample can be modulated by the field, providing a light modulator. The apparatus and method has applications for detecting acceleration information within a gyroscope and for use in toys

    New Graph Model for Channel Assignment in Ad Hoc Wireless Networks

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    The channel assignment problem in ad hoc wireless networks is investigated. The problem is to assign channels to hosts in such a way that interference among hosts is eliminated and the total number of channels is minimised. Interference is caused by direct collisions from hosts that can hear each other or indirect collisions from hosts that cannot hear each other, but simultaneously transmit to the same destination. A new class of disk graphs (FDD: interFerence Double Disk graphs) is proposed that include both kinds of interference edges. Channel assignment in wireless networks is a vertex colouring problem in FDD graphs. It is shown that vertex colouring in FDD graphs is NP-complete and the chromatic number of an FDD graph is bounded by its clique number times a constant. A polynomial time approximation algorithm is presented for channel assignment and an upper bound 14 on its performance ratio is obtained. Results from a simulation study reveal that the new graph model can provide a more accurate estimation of the number of channels required for collision avoidance than previous models

    Continuous Influence-based Community Partition for Social Networks

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    Community partition is of great importance in social networks because of the rapid increasing network scale, data and applications. We consider the community partition problem under LT model in social networks, which is a combinatorial optimization problem that divides the social network to disjoint mm communities. Our goal is to maximize the sum of influence propagation through maximizing it within each community. As the influence propagation function of community partition problem is supermodular under LT model, we use the method of Lov{aˊ\acute{a}}sz Extension to relax the target influence function and transfer our goal to maximize the relaxed function over a matroid polytope. Next, we propose a continuous greedy algorithm using the properties of the relaxed function to solve our problem, which needs to be discretized in concrete implementation. Then, random rounding technique is used to convert the fractional solution to integer solution. We present a theoretical analysis with 1−1/e1-1/e approximation ratio for the proposed algorithms. Extensive experiments are conducted to evaluate the performance of the proposed continuous greedy algorithms on real-world online social networks datasets and the results demonstrate that continuous community partition method can improve influence spread and accuracy of the community partition effectively.Comment: arXiv admin note: text overlap with arXiv:2003.1043

    The Non-Coding RNA Ontology : a comprehensive resource for the unification of non-coding RNA biology

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    In recent years, sequencing technologies have enabled the identification of a wide range of non-coding RNAs (ncRNAs). Unfortunately, annotation and integration of ncRNA data has lagged behind their identification. Given the large quantity of information being obtained in this area, there emerges an urgent need to integrate what is being discovered by a broad range of relevant communities. To this end, the Non-Coding RNA Ontology (NCRO) is being developed to provide a systematically structured and precisely defined controlled vocabulary for the domain of ncRNAs, thereby facilitating the discovery, curation, analysis, exchange, and reasoning of data about structures of ncRNAs, their molecular and cellular functions, and their impacts upon phenotypes. The goal of NCRO is to serve as a common resource for annotations of diverse research in a way that will significantly enhance integrative and comparative analysis of the myriad resources currently housed in disparate sources. It is our belief that the NCRO ontology can perform an important role in the comprehensive unification of ncRNA biology and, indeed, fill a critical gap in both the Open Biological and Biomedical Ontologies (OBO) Library and the National Center for Biomedical Ontology (NCBO) BioPortal. Our initial focus is on the ontological representation of small regulatory ncRNAs, which we see as the first step in providing a resource for the annotation of data about all forms of ncRNAs. The NCRO ontology is free and open to all users

    The effects of salt on the physicochemical properties and immunogenicity of protein based vaccine formulated in cationic liposome

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    Recently, we have developed a simple and potent therapeutic cancer vaccine consisting of a cationic lipid and a peptide antigen. In this report, we expanded the utility of this formulation to a protein based vaccine. First, we formulated the human papillomavirus (HPV) 16 E7 protein (E7) in different doses of DOTAP liposome. The results showed that these formulations failed to regress an established tumor. However, when sodium chloride (30 mM) was added to the DOTAP (100 nmol) / E7 (20 μg) formulation, anti-tumor activity was generated in the immunized mice. Correlatively, 30 mM NaCl in the DOTAP/E7 protein formulation increased the particle size from ∼350 to 550 nm, decreased the protein loading capacity (from 95 to 90%), and finally increased the zeta potential (from 29 mV to 38 mV). Next, a model protein antigen ovalbumin (OVA) was formulated in different doses of DOTAP liposomes. Similarly, the results showed that 20 μg OVA formulated in 200 nmol DOTAP with 30 mM NaCl had the best OVA- specific antibody response, including both IgG1 and IgG2a, suggesting both Th1 and Th2 immune responses were generated by this formulation. In conclusion, we have expanded the application of cationic DOTAP liposome formulation to protein based vaccines and also identified that small amounts of salt could change the physicochemical properties of the vaccine formulation and enhance the activity of the DOTAP/protein based vaccine. The enhancement of immune responses by salt is possibly due to its interference of the electrostatic interaction between the cationic lipid and the protein antigen to facilitate the antigen release from the carrier and at the same time activate the antigen presenting cells

    Human posture recognition based on multiple features and rule learning

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    The use of skeleton data for human posture recognition is a key research topic in the human-computer interaction field. To improve the accuracy of human posture recognition, a new algorithm based on multiple features and rule learning is proposed in this paper. Firstly, a 219-dimensional vector that includes angle features and distance features is defined. Specifically, the angle and distance features are defined in terms of the local relationship between joints and the global spatial location of joints. Then, during human posture classification, the rule learning method is used together with the Bagging and random sub-Weili Ding space methods to create different samples and features for improved classification of sub-classifiers for different samples. Finally, the performance of our proposed algorithm is evaluated on four human posture datasets. The experimental results show that our algorithm can recognize many kinds of human postures effectively, and the results obtained by the rule-based learning method are of higher interpretability than those by traditional machine learning methods and CNNs

    Relationship Among Children’s Social-emotional Competence, Social Support, Academic Achievement and Aggressive Behavior in the Primary School in China

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    With the development of humanistic education, scholars believe that children’s social-emotional competence mostly will take charge of their future family, school and life success in the future. Because of too much time focusing on social-skills training and few about children’ s social-emotional competence and relationship between social-emotional competence and aggressive behavior in China, and this article firstly shows concepts of social-emotional competence, social support, academic achievement and aggressive behavior. Secondly, social-emotional competence and social support were hypothesized to have strong influences on academic achievement and aggressive behavior in the study. Participants were 301 pupils (151 boys and 150 girls) from 2 elementary schools in Nanjing, China. The findings suggest that the students with stronger social-emotional competence performed fewer aggressive behaviors than the other peers. Keywords: children; social-emotions competence; social support; aggressio
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