1,465 research outputs found
Efficient Truss Maintenance in Evolving Networks
Truss was proposed to study social network data represented by graphs. A
k-truss of a graph is a cohesive subgraph, in which each edge is contained in
at least k-2 triangles within the subgraph. While truss has been demonstrated
as superior to model the close relationship in social networks and efficient
algorithms for finding trusses have been extensively studied, very little
attention has been paid to truss maintenance. However, most social networks are
evolving networks. It may be infeasible to recompute trusses from scratch from
time to time in order to find the up-to-date -trusses in the evolving
networks. In this paper, we discuss how to maintain trusses in a graph with
dynamic updates. We first discuss a set of properties on maintaining trusses,
then propose algorithms on maintaining trusses on edge deletions and
insertions, finally, we discuss truss index maintenance. We test the proposed
techniques on real datasets. The experiment results show the promise of our
work
Medicinal plants used by Tibetans in Shangri-la, Yunnan, China
<p>Abstract</p> <p>Background</p> <p>Medicinal plants used by the local people in Xizang (Tibet) have been investigated since the 1960s. The others out of Xizang, however, have been less understood, although they may be easily and strongly influenced by the various local herbal practices, diverse environments, local religious beliefs and different prevalent types of diseases. In 2006, two ethnobotanical surveys were organized in the county of Shangri-la, Yunnan Province, SW China, to document the traditional medicinal plants used by the Tibetan people.</p> <p>Methods</p> <p>After literature surveying, four local townships were selected to carry out the field investigation. Three local healers were interviewed as key informants. The methods of ethnobotany, anthropology and participatory rural appraisal (PRA) were used in the field surveys. Plant taxonomic approach was adopted for voucher specimen identification.</p> <p>Results</p> <p>Sixty-eight medicinal plant species in 64 genera of 40 families were recorded and collected. Among them, 23 species were found to have medicinal values that have not been recorded in any existing Tibetan literatures before, and 31 species were recorded to have traditional prescriptions. Moreover, the traditional preparations of each species and some folk medicinal knowledge were recorded and analyzed. These traditional prescriptions, preparations, new medicinal plants and folk medicinal knowledge and principles were discovered and summarized by local traditional Tibetan healers through times of treatment practices, and were passed down from generation to generation.</p> <p>Conclusion</p> <p>As a part of the cultural diversity of Tibetan community, these traditional medicinal knowledge and experiences may provide data and information basis for the sustainable utilization and development of Tibetan medicine, and may contribute to the local economic development. However, for many reasons, they are disappearing gradually as time goes by. Our study showed that there were abundant traditional Tibetan medicinal prescriptions and using methods. It implies that more Tibetan medicinal plants and traditional knowledge can be discovered. Further research should be done to save the wealth of these traditional medicinal knowledge and experiences before they are dying out.</p
A Solution to the Ambiguity Problem in Depth Contouring
Depth contours on a chart are important for safe navigation. The ambiguity problem can appear when points of equal depth are joined in contouring. Unreasonable solutions may mistake a shallow area for a deep one, which could result in a potential danger for navigation. A solution is presented to solve the ambiguity problem using constrained lines formed by two shallow depths. The constrained lines are used to limit the joining of the points with equal depth. Experimental results demonstrate that the proposed solution can reduce the dangers of producing non-existent deep areas in bathymetric contouring.Las isobatas en una carta son importantes para la seguridad de la navegaciôn. El problema de ambiguedad puede aparecer cuando puntos de igual profundidad se unen en el trazado de la isobata. Soluciones no razonadas pueden confundir un area somera por una profunda, lo que podria resultar en un peligro potencial a la navegaciôn. Una soluciôn se présenta para resolver el problema de ambigüedad utilizando lineas forzadas formadas por dos profundidades s orneras. Las lineas forzadas se ut Uizan para limitar la union de puntos con igual profundidad. Los resultados expérimentales demuestran que la soluciôn propuesta puede reducir los peligros de producir areas profundas no existentes en los contornos batimétricos.Sur une carte, les isobathes sont importantes en ce qui concerne la sécurité de la navigation. Le problème de l'ambiguïté peut apparaître lorsque des points de profondeur égale se rejoignent sur le tracé de l'isobathe. Certaines solutions non fondées rationnellement peuvent prendre par erreur une zone peu profonde pour une zone profonde, ce qui peut entraîner un danger potentiel pour la navigation. Une solution est présentée pour résoudre le problème de l’ambiguïté en utilisant des lignes contraintes formées par deux faibles profondeurs. Les lignes contraintes sont utilisées pour limiter la réunion de points d’une égale profondeur. Des résultats expérimentaux ont montré que la solution proposée peut réduire les dangers liés à la création de zones profondes non existantes dans le tracé bathymétrique
(E)-N′-[4-(DimethylÂamino)ÂbenzylÂidene]-4-methylÂbenzohydrazide methanol monosolvate
In the title compound, C17H19N3O·CH3OH, the hydrazone molÂecule exists in a trans geometry with respect to the methylÂidene unit and the dihedral angle between the two substituted benzene rings is 42.6 (2)°. In the crystal, the components are linked through N—H⋯O and O—H⋯O hydrogen bonds, forming [100] chains of alternating hydrazone and methanol molÂecules
BioNMT: A Biomedical Neural Machine Translation System
To solve the problem of translation of professional vocabulary in the biomedical field and help biological researchers to translate and understand foreign language documents, we proposed a semantic disambiguation model and external dictionaries to build a novel translation model for biomedical texts based on the transformer model. The proposed biomedical neural machine translation system (BioNMT) adopts the sequence-to-sequence translation framework, which is based on deep neural networks. To construct the specialized vocabulary of biology and medicine, a hybrid corpus was obtained using a crawler system extracting from universal corpus and biomedical corpus. The experimental results showed that BioNMT which composed by professional biological dictionary and Transformer model increased the bilingual evaluation understudy (BLEU) value by 14.14%, and the perplexity was reduced by 40%. And compared with Google Translation System and Baidu Translation System, BioNMT achieved better translations about paragraphs and resolve the ambiguity of biomedical name entities to greatly improved
A Method for Detecting and Adjusting Systematic Errors of Singlebeam Sounding Data Acquired in a Grid Pattern*
A study of background in a long sensitive time Wilson cloud chamber
A long-sensitive time Wilson Cloud Chamber has been built and tested. A usable sensitive time of 2.5 seconds has been achieved by the use of a system of five expansion valves, the first three of which are used to obtain the sensitive time and the final two to continue the expansion at a supersaturation slightly less than critical in order to allow all droplets formed to grow in size and fall into the liquid. This system of continued expansion, coupled with delayed recompression, has been proved to reduce the background density in the chamber to an average operating value of one drop in 20 cm3.
Re-evaporation nuclei have been investigated and evidence has been given supporting their existence as well as their virtual elimination as a source of background in this chamber. The production and existence of photochemical nuclei has been studied, the primary results being that these nuclei are uncharged and that the supersaturation required for condensation depends upon the duration and intensity of ultraviolet irradiation.
Five classes of condensation nuclei were observed in the chamber, each of which present a potential source of chamber background. These are: (1) uncharged aggregates of molecules condensed upon at supersaturations greater than that required for ions, (2) ions formed by high energy particles, (3) field sensitive nuclei produced by the clearing field electrode which are condensed upon at supersaturations less than critical, (4) field-sensitive nuclei condensed upon in the absence of an electric field and requiring less than critical super-saturation, and (5) field-insensitive photo-chemical nuclei which may be condensed upon at most any degree of supersaturation depending upon the period of time and intensity of ultra-violet irradiation.
The low background and long sensitive time mentioned can be achieved easily due to the great versatility in operating conditions afforded by the expansion valve system and the electronic time delay and cycling units --Abstract
The Influence of Carrier's Attitude and the Position Reduction in Multibeam Echosounding and Airborne Laser Depth Sounding
Having finished the development of the multibeam echosounding system, China is making a great effort to develop an airborne laser depth sounding system. According to the principle of the two kinds of sounding system mentioned above, a series of position reduction formulas and their error equations are developed in this paper. The dynamic effect of marine sounding, i.e., the influence of carrier's attitude, is taken into full account in developing the equations. Finally, the real parameters of the two sounding systems developed by China are used to calculate the position reductions and their accuracies at different heading angles. The results show that the accuracies of depths and positions in multibeam echosounding and airborne laser depth sounding are dependent not only on their own sensors but also on the additional sensors
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