oalib
Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
Analysis of the Incircle predicate for the Euclidean Voronoi diagram of axes-aligned line segments  [PDF]
Manos N. Kamarianakis,Menelaos I. Karavelas
Computer Science , 2011,
Abstract: In this paper we study the most-demanding predicate for computing the Euclidean Voronoi diagram of axes-aligned line segments, namely the Incircle predicate. Our contribution is two-fold: firstly, we describe, in algorithmic terms, how to compute the Incircle predicate for axes-aligned line segments, and secondly we compute its algebraic degree. Our primary aim is to minimize the algebraic degree, while, at the same time, taking into account the amount of operations needed to compute our predicate of interest. In our predicate analysis we show that the Incircle predicate can be answered by evaluating the signs of algebraic expressions of degree at most 6; this is half the algebraic degree we get when we evaluate the Incircle predicate using the current state-of-the-art approach. In the most demanding cases of our predicate evaluation, we reduce the problem of answering the Incircle predicate to the problem of computing the sign of the value of a linear polynomial (in one variable), when evaluated at a known specific root of a quadratic polynomial (again in one variable). Another important aspect of our approach is that, from a geometric point of view, we answer the most difficult case of the predicate via implicitly performing point locations on an appropriately defined subdivision of the place induced by the Voronoi circle implicated in the Incircle predicate.
Dirichlet-like space and capacity in complex analysis in several variables  [PDF]
Vigny Gabriel
Mathematics , 2007,
Abstract: For a Kahler manifold X, we study a space of test functions W* which is a complex version of H1. We prove for W* the classical results of the theory of Dirichlet spaces: the functions in W* are defined up to a pluripolar set and the functional capacity associated to W* tests the pluripolar sets. This functional capacity is a Choquet capacity. The space W* is not reflexive and the smooth functions are not dense in it for the strong topology. So the classical tools of potential theory do not apply here. We use instead pluripotential theory and Dirichlet spaces associated to a current.
Capacity Comparison of Several-time Codes
几种空时码容量对比

ZHANG Bi-Jun,ZHU Guang-Xi,
张碧军
,朱光喜

计算机科学 , 2006,
Abstract: Layered space-time code(LSTC)proposed by Bell lAbs is mostly based on spatial multiplexing,its main object is to improve the system frequency efficiency.Yet a variety of space-time codes(STC),such as space-time block code(STBC)and space-time trellis code(STTC),are mostly based on transmit diversity.They predominantly take advantage of the gain produced by spatial diversity,including diversity gain and coding gain,to combat various fading of radio channel.This paper evaluates performance of several STC from the view of channel capacity,and at the same time,compares it with channel capacity of MIMO with the same transmit and receive antenna number.
The Contribution of dα-Tocopherol and dγ-Tocopherol to the Antioxidant Capacity of Several Edible Plant Oils  [PDF]
Garry G. Duthie, Peter T. Gardner, Philip C. Morrice, Donald B. McPhail
Natural Science (NS) , 2016, DOI: 10.4236/ns.2016.82005
Abstract: Many oils from plants are important components of our food chain and maintaining their oxidative stability (OS) is economically and nutritionally important. OS is dependent in part on antioxidant capacity (AC) arising from the electron donating ability of endogenous compounds in the oils. Attention has focused on the contribution to AC of phenolic compounds in oils as many have bioactivities in vitro. However, the relevance of such phenolics to healthy nutrition remains unclear. In contrast, many plant-derived oils also contain tocopherol homologs, which as vitamin E are dietary-essential, lipid-soluble antioxidants. We have determined the AC of twelve “off the shelf” edible oils by assessing their ability to quench galvinoxyl, a stable free radical species. The stochiometric reactivity of vitamin E with galvinoxyl indicates that the combined dα-tocopherol and dγ-tocopherol homologs contribute between 20% (olive) and 85% (soya) to AC depending on type of oil. Tocopherols are important contributors to the AC of several vegetable oils. Breeding and photo mixotrophic programmes to enhance content in edible oil crops of this important vitamin may have a positive impact not only on oil stability during storage but also in contributing to provision of optimum dietary intakes for health.
IRIS: ALLOCYCLIC SEGMENTS AS CHROMOSOME MARKERS?  [cached]
M. COLASANTE,C.G. VOSA
Annali di Botanica , 2000,
Abstract: Besides the linear differentiation of chromosomes, obtained by various methods including C banding, Q-banding llild G- banding, a type of differentiation is sometimes visible after Donnal fixation and Feulgen staining. Such differential segments are found in the chromosomes of many bulbous and rhizomatous Iris species and appear to be species and population specific. Chromosome analysis of several Irises has shown that there is some variation in the length and distribution of the AC-segmenl~ in different species and occasionally also in different populations of the same homeologous chromosomes. Therefore the AC-segments could be used as markers Lo eluddate the ancestry ofIris natural hybrids.
Consistent digital line segments  [PDF]
Tobias Christ,D?m?t?r Pálv?lgyi,Milo? Stojakovi?
Computer Science , 2010,
Abstract: We introduce a novel and general approach for digitalization of line segments in the plane that satisfies a set of axioms naturally arising from Euclidean axioms. In particular, we show how to derive such a system of digital segments from any total order on the integers. As a consequence, using a well-chosen total order, we manage to define a system of digital segments such that all digital segments are, in Hausdorff metric, optimally close to their corresponding Euclidean segments, thus giving an explicit construction that resolves the main question of Chun et al.
SEVERAL PROBLEMS TO STUDY THE POPULATION SUPPORTING CAPACITY OF LAND
土地人口承载量研究中的几个问题

Mei Chengrui,
梅成瑞

自然资源学报 , 1988,
Abstract: <> has been an important strategic study on harmonious development in China.This paper discussed the population supporting capacity of land in relation to the quantity and quality of land resources, ecosystem and technological economics. Undoubted, It is the nucleus in the study.1. The quantity and quality of land resources is the foundation and essential reliance to study the population supporting capacity of land. But should also pay special attent to the capacity and exploitable condition of preparing arable land resources.2. The land ecosytem is the basic arena of human activity. Its balance should be regulated and controled with artificial method to maintain continuous increase in productive forces. The regulation of ecosytem includes mainly the macrostructure effect on rational exploitation and utilization of land; the balance of input and output in land ecosystem; and the relationship between ecologic and economics efficiency.3. The development of agro-technical economics inevitably has an effect on the quality and range of land utilization and also the population supporting capacity. It must be fully consider the economic efficiency of different use way of land and the technical systems of regional agro-modernization effect on raising productive forces of land.In view of the balance among the population increase, resources capacity and productive development, it is suggested that the population supporting capacity must rationly coordinate with the speed of social development in a certain period.
Straight segments in the galactic discs  [PDF]
A. M. Mel'nik,P. Rautiainen
Physics , 2013, DOI: 10.1093/mnras/stt1098
Abstract: We study the properties of the straight segments forming in N-body simulations of the galactic discs. The properties of these features are consistent with the observational ones summarized by Chernin at al. (2001). Unlike some previous suggestions to explain the straight segments as gas dynamical instabilities, they form in our models in the stellar system. We suggest that the straight segments are forming as a response of the rotating disc to a gravity of the regions of enhanced density (overdensities) corotating with the disc. The kinematics of stars near the prominent overdensities is consistent with this hypothesis.
Maximum thermal conductivity of aligned single wall carbon nanotubes  [PDF]
A. L. Efros
Physics , 2004,
Abstract: I estimate maximum thermal conductivity $\kappa$ of a perfectly aligned bundle of single wall carbon nanotubes. Each row of aligned nanotubes has a discrete structure. It consists of segments of nanotubes with length $L$. The spacing between the segments block the phonon path through the row. Only the scattering due to the finite length of the segments is taken into account. The result is that the 'effective'' mean free path is of the order of $L/7$. For 1 micron tubes (10,10) we get maximum value of $\kappa\approx 300$W/m K at room temperature. This result is in a reasonable agreement with the experiment by Hone {\it et al.} assuming that in their samples $L\approx 1\mu{\rm m}$
Proportions of Hand Segments
Buryanov,Alexander; Kotiuk,Viktor;
International Journal of Morphology , 2010, DOI: 10.4067/S0717-95022010000300015
Abstract: the analysis of proportions of hand segments has been carried out on the basis of x-ray films of 66 adult patients without developmental abnormalities. there were hand joint topographies determined proceeding from the data obtained. there were suggested methods of practical utilization of the obtained data in the field of medicine.
Page 1 /100
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.