Extracting surface representations from rim curves

LNCS v. 3852 is the conference proceedings of ACCV 2006In this paper, we design and implement a novel method for constructing a mixed triangle/quadrangle mesh from the 3D space curves (rims) estimated from the profiles of an object in an image sequence without knowing the original 3D topology of the object. To this aim, a contour data structure for representing visual hull, which is different from that for CT/MRI, is introduced. In this paper, we (1) solve the "branching structure" problem by introducing some additional "directed edge", and (2) extract a triangle/ quadrangle closed mesh from the contour structure with an algorithm based on dynamic programming. Both theoretical demonstration and real world results show that our proposed method has sufficient robustness with respect to the complex topology of the object, and the extracted mesh is of high quality. © Springer-Verlag Berlin Heidelberg 2006.postprintThe 7th Asian Conference on Computer Vision (ACCV 2006), Hyderabad, India, 13-16 January 2006. In Lecture Notes in Computer Science, 2006, v. 3852, p. 732-74

Two-photon spin injection in semiconductors

A comparison is made between the degree of spin polarization of electrons excited by one- and two-photon absorption of circularly polarized light in bulk zincblende semiconductors. Time- and polarization-resolved experiments in (001)-oriented GaAs reveal an initial degree of spin polarization of 49% for both one- and two-photon spin injection at wavelengths of 775 and 1550 nm, in agreement with theory. The macroscopic symmetry and microscopic theory for two-photon spin injection are reviewed, and the latter is generalized to account for spin-splitting of the bands. The degree of spin polarization of one- and two-photon optical orientation need not be equal, as shown by calculations of spectra for GaAs, InP, GaSb, InSb, and ZnSe using a 14x14 k.p Hamiltonian including remote band effects. By including the higher conduction bands in the calculation, cubic anisotropy and the role of allowed-allowed transitions can be investigated. The allowed-allowed transitions do not conserve angular momentum and can cause a high degree of spin polarization close to the band edge; a value of 78% is calculated in GaSb, but by varying the material parameters it could be as high as 100%. The selection rules for spin injection from allowed-allowed transitions are presented, and interband spin-orbit coupling is found to play an important role.Comment: 12 pages including 7 figure

Nomadism and movement as epistemologies of the contemporary world (El nomadismo y el movimiento como epistemologías del mundo contemporáneo)

In the same way that movement and nomadism as a lifestyles opposite to sedentism involve not only the abandonment of the idea of a permanent home, but also an active challenge or furtive avoidance of the state's sedentary authority, movement and nomadism as epistemologies confront the generally fixed order of languages, discourses and perspectives with which science tries to explain our social world. New ways of thinking about movement, subjectivities, groups and institutions emerge, in a world that is not only global, but real and virtual at the same time. In this special issue we have gathered the contributions that experiment and questioning static thinking

Визначення кількості рослинних антиоксидантів для захисту гірких хмелевих речовин від окисної деструкції

Досліджено кінетику окиснення гірких речовин водного розчину екстракту хмелю у прискорених умовах з різною концентрацією антиоксидантів із рослинної сировини. Визначено ефективну концентрацію антиоксидантів із кори дубу, трави звіробою та трави м'яти.Kinetics of bitter matters in aquatic solution of hope extract in speed-up terms with different concentration of antioxidants from the digister are investigated. Certainly effective concentration of antioxidants from the bark oak, st-john's-wort herbares and mint herbares are determinated

Parental Height Differences Predict the Need for an Emergency Caesarean Section

More than 30% of all pregnancies in the UK require some form of assistance at delivery, with one of the more severe forms of assistance being an emergency Caesarean section (ECS). Previously it has been shown that the likelihood of a delivery via ECS is positively associated with the birth weight and size of the newborn and negatively with maternal height. Paternal height affects skeletal growth and mass of the fetus, and thus might also affect pregnancy outcomes. We hypothesized that the effect of newborn birth weight on the risk of ECS would decrease with increasing maternal height. Similarly, we predicted that there would be an increase in ECS risk as a function of paternal height, but that this effect would be relative to maternal height (i.e., parental height differences). We used data from the Millennium Cohort Study: a large-scale survey (N = 18,819 births) with data on babies born and their parents from the United Kingdom surveyed 9 to 12-months after birth. We found that in primiparous women, both maternal height and parental height differences interacted with birth weight and predicted the likelihood of an ECS. When carrying a heavy newborn, the risk of ECS was more than doubled for short women (46.3%) compared to tall women (21.7%), in agreement with earlier findings. For women of average height carrying a heavy newborn while having a relatively short compared to tall partner reduced the risk by 6.7%. In conclusion, the size of the baby, the height of the mother and parental height differences affect the likelihood of an ECS in primiparous women

Organic Geochemical Studies. I. Molecular Criteria for Hydrocarbon Genesis

In recent years the search for life-forms at the earliest periods of geological time has been continued not only at the morphological level but also at the molecular level. This has been possible as a result of the increase in the biochemical knowledge and with the advent of analytical techniques that are capable of describing the intimate molecular architecture of individual molecules in acute detail. The fundamental premises upon which this organic geochemical approach rest are the following: that certain molecules, possessing a characteristic structural skeleton, show a reasonable stability to degradation over long periods of geological time; that their structural specificity can be understood in terms of known biosynthetic sequences; and that their formation by any non-biological means is of negligible probability. In this manuscript it is proposed to critically re-examine these premises and to establish criteria whereby one can differentiate molecules derived from biological systems from those that have their origin in non-biological processes. The importance of establishing such criteria lies in the significance these criteria have in determining whether life exists, or has existed, on other planets. Within the very near future it may be possible to provide an initial answer to this question when the first lunar samples are returned to the earth for analysis