Effect of magnetic-field-induced torsion on neutrinos and supernova collapse

Summary The neutrino emission from supernova 1987A is being studied by taking into consideration the effect of the magnetic field present in the star. The magnetic field generates an anisotropic feature in the local space-time, which in turn leads to the cancellation of the axial-vector part of the neutrino current. The interaction cross-section of these neutrinos in the course of their interaction with matter on Earth has an inverse square energy dependence. The present work presents the calculations based on this changed cross-section that relates to predictions of the expected number of events at KAMIOKANDE on the basis of the Mont Blanc signal. It might be interesting to take a look into the implications of these results. The author of this paper has agreed to not receive the proofs for correction.     

A continuous parametric shape model

In this paper we propose a flexible continuous parametric shape model for star-shaped planar objects. The model is based on a polar Fourier expansion of the normalized radius-vector function. The expected phase amplitudes are modelled by a simple regression with parameters having nice geometric interpretations. The suggestedgeneralized p-order model is an extension of first- and second-order Gaussian shape models, and in particular the Gaussian assumption is relaxed. The statistical analysis is straightforward, as demonstrated by an application concerning shape discrimination of two cell nuclei populations.     

A result about a selection problem of Michael

It is shown that a continuum that is an space in the sense of Michael must be hereditarily decomposable. This improves known results, thereby providing more evidence that such continua must be dendrites.

     

A universal property of reflexive hereditarily indecomposable Banach spaces

It is shown that every separable Banach space universal for the class of reflexive Hereditarily Indecomposable space contains isomorphically and hence it is universal for all separable spaces. This result shows the large variety of reflexive H.I. spaces.

     

用于彩色目标跟踪的改进粒子群优化算法

提出一种用于彩色目标跟踪的改进粒子群优化算法(Improved Particle Swarm Optimization Algorithms,IP-SOA)。针对彩色目标,选择加权彩色直方图作为目标的特征,选用Bhattacharyya系数作为特征相似性度量,其最大值位置表示目标位置。对粒子群优化算法进行了改进,即自动调整惯性权重函数与认知学习因子,每次递推时对粒子速度、单帧位移总量加以限制,对Bhattacharyya系数优化,快速求取函数最大值位置。利用彩色序列图像进行仿真实验,结果表明,该方法能够实时跟踪飞机、车辆等目标,在目标被部分遮挡时能稳健跟踪。     

Dynamic data structures for fat objects and their applications

We present several efficient dynamic data structures for point-enclosure queries, involving convex fat objects in or . Our planar structures are actually fitted for a more general class of objects – (β,δ)-covered objects – which are not necessarily convex, see definition below. These structures are more efficient than alternative known structures, because they exploit the fatness of the objects. We then apply these structures to obtain efficient solutions to two problems: (i) finding a perfect containment matching between a set of points and a set of convex fat objects, and (ii) finding a piercing set for a collection of convex fat objects, whose size is optimal up to some constant factor.     

旋转物体温度的非接触检测原理

本文讨论了利用交流电桥作感温部件及旋转变压器原理实验对旋转体温度的非接触检测。     

On the scarcity of contravariant left adjunctions

It is shown that any pair of contravariant mutually left adjoint functors between varieties of algebrasC andD factors through the retractions of these categories onto the complete lattices of epimorphs of their respective initial objects, and is thus fairly degenerate. However, some interesting contravariant left adjoint functors do exist between categories of finitely generated (or otherwise restricted) algebras.This work was done while the author was partly supported by NSF contract DMS 85-02330.Presented by F. E. J. Linton.     

水下物体视觉形象的分析与模拟研究

水下物体的视觉形象是一个看似简单但极易出错的问题.本文对此问题进行了较为系统的分析和模拟计算,纠正了一些流行的错误看法,指出在不同情况下水下物体的表观位置、表观大小及表观形状均会发生通常直观想象难以预见的复杂变化.该问题的讨论提供了一个培养学习者创新思维和利用基本知识分析及解决实际问题的能力的极好例证.     

Jordan李超代数的一些性质

代数A称为不可分解的,如果A不能分解成理想的直和.证明了满足C(L_o)=C(L)={0}的Jordan李超代数L一些重要性质.