A <Emphasis Type="Italic">Z</Emphasis>-monitor to calibrate Higgs production via vector boson fusion with rapidity gaps at the LHC

We study central Z-boson production accompanied by rapidity gaps on either side as a way to gauge Higgs weak boson fusion production at the LHC. We analyse the possible backgrounds for the -decay mode and show that these can be substantially reduced. Special attention is paid to the evaluation of the gap survival factor, which is the major source of theoretical uncertainty in the rate of H, Z and W central production events with rapidity gaps. Received: 1 August 2002 / Revised version: 27 September 2002 / Published online: 31 October 2002     

Visual discriminability of headings in text

It is pointed out that writers and editors have powerful formatting and typographical tools available in word processing and desktop publishing software that can be applied to headings to visually reveal or signal the structure of text, and thus the author's perspective. Results of studies are presented which suggest that (1) visual discriminations among headings are easier for a reader to make when headings vary on fewer rather than more formatting and typographical dimensions, (2) size is the most powerful visual cue to a heading's hierarchical position, (3) relative size differences among different levels of headings of about 20% are more discriminable than are absolute size differences, and (4) formatting cues are perceived by readers consistently but not necessarily conventionally     

The Elimination of Integer Variables

It is pointed out that the projection of a Linear Programme (LP) into a lower dimension still results in an LP. For an Integer Programme (IP) this is not generally the case. Circumstances in which the projection (after eliminating integer variables) is still an IP are given.     

A simple energy recovery circuit for high-power inverters with complete turn-on and turn-off snubbers

This paper presents and analyzes an active energy recovery circuit for the inductive turn-on snubber and capacitive turn-off snubber used on high-power gate-turn-off thyristor inverters. The circuit performs as a simple switched-mode power supply and recovers the inductive and capacitive snubbers energy induced in power inverters back into the dc rail with the aid of an extra switch. The features and operation of the proposed circuit are given and supported by PSpice simulations and experimental results.     

Leakage of the dominant mode on stripline with a small air gap

In addition to the expected bound (proper) dominant mode, an independent leaky, (improper) dominant mode has been found to exist on a conventional stripline that has a small air gap above the conducting strip. Such an air gap often occurs during the fabrication process, and has in the past been suspected as the cause of spurious performance. This newly discovered leaky dominant mode leaks into the fundamental TM ₀ parallel-plate mode of the background structure, which is a parallel-plate guide with an air gap. Furthermore, it is found that the leaky dominant mode, not the bound dominant mode, is the continuation of the stripline TEM mode that exists with no air gap. Hence, it is the leaky mode that is excited predominantly by a conventional feed for the small air-gap structure. The general properties of both the bound and leaky dominant modes are obtained by using a full-wave spectral-domain approach. The primary purposes of this paper are to discuss the nature of the leaky dominant mode, and to show that its presence is indeed responsible for spurious transmission-line performance, such as unexpected loss and crosstalk, and interference between the bound and leaky dominant modes. These conclusions are verified experimentally     

Conic Set-Valued Maps in Vector Optimization

The paper deals with the properties of a conic set-valued function defined on the set of all ideal points of vector programming problems. The results here about the continuity and derivability of this conic set-valued map, can be used to get information about the sensitivity of the problem and the stability of the order associated to every ideal point. Furthermore, it is proved that certain contingent cones are determined by the ideal conic set-valued map.      

功率转换应用中更高集成度的挑战

终端产品的上市时间在不断缩短,意味着元件必须易于应用,而且满足终端产品更轻盈、小巧的要求,既在日益缩小的空间内集成更多的功能.这及其它种种元素推动了元件向更高集成度发展的趋势.在本文中,我们将从功率转换器方面看这一趋势的发展,说明单片集成水平的提高,以及要在相同的板级裸片上"塞入"更多信号和功率功能所带来的相应技术挑战.此外还适时地指出单片集成的挑战可以通过使用多芯片封装来化解.