Common2 extended to stacks and unbounded concurrency

This paper extends Common2, the family of objects that implement and are wait-free implementable from 2 consensus objects, in two ways: First, the stack object is shown to be in the family, refuting a conjecture to the contrary [6]. Second, Common2 is investigated in the unbounded concurrency model, whereas until now it was considered only in an n-process model. We show that the fetch-and-add, test-and-set , and stack objects are in Common2 even with respect to this stronger notion of wait-free implementation. Our constructions rely on a wait-free implementation of immediate snapshots in the unbounded concurrency model, which was previously not known to be possible. The introduction of unbounded concurrency to the study of Common2 opens several directions of research: are there objects that have n-process implementations but are not unbounded concurrency implementable? We conjecture that swap is such an object. Additionally, the hope is that a queue impossibility proof, which eludes us in the n-process model, will be easier to establish in the unbounded concurrency model.     

Drawing directed graphs using quadratic programming

We describe a new method for visualization of directed graphs. The method combines constraint programming techniques with a high performance force-directed placement (FDP) algorithm. The resulting placements highlight hierarchy in directed graphs while retaining useful properties of FDP; such as emphasis of symmetries and preservation of proximity relations. Our algorithm automatically identifies those parts of the digraph that contain hierarchical information and draws them accordingly. Additionally, those parts that do not contain hierarchy are drawn at the same quality expected from a nonhierarchical, undirected layout algorithm. Our experiments show that this new approach is better able to convey the structure of large digraphs than the most widely used hierarchical graph-drawing method. An interesting application of our algorithm is directional multidimensional scaling (DMDS). DMDS deals with low-dimensional embedding of multivariate data where we want to emphasize the overall flow in the data (e.g., chronological progress) along one of the axes.     

Solute dispersion in oscillating electro-osmotic flow with boundary mass exchange

Mass transfer in an oscillatory electro-osmotic flow (EOF) is theoretically studied, for the case of a cylindrical tube with a reactive wall. An expression for the dispersion coefficient, reflecting the time-averaged mass flux of an electrically neutral solute, is derived analytically. Under the influence of a reversible solute-wall mass exchange, the dispersion coefficient exhibits a complex dependence on the various parameters representing the effects of the electric double-layer thickness, oscillation frequency, solution transport properties, solute partitioning, and reaction kinetics. Our results suggest that, in the presence of a reversible mass exchange at the wall, an oscillatory EOF may be used for separation of species. It is found that optimal conditions for separation are achieved for a thin double-layer, where an inert solute, or one with slow exchange kinetics, experiences virtually no dispersion while the dispersion is maximized for the reactive solute exhibiting fast kinetics.     

电气监控管理系统在发电生产中的应用研究

针对电气联网接入DCS存在的实际问题,提出发电厂电气监控管理系统的概念和技术改进措施,并根据电厂电气系统的特点和功能需求设计了电气监控管理系统的硬件系统,再根据硬件系统要求设计了由多个功能模块构成的软件平台.根据软件模块的功能,开发并组成一个完整的运行系统,从而可以提高发电厂电气自动化水平和运行管理水平.最后通过实际应用验证了该系统的科学性与可行性.     

A Statistical Theory for Quantitative Association Rules

Association rules are a key data-mining tool and as such have been well researched. So far, this research has focused predominantly on databases containing categorical data only. However, many real-world databases contain quantitative attributes and current solutions for this case are so far inadequate. In this paper we introduce a new definition of quantitative association rules based on statistical inference theory. Our definition reflects the intuition that the goal of association rules is to find extraordinary and therefore interesting phenomena in databases. We also introduce the concept of sub-rules which can be applied to any type of association rule. Rigorous experimental evaluation on real-world datasets is presented, demonstrating the usefulness and characteristics of rules mined according to our definition.     

Automatic MR-PET registration algorithm

We present an algorithm to automatically register magnetic resonance (MR) and positron emission tomographic (PET) images of the human brain. Our algorithm takes an integrated approach: we simultaneously segment the brain in both modalities and register the slices. The algorithm does not attempt to remove the skull from the MR image, but rather uses “templates” constructed from PET images to locate the boundary between the brain and the surrounding tissue in the MR images. The PET templates are a sequence of estimates of the boundary of the brain in the PET images. For each of the templates, the registration algorithm aligns the MR and PET images by minimizing an energy function. The energy function is designed to implicitly model the relevant anatomical structure in the MR image. The template with the lowest energy after registration is the PET brain boundary. The alignment of this template in the MR image marks the MR brain boundary and gives the transformation between the two images. © 1998 John Wiley & Sons, Inc. Int J Imaging Syst Technol, 9, 46–50, 1998     

搅打稀奶油品质及其影响因素的研究进展

搅打稀奶油是一类可搅打起泡的水包油乳液。作为重要的食品工业原料,搅打稀奶油可作为呈味物质赋予食品良好的感官特性,应用前景广阔。本文首先介绍搅打稀奶油贮藏期内常见的失稳作用,包括乳析、聚集、聚结、部分聚结及奥氏熟化,并阐述界面特性及脂肪球间的交互作如何影响搅打稀奶油的稳定性;其次介绍搅打稀奶油的搅打过程,阐述结晶特性、界面特性和液相蛋白特性如何影响搅打特性。本文可为搅打稀奶油产品的工业化生产提供一定的理论指导。     

豫西熊耳山铁炉坪、蒿坪沟矿床银铅矿石稳定同位素研究

稳定同位素研究表明，铁炉坪、蒿坪沟矿床原生银铅矿石是同一成矿热液体系的产物。成矿物质主要来自花岗岩，成矿热液环境较为稳定。铁炉坪矿床深部具较大找矿潜力。     

A Simpler Construction of CCA2-Secure Public-Key Encryption under General Assumptions

In this paper we present a simpler construction of a public-key encryption scheme that achieves adaptive chosen ciphertext security (CCA2), assuming the existence of trapdoor permutations. We build on previous works of Sahai and De Santis et al. and construct a scheme that we believe is the easiest to understand to date. In particular, it is only slightly more involved than the Naor--Yung encryption scheme that is secure against passive chosen-ciphertext attacks (CCA1). We stress that the focus of this paper is on simplicity only.