Adiabatic shear localization: occurrence, theories, and applications

多粒度多维度软件过程度量和改进方法研究

随着软件对社会各领域、各层次的渗透，软件逐渐转变为一种对社会团体、 甚至对社会公众的服务，软件的规模越来越大、用户需求越来越多、功能和性能 要求也越来越复杂。因此，对软件的可用性、可靠性、可信性等质量要求不断提 高。伴随着软件业的逐渐发展，软件过程技术逐渐被应用于软件产品的开发当中。 “质量形成于产品的生产过程”这一理念逐渐被软件组织所接受。其核心思想体 现在通过对软件过程的策划、控制和改进来保证软件产品的质量，进而提高软件 组织的经营业绩。软件过程度量作为软件过程管理和过程改进的关键活动，越来 越为软件组织所重视。 通过实施过程管理，能够刻画项目或过程目标的满足程度，找到造成过程 或产品重大偏差的根本原因，进而实施过程改进。然而，在软件过程度量实施期 间，软件组织面对不同的软件开发过程、众多的过程性能度量指标、复杂的统计 分析方法，既要考虑量化管理方法的合理性和复杂程度，又要权衡量化管理的实 施成本，这使得实施有效的过程度量充满挑战。本文基于经验软件工程方法，提 出一种多粒度多维度软件过程度量框架，以及实现该框架的关键技术：软件过程 性能基线的建立和维护方法；同时介绍了该框架下的软件项目进度量化控制模 型，支持软件组织实施有效的过程管理和改进。 本文的主要贡献包括： 提出了一种多粒度多维度软件过程度量框架(Multi-granularity Multi-dimensional software Process Measurement Framework，M2-PMF)，该框架通 过综合考虑软件过程管理和改进的必要信息所属的特征维度和软件组织的过程 管理粒度，自底向上的通过实体层、度量分析层和目标层指导软件组织建立一套 可以覆盖软件全生命周期的、开放的、支持过程改进的综合指标体系和模型。支 持软件组织裁减和定制确定环境下的度量体系，清晰了解其软件过程能力和性 能，提高软件组织对软件过程的控制能力，保障软件开发过程和软件产品的质量。 提出了基于统计分析的过程性能基线的建立和改进方法（Baseline – Statistic - Refinement， BSR），该方法可以有效地建立和维护过程性能基线，支持软件 组织从定性管理提升到定量管理。该方法应用波动图，在过程尚不稳定、数据样 本不足的情况下尽可能多的获得过程改进信息，识别过程改进机会，确定过程改 进途径，帮助软件组织高效地改进其过程中明显的弱项。在过程逐步稳定之后， 利用控制图、排列图、因果图、散点图等统计工具，分析过程性能，建立过程性 多粒度多维度软件过程度量和改进方法研究 ii 能基线，并不断精化。 在M2-PMF 框架下，提出了基于统计过程控制（Statitical Process Control， SPC）和挣值管理（Earned Value Management，EVM）的项目进度量化控制模型 SEVM，该方法通过对项目进度指数的统计控制，分析其稳定性，并通过估算模 型，根据项目当前挣值数据推算项目总进度偏差，并加以控制。支持软件组织对 项目进度进行量化控制，提高了项目按期交付的可能性。 最后，介绍了本文提出的过程度量框架和量化管理方法在国内多家软件组 织中的实际应用。应用案例表明，本文的方法和模型具有广泛的适应性和高度的 可操作性。应用本文方法能够对项目进行有效的估算、度量和控制，进而提高产 品质量并改善客户满意度。

Web-based spatiotemporal visualization of marine environment data

With long-term marine surveys and research, and especially with the development of new marine environment monitoring technologies, prodigious amounts of complex marine environmental data are generated, and continuously increase rapidly. Features of these data include massive volume, widespread distribution, multiple-sources, heterogeneous, multi-dimensional and dynamic in structure and time. The present study recommends an integrative visualization solution for these data, to enhance the visual display of data and data archives, and to develop a joint use of these data distributed among different organizations or communities. This study also analyses the web services technologies and defines the concept of the marine information gird, then focuses on the spatiotemporal visualization method and proposes a process-oriented spatiotemporal visualization method. We discuss how marine environmental data can be organized based on the spatiotemporal visualization method, and how organized data are represented for use with web services and stored in a reusable fashion. In addition, we provide an original visualization architecture that is integrative and based on the explored technologies. In the end, we propose a prototype system of marine environmental data of the South China Sea for visualizations of Argo floats, sea surface temperature fields, sea current fields, salinity, in-situ investigation data, and ocean stations. An integration visualization architecture is illustrated on the prototype system, which highlights the process-oriented temporal visualization method and demonstrates the benefit of the architecture and the methods described in this study.

汉语文本语篇语句焦点确定及焦点与重音关系研究

This study investigated the method of the focus identification in Chinese text discourse and the relationship between accent and focus, large corpus analysis and decision tree were used in the research. The main results are: 1. Based on the concept of the Focus and understanding of the discourse, Foci identification is consistent and steady; 2. Special Focus markers and specific Focus constructions have greater influence than special constituent order on identifying Focus in Chinese discourse; while information states also have great influence on focus identifying; part of speech，information state, the relative position in the sentence, focus-sensitive operator, specific Focus constructions, contrast relations, relations between the sentences are important factors to focus identifying; 3. Using multi-dimensional tagging and knowledge discovery, it is a feasible way to construct and employ decision trees by computing tagging results to identify Focus; 4. Focus predicting also depends on literal types and styles of the discourse, several types of decision trees should be constructed for different literal types; 5. In the monologue discourse, the most prominent accent is located on the Focus word or in the scope of the Focus; there are some kinds of rules on accent assignment in broad Focus; it is necessary to analyze and classify focus structure for the research of relations between accent and Focus.

A proposal design of a multi-hit two-dimensional position-sensitive energy spectrum detector

A new non-linear comparison method of charge-division readout scheme is conceived and the first design of a multi-hit two-dimensional position-sensitive energy spectrum Si(Au) surface barrier detector with a continuous sensitive area is proposed.

An Extension of Self-Organizing Maps to Categorical Data

Self-organizing maps (SOM) have been recognized as a powerful tool in data exploratoration, especially for the tasks of clustering on high dimensional data. However, clustering on categorical data is still a challenge for SOM. This paper aims to extend standard SOM to handle feature values of categorical type. A batch SOM algorithm (NCSOM) is presented concerning the dissimilarity measure and update method of map evolution for both numeric and categorical features simultaneously.

High Order Multi-Moment Constrained Finite Volume Method. Part I: Basic Formulation

A new high-order finite volume method based on local reconstruction is presented in this paper. The method, so-called the multi-moment constrained finite volume (MCV) method, uses the point values defined within single cell at equally spaced points as the model variables (or unknowns). The time evolution equations used to update the unknowns are derived from a set of constraint conditions imposed on multi kinds of moments, i.e. the cell-averaged value and the point-wise value of the state variable and its derivatives. The finite volume constraint on the cell-average guarantees the numerical conservativeness of the method. Most constraint conditions are imposed on the cell boundaries, where the numerical flux and its derivatives are solved as general Riemann problems. A multi-moment constrained Lagrange interpolation reconstruction for the demanded order of accuracy is constructed over single cell and converts the evolution equations of the moments to those of the unknowns. The presented method provides a general framework to construct efficient schemes of high orders. The basic formulations for hyperbolic conservation laws in 1- and 2D structured grids are detailed with the numerical results of widely used benchmark tests. (C) 2009 Elsevier Inc. All rights reserved.

Optimization of multi-cycle two-color laser fields for the generation of an isolated attosecond pulse

The effect of the mixing of pulsed two color fields on the generation of an isolated attosecond pulse has been systematically investigated. One main color is 800 nm and the other color (or secondary color) is varied from 1.2 to 2.4 mu m. This work shows that the continuum length behaves in a similar way to the behavior of the difference in the square of the amplitude of the strongest and next strongest cycle. As the mixing ratio is increased, the optimal wavelength for the extended continuum shifts toward shorter wavelength side. There is a certain mixing ratio of intensities at which the continuum length bifurcates, i.e., the existence of two optimal wavelengths. As the mixing ratio is further increased, each branch bifurcates again into two sub-branches. This 2D map analysis of the mixing ratio and the wavelength of the secondary field easily allows one to select a proper wavelength and the mixing ratio for a given pulse duration of the primary field. The study shows that an isolated sub-100 attosecond pulse can be generated mixing an 11 fs full-width-half-maximum (FWHM), 800 laser pulse with an 1840 nm FWHM pulse. Furthermore the result reveals that a 33 fs FWHM, 800 nm pulse can produce an isolated pulse below 200 as, when properly mixed. (c) 2008 Optical Society of America.

Reduced deep-tissue image degradation in three-dimensional multiphoton microscopy with concentric two-color two-photon fluorescence excitation

We theoretically demonstrate that enhanced penetration depth in three-dimensional multiphoton microscopy can be achieved using concentric two-color two-photon (C2C2P) fluorescence excitation in which the two excitation beams are separated in space before reaching their common focal spot. Monte Carlo simulation shows that, in comparison with the one-color two-photon excitation scheme, the C2C2P fluorescence microscopy provides a significantly greater penetration depth for imaging into a highly scattering medium. (C) 2008 Optical Society of America.

Multi-channel 2-D pattern transfer model based on imaging optics for submarine laser uplink communication

An optical communication scheme of 2-D pattern transfer based on imaging optics for submarine laser uplink communication (SLUC) is suggested. Unlike the methods aiming at avoiding neighboring crosstalk used in traditional multi-channel optical beam transferring, we make full use of the overlapping of each spreading beam other than controlling divergence effect of each beam to avoid interference noise. The apparent parameters have been introduced to simplify theoretical analysis of optical pattern transfer problem involving underwater condition, with the help of which the complex beam propagation inside two kinds of mediums can be easily reduced to brief beam transfer only inside air medium. In this paper, optical transmission path and receiver terminal optics geometry have been described in detail. The link range equation and system uplink performance analysis have also been given. At last, results of a proof-of-concept experiment indicate good feasibility of the proposed SLUC model. © 2007 Elsevier GmbH. All rights reserved.

The multi-weight neuron with geometry algorithm and its application

A novel approach for multi-dimension signals processing, that is multi-weight neural network based on high dimensional geometry theory, is proposed. With this theory, the geometry algorithm for building the multi-weight neuron is mentioned. To illustrate the advantage of the novel approach, a Chinese speech emotion recognition experiment has been done. From this experiment, the human emotions are classified into 6 archetypal classes: fear, anger, happiness, sadness, surprise and disgust. And the amplitude, pitch frequency and formant are used as the feature parameters for speech emotion recognition. Compared with traditional GSVM model, the new method has its superiority. It is noted that this method has significant values for researches and applications henceforth.

Mathematical symbols and computing methods in high dimensional biomimetic informatics and their applications

High dimensional biomimetic informatics (HDBI) is a novel theory of informatics developed in recent years. Its primary object of research is points in high dimensional Euclidean space, and its exploratory and resolving procedures are based on simple geometric computations. However, the mathematical descriptions and computing of geometric objects are inconvenient because of the characters of geometry. With the increase of the dimension and the multiformity of geometric objects, these descriptions are more complicated and prolix especially in high dimensional space. In this paper, we give some definitions and mathematical symbols, and discuss some symbolic computing methods in high dimensional space systematically from the viewpoint of HDBI. With these methods, some multi-variables problems in high dimensional space can be solved easily. Three detailed algorithms are presented as examples to show the efficiency of our symbolic computing methods: the algorithm for judging the center of a circle given three points on this circle, the algorithm for judging whether two points are on the same side of a hyperplane, and the algorithm for judging whether a point is in a simplex constructed by points in high dimensional space. Two experiments in blurred image restoration and uneven lighting image correction are presented for all these algorithms to show their good behaviors.

A mini-staged multi-stacked quantum cascade laser for improved optical and thermal performance

In this paper, a mini-staged multi-stacked quantum cascade laser structure with a designed wavelength of 4.7 mu m is presented. By introducing five 0.5 mu m thick high thermal conductivity InP interbuffer layers, the 60-stages active region core of the quantum cascade laser is divided into six equal parts. Based on simulation, this kind of quantum cascade laser with a 10 mu m ridge width gives nearly circular two-dimensional far-field distribution (FWHM = 32.8 degrees x 29 degrees) and good beam quality parameters M-2 = 1.32 x 1.31 in the fast axis (growth direction) and the slow axis (lateral direction). Due to the enhancement of lateral heat extraction through the interbuffer layers, compared to the conventional structure, a decrease of about 5-6% for the maximum temperature in the active region core of the mini-staged multi-stacked quantum cascade laser with indium-surrounded and gold-electroplated packaging profiles is obtained at all possible dissipated electrical power levels.

Effects of polarization field on formation of two-dimensional electron gas in (0001) and (11(2)over-bar0) plane AlGaN/GaN heterostructures

Photoluminescence (PL) and temperature-dependent Hall effect measurements were carried out in (0001) and (11 (2) over bar0) AlGaN/GaN heterostructures grown on sapphire substrates by metalorganic chemical vapor deposition. There are strong spontaneous and piezoelectric electric fields (SPF) along the growth orientation of the (0001) AlGaN/GaN heterostructures. At the same time there are no corresponding SPF along that of the (1120) AlGaN/GaN. A strong PL peak related to the recombination between two-dimensional electron gas (2DEG) and photoexcited holes was observed at 3.258 eV at room temperature in (0001) AlGaN/GaN heterointerfaces while no corresponding PL peak was observed in (11 (2) over bar0). The existence of a 2DEG was observed in (0001) AlGaN/GaN multi-layers with a mobility saturated at 6000 cm(2)/V s below 80 K, whereas a much lower mobility was measured in (11 (2) over bar0). These results indicated that the SPF was the main element to cause the high mobility and high sheet-electron-density 2DEG in AlGaN/GaN heterostructures. (C) 2004 Elsevier B.V. All rights reserved.

Iris recognition algorithm based on point covering of high-dimensional space and neural network

In this paper, we constructed a Iris recognition algorithm based on point covering of high-dimensional space and Multi-weighted neuron of point covering of high-dimensional space, and proposed a new method for iris recognition based on point covering theory of high-dimensional space. In this method, irises are trained as "cognition" one class by one class, and it doesn't influence the original recognition knowledge for samples of the new added class. The results of experiments show the rejection rate is 98.9%, the correct cognition rate and the error rate are 95.71% and 3.5% respectively. The experimental results demonstrate that the rejection rate of test samples excluded in the training samples class is very high. It proves the proposed method for iris recognition is effective.