具有最优代数免疫阶的一类新布尔函数的构造

构造了一类至少具有次优代数免疫阶的布尔函数f,并利用级联的方法构造了一类具有最优代数免疫阶的布尔函数h。这类函数h不同于以前相关文献中所提出的最优代数免疫的布尔函数,给出了f的数目,并进一步讨论了h（偶数个变元的情况下）的非线性度,发现利用择多函数F_n构造的一类函数h非线性度达到Lobanov界。     

满足严格雪崩准则相关免疫函数的代数免疫阶

以布尔函数的导数和自定义的e-导数为研究工具,讨论满足严格雪崩准则、具有相关免疫性、重量为2n－1+2n－2的H布尔函数的代数免疫问题。得出这类函数奇数(n≥17)元、偶数(n≥16)元的最优代数免疫函数及其构造方法,给出了代数免疫阶AI(f)≥8的n元代数免疫函数的构造方法;还给出了零化子及最低代数次数零化子的求法及其与布尔函数的导数的关系等结果。     

代数免疫度最优的偶数元旋转对称布尔函数的构造

针对目前许多流密码算法无法抵抗代数攻击问题,提出了一种构造代数免疫度最优的偶数元旋转对称布尔函数的新方法。该方法在择多函数的基础上,通过巧妙选择汉明重量不一的若干轨道,并改变这些轨道上的函数值,从而构造出一类新的旋转对称布尔函数。给定布尔函数达到代数免疫度最优的一个充分条件,通过证明新构造的布尔函数满足该充分条件,从而表明该类函数代数免疫度最优,能够有效抵抗代数攻击。     

代数免疫度最优的偶数元旋转对称布尔函数的构造

针对目前许多流密码算法无法抵抗代数攻击问题,提出了一种构造代数免疫度最优的偶数元旋转对称布尔函数的新方法。该方法在择多函数的基础上,通过巧妙选择汉明重量不一的若干轨道,并改变这些轨道上的函数值,从而构造出一类新的旋转对称布尔函数。给定布尔函数达到代数免疫度最优的一个充分条件,通过证明新构造的布尔函数满足该充分条件,从而表明该类函数代数免疫度最优,能够有效抵抗代数攻击。     

一类代数免疫度达到最优的布尔函数的构造

给出了一种具有最优代数免疫度的偶数元布尔函数的构造,同时还给出了一种具有最优代数免疫度的平衡旋转对称偶数元布尔函数的构造.在构造过程中用到了线性代数和组合计数中的有关结论,这些函数对代数攻击均有很强的抵抗能力.构造的平衡旋转对称布尔函数还可用在Hash算法的轮函数中,增加了算法的安全性.     

一类代数免疫度达到最优的布尔函数的构造

给出了一种具有最优代数免疫度的偶数元布尔函数的构造,同时还给出了一种具有最优代数免疫度的平衡旋转对称偶数元布尔函数的构造.在构造过程中用到了线性代数和组合计数中的有关结论,这些函数对代数攻击均有很强的抵抗能力.构造的平衡旋转对称布尔函数还可用在Hash算法的轮函数中,增加了算法的安全性.     

基于T-D猜想上MAI函数的构造

对涂自然等人提出的组合猜想上的构造方法及有关结论进行了改良推广,在假设更一般的组合猜想成立的前提下构造了一种具有最优代数免疫度的偶数元布尔函数f,同时还利用f构造了一种具有最优代数免疫度的平衡的偶数元布尔函数F。且这些函数也具有很高的代数次数和非线性度,对代数攻击具有较强的抵抗能力。     

最大代数免疫度的偶变元对称函数的性质

代数免疫度达到最大的偶变元对称布尔函数的特征仍然是个公开问题。结合组合数学和数论的相关结论研究这类函数的性质,得到了此类函数值向量的几个特征。最后,对于变元个数为两类特殊偶数的情况,得到了代数免疫度达到最大的对称函数的一个特征。     

具有几乎完美代数免疫的偶数元弹性函数构造

完美代数免疫(PAI)的布尔函数能够抵御代数攻击和快速代数攻击。PAI函数的构造是目前布尔函数研究最具挑战性的问题之一。利用布尔函数的双变元表达式和有限域理论,基于Carlet-Feng函数提出一种新的偶数元布尔函数的一般性构造。证明由该构造得到的函数具有一阶弹性和至少次优代数免疫度等密码学性质,给出其代数免疫度达到最优时的充分条件,并比较该类函数、Carlet-Feng函数和由一阶级联方式构造的函数在6~16之间的所有偶数变元下抵抗快速代数攻击能力。实验结果表明,该类函数能更好地抵抗快速代数攻击,且具有几乎完美的代数免疫性能。     

几类对称布尔函数的非线性度、代数次数和代数免疫阶

该文讨论了几类偶数个变元n的对称布尔函数的一些密码性质,包括非线性度、代数次数、代数免疫阶、严格雪崩准则和相关免疫性等.我们的讨论显示这些对称布尔函数有好的非线性度和代数次数,并且有两类对称布尔函数的代数免疫阶达到最大n/2,一类对称布尔函数的代数免疫阶为1,但是它们基本上不具有相关免疫性和不满足严格雪崩准则,因此这些布尔函数都不能直接应用到密码系统中.     

A model-based DSS for integrating the impact of learning in project control

Earned Value Method (EVM) is a popular project control technique. In this paper, we discuss the extended version of EVM (EVM/LC) that addresses the effect of learning on the performance of project teams. These effects have so far been ignored in most EVM applications. We present a spreadsheet-based decision support tool that automates the calculations and analyses in EVM/LC. Using this tool would save the project manager from having to perform complicated calculations while still taking advantage of the relatively accurate estimates generated by EVM/LC. Consequently, this paper contributes to both research and practice in project management.     

On the Nonlinearity and Correlation Immunity of Two Classes of Boolean Functions

Recently, Liu et al. have proved a class of 2k-variable Boolean functions to have optimal algebraic immunity and good immunity to fast algebraic attacks. In this paper, we proceed to study those functions in aspect of correlation immunity and nonlinearity and through restrictions to those functions we propose two sub-classes of 2k-variable Boolean functions with good cryptographic properties. To the best of our knowledge, this is the first time whole classes of Boolean functions with high nonlinearity, 1-correlation immunity and good immunity against FAA can be found.     

On the number of rotation symmetric Boolean functions

Rotation symmetric Boolean functions (RSBFs) have been used as components of different cryptosystems. This class of functions are invariant under circular translation of indices. In this paper, we investigated balanced RSBFs and 1st order correlation immune RSBFs. Based on constructive techniques, we give an accurate enumeration formula for n-variable balanced RSBFs when n is a power of a prime. Furthermore, an original and efficient method to enumerate all n-variable (n prime) 1st order correlationimmune f...     

A change management model and its application in software development projects

Change is inevitable in software projects and software engineers strive to find ways to manage changes. A complete task could be easily in a team`s agenda sometime later due to change demands. Change demands are caused by failures and/or improvements and require additional effort which in most cases have not been planned upfront and affect project progress significantly. Earned Value Management (EVM) is a powerful performance management and feedback tool for project management. EVM depicts the project progress in terms of scope, cost, and schedule and provides future predictions based on trends and patterns of the past. Even though EVM works quite well and widely used in disciplines like construction and mining, it is not the case for software discipline. Software projects require special attention and adoption for change. In this study, we present a model to measure change and subsequent rework and evolution costs to monitor software projects accurately. We have performed five case studies in five different companies to explore the usability of the proposed model. This paper depicts the proposed model and discusses the results of the case studies.     

实绩价值管理成熟度模型及其支持工具SPIF

EVM是一种能够帮助软件组织降低项目风险、提高开发效率、减少项目开支的行之有效的软件过程改进方法,EVM~3是一个提高软件组织使用EVM管理项目能力的模型。本文介绍了EVM~3的基本概念、与CMMI的关系,以及一个支持EVM~3进行软件过程改进的工具SPIF。     

GF(q)上置换多项式与函数的相关免疫性

本文提出了GF(q)上(n,k)置换多项式的概念，建立了它与函数相关免疫性之间的联系，并研究了它们的性质．得到了GF(q)(q＞2)上一些特殊类型的函数是ｍ阶和所有二次多项式是最大阶相关免疫的充分必要条件．证明了在GF(q)(q＞4)上存在非线性的具有最大阶相关免疫阶的函数，也给出了一种由低次数具有特定相关免疫阶的函数构造非线性次数高的同阶相关免疫函数的有效方法.     

DELIVER! - An educational game for teaching Earned Value Management in computing courses

Context

To meet the growing need for education in Software Project Management, educational games have been introduced as a beneficial instructional strategy. However, there are no low-cost board games openly available to teach Earned Value Management (EVM) in computing programs.

Objective

This paper presents an educational board game to reinforce and teach the application of EVM concepts in the context of undergraduate computing programs complementing expository lessons on EVM basics.

Method

The game has been developed based on project management fundamentals and teaching experience in this area. So far, it has been applied in two project management courses in undergraduate computing programs at the Federal University of Santa Catarina. We evaluated motivation, user experience and the game’s contribution to learning through case studies on Kirkpatrick’s level one based on the perception of the students.

Results

First results of the evaluation of the game indicate a perceived potential of the game to contribute to the learning of EVM concepts and their application. The results also point out a very positive effect of the game on social interaction, engagement, immersion, attention and relevance to the course objectives.

Conclusion

We conclude that the game DELIVER! can contribute to the learning of the EVM on the cognitive levels of remembering, understanding and application. The illustration of the application of EVM through the game can motivate its usefulness. The game has proven to be an engaging instructional strategy, keeping students on the task and attentive. In this respect, the game offers a possibility to complement traditional instructional strategies for teaching EVM. In order to further generalize and to strengthen the validity of the results, it is important to obtain further evaluations.     

最高非线性度旋转对称布尔函数与最优代数免疫函数

研究了旋转对称布尔函数的最高扩散次数、最高非线性度、代数免疫性和最优代数免疫函数的存在性与构造等问题。利用导数和e-导数证明了非线性度达到最高的旋转对称布尔函数的存在性,并利用导数,由扩散性达到最高n次的Bent函数来验证一类旋转对称Bent函数的存在性。同时证明了1阶代数免疫和2阶以上代数免疫旋转对称布尔函数的存在性。另外,利用旋转对称Bent函数构造了非齐次完全旋转对称最优代数免疫布尔函数以及一类众多的最优代数免疫布尔函数,并证明了这两类函数的存在性。同时,也得到了非齐次完全旋转对称相关免疫布尔函数。     

Boolean functions of an odd number of variables with maximum algebraic immunity

In this paper, we study Boolean functions of an odd number of variables with maximum algebraic immunity. We identify three classes of such functions, and give some necessary conditions of such functions, which help to examine whether a Boolean function of an odd number of variables has the maximum algebraic immunity. Further, some necessary conditions for such functions to have also higher nonlinearity are proposed, and a class of these functions are also obtained. Finally, we present a sufficient and necessary condition for Boolean functions of an odd number of variables to achieve maximum algebraic immunity and to be also 1-resilient.     

EVM 在车间工时管理系统中的应用

研究如何将EVM理论实际应用到生产车间信息管理系统中的问题。基于EVM理论中提出的基本参数和重要指标,对生产车间工时管理系统进行流程分析后,编制出符合EVM参数和指标要求的WBS和CBS,利用车间工时管理系统中现有的数据信息,在EVM理论和WBS、CBS理论分析的支撑下采集所需要的数据实现EVM公式的计算,并进一步构造出绩效考核指标IPI。以EVM理论为基础实现的车间工时管理系统在产品进度分析和成本预算报表上比以往更精确,更能及时反映车间生产情况。