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对Cachin理论安全性进行分析,应用该模型对信息隐藏的统计不可见性进行评价。通过将图像分块去相关性,运用DCT变换得到载体的平稳概率分布,计算DCT系数的联合概率分布的相对熵来评估隐藏算法的统计不可见性。实验结果表明,该评估方法不仅能有效衡量隐藏统计不可见性,还能用以指导隐藏算法的设计。 相似文献
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DANIEL TABAK 《国际通用系统杂志》2013,42(1):55-56
A number of “normalized” measures of entropy have been obtained to measure the “intrinsic” uncertainty of a probability distribution. Their graphs have been drawn and it has been shown that the normalized measures of a given probability distribution are much closer to one another than the corresponding absolute measures of entropy. 相似文献
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曾子林 《计算机工程与应用》2012,48(30):40-42,61
在R.Haenni构造的概率推理系统中,给出了一种基于条件概率思想计算逻辑结果支持度的新方法,将该方法应用于一个逻辑电路中元件是否正常的可能性判定。 相似文献
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Gregor Chliamovitch Lino Velasquez Jean-Luc Falcone Bastien Chopard 《International Journal of Parallel, Emergent and Distributed Systems》2019,34(1):142-160
ABSTRACTWe discuss two ways in which information theory can be used to assess complexity in a system of interacting agents. In the first part, we adopt a global viewpoint and propose a characterization of complexity based on successive maximum entropy estimations of the probability density describing the system, thereby quantifying the respective role played by low and high orders of interaction. In the second part we reconsider the question from a local perspective, focussing on the statistical dependencies between neighbouring agents. These tools are tried on simple cellular automata in order to put them in perspective with other notions of complexity usually employed for such systems. We show that these approaches are hardly comparable, despite some overlap in simple cases. However this allows to interpret complexity in terms of interactions at work in a system (instead of making reference to any particular realization of this dynamics), and to shed some light on the role of initial conditions in complex systems.Clustering of the 88 non-equivalent Elementary Cellular Automata according to their position in the space of information processing features. Rules are coloured according to their Wolfram class. ECA in class I are shown in black, class II in red, chaotic automata (class III) in green and automata displaying complex behaviour (class IV) in blue. In spite of some important important differences, information features and Wolfram class are seen to overlap to a certain extent. 相似文献
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Abstract This paper outlines a new approach to the synthesis of information from data. Information is defined as a detected organization of data after a process of discretization (or partitioning) and event covering. The discretization is based on a hierarchical maximum entropy scheme which iteratively minimizes the loss of information according to Shannon. The event-covering process is based on an evaluation of the deviation of the observed frequencies of an event from the expectation due to prior knowledge (defined by the null hypothesis and/or domain knowledge). The hierarchical maximum entropy discretization scheme provides a rigorous and efficient way in solving the non-uniform scaling problem in multivariate data analysis. Because our method refines the boundaries dynamically depending on the detection of information, it directs the analysis on the outcome subspace with high information content. In addition, it naturally produces a hierarchical view of information so that data can be analyzed/synthesized with respect to an outcome context. The method has been tested using simulated and real life data with very good result. 相似文献
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BUSH JONES 《国际通用系统杂志》2013,42(2):133-142
The new discipline of reconstructability analysis has provided a powerful framework for the study of the relationships between parts and wholes. The concentration of effort has been on systems with probabilistic or possibilistic behavior functions. This paper extends aspects of reconstructability analysis to general functions which need not be behavior functions. We refer to a system with such a function as a g-system.
First, a g-system is transformed to a dimensionless form (borrowing a term from partial differential equations). A mathematical structure is then induced via a type of isomorphism onto this system which renders it amenable to analysis by established techniques in reconstructability analysis. Absolutely no restrictions are placed on the units or mathematical structure of the g-system. We refer to the system induced from the g-system as a Klir system or k-system. These systems are named in honor of the reconstructability analysis founder.
Finally, we explicate some uses of k-systems induced from given g-systems. k-systems have easy immediate application (e.g. minimal storage of system information), but, more importantly, they render accessible new tracts of system dynamics studies. 相似文献
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ARTHUR E. FERDINAND 《国际通用系统杂志》2013,42(1):19-33
A theory is developed, using the basic principles of information theory, which explains the error behavior in systems. The results are system and configuration independent and have applicability across many disciplines. As an example, the results may be used in understanding the defect properties of computer programs. An explicit formula is given for deriving the critical size of systems. The effect of modularity on system properties is analyzed and the optimum size of a subsystem is derived. It is shown that modularity increases the critical size and decreases the number of expected faults in the system. 相似文献
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BUSH JONES 《国际通用系统杂志》2013,42(2):143-151
The advent of the Klir system has greatly expanded the realm of applicability of reconstructability analysis. Theoretically reconstructability analysis can be applied to general multivariate data. However, real world data will usually contain impediments to the use of the Klir system. This paper identifies these impediments, and methodology for their resolution is given. 相似文献
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RONALD CHRISTENSEN 《国际通用系统杂志》2013,42(3):231-277
The theory of entropy mimmax, an information theoretic approach to predictive modeling, is reviewed. Comparisons are given to other methodologies, including: Neyman-Pearson hypothesis testing, James-Stein “empirical Bayes” estimation, maximum likelihood estimation, least-squares fitting, linear regression and logistic regression. Examples are provided showing how maximum entropy expectation probabilities are computed and how minimum entropy partitions are determined. The importance of the a priori weight normalization, in establishing the coarse-grain of the minimum entropy partition, is discussed. The trial crossvalidation procedure for determining the normalization is described. Generalizations utilizing Zadeh's fuzzy entropies are provided for variables involving indistinguishability, partial or total. Specific cases are discussed of maximum likelihood estimation, illustrating ils “data range irregularity” which is avoided by methods such as entropy minimization that account for residuals over the full distribution range. Discriminant analysis and polynomial fitting are discussed as examples of areas of application of the principles of entropy minimax. In curve fitting, the order of the polynomial is determined by entropy minimization, and the coefficients are determined by entropy maximization. Entropy maximization operates as a goodness-of-fit criterion, while entropy minimization operates as a mathematical formulation of Ockham's razor, controlling the level of smoothness in fitting models to data. 相似文献
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随着数据时代的到来,非平衡数据的分类问题受到越来越多的关注。在非平衡数据的分类问题中,往往因为少数类样本与多数类样本比例失衡而导致分类结果错误。因此,提出了一种在最大熵原理下基于自助法（Bootstrap method）的过采样算法。首先,通过自助法获得数据样本的概率分布,并用最大熵原理对概率分布进行优化;其次,根据少数类生成新的少数类的能力不同,提出基于少数类样本分布的概率增强算法。该算法使数据随机性得到了充分体现,保证了少数类样本的概率密度在数据集平衡前后保持一致性,从而提高分类算法的有效性;最后,通过从UCI和KEEL数据库选取8组数据进行实验,实验结果表明所提出的新算法比现有的其他算法更有效。 相似文献
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For many years, systems, developed to be integrated into a layered defense array, were planned through the “Stand Alone” paradigm, assuming that the layers of defense are independent. Almost all published literature dealing with Layered Defense automatically assumes that the layers of defense are independent of each other. The fact is they are not! Defense layers may influence one another in positive and/or negative ways. We attempt to initiate a new look at developing and deploying systems in an integrated array of defense systems, based on the understanding that influences between systems must be taken into account. A methodology for modeling the dependencies between defense systems engagements, of a single attacker, or of a salvo of attackers, is developed in this paper through an “Influence Decay Function” model. A tractable algorithm is developed to compute the complex effectiveness objective functions. The Non Independent Layered Defense Problem (NILDP) is formulated as a Mixed Integer Non Linear Programming problem. The optimization problem for maximum layered defense effectiveness is solved through powerful heuristic methods. The discussion deals with engineering defense systems to operate within complex environments which include not only threat from an opponent but also friendly systems to which integration is not at all trivial. © 2009 Wiley Periodicals, Inc. Syst Eng 相似文献
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随着科技的进步,新型复杂系统例如人机物融合系统（Human Cyber-Physical Systems,HCPS）已经与人类社会生活越来越密不可分.软件系统所处的信息空间与人们日常生活所处的物理空间日渐融合.物理空间内环境的复杂多变、时空数据的爆发增长以及难以预料的人类行为等不确定因素威胁着系统安全.由于系统安全需求的增长,系统的规模和复杂度随之增加所带来的一系列问题亟待解决.因此,在不确定性环境下,构造智能、安全的人机物融合系统已经成为软件行业不可回避的挑战.环境不确定性使得人机物融合系统软件无法准确感知其所处的运行环境.感知的不确定性将导致系统的误判,从而影响系统的安全性.环境不确定性使得系统设计人员无法为人机物融合系统软件的运行环境提供准确的形式化规约.而对于安全要求较高的系统,准确的形式化规约是保证系统安全的首要条件.为了应对规约的不确定性,本文提出时空数据驱动与模型驱动相结合的建模方式,即通过使用机器学习算法,基于环境中时空数据对环境进行建模.根据安全软件的典型特征,采用动态验证的方式保证系统的安全,从而构建统一安全的理论框架.为了展示方案的可行性,本文以自动驾驶车辆与人驾驶的摩托车的交互场景为例说明了在不确定性环境下的人机物融合系统的建模与验证的具体应用. 相似文献
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A complex system is a system composed of many dynamic elements with mutual interactions. This paper proposes a unified approach
for the design of an information processing system using a complex system. The method of design is based on the maximum entropy
principle. After a detailed explanation, the proposed method is applied to the design of a spatial filter using a complex
system.
This work was presented, in part, at the International Symposium on Artificial Life and Robotics, Oita, Japan, February 18–20,
1996. 相似文献
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与线性恢复算法相比,基于最大熵的图像恢复算法具有更好的图像恢复效果,但其收敛速度较慢。为了提高最大熵图像恢复算法的收敛速度,首先给出了算法的非周期反卷积模型,然后采用模糊推理系统在线确定算法的迭代步长。由于采用了可变步长,因此极大地提高了算法的收敛速度。仿真实验表明提出的算法收敛速度快,图像恢复效果好。 相似文献
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Architecting complex systems and complex system‐of‐systems (SoS) have evinced keen interest recently. Architectural design decisions have a significant bearing on the operational measures of success, referred to as Measures of Effectiveness (MOEs), of the systems and SoS. Architecting complex systems and SoS involves making architecture design decisions despite uncertainty (due to knowledge gaps) on the implications associated with the decisions. The learning of whether the decision is optimal or not, and the impact on the MOEs and the emergent behavior of the SoS, often occur later, resulting in Learning Cycles. This paper proposes an integrated decision learning framework for architecture design decisions for complex systems and SoS. The proposed framework adopts a decision oriented view that factors the uncertainty associated with architectural decisions and the learning cycles and feedback loops experienced. The framework enables leverage of machine learning approaches to learn from the decision learning cycles experienced and factor it into the uncertainty assessments of the decisions. By inculcating various aspects such as knowledge gaps and learning cycles, by building models such as Learning Cycle Model and Uncertainty Model, and by incorporating deployment approaches such as codification of decision attributes and decision uncertainty assessments, the proposed framework enables progressive maturity of the architectural knowledge base and aids robustness in architecture design decisions. 相似文献
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For many engineering systems, flexibility is an important attribute that allows them to adapt to emerging changes. The existence of flexibility can help space systems adapt themselves to internal/external changes, or even take advantage of new possibilities while in space. Given the potential upfront cost of designing an engineering system to be more flexible, there is a need for a comprehensive framework that allows decision‐makers to measure the value of flexible systems design in its different dimensions. Based on insights from the flexibility literature, this paper proposes a unified and comprehensive framework for measuring the value of flexibility in space systems based on six fundamental elements through which flexibility in engineering systems can be mapped. While the illustrative case study presented in this paper focuses on the value of flexibility in a space system, DARPA's Orbital Express program, this framework could generally be applicable for many other engineering systems. © 2006 Wiley Periodicals, Inc. Syst Eng 10: 26–44, 2007 相似文献
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This paper introduces a framework for studying the interactions of autonomous system components and the design of the connectivity structure in Systems of Systems (SoSs). This framework, which uses complex network models, is also used to study the connectivity structure's impact on resource management. We discuss resource sharing as a mechanism that adds a level of flexibility to distributed systems and describe the connectivity structures that enhance components' access to the resources available within the system. The framework introduced in this paper explicitly incorporates costs of connection and the benefits that are received by direct and indirect access to resources and provides measures of the optimality of connectivity structures. We discuss central and a distributed schemes that, respectively, represent systems in which a central planner determines the connectivity structure and systems in which distributed components are allowed to add and sever connections to improve their own resource access. Furthermore, we identify optimal connectivity structures for systems with various heterogeneity conditions. 相似文献