15147551
Specification and Runtime Enforcement of Security Policies
The rapid growth in mobile and wireless communications entails serious problem of security. Formal methods can be used to help building secure mobile computing environment. Tabular expressions have proved to be useful and practical in formulating precise and complete documentation for computer systems. In this paper a framework for specification and runtime enforcement of security policies is proposed basing on the use of tabular expressions. A security policy can be specified with a tabular expression, and checking whether an application adheres to a given policy can be achieved by evaluating the tabular expression with respect to information intercepted at runtime. The advantages of our approach includes: (1) providing precise and readable specification of security policies; (2) developing a general policy enforcement engine rather than one policy enforcement engine for each security policy; (3)achieving low overheads by simplifying tabular expressions with static information of mobile code.
2730805
Applying PageRank Algorithm in Requirement Concern Impact Analysis
As an important part of requirement management, managing requirement change plays a key role in controlling project schedule and costs at early stage. Effective requirement impact analysis would give proper assessment on the effect of certain requirement changes on the whole system, and provide useful information for making trade-off decisions on future system design and implementation. In this paper a quantitative approach to concern impact analysis at requirement level has been proposed with the application of PageRank algorithm, which is a successful link based web page sorting algorithm. At first, separation of concerns is applied during deriving formal requirement specification from textual requirement statements. Next, concerns are specified and concern relationship graph is established. Finally, PageRank algorithm is utilized on concern relationship graph for assessing the impact of concern changes. Our approach has been applied to hallway section in Light Control System and validation of analysis result has been stated.
14644950
Concern Based Approach to Generating SCR Requirement Specification: A Case Study
SCR is a mature and widely used document driven requirement method, which emphasizes creating strict and complete formal requirement documents during software requirement analysis to serve the whole life circle. However, due to the big gap between textual requirement description and formal requirement document, how to obtain formal SCR requirements specification from informal textual description becomes an obstacle of applying SCR to real projects. In this paper, a concern based approach to generating SCR requirement specification from textual requirement document is proposed. The requirement analysis process includes concerns elicitation, specification of concerns and their relationship, identification of concepts, definition and classification of variables, derivation of SCR requirement specification, and validation of requirement specification. The method introduced in this paper has been applied to a classical case – Light Control System by documenting the requirements of hallway section. It is indicated that our approach bridges the gap between textual requirement description and formal SCR requirement document.
26080905
Implementation Technique of Unrestricted LL Action Grammar
Action Grammar is a grammar with action symbols appearing in the right part of production rules, which can be used to implement semantic analyzer automatically. An action symbol represents the name of a semantic routine. Implementation of action grammar relies on specific parsing methods, such as LL(K), recursive-descent or LR, and so on. However, these parsing methods have their own restrictions on grammars, therefore, in order to accomplish these parsing methods certain equivalent transformations have been done to make the grammars meet the restrictions. This paper has proposed an implementation technique of LL action grammar, which requires no transformation to the original grammar. Our approach includes following steps: parsing the input string with back-tracking and producing the parsing paths for each non-terminal symbol, then constructing LL parsing table with the parsing paths obtained, finally conducting semantic analysis with LL parsing table. The main contribution of this paper is that non-backtracking semantic analyzer has been achieved without making any transformations to the grammar.
7377058
Work-flow based multi-domain certificate in e-Commerce
Workflow technology is directly objected to the application of industry and business. In a networked e-Commerce system, network programming brings many threats to whole network, such as spoof of identity, unauthorized access and damage to network. We propose a multidomain certificate mechanism based on work-flow requirements. By using multidomain certificate mechanism, we can provide higher security for authentication and authorization in a networked e-Commerce system
815255
Detecting Projected Outliers in High-Dimensional Data Streams
In this paper, we study the problem of projected outlier detection in high dimensional data streams and propose a new technique, called Stream Projected Ouliter deTector (SPOT), to identify outliers embedded in subspaces. Sparse Subspace Template (SST), a set of subspaces obtained by unsupervised and/or supervised learning processes, is constructed in SPOT to detect projected outliers effectively. Multi-Objective Genetic Algorithm (MOGA) is employed as an effective search method for finding outlying subspaces from training data to construct SST. SST is able to carry out online self-evolution in the detection stage to cope with dynamics of data streams. The experimental results demonstrate the efficiency and effectiveness of SPOT in detecting outliers in high-dimensional data streams.
28161769
Extraction of Text Objects in Video Documents: Recent Progress
Text extraction in video documents, as an important research field of content-based information indexing and retrieval, has been developing rapidly since 1990s. This has led to much progress in text extraction, performance evaluation, and related applications. By reviewing the approaches proposed during the past five years, this paper introduces the progress made in this area and discusses promising directions for future research.
13312738
Autonomous Objects and Bottom-Up Composition in ZOO Applied to a Case Study of Biological Reactivity
As part of our work on the formal analysis of object-oriented models, we turn to systems where many autonomous individuals interact to give rise to complex collective behaviour. We adapt our ZOO [1,2] structuring and apply it to a case study based on a published model of part of the immune system [3]. The formalisation calls for a bottom-up solution with no central control over individual units, and includes an approach to represent feedback channelsenabling broadcast communication between individuals and across levels.
44524631
Evaluating the Disaster Defense Ability of Information Systems
Disaster prevention and recovery is an important branch of security informatics. People need to investigate the disaster prevention and recovery capacity of information systems in order to make them more robust. In this paper we propose a framework to evaluate the disaster defense ability of information systems. In the research a hierarchy of criterions is built up which covers both the disaster prevention ability and the disaster recovery ability. And a fuzzy assessment method is designed to fit the evaluating process. We also develop a software tool based on the framework to assist the information security evaluators.
11446949
Composite Evaluation of Replacing Small Generation Units with Large Ones in the Electricity Sector in China
This paper applies two methods to evaluate the economic effects of the policy of "replacing small units with large ones (RSWL)," one is Discounted Cash Flow (DCF) method which performs a technology economic analysis both from the financial and the economic perspectives, the other one is to use the Real Option theory to study the lagging investment problem of the big unit. Through an illustrative example, three alternatives of replacing 200 MW units with 600 MW units are compared. The sensitivity analysis is made to evaluate the impact of uncertain factors on the financial and economic indicators of the execution of RSWL. The environmental costs are also taken into account in the comparison and analysis. The proposed methods can aid the decision-making in the implementation of the policy of RSWL from a wider perspective and it can be used to evaluate the economic benefits and costs of the RSWL projects.