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关键词： Optimization   Viruses (medical)   Resource management   Computer science   Genetic algorithms   Complex networks   Cooperative coevolution (CC)   evolutionary algorithm (EA)   networked system   resource allocation   spreading control  

摘要： The control of virus spreading over complex networks with a limited budget has attracted much attention but remains challenging. This article aims at addressing the combinatorial, discrete resource allocation problems (RAPs) in virus spreading control. To meet the challenges of increasing network scales and improve the solving efficiency, an evolutionary divide-and-conquer algorithm is proposed, namely, a coevolutionary algorithm with network-community-based decomposition (NCD-CEA). It is characterized by the community-based dividing technique and cooperative coevolution conquering thought. First, to reduce the time complexity, NCD-CEA divides a network into multiple communities by a modified community detection method such that the most relevant variables in the solution space are clustered together. The problem and the global swarm are subsequently decomposed into subproblems and subswarms with low-dimensional embeddings. Second, to obtain high-quality solutions, an alternative evolutionary approach is designed by promoting the evolution of subswarms and the global swarm, in turn, with subsolutions evaluated by local fitness functions and global solutions evaluated by a global fitness function. Extensive experiments on different networks show that NCD-CEA has a competitive performance in solving RAPs. This article advances toward controlling virus spreading over large-scale networks.

关键词： Computer Science   general   Software Engineering/Programming and Operating Systems   Operating Systems   Software Engineering   Artificial Intelligence  

摘要： In 2020 the outbreak of Covid-19 influenced lives of billions of people all around the globe and motivated governments of different countries to revisit the current situation with regards to public healthcare systems and to methods used in modern medicine. As the workload on radiologists and physicians increased, so did the demand on systems that automatically analyse medical images and detect pathologies. Many current computer vision papers assume that the solution would be integrated into a healthcare system. However improvement according to "classic" metrics like mAP or IoU does not necessarily mean improvement from the radiologist's point of view. In this paper we suggest that while calculating metrics, averaging should be performed not by all studies, but by different groups of studies, in order to be close to human perception of a quality of a segmentation. And that we should count the number of false positive components, found outside lungs, because the presence of such components is negatively perceived by radiologists. Also we propose a method that improves the segmentation of lung pathologies and pleural effusion according to the points given above.

关键词： Data Mining and Knowledge Discovery   Artificial Intelligence   Information Storage and Retrieval   Statistics for Engineering   Physics   Computer Science   Chemistry and Earth Sciences  

关键词： Game-based learning   Computational thinking   Computer science   Information communication technology (ICT)   Minecraft  

摘要： In the modern education system, new technological teaching aids are used to support learning, to increase motivation and adaptation of students. Game-based Learning (GBL) is one of such aids that it can be successfully integrated to improve teaching and learning in diverse courses. In computer science courses, the concept of programming is found confusing and difficult to understand by students. This study is conducted to investigate and analyze the disposition of 5th grade primary school students on programming through a digital game-play. Sixty-three 5th grade primary school students, with little or no programming knowledge, performed various activities through a digital game framework. The study is based on a descriptive survey model and was carried out by using convergent mixed method design for data collection process. The data were collected through quantitative and qualitative approaches consecutively after the students were experimenting on the given digital game-based activity. The findings indicated that digital game-play helped the students to understand the concept of programming and it is observed that students have developed positive disposition towards programming through game-based activities even if they can have preconceptions.

关键词： Privacy   Authentication   Complexity theory   Computer crime   Computer science   Cryptography   Anonymity   attribute-based credentials   privacy-enhanced authentication   electronic ticket  

摘要： Users accessing services are often required to provide personal information, for example, age, profession and location, in order to satisfy access polices. This personal information is evident in the application of e-ticketing where discounted access is granted to visitor attractions or transport services if users satisfy policies related to their age or disability or other defined over attributes. We propose a privacy-preserving electronic ticket scheme using attribute-based credentials to protect users' privacy. The benefit of our scheme is that the attributes of a user are certified by a trusted third party so that the scheme can provide assurances to a seller that a user's attributes are valid. The scheme makes the following contributions: (1) users can buy different tickets from ticket sellers without releasing their exact attributes;(2) two tickets of the same user cannot be linked;(3) a ticket cannot be transferred to another user;(4) a ticket cannot be double spent. The novelty of our scheme is to enable users to convince ticket sellers that their attributes satisfy the ticket policies and buy discounted tickets anonymously. This is a step towards identifying an e-ticketing scheme that captures user privacy requirements in transport services. The security of our scheme is proved and reduced to a well-known complexity assumption. The scheme is also implemented and its performance is empirically evaluated.

关键词： Tensile stress   Smart cities   Big Data   Cloud computing   Computer science   Big data   smart city   tensor   multi-order HOSVD   distributed computing   incremental computing  

摘要： Smart city, a focus of many researchers from academia and industry, is a successful example of Cyber-Physical-Social Systems (CPSS). Based on the rapid and efficient processing of large-scale data, Smart city, an example of CPSS, has revolutionized the service provision model by providing proactive services for humans. However, to operationalize the services provided in smart cities, a comprehensive analysis of heterogeneous and large-scale big data is required. Further, to speed up data processing and improve the adaptability and extensibility of big data, CPSS big data processing should be realized in the form of blocks and avoid redundant computing on historical data. In this paper, as an extension of multi-order distributed and incremental High-Order Singular Value Decomposition (HOSVD) computing, Ring-based Tree algorithm and Tree-based Tree algorithm are proposed for the problems of increasing scale of processable data and computational efficiency. The experimental and simulation results demonstrate that the proposed algorithms have high performance in terms of error, improvement factor, and improvement factor ratio. At last, to demonstrate the performance of our improved algorithms, a case study about CPSS big data processing is provided.

关键词： Computer Science   general   Software Engineering/Programming and Operating Systems   Operating Systems   Software Engineering   Artificial Intelligence  

摘要： This paper provides a survey of methods and tools for automated code-reuse exploit generation. Such exploits use code that is already contained in a vulnerable program. The code-reuse approach allows one to exploit vulnerabilities in the presence of operating system protection that prohibits data memory execution. This paper contains a description of various code-reuse methods: return-to-libc attack, return-oriented programming, jump-oriented programming, and others. We define fundamental terms: gadget, gadget frame, gadget catalog. Moreover, we show that, in fact, a gadget is an instruction, and a set of gadgets defines a virtual machine. We can reduce an exploit creation problem to code generation for this virtual machine. Each particular executable file defines a virtual machine instruction set. We provide a survey of methods for gadgets searching and determining their semantics (creating a gadget catalog). These methods allow one to get the virtual machine instruction set. If a set of gadgets is Turing-complete, then a compiler can use a gadget catalog as a target architecture. However, some instructions can be absent. Hence we discuss several approaches to replace missing instructions with multiple gadgets. An exploit generation tool can chain gadgets by pattern searching (regular expressions) or considering gadgets semantics. Furthermore, some chaining methods use genetic algorithms, while others use SMT-solvers. We compare existing open-source tools and propose a testing system rop-benchmark that can be used to verify whether a generated chain successfully opens a shell.

关键词： Indexes   Adders   Task analysis   Fans   Data processing   Solids   Computer science   Computer arithmetic   formal verification   parallel adders   recurrence equation  

摘要： Parallel adders are extensively used in high-performance computer design and hardware acceleration for large-scale data processing. In the adder design theory, a key property of the group propagated carry and the group generated carry is based on the two recurrence equations. The property is fundamental to many parallel prefix adders. However, there is no proof of the property in the literature. This article presents a rigorous and complete proof for it. The proof can leverage a solid ground for a formal verification methodology for parallel adder-based chip design.

摘要： One argument often made against capital punishment is that it would involve the risk of killing innocent people and that such a mistake cannot be corrected in ways that other punishments can. I call this the 'Irrevocability Argument'. In this article, I argue that the Irrevocability Argument is symmetrical with respect to capital punishment and active voluntary euthanasia. If the Irrevocability Argument works against capital punishment, then it also works against active voluntary euthanasia and vice versa. The main upshot of this is that it means at least some of the moral positions that people hold to treat them differently are untenable. Those who rely on the Irrevocability Argument as an argument against capital punishment are also committed to it as an argument against active voluntary euthanasia.

关键词： Computer Science   general   Software Engineering/Programming and Operating Systems   Operating Systems   Software Engineering   Artificial Intelligence  

摘要： In this paper, we show that a ring of p-adic integers Z(p) can be used to represent subsets of a bounded number set. We propose an approach to define a set of p-adic balls. The union of their images is a subset of the bounded number set. The cover of the set of p-adic balls and the p-adic density of the subset of the bounded number set are defined. We also define the operations of p-adic intersection, union, and complement over sets of p-adic balls that can generate the corresponding algebra.