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81.
DAVID AUGUST 《Cryptologia》2013,37(4):351-359
To break a normal LFSR cipher, a cryptanalyst needs only 2n bits of corresponding plain and ciphertext, where n is the number of stages of the shift register.[l] In this paper, a method of substituting completely random characters into the ciphertext and therefore preventing the encipherment of a full 2n-length sequence (under its proper key) will be discussed. Due to the high redundancy of English, a cipher containing several completely random characters will still be readable. 相似文献
82.
Supervision and control systems rely on signals from sensors to receive information to monitor the operation of a system and adjust manipulated variables to achieve the control objective. However, sensor performance is often limited by their working conditions and sensors may also be subjected to interference by other devices. Many different types of sensor errors such as outliers, missing values, drifts and corruption with noise may occur during process operation. A hybrid online sensor error detection and functional redundancy system is developed to detect errors in online signals, and replace erroneous or missing values detected with model-based estimates. The proposed hybrid system relies on two techniques, an outlier-robust Kalman filter (ORKF) and a locally-weighted partial least squares (LW-PLS) regression model, which leverage the advantages of automatic measurement error elimination with ORKF and data-driven prediction with LW-PLS. The system includes a nominal angle analysis (NAA) method to distinguish between signal faults and large changes in sensor values caused by real dynamic changes in process operation. The performance of the system is illustrated with clinical data continuous glucose monitoring (CGM) sensors from people with type 1 diabetes. More than 50,000 CGM sensor errors were added to original CGM signals from 25 clinical experiments, then the performance of error detection and functional redundancy algorithms were analyzed. The results indicate that the proposed system can successfully detect most of the erroneous signals and substitute them with reasonable estimated values computed by functional redundancy system. 相似文献
83.
Offshore operational conditions for wind farms differ from onshore especially because of their exposure to extreme weather, their remote locations and their inaccessibility in certain periods of the year. This brings a new challenge for the wind energy industry, which faces the need of more reliable systems. A common approach to improve reliability is to use component redundancies. Although this may be a good solution in some cases, it can also give undesirable consequences such as additional weight, need of additional space and cost increase. Another approach is to look at the functional capabilities of existing components to accomplish functions not initially intended to do so. In the event of a fault, these additional capabilities may be used to substitute the function of a faulty component and to have the system available for operation. This paper presents a new design philosophy based on functional redundancies and reconfiguration that can help to increase availability of wind turbines. It has a special impact on offshore applications where, in addition to the difficult accessibility, energy output per unit is more significant because of the continuous increase in sizes. An example is presented using a conceptual design of a wind turbine, showing how to find potential functional redundancies that can provide fault‐tolerant solutions and bring flexibility to the system's operation, at no significant additional weight and cost. The methodology is implemented in a software tool named Knowledge Intensive Engineering Framework, which supports functional representation and, more specifically, function‐behavior‐state modeling. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
84.
Ali Emrouznejad 《国际生产研究杂志》2017,55(22):6653-6675
Although many papers describe the evolution of the analytic hierarchy process (AHP), most adopt a subjective approach. This paper examines the pattern of development of the AHP research field using social network analysis and scientometrics, and identifies its intellectual structure. The objectives are: (i) to trace the pattern of development of AHP research; (ii) to identify the patterns of collaboration among authors; (iii) to identify the most important papers underpinning the development of AHP; and (iv) to discover recent areas of interest. We analyse two types of networks: social networks, that is, co-authorship networks, and cognitive mapping or the network of disciplines affected by AHP. Our analyses are based on 8441 papers published between 1979 and 2017, retrieved from the ISI Web of Science database. To provide a longitudinal perspective on the pattern of evolution of AHP, we analyse these two types of networks during the three periods 1979–1990, 1991–2001 and 2002–2017. We provide some basic statistics on AHP journals and researchers, review the main topics and applications of integrated AHPs and provide direction for future research by highlighting some open questions. 相似文献
85.
曾婷 《湖南城建高等专科学校学报》2014,(3):39-42
引入了一类由Cho-Kwon-Srivastava算子定义的新p-叶解析函数族.利用从属定理得到了此函数族上的从属关系、包含关系及一些卷积性质,推广了前人的一些结果. 相似文献
86.
We define the emerging research field of applied data science as the knowledge discovery process in which analytic systems are designed and evaluated to improve the daily practices of domain experts. We investigate adaptive analytic systems as a novel research perspective of the three intertwining aspects within the knowledge discovery process in healthcare: domain and data understanding for physician- and patient-centric healthcare, data preprocessing and modelling using natural language processing and (big) data analytic techniques, and model evaluation and knowledge deployment through information infrastructures. We align these knowledge discovery aspects with the design science research steps of problem investigation, treatment design, and treatment validation, respectively. We note that the adaptive component in healthcare system prototypes may translate to data-driven personalisation aspects including personalised medicine. We explore how applied data science for patient-centric healthcare can thus empower physicians and patients to more effectively and efficiently improve healthcare. We propose meta-algorithmic modelling as a solution-oriented design science research framework in alignment with the knowledge discovery process to address the three key dilemmas in the emerging “post-algorithmic era” of data science: depth versus breadth, selection versus configuration, and accuracy versus transparency. 相似文献
87.
88.
Unstructured and multi-objective task arrangement in radiation field is a complicating problem decision-makers are most concerned about. Proper task arrangement is helpful to improve efficiency of engineering and reduce hazard. The goal of this work is to discuss some criteria of task, build task hierarchy structure model, and then propose a task analytic method in radiation field based on analytic hierarchy process (AHP). The proposed method is useful for selection of schemes to reduce hazard and increase efficiency of task. In addition, we use this proposed method solve a hypothetical case, which is utilized to explain how the method works and to prove the method effective. 相似文献
89.
90.