Current Issue : January - March Volume : 2021 Issue Number : 1 Articles : 5 Articles
Load is one of the main causes of structural failure, and the correlation among loads would affect the evaluation results of\nstructural performance. The purpose of this paper is to analyze the influence of the correlation among multiple loads on the\nstructural reliability. In this paper, the nonparametric kernel density estimation (NKDE) method is used to estimate the\nprobability density function (PDF) of related loads. In addition, the mixed copula (M-Copula) model is proposed, which combines\nGumbel copula, Frank copula, Clayton copula, and weight coefficient, and the model parameters are fitted by MATLAB software\nto get the correlation of related loads. The reliability based on the related load combination is calculated according to the\nconstructed model. After analyzing three numerical cases, the results show that the probability characteristics of NKDE estimation\nare very close to the actual conditions, and the reliability calculated by the M-Copula model is larger than those calculated by JCSS,\nTurkstra, and Gong methods. Using the M-Copula model for load correlation would avoid underestimating the reliability of the\nstructure, which is conducive to structural economic development....
Several researches and case studies have been revealing a repetitive issue and\nthat is monopolization of controlling, measuring, and metering of the consumerâ??s\nbilling for the consumed Cloud Services. The Cloud Service Providers\n(CSPs) have been hiding, or monopolizing the controlling, metering tools\nand ignoring the calculation and consideration of the service defects like downtime,\nservice outage, poor performance and client service migration delays\nduring overloads of the servers. The main issues behind these discrepancies\nare the Service Level Agreement (SLA), its violation, and the monopolized\nCloud Governance. Till now there is a lack of parallel monitoring and metering\nsystem of the consumed cloud services at the customer level under the provisions\nof SLAs....
In cyber-physical systems, sensor transactions should be effectively scheduled to maintain the temporal validity of real-time data\nobjects. Previous studies on sensor transaction scheduling mainly focus on uniprocessor systems. In this paper, we study the\nproblem of data quality-based scheduling of sensor transactions on multiprocessor platforms. The data quality is defined to\ndescribe the validity degree of real-time data objects. Two methods, named the Partitioned Scheduling for Quality Maximization\n(P-QM) and the improved P-QM scheduling (IP-QM), are proposed. P-QM maximizes the data quality by judiciously determining\nthe preallocated computation time of each sensor transaction and assigns the transactions to different processors. IPQM\nimproves the data quality obtained from P-QM by adaptively executing transaction instances on each processor based on the\ncurrent status of the system. It is demonstrated through experiments that IP-QM can provide higher data quality than P-QM\nunder different system workloads....
In Ethiopia, the majority of rural household uses firewood with three-stone fire for cooking. Due to poor performance of the stove,\nthere are major health issues created by indoor air pollution. To alleviate this problem, various efforts are undergoing such as the\nuse of plant oil as an alternative fuel for cooking. This plantâ??s oils are available in the rural areas with minimal effort and water. In\nthis study, Jatropha oil was blended with kerosene to present it as an alternative fuel for the rural poor in Ethiopia. The blends of\nvarying proportions of Jatropha oil and kerosene were prepared, analyzed, and compared with the fuel properties of kerosene. ......................
For improving the reliability of key components in an airborne pod, gray system theory is introduced into the virtual design of\nairborne pod. Based on this theory, key components of airborne pod are analyzed and mathematical models of the gray relational\nmodel and absolute and relative gray relational model are established, respectively. The differences and relations of the three\nmethods for evaluating the robustness of products are researched. Considering the influence of relevant factors, the change rate of\neach evaluation index is calculated, and the reliability analysis of the airborne pod body is realized ultimately. Finally, the No. 2 test\npod body is the optimal solution, which provides an effective theoretical basis for determining the optimal structure of the\nairborne pod body....
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