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Copyright of Control Theory & Applications / Kongzhi Lilun Yu Yinyong is the property of Editorial Department of Control Theory & Applications and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

BACKGROUND: Multi - collector inductively coupled plasma - mass spectrometry ( MC - ICP - MS) has been widely applied to accurate and precise measurements of isotope ratios due to its high sample throughput, strong ionization ability of ICP sources and high mass resolution. For decades, the standard - sample bracketing (SSB) method has been used to correct for instrumental mass bias during the measurement to achieve accurate results. When the content of the target isotope in samples is low, the measurement results are easily influenced by the background signals. “On Peak Zero” correction deducts the background signal from the total signal, which is an effective method to eliminate the background interference and has been widely used, but no research has been conducted to systematically explore the mathematical principles behind this correction. OBJECTIVES: To establish a mathematical model for the “On Peak Zero” correction, and verify its confidence by applying it to isotope measurements of different concentrations of Li, S, Fe, Sr, Nd and Pb standard solutions. METHODS: In this study, a mathematical model of the influence by the background signal on isotopic composition was established by mathematical reasoning and approximate substitution. Standard solutions of different concentrations of Li, S, Fe, Sr, Nd and Pb were prepared for the application of the “On Peak Zero” method through experimental analysis. Two types of blank signals were subtracted separately from the aggregate signals to simulate isotope measurements without and with “On Peak Zero” correction. RESULTS: The results indicate that the lower the concentration of the target element, the greater is the blank solution signal influence on the accuracy of the sample to be tested, and the “On Peak Zero” method can better eliminate the influence of the blank solution on the sample measurements. The simulation results based on this model were consistent with the real experimental results in this study. CONCLUSIONS: The mathematical model and the data explain well the effect of background concentration on the experimental isotope values, and are useful for understanding the application of the “On Peak Zero” method in MC-ICP-MS isotope analysis. [ABSTRACT FROM AUTHOR]

Quantifying the related concepts of propositional logic is a new method of propositional logic research. It is differe.nt from the syntax and semantics method and is a powerful tool for studying the structure of propositional sets. By using the Jaccard similarity coefficient, this paper introduces the concepts of Jaccard similarity degree, Jaccard pseudo-metric and Jaccard similarity degree representation method of the truth degree of a formulae in quantitative logic, and constructs a new kind of quantitative model of logic system L. This paper investigates the basic properties of Jaccard logic metric space[(F(S),ρJ),]which is induced by Jaccard pseudo-metric. This paper gets the following results: firstly, contradictory is the only isolated point in logic metric space[(F(S),ρJ);]secondly, every non-empty sphere in [(F(S),ρJ)]is an inconsistency theory.

As a decision support system,fuzzy system can deal with uncertainty and has a clear representation of uncertainty knowledge and inference process.But one problem that exists is that computerized decision support systems,including systems that use fuzzy methods,do not have a clear assessment method to determine whether they can be allowed to be used in the real world.A conceptual framework of indistinguishable lines as a key component in evaluating computerized decision support systems was proposed,and some case studies were given.The case proves that the performance of human experts is not perfect,and the fuzzy system can simulate human performance at the technical level,including the variation of human experts.In summary,fuzzy methods are necessary for the representation and reasoning of uncertainty of the knowledge-based systems.Variation is an important form of learning.When evaluating AI systems,imperfect performance should be accepted.

Copyright of Journal of Frontiers of Computer Science & Technology is the property of Beijing Journal of Computer Engineering & Applications Journal Co Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of China Sciencepaper is the property of China Sciencepaper and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)