Papers by Keyword: Probability Theory

Abstract: Critical Chain Project Management (CCPM) is based on a network planning and the Theory of Constraints. The importance of management of uncertainty and deviations that occur during a project is emphasized. The probability of the project completion in a predefined time limit, or even before the time limit is increased. Literature analysis indicates that other types of buffers must be applied (buffer supporting a project, buffer reacting on a critical path, buffer reacting on a non-critical path) apart of feeding, resource and project buffers. Applying the additional buffers keeps the critical path in the same position and maintains the unchanging due date of the project. Methods estimating size of feeding and project buffers are identified: half of the chain method, square root of fault method, modified method of square root of fault, method taking into account due date of the project. In this paper, a new method estimating a size of resource buffer and selecting a location of resource buffer based on the theory of probability is presented. In this paper, the CCPM method is applied to estimate due date of the mining machine production project.

Abstract: This paper discusses the main issues of Uncertainty Analysis (UA) in general and also argues and illustrates its particular relevance to structural dynamics. Brief descriptions are given of the most prevalent of the many frameworks for uncertainty representation. The three main uncertainty-related problems of relevance to structural dynamics are then discussed, namely quantification, fusion and propagation. In order to illustrate the application of ideas of UA in a realistic scenario, there then follows a case study conducted on an aerospace structure, namely the wing of a Gnat trainer aircraft. The case study considers evidence-based classifiers as an alternative to probabilistic classifiers for the problem of damage location within the context of Structural Health Monitoring. Dempster-Shafer theory is employed to construct neural network classifiers with the potential to admit ignorance, rather than misclassify.

Abstract: The paper has put forward an idea about the teaching reform of probability and statistics for financial mathematics. We have paid attention to the theory contact with practice. By constructing the teaching reform, particularly, paying more attentions to mathematical experiment, cultivating the stochastic thinking mode, improving the single teaching method, we present a new teaching curriculum reform and seek new teaching modes. With teaching reform and practice, students comprehensive quality can be improved and better teaching results can be gained.

Abstract: This article put forward drilling mechanism reliability evaluation method on the lunar surface based on probability theory of stress-strength according to the characteristic, working environment and force condition of drilling automatic sampling mechanism on the lunar surface, ABAQUS was utilized to model and simulate the drilling automatic sampling mechanisms, and the dynamic distribution of stress of drilling automatic sampling mechanisms was obtained. According to analytic system reliability and the reliability evaluation reasonably, the optimization allocation to the use of material and system reliability can be realized.

Abstract: Deformation of shaft and turning process control mechanism were studied. When its clamping methods were different, its theoretical mechanics models were established. Based on probability theory, considering the randomness of cutting force, elastic modulus, its length and its diameter, its theoretical model was established to calculate its standard deviation of the roundness and typical parameters process systems were calculated. Moreover, its dynamic response finite element model was established, and the model was verified through comparison with the theoretical calculation results. The study provides the method and theoretical basis for the precision turning process planning.

Abstract: Deformation of the big-diameter length rate shaft and turning process control mechanism were studied. When it was supported by the central frame, its theoretical mechanics models were established. Based on probability theory, considering the randomness of cutting force, elastic modulus, its length and its diameter, its theoretical model was established to calculate its standard deviation of the roundness. Moreover, its dynamic response finite element model was established, and the model was verified through comparison with the theoretical calculation results. The study provides the method and theoretical basis for the precision turning process planning of the big-diameter length rate shaft.

Abstract: Everyday engineering work is rife with uncertainty and complexity. Some of the uncertainty stems from highly variable natural phenomena such as wind and earthquakes. More prevalent is the uncertainty that arises from a simple lack of knowledge, especially in complex problems. This paper describes the key considerations of designing, manufacturing, and installing large amusement devices, with characteristics complex and uncertain by nature. A range of techniques for engineering decision-making and reasoning in the presence of uncertainty and complexity are described. The techniques may be applied throughout the design and manufacturing process, but are particularly effective in the early or conceptual stages, which are characterized by greater uncertainty than the latter design phases. The techniques described include qualitative reasoning, adaptive interval plotting, design space mapping, and design space reliability estimation. These methods allow the engineer to solve and visualize the design space. In contrast to engineering problem-solving approaches which find a single point configuration, a design space may include a large number of feasible solutions. The range of solutions may be used effectively in engineering decision making.

Abstract: In this paper, taking the characteristics of NGI (Next Generation Internet) into account, and base on its network model and mathematical model, a probability theory based intelligent QoS multicast routing algorithm is presented. Under inaccurate information of QoS parameters, using fast searching ability of DE (Differential Evolution), the proposed algorithm tries to find a multicast routing tree with the maximum probability of meeting with QoS requirement under the given cost. Simulation results have shown that the proposed algorithm is both feasible and effective.

Abstract: According to traffic operation characteristics and lane changing maneuvers, combining with the export notice signs and considering the worst driving conditions, the gap acceptance theory and kinematics are employed to establish the length of lane change operation between interchanges with probability theory. To operating speed as the premise, the necessary length that drivers change to the inside lane from the nearside lane is analyzed in terms of waiting for the gap acceptance, and the necessary length that drivers change to the nearside lane from the inside lane is also analyzed in terms of running for the gap acceptance, then calculation model of minimum net distance between interchanges on eight-lane expressway is constructed. The recommended value is then put forward.

Abstract: Based on the author’teaching practice, this paper introduced some learning and experience from teaching in Probability Theory and Mathematical Statistics. The main content includes five aspect as follows：Integrate with historical backgrounds and inspire the passion of students,Apply ways of induction and analogy in order to deepen the comprehension of conceptions, Combine theory teaching and modeling teaching, Highlight the applied background of fundamental conceptions in class,Utilize computer aided instruction and visualize abstract content, etc.