817 research outputs found

    LL-fuzzy ideal degrees in effect algebras

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    summary:In this paper, considering LL being a completely distributive lattice, we first introduce the concept of LL-fuzzy ideal degrees in an effect algebra EE, in symbol Dei\mathfrak{D}_{ei}. Further, we characterize LL-fuzzy ideal degrees by cut sets. Then it is shown that an LL-fuzzy subset AA in EE is an LL-fuzzy ideal if and only if Dei(A)=,\mathfrak{D}_{ei}(A)=\top, which can be seen as a generalization of fuzzy ideals. Later, we discuss the relations between LL-fuzzy ideals and cut sets (LβL_{\beta}-nested sets and LαL_{\alpha}-nested sets). Finally, we obtain that the LL-fuzzy ideal degree is an (L,L)(L,L)-fuzzy convexity. The morphism between two effect algebras is an (L,L)(L,L)-fuzzy convexity-preserving mapping

    Load reduction of a monopile wind turbine tower using optimal tuned mass dampers

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    We investigate to apply tuned mass dampers (TMDs) (one in the fore–aft direction, one in the side– side direction) to suppress the vibration of a monopile wind turbine tower. Using the spectral element method, we derive a finite-dimensional state-space model d from an infinite-dimensional model d of a monopile wind turbine tower stabilised by a TMD located in the nacelle. and d can be used to represent the dynamics of the tower and TMD in either the fore–aft direction or the side– side direction. The wind turbine tower subsystem of is modelled as a non-uniform SCOLE (NASA Spacecraft Control Laboratory Experiment) system consisting of an Euler–Bernoulli beam equation describing the dynamics of the flexible tower and the Newton–Euler rigid body equations describing the dynamics of the heavy rotor-nacelle assembly (RNA) by neglecting any coupling with blade motions. d can be used for fast and accurate simulation for the dynamics of the wind turbine tower as well as for optimal TMD designs. We show that d agrees very well with the FAST (fatigue, aerodynamics, structures and turbulence) simulation of the NREL 5-MW wind turbine model. We optimise the parameters of the TMD by minimising the frequency-limited H2-norm of the transfer function matrix of d which has input of force and torque acting on the RNA, and output of tower-top displacement. The performances of the optimal TMDs in the fore–aft and side–side directions are tested through FAST simulations, which achieve substantial fatigue load reductions. This research also demonstrates how to optimally tune TMDs to reduce vibrations of flexible structures described by partial differential equations

    Theory-driven Bilateral Dynamic Preference Learning for Person and Job Match: A Process-oriented Multi-step Multi-objective Method

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    Person-job matching is a typical dynamic process with bilateral interactions between job seekers and jobs, along with sample imbalance issues. These characteristics pose significant challenges when designing an intelligent person-job match method. In this paper, we propose a novel process-oriented view of the person-job matching problem and formulate it as a multi-step multi-objective bilateral match learning problem. Our method combines profile features and historical sequential behaviors to learn the bilateral attributes and dynamic preferences, with multimodal data integrated through various attention mechanisms, such as the orthogonal multi-head and gated mechanisms. The method includes a sequence update module to learn the bilateral preferences and their updates sensitive to feedback. Furthermore, the multi-step constraint effectively solves the problem of imbalanced samples through partial relationships and information transmission between multi-objectives. Abundant experiments show that our method outperforms state-of-the-art methods in providing successful matches and improving recruitment efficiency
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