(A) Study on the Vibration Analysis of a Power Transmission Converter by Sub-structure Synthesis Method

This study intends to improve the machinery properties by reducing the weight of the converter without changing the dynamic characteristics. At first, the Vibration analyses by the Substructure Synthesis Method and by F.E.A using the ANSYS are performed for the converter model to confirm the reliability of the analyzing tools. Weight minimization is performed by the Sensitivity Analysis and the Optimum Structural Modification. To decrease the converter weight ideally, the weight parts with low sensitivity is to be cut mainly, and the changing quantity of the natural frequency by the cut is to be recovered by the weight modification of the parts with high sensitivity. Mathematically unique solution for the homogeneous problem( i. e. 0 object function problem) does not exist, then the converter is redesigned with much thinner initial thickness, The natural frequencies and natural modes of original structure by the sensitivity analysis, and then observed the Frequency Response Functions(FRF) are observed for some interesting points. In this analysis, the original thickness of the converter model is 84 mm, and the redesigned initial thickness is 60 mm and 70 mm. And the numbers of the interesting natural frequencies are 1, 2, 4 respectively. The results are as follows : (1) The weight for the each case could be reduced without changing the objective natural frequencies. (2) According to the exciting frequency range of the converter, effective weight minimization is possible. For the case of narrow frequency band, weight reduction effect is higher than that of wide frequency band's. (3) The method could be applied not only for the weight minimization, but also for the improvement of dynamic characteristics of the converter

MEBN-RM: A Mapping between Multi-Entity Bayesian Network and Relational Model

Multi-Entity Bayesian Network (MEBN) is a knowledge representation formalism combining Bayesian Networks (BN) with First-Order Logic (FOL). MEBN has sufficient expressive power for general-purpose knowledge representation and reasoning. Developing a MEBN model to support a given application is a challenge, requiring definition of entities, relationships, random variables, conditional dependence relationships, and probability distributions. When available, data can be invaluable both to improve performance and to streamline development. By far the most common format for available data is the relational database (RDB). Relational databases describe and organize data according to the Relational Model (RM). Developing a MEBN model from data stored in an RDB therefore requires mapping between the two formalisms. This paper presents MEBN-RM, a set of mapping rules between key elements of MEBN and RM. We identify links between the two languages (RM and MEBN) and define four levels of mapping from elements of RM to elements of MEBN. These definitions are implemented in the MEBN-RM algorithm, which converts a relational schema in RM to a partial MEBN model. Through this research, the software has been released as a MEBN-RM open-source software tool. The method is illustrated through two example use cases using MEBN-RM to develop MEBN models: a Critical Infrastructure Defense System and a Smart Manufacturing System

Electron Beam Supercollimation in Graphene Superlattices

Although electrons and photons are intrinsically different, importing useful concepts in optics to electronics performing similar functions has been actively pursued over the last two decades. In particular, collimation of an electron beam is a long-standing goal. We show that ballistic propagation of an electron beam with virtual no spatial spreading or diffraction, without a waveguide or external magnetic field, can be achieved in graphene under an appropriate class of experimentally feasible one-dimensional external periodic potentials. The novel chiral quasi-one-dimensional metallic state that the charge carriers are in originates from a collapse of the intrinsic helical nature of the charge carriers in graphene owing to the superlattice potential. Beyond providing a new way to constructing chiral one-dimensional states in two dimensions, our findings should be useful in graphene-based electronic devices (e.g., for information processing) utilizing some of the highly developed concepts in optics.Comment: 7 pages, 4 figures (including supporting online material), published online in Nano Letter

COMPARATIVE ANALYSIS OF YANG HAK-SEON VAULT AND TSUKAHARA 1260? VAULT IN GYMNASTICS

The study was a single-subject study on the top-elite vaulter in the world. This study was purposed to compare kinematic differences between Yang Hak-Seon vault (Yang-1) and Tsukahara 1260? vault (Yang-2) performed by Yang Hak-Seon. Fourteen high-speed cameras were used to capture a whole body segment motion of Yang-2 vault during the practice session. Yang-1 vault showed faster CM vertical velocity until the vault table takeoff and faster CM horizontal velocity prior to the vault table touchdown. However, the trunk rotation angle and its angular velocity of Yang-2 vault exceeded Yang-1 vault significantly. This might be due to a half turn off the springboard onto the vault table of Yang-2 vault, which resulted in larger initial angular momentum at the vault table touchdown and further increase in angular velocity during the vault table contact