Economic development through knowledge creation

노트 : Proceedings of the 34th Hawaii International Conference on System Science

Quark number Susceptibility and Phase Transition in hQCD Models

We study the quark number susceptibility, an indicator of QCD phase transition, in the hard wall and soft wall models of hQCD. We find that the susceptibilities in both models are the same, jumping up at the deconfinement phase transition temperature. We also find that the diffusion constant in the soft wall model is enhanced compared to the one in the hard wall model.Comment: 14 pages, 2 figure

The Origin of Taegilm, the Large Transverse Flute of Korea

The taegum (大笒), a large transverse flute having various tone colors such as a clear dignified sound and a fascinating sound produced by a vibrating reed membrane, can be divided into two categories: the classical taegum and the folkloric taegCtm. The former is widely used in classical music such as the court music, the ensemble music of the literati, and the accompaniment of classical songs, and the latter in folk music such as improvised ensemble music (shinawi), solo instrumental music (sanjo), and the accompaniment of folk songs. Owing to the exciting vibration of the reed membrane, the taegum proves its worth particularly in solo performances. The first written reference to the taegum appears in the Samguk sagi (三國史記, Chronicles of the Three Kingdoms). Other historical treatises and archaeological findings prove that the prototype of the taegum, the hoengjok(橫笛), was already in use during the early years of the Koguryo Kingdom(37 BC-AD 668), which had accepted the music from the so-called Western Region (西城), the present Central Asia and Indian region. The taegum, one of three bamboo transverse flutes (taegum, chunggum, 中笒, and sogum, 小笒) of the Shilla Kingdom (57 BC-AD 935), is a legacy of the musical culture of the Koguryo and Paekche Kingdom. 장중하면서도 맑은 소리와, 갈대청을 울려 장쾌한 소리를 내는 등 다양한 음빛깔을 구사하는 大笒은 그 용례에 따라 정악대금과 산조대금의 두 종류로 구분된다. 즉 수제천이나 여민락 등 궁중의 어전에서 연주되던 雅樂과 宴禮樂·祭禮樂은 물론 영산회상 등 민간의 줄풍류나 대풍류, 가곡·가사·시조의 반주에 이르기까지 正樂계통의 음악 전반에 걸쳐 사용되는 정악대금과, 시나위나 산조·민요반주 등 민속음악에 사용되는 산조대금이 바로 그것이다. 이러한 대금은 장쾌한 갈대막의 떨림소리 때문에 특히 독주곡에서 그 진가를 발휘한다. 대금은 『三國史記』에 처음 기록이 나타나는데, 여러 고고학 자료와 문헌사료를 검토한 결과, 대금의 전신인 橫笛이나 笛 등의 악기가 고구려와 백제에서 이미 사용되었으며, 그에 따라 대금을 포함한 신라의 三竹은 신라가 삼국통일 이후 고구려와 백제의 음악문화를 수용한 결과라고 한다

Progressive Processing of Continuous Range Queries in Hierarchical Wireless Sensor Networks

In this paper, we study the problem of processing continuous range queries in a hierarchical wireless sensor network. Contrasted with the traditional approach of building networks in a "flat" structure using sensor devices of the same capability, the hierarchical approach deploys devices of higher capability in a higher tier, i.e., a tier closer to the server. While query processing in flat sensor networks has been widely studied, the study on query processing in hierarchical sensor networks has been inadequate. In wireless sensor networks, the main costs that should be considered are the energy for sending data and the storage for storing queries. There is a trade-off between these two costs. Based on this, we first propose a progressive processing method that effectively processes a large number of continuous range queries in hierarchical sensor networks. The proposed method uses the query merging technique proposed by Xiang et al. as the basis and additionally considers the trade-off between the two costs. More specifically, it works toward reducing the storage cost at lower-tier nodes by merging more queries, and toward reducing the energy cost at higher-tier nodes by merging fewer queries (thereby reducing "false alarms"). We then present how to build a hierarchical sensor network that is optimal with respect to the weighted sum of the two costs. It allows for a cost-based systematic control of the trade-off based on the relative importance between the storage and energy in a given network environment and application. Experimental results show that the proposed method achieves a near-optimal control between the storage and energy and reduces the cost by 0.989~84.995 times compared with the cost achieved using the flat (i.e., non-hierarchical) setup as in the work by Xiang et al.Comment: 41 pages, 20 figure

Test Platform Development of Vessel???s Power Management System Using Hardware- in-the-Loop-Simulation Technique

A PMS (Power Management System) controls vessel's power systems to improve the system efficiency and to protect a blackout condition. The PMS should be developed with considering the type and the capacity of the vessel???s power system. It is necessary to test the PMS functions developed for vessel???s safe operations under various sailing situations. Therefore, the function tests in cooperation with practical power systems are required in the PMS development. In this paper, a hardware-in-the-loop (HIL) simulator is developed for the purposes of the PMS function tests. The HIL simulator can be more cost-effective, more time-saved, easier to reproduce, and safer beyond the normal operating range than conventional off-line simulators, especially at early stages in development processes or during fault tests. Vessel's power system model is developed by using a MATLAB/SIMULINK software and by communicating between an OPAL-RT???s OP5600 simulator. The PMS uses a Modbus communication protocol implemented using LabVIEW software. Representative tests of the PMS functions are performed to verify the validity of the proposed HIL-based test platform

Free Vibration of Axially Functionally Graded Timoshenko Circular Arch

Functionally graded materials are innovative composites of hybrid ceramics and metals that exhibit excellent mechanical performance in harsh temperature environments and under various external loads. In this study, the free vibrations of Timoshenko circular arches, made of functionally graded materials in the axial direction, are investigated. The material properties of Young's modulus and mass density of the arch vary according to a symmetric quadratic function along the arch axis. Differential equations governing the free vibration of the arch including the rotatory inertia and shear deformation, called the Timoshenko arch, are derived. A novel numerical solution method is developed to calculate the natural frequencies and mode shapes of the arch. Parametric studies of the modular ratio, shear correction factor, shear modulus ratio, and slenderness ratio on the natural frequencies are conducted, and the results are reported in the tables and figures