Scour depth around multiple piles for current and wave

Experiments on scour around multiple piles were carried out for several current and wave conditions: pile numbers were 1, 3, and 7; and wave only, current only, and current and wave flows. A moderate wave condition was chosen as the representative wave, which produced relatively small scour depth. A depth-average current speed was chosen as the representative current, which produced relatively large scour hole. When waves were superimposed on current, scour hole depth decreased. Existing the Sumer and Fredsøe’s prediction formula of scour hole depth for current and wave flows for multiple piles describes the present experimental results reasonably well

Design and Analysis of Multiple OS Implementation on a Single ARM-Based Embedded Platform

Recently, with the development of embedded system hardware technology, there is a need to support various kinds of operating system (OS) operation in embedded systems. In mobile processors, ARM started to provide the virtualization extension support technology which was intended for processors in PC processors. Virtualization technology has the advantage of using hardware resources effectively. If the real-time operating system (RTOS) is operated on a hypervisor, there is a problem that RTOS performance is degraded due to overhead. Thus, we need to compare the performance between a single execution of the RTOS and simultaneous execution of multiple OS (RTOS + Linux). Therefore, in this paper, we measure the performance when the RTOS operates independently on the NVidia Jetson TK-1 embedded board supporting virtualization technology. Then, we measure the performance when the RTOS and Linux are operating simultaneously on top of a hypervisor. For this purpose, we implemented and ported such a RTOS, especially FreeRTOS and uC/OS, onto two embedded boards, such as the Arndale board (SAMSUNG, Seoul, South Korea) and the NVidia TK1 board (NVIDIA, Santa Clara, CA, USA)

Power and Public Space: A Historical Observation of Seoul Plaza

Power creates and changes space. Power may be various forms of authority, individual or social structure, complex situations or an unidentifiable force. This study focuses on understanding how power influences a space which is a social product of the exercise of power, thus re-defining power in spatial practices as an extensive introduction to the literature on power. This historical observation study conducts a case review on Seoul Plaza, a socio-political center of downtown Seoul, South Korea. A systematic review of widespread media coverage of the space and its events was performed, using newspaper articles and governmental database search systems for the time period from 1922 to 2016. Believing that power is as an endless structural process of competition and positing in which three social entities, authority, market and people, interplay towards an equilibrium stage of the process, this study concludes that a public space can be formed, transformed or characterized based on outcomes of such power competitions among social entities depending on their social status and how they are displayed