U.G Science for a Changing World, "Geological survey science for a changing world: Worldwide earthquakes 2000–2015." Retrieved from http://earthquake.usgs.gov/earthquakes/browse/stats.php, 2016.
United Nations Development Programmer, Retrieved from http://www.undp.org/, 2016.
City of Kobe, "Comprehensive strategy for re-covery from the great Hanshin-Awaji earth-quake," pp. 25-43, 2011.
National Institute for Land and Infrastructure Management, "NILIM lews letter." Retrieved from http://www.nilim.go.jp/english/nnl/no57p.pdf, 2016.
M. Yanagi, "Study of base isolation system for railroad side buildings," SWCC Showa Group Technical Review, vol. 58, pp. 57-62, 2008.
K. Moriya, "Development of a variable damper using MR fluid," Journal of the Faculty of Science and Technology Seikei University, vol. 43, pp. 1-8, 2006.
JCAST, "JCAST business news business & media watch." Retrieved from http://www.j-cast.com/2016/04/22264988.html, 2016.
K. Takahara, "Characteristic analysis and trial manufacture of permanent-magnetic type linear generator," IEEJ Transactions on Industry Applications, vol. 127, pp. 669-674, 2007.
K. Kubo, "Measurement of basic characteris-tics of electromagnetic linear actuator," presented at the Record of Joint Conference of Electrical and Electronics Engineers in Kyushu, 2010.
T. Adachi and K. Takahara, "Analysis and measurement of damping characteristic of linear generator," International Journal of Applied Electromagnetics and Mechanics, vol. Preprint, pp. 1-8, 2016. View at Google Scholar | View at Publisher
Takahito ADACHI , Kenji TAKAHARA (2016). Structural Design of A Linear-Motion Type Semi-Active Damper by Finite Element Method. International Journal of Natural Sciences Research, 4(6): 107-111. DOI: 10.18488/journal.63/2016.4.6/126.96.36.199
The purpose of this study is to design a structure of a linear-motion
type semi-active damper which can reduce the vibration caused by an
earthquake. This paper proposes the more effective structure of the
linear motion semi-active damper by magnetic-structure interaction
analysis of finite element method using ANSYS. The semi-active damper
has a simple structure that a linear mover, a magnet bar, reciprocates
in coils of a stator. The size of the coils and the size of the magnetic
material cover which can produce the maximum damping force are
simulated under the condition that the size of the mover is fixed. The
electromotive force is calculated based on the change of the produced
magnetic field according to the change of the given velocity of the
mover in a short time. The damping force is calculated according to the
electric current which the electromotive force supplies to the connected
resistance. By the simulations, more than 120 [N s/m] of the maximum
damping coefficient is acquired in the case that the coil is wound up
from 28.0[mm] of the inner diameter to 60.0 [mm] of the outer diameter.
Improving Cloud System Performances by Adopting Nvram-Based Storage Systems
E. Lee, J. Jang, T. Kim, and H. Bahn, "On-demand snapshot: An efficient versioning file system for phase-change memory," IEEE Transactions on Knowledge and Data Engineering, vol. 25, pp. 2841-2853, 2013.
E. Lee, S. Yoo, and H. Bahn, "Design and implementation of a journaling file system for phase-change memory," IEEE Transactions on Computers, vol. 64, pp. 1349-1360, 2015.
E. Lee and H. Bahn, "Caching strategies for high performance storage media," ACM Transactions on Storage, vol. 10, pp.1-22, 2014.
L. Belady, "A study of replacement of algorithms for a virtual storage computer," IBM Systems Journal, vol. 5, pp. 78–101, 1996.
K. Lee, I. Doh, J. Choi, D. Lee, and S. H. Noh, "Write-aware buffer cache management scheme for nonvolatile RAM," presented at the IASTED International Conference: Advances in Computer Science and Technology, 2007.
D. Roselli, J. R. Lorch, and T. E. Anderson, "A comparison of file system workloads," presented at the USENIX Annual Technical Conference, 2000.
Jisun Kim , Yunjoo Park , Sunhwa A. Nam , Hyunkyoung Choi , KyungWoon Cho , Hyokyung Bahn (2016). Improving Cloud System Performances by Adopting Nvram-Based Storage Systems. International Journal of Natural Sciences Research, 4(6): 100-106. DOI: 10.18488/journal.63/2016.4.6/188.8.131.52
NVRAM is being considered as an additional memory/storage component of
future cloud computing systems. This paper investigates how much
performance improvement can be obtained if we add NVRAM as the
memory/storage media of cloud systems. As NVRAM is put on DDR slots, it
is byte-accessible and hence can be used as a memory medium like DRAM.
It can also be utilized as swap or journal devices if we use it as a
block I/O device. We first consider NVRAM as a storage cache, and then,
we measure the performance of systems that additionally use NVRAM as
memory, swap, and journal devices. We use two workloads, I/O and memory
intensive workloads. Our experiments show that using NVRAM as a journal
device performs the best in I/O-intensive workload as it performs
journaling I/O on NVRAM instead of slow storage. Using NVRAM as memory
or swap devices does not show good results in I/O-intensive workload.
However, in case of memory-intensive workload, NVRAM memory
significantly improves the performance, and NVRAM swap also gains a
certain level of improvement. We expect that our experiments will be
helpful in the design of NVRAM-based cloud systems for memory or I/O
intensive workload situations.
The paper’s primary contribution is finding the NVRAM’s effectiveness on
the performance of future cloud systems. Specifically, we show the
effectiveness of NVRAM if it is used as storage cache, main memory,
journal device, or swap device in the memory hierarchy of cloud