著者

KIM Suk Woo LEE Jin Ho CHUN Kun Woo

出版者

公益社団法人 砂防学会

雑誌

International Journal of Erosion Control Engineering

巻号頁・発行日

vol.1, no.2, pp.44-53, 2008

被引用文献数

3

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Recent climate change caused by global warming has affected the environment in Korea, resulting in increased precipitation and frequency and magnitudes of typhoons. From 1994-2003, a mean of 2.3 days/year experienced heavy rainfall (≥80 mm), in contrast to a mean of 1.6 days/year from 1954-1963. Of the ten typhoons that have resulted in the maximum daily rainfall over the last ten decades, seven occurred between 1990 and 2007. The maximum instantaneous wind velocity of typhoons has greatly increased from 20 m/sec (in the 1970s) to 40 m/sec (in the 2000s). Furthermore, increases in the occurrence and scale of forest fires and landslides, as well as increased infrastructure and land use, contribute to sediment disasters. Accordingly, environmental changes and human-induced factors have resulted in significant increases in the magnitude and frequency of natural disasters, especially in the Gangwon region on the east coast of Korea. Therefore, in 2004 the Korea Forest Service instituted an integrated and environmentally-friendly system for forest management, which has helped prevent sediment disasters. Multiple prevention strategies are also required in addition to these systemic changes to forest structure management, including control of hill-slope erosion and torrent erosion, debris flow mitigation, water storage and slit dams, grade-stabilization structures and forest improvement, and watershed management.

著者

Kang Sung-Mook Lee Jin-Eui Kim Wan-Chin Park No-Cheol Park Young-Pil Cho Eun-Hyoung Sohn Jin-Seung Suh Sung-Dong

出版者

Published by the Japan Society of Applied Physics through the Institute of Pure and Applied Physics

雑誌

Jpn J Appl Phys (ISSN:00214922)

巻号頁・発行日

vol.45, no.8, pp.6723-6729, 2006-08-30

被引用文献数

12

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In this study, a small-form-factor optical pickup (SFFOP), corresponding to the Blu-ray disc (BD) specifications has been developed. The developed SFFOP is composed of an integrated optical pickup and a swing-arm-type actuator. The integrated optical pickup has been developed in the form of an array using wafer-level fabrication technology. The developed SFFOP is composed of the fundamental optics which yields a numerical aperture (NA) of 0.85 and uses a blue laser diode having a short wavelength of 407 nm and a silicon optical bench, which consists of a laser diode, a photodiode and several mounts for the laser diode, an objective lens and mirrors. The micro objective lens is bonded to the lens holder on the SFFOP by an active alignment using a modified Mach–Zehnder interferometer. Also, a static focus error signal was detected to assemble a polarized holographic optical element. Through the measurement of the focus error signal with a swing-arm-type actuator, which was developed for the SFFOP, it is estimated that the developed SFFOP satisfies the BD specifications with the balance of the focus error signal below 10%.

著者

HUANG Min Li LEE Jin SETIAWAN Hendra OCHI Hiroshi PARK Sin-Chong

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

IEICE transactions on communications (ISSN:09168516)

巻号頁・発行日

vol.93, no.4, pp.948-960, 2010-04-01

参考文献数

15

被引用文献数

1 2

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With the growing demand for high-performance multimedia applications over wireless channels, we need to develop a Medium Access Control (MAC) system that supports high throughput and quality of service enhancements. This paper presents the standard analysis, design architecture and design issues leading to the implementation of an IEEE 802.11e based MAC system that supports MAC throughput of over 100Mbps. In order to meet the MAC layer timing constraints, a hardware/software co-design approach is adopted. The proposed MAC architecture is implemented on the Xilinx Virtex-II Pro Field-Programmable Gate Array (FPGA) (XC2VP70-5FF1704C) prototype, and connected to a host computer through an external Universal Serial Bus (USB) interface. The total FPGA resource utilization is 11, 508 out of 33, 088 (34%) available slices. The measured MAC throughput is 100.7Mbps and 109.2Mbps for voice and video access categories, transmitted at a data rate of 260Mbps based on IEEE 802.11n Physical Layer (PHY), using the contention-based hybrid coordination function channel access mechanism.

著者

Kim Chang-Hwan Lee Beom-Jun Yoon Junghee SEO Kang-Moon PARK Jong-Hwan LEE Jin-Won CHOI Eun-Sil HONG Jung-Ju LEE Yong-Soon PARK Jae-Hak

出版者

社団法人日本獣医学会

雑誌

The journal of veterinary medical science (ISSN:09167250)

巻号頁・発行日

vol.63, no.10, pp.1083-1089, 2001-10

被引用文献数

19

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実験的に誘発された羊骨関節症において, 連鎖球菌により合成されるヒアルロン酸(HA, MW:3.5×10^6)によって症状軽減が観察された.顎関節(TMJs)の両側骨関節症(OA)は, 関節円板に穴を開け, 軟骨下まで関節顆表面を掻き取ることにより引き起こされた.HAを術後7, 10, 14, 17, 21日に6頭の左関節に関節内投与し, 対照として, 生理食塩水を同じ日に反対側(右)の関節内に投与した.術後1ヶ月(1MPO)で羊3頭を殺処分し, 3MPOで残りの3頭を殺処分した.線維組織の増殖, 剥離, び爛, 骨増殖体形成, 皮質下嚢胞形成, 関節強直などの色々な反応がX線写真や病理組織学的検索により観察された.HAの処置は変性的変化を改善し, 右関節と比較して, 1MPO(9.96対5.81)と3MPO(10.86対5.29)において左関節の骨関節症スコアーを低下させた.これらの結果は, HAの関節内への繰り返し投与は, 羊TMJsの関節軟骨の発達を促すことにより, また線維組織の増殖を減じることにより, OAの進行を抑制することを示している.