著者
László Oláh Gergő Hamar Shinichi Miyamoto Hiroyuki K. M. Tanaka Dezső Varga
出版者
社団法人 物理探査学会
雑誌
物理探査 (ISSN:09127984)
巻号頁・発行日
vol.71, pp.161-168, 2018 (Released:2018-12-28)
参考文献数
42
被引用文献数
3 4

Muography is an emerging visualization technique for inspection of large-sized objects with the measurement of the absorption rate of cosmic-ray muons. Present paper introduces the first prototype of a Multi-Wire-Proportional-Camber (MWPC)-based borehole detector. The designed tracking system is based on the so-called Close Cathode Chamber (CCC) concept, which provides easily handling and robust detectors. The 18-cm-length detector is covering a sensitive area of 20 cm × 32 cm and an angular acceptance up to 60 deg with close to full tracking efficiency (99 %), reasonable position resolution of 1.8 mm and angular resolution of 10 mrad. The detector has been tested inside a shallow shaft and an underground iron pillar with concrete basement has successfully been imaged with the resolution of 15 cm within 15 days, which indicates the future industrial usage of MWPC detectors and encourages the application oriented development of this technology for borehole-based muography.
著者
Kei SAKAGUCHI Ehab Mahmoud MOHAMED Hideyuki KUSANO Makoto MIZUKAMI Shinichi MIYAMOTO Roya E. REZAGAH Koji TAKINAMI Kazuaki TAKAHASHI Naganori SHIRAKATA Hailan PENG Toshiaki YAMAMOTO Shinobu NANBA
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.E98-B, no.10, pp.1932-1948, 2015-10-01

Millimeter-wave (mmw) frequency bands, especially 60GHz unlicensed band, are considered as a promising solution for gigabit short range wireless communication systems. IEEE standard 802.11ad, also known as WiGig, is standardized for the usage of the 60GHz unlicensed band for wireless local area networks (WLANs). By using this mmw WLAN, multi-Gbps rate can be achieved to support bandwidth-intensive multimedia applications. Exhaustive search along with beamforming (BF) is usually used to overcome 60GHz channel propagation loss and accomplish data transmissions in such mmw WLANs. Because of its short range transmission with a high susceptibility to path blocking, multiple number of mmw access points (APs) should be used to fully cover a typical target environment for future high capacity multi-Gbps WLANs. Therefore, coordination among mmw APs is highly needed to overcome packet collisions resulting from un-coordinated exhaustive search BF and to increase total capacity of mmw WLANs. In this paper, we firstly give the current status of mmw WLANs with our developed WiGig AP prototype. Then, we highlight the great need for coordinated transmissions among mmw APs as a key enabler for future high capacity mmw WLANs. Two different types of coordinated mmw WLAN architecture are introduced. One is distributed antenna type architecture to realize centralized coordination, while the other is autonomous coordination with the assistance of legacy Wi-Fi signaling. Moreover, two heterogeneous network (HetNet) architectures are also introduced to efficiently extend the coordinated mmw WLANs to be used for future 5th Generation (5G) cellular networks.