Atsushi Fujiwara

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We provide a design framework for hop-by-hop congestion control algorithms in wireless mesh networks. Mesh networks are becoming increasingly popular and standardization process for development of IEEE 802.11 based mesh networks is an ongoing effort (in 802.11 Task Group S). However, by use of an existing CSMA/CA MAC in such networks, application sources(More)
This paper proposes a Multi-hop Radio Access Cellular (MRAC) scheme for achieving both high-speed/high-capacity and good area coverage in fourth generation mobile communications systems. In this scheme, we assume two kinds of hop stations, one is a dedicated repeater station installed at a good propagation location such as a rooftop, and the other is a user(More)
BACKGROUND Transurethral resection of the prostate (TURP) involves the risk of transurethral resection (TUR) syndrome owing to hyponatremia. Irrigation fluid type, duration of operation, and weight of resected mass have been evaluated as risk factors for TUR syndrome. The purpose of the present study was to identify risk factors related to TUR syndrome in(More)
We present a 32-bit RISC microcontroller having an on-chip DC/DC converter. The chip standby power including the DC/DC converter is reduced to 63µW with a new hybrid regulator scheme in which the microcontroller selects a switching regulator in active mode and a series regulator in standby mode. The achieved standby power corresponds to only about 1% the(More)
BACKGROUND This study aimed to investigate the relationship between preoperative estimated prostate weight on ultrasonography and clinical manifestations of transurethral resection (TUR) syndrome. METHODS The records of patients who underwent TUR of the prostate under regional anesthesia over a 6-year period were retrospectively reviewed. TUR syndrome is(More)
A 71-year-old man was scheduled to undergo cardiac resynchronization therapy device (CRTD) implantation. He was combined with severe chronic heart failure due to ischemic heart disease. NYHA class was 3 to 4 and electrocardiogram showed non-sustained ventricular. Ejection fraction was about 20% revealed by transthoracic echocardiogram. He was also on(More)