Designing and Implementation of ZigBee Network Layer

Zigbee标准具有低速率、低能耗、安全可靠等特点,非常适合于家庭自动化、建筑自动化和工业自动化应用。本文根据国际标准,分析、设计和实现了ZigBee协议栈。采用的单片机Atmega128,它仅有128K字节系统可编程闪存空间和4K字节的内部SRAM,所以本协议栈没有引入任何操作系统而且采用共享缓冲区进行数据收发和交换以节约有限的存储空间。最终,实现了规范中定义的所有功能,包括网络设备管理和mesh路由

Wireless mesh routing architecture optimized for industry applications

Wireless mesh network, consisting of thousands of low-cost field devices, has been an exciting new technology to industry applications (e.g.: data monitoring and controlling). It is desired to have high throughput in data monitoring and realtime in controlling, though the field device is low cost with small storage, limited energy and processing capacity. Hence, it is expected to satisfy the performance requirement with constrained resources. This work presents a routing architecture for the large scale wireless mesh network used in data monitoring and controlling. Specifically, we identify three challenge problems: (1) Robust routing (2) QoS supported routing tradeoff between high performance and energy efficiency (3) Low cost End-to-End routing. For each of these problems, we describe in detail our analysis, design and performance results

高LET放射線とフリーラジカルの生物影響

放射線の生物学的効果は、生体高分子に対する放射線の相互作用から始まり化学過程を経て生物効果として観察される。放射線と生体高分子との相互作用は、放射線のエネルギーが直接的に標的へ付与して障害が生じる直接作用と放射線が細胞内の水と作用し、フリーラジカルが生成され、それが標的に達し障害を及ぼす間接作用に分けられる。X線やガンマ線などの低LET放射線は細胞致死に対し、間接作用が主作用とされ、重粒子線のような高LET放射線では細胞致死に対する放射線作用は直接作用が主作用と報告されている。ただし、我々の実験結果ではLET 90 keV/µm程度の重粒子線でも細胞致死において間接作用が主作用（＞50%）であることを報告している。水の放射線分解によって生じたフリーラジカルの中で活性が一番強いOHラジカルに着目すると、OHラジカルの収量（G値）はLET依存的に減少し、LET 90 keV/µm程度ではOHラジカルの収量はガンマ線の約半分にまで減少する。我々は細胞生存率曲線を放射線の直接作用と間接作用それぞれに起因する線量効果関係を導き出し、炭素線（90 keV/µm）の間接作用による生物学的効果をX線の場合と比較すると、約1.7倍も大きいことがわかった。このことは高LET放射線で誘発されるOHラジカルは収量が減少するものの生物学的効果はX線誘発のOHラジカルよりも高い細胞致死作用を示していることになる。X線誘発ならびに重粒子線誘発の“OHラジカル”は当然ながら構造的な違いはなく、生体高分子への作用としては変わらないはずであるので、OHラジカルの発生した空間的分布が生物効果の違いに反映し、重粒子線のような密にフリーラジカルを発生させる放射線では、非常に効果的または効率的に細胞へ障害をもたらしているものと考えている。日本放射線影響学会　第56回大

Anti-obesity activity of Yamabushitake (Hericium erinaceus) powder in ovariectomized mice, and its potentially active compounds

Hericium erinaceus (H. erinaceus) improves the symptoms of menopause. In this study, using ovariectomized mice as a model of menopause, we investigated the anti-obesity effect of this mushroom in menopause. Mice fed diets containing H. erinaceus powder showed significant decreases in the amounts of fat tissue, plasma levels of total cholesterol, and leptin. To determine the mechanism, groups of mice were respectively fed a diet containing H. erinaceus powder, a diet containing ethanol extract of H. erinaceus, and a diet containing a residue of the extract. As a result, H. erinaceus powder was found to increase fecal lipid levels in excreted matter. Further in vitro investigation showed that ethanol extract inhibited the activity of lipase, and four lipase-inhibitory compounds were isolated from the extract: hericenone C, hericenone D, hericenone F, and hericenone G. In short, we suggest that H. erinaceus has an anti-obesity effect during menopause because it decreases the ability to absorb lipids

JUNO Sensitivity on Proton Decay p→νˉK+p\to \bar\nu K^+ Searches

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this paper, the potential on searching for proton decay in $p\to \bar\nu K^+$ mode with JUNO is investigated.The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits to suppress the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar\nu K^+$ is 36.9% with a background level of 0.2 events after 10 years of data taking. The estimated sensitivity based on 200 kton-years exposure is $9.6 \times 10^{33}$ years, competitive with the current best limits on the proton lifetime in this channel

JUNO sensitivity on proton decay p → ν K + searches*

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this study, the potential of searching for proton decay in the $p\to \bar{\nu} K^+$ mode with JUNO is investigated. The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits suppression of the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar{\nu} K^+$ is 36.9% ± 4.9% with a background level of $0.2\pm 0.05({\rm syst})\pm$$0.2({\rm stat})$ events after 10 years of data collection. The estimated sensitivity based on 200 kton-years of exposure is $9.6 \times 10^{33}$ years, which is competitive with the current best limits on the proton lifetime in this channel and complements the use of different detection technologies