- 著者
- Ryohei Banno Susumu Takeuchi Michiharu Takemoto Tetsuo Kawano Takashi Kambayashi Masato Matsuo
- 出版者
- 一般社団法人 情報処理学会
- 雑誌
- Journal of Information Processing (ISSN:18826652)
- 巻号頁・発行日
- vol.23, no.2, pp.105-116, 2015 (Released:2015-03-15)
- 参考文献数
- 22
- 被引用文献数
- 2 19
To provide event-driven services in IoT, scalable methods of topic-based pub/sub messaging are indispensable. Methods using structured overlay networks are promising candidates. However, existing methods have the problem of wasting network resources, because they lack adaptivity to “exhaust data, ” which have low or no value most of the time. The problem contains two aspects. One is that each publisher node continues to forward data to a relay node even if there are no subscribers. The other is that excessively large multicast trees are constructed for low value data, which will be received by only a small number of subscribers. In this paper, we formulate the desirable design of overlay networks by defining a property called “strong relay-free” as an expansion of relay-free property. The property involves publishers and subscribers composing connected subgraphs to enable detecting the absence of subscribers and autonomously adjusting the tree size. We also propose a practical method satisfying the property by using Skip Graph, and evaluate it through simulation experiments. We confirmed that the proposed method can suspend publishing adaptively, and shorten the path length on multicast trees by more than 75% under an experimental condition with 100,000 nodes.
- 著者
- Satoru Ozono Tadahiro Fujita Masato Matsuo Kazuo Todoki Takatsune Ohtomo Hideyuki Negishi Toshio Kawase
- 出版者
- Japan Prosthodontic Society
- 雑誌
- 日本補綴歯科学会雑誌 (ISSN:03895386)
- 巻号頁・発行日
- vol.52, no.3, pp.366-374, 2008-07-10 (Released:2008-10-10)
- 参考文献数
- 36
- 被引用文献数
- 5 6
Purpose: Bone marrow stromal cells (BMSCs) are a promising cell source in applications for tissue engineering and regenerative medicine. Optimization and control of the growth and differentiation of cultivated cells can be achieved by the administration of growth factors and hormones in vitro. This study provided experimental information on the enhancement of the osteogenic potential of rat BMSCs in vitro and in vivo.Methods: Mineralized nodule formation of rat BMSCs in culture for 3 weeks with dexamethasone (Dex)-treated media supplemented with both basic fibroblast growth factor (bFGF) and 17β-estradiol (E2) was examined by histology. In porous β-tricalcium phosphate (β-TCP), proliferation, migration, and differentiation of BMSCs were examined by histology and transmission electron microscopy. After culturing, the composites were subcutaneously implanted into syngeneic rats. The tissues with implants were harvested after 4 weeks and evaluated microscopically by using histological stain.Results: Dex-treated media supplemented with both bFGF and E2 was the most effective in mineralized nodule formation of BMSCs in vitro. Light and electron microscopy revealed the presence of many cells with developed rough endoplasmic reticulum. Bone formation in the BMSC/β-TCP composites in cultures in vitro for 3 weeks was observed histologically at 4 weeks after implantation. When BMSC/β-TCP composites were cultured in Dex-treated media supplemented with both bFGF and E2, the amount of bone formation at implants was substantially greater than that of composites cultured in Dex-treated media supplemented with bFGF.Conclusion: The combined use of bFGF and E2 could effectively improve the bone-forming ability of BMSCs.