- 著者
- Mizuki Watanabe Honoka Takahashi Kazuyoshi Uematsu Mineo Sato Takaki Masaki Dae-Ho Yoon Kenji Toda
- 出版者
- The Ceramic Society of Japan
- 雑誌
- Journal of the Ceramic Society of Japan (ISSN:18820743)
- 巻号頁・発行日
- vol.130, no.7, pp.458-463, 2022-07-01 (Released:2022-07-01)
- 参考文献数
- 49
- 被引用文献数
- 2
All-inorganic halides exhibit excellent optical as well as luminescence properties. Among them, non-toxic copper-doped halide Cs2ZnCl4 with high stability is a promising material. However, the conventional method for preparing these materials, using the hot injection technique, is unsuitable for mass production. Therefore, herein, we suggest a simple and low-temperature (below 100 °C) method without using special equipment, regents, and treatments. Cu-doped Cs2ZnCl4 was successfully synthesized using the water-assisted solid-state reaction (WASSR) method, and the oxidation state of Cu in the samples was estimated through the iodometric titration technique. The optical and luminescence properties were investigated using the absorption and photoluminescence excitation/emission spectra. Significantly, Cu-doped Cs2ZnCl4 exhibited unique green emission centered at ∼520 nm under ultraviolet irradiation. Moreover, the oxidation of Cu in the Cs2ZnCl4 lattice was suppressed owing to the low-temperature conditions in the WASSR.
- 著者
- Mizuki Watanabe Ryotaro Kobayashi Masahiko Kato
- 出版者
- Information Processing Society of Japan
- 雑誌
- Journal of Information Processing (ISSN:18826652)
- 巻号頁・発行日
- vol.23, no.5, pp.655-663, 2015 (Released:2015-09-15)
- 参考文献数
- 15
- 被引用文献数
- 1 1
Currently, Web services are widely utilized to disclose company information, and offer online services and e-commerce. As these services have become an essential part of our everyday lives, the public is greatly inconvenienced when they are disrupted. Denial of service (DoS) attacks exert adverse influences on Web services. We focus on HTTP-GET Flood attacks, which are manually operable DoS attacks. It is possible to simply block manually operable DoS attacks such as F5 attacks on the server side; however, such measures could be noticed by the attackers. Therefore, to prevent the attacker changing their method of attack, it is possible to overcome the attack by redirecting the attack to another system, for which a previous study has proposed a feasible technique located in the service provider. The previous study assumes a correlation between the CPU resource and the request error rate. However, the Web Server actually has multiple resources. Therefore, it is important to be able to control the server resources rather than the CPU and the memory. The operational implementation of the proposed method and the evaluation experiments confirm the effectiveness of the proposed method.