Impact of the central refractive index dip of fibers on high-power applications

Central refractive index dip is a common phenomenon in the fibers fabricated by the modified chemical vapor deposition (MCVD) technology, which is the main fabrication technique for high-power laser fibers. In this paper, we present a numerical analysis of the dip effect on high-power-related parameters for the first time, to the best of our knowledge. Three aspects including mode field parameter, beam quality, and bending performance are studied under different dip parameters and bending radii. It is found that the dip is possible to increase the effective mode area and the bending loss, which offers a flexible way to suppress the non-linear effects and filter the higher-order modes by optimizing the dip parameters. Besides, different from the mode area and bending loss, beam quality exhibits an interesting trend when the dip radius increases. The results could facilitate a comprehensive understanding of the dip fiber properties, which also offer guidance to evaluate and design the fiber with central refractive index dip for high-power applications

コンテンツ保護機能を備えたインターネット生放送システムの実現可能性の研究

コンピュータセキュリティシンポジウム 2012 (Computer Security Symposium 2012, CSS 2012) : 2012年10月30日(火)～11月1日(木) : くにびきメッセ (島根県立産業交流会館)With the popularity of live broadcasting websites such as USTREAM, the maturity of live broadcasting technology, and the improvement of network condition, more and more multimedia service providers are using Internet to do the pay-per-view live broadcasting business instead of traditional TV platform. It becomes an issue which is how to provide an integrated protection scheme to the multimedia contents in the pay-per-view business. For our research, we aim to develop an Internet live broadcasting system with contents protection to solve this issue. We use Home Page cryptosystem to encrypt the contents and use JFD (Joint Fingerprinting and Decryption) method to embed the fingerprint. And it proved feasible according to the evaluation to the system.USTREAMのようなインターネット生放送のWebサイトの人気や配信技術の向上や高速インターネット環境の成熟により, テレビ放送に取って代わるコンテンツ課金型のインターネット生放送の需要が高まってきている. コンテンツ課金型のインターネット生放送を展開する場合は課金したユーザのみがインターネット生放送を視聴できるような仕組みが必要となる. そこで我々は課金したユーザのみがその映像を視聴できるようにするために, 映像に対してJFD(Joint Fingerprinting and Decyption)と呼ばれる手法を用いた暗号化と電子指紋の埋込みを同時に行う仕組みを持ったインターネット生放送を開発した. そして, 開発したインターネット生放送の実現可能性を評価した

Fig. 2. The key HMBC and 1H-1H in Chiral separation, absolute configuration, and bioactivity of two pairs of flavonoid enantiomers from Morus nigra

Fig. 2. The key HMBC and 1H-1H COSY correlations of compound 1.Published as part of <i>Xu, Liangjin, Huang, Tao, Huang, Chunyue, Wu, Chunzhen, Jia, An & Hu, Xiao, 2019, Chiral separation, absolute configuration, and bioactivity of two pairs of flavonoid enantiomers from Morus nigra, pp. 33-37 in Phytochemistry 163</i> on page 34, DOI: 10.1016/j.phytochem.2019.03.029, <a href="http://zenodo.org/record/10482725">http://zenodo.org/record/10482725</a&gt