19,879 research outputs found
Hui tu zhen ben jing shi mu yu jin gang zuan
著作者余好辯, 伍憤時.Cover title.上下卷.On double leaves, East Asian binding.木魚歌文.zhu zuo zhe Yu Haobian, Wu Fenshi.Shang xia juan.Mu yu ge wen
Review: Spin photocurrents in quantum wells
Spin photocurrents generated by homogeneous optical excitation with circularly polarized radiation in quantum wells (QWs) are reviewed. The absorption of circularly polarized light results in optical spin orientation due to the transfer of the angular momentum of photons to electrons of a two-dimensional electron gas. It is shown that in QWs belonging to one of the gyrotropic crystal classes a non-equilibrium spin polarization of uniformly distributed electrons causes a directed motion of electrons in the plane of the QW. A characteristic feature of this electric current, which occurs in unbiased samples, is that it reverses its direction upon changing the radiation helicity from left-handed to right-handed and vice versa. Two microscopic mechanisms are responsible for the occurrence of an electric current linked to a uniform spin polarization in a QW: the spin polarization-induced circular photogalvanic effect and the spin-galvanic effect. In both effects the current flow is driven by an asymmetric distribution of spin-polarized carriers in k-space of systems with lifted spin degeneracy due to k-linear terms in the Hamiltonian. Spin photocurrents provide methods to investigate spin relaxation and to reach a conclusion as regards the in-plane symmetry of QWs. The effect can also be utilized to develop fast detectors for determining the degree of circular polarization of a radiation beam. Furthermore, spin photocurrents under infrared excitation were used to demonstrate and investigate monopolar spin orientation of free carriers
Global Fourier Integral Operators and semiclassical asymptotics
In this paper we introduce a class of semiclassical Fourier integral operators with global complex phases approximating the fundamental solutions (propagators) for time-dependent Schrödinger equations. Our construction is elementary, it is inspired by the joint work of the rst author with Yu. Safarov and D. Vasiliev. We consider several simple but basic examples
Yu Takeuchi
Yu Takeuchi is serving for JAXA since 2007 and currently working as Associate Senior Administrator at Management and Integration Department of Human Spaceflight Technology Directorate. He is also working as Researcher at the Institute of Space Law of Keio University. He received LL.M. degree from the Institute of Air and Space Law of McGill University in 2015. His main interest is in international space law inter alia the legal aspects of space traffic management and sustainable space development. He is a member of the Air Law Institute of Japan, Japanese Society of International Law, and the International Institute of Space Law (IISL).
Main Works Published in English
- “Toward the International Regime for Space Traffic Management -What to Fix the Current International Regulations-”, (November 5, 2014). Space Traffic Management Conference, Paper 23 (http://commons.erau.edu/stm/2014/wednesday/23).
- “Regulatory Regime for Tomorrow’s Suborbital Space Flights: Point-to-point International Flights”, 56th Colloquium on the Law of Outer Space, 2013.
- “Space Traffic Management as a Guiding Principle of the International Regime of Sustainable Space Activities,” 4 Journal of East Asia and International Law, 2011
- “Japanese Perspective on Legal Issues of Commercial Human Spaceflight” (co-author), 53rd Colloquium on the Law of Outer Space, 2011
- “Legal Points at Issue about NEO Threat Response and International Cooperation” (co-author), 28th International Symposium on Space Technology and Science, 2011
- “From Guideline to International Treaty for Rule of Law concerning Mitigation of Space Debris?” (co-author), 52nd Colloquium on the Law of Outer Space, 2010
Main Works Published in Japanese (title translated into English)
- “What is Space Traffic Management”, Vol. 46, No.9, Journal of the Japanese Institute of International Business Law, 2018.
- Soichiro Kozuka & Masahiko Sato eds., Introduction of Space Law for Entrepreneur (2nd. Ed.), Yuhikaku, 2018. (co-authored)
-“Challenges to International Space Law for Managing Space Traffic”, 55 Kuho (Air Law), 2014.
-“Legal Points as Issues of NEO Threat Response and International Cooperation” (co-author), 3 Spaceguard Research, Japan Spaceguard Association, 2011https://commons.erau.edu/stm-images/1121/thumbnail.jp
Chao cai liao yong yu ya bo chang ju jiao: ge xiang yi xing hao sun cai liao yu ti du guang xue na mi bo dao guan
Kwok, Hui Kin = 超材料用於亞波長聚焦 : 各向異性耗損材料與梯度光學納米波導管 / 郭栩健.Thesis M.Phil. Chinese University of Hong Kong 2015.Includes bibliographical references (leaves 67-69).Abstracts also in Chinese.Title from PDF title page (viewed on 26, September, 2016).Kwok, Hui Kin = Chao cai liao yong yu ya bo chang ju jiao : ge xiang yi xing hao sun cai liao yu ti du guang xue na mi bo dao guan / Guo Xujian
On an algorithm for two-term spectral asymptotic formulas
In the book [Yu. Safarov and D. Vassiliev, The asymptotic distribution of
eigenvalues of partial differential operators, Amer. Math. Soc., Providence,
RI, 1997], a key and central ``algorithm'' was established, by which the
coefficients of two-term asymptotic expansions of the eigenvalue counting
functions can be explicitly calculated for many partial differential operators
under an additional geometric assumption. In this paper, we give a
counter-example to this ``algorithm'' by discussing the case of elastic
eigenvalues. This implies that the most conclusions in the above book written
by Yu. Safarov and D. Vassiliev are fundamentally wrong because they are based
on the erroneous ``algorithm''.Comment: 17 pages. Some detailed explanations for the range of the Lame
coefficients are added in section 2 (in particular, on p.10). The Green's
function for the Laplacian with free boundary condition are structured by
adding a smooth auxiliary (matrix-valued) function in section 2 (i.e.,
argument are added, results unchanged). Typos correcte
Yi ge zai Jianada wei qi si xing qi de Ying yu ke cheng de yu wen ji wen hua xue xi
Chan, Sin Yu.Thesis M.Phil. Chinese University of Hong Kong 2015.Includes bibliographical references (leaves 260-268).Abstracts also in Chinese; some appendixes in Chinese.Title from PDF title page (viewed on 11, November, 2016).Chan, Sin Yu
Intractability of Optimal Multi-Robot Path Planning on Planar Graphs
We study the computational complexity of optimally solving multi-robot path planning problems on planar graphs. For four common time- and distance-based objectives, we show that the associated path optimization problems for multiple robots are all NP-complete, even when the underlying graph is planar. Establishing the computational intractability of optimal multi-robot path planning problems on planar graphs has important practical implications. In particular, our result suggests the preferred approach toward solving such problems, when the number of robots is large, is to augment the planar environment to reduce the sharing of paths among robots traveling in opposite directions on those paths. Indeed, such efficiency boosting structures, such as highways and elevated intersections, are ubiquitous in robotics and transportation applications.Peer reviewe
Er tong shui mian jie lü: zheng chang can kao zhi, xiang guan yin su, dui jian kang de ying xiang, he gan yu gai shan
Yu, Xinting.Thesis Ph.D. Chinese University of Hong Kong 2014.Includes bibliographical references (leaves 188-207).Abstracts also in Chinese; appendixes in Chinese.Title from PDF title page (viewed on 14, September, 2016).Yu, Xinting
Nan Song Shuzhou gong du yi jian zheng li yu yan jiu Zheng li yu yan jiu
Ben shu shi dui wo she yu 1990 nian chu ban de ying yin ben "Song ren yi jian" de zheng li yu yan jiu. Gai shu shi liao feng fu, she ji zheng zhi, jing ji, jun shi yi ji Song dai gong wen ge shi he shu yi, shi zhen gui de shi wu wen xian. "Song ren yi jian" fan ying le bu shao nan Song shi qi di fang guan fu ji gou she zhi he xing zheng guan li zhi du, bu chong le xu duo Song dai cai zheng, shui shou zheng ce de xin cai liao, bao liu le nan Song chu nian Jiang Huai di qu zhan bei zhuang kuang de xi jie cai liao, hai shi Song dai wen shu zhi du de zhong yao cai liao, you zhu yu Song shi yan jiu de shen ru. Zheng li ben yan jin gui fan, ge shi ming xi, ji ben huan yuan le Song jian tu ban de ben lai mian mao, ju you jiao qiang de can kao jia zh
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