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1.
本文从光的电磁波谐波时域函数及光子动量公式出发,推导出光色映射复频谱颜色表达式（二维平面函数）。通过公式得出,矢径与光的量子数有关,位相角与光的频率有关。通过分光光度计测量出色光的反（透）射率,经过计算得到复频谱矢端函数,在二维复平面上对矢端函数积分整合,给出表征颜色性能的色相、色强度、亮度、色饱和度及主波长等颜色特征数值,从而为进一步解析颜色奠定基础。 相似文献
2.
Veronika Grimm Frank Riedel Elmar Wolfstetter 《International Journal of Industrial Organization》2003,21(10):1557-1569
The second–generation (GSM) spectrum auction in Germany is probably the most clear cut example of a low price outcome in a simultaneous ascending-bid multi-unit auction. The present paper gives an account of the events, describes the auction rules and market conditions, and provides a game theoretic explanation of low price equilibrium in simultaneous, ascending-bid multi-unit auctions. In particular, it is shown that in the unique equilibrium that survives iterated elimination of dominated strategies, the efficient allocation is reached at minimum bids. 相似文献
3.
《Telecommunications Policy》2020,44(9):102011
This paper tracks increasingly aggressive initiatives by the United States government to reallocate spectrum on an expedited and unilateral basis well before conclusion of inter-governmental coordination. Rather than embrace the customary commitment to achieve consensus on global spectrum allocations at the International Telecommunication Union (“ITU”), the Federal Communications Commission (“FCC”) has auctioned off large blocks of frequencies for the next generation (“5G”) of wireless services.The FCC might have framed its first 5G auction, reassigning Ultra High Frequency (“UHF”) spectrum, as a one-time deviation from compliance with long standing, intergovernmental coordination procedures. These frequencies have ideal signal propagation characteristics and the Commission could use financial incentives—unavailable in most nations—to expedite “repacking” by incumbent broadcasters willing to move, share or abandon spectrum in exchange for ample financial compensation. However, the FCC has continued to auction off 5G spectrum on grounds that it must find ways to abate an acute shortage of wireless bandwidth and doing so will regain or maintain global leadership in wireless technologies. This paper offers a critical rebuke to unilateral spectrum management, because the short-term benefits expected by the U. S. government likely will be offset by countervailing harms to 5G manufacturers, carriers and consumers. The paper tracks fractious preparation for the ITU's 2019 World Radio Conference by the U.S. delegation and the mixed record achieved there. Additionally, the paper explains how injecting trade, industrial policy and national security issues at the ITU can trigger more delays and disputes, including possible retaliation by nations displeased with U.S. efforts to subvert traditional technology optimization goals.A worst case scenario has the ITU deadlocked and unable to reach closure on “mission critical” spectrum planning issues at World Radio Conferences, convened every four years. The paper concludes that costs and likely challenges to the efficacy and legitimacy of the ITU will reduce the benefits accruing from the FCC's unilateral, spectrum planning campaign. 相似文献
4.
Andreas Grünwald 《Telecommunications Policy》2001,25(10-11):719-728
Given its significant technological advantages compared to analog broadcasting, digital television (DTV) will be the television system of the future. However, it requires a full replacement of analog television sets by digital receivers, as DTV can only be watched with special equipment. In order to make this transition happen smoothly without losing the analog television audience, both signals have to be simulcasted until a substantial coverage with DTV broadcasting has been achieved. Australia and the US meanwhile have established a regulatory framework to lead this transition towards the end of analog broadcasting, the so-called analog switch-off. Part of the US regime is the FCC's obligation to reassign analog frequencies after the switch-off has taken place by means of auction. Spectrum auctions, however, originate not from the US but from New Zealand, where they have been used since the end of 1989 and ever since been subject to legal and political criticism. The article outlines the principles of both the DTV and spectrum auctions regulation and shows the links between both areas of telecommunications regulation. It concludes by suggesting that the analog switch-off is a unique opportunity to reconsider current spectrum policies, as it frees large amounts of the radio spectrum that are today occupied by analog broadcasting and will soon be subject to one of the biggest frequency reassignment processes in the history of telecommunications regulation. 相似文献
5.
6.
《Telecommunications Policy》2018,42(8):622-635
Future 5G networks aim at providing new high-quality wireless services to meet stringent and case-specific needs of various vertical sectors beyond traditional mobile broadband offerings. 5G is expected to disrupt the mobile communication business ecosystem and open the market to drastically new sharing based network operational models. 5G technical features of network slicing and small cell deployments in higher carrier frequencies will lower the investment barrier for new entrants to deploy local radio access networks and offer vertical specific services in specific areas and allow them lease the remaining required infrastructure on demand from mobile network operators (MNO) or infrastructure vendors. To realize the full vision of 5G to benefit the society and promote competition, innovation and emergence of new services when the 5G end-to-end network spans across different stakeholders administrative domains, the existing regulations governing the mobile communication business ecosystem are being refined. This paper provides a tutorial overview on how 5G innovations impact mobile communications and reviews the regulatory elements relevant to 5G development for locally deployed networks. This paper expands the recent micro licensing model for local spectrum authorization in future 5G systems and provides guidelines for the development of the key micro licensing elements. This local micro licensing model can open the mobile market by allowing different stakeholders to deploy local small cell networks with locally issued spectrum licenses ensuring pre-defined quality guarantees for the vertical sectors’ case specific needs. 相似文献
7.
本文扼要概述直接序列扩频信号的解扩方法,着重介绍数字解扩的基本原理及其在工程上实现的途径,通过对模拟处理器件和数字处理器件的比较,指出数字处理器件具有很大的潜力和广阔的应用前景。 相似文献
8.
<正> 我国是一个人口众多,人均资源相对贫乏,经济、文化比较落后的发展中国家。要在这样的国家实现科学技术的现代化,建设一个现代化的工业强国,依赖外国不行,闭关自守也不行。坚持自力更生为主,积极吸收国外科学技 相似文献
9.
Dong Mingsheng 《国际商务研究》1990,(6)
GEOSTAR卫星无线电定位系统是为美国本土和世界各地妁地面移动用户以及航海、航空用户提供准确的位置信息和辅助双向信息。用户至Geostar中心线路由移动站的发射机、中继卫星和中心接收站组成并已经建成。来自用户终端的扩频和卷积编码的突发射频信号通过卫星被中继到GEOSTAR中心,由该中心进行信息包的捕获、解调和处理。在突发工作方式的扩频系统中,传输和数据误差率取决予线路特性、捕获概率、虚警概率和使用的解调器数量。本文比较了用户至GEOSTAR中心线路理论和实测传输特性和数据误差特性。 相似文献
10.
The debate on spectrum reforms has mostly focused on the choice between a property rights and a commons regime. This article argues that moving to a property right system requires careful attention to details in order to avoid that “micro” rather than “macro” factors may prevent efficient trades from taking place. It provides a framework to conduct this assessment, identifies a number of possible concerns and puts forward some solutions. 相似文献