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91.
微波功率放大器预失真线性化技术分析 总被引:2,自引:2,他引:0
给出了两种基本形式的预失真线性化电路,对其工作原理和技术特点进行了分析。 相似文献
92.
Huang J.C. Newell S. Galliers R.D. Shan-Ling Pan 《Engineering Management, IEEE Transactions on》2003,50(1):89-99
This paper presents an exploratory case study of the investment banking arm of a multinational banking corporation (Invebank) and its attempt to introduce component-based development (CBD). Based on a logic of opposition and utilizing literature on organizational culture and metaphors as an analytical device, issues confronting Invebank in CBD adoption are identified. In particular, problems in CBD implementation were encountered because, while CBD requires extensive knowledge sharing and collaboration, subcultural differences in Invebank meant that this proved difficult to enact. Thus, the paper considers the complexities of subcultural differences in firms and provides a salutary reminder that the implementation of corporate-wide integrative "solutions" such as CBD, may be problematic. Further, there is more to the issue of organizational subcultural differences than the oft-cited business-information technology (IT) divide. Nevertheless, the case demonstrates that subcultural differences should not simply be viewed as a threat. Rather, the recognition and discussion of these differences can provide a stimulus for identifying limitations of the policies surrounding technology implementation and use that if changed could help to maximize the benefits of the technology. Simplistic entreaties to knowledge sharing and the nurture of collaboration and consensus are, thus, brought into question. Implications for further research into the implementation of integrative software solutions like CBD in multifunctional and multifarious organizations are also considered. 相似文献
93.
Chengju Huang 《The Journal of communication》2003,53(3):444-459
Wilbur Schramm's "Soviet" communist model and J. Herbert Altschull's "Marxist" approach have been widely used as general theoretical frameworks to examine press systems in the Marxist world in general and China in particular. Though a growing literature suggested significant changes in Chinese journalism in the past 2 decades, very few studies have sent a direct challenge to the 2 models' theoretical wisdom through the Chinese case. This article finds neither of the 2 models is sufficient in conceptualizing the Chinese case because of Chinese news media's transitional nature and the 2 models' inner theoretical flaws as normative press theories. Furthermore, realizing the growing conflict between normative media theories and accelerated post-Cold War global media transformation, the author suggests using a transitional media approach to revisit the traditional normative media approach and calls for a more systematic study of the transitional phenomenon of global media systems. 相似文献
94.
提出并证明了一种群路FDMA/QPSK(频分多址/正交相移键控)信号全数字化整体解调的新方法,该方法根据信道构成特点和信号调制方式,将直接分路法和常规多相FFT(快速傅里叶变换)分离法相结合,构成了一种简化的等效多相FFT分路方法,再将输出的数字信号送到数字式解调器,实现了多载波信号的全数字化整体解调,其特点是软件和硬件结构简单、系统计算量小,且易于DSP实时实现,现已用该算法进行了32路FDMA/QPSK信号整体解调的计算机仿真实验,结果表明该方法是可行的. 相似文献
95.
Sarkar M. Ang Chew Hoe Huang Jiayi Chen T.P. 《Electron Devices, IEEE Transactions on》2005,52(6):1200-1204
In a MOSFET, a nonuniform, graded vertical dopant profile in the polysilicon gate causes a potential drop at the polysilicon/oxide interface. In this paper, the effect of this potential drop on the gate leakage current has been evaluated for the first time. The extent of variations of this affected gate leakage current with gate oxide thickness, gate length, and gate and drain bias conditions have been assessed with device simulation for an nMOS at 0.13 /spl mu/m low-voltage process. The results provide a guideline to the severity of this effect from the point of view of device and circuit operation and standby power consumption. 相似文献
96.
TheImprovementofFischer'sInequalityandHadamard'sInequalityHuangLiping(黄礼平)(DepartmentofBasicSciences,XiangtanMiningInstitute,... 相似文献
97.
Ho A.N. Pantell R.H. Feinstein J. Huang Y.C. 《Quantum Electronics, IEEE Journal of》1991,27(12):2650-2655
A novel wiggler design for use in free-electron lasers (FELs) is proposed, consisting of a staggered array of magnetic poles situated inside the bore of a solenoid. The resultant field pattern consists of a periodic transverse magnetic field on axis, as well as a longitudinal guide field. Such a wiggler has several advantages: the longitudinal field acts to confine the electrons near the FEL axis, high fields can be attained at short wiggler periods, the field strength is easily varied, and fabrication and testing of the wiggler are relatively easy. It is planned to use this wiggler design in a far infrared FEL to be built at Stanford University 相似文献
98.
99.
Huang L. Chew K. A. Thilakawardana S. Liu Y. Moessner K. Tafazolli R. 《Broadcasting, IEEE Transactions on》2006,52(4):492-504
Recently, an upsurge of interest has been observed in providing multimedia on-demand (MoD) services to mobile users over wireless networks. Nevertheless, due to the rapidly varying nature of mobile networks and the scarcity of radio resources, the commercial implementation is still limited. This paper presents an efficient group-based multimedia-on-demand (GMoD) service model over multicast-enabled wireless infrastructures, where users requesting the same content are grouped and served simultaneously with a single multicast stream. The grouping is fulfilled through a process named "batching". An analytical model is derived to analyse a timeout-based batching scheme with respect to the tradeoff between user blocking probability and reneging probability. Based on the deduced analytical model, an optimal timeout-based batching scheme is proposed to dynamically identify the optimal tradeoff point that maximizes the system satisfaction ratio given a particular system status. The proposed scheme is evaluated by means of simulation and compared with two basic batching schemes (timeout-based, size-based), and two hybrid ones (combined-for-profit, combined-for-loss). The simulation results demonstrate the proposed approach can ensure significant gains in terms of user satisfaction ratio, with low reneging and blocking probabilities 相似文献
100.
Morphology of intermetallic compounds formed between lead-free Sn-Zn based solders and Cu substrates
The morphologies of intermetallic compounds formed between Sn-Zn based solders and Cu substrates were investigated in this
study. The investigated solders were Sn-9Zn, Sn-8.55Zn-0.45Al, and Sn-8.55Zn-0.45Al-0.5Ag. The experimental results indicated
that the Sn-9Zn solder formed Cu5Zn8 and CuZn5 compounds on the Cu substrate, while the Al-containing solders formed the Al4.2Cu3.2Zn0.7 compound. The addition of Ag to the Sn-8.55Zn-0.45Al solder resulted in the formation of the AgZn3 compound at the interface between the Al4.2Cu3.2Zn0.7 compound and the solder. Furthermore, it was found that the cooling rate of the specimen after soldering had an effect on
the quantity of AgZn3 compound formed at the interface. The AgZn3 compound formed with an air-cooling condition exhibited a rougher surface and larger size than with a water-quenched condition.
It was believed that the formation of the AgZn3 compound at the interface occurs through heterogenous nucleation during solidification. 相似文献