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951.
As the population ages in Taiwan, stroke research has received greater attention in recent years. Strokes have significant
impacts on the health and well-being of the elderly. To formulate future research policy, information on stroke publications
should be collected. In this research, we studied stroke-related research articles published by Taiwan researchers which were
indexed in the Science Citation Index from 1991 to 2005. We found that the quantity of publications has increased at a quicker
pace than the worldwide trend. Over the years, there has been an increase in international collaboration, mainly with researchers
in the U.S. Article visibility, measured as the frequency of being cited, also increased during the period. It appears that
stroke research in Taiwan has become more globally connected and has also improved in quality. The publication output was
concentrated in a few institutes, but there was a wide variation among these institutes in the ability to independently conduct
research. A wide array of keywords indicated a probable lack of continuity in research. Nevertheless, there was an inverse
relationship between stroke mortality and number of published articles in Taiwan. To improve the quality and efficiency of
stroke research, continuity in research focuses needs to be maintained, and thus funding should be allocated on a long-term
basis to institutes with a proven record of success. 相似文献
952.
Jui-I Tsai Woei-Wu Pai Feng-Chang Hsu Po-Jui Chen Ching-Cheng Teng Tai-Shan Liao 《电子设计技术》2007,14(12):112-112,114
大多数实验室和工业环境中都存在着多种全频带电气噪声源,它们来自于重型机器、仪表、电源和电视台.工程师要用很多设备和技术来对付这种噪声.这些技术包括采用正确的接地方式、屏蔽和双绞线、信号均化、差分输入电压放大器和滤波器. 相似文献
953.
In this paper, we investigate the performance of differentially detected differential phase-shift keying (DPSK) modulation with postdetection maximal ratio combining, in nonselective Rayleigh fading channels with multiple asynchronous cochannel interferers. The approach is based on an analytical technique we have presented earlier in the literature. Exact bit-error probability (BEP) results for binary DPSK and quaternary DPSK are derived. More specifically, we look into the effects of symbol-timing offsets between the interfering signals and the desired signal on the error performance. Our results show that when all the interfering signals are synchronous with the desired signal, the impairment caused by the cochannel interference to the desired user is maximum. On the other hand, when all the interfering signals are half-symbol-duration-delayed with respect to the desired user, they introduce the minimum impairment. Based on these findings, upper and lower bounds on the BEP are derived in simple closed form. Our explicit BEP results also show that the error probabilities of different transmitted symbols of the desired user are affected differently by the interfering signal 相似文献
954.
Xuezhe Zheng Lexau J.K. Bergey J. Cunningham J.E. Ron Ho Drost R. Krishnamoorthy A.V. 《Photonics Technology Letters, IEEE》2007,19(7):453-455
Combining the strengths of both proximity communication and optical communication, a new hybrid input-output (I/O) platform delivers on-chip bandwidth off-chip and over distance. We demonstrate, for the first time, a four-channel hybrid I/O interface by integrating proximity communication and vertical-cavity surface-emitting-laser-based parallel optical interconnects on the same commercial 90-nm complementary metal-oxide-semiconductor platform. The optical I/O can operate at 5 Gb/s per channel, and the complete hybrid I/O interface achieved 2.5 Gb/s per channel. We characterize the I/O link performance for various data rates and chip separations, and show 10-mum chip separation tolerance for proximity communication 相似文献
955.
A fast mode decision algorithm for H.264/AVC inter-prediction to reduce computational complexity of the H.264 encoder is presented. Experimental results show that the algorithm can save the entire encoding time by 77% on average while introducing only negligible loss in PSNR value and small increment of bit rate. 相似文献
956.
Dong Ho Lee Jeonghu Han Changkun Park Songcheol Hong 《Microwave and Wireless Components Letters, IEEE》2007,17(9):676-678
An active balun with a single-ended input and a pair of differential outputs is presented for the input stages of differential circuits. The active balun, which is composed of an input resonator and cascaded common-gate amplifiers, was implemented using 0.18-mum CMOS technology and bond wire inductors. A body-source cross-coupled configuration was used to enhance the gain of the active balun. The gain is 9.3 dB at 1.8 GHz, and the phase and the amplitude error are less than 2deg and 1 dB, respectively, in the frequency range of 1 to 2 GHz, even for a P1dB of -2.7 dBm. The balun consumes 9 mA for 3-V supply voltage. 相似文献
957.
We introduce a space-time (ST) continuous phase modulation (CPM) and its companion noncoherent receiver. Through careful selection of an underlying differential code, the defining characteristics of the CPM transmissions are effectively maintained. Using a set of interference suppressed statistics and taking advantage of the ST differential encoding, the receiver first performs low complexity block detection. Channel estimates are then obtained at a rate notably higher than the CPM symbol rate, enabling a second-stage coherent sequence detector to refine the initial decisions. Simulation results for two CPM formats, with two and four transmit antennas, validate the proposed ST-CPM scheme. 相似文献
958.
959.
(Pt/Co)n/FeMn multilayers with perpendicular anisotropy (PA) were prepared by magnetron sputtering with Pt as the buffer layer and the capping layer. The dependence of perpendicular exchange bias (PEB), Hex, on the thickness of the FeMn antiferromagnet (AFM) layer is similar to that of in-plane exchange bias. The value of Hex for the (Pt/Co)3/FeMn multilayer reaches 22.3 kA/m. A thin Pt spacer was inserted between the Co/FeMn interface to enhance PEB. The PEB reaches the largest at 39.8 kA/m when the thickness of the Pt spacer is 0.4 nm. 相似文献
960.
C.‐L. Ho W.‐Y. Wong G.‐J. Zhou B. Yao Z. Xie L. Wang 《Advanced functional materials》2007,17(15):2925-2936
The synthesis and photophysical studies of several multifunctional phosphorescent iridium(III) cyclometalated complexes consisting of the hole‐transporting carbazole and fluorene‐based 2‐phenylpyridine moieties are reported. All of them are isolated as thermally and morphological stable amorphous solids. Extension of the π‐conjugation through incorporation of electron‐pushing carbazole units to the fluorene fragment leads to bathochromic shifts in the emission profile, increases the highest occupied molecular orbital levels and improves the charge balance in the resulting complexes because of the propensity of the carbazole unit to facilitate hole transport. These iridium‐based triplet emitters give a strong orange phosphorescence light at room temperature with relatively short lifetimes in the solution phase. The photo‐ and electroluminescence properties of these phosphorescent carbazolylfluorene‐functionalized metalated complexes have been studied in terms of the coordinating position of carbazole to the fluorene unit. Organic light‐emitting diodes (OLEDs) using these complexes as the solution‐processed emissive layers have been fabricated which show very high efficiencies even without the need for the typical hole‐transporting layer. These orange‐emitting devices can produce a maximum current efficiency of ~ 30 cd A–1 corresponding to an external quantum efficiency of ~ 10 % ph/el (photons per electron) and a power efficiency of ~ 14 lm W–1. The homoleptic iridium phosphors generally outperform the heteroleptic counterparts in device performance. The potential of exploiting these orange phosphor dyes in the realization of white OLEDs is also discussed. 相似文献