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41.
42.
In recent years, the Asia-Pacific region has experienced several financial setbacks, including speculative attacks in 1998 and the SARS outbreak in 2003. Financial stresses of this nature are unanticipated, and not all of the dangers can be predicted by the examination of market information and macroeconomic indicators. The Early Warning System (EWS) that has been adopted by the International Monetary Fund may not be able to predict future financial crises for all possible scenarios, because shocks come in many different forms. To supplement the EWS, this paper proposes a data mining framework to measure the resilience of an economy. The resilience framework does not predict a crisis, but rather assesses the current state of health of an economy and its ability to withstand a financial shock should one occur. The framework is based on a feedback system consisting of two stages. The first stage assigns a resilience score to each economy based on a fuzzy logic scoring scheme that is built on the ambiguous reasoning of experts. The second stage uses the classification tree approach to estimate thresholds for each economic indicator, and examines the quality of the fuzzy score. The result from the second stage is then passed back to the first stage as feedback. The final result is obtained when the feedback system reaches its equilibrium state. The proposed resilience framework is applied to the external-sector and the public-sector economies of several countries to illustrate its applicability. 相似文献
43.
Kin-Lu Wong Chih-Hua Chang 《Antennas and Propagation, IEEE Transactions on》2005,53(11):3496-3499
A novel wireless local-area network (WLAN) chip antenna suitable to be mounted above the system ground plane of a mobile device is presented. The antenna in the study is easily fabricated from folding a single metal plate onto a foam base, and mainly comprises a short-circuited radiating strip and an antenna ground. The antenna ground occupies the bottom surface and two adjacent side surfaces of the foam base. When the antenna is mounted at the corner of the system ground plane, this antenna ground structure is expected to effectively reduce the antenna's possible fringing electromagnetic fields inside the mobile device. In this case, when the associated element such as the radio-frequency shielding metal case is placed under the proposed antenna, small or negligible variations in the antenna performance are obtained. Design considerations of the proposed antenna for WLAN operation in the 2.4 GHz band are described, and results of the constructed prototypes are presented. 相似文献
44.
Chia-Ching Lin Gwo-Yun Lee Kin-Lu Wong 《Electronics letters》2003,39(18):1302-1304
A surface-mount dual-loop antenna suitable for dual-frequency WLAN operation is presented. For achieving dual-frequency operation with a compact size, the antenna comprises two loop strips of different sizes printed on a flexible printed circuit board, which is then bent and attached onto a foam base of compact size. The antenna shows an attractive feature of high antenna gain, about 4 and 5 dBi for frequencies across the 2.4 and 5 GHz WLAN bands, respectively. 相似文献
45.
A jet-printed digital-lithographic method, in place of conventional photolithography, was used to fabricate 64 /spl times/ 64 pixel (300 /spl mu/m pitch) matrix addressing thin-film transistor (TFT) arrays. The average hydrogenated amorphous silicon TFT device within an array had a threshold voltage of /spl sim/3.5 V, carrier mobility of 0.7 cm/sup 2//V/spl middot/s, subthreshold slope of 0.76 V/decade, and an on/off ratio of 10/sup 8/. 相似文献
46.
Zukerman M. Wong E.W.M. Rosberg Z. Gyu Myoung Lee Hai Le Vu 《Communications Letters, IEEE》2004,8(2):116-118
We provide teletraffic models for loss probability evaluation of optical burst switching (OBS). We show that the popular Engset formula is not exact for OBS modeling and demonstrate that in certain cases it is not appropriate. A new exact model is provided. The various models are compared using numerical results for various OBS alternatives with and without burst segmentation. 相似文献
47.
The excavation of soil for the construction of basements or cut-and-cover tunnels results in ground movements. One particular concern is that the excavation-induced lateral soil movements may adversely affect any nearby pile foundation. The lateral loads imposed by the soil movements induce bending moments and deflections in the pile, which may lead to structural distress and failure. This paper presents the results of an actual full-scale instrumented study that was carried to examine the behavior of an existing pile due to nearby excavation activities resulting from the construction of a 16 m deep cut-and-cover tunnel. The pile was located 3 m behind a 0.8 m thick diaphragm wall. Excavation to the formation level that was 16 m below the ground surface resulted in a maximum lateral pile movement of 28 mm. A simplified numerical procedure based on the finite-element method was used to analyze the pile response. Generally, the theoretical predictions were in reasonable agreement with the measured results. 相似文献
48.
49.
DB Fenske KF Wong E Maurer N Maurer JM Leenhouts N Boman L Amankwa PR Cullis 《Canadian Metallurgical Quarterly》1998,1414(1-2):188-204
A new method, based on the ion-translocating properties of the ionophores nigericin and A23187, is described for loading large unilamellar vesicles (LUVs) with the drugs vincristine and ciprofloxacin. LUVs composed of distearoylphosphatidylcholine/cholesterol (DSPC/Chol) (55:45 mol/mol) or sphingomyelin (SPM)/Chol (55:45 mol/mol) exhibiting a transmembrane salt gradient (for example, internal solution 300 mM MnSO4 or K2SO4; external solution 300 mM sucrose) are incubated in the presence of drug and, for experiments involving divalent cations, the chelator EDTA. The addition of ionophore couples the outward movement of the entrapped cation to the inward movement of protons, thus acidifying the vesicle interior. External drugs that are weak bases can be taken up in response to this induced transmembrane pH gradient. It is shown that both nigericin and A23187 facilitate the rapid uptake of vincristine and ciprofloxacin, with entrapment levels approaching 100% and excellent retention in vitro. Following drug loading, the ionophores can be removed by gel exclusion chromatography, dialysis, or treatment with biobeads. In vitro leakage assays (addition of 50% mouse serum) and in vivo pharmacokinetic studies (in mice) reveal that the A23187/Mn2+ system exhibits superior drug retention over the nigericin/K+ system, and compares favorably with vesicles loaded by the standard DeltapH or amine methods. The unique features of this methodology and possible benefits are discussed. 相似文献
50.
Lee V.V. Kuehne S.C. Nguyen C.T. Beiley M.A. Wong S.S. 《Electron Devices, IEEE Transactions on》1993,40(7):1223-1230
A local interconnection technology utilizing polysilicon strapped with selective-chemical-vapor-deposited (CVD) tungsten has been developed. Both n- and p-channel MOS transistors have been successfully fabricated using this technology. Tungsten deposited on polysilicon is an attractive gate shunt and local interconnection material because of its low resistivity, immunity to dopant segregation and diffusion, and resistance to electromigration. A potential problem of this technology is the excessive diode leakage current associated with strapping shallow source/drain diodes with tungsten. The leakage is attributed to defects induced by the heavy source/drain implant, which can be effectively eliminated with a proper annealing procedure 相似文献