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971.
In this paper, a new six-phase pole-changing induction motor drive is proposed to extend the constant-power operating range for electric vehicle application. The double Fourier series is newly employed to analyze the spectra of the motor phase voltage and current. Consequently, the harmonic expression of the inverter DC-link current can be derived. In order to reduce the DC-link harmonics, a new sinusoidal pulsewidth-modulation strategy is developed for the proposed six-phase inverter. Experimental results, particularly the spectra of the phase current and the DC-link current, are given to verify the theoretical analysis. 相似文献
972.
Ragnarok Pak-Kee Chan Oliver Chiu-Sing Choy Cheong-Fat Chan Kong-Pang Pun 《Circuits and Systems II: Express Briefs, IEEE Transactions on》2004,51(5):217-221
In this paper, we first introduce a straightforward asynchronous shift register design implemented by differential cascode voltage switch logic and micropipeline. The corresponding latency defect between data readout is then described. To solve this problem, we propose a new architecture for the design. Finally, a basic building block with respect to our architecture is proposed. 相似文献
973.
Chan K.T. Chin A. Lin Y.D. Chang C.Y. Zhu C.X. Li M.F. Kwong D.L. McAlister S. Duh D.S. Lin W.J. 《Microwave and Wireless Components Letters, IEEE》2003,13(11):487-489
We have improved the performance of integrated antennas on Si for possible application in wireless communications and wireless interconnects. For practical VLSI integration, we have reduced the antenna size and optimized the proton implantation to a low energy of /spl sim/4 MeV with a depth of /spl sim/175 /spl mu/m. To avoid any possible contamination, the ion implantation is applied after device fabrication. Excellent performance such as very low RF power loss up to 50 GHz, record high 103 GHz antenna resonance, and sharp 5 GHz bandwidth have been achieved. 相似文献
974.
This letter presents an enhanced handoff control scheme allowing dynamic bandwidth sharing between different types of traffic for improving bandwidth utilization in multimedia mobile cellular networks. Performance results for the proposed scheme are obtained analytically and by simulation. The results demonstrate superior efficiency achieved by the proposed scheme. 相似文献
975.
Large Q-factor improvement for spiral inductors on silicon using proton implantation 总被引:1,自引:0,他引:1
Chan K.T. Huang C.H. Chin A. Li M.F. Dim-Lee Kwong McAlister S.P. Duh D.S. Lin W.J. 《Microwave and Wireless Components Letters, IEEE》2003,13(11):460-462
We have improved the Q-factor of a 4.6 nH spiral inductor, fabricated on a standard Si substrate, by more than 60%, by using an optimized proton implantation process. The inductor was fabricated in a 1-poly-6-metal process, and implanted after processing. The implantation increased the substrate impedance by /spl sim/ one order of magnitude without disturbing the inductor value before resonance. The S-parameters were well described by an equivalent circuit model. The significantly improved inductor performance and VLSI-compatible process makes the proton implantation suitable for high performance RF ICs. 相似文献
976.
Jinsheng Sun Ko K.-T. Guanrong Chen Chan S. Zukerman M. 《Communications Letters, IEEE》2003,7(8):406-408
We propose a new active queue management (AQM) scheme to improve the performance of the well-known random early detection (RED) AQM. The new AQM is based on the proportional derivative (PD) control principle, and we call it PD-RED. In PD-RED we introduce minimal changes to RED. We demonstrate the improvement in performance of PD-RED over adaptive RED AQM by simulations. 相似文献
977.
Kyoung Hwan Yeo Chang Woo Oh Sung Min Kim Min Sang Kim Chang Sub Lee Sung Young Lee Sang Yeon Han Eun Jung Yoon Hye Jin Cho Doo Youl Lee Byung Moon Yoon Hwa Sung Rhee Byung Chan Lee Jeong Dong Choe Ilsub Chung Donggun Park Kinam Kim 《Electron Device Letters, IEEE》2004,25(6):387-389
Highly manufacturable partially insulated field-effect transistors (PiFETs) were fabricated by using Si-SiGe epitaxial growth and selective SiGe etch process. Owing to these technologies, pseudo-silicon-on-insulator (SOI) structures, partially insulating oxide (PiOX) under source/drain (PUSD) and PiOX under channel (PUC), could be easily realized with excellent structural and process advantages. We are demonstrating their preliminary characteristics and properties. Especially, in the PUSD PiFET, junction capacitance, leakage current, and DIBL in bulk devices could be reduced and the floating body problem in SOI devices was also cleared without any area penalty. Thus, this PiFET structure can be a promising candidate for the future DRAM cell transistor. 相似文献
978.
C. W. Tan Y. C. Chan H. P. Chan N. W. Leung C. K. So 《Microelectronics Reliability》2004,44(5):2396-831
The demand for volume deployment of photonic components has increased, and with it the need to effectively manufacture in a reproducible and cost effective way. Therefore, it is important to keep the assembly process consistent and stable. A simple shear test setup was used in this study to determine the shear force that can be used as an instant indicator to the process stability of fiber arrays assembly. The shear test was then used to study the effect of curing conditions, surface roughness, and reliability test on the adhesion of the adhesive joints of single channel fiber arrays. In general, shear force increases with the curing conditions. However, thermal-induced residue stress during improper controlled curing process might lead to loss in ductility and reliability of the joints. Results showed that rough bonding surface for the coverlid can provide better wettability and enhances the shear strength. However, it might result in incomplete polymerization due to transmission loss of UV radiation during assembly process that was caused by the uneven surface. Furthermore, rough surface can affect the flow of adhesive that could result in incomplete-fills. Adhesives at the surrounding of V-grooves and edges of the joints were attacked by moisture at elevated temperature. This paper also discussed in details the possible failure mechanism of adhesive joints after temperature and humidity test. 相似文献
979.
980.
Don Woong Choi Jee Yeun Kim Seon Hee Choi Hee Su Jung Hyo Joo Kim So Yean Cho Chan Soon Kang Seung Yeup Chang 《Food chemistry》2006
Although it has been known that pomegranate (Punica granatum L.) contains several steroid hormones, concrete experimental proofs about that have not been published until now. In order to identify and evaluate the contents of steroid hormones including estrone in pomegranate, we analyzed pomegranate seed, fruit juice and commercial preparations. We developed a reproducible and sensitive method for separation and identification of steroid hormones in pomegranate samples using both high performance liquid chromatography (HPLC)–PDA and gas chromatography (GC)–MS. In case of HPLC, an isocratic elution method using 35% aqueous acetonitrile solution at 1.0 ml/min with photodiode-array (PDA) detection at 225 nm and 254 nm was found to optimally separate and identify the steroid hormones from the pomegranate samples with a run time of less than 30 min. The pomegranate samples were comparatively analyzed to the HPLC results by GC/FID or GC/MS detection on a HP-1 (30 m length, 0.32 mm I.D.) with helium as carrier gas under the oven temperature control as follows: start 220 °C for 5 min, raising 5 °C per min, final 280 °C for 10 min. The HPLC and GC methods were successfully applied to the identification of steroid hormones in pomegranate samples. Our results suggested that there were no steroid estrogens including estrone, estradiol and testosterone in pomegranate seed, fruit juice and preparations. Consequently, we assumed that the previously reported analysts of pomegranate were misunderstood their analytical results according to either the estrogen-like effects or similarity of peak retention time and Rf values in experiments. 相似文献