Browsing by Author "Chu, YS"

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10Gbps operation of a metamorphic InGaP buffered In0.53Ga0.47As p-i-n photodetector grown on GaAs substrate - art. no. 602023
(2005)
Liao, YS
;
Lin, GR
;
Lin, CK
;
Chu, YS
;
Kuo, HC
A novel top-illuminated In0.53Ga0.47As p-i-n photodiodes (MM-PINPD) grown on GaAs substrate by using a linearly graded metamorphic InxGa1-xP (x graded from 0.49 to 1) buffer layer has been demonstrated on the SONET OC-192 receiving performance. With a cost-efficient TO-46 package, the MM-PINPD at data rate of 10 Gbit/s can be obtained at minimum optical power of -19.5 dBm. At wavelength of 1550nm, the dark current, optical responsivities, noise equivalent power, and operational bandwidth of the MM-PIND with aperture diameter of 60 mu m are 13 pA, 0.6 A/W, 3.4 x 10(-15) W/Hz(1/2), and 8 GHz, respectively. All the parameters are comparable to those of similar devices made on InP substrate or other InGaAs products epitaxially grown on an InGaAlAs buffered GaAs substrate. The performances of the MM-PINPD on GaAs are analyzed by impulse injecting of 1.2-ps pulse-train, eye pattern at 10Gbps, and frequency response from VNA.
A low-power ASIC design for cell search in the W-CDMA system
(2004-05-01)
Li, CF
;
Chu, YS
;
Sheen, WH
;
Tian, FC
;
Ho, JS
This paper presents a low-power ASIC design for cell search in the wideband code-division multiple-access (W-CDMA) system. A low-complexity algorithm that is able to work satisfactorily under the effect of large frequency and clock errors is designed first. Then, a set of low-power measures are employed in the design of hardware architecture and circuits. Finally, through power analysis, critical blocks are identified and redesigned so as to further reduce the power consumption. The final design shows that the power is reduced by 51 % from the original design of 133.6 mW to 65.49 mW, and its core area is also reduced by 31.9% from 3.4 x 3.4 mm(2) to 2.8 x 2.8 mm(2). The design is implemented and verified in a 3.3-V 0.35-mum CMOS technology with clock rate 1 36 MHz.
A three-phased online association rule mining approach for diverse mining requests
(2004)
Wang, CY
;
Tseng, SS
;
Hong, TP
;
Chu, YS
;
資訊工程學系
In the past, most incremental mining and online mining algorithms considered finding the set of association rules or patterns consistent with the entire set of data inserted so far. Users can not easily obtain the results from their only interested portion of data. For providing ad-hoc, query-driven and online mining supports, we first propose a relation called multidimensional pattern relation to structurally and systematically store the context information and the mining information for later analysis. Each tuple in the relation comes from an inserted dataset in the database. This concept is similar to the construction of a data warehouse for OLAP. However, unlike the summarized information of fact attributes in a data warehouse, the mined patterns in the multidimensional pattern relation can not be directly aggregated to satisfy, users' mining requests. We then develop an online mining approach called Three-phased Online Association Rule Mining (TOARM) based on the proposed multidimensional pattern relation to support online generation of association rules under multidimensional considerations. Experiments for both homogeneous and heterogeneous datasets are made, with results showing the effectiveness of the proposed approach.
The effect of backward injecting wavelength on the mode-locking dynamics of a semiconductor amplifier based fiber laser
(2005)
Chu, YS
;
Liao, YS
;
Lin, YH
;
Chang, YC
;
Lin, GR
The wavelength dependent mode-locking performances of a SOAFL under the backward optical injection via a sinusoidal-modulated distributed feedback laser diode (DFBLD) at 1 GHz repetition rate are characterized. The backward optical injection has to be sufficiently high to saturate a SOA and then depletes most of the excited state electrons in the SOA. In order to obtain shorter mode-locking pulsewidth, the DFBLD injecting wavelength should be slightly longer than the peak wavelength of SOA gain to benefit from shorter gain-recovery time and larger modulation depth. As the wavelength of a DFBLD approach the central wavelength of SOA, the shortest pulse was measured via a digital sampling oscilloscope (DSO). The pulses can also be obtained by DFBLD backward injection at 1535 rum in feedback of SOAFL, leading to the optimized pulsewidths of 22.7 ps.