Browsing by Author "Wang, CY"

Now showing 1 - 20 of 31

A background timing-skew calibration technique for time-interleaved analog-to-digital converters
(2006-04-01)
Wang, CY
;
Wu, JT
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
This paper presents a background timing-skew calibration technique for time-interleaved analog-to-digital converters (ADCs). The timing skew between any two adjacent analog-digital (AID) channels is detected by counting the number of zero crossings of the ADCs input while randomly alternating their sampling sequence. Digitally controlled delay units are adjusted to minimize the timing skews among the AID channels caused by the mismatches among the clock routes. The calibration behaviors, including converging speed and timing jitter, are theoretically analyzed and verified with simulations. A 6-bit 16-channel ADC is used as an example.
A content management scheme in a SCORM compliant learning object repository
(2005-09-01)
Su, JM
;
Tseng, SS
;
Wang, CY
;
Lei, YC
;
Sung, YC
With the rapid development of the Internet, e-learning systems have become more and more popular. For sharing and reusing teaching materials in different c-learning system, the Sharable Content Object Reference Model (SCORM) has become the most popular international standard among the existing ones. In an e-learning system, teaching materials are usually stored in a database, called the Learning Object Repository (LOR). In the LOR, a huge amount of SCORM teaching materials, including associated learning objects, will result in management problems in a wired/wireless environment. Recently, the SCORM organization has focused on devising ways to efficiently maintain, search. and retrieve desired learning objects in LORs for users. This effort is referred to as the Content Object Repository Discovery and Resolution Architecture (CORDRA). In this paper, we propose a management approach, called the Level-wise Content Management Scheme (LCMS), that can be used to efficiently maintain, search, and retrieve learning contents from a SCORM compliant LOR. LCMS includes two phases: the Construction phase and Search phase. In the former, the content structure of SCORM teaching materials (Content Package) is first transformed into a tree-like structure. called a Content Tree (CT), to represent each piece of teaching material. Based on Content Trees (CTs), the proposed Level-wise Content Clustering Algorithm (LCCAIg) then creates a multistage graph showing relationships among learning objects (LOs), e.g.. a Directed Acyclic Graph (DAG), called the Level-wise Content Clustering Graph (LCCG). The LCCAIg determines the relationships among LOs in different teaching materials by clustering all of the LOs for each level from bottom to top, according to a similarity measure. Moreover, a maintenance strategy is employed to rebuild the LCCG if necessary by monitoring the condition of each node within the LCCG. The latter employs the LCCG Content Searching Algorithm (LCCG-CSAlg) to traverse the LCCG and retrieve desired learning content with both general and specific LOs, according to queries sent by users in the wire/wireless environment. Some experiments have been done conducted to test the proposed scheme, and the results are reported here.
A GaInP/GaAs HBT micromixer for 2.4/5.2/5.7-Ghz multiband WLAN applications
(2004-10-05)
Wang, CY
;
Lu, SS
;
Meng, CC
;
Lin, YS
;
電信工程研究所
A GaInP/GaAs HBT micromixer for 2.4/5.2/5.7-GHz multiband WLAN applications is demonstrated. Our experimental results show that the input return loss |S-11| is below -25 dB from DC to 10 GHz with power-conversion gains of 11.7, 11.9, and 11.5 dB at frequencies of 2.4, 5.2, and 5.7 GHz, respectively. The wideband matching characteristic makes the micromixer very suitable for multiband applications. Input P-IdB is -4 dBm and IIP3 is 2.36 dBm. Port-to-port isolation is also quite satisfactory. In addition, the single-to-differential input stage in the Gilbert micromixer eliminates the need for common-mode rejection. (C) 2004 Wiley Periodicals, Inc.
A novel manufacturing defect detection method using association rule mining techniques
(2005-11-01)
Chen, WC
;
Tseng, SS
;
Wang, CY
;
資訊工程學系
;
Department of Computer Science
In recent years, manufacturing processes have become more and more complex, and meeting high-yield target expectations and quickly identifying root-cause machinesets, the most likely sources of defective products, also become essential issues. In this paper, we first define the root-cause machineset identification problem of analyzing correlations between combinations of machines and the defective products. We then propose the Root-cause Machine Identifier (RMI) method using the technique of association rule mining to solve the problem efficiently and effectively. The experimental results of real datasets show that the actual root-cause machinesets are almost ranked in the top 10 by the proposed RMI method. (c) 2005 Elsevier Ltd. All rights reserved.
A novel manufacturing defect detection method using data mining approach
(2004)
Chen, WC
;
Tseng, SS
;
Wang, CY
;
資訊工程學系
;
Department of Computer Science
In recent years, the procedure of manufacturing has become more and more complex. In order to meet high expectation on quality target, quick identification of root cause that makes defects is an essential issue. In this paper, we will refer to a typical algorithm of mining association rules and propose a novel interestingness measurement to provide an effective and accurate solution. First, the manufacturing defect detection problem of analyzing the correlation between combinations of machines and the result of defect is defined. Then, we propose an integrated processing procedure RMI (Root cause Machine Identifier) to discover the root cause in this problem. Finally, the results of experiments show the accuracy and efficiency of RMI are both well with real manufacturing cases.
A SiGe micromixer for 2.4/5.2/5.7GHz multiband WLAN applications
(2004-06-05)
Wang, CY
;
Lu, SS
;
Meng, CC
;
Lin, YS
;
電信工程研究所
A SiGe micromixer for 2.4/5.2/5.7-GHz multiband WLAN applications is demonstrated for the first time. Our experimental results show that the input return loss S-11 is below -18 dB from DC to 20 GHz with voltage gains of 32, 26, and 25 dB at frequencies of 2.4, 5.2, and 5.7 GHz, respectively. The wideband matching characteristic makes the micromixer very suitable for multiband applications. Input P-1dB = -14 dBm and IIP3 = -6dBm. Port-to-port isolation is also quite satisfactory. In addition, the single-to-differential input stage in the Gilbert micromixer eliminates the need for common-mode rejection. 2004 Wiley Periodicals, Inc.
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.
An automatic interconnection rectification technique for SoC design integration
(2003)
Wang, CY
;
Tung, SW
;
Jou, JY
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
This paper presents an automatic interconnection rectification (AIR) technique to correct the misplaced interconnection occurred in the integration of a SoC design automatically. The experimental results show that the AIR can correct the misplaced interconnection and therefore accelerates the integration verification of a SoC design.
An automorphic approach to verification pattern generation for SoC design verification using port-order fault model
(2002-10-01)
Wang, CY
;
Tung, SW
;
Jou, JY
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
Embedded cores are being increasingly used in the design of large system-on-a-chip (SoC). Because of the high complexity of SoC, the design verification is a challenge for system integrators. To reduce the verification complexity, the port-order fault (POF) model was proposed. It has been used for verifying core-based designs and the corresponding verification pattern generation has been developed. Here, the authors present an automorphic technique to improve the efficiency of the automatic verification pattern generation (AVPG) for SoC design verification based on the POF model. On average, the size of pattern sets obtained on the ISCAS-85 and MCNC benchmarks are 45 % smaller and the run time decreases 16 % as compared with the previous results of AVPG.
An effective physical synthesis technique for multiplier
(2003)
Wang, CY
;
Yang, YC
;
Jon, JY
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
This paper presents an effective multiplier synthesis algorithm for cell-based multipliers. By using a novel tree generation algorithm with timing consideration for each vertical compressor slice(VCS), our synthesizer generates multipliers automatically with very promising results.
An efficient heterogeneous tree multiplexer synthesis technique
(2005-10-01)
Huang, HW
;
Wang, CY
;
Jou, JY
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
In this paper, a novel strategy for designing the heterogeneous tree multiplexer is proposed. The authors build the multiplexer delay model by curve fitting and then formulate the heterogeneous tree multiplexer design problem as a special type of optimization problem called mixed-integer nonlinear programming (MINLP). A new design parameter, the switch size in each stage, is introduced to improve the speed of the heterogeneous tree multiplexer. The proposed strategy can determine the multiplexer architecture and the switch size in each stage simultaneously. Three optimization methods are provided to synthesize the heterogeneous tree multiplexer according to the design specifications.
An improved AVPG algorithm for SoC design verification using port order fault model
(2001)
Wang, CY
;
Tung, SW
;
Jou, JY
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
Embedded cores are being increasingly used in the design of large System-on-a-Chip (SoC). Because of the high complexity of SoC, the design verification is a challenge for system integrator To reduce the verification complexity, the Port order fault (POF) model proposed in [1] has been used for verifying core-based designs and the corresponding verification pattern generation have been developed [2] [3]. Here we present in automorphic technique to improve the efficiency of the automatic verification pattern generation (AVPG) proposed in [3] for SoC design verification based on POF model. On average, the size of pattern sets obtained on the ISCAS-85 and MCNC benchmarks are 45% smaller and the run time decreases 16% as compared with the results of AVPG.
Analysis of chitin oligosaccharides by capillary electrophoresis with laser-induced fluorescence
(2002-12-06)
Wang, CY
;
Hsieh, YZ
;
應用化學系
;
Department of Applied Chemistry
A method, using capillary electrophoresis (CE) with laser-induced fluorescence (LIF) detection for analyzing chitin oligosaccharides is described. Chitin oligosaccharides were derivatized with 9-aminopyrene-1,4,6-trisulfonate (APTS) via reductive amination at 37 degreesC for 16 h (optimized conditions). The APTS-chitin oligosaccharides were analyzed using either an acidic citric acid-phosphate buffer or an alkaline borate buffer. The effects of buffer types, buffer pH values, and buffer concentrations on the separation were examined. The analytes were successfully separated by using a pH 4.6 citric acid-phosphate within 19 min. The APTS-derivatized chitin monosaccharide (D-glucosamine) migrated first. The analytes were also completely separated by using a pH 9.0 borate buffer within 24 min. Moreover, the specificity of enzyme digestion on chitin polysaccharides using the optimized APTS labeling procedure and the CE-LIF method was demonstrated. (C) 2002 Elsevier Science B.V. All rights reserved.
Analysis of Puerariae radix and its medicinal preparations by capillary electrophoresis
(1998-04-03)
Wang, CY
;
Huang, HY
;
Kuo, KL
;
Hsieh, YZ
;
應用化學系
This study presents a high-performance capillary electrophoresis (CE) method to analyze five constituents of Puerariae radix, an important crude herb used in Chinese medicine. Puerarin, daidzin, daidzein, genistein and biochanin A are the bioactive constituents of Puerariae radix. Herein, those analytes were successfully separated within 6 min using a pH 10.1 borax-NaOH buffer. The effects of pH value and concentration of the running buffer on the separation of the fie analytes were also examined. The relative standard deviations of the analytes' migration times were less than 0.38% under the optimized separation conditions. Notably, the correlation coefficients of the analytes' linear calibration graphs exceeded 0.998. Moreover, the amounts of the five constituents in three different Puerariae radix samples were determined by the CE method with a relatively simple extraction procedure. (C) 1998 Elsevier Science B.V.
ASIC implementation of a programmable servo control IC with digital phase-locked loop
(2002)
Cheng, KY
;
Wang, CY
;
Tzou, YY
;
電控工程研究所
;
Institute of Electrical and Control Engineering
This paper presents a new application-specific integrated circuit (ASIC) realization of a programmable servo control IC for high-performance BLDC spindle motors. The advantage of ASIC technology is that the design is specific to the application and can be optimized by designers. In order to achieve precise speed regulation without high-resolution encoder feedback, a digital phase-locked loop is implemented in the proposed servo control IC. Furthermore, by incorporating the proposed servo control IC with a general-purpose microprocessor or digital signal processor (DSP), a simple, yet high performance solution can be achieved. Simulation and experimental results indicate that precise speed regulation of BLDC motors can be achieved with the proposed servo control IC.
Automatic interconnection rectification for SoC design verification based on the port order fault model
(2003-01-01)
Wang, CY
;
Tung, SW
;
Jou, JY
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
Embedded cores are being increasingly used in large system-on-a-chip (SoC) designs. The high complexity of SoC designs lead the design verification to be a challenge for system integrators. This paper presents an automatic interconnection rectification (AIR) technique based on the port order fault model to detect, diagnose, and correct the misplacements of interconnection that occurred in the integration of a SoC design automatically. The experiments are conducted on combinational and sequential benchmarks. Experimental results show that the AIR can correct the misplaced interconnection exactly within reasonable efforts and, therefore, accelerates the integration verification of SoC designs.
Delayed onset of return flow by substrate inclination in model horizontal longitudinal MOCVD processes
(2005-01-15)
Kuo, WS
;
Wang, CY
;
Tuh, JL
;
Lin, TF
;
機械工程學系
In this study an experimental flow visualization is carried out to investigate how the substrate inclination affects the buoyancy-induced return flow structure in mixed convection of gas in a horizontal rectangular duct. The return flow is driven by a heated circular disk embedded in the bottom plate of the duct. simulating that in a horizontal longitudinal MOCVD reactor. Specifically, the bottom plate of the duct is inclined so that the gas flow in the duct is accelerated, causing the buoyancy-to-inertia ratio to decrease in the main flow direction. In the experiment. the Reynolds and Rayleigh numbers of the flow at the duct inlet are respectively varied from 3.7 to 79.7 and from 90,40 to 24,000 for the inclined angle of the bottom plate fixed at 0degrees, 0.34degrees and 0.97degrees. Particular attention is paid to delineating the spatial changes of the return flow structure with the plate inclination angle and to how the bottom plate tilting possibly, suppresses and stabilizes the flow. The results show a substantial delay in the onset of the return flow and the effctive suppression of the buoyancy-driven unstable vortex flow by the bottom plate inclination. Besides, the bottom, plate inclination can effectively weaken the return flow at slightly higher Reynolds numbers. An empirical equation is provided to correlate the present data for the onset of the return flow in the duct with its bottom inclined at 0: and 0.97degrees. (C) 2004 Elsevier B.V. All rights reserved.
Determination of metabolites of benzene, toluene, ethylbenzene, and xylene by beta-cyclodextrin modified capillary electrophoresis
(2003-01-01)
Wang, CY
;
Huang, CT
;
Hsieh, YZ
;
應用化學系
;
Department of Applied Chemistry
A beta-cycloclextrin modified capillary electrophoresis method for determining the metabolites of benzene, toluene, ethyl benzene, and xylene (BTEX) is described. Creatinine and uric acid were also examined as reference compounds. By employing a 20 mM, pH 10.0 borax-NaOH buffer containing 7-mM of beta-CD, ten analytes could be successfully separated within 10 min on a 50 pm capillary at an electric potential of 25 kV. The effects of pH and the concentration of beta-CD on the separation of the ten analytes are discussed. Under optimized separation conditions, the relative standard deviations for the migration times of the analytes were less than 0.93% and the correlation coefficients of the analyte linear calibration graphs exceeded 0.998 in the range from 1 to 300 mug/mL. Analyses of BTEX metabolites in urine samples from both occupationally exposed and non-exposed subjects are shown herein. BTEX metabolites were determined in the urine sample of a gas station attendant.
Flexible online association rule mining based on multidimensional pattern relations
(2006-06-22)
Wang, CY
;
Tseng, SS
;
Hong, TP
;
資訊工程學系
;
Department of Computer Science
Most incremental mining and online mining algorithms concentrate on finding association rules or patterns consistent with entire current sets of data. Users cannot easily obtain results from only interesting portion of data. This may prevent the usage of mining from online decision support for multidimensional data. To provide ad-hoc, query-driven, and online mining support, we first propose a relation called the multidimensional pattern relation to structurally and systematically store context and mining information for later analysis. Each tuple in the relation comes from an inserted dataset in the database. We then develop an online mining approach called three-phase online association rule mining (TOARM) based on this proposed multidimensional pattern relation to support online generation of association rules under multidimensional considerations. The TOARM approach consists of three phases during which final sets of patterns satisfying various mining requests are found. It first selects and integrates related mining information in the multidimensional pattern relation, and then if necessary, re-processes itemsets without sufficient information against the underlying datasets. Some implementation considerations for the algorithm are also stated in detail. Experiments on homogeneous and heterogeneous datasets were made and the results show the effectiveness of the proposed approach. (c) 2005 Elsevier Inc. All rights reserved.
Formation of carbon cluster on the surface of diamond films for improving electron field emission properties
(2002-10-01)
Chang, YC
;
Tu, JC
;
Kuo, CT
;
Wang, CY
;
Lin, IN
The electron field emission properties of the diamond films were significantly improved via the formation of nanosized carbon clusters on their surface. The microstructures and Raman spectroscopy are markedly altered when the diamond films were coated with a thin layer of Fe/Co films (< 10 nm) and then post-annealed at high enough temperature ( > 800degreesC). The turn-on field was decreased from 14.8 to 7.6 V/mum and the electron field emission current density was increased more than 2 order of magnitude, from 20 to 2400 muA/cm(2), due to post-annealing process. (C) 2002 Elsevier Science B.V. All rights reserved.