學術出版;;Publications

Permanent URI for this communityhdl:11536/1

收集所有交通大學研究人員與學生個人或團體所發表之各項學術著作，涵蓋期刊論文、教師專書、學位論文等項。;;Collections of Publications of NCTU Researchers and Students Like Journal Papers and Thesis.

Browse

🏛️國立陽明交通大學機構典藏

Search Results

Now showing 1 - 10 of 12

Frequency estimation of phase-modulated carriers
(1998-12-01)
Su, YT
;
Wu, RC
;
電信工程研究所
;
Institute of Communications Engineering
Conventional approach for frequency estimation usually assume a single tone without data modulation. In many applications such an assumption, realized by using either a separate pilot beacon or synchronization preamble is not feasible. This paper deals with frequency estimation of phase-modulated carriers in the absence of timing information and known data pattern. We introduce new frequency estimators that are based on the generalized maximum likelihood principle. The communication channels under consideration include both additive white Gaussian noise (AWGN) channels and correlated Rician fading channels. For the latter class, we distinguish between the case when the fading (amplitude) process is tracked and that when it is not tracked.
Noncoherent detectors for PN code acquisition in the presence of data modulation
(2000-11-01)
Wu, RC
;
Su, YT
;
Lin, WC
;
電信工程研究所
;
Institute of Communications Engineering
Noncoherent detectors for use in acquiring data-modulated direct-sequence spread-spectrum (DS/SS) signals are considered in this paper. Taking data modulation and timing uncertainty into account and using the generalized maximum likelihood (GML) or maximum likelihood (ML) detection approaches, we derive optimal detectors in the sense of Bayes or Neyman-Pearson and propose various suboptimal detectors. A simple systematic means for their realization is suggested and the numerical performance of these detectors is presented. We also compare their performance with that of the noncoherent combining (NC1) detector that had been proposed to serve the same need. Numerical results show that even the proposed suboptimal detectors can outperform the NC1 detector in most cases of interest.
Design an intelligent CIM system based on data mining technology for new manufacturing processes
(2004)
Wu, RC
;
Chen, RS
;
Fan, CR
;
資訊管理與財務金融系註：原資管所+財金所
;
Department of Information Management and Finance
The purpose of this paper is to explain a specific intelligent CIM (computer integrated manufacturing) system by integrating the following five major subject areas: computer integrated manufacturing, data warehouse, online analytical processing (OLAP), data mining and artificial intelligence. The data mining system makes use of the decision tree algorithm and classification model in exploring the meaningful information, which is useful in the process of decision making. Subsequently, the rules discovered by the data mining system are expressed through the rule based knowledge presentation method of the expert system. The intelligent CIM system is applied to semiconductor packing factories and also point at the great fluctuation of DRAM (dynamic random access memory) prices. The results of this paper are the product yield, the manufacturing cycle time and the frequency of holding lot, which have been improved. The contribution can increase business competitiveness, reduce production cost, and promote the rate of available promise for order.
Frequency acquisition and tracking for mobile LEO satellite communications
(1997)
Su, YT
;
Wu, RC
;
交大名義發表
;
電信工程研究所
;
National Chiao Tung University
A class of recursive frequency acquisition and tracking algorithms for use in high dynamic mobile low earth orbit (LEO) satellite communication systems is proposed. The underlying principle of these algorithms is to apply the least-squares method to the reconstructed phase trajectories to estimate and predict the received frequency variations (Doppler frequency, Doppler rate, etc.). We consider both additive white Gaussian noise (AWGN) and Rician fading channels and analyze the corresponding mean squared errors (MSE). Numerical performance of the proposed algorithms demonstrates that the new frequency tracking algorithms not only has rapid acquisition times but also gives smaller tracking jitters.
Code acquisition in a class of time-varying channels
(1998)
Su, YT
;
Wu, RC
;
電信工程研究所
;
Institute of Communications Engineering
This paper presents a model for the code acquisition in a time-varying channel and evaluates the associated acquisition time statistics. We first use a finite-state Markov chain to represent the time-varying channel. Each channel state can have either a frequency-selective or a frequency-nonselective fading characteristic. This model is an unconstrained model as it does not take into account two time-parameters. The first time-parameters the "time unit" for the Markov channel, which has to be determined by the channel Doppler spread or its fading rate. The second time-parameter has to do with the detection structure. Incorporating the constraints imposed by these two time-parameters we discuss modifications of the unconstrained model, derive related statistics (e.g., probability distribution function or characteristic function) of the acquisition time and then provide numerical examples of the acquisition time performance.
Optimal and suboptimal noncoherent detectors for PN code acquisition in the presence of data modulation
(1998)
Su, YT
;
Lin, WC
;
Wu, RC
;
電信工程研究所
;
Institute of Communications Engineering
Noncoherent detectors for use in acquiring data-modulated direct-sequence spread-spectrum (DS/SS) signals are considered in this paper. Taking data modulation into account, we examine maximum likelihood (ML) and generalized maximum likelihood (GML) detection structures and then derive suboptimal detectors. We call one of the suboptimal detector as noncoherent partially matched filter (PMF) as it matches only part of the family of legitimate data patterns, We compare the detector operating characteristic (DOC) performance of the PM filter and that of the noncoherent combining (NC) detector that had been proposed to serve the same need. Although the PM filter requires a little more computing it does give better performance.
EEG-based fuzzy neural network estimator for driving performance
(2004)
Wu, RC
;
Lin, CT
;
Liang, SF
;
Huang, TY
;
Jung, TP
Accidents caused by drivers' drowsiness have a high fatality rate because of the marked decline in the drivers' vehicle control abilities. Preventing accidents caused by drowsiness is highly desirable but requires techniques for continuously detecting, estimating, and predicting the level. of alertness of drivers. This paper proposes a brain-machine interface that combines electroencephalographic power spectrum estimation, principal. component analysis, and fuzzy neural networks to estimate/predict drivers' drowsiness level in a virtual-reality-based driving simulator. The driving performance is defined as deviation between the center of the vehicle and the center of the cruising lane. Our results demonstrated that the proposed method is feasible to accurately estimate quantitatively driving performance in a realistic driving simulator.
Estimating driving performance based on EEG spectrum and fuzzy neural network
(2004)
Wu, RC
;
Lin, CT
;
Liang, SF
;
Huang, TY
;
Chen, YC
The growing number of traffic fatalities in recent years has become a serious concern to society. Accidents caused by drivers' drowsiness behind the steering wheel have a high fatality rate because of the marked decline in the drivers' abilities of perception, recognition! and vehicle control abilities while sleepy. Preventing accidents caused by drowsiness requires a technique for detecting, estimating, and predicting the level of alertness of a driver and a mechanism for maintaining his/her maximum performance. This paper describes a system that combines electroencephalographic (EEG) power spectrum estimation, principal component analysis, and fuzzy neural network model to estimate/predict drivers' drowsiness level in a driving simulator. Our results demonstrated that, for the first time, it is feasible to accurately estimate task performance, accurately estimate quantitatively measured driving performance, expressed as deviation between the center of the vehicle and the center of the cruising lane, in a realistic driving simulation.
Using data mining technology to design an intelligent CIM system for IC manufacturing
(2005)
Chen, RS
;
Wu, RC
;
Chang, CC
;
資訊管理與財務金融系註：原資管所+財金所
;
Department of Information Management and Finance
This paper aims to explain a specific intelligent computer integrated manufacturing system by integrating the following five major domains: computer integrated manufacturing, data warehouse, online analytical processing, data mining and artificial intelligence. The data mining system makes use of the decision tree algorithm and classification model in exploring the meaningful information, which is useful in the process of decision making. Subsequently, the rules discovered by the data mining system are expressed through the rule based knowledge presentation method of the expert system. The intelligent CIM system is applied to semiconductor packing factories and also point at the great fluctuation of dynamic random access memory prices. The contribution can increase business competitiveness, reduce production cost, and promote the rate Of available promise for order.
Data mining application in customer relationship management of credit card business
(2005)
Wu, RC
;
Chen, RS
;
Chang, CC
;
Chen, JY
;
資訊管理與財務金融系註：原資管所+財金所
First, we classify the selected customers into clusters using RFM model to identify high-profit, gold customers. Subsequently, we carry out data mining using association rules algorithm. We measure the similarity, difference and modified difference of mined association rules based on three rules, i.e. Emerging Patten Rule, Unexpected Change Rule, and Added/Perished Rule. In the meantime, we use rule matching threshold to derive all types of rules and explore the rules with significant change based on the degree of change measured. In this paper, we employ data mining tools and effectively discover the current spending pattern of customers and trends of behavioral change, which will allow management to detect in a large database potential changes of customer preference, and provide as early as possible products and services desired by the customers to expand the clientele base and prevent customer attrition.

學術出版;;Publications

Browse

Filters

Settings

Sort By

Results per page

🏛️國立陽明交通大學機構典藏

Search Results