DCT-domain spatial transcoding using generalized DCT decimation

[[abstract]]In this paper, we propose a generalized DCT-domain spatial downscaling scheme to improve the visual quality. We analyze the filtering performances and computational complexities of the proposed scheme and the pixel-domain downscaling schemes. The analyses show that the proposed scheme can reduce the aliasing artifact compared to the existing schemes, while the computational complexity may be increased. We also integrate the proposed decimation scheme into the cascaded DCT-domain transcoder for spatial downscaling of a pre-encoded video into its quarter size. Experiments show the proposed approach can achieve better visual quality than the existing schemes.[[fileno]]2030144030019[[department]]電機工程學

Automatic fall incident detection in compressed video for intelligent homecare

[[abstract]]This paper presents a compressed-domain fall incident detection scheme for intelligent homecare applications. First, a compressed-domain object segmentation scheme is performed to extract moving objects based on global motion estimation and local motion clustering. After detecting the moving objects, three compressed-domain features of each object are then extracted for identifying and locating fall incidents. The proposed system can differentiate fall-down from squatting by taking into account the event duration. Our experiments show that the proposed method can correctly detect fall incidents in real time.[[fileno]]2030144030047[[department]]電機工程學

Modelling the Asymmetric Volatility in Hog Prices in Taiwan: The Impact of Joining the WTO

The hog industry, where prices are determined according to an auction system, is of vital importance to the agricultural industry in Taiwan by providing significant production and employment. In particular, there were significant impacts on daily hog prices in the periods before, during and after joining the WTO, which we will refer to as periods of anticipation, adjustment and settlement. The purpose of the paper is to model the growth rates and volatility in daily hog prices in Taiwan from 23 March 1999 to 30 June 2007, which enables an analysis of the effects of joining the WTO. The paper provides a novel application of financial volatility models to agricultural finance. The empirical results have significant implications for risk management and policy considerations in the agricultural industry in Taiwan, especially when significant structural changes, such as joining the WTO, are concerned. The three sub-samples relating to the period before, during and after joining the WTO display significantly different volatility persistence, namely symmetry, asymmetry but not leverage, and leverage, respectively, whereby negative shocks increase volatility but positive shocks of a similar magnitude decrease volatility.Hog prices, joining the WTO, conditional volatility models, asymmetry, leverage, moment conditions.

Modelling the Asymmetric Volatility in Hog Prices in Taiwan: The Impact of Joining the WTO

Prices in the hog industry in Taiwan are determined according to an auction system. There are significant differences in hog prices before, during and after joining the World Trade Organization (WTO). The paper models growth rates and volatility in daily hog prices in Taiwan from 23 March 1999 to 30 June 2007, which enables an analysis of the effects of joining the WTO. The empirical results have significant implications for risk management and policy in the agricultural industry. The three sub-samples for the periods before, during and after joining the WTO display significantly different volatility persistence of symmetry, asymmetry and leverage, respectively.Hog prices; joining the WTO; conditional volatility models; asymmetry; leverage; moment conditions

"Modelling the Asymmetric Volatility in Hog Prices in Taiwan: The Impact of Joining the WTO"

The hog industry, where prices are determined according to an auction system, is of vital importance to the agricultural industry in Taiwan by providing significant production and employment. In particular, there were significant impacts on daily hog prices in the periods before, during and after joining the WTO, which we will refer to as periods of anticipation, adjustment and settlement. The purpose of the paper is to model the growth rates and volatility in daily hog prices in Taiwan from 23 March 1999 to 30 June 2007, which enables an analysis of the effects of joining the WTO. The paper provides a novel application of financial volatility models to agricultural finance. The empirical results have significant implications for risk management and policy considerations in the agricultural industry in Taiwan, especially when significant structural changes, such as joining the WTO, are concerned. The three sub-samples relating to the period before, during and after joining the WTO display significantly different volatility persistence, namely symmetry, asymmetry but not leverage, and leverage, respectively, whereby negative shocks increase volatility but positive shocks of a similar magnitude decrease volatility.

Fast Mode Decision Algorithms for Adaptive GOP Structure in the Scalable Extension of H.264/AVC

[[abstract]]We propose a fast mode decision algorithm to reduce the computational complexity of adaptive GOP structure (AGS) in the scalable extension of H.264/AVC. AGS can improve the coding efficiency of the scalable extension of H.264. It, however, needs to perform motion-compensated temporal filtering (MCTF) of all possible GOP sizes, leading to much higher computation than the fixed GOP structure. In our proposed algorithm, after performing the MCTF with the maximum GOP size, we utilize two features to decide whether to perform the remaining MCTFs of sub-GOPs and mode selection. Experimental results show that the proposed algorithm can significantly reduce unnecessary MCTF computation for AGS, while maintaining good coding efficiency.[[fileno]]2030144030011[[department]]電機工程學

Effects of System Characteristics on Adopting Web-Based Advanced Traveller Information System: Evidence from Taiwan

This study proposes a behavioural intention model that integrates information quality, response time, and system accessibility into the original technology acceptance model (TAM) to investigate whether system characteristics affect the adoption of Web-based advanced traveller information systems (ATIS). This study empirically tests the proposed model using data collected from an online survey of Web-based advanced traveller information system users. Con­firmatory factor analysis (CFA) was performed to examine the reliability and validity of the measurement model, and structural equation modelling (SEM) was used to evaluate the structural model. The results indicate that three system characteristics had indirect effects on the intention to use through perceived usefulness, perceived ease of use, and attitude toward using. Information quality was the most im­portant system characteristic factor, followed by response time and system accessibility. This study presents implica­tions for practitioners and researchers, and suggests direc­tions for future research.</p