Combination of Multiple Bipartite Ranking for Web Content Quality Evaluation

Web content quality estimation is crucial to various web content processing applications. Our previous work applied Bagging + C4.5 to achive the best results on the ECML/PKDD Discovery Challenge 2010, which is the comibination of many point-wise rankinig models. In this paper, we combine multiple pair-wise bipartite ranking learner to solve the multi-partite ranking problems for the web quality estimation. In encoding stage, we present the ternary encoding and the binary coding extending each rank value to $L - 1$ (L is the number of the different ranking value). For the decoding, we discuss the combination of multiple ranking results from multiple bipartite ranking models with the predefined weighting and the adaptive weighting. The experiments on ECML/PKDD 2010 Discovery Challenge datasets show that \textit{binary coding} + \textit{predefined weighting} yields the highest performance in all four combinations and furthermore it is better than the best results reported in ECML/PKDD 2010 Discovery Challenge competition.Comment: 17 pages, 8 figures, 2 table

A Taxonomy of Hyperlink Hiding Techniques

Hidden links are designed solely for search engines rather than visitors. To get high search engine rankings, link hiding techniques are usually used for the profitability of black industries, such as illicit game servers, false medical services, illegal gambling, and less attractive high-profit industry, etc. This paper investigates hyperlink hiding techniques on the Web, and gives a detailed taxonomy. We believe the taxonomy can help develop appropriate countermeasures. Study on 5,583,451 Chinese sites' home pages indicate that link hidden techniques are very prevalent on the Web. We also tried to explore the attitude of Google towards link hiding spam by analyzing the PageRank values of relative links. The results show that more should be done to punish the hidden link spam.Comment: 12 pages, 2 figure

Photothermal Conversion Applications of the Transition Metal (Cu, Mn, Co, Cr, and Fe) Oxides with Spinel Structure

The transition metal (Cu, Mn, Co, Cr, and Fe) oxides with spinel structure can be used as solar absorber materials due to their unique properties. Copper-based spinel ceramic pigments have been successfully prepared by sol-gel combustion method at low temperatures. Subsequently, spinel ceramic pigments have been employed to fabricate selective absorber paint coating by spraying-coating. The paint coating showed good spectral selectivity and thermal stability at low-to-mid temperature region. Spinel ceramic films have also been deposited on metal substrates by one dipping/annealing cycle. Spinel phase for single-layer ceramic film could be achieved at low annealing temperatures, and the single-layer ceramic film showed good spectral selectivity and benign thermal stability. Results presented here show that spinel compounds based on transition metal (Cu, Mn, Co, Cr, and Fe) oxides are promising materials for photothermal conversion applications

CODE ARCHITECTURE AND OPEN SOURCE SOFTWARE DEVELOPMENT

A model is developed to study how the code architecture affects open source software (OSS) development. The model incorporates the resource heterogeneity and diverse motivations of various groups of programmers as well as the strategic interactions among them. We argue that the major advantage brought by a modular architecture of OSS code base is that it reduces both the cognitive cost and the coordination cost associated with OSS development, thus allowing programmers more easily to locate, manage, and contribute to the code base. We show that in OSS development, while modular architecture can potentially increase code contribution, it does not necessarily reduce free-riding; in fact it may well increase free-riding due to the strategic interactions among the programmers. We further empirically test the predictions using the SourceForge OSS development data, and the results confirm our theoretical predictions. The findings bear important theoretical as well as practical implications and provide guidelines for practitioners of OSS development and the collective innovation in general

SOCIAL PREFERENCES AND OPEN SOURCE SOFTWARE DEVELOPMENT

Open source software (OSS), and open innovation in general, has received increasing attention from both researchers and practitioners. Based on recent literature on social preference from behavior economics, we propose a finite-horizon dynamic model to study the interactions between OSS developers who are either purely self-interested or conditional cooperators. We find that selfinterested developers who are predicted to free ride under conventional analysis may contribute to a public good, and the existence of purely these developers may, under certain conditions, even benefit the provision of a public good. We further analyze how code architecture affects OSS development outcome and propose that a higher level of code modularity leads to more code contributions overall, due to the strategic behavior of self-interested developers. However, a right mix of the two types of developers plays a critical role for modular design to make an impact. The findings bear important theoretical as well as practical implications and provide guidelines for OSS development and the collective innovation in general

Chirped ultrasound-modulated optical tomography

A novel chirped ultrasound-modulated optical tomography technique was developed to image turbid media. Frequency analysis was employed to obtain spatial resolution along the ultrasonic axis. 2D images from scattering medium were obtained. The chirped ultrasound modulated signal was detected in chicken breast tissue