Computing Multi-Relational Sufficient Statistics for Large Databases

Databases contain information about which relationships do and do not hold among entities. To make this information accessible for statistical analysis requires computing sufficient statistics that combine information from different database tables. Such statistics may involve any number of {\em positive and negative} relationships. With a naive enumeration approach, computing sufficient statistics for negative relationships is feasible only for small databases. We solve this problem with a new dynamic programming algorithm that performs a virtual join, where the requisite counts are computed without materializing join tables. Contingency table algebra is a new extension of relational algebra, that facilitates the efficient implementation of this M\"obius virtual join operation. The M\"obius Join scales to large datasets (over 1M tuples) with complex schemas. Empirical evaluation with seven benchmark datasets showed that information about the presence and absence of links can be exploited in feature selection, association rule mining, and Bayesian network learning.Comment: 11pages, 8 figures, 8 tables, CIKM'14,November 3--7, 2014, Shanghai, Chin

Horizon-unbiased Investment with Ambiguity

In the presence of ambiguity on the driving force of market randomness, we consider the dynamic portfolio choice without any predetermined investment horizon. The investment criteria is formulated as a robust forward performance process, reflecting an investor's dynamic preference. We show that the market risk premium and the utility risk premium jointly determine the investors' trading direction and the worst-case scenarios of the risky asset's mean return and volatility. The closed-form formulas for the optimal investment strategies are given in the special settings of the CRRA preference

Emerging Trends of Design Policy in the UK

This paper reviews design policy in the UK. As the UK does not currently have any written and acknowledged statement of cross-governmental design strategy, this article investigates the key organisations involved in developing and delivering policies that impact on design in the UK by reviewing their missions and strategies, thereby identifying opportunities, challenges and trends in British design policy

‘The Conception of Branding in Not-for-Profit SMEs’

Building on her previously published work (2004, 2006, 2007), Sun’s new research reported in this paper contributes to an understanding of the apparent resistance to branding among small not-for-profit (NfP) organisations. The originality of Sun’s approach is to apply existing models drawn from the literature of branding, which until now has focused on multinationals, to her case study. She asks how this modifies our understanding of branding more generally. The research addresses the issue that, while large NfPs have embraced branding in similar ways to for-profit companies, small and medium NfPs have not. Sun's survey as part of this research clarifies several issues of attitude and practice. There may be reluctance among NfPs to embrace ‘alien’ commercial behaviours, although it can be argued that branding is actually a good fit to the rationale of NfPs by contrast with perhaps superficial marketing stances in the commercial world. Sun shows that small and medium NfPs tend to mirror the poor use of branding among SMEs generally. An online questionnaire was targeted at 130 NfP SMEs, using 33 questions on attitudinal and practical issues, with Likert scale responses. The results showed that, although the general attitude towards the value of branding is positive, even among these the nature of marketing is poorly understood. Perceptions of impediments to brand development revealed little consensus, though size was a significant determinant. Respondent misunderstandings included a heavy emphasis on visual identity and image advertising; brand as the product of the marketer; brand maintenance focusing on appearance and style; and belief in reliance on a large marketing budget. Further aspects of branding are represented by Sun et al. on Indian consumer psychology in new product strategy and O'Brien, Sun et al. 2009 on managing brands in China, both in ‘D2B2 Tsinghua International Design Management Symposium 2009’, Beijing, China

On construction of optimal mixed-level supersaturated designs

Supersaturated design (SSD) has received much recent interest because of its potential in factor screening experiments. In this paper, we provide equivalent conditions for two columns to be fully aliased and consequently propose methods for constructing $E(f_{\mathrm{NOD}})$- and $\chi^2$-optimal mixed-level SSDs without fully aliased columns, via equidistant designs and difference matrices. The methods can be easily performed and many new optimal mixed-level SSDs have been obtained. Furthermore, it is proved that the nonorthogonality between columns of the resulting design is well controlled by the source designs. A rather complete list of newly generated optimal mixed-level SSDs are tabulated for practical use.Comment: Published in at http://dx.doi.org/10.1214/11-AOS877 the Annals of Statistics (http://www.imstat.org/aos/) by the Institute of Mathematical Statistics (http://www.imstat.org