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

Interfacial Tailoring of Lithium-ion Batteries by Atomic/Molecular Layer Deposition

Lithium-ion batteries (LIBs) are promising energy storage devices, which play significant roles in addressing problems related to fossil fuels depletion and environmental pollution. Since the 1990s, LIBs have attracted great attention for many applications. Nowadays, LIBs are dominating portable electronics, having several advantages over their forerunners, such as high voltage (3.3~4.2 V) [1,2], low self-discharge (\u3c 5~10 %/month) [3,4], wide operation temperature (-20~60 °C) [5,6], and fast charge/discharge rate [7,8]. However, LIBs deliver an energy density of 100-220 Wh/kg in practice to date, which is far from their theoretical ones, thus hindering their further applications in electric vehicles. Additionally, LIBs have been plagued by other problems, such as intolerance to overcharge/overdischarge, low heat resistance, lithium dendrites growth, large volume change of the silicon anode, large polarization and even safety problems. Atomic layer deposition (ALD) and molecular layer deposition (MLD) are two important techniques, both proceeding in self-limiting gas-solid reactions and exhibiting excellent capabilities for ultra-thin films, conformal coatings, and controllable growth. They can be employed to address the problems of LIBs mentioned above by surface coatings, electrode designs, and solid-state electrolyte preparations. In this thesis, ALD is utilized to modify the interface between the electrolyte and Si anode in LIBs and to improve the performance of LIBs. ZnO coating deposited by ALD using precursors of diethylzinc (DEZ) and H2O was found to be effective in accommodating the volume expansion of Si during charging-discharging process and preventing the direct Si-electrolyte contact, thus improving the performance of Li/Si-G battery. Additionally, effects of ALD coatings (Al2O3 and ZnO) on stabilizing lithium metal are investigated. In chapter 1, the background of LIBs is introduced, as well as ALD and MLD. Chapter 2 investigates the growth properties of different coatings (Al2O3, ZnO, TiO2, AlGL and ZnGL) using quartz crystal microbalance (QCM) method. Chapter 3 reports the modification of Si-electrolyte interface via ALD coatings and the performance of Li/Si-G (silicon-graphite) batteries. Chapter 4 investigates the stabilization of lithium metal using ALD coatings. Conclusions are shown in chapter 5. Future work and promising developments are given in chapter 6