Incorporating Side Information in Probabilistic Matrix Factorization with Gaussian Processes

Probabilistic matrix factorization (PMF) is a powerful method for modeling data associated with pairwise relationships, finding use in collaborative filtering, computational biology, and document analysis, among other areas. In many domains, there is additional information that can assist in prediction. For example, when modeling movie ratings, we might know when the rating occurred, where the user lives, or what actors appear in the movie. It is difficult, however, to incorporate this side information into the PMF model. We propose a framework for incorporating side information by coupling together multiple PMF problems via Gaussian process priors. We replace scalar latent features with functions that vary over the space of side information. The GP priors on these functions require them to vary smoothly and share information. We successfully use this new method to predict the scores of professional basketball games, where side information about the venue and date of the game are relevant for the outcome.Comment: 18 pages, 4 figures, Submitted to UAI 201

Supply Chain Information Systems and Organisational Performance in Economic Turbulent Times

Supply Chain Information Systems and their impact on organisational performance has been studied by a number of studies. This study seeks to extend this body of knowledge by adopting a fresh lens to explore empirically the relationship between organizational performance and SCIS in circumstances of economic downturn and financial turbulence. The statistical relationship between Supply Chain Information Systems (SCIS) ˜Effectiveness and ˜Organisational Performance is tested and measured by multidimensional financial and non-financial variables. So even though complexities associated with measuring SCIS efficiency and Organisational Performance continue to dominate research discussions these are somewhat limited to just explaining the phenomenon without addressing the misalignment of the information provided by SCIS, business expectations and Organisational Performance. In consequence this papers reports findings from a large survey of 168 SCIS managers in Greek SMEs where even through economic downturn a strong correlation between SCIS and non-financial Organisational Performance is evidenced. In considering the findings this study proposes guidance to enhance SCIS Effectiveness and Organisational Performance

Efficient vasculature investment in tissues can be determined without global information

Cells are the fundamental building blocks of organs and tissues. Information and mass flow through cellular contacts in these structures is vital for the orchestration of organ function. Constraints imposed by packing and cell immobility limit intercellular communication, particularly as organs and organisms scale up to greater sizes. In order to transcend transport limitations, delivery systems including vascular and respiratory systems evolved to facilitate the movement of matter and information. The construction of these delivery systems has an associated cost, as vascular elements do not perform the metabolic functions of the organs they are part of. This study investigates a fundamental trade-off in vascularization in multicellular tissues: the reduction of path lengths for communication versus the cost associated with producing vasculature. Biologically realistic generative models, using multicellular templates of different dimensionalities, revealed a limited advantage to the vascularization of two-dimensional tissues. Strikingly, scale-free improvements in transport efficiency can be achieved even in the absence of global knowledge of tissue organization. A point of diminishing returns in the investment of additional vascular tissue to the increased reduction of path length in 2.5- and three-dimensional tissues was identified. Applying this theory to experimentally determined biological tissue structures, we show the possibility of a co-dependency between the method used to limit path length and the organization of cells it acts upon. These results provide insight as to why tissues are or are not vascularized in nature, the robustness of developmental generative mechanisms and the extent to which vasculature is advantageous in the support of organ function

Castleman disease and lymphocytic interstitial pneumonia: a complex diagnostic and management challenge

No abstract available

Input usage, output mix and industry deregulation: an analysis of the Australian dairy manufacturing industry

In this paper we estimate a Translog output distance function for a balanced panel of state level data for the Australian dairy processing sector. We estimate a fixed effects specification employing Bayesian methods, with and without the imposition of monotonicity and curvature restrictions. Our results indicate that Tasmania and Victoria are the most technically efficient states with New South Wales being the least efficient. The imposition of theoretical restrictions marginally affects the results especially with respect to estimates of technical change and industry deregulation. Importantly, our bias estimates show changes in both input use and output mix that result from deregulation. Specifically, we find that deregulation has positively biased the production of butter, cheese and powders.Bayesian, deregulation, output distance function, Agribusiness,

Optimal strategies in the Fighting Fantasy gaming system: influencing stochastic dynamics by gambling with limited resource

In many games and other processes, participants can choose to intervene in some way that does not follow the usual progress of the game (for example, cheating at cards, or spying on rivals) which may provide benefits, but also possibly incur substantial costs. Here, repeated interventions may be more likely to incur negative outcomes – for example, as the chance of getting caught increases. How to optimally employ these risky interventions, trading off potential advantages and disadvantages, can then be challenging to identify. Here, we study such a game, taken from the popular ‘Fighting Fantasy’ gamebook series. This stochastic game involves a series of rounds, each of which may be won or lost. Each round, a unit of limited resource (‘luck’) may be spent on a gamble to amplify benefits from a win or to mitigate deficits from a loss. However, the success of this gamble depends on the number of units of remaining resource, and if the gamble is unsuccessful, benefits are reduced and deficits increased. By choosing to expending resource, a player thus has diminishing probability of positive return, as in the cheating and espionage examples above. We characterise the dynamics of this system using stochastic analysis and dynamic programming, solve the Bellman equation for the complete system with diminishing returns, and identify the optimal strategy for any given state during the game. We use classification tools to distil general principles for this and related problems, informing resource allocation problems with diminishing returns in stochastic decision theory.publishedVersio

nformation Quality, Reporting and Organisational Performance

This study aims at the exploration of the statistical relationship between the quality of the Information produced by Information Systems (IS) such as ERPs and Organisational Performance. The definition of information quality encompasses measures such as accuracy, precision, currency, timeliness, conciseness, which aim at providing decision tools to the users of any Information System. Producing quality information /reports is the primary purpose of any IS. The results from a survey on 168 Greek companies show a strong correlation between Information Quality and Organisational Performance when this is expressed by financial and not financial measures