Practical Bayesian optimization in the presence of outliers

Inference in the presence of outliers is an important field of research as outliers are ubiquitous and may arise across a variety of problems and domains. Bayesian optimization is method that heavily relies on probabilistic inference. This allows outstanding sample efficiency because the probabilistic machinery provides a memory of the whole optimization process. However, that virtue becomes a disadvantage when the memory is populated with outliers, inducing bias in the estimation. In this paper, we present an empirical evaluation of Bayesian optimization methods in the presence of outliers. The empirical evidence shows that Bayesian optimization with robust regression often produces suboptimal results. We then propose a new algorithm which combines robust regression (a Gaussian process with Student-t likelihood) with outlier diagnostics to classify data points as outliers or inliers. By using an scheduler for the classification of outliers, our method is more efficient and has better convergence over the standard robust regression. Furthermore, we show that even in controlled situations with no expected outliers, our method is able to produce better results.Comment: 10 pages (2 of references), 6 figures, 1 algorith

Integrating Thermodynamics and Biology for Sustainable Product Lifecycle Design

The linkage between raw resources consumption and economic growth through product manufacture and disposal is creating an untenable pressure on the planet’s natural systems; therefore understanding and embracing the mechanics of the biology and physics of our context could lead to novel approaches in the design of human-built systems/products. Designers are, by active association, responsible for that pressure and much of the impact can be traced back to the early stages of the design process. For designers and engineers the main constraint is accessibility to knowledge of multiple and complex factors in easily digestible form when starting a project. Added to this is the possibility to transcend the realm of products and explore creative solutions throughout the entire life cycle, giving designers the opportunity to propose entire new business models and systems. This paper exposes the search for an intuitive soft modeling tool that considers some of these factors and inspires the innovation of business and systems innovation from a biophysical perspective. The aim of this tool is to enable the exploration of these factors in a playful intuitive way and relate these outcomes to the design of a business model operating within the principles of trophic levels. The first key question to the development of this approach has been: how does it work in nature? Organisms search for their food in other organisms and at the same time are the food of others; biomass and energy are transferred from one level to another, losses occur, higher qualities of energy are created and all is maintained in continuous cycles. The linear human production of goods can be rethought by taking into account this basic principle of thermodynamics and although this is not a technological problem, the relevant constrains need to be integrated for this approach to be feasible. These are from an economics origin: how to achieve a healthy business from a non-linear process? It is proposed that an analogy between natural and human systems: autotrophs = manufacturing, heterotrophs = distributors and consumers, their concentration and size, their possible combinations and their eventual business interpretations, is referred to as Trophic Economics. The envisioned tool will combine the exploration of the complex factors involved in the lifecycle of a product with the suggested Trophic Economics models. The outcome could be sketches of the possible boundaries and structures of new business and products, to be resolved later on the drawing board. In order to measure and keep track of the most relevant decisions, a designer must embrace tools like emergy accounting, MIPS and MI (Wuppertal Institute, 2002) used in related combination, plus indexes of CO2 emissions and relevant economic, social-demographic and ecosystems information about the countries involved in any give proposition of manufacture and use

REST and Linked Data: a match made for domain driven development?

At a first glance there might appear to be an obvious alignment and overlap between the approaches prescribed by REST and Linked Data. On more detailed inspection divergences in scope and applicability present themselves, and for some aspects, incompatibility. In this paper we investigate these similarities and differences and suggest the coupling is worthy of a third look: in combination as a flexible environment in which the developer can focus on domain driven applications

A study of finite symmetrical groups

This study discovered several important groups that involve the classical and sporadic groups. These groups appeared as finite homomorphic images of the progenitors 3*8 : PGL₂(7), 2*¹⁴ : L₃ (2), 5*³ : S₃ and 7*2 : m S₃

Specification of high-level application programming interfaces (SemSorGrid4Env)

This document defines an Application Tier for the SemsorGrid4Env project. Within the Application Tier we distinguish between Web Applications - which provide a User Interface atop a more traditional Service Oriented Architecture - and Mashups which are driven by a REST API and a Resource Oriented Architecture. A pragmatic boundary is set to enable initial development of Web Applications and Mashups; as the project progresses an evaluation and comparison of the two paradigms may lead to a reassessment of where each can be applied within the project, with the experience gained providing a basis for general guidelines and best practice. Both Web Applications and Mashups are designed and delivered through an iterative user-centric process; requirements generated by the project case studies are a key element of this approach

ANALYSIS OF CHANGING METHODS OF VERTICAL COORDINATION IN THE PORK INDUSTRY

This study examines the motivation behind contracts and vertical integration in the pork industry, and simulates the effects of potential improvements in coordination. Incentives related to lowering costs of measuring and sorting hogs, and protecting against opportunistic behavior associated with specific assets, can result in hog quality improvements. A framework for simulating the effects of increased coordination through contracts and vertical integration was developed and used to evaluate potential improvements in leanness. Although simulations suggest only modest changes in pork prices and supplies, gains in consumers' surplus could be substantial for larger demand shifts due to quality improvements.Contracts, Hogs, Lean pork, Simulation model, Vertical coordination, Vertical integration, Industrial Organization, Livestock Production/Industries,

Strategic Alliances in U.S. Branded Beef Programs

In this paper, we combine concepts from organizational economics to examine supply chain alliances formed to market branded beef products. To illustrate application of the framework, we examine three different types of alliances. We conclude that measuring costs associated with quality attributes have an important role in alliance structure.Agribusiness,