Analysing the results of a designed experiment when the response is a curve: Methodology and application in metal injection moulding

In (designed) industrial experiments, the response observed often takes the form of a curve representing, for example, the evolution of a quality characteristic over a period of time. In such a context, the polynomial regression approach, usually used in response surface analysis to predict the response as a function of the experimental factors, should be adapted to the functional character of the response. This paper reviews several possible methods of analysing the results of a designed experiment when the response is a curve and compares them with a case study from the metal injection-moulding industry. Three different approaches are first presented to fit a model to the (functional) data: two-step nonlinear modelling; pointwise functional regression; and smoothed functional regression. All of the models derived are able to predict the functional response from any design factor setting chosen in the experimental domain. Two inferential problems are then discussed: the significance testing of experimental factor effects and the calculation of prediction intervals around predicted curves. Asymptotic results and bootstrap procedures are compared in this context. Copyright (c) 2005 John Wiley & Sons, Ltd

A new concurrency model for scala based on a declarative dataflow core

Declarative dataflow values are single assignment variables such that all operations needing their values wait automatically until the values are available. Adding threads and declarative dataflow values to a functional language gives declarative concurrency, a model in which concurrency is deterministic and explicit synchronization is not needed. In our experience, this greatly simplifies the writing of concurrent programs (as explained in several chapters of CTM [20]). We complete this model with lazy execution and message-passing concurrency. Both extensions are tightly integrated with the declarative dataflow core. Lazy execution is provided by extending declarative dataflow with a by-need synchronization operation. Message passing is provided by adding streams equipped with a send operation, where a stream is a list with an unbound single-assignment variable. This paper presents the Ozma language, a conservative extension of Scala that supports all these concepts. We have made a complete implementation of Ozma by combining the implementations of Scala and Oz. Evaluation shows that this implementation supports the full semantics of Scala with concurrent programs based on the new concurrency model. In particular, within the functional subset of Scala the new concurrency model fully supports deterministic concurrency

Open Multi-Agent Systems : Gossiping with Deterministic Arrivals and Departures

This work is a first step towards the study of open multi-agent systems : systems that agents can join and leave, and where arrivals and departures happen on a time-scale comparable to that of the process running on the system. We study the behavior of the average pairwise gossip algorithm on such open systems, and provide an exact characterization of its evolution in terms of three scale-independent quantities that are shown to be solutions of a 3-dimensional linear dynamical system. We then focus on two particular cases: one where each departure is immediately followed by an arrival, and one where agents keep arriving without ever leaving the system, so that the number of agents grows unbounded

Incremental Grammar Induction from Child-Directed Dialogue Utterances

We describe a method for learning an incremental semantic grammar from data in which utterances are paired with logical forms representing their meaning. Work- ing in an inherently incremental framework, Dynamic Syntax, we show how words can be associated with probabilistic procedures for the incremental projection of meaning, providing a grammar which can be used directly in incremental prob- abilistic parsing and generation. We test this on child-directed utterances from the CHILDES corpus, and show that it results in good coverage and semantic accuracy, without requiring annotation at the word level or any independent notion of synta