Modelling workplace contact networks: the effects of organizational structure, architecture, and reporting errors on epidemic predictions

Face-to-face social contacts are potentially important transmission routes for acute respiratory infections, and understanding the contact network can improve our ability to predict, contain, and control epidemics. Although workplaces are important settings for infectious disease transmission, few studies have collected workplace contact data and estimated workplace contact networks. We use contact diaries, architectural distance measures, and institutional structures to estimate social contact networks within a Swiss research institute. Some contact reports were inconsistent, indicating reporting errors. We adjust for this with a latent variable model, jointly estimating the true (unobserved) network of contacts and duration-specific reporting probabilities. We find that contact probability decreases with distance, and research group membership, role, and shared projects are strongly predictive of contact patterns. Estimated reporting probabilities were low only for 0-5 minute contacts. Adjusting for reporting error changed the estimate of the duration distribution, but did not change the estimates of covariate effects and had little effect on epidemic predictions. Our epidemic simulation study indicates that inclusion of network structure based on architectural and organizational structure data can improve the accuracy of epidemic forecasting models.Comment: 36 pages, 4 figure

A description of within-family resource exchange networks in a Malawian village

In this paper we explore patterns of economic transfers between adults within household and family networks in a village in Malawi’s Rumphi district, using data from the 2006 round of the Malawi Longitudinal Study of Families and Health. We fit Exponential-family Random Graph Models (ERGMs) to assess individual, relational, and higher-order network effects. The network effects of cyclic giving, reciprocity, and in-degree and out-degree distribution suggest a network with a tendency away from the formation of hierarchies or "hubs." Effects of age, sex, working status, education, health status, and kinship relation are also considered.Malawi, Malawi Longitudinal Study of Families and Health, networks, resource exchange, social network

Micromechanics of composite laminate compression failure

The Dugdale analysis for metals loaded in tension was adapted to model the failure of notched composite laminates loaded in compression. Compression testing details, MTS alignment verification, and equipment needs were resolved. Thus far, only 2 ductile material systems, HST7 and F155, were selected for study. A Wild M8 Zoom Stereomicroscope and necessary attachments for video taping and 35 mm pictures were purchased. Currently, this compression test system is fully operational. A specimen is loaded in compression, and load vs shear-crippling zone size is monitored and recorded. Data from initial compression tests indicate that the Dugdale model does not accurately predict the load vs damage zone size relationship of notched composite specimens loaded in compression

Reporting on the Annual Report

Annual reports provide an important source of information for investors. The SEC guidance to companies that requires forward-looking discussions of events is far from uniform but a constructive step in providing information

Extended Transaction Models for Software Development Environments

This technical report consists of two papers discussing concurrency control facilities for multiuser software development environments. A Marvelous Extended Transaction Processing Model briefly sketches the previously developed commit-serializability model and then applies it to the MARVEL kernel for software development environments. A Participant Semantics for Serializable Transactions describes our first pass at a different extended transaction model that moves users inside the system, so certain users may participate in transactions and the interactions among transactions while all other users observe only a serial order for the transactions

AI Techniques in Software Engineering

The idea of using artificial intelligence techniques to support programming has been around for a long time. The earliest notion was to avoid programming entirely. The human user would just tell the computer what to do, without saying how to do it, and the computer would do the right thing. Even if this were feasible, however, it would be much too tedious, since each time the user would have to repeat the details of what he wanted done. So the goal of programming was to explain things to the computer only once, and then later on be able to tell the computer to do the same thing again in some short form, such as the name of the "program." Thus the idea evolved that a user would somehow tell the computer what program was desired, and the computer would write down the program in some internal form so that it could be remembered and repeated later. The assumption was that the resulting program would be correct, complete, efficient, easy to use, and so forth. It would also be exactly what the human user wanted

Incremental Dynamic Semantics for Language-Based Programming Environments

Attribute grammars are a formal notation for expressing the static semantics of programming languages — those properties that can be derived from inspection of the program text. Attribute grammars have become popular as a mechanism for generating language-based programming environments that incrementally perform symbol resolution, type checking, code generation and derivation of other static semantic properties as the program is modified. However, attribute grammars are not suitable for expressing dynamic semantics — those properties that reflect the history of program execution and/or user interactions with the programming environment. This article presents action equations, an extension of attribute grammars suitable for specifying the static and the dynamic semantics of programming languages. It describes how action equations can be used to generate language-based programming environments that incrementally derive static and dynamic properties as the user modifies and debugs the program