Social Construction: Understanding Construction in a Human Context

As lean construction has evolved as a practice, efforts have been made to develop theoretical foundations for understanding it. These efforts have been informed by our understanding of lean manufacturing, a source of many of the seminal ideas for lean construction. One key insight has been the shift from the understanding of a process as the transformation of materials from inputs to outputs to the view of a process as a flow of materials through a sequence of steps or operations. Another has been the recognition that value must be considered from the customer perspective. More recently, several authors have proposed more general contexts for understanding the entire construction process. These proposals have included observing the essential role of language in the conduct of projects, recognizing the limitations of a purely economic context, and adopting a more comprehensive flow perspective. In this paper, we propose a framework for situating the construction process in the world of human concerns. We show that consideration of the human being as actor within a world of concerns provides a necessary context and foundational explanation for all subsequent discussions of process, flow, value, and commitment. We also suggest a new perspective for understanding and addressing the issue of risk

Brief Announcement: Asymmetric Mutual Exclusion for RDMA

In this brief announcement, we define operation asymmetry, which captures how processes may interact with an object differently, and discuss its implications in the context of a popular network communication technology, remote direct memory access (RDMA). Then, we present a novel approach to mutual exclusion for RDMA-based distributed synchronization under operation asymmetry. Our approach avoids RDMA loopback for local processes and guarantees starvation-freedom and fairness

Spacelab Charcoal Analyses

This report describes analytical methods and results obtained from chemical analysis of 31 charcoal samples in five sets. Each set was obtained from a single scrubber used to filter ambient air on board a Spacelab mission. Analysis of the charcoal samples was conducted by thermal desorption followed by gas chromatography/mass spectrometry (GC/MS). All samples were analyzed using identical methods. The method used for these analyses was able to detect compounds independent of their polarity or volatility. In addition to the charcoal samples, analyses of three Environmental Control and Life Support System (ECLSS) water samples were conducted specifically for trimethylamine