Change Management Support for Large Software Systems

This technical report consists of three related papers in the area of management of source code changes for large software systems. Infuse: A Toolfor Automatically Managing and Coordinating Source Changes in Large Systems presents Infuse, a software engineering environment that automatically panitions the source code files to be changed in order to limit the complexity of change propagation and negotiation of conflicting changes. Workspaces and Experimental Databases: Automated Support for Cooperation Among Programmers describes Infuse in more detail, focusing on the interactions between Infuse and source code modification tools. Smarter Recompilation presents an algorithm that could be used by Infuse or other software engineering environments to reduce recompilation costs after source code changes

Modelling human choices: MADeM and decision‑making

Research supported by FAPESP 2015/50122-0 and DFG-GRTK 1740/2. RP and AR are also part of the Research, Innovation and Dissemination Center for Neuromathematics FAPESP grant (2013/07699-0). RP is supported by a FAPESP scholarship (2013/25667-8). ACR is partially supported by a CNPq fellowship (grant 306251/2014-0)

Broadband Multi-wavelength Properties of M87 during the 2017 Event Horizon Telescope Campaign

Abstract: In 2017, the Event Horizon Telescope (EHT) Collaboration succeeded in capturing the first direct image of the center of the M87 galaxy. The asymmetric ring morphology and size are consistent with theoretical expectations for a weakly accreting supermassive black hole of mass ∼6.5 × 109 M ⊙. The EHTC also partnered with several international facilities in space and on the ground, to arrange an extensive, quasi-simultaneous multi-wavelength campaign. This Letter presents the results and analysis of this campaign, as well as the multi-wavelength data as a legacy data repository. We captured M87 in a historically low state, and the core flux dominates over HST-1 at high energies, making it possible to combine core flux constraints with the more spatially precise very long baseline interferometry data. We present the most complete simultaneous multi-wavelength spectrum of the active nucleus to date, and discuss the complexity and caveats of combining data from different spatial scales into one broadband spectrum. We apply two heuristic, isotropic leptonic single-zone models to provide insight into the basic source properties, but conclude that a structured jet is necessary to explain M87’s spectrum. We can exclude that the simultaneous γ-ray emission is produced via inverse Compton emission in the same region producing the EHT mm-band emission, and further conclude that the γ-rays can only be produced in the inner jets (inward of HST-1) if there are strongly particle-dominated regions. Direct synchrotron emission from accelerated protons and secondaries cannot yet be excluded

Experience with the architectural design of a modest product family

Many product families are modest in the sense that they consist of a sequence of incremental products with, at any point in time, only a few distinct products available and minimal variations among the products. Such product families, nevertheless, are often large, complex systems, widely deployed, and possessing stringent safety and performance requirements. This paper describes a case study that tends to confirm the value of using a product-line approach for the architectural design of a modest product family. The paper describes the process, design alternatives, and lessons learned, both positive and negative, from the architectural design of one such family of medical image analysis products. Realized benefits included identifying previously unrecognized common behavior and sets of features that were likely to change together, aligning the architecture with specific market needs and with the organization, and reducing unplanned dependencies. Most interesting were the unanticipated benefits, including decoupling the product-family architecture from the order of implementation of features, and using the product-family architecture as a “guiding star with subsequent releases moving toward, rather than away from, the planned architecture

Software Development Environments for Very Large Software Systems

This technical report consists of the three related papers. Living with Inconsistency in Large Systems describes CONMAN, an environment that identifies and tracks version inconsistencies, permitting debugging and testing to proceed even though the executable image contains certain non-fatal inconsistencies. The next two papers are both from the INFUSE project. Change Management for Very Large Software Systems presents the new non-Euclidean hierarchical clustering algorithm used by the INFUSE change management system to cluster modules according to the strengths of their interdependencies. Models of Software Development Environments presents a general model of software development environments consisting of three components - policies, mechanisms and structures - and classifies existing and proposed environments into the individual, family, city and state classes according to the size of projects that could be adequately supported