Collaboration In Software Engineering Projects: A Theory Of Coordination

Coordination of engineering decisions is a central concern of software engineering. We present a theory in which coordination of engineering decisions is modeled as a distributed constraint satisfaction problem (DCSP). We derive six hypotheses, predicting how the distribution of decisions over developers and the density of constraints among decisions will affect development time, probability that a file contains a field defect, and developer productivity. We test these hypotheses using data from a commercial project. We find support for all hypotheses predicting detrimental effects from poor distribution of decisions over developers. The effects of constraint density were mixed, showing that dense constraints slowed development but did not significantly affect productivity. Dense data dependencies increased the chances that a file contained a field defect, but, very surprisingly, dense call dependencies significantly lowered the chances that a file contained a field defect. We discuss the implications of these findings

Percy Julian and the Rise in Inclusive Pedagogy in the Department of Chemistry and Biochemistry

As a research fellow at DePauw, Dr. Percy L. Julian included undergratuate students in his research to synthesize physostigmine. Building on that legacy, the Department of Chemistry and Biochemistry continues a longstanding history of supporting undergraduate research. Recongnizing tht there is inequity in who participates in research, our department recently initiated an application process open to all students in our courses to equalize the way in which stuents learn about and get started in research. Students in our structure and propterties of organiz molecules course view and reflect on the Forgotten Genius documentary and the recently awarded HHMU Inclusive Excellence Initiative grant has provided many faculty members development opportunities in inclusive pedagogy. In May, Dr. Julian was appointed posthumously to the DePauw University faculty. The Department of Chemistry and Biochemistry celebrates this appointment and continues to work toward creating a positive and inviting atmosphere for all students at DePauw

Why Developers Participate in Open Source Software Projects: An Empirical Investigation

Our goal in this study is to provide insight into the motivational profiles of open source contributors. Adopting a functionalist view of motivation, we identify five functional dimensions from the literature on volunteerism that are relevant to the open source context and three functional dimensions from the literature on open source development. To assess the salience and relative strength of each functional explanation for open source participation, we conducted secure Web-based surveys of developers who participated in three large Apache open source projects. Applying exploratory factor analytic techniques to analyze the survey data collected from 122 Apache participants, we found 5 distinct factors underlying the motivation to participate in open source projects. We then used conjoint analysis to assess the relative importance of these underlying motivations. Results from the conjoint analysis indicate that while several dimensions are significant in explaining the motivation to participate in open source projects, the dominant motivations include increasing the contributor’s use value of the software (27 percent) followed by the recreational value of the task (19 percent) and the potential career impacts from participation (12 percent). This study contributes to the growing literature on open source software development by providing insight into the underlying motivational profiles of open source participation and by identifying the relative importance of different motivations within those profiles

Search for domain wall dark matter with atomic clocks on board global positioning system satellites

Cosmological observations indicate that 85% of all matter in the Universe is dark matter (DM), yet its microscopic composition remains a mystery. One hypothesis is that DM arises from ultralight quantum fields that form macroscopic objects such as topological defects. Here we use GPS as a ~ 50,000 km aperture DM detector to search for such defects in the form of domain walls. GPS navigation relies on precision timing signals furnished by atomic clocks hosted on board GPS satellites. As the Earth moves through the galactic DM halo, interactions with topological defects could cause atomic clock glitches that propagate through the GPS satellite constellation at galactic velocities ~ 300 km/s. Mining 16 years of archival GPS data, we find no evidence for DM in the form of domain walls at our current sensitivity level. This allows us to improve the limits on certain quadratic scalar couplings of domain wall DM to standard model particles by several orders of magnitude.Comment: 7 pages (main text), and 12 pages for Supplementary Information. v3: Update titl

Economic Incentives for Participating in Open Source Software Projects

Using the Internet as a basis for communication, collaboration, and storage of artifacts, the open source community is producing software of a quality that was previously thought to be achievable only by professional engineers following strict software development paradigms. This accomplishment is even more astounding as developers contribute to the source code without any remuneration. Open source leaders as well as academics have proposed theories about the motivation of open source developers that are rooted in diverse fields such as social psychology and anthropology. However, Lerner and Tirole (2000) argue that developer participation in open source projects may, in part, be explained by existing economic theory regarding career concerns. This research seeks to confirm or disconfirm the existence of economic returns to participation in open source development. Our findings suggest that greater open source participation per se, as measured in contributions made, is not associated with wage increases. However, a higher status in a merit-based ranking within the Apache Project is associated with significantly higher wages. This suggests that employers do not reward the gain in experience through open source participation as an increase in human capital. The results are also consistent with the notion that a high rank within the Apache Software Foundation is a credible signal of the productive capacity of a programmer

Patterns of Lone Actor Terrorism in the United States

This research explores the differences in geospatial and temporal patterns between lone actor and group-based terrorists in the United States. These include differences in demographics, precursor activities, proximity to the terrorism incidents, and longevity of conducting terrorist activities. Data for this analysis were derived from the American Terrorism Study (ATS). The ATS includes information on federal criminal cases resulting from FBI investigations for “terrorism or terrorism-related activities.” The analysis includes data from 264 prevented or completed terrorism incidents in the United States from 1980-present. These incidents involved 314 indictees charged with over 3,000 federal criminal counts. They were responsible for 1,788 recorded precursor activities that occurred at over 1,100 geocoded addresses

The Longevity of American Terrorists: Factors Affecting Sustainability

This project was an outgrowth of two previous NIJ projects being conducted under NIJ’s Research and Evaluation on Domestic Radicalization to Violent Extremism program area. The first of these projects, which ended in 2015, focused upon testing one of the most prominent theoretical models of extremist radicalization -- identity and framing theory. One of the findings from examination of this theoretical model is consistent with the notion that “people want to be associated with a winner.” Recruitment and commitment, crucial to the lifespan of any terrorist movement, improve when the movement has been able to commit successful terrorist incidents (Freilich, Chermak, and Caspi, 2009), particularly if the offenders escaped unscathed. In the second project, which focused upon the temporal sequencing of terrorists’ precursor behaviors,2 a somewhat serendipitous finding emerged to crystalize the current issue. A preliminary analysis of the differences between “lone actors” and members of “cells or groups” revealed that lone actors “survived” substantially longer than members of cells or groups before being arrested or indicted. Although we later found this relationship to be spurious, it was worthy of further examination