A collaboration environment to support distributed eXtreme programming

NUL

Quantifying the impact of weak, strong, and super ties in scientific careers

Scientists are frequently faced with the important decision to start or terminate a creative partnership. This process can be influenced by strategic motivations, as early career researchers are pursuers, whereas senior researchers are typically attractors, of new collaborative opportunities. Focusing on the longitudinal aspects of scientific collaboration, we analyzed 473 collaboration profiles using an ego-centric perspective which accounts for researcher-specific characteristics and provides insight into a range of topics, from career achievement and sustainability to team dynamics and efficiency. From more than 166,000 collaboration records, we quantify the frequency distributions of collaboration duration and tie-strength, showing that collaboration networks are dominated by weak ties characterized by high turnover rates. We use analytic extreme-value thresholds to identify a new class of indispensable `super ties', the strongest of which commonly exhibit >50% publication overlap with the central scientist. The prevalence of super ties suggests that they arise from career strategies based upon cost, risk, and reward sharing and complementary skill matching. We then use a combination of descriptive and panel regression methods to compare the subset of publications coauthored with a super tie to the subset without one, controlling for pertinent features such as career age, prestige, team size, and prior group experience. We find that super ties contribute to above-average productivity and a 17% citation increase per publication, thus identifying these partnerships - the analog of life partners - as a major factor in science career development.Comment: 13 pages, 5 figures, 1 Tabl

Utilizing the Human Rights Framework: Lessons Learned from the From Poverty to Opportunity Campaign: Realizing Human Rights in Illinois

In response to the growth and deepening of poverty in Illinois and the collateral human rights consequences, in December of 2006, Heartland Alliance for Human Needs & Human Rights initiated the "From Poverty to Opportunity Campaign: Realizing Human Rights in Illinois". Working in collaboration with a coalition of community members, advocates, organizers, faith-based institutions, and policy leaders, the campaign advocated state-wide for an improved response to the growing problem of poverty in Illinois. This paper documents some of the lessons Heartland Alliance has learned while using the human rights framework to build and advance a campaign to eliminate extreme poverty in Illinois

Instrumentation for and First Results on Nuclear Responses for Supernova Explosions

Our collaboration has set up a focal plane detection system and a focal plane polarimeter at the large acceptance Big-Bite Spectrometer at AGOR. The detector systems are equipped with a high performance readout and online data processing system, which allows polarization transfer and charge transfer measurements at extreme forward angles with high precision. Preliminary results on GT+ strength distributions obtained in (d,2He) measurements revealing the fine structure of the distributions are presented. Their relation to recent calculations of stellar weak interaction rates is discussed.Comment: 8 pages, 4 figures, conference proceeding GR2000, Osaka, June 200

Musings on Lorentz Violation Given the Recent Gravitational-Wave Observations of Coalescing Binary Black Holes

The recent observation of gravitational waves by the LIGO/Virgo collaboration provides a unique opportunity to probe the extreme gravity of coalescing binary black holes. In this regime, the gravitational interaction is not only strong, but the spacetime curvature is large, characteristic velocities are a non-negligible fraction of the speed of light, and the time scale on which the curvature and gravity change is small. This contribution discusses some consequences of these observations on modifications to General Relativity, with a special emphasis on Lorentz-violating theories.Comment: Presented at the Seventh Meeting on CPT and Lorentz Symmetry, Bloomington, Indiana, June 20-24, 201

Compact Binary Waveform Center-of-Mass Corrections

We present a detailed study of the center-of-mass (c.m.) motion seen in simulations produced by the Simulating eXtreme Spacetimes (SXS) collaboration. We investigate potential physical sources for the large c.m. motion in binary black hole simulations and find that a significant fraction of the c.m. motion cannot be explained physically, thus concluding that it is largely a gauge effect. These large c.m. displacements cause mode mixing in the gravitational waveform, most easily recognized as amplitude oscillations caused by the dominant (2,$\pm$2) modes mixing into subdominant modes. This mixing does not diminish with increasing distance from the source; it is present even in asymptotic waveforms, regardless of the method of data extraction. We describe the current c.m.-correction method used by the SXS collaboration, which is based on counteracting the motion of the c.m. as measured by the trajectories of the apparent horizons in the simulations, and investigate potential methods to improve that correction to the waveform. We also present a complementary method for computing an optimal c.m. correction or evaluating any other c.m. transformation based solely on the asymptotic waveform data.Comment: 20 pages, 15 figure

Collaboration and co-ordination in mature eXtreme programming teams

Mature eXtreme programming (XP) teams are highly collaborative and selforganising. In previous studies, we have observed that these teams rely on two apparently simple mechanisms of co-ordination and collaboration: story cards and the Wall. Story cards capture and embody the user stories which form the basis of implementation, while the Wall is a physical space used to organise and display the cards being implemented during the current development cycle (called an iteration). In this paper we analyse the structure and use of story cards and the Wall in three mature XP teams, using a distributed cognition approach. The teams work in different commercial organisations developing different systems, yet we find significant similarities between their use of these two artefacts. Although simple, teams use the cards and the Wall in sophisticated ways to represent and communicate information that is vital to support their activities. We discuss the significance of the physical medium for the story cards and the Wall in an XP team and discuss the considerations that need to be taken into account for the design of technology to support the teams