Survey data sets are often wider than they are long. This high ratio of variables to observations raises concerns about overfitting during prediction, making informed variable selection important. ...Recent applications in computer science have sought to incorporate human knowledge into machine-learning methods to address these problems. The authors implement such a “human-in-the-loop” approach in the Fragile Families Challenge. The authors use surveys to elicit knowledge from experts and laypeople about the importance of different variables to different outcomes. This strategy offers the option to subset the data before prediction or to incorporate human knowledge as scores in prediction models, or both together. The authors find that human intervention is not obviously helpful. Human-informed subsetting reduces predictive performance, and considered alone, approaches incorporating scores perform marginally worse than approaches that do not. However, incorporating human knowledge may still improve predictive performance, and future research should consider new ways of doing so.
The relationship of the polychaete taxa Syllidae and Sphaerodoridae within Phyllodocida is still unresolved: phylogenetic analyses either show them as sister groups or more widely separated. The ...present article aims to provide information about the structure of the muscular system that could be essential for understanding their relationship. A crucial point is whether the body wall contains circular muscles, which has recently been shown to be absent in more taxa than previously known. The F-actin filaments in members of Myrianida prolifera (Syllidae) and Sphaerodoropsis sp. (Sphaerodoridae) were labeled with phalloidin and their three-dimensional relationships reconstructed by means of confocal laser scanning microscopy. Among the noteworthy differences that emerged between the species are (1) members of M. prolifera possess four, those of Sphaerodoropsis sp. eight, longitudinal muscle strands; (2) the body wall in M. prolifera contains transverse fibers in a typical, supralongitudinal position, while in Sphaerodoropsis sp., corresponding fibers lie beneath the longitudinal strands; (3) pro- and peristomium in M. prolifera have no distinct F-actin fibers, while five longitudinal pairs and three single transverse muscular fibers shape the anterior end in Sphaerodoropsis sp.; (4) the proventricle of M. prolifera comprises primarily radial muscle fibers arranged in distinct rows, while in Sphaerodoropsis sp. the axial proboscis consists of longitudinal and circular fibers and radial fibers are lacking; (5) in M. prolifera, the proximal and distal sections of the two anteriormost pairs of dorsal cirri possess longitudinal myofilaments, which are separate from the body wall musculature; by contrast, all appendages in Sphaerodoropsis sp. do not; (6) both species have bracing muscles: in M. prolifera they are positioned above the longitudinal fibers, whereas in Sphaerodoropsis sp. they are uniquely positioned between longitudinal and sublongitudinal transverse fibers. These results do not support a sister-group relationship of Syllidae and Sphaerodoridae. In addition, Sphaerodoropsis sp. is yet another example in the list of polychaetes lacking typical circular muscles in the body wall.
Mudslinging and Manners Filippova, Anna; Cho, Hichang
Proceedings of the 18th ACM Conference on Computer Supported Cooperative Work & Social Computing,
02/2015
Conference Proceeding
As the nature of virtual work changes, so must our understanding of important processes such as conflict. The present study examines conflict in ongoing virtual teams by situating itself in the ...context of Free and Open Source Software (FOSS) development. A series of semi-structured interviews with diverse representatives of the FOSS community highlight differences in the way conflict occurs. Specifically, a transformation of conflict types is observed together with a form of conflict previously unidentified in work on virtual teams. Findings suggest that the changing structure of ongoing virtual teams has important consequences for team processes like conflict.
The voluntary and computer mediated nature of FOSS work presents unique challenges and opportunities for effective collaboration. Conflict is one such challenge, magnified by the distributed nature ...of work and limited communication channels. Though conflict is recognized as an important social process in FOSS development teams, few studies have adequately addressed this issue. Drawing on theoretical frameworks in organizational behavior and social psychology, her dissertation investigates how conflict arises in voluntary distributed virtual teams such as FOSS, and its impact on group function. The work first explores the emergence and experience of conflict during the life cycle of a project. Different types and sources of conflict are identified, as well as their relationship with group outcomes. Various conflict types are expected to affect group function differently: some conflict sources may present a challenge, while others may prove necessary for successful group function. The dissertation expands theory and research on distributed work, in examining on-going processes of conflict in voluntary teams. This work also informs community design, as understanding conflict antecedents in voluntary virtual teams aids in reducing unproductive conflict and facilitates conflict that spurs innovation.
This article describes the project result of modeling and optimizing Radio Access Network. We have proposed a solution for controlling a large number of antennas in the conditions of engineering ...constraints and a large search space dimension. For estimating the performance, a virtual environment has been developed, that allows changing the parameters of Radio Access antennas to control the coverage and signal quality for all User Equipments. To optimize the Radio Access network, we have analyzed DE, CMA-ES, MOS, self-adaptive surrogate CMA-ES, lq-CMA-ES, BIPOP CMA-ES, sep-CMA-ES, lm-CMA-ES, HMO-CMA-ES, JADE, PSO, which have been adapted to the constraints of the task. To reduce dimension, graph clustering methods - Spectral clustering, Label propagation, Markov Clustering - are compared in dividing the network into groups. The experiments illustrate the efficiency of optimizing a large Radio Access network by the cluster approach.
Recent investigations have suggested that a lack of circular muscle fibers may be a common situation rather than a rare exception in polychaetes. As part of a comparative survey of polychaete muscle ...systems, the F-actin musculature subset of Magelona cf. mirabilis and Prionospio cirrifera were labeled with phalloidin and three-dimensionally analyzed and reconstructed by means of cLSM. Obvious similarities are sublongitudinal lateral, circumbuccal, palp retractor, dominating dorsal longitudinal, perpendicular lateral and ventral transverse muscles. Differences between M. cf. mirabilis and P. cirrifera are: (1) two types of prostomial muscles (transversal and longitudinal) in M. cf. mirabilis versus one type (diagonal) in P. cirrifera; (2) one type of palp muscles (longitudinal) in M. cf. mirabilis versus three types (longitudinal, diagonal, circular) in P. cirrifera; (3) five ventral longitudinal muscles (ventromedian, paramedian, ventral) in M. cf. mirabilis versus four (two paramedian, two ventral) in P. cirrifera. Ventral and lateral transverse fibers are present in the thorax, but absent in the abdomen of M. cf. mirabilis. The triangular lumen of the pharynx in M. cf. mirabilis is surrounded by radial muscle fibers; three sets of pharynx diductors attach to its dorsal side. The unique features of P. cirrifera are one pair of brain muscles and segmentally arranged dorsal transverse muscles, the latter located outside the longitudinal muscles. The transverse lateral muscles are restricted to the sides and lie beneath the longitudinal muscles, a pattern described here for the first time. A true, outer layer of circular fibers is absent in both species of Spionida that were investigated.
Background: Some developer activity traditionally performed manually, such as making code commits, opening, managing, or closing issues is increasingly subject to automation in many OSS projects. ...Specifically, such activity is often performed by tools that react to events or run at specific times. We refer to such automation tools as bots and, in many software mining scenarios related to developer productivity or code quality it is desirable to identify bots in order to separate their actions from actions of individuals. Aim: Find an automated way of identifying bots and code committed by these bots, and to characterize the types of bots based on their activity patterns. Method and Result: We propose BIMAN, a systematic approach to detect bots using author names, commit messages, files modified by the commit, and projects associated with the ommits. For our test data, the value for AUC-ROC was 0.9. We also characterized these bots based on the time patterns of their code commits and the types of files modified, and found that they primarily work with documentation files and web pages, and these files are most prevalent in HTML and JavaScript ecosystems. We have compiled a shareable dataset containing detailed information about 461 bots we found (all of whom have more than 1000 commits) and 13,762,430 commits they created.
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