A case study of open source and public participation in catalyzing social innovations

Our study investigates the use of a new open source platform in catalyzing social innovations and participation of its members over time. We empirically examined how the nature of project designs and social pressure affect contribution to the open source platform. In the twenty-one projects (3,998 contributions) from 2004 to 2009, we find that the average number of contributions is higher when the projects are highly visible, when the project is designed to require specific skills from participants, and when it requires outcome measurement from participants' proposals. Also, we verified that actors join collective action when they believe their contribution is meaningful and they would stop when they believe their contribution could be marginal. These results provide implications for open source platform design in the philanthropic sector. © 2010 IEEE.published_or_final_versio

Exploring Online Engagement in Public Policy Consultation: The Crowd or the Few?

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An Analysis of the Social Process in Ideas Generation for Public Policies

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Relaxed stability conditions based on Taylor series membership functions for polynomial fuzzy-model-based control systems

© 2014 IEEE. In this paper, we investigate the stability of polynomial fuzzy-model-based (PFMB) control systems, aiming to relax stability conditions by considering the information of membership functions. To facilitate the stability analysis, we propose a general form of approximated membership functions, which is implemented by Taylor series expansion. Taylor series membership functions (TSMF) can be brought into stability conditions such that the relation between membership grades and system states is expressed. To further reduce the con-servativeness, different types of information are taken into account: the boundary of membership functions, the property of membership functions, and the boundary of operating domain. Stability conditions are obtained from Lyapunov stability theory by sum of squares (SOS) approach. Simulation examples demonstrate the effect of each piece of information

Design of hybrid continuous-time discrete-time delta-sigma modulators

Recent attention has been drawn to the hybrid Delta-Sigma (ΔΣ) structure featuring the integration of continuous-time (CT) and discrete-time (DT) structures in the loop filter. It combines the accurate loop filter characteristic of a DT ΔΣ modulator and the inherent anti-aliasing of a CT ΔΣ modulator. We present a design methodology for building a CT-DT ΔΣ modulator via the transformation from a DT ΔΣ modulator prototype. We also demonstrate the tradeoff of applying this structure to cascaded Delta-Sigma modulators compared to pure CT or DT implementations. ©2008 IEEE.published_or_final_versio

Multi-site evaluation of a computer aided detection (CAD) algorithm for small acute intra-cranial hemorrhage and development of a stand-alone CAD system ready for deployment in a clinical environment

Timely detection of Acute Intra-cranial Hemorrhage (AIH) in an emergency environment is essential for the triage of patients suffering from Traumatic Brain Injury. Moreover, the small size of lesions and lack of experience on the reader's part could lead to difficulties in the detection of AIH. A CT based CAD algorithm for the detection of AIH has been developed in order to improve upon the current standard of identification and treatment of AIH. A retrospective analysis of the algorithm has already been carried out with 135 AIH CT studies with 135 matched normal head CT studies from the Los Angeles County General Hospital/ University of Southern California Hospital System (LAC/USC). In the next step, AIH studies have been collected from Walter Reed Army Medical Center, and are currently being processed using the AIH CAD system as part of implementing a multi-site assessment and evaluation of the performance of the algorithm. The sensitivity and specificity numbers from the Walter Reed study will be compared with the numbers from the LAC/USC study to determine if there are differences in the presentation and detection due to the difference in the nature of trauma between the two sites. Simultaneously, a stand-alone system with a user friendly GUI has been developed to facilitate implementation in a clinical setting. © 2010 Copyright SPIE - The International Society for Optical Engineering.published_or_final_versio

Open source platforms for citizen engagement: examining Ashoka’s design and implementation

This paper investigates the use of open source, idea competition platforms to catalyze citizen participation. It specifically focuses on an initiative of Ashoka’s Changemakers, an innovative international nonprofit to develop this capacity to leverage modest philanthropic resources and inspire citizens to offer ideas about solutions to public problems. Drawing upon theory from collective action, we empirically examined how project design affects contribution to forty-seven projects held from 2004 to 2011. The analysis reveals the number of contributions is higher when the projects are highly visible, when specific skills are required, and when outcome measures are specified in participants’ proposals. This analysis gives support to existing theory about online engagement and considers implications for policy, practice and future research about use of and design of open source platforms in public affairs.published_or_final_versio

A timely computer-aided detection system for acute ischemic and hemorrhagic stroke on CT in an emergency environment

Standalone Presentations: no. LL-IN1105BACKGROUND: When a patient is accepted in the emergency room suspected of stroke, time is of the most importance. The infarct brain area suffers irreparable damage as soon as three hours after the onset of stroke symptoms. Non-contrast CT scan is the standard first line of investigation used to identify hemorrhagic stroke cases. However, CT brain images do not show hyperacute ischemia and small hemorrhage clearly and thus may be missed by emergency physicians. We reported a timely computer-aided detection (CAD) system for small hemorrhages on CT that has been successfully developed as an aid to ER physicians to help improve detection for Acute Intracranial Hemorrhage (AIH). This CAD system has been enhanced for diagnosis of acute ischemic stroke in addition to hemorrhagic stroke, which becomes a more complete and clinically useful tool for assisting emergency physicians and radiologists. In the detection algorithm, brain matter is first segmented, realigned, and left-right brain symmetry is evaluated. As in the AIH system, the system confirms hemorrhagic stroke by detecting blood presence with anatomical and medical knowledge-based criteria. For detecting ischemia, signs such as regional hypodensity, blurring of grey and white matter differentiation, effacement of cerebral sulci, and hyperdensity in middle cerebral artery, are evaluated …published_or_final_versio

WIJAM: a mobile collaborative improvisation platform under Master-players Paradigm

Music jamming is an extremely difficult task for musical novices. Trying to extend this meaningful and highly enjoyable activity to a larger recipient group, we present WIJAM, a mobile application for an ad-hoc group of musical novices to perform improvisation along with a music master. In this master-players' paradigm, the master offers a music backing, orchestrates the musical flow, and gives feedbacks to the players; the players improvise by tapping and sketching on their smartphones. We argue that this paradigm can be a significant contribution to the possibility of music playing by a group of novices with no instrumental training leading to decent musical results.published_or_final_versio