Attracting solutions in crowdsourcing contests: The role of knowledge distance,identity disclosure,and seeker status

We investigate in the context of crowdsourcing how seekers can increase open innovation performance, measured as received solver attention, by making two strategic decisions: selecting innovation tasks that are well suited for crowdsourcing and choosing between the potentials of status signalling through identity disclosure versus enjoying the benefits of anonymity. Drawing on uncertainty reduction theory, we suggest that a well-articulated problem statement reduces uncertainties of potential solvers and increases their willingness to participate. We argue that the ability of seekers to draft high-quality problem statements depends on the distance between the problem domain and their current knowledge stock. An analysis of 637 crowdsourcing projects finds that problem-seeker knowledge distance and received solver attention are curvilinear related such that moderate levels of knowledge distance maximize solver participation. However, high-status seekers who engage in identity-based status signalling are able to benefit from crowdsourcing across all levels of problem-seeker knowledge distance.     

Validation of a videogrammetry technique for analysing American football helmet kinematics

ABSTRACT

Professional American football games are recorded in digital video with multiple cameras, often at high resolution and high frame rates. The purpose of this study was to evaluate the accuracy of a videogrammetry technique to calculate translational and rotational helmet velocity before, during and after a helmet impact. In total, 10 football impacts were staged in a National Football League (NFL) stadium by propelling helmeted 50th percentile male crash test dummies into each other or the ground at speeds and orientations representative of concussive impacts for NFL players. The tests were recorded by experienced sports film crews to obtain video coverage and quality typically available for NFL games. A videogrammetry procedure was used to track the position and rotation of the helmet throughout the relevant time interval of the head impact. Compared with rigidly mounted retroreflective marker three dimensional (3-D) motion tracking that was concurrently collected in the experiments, videogrammetry accurately calculated changes in translational and rotational velocity of the helmet using high frame rate (two cameras at 240 Hz) video (7% and 15% error, respectively). Low frame rate (2 cameras at 60 Hz) video was adequate for calculating pre-impact translational velocity but not for calculating the translational or rotational velocity change of the helmet during impact.     

Cognitive-inspired domain adaptation of sentiment lexicons

Sentiment lexicons are essential tools for polarity classification and opinion mining. In contrast to machine learning methods that only leverage text features or raw text for sentiment analysis, methods that use sentiment lexicons embrace higher interpretability. Although a number of domain-specific sentiment lexicons are made available, it is impractical to build an ex ante lexicon that fully reflects the characteristics of the language usage in endless domains. In this article, we propose a novel approach to simultaneously train a vanilla sentiment classifier and adapt word polarities to the target domain. Specifically, we sequentially track the wrongly predicted sentences and use them as the supervision instead of addressing the gold standard as a whole to emulate the life-long cognitive process of lexicon learning. An exploration-exploitation mechanism is designed to trade off between searching for new sentiment words and updating the polarity score of one word. Experimental results on several popular datasets show that our approach significantly improves the sentiment classification performance for a variety of domains by means of improving the quality of sentiment lexicons. Case-studies also illustrate how polarity scores of the same words are discovered for different domains.     

书刊市场 数码印刷的巨大商机

有关书刊市场,最重要的莫过于它为胶印和数码印刷提供的市场机遇了。胶印在这个市场机遇中占据着最大的份额,而数码印刷则面临着实实在在的增长机遇。     

数码照片市场一个真正的大机遇

上个月,我参加了在美国内华达州拉斯维加斯举行的国际影像器材及电子贸易博览会。有2万多人参观了这次展会,他们中包括许多专业摄影师和数码印刷商。     

与营销及设计人员一起促进业务增长

增加数码印刷收入最有效的方法是与客户的营销人员和设计人员形成伙伴关系．正如施乐公司所绘制的图1所示。     

The long tail: a usage analysis of pre-1993 print biomedical journal literature

Objective: The research analyzes usage of a major biomedical library''s pre-1993 print journal collection.Methodology: In July 2003, in preparation for a renovation and expansion project, the Biomedical Library at the University of California, San Diego, moved all of its pre-1993 journal volumes off-site, with the exception of twenty-two heavily used titles. Patrons wishing to consult one of these stored volumes could request that it be delivered to the library for their use. In the spring of 2006, an analysis was made of these requests.Results: By July of 2006, 79,827 journal volumes published in 1992 or earlier had been requested from storage. The number of requests received declined with age of publication. The usage distribution exhibited a “long tail”: 50% of the 79,827 requests were for journal volumes published before 1986. The availability of electronic access dramatically reduced the chance that corresponding print journal volumes would be requested.Conclusions: The older biomedical print journal literature appears to be of continued value to the biomedical research community. When electronic access was provided to the older literature, demand for older print volumes declined dramatically.

Highlights

• Analysis of requests for stored biomedical journal volumes published prior to 1993 indicates that older biomedical journal literature receives substantial use: during this 3-year study, there were nearly 80,000 requests for journal volumes published in 1992 or earlier, with half the requests for volumes published from 1986–1992 and 40% of the request for volumes published from 1970–1985. These results indicate that retaining older print volumes, or providing easy access to the older literature through electronic journals or other means, will likely be required to meet user information needs.
• Use of older journal volumes varies by title and by user population, and a small number of journal titles were responsible for most of the use.
• Requests for older print biomedical journal titles dropped significantly when electronic access became available.

Implications

• Biomedical libraries should carefully consider implications of eliminating on-site access to older journal literature for users and budgets.
• Removing access to older journal literature may result in higher demand for interlibrary loan and document delivery services.
• Biomedical libraries can safely substitute reliable electronic access to older literature to meet ongoing needs for this information, thereby creating space for other purposes.