The Solar Upper Transition Region Imager(SUTRI)onboard the Space Advanced Technology demonstration satellite(SATech-01),which was launched to a Sun-synchronous orbit at a height of~500 km in 2022 July,aims to test the...The Solar Upper Transition Region Imager(SUTRI)onboard the Space Advanced Technology demonstration satellite(SATech-01),which was launched to a Sun-synchronous orbit at a height of~500 km in 2022 July,aims to test the on-orbit performance of our newly developed Sc/Si multi-layer reflecting mirror and the 2k×2k EUV CMOS imaging camera and to take full-disk solar images at the Ne VII 46.5 nm spectral line with a filter width of~3 nm.SUTRI employs a Ritchey-Chrétien optical system with an aperture of 18 cm.The on-orbit observations show that SUTRI images have a field of view of~416×416 and a moderate spatial resolution of~8″without an image stabilization system.The normal cadence of SUTRI images is 30 s and the solar observation time is about16 hr each day because the earth eclipse time accounts for about 1/3 of SATech-01's orbit period.Approximately15 GB data is acquired each day and made available online after processing.SUTRI images are valuable as the Ne VII 46.5 nm line is formed at a temperature regime of~0.5 MK in the solar atmosphere,which has rarely been sampled by existing solar imagers.SUTRI observations will establish connections between structures in the lower solar atmosphere and corona,and advance our understanding of various types of solar activity such as flares,filament eruptions,coronal jets and coronal mass ejections.展开更多
Recently software crowdsourcing has become a viable development paradigm for Software-as-a-Service （SaaS） ecosystems. TopCoder, one of the largest competi- tive programming communities, enables enterprises to tap in...Recently software crowdsourcing has become a viable development paradigm for Software-as-a-Service （SaaS） ecosystems. TopCoder, one of the largest competi- tive programming communities, enables enterprises to tap into its global talent pool and crowdsource a variety of SaaS development tasks including requirement analysis, architec- ture design, code, and testing. Many researchers have pro- posed auction-based modelling methods to characterize gen- eral software crowdsourcing. But there are few papers on the comprehensive analysis of SaaS crowdsourcing process and developer community. This paper introduces a holistic analysis framework to model the SaaS-oriented software crowdsourcing from two dimensions： individual behavior in crowdsourcing contests and collective competition in the community. The framework includes a game-theoretical model to describe the compet- itive nature of software crowdsourcing process. Moreover, the framework defines a competition network to characterize the topological properties of a crowdsourcing community for SaaS development. The analysis of this model indicates that the success of a competitive software crowdsourcing project essentially depends upon the networks of key participants with sufficient skills and dedication for the project. This is validated by a large historical data collected from the Top- Coder website over a ten-year period.展开更多
基金supported by the National Natural Science Foundation of China(NSFC)under Grants 11825301,12003016,12073077the National Key R&D Program of China No.2021YFA0718600+1 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences with the Grant No.XDA15018400the Youth Innovation Promotion Association of CAS(2023061)。
文摘The Solar Upper Transition Region Imager(SUTRI)onboard the Space Advanced Technology demonstration satellite(SATech-01),which was launched to a Sun-synchronous orbit at a height of~500 km in 2022 July,aims to test the on-orbit performance of our newly developed Sc/Si multi-layer reflecting mirror and the 2k×2k EUV CMOS imaging camera and to take full-disk solar images at the Ne VII 46.5 nm spectral line with a filter width of~3 nm.SUTRI employs a Ritchey-Chrétien optical system with an aperture of 18 cm.The on-orbit observations show that SUTRI images have a field of view of~416×416 and a moderate spatial resolution of~8″without an image stabilization system.The normal cadence of SUTRI images is 30 s and the solar observation time is about16 hr each day because the earth eclipse time accounts for about 1/3 of SATech-01's orbit period.Approximately15 GB data is acquired each day and made available online after processing.SUTRI images are valuable as the Ne VII 46.5 nm line is formed at a temperature regime of~0.5 MK in the solar atmosphere,which has rarely been sampled by existing solar imagers.SUTRI observations will establish connections between structures in the lower solar atmosphere and corona,and advance our understanding of various types of solar activity such as flares,filament eruptions,coronal jets and coronal mass ejections.
文摘Recently software crowdsourcing has become a viable development paradigm for Software-as-a-Service （SaaS） ecosystems. TopCoder, one of the largest competi- tive programming communities, enables enterprises to tap into its global talent pool and crowdsource a variety of SaaS development tasks including requirement analysis, architec- ture design, code, and testing. Many researchers have pro- posed auction-based modelling methods to characterize gen- eral software crowdsourcing. But there are few papers on the comprehensive analysis of SaaS crowdsourcing process and developer community. This paper introduces a holistic analysis framework to model the SaaS-oriented software crowdsourcing from two dimensions： individual behavior in crowdsourcing contests and collective competition in the community. The framework includes a game-theoretical model to describe the compet- itive nature of software crowdsourcing process. Moreover, the framework defines a competition network to characterize the topological properties of a crowdsourcing community for SaaS development. The analysis of this model indicates that the success of a competitive software crowdsourcing project essentially depends upon the networks of key participants with sufficient skills and dedication for the project. This is validated by a large historical data collected from the Top- Coder website over a ten-year period.
