Umbilic hypersurfaces of constant sigma-k curvature in the Heisenberg group

We study immersed, connected, umbilic hypersurfaces in the Heisenberg group $H_{n}$ with $n$ $\geq$ $2.$ We show that such a hypersurface, if closed, must be rotationally invariant up to a Heisenberg translation. Moreover, we prove that, among others, Pansu spheres are the only such spheres with positive constant sigma-k curvature up to Heisenberg translations.Comment: 28 pages, 6 figure

Umbilicity and characterization of Pansu spheres in the Heisenberg group

For $n\geq 2$ we define a notion of umbilicity for hypersurfaces in the Heisenberg group $H_{n}$. We classify umbilic hypersurfaces in some cases, and prove that Pansu spheres are the only umbilic spheres with positive constant $p$(or horizontal)-mean curvature in $H_{n}$ up to Heisenberg translations.Comment: 32 pages, 2 figures; in Crelle's journal, 201

Factors Influencing Practitioners’ Experience of Utilizing Open Government Data

Open government data (OGD) has been discussed globally for its value in improving the government’s service quality and transparency. However, most OGD must be utilized by the practitioners in their projects so that the public can benefit from the outcomes and realize the philosophy of OGD. This study investigated 35 practitioners’ experiences utilizing OGD with semi-structured interviews and analyzed transcripts via a qualitative approach based on grounded theory. The results present five factors that influence practitioners’ experiences: data quality, service quality, product quality, experience quality, and feedback quality; moreover, 15 indicators among the above factors were identified. In conclusion, practitioners play a crucial role in turning OGD into valuable products to engage the public in the OGD ecosystem and expand the value of such data. This paper gives specific recommendations to the government to improve the OGD environment from a practical perspective and demonstrates the meanings of practitioners’ contributions to the OGD movement. (Article content in Chinese with English extended abstract