Please wait, while we are loading the content...
Please wait, while we are loading the content...
| Content Provider | Society for Industrial and Applied Mathematics (SIAM) |
|---|---|
| Author | Gritzmann, Peter Habsieger, Laurent Klee, Victor |
| Copyright Year | 1991 |
| Abstract | The radii considered here are the inradius $\rho $, the circumradius R, the diameter $\delta $, and the width $\Delta $. The convex polygons in question have their vertices at points of the integer lattice in $\mathbb{R}^2 $, and their radii are measured with respect to an $\ell ^p $ norm. Computation of these radii for convex polygons (and of their higher-dimensional analogues for convex polytopes) is of interest in connection with a number of applications, and may be regarded as a basic problem in computational geometry. The terms good radius and bad radius refer to the existence or nonexistence of a rationalizing polynomiala nonconstant rational polynomial q such that $q(\varphi (C))$ is rational whenever C is a convex lattice polygon and $\varphi $ is the radius function in question. When a radius is good, the polynomial is a tool for implicit computation of the radius in the binary model of computation; otherwise it seems to be necessary to resort to approximation. It is proved here that all four radii are good when $p \in \{ 1,\infty \} $, while $\delta $ is good when p is an integer and $\Delta $ is good when $p / (p - 1)$ is an integer. Thus $\delta $ and $\Delta $ are both good when $p = 2$, and it turns out that R is also good in this case. However, the main results are that r is bad when $p = 2$ and R is bad for each integer $p \geq 3$. |
| Starting Page | 395 |
| Ending Page | 403 |
| Page Count | 9 |
| File Format | |
| ISSN | 00975397 |
| DOI | 10.1137/0220024 |
| e-ISSN | 10957111 |
| Journal | SIAM Journal on Computing (SMJCAT) |
| Issue Number | 2 |
| Volume Number | 20 |
| Language | English |
| Publisher | Society for Industrial and Applied Mathematics |
| Publisher Date | 2006-07-31 |
| Access Restriction | Subscribed |
| Subject Keyword | inradius implicit computation Linear programming circumradius Irrationality; linear independence over a field Inequalities and extremum problems convex lattice polygon algebraic number rationalizing polynomial diameter Polynomials: factorization Computer graphics; computational geometry width Convex sets in $2$ dimensions polarity |
| Content Type | Text |
| Resource Type | Article |
| Subject | Mathematics Computer Science |
National Digital Library of India (NDLI) is a virtual repository of learning resources which is not just a repository with search/browse facilities but provides a host of services for the learner community. It is sponsored and mentored by Ministry of Education, Government of India, through its National Mission on Education through Information and Communication Technology (NMEICT). Filtered and federated searching is employed to facilitate focused searching so that learners can find the right resource with least effort and in minimum time. NDLI provides user group-specific services such as Examination Preparatory for School and College students and job aspirants. Services for Researchers and general learners are also provided. NDLI is designed to hold content of any language and provides interface support for 10 most widely used Indian languages. It is built to provide support for all academic levels including researchers and life-long learners, all disciplines, all popular forms of access devices and differently-abled learners. It is designed to enable people to learn and prepare from best practices from all over the world and to facilitate researchers to perform inter-linked exploration from multiple sources. It is developed, operated and maintained from Indian Institute of Technology Kharagpur.
Learn more about this project from here.
NDLI is a conglomeration of freely available or institutionally contributed or donated or publisher managed contents. Almost all these contents are hosted and accessed from respective sources. The responsibility for authenticity, relevance, completeness, accuracy, reliability and suitability of these contents rests with the respective organization and NDLI has no responsibility or liability for these. Every effort is made to keep the NDLI portal up and running smoothly unless there are some unavoidable technical issues.
Ministry of Education, through its National Mission on Education through Information and Communication Technology (NMEICT), has sponsored and funded the National Digital Library of India (NDLI) project.
| Sl. | Authority | Responsibilities | Communication Details |
|---|---|---|---|
| 1 | Ministry of Education (GoI), Department of Higher Education |
Sanctioning Authority | https://www.education.gov.in/ict-initiatives |
| 2 | Indian Institute of Technology Kharagpur | Host Institute of the Project: The host institute of the project is responsible for providing infrastructure support and hosting the project | https://www.iitkgp.ac.in |
| 3 | National Digital Library of India Office, Indian Institute of Technology Kharagpur | The administrative and infrastructural headquarters of the project | Dr. B. Sutradhar bsutra@ndl.gov.in |
| 4 | Project PI / Joint PI | Principal Investigator and Joint Principal Investigators of the project |
Dr. B. Sutradhar bsutra@ndl.gov.in Prof. Saswat Chakrabarti will be added soon |
| 5 | Website/Portal (Helpdesk) | Queries regarding NDLI and its services | support@ndl.gov.in |
| 6 | Contents and Copyright Issues | Queries related to content curation and copyright issues | content@ndl.gov.in |
| 7 | National Digital Library of India Club (NDLI Club) | Queries related to NDLI Club formation, support, user awareness program, seminar/symposium, collaboration, social media, promotion, and outreach | clubsupport@ndl.gov.in |
| 8 | Digital Preservation Centre (DPC) | Assistance with digitizing and archiving copyright-free printed books | dpc@ndl.gov.in |
| 9 | IDR Setup or Support | Queries related to establishment and support of Institutional Digital Repository (IDR) and IDR workshops | idr@ndl.gov.in |
|
Loading...
|