Please wait, while we are loading the content...
Please wait, while we are loading the content...
| Content Provider | Springer Nature Link |
|---|---|
| Author | Sabharwal, Ashish Dilkina, Bistra Gomes, Carla P. |
| Copyright Year | 2014 |
| Abstract | There has been considerable interest in the identification of structural properties of combinatorial problems that lead to efficient algorithms for solving them. Some forms of structure, such as properties of the underlying constraint graph, are “easily” identifiable. Others, such as backdoor sets, are of interest because they capture key aspects of state-of-the-art constraint solvers as well as of many real-world problem instances. While backdoors were originally introduced to capture propagation based simplification mechanisms of solvers, they have recently been studied also in the context of tractable syntactic classes such as 2CNF and Horn. These syntactic classes, however, do not capture key aspects of solvers such as empty clause (i.e., violated constraint) detection. We show that incorporating inconsequential sounding features such as empty clause detection has a dramatic impact on both the complexity of finding a backdoor of size k (which becomes harder in the worst case) and on the size of the resulting backdoor (which can become arbitrarily smaller). Empirically, we show that commonly employed polynomial-time “dynamic” constraint propagation mechanisms, such as unit propagation, pure literal elimination, and probing, often lead to much smaller backdoor sets in real-world domains than “statically” defined classes such as Horn and RHorn, thereby capturing structure much more succinctly. We also reveal the inherent limits of the simpler concept of deletion backdoors, specifically by looking at renamable Horn sub-formulas. Finally, we extend the notion of backdoors to incorporate learning during search—a key aspect of nearly all state-of-the-art systematic SAT solvers—and show, both theoretically and empirically, that this drastically reduces the size of the resulting backdoor set. Our results suggest that structural notions explored for designing efficient algorithms for combinatorial problems should capture both statically and dynamically identifiable properties of the combinatorial problem being solved. |
| Ending Page | 431 |
| Page Count | 33 |
| Starting Page | 399 |
| File Format | |
| ISSN | 10122443 |
| e-ISSN | 15737470 |
| Journal | Annals of Mathematics and Artificial Intelligence |
| Issue Number | 4 |
| Volume Number | 70 |
| Language | English |
| Publisher | Springer International Publishing |
| Publisher Date | 2014-03-15 |
| Publisher Place | Cham |
| Access Restriction | One Nation One Subscription (ONOS) |
| Subject Keyword | Horn RHorn Backdoor sets Clause learning Problem solving (heuristics, search strategies, etc.) Search Computer Science Artificial Intelligence (incl. Robotics) Mathematics Statistical Physics, Dynamical Systems and Complexity Boolean satisfiability |
| Content Type | Text |
| Resource Type | Article |
| Subject | Applied Mathematics Artificial Intelligence |
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...
|