anchor academic publishing dez 2014 (3 resultados)

Taschenbuch. Condición: Neu. This item is printed on demand - it takes 3-4 days longer - Neuware -More than a decade ago, in 2002, al-Qaeda declared their cyber-aspirations: 'We strongly urge Muslim Internet professionals to spread and disseminate news and information about the jihad through e-mail lists, discussion groups and their own Web sites (.). The more Web sites, the better it is for us. We must make the Internet our tool.'Social media is part of today s battlefield. Over the past decade the Internet has become increasingly important to the loose and decentralized jihadist movement. This book illustrates that Jihadism online has had tremendous significance within the global jihad movement and no doubt its importance will rise in the future, as improved bandwidth, increased functionality, and the fast growing number of users will make the Internet a far more vital nerve than it is today. Salafi-Jihadist websites and social media spaces legitimate the actions of Islamic terrorists and encourage readers to support the Jihad wherever they can. Social media has offered new ways in which to promote terrorism or Jihad, and thus facilitated its intensification. Today everyone can be a part of a radical movement, anywhere. Due to the availability of propaganda material online, the Internet has not only changed the process of radicalization but influenced the nature of terrorism: the autodidactiv terrorist has become the new threat to Western security services. 72 pp. Englisch.

Taschenbuch. Condición: Neu. This item is printed on demand - it takes 3-4 days longer - Neuware -This research study deals with the design and development of non-invasive and reflectance type (photoplethysmogram) wearable PPG prototype for measuring heart rate.It explains the processing of heart rate from the measured PPG signal.Illustrates the heart rate measurements at different measurement sites.Explains benchmarking of realtime measured heart rate with other standard heart rate measuring units.Presents the heart rate measurements during different actions of swimming when the prototype is mounted on the forhead of swimmer. 76 pp. Englisch.

Taschenbuch. Condición: Neu. This item is printed on demand - it takes 3-4 days longer - Neuware -For a DBMS that provides support for a declarative query language like SQL, the query optimizer is a crucial piece of software. The declarative nature of a query allows it to be translated into many equivalent evaluation plans. The process of choosing a suitable plan from all alternatives is known as query optimization. The basis of this choice are a cost model and statistics over the data. Essential for the costs of a plan is the execution order of join operations in its operator tree, since the runtime of plans with different join orders can vary by several orders of magnitude. An exhaustive search for an optimal solution over all possible operator trees is computationally infeasible. To decrease complexity, the search space must be restricted. Therefore, a well-accepted heuristic is applied: All possible bushy join trees are considered, while cross products are excluded from the search.There are two efficient approaches to identify the best plan: bottom-up and top- down join enumeration. But only the top-down approach allows for branch-and-bound pruning, which can improve compile time by several orders of magnitude, while still preserving optimality.Hence, this book focuses on the top-down join enumeration. In the first part, we present two efficient graph-partitioning algorithms suitable for top-down join enumer- ation. However, as we will see, there are two severe limitations: The proposed algo- rithms can handle only (1) simple (binary) join predicates and (2) inner joins. There- fore, the second part adopts one of the proposed partitioning strategies to overcome those limitations. Furthermore, we propose a more generic partitioning framework that enables every graph-partitioning algorithm to handle join predicates involving more than two relations, and outer joins as well as other non-inner joins. As we will see, our framework is more efficient than the adopted graph-partitioning algorithm. The third part of this book discusses the two branch-and-bound pruning strategies that can be found in the literature. We present seven advancements to the combined strategy that improve pruning (1) in terms of effectiveness, (2) in terms of robustness and (3), most importantly, avoid the worst-case behavior otherwise observed.Different experiments evaluate the performance improvements of our proposed methods. We use the TPC-H, TPC-DS and SQLite test suite benchmarks to evalu- ate our joined contributions. As we show, the average compile time improvement in those settings is 100% when compared with the state of the art in bottom-up join enu- meration. Our synthetic workloads show even higher improvement factors. 204 pp. Englisch.