TY - GEN A1 - Nattke, Matthias A1 - Rotta, Randolf A1 - Natarov, Roman A1 - Archila, Oscar A1 - Mykytyn, Pavlo T1 - Precise sensors for localization in the drone swarm T2 - Proceedings iCCC2024 - iCampµs Cottbus Conference, 2024-05-14 - 2024-05-16, Cottbus N2 - Drones can be connected as a swarm to precisely monitor large agricultural areas and manage them more sustainable. They test sensor technology in real environments and solve complex tasks faster. Key aspects include accurate localization, reliable communication, and dynamic flight control. The localization accuracy of RTK-GNSS-enabled system, which includes GPS, GLONASS, GALILEO positioning systems is compared with Ultra-Wideband (UWB) one. The UPWARDS communication hub is presented as a processing and connection point across swarm agents. This controller also incorporates collision avoidance features and testing of evasion strategies. KW - ROS KW - GNSS KW - UWB KW - communication hub KW - UAV swarm Y1 - 2024 UR - https://www.ama-science.org/proceedings/details/4724 SN - 978-3-910600-00-3 U6 - https://doi.org/10.5162/iCCC2024/P16 VL - 2024 SP - 166 EP - 169 PB - AMA ER - TY - GEN A1 - Rotta, Randolf A1 - Büchner, Steffen A1 - Nolte, Jörg T1 - Middleware for Many-Cores - Why It Is Needed and What Functionality It Should Provide T2 - 4th USENIX Workshop on Hot Topics in Parallelism (HotPar '12), Berkeley, 2012 N2 - Today's multi-cores and future many-cores are NUMA architectures with complex cache hierarchies and multiple memory channels. Depending on the topologies of these memory networks we find everything from true data sharing with shared caches to distributed memory architectures which just pretend to be physical shared memory systems. In fact, most many-cores are hybrid systems that exhibit the characteristics of both distributed systems and SMPs. In this paper we argue in favor of middleware platforms for many-cores. We will discuss the needed functionality in contrast to common distributed system middleware and present micro benchmarks on several architectures to substantiate our claims. Y1 - 2012 UR - https://www.usenix.org/conference/hotpar12/tech-schedule/poster-session ER - TY - CHAP A1 - Noack, Andreas A1 - Rotta, Randolf T1 - Multi-level Algorithms for Modularity Clustering N2 - Modularity is a widely used quality measure for graph clusterings. Its exact maximization is prohibitively expensive for large graphs. Popular heuristics progressively merge clusters starting from singletons (coarsening), and optionally improve the resulting clustering by moving vertices between clusters (refinement). This paper experimentally compares existing and new heuristics of this type with respect to their effectiveness (achieved modularity) and runtime. For coarsening, it turns out that the most widely used criterion for merging clusters (modularity increase) is outperformed by other simple criteria, and that a recent multi-step algorithm is no improvement over simple single-step coarsening for these criteria. For refinement, a new multi-level algorithm produces significantly better clusterings than conventional single-level algorithms. A comparison with published benchmark results and algorithm implementations shows that combinations of coarsening and multi-level refinement are competitive with the best algorithms in the literature. KW - Clustering KW - Algorithmen Y1 - 2009 UR - http://www.springerlink.com/content/qugv7708h3806230/ ER - TY - GEN A1 - Rotta, Randolf A1 - Traue, Jana A1 - Prescher, Thomas A1 - Nolte, Jörg T1 - Interrupt-Driven Cross-Core Invocation Mechanisms on the Intel SCC T2 - Proceedings of the Many-core Applications Research Community (MARC) Symposium at RWTH Aachen University 2012 N2 - On many-core processors, both operating system kernels and bare metal applications need efficient cross-core coordination and communication. Although explicit shared- memory programming and message passing might provide the best performance, they also limit the system’s control over scheduling. In contrast, interrupt-driven cross-core invocations provide universal coordination mechanisms that also enable preemptive operations across cores. This paper surveys cross- core invocation mechanisms and their usability with respect to prevalent coordination scenarios. We integrated some of these mechanisms into a bare-metal environment for the Intel SCC pro- cessor and will discuss implementation aspects of the interrupt- driven invocations. In conclusion, such invocation mechanisms provide an expressive platform for future operating systems kernels and bare-metal applications. KW - many-core KW - remote invocations KW - bare-metal Y1 - 2012 SN - 978-3-00-039545-1 SP - 1 EP - 6 PB - Technische Hochschule CY - Aachen ER - TY - GEN A1 - Rotta, Randolf A1 - Prescher, Thomas A1 - Traue, Jana A1 - Nolte, Jörg T1 - Data Sharing Mechanisms for Parallel Graph Algorithms on the Intel SCC T2 - MARC Symposium at ONERA'2012, July 19th–20th 2012, Toulouse, Frankreich Y1 - 2012 UR - http://hal.archives-ouvertes.fr/hal-00718993 SN - 978-2-7257-0016-8 N1 - Best Paper Award 2012 SP - 13 EP - 18 ER - TY - GEN A1 - Rotta, Randolf A1 - Prescher, Thomas A1 - Traue, Jana A1 - Nolte, Jörg T1 - In-Memory Communication Mechanisms for Many-Cores – Experiences with the Intel SCC T2 - TACC-Intel Highly Parallel Computing Symposium (TIHPCS), Austin/Texas, 2012 N2 - Many-core processors combine fast on-chip communication with access to large amounts of shared memory. This makes it possible to exploit the benefits of distributed as well as shared memory programming models within single parallel algorithms. While large amounts of data can be shared in the memory and caches, coordinating the activities of hundreds of cores relies on cross core communication mechanisms with ultra low latency for very small messages. In this paper we discuss two communication protocols for the Intel SCC and compare them to the MPI implementation of the SCC. Our micro-benchmark results underline that special purpose protocols for small messages make much finer levels of parallelism possible than general purpose message passing systems. Index Terms—many-core, message passing, shared memory Y1 - 2012 UR - http://www.tacc.utexas.edu/documents/13601/4234acca-2171-4465-aa48-7592d5e577f9 UR - http://www.tacc.utexas.edu/documents/13601/06d702ab-3f48-4942-9b07-2fbd880d4310 UR - http://www.tacc.utexas.edu/ti-hpcs12 ER - TY - GEN A1 - Nürnberger, Stefan A1 - Drescher, Gabor A1 - Rotta, Randolf A1 - Nolte, Jörg A1 - Schröder-Preikschat, Wolfgang T1 - Shared Memory in the Many-Core Age T2 - Euro-Par 2014: Parallel Processing Workshops, Porto, 2014 N2 - With the evolution toward fast networks of many-core processors, the design assumptions at the basis of software-level distributed shared memory (DSM) systems change considerably. But efficient DSMs are needed because they can significantly simplify the implementation of complex distributed algorithms. This paper discusses implications of the many-core evolution and derives a set of reusable elementary operations for future software DSMs. These elementary operations will help in exploring and evaluating new memory models and consistency protocols. Y1 - 2014 UR - http://link.springer.com/chapter/10.1007%2F978-3-319-14313-2_30 SN - 978-3-319-14312-5 U6 - https://doi.org/10.1007/978-3-319-14313-2_30 SP - 351 EP - 362 PB - Springer International Publishing CY - Cham ER - TY - GEN A1 - Prescher, Thomas A1 - Rotta, Randolf A1 - Nolte, Jörg T1 - Flexible Sharing and Replication Mechanisms for Hybrid Memory Architectures T2 - Proceedings of the 4th Many-Core Applications Research Community (MARC) Symposium Y1 - 2011 SN - 978-3-86956-169-1 SP - 67 EP - 72 PB - Univ.-Verl. CY - Potsdam ER - TY - GEN A1 - Rotta, Randolf A1 - Noack, Andreas T1 - Multilevel local search algorithms for modularity clusterin T2 - Journal on Experimental Algorithmics Y1 - 2011 SN - 1084-6654 VL - 16 IS - 2 ER - TY - GEN A1 - Chatharajupalli, Navya Sneha A1 - Rotta, Randolf A1 - Karnapke, Reinhardt A1 - Nolte, Jörg T1 - Assessing the Feasibility of Combined BLE and Wi-Fi Communication for High Data Sensing Applications T2 - EWSN '23: Proceedings of the 2023 International Conference on Embedded Wireless Systems and Networks N2 - Advanced sensors generate more data than can be transmitted using classic battery-powered wireless sensor networks. While using Wi-Fi would provide plenty of throughput, the receivers are energy hungry and, thus, the radio time needs to be reduced. Previous research suggests to combine Wi-Fi with low-power technologies such as BLE for an energy efficient coordination of the Wi-Fi radios. Existing approaches focus on individual point-to-point routes whereas certain applications require concurrent transmissions. We evaluated the combination of BLE and Wi-Fi on the ESP32-S3 multi-radio microcontroller through detailed energy and throughput measurements. The results show that established BLE connections allow to activateWi-Fi quickly on-demand; the energy efficiency of the data transmission is significantly improved over previous works but the BLE connection setup is prohibitively slow. While the combination of BLE and Wi-Fi provides high throughput with good energy efficiency, careful design of the BLE-based signalling protocol is necessary to also achieve low latency. Y1 - 2023 U6 - https://doi.org/10.5555/3639940.3639948 SP - 56 EP - 59 PB - Association for Computing Machinery CY - New York ER -