Federated Robust Embedded Systems: Concepts and Challenges

The development within the area of embedded systems (ESs) is moving rapidly, not least due to falling costs of computation and communication equipment. It is believed that increased communication opportunities will lead to the future ESs no longer being parts of isolated products, but rather parts of larger communities or federations of ESs, within which information is exchanged for the benefit of all participants. This vision is asserted by a number of interrelated research topics, such as the internet of things, cyber-physical systems, systems of systems, and multi-agent systems. In this work, the focus is primarily on ESs, with their specific real-time and safety requirements. While the vision of interconnected ESs is quite promising, it also brings great challenges to the development of future systems in an efficient, safe, and reliable way. In this work, a pre-study has been carried out in order to gain a better understanding about common concepts and challenges that naturally arise in federations of ESs. The work was organized around a series of workshops, with contributions from both academic participants and industrial partners with a strong experience in ES development. During the workshops, a portfolio of possible ES federation scenarios was collected, and a number of application examples were discussed more thoroughly on different abstraction levels, starting from screening the nature of interactions on the federation level and proceeding down to the implementation details within each ES. These discussions led to a better understanding of what can be expected in the future federated ESs. In this report, the discussed applications are summarized, together with their characteristics, challenges, and necessary solution elements, providing a ground for the future research within the area of communicating ESs

Long-term Running Experience with the Silicon Micro-strip Tracker at the D{\O} detector

The SiliconMicro-strip Tracker (SMT) at the D{\O} experiment in the Fermilab Tevatron collider has been operating since 2001. In 2006, an additional layer, referred to as 'Layer 0', was installed to improve impact parameter resolution and compensate for detector degradation due to radiation damage to the original innermost SMT layer. The SMT detector provides valuable tracking and vertexing information for the experiment. This contribution will highlight aspects of the long term operation of the SMT, including the impact of the silicon readout test-stand. Due to the full integration of the test-stand into the D{\O} trigger framework, this test-stand provides an advantageous tool for training of new experts and studying subtle effects in the SMT while minimizing impact on the global data acquisition.Comment: Proceedings of TIPP 2011 (Technology and Instrumentation for Particle Physics 2011), June 9-14 2011, Chicago, US

Locality-Adaptive Parallel Hash Joins Using Hardware Transactional Memory

Previous work [1] has claimed that the best performing implementation of in-memory hash joins is based on (radix-)partitioning of the build-side input. Indeed, despite the overhead of partitioning, the benefits from increased cache-locality and synchronization free parallelism in the build-phase outweigh the costs when the input data is randomly ordered. However, many datasets already exhibit significant spatial locality (i.e., non-randomness) due to the way data items enter the database: through periodic ETL or trickle loaded in the form of transactions. In such cases, the first benefit of partitioning — increased locality — is largely irrelevant. In this paper, we demonstrate how hardware transactional memory (HTM) can render the other benefit, freedom from synchronization, irrelevant as well. Specifically, using careful analysis and engineering, we develop an adaptive hash join implementation that outperforms parallel radix-partitioned hash joins as well as sort-merge joins on data with high spatial locality. In addition, we show how, through lightweight (less than 1% overhead) runtime monitoring of the transaction abort rate, our implementation can detect inputs with low spatial locality and dynamically fall back to radix-partitioning of the build-side input. The result is a hash join implementation that is more than 3 times faster than the state-of-the-art on high-locality data and never more than 1% slower

A Fault Injection Environment for Microprocessor-based Board

Evaluating the faulty behaviour of low-cost microprocessor-based boards is an increasingly important issue, due to their usage in many safety critical systems. To address this issue, the paper describes a software-implemented fault injection system based on the trace exception mode available in most microprocessors. The architecture of the complete fault injection environment is proposed, integrating modules for generating a fault list, for performing their injection and for gathering the results, respectively. Data gathered from some sample benchmark applications are presented The main advantages of the approach are low cost, good portability, and high efficienc

Advanced EVA system design requirements study

The results are presented of a study to identify specific criteria regarding space station extravehicular activity system (EVAS) hardware requirements. Key EVA design issues include maintainability, technology readiness, LSS volume vs. EVA time available, suit pressure/cabin pressure relationship and productivity effects, crew autonomy, integration of EVA as a program resource, and standardization of task interfaces. A variety of DOD EVA systems issues were taken into consideration. Recommendations include: (1) crew limitations, not hardware limitations; (2) capability to perform all of 15 generic missions; (3) 90 days on-orbit maintainability with 50 percent duty cycle as minimum; and (4) use by payload sponsors of JSC document 10615A plus a Generic Tool Kit and Specialized Tool Kit description. EVA baseline design requirements and criteria, including requirements of various subsystems, are outlined. Space station/EVA system interface requirements and EVA accommodations are discussed in the areas of atmosphere composition and pressure, communications, data management, logistics, safe haven, SS exterior and interior requirements, and SS airlock

The Application of Minicomputers to Problems of Information Retrieval

Although minicomputers can be used in many types of information retrieval facilities, this paper deals primarily with bibliographic reference re- trieval systems. There are two main reasons why it is attractive to consider using a minicomputer for on-line applications: (1) the relatively low cost and (2) the hardware and software provided.published or submitted for publicatio