Monitoring and Control of Temperature in Networks-on-Chip

Increasing integration densities and the emergence of nanotechnology cause issues related to reliability and power consumption to become dominant factors for the design of modern multi-core systems. Since the arising problems are enforced by high circuit temperatures, monitoring and control of on-chip temperature profiles need to be considered during design phase as well as during system operation. Hence, in this paper different approaches for the realization and integration of a monitoring system for temperature in multi-core systems based on Networks-on-Chip (NoCs) in combination with Dynamic Frequency Scaling (DFS) are investigated. Results show that both combinations using event-driven and time-driven forwarding more than double overall execution time and considerably reduce throughput of application data. Regarding performance of notification and reaction to temperature development event-driven forwarding clearly outperforms time-driven forwarding

Realtime Publish/Subscribe for the Industrial Internet of Things

Publish/subscribe communication offers outstanding flexibility, but lacks the predictability required for guaranteeing (hard) realtime constraints in industrial environments such as future smart factories. In this paper, we review existing publish/ subscribe systems, identify their shortcomings, and derive research objectives for a converged realtime network infrastructure for the Industrial Internet of Things (IIoT) that is based on publish/subscribe and Software-Defined Networking (SDN)

Monitoring and Control of Temperature in Networks-on-Chip

Abstract Increasing integration densities and the emergence of nanotechnology cause issues related to reliability and power consumption to become dominant factors for the design of modern multi-core systems. Since the arising problems are enforced by high circuit temperatures, monitoring and control of on-chip temperature profiles need to be considered during design phase as well as during system operation. Hence, in this paper different approaches for the realization and integration of a monitoring system for temperature in multi-core systems based on Networks-on-Chip (NoCs) in combination with Dynamic Frequency Scaling (DFS) are investigated. Results show that both combinations using event-driven and time-driven forwarding more than double overall execution time and considerably reduce throughput of application data. Regarding performance of notification and reaction to temperature development event-driven forwarding clearly outperforms time-driven forwarding

A Simulation Model for Investigating Clock Synchronization Issues in Time-Sensitive Networks

The IEEE 802.1 Time-Sensitive Networking (TSN) task force has set guidelines for IEEE 802.3 networks allowing deterministic realtime communication over Ethernet. To execute deterministic time-triggered scheduling operations, the network nodes need to be synchronized. One application of time synchronization is distributed data acquisition for the Wendelstein 7-X nuclear fusion experiment. Both the system control and the scientific evaluation of the experiments need measurement timestamps with accuracies in the nanosecond range. The TSN standard IEEE 802.1AS has specified the generalized Precision Time Protocol (gPTP) which executes the synchronization process. However, there are some issues that are not addressed in the standard such as the impact of clock skew and drift of network nodes on the number of resynchronizations needed to maintain the required synchronization accuracy. This paper introduces an OMNeT++ simulation model, which can be used to investigate clock synchronization issues in time-sensitive networks

Early Pliocene increase in thermohaline overturning : a precondition for the development of the modern equatorial Pacific cold tongue

Author Posting. © American Geophysical Union, 2010. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Paleoceanography 25 (2010): PA2202, doi:10.1029/2008PA001645.Unraveling the processes responsible for Earth's climate transition from an “El Niño–like state” during the warm early Pliocene into a modern-like “La Niña–dominated state” currently challenges the scientific community. Recently, the Pliocene climate switch has been linked to oceanic thermocline shoaling at ∼3 million years ago along with Earth's final transition into a bipolar icehouse world. Here we present Pliocene proxy data and climate model results, which suggest an earlier timing of the Pliocene climate switch and a different chain of forcing mechanisms. We show that the increase in North Atlantic meridional overturning circulation between 4.8 and 4.0 million years ago, initiated by the progressive closure of the Central American Seaway, triggered overall shoaling of the tropical thermocline. This preconditioned the turnaround from a warm eastern equatorial Pacific to the modern equatorial cold tongue state about 1 million years earlier than previously assumed. Since ∼3.6–3.5 million years ago, the intensification of Northern Hemisphere glaciation resulted in a strengthening of the trade winds, thereby amplifying upwelling and biogenic productivity at low latitudes.Funding for this research was provided by the Deutsche Forschungsgemeinschaft (DFG) through projects Ti 240/7, Ti 240/12 (being part of the DFG Research Unit, FOR 451: Impact of Gateways on Ocean Circulation, Climate, and Evolution at Kiel University), and Ti 240/17 and through the DFG Research Center/Excellence Cluster “The Ocean in the Earth System” at the University of Bremen. A. Timmermann is supported by the Japan Agency for Marine-Earth Science and Technology through its sponsorship of the International Pacific Research Center

Sea surface and subsurface circulation dynamics off equatorial Peru during the last ~17 kyr

The complex deglacial to Holocene oceanographic development in the Gulf of Guayaquil (Eastern Equatorial Pacific) is reconstructed for sea surface and subsurface ocean levels from (isotope) geochemical proxies based on marine sediment cores. At sea surface, southern sourced Cold Coastal Water and tropical Equatorial Surface Water/Tropical Surface Water are intimately related. In particular since ~10 ka, independent sea surface temperature proxies capturing different seasons emphasize the growing seasonal contrast in the Gulf of Guayaquil, which is in contrast to ocean areas further offshore. Cold Coastal Water became rapidly present in the Gulf of Guayaquil during the austral winter season in line with the strengthening of the Southeast Trades, while coastal upwelling off Peru gradually intensified and expanded northward in response to a seasonally changing atmospheric circulation pattern affecting the core locations intensively since 4 ka BP. Equatorial Surface Water, instead, was displaced and Tropical Surface Water moved northward together with the Equatorial Front. At subsurface, the presence of Equatorial Under Current-sourced Equatorial Subsurface Water was continuously growing, prominently since ~10–8 ka B.P. During Heinrich Stadial 1 and large parts of the Bølling/Allerød, and similarly during short Holocene time intervals at ~5.1–4 ka B.P. and ~1.5–0.5 ka B.P., the admixture of Equatorial Subsurface Water was reduced in response to both short-term weakening of Equatorial Under Current strength from the northwest and emplacement by tropical Equatorial Surface Water, considerably warming the uppermost ocean layers

Low catalytic activity is insufficient to induce disease pathology in triosephosphate isomerase deficiency

Triosephosphate isomerase (TPI) deficiency is a fatal genetic disorder characterized by hemolytic anemia and neurological dysfunction. Although the enzyme defect in TPI was discovered in the 1960s, the exact etiology of the disease is still debated. Some aspects indicate the disease could be caused by insufficient enzyme activity, whereas other observations indicate it could be a protein misfolding disease with tissue-specific differences in TPI activity. We generated a mouse model in which exchange of a conserved catalytic amino acid residue (isoleucine to valine, Ile170Val) reduces TPI specific activity without affecting the stability of the protein dimer. TPIIle170Val/Ile170Val mice exhibit an approximately 85% reduction in TPI activity consistently across all examined tissues, which is a stronger average, but more consistent, activity decline than observed in patients or symptomatic mouse models that carry structural defect mutant alleles. While monitoring protein expression levels revealed no evidence for protein instability, metabolite quantification indicated that glycolysis is affected by the active site mutation. TPIIle170Val/Ile170Val mice develop normally and show none of the disease symptoms associated with TPI deficiency. Therefore, without the stability defect that affects TPI activity in a tissue-specific manner, a strong decline in TPI catalytic activity is not sufficient to explain the pathological onset of TPI deficiency