Hedgehog Zoonoses

Pet hedgehogs pose a zoonotic risk to owners

Resolve: Enabling Accurate Parallel Monitoring under Relaxed Memory Models

Hardware-assisted instruction-grain monitoring frameworks provide high-coverage, low overhead debugging support for parallel programs. Unfortunately, existing frameworks are ill-suited for the relaxed memory models employed by nearly all modern processor architectures—e.g., TSO (x86, SPARC), RMO (SPARC), and Weak Consistency (ARMv7). For TSO, prior proposals hint at a solution, but provide no implementation or evaluation, and fail to correctly handle important corner cases such as byte-level dependences. For more relaxed memory models such as RMO and Weak Consistency, prior frameworks deadlock, rendering them unable to detect any bugs past the first deadlock! This paper presents Resolve, the first hardware-assisted instruction-grain monitoring framework that is complete, correct and deadlock-free under relaxed memory models. Resolve is based on the observation that while relaxed memory models can produce cycles of dependences that deadlock prior approaches, these cycles can be overcome by consulting the dataflow graph of the application threads being monitored, instead of their program order. Resolve handles all possible cycles arising in relaxed memory models, through a careful approach that uses both dataflow-based processing and versioning of monitoring state, as appropriate. Moreover, we provide the first quantitative characterization of the cycles arising under RMO, demonstrating that such cycles are prevalent and persistent, and hence deadlock is a real problem that must be addressed. Yet they are not so frequent or complex, so that Resolve’s overheads are negligible. Finally, we present a simple and novel hardware mechanism for properly synchronizing updates to monitoring state under relaxed memory models, improving performance by up to 35% over the judicious use of memory fences

MIMO-OFDM WDM PON with DM-VCSEL for femtocells application

Globalization, rapid technological changes, and growing competition not only facilitate but also make the supply chain more complex and fragile. Any disruption can disturb many organizations and even the whole system. There are many theories and frameworks that present a solution but no study is available that theoretically development framework for supply chain risk management. The focus of this study is to develop a novel framework for identifying the potential risks and assessment of their effects on supply chain performance. Additionally, evaluate the role of supply chain interaction in risk mitigation and performance improvement in Malaysian manufacturing. This is a conceptual paper, systematic as well as content analysis have been done for the literature review. For future study, there is a need to empirically verification of this theoretical framework. The proposed methodology to achieve this framework is; a questionnaire will be developed from a pool and will be validated by exploratory view for risk identification. This questionnaire will be distributed among Malaysian manufacturing and data will be analyzed through Structural Equation Modelling (SEM) for risk assessment and mitigation. The theoretical contribution of this study is support of the theory of swift, even flow as underpinning theory and information processing theory as supportive theory

ParaLog: enabling and accelerating online parallel monitoring of multithreaded applications

Instruction-grain lifeguards monitor the events of a running application at the level of individual instructions in order to identify and help mitigate application bugs and security exploits. Because such lifeguards impose a 10-100X slowdown on existing platforms, previous studies have proposed hardware designs to accelerate lifeguard processing. However, these accelerators are either tailored to a specific class of lifeguards or suitable only for monitoring singlethreaded programs. We present ParaLog, the first design of a system enabling fast online parallel monitoring of multithreaded parallel applications. ParaLog supports a broad class of software-defined lifeguards. We show how three existing accelerators can be enhanced to support online multithreaded monitoring, dramatically reducing lifeguard overheads. We identify and solve several challenges in monitoring parallel applications and/or parallelizing these accelerators, including (i) enforcing inter-thread data dependences, (ii) dealing with inter-thread effects that are not reflected in coherence traffic, (iii) dealing with unmonitored operating system activity, and (iv) ensuring lifeguards can access shared metadata with negligible synchronization overheads. We present our system design for both Sequentially Consistent and Total Store Ordering processors. We implement and evaluate our design on a 16 core simulated CMP, using benchmarks from SPLASH-2 and PARSEC and two lifeguards: a data-flow tracking lifeguard and a memory-access checker lifeguard. Our results show that (i) our parallel accelerators improve performance by 2-9X and 1.13-3.4X for our two lifeguards, respectively, (ii) we are 5-126X faster than the time-slicing approach required by existing techniques, and (iii) our average overheads for applications with eight threads are 51% and 28% for the two lifeguards, respectively

Inclusive dielectron production in proton-proton collisions at 2.2 GeV beam energy

Data on inclusive dielectron production are presented for the reaction p+p at 2.2 GeV measured with the High Acceptance DiElectron Spectrometer (HADES). Our results supplement data obtained earlier in this bombarding energy regime by DLS and HADES. The comparison with the 2.09 GeV DLS data is discussed. The reconstructed e+e- distributions are confronted with simulated pair cocktails, revealing an excess yield at invariant masses around 0.5 GeV/c2. Inclusive cross sections of neutral pion and eta production are obtained

Dilepton production in pp and CC collisions with HADES

Dilepton production has been measured with HADES, the "High Acceptance DiElectron Spectrometer". In pp collisions at 2.2GeV kinetic beam energy, exclusive eta production and the Dalitz decay eta -> gamma e+e- has been reconstructed. The electromagnetic form factor is well in agreement with existing data. In addition, an inclusive e+e- spectrum from the C+C reaction at 2AGeV is presented and compared with a thermal model.Comment: 11 pages, 3 figures, proceedings of the IVth International Conference on Quarks and Nuclear Physics, Madrid, June 5th-10th, submitted to Eur.Phys.J.

Flexible hardware acceleration for instruction-grain program monitoring

Instruction-grain program monitoring tools, which check and analyze executing programs at the granularity of individual instructions, are invaluable for quickly detecting bugs and security attacks and then limiting their damage (via containment and/or recovery). Unfortunately, their fine-grain nature implies very high monitoring overheads for software-only tools, which are typically based on dynamic binary instrumentation. Previous hardware proposals either focus on mechanisms that target specific bugs or address only the cost of binary instrumentation. In this paper, we propose a flexible hardware solution for accelerating a wide range of instruction-grain monitoring tools. By examining a number of diverse tools (for memory checking, security tracking, and data race detection), we identify three significant common sources of overheads and then propose three novel hardware techniques for addressing these overheads; Inheritance Tracking, Idempotent Filters, and Metadata-TLBs. Together, these constitute a general-purpose hardware acceleration framework. Experimental results show our framework reduces overheads by 2-3X over the previous state-of-the-art, while supporting the needed flexibility. © 2008 IEEE

Meson and di-electron production with HADES

The HADES experiment, installed at GSI, Darmstadt, measures di-electron production in A+A, p/pi+N and p/pi+A collisions. Here, the pi0 and eta Dalitz decays have been reconstructed in the exclusive p+p reaction at 2.2 GeV to form a reference cocktail for long-lived di-electron sources. In the C+C reaction at 1 and 2 GeV/u, these long-lived sources have been subtracted from the measured inclusive e+e- yield to exhibit the signal from the early phase of the collision. The results suggest that resonances play an important role in dense nuclear matter.Comment: Invited plenary talk at the 10th International Workshop On Meson Production, Properties And Interaction (MESON 2008) 6-10 Jun 2008, Cracow, Polan

Flexible Hardware Acceleration for Instruction-Grain Lifeguards

Instruction-grain lifeguards monitor executing programs at the granularity of individual instructions to quickly detect bugs and security attacks, but their fine-grain nature incurs high monitoring overheads. This article identifies three common sources of these overheads and proposes three techniques that together constitute a general-purpose hardware acceleration framework for lifeguards