Surgical Options for Failed Rotator Cuff Repair, except Arthroplasty: Review of Current Methods

Although the prevalence of rotator cuff tears is dependent on the size, 11% to 94% of patients experience retear or healing failure after rotator cuff repair. Treatment of patients with failed rotator cuff repair ranges widely, from conservative treatment to arthroplasty. This review article attempts to summarize the most recent and relevant surgical options for failed rotator cuff repair patients, and the outcomes of each treatment, except arthroplasty

PAI: A lightweight mechanism for single-node memory recovery in DSM servers

Several recent studies identify the memory system as the most frequent source of hardware failures in commercial servers. Techniques to protect the memory system from failures must continue to service memory requests, despite hardware failures. Furthermore, to support existing OS's, the physical address space must be retained following reconfiguration. Existing techniques either suffer from a high performance overhead or require pervasive hardware changes to support transparent recovery. In this paper, we propose Physical Address Indirection (PAI), a lightweight, hardware-based mechanism for memory system failure recovery. PAI provides a simple hardware mapping to transparently reconstruct affected data in alternate locations, while maintaining high performance and avoiding physical address changes. With full-system simulation of commercial and scientific workloads on a 16-node distributed shared memory server, we show that prior techniques have an average degraded mode performance loss of 14% and 51% for commercial and scientific workloads, respectively. Using PAI's dataswap reconstruction, the same workloads have 1% and 32% average performance losses. © 2007 IEEE

Understanding the performance of concurrent error detecting superscalar microarchitectures

Superscalar out-of-order microarchitectures can be modified to support redundant execution of a program as two concurrent threads for soft-error detection. However, the extra workload from redundant execution incurs a performance penalty due to increased contention for resources throughout the datapath. We present four key parameters that affect performance of these designs, namely 1) issue and functional unit bandwidth, 2) issue queue and reorder buffer capacity, 3) decode and retirement bandwidth, and 4) coupling between redundant threads' instantaneous resource requirements. We then survey existing work in concurrent error detecting superscalar microarchitectures and evaluate these proposals with respect to the four factors. © 2005 IEEE

Memory coherence activity prediction in commercial workloads

Recent research indicates that prediction-based coherence optimizations offer substantial performance improvements for scientific applications in distributed shared memory multiprocessors. Important commercial applications also show sensitivity to coherence latency, which will become more acute in the future as technology scales. Therefore it is important to investigate prediction of memory coherence activity in the context of commercial workloads.This paper studies a trace-based Downgrade Predictor (DGP) for predicting last stores to shared cache blocks, and a pattern-based Consumer Set Predictor (CSP) for predicting subsequent readers. We evaluate this class of predictors for the first time on commercial applications and demonstrate that our DGP correctly predicts 47%-76% of last stores. Memory sharing patterns in commercial workloads are inherently non-repetitive; hence CSP cannot attain high coverage. We perform an opportunity study of a DGP enhanced through competitive underlying predictors, and in commercial and scientific applications, demonstrate potential to increase coverage up to 14%

Temporal Streaming of Shared Memory

Coherent read misses in shared-memory multiprocessors account for a substantial fraction of execution time in many important scientific and commercial workloads. We propose Temporal Streaming, to eliminate coherent read misses by streaming data to a processor in advance of the corresponding memory accesses. Temporal streaming dynamically identifies address sequences to be streamed by exploiting two common phenomena in shared-memory access patterns: (1) temporal address correlation — groups of shared addresses tend to be accessed together and in the same order, and (2) temporal stream locality — recently- accessed address streams are likely to recur. We present a practical design for temporal streaming. We evaluate our design using a combination of trace-driven and cycle- accurate full-system simulation of a cache-coherent distributed shared-memory system. We show that temporal streaming can eliminate 98% of coherent read misses in scientific applications, and between 43% and 60% in database and web server workloads. Our design yields speedups of 1.07 to 3.29 in scientific applications, and 1.06 to 1.21 in commercial workloads

Damage characteristics of platinum/carbon multilayers under X-ray free-electron laser irradiation

Jangwoo Kim, Takahisa Koyama, Hirokatsu Yumoto, Ayaka Nagahira, Satoshi Matsuyama, Yasuhisa Sano, Makina Yabashi, Haruhiko Ohashi, Tetsuya Ishikawa, and Kazuto Yamauchi "Damage characteristics of platinum/carbon multilayers under x-ray free-electron laser irradiation", Proc. SPIE 8848, Advances in X-Ray/EUV Optics and Components VIII, 88480S (27 September 2013); https://doi.org/10.1117/12.2022735

Damage to inorganic materials illuminated by focused beam of X-ray free-electron laser radiation

X-ray free-electron lasers (XFELs) that utilize intense and ultra-short pulse X-rays may damage optical elements. We investigated the damage fluence thresholds of optical materials by using an XFEL focusing beam that had a power density sufficient to induce ablation phenomena. The 1 μ4m focusing beams with 5.5 keV and/or 10 keV photon energies were produced at the XFEL facility SACLA (SPring-8 Angstrom Compact free electron LAser). Test samples were irradiated with the focusing beams under normal and/or grazing incidence conditions. The samples were uncoated Si, synthetic silica glass (SiO2), and metal (Rh, Pt)-coated substrates, which are often used as X-ray mirror materials.Takahisa Koyama, Hirokatsu Yumoto, Kensuke Tono, Tadashi Togashi, Yuichi Inubushi, Tetsuo Katayama, Jangwoo Kim, Satoshi Matsuyama, Makina Yabashi, Kazuto Yamauchi, and Haruhiko Ohashi "Damage to inorganic materials illuminated by focused beam of x-ray free-electron laser radiation", Proc. SPIE 9511, Damage to VUV, EUV, and X-ray Optics V, 951107 (12 May 2015); https://doi.org/10.1117/12.218277

Measurement of the X-ray spectrum of a free electron laser with a wide-range high-resolution single-shot spectrometer

We developed a single-shot X-ray spectrometer for wide-range high-resolution measurements of Self-Amplified Spontaneous Emission (SASE) X-ray Free Electron Laser (XFEL) pulses. The spectrometer consists of a multi-layer elliptical mirror for producing a large divergence of 22 mrad around 9070 eV and a silicon (553) analyzer crystal. We achieved a wide energy range of 55 eV with a fine spectral resolution of 80 meV, which enabled the observation of a whole SASE-XFEL spectrum with fully-resolved spike structures. We found that a SASE-XFEL pulse has around 60 longitudinal modes with a pulse duration of 7.7 ± 1.1 fs.Inubushi, Y.; Inoue, I.; Kim, J.; Nishihara, A.; Matsuyama, S.; Yumoto, H.; Koyama, T.; Tono, K.; Ohashi, H.; Yamauchi, K.; Yabashi, M. Measurement of the X-ray Spectrum of a Free Electron Laser with a Wide-Range High-Resolution Single-Shot Spectrometer. Appl. Sci. 2017, 7, 584. https://doi.org/10.3390/app7060584

Fingerprinting: Bounding the Soft-Error Detection Latency and Bandwidth

Recent studies have suggested that the soft-error rate in microprocessor logic will become a reliability concern by 2010. This paper proposes an efficient error detection technique, called fingerprinting, that detects differences in execution across a dual modular redundant (DMR) processor pair. Fingerprinting summarizes a processor's execution history in a hash- based signature; differences between two mirrored processors are exposed by comparing their fingerprints. Fingerprinting tightly bounds detection latency and greatly reduces the interprocessor communication bandwidth required for checking. This paper presents a study that evaluates fingerprinting against a range of current approaches to error detection. The result of this study shows that fingerprinting is the only error detection mechanism that simultaneously allows high-error coverage, low error detection bandwidth, and high I/O performance