Improving the Performance and Endurance of Persistent Memory with Loose-Ordering Consistency

Persistent memory provides high-performance data persistence at main memory. Memory writes need to be performed in strict order to satisfy storage consistency requirements and enable correct recovery from system crashes. Unfortunately, adhering to such a strict order significantly degrades system performance and persistent memory endurance. This paper introduces a new mechanism, Loose-Ordering Consistency (LOC), that satisfies the ordering requirements at significantly lower performance and endurance loss. LOC consists of two key techniques. First, Eager Commit eliminates the need to perform a persistent commit record write within a transaction. We do so by ensuring that we can determine the status of all committed transactions during recovery by storing necessary metadata information statically with blocks of data written to memory. Second, Speculative Persistence relaxes the write ordering between transactions by allowing writes to be speculatively written to persistent memory. A speculative write is made visible to software only after its associated transaction commits. To enable this, our mechanism supports the tracking of committed transaction ID and multi-versioning in the CPU cache. Our evaluations show that LOC reduces the average performance overhead of memory persistence from 66.9% to 34.9% and the memory write traffic overhead from 17.1% to 3.4% on a variety of workloads.Comment: This paper has been accepted by IEEE Transactions on Parallel and Distributed System

Simple, high-performance type II β-BaB2O4 optical parametric oscillator

A visible /near-IR optical parametric oscillator (OPO) based on type II phase matching in β-BaB2O4 (BBO) is described. Pumped at 355 nm, this OPO covers 410-2500 nm completely with a single set of standard Nd:YAG cavity optics. The output efficiency is >25 %, the linewidth of the OPO is narrower than 1 -2 cm^-1 without the use of gratings or etalons, and the signal-beam divergence is <400 µrad. Three type I BBO doubling crystals are used to extend the tuning range from 208 to 415 nm. Doubling efficiencies as high as 40% are easily obtained. The reasons for the high doubling and overall system efficiency are discussed

Application of H

The transfer alignment (TA) scheme is used for the initial alignment of Inertial Navigation System (INS) on dynamical base. The Kalman filter is often used in TA to improve the precision of TA. And the statistical characteristics of interference signal which is difficult to get must be known before the Kalman filter is used in the TA, because the interference signal is a random signal and there are some changes on the dynamic model of system. In this paper, the H∞ filter is adopted in the TA scheme of the angular rate matching when the various stages of disturbance in measurement are unknown. And it is compared with the Kalman filter in the same environment of simulation and evaluation. The result of simulation shows that the H∞ filter and the Kalman filter are both effective. The Kalman filter is more accurate than the H∞ filter when system noise and measurement noise are white noise, but the H∞ filter is more accurate and quicker than the Kalman filter when system noise and measurement noise are color noise. In the engineering practice, system noise and measurement noise are always color noise, so the H∞ filter is more suitable for engineering practice than the Kalman filter

Low-threshold BBO OPO with cylindrical focusing

The design of a BBO OPO cavity based on cylindrical focusing of the pump beam in the insensitive plane of the non-linear crystal is presented and characterized. A variety of beam sizes in the sensitive plane of the BBO crystal are investigated, and in all cases this cavity design is found to significantly lower the operational threshold pulse energy of 355 nm pumped type I BBO OPOs. With optimal beam focussing parameters, the measured threshold intensity of 45 MW/cm^2 is similar to that of conventional OPOs, but the threshold pulse energy of 0.4 mJ is some twenty times lower than that found in circularly symmetric pump beams. Pump pulse energies in this range can now be routinely achieved with diode-pumped Q-switched lasers, and the combination of these sources with cylindrically-focussed OPO cavities should result in a new class of all-solid-state high repetition rate and high average power non-linear light sources that can be tuned over the entire visible wavelength region

Low-threshold BBO OPO with cylindrical focusing

The design of a BBO OPO cavity based on cylindrical focusing of the pump beam in the insensitive plane of the non-linear crystal is presented and characterized. A variety of beam sizes in the sensitive plane of the BBO crystal are investigated, and in all cases this cavity design is found to significantly lower the operational threshold pulse energy of 355 nm pumped type I BBO OPOs. With optimal beam focussing parameters, the measured threshold intensity of 45 MW/cm^2 is similar to that of conventional OPOs, but the threshold pulse energy of 0.4 mJ is some twenty times lower than that found in circularly symmetric pump beams. Pump pulse energies in this range can now be routinely achieved with diode-pumped Q-switched lasers, and the combination of these sources with cylindrically-focussed OPO cavities should result in a new class of all-solid-state high repetition rate and high average power non-linear light sources that can be tuned over the entire visible wavelength region

Electronic specific heat and low energy quasiparticle excitations in superconducting state of La2−xSrxCuO4La_{2-x}Sr_xCuO_4 single crystals

Low temperature specific heat has been measured and extensively analyzed on a series of $La_{2-x}Sr_xCuO_4$ single crystals from underdoped to overdoped regime. From these data the quasiparticle density of states (DOS) in the mixed state is derived and compared to the predicted scaling law $C_{vol}/T\sqrt{H}=f(T/\sqrt{H})$ of d-wave superconductivity. It is found that the scaling law can be nicely followed by the optimally doped sample (x=0.15) in quite wide region of ($T/\sqrt{H} \leq 8 K /\sqrt{T}$). However, the region for this scaling becomes smaller and smaller towards more underdoped region: a clear trend can be seen for samples from x=0.15 to 0.069. Therefore, generally speaking, the scaling quality becomes worse on the underdoped samples in terms of scalable region of $T/\sqrt{H}$. This feature in the underdoped region is explained as due to the low energy excitations from a second order (for example, anti-ferromagnetic correlation, d-density wave, spin density wave or charge density wave order) that may co-exist or compete with superconductivity. Surprisingly, deviations from the d-wave scaling law have also been found for the overdoped sample (x=0.22). While the scaling law is reconciled for the overdoped sample when the core size effect is taken into account. An important discovery of present work is that the zero-temperature data follow the Volovik's relation $\Delta \gamma(T=0)=A\sqrt{H}$ quite well for all samples investigated here although the applicability of the d-wave scaling law to the data at finite temperatures varies with doped hole concentration. Finally we present the doping dependence of some parameters, such as, the residual linear term $\gamma_0$, the $\alpha$ value, etc. ...Comment: 15 pages, 24 figure

Identification and validation of a muscle failure index to predict prognosis and immunotherapy in lung adenocarcinoma through integrated analysis of bulk and single-cell RNA sequencing data

BackgroundIt was previously reported that the production of exerkines is positively associated with the beneficial effects of exercise in lung adenocarcinoma (LUAD) patients. This study proposes a novel scoring system based on muscle failure-related genes, to assist in clinical decision making.MethodsA comprehensive analysis of bulk and single cell RNA sequencing (scRNA-seq) of early, advanced and brain metastatic LUAD tissues and normal lung tissues was performed to identify muscle failure-related genes in LUAD and to determine the distribution of muscle failure-related genes in different cell populations. A novel scoring system, named MFI (Muscle failure index), was developed and validated. The differences in biological functions, immune infiltration, genomic alterations, and clinical significance of different subtypes were also investigated.ResultsFirst, we conducted single cell analysis on the dataset GSE131907 and identified eight cell subpopulations. We found that four muscle failure-related genes (BDNF, FNDC5, IL15, MSTN) were significantly increased in tumor cells. In addition, IL15 was widely distributed in the immune cell population. And we have validated it in our own clinical cohort. Then we created the MFI model based on 10 muscle failure-related genes using the LASSO algorithm, and MFI remained an independent prognostic factor of OS in both the training and validation cohorts. Moreover, we generated MFI in the single-cell dataset, in which cells with high MFI received and sent more signals compared to those with low MFI. Biological function analysis of both subtypes revealed stronger anti-tumor immune activity in the low MFI group, while tumor cells with high MFI had stronger metabolic and proliferative activity. Finally, we systematically assessed the immune cell activity and immunotherapy responses in LUAD patients, finding that the low MFI group was more sensitive to immunotherapy.ConclusionOverall, our study can improve the understanding of the role of muscle failure-related genes in tumorigenesis and we constructed a reliable MFI model for predicting prognosis and guiding future clinical decision making

LMS-SM3 and HSS-SM3: Instantiating Hash-based Post-Quantum Signature Schemes with SM3

We instantiate the hash-based post-quantum stateful signature schemes LMS and HSS described in RFC 8554 and NIST SP 800-208 with SM3, and report on the results of the preliminary performance test

XMSS-SM3 and MT-XMSS-SM3: Instantiating Extended Merkle Signature Schemes with SM3

We instantiate the hash-based post-quantum stateful signature schemes XMSS and its multi-tree version described in RFC 8391 and NIST SP 800-208 with SM3, and report on the results of the preliminary performance test