A Large-scale Benchmark for Log Parsing

Log data is pivotal in activities like anomaly detection and failure diagnosis in the automated maintenance of software systems. Due to their unstructured format, log parsing is often required to transform them into a structured format for automated analysis. A variety of log parsers exist, making it vital to benchmark these tools to comprehend their features and performance. However, existing datasets for log parsing are limited in terms of scale and representativeness, posing challenges for studies that aim to evaluate or develop log parsers. This problem becomes more pronounced when these parsers are evaluated for production use. To address these issues, we introduce a new collection of large-scale annotated log datasets, named LogPub, which more accurately mirrors log data observed in real-world software systems. LogPub comprises 14 datasets, each averaging 3.6 million log lines. Utilizing LogPub, we re-evaluate 15 log parsers in a more rigorous and practical setting. We also propose a new evaluation metric to lessen the sensitivity of current metrics to imbalanced data distribution. Furthermore, we are the first to scrutinize the detailed performance of log parsers on logs that represent rare system events and offer comprehensive information for system troubleshooting. Parsing such logs accurately is vital yet challenging. We believe that our work could shed light on the design and evaluation of log parsers in more realistic settings, thereby facilitating their implementation in production systems

Nanocellulose Paper Semiconductor with a 3D Network Structure and Its Nano-Micro-Macro Trans-Scale Design

Semiconducting nanomaterials with 3D network structures exhibit various fascinating properties such as electrical conduction, high permeability, and large surface areas, which are beneficial for adsorption, separation, and sensing applications. However, research on these materials is substantially restricted by the limited trans-scalability of their structural design and tunability of electrical conductivity. To overcome this challenge, a pyrolyzed cellulose nanofiber paper (CNP) semiconductor with a 3D network structure is proposed. Its nano-micro-macro trans-scale structural design is achieved by a combination of iodine-mediated morphology-retaining pyrolysis with spatially controlled drying of a cellulose nanofiber dispersion and paper-crafting techniques, such as microembossing, origami, and kirigami. The electrical conduction of this semiconductor is widely and systematically tuned, via the temperature-controlled progressive pyrolysis of CNP, from insulating (1012 ω cm) to quasimetallic (10-2 ω cm), which considerably exceeds that attained in other previously reported nanomaterials with 3D networks. The pyrolyzed CNP semiconductor provides not only the tailorable functionality for applications ranging from water-vapor-selective sensors to enzymatic biofuel cell electrodes but also the designability of macroscopic device configurations for stretchable and wearable applications. This study provides a pathway to realize structurally and functionally designable semiconducting nanomaterials and all-nanocellulose semiconducting technology for diverse electronics.Koga H., Nagashima K., Suematsu K., et al. Nanocellulose Paper Semiconductor with a 3D Network Structure and Its Nano-Micro-Macro Trans-Scale Design. ACS Nano, 16(6), 8630-8640, 2022. https://doi.org/10.1021/acsnano.1c10728

Cellulose paper support with dual-layered nano-microstructures for enhanced plasmonic photothermal heating and solar vapor generation

Y. Huang, Y. Morishita, K. Uetani, M. Nogi and H. Koga. Cellulose paper support with dual-layered nano–microstructures for enhanced plasmonic photothermal heating and solar vapor generation. Nanoscale Adv., 2020, 2, 2339. https://doi.org/10.1039/D0NA00163E

Effect of Hydration under High Temperature and Pressure on the Stress Thresholds of Shale

The stress threshold of deep reservoir shale subjected to fracturing fluid immersion is an important factor affecting fracture initiation and propagation during fracturing. However, little information has been reported on the effect on shale of soaking at high temperature and high pressure (HTHP). In this study, immersion tests and triaxial compression tests were carried out at reservoir temperature and in-situ stress on the downhole cores with different mineral compositions. The characteristics of stress thresholds, i.e., crack initiation stress (σci), crack damage stress (σcd), and peak deviator stress (σp), of shale affected by the different times of soaking with low-viscosity fracturing fluid (a) and the different viscosity fracturing fluids (a, b, and c) were investigated. The results show that hydration at HTHP has a significant softening effect on the stress thresholds (σci, σcd, σp) of reservoir shale, but the softening rate varies for samples with different mineral compositions. The crack initiation stresses of quartz-rich and clay-rich shales treated with different soaking times and different soaking media remain almost unchanged in the range of 47 to 54% of the corresponding peak strength, while the crack initiation stresses of carbonate-rich shales are significantly affected. The ratio σcd/σp of quartz-rich shale is significantly affected by the different viscosity fracturing fluids (a, b) and the different times of soaking with low-viscosity fracturing fluid (a), while clay- and carbonate-rich shales are less affected. The results of this study can provide a reference for the fracturing design of deep shale gas development

Skin‐Adhesive, ‐Breathable, and ‐Compatible Nanopaper Electronics for Harmonious On‐Skin Electrophysiological Monitoring

Abstract On‐skin electronics, which offers an interface for extracting electrophysiological signals from skin, is intensively investigated using electrodes mounted on flexible substrates. Despite numerous efforts toward substrate design to optimize user comfort, substrates with skin‐adhesion, skin‐breathability, skin‐compatibility, mechanical endurance, sterilizability, sustainability, and biodegradability remain desirable candidates for human‐ and environment‐friendly on‐skin electronics. To this end, a wood‐derived cellulose nanofiber paper (denoted nanopaper) with customized porous nanostructures is developed in this study. The customized porous nanopaper enables water‐assisted deformation for skin‐conformability, thereby realizing outstanding skin‐adhesion force, along with high skin‐breathability and compatibility, superior to those of conventional substrates reported for on‐skin electronics. By mounting gold electrodes on the porous nanopaper and adhering them to human skin, the real‐time monitoring of electroencephalogram, electromyogram, and electrocardiogram for diagnosing the human physiological state is successfully achieved. Furthermore, the gold‐electrode‐mounted porous nanopaper affords unique characteristics including durability against skin deformation, reusability, and even sterilizability, owing to its high mechanical endurance, and thermal stabilities. Thus, the as‐prepared porous nanopaper serves a fascinating platform for human‐ and environment‐harmonious on‐skin electronics

Semicarbonized Subwavelength-Nanopore-Structured Nanocellulose Paper for Applications in Solar Thermal Heating

Recently, there has been remarkable progress in solar thermal heating by applying biomass-derived carbons, which can absorb and convert solar light into thermal energy. The design of subwavelength nanoporous and molecular structures of biomass-derived carbons is required for suppressed reflection and enhanced absorption of solar light. However, such designs are difficult because conventional biomass-derived carbons exhibit intrinsic microstructures and are prepared under specific carbonization conditions. In this study, a wood cellulose nanofiber-derived carbon is proposed to tailor both subwavelength nanoporous and molecular structures. Cellulose nanofibers are first constructed into a paper, denoted as "nanopaper", exhibiting subwavelength nanoporous structures by tailoring the pore spaces between cellulose nanofibers. The as-prepared nanopaper is then carbonized at various controlled temperatures to tailor the cellulose molecular structure, i.e., grow graphitic carbon domains. The graphitic carbon domains grown by semicarbonization at 500 °C adequately balance solar absorption and reflection, while the subwavelength nanoporous structures suppress solar reflection. Thus, the semicarbonized nanopaper with tailored nanoporous and molecular structures exhibits superior solar thermal heating to competitive nanocarbons, also affording thermoelectric power generation. This study can guide the structural and functional design of bionanocarbons for solar thermal heating.Thanakorn Yeamsuksawat, Yoshitaka Morishita, Jun Shirahama, Yintong Huang, Takaaki Kasuga, Masaya Nogi, and Hirotaka Koga, Semicarbonized Subwavelength-Nanopore-Structured Nanocellulose Paper for Applications in Solar Thermal Heating, Chem. Mater. 2022, 34, 16, 7379–7388. ©2022 American Chemical Society

Silica Modified Alumina As Supports of Fe2O3 with High Performance in Chemical Looping Combustion of Methane

Fe2O3/Al2O3 oxygen carriers (OCs) are considered to be promising due to their high reactivity in chemical looping combustion (CLC). However, iron species and supports suffered from severe sintering, leading to the deactivation of this OC during multiple redox reaction. In this work, a series of silica modified alumina were used as supports of Fe2O3 and found that the OC with the addition of 5% Si (Si-5) exhibited the highest performance for CLC of CH4 during 60 redox cycles. Si was discovered to be incorporated into Al rich coordination environment and the formed Si-O-Al structure inhibited phase transformation of gamma-Al2O3 to alpha-Al2O3, which stabilized the support with high specific surface area. This led to the best dispersion of iron oxides during reaction (77%), confirmed by the formation of the highly dispersed epsilon-Fe2O3 phase identified in the reaction, which resulted in the largest amount of active FeAl2O4 (47%) in the reduction step