36 research outputs found
Xpert: Empowering Incident Management with Query Recommendations via Large Language Models
Large-scale cloud systems play a pivotal role in modern IT infrastructure.
However, incidents occurring within these systems can lead to service
disruptions and adversely affect user experience. To swiftly resolve such
incidents, on-call engineers depend on crafting domain-specific language (DSL)
queries to analyze telemetry data. However, writing these queries can be
challenging and time-consuming. This paper presents a thorough empirical study
on the utilization of queries of KQL, a DSL employed for incident management in
a large-scale cloud management system at Microsoft. The findings obtained
underscore the importance and viability of KQL queries recommendation to
enhance incident management.
Building upon these valuable insights, we introduce Xpert, an end-to-end
machine learning framework that automates KQL recommendation process. By
leveraging historical incident data and large language models, Xpert generates
customized KQL queries tailored to new incidents. Furthermore, Xpert
incorporates a novel performance metric called Xcore, enabling a thorough
evaluation of query quality from three comprehensive perspectives. We conduct
extensive evaluations of Xpert, demonstrating its effectiveness in offline
settings. Notably, we deploy Xpert in the real production environment of a
large-scale incident management system in Microsoft, validating its efficiency
in supporting incident management. To the best of our knowledge, this paper
represents the first empirical study of its kind, and Xpert stands as a
pioneering DSL query recommendation framework designed for incident management.Comment: Accepted as a reseach paper at ICSE 202
Damage Identification of Concrete Arch Dams Based on Wavelet Packets and Neural Networks
A dam may be damaged by occasional extreme loads such as major earthquakes or terrorist attacks during its service. According to the needs of emergency assessment, this paper studies a rapid damage identification method for damage location and damage degree in concrete arch dams which is based on the dynamic characteristics of concrete arch dam data, using wavelet transform, wavelet packet decomposition, a BP neural network and D-S evidence theory for damage identification and related experimental verification. The results show that the relative difference of the curvature mode (δφk), the wavelet coefficient (Wfk) and the relative difference of the wavelet packet energy (δKk) can effectively identify the damage position of the arch dam, and δφk in the first four modalities has the best overall recognition effect; Wfk requires a high number of measurement points, which should be at least 64 or as close as possible; δKk has a better damage recognition effect than the first two at the same number of measurement points. D-S evidence theory significantly improves the damage identification effect and reduces the misjudgment of the single-damage method. The trained neural network can effectively identify the damage degree based on the data of one measuring point when there is a single damage instance, and the number of measuring points should be no fewer than two when there is double damage. The test results verify the feasibility of the method in this paper, which can provide a theoretical basis for a post-disaster emergency assessment information system of concrete arch dams
Research on Impact Resistance of Reinforced Concrete Beams Strengthened with Carbon Fiber Reinforced Polymer Grid and Engineered Cementitious Composites
When reinforced concrete structures are subjected to impact loads, they may suddenly yield or fail, or even collapse as a whole. In this paper, the impact resistance of reinforced concrete (RC) beams strengthened with carbon fiber reinforced polymer (CFRP) grid and engineered cementitious composites (ECC) was studied. Drop hammer impact tests were conducted on eight beams, then the finite element model was used to simulate the impact test, finally a simplified two-degree-of-freedom (TDOF) model was proposed for CFRP grid reinforced ECC layer strengthened RC beams under impact loading. The results showed that CFRP grid reinforced ECC layer significantly improved the impact resistance of RC beams. When the ECC and CFRP grid were used, the crack development was inhibited after the concrete cracked in the tensile area, avoiding the brittle damage of concrete beams with one crack to the end. Compared with the control beam, the reaction force of RC beams strengthened with CFRP grid and ECC under impact load increased by 16.2%~34.5%, the maximum mid-span displacement decreased by 16.3%~31.6% and the mid-span residual displacement decreased by 36.02%~49.53%. The finite element model and the proposed TDOF mode were demonstrated to effectively simulate the strengthened beam under impact loading
Design and Test of a Force Feedback Seedling Pick-Up Gripper for an Automatic Transplanter
Aiming at the problems of seedling injury and planting leakage due to the lack of seeding clamping force detection and real-time control in vegetable transplanting, a force feedback gripper was developed based on the linear Hall element. The mechanical properties of the stem of pepper cavity seedlings were first analyzed to provide a basis for the design of the gripper. A linear Hall sensor, a magnet, an elastic actuator, and an Arduino Uno development board make up the grasping force detecting system. Upon picking up a seedling, the elastic actuator, which is connected to the magnet, bends like a cantilever beam. As a result of the micro-displacement created by the elastic actuator, the Hall sensor’s voltage changes and can be used to determine the clamping force. Detection avoids direct contact between the sensor and the cavity seedlings, reducing the risk of sensor damage. Finite element method (FEM) simulations were used to determine the initial spacing between the magnet and Hall sensor and the effect of the elastic actuator. Control commands are sent to the servo based on the gripping force collected by the Arduino Uno board. Finally, the functions of accurate measurement, display, storage, and control of the clamping force of the cavity tray seedlings are realized, so that the damage rate of the cavity tray seedlings is reduced. In order to explore the influence of the elastic actuators on the clamping force detection system and the performance of the force feedback gripper, a calibration test of the clamping force detection system and a test of the indoor transplantation of pepper seedlings were carried out. Based on the calibration test, the clamping force detection system has a sensitivity of 0.0693 V/N, linearity of 3.21%, an average linear coefficient of determination of 0.986, and a range of 10 N, which fully meet the clamping force detection accuracy requirements during transplantation. Indoor tests showed that the force feedback gripper was stable and adaptable. This study can provide a reference for detecting and controlling clamping forces during transplantation
Fluoride ion adsorption from wastewater using magnesium(II), aluminum(III) and titanium(IV) modified natural zeolite: kinetics, thermodynamics, and mechanistic aspects of adsorption
Natural zeolite was modified using metal ions, including magnesium(II), aluminum(III) and titanium(IV). The modified zeolite was then used as an adsorbent for the investigation of the adsorption kinetics, isotherms, and thermodynamic parameters of fluoride ions in wastewater at various pHs and temperatures. The kinetics and thermodynamics for the removal of the fluoride ions onto the modified zeolite have also been investigated. The fluoride ion adsorption capacity of the three types of modified zeolites exhibited an increase, then decrease, with rising pH. The fluoride adsorption capacity of the modified zeolites decreased with an increase in temperature. The pseudo-second-order model is more suitable for describing the adsorption kinetic data than the pseudo-first-order model for modified zeolite and the adsorption process of the fluoride ions reveals pseudo-second-order kinetic behavior, respectively. It was found that the adsorption equilibrium data fit the Freundlich isothermal equation better than that of the Langmuir isothermal and Dubinin–Radushkevich (D–R) isothermal equations. Thermodynamic analysis suggests that the negative values of ΔG0 and ΔH0 further indicate that the fluoride adsorption process is both spontaneous and exothermic. The results of competitive adsorption tests suggest that the modified metal zeolite materials adsorb fluoride ions with high selectivity
Fluoroalkyl-grafted methacrylate-PDMS membranes using fluoromonomer as a diluent for enhancing biobutanol pervaporation
In bioalcohol production, alcohol-permselective membranes have an important role to play in the growing demand for biofuels, where polydimethylsiloxane (PDMS) membranes are considered as a benchmark of alcohol-permselective membranes. However, two key technical barriers still need to be addressed, i.e., (i) the long curing time and the use of toxic solvents hamper their large-scale application and (ii) the trade-off between pervaporation performance and anti-biofouling ability limits the separation of biobutanol from fermentation broths. To overcome these bottlenecks, in this study, a UV-polymerizable fluoromonomer (F-monomer) is introduced into a methacrylate-PDMS (MA-PDMS) membrane-forming system instead of toxic solvents. The green and ultrafast membrane preparation (31–72 s) via UV polymerization is realized. The results indicate that the fluoroalkyl groups –(CF2)6 of the F-monomer enhance the hydrophobicity of the membrane surface, yielding a high water contact angle of 112°. Compared with an MA-PDMS membrane, the as-prepared MA-PDMS-F membranes were found to have a simultaneously enhanced membrane flux (862–1216 g m−2 h−1) and separation factor (34–41) when used in the separation of a butanol/water binary solution. Importantly, the MA-PDMS-F membrane surface weakly interacts with microbes in the fermentation broth because of its much lower polarizability, which leads to an outstanding anti-biofouling ability
The Ultrafast and Continuous Fabrication of a Polydimethylsiloxane Membrane by Ultraviolet-Induced Polymerization
The polydimethylsiloxane (PDMS) membrane commonly used for separation of biobutanol from fermentation broth fails to meet demand owing to its discontinuous and polluting thermal fabrication. Now, an UV-induced polymerization strategy is proposed to realize the ultrafast and continuous fabrication of the PDMS membrane. UV-crosslinking of synthesized methacrylate-functionalized PDMS (MA-PDMS) is complete within 30 s. The crosslinking rate is three orders of magnitude larger than the conventional thermal crosslinking. The MA-PDMS membrane shows a versatile potential for liquid and gas separations, especially featuring an excellent pervaporation performance for n-butanol. Filler aggregation, the major bottleneck for the development of high-performance mixed matrix membranes (MMMs), is overcome, because the UV polymerization strategy demonstrates a freezing effect towards fillers in polymer, resulting in an extremely high-loading silicalite-1/MA-PDMS MMM with uniform particle distribution.status: publishe
Antibacterial Activity of Trypsin-Hydrolyzed Camel and Cow Whey and Their Fractions
Antibacterial peptides were isolated and purified from whey proteins of camel milk (CaW) and cow milk (CoW) and their antimicrobial activities were studied. The whey proteins were hydrolyzed using trypsin, and the degree of hydrolysis was identified by gel electrophoresis. The whey hydrolysate (WH) was purified using ultrafiltration and Dextran gel chromatography to obtain small peptides with antibacterial activity. The effect of the antimicrobial peptides on the morphology of bacterial strains was investigated using transmission electron microscopy. Their amino acid composition and antimicrobial activities were then determined. Polypeptides CaWH-III (<3 kDa) and CoWH-III (<3 kDa) had the strongest antibacterial activity. Both Fr.A2 (CaWH-â…¢’s fraction 2) and Fr.B1 (CoWH-â…¢’s fraction 1) had antibacterial effects toward Escherichia coli and Staphylococcus aureus, with minimum antimicrobial mass concentrations of 65 mg/mL and 130 mg/mL for Fr.A2, and 130 mg/mL and 130 mg/mL for Fr.B1, respectively. The highly active antimicrobial peptides had high amounts of alkaline amino acids (28.13% in camel milk Fr.A2 and 25.07% in the cow milk Fr.B1) and hydrophobic amino acids. (51.29% in camel milk Fr.A2 and 57.69% in the cow milk Fr.B1). This results showed that hydrolysis of CaW and CoW using trypsin produced a variety of effective antimicrobial peptides against selected pathogens, and the antibacterial activity of camel milk whey was slightly higher than that of cow milk whey