CA2: Cyber Attacks Analytics

The VAST Challenge 2020 Mini-Challenge 1 requires participants to identify the responsible white hat groups behind a fictional Internet outage. To address this task, we have created a visual analytics system named CA2: Cyber Attacks Analytics. This system is designed to efficiently compare and match subgraphs within an extensive graph containing anonymized profiles. Additionally, we showcase an iterative workflow that utilizes our system's capabilities to pinpoint the responsible group.Comment: IEEE Conference on Visual Analytics Science and Technology (VAST) Challenge Workshop 202

Terlipressin May Decrease In-Hospital Mortality of Cirrhotic Patients with Acute Gastrointestinal Bleeding and Renal Dysfunction: A Retrospective Multicenter Observational Study

Acute gastrointestinal bleeding (GIB) rapidly reduces effective blood volume, thereby precipitating acute kidney injury (AKI). Terlipressin, which can induce splanchnic vasoconstriction and increase renal perfusion, has been recommended for acute GIB and hepatorenal syndrome in liver cirrhosis. Thus, we hypothesized that terlipressin might be beneficial for cirrhotic patients with acute GIB and renal impairment. In this Chinese multi-center study, 1644 cirrhotic patients with acute GIB were retrospectively enrolled. AKI was defined according to the International Club of Ascites (ICA) criteria. Renal dysfunction was defined as serum creatinine (sCr) > 133 μmol/L at admission and/or any time point during hospitalization. Incidence of renal impairment and in-hospital mortality were the primary end-points. The incidence of any stage ICA-AKI, ICA-AKI stages 1B, 2, and 3, and renal dysfunction in cirrhotic patients with acute GIB was 7.1%, 1.8%, and 5.0%, respectively. The in-hospital mortality was significantly increased by renal dysfunction (14.5% vs. 2.2%, P < 0.001) and ICA-AKI stages 1B, 2, and 3 (11.1% vs. 2.8%, P = 0.011), but not any stage ICA-AKI (5.7% vs. 2.7%, P = 0.083). The in-hospital mortality was significantly decreased by terlipressin in patients with renal dysfunction (3.6% vs. 20.0%, P = 0.044), but not in those with any stage ICA-AKI (4.5% vs. 6.0%, P = 0.799) or ICA-AKI stages 1B, 2, and 3 (0.0% vs. 14.3%, P = 0.326). Renal dysfunction increased the in-hospital mortality of cirrhotic patients with acute GIB. Terlipressin might decrease the in-hospital mortality of cirrhotic patients with acute GIB and renal dysfunction. NCT03846180 ( https://clinicaltrials.gov )

TextNAS: A Neural Architecture Search Space tailored for Text Representation

Learning text representation is crucial for text classification and other language related tasks. There are a diverse set of text representation networks in the literature, and how to find the optimal one is a non-trivial problem. Recently, the emerging Neural Architecture Search (NAS) techniques have demonstrated good potential to solve the problem. Nevertheless, most of the existing works of NAS focus on the search algorithms and pay little attention to the search space. In this paper, we argue that the search space is also an important human prior to the success of NAS in different applications. Thus, we propose a novel search space tailored for text representation. Through automatic search, the discovered network architecture outperforms state-of-the-art models on various public datasets on text classification and natural language inference tasks. Furthermore, some of the design principles found in the automatic network agree well with human intuition

Study on Creep Properties of Al-Zn-Mg-Cu Alloys

This article conducts high-temperature creep tests on an Al-6.5Zn-2.3Mg-2.5Cu-0.1Zr-0.2Sc alloy in a solid solution + aging state at 200 °C and 150–180 MPa. Characterization of the microstructure of the specimen after creep test fracture was performed using SEM and TEM. The results indicate that the steady-state creep rate range of the alloy was 10−9 to 10−8 s−1, which was positively correlated with applied stress, while the creep life was negatively correlated with applied stress. Through failure analysis, it was found that the main deformation mechanism of the alloy was the dislocation climbing mechanism. The fracture mode of the alloy was ductile fracture

Study of Microstructure and Properties of AZ91 Magnesium Alloy Welded Joint with Magnetic Field and TiO2 Activated Flux

In order to improve the weldability and bearing capacity of AZ91 magnesium alloy welded joints, magnetic field and active flux were added in the TIG welding process. In the welding process, the magnetic field and welding parameters were unchanged, and the coating amount of active flux was adjusted. The formability, mechanical properties, and microstructure of the welded joints under different coating amounts of activated flux were analyzed, and the crystallization nucleation characteristics of molten pool were discussed. The experimental results reveal that the combined effect of the magnetic field and activated flux has a significant effect on increasing the penetration and promoting mechanical properties. When the coating amount of activated flux is 3 mg/cm2, the highest penetration of the welded joint is obtained, which is 141% of that without activated flux. Meanwhile, the mechanical properties reach the maximum, which is a tensile strength of 292 MPa, elongation of 11.2%, and weld zone hardness of 75.6 HV (0.5 Kgf). The combined effect of TiO2 flux and magnetic field does not change the phase composition and the grain orientation of a weld metal but can affect the grain size. The average grain size of a weld metal under an activated flux coating amount of 3 mg/cm2 is 18.2% smaller than that under an activated flux coating amount of 1 mg/cm2

Microstructure Evolution of AZ91 Magnesium Alloy Welded Joint under Magnetic Field and NiCl₂ Activated Flux

As the lightest engineering materials, magnesium alloys have been widely used. Because of the specific chemical and physical characteristics, the weldability of magnesium alloy is poor. Adopting suitable welding technology and improving the quality of magnesium alloy welded joints is key to their successful application. According to previous research data, it was found that the combined action of magnetic field and activated flux has a positive effect on improving-welding efficiency and improving the properties of a welded joint, butanalysis of microstructure evolution is insufficient. In this paper, AZ91 magnesium alloy was welded by TIG welding with activated flux and external longitudinal AC magnetic field. The phase composition and microstructure evolution were investigated. The experimental results revealed that the phase composition of welded joint was not changed due to the introduction of the magnetic field and activated flux, the growth patterns of grain in the weld seam and heat-affected zone were different. When the activated flux amount was 3 mg/cm2 with the effect of the magnetic field, the grain size of the weld seam was the finest, which was 18.96 μm. However, the grain size of the weld seam was larger than that of base metal. The crystallographic characteristics of grain boundaries in the weld seam and base metal were both LAGBs. The microstructure of the weld seam was messier than the base metal due to the larger misorientation angle. Under the combined action of the magnetic field and activated flux, the crystallization nucleation condition of the molten pool was changed, the formation of twins was promoted, and the crystal could selectively grow parallel with the (0001) basal plane

Effect of B on Microstructure and Properties of Surfacing Layer of Austenitic Stainless Steel Flux Cored Wire

In order to study the effect of element B on the corrosion resistance of stainless steel-based flux cored wire surfacing alloy, a stainless steel surfacing layer was prepared on the surface of carbon steel plate by melt electrode gas shielded welding, and then the microstructure, electrochemical corrosion resistance, and wear resistance of the surfacing layer were analyzed. The results show that the surfacing layer of surfacing alloy presents M2B and Fe3(C, B) phases based on austenite. Boride formed in deposited metal has good corrosion resistance. Therefore, adding the proper amount of B can significantly improve the corrosion resistance of the surfacing layer. When the boron content is 2%, the corrosion resistance is the best. The minimum self-corrosion current density is 1.75766 × 10−11 mA·cm2, and the maximum self-corrosion potential is −0.254438 V. Maximum impedance curve radius. At this time, the wear resistance of the surfacing layer is also the best

Research for microstructure and mechanical properties of AZ91 magnesium alloy welded joint with magnetic field and activated flux

Although many experimental researches have been carried out on the effect of different fluxes and the mechanism responsible for the higher penetration in activated TIG welding of magnesium alloy, few works as reported in literatures are available concering the grain refinement and the improvement of mechanical properties of welding joints. This is because the activated flux has very limited or even negative effects on improving the mechanical properties of welded joints. In order to find a method that can improve welding efficiency and mechanical properties of welded joints, the longitudinal alternating magnetic field and NiCl _2 activated flux were used during TIG welding of AZ91 magnesium alloy. The formation, mechanical properties, phase composition and crystal growth pattern of the weld seam were tested and analyzed to study the mechanism. The experimental results reveal that with proper parameter matching (magnetic field and activated flux), larger weld penetration and smaller form factor can be obtained, welding efficiency is improved accordingly, but the form factor with the magnetic field is bigger than that without magnetic field. When the activated flux amount is 3 mg cm ^−2 with the magnetic field, the optimal value of mechanical properties of welded joint is obtained, tensile strength is 385 MPa, elongation is 13.3%, micohardness is 67 HV, respectively. All of these are better than those without the magnetic field, the optimal activated flux amount is 2 mg cm ^−2 . The application of magnetic field and activated flux has no noticeable effect on the phase composition of weld seam. Under the combined action of magnetic field and activated flux, the crystallization nucleation condition of molten pool was changed, the grain size was refined, the formation of twins was promoted, and the crystals selectively grew within the basal (0001) plane

Study of Microstructure and Properties of AZ91 Magnesium Alloy Welded Joint with Magnetic Field and TiO₂ Activated Flux

In order to improve the weldability and bearing capacity of AZ91 magnesium alloy welded joints, magnetic field and active flux were added in the TIG welding process. In the welding process, the magnetic field and welding parameters were unchanged, and the coating amount of active flux was adjusted. The formability, mechanical properties, and microstructure of the welded joints under different coating amounts of activated flux were analyzed, and the crystallization nucleation characteristics of molten pool were discussed. The experimental results reveal that the combined effect of the magnetic field and activated flux has a significant effect on increasing the penetration and promoting mechanical properties. When the coating amount of activated flux is 3 mg/cm2, the highest penetration of the welded joint is obtained, which is 141% of that without activated flux. Meanwhile, the mechanical properties reach the maximum, which is a tensile strength of 292 MPa, elongation of 11.2%, and weld zone hardness of 75.6 HV (0.5 Kgf). The combined effect of TiO2 flux and magnetic field does not change the phase composition and the grain orientation of a weld metal but can affect the grain size. The average grain size of a weld metal under an activated flux coating amount of 3 mg/cm2 is 18.2% smaller than that under an activated flux coating amount of 1 mg/cm2

Clinical Features, Risk Factors, and Therapy of Epithelial Keratitis after Cataract Surgery

Purpose. The study aimed to assess the clinical characteristics, risk factors, and therapy of epithelial keratitis after cataract surgery. Methods. Medical data of 89 consecutive patients who developed epithelial keratitis after cataract surgery, including 37 patients with diabetes mellitus (37 eyes) and 52 patients without diabetes mellitus (52 eyes), were retrospectively reviewed. The clinical characteristics, risk factors, and therapy in those patients were evaluated. Results. The preoperative tear film function determined by the tear breakup time, meibomian gland atrophy score, and low tear meniscus height in diabetic patients was poorer than nondiabetic patients (P<0.001). Of diabetic patients, 83.78% (31/37) had been diagnosed with meibomian gland dysfunction before cataract surgery and treated with topical nonsteroidal anti-inflammatory drugs after cataract surgery for 44.69 ± 10.51 days, compared to 42.31% (22/52) of nondiabetic patients receiving the topical nonsteroidal anti-inflammatory treatment for 33.35 ± 5.16 days (both P<0.001). Epithelial lesions progressed within three to four days following cataract surgery in 59.46% (22/37) of diabetic patients, versus 30.77% (16/52) of the nondiabetic patients (P=0.025). Patients with combined meibomian gland dysfunction and epithelial defects accounted for 48.65% (18/37) in the diabetic group and 25.00% (13/52) in the nondiabetic group (P<0.001). In vivo confocal microscopy showed absence of subbasal never fibers in eyes with epithelial defects, and central corneal sensation was also significantly depressed in those eyes, but there was no significant difference between the two groups (P=0.227). Corneal ulceration and herpes simplex keratitis were found in 2.70% (1/37) and 5.41% (2/37) of diabetic patients, respectively. Amniotic membrane transplantation was required in 32.43% (12/37) of patients in the diabetic group, and the proportion was higher than 1.92% (1/52) in the nondiabetic group (P<0.001). Average healing time of the corneal epithelium in the diabetic group was 40.62 ± 20.0 days, much longer than 21.74 ± 6.94 days in the nondiabetic group (P=0.002). Conclusion. Epithelial keratitis after cataract surgery in diabetic patients has the characteristics of rapid development, severe epithelial damage, and slow repair of the corneal epithelium. Amniotic membrane transplantation is a good choice for persistent epithelial defects associated with such epithelial keratitis. Attention should be paid to the tear film function and use of topical nonsteroidal anti-inflammatory drugs in patients undergoing cataract surgery