A Virtual Motion Camouflage Approach for Cooperative Trajectory Planning of Multiple UCAVs

This paper investigates cooperative trajectory planning of multiple unmanned combat aerial vehicles (multi-UCAV) in performing autonomous cooperative air-to-ground target attack missions. By integrating an approximate allowable attack region model, several constraint models, and a multicriterion objective function, the problem is formulated as a cooperative trajectory optimal control problem (CTOCP). Then, a virtual motion camouflage (VMC) for cooperative trajectory planning of multi-UCAV, combining with the differential flatness theory, Gauss pseudospectral method (GPM), and nonlinear programming, is designed to solve the CTOCP. In particular, the notion of the virtual time is introduced to the VMC problem formulation to handle the temporal cooperative constraints. The simulation experiments validate that the CTOCP can be effectively solved by the cooperative trajectory planning algorithm based on VMC which integrates the spatial and temporal constraints on the trajectory level, and the comparative experiments illustrate that VMC based algorithm is more efficient than GPM based direct collocation method in tackling the CTOCP

Source parameters of the 2017 M_w 6.2 Yukon earthquake doublet inferred from coseismic GPS and ALOS-2 deformation measurements

We investigated an M_w ∼ 6.2 earthquake doublet on the border of the USA and Canada using ALOS2 Light-of-Sight displacements and GPS measurements. We selected three L-band ALOS-2 interfergorams with temporal baselines of one yr to extract coseismic deformation maps, in which master and slave images were both acquired in July. A subpixel-based alignment and another range spectral splitting techniques under the GAMMA InSAR software framework were applied to improve the interferometric coherence and reduce the effects of phase anomalies in two of the three interferometric pairs due to either ionospheric delay or a potential focusing issues in the generation of the ALOS2 SLC data. The updated interferograms convincingly reveal deformation fringe patterns produced by the two earthquakes. We conducted a nonlinear geophysical inversion to estimate the geometric parameters of the earthquakes with the InSAR and GPS measurements. The best-fitting model shows that a thrust faulting on a reverse fault and left-lateral strike-slip faulting on a nearly vertical fault with the centroid depths of 9.3±0.6 and 8.4±0.7 km, respectively, are most likely responsible for the earthquake doublet. The eastern Denali fault (EDF) and Duke River fault are major active faults in the region and the earthquake doublet could be due to reactivation of the part of the two faults system

miR-499-5p Attenuates Mitochondrial Fission and Cell Apoptosis via p21 in Doxorubicin Cardiotoxicity

Doxorubicin (DOX) is a broad-spectrum anti-tumor drug, but its cardiotoxicity limits its clinical application. A better understanding of the molecular mechanisms underlying DOX cardiotoxicity will benefit clinical practice and remedy heart failure. Our present study observed that DOX caused cardiomyocyte (H9c2) apoptosis via the induction of abnormal mitochondrial fission. Notably, the expression levels of p21 increased in DOX-treated cardiomyocytes, and the silencing of p21 using siRNA greatly attenuated mitochondrial fission and apoptosis in cardiomyocytes. We also found that miR-499-5p could directly target p21 and attenuated DOX-induced mitochondrial fission and apoptosis. The role of the miR-499-5p-p21 axis in the prevention of DOX cardiotoxicity was also validated in the mice model. DOX treatment induced an upregulation of p21, which induced subsequent abnormal mitochondrial fission and myocardial apoptosis in mouse heart. Adenovirus-harboring miR-499-5p-overexpressing mice exhibited significantly reduced p21 expression, mitochondrial fission and myocardial apoptosis in hearts following DOX administration. The miR-499-5p-overexpressing mice also exhibited improved cardiomyocyte hypertrophy and cardiac function after DOX treatment. However, miR-499-5p was not involved in the DOX-induced apoptosis of cancer cells. Taken together, these findings reveal an emerging role of p21 in the regulation of mitochondrial fission program. miR-499-5p attenuated mitochondrial fission and DOX cardiotoxicity via the targeting of p21. These results provide new evidence for the miR-499-5p-p21 axis in the attenuation of DOX cardiotoxicity. The development of new therapeutic strategies based on the miR-499-5p-p21 axis is a promising path to overcome DOX cardiotoxicity as a chemotherapy for cancer treatment

Experimental study on creep-feed grinding burn of DD9 Nickel-based single crystal superalloy

Aiming at the problem of grinding burns on the third-generation single crystal superalloy DD9, a three-factor and five-level experiment is designed in this paper. From the perspectives of surface morphology, microhardness and microstructure, the effect of grinding process parameters on grinding burns are studied. The experimental results show that: when the workpiece feed speed is less than 250 mm/min, the grinding surface roughness Ra changes slightly around 0.8 μm, and the surface quality is good. When the feed speed is more than 250 mm/min and the grinding depth is more than 1.0 mm, the temperature in the grinding area rises sharply, the grinding lines are destroyed, grinding defects such as coating and pits appear, and the surface of the workpiece burns. The surface and surface of DD9 alloy are work hardened by slow feed grinding. The microhardness range is 400 to 600 HV, the depth of hardened layer is 50 to 110 μm, and the thickness range of plastic deformation layer is 1 to 10 μm. The recommended combination of DD9 grinding process parameters is: grinding wheel linear velocity vs=20 m/s, feed speed vw=250 mm/min, grinding depth ap=0.6 mm

MRCIF: A Memory-Reverse-Based Code Injection Forensics Algorithm

The new DLL injection method and its variants can prevent the injected process from calling the common system API to load the injected DLL module so that the malicious module is invisible to the LDR linked list of the process. Traditional injection detection methods have low accuracy in forensic detection of new injection attacks. To solve this problem, this paper proposes a code injection covert memory page detection and forensic detection forensic algorithm based on a memory structure reverse analysis named MRCIF. First, the physical memory pages containing DLL features from the memory image are located, and a sub-algorithm is designed for mapping physical memory space and virtual memory space, thus realizing the reverse reconstruction of the physical page subset corresponding to the DLL code module. Then, in the virtual memory space, the LDR linked list structure of the process is reversely reconstructed, and a reverse reconstruction algorithm of the DLL virtual page subset is developed to reconstruct its virtual space. Finally, a DLL injection covert page detection sub-algorithm is designed based on the physical memory page subset and virtual space page subset. The experimental results indicate that MRCIF achieves an accuracy of 88.89%, which is much higher than that of the traditional DLL module injection detection method, and only MRCIF can accurately detect the Virtual Address Descriptor (VAD) remapping attack

Rapamycin attenuates ioversol-induced acute kidney injury in rat models

Objective To investigate the role of autophagy in contrast-induced acute kidney injury (CI-AKI) in rats and to explore its possible mechanism. Methods SD rats were randomly divided into control group, acute kidney injury model group (intravenous injection of contrast medium ioversol via tail vein; model), rapamycin(RAPA) group and hydroxychloroquine (HCQ)group. Blood urea nitrogen(BUN) and serum creatinine(Scr) contents were measured and the potential change foun in renal pathology was detected by HE staining and microscopy. Transmission electron microscopy was used to observe auto-phagy-related changes in ultrastructure.Western blot was used to observe the expression of microtubule-associated protein 1 light chain 3(LC3)Ⅱ/LC3Ⅰ,ubiquitin-binding protein p62 and Histone deacetylase 4(HDAC4). The expression of HDAC4 was also observed by RT-qPCR. Results Compared with control group, the level of BUN, Scr and HDAC4 expression in the model and HCQ group was increased (P＜0.01),the proximal tubules of the kidney were significantly damaged. In the model group, autophagososomes and autolysosomes increased, accompanied by an increase of LC3Ⅱ/LC3Ⅰ and a decrease in the p62 level (P＜0.05,P＜0.01); Compared with model group, there were more autophagosomes and autolysosomes were found in RAPA group(P＜0.01), accompanied by increased LC3Ⅱ/LC3Ⅰ ratio and decrease in the p62 and HDAC4(P＜0.05,P＜0.01). In contrast, the number of autophagy related structures decreased in HCQ group(P＜0.01), accompanied by the simultaneous increase of LC3Ⅱ/LC3Ⅰ, p62 and the increase of HDAC4(P＜0.01). Conclusions Ioversol may induce autophagy activation, while enhancing autophagy by RAPA alleviates CI-AKI induced renal dysfunction. The mechanism is potentially atributed to the regulation of HDAC4

Sheet Stamping Formability Test System based Servo Crank Press

AbstractProposed the tentative plan that carries on the formability test by simulation practical crank punch press slide speed characteristic, designed the solution to the implementation difficulty, and has carried on the actual attempt. The servo motor drive crank press speed alters at more sects which can get slider speed characteristic coherent with crank press varies. The system can test varies stamping formability that speed changeable based on sine curve. The system is composed of 600kN servo crank press, double action and all-purpose moldbase, date get and inspect analyze system. The moldbase adopted positive direction structural and self-motion, with variable blank holder force and counterforce controlled by hydraulic system with closed loop. The blank holder force can be set up in 5 sects which following with slide position, shortest control sect in 200ms. Appropriate profile of blank holder force can setup with the process needed. Blank holder has quartz force sensor which can inspect blank holder force and the control precision is in 0.1kN

The impact of feature selection techniques on effort‐aware defect prediction: An empirical study

Abstract Effort‐Aware Defect Prediction (EADP) methods sort software modules based on the defect density and guide the testing team to inspect the modules with high defect density first. Previous studies indicated that some feature selection methods could improve the performance of Classification‐Based Defect Prediction (CBDP) models, and the Correlation‐based feature subset selection method with the Best First strategy (CorBF) performed the best. However, the practical benefits of feature selection methods on EADP performance are still unknown, and blindly employing the best‐performing CorBF method in CBDP to pre‐process the defect datasets may not improve the performance of EADP models but possibly result in performance degradation. To assess the impact of the feature selection techniques on EADP, a total of 24 feature selection methods with 10 classifiers embedded in a state‐of‐the‐art EADP model (CBS+) on the 41 PROMISE defect datasets were examined. We employ six evaluation metrics to assess the performance of EADP models comprehensively. The results show that (1) The impact of the feature selection methods varies in classifiers and datasets. (2) The four wrapper‐based feature subset selection methods with forwards search, that is, AdaBoost with Forwards Search, Deep Forest with Forwards Search, Random Forest with Forwards Search, and XGBoost with Forwards Search (XGBF) are better than other methods across the studied classifiers and the used datasets. And XGBF with XGBoost as the embedded classifier in CBS+ performs the best on the datasets. (3) The best‐performing CorBF method in CBDP does not perform well on the EADP task. (4) The selected features vary with different feature selection methods and different datasets, and the features noc (number of children), ic (inheritance coupling), cbo (coupling between object classes), and cbm (coupling between methods) are frequently selected by the four wrapper‐based feature subset selection methods with forwards search. (5) Using AdaBoost, deep forest, random forest, and XGBoost as the base classifiers embedded in CBS+ can achieve the best performance. In summary, we recommend the software testing team should employ XGBF with XGBoost as the embedded classifier in CBS+ to enhance the EADP performance

An interface for online coupling capillary electrophoresis to dielectric barrier discharge ionization mass spectrometry

The online combination of capillary electrophoresis (CE) with mass spectrometry (MS) has long been desired for the capability of direct and simultaneous separation and detection with high efficiency, accuracy, and throughput. In this work, a novel CE-MS interface was developed, using dielectric barrier discharge ionization (DBDI). The interface employed a spray tip with a coaxial three-layer structure, into which the CE sample solution, the sheath liquid, and the nebulizing gas were introduced. The spray tip was put between the DBDI outlet and the MS inlet, thus the CE sample solution could be blended with the sheath liquid, then nebulized. The nebulized sample could be ionized by DBDI, and finally analyzed by MS. The key parameters of the interface were optimized. Then, proof-of-concept experiments separating and detecting the mixture of metronidazole and acetaminophen solutions were conducted. The results showed high separation efficiency, low time consumption, high reproducibility, and convenience in operation. In addition, the interface exhibited a high tolerance of non-volatile salts and surfactants, which would be widely used in CE analyses. All of these results demonstrated that the newly developed CE-DBDI-MS interface could be successfully used in CE-MS studies, and could be further utilized in multiple areas involving efficient separation and detection