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A Light-weight Mitigation Scheme on the Mole Content Poisoning Attack in NDN
Pengfei Yue,Ru Li,Bin Pang 한국통신학회 2020 한국통신학회 APNOMS Vol.2020 No.09
With a novel content-based communication model that is designed for data sharing, Named Data Networking (NDN) borns with innate security by per package encryption and achieves better scalability and mobility. Security attacks in the current Internet, e.g., IP and/or DNS spoofing, can hardly hazard NDN since there is no address and the embedded security in the data packet. However, some new kinds of attacks (e.g., interest flooding attack and content poisoning attack) damage NDN if not investigated thoroughly. In NDN, there exists a variant of content poisoning attack (CPA) that the attack is launched by some compromised core routers and this kind of attack causes severe damage to the network. In this paper, this variant of CPA has named the mole content poisoning attack (MCPA), and a Kalman filter based light-weight mitigation scheme is proposed. Besides, random sampling is imposed on the data traffic and tunes the state parameters in the Kalman filter to achieve faster convergence in a router. Compared with the mitigation scheme by the probabilistically checking of signatures on the data traffic, the proposed light-weight mitigation scheme recovers interest satisfaction rates (ISRs) of consumers while introducing less computation overhead.
Peng Pengfei,Yue Xun,Tang Lu,Wu Xi,Deng Qiao,Wu Tao,Cai Lei,Liu Qi,Xu Jian,Huang Xiaoqi,Chen Yucheng,Diao Kaiyue,Sun Jiayu 대한영상의학회 2023 Korean Journal of Radiology Vol.24 No.12
Objective: To clinically validate the feasibility and accuracy of cine images acquired through the multitasking method, with no electrocardiogram gating and free-breathing, in measuring left ventricular (LV) function indices by comparing them with those acquired through the balanced steady-state free precession (bSSFP) method, with multiple breath-holds and electrocardiogram gating. Materials and Methods: Forty-three healthy volunteers (female:male, 30:13; mean age, 23.1 ± 2.3 years) and 36 patients requiring an assessment of LV function for various clinical indications (female:male, 22:14; 57.8 ± 11.3 years) were enrolled in this prospective study. Each participant underwent cardiac magnetic resonance imaging (MRI) using the multiple breath-hold bSSFP method and free-breathing multitasking method. LV function parameters were measured for both MRI methods. Image quality was assessed through subjective image quality scores (1 to 5) and calculation of the contrast-to-noise ratio (CNR) between the myocardium and blood pool. Differences between the two MRI methods were analyzed using the Bland–Altman plot, paired t-test, or Wilcoxon signed-rank test, as appropriate. Results: LV ejection fraction (LVEF) was not significantly different between the two MRI methods (P = 0.222 in healthy volunteers and P = 0.343 in patients). LV end-diastolic mass was slightly overestimated with multitasking in both healthy volunteers (multitasking vs. bSSFP, 60.5 ± 10.7 g vs. 58.0 ± 10.4 g, respectively; P < 0.001) and patients (69.4 ± 18.1 g vs. 66.8 ± 18.0 g, respectively; P = 0.003). Acceptable and comparable image quality was achieved for both MRI methods (multitasking vs. bSSFP, 4.5 ± 0.7 vs. 4.6 ± 0.6, respectively; P = 0.203). The CNR between the myocardium and blood pool showed no significant differences between the two MRI methods (18.89 ± 6.65 vs. 18.19 ± 5.83, respectively; P = 0.480). Conclusion: Multitasking-derived cine images obtained without electrocardiogram gating and breath-holding achieved similar image quality and accurate quantification of LVEF in healthy volunteers and patients.
LIMIT OF FUEL INJECTION RATE IN THE COMMON RAIL SYSTEM UNDER ULTRA-HIGH PRESSURES
Jianhui Zhao,Leonid Grekhov,Pengfei Yue 한국자동차공학회 2020 International journal of automotive technology Vol.21 No.3
The common rail injection system with higher injection pressure can improve injection characteristics. However, relevant researches for injection characteristics under ultra-high pressures are insufficient. In this article, the results of experiments with a maximum injection pressure of 390 MPa for nine different injectors of four types are presented. The experiment showed the existence of supercritical pressure during injection. At pressures below the supercritical pressure, the injection quantity increases with increasing injection pressure, however, when the injection pressure is over supercritical pressure, the injection quantity does not increase. According to the experiment results, the supercritical injection pressure is about 300 ~ 350 MPa. Under ultra-high pressures, fuel is strongly heated and the local sound velocity decreases, and the adiabatic flow velocity reaches the sound velocity. Under supercritical pressure, the injection rate ceases to increase and even begins to fall. The traditional equations for calculating the injection rate cannot correctly describe the injection under ultrahigh pressures. A new mathematic model with considering the fuel heating for describing the injection quantity of compressible fluid was developed, this model is not only suitable for calculating the injection quantity under ultra-high pressures, but under traditional injection pressures.
Three-Dimensional Analysis of Chloroplast Structures Associated with Virus Infection
Jin, Xuejiao,Jiang, Zhihao,Zhang, Kun,Wang, Pengfei,Cao, Xiuling,Yue, Ning,Wang, Xueting,Zhang, Xuan,Li, Yunqin,Li, Dawei,Kang, Byung-Ho,Zhang, Yongliang American Society of Plant Biologists 2018 Plant Physiology Vol.176 No.1
<P>Three-dimensional visualization identifies structural remodeling in chloroplasts during barley stripe mosaic virus infection.</P><P>Chloroplasts are multifunctional organelles whose morphology is affected by environmental stresses. Although the three-dimensional (3D) architecture of thylakoid membranes has been reported previously, a 3D visualization of chloroplast under stress has not been explored. In this work, we used a positive-strand RNA ((+)RNA) virus, barley stripe mosaic virus (BSMV) to observe chloroplast structural changes during infection by electron tomography. The analyses revealed remodeling of the chloroplast membranes, characterized by the clustering of outer membrane-invaginated spherules in inner membrane-derived packets. Diverse morphologies of cytoplasmic invaginations (CIs) were evident with spherules at the periphery and different sized openings connecting the CIs to the cytoplasm. Immunoelectron microscopy of these viral components verified that the aberrant membrane structures were sites for BSMV replication. The BSMV αa replication protein localized at the surface of the chloroplasts and played a prominent role in eliciting chloroplast membrane rearrangements. In sum, our results have revealed the 3D structure of the chloroplasts induced by BSMV infection. These findings contribute to our understanding of chloroplast morphological changes under stress conditions and during assembly of plant (+)RNA virus replication complexes.</P>