Efficient Network Traffic Classification and Visualizing Abnormal Part Via Hybrid Deep Learning Approach : Xception + Bidirectional GRU

Due to a rapid development in the field of information and communication, the information technologies yielded novel changes in both individual and organizational operations. Therefore, the accessibility of information became easier and more convenient than before, and malicious approaches such as hacking or spying aimed at various information kept increasing. With the aim of preventing malicious approaches, both classification and detecting malicious traffic are vital. Therefore, our research utilized various deep learning and machine learning models for better classification. The given dataset consists of normal and malicious data and these data types are png files. In order to achieve precise classification, our experiment consists of three steps. Firstly, only vanilla CNN was used for the classification and the highest score was 86.2%. Second of all, for the hybrid approach, the machine learning classifiers were used instead of fully connected layers from the vanilla CNN and it yielded about 87% with the extra tree classifier. At last, the Xception model was combined with the bidirectional GRU and it attained a 95.6% accuracy score, which was the highest among all

Improving ionic conductivity of von-Alpen-type NASICON ceramic electrolytes via magnesium doping

NASICON (sodium (Na) superionic conductor) compounds have attracted considerable attention as promising solid electrolyte materials for advanced Na-based batteries. In this study, we investigated the improvement in ionic conductivities of von-Alpen-type NASICON (vA-NASICON) ceramic electrolytes by introducing a magnesium ion (Mg2+) as a heterogeneous element. The optimal Mg-doped vA-NASICON exhibited a high ionic conductivity of 3.64×10−3 S·cm−1, which was almost 80% higher than that of un-doped vA-NASICON. The changes in physicochemical properties of the vA-NASICONs through the Mg introduction were systematically analyzed, and their effects on the ionic conductivities of the vA-NASICON were studied in detail. When the optimal ratio of Mg2+ was used in a synthetic process, the relative density (96.6%) and grain boundary ionic conductivity (σgb) were maximized, which improved the total ionic conductivity (σt) of the vA-NASICON. However, when Mg2+ was introduced in excess, the ionic conductivity decreased because of the formation of an undesired sodium magnesium phosphate (NaxMgyPO4) secondary phase. The results of this study are expected to be effectively applied in the development of advanced sodium-based solid electrolytes with high ionic conductivities

Light and thermal responses of liquid-crystal-network films: A finite element study

As a polymeric system incorporating rigid molecules within its structure, the liquid-crystal network (LCN) has been envisaged as a novel heterogeneous material. Under the influence of external stimuli, the orientational order of the liquid-crystalline phase becomes dilute and overall anisotropy is hence decreased; the actinic light absorbed by photochromic molecules, for example, induces the geometric isomerization and subsequently yields internal stress within the local network. In this study we investigate light-and temperature-induced spontaneous deformations of the LCN structure via a three-dimensional finite element model that incorporates geometric nonlinearity with a photomechanical constitutive model. We first examine the bending behavior and its nonlinearity and then parametrically study the various behaviors that stem from different origins ranging from the microscale to the macroscale: (i) the geometry of the LCN film, (ii) the macroscopic global order, (iii) the distorted mesogenic orientation due to the Fredericks distortion, and (iv) defect-induced instability. These interrelated behaviors demonstrate both the simulation capability and the necessity of the presenting framework. By employing a nonlinear consideration along with a microscopic shape parameter r the present approach facilitates further understanding of photomechanical physics such as the deconvolution of various stimuli and the deformed shape obtained due to snap-through instability. Furthermore, this study may offer insight into the design of light-sensitive actuation systems by deepening our knowledge and providing an efficient measure

Photo-isomerization effect of the azobenzene chain on the opto-mechanical behavior of nematic polymer: A molecular dynamics study

The opto-mechanical properties of a photo-responsive nematic polymer network (PRPN) are investigated using molecular dynamics simulation. For the implementation of the trans-to-cis isomerization of azo compounds, a switchable potential formalism for the N = N bond is applied to the crosslinked PRPN unit cell model. During the light switch-on and heating-up simulations at a wide range of temperatures, the scalar orientational order parameter for the mesogenic side group molecules, the effective photo-induced strain of the bulk polymer network, and the opto-mechanical properties are characterized. The correlation between the microstate which belongs to the molecular location and the macroscopically observed photostrain is identified according to the isomerization ratio of the diazene groups

Nonlinear photomechanics of nematic networks: upscaling microscopic behaviour to macroscopic deformation

A liquid crystal network whose chromophores are functionalized by photochromic dye exhibits light-induced mechanical behaviour. As a result, the micro-scaled thermotropic traits of the network and the macroscopic phase behaviour are both influenced as light alternates the shape of the dyes. In this paper, we present an analysis of this photomechanical behaviour based on the proposed multiscale framework, which incorporates the molecular details of microstate evolution into a continuum-based understanding. The effects of trans-to-cis photoisomerization driven by actinic light irradiation are first examined using molecular dynamics simulations, and are compared against the predictions of the classical dilution model; this reveals certain characteristics of mesogenic interaction upon isomerization, followed by changes in the polymeric structure. We then upscale the thermotropic phase-related information with the aid of a nonlinear finite element analysis; macroscopic deflection with respect to the wide ranges of temperature and actinic light intensity are thereby examined, which reveals that the classical model underestimates the true deformation. This work therefore provides measures for analysing photomechanics in general by bridging the gap between the micro-and macroscales

Photo deformation in azobenzene liquid-crystal network: Multiscale model prediction and its validation

Azobenzene liquid-crystal networks (LCNs) are well known for their photo-deformation, shrinking in UV light, and reverting to their original shape in visible light. Such reversible deformation is due to trans-cis photoisomerization of the azobenzene monomer, which disturbs well-aligned order of nematic LCN. In order to predict the photo-strain of azobenzene LCNs in multiple conditions (light intensity, polarization angle, and temperature), we propose using a density functional theory (DFT)-based modeling approach, which integrates stimulated Raman adiabatic passage calculations (STIRAP), non-linear Beer's law, and polymer physics. The model predicts that as the azobenzene ratio increases, the penetration depth of photo strain decreases, whereas the shrinkage ratio of the LCN in the unit cell increases. We identify that this opposite tendency of change is the reason why there is bending limit during the photo bending of azobenzene LCN films when increasing the ratio of the azobenzene monomer, which was also measured in experimental data

Molecular Dynamics Study on the Photothermal Actuation of a Glassy Photoresponsive Polymer Reinforced with Gold Nanoparticles with Size Effect

We investigated the optical and thermal actuation behavior of densely cross-linked photoresponsive polymer (PRP) and polymer nano composites containing gold nanoparticles (PRP/Au) using all-atom molecular dynamics (MD) simulations. The modeled molecular structures contain a large number of photoreactive mesogens with linear orientation. Flexible side chains are interconnected through covalent bonds under periodic boundary conditions. A switchable dihedral potential was applied on a diazene moiety to describe the photochemical trans-to-cis isomerization. To quantify the photoinduced molecular reorientation and its effect on the macroscopic actuation of the neat PRP and PRP/Au materials, we characterized the photostrain and other material properties including elastic stiffness and thermal stability according to the photoisomerization ratio of the reactive groups. We particularly examined the effect of nanoparticle size on the photothermal actuation by varying the diameter of the nanofiller (10-20 angstrom) under the same volume fraction of 1.62%. The results indicated that the insertion of the gold nanoparticles enlarges the photostrain of the material while enhancing its mechanical stiffness and thermal stability. When the diameter of the nanoparticle reaches a size similar to or smaller than the length of the mesogen, the interfacial energy between the nanofiller and the surrounding polymer matrix does not significantly affect the alignment of the mesogens, but rather the adsorption energy at the interface generates a stable interphase layer. Hence, these improvements were more effective as the size of the gold nanoparticle decreased. The present findings suggest a wider analysis of the nanofiller-reinforced PRP composites and could be a guide for the mechanical design of the PRP actuator system

Quantitative Analysis of the Head Tilt Using Three-Dimensional Temporal Scan in Children with Torticollis

The head tilt of patients with torticollis is usually evaluated subjectively in clinical practice and measuring it in young children is very limited due to poor cooperation. No study has yet evaluated the head tilt using a three-dimensional (3D) scan and compared it with other measurement methods. Therefore, this study aimed to objectively demonstrate head tilt through clinical measurements and a 3D scan in children with torticollis. A total of 52 children (30 males, 22 females; age 4.6 ± 3.2 years) diagnosed with torticollis and 52 adults (26 men, 26 women; age 34.42 ± 10.4 years) without torticollis participated in this study. The clinical measurements were performed using a goniometer and still photography methods. Additionally, the head tilt was analyzed using a 3D scanner (3dMD scan, 3dMD Inc., Atlanta, GA, USA). There was a high correlation between the other methods and 3D angles, and the cut-off value of the 3D angles for the diagnosis of torticollis was also presented. The area under the curve of the 3D angle was 0.872, which was confirmed by a moderately accurate test and showed a strong correlation compared with other conventional tests. Therefore, we suggest that measuring the degree of torticollis three-dimensionally is significant

Effect of emergency physician-operated emergency short-stay ward on emergency department stay length and clinical outcomes: a case-control study

Abstract Background We hypothesized that an emergency short-stay ward (ESSW) mainly operated by emergency medicine physicians may reduce the length of patient stay in emergency department without expense of clinical outcomes. Methods We retrospectively analysed adult patients who visited the emergency department of the study hospital and were subsequently admitted to wards from 2017 to 2019. We divided study participants into three groups: patients admitted to ESSW and treated by the department of emergency medicine (ESSW-EM), patients admitted to ESSW and treated by other departments (ESSW-Other) and patients admitted to general wards (GW). The co-primary outcomes were ED length of stay and 28-day hospital mortality. Results In total, 29,596 patients were included in the study, and 8,328 (31.3%), 2,356 (8.9%), and 15,912 (59.8%) of them were classified as ESSW-EM, ESSW-Other and GW groups, respectively. The ED length of stay of the ESSW-EM (7.1 h ± 5.4) was shorter than those of the ESSW-Other (8.0 ± 6.2, P < 0.001) and the GW (10.2 ± 9.8, P < 0.001 for both). Hospital mortality of ESSW-EM (1.9%) was lower than that of GW (4.1%, P < 0.001). In the multivariable linear regression analysis, the ESSW-EM was independently associated with shorter ED length of stay compared with the both ESSW-Other (coefficient, 1.08; 95% confidence interval, 0.70–1.46; P < 0.001) and GW (coefficient, 3.35; 95% confidence interval, 3.12–3.57; P < 0.001). In the multivariable logistic regression analyses, the ESSW-EM was independently associated with lower hospital mortality compared with both the ESSW-Other group (adjusted P = 0.030) and the GW group (adjusted P < 0.001). Conclusions In conclusion, the ESSW-EM was independently associated with shorter ED length of stay compared with both the ESSW-Other and the GW in the adult ED patients. Independent association was found between the ESSW-EM and lower hospital mortality compared with the GW