Adaptively Secure Anonymous Identity-based Broadcast Encryption for Data Access Control in Cloud Storage Service

( Liqing Chen ),( Jiguo Li ),( Yichen Zhang ) 한국인터넷정보학회 2019 KSII Transactions on Internet and Information Syst Vol.13 No.3

Cloud computing is now a widespread and economical option when data owners need to outsource or share their data. Designing secure and efficient data access control mechanism is one of the most challenging issues in cloud storage service. Anonymous broadcast encryption is a promising solution for its advantages in the respects of computation cost and communication overload. We bring forward an efficient anonymous identity-based broadcast encryption construction combined its application to the data access control mechanism in cloud storage service. The lengths for public parameters, user private key and ciphertext in the proposed scheme are all constant. Compared with the existing schemes, in terms of encrypting and decrypting computation cost, the construction of our scheme is more efficient. Furthermore, the proposed scheme is proved to achieve adaptive security against chosen-ciphertext attack adversaries in the standard model. Therefore, the proposed scheme is feasible for the system of data access control in cloud storage service.

Fishbone Oscillations in the Experimental Advanced Superconductivity Tokamak

Liqing Xu,Liqun Hu,Yi Yuan,Yingying Li,Guo-Qiang Zhong,Hai-Qing Liu,Kaiyun Chen,Tong-Hui Shi,Yan-Min Duan 한국물리학회 2018 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.72 No.6

A fishbone oscillation was observed in the neutral beam injection plasma at Experimental Ad- vanced Superconductivity Tokamak (EAST). This m = 1/n = 1 (m, n: poloidal, toroidal mode numbers, respectively) typical internal kink mode travels in the ion-diamagnetism direction in the poloidal section with a rotation speed close to the ion diamagnetic drift frequency. A high thermal plasma beta and high amounts of energetic ions are necessary for the mode to develop. Fishbone oscillations can expel heavy impurities in the core, which favors sustaining a high-performance plasma. The born frequency of the fishbone oscillation is the ion diamagnetic drift frequency and the chirping down of the frequency during the initial growth phase is the result of a drop in ion- diamagnetic drift frequency. The excitation energy is thought to be due to the thermal plasma pressure gradient; however, the development of a fishbone oscillation is related to energetic ions. A fishbone oscillation was observed in the neutral beam injection plasma at Experimental Advanced Superconductivity Tokamak (EAST). This m = 1/n = 1 (m, n: poloidal, toroidal mode numbers, respectively) typical internal kink mode travels in the ion-diamagnetism direction in the poloidal section with a rotation speed close to the ion diamagnetic drift frequency. A high thermal plasma beta and high amounts of energetic ions are necessary for the mode to develop. Fishbone oscillations can expel heavy impurities in the core, which favors sustaining a high-performance plasma. The born frequency of the fishbone oscillation is the ion diamagnetic drift frequency and the chirping down of the frequency during the initial growth phase is the result of a drop in ion- diamagnetic drift frequency. The excitation energy is thought to be due to the thermal plasma pressure gradient; however, the development of a fishbone oscillation is related to energetic ions.

Deep Learning: High-quality Imaging through Multicore Fiber

Liqing Wu,Jun Zhao,Minghai Zhang,Yanzhu Zhang,Xiaoyan Wang,Ziyang Chen,Jixiong Pu 한국광학회 2020 Current Optics and Photonics Vol.4 No.4

Imaging through multicore fiber (MCF) is of great significance in the biomedical domain. Although several techniques have been developed to image an object from a signal passing through MCF, these methods are strongly dependent on the surroundings, such as vibration and the temperature fluctuation of the fiber’s environment. In this paper, we apply a new, strong technique called deep learning to reconstruct the phase image through a MCF in which each core is multimode. To evaluate the network, we employ the binary cross-entropy as the loss function of a convolutional neural network (CNN) with improved U-net structure. The high-quality reconstruction of input objects upon spatial light modulation (SLM) can be realized from the speckle patterns of intensity that contain the information about the objects. Moreover, we study the effect of MCF length on image recovery. It is shown that the shorter the fiber, the better the imaging quality. Based on our findings, MCF may have applications in fields such as endoscopic imaging and optical communication.

Dynamic recrystallization and microstructure evolution of a Nb-V microalloyed forging steel during hot deformation

Zhao, Yang,Chen, Liqing,Liu, Xianghua Techno-Press 2014 Advances in materials research Vol.3 No.4

In this study, a forging steel alloyed with both Nb and V was used as experimental material and the hot deformation behavior has been studied for this steel by conducting the compressive deformation test at temperature of $900-1150^{\circ}C$ and strain rate of $0.01-0.01s^{-1}$ in a MMS-300 thermo-mechanical simulator. The microstructure evolution, particularly the dynamically recrystallized microstructure, of the experimental steel at elevated temperatures, strain rates and strain levels, was characterized by optical microstructural observation and the constitutive equation in association with the activation energy and Zener-Hollomon parameter. The curves of strain hardening rate versus stress were used to determine the critical strain and peak strain, and their relation was connected with Zener-Hollomon parameter. Under the conditions of processing temperature $900^{\circ}C$ and strain rate $0.01s^{-1}$, the dynamic recrystallization took place and the austenite grain size was refined from $164.5{\mu}m$ to $28.9{\mu}m$.

Transient Snakes in an Ohmic Plasma Associated with a Minor Disruption in the HT-7 Tokamak

Songtao Mao,Liqing Xu,Liqun Hu,Kaiyun Chen 한국물리학회 2014 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.64 No.9

A transient burst (2 ms, an order of the fast-particle slowdown timescale) of a spontaneous snakeis observed for the first time in a HT-7 heavy impurity ohmic plasma. The features of the low-Zimpurity snake are presented. The flatten electron profile due to the heavy impurity reveals theformation of a large magnetic island. The foot of the impurity accumulation is consistent with thelocation of the transient snake. The strong frequency-chirping behaviors and the spatial structuresof the snake are also presented.

Tailoring Mechanical Properties of a Low Carbon Cu-Containing Structural Steel by Two-Step Intercritical Heat Treatment

Xiaohui Xi,Jinliang Wang,Liqing Chen,Zhaodong Wang 대한금속·재료학회 2019 METALS AND MATERIALS International Vol.25 No.6

In this paper, a process of two-step intercritical heat treatment was used to control the amount of retained austenite andnano-scaled precipitates for a low carbon Cu-containing structural steel such that the mechanical properties of this steelcan be tailored. In this process, the first step is intercritical annealing and a mixed microstructure can be obtained whichcontains intercritical ferrite, tempered martensite, fresh martensite and a small amount of retained austenite. The subsequentintercritical tempering was introduced to be beneficial for producing more stable retained austenite at room temperaturethrough secondary enrichment of stabilizers (Mn, Ni). Also, (Nb, V, Mo) (C, N) precipitates were formed during intercriticalannealing, while smaller (Nb, V, Mo) (C, N) precipitates and Cu-rich particles with diameter of 5–15 nm were obtainedafter intercritical tempering. It is due to the contributions from multi-phase microstructure, strain-induced transformation ofstable retained austenite and strengthening of nano-scaled precipitates that a combination of high strength, good ductility,low yield to tensile ratio (Y/T ratio) and excellent low-temperature toughness was achieved. The strengthening and tougheningmechanism were discussed on the basis of retained austenite formation and interaction between Cu precipitates and thematrix, together with the crack propagation.

국외논문정보 - 교대근무와 당뇨병: 관찰연구의 메타분석

Gan, Yong,Yang, Chen,Tong, Xinyue,Sun, Huilian,Cong, Yingjje,Yin, Xiaoxu,Li, Liqing,Cao, Shiyi,Dong, Xiaoxin,Gong, Yanhong,Shi, Oumin,Deng, Jian,Bi, Huashan,Lu, Zuxun 대한산업보건협회 2015 산업보건 Vol.331 No.-

Hierarchical porous composites derived from spent tire char for CO2 capture: K-N co-doped, process intensification and thermodynamic analysis

Hongguan Wang,Guofeng Qiu,Yanjie Niu,Liqing Chen,Yan Li,Sixi Guo,Yixin Zhang,Jianjun Wu,Fanhui Guo 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.125 No.-

Spent tire is a kind of solid waste with large production, accumulation and great pollution. Spent tire charis the primary product of tire harmless disposal. Its commercial value is enhanced by modification. In thisstudy, K-N co-doped activated carbon was prepared by using spent tire char as raw material, KOH andmelamine as activator and dopant to enhance CO2 capture. In comparison with traditional process, thereasons for the decrease in specific surface area and pore volume caused by K doped have been identified,and a potential doped mechanism has been proposed. It was determined that pyridine nitrogen in theamino functional group played a key role in CO2 adsorption. Meanwhile, the synergistic intensificationof CO2 adsorption by potassium phenolic and pyridine nitrogen was verified by simplified model simulation. The precise K-N doping significantly intensify the CO2 adsorption capacity of spent tire char from0.45 to 2.60 mmol/g (1 bar, 0℃), an increase of 4.78 times. Thermodynamic studies have demonstratedthat the Langmuir model accurately describes the adsorption process, and the adsorption reaction takesplace spontaneously at temperatures below 80.52 C. This work presents an efficient process for upgradingspent tire char, and a novel method of co-treating waste and CO2.

Efficient removal of methylene blue via two-step modification hazelnut shell biochar: Process intensification, kinetics and thermodynamics

Fanhui Guo,Sixi Guo,Yanjie Niu,Guofeng Qiu,Yang Guo,Yan Li,Liqing Chen,Yixin Zhang,Jianjun Wu 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.125 No.-

Porous carbon materials with ultra-high specific surface area and adjustable pore structure characteristicswere prepared from food industry waste hazelnut shells for the adsorption of methylene blue (MB)wastewater by two-step activation by impregnation with ZnCl2 followed by chemical activation withKOH. The Fusso effect, which can reduce the size of MB molecules, was further used to enhance theadsorption of MB on porous carbon. The results show that both HSBC-a and HSBC-a-b have ultra-highspecific surface area (2979.59 m2/g for HSBC-a, 2882.73 m2/g for HSBC-a-b). The mesopore ratio ofHSBC-a-b (Vmeso/Vtotal % = 14.05%) was doubled compared to HSBC-a. It showed an excellent adsorptionperformance of 694.03 mg/g for MB. It showed a fast adsorption kinetics and the adsorbed amountincreased to 882.46 mg/g at 0.1 M NaCl solution. In addition, adsorption processes were studied usingadsorption kinetics and adsorption isotherm model fitting. The results of this research confirm that hazelnutshell is a kind of promising and sustainable porous carbon raw material, and its ultra-high specificsurface area and adjustable pore structure characteristics are favorable for the efficient treatment ofMB from dyeing wastewater. This work could provide potential guidance for the high-value utilizationof waste hazelnut shell biochar.