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An Efficient Authentication Protocol for WLAN Mesh Networks in Trusted Environment
MA, Zhuo,MA, Jianfeng,MOON, SangJae,LI, Xinghua The Institute of Electronics, Information and Comm 2010 IEICE transactions on information and systems Vol.93 No.3
<P>Trusted Network Connect provides the functionality of the platform authentication and integrity verification which is crucial for enhancing the security of authentication protocols. However, applying this functionality directly to concrete authentications is susceptible to unknown attacks and efficiency degradation. In this paper, we propose TWMAP, a novel authentication protocol for WLAN Mesh networks in a trusted environment which completed the platform authentication and integrity verification during the user authentication. And, the Schnorr asymmetric signature scheme is utilized to reduce the overhead of the client. The security properties of the new protocol are examined using the Universally Composable Security model. The analytic comparisons and simulation results show that the new protocol is very efficient in both computing and communication costs.</P>
Improved Reliability-Based Iterative Decoding of LDPC Codes Based on Dynamic Threshold
Ma Zhuo,Du Shuanyi 한국전자통신연구원 2015 ETRI Journal Vol.37 No.4
A serial concatenated decoding algorithm with dynamic threshold is proposed for low-density parity-check codes with short and medium code lengths. The proposed approach uses a dynamic threshold to select a decoding result from belief propagation decoding and order statistic decoding, which improves the performance of the decoder at a negligible cost. Simulation results show that, under a high SNR region, the proposed concatenated decoder performs better than a serial concatenated decoder without threshold with an Eb/N0 gain of above 0.1 dB.
Effect of Sub-Structure and Precipitation Behavior on Mechanical Properties of Al–xCu–Li Alloys
Yu‑zhuo Li,Guang‑jun Zeng,Ding‑ding Lu,Zhen‑zhen Liu,San‑xi Deng,Peng‑cheng Ma,Yong‑lai Chen,Rui‑feng Zhang,Jin‑feng Li 대한금속·재료학회 2023 METALS AND MATERIALS International Vol.29 No.11
The tensile properties and microstructure of extruded and cold rolled 2A55 Al–Li alloys with different Cu content werestudied. After solution treatment, the strength of extruded sheets is slightly higher than that of cold rolled sheets due to strongdeformation texture and high density of substructure. However, the strength change order is different with the increase of Cucontent with T6-24 h. The extruded sample with higher Cu content have higher strength due to many dense T1precipitates. The δ′/θ′/δ′ composite precipitates and θ′ precipitates suppress the formation of T1precipitates, which cause cold rolled samplewith higher Cu content shows lower strength. Additionally, many fine T1precipitates nucleate at the sub-grain boundariesformed in the extrusion process, which have a significant effect on the mechanical property.
Shear Behavior of Corroded Post-Tensioned Prestressed Concrete Beams with Full/Insufficient Grouting
Lei Wang,Zhuo Hu,Ju Yi,Lizhao Dai,Yafei Ma,Xuhui Zhang 대한토목학회 2020 KSCE Journal of Civil Engineering Vol.24 No.6
This paper experimentally studied the shear behavior of corroded post-tensioned prestressed concrete beams with full grouting. The effects of insufficient grouting in shear span on the shear behavior were also investigated. Eight beams were fabricated and divided into two groups: four beams with full grouting and four beams with insufficient grouting. Three beams in each group were subjected to accelerated corrosion. All beams were tested to failure in four-point loading. Experimental data on shear cracking, load-deflection response, shear strength and failure modes were presented. Results showed that strand corrosion accelerated the formation and propagation of diagonal crack. Insufficient grouting decreased the number of diagonal cracks. Strand corrosion degraded the post-cracking stiffness and shear strength. Insufficient grouting aggravated the propagation of diagonal crack and the degradation of post-cracking stiffness. The shear strength of corroded beam with 31.7% corrosion loss decreased by 15.44% as compared to that of the uncorroded beam. Strand corrosion loss less than 31.7% did not change the shear compression failure mode in fully grouted beams. The failure modes of locally ungrouted beams changed from shear compression failure to rupture of wires as the corrosion loss exceeded 39.6%.
Power Balance for Voltage-controlled PV Generator without Robust Voltage Source
Wang Zhenxiong,Zhuo Fang,Lv Nian,Yi Hao,Wu Jiaqi,Yan Hui,Ma Zekun 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5
Voltage control mode is preferable because of better bus voltage support and low reliance on communication. However, that is difficult to implement on photovoltaic inverter without robust voltage source. Meanwhile, photovoltaic arrays have some power management ability that usually neglected due to the use of MPPT, which in fact damages balanced power flow and a robust and stable grid. As a result, control of dc and ac side of photovoltaic inverter is usually separated and broken, where the dc side is usually supposed as an ideal voltage source and the corresponding relationships are neglected. This paper proposes a control scheme called photovoltaic generator for photovoltaic microgrid without robust voltage source, which imitates the principle of power conversion from mature synchronous generator theory. The scheme focuses on the active participation of solar energy in power management and voltage support. The effectiveness is verified in simulation and experiment.
Functional roles of Tryptophan residues in diketoreductase from Acinetobacter baylyi
( Yan Huang ),( Zhuo Lu ),( Min Ma ),( Nan Liu ),( Yi Jun Chen ) 생화학분자생물학회(구 한국생화학분자생물학회) 2012 BMB Reports Vol.45 No.8
Diketoreductase (DKR) from Acinetobacter baylyi contains two tryptophan residues at positions 149 and 222. Trp-149 and Trp-222 are located along the entry path of substrate into active site and at the dimer interface of DKR, respectively. Single and double substitutions of these positions were generated to probe the roles of tryptophan residues. After replacing Trp with Ala and Phe, biochemical and biophysical characteristics of the mutants were thoroughly investigated. Enzyme activity and substrate binding affinity of W149A and W149F were remarkably decreased, suggesting that Trp-149 regulates the position of substrate at the binding site. Meanwhile, enzyme activity of W222F was increased by 1.7-fold while W222A was completely inactive. In addition to lower thermostability of Trp-222 mutants, molecular modeling of the mutants revealed that Trp-222 is vital to protein folding and dimerization of the enzyme. [BMB Reports 2012; 45(8): 452-457]
Gao Hang Cui,Zhuo Cheng,Fanyue Sun,Shuxian Ma,Zhiqiang Liu 대한토목학회 2024 KSCE Journal of Civil Engineering Vol.28 No.1
The freezing and thawing of roadbed soils in seasonal frozen zones can cause uneven settlement and other road problems, which puts road operation at risk. This paper focuses on the rapid construction of expressways and analyzes the effects of using fly ash and cement as modifiers on the physical properties and chemical composition of subgrade soil. The study found that cement admixtures can improve soil mechanical attributes and frost resistance, while also increasing the degree of fly ash hydration.And the freeze-thaw cycle process can enhance the mechanical characteristics of soils with higher cement admixture content. This is due to the development of hydrates in cement fly ash-enhanced soils during freeze?thaw cycles, resulting in a denser interior structure. The use of neural network prediction analysis showed that using ANN4-10-3 to forecast soil mechanical property parameters can produce superior results. Therefore, it is recommended to use cement fly ash-enhanced soil for roadbed construction in seasonal freezing areas, and neural network can be used to predict soil mechanical parameters.
Effect of Freeze-Thaw Cycles on Dynamic Characteristics of Undisturbed Silty Clay
Gao Hang Cui,Zhuo Cheng,Daili Zhang,Shuxian Ma,Zhiqiang Liu 대한토목학회 2022 KSCE JOURNAL OF CIVIL ENGINEERING Vol.26 No.9
We conducted dynamic triaxial tests of undisturbed soil samples under different control parameters using the Global Digital Systems (GDS) dynamic triaxial instrument. We investigated the dynamic and engineering characteristics of undisturbed soil under a freeze–thaw cycle. When the dynamic load amplitude and the number of freeze–thaw cycles were adjusted, we explored the cumulative plastic strain, dynamic elastic modulus, and dynamic strength of undisturbed soil, and we then proposed appropriate fitting formulae to compute the cumulative plastic strain, dynamic elastic modulus, and dynamic strength. The findings revealed that as the number of freeze–thaw cycles increased, the cumulative plastic strain grew, the dynamic strength progressively fell, and the dynamic elastic modulus dropped first, but then increased. The critical physical and dynamic features of soil changed dramatically during one to six freeze–thaw cycles. This study’s suggested formula for the average growth ratio can directly reflect the cumulative plastic strain fluctuation of soil throughout freeze–thaw cycles. The formula has a good fitting effect on undisturbed soil, according to the test findings, and the accumulative plastic strain, dynamic elastic modulus, and dynamic strength may be computed within a specified range. The findings of this study contribute to a better understanding of the effect of the freeze–thaw cycle on the dynamic characteristics of undisturbed silty clay, as well as a theoretical foundation for the design and construction of silty clay highway subgrade in seasonally frozen regions as well as the dynamic analysis of vehicle simulation in seasonally frozen regions.