An Optimal ODAM-Based Broadcast Algorithm for Vehicular Ad-Hoc Networks

( Weifeng Sun ),( Feng Xia ),( Jianhua Ma ),( Tong Fu ),( Yu Sun ) 한국인터넷정보학회 2012 KSII Transactions on Internet and Information Syst Vol.6 No.12

Broadcast routing has become an important research field for vehicular ad-hoc networks (VANETs) recently. However, the packet delivery rate is generally low in existing VANET broadcast routing protocols. Therefore, the design of an appropriate broadcast protocol based on the features of VANET has become a crucial part of the development of VANET. This paper analyzes the disadvantage of existing broadcast routing protocols in VANETs, and proposes an improved algorithm (namely ODAM-C) based on the ODAM (Optimized Dissemination of Alarm Messages) protocol. The ODAM-C algorithm improves the packet delivery rate by two mechanisms based on the forwarding features of ODAM. The first distance-based mechanism reduces the possibility of packet loss by considering the angles between source nodes, forwarding nodes and receiving nodes. The second mechanism increases the redundancy of forwarding nodes to guarantee the packet success delivery ratio. We show by analysis and simulations that the proposed algorithm can improve packet delivery rate for vehicular networks compared against two widely-used existing protocols.

Compressive force regulates ephrinB2 and EphB4 in osteoblasts and osteoclasts contributing to alveolar bone resorption during experimental tooth movement

Jianhua Hou,Yanze Chen,Xiuping Meng,Ce Shi,Chen Li,Yuanping Chen,Hongchen Sun 대한치과교정학회 2014 대한치과교정학회지 Vol.44 No.6

Objective: To investigate the involvement of ephrinB2 in periodontal tissue remodeling in compression areas during orthodontic tooth movement and the effects of compressive force on EphB4 and ephrinB2 expression in osteoblasts and osteoclasts. Methods: A rat model of experimental tooth movement was established to examine the histological changes and the localization of ephrinB2 in compressed periodontal tissues during experimental tooth movement. RAW264.7 cells and ST2 cells, used as precursor cells of osteoclasts and osteoblasts, respectively, were subjected to compressive force in vitro. The gene expression of EphB4 and ephrinB2, as well as bone-associated factors including Runx2, Sp7, NFATc1, and calcitonin receptor, were examined by quantitative real-time polymerase chain reaction (PCR). Results: Histological examination of the compression areas of alveolar bone from experimental rats showed that osteoclastogenic activities were promoted while osteogenic activities were inhibited. Immunohistochemistry revealed that ephrinB2 was strongly expressed in osteoclasts in these areas. Quantitative real-time PCR showed that mRNA levels of NFATc1, calcitonin receptor, and ephrinB2 were increased significantly in compressed RAW264.7 cells, and the expression of ephrinB2, EphB4, Sp7, and Runx2 was decreased significantly in compressed ST2 cells. Conclusions: Our results indicate that compressive force can regulate EphB4 and ephrinB2 expression in osteoblasts and osteoclasts, which might contribute to alveolar bone resorption in compression areas during orthodontic tooth movement.

Necessary Experimental Conditions for Single-Shot Diffraction Imaging of DNA-Based Structures with X-ray Free-Electron Lasers

Sun, Zhibin,Fan, Jiadong,Li, Haoyuan,Liu, Huajie,Nam, Daewoong,Kim, Chan,Kim, Yoonhee,Han, Yubo,Zhang, Jianhua,Yao, Shengkun,Park, Jaehyun,Kim, Sunam,Tono, Kensuke,Yabashi, Makina,Ishikawa, Tetsuya,So American Chemical Society 2018 ACS NANO Vol.12 No.8

<P>It has been proposed that the radiation damage to biological particles and soft condensed matter can be overcome by ultrafast and ultraintense X-ray free-electron lasers (FELs) with short pulse durations. The successful demonstration of the “diffraction-before-destruction” concept has made single-shot diffraction imaging a promising tool to achieve high resolutions under the native states of samples. However, the resolution is still limited because of the low signal-to-noise ratio, especially for biological specimens such as cells, viruses, and macromolecular particles. Here, we present a demonstration single-shot diffraction imaging experiment of DNA-based structures at SPring-8 Angstrom Compact Free Electron Laser (SACLA), Japan. Through quantitative analysis of the reconstructed images, the scattering abilities of gold and DNA were demonstrated. Suggestions for extracting valid DNA signals from noisy diffraction patterns were also explained and outlined. To sketch out the necessary experimental conditions for the 3D imaging of DNA origami or DNA macromolecular particles, we carried out numerical simulations with practical detector noise and experimental geometry using the Linac Coherent Light Source (LCLS) at the SLAC National Accelerator Laboratory, USA. The simulated results demonstrate that it is possible to capture images of DNA-based structures at high resolutions with the technique development of current and next-generation X-ray FEL facilities.</P> [FIG OMISSION]</BR>

Secure and Efficient Conjunctive Keyword Search Scheme without Secure Channel

( Jianhua Wang ),( Zhiyuan Zhao ),( Lei Sun ),( Zhiqiang Zhu ) 한국인터넷정보학회 2019 KSII Transactions on Internet and Information Syst Vol.13 No.5

Conjunctive keyword search encryption is an important technique for protecting sensitive data that is outsourced to cloud servers. However, the process of searching outsourced data may facilitate the leakage of sensitive data. Thus, an efficient data search approach with high security is critical. To solve this problem, an efficient conjunctive keyword search scheme based on ciphertext-policy attribute-based encryption is proposed for cloud storage environment. This paper proposes an efficient mechanism for removing the secure channel and resisting off-line keyword-guessing attacks. The storage overhead and the computational complexity are regardless of the number of keywords. This scheme is proved adaptively secure based on the decisional bilinear Diffie-Hellman assumption in the standard model. Finally, the results of theoretical analysis and experimental simulation show that the proposed scheme has advantages in security, storage overhead and efficiency, and it is more suitable for practical applications.

한반도에서 발생하는 밴드형 대류계의 발달기구

이태영,Sun Jianhua 한국기상학회 2001 대기 Vol.11 No.3

Overexpression and characterization of a novel cold-adapted and salt-tolerant GH1 β-glucosidase from the marine bacterium Alteromonas sp. L82

Jingjing Sun,Wei Wang,Congyu Yao,Fangqun Dai,Xiangjie Zhu,Junzhong Liu,Jianhua Hao 한국미생물학회 2018 The journal of microbiology Vol.56 No.9

A novel gene (bgl) encoding a cold-adapted β-glucosidase was cloned from the marine bacterium Alteromonas sp. L82. Based on sequence analysis and its putative catalytic conserved region, Bgl belonged to the glycoside hydrolase family 1. Bgl was overexpressed in E. coli and purified by Ni2+ affinity chromatography. The purified recombinant β- glucosidase showed maximum activity at temperatures between 25°C to 45°C and over the pH range 6 to 8. The enzyme lost activity quickly after incubation at 40°C. Therefore, recombinant β-glucosidase appears to be a cold-adapted enzyme. The addition of reducing agent doubled its activity and 2 M NaCl did not influence its activity. Recombinant β-glucosidase was also tolerant of 700 mM glucose and some organic solvents. Bgl had a Km of 0.55 mM, a Vmax of 83.6 U/mg, a kcat of 74.3 s-1 and kcat/Km of 135.1 at 40°C, pH 7 with 4-nitrophenyl-β-D-glucopyranoside as a substrate. These properties indicate Bgl may be an interesting candidate for biotechnological and industrial applications.

Experimental and numerical analyses on axial cyclic behavior of H-section aluminium alloy members

Jinzhi Wu,Jianhua Zheng,Guojun Sun,Xinquan Chang 국제구조공학회 2022 Structural Engineering and Mechanics, An Int'l Jou Vol.81 No.1

This paper considers the combination of cyclic and axial loads to investigate the hysteretic performance of Hsection 6061-T6 aluminum alloy members. The hysteretic performance of aluminum alloy members is the basis for the seismic performance of aluminum alloy structures. Despite the prevalence of aluminum alloy reticulated shells structures worldwide, research into the seismic performance of aluminum alloy structures remains inadequate. To address this deficiency, we design and conduct cyclic axial load testing of three H-section members based on a reliable testing system. The influence of slenderness ratios and bending direction on the failure form, bearing capacity, and stiffness degradation of each member are analyzed. The experiment results show that overall buckling dominates the failure mechanism of all test members before local buckling occurs. As the load increases after overall buckling, the plasticity of the member develops, finally leading to local buckling and fracture failure. The results illustrate that the plasticity development of the local buckling position is the main reason for the stiffness degradation and failure of the member. Additionally, with the increase of the slenderness ratio, the energy-dissipation capacity and stiffness of the member decrease significantly. Simultaneously, a finite element model based on the Chaboche hybrid strengthening model is established according to the experiment, and the rationality of the constitutive model and validity of the finite element simulation method are verified. The parameter analysis of twenty-four members with different sections, slenderness ratios, bending directions, and boundary conditions are also carried out. Results show that the section size and boundary condition of the member have a significant influence on stiffness degradation and energy dissipation capacity. Based on the above, the appropriate material constitutive relationship and analysis method of H-section aluminum alloy members under cyclic loading are determined, providing a reference for the seismic design of aluminum alloy structures.

A Novel Robust Neural Network Sliding-Mode Control Method for Synchronizing Fractional Order Chaotic Systems in the Presence of Uncertainty, Disturbance and Time-Varying Delay

Gu Yan,Sun Jianhua,Fu Xiuwei 대한전기학회 2023 Journal of Electrical Engineering & Technology Vol.18 No.2

Given the importance of synchronization in chaotic systems, this paper presents a new approach to achieve this goal. Simultaneous consideration of time-varying delays, disturbances, uncertainties, and nonlinear terms in a fractional order chaotic system poses a fundamental challenge for achieving the synchronization goal and this paper presents a novel complex approach resulting from neural network and sliding mode approaches to overcome it. The Chebyshev neural network has been used to estimate the delayed nonlinear functions as well as the uncertain parts of the fractional order chaotic system, and the robust sliding mode technique has been considered to ensure stability against the effects of multiple inconveniences. Finally, simulation and comparison in MATLAB environment confirms the efficiency and ability of the proposed scheme in achieving the goal of robust synchronization despite the uncertainty, variable time delay, disturbance and nonlinear terms.

Application of ATOVS Microwave Radiance Assimilation to Rainfall Prediction in summer 2004

Linlin Qi,Jianhua Sun 한국기상학회 2006 한국기상학회 학술대회 논문집 Vol.2006 No.-

Study of Boiler NOx Emission Model Based on Improved Deep Learning and Genetic Algorithm

Mingzhu LU,Jianhua GANG,Haiyi SUN,Wei ZHENG 보안공학연구지원센터 2016 International Journal of u- and e- Service, Scienc Vol.9 No.12

Boiler efficiency and emission load of NOX are the key evaluation indicators of operation performance of the coal-fired boiler. It has become a popular academic research topic concerning the reduction of NOX emissions while maintaining the same boiler efficiency, as well as how to build a model for boiler emission. Based on a prediction model that is constructed for boiler efficiency and emission load of NOX with the application of deep belief algorithm, genetic algorithm is used to optimize the tilting angel of boiler burners and the flow velocity of pulverized coal, thereby effectively reducing the emission load of NOX. Simulation results indicate that this method effectively optimizes the parameters of the boiler, and provides a new way to optimize the parameters of the boiler.