A novel, reversible, Chinese text information hiding scheme based on lookalike traditional and simplified Chinese characters

( Bin Feng ),( Zhi-hui Wang ),( Duo Wang ),( Ching-yun Chang ),( Ming-chu Li ) 한국인터넷정보학회 2014 KSII Transactions on Internet and Information Syst Vol.8 No.1

Compared to hiding information into digital image, hiding information into digital text file requires less storage space and smaller bandwidth for data transmission, and it has obvious universality and extensiveness. However, text files have low redundancy, so it is more difficult to hide information in text files. To overcome this difficulty, Wang et al. proposed a reversible information hiding scheme using left-right and up-down representations of Chinese characters, but, when the scheme is implemented, it does not provide good visual steganographic effectiveness, and the embedding and extracting processes are too complicated to be done with reasonable effort and cost. We observed that a lot of traditional and simplified Chinese characters look somewhat the same (also called lookalike), so we utilize this feature to propose a novel information hiding scheme for hiding secret data in lookalike Chinese characters. Comparing to Wang et al.`s scheme, the proposed scheme simplifies the embedding and extracting procedures significantly and improves the effectiveness of visual steganographic images. The experimental results demonstrated the advantages of our proposed scheme.

PCIA 클라우드 서비스 모델링 및 자원 구성에 따른 성능 영향도 분석

윤빈풍(Binfeng Yin),곽종욱(Jong Wook Kwak) 한국컴퓨터정보학회 2014 韓國컴퓨터情報學會論文誌 Vol.19 No.2

클라우드 컴퓨팅은 융통성 있는 연산능력과 대량의 데이터를 분석하는 효과적인 환경을 제공한다. 본 논문에서는 공용 클라우드를 위한 새로운 타입의 자원 배치 구조를 정의하고 이를 PCIA라고 명명한다. 아울러, PCIA 구조에서 서비스 모델에 대해 소개하며, 이를 위한 클라우드 명명 기법도 제시한다. 제안된 클라우드 시스템은 어플리케이션의 다양한 특징에 따라 사용자의 가상 자원 요구에 기반하는 적절한 물리적 자원을 선택하게 된다. 이를 통해 자원 제공의 변화에 따른 성능 변화의 연관성 및 클라우드 시스템의 효과적 구축을 위한 시스템 구성 요소의 영향도를 분석하며, 클라우드 서비스 제공자와 사용자 양쪽 모두에게 중요한 리소스 프로비져닝의 주요 기준을 제시한다. Cloud computing provides flexible and efficient mass data analysis platform. In this paper, we define a new resource provisioning architecture in the public cloud, named PCIA. In addition, we provide a service model of PCIA and its new naming scheme. Our model selects the proper number of physical or virtual resources based on the requirements of clients. By the analysis of performance variation in the PCIA, we evaluate the relationship between performance variation and resource provisioning, and we present key standards for cloud system constructions, which can be an important resource provisioning criteria for both cloud service providers and clients.

An enzyme-mediated competitive colorimetric sensor based on Au@Ag bimetallic nanoparticles for highly sensitive detection of disease biomarkers

Yin, Binfeng,Zheng, Wenshu,Dong, Mingling,Yu, Wenbo,Chen, Yiping,Joo, Sang Woo,Jiang, Xingyu The Royal Society of Chemistry 2017 The Analyst Vol.142 No.16

<P>We developed a competitive colorimetric nanosensor based on Au@Ag bimetallic nanoparticles for the detection of interleukin-6 (IL-6) in clinical samples. Antibody-conjugated magnetic nanoparticles (MNPs) and polystyrene (PS) microparticles conjugated with both catalase and a secondary antibody can form sandwich structures that enable one-step target enrichment and separation. The catalase on the surface of the PS can catalyze the hydrolysis of hydrogen peroxide (H2O2) to regulate the deposition of Ag<SUP>+</SUP> on the surface of gold nanoparticles (AuNPs), and forms different sizes and amounts of Au@Ag bimetallic nanoparticles (Au@AgNPs) which produce a distinct color signal for readout with the naked eye. Our sensor features high sensitivity, selectivity, reproducibility and anti-interference property as a result of comprehensive parameter optimization. The limit of detection of IL-6 can reach 11 pg mL<SUP>−1</SUP> with the naked eye and 1.2 pg mL<SUP>−1</SUP> by quantitative instrumental analysis. The whole analysis can be finished within 1 h. More importantly, we successfully apply our platform or the detection of IL-6 in clinical samples with better accuracy than conventional enzyme-linked immunosorbent assay (ELISA).</P>

One-step multiplexed detection of foodborne pathogens: Combining a quantum dot-mediated reverse assaying strategy and magnetic separation

Yin, Binfeng,Wang, Yu,Dong, Mingling,Wu, Jing,Ran, Bei,Xie, Mengxia,Joo, Sang Woo,Chen, Yiping Elsevier 2016 Biosensors & bioelectronics Vol.86 No.-

<P><B>Abstract</B></P> <P>A rapid and multiplexed immunosensor was developed based on a quantum dot (QD)-reverse assaying strategy (RAS) and immuno-magnetic beads (IMBs) for one-step and simultaneous detection of <I>Escherichia coli O157: H7</I> and <I>Salmonella</I>. In a conventional QD-based immunosensor, the fluorescence signal of the “IMBs-target-QD” immunoconjugate is directly used as the assaying readout. However, the fluorescence signal is affected by IMBs due to light scattering and the “IMBs-target-QD” immunoconjugate needs multiple washing and re-suspension steps. To address these problems, we use the surplus QD-antibody conjugate as signal readout in the RAS, which prevents interference from the IMBs, increases the fluorescence signal, and avoids complex operations. Compared with conventional QD-based immunosensor, the sensitivity of QD-RSA immunosensor for detection of <I>Escherichia coli O157: H7</I> has been improved fifty-fold, and whole analysis procedure can be finished within 1h. Therefore, this RSA strategy is promising for improving the performance of QD-based immunosensors and could greatly broaden their applications.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The immunosensor based on quantum dot-reverse assaying strategy (QD-RAS) was developed. </LI> <LI> The sensitivity of QD-RAS improved 50 times compared to conventional QDs-immunosensor. </LI> <LI> The whole analysis in QD-RAS can be finished in one-step within 1h. </LI> </UL> </P>

Current Harmonics Rejection and Improvement of Inverter-Side Current Control for the LCL Filters in Grid-Connected Applications

Jinming Xu,Shaojun Xie,Binfeng Zhang 전력전자학회 2017 JOURNAL OF POWER ELECTRONICS Vol.17 No.6

For grid-connected LCL-filtered inverters, the inverter-side current can be used as the control object with one current sensor for both LCL resonance damping and over-current protection, while the grid-voltage feedforward or harmonic resonant compensator is used for suppressing low-order grid current harmonics. However, it was found that the grid current harmonics were high and often beyond the standard limitations with this control. The limitations of the inverter-side current control in suppressing low-order grid current harmonics are analyzed through inverter output impedance modeling. No matter which compensator is used, the maximum magnitudes of the inverter output impedance at lower frequencies are closely related to the LCL parameters and are decreased by increasing the control delay. Then, to improve the grid current quality without complicating the control or design, this study proposes designing the filter capacitance considering the current harmonic constraint and using a PWM mode with a short control delay. Test results have confirmed the limitation and verified the performance of the improved approaches.

Stability Analysis and Improvement of the Capacitor Current Active Damping of the LCL Filters in Grid-Connected Applications

Jinming Xu,Shaojun Xie,Binfeng Zhang 전력전자학회 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.4

For grid-connected LCL-filtered inverters, dual-loop current control with an inner-loop active damping (AD) based on capacitor current feedback is generally used for the sake of current quality. However, existing studies on capacitor current feedback AD with a control delay do not reveal the mathematical relation among the dual-loop stability, capacitor current feedback factor, delay time and LCL parameters. The robustness was not investigated through mathematical derivations. Thus, this paper aims to provide a systematic study of dual-loop current control in a digitally-controlled inverter. At first, the stable region of the inner-loop AD is derived. Then, the dual-loop stability and robustness are analyzed by mathematical derivations when the inner-loop AD is stable and unstable. Robust design principles for the inner-loop AD feedback factor and the outer-loop current controller are derived. Most importantly, ensuring the stability of the inner-loop AD is critical for achieving high robustness against a large grid impedance. Then, several improved approaches are proposed and synthesized. The limitations and benefits of all of the approaches are identified to help engineers apply capacitor current feedback AD in practice.

Research on Stability of Grid-Connected LCL-Filtered Inverter with Capacitor Current Feedback Active Damping Control

Jinming Xu,Shaojun Xie,Jiarong Kan,Binfeng Zhang 전력전자학회 2015 ICPE(ISPE)논문집 Vol.2015 No.6

For grid-connected LCL-filtered inverter, the inherent resonance of LCL filter endangers the stability so that the inverter is hard to be controlled. To solve the resonance, the capacitor-current-feedback active damping (AD) is welcomed. However, the digital control delay was not seriously considered in the previous studies. The research on the stability with such control considering the digital control delay is lacking. Thus, this paper aims to provide a deep analysis of the capacitor-current-feedback AD in a digitally-controlled inverter. A stable region is derived. It is proved that the stable region for the capacitor-current- feedback AD is closely related to the sampling and computation delay, the control frequency, the resonance frequency and the capacitor-current-feedback factor. Several suitable approaches are then proposed to improve the performance with the capacitor-current-feedback AD. The experimental results verify the presented research.

Stability Analysis and Improvement of the Capacitor Current Active Damping of the LCL Filters in Grid-Connected Applications

Xu, Jinming,Xie, Shaojun,Zhang, Binfeng The Korean Institute of Power Electronics 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.4

For grid-connected LCL-filtered inverters, dual-loop current control with an inner-loop active damping (AD) based on capacitor current feedback is generally used for the sake of current quality. However, existing studies on capacitor current feedback AD with a control delay do not reveal the mathematical relation among the dual-loop stability, capacitor current feedback factor, delay time and LCL parameters. The robustness was not investigated through mathematical derivations. Thus, this paper aims to provide a systematic study of dual-loop current control in a digitally-controlled inverter. At first, the stable region of the inner-loop AD is derived. Then, the dual-loop stability and robustness are analyzed by mathematical derivations when the inner-loop AD is stable and unstable. Robust design principles for the inner-loop AD feedback factor and the outer-loop current controller are derived. Most importantly, ensuring the stability of the inner-loop AD is critical for achieving high robustness against a large grid impedance. Then, several improved approaches are proposed and synthesized. The limitations and benefits of all of the approaches are identified to help engineers apply capacitor current feedback AD in practice.

Current Harmonics Rejection and Improvement of Inverter-Side Current Control for the LCL Filters in Grid-Connected Applications

Xu, Jinming,Xie, Shaojun,Zhang, Binfeng The Korean Institute of Power Electronics 2017 JOURNAL OF POWER ELECTRONICS Vol.17 No.6

For grid-connected LCL-filtered inverters, the inverter-side current can be used as the control object with one current sensor for both LCL resonance damping and over-current protection, while the grid-voltage feedforward or harmonic resonant compensator is used for suppressing low-order grid current harmonics. However, it was found that the grid current harmonics were high and often beyond the standard limitations with this control. The limitations of the inverter-side current control in suppressing low-order grid current harmonics are analyzed through inverter output impedance modeling. No matter which compensator is used, the maximum magnitudes of the inverter output impedance at lower frequencies are closely related to the LCL parameters and are decreased by increasing the control delay. Then, to improve the grid current quality without complicating the control or design, this study proposes designing the filter capacitance considering the current harmonic constraint and using a PWM mode with a short control delay. Test results have confirmed the limitation and verified the performance of the improved approaches.

A High-speed Atomic Force Microscope for Precision Measurement of Microstructured Surfaces

Yuguo Cui,Yoshikazu Arai,Takemi Asai,BinFeng Ju,Wei Gao 한국정밀공학회 2008 International Journal of Precision Engineering and Vol.9 No.3

This paper describes a contact atomic force microscope (AFM) that can be used for high-speed precision measurements of microstructured surfaces. The AFM is composed of an air-bearing X stage, an air-bearing spindle with the axis of rotation in the Z direction, and an AFM probe unit. The traversing distance and maximum speed of the X stage are 300 ㎜ and 400 ㎜/s, respectively. The spindle has the ability to hold a sample in a vacuum chuck with a maximum diameter of 130 ㎜ and has a maximum rotation speed of 300 rpm. The bandwidth of the AFM probe unit in an open loop control circuit is more than 40 ㎑. To achieve precision measurements of microstructured surfaces with slopes, a scanning strategy combining constant height measurements with a slope compensation technique is proposed. In this scanning strategy, the Z direction PZT actuator of the AFM probe unit is employed to compensate for the slope of the sample surface while the microstructures are scanned by the AFM probe at a constant height. The precision of such a scanning strategy is demonstrated by obtaining profile measurements of a microstructure surface at a series of scanning speeds ranging from 0.1 to 20.0 ㎜/s.