Design and Implementation of iOS-based Mobile Application about Awakening by CNR

Canlin Li,Baohua Jin,Wenjie Cao 보안공학연구지원센터 2014 International Journal of u- and e- Service, Scienc Vol.7 No.6

With the growing popularity of the iPhone, there is a constantly increasing demand of users for mobile applications of iPhone, in which the alarm clock application is contained. But existing alarm clock application is not favored by many users because of functional singleness. This paper presents an iOS-based mobile application on alarm clock with online radio support, and designs and implements its framework by virtue of Objective-C and SQLite in the Xcode 4.5.2 development environment, based on the popular three-tier MVC software design structure. After the application is installed and deployed on iPhone, it is available to users by providing some functions such as auto-playing radio, setting radio alarm clock, turning off the alarm by shaking iPhone, sleeping timer by radio, reserving radio program, binding and sharing microblog. This proposed iOS-based mobile application provides users with more choices and allows the user to enjoy a more colorful leisure time. The practical test from some people shows that the proposed application is very popular with users, which also illustrates its practicability and effectiveness.

The Design of All Fiber Laser Heterodyne Detection System

Cao Miao,Cui Wenjie,Yao Qinghua 보안공학연구지원센터 2016 International Journal of Signal Processing, Image Vol.9 No.5

The traditional method of heterodyne detection is improved in this paper based on the principle of laser heterodyne detection. The laser heterodyne detection system is designed with all-fiber laser radar in all fiber system, and the laser, the optical system, the receiving device and so on are connected via the passive component. The system can mix the local oscillation light with signal light of measured object information in the photodetector surface, and the difference frequency signal is obtained. Then the signal is filtered and amplified by the signal processing technique to eliminate the DC component, and the desired difference frequency signal is obtained. Through the analysis of the performance of all fiber laser heterodyne detection system, the system has a strong ability to detect weak signal, high conversion gain and signal to noise ratio, and has a good filtering effect. The system is very suitable for the application of laser ranging and so on.

Flexural Performance of Steel Reinforced ECC-Concrete Composite Beams Subjected to Freeze-Thaw Cycles

Wenjie Ge,Ashraf F. Ashour,Weigang Lu,Dafu Cao 한국콘크리트학회 2020 International Journal of Concrete Structures and M Vol.14 No.2

Experimental and theoretical investigations on the flexural performance of steel reinforced ECC-concrete composite beams subjected to freeze-thaw cycles are presented in this paper. Four groups of reinforced composite beams with different ECC height replacement ratios subject to 0, 50, 100 and 150 cycles of freeze-thaw were physically tested to failure. Experimental results show that the bending capacity decreases with the increase of freeze-thaw cycles regardless of ECC height replacement ratios. However, the ultimate moment, stiffness and durability of ECC specimens and ECC-concrete composite specimens are greater than those of traditional concrete specimens, owing to the excellent tensile performance of ECC materials. With the increase of ECC height, the crack width and average crack spacing gradually decrease. According to materials’ constitutive models, compatibility and equilibrium conditions, three failure modes with two boundary failure conditions are proposed. Simplified formulas for the moment capacity are also developed. The results predicted by the simplified formulas show good agreement with the experimental moment capacity and failure modes. A parametric analysis is conducted to study the influence of strength and height of ECC, amount of reinforcement, concrete strength and cycles of freeze-thaw on moment capacity and curvature ductility of ECC-concrete composite beams.

The Study on the MRTD Measurement System of Medical Infrared Thermal Imager Based on Sub-Pixel Edge Detection Algorithm

Cao Miao,Cui Wenjie,Yao qinghua 보안공학연구지원센터 2016 International Journal of Multimedia and Ubiquitous Vol.11 No.7

MRTD (minimum resolvable temperature difference) is an important parameter to evaluate the infrared thermal imager. MRTD is not only related to the spatial resolution of the system, but also to many factors such as optical system, detector array and so on. The measurement technique and principle of the medical infrared thermal imager’s MRTD is deeply analyzed, and the MRTD measurement model is established in this paper. The MRTD measurement system of infrared thermal imager based on CCD imaging technology is designed. CCD is used to carry on the interpretation of temperature difference in this system instead of the human eye, which can avoid the effect of some factors on the subjective image quality evaluation, such as the contrast, the human interference flaw and so on. The sub-pixel edge detection algorithm is used to deal with the four-bar target image, which can effectively suppress the interface of the random noise on four-bar target image. The experimental results show that the MRTD testing accuracy of the system can reach 0.055℃.

Research on NETD Test System of Medical Infrared Thermal Imager Based on CCD Imaging Technology

Miao Cao,Wenjie Cui 보안공학연구지원센터 2016 International Journal of Multimedia and Ubiquitous Vol.11 No.3

Under the conditions that the target and background are bold and the transmission loss in atmosphere between systems is neglected, the SNR of the thermal imaging system, the radiation flux of the target and the NETD expression are derived. On this basis, the NETD test system of the modern infrared thermal imager is studied. The system is constructed by a Newton type reflecting parallel light tube, and the off-axis parabolic reflector is as the main body, which provides infinity infrared observation target for infrared thermal imager being tested. The target is composed of the infrared reticle located at the focus of off-axis parabolic reflector and the high precision temperature blackbody at the back of the reticle. The image of infinity infrared target is displayed on its own screen by the infrared thermal imager. CCD shoots the screen of infrared thermal imager, and NETD value is obtained by processing the camera's video signal. The experimental results show that the accuracy of NETD synthesis can reach 0.03℃ in this paper.

Study on the Measurement Technique of the Alignment Variation of Medical Infrared Thermal Imaging System

Miao Cao,Wenjie Cui 보안공학연구지원센터 2016 International Journal of Smart Home Vol.10 No.1

The change cause of the thermal imager alignment and its detection principle are analyzed in this paper. On this basis, an infrared thermal imaging is designed for the shortcomings of the traditional detection method, that alignment change detection system is based on CCD imaging technology. The cross pinhole target is used to establish the measurement space coordinate system for the digital image interpretation program in this system. The interpretation software is called about aiming at the baseline variation in the data processing system. According to the position relationship of the 5 pin hole in the field of the infrared thermal imager, the alignment change can be measured. The experimental results show that the system can effectively test the change in the baseline of the thermal imager, and the uncertainty of the test is better than 0.05mil.

The Study of aDigital Equivalent Capacitor Circuit

QingHua Shang,Wenjie Cao,Zhen Huang,Xiaoqing Zhang 보안공학연구지원센터 2014 International Journal of Hybrid Information Techno Vol.7 No.3

Power Quality Optimal Control of Railway Static Power Conditioners Based on Electric Railway Power Supply Systems

Youhua Jiang,Wenji Wang,Xiangwei Jiang,Le Zhao,Yilong Cao 전력전자학회 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.5

Aiming at the negative sequence and harmonic problems in the operation of railway static power conditioners, an optimization compensation strategy for negative sequence and harmonics is studied in this paper. First, the hybrid RPC topology and compensation principle are analyzed to obtain different compensation zone states and current capacities. Second, in order to optimize the RPC capacity configuration, the minimum RPC compensation capacity is calculated according to constraint conditions, and the optimal compensation coefficient and compensation angle are obtained. In addition, the voltage unbalance EU and power factor requirements are satisfied. A PSO (Particle Swarm Optimization) algorithm is used to calculate the three indexes for minimum compensating energy. The proposed method can precisely calculate the optimal compensation capacity in real time. Finally, MATLAB simulations and an experimental platform verify the effectiveness and economics of the proposed algorithm.

Power Quality Optimal Control of Railway Static Power Conditioners Based on Electric Railway Power Supply Systems

Jiang, Youhua,Wang, Wenji,Jiang, Xiangwei,Zhao, Le,Cao, Yilong The Korean Institute of Power Electronics 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.5

Aiming at the negative sequence and harmonic problems in the operation of railway static power conditioners, an optimization compensation strategy for negative sequence and harmonics is studied in this paper. First, the hybrid RPC topology and compensation principle are analyzed to obtain different compensation zone states and current capacities. Second, in order to optimize the RPC capacity configuration, the minimum RPC compensation capacity is calculated according to constraint conditions, and the optimal compensation coefficient and compensation angle are obtained. In addition, the voltage unbalance ${\varepsilon}_U$ and power factor requirements are satisfied. A PSO (Particle Swarm Optimization) algorithm is used to calculate the three indexes for minimum compensating energy. The proposed method can precisely calculate the optimal compensation capacity in real time. Finally, MATLAB simulations and an experimental platform verify the effectiveness and economics of the proposed algorithm.

The Stabilizing Role of Cyclodextrins on Keggin Phosphotungstic Acid by Complexation Unveiled by Electrospray Mass Spectrometry

( Yanxuan Fan ),( Yan Zhang ),( Qiaodi Jia ),( Jie Cao ),( Wenjie Wu ) 한국질량분석학회 2015 Mass spectrometry letters Vol.6 No.1

This study demonstrated the stabilizing role of a cyclodextrin on Keggin [PW12O40]3- via hydrogen bonding complexation unveiled by ESI-MS. The distinctive fragmentation pathways of the {PW12}/γ-CD complexes from that of discrete [PW12O40]3- showed that the so-called “weak” non-covalent interactions can effectively change the dissociation chemistry of POM in the gas phase. The influence of different types of solvents and organic additives such as γ-CD on the stability of Keggin [PW12O40]3- was also addressed firstly by ESI-MS.