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Quantum Cryptanalysis of Multivariate Permutation Problem
Guodong Sun,Shenghui Su,Maozhi Xu 보안공학연구지원센터 2014 International Journal of Security and Its Applicat Vol.8 No.6
Quantum computation is a new computational model based on quantum mechanical principle. Shor invented the polynomial time algorithms for the prime factorization and discrete logarithm problem, which indicated that the cryptosystems based on them are totally unsafe in the quantum world. Grover constructed an algorithm that finds a solution in only O(2n)steps whereas the exhaustive search algorithm needs O(2n) steps on average. In this paper we investigate the cryptanalysis of a new cryptography problem----multivariate permutation problem (MPP), which could be used to design public-key cryptosystem, with the help of the two quantum algorithms. Specially, we discuss the strength of a private key of the REESSE1+ public-key cryptosystem, whose security is based on the hardness of MPP. Besides, some suggestions are also given about the implementation of the REESSE1+.
Recognizing Comparative Sentences from Chinese Review Texts
Wei Wang,TieJun Zhao,GuoDong Xin,YongDong Xu 보안공학연구지원센터 2014 International Journal of Database Theory and Appli Vol.7 No.5
Comparisons play an important role in making decisions by referring to the comparative opinions of opinion holders in earlier customer reviews. Recognizing comparative sentences from review texts contributes to opinion mining and information recommendation. Our objective is to automatically recognize comparative sentences from Chinese text documents. In this paper, an effective approach is proposed based on comparative patterns to recognize comparative sentences in Chinese. Our experiments on customer-generated product reviews show that the proposed approach is effective.
Guodong Chen,Miao Zhu,Xu Cai 전력전자학회 2014 JOURNAL OF POWER ELECTRONICS Vol.14 No.1
The cascaded H-Bridge Dynamic Voltage Restorer (DVR) is used for protecting high voltage and large capacity loads from voltage sags. The LC filter in the DVR is needed to eliminate switching ripples, which also provides an accurate tracking feature in a certain frequency range. Therefore, the parameter optimization of the LC filter is especially important. In this paper, the value range functions for the inductance and capacitance in LC filters are discussed. Then, parameter variations under different conditions of voltage sags and power factors are analyzed. In addition, an optimized design method is also proposed with the consideration of multiple impact factors. A detailed optimization procedure is presented, and its validity is demonstrated by simulation and experimental results. Both results show that the proposed method can improve the LC filter design for a cascaded H-Bridge DVR and enhance the performance of the whole system.
Guodong Zhang,Yang Xu,Peng Jin,Zhiyong Xie,Gang Sun 대한비뇨의학회 2013 Investigative and Clinical Urology Vol.54 No.12
Purpose: The aim of this research was to evaluate the efficacy of the cystoscopic extraction and external drainage techniques for unsuccessful antegrade stenting in transplanted severe ureteral obstruction. Materials and Methods: A total of 26 patients with severe transplanted ureteral obstruction in whom the cystoscopic extraction technique and/or external drainage technique was performed were retrospectively evaluated. After the severe obstruction was successfully traversed, balloon dilatation followed by double-J stent insertion was performed. Results: Of the 26 patients (male:female, 9:4; mean age, 38.1 years) who underwent failed ureteral stenting with the conventional procedure, 16 patients underwent successful stenting with the cystoscopic extraction technique, and 10 patients underwent successful stenting following external drainage. The mean serum creatinine of the 26 patients before stenting was 42.9 mg/dL (range, 32.7 to 54.1 mg/dL), which decreased to 10.3 mg/dL (range, 8.7 to 11.8 mg/dL) after stenting. The complications of the procedure were lower abdominal pain in 22 patients and gross hematuria in 9 patients. All complications were relieved with medical care within 3 to 5 days after the procedure. No major complications occurred. Conclusions: The cystoscopic extraction technique and external drainage technique are safe and useful for traversing a severe transplanted ureteral obstruction after a failed conventional procedure.
Chen, Guodong,Zhu, Miao,Cai, Xu The Korean Institute of Power Electronics 2014 JOURNAL OF POWER ELECTRONICS Vol.14 No.1
The cascaded H-Bridge Dynamic Voltage Restorer (DVR) is used for protecting high voltage and large capacity loads from voltage sags. The LC filter in the DVR is needed to eliminate switching ripples, which also provides an accurate tracking feature in a certain frequency range. Therefore, the parameter optimization of the LC filter is especially important. In this paper, the value range functions for the inductance and capacitance in LC filters are discussed. Then, parameter variations under different conditions of voltage sags and power factors are analyzed. In addition, an optimized design method is also proposed with the consideration of multiple impact factors. A detailed optimization procedure is presented, and its validity is demonstrated by simulation and experimental results. Both results show that the proposed method can improve the LC filter design for a cascaded H-Bridge DVR and enhance the performance of the whole system.
DISTRIBUTED FORMATION CONTROL OF HOMOGENEOUS VEHICLE PLATOON CONSIDERING VEHICLE DYNAMICS
Liwei Xu,Weichao Zhuang,Guodong Yin,Chentong Bian 한국자동차공학회 2019 International journal of automotive technology Vol.20 No.6
Vehicle dynamics plays a significant role on the formation of a vehicle platoon, especially at high speed condition. This paper proposes a distributed platoon formation framework for homogeneous autonomous vehicles which takes the vehicle dynamics into consideration. The boundaries of vehicle stability are firstly calculated by considering both lateral dynamics and actuator saturation. By combining the stability boundaries with multi-objective flocking (MOF) algorithm, a distributed formation controller is designed, which can form the vehicle platoon with high cruising speed steadily and rapidly. In addition, a low-level tracking controller is proposed to constitute a hierarchical control architecture which can achieve stable and accurate formation of platoon. Simulation results show the proposed platoon formation controller achieves safe, stable and rapid platoon formation than the traditional MOF-based formation controller which does not consider the vehicle dynamics.
Jing Xu,Guodong Liu,Jiadi Lian,Jing Ni,Jing Xiao 한국물리학회 2018 Current Applied Physics Vol.18 No.11
In this paper, forced vibration was used to regulate the droplet migration, fully recording the transient migration of droplets on a micro-textured substrate under the resonance frequency by a high-speed camera. The influence of resonance frequency and dynamic migration characteristics of droplets on the solid micro-texture surface under lateral vibration were researched. The experiment demonstrates that the driving force is caused by the difference between the left and right contact angles made the droplet oscillate and migrate, and as time t increases, the left and right contact points are periodically shifted and the amplitude of migration increases. Therefore, based on the droplet migration behavior and its force balance mechanism, a spring vibration model of migration behavior of the vibrating droplet micro unit was set up to predict the complete trajectory of its migration on a solid surface. The calculation results show that the theoretical displacement is less than the experimental displacement, and the longer the time, the larger the difference. Affected by the vibration, part of the droplet permeates through the micro-texture, resulting in the droplet losing height and the contact angle becoming smaller as well. While the other part of droplet overcomes the internal surface tension to migrate.
Yuanyuan Yan,Guodong Ding,Hui Xu 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.25 No.-
A selective and sensitive ‘‘naked-eye’’ rhodamine-based ‘‘turn-on’’ chemosensor for detection of Hg2+ ion over other metal ions such as Ni2+, Ca2+, Ba2+, Cs+, Fe3+, Mn2+, Cd2+, Zn2+, Mg2+, K+, Ag+, Hg2+, Co2+, and Pb2+ in aqueous solution was prepared. Meanwhile, a new method for the synthesis of rhodamine amide directly from rhodamine hydrazide in the presence of NaH was reported for the first time. It was observed that once Hg2+ ion was added to the sensor 4, a 91.4-fold enhancement of the absorption at 570 nm was observed. Its selectivity toward Hg2+ ion was very high, and little interference was detected for other commonly coexistent metal ions. The fluorescent intensity was almost a constant minimal value when pH = 5–8 in aqueous solution. It demonstrated that Hg2+ could be detected at least down to 3 108 M. Moreover, the Hg2+-promoted selective desulfurization reaction was further confirmed by MS spectra. The present probe could be used to determine Hg2+ ion concentrations in aqueous environments.