Gen2-Based Tag Anti-collision Algorithms Using Chebyshev’s Inequality and Adjustable Frame Size

Xiao Fan,InChan Song,장경희,Dong-Beom Shin,Heyung-Sub Lee,Cheol-Sig Pyo,Jong-Suk Chae 한국전자통신연구원 2008 ETRI Journal Vol.30 No.5

Arbitration of tag collision is a significant issue for fast tag identification in RFID systems. A good tag anticollision algorithm can reduce collisions and increase the efficiency of tag identification. EPCglobal Generation-2 (Gen2) for passive RFID systems uses probabilistic slotted ALOHA with a Q algorithm, which is a kind of dynamic framed slotted ALOHA (DFSA), as the tag anti-collision algorithm. In this paper, we analyze the performance of the Q algorithm used in Gen2, and analyze the methods for estimating the number of slots and tags for DFSA. To increase the efficiency of tag identification, we propose new tag anti-collision algorithms, namely, Chebyshev’s inequality, fixed adjustable framed Q, adaptive adjustable framed Q, and hybrid Q. The simulation results show that all the proposed algorithms outperform the conventional Q algorithm used in Gen2. Of all the proposed algorithms, AAFQ provides the best performance in terms of identification time and collision ratio and maximizes throughput and system efficiency. However, there is a tradeoff of complexity and performance between the CHI and AAFQ algorithms.

An Improved EPCglobal Gen2-based Anti-collision Algorithm by using Chebyshev's Inequality in Passive RFID Systems

Xiao Fan,InChan Song,KyungHi Chang 한국통신학회 2008 한국통신학회 학술대회 및 강연회 Vol.2008 No.4

Analysis of GPS Signal Acquisition Performance

Xiaofan LI,Dinesh MANANDHAR,Ryosuke SHIBASAKI 한국항해항만학회 2006 한국항해항만학회 학술대회논문집 Vol.2 No.-

Acquisition is to detect the presence of the GPS signal. Once the signal is detected, the estimated frequency and code phase are passed to a tracking loop to demodulate the navigation data. In order to detect the weak signal, multiple length of data integration is always needed. In this paper, we present five different acquisition approaches based on circular correlation and Fast Fourier Transform (FFT), using coherent as well as non-coherent integration techniques for the multiple length of collected GPS satellite signal. Moreover a general approach of determining the acquisition threshold is introduced based on noise distribution which has been proved effective, and independent of the hardware. In the end of this paper, the processing speed and acquisition gain of each method are illustrated, compared, and analyzed. The results show that coherent approach is much more time consuming compared to noncoherent approaches, and in the case of multiple length of data integration from 2ms to 8ms, the processing times consumed by the fastest non-coherent acquisition method are only 25.87% to 1.52% in a single search, and 34.76% to 1.06% in a global search of those in the coherent acquisition. However, coherent acquisition also demonstrates its better performance in the acquisition gain, and in the case of 8ms of data integration it is 4.23 to 4.41 dB higher than that in the non-coherent approaches. Finally, an applicable scheme of combining coherent and non-coherent acquisition approaches in the development of a real-time Software GPS receiver in the University of Tokyo is provided.

Experimental Study on Dynamic Water Grouting of Modified Water-Soluble Polyurethane

Xiaofan Liu,Junguang Wang,Kun Huang,Fengyun Li 대한토목학회 2019 KSCE Journal of Civil Engineering Vol.23 No.9

In underground project, water inrush disaster often occurs, resulting in a large number of casualties and economic losses. To solve these problems, grouting is one of the main techniques for controlling water inrush. At present, the research results on the treatment of water inrush by grouting are based on anhydrous or hydrostatic grouting. However, the study of dynamic water grouting is relatively few and the grouting materials are a little bit. In this paper, water-soluble polyurethane was selected as grouting material, modified by adding hydroxypropyl methyl cellulose, and the bond strength and microstructure change before and after modification are studied via bond strength experiment and microscopic observation. In addition, the WPU (water-soluble polyurethane) diffusion regularity of dynamic water grouting is studied by indoor flat grouting test. The research also adopts the Bingham fluid model according to the slurry characteristics to derive the grouting diffusion radius. The results show that the compactness of HPMC (hydroxypropyl methyl cellulose)-WPU is improved, the heterogeneity is reduced by 50.4%, and the bonding strength is increased by 153%. Therefore, the anti-scour ability of the HPMC-WPU is enhanced. The deviation of the WPU in the X-axis diffusion radius is 7.7 cm, and the HPMC-WPU is 4.39 cm. What’s more, the formula of grouting diffusion radius is derived. By comparing the formula with experiment results, the deviation is less than 15%, therefore, the formula has the significance of guiding engineering practice.

“One-Time” versus Staged Multivessel Intervention in Intermediate to Very High-Risk Patients with Non-ST-Segment Elevation Acute Coronary Syndromes

Xiaofan Yu,Yi Li,Qiancheng Wang,Ming Liang,Kai Xu,Yaling Han 대한심장학회 2016 Korean Circulation Journal Vol.46 No.6

Background and Objectives: To compare clinical outcomes of staged versus “one-time” percutaneous coronary intervention (PCI) in intermediate to very high-risk patients with non–ST-segment elevation acute coronary syndromes (NSTE-ACS) and multivessel coronary disease (MVD). Subjects and Methods: 1531 NSTE-ACS patients with multivessel PCI and meeting the criteria of intermediate to very high risk were screened from a prospectively registered database obtained from General Hospital of Shenyang Military Region between 2008 and 2012. They were categorized into “one-time” PCI (n=859) and staged PCI (n=672) according to intervention strategy. The primary outcomes included a 3-year major adverse cardiac event (MACE), a composite of cardiac death, myocardial infarction (MI), and target vessel revascularization. Results: At 3 years, no significant differences in MACE (20.8% vs. 19.7%, p=0.608) and cardiac death/MI (7.1% vs. 9.1%, p=0.129) were observed between the two groups. After propensity score matching, there was no statistical significance in MACE (18.9% vs. 21.8%, p=0.249); whereas cardiac death/MI was significantly lower in the staged PCI group (7.0% vs.11.1%, p=0.033). Ninety-day landmark analysis showed that the staged PCI group had a lower 90-day incidence of MACE (1.2% vs. 3.3%, p= 0.037) and cardiac death/MI (0.7% vs. 2.6%, p=0.031). For the 90-day to 3-year follow-up period, the incidences of MACE (17.9% vs. 19.1%, p=0.641) and cardiac death/MI (6.3% vs. 8.7%, p=0.191) were similar in both groups. Conclusion: In intermediate- to very high-risk NSTE-ACS patients with MVD, staged PCI is superior to “one-time” PCI in terms of cardiac death/MI.

Exponential Synchronization of Stochastic Memristive Recurrent Neural Networks Under Alternate State Feedback Control

Xiaofan Li,Jian-an Fang,Huiyuan Li 제어·로봇·시스템학회 2018 International Journal of Control, Automation, and Vol.16 No.6

This paper solves the exponential synchronization problem of two memristive recurrent neural networks with both stochastic disturbance and time-varying delays via periodically alternate state feedback control. First, a periodically alternate state feedback control rule is designed. Then, on the basis of the Lyapunov stability theory, some novel sufficient conditions guaranteeing exponential synchronization of drive-response stochastic memristive recurrent neural networks via periodically alternate state feedback control are derived. In contrast to some previous works about synchronization of memristive recurrent neural networks, the obtained results in this paper are not difficult to be validated, and complement, extend and generalize the earlier papers. Lastly, an illustrative example is provided to indicate the effectiveness and applicability of the obtained theoretical results.

Self-adjusting strategy based on rotating injection for sensorless control of high-power PMSM drives

Xiaofan Wang,Xiaochun Fang,Zhi Wang,Zhihong Zhong,Yizhi Wang,Fei Lin,Zhongping Yang 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5

As a sensorless control method suitable for permanent magnet synchronous motor (PMSM) at lowspeed, rotating high-frequency injection method will face some special problems in high power applications. On the one hand, the low switching frequency limits the injected signal frequency, which is very close to the fundamental frequency. On the other hand, under heavy load conditions, the fundamental current amplitude is several hundred times of the negative sequence current. This will result in difficulty in signal extraction. In this paper, current spectrum is analyzed quantitatively based on the parameters of PMSM drive for rail vehicles, which illustrates the limitations of conventional bandpass filters. A method based on self-adjusting filter is proposed. The negative sequence current is successfully extracted, and the precise rotor position is obtained under the condition of variable speed and variable load. Based on a fullscale test platform the effectiveness of the proposed method is proved.

Composite deposition mechanism of 4,5-dichloro-2-n-octyl- 4-isothiazolin-3-one in zinc films for enhanced corrosion resistant properties

Xiaofan Zhai,Congtao Sun,Ke Li,Maria Agievich,Jizhou Duan,Baorong Hou 한국공업화학회 2016 Journal of Industrial and Engineering Chemistry Vol.36 No.-

The present research seeks to address biologically influenced corrosion by electrodepositing a novel 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one(DCOIT)-zinc composite films for enhanced corrosion resistantproperties. Investigated by electrochemical methods, energy dispersive spectroscopy distributionmapping, and infrared absorption spectroscopy, a deposition mechanism was proposed wherein theDCOIT molecule chelated the zinc ion to participate in electrodeposition. The DCOIT-zinc chelateproduced obvious alterations in the surface morphology and crystal orientations. Thermogravimetricanalysis determined the DCOIT mass fraction in the composite film was 5%. The DCOIT-zinc compositefilm demonstrated uniform corrosion in natural seawater and the enhanced anticorrosion property wasachieved by successfully embedding DCOIT.

The FvCYP714C2 gene plays an important role in gibberellin synthesis in the woodland strawberry

Xiaofan Guo,Zhibing Xie,Yang Zhang,Shouming Wang 한국유전학회 2021 Genes & Genomics Vol.43 No.1

Background Fragaria vesca, the woodland strawberry, is a diploid relative of the cultivated strawberry. A GA-defcient mutant was found in ethyl methanesulfonate (EMS)-mutagenized lines of the Fragaria vesca accession ‘Yellow Wonder’. Objective CYP714C2 was found to be diferentially expressed using RNA-seq analysis. It is necessary to identify the function of this gene. Methods In order to identify the function of this gene, it was cloned and transformed into Arabidopsis thaliana. Results The DNA sequence of CYP714C2 was found to be 1940 bp in length, with an open reading frame (ORF) of 1539 bp that is predicted to encode a protein of 512 amino acids. The hydrophilicity of this protein is low and it is unstable. The highest relative expression of FvCYP714C2 was found in the leaves, followed by the pedicels, and low expression levels were found in the other tissues examined. Constitutive expression of FvCYP714C2 signifcantly promoted the growth of transgenic A. thaliana plants; transgenic Arabidopsis plants grew faster and grew well than wild type Col-0 plants. GA1+3 contents of the genetically modifed Arabidopsis lines were signifcantly higher than that in the wild type. Conclusion We conclude that FvCYP714C2 is a gene that functions in the gibberellin biosynthesis pathway in strawberry.

Screening and Characterization of an Aerobic Nitrifying-denitrifying Bacterium from Activated Sludge

Xiaofan Qiu,Tianwen Wang,Xiaomin Zhong,Guocheng Du,Jian Chen 한국생물공학회 2012 Biotechnology and Bioprocess Engineering Vol.17 No.2

Taking advantage of the good biocompatibility and high efficiency of nitrogen removal with microbes,nitrifying and denitrifying bacteria, are becoming increasingly more widely used for wastewater treatment and prevention of eutrophication. In this research, an aerobic nitrifying-denitrifying bacterium was successfully screened from activated sludge and identified as Pseudomonas sp. (CCTCC No M2010209) by the 16S rDNA sequence. The activity verification confirmed its nitrifying-denitrifying capability of removing ammonium, nitrate and nitrite nitrogen. The types of carbon sources and carbon-nitrogen ratio greatly influenced the removal efficiency of NH4+-N and NO3−-N. When the initial concentrations of NH4+-N and NO3−-N in synthetic wastewater were less than 70 and 50mg/L, the nitrogen removal rates reached 94 and 90% in 9 h, respectively. Preliminary comparisons of nitrogen removal capacity between this isolate and other commercial preparations in the treatment of synthetic wastewater revealed its promising potential to be used in the actual wastewater treatment.