A Novel Calibration Method Research of the Scale Factor for the All-optical Atomic Spin Inertial Measurement Device

Sheng Zou,Xi-Yuan Chen,Hong Zhang,Yao Chen,Jian-cheng Fang 한국광학회 2015 Current Optics and Photonics Vol.19 No.4

A novel method to measure the scale factor for the all-optical atomic spin inertial measurement device(ASIMD) is demonstrated in this paper. The method can realize the calibration of the scale factor by aself-consistent method with small errors in the quiescent state. At first, the matured IMU (inertialmeasurement unit) device was fixed on an optical platform together with the ASIMD, and it has beenused to calibrate the scale factor for the ASIMD. The results show that there were some errors causingthe inaccuracy of the experiment. By the comparative analysis of theory and experiment, the ASIMD wasunable to keep pace with the IMU. Considering the characteristics of the ASIMD, the mismatch betweenthe driven frequency of the optical platform and the bandwidth of the ASIMD was the major reason. Anall-optical atomic spin magnetometer was set up at first. The sensitivity of the magnetometer is ultra-high,and it can be used to detect the magnetization of spin-polarized noble gas. The gyromagnetic ratio ofthe noble gas is a physical constant, and it has already been measured accurately. So a novel calibrationmethod for scale factor based on the gyromagnetic ratio has been presented. The relevant theoreticalanalysis and experiments have been implemented. The results showed that the scale factor of the devicewas 7.272 V/°/s by multi-group experiments with the maximum error value 0.49%

Determination of Thermal Equilibrium in a Sealed Cell Based on Optical Depth

Sheng Zou,Hong Zhang,Xi-Yuan Chen,Guang-cun Shan,Wei Quan 한국물리학회 2017 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.70 No.2

An effective method based on optical depth (OD) is presented to measure thermal equilibrium in a cell. First, the principle of determining the temperature distribution in the cell by using the OD is demonstrated. Subsequently, relevant experiments are carried out. Original experimental results showed that some gradients of OD distributions in the cell at different wavelengths and variations of the OD increased slowly along the direction of motion of the beam at a fixed wavelength. At a wavelength of 766.6839 nm, which is about 7 GHz blue shifted with respect to the potassium resonance, the average value of the OD was about 0.764 and the maximal and the minimum inhomogeneity biases among all location points were about 6.07% and 0.56%, respectively. As for the corresponding wavelengths of 766.67785 nm and 766.73004 nm, some deviations from previous results, which were caused by different absorptions of the alkali-metal atoms at different frequencies of the laser beam, were observed. The nonuniform OD values along the direction of motion of the beam reflected an inhomogeneous distribution of the temperature in the cell, which may have been caused by layout of the oven. When the layout of the oven was modified, comparative experiments comparable to these with the previous layout of the oven demonstrated that the uniformity of the temperature distribution in the cell was improved and that thermal equilibrium time was shorter by about 10 minutes. This method played an important role in determining the thermal equilibrium time in the cell.

Magnetization Produced by Spin-polarized Xenon-129 Gas Detected by Using All-optical Atomic Magnetometer

Sheng Zou,Hong Zhang,Xi-yuan Chen,Wei Quan 한국물리학회 2015 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.66 No.6

The method to produce spin-polarized xenon-129 gas was based on the method of spin-exchangeoptical pumping (SEOP). The magnetizations produced by the hyperpolarized (HP) xenon-129gas were analyzed from the perspective of theoretical and experimental research. The theoreticalsimulation was based on the conventional Bloch equation. The experimental research was based onmeasurements made by using an all-optical atomic magnetometer. The experimental results agreedwith the theoretical simulated results, which proved that an all-optical atomic magnetometer hadthe ability to measure the magnetic field produced by xenon-129 nuclei in a low external magneticfield. Because the frequency of the nuclear spin precession could be detected precisely, the resultsshowed that the mean measurement error of the gyromagnetic ratio was 1.1 × 10−4 Hz/nT.

Research on the Influence of Alkali Polarization on an All-Optical Atomic Spin Magnetometer Based on Hybrid Pumping Potassium and Rubidium

Hong Zhang,Sheng Zou,Xi-Yuan Chen,Yang Liu 한국물리학회 2015 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.66 No.8

An all-optical atomic spin magnetometer using a hybrid cell of K and Rb atoms is demonstrated in this paper. Via deriving and solving the Bloch equations, we established the models for the polarization rate of Rb and the magnetometer’s output signal, respectively. In order to achieve the maximum sensitivity, we carried out research on the influence of the pump power on the polarization rate and magnetometer’s output signal. The magnetometer’s sensitivity was found to be proportional to the polarization rate of Rb, which was confined by the pump power. In a certain context, theoretical predictions indicated that the larger the pump power was, the higher magnetometer’s sensitivity that could be realized. However, the theoretical estimate deviated from the experimental results. An analysis of the errors between the actual value and the theoretical value showed that the different molar ratio between the two species of alkali-metal atoms was the primary reason causing the deviation. By comparing the experimental measurement result with simulation result, we found the difference in the molar ratio to be approximate 4 times. After various parameters had been optimized, a sensitivity of 18 fT/Hz1/2 was achieved by analyzing the signal-to-noise ratio.

Transarterial Chemoembolization Using Gelatin Sponges or Microspheres Plus Lipiodol-Doxorubicin versus Doxorubicin-Loaded Beads for the Treatment of Hepatocellular Carcinoma

Yi-Sheng Liu,Ming-Ching Ou,Yi-Shan Tsai,Xi-Zhang Lin,Chien-Kuo Wang,Hong-Ming Tsai,Ming-Tsung Chuang 대한영상의학회 2015 Korean Journal of Radiology Vol.16 No.1

To retrospectively compare treatment of hepatocellular carcinoma (HCC) with transarterial chemoembolization (TACE) using gelatin sponges or microspheres plus lipiodol-doxorubicin vs. doxorubicin-loaded drug-eluting beads (DEB). A total of 158 patients with HCC received TACE from November 2010 to November 2011 were enrolled in this study, including 64 (40.5%) received TACE with lipiodol-doxorubicin and gelatin sponges (group A), 41 (25.9%) received TACE with lipiodol-doxorubicin and microspheres (group B), and 53 (33.5%) received TACE with doxorubicin-loaded DEB (group C). Tumor response and adverse events (AEs) were evaluated. No significant difference was found at baseline among the three groups. The doxorubicin dosage in group C wassignificantly (p < 0.001) higher compared to the dose used in groups A or B (median, 50 mg vs. 31 mg or 25 mg). Significantly (p < 0.001) more patients in group C achieved complete response compared to those in groups A or B (32.1% vs. 6.3% or 2.4%). Significantly (p < 0.001) less patients in group C had progressive disease compared to those in groups A or B (34.0% vs. 57.8% or 68.3%). Minor AEs were more common in groups A and B compared to group C, with rates of 54.7%, 34.1%, and 5.7%, respectively. In patients with HCC, TACE with DEB offers better safety and efficacy profiles compared to either TACE with gelatin sponges or TACE with microspheres.

On Exponential Stability of Neutral Delay Markovian Jump Systems with Nonlinear Perturbations and Partially Unknown Transition Rates

Xinghua Liu,Hong-sheng Xi 제어·로봇·시스템학회 2014 International Journal of Control, Automation, and Vol.12 No.1

The exponential stability for neutral delay Markovian jump systems with nonlinear perturbations and partially unknown transition rates is investigated in this paper. With creative Lyapunov functional and novel matrix inequalities analysis, delay-range-dependent and rate-dependent exponential stability conditions are presented by reciprocally convex lemma and free weighting matrices. Numerical exam-ples are given to demonstrate the effectiveness of the proposed methods.

Dynamic File Grouping for Load Balancing in Streaming Media Clustered Server Systems

Qi Jiang,Hong-Sheng Xi,Bao-Chen Yin 제어·로봇·시스템학회 2009 International Journal of Control, Automation, and Vol.7 No.4

A dynamic file grouping strategy is presented to address the load balancing problem in streaming media clustered server systems. This strategy increases the server cluster availability by balancing the workloads among the servers within a cluster. Additionally, it improves the access hit ratio of cached files in delivery servers to alleviate the limitation of I/O bandwidth of storage node. First, the load balancing problem is formulated as a two layers semi-Markov switching state-space control process. This analytic model captures the behaviors of streaming media clustered server systems accurately, and is with constructional flexibility and scalability. Then, a policy iteration based reinforcement learning algorithm is proposed to optimize the file grouping policy online. By utilizing the features of the event-driven policy, the proposed optimization algorithm is adaptive and with less computational cost. Simulation results demonstrate the effectiveness of the proposed approach.

A Robust Adaptive Controller for Markovian Jump Uncertain Nonlinear Systems with Wiener Noises of Unknown Covariance

Jin Zhu,Hong-sheng Xi,Hai-bo Ji,Bing Wang 대한전기학회 2007 International Journal of Control, Automation, and Vol.5 No.2

A robust adaptive controller design for a class of Markovian jump parametric -strict-feedback systems is given. The disturbances considered herein include both uncertain nonlinearities and Wiener noises of unknown covariance. And they satisfy some bound-conditions. By using stochastic Lyapunov method in Markovian jump systems, a switching robust adaptive controller was obtained that guarantees global uniform ultimate boundedness of the closed-loop jump system.

Quasi-synchronization of Markovian Jump Complex Heterogeneous Networks with Partly Unknown Transition Rates

Xinghua Liu,Hong-sheng Xi 제어·로봇·시스템학회 2014 International Journal of Control, Automation, and Vol.12 No.6

This paper is concerned with the synchronization problem for a class of Markovian jump complex heterogeneous networks with partly unknown transition rates and time-varying delay. Based on the concept of quasi-synchronization, a novel stochastic Lyapunov functional is constructed to solve the problem. Then sufficient quasi-synchronization conditions are presented, and explicit expressions of error levels are proposed to estimate the synchronization error. Finally, numerical examples are provided to demonstrate the feasibility and effectiveness of the proposed theoretic result.

Effects of Endogenous Hormones on Variation of Shoot Branching in a Variety of Non-heading Chinese Cabbage and Related Gene Expression

Xue-Wei Cao,Hong-Mi Cui,Yuan Yao,Ai-Sheng Xiong,Xi-Lin Hou,Ying Li 한국식물학회 2017 Journal of Plant Biology Vol.60 No.4

Shoot branching (tillering) primarily determinesplant shoot architecture and has been studied in many plants. Shoot branching is an important trait in non-heading Chinesecabbage (Brassica rapa ssp. chinensis Makino). The B. rapassp. chinensis var. multiceps exhibits unique and multipleshoot branching characteristics. Here, we analyzed the variationin shoot branching between ‘Maertou,’ with multiple shootbranching, and ‘Suzhouqing,’ a common variety. The levelsof endogenous indole-3-acetic acid (IAA), zeatin ribosideand active gibberellins in the shoot meristem tissues of thetwo cultivars were quantified by enzyme-linked immunosorbentassay during the vegetative growth stage. High levels of IAAmaintained axillary bud dormancy and repressed axillary budoutgrowth allowing shoot branching to form in the vegetativestage in ‘Suzhouqing.’ In contrast, low levels of IAA did notinhibit axillary buds in ‘Maertou,’ while a high level of cytokininpromoted axillary bud growth and branch shoot development. Exogenous hormone (rac-GR24 and 6-benzylaminopurine)treatment showed that ‘Maertou’ was relatively sensitive tocytokinin, because the fold changes of cytokinin-responsivegenes in ‘Maertou’ were significantly more frequent than thosein ‘Suzhouqing’. Cytokinin was the direct regulator for axillarybud growth of ‘Maertou’. Compared with ‘Suzhouqing’,‘Maertou’ was sensitive to cytokinin and this weakened thestrigolactone–cytokinin branching pathway.