Three-dimensional millimetre wave beam tracking based on handset MEMS sensors with extended Kalman filtering

Due to the narrow beam in millimetre wave communication for future 5G networks, small device movements in the form of either self-rotation or displacement can result in serious power loss. In this paper, a three-dimensional (3-D) beam tracking method employing extended Kalman filtering (EKF) is proposed based on antenna arrays and the three smart phone sensors, which are gyroscope, accelerometer and magnetometer, embedded in the micro-electro-mechanical system (MEMS) inside the smart phone. The EKF-based location tracking is also incorporated into the design by combing the data from direction of arrival (DoA) and time of arrival (ToA) estimation results of the user node (UN), since accurate UN location information is also very important in the process of beam tracking to achieve beam alignment between the access node (AN) and the UN

Two monotonic functions involving gamma function and volume of unit ball

In present paper, we prove the monotonicity of two functions involving the gamma function $\Gamma(x)$ and relating to the $n$-dimensional volume of the unit ball $\mathbb{B}^n$ in $\mathbb{R}^n$.Comment: 7 page

Critical behaviours of contact near phase transitions

A central quantity of importance for ultracold atoms is contact, which measures two-body correlations at short distances in dilute systems. It appears in universal relations among thermodynamic quantities, such as large momentum tails, energy, and dynamic structure factors, through the renowned Tan relations. However, a conceptual question remains open as to whether or not contact can signify phase transitions that are insensitive to short-range physics. Here we show that, near a continuous classical or quantum phase transition, contact exhibits a variety of critical behaviors, including scaling laws and critical exponents that are uniquely determined by the universality class of the phase transition and a constant contact per particle. We also use a prototypical exactly solvable model to demonstrate these critical behaviors in one-dimensional strongly interacting fermions. Our work establishes an intrinsic connection between the universality of dilute many-body systems and universal critical phenomena near a phase transition.Comment: Final version published in Nat. Commun. 5:5140 doi: 10.1038/ncomms6140 (2014

Optimization of β-Mannanase Production from Bacillus licheniformis TJ-101 Using Response Surface Methodology

Plackett-Burman design, central composite design and response surface analysis were carried out with the aim of optimizing culture conditions for β-mannanase production from Bacillus licheniformis TJ-101. Screening experiments of Plackett-Burman design were firstly employed to evaluate the effects of 16 variables on β-mannanase production. The four identified significant variables, i.e. the mass concentration of Na2HPO4, the mass concentration of KH2PO4, initial pH and medium volume, were further optimized by central composite design and response surface analysis. The optimum values of four critical variables were determined as Na2HPO4 6.4 g/ lL-1, KH2PO4 0.36 g L-1g/l, initial pH 7.7 and medium volume V = 30.1 mlmL. Under these conditions, the β-mannanase activity can experimentally reach a = 523.1±5.9 U/ ml mL-1 (127.7 % increase compared with the enzyme activity before optimization) at the flask level. Moreover, oxygen limitation and initial pH remarkably affected β-mannanase production from Bacillus licheniformis TJ-101 as revealed by response surface analysis. Maximum β-mannanase activity was increased by 73.7 % in a 6.6- l L fermenter using the optimized medium and dissolved oxygen at 20 % saturation

Non-Abelian Josephson effect between two spinor Bose-Einstein condensates in double optical traps

We investigate the non-Abelian Josephson effect in spinor Bose-Einstein condensates with double optical traps. We propose, for the first time, a real physical system which contains non-Abelian Josephson effects. The collective modes of this weak coupling system have very different density and spin tunneling characters comparing to the Abelian case. We calculate the frequencies of the pseudo Goldstone modes in different phases between two traps respectively, which are a crucial feature of the non-Abelian Josephson effects. We also give an experimental protocol to observe this novel effect in future experiments.Comment: 5 pages, 3 figure

Research on UBI auto insurance pricing model based on parameter adaptive SAPSO optimal fuzzy controller

Aiming at the problem of “dynamic” accurate determination of rates in UBI auto insurance pricing, this paper proposes a UBI auto insurance pricing model based on fuzzy controller and optimizes it with a parameter adaptive SASPO. On the basis of the SASPO algorithm, the movement direction of the particles can be mutated and the direction can be dynamically controlled, the inertia weight value is given by the distance between the particle and the global optimal particle, and the learning factor is calculated according to the change of the fitness value, which realizes the parameter in the running process. Effective self-adjustment. A five-dimensional fuzzy controller is constructed by selecting the monthly driving mileage, the number of violations, and the driving time at night in the UBI auto insurance data. The weights are used to form fuzzy rules, and a variety of algorithms are used to optimize the membership function and fuzzy rules and compare them. The research results show that, compared with other algorithms, the parameter adaptive SAPAO algorithm can calculate more reasonable, accurate and high-quality fuzzy rules and membership functions when processing UBI auto insurance data. The accuracy and robustness of UBI auto insurance rate determination can realize dynamic and accurate determination of UBI auto insurance rates