Radio Frequency Response of the Strongly Interacting Fermi Gases at Finite Temperatures

The radio frequency spectrum of the fermions in the unitary limit at finite temperatures is characterized by the sum rule relations. We consider a simple picture where the atoms are removed by radio frequency excitations from the strongly interacting states into a state of negligible interaction. We calculate the moments of the response function in the range of temperature $0.08 \epsilon_F < T < 0.8 \epsilon_F$ using auxiliary field Monte Carlo technique (AFMC) in which continuum auxiliary fields with a density dependent shift are used. We estimate the effects of superfluid pairing from the clock shift. We find a qualitative agreement with the pairing gap - pseudogap transition behavior. We also find within the quasiparticle picture that in order for the gap to come into quantitative agreement with the previously known value at T=0, the effective mass has to be $m^* \sim 1.43 m$. Finally, we discuss implications for the adiabatic sweep of the resonant magnetic field.Comment: 2 figure

The Approach of Complex Insert Packaging Fabrication in Stereolithography

The approach of complex insert packaging fabrication in stereolithography is studied in the paper. There are many difficulties being overcome, such as the dispensing shadowing problem caused by the geometric shape of insert, the polymer feeding problem caused by greater insert height than the layer thickness, and the positioning problem of insert that leads to instability of packaging. These drawbacks led to unsatisfactory results of the insert packaging in stereolithography. In order to solve the problems, a new method of complex inserts packaging fabrication in stereolithography is proposed in this paper. Based on the geometric information, function and assembly direction of the inserts, the packaging approach is developed. The approach proposed in this paper has been verified by experiments. It brings considerable contributions to the application of insert packaging in stereolithography. It is also favorable to the improvement of insert packaging efficiency and assembly fabricationMechanical Engineerin

Unsupervised Learning of Complex Articulated Kinematic Structures combining Motion and Skeleton Information

In this paper we present a novel framework for unsupervised kinematic structure learning of complex articulated objects from a single-view image sequence. In contrast to prior motion information based methods, which estimate relatively simple articulations, our method can generate arbitrarily complex kinematic structures with skeletal topology by a successive iterative merge process. The iterative merge process is guided by a skeleton distance function which is generated from a novel object boundary generation method from sparse points. Our main contributions can be summarised as follows: (i) Unsupervised complex articulated kinematic structure learning by combining motion and skeleton information. (ii) Iterative fine-to-coarse merging strategy for adaptive motion segmentation and structure smoothing. (iii) Skeleton estimation from sparse feature points. (iv) A new highly articulated object dataset containing multi-stage complexity with ground truth. Our experiments show that the proposed method out-performs state-of-the-art methods both quantitatively and qualitatively

Fractional unit root tests allowing for a structural change in trend under both the null and alternative hypotheses

This paper considers testing procedures for the null hypothesis of a unit root process against the alternative of a fractional process, called a fractional unit root test. We extend the Lagrange Multiplier (LM) tests of Robinson (1994) and Tanaka (1999), which are locally best invariant and uniformly most powerful, to allow for a slope change in trend with or without a concurrent level shift under both the null and alternative hypotheses. We show that the limit distribution of the proposed LM tests is standard normal. Finite sample simulation experiments show that the tests have good size and power. As an empirical analysis, we apply the tests to the Consumer Price Indices of the G7 countries