Topological Quantum Phase Transition in Synthetic Non-Abelian Gauge Potential

The method of synthetic gauge potentials opens up a new avenue for our understanding and discovering novel quantum states of matter. We investigate the topological quantum phase transition of Fermi gases trapped in a honeycomb lattice in the presence of a synthetic non- Abelian gauge potential. We develop a systematic fermionic effective field theory to describe a topological quantum phase transition tuned by the non-Abelian gauge potential and ex- plore its various important experimental consequences. Numerical calculations on lattice scales are performed to compare with the results achieved by the fermionic effective field theory. Several possible experimental detection methods of topological quantum phase tran- sition are proposed. In contrast to condensed matter experiments where only gauge invariant quantities can be measured, both gauge invariant and non-gauge invariant quantities can be measured by experimentally generating various non-Abelian gauges corresponding to the same set of Wilson loops

Analysis of Power-aware Buffering Schemes in Wireless Sensor Networks

We study the power-aware buffering problem in battery-powered sensor networks, focusing on the fixed-size and fixed-interval buffering schemes. The main motivation is to address the yet poorly understood size variation-induced effect on power-aware buffering schemes. Our theoretical analysis elucidates the fundamental differences between the fixed-size and fixed-interval buffering schemes in the presence of data size variation. It shows that data size variation has detrimental effects on the power expenditure of the fixed-size buffering in general, and reveals that the size variation induced effects can be either mitigated by a positive skewness or promoted by a negative skewness in size distribution. By contrast, the fixed-interval buffering scheme has an obvious advantage of being eminently immune to the data-size variation. Hence the fixed-interval buffering scheme is a risk-averse strategy for its robustness in a variety of operational environments. In addition, based on the fixed-interval buffering scheme, we establish the power consumption relationship between child nodes and parent node in a static data collection tree, and give an in-depth analysis of the impact of child bandwidth distribution on parent's power consumption. This study is of practical significance: it sheds new light on the relationship among power consumption of buffering schemes, power parameters of radio module and memory bank, data arrival rate and data size variation, thereby providing well-informed guidance in determining an optimal buffer size (interval) to maximize the operational lifespan of sensor networks

Suppression of collisional shifts in a strongly interacting lattice clock

Optical lattice clocks have the potential for extremely high frequency stability owing to the simultaneous interrogation of many atoms, but this precision may come at the cost of systematic inaccuracy due to atomic interactions. Density-dependent frequency shifts can occur even in a clock that uses fermionic atoms if they are subject to inhomogeneous optical excitation [1, 2]. Here we present a seemingly paradoxical solution to this problem. By dramatically increasing the strength of atomic interactions, we suppress collisional shifts in lattice sites containing $N$ > 1 atoms; strong interactions introduce an energy splitting into the system, and evolution into a many-particle state in which collisions occur is inhibited. We demonstrate the effectiveness of this approach with the JILA Sr lattice clock by reducing both the collisional frequency shift and its uncertainty by more than a factor of ten [3], to the level of $10^{-17}$. This result eliminates the compromise between precision and accuracy in a many-particle system, since both will continue to improve as the particle number increases.Comment: 13 pages, 6 figure

Minority-carrier characteristics of InGaAs metal-oxide-semiconductor structures using atomic-layer-deposited A12O3 gate dielectric

Atomic layer depositio

The reliability and validity of Bayley-III cognitive scale in China's male and female children

Background: Since publication in 2006, the Bayley-III scale has been used widely in pediatric populations worldwide; however, there have been very few studies which examined the usefulness and the potential sex differences in a Chinese context. Aims: To assess the reliability and validity of the Bayley-III cognitive scale, and detect possible sex differences in term children so as to provide evidence for clinical and research use in China. Study design: Cross-sectional study. Participants and outcome measures: Of the 1589 children from 3 healthcare institutions that were initially recruited, a total of 1444 children were included in the final analysis. We randomly selected 5-10% children from the total sample to evaluate the test–retest, inter-rater and criteria-related reliability in order to meet the psychometric criteria of Bayley-III scale. Inter-item consistency, test-retest and inter-rater reliability of the scale were estimated using Split-half method and Intra-class Correlation Coefficient (ICC). The content validity was evaluated by the Item-level Content Validity Index (I-CVI). The Mann-Kendall trend test was performed to assess trends of cognitive development, and post-hos Least Significant Difference test was used to detect age-appropriateness of items. Results: Six developmental pediatricians were trained to administer the Bayley-III cognitive scale. Inter-item consistency (n=1444) with Guttman split-half coefficient was above 0.8, while test-retest (n=144) and inter-rater reliability (n=74) had good to excellent ICCs of over 0.9. The criteria-related validity (n=74) of Bayley-III was acceptable, and associations with Gesell Developmental Schedules (GDS) were mainly above 0.8. The raw score of Bayley-III scale in total subjects (n=1444) showed an increased trend across all months of age (p<0.05), and only the score in age group of 35M16D to 36M15D declined in females (p<0.05, n=722). Female children presented a higher score than male children in all subjects and in the 18–23 months age group (p< 0.05). Conclusions: Our findings provide important evidence that the Bayley-III cognitive scale ia valid measurement which could be used in Chinese population, as well as the consideration of sex differences when used in a Chinese context

Multiple source transfer learning for dynamic multiobjective optimization

Recently, dynamic multiobjective evolutionary algorithms (DMOEAs) with transfer learning have become popular for solving dynamic multiobjective optimization problems (DMOPs), as the used transfer learning methods in DMOEAs can effectively generate a good initial population for the new environment. However, most of them only transfer non-dominated solutions from the previous one or two environments, which cannot fully exploit all historical information and may easily induce negative transfer as only limited knowledge is available. To address this problem, this paper presents a multiple source transfer learning method for DMOEA, called MSTL-DMOEA, which runs two transfer learning procedures to fully exploit the historical information from all previous environments. First, to select some representative solutions for knowledge transfer, one clustering-based manifold transfer learning is run to cluster non-dominated solutions of the last environment to obtain their centroids, which are then fed into the manifold transfer learning model to predict the corresponding centroids for the new environment. After that, multiple source transfer learning is further run by using multisource TrAdaboost, which can fully exploit information from the above centroids in new environment and old centroids from all previous environments, aiming to construct a more accurate prediction model. This way, MSTL-DMOEA can predict an initial population with better quality for the new environment. The experimental results also validate the superiority of MSTL-DMOEA over several competitive state-of-the-art DMOEAs in solving various kinds of DMOPs

A localized decomposition evolutionary algorithm for imbalanced multi-objective optimization

Multi-objective evolutionary algorithms based on decomposition (MOEA/Ds) convert a multi-objective optimization problem (MOP) into a set of scalar subproblems, which are then optimized in a collaborative manner. However, when tackling imbalanced MOPs, the performance of most MOEA/Ds will evidently deteriorate, as a few solutions will replace most of the others in the evolutionary process, resulting in a significant loss of diversity. To address this issue, this paper suggests a localized decomposition evolutionary algorithm (LDEA) for imbalanced MOPs. A localized decomposition method is proposed to assign a local region for each subproblem, where the inside solutions are associated and the solution update is restricted inside (i.e., solutions are only replaced by offspring within the same local region). Once off-spring are generated within an originally empty region, the best one is reserved for this subproblem to extend diversity. Meanwhile, the subproblem with the largest number of associated solutions will be found and one of its associated solutions with the worst aggregated value will be removed. Moreover, to speed up convergence for each subproblem while balancing the population's diversity, LDEA only evolves the best-associated solution in each subproblem and correspondingly tailors two decomposition methods in the environmental selection. When compared to nine competitive MOEAs, LDEA has shown the advantages in tackling two benchmark sets of imbalanced MOPs, one benchmark set of balanced yet complicated MOPs, and one real-world MOP

Numerical analysis of integrated forming process of diagonal rolling and piercing of flange nuts

In this paper, Simufact FE software is used to establish a simulation model of three-roll diagonal roll piercing integrated forming flange nut blanks, elaborate its process principle, analyze its forming process through numerical simulation. The law of load change, equivalent plastic strain distribution and wall thickness uniformity during the piercing process and diameter reduction process were investigated, and verify the feasibility of this forming process for manufacturing flange nut blanks

Numerical analysis of integrated forming process of diagonal rolling and piercing of flange nuts

In this paper, Simufact FE software is used to establish a simulation model of three-roll diagonal roll piercing integrated forming flange nut blanks, elaborate its process principle, analyze its forming process through numerical simulation. The law of load change, equivalent plastic strain distribution and wall thickness uniformity during the piercing process and diameter reduction process were investigated, and verify the feasibility of this forming process for manufacturing flange nut blanks