Exact Pseudofermion Action for Monte Carlo Simulation of Domain-Wall Fermion

We present an exact pseudofermion action for hybrid Monte Carlo simulation (HMC) of one-flavor domain-wall fermion (DWF), with the effective 4-dimensional Dirac operator equal to the optimal rational approximation of the overlap-Dirac operator with kernel $H = c H_w (1 + d \gamma_5 H_w)^{-1}$, where $c$ and $d$ are constants. Using this exact pseudofermion action, we perform HMC of one-flavor QCD, and compare its characteristics with the widely used rational hybrid Monte Carlo algorithm (RHMC). Moreover, to demonstrate the practicality of the exact one-flavor algorithm (EOFA), we perform the first dynamical simulation of the (1+1)-flavors QCD with DWF.Comment: 13 pages, 4 figures, v2: Simulation of (1+1)-flavors QCD with DWF, and references added. To appear in Phys. Lett.

Comparison of Particle Swarm Optimization and Self-Adaptive Dynamic Differential Evolution for the Imaging of a Periodic Conductor

[[abstract]]The application of two techniques to reconstruct the shape of a two-dimensional periodic perfect conductor from mimic the measurement data is presented. A periodic conducting cylinder of unknown periodic length and shape scatters the incident wave in half-space and the scattered field is recorded outside. After an integral formulation, the microwave imaging is recast as a nonlinear optimization problem; a cost functional is defined by the norm of a difference between the measured scattered electric fields and the calculated scattered fields for an estimated shape of a conductor. Thus, the shape of conductor can be obtained by minimizing the cost function. In order to solve this inverse scattering problem, transverse magnetic (TM) waves are incident upon the objects and two techniques are employed to solve these problems. The first is based on an particle swarm optimization (PSO) and the second is a self-adaptive dynamic differential evolution (SADDE). Both techniques have been tested in the case of simulated mimic the measurement data contaminated by additive white Gaussian noise. Numerical results indicate that the SADDE algorithm is better than the PSO in reconstructed accuracy and convergence speed.[[notice]]補正完畢[[incitationindex]]SC

An Investigation of Consumer Participation and Co-Creation Value in Facebook

With the rapid growth of virtual communities, more and more people rely on participating in virtual communities to communicate with others, exchange information or use entertainment functions. Many researchers have explored consumer behaviour in virtual communities; however, there is still a lack of research concerning consumers’ motivation factors in participating in the most popular virtual community, Facebook. Hence, the aim of the research is to investigate factors which influence consumers’ participation in Facebook and to explore the underlying value of Facebook. An online questionnaire survey was conducted to answer the research questions. Effective samples were collected from 268 respondents who have used Facebook. The results show that purposive value, interpersonal interconnectivity and interactive function have a significant influence on consumers’ participation in Facebook. Moreover, Facebook provides an efficient platform for both consumers and businesses to co-create value. The study gives academics new perspectives regarding consumer behaviour in Facebook. It also provides practitioners with a better understanding when conducting marketing strategies on Facebook. Finally, future research is recommended in the marketing area

Exploring Consumers’ Coping Behaviors in Online Double Deviation Scenarios: From Power Perspective

Service recovery is a critical moment of truth in retaining customers and reinforcing customer relationships, and has been considered as an “Achilles\u27 heel” in online marketplaces. Poor service recoveries exacerbate the negative effects of the failure, producing a “double deviation” effect. The double deviation effect may arise from the seller’s power misuse and then dissolve the buyer-seller relationship (e.g., violate consumer psychological contract), elicit consumer negative emotions which lead to customer coping behaviors. This study links the theories of psychological contract violation (PCV), emotion, and coping from the power perspective to investigate the double deviation scenario in online auction marketplaces. Two moderators (perceived power and perceived consumer empowerment) are considered in our proposed model. Data collected from 181 consumers of one auction website provide support for the proposed model. The results shed light on what constitutes the determinants of consumer judgments while facing double deviation scenario and how consumers react to and cope with it in online marketplaces. Implications and limitations are discussed

Topological susceptibility in finite temperature QCD with physical (u/d,s,c)(u/d, s, c) domain-wall quarks

We perform hybrid Monte-Carlo (HMC) simulation of lattice QCD with $N_f=2+1+1$ domain-wall quarks at the physical point, on the $64^3 \times (64,20,16,12,10,8,6)$ lattices, each with three lattice spacings. The lattice spacings and the bare quark masses are determined on the $64^4$ lattices. The resulting gauge ensembles provide a basis for studying finite temperature QCD with $N_f=2+1+1$ domain-wall quarks at the physical point. In this paper, we determine the topological susceptibility of the QCD vacuum for $T > T_c \sim 150$ MeV. The topological charge of each gauge configuration is measured by the clover charge in the Wilson flow at the same flow time in physical units, and the topological susceptibility $\chi_t(a,T)$ is determined for each ensemble with lattice spacing $a$ and temperature $T$. Using the topological susceptibility $\chi_t(a,T)$ of 15 gauge ensembles with three lattice spacings and different temperatures in the range $T \sim 155-516$ MeV, we extract the topological susceptibility $\chi_t(T)$ in the continuum limit. Moreover, a detailed discussion on the reweighting method for domain-wall fermion is presented.Comment: 36 pages, 5 figure