Masses of Scalar and Axial-Vector B Mesons Revisited

The SU(3) quark model encounters a great challenge in describing even-parity mesons. Specifically, the $q\bar q$ quark model has difficulties in understanding the light scalar mesons below 1 GeV, scalar and axial-vector charmed mesons and $1^+$ charmonium-like state $X(3872)$. A common wisdom for the resolution of these difficulties lies on the coupled channel effects which will distort the quark model calculations. In this work, we focus on the near mass degeneracy of scalar charmed mesons, $D_{s0}^*$ and $D_0^{*0}$, and its implications. Within the framework of heavy meson chiral perturbation theory, we show that near degeneracy can be qualitatively understood as a consequence of self-energy effects due to strong coupled channels. Quantitatively, the closeness of $D_{s0}^*$ and $D_0^{*0}$ masses can be implemented by adjusting two relevant strong couplings and the renormalization scale appearing in the loop diagram. Then this in turn implies the mass similarity of $B_{s0}^*$ and $B_0^{*0}$ mesons. The $P_0^* P'_1$ interaction with the Goldstone boson is crucial for understanding the phenomenon of near degeneracy. Based on heavy quark symmetry in conjunction with corrections from QCD and $1/m_Q$ effects, we obtain the masses of $B^*_{(s)0}$ and $B'_{(s)1}$ mesons, for example, $M_{B_{s0}^*}= (5715\pm1)\,{\rm MeV}+\delta\Delta_S$, $M_{B'_{s1}}=(5763\pm1)\,{\rm MeV}+\delta\Delta_S$ with $\delta\Delta_S$ being $1/m_Q$ corrections. We find that the predicted mass difference of 48 MeV between $B'_{s1}$ and $B_{s0}^*$ is larger than that of $20\sim 30$ MeV inferred from the relativistic quark models, whereas the difference of 15 MeV between the central values of $M_{B'_{s1}}$ and $M_{B'_1}$ is much smaller than the quark model expectation of $60-100$ MeV.Comment: 21 pages, 1 figure, to appear in Eur. Phys. J. (2017). arXiv admin note: text overlap with arXiv:1404.377

Fault severity assessment of rolling element bearings based on bicoherence spectrum

The condition monitoring and fault diagnosis of rolling element bearings not only depend on fault type but also fault severity which is also essential for making proper maintenance decision. Aiming at fault severity assessment of rolling element bearings, a new indicator based on the bicoherence spectrum is proposed. The quadratic phase coupling (QPC) which is one of the most important nonlinear characteristics of fault-related signals can be detected by the bicoherence spectrum. The deepening fault severity usually results in more frequency components involving in coupling. In order to quantify the coupling degree which is closely related to fault severity, we choose the mean value of the bicoherence spectrum as an indicator. Experiments results showed that the quantitative trend prediction of different fault severities of bearing is realized

Resource Slack, Innovation Ambidexterity, and Quality Performance: Knowledge Heterogeneity Perspective

Abstract. Resource slack and innovation ambidexterity can both be represented and connected conceptually with heterogeneous knowledge structure. Hypothesizing with the logic of knowledge heterogeneity, the present study empirically examined ambidexterity’s mediation effect in the relationship between two forms of resource slacks (i.e., human and financial resources) and product quality. Companies in Taiwanese manufacturing industry were located based on the random inspection conducted by the Department of Budget, Accounting and Statistics of the Government in 2011, and surveyed. Our findings demonstrated that slack resource is only an indirect factor for product quality evaluated by internal developers and producers (i.e. development and delivery processes) and external customers (product-specific quality). Specifically, first, different resource slacks influence differently on ambidexterity; second, both exploration and exploitation positively influence quality of innovation; third, ambidexterity plays a significant mediator’s role that may strategically alter the relationship between slack and quality. Research has paid increasing attention to ambidexterity (i.e., exploration and exploitation) in organizational innovation. Mostly, however, focus on the influencing factors leading to possible ambidextrous design or implementation of innovation. Few have examined ambidexterity’s effects on specific dimensions of innovation as outcomes.Keywords. Resource slacks, Ambidexterity, Quality, Knowledge heterogeneity.JEL. M10; M11; M14

Severity and prevalence of behavioral and psychological symptoms among patients of different dementia stages in Taiwan

Background To better understand the trends of behavioral and psychological symptoms of dementia (BPSD) over the disease progression is important to provide psychoeducation for dementia caregivers. Objective This study examined the severity and occurrence of BPSD across the various degrees of the disease. Methods This study was a cross-sectional design. Patients (N = 276) who had dementia from July 2001 to October 2008 were surveyed and assessed for dementia stage, using the clinical dementia rating scale (CDR). BPSD was evaluated using the Neuropsychiatric Inventory (NPI). We examined the differences between the severities and occurrence of the individual’s BPSD among various CDR stages with the Kruskal-Wallis test and Chi-square test. Results Delusion (p = 0.01), agitation/aggression (p = 0.033), apathy/indifference (p = 0.009), aberrant motor behavior (p < 0.001), nighttime behavior disturbances (p < 0.001), and eating abnormalities (p = 0.001) were significantly different among stages of dementia. The severity of BPSD became exacerbated over the course of the disease, and was highest in moderate (CDR = 2) or severe (CDR = 3) dementia. The occurrence of BPSD was highest when the CDR equaled 2 (97.5%). Discussion The association of global (or certain) BPSD, across different stages of dementia, is a non-linear relationship. These findings suggest the importance of taking into account clinical dementia stage for managing BPSD