Quasi-Normal Modes of a Natural AdS Wormhole in Einstein-Born-Infeld Gravity

We study the matter perturbations of a new AdS wormhole in (3+1)-dimensional Einstein-Born-Infeld gravity, called "natural wormhole", which does not require exotic matters. We discuss the stability of the perturbations by numerically computing the quasi-normal modes (QNMs) of a massive scalar field in the wormhole background. We investigate the dependence of quasi-normal frequencies on the mass of scalar field as well as other parameters of the wormhole. It is found that the perturbations are always stable for the wormhole geometry which has the general relativity (GR) limit when the scalar field mass m satisfies a certain, tachyonic mass bound m^2 > m^2_* with m^2_* < 0, analogous to the Breitenlohner-Freedman (BF) bound in the global-AdS space, m^2_BF = 3 Lambda/4. It is also found that the BF-like bound m^2_* shifts by the changes of the cosmological constant Lambda or angular-momentum number l, with a level crossing between the lowest complex and pure-imaginary modes for zero angular momentum l = 0. Furthermore, it is found that the unstable modes can also have oscillatory parts as well as non-oscillatory parts depending on whether the real and imaginary parts of frequencies are dependent on each other or not, contrary to arguments in the literature. For wormhole geometries which do not have the GR limit, the BF-like bound does not occur and the perturbations are stable for arbitrary tachyonic and non-tachyonic masses, up to a critical mass m^2_c > 0 where the perturbations are completely frozen.Comment: Added comments and references, Accepted in EPJ

Soft skills in health careers programs: a case study of a regional vocational technical high school

The purpose of this study is to develop an understanding of the ways in which educational experiences might differ between a regional vocational technical high school (RVTH) and short-term career-training programs. A particular regional vocational technical high school was selected for its outstanding academic records and placement rates, and a particular industry--healthcare--was chosen for its high demand and short supply of labor in the state. The study is a qualitative case study that primarily utilized in-depth, one-on-one interviews with semi-structured questions. The participants of this study fall into one of three groups: seniors in RVTH health services, students in the RVTH postsecondary practical nursing (PN) program, and certified nursing assistants (CNAs) who received CNA training from short-term career-training programs in Massachusetts. The researcher collected additional qualitative data through various sources such as classroom observation, field notes, program descriptions, lesson plans, syllabi, and class materials. The interview data were transcribed, segmented, and coded; any relevant qualitative data were later added to supplement the interview data. There were four consistent areas raised across participants that suggest salient components of their experiences. First, school choice was made by students themselves in the cases of RVTH seniors, which might have influenced the culture of togetherness and acceptance at RVTH. Second, shop instructors played an important role in creating a school culture where students helped each other and accepted everyone. In particular, the instructors’ emotional support seemed to differentiate the educational experiences of RVTH seniors from the students in other programs. Third, all RVTH seniors frequently identified soft skills such as communication and time-management skills when reflecting on their education experiences whereas participants in the short-term programs focused on technical skills. Lastly, RVTH seniors strongly believed they were career-ready. The findings of the current research on the workplace skills students acquired in the programs showed some congruencies with the existing inter-industry literature that described the importance of certain skills, such as communication and professionalism. Participants from alternative career-training programs did not identify the same types of elements in their educational experiences. The study ends with implications by contemplating what aspects of RVTH can be replicated in which settings

Construction of controlled-NOT gate based on microwave-activated phase (MAP) gate in two transmon system

We experimentally constructed an all-microwave scheme for the controlled-NOT (cNOT) gate between two superconducting transmon qubits in a three dimensional cavity. Our cNOT gate is based on the microwave-activated phase (MAP) gate, which requires an additional procedure to compensate the accumulated phases during the operation of the MAP gate. We applied Z-axis phase gates using microwave hyperbolic secant pulse on both qubits with adequate rotation angles systematically calibrated by separate measurements.We evaluated the gate performance of the constructed cNOT gate by performing two-qubit quantum process tomography (QPT). Finally, we present the experimental implementation of Deutsch-Jozsa algorithm using the cNOT gate

Parametric approaches to fractional programs: Analytical and empirical study

Fractional programming is used to model problems where the objective function is a ratio of functions. A parametric modeling approach provides effective technique for obtaining optimal solutions of these fractional programming problems. Although many heuristic algorithms have been proposed and assessed relative to each other, there are limited theoretical studies on the number of steps to obtain the solution. In this dissertation, I focus on the linear fractional combinatorial optimization problem, a special case of fractional programming where all functions in the objective function and constraints are linear and all variables are binary that model certain combinatorial structures. Two parametric algorithms are considered and the efficiency of the algorithms is investigated both theoretically and computationally. I develop the complexity bounds for these algorithms, and show that they can solve the linear fractional combinatorial optimization problem in polynomial time. In the computational study, the algorithms are used to solve fractional knapsack problem, fractional facility location problem, and fractional transportation problem by comparison to other algorithms (e.g., Newton\u27s method). The relative practical performance measured by the number of function calls demonstrates that the proposed algorithms are fast and robust for solving the linear fractional programs with discrete variables

The collision avoidance and the controllability for nn bodies in dimension one

We present a method of design of control systems for $n$ bodies in the real line $\Bbb R^1$ and on the unit circle $S^1$, to be collision-free and controllable. The problem reduces to designing a control-affine system in $\Bbb R^n$ and in $n$-torus $T^n,$ respectively, that avoids certain obstacles. We prove the controllability of the system by showing that the vector fields that define the control-affine system, together with their brackets of first order, span the whole tangent space of the state space, and then by applying the Rashevsky-Chow theorem

USA educator perspectives regarding the nature and value of social and emotional learning

This paper discusses the US educator perspectives regarding the nature and value of Social Emotional Learning (SEL) skills. This research is part of a larger study being conducted by 33 career development investigators from 15 countries. SEL skills are becoming increasingly critical to helping youth develop the competencies needed to become employable within the emergent 4th Industrial Revolution. Today’s youth must articulate how their competencies align to multiple career opportunities. They need relationship skills and social awareness to interact with different managers and work environments. Youth need self-management skills to advance in the workplace and engage in lifelong learning. For this study, educators were asked to provide written responses to a series of open-ended questions about their understanding of SEL, their perspective on SEL’s relevance to their own effectiveness as educators, and whether and how they perceive SEL as relevant to teaching in classroom settings. This paper will report on the results of how U.S. educators perceive the value and relevance of SEL. Using a modified grounded theory approach, responses from 40 educators were analyzed and 123 SEL themes emerged. The results will be discussed in relation to existing SEL and career readiness frameworks.First author draf