Kernelizing LSPE λ

We propose the use of kernel-based methods as underlying function approximator in the least-squares based policy evaluation framework of LSPE(λ) and LSTD(λ). In particular we present the ‘kernelization’ of model-free LSPE(λ). The ‘kernelization’ is computationally made possible by using the subset of regressors approximation, which approximates the kernel using a vastly reduced number of basis functions. The core of our proposed solution is an efficient recursive implementation with automatic supervised selection of the relevant basis functions. The LSPE method is well-suited for optimistic policy iteration and can thus be used in the context of online reinforcement learning. We use the high-dimensional Octopus benchmark to demonstrate this

Oscillatory convection in binary mixtures: thermodiffusion, solutal buoyancy, and advection

The role of thermodiffusive generation of concentration fluctuations via the Soret effect, their contribution to the buoyancy forces that drive convection, the advective mixing effect of the latter, and the diffusive homogenisation are compared and elucidated for oscillatory convection. Numerically obtained solutions of the field equations in the form of spatially extended relaxed traveling waves, of standing waves, and of the transient growth of standing waves and their transition to traveling waves are discussed as well as spatially localized convective states of traveling waves that are surrounded by the quiescent fluid.Comment: 30 pages, 10 figure

Top asymmetry and the search for a light hadronic resonance in association with single top

The exchange of a light $t$-channel flavor-changing gauge boson, \Vp, with mass $\sim m_{top}$ remains a leading explanation for the anomalous forward backward asymmetry in top quark production at the Tevatron. Unlike other ideas, including heavier $t$-channel mediators, the light \Vp model is not easily seen in the \mtt distribution. We advocate a more promising strategy. While current analyses at hadron colliders may not be sensitive, we propose searching for a $jj$ resonance in association with single top that may allow discovery in existing data. Deviations in the lepton charge asymmetry in this sample should also be present.Comment: 5 pages, 2 figur

Top quark asymmetry and dijet resonances

CDF recently reported an anomaly in the $m_{jj}$ distribution of dijet events produced in association with a $W$ boson. If this anomaly is associated with a new flavor conserving vector resonance, $V$, one might have expected to observe effects in the analogous $m_{jj}$ distribution produced in association with a $\gamma$. No such excess is observed. A single $u-t-V$ flavor changing coupling, however, can contribute to the $m_{jj}$ anomaly while being consistent with other resonance searches. Furthermore, it gives a potential explanation of the observed forward-backward asymmetry in top quark production.Comment: 4 pages, 1 figur

Vietnamese women marriage migrants in South Korea: A study of their sense of well-being in the process of their settlement

The purpose of this study is to understand the experience of the Vietnamese women marriage migrants overcoming difficulties in the process of settlement in South Korea through international marriage, and to suggest the directions for achieving a stable settlement by maintaining their sense of well-being, based on the factors overcoming their difficulties. For this purpose, the research question in this study was set as: 'To what extent do the resources of Vietnamese women marriage migrants against the challenges in their settlement to South Korea influence their sense of well-being?' I applied the phenomenological method of Giorgi and Schütze’s biographical narrative interview method to analyse the interview data in the qualitative research methodology. Participants of this study, the Vietnamese women marriage migrants, were found to have the curiosity and desire to live in a new country free from the reality of difficult family situations and a poor society, and they chose international marriage with great anticipation and longing for South Korea. However, they have gone through many difficulties during their settlement process. Two factors are crucial: Without enough information on their marriage migration, and their family’s strong opposition, led to their worries about international marriage before migration. Even after migration, they spent the time of pregnancy, childbirth and child care without the help of their husbands under the influence of their mothers-in-law who showed an authoritarian style within their family. Outside their family, they were discriminated against and ignored by South Koreans with added inconveniences caused by the unfamiliar surroundings and their limited communication. The factors that overcome the difficulties and maintain their sense of well-being in the settlement process, are found in four aspects: internally, externally, transnationally, and demographically. The results of this study provide in-depth data not only to understand the experiences of the Vietnamese marriage migrants, but also to expand support programmes and centres for their stable settlement in South Korean society

Field Tuning the G-Factor in InAs Nanowire Double Quantum Dots

We study the effects of magnetic and electric fields on the g-factors of spins confined in a two-electron InAs nanowire double quantum dot. Spin sensitive measurements are performed by monitoring the leakage current in the Pauli blockade regime. Rotations of single spins are driven using electric-dipole spin resonance. The g-factors are extracted from the spin resonance condition as a function of the magnetic field direction, allowing determination of the full g-tensor. Electric and magnetic field tuning can be used to maximize the g-factor difference and in some cases altogether quench the EDSR response, allowing selective single spin control.Comment: Related papers at http://pettagroup.princeton.ed