Automatic tools for analyzing student online discussions are highly desirable for better assistance and scaffolding. This paper presents an approach for automatically identifying student discussions with unresolved issues or unanswered questions. We apply a two-phase classification algorithm. First, we classify “speech acts” of individual messages to identify the roles that the messages play, s...

The aim of the present study was to investigate the relations between psychological and physical workload and musculoskeletal neck, shoulder and upper back symptoms. In this longitudinal two-phase cohort study a survey was conducted among non-managerial female elderly-care workers (n = 553). The analyses were based on respondents who were considered free from the respective symptoms at initial ...

This paper presents modelling of non-invasive Ultrasonic Tomography via transmission-mode method for imaging liquid and gas flow. Transmission-mode approach has been used for sensing the liquid/gas two-phase flow, which is a kind of strongly inhomogeneous medium. The concept of observation time and the imaging technique for twophase flow using fan-shaped beam scanning geometry were presented.

We investigate a reaction–diffusion process in a two-phase medium with microscopic length scale ε. The diffusion coefficients in the two phases are highly different (d1/D = ε2) and the reaction constant k is large. First, the homogenisation limit ε → 0 is taken, which leads to a two-scale model. Afterwards, we pass to the fast-reaction limit k →∞ and obtain a two-scale reaction-diffusion system...

simulation of turbulence boiling, generation of vapour and predication of its behaviour are still subject to debate in the two-phase flow area and they receive a high level of worldwide attention. in this study, a new arrangement of the three dimensional governing equations for turbulence two-phase flow with heat and mass transfer are derived by using ensemble averaging two-fluid model and util...

in this paper we consider a nonlinear two-phase stefan problem in one-dimensional space. the problem is mapped into a nonlinear volterra integral equation for the free boundary.

This paper describes the occurence of phase anholonomies in the context of point vortex problems for two-dimensional incompressible ows. After giving a brief description of anholo-nomic eeects in other contexts, we focus attention on the restricted three-vortex problem and a simpler modiied problem where thèHannay-Berry' phase can be computed using multi-scale asymptotic methods. Our main empha...

Two-phase bubble formation coupled with phase change at a submerged nozzle is studied theoretically. The whole bubble consists of a ®apor and a liquid phase. The inner ®apor phase is assumed to be surrounded by a thin condensate layer, in which the ®apor condenses partially as the two-phase bubble grows. The interface element approach is applied to describe the dynamics of bubble formation. The...