A multi-sensor based online tool condition monitoring system for milling process

Tool condition monitoring has been considered as one of the key enabling technologies for manufacturing optimization. Due to the high cost and limited system openness, the relevant developed systems have not been widely adopted by industries, especially Small and Medium-sized Enterprises. In this research, a cost-effective, wireless communication enabled, multi-sensor based tool condition monitoring system has been developed. Various sensor data, such as vibration, cutting force and power data, as well as actual machining parameters, have been collected to support efficient tool condition monitoring and life estimation. The effectiveness of the developed system has been validated via machining cases. The system can be extended to wide manufacturing applications

Two Speed TASEP with Step Initial Condition

In this paper, we consider zero range process with an initial condition which is equivalent to step initial condition in total asymmetric simple exclusion process (TASEP) as described in a paper by R\'akos, A. and Sch\"utz by using techniques developed by Borodin, Ferrari, and Sasamoto. The solution for the transition probability of total asymmetric simple exclusion process for particles with different hopping rates was first worked out by Sch\"utz and Rak\"os (2005) for the case when $p=1$ or $q=1$. The formula was later applied to analyze two speed TASEP (Borodin, Ferrari, and Sasamoto, 2009) with alternating initial condition. Here we will investigate the two speed TASEP case with step initial condition

Self-Regulation of Solar Coronal Heating Process via Collisionless Reconnection Condition

I propose a new paradigm for solar coronal heating viewed as a self-regulating process keeping the plasma marginally collisionless. The mechanism is based on the coupling between two effects. First, coronal density controls the plasma collisionality and hence the transition between the slow collisional Sweet-Parker and the fast collisionless reconnection regimes. In turn, coronal energy release leads to chromospheric evaporation, increasing the density and thus inhibiting subsequent reconnection of the newly-reconnected loops. As a result, statistically, the density fluctuates around some critical level, comparable to that observed in the corona. In the long run, coronal heating can be represented by repeating cycles of fast reconnection events (nano-flares), evaporation episodes, and long periods of slow magnetic stress build-up and radiative cooling of the coronal plasma.Comment: 4 pages; Phys. Rev. Lett., in pres

Weak convergence of conditioned birth-death processes in discrete time

We consider a discrete-time birth-death process on the nonnegative integers with -1 as an absorbing state and study the limiting behaviour as $n \to \infty$ of the process conditioned on nonabsorption until time $n$. By proving that a condition recently proposed by Martinez and Vares is vacuously true, we establish that the conditioned process is always weakly convergent when all self-transition probabilities are zero. In the aperiodic case we obtain a necessary and sufficient condition for weak convergence

On the Strong Ratio Limit Property for Discrete-Time Birth-Death Processes

A sufficient condition is obtained for a discrete-time birth-death process to possess the strong ratio limit property, directly in terms of the one-step transition probabilities of the process. The condition encompasses all previously known sufficient conditions

Brownian Super-exponents

We introduce a transform on the class of stochastic exponentials for d-dimensional Brownian motions. Each stochastic exponential generates another stochastic exponential under the transform. The new exponential process is often merely a supermartingale even in cases where the original process is a martingale. We determine a necessary and sufficient condition for the transform to be a martingale process. The condition links expected values of the transformed stochastic exponential to the distribution function of certain time-integrals.Comment: 10 page

Control of black hole evaporation?

Contradiction between Hawking's semi-classical arguments and string theory on the evaporation of black hole has been one of the most intriguing problems in fundamental physics. A final-state boundary condition inside the black hole was proposed by Horowitz and Maldacena to resolve this contradiction. We point out that original Hawking effect can be also regarded as a separate boundary condition at the event horizon for this scenario. Here, we found that the change of Hawking boundary condition may affect the information transfer from the initial collapsing matter to the outgoing Hawking radiation during evaporation process and as a result the evaporation process itself, significantly.Comment: Journal of High Energy Physics, to be publishe

In-situ EXAFS study on the thermal decomposition of TiH2

Thermal decomposition behaviors of TiH2 powder under a flowing helium atmosphere and in a low vacuum condition have been studied by using in-situ EXAFS technique. By an EXAFS analysis containing the multiple scattering paths including H atoms, the changes of hydrogen stoichiometric ratio and the phase transformation sequence are obtained. The results demonstrate that the initial decomposition temperature is dependent on experimental conditions, which occurs, respectively, at about 300 and 400 degree in a low vacuum condition and under a flowing helium atmosphere. During the decomposition process of TiH2 in a low vacuum condition, the sample experiences a phase change process: {\delta}(TiH2) - {\delta}(TiHx) - {\delta}(TiHx)+{\beta}(TiHx) - {\delta}(TiHx)+{\beta}(TiHx)+{\alpha}(Ti) - {\beta}(TiHx)+{\alpha}(Ti) - {\alpha}(Ti)+{\beta}(Ti). This study offers a way to detect the structural information of hydrogen. A detailed discussion about the decomposition process of TiH2 is given in this paper.Comment: 9 pages, 7 figure