Developing a virtual machining model to generate MTConnect machine-monitoring data from STEP-NC

The ability to predict performance of manufacturing equipment during early stages of process planning is vital for improving efficiency of manufacturing processes. In the metal cutting industry, measurement of machining performance is usually carried out by collecting machine-monitoring data that record the machine tool’s actions (e.g. coordinates of axis location and power consumption). Understanding the impacts of process planning decisions is central to the enhancement of the machining performance. However, current methodologies lack the necessary models and tools to predict impacts of process planning decisions on the machining performance. This paper presents the development of a virtual machining model (called STEP2M model) that generates machine-monitoring data from process planning data. The STEP2M model builds upon a physical model-based analysis for the sources of energy on a machine tool, and adopts STEP-NC and MTConnect standardised interfaces to represent process planning and machine-monitoring data. We have developed a prototype system for 2-axis turning operation and validated the system by conducting an experiment using a Computer Numerical Control lathe. The virtual machining model presented in this paper enables process planners to analyse machining performance through virtual measurement and to perform interoperable data communication through standardised interfaces.     

Tweet-scan-post: a system for analysis of sensitive private data disclosure in online social media

Knowledge and Information Systems - The social media technologies are open to users who are intended in creating a community and publishing their opinions of recent incidents. The participants of...     

Lethal toxicity of permethrin (NRDC-143) to rainbow trout, salmo gairdneri, in relation to body weight and water temperature

Lethal toxicity of permethrin varied inversely with water temperature and body weight. The 96 h LC 50 (median lethal concentration) for 1 g trout increased by an order of magnitude from 0.62 to 6.43 μg 1⁻¹ between 5 and 20°C. However between 5 and 10°C the 96 h LC 50 changed little from 0.6 μg 1⁻¹. Large trout (200 g) were considerably more tolerant to permethrin than small fish. Thus, the 96 h LC 50s for 1 and 200 g trout were 3.17 and 314 μg 1⁻¹ respectively at 15°C. The size effect was most pronounced between 1 and 50 g.It is to be noted that the application of permethrin for insect control coincides with the usual period of emergence of rainbow trout fry subsequent to a spawning period of April to late June.     

Visualization of internal energy flows in optical fields carrying a pair of fractional vortices

The internal energy flows resulting from the azimuthal component of optical currents in beams carrying a pair of fractional vortices during propagation have been experimentally detected in a knife edge test. Two optical vortices of fractional charge in a beam pair up by means of a connecting dark intensity line between intensity zeros of the vortices. Independent of the polarity of the fractional vortices, this pairing up process occurs. This is in contrast to the isolated intensity null points of vortices of integer charges and thus calls for a study on the internal energy flows in such beams.     

Design of an All-dielectric Self-supporting Cable System

All-dielectric self-supporting （ADSS） cables are installed along with transmission line for the purpose of communication. During installation the outer layer of the cable is hydrophobic and is not pron...     

Optimization of Friction Welding of Tube-to-Tube Plate Using an External Tool with Filler Plate

Friction welding of tube-to-tube plate using an external tool (FWTPET) process with filler plate was successfully applied and optimized for joining commercially pure aluminum tube and tube plate. Taguchi approach was applied to determine the most influential control factors which will yield better joint strength. L₉ orthogonal array was used in this study. Through the Taguchi parametric design approach, the optimum levels of process parameters were determined. The percentage of contribution of each process parameter was determined by Analysis of variance. The predicted optimal value of joint strength was found to be 83.26?MPa. The results were confirmed by further experiments.     

Effect of surface plasmons on spectral switching of polychromatic light with Au-double-slit

It is shown that the generation of surface plasmons on a metal-dielectric interface, i.e., a Au-double-slit and air interface, appreciably affects the intensity of the diffracted light. With a specific example of Au-double-slit and electro-optic devices before the slits, the spectral switching in the diffracted field with the polychromatic light is shown for the first time, to our knowledge. It is found that at the observation point due to the surface plasmon effect the intensity of the diffracted light periodically increases and decreases with the separation of the double-slit.     

Controlled modulation of laser beam and dynamic patterning of colloidal particles using optical tweezers

We present controlled generation of complex-structured beam profiles using diffractive optical element and demonstrate multiple dynamic trapping of colloidal particles. The phase element is programmed to generate various tailored optical fields having structures, similar to that of number three, spiral, and circle but in a tractable manner. Thus, the generated spatially tailored optical fields are confined to focal volume in optical tweezers. This enabled real-time trapping of multiple microscopic objects whereby its transverse organization was controlled in a dynamic manner from one structure to another with the help of spatial light modulator. Such a controlled beam shaping finds potential applications in biophotonics, super resolution imaging, and measurement of biophysical parameters, cell sorting, and micro-manipulation of colloidal particles.     

Effect of primary spherical aberration on high-numerical-aperture focusing of a Laguerre-Gaussian beam

Effect of primary spherical aberration on the tight focusing of linearly and circularly polarized Laguerre-Gaussian (LG) beams is studied by using the vectorial Debye integral. Results are presented for the intensity distribution and square of the polarization components. In the case of the linearly polarized LG beam with unit and double topological charge, the presence of aberration reduces the residual intensity at the focal point and spreads the sidelobes. If the beam is circularly polarized, the aberration results in an increase in the size of the dark core along with a reduction in the intensity at the periphery of the bright ring. The effect of aberration is also discussed in the context of the fluorescent spot size in the focal plane of a stimulated-emission-depletion microscope.