Optical-LSP Establishment and a QoS Maintenance Scheme Based on Differentiated Optical QoS Classes in OVPNs

A virtual private network (VPN) over Internet has the benefit of being cost-effective and flexible. However, it has difficulties providing sufficient QoS and adequate transmission capacity for high bandwidth services. Given the increasing demand for high bandwidth Internet and the demand for QoS assurances in a VPN over Internet, IP/generalized multi-protocol label switching (GMPLS) based on a control plane combined with a high-bandwidth, dense-wavelength division multiplexing (DWDM) optical network is seen as a very favorable approach for realizing the future optical VPN (OVPN) over IP/GMPLS over DWDM. Within this architecture, providing QoS guaranteed multimedia services with a differentiated QoS guaranteed protocol framework with QoS recovery is one of the key issues to implement. Therefore, we suggest in this paper optical-label switched path (O-LSP) establishment and its QoS maintenance scheme based on differentiated optical QoS-service (DOQoS) classes. They are the key components for this DOQoS framework in assuring end-to-end QoS in an OVPN over IP/GMPLS over DWDM architecture.     

Autostereoscopic three-dimensional display based on a micromirror array

A novel approach for three-dimensional (3-D) display systems implemented with a micromirror array was proposed, designed, realized, and tested. The major advantages of this approach include the following: (1) micromirrors are reflective and hence achromatic (panchromatic), (2) a wide variety of displays can be used as image sources, and (3) time multiplexing can be introduced on top of space multiplexing to optimize the viewing zone arrangements. A two-view (left and right) 3-D autostereoscopic display system was first constructed. Left- and right-eye views in the forms of both still and motion 3-D scenes were displayed, and viewers were able to fuse the stereo information. A multiview (two left and two right) 3-D autostereoscopic display system was then simulated.     

Flow condensation heat transfer coefficients of R22, R134a, R407C, and R410A inside plain and microfin tubes

Flow condensation heat transfer coefficients (HTCs) of R22, R134a, R407C, and R410A inside horizontal plain and microfin tubes of 9.52 mm outside diameter and 1 m length were measured at the condensation temperature of 40 °C with mass fluxes of 100, 200, and 300 kg m⁻² s⁻¹ and a heat flux of 7.7–7.9 kW m⁻². For a plain tube, HTCs of R134a and R410A were similar to those of R22 while HTCs of R407C are 11–15% lower than those of R22. For a microfin tube, HTCs of R134a were similar to those of R22 while HTCs of R407C and R410A were 23–53% and 10–21% lower than those of R22. For a plain tube, our correlation agreed well with the present data for all refrigerants exhibiting a mean deviation of 11.6%. Finally, HTCs of a microfin tube were 2–3 times higher than those of a plain tube and the heat transfer enhancement factor decreased as the mass flux increased for all refrigerants tested.     

An evaluation of radiation damage to solid state components flown in low earth orbit satellites

The effects of total ionising radiation dose upon commercial off-the-shelf semiconductors fitted to satellites operating in low Earth orbit (LEO) conditions was evaluated. The evaluation was performed for the Korea Institute of Technology SATellite-1, (KITSAT-1) which was equipped with commercial solid state components. Two approximate calculation models for space radiation shielding were developed. Verification was performed by comparing the results with detailed three-dimensional calculations using the Monte-Carlo method and measured data from KITSAT-1. It was confirmed that the developed approximate models were reliable for satellite shielding calculations. It was also found that commercial semiconductor devices, which were not radiation hardened, could be damaged within their lifetime due to the total ionising dose they are subject to in the LEO environment. To conclude, an intensive shielding analysis should be considered when commercial devices are used.     

Fe2O3 aggregation and formation of Ba-ferrite

The effect of Fe₂O₃ aggregation on the formation of Ba-ferrite (BaFe₁₂O₁₉) was studied. BaCO₃-Fe₂O₃ mixtures were prepared by using partial precipitation mixing and ball mill mixing methods in two separate batches. Thermogravimetry, x-ray diffraction analysis, scanning electron photomicrographs and magnetic hysteresis loop tracer analysis were used for characterization of the materials. It is shown that the aggregation state of Fe₂O₃ powders as well as the mixing methods have a significant effect on the formation of Ba-ferrite, sintering and magnetic properties.     

Effect of chelators and reductants on the mobilization of metals from ambient particulate matter

Ambient urban particulate matter (PM) contains various transition metals. When the PM is inhaled into the lung, not all but some part of metals from the particles might be mobilized to participate in a reaction that can damage various biomolecules, such as DNA and proteins. The dust particle size as well as organic acids may influence the metal mobilization. Thus, the mobilization of the metal from two standard reference materials (SRM; NIST, USA) and urban PM (PM2.5 and PM10) collected in the Seoul area was measured in the presence of artificial or biological chelator with or without reductant. The degree of the mobilization was higher with the artificial or biological chelator than the control with saline. In some cases, a reductant increased the mobilization as much as about 5 times the control without the reductant. Especially, the mobilization of Fe was greatly influenced by the presence of reductants. In general, the degree of the mobilization of the transition metal was higher with PM2.5 than with PM10. Therefore, it is expected that, considering the previously known toxicities of the transition metals, PM2.5 is more damaging to various biomolecules than PM10. The results also suggest that not the total amount but the mobilizable fraction of the metal in the ambient PM should be considered with regard to the toxicity of the urban particulate matter.     

The effects of impeller characteristics in the hydrogenation of aniline on Ru/C catalyst

Effects of impeller characteristics have been studied in the hydrogenation of aniline on Ru/C catalyst. Dual impellers were employed and the experiments were performed at 300 rpm using a lab-scale reactor. Reaction with disk turbines (DT) resulted in the higher cyclohexylamine (CHA) selectivity and higher reaction rate compared to that with pitched blade turbines (PBT). When a combination of PBT and DT impellers was employed, high product selectivity and reaction rate were obtained and the selectivity was maintained constant. Changes in the product selectivity with the impeller geometry were explained in terms of the relative rates of the side reactions depending on the hydrogen concentration in the reaction mixture.     

Lineage of non-cranial neural crest cell in the dental mesenchyme: using a lacZ reporter gene during early tooth development

The tooth is one of the ectodermal organs controlled by reciprocal interactions between the epithelium and the mesenchyme. Mesenchymal cells in the developing tooth, so-called dental mesenchymal cells, are derived from two different origins: the cranial neural crest (CNC) and the non-CNC. These CNC-derived cells migrate, proliferate and differentiate into odontoblasts, cementoblasts, fibroblasts, osteoblasts and chondroblasts. Tooth germs of wild-type mice were transplanted into the kidney of adult lacZ-transgenic mice. After 1 week of transplantation, a few lacZ-expressing cells and many red blood cells were found near or inside the blood vessels in the pulp of wild-type tooth germs. This result shows that circulating cells of the adult host could invade the dental pulp during tooth development, through the blood vessels, and be a part of dental pulp tissue. Therefore, it can be suggested that these circulating progenitor cells could be the origin of non-CNC-derived cells in tooth germ and their migration pathways would be the blood vessels invading the dental pulp during tooth development. If variations of this experiment were suitably adjusted, such as the embryonic stage of the tooth germ, duration of transplantation, etc., this transplantation experiment using adult lacZ-transgenic mice could be a good system to reveal the origin and migration pathway of cells in developing organs as well as in dental mesenchymal cells.     

Height measurement of microchip connecting pins by use of stereovision

A stereovision method for estimating the height of connecting pins on a microchip is described. The technique uses a centroidal method to simplify the calculation. A few seconds are required for a Pentium 586 PC to calculate the heights of 300 connecting pins on a 50 mm x 50 mm microchip. The method is described, and experimental results are presented. The optical system, which consists of two CCD cameras with long-focal-length lenses and a two-channel digital image grabber, is capable of in situ measurement.     

Estimation of anomaly location and size using electrical impedance tomography

We developed a new algorithm that estimates locations and sizes of anomalies in electrically conducting medium based on electrical impedance tomography (EIT) technique. When only the boundary current and voltage measurements are available, it is not practically feasible to reconstruct accurate high-resolution cross-sectional conductivity or resistivity images of a subject. In this paper, we focus our attention on the estimation of locations and sizes of anomalies with different conductivity values compared with the background tissues. We showed the performance of the algorithm from experimental results using a 32-channel EIT system and saline phantom. With about 1.73% measurement error in boundary current-voltage data, we found that the minimal size (area) of the detectable anomaly is about 0.72% of the size (area) of the phantom. Potential applications include the monitoring of impedance related physiological events and bubble detection in two-phase flow. Since this new algorithm requires neither any forward solver nor time-consuming minimization process, it is fast enough for various real-time applications in medicine and nondestructive testing.