Bandwidth-Compensation Method for Miniaturized Parallel Coupled-Line Filters

This paper proposes a bandwidth-compensation method for miniaturized filters based on short-ended parallel coupled lines. Capacitive loading of such coupled lines is a relatively simple means of reducing the line lengths. In this study, a method is developed that predicts exactly the degree of reduction in the fractional bandwidth due to miniaturization. Using this method, the fractional bandwidth of the prototype coupled line filter can be adjusted, enabling miniaturized filters to maintain the targeted fractional bandwidth. The proposed bandwidth-compensation method applies for any type of filters with coupled lines realized with various transmission lines, with uniform or nonuniform line lengths. Experimental results are also presented that verify the validity of the method.     

Note: Interpolation for evaluation of a two-dimensional spatial profile of plasma densities at low gas pressures

An interpolation algorithm for the evaluation of the spatial profile of plasma densities in a cylindrical reactor was developed for low gas pressures. The algorithm is based on a collisionless two-dimensional fluid model. Contrary to the collisional case, i.e., diffusion fluid model, the fitting algorithm depends on the aspect ratio of the cylindrical reactor. The spatial density profile of the collisionless fitting algorithm is presented in two-dimensional images and compared with the results of the diffusion fluid model.     

Sonar Sensor-Based Efficient Exploration Method Using Sonar Salient Features and Several Gains

This paper describes a sonar sensor-based exploration method. To build an accurate map in an unknown environment during exploration, a simultaneous localization and mapping problem must be solved. Therefore, a new type of sonar feature called a ??sonar salient feature?? (SS-feature), is proposed for robust data association. The key concept of an SS-feature is to extract circle feature clouds on salient convex objects from environments by associating sets of sonar data. The SS-feature is used as an observation in the extended Kalman filter (EKF)-based SLAM framework. A suitable strategy is needed to efficiently explore the environment. We used utilities of driving cost, expected information about an unknown area, and localization quality. Through this strategy, the exploration method can greatly reduce behavior that leads a robot to explore a previously visited place, and thus shorten the exploration distance. A robot can select a favorable path for localization by localization gain during exploration. Thus, the robot can estimate its pose more robustly than other methods that do not consider localizability during exploration. This proposed exploration method was verified by various experiments, and it ensures that a robot can build an accurate map fully autonomously with sonar sensors in various home environments.     

Korean language math-to-speech rules for digital books for people with reading disabilities and their usability evaluation

The Journal of Supercomputing - Although Digital Accessible Information System, an international digital talking book standard, is conducting active research on upper level education for people...     

Modeling of hermetic transitions for microwave packages

Two numerical techniques, the finite difference in time domain (FDTD) and the finite element method (FEM) in frequency domain, are employed to characterize microstrip hermetic transition geometries in an effort to investigate high-frequency effects. Measurements performed on these transitions compare favorably with theory. Two different types of transitions have been analyzed from 10 to 25 GHz and have been found to be limited in performance by higher return loss as frequency increases. It is shown that microstrip-through-CPW hermetic transitions in the shielded environment may suffer from parasitic waveguide modes which, however, can be eliminated with the use of vias at appropriate locations. The hermetic wall on top of the CPW section shows a relatively small (≤ 2 dB) effect on the original circuit performance. Similarly, the hermetic bead transition shows good performance at a lower frequency region while it degrades as frequency increases. This indicates the need for very careful characterization of transitions intended for use in microwave and millimeter-wave applications. © 1996 John Wiley & Sons, Inc.     

Irradiation Effects on Free Radical Scavenging and Antioxidant Activity of Phytic Acid

ABSTRACT: Free radical scavenging and antioxidant activities of irradiated phytic acid at various concentrations were studied. Phytic acid sodium salt dissolved in deionized distilled water was irradiated at 0, 5, 10, 15, and 20 kGy. The degradation of phytic acid by irradiation was observed, and it was found that the concentrations had an effect on the degree of degradation. Stable 2,2-diphenyl-1-picrylhydrazyl radical scavenging ability of phytic acid was significantly increased by irradiation ( P < 0.05) and was positively correlated with irradiation dose ( P < 0.01). Antioxidant activity of phytic acid in lipid model systems was slightly increased by irradiation; however, at higher concentrations, the activity was reduced or was the same compared with nonirradiated phytic acid.     

Cyanidin-3-glucoside ameliorates CCl4-induced liver injury in mice

The protective effect of cyanidin-3-glucoside (C3G) against carbon tetrachloride (CCl₄)-induced liver injury in mice was investigated. Administration of C3G attenuated the levels of serum aspartate aminotransferase, alanine aminotransferase, and liver lipid peroxidation in CCl₄-treated mice. Histopathological examination of mouse livers showed that C3G reduced the incidence of liver lesions induced by CCl₄. Moreover, C3G prevented DNA damage and decreased the protein levels of γ-H2AX in CCl₄-treated mouse livers. C3G also increased the activity of the antioxidant enzymes superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase, which were decreased due to CCl₄ administration in CCl₄-treated mouse livers. C3G inhibited the expression levels of IL-6 and iNOS in CCl₄-treated mice. C3G apparently protects the liver from CCl₄-induced hepatic damage through antioxidant and anti-inflammatory mechanisms.     

Efficiency improvement of polymer light-emitting diodes using a quantum dot interlayer between a hole transport layer and an emitting layer

The current efficiency of polymer light-emitting diodes (PLEDs) were improved using a quantum dot interlayer between a hole transport layer and an emitting layer. The quantum dot interlayer played a role of controlling the hole transport in the PLEDs and enhanced the charge balance in the emitting layer. The current efficiency of the PLEDs was increased by more than 20% by the quantum dot interlayer. In particular, the efficiency improvement was significant at high luminance due to reduced efficiency roll-off in the quantum dot-embedded PLEDs.     

The improvement of color and shelf life of ham by gamma irradiation.

This study was undertaken to determine if gamma irradiation can circumvent the need for sodium nitrite to obtain and maintain the desired color of pork loin ham. A dose of 5 kGy was observed to be as effective as the use of 200 ppm of sodium nitrite to provide and maintain the desired color of the product for 30 days. Peroxidation of the product was reduced with addition of sodium nitrite but increased with irradiation. However, organoleptic quality of the irradiated ham without added sodium nitrite was acceptable.     

Compact stripline-fed meander slot antenna

A meander-type slot antenna fed by a stripline is proposed for use in miniaturised personal communication systems. By varying the slot configuration of the antenna, a 56% smaller antenna to substitute the conventional slot antenna is achieved. Simulated and measured results are presented