Institute of Electronics, Information and Communication Engineers

A total-field/scattered-field (TF/SF) boundary which is commonly used in the finite-difference time-domain (FDTD) method to illuminate scatterers by plane waves, is developed for use in the constrained interpolation profile (CIP) method. By taking the numerical dispersion into account, the nearly perfect TF/SF boundary can be achieved, which allows us to calculate incident fields containing high frequency components without fictitious scattered fields. First of all, we formulate the TF/SF boundary in the CIP scheme. The numerical dispersion relation is then reviewed. Finally the numerical dispersion is implemented in the TF/SF boundary to estimate deformed incident fields. The performance of the nearly perfect TF/SF boundary is examined by measuring leaked fields in the SF region, and the proposed method drastically diminish the leakage compared with the simple TF/SF boundary.

This paper considers a proportional fairness of end-to-end session rates in a multihop wireless network through the rate control framework. In multihop wireless networks, there are two classes of rate control problem. One focuses in optimizing the transmission attempt probabilities at the lower layers, but not the transmit powers while other problem is closely related to jointly optimal congestion control and power control. Proportional fairness is a fundamental concept in flow control problems. In this paper, we give in-depth analysis and show that the optimal solutions of these problems are proportionally fair provided that the objective functions are suitably chosen.

In this paper, we proposed a new high-rate oblique deposition method using two sputtering sources to obtain SiO2 films for a liquid crystal alignment layer. One sputtering source that operates in a metal mode supplies Si atoms to a substrate, and the other source that operates in an oxide mode supplies oxygen radicals to a substrate. To reduce the gas pressure of a deposition chamber and make the two sputtering sources operate in different modes, the sputtering sources were separated from the deposition chamber with stainless meshes, and Ar and oxygen gases were introduced separately through the two sputtering sources, i. e., Ar gas was introduced through the Si supply source and oxygen gas was introduced through the oxygen radical source. When Ar gas of 30sccm and oxygen gas of 4sccm were introduced into the system, the gas pressure of the deposition chamber was maintained below 1.7m Torr and the films deposited at an incidence angle of more than 70° showed an elongated inclined columnar structure. Under this condition, a deposition rate of 30nm/min was realized even at an incidence angle above 70°, where most of the Si atoms incident to the substrate were supplied by the Si supply source and the oxygen radical source supplied oxygen radicals and promoted the oxidation of the film.

In this paper, BER (Bit Error Rate) performance in 2×2 MIMO (Multiple-Input Multiple-Output) spatial multiplexing systems under Rician fading channels is evaluated. We examine BER performances employing inverse channel detection (ICD) under Rician fading channels, adding the phase of the direct path and Rician factor as a parameter. The results clearly indicate that the phase of the direct path and Rician factor have a great influence on BER performances employing ICD under Rician fading channels.

We propose an antenna grouping method that improves the error rate performance of space-time codes in a wide range of mobility environments. The idea is to group symbols to antennas based on limited feedback from the mobile station to utilize all antennas. Our approach requires only two bits of feedback information to achieve better link performance and full rate for a certain four transmit antenna system. Numerical results confirm the bit/frame error gains over the Alamouti-based space-time block code and antenna subset selection strategies.

Liquid crystal (LC) lenses that have hole-patterned electrodes and are driven by two voltages used as imaging devices are reported. Two different LC lenses are applied in image formation systems. One LC lens is used with a polarizer in a relay lens scope, and another LC lens that is polarization independent is used in a TV lens. Both LC lenses play roles of focusing elements in lens systems; objects are separately brought into focus by the LC lenses. Very sharp black-and-white and color images are formed by the systems.

Since Bellare and Ristenpart showed a multi-property preserving domain extension transform, the problem of the construction for multi-property hash functions has been reduced to that of the construction for multi-property compression functions. However, the Davies-Meyer compression function that is commonly used for standard hash functions is not a multi-property compression function. That is, in the ideal cipher model, the Davies-Meyer compression function is collision resistant, but it is not indifferentiable from a random oracle. In this paper, we show that the compression function proposed by Lai and Massey is a multi-property compression function. In addition, we show that the simplified version of the Lai-Massey compression function is also a multi-property compression function. The use of these compression functions enables us to construct multi-property hash functions by the multi-property preserving domain extension transform.

In this study, attenuated total reflection (ATR) utilizing surface plasmon (SP) excitation and SP emission lights were observed for the adsorption of polystyrene (PS) spheres and a water-soluble polymer. The PS spheres contained fluorescent dyes and exhibited red fluorescence. The ATR properties indicated film deposition with increasing number of adsorption cycles. The SP emission light induced by the fluorescent dye in the spheres was also measured, and an increase in the peak intensity, as well as an angle shift, was observed. Furthermore, the SP emission light spectra were investigated at various emission angles. The dispersion relation obtained from the SP emission light almost corresponded to that obtained from the ATR curves.

SUMMARY This paper proposes new switch architectures for hierarchical optical path cross-connect (HOXC) systems. The architectures allow incremental expansion of system scale in terms of the number of input/output fiber ports, wavebands, and optical paths per waveband. These features assure the cost-effective introduction of HOXCs even at the outset when traffic volume is not so large. Furthermore the effectiveness of the proposed switch architectures is demonstrated in a comparison with singlelayer OXCs (conventional OXCs). The results provide useful criteria for the introduction of HOXCs in terms of hardware scale. Broadband access including ADSL and FTTH is being rapidly adopted throughout the world and, as a result, traffic is continually increasing. The maximum number of WDM wavelengths per fiber now exceeds one hundred, and wavelength routing using ROADMs (Reconfigurable OADMs) is being widely adopted to develop cost-effective networks [1]. GMPLS controlled OXCs have also been used to create nation-wide testbeds [2]. Further traffic expansion is expected in the near future with the introduction of new broadband services including IP TV and high definition TV. This will result in a significant increase in the number of wavelength paths that are to be cross-connected at nodes, and hence optical node throughput needs to be greatly enhanced. To resolve this problem, the hierarchical optical path crossconnect (HOXC) [3]–[5] is being investigated; it can handle hierarchical bandwidth optical paths, wavelength paths and wavebands (WBs) which consist of multiple wavelength paths. Indeed, several studies have targeted the development of hierarchical optical path network design algorithms [6]– [9], these algorithms were shown to greatly lower network cost compared to conventional single-layer optical path networks for a wide range of traffic demand. Most of the works evaluated the effectiveness in terms of the total number of OXC and HOXC ports compared to those of single-layer OXCs. Another study [10] showed that an HOXC with nonuniform WB size can not only improve node throughput but also reduce cross-connect node cost. The key components needed to develop HOXCs are waveband multi/demultiplexers (WB MUX/DEMUX),

Data transmission via audio link on AM radio system is shown to be achievable by using Acoustic OFDM. We employ Acoustic OFDM to embed data onto audio contents that are then broadcast as AM radio signals. We tuned the parameters, and performed experiments. Text data as URL can be delivered to mobile phone through existing MF AM radio system and radios.