This paper describes an efficient PCRD (Post-Compression Rate-Distortion) scheme for rate control of JPEG2000. The proposed method determines the rate constant in consideration of the decreasing characteristic of RD-slopes and conducts rate allocation about only coding passes excluded from the previous rate allocation. As a result, it can considerably reduce the number of operations and encoding time with nearly the same PSNR performance as the conventional rate control scheme of JPEG2000.

In this paper, ultra-wideband (UWB) multiple access systems are introduced by using direct-sequence (DS) and hybrid direct-sequence time-hopping (DS/TH) code division multiple access (CDMA) that use arbitrary chip-duty of the spreading sequences. The bit error probabilities are presented. First of all, the variances of the multiple access interference are developed by investigating the collision properties of the signals. Afterward, various approximations are applied. The standard Gaussian approximation (SGA) for the DS system is shown to become extremely optimistic as the chip-duty becomes low. Though the hybrid system performs better, the SGA still remains optimistic. To obtain accurate results, Holtzman's simplified improved Gaussian approximation (SIGA) and Morrow and Lehnert's improved Gaussian approximation (IGA) are used. A shortcoming of the SIGA is rediscovered that renders it unusable for low-duty DS systems, especially, at high signal-to-noise ratio. However, for the hybrid system, the SIGA works as an excellent tool. The IGA is used to get accurate results for the low-duty DS systems. It is shown that lowering of chip-duty by keeping chip rate and chip length unchanged improves performance for asynchronous DS and both asynchronous and synchronous hybrid systems. However, under the same processing gain, a high-duty system performs better than a low-duty system. Performance of synchronous DS system remains independent of chip-duty.

A triple density Error Diffusion for medical monochrome LCDs is proposed to improve their gray-scale precisions. In addition, a measurement technique of image qualities based on E-MSE (Eye model-based Mean Square Error) is proposed. Several conventional techniques for medical LCDs, such as Sub-Pixel Modulation and Error Diffusion, are evaluated based on E-MSE and the validity of the proposed technique is ensured objectively.

This paper proposed a novel intelligent intrusion detection, decision, response system with fuzzy theory. This system utilized the two essential informations: times and time, of the failed login to decide automatically whether this login is a misuse user as alike as experienced system/security administrators. The database of this system isn't preestablished before working but is built and updated automatically during working. And this system is not only notification system but gives the exact and rapid decision and response to a misuse.

Feedback-type Adaptive Array Antenna has been proposed for frequency division duplexed (FDD) system, where the mobile station (MS) measures channel characteristics and sends those back to the base station (BS). Using a higher number of feed-back bits provides better performance. However it wastes channel capacity of the up-link. On the other hand, error in feedback signals transmission causes significant performance degradation. To solve these problems, this paper proposes a method that the MS sends back the difference between the optimum weights calculated at the MS and weights which are currently used at the BS. Bit error rate performance of the system is shown under a realistic propagation condition.

This paper presents a hybrid decimal division algorithm to improve division speed. The proposed hybrid algorithm employs either non-restoring or restoring algorithm on each digit to reduce iterative computations. The selection of the algorithm is based on the relative remainder values with respect to the half of its divisor. The proposed algorithm requires maximum 7n+4 add/subtract operations for an n-digit quotient, whereas other restoring or non-restoring schemes comprise more than 10n+1 operations.

This paper proposes a multiple-input multiple-output (MIMO) eigenmode transmission technique which transmits different data streams on eigenmodes of different multi-path components while suppressing intra and inter-eigenmode interferences by means of a turbo equalization technique. This paper also evaluates the effectiveness of the proposed system in frequency selective fading conditions. Computer simulation results confirms the proposed technique is effective even in high spatial correlation cases.

Our investigation is presented into analysis of the co-channel interference (CCI) statistic in orthogonal frequency-division multiple access (OFDMA) uplink systems. The derived statistic is then used to analyze the performance of reuse partitioning (RP)-based dynamic channel allocation (DCA). Analysis and simulation results show that the performance of DCA in multi-cell environments is noticeably dependent on the CCI. Finally, the results of the analysis yield the optimum RP area for achieving the maximum spectral efficiency.

A baseband transmission scheme for wireless communications has been proposed and examined using a pair of discone antennas for transmission and reception. The wireless baseband transmission scheme radiates a baseband signal stream, such as non-return-to-zero (NRZ), return-to-zero (RZ), or Manchester encoded signals, directly from an antenna. Namely, a carrier in terms of a sinusoidal radio wave or light wave is not used in the transmission. In experiments, baseband pulses generated with a data generator were radiated directly from the discone antenna, and received waveforms were observed with a digital storage oscilloscope. The experiments showed that wireless baseband transmission is realisable when using antennas with a flat amplitude spectrum and a linear phase characteristic, such as discone antennas, over a given band. Manchester encoding is promising for this wireless baseband transmission.

This study investigates a band extension technique for speech data encoded with G.711, the most common codec for digital speech communications system such as VoIP. The proposed technique employs steganography for the transmission of the side information required for the band extension. Due to the steganography, the proposed technique is able to enhance the speech quality without an increase of the amount of data transmission. From the results of a subjective experiment, it is indicated that the proposed technique may potentially be useful for improving the speech quality, compared with the conventional technique.

This paper discusses the design and performance of on-chip passive components of transmission lines (TR) and inductors. First, the measurement technique of on chip passives is discussed. A transmission line that can be used for Gbps signal propagation on Si CMOS is examined. As a high density transmission line structure of diagonal-pair differential TR line is described. Also, a circuit and TR line is introduced for above 10 Gbps signal propagation. The on-chip inductor which is a key passive component in RF application of Si CMOS technology is discussed. We examine some on-chip inductors that have been developed in our group: small area inductor, high performance inductor using WL-CSP (Wafer-Level Chip-Size-Packaging) technology. Finally, a wide tuning range LC-VCO using a variable inductor for RF reconfigurable circuit is introduced.

Visualizing occluded objects is a useful applications of Mixed Reality (MR), which we call "see-through vision." For this application, it is important to display occluded objects in such a manner that they can be recognized intuitively by the user. Here, we evaluated four visualization methods for see-through vision that can aid the user to recognize occluded objects in outdoor scenes intuitively: "elimination of occluding objects," "ground grid," "overlaying model of occluding object," and "top-down view." As we used a new handheld MR device for outdoor see-through vision, we performed subjective experiments to determine the best combination of methods. The experimental results indicated that a combination of showing the ground grid, overlaying wireframe models of occluding objects, and top-down view to be optimal, while it was not necessary to display occluding objects for outdoor see-through vision with a handheld device, because users can see them with the naked eye.

In this paper, we discuss the issue of empathy-inducing effect brought by Japanese Haiku, regarded as the world-shortest poetry. Its condensed form of word combination sometimes arouses deep impression and empathy in readers. Its possibilities as communication media would be enhanced in multimedia contexts, when considering educational purpose or cross-cultural interchanges. An experimental result is shown for evaluating multimedia effect on combined presentation of a CG drawing and its associated haiku in English. We confirmed that various aspects of visual impression and empathy were sometimes enhanced with certain haiku text as linguistic stimuli, compared with the condition of viewing a CG drawing only. The reason of raised empathy was analyzed from the various aspects of the content provided by the associated haiku text complementary for the drawing. Moreover, we examined the effects of poetic styles on subjects' empathy, using Japanese prose and conventional haiku style (5-7-5 syllabic rhyme), both of them were translated from the same haiku in English.

Two schemes for fast identification of JPEG coded images are proposed in this paper. The aim is to identify the JPEG images that are generated from the same original image and have equivalent or different compression ratios. Fast identification can be achieved since the schemes work on the quantized Discrete Cosine Transform (DCT) domain. It is not required to inverse the quantization and the DCT. Moreover, only a few coefficients are commonly required for identification. The first approach can avoid identification leakage or false negative (FN), and probably result in a few false positives (FP). The second approach can avoid both FN and FP, with a slightly higher processing time. By combining the two schemes, a faster and a more perfect identification can be achieved, in which FN and FP can be avoided.

This paper describes the efficiency of VLSI architecture for UMHexagonS (hybrid Unsymmetrical cross Multi Hexagon grid Search) matching algorithm. This algorithm is used for ME (Motion Estimation) of H.264/AVC video compression standard. The UMHexagonS is called a hybrid algorithm since it uses different kinds of searching patterns. VLSI architecture based on UMHexagonS is designed to provide a good tradeoff between gate sizes and high throughput. We implemented this architecture with about 309 K gates and 1/1792 throughput [block/cycle] for a search range of 16 and 44 macro blocks using synthesizable Verilog HDL.

The present research examines the relationship between texture processing and object processing in human vision. Recent computational studies have suggested a difference between the stages of processing. Texture processing can be performed by using statistical parameterization of the response of primary spatial filters. Object processing requires more complex and elaborate computation at a higher stage than texture processing. Our psychophysical experiments are conducted to clarify the relationship of the stages of texture processing and object processing, by focusing on same-object effect which facilitates and speeds attention shifts within the same object and also costs and delays attention shifts if the attention focus moves from one object to another. Texture is composed of lines parallel to, perpendicular to or inside of elongated rectangles used as objects. The same-object effect is measured with reaction time in a cued detection task. Vertical rectangles are used in xperiment 1 and horizontal ones are used in Experiment 2. Experiment 1 shows that the texture lines interrupt the same-object effect and that the interruption is nearly equal if texture lines are added both to the background and the inside of the objects. Experiment 2 yields the result same as Experiment 1. The interruption of the same-object effect by adding texture lines suggests that texture processing affects object processing.

In this letter, orthogonal frequency division multiplexing-code division multiplexing (OFDM-CDM) using a novel 2-dimensional spreading scheme is proposed as a candidate for a next-generation multiple access scheme. Full residual frequency diversity gain can be obtained with OFDM-CDM by adapting the proposed 2-dimensional spreading scheme with a novel frequency-hopping technique. Setting the frequency-hopping pattern in proper consideration of the coherent channel bandwidth allows us to exploit both the full frequency diversity and the time diversity in any channel environment.

An all-digital clock deskew buffer with variable duty cycles is presented. The proposed circuit aligns the input and output clocks with two cycles. A pulsewidth detector using the sequential time-to-digital conversion is employed to detect the duty cycle. The output clock with adjustable duty cycles can be generated. The proposed circuit has been fabricated in a 0.35 µm CMOS technology. The measured duty cycle of the output clock can be adjusted from 30% to 70% in steps of 10%. The operation frequency range is from 400 MHz to 600 MHz.

This paper focuses on the design and the performance evaluation of a p-persistent transmission control protocol that can enhance the IEEE 802.11 MAC, namely the p-persistent IEEE 802.11 DCF. Unlike the well-known p-persistent CSMA for modeling the legacy IEEE 802.11 MAC, the proposed protocol truly exploits the p-persistent transmission capability for this MAC. Moreover, the protocol is not restricted to IEEE 802.11 and, in fact, it can be executed on the top of a pre-existent access protocol without introducing additional overhead. When considered with WLAN, this protocol can optimize the throughput of the wireless network by setting the optimal transmission probability in the IEEE 802.11 MAC according to the throughput calculation given in this paper. The key characteristics of this protocol are represented by its simplicity, integration with the Standard, complete distribution, absence of modifications to the original IEEE 802.11 MAC frame format, and no requirement of extra messages being shared by the cooperating nodes. Analysis and simulation results confirm the effectiveness of the p-persistent protocol in achieving the optimal throughput and in improving the frame delay. In addition, the protocol can be easily extended to be a distributed priority mechanism, which requires further research.

In this paper, for the fully-implantable middle ear hearing devices (F-IMEHD), a transcutaneous recharging system that has the function of the bi-directional signal transmission with the implant module in a body as well as recharging battery has been designed and implemented. The electromagnetic coupling method using two coils has been adopted for the transfer of electrical power to recharge internal battery of the implant module. To increase the efficiency of power transfer, the switching frequency of recharging system is determined by the consideration of the resonance of LC tank circuits. The bidirectional signal transmission between the recharging system and the implant module has been designed through the on-off keying modulation of switching signal in the recharging system and the impedance variation of LC tank circuit in the implant module. Through the demonstration of the implemented system, it has been verified that the proposed system has the performance of bidirectional signal transmission with the implant module of F-IMEHDs as well as the battery recharging.