According to the Gestalt principals, this paper presents a recognition method of grouping areas in trademark images modeling features for measuring the attraction degree between couples of image components. This investigation would be used for content-based image retrieval from the view of mirroring human perception for images. Depending on variability in human perception for trademark images, the proposed method finds grouping areas by calculating Mahalanobis distance with the features to every combination of two components in images. The features are extracted from every combination of two components in images, and the features represent proximity, shape similarity, and closure between two components. In addition, changing combination of the features, plural grouping patterns are output. Besides, this paper shows the efficiency and limits of the proposed method from experimental results. In the experiments, 104 participants have perceived grouping patterns to 74 trademark images and the human perceptions have been compared with outputs by the proposed method for the 74 images.

The operation of analog circuits from ultra low supply voltages becomes necessary due to semiconductor technology scaling. Yet traditional design techniques cannot be used. In this paper, we review techniques that allow analog circuits to operate with supply voltages as low as 0.5 V. Biasing considerations are given, and robust bias circuits are discussed. For frequency-tunable circuits, a low-voltage MOS varactor tuning technique is presented. The techniques discussed are applied to two different OTA topologies, as well as to an automatically tuned, fifth-order active RC filter. This material is largely based on the work of the authors as described in [1]-[5].

In this letter two noise-predictive equalization schemes, which are based on zero-forcing (ZF) and minimum mean square error (MMSE) criteria, are presented for unique-word (UW) based single-carrier systems. The correlation properties of the noises in the outputs of the frequency domain equalizer are exploited to predict and cancel the noise contained in the estimation of data. Theoretical analyses show that both of the proposed techniques perform better than the conventional frequency domain equalizers. Simulation results have confirmed the significant performance improvement they could achieve.

This paper proposes a new all digital dividing ratio changeable phase locked loop (D-DCPLL) using delay clock pulse that exhibits low output jitter characteristics compared with the conventional DCPLL. This is achieved by employing the delay clock pulse generated from the ring oscillator for the standard clock controlling the loop. This output jitter is always constant regardless of the frequency fluctuation of the delay clock, and the fluctuation coefficient has little effect on the output jitter. This circuit can expand the upper bound frequency of the lock-in range compared with conventional DCPLL when the permissible output jitter is identical. Furthermore, the proposed D-DCPLL can obtain an initial pull-in in one period of the input signal and the multiplication output signal of the constant pulse interval can be obtained by using the remainder control circuit.

High-resolution FMCW reflectometry is often realized by sampling the beat signal with a clock signal generated from an auxiliary interferometer. The drawback of this system is that the measurement range is limited to less than half of the optical path difference of the auxiliary interferometer to satisfy the Sampling theorem. We propose and demonstrate a method to extend the measurement range of the system. The clock signal gerenerated from the auxiliary interferometer is electronically frequency-multipled by using a PLL circuit. The measurement range is experimentally extended by a factor of 20 while keeping high spatial resolution, and is theoretically extended by a factor of 128. The advantage of the proposed system is that the optical path difference of the auxiliary interferometer can be kept short, which is very effective for obtaining the stable and low time-jitter clock signal.

We study the configuration issue of three-stage multi-granularity optical cross-connects (MG-OXC) for the dynamic traffic model in all-optical networks. From the single node point of view, we propose a configuration algorithm to configure different granularity cross-connects for arrival sub-requests with different traffic types and bandwidths. The performance of the configuration algorithm is evaluated by simulation and, furthermore, is validated by experiment based on our flexible Multi-functional Optical Switching Testbed (MOST).

Real-time object detection or recognition technology becomes more important for various intelligent vision systems. Processing models for object detection or recognition from natural images should tolerate pattern deformations and pattern position shifts. The hierarchical convolutional neural networks are considered as a promising model for robust object detection/recognition. This model requires huge computational power for a large number of multiply-and-accumulation operations. In order to apply this model to robot vision or various intelligent real-time vision systems, its LSI implementation is essential. This paper proposes a new algorithm for reducing multiply-and-accumulation operation by sorting neuron outputs by magnitude. We also propose an LSI architecture based on this algorithm. As a proof of concept for our LSI architecture, we have designed, fabricated and tested two test LSIs: a sorting LSI and an image-filtering LSI. The sorting LSI is designed based on the content addressable memory (CAM) circuit technology. The image-filtering LSI is designed for parallel processing by analog circuit array based on the merged/mixed analog-digital approach. We have verified the validity of our LSI architecture by measuring the LSIs.

If a certain number of receiver processors (RPs) are reserved exclusively for new calls, some decrease in the probability of blocking new calls (Pn) can be obtained at the expense of increase in dropping handoff calls (Ph). This kind of prioritization has been often considered for handoff calls. Since soft handoff in CDMA systems results in sufficiently low Ph, an idea of prioritizing new calls is interesting when admitting more originating traffic into the system is relatively beneficial, which will be further investigated in this paper. An obvious constraint of the above idea is that Ph should be maintained below a given requirement. We formulate the proposed scheme as a mathematical programming problem and prove it improves the performance in terms of weighted carried traffic. As a result of this work, the prioritization of new calls is shown to possibly improve the traffic-carrying performance of a CDMA base station (BS) while maintaining an acceptable level of Ph, which can be prespecified by a system engineer.

We describe attempts to have robots behave as embodied knowledge media that will permit knowledge to be communicated through embodied interactions in the real world. The key issue here is to give robots the ability to associate interactions with information content while interacting with a communication partner. Toward this end, we present two contributions in this paper. The first concerns the formation and maintenance of joint intention, which is needed to sustain the communication of knowledge between humans and robots. We describe an architecture consisting of multiple layers that enables interaction with people at different speeds. We propose the use of an affordance-based method for fast interactions. For medium-speed interactions, we propose basing control on an entrainment mechanism. For slow interactions, we propose employing defeasible interaction patterns based on probabilistic reasoning. The second contribution is concerned with the design and implementation of a robot that can listen to a human instructor to elicit knowledge, and present the content of this knowledge to a person who needs it in an appropriate situation. In addition, we discuss future research agenda toward achieving robots serving as embodied knowledge media, and fit the robots-as-embodied-knowledge-media view in a larger perspective of Conversational Informatics.

The rapid hybrid acquisition of PN sequences is proposed for DS/CDMA systems. The system introduces the excision CFAR method into the background power estimation. A mathematical analysis is done for the single path and multipath environments. The detection performance of the proposed scheme is compared with that of other acquisition schemes. Results show that the proposed method has better detection performance if the excision coefficient is properly selected.

A wireless sensor network is a network of compact micro-sensors equipped with wireless communication capability. In a wireless sensor network, saving energy is a critical issue. Furthermore, a sensor node is expected to face many difficulties in signaling and computing. As a MAC scheme for a wireless sensor network, we thus propose an energy-aware version of pure ALOHA scheme, where rather than sacrificing the simplicity of pure ALOHA, we take a straightforward approach in saving energy by trading off throughput performance. First, we add a step of deciding between stop and continuation prior to each delivery attempt for a MAC PDU. Secondly, we find an optimal stopping rule for such a decision in consideration of the losses reflecting energy consumption as well as throughput degradation. In particular, we note that the results of delivery attempts are hardly predictable in the environment that sensor nodes contend for the error-prone wireless resource. Thus, presuming that only partial information about such results is available to sensor nodes, we explicitly draw an optimal stopping rule. Finally, numerical examples are given to demonstrate the expected losses incurred by optimal stopping rules with full and partial information.

In this study, we achieved predictable control of a wheelchair by changing the existing mapping method of the joystick, which considers the consecutive operations of a motor of a wheelchair, to a new mapping method that corresponds to the internal model of a human being. Since the existing method uses the polar coordinate system, it is not easy at all to use this method to predict either the direction of motion or the operating order for changing the position of the wheelchair according to the requirements of an operator. In order to improve the embodiment, we divided the existing joystick mapping method into two degrees of freedom-one in the vertical axis that can control the velocity and the other, in the horizontal axis for direction control. Based on this division, we implemented a wheelchair model that can be controlled by the electromyography (EMG) signal from the neck and the arm muscles of an operator. This was achieved by mapping the divided degrees of freedom onto the degrees of freedom of the neck and arm of the operator. In this case, since the operator controls the direction of motion by the joint of his/her neck, he/she can move the wheelchair in the desired direction; thus, a more intuitive human interface is implemented.

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.

Quantum-dot Cellular Automata (QCA) is attracting a lot of attentions due to its extremely small feature sizes and ultra low power consumption. Up to now several designs using QCA technology have been proposed. However, we found not all of the designs function properly. Further, no general design guidelines have been proposed so far. A straightforward extension of a simple functional design pattern may fail. This makes designing a large scale circuits using QCA technology an extremely time-consuming process. In this paper we show several critical vulnerabilities in the structures of primitive QCA gates and QCA interconnects, and propose a disciplinary guideline to prevent any additional plausible but malfunctioning QCA designs.

A new method to reduce power consumption of a linear transconductor is proposed in this paper. The minimum tail current for the operation of the transconductor is supplied by a new current source circuit. The proposed circuit is based on a dynamic biasing current technique. Results of SPICE simulation show that the proposed technique is very effective to reduce power consumption of the transconductor.

A LC oscillator based upon the quadrature magnetic coupling to generate a mutual negative resistance (mu-R) is introduced. The topology offers enhanced optimum phase noise at low supply voltages by enabling extended circuit operation in the current-limited regime through the control of its mutual inductors' coupling factor, k. The principal operation of the mu-R oscillator is described and its comparison with the popular cross-coupled topology is discussed. The capability of the technique is demonstrated via design examples of 1.8 GHz oscillators. Simulations show that, by employing inductors with a self-inductance of 2 nH, a quality factor of about 7.5 and a coupling k=0.52, the mu-R oscillator exhibits the minimum phase noise of -142 dBc/Hz at 3 MHz-offset with 18 mA bias current and 2 V supply. This is 3-dB more than the minimum achievable phase noise in the cross-coupled oscillator with identical component parameters and supply voltage level.

In this paper, the voice signal processing module has been designed using the micro processor for the use of fully implantable middle ear devices (F-IMEHD). The voice signal processing module for F-IMEHD should be designed to compensate for the hearing loss of hearing impaired person and have the flexibility for compensating various hearing threshold level. So, the voice signal processing module has been designed and implemented to present the various frequency characteristics using the low-power micro processor, MSP430F169. The different voice signal path to the inner ear entrance was considered so that two voice signal would be combined in-phase using an all pass filter with a constant time-delay to improve the vibration of the ossicles.

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.

We report a specially designed encoding technique for sign language video sequences supposing that the technique is for sign telecommunication such as that using mobile videophones with a low bitrate. The technique is composed of three methods: gradient coding, precedence macroblock coding, and not-coded coding. These methods are based on the idea to distribute a certain number of bits for each macroblock according to the evaluation of importance of parts of the picture. They were implemented on a computer and encoded data of a short clip of sign language dialogue was evaluated by deaf subjects. As a result, the efficiency of the technique was confirmed.

Assistive technology (AT) is becoming increasingly important for improving the mobility and language learning capabilities of persons with disabilities, thus enabling them to function independently and to improve their social opportunities. The Morse code has been shown to be a valuable tool in assistive technology, augmentative and alternative communication, and rehabilitation for people with neuromuscular diseases such as amyotrophic lateral sclerosis, multiple sclerosis, and muscular dystrophy. In this paper, we designed and implemented a wireless environmental control aid system using the Morse code as an adapted access communication tool, which includes three types of switch: single-switch, double-switch, and six-switch types. People with disabilities can easily control all types of electronic appliance without restrictions owing to spatial arrangements using a signal transmission based on radio frequency (RF). Experimental results revealed that three participants with disabilities were able to gain access to electronic facilities after six weeks of practice with the new system.