An equalizer initialization technique for least mean squares (LMS) algorithm, which can equalize frequency selective multiple input multiple output (MIMO) channels, is presented and analyzed. The proposed method conducts an initial convergence step for superior training prior to running the LMS algorithm. This approach raises the training performance while the complexity of the LMS algorithm, which is known as the simplest training algorithm, is almost the same. The proposed technique is analyzed for the initial convergence and simulated for a possible single carrier MIMO application in single carrier (SC) IEEE802.16-2004 standards. The obtained performance after coding approximates the performance of the recursive least squares (RLS) algorithm as it is presented for 33 and 55 MIMO for comparisons.
Chano KIM Seungjae SHIN Chanil PARK Hyunsoo YOON
In a large-scale sensor network, replicated hostile nodes may be used for harsh inner attacks. To detect replicas, this paper presents a distributed, deterministic, and efficient approach robust to node compromise attacks without incurring significant resource overheads.
In this paper, a novel method of partially placing electromagnetic band-gap (EBG) unit cells on both the power and ground planes in multi-layer PCBs and packages is proposed; it can not only sufficiently eliminate simultaneous switching noise (SSN), but also prevent severe degradation of signal quality in high-speed systems with imperfect reference planes resulting from the perforated structures of uni-planar EBG unit cells. On the assumption that the noise sources and noise-sensitive devices exist only in specific areas, the proposed method partially arranges the EBG unit cells on both the power and ground planes, but only around the critical areas. The SSN suppression performance of the proposed structure is verified by a simulation and measurements.
Hisashi YAMAMOTO Tomoaki AKIBA Hideki NAGATSUKA
In this paper, first, we propose a new recursive algorithm for evaluating generalized multi-state k-out-of-n:F systems. This recursive algorithm can be applied to the systems even though the states of all components in the system are assumed to be non-i.i.d. random variables. Our algorithm is useful for any multi-state k-out-of-n:F system, including the decreasing, increasing and constant multi-state k-out-of-n:F system. Furthermore, our algorithm can evaluate the state distributions of the other non-monotonic multi-state k-out-of-n:F systems. Next, we calculate the order of computing time and memory capacity of the proposed algorithm. We perform numerical experiments in the non-i.i.d. case. The results show that the proposed algorithm is efficient for evaluating the system state distribution of multi-state k-out-of-n:F system when n is large and kl are small.
Yongjoon KIM Myung-Hoon YANG Jaeseok PARK Eunsei PARK Sungho KANG
This paper presents a grouped scan slice encoding technique using scan slice repetition to simultaneously reduce test data volume and test application time. Using this method, many scan slices that would be incompatible with the conventional selective scan slice method can be encoded as compatible scan slices. Experiments were performed with ISCAS'89 and ITC'99 benchmark circuits, and results show the effectiveness of the proposed method.
Hiroki IMAMURA Asami HISAMATSU Makoto FUJIMURA Hideo KURODA
We propose an automatic generative method for stylus style CG as automatic generative method for non-photorealistic CG.
Toshio ITO Tetsuya SATO Kan TULATHIMUTTE Masanori SUGIMOTO Hiromichi HASHIZUME
We have introduced a new ultrasonic-based localization method that requires only one ultrasonic receiver to locate transmitters. In our previous reports [1],[2], we conducted several fundamental experiments, and proved the feasibility and accuracy of our system. However the performance in a more realistic environment has not yet been evaluated. In this paper, we have extended our localization system into a robot tracking system, and conducted experiments where the system tracked a moving robot. Localization was executed both by our proposed method and by the conventional TOA method. The experiment was repeated with different density of receivers. Thus we were able to compare the accuracy and the scalability between our proposed method and the conventional method. As a result 90-percentile of the position error was from 6.2 cm to 14.6 cm for the proposed method, from 4.0 cm to 6.1 cm for the conventional method. However our proposed method succeeded in calculating the position of the transmitter in 95% out of total attempts of localization with sparse receivers (4 receivers in about 5 m 5 m area), whereas the success rate was only 31% for the conventional method. From the result we concluded that although the proposed method is less accurate it can cover a wider area with sparse receivers than the conventional method. In addition to the dynamic tracking experiments, we also conducted some localization experiments where the robot stood still. This was because we wanted to investigate the reason why the localization accuracy degraded in the dynamic tracking. According to the result, the degradation of accuracy might be due to the systematic error in localization which is dependent on the geometric relationship between the transmitter and the receiver.
Masataka MIYAKE Daisuke HORI Norio SADACHIKA Uwe FELDMANN Mitiko MIURA-MATTAUSCH Hans Jurgen MATTAUSCH Tatsuya OHGURO Takahiro IIZUKA Masahiko TAGUCHI Shunsuke MIYAMOTO
Frequency dependent properties of accumulation-mode MOS varactors, which are key elements in many RF circuits, are dominated by Non-Quasi-Static (NQS) effects in the carrier transport. The circuit performances containing MOS varactors can hardly be reproduced without considering the NQS effect in MOS-varactor models. For the LC-VCO circuit as an example it is verified that frequency-tuning range and oscillation amplitude can be overestimated by over 20% and more than a factor 2, respectively, without inclusion of the NQS effect.
Fengchao XIAO Kimitoshi MURANO Yoshio KAMI
In this paper the time-domain analysis of two parallel traces is investigated. First, the telegrapher's equations for transmission line are applied to the parallel traces on printed circuit board (PCB), and are solved by using the mode decomposition technique. The time-domain solutions are then obtained by using the inverse Laplace transform. Although the Fourier-transform technique is also applicable for this problem, the solution is given numerically. Contrarily, the inverse Laplace transform successfully leads to an analytical expression for the transmission characteristics. The analytical expression is represented by series, which clearly explains the coupling mechanism. The analytical expression for the fundamental section of a meander delay line is investigated in detail. The analytical solution is validated by measurements, and the characteristics of the distortions in the output waveforms of meander delay lines due to the crosstalk are also investigated.
Tatsuo NAKAGAWA Tatsuji MATSUURA Eiki IMAIZUMI Junya KUDOH Goichi ONO Masayuki MIYAZAKI
A 1-GHz input bandwidth analog-to-digital (A/D) converter for an ultra-wideband impulse radio (UWB-IR) receiver is developed. Both an under-sampling sample-and-hold (S/H) circuit and a dynamic current-reduction comparator are proposed for the A/D converter. An under-sampling S/H circuit, which digitizes an input signal at a higher frequency than the sampling frequency with low power consumption, is required because the UWB-IR system utilizes intermittent ultrashort impulses. The proposed S/H circuit executes sampling by separating a sampling capacitor from an operational amplifier and accumulating the offset voltage of the amplifier in the other capacitor. The proposed dynamic current reduction comparator reduces bias current dynamically corresponding to its input-voltage level. The A/D converter is implemented in a 0.18-µm CMOS process technology, which achieves an effective number of bits of 5.5, 5.4, and 4.9 for input signals with frequencies of 1, 513, and 1057 MHz, respectively, at 32 M samples/s. The converter consumes 0.89 mA and 0.42 mA in the analog and digital component, respectively, at a 1.8-V supply.
Jong Hwa KWON Dong Uk SIM Sang Il KWAK Jong Gwan YOOK
To build a stable power distribution network for high-speed digital systems, simultaneous switching noise (SSN) should be sufficiently suppressed in multi-layer PCBs and packages. In this paper, a novel hybrid uni-planar compact electromagnetic bandgap (UC-EBG) with two triangular-type unit cells designed on power/ground planes is proposed for the ultra-broadband suppression of SSN. The SSN suppression performance of the proposed structure is validated both numerically and experimentally. A -35 dB suppression bandwidth for SSN is achieved, starting at 800 MHz and extending to 15 GHz and beyond, thereby covering almost the entire noise band.
Buddika ADIKARI Anil FERNANDO Rajitha WEERAKKODY Ahmet M. KONDOZ
Distributed video coding (DVC) technology has been considered to be capable of reducing the processing complexity of the encoder immensely, while majority of the computational overheads are taken over by the decoder. In the common DVC framework, the pictures are decoded using the Wyner-Ziv encoded bit stream received from the encoder and the side information estimated using previously decoded information. As a result, accuracy of the side information estimation is very critical in improving the coding efficiency. In this paper we propose a novel side information refinement technique for DVC using multiple side information streams and sequential motion compensation with luminance and chrominance information involving iterative fusion of parallel information streams. In the bit plane wise coding architecture, previously decoded higher order bit planes are incrementally used to perform the motion estimation jointly in luminance and chrominance spaces to estimate multiple redundant bit streams for iterative fusion to produce more improved side information for subsequent bit planes. Simulation results show significant objective quality gain can be achieved at the same bit rate by utilizing the proposed refinement algorithms.
Choonhwa LEE Seungjae LEE Eunsam KIM Wonjun LEE
This letter presents a new approach to provide inter-domain service compositions for OSGi environments. Our proposal of remote wire objects extends OSGi's wiring capability across the framework boundaries, so that even remote services can join in the composition. Hence, a better composition is made possible with a richer set of candidate services from foreign domains.
Cognitive radio (CR) is an adaptive spectrum sharing paradigm targeted to provide opportunistic spectrum access to secondary users for whom the frequency bands have not been licensed. The key tasks in a CR are to sense the spectral environment over a wide frequency band and allow unlicensed secondary users (CR users) to dynamically transmit/receive data over frequency bands unutilized by licensed primary users. Thus the CR transceiver should dynamically adapt its channel (frequency band) in response to the time-varying frequencies of wideband signal for seamless communication. In this paper, we present a low complexity reconfigurable filter architecture based on multi-band filtering and frequency masking techniques for dynamic channel adaptation in CR terminal. The proposed multi-standard architecture is capable of adapting to channels having different bandwidths corresponding to the channel spacing of time-varying channels. Design examples show that proposed architecture offers 12.2% power reduction and 26.5% average gate count reduction over conventional Per-Channel based architecture.
Alexis ANDRE Suguru SAITO Masayuki NAKAJIMA
We propose a sketch-based modeling system where all user input is performed from a unique viewpoint. The strokes drawn by the user must not then be restricted to the drawing plane: their orientation in the 3D space is automatically determined by the system. The desired surface is reconstructed from a grid made of two groups of similar lines, that are considered co-planar. The orientation of the two sets of planes is determined by assuming that at the intersection of a representative line of each group, those two lines are perpendicular.
David AVIS Sonoko MORIYAMA Masaki OWARI
The first part of this paper contains an introduction to Bell inequalities and Tsirelson's theorem for the non-specialist. The next part gives an explicit optimum construction for the "hard" part of Tsirelson's theorem. In the final part we describe how upper bounds on the maximal quantum violation of Bell inequalities can be obtained by an extension of Tsirelson's theorem, and survey very recent results on how exact bounds may be obtained by solving an infinite series of semidefinite programs.
Choonhwa LEE Sunghoon KO Eunsam KIM Wonjun LEE
This letter describes combining OSGi and Web Services in service composition. According to our approach, a composite service is described in WS-BPEL. Each component service in the description may be resolved to either an OSGi service or Web Service at runtime. The proposal can overcome current limitations with OSGi technology in terms of its geographical coverage and candidate service population available for service composition.
Teruya MINAMOTO Mitsuaki YOSHIHARA
In this letter, we propose new digital audio watermarking methods using interval wavelet decomposition. We develop not only non-blind type method, but also blind one. Experimental results demonstrate that the proposed methods give a watermarked audio clip of better quality and are robust against some attacks.
Yong ZHANG Shensheng ZHANG Songqiao HAN
This paper proposes a novel service configuration approach that can realize dynamic critical Quality of Service (QoS) adaptation to ever-changing and resource-limited ubiquitous computing environments. In the approach, service configuration is reduced to a Fuzzy Control System (FCS) which aims to achieve critical QoS variations on minimal level with less power cost. Two configuration strategies, service chain reconfiguration and QoS parameters adjustment, along with a configuration algorithm, are implemented to handle different types of QoS variations. A self-optimizing algorithm is designed to enhance the adaptation of the FCS. Simulation results validate the proposed approach.
Masataka MIYAKE Daisuke HORI Norio SADACHIKA Uwe FELDMANN Mitiko MIURA-MATTAUSCH Hans Jurgen MATTAUSCH Takahiro IIZUKA Kazuya MATSUZAWA Yasuyuki SAHARA Teruhiko HOSHIDA Toshiro TSUKADA
We analyze the carrier dynamics in MOSFETs under low-voltage operation. For this purpose the displacement (charging/discharging) current, induced during switching operations is studied experimentally and theoretically for a 90 nm CMOS technology. It is found that the experimental transient characteristics can only be well reproduced in the circuit simulation of low voltage applications by considering the carrier-transit delay in the compact MOSFET model. Long carrier transit delay under the low voltage switching-on operation results in long duration of the displacement current flow. On the other hand, the switching-off characteristics are independent of the bias condition.