One of the important topics of watermarking technique is a robustness against geometrical transformations. In the previous schemes, a template matching is performed or an additional signal is embedded for the recovery of a synchronization loss. However, the former requires the original template, and the latter degrades the quality of image because both a watermark and a synchronization signal must be embedded. In the proposed scheme only a synchronization signal is embedded for the recovery of both a watermark and a synchronization loss. Then the embedded information depends on the distance between two embedded signal positions. The distance is not changed seriously by random geometrical transformations like StirMark attack unless the embedded signal is disturbed. Therefore, a watermark can be extracted correctly from such geometrically transformed image if the synchronization signal can be recovered.

The measurement of the 3-dimensional behavior of early reflections in a sound field has been an important issue in auditorium acoustics since the reflection profile has been found to be strongly correlated with the subjective responsiveness of a listener. In order to detect the incidence angle and relative amplitude of reflections, a 4-point microphone system has conventionally been used. A new measurement system is proposed in this paper, which has 5 microphones. Microphones are located on each four apex of a tetrahedron and at the center of gravity. Early reflections, including simultaneously incident reflections,which previous 4-point microphone system could not discriminate as individual wavefronts, were successfully found with the new system. In order to calculate accurate image source positions, it is necessary to determine the exact peak positions from measured impulse responses composed of highly deformed and overlapped impulse trains. For this purpose, a peak-detecting algorithm, which finds dominant peaks in the impulse response by an iteration method, is introduced. In this paper, the theoretical background and features of the 5-microphone system are described. Also, some results of experiments using this system are described.

This paper proposes a model to calculate statistical gate-delay variation caused by intra-chip and inter-chip variabilities. The variation of each gate delay directly influences the circuit-delay variation, so it is important to characterize each gate-delay variation accurately. Every transistor in a gate affects transient characteristics of the gate, so it is indispensable to consider an intra-gate variability for the modeling of gate-delay variation. This effect is not captured in a statistical delay analysis reported so far. Our model considers the intra-gate variability by sensitivity constants. We evaluate our modeling accuracy, and we show some simulated results of a circuit delay variation.

We propose a stochastic model for signals generated through the electron multiplying effect of detectors in charged particle beam equipments. This model is based on a stochastic variable characterized by a log-normal type distribution. The model is simple and can be used to represent a wide dynamic range of signals from pulse-like signals when the primary beam current is small to continuous signals when the primary beam current is large. For the model base reference a normalization of actual signal detectors is presented. This base reference yields the unique stochastic parameter used in our model. The proposed model better approximates the actual signals in the power spectrum distribution as compared to the filtered Poisson method presented elsewhere.

In supervised learning, the selection of sample points and models is crucial for acquiring a higher level of the generalization capability. So far, the problems of active learning and model selection have been independently studied. If sample points and models are simultaneously optimized, then a higher level of the generalization capability is expected. We call this problem active learning with model selection. However, active learning with model selection can not be generally solved by simply combining existing active learning and model selection techniques because of the active learning/model selection dilemma: the model should be fixed for selecting sample points and conversely the sample points should be fixed for selecting models. In this paper, we show that the dilemma can be dissolved if there is a set of sample points that is optimal for all models in consideration. Based on this idea, we give a practical procedure for active learning with model selection in trigonometric polynomial models. The effectiveness of the proposed procedure is demonstrated through computer simulations.

Chain codes were developed for storing contour information for shape matching. The traditional chain codes are highly susceptible to small perturbations in the contours of the objects. Therefore, traditional chain codes could not be used for image retrieval based on the shape boundaries from the large databases. In this paper, a histogram based chain codes are proposed which could be used for image retrieval. The proposed chain codes are invariant to translation, rotation and scaling transformations, and have high immunity to noise and small perturbations.

This paper presents a variable pipeline depth processor, which can dynamically adjust its pipeline depth and operating voltage at run-time, we call dynamic pipeline and voltage scaling (DPVS), depending on the workload characteristics under timing constraints. The advantage of adjusting pipeline depth is that it can eliminate the useless energy dissipation of the additional stalls, or NOPs and wrong-path instructions which would increase as the pipeline depth grow deeper in excess of the inherent parallelism. Although dynamic voltage scaling (DVS) is a very effective technique in itself for reducing energy dissipation, lowering supply voltage also causes performance degradation. By combining with dynamic pipeline scaling (DPS), it would be possible to retain performance at required level while reducing energy dissipation much further. Experimental results show the effectiveness of our DPVS approach for a variety of benchmarks, reducing total energy dissipation by up to 64.90% with an average of 27.42% without any effect on performance, compared with a processor using only DVS.

As the CMOS technology enters the very deep submicron era, inter-wire coupling capacitance becomes the dominant part of load capacitance. The coupling effects have brought new challenges to routing algorithms on both delay estimation and optimization. In this paper, we propose a timing-driven global routing algorithm with consideration of coupling effects. Our two-phase algorithm based on timing-relax method includes a heuristic Steiner tree algorithm to guarantee the timing performance of the initial solution and an optimization algorithm based on coupling-effect-transference. Experimental results are given to demonstrate the efficiency and accuracy of the algorithm.

A good watermark is known to be perceptually invisible, undetectable without key and robust to spatial/temporal data modification. In this paper, we utilize the characteristics of the human visual system (HVS) for watermarking. In HVS, the response of visual cortex decomposes the image spectra into perceptual channels that are octave bands in spatial frequency. Based on the octave-bands division, same numbers of bits of the watermark are inserted into each channel. Experimental results show that the proposed method based on HVS method gives strong robustness to the attacks compared with conventional DCT, wavelet and DFT watermarking methods.

Parameter-optimized cubic convolution is used to accurately analyze the pitch center, rate and extent of vibrato tones. We interpolate the time-tracing fundamental frequencies of vibrato tones using parametric cubic convolution, and analytically estimate the positions and values of the extrema, which are used to analyze the characteristics of the vibrato. The optimal values of α, the parameter of the interpolation kernel, are also shown as a function of the normalized vibrato rates.

The purpose of this paper is to propose a novel cluster map based blind RBF equalizer for received signal constellation (RSC) independent channel, which belongs to RSC based blind equalization approach. Without channel estimator, firstly, the desired numbers of unlabeled RBF centers are obtained by an unsupervised clustering algorithm. Then a cluster map generated from the known RBF equalizer structure is used to partition the unlabeled centers into appropriate subsets merely by several simple sorting operations, which corresponds to the weight initialization. Finally, the weight is adjusted iteratively by an unsupervised least mean square (LMS) algorithm. Since the process of the weight initialization using the underlying structure of RBF equalizer is very effective, the proposed blind RBF equalizer can achieve almost identical performance with the optimal RBF equalizer. The validity of the proposed equalizer is also demonstrated by computer simulations.

The paper develops the transformation rules in order to use the Stochastic Petri Net model to evaluate the performance of various task scheduling algorithms. The transformation rules are applied to DFRN scheduling algorithm to investigate its effectiveness. The performance comparison reveals that the proposed approach provides very accurate evaluation for the scheduling algorithm when the Communication to Computation Ratio value is small.

Temporal locality in IP destination address sequences can be captured by the addresses' reuse distance distribution. Based on measurements from data for a wide range of networks, we propose an accurate empirical model in contrast to results derived from the stationarity assumption of address generation processes.

Recently routing protocols for QoS aware multicast are actively studied, but there are few studies focusing on the scalability of link state advertisement when the available bandwidth of a link is updated along with the QoS aware multicast tree construction. This paper proposes a new QoS aware multicast routing protocol that is scalable in terms of the link state advertisement exchange. Our protocol has the following features; (1) A multicast network is divided into domains, and the advertisement of information on links within a domain is limited within the domain. (2) Among the border multicast routers, only the link state information of inter-domain links is advertised. As a result, the number of link state advertisement messages will be drastically reduced. (3) When a multicast tree spreads over multiple domains, the tree construction needs to be performed without information on links in other domains, and it is possible that the construction may fail. In order to cope with this problem, the crank back mechanism of a tree construction is introduced. This paper describes the detailed procedures and the message formats of our protocol. It also describes the evaluation of the number of exchanged link state advertisement messages and shows that our protocol can reduce the number comparing with the conventional protocols.

For the reception of MC-CDMA signals in a frequency-selective fading channel, frequency-domain equalization is necessary before despreading. In this paper, joint antenna diversity combining and one-tap frequency-domain equalization is considered (simply referred to as the joint antenna diversity & equalization, in this paper). A receiver structure for joint antenna diversity & equalization is presented and the unified weights based on minimum mean square error (MMSE) criterion are found in the presence of multi-users with different spreading factors and transmit powers. For comparison, antenna diversity combining after despreading using MMSE combining (MMSEC) is also considered. The achievable bit error rate (BER) performances with joint antenna diversity & equalization and with antenna diversity after MMSEC despreading in a frequency-selective Rayleigh fading channel are evaluated by computer simulations and compared.

OFDM is a good scheme to transmit high rate data under a multi-path environment. With a sufficiently long guard interval (GI), it is possible to totally eliminate interference between symbols or carriers with OFDM. However, long guard intervals reduce the spectrum efficiency of OFDM. Thus, shortening the guard interval as much as possible is highly desirable. As short guard intervals will usually result in interference in an OFDM system, an interference canceller would be necessary to enable the use of short guard intervals without unduly degrading system performance. This paper presents a possible adaptive interference cancellation scheme for OFDM to help attain this objective.

A mathematical expression for the received signal power in a severe frequency-selective fading channel is derived. Using the derived expression, the signal power distributions are obtained by Monte-Carlo simulation and compared with the Nakagami m-power distribution. It is found that the power distribution matches well with the Nakagami m-power distribution when the multipath channel has a uniform power delay profile.

A two-dimensional laser beam profiler has been developed that can measure the intensity distribution on a sample surface of a single-shot of an excimer-laser light beam from not only the macroscopic viewpoint, but also the microscopic viewpoint, which is important to excimer-laser triggered lateral large-grain growth of Si. A resolution as fine as 0.4 µm was obtained with a field of view of as large as 30 µm 30 µm. The effects of homogenizers, phase-shifters, and their combination on beam profiles were quantitatively investigated by using this apparatus. The relationship between the microscopic beam profile and the surface morphology of laterally grown grains was also examined.

To speed up on-line analytical processing (OLAP), data warehouse, which is usually derived from operational databases, is introduced. When the operational databases happen to change, the data warehouse gets stale. To maintain the freshness of data warehouse, operational database changes need to be frequently and concurrently propagated into the data warehouse. However, if several update transactions are allowed to execute concurrently without an appropriate concurrency control, data inconsistency between data warehouse and operational databases could arise due to incorrect propagation of changes on the operational databases into the data warehouse. In this paper, we propose a new concurrency control scheme, which could execute a number of update transactions in a consistent way. Whenever an update transaction tries to update a data that is being used by OLAP transactions, our scheme allows the update transaction to create a new version of the data. To investigate the applicable areas of our scheme, its performance is evaluated by means of simulation approach. Our experimental results show that the proposed scheme enables OLAP transactions to continuously read a very fresh data without wasting a lot of time to find out an appropriate version of the data from the version pool.

Hash-based IP traceback is a technique to generate audit trails for traffic within a network. Using the audit trails, it reconstructs not only the true attack paths of a Distributed Denial of Service attack (DDoS attack), but also the true path of a single packet attack. However, hash-based IP traceback cannot identify attacker nodes themselves because it has no audit trail on the subnet's layer-2 network under the detected leaf router, which is the nearest node to an attacker node on a layer-3 network. We propose a layer-2 extension to hash-based IP traceback, which stores two identifiers with packets' audit trails while reducing the memory requirement for storing identifiers. One of these identifiers shows the leaf router's interface through which an attacking packet came, and the other represents the ingress port on a layer-2 switch through which the attacking packet came. We implement a prototype on FreeBSD and evaluate it in a preliminary experiment.