This paper propose a method for improving the image quality of motion estimation (ME) using low-bit images. By using edge-enhanced images for quantization, we can increase the accuracy of the ME and improve the image quality. It is known that using low-bit images for ME is effective for reducing power consumption but it slightly degrades image quality. The quality of the encoded image depends on the thresholds for data quantization, thus, algorithms for determining thresholds are studied. The proposed method uses linear quantization, which simply truncates the least significant bits. This method is simple without any complicated threshold calculations, and the resultant image quality is improved as much as the methods that use threshold calculations. To evaluate the effectiveness, we simulate results for image quality and estimate the power consumption using synthesis results from a VHDL model motion estimator.

A halftoning technique that uses a simple GA has proven to be very effective to generate high quality halftone images. Recently, the two major drawbacks of this conventional halftoning technique with GAs, i.e. it uses a substantial amount of computer memory and processing time, have been overcome by using an improved GA (GA-SRM) that applies genetic operators in parallel putting them in a cooperative-competitive stand with each other. The halftoning problem is a true multiobjective optimization problem. However, so far, the GA based halftoning techniques have treated the problem as a single objective optimization problem. In this work, the improved GA-SRM is extended to a multiobjective optimization GA to simultaneously generate halftone images with various combinations of gray level precision and spatial resolution. Simulation results verify that the proposed scheme can effectively generate several high quality images simultaneously in a single run reducing even further the overall processing time.

We have proposed area-reduction techniques for superscalar datapath architectures with 34 SIMD instructions and have developed an integer-media unit based on these techniques. The unit's design is both functionally asymmetrical and integer-SIMD unified, and the resulting savings in area are 27%-48% as compared to other, functionally equivalent mid-level microprocessor designs, with performance that is, at most, only 7.2% lower. Further, in 2-D IDCT processing, the unit outperforms embedded microprocessor designs without SIMD functions by 49%-118%. Specifically, effective area reduction of adders, shifters, and multiply-and-adders has been achieved by using the unified design. These area-effective techniques are useful for embedded microprocessors and scalable systems that employ highly parallel superscalar and on-chip parallel architectures. The integer-media unit has been implemented in an evaluation chip fabricated with 0.15-µm 5-metal CMOS technology.

This paper presents a digital reaction-diffusion system (DRDS)--a model of a discrete-time discrete-space reaction-diffusion dynamical system--for designing new image processing algorithms inspired by biological pattern formation phenomena. The original idea is based on the Turing's model of pattern formation which is widely known in mathematical biology. We first show that the Turing's morphogenesis can be understood by analyzing the pattern forming property of the DRDS within the framework of multidimensional digital signal processing theory. This paper also describes the design of an adaptive DRDS for image processing tasks, such as enhancement and restoration of fingerprint images.

An uplink synchronised CDMA system through transmission timing control at mobile users has been proposed to improve the uplink capacity. This Letter mathematically investigates its capacity, considering perfect fast TPC and two antenna diversity reception in a single cell environment and compares it with that of a conventional CDMA system.

In this paper, we propose an ECG waveform compression technique based on the matching pursuit. The matching pursuit is an iterative non-orthogonal signal expansion technique. A signal is decomposed to atoms in a function dictionary. The constraint to the dictionary is only the over-completeness to signals. The function dictionary can be defined to be best match to the structure of the ECG waveform. In this paper, we introduce the multiscale analysis to the implementation of inner product computations between signals and atoms in the matching pursuit iteration. The computational cost can be reduced by utilization of the filter bank of the multiscale analysis. We show the waveform approximation capability of the matching pursuit with multiscale analysis. We show that a simple 4-tap integer filter bank is enough to the approximation and compression of ECG waveforms. In ECG waveform compression, we apply the error feed-back procedure to the matching pursuit iteration to reduce the norm of the approximation error. Finally, actual ECG waveform compression by the proposed method are demonstrated. The proposed method achieve the compression by the factor 10 to 30. The compression ratio given by the proposed method is higher than the orthogonal wavelet transform coding in the range of the reconstruction precision lower than 9% in PRD.

Although previous studies using artificial neural networks have been actively applied to object shape recognition, little attention has been paid to the recognition of spatial elements (e.g. position, rotation and size). In the present study, a rotation and size spreading associative neural network (RS-SAN net) is proposed and the efficacy of the RS-SAN net in object orientation (rotation), size and shape recognition is shown. The RS-SAN net pays attention to the fact that the spatial recognition system in the brain (parietal cortex) is involved in both the spatial (e.g. position, rotation and size) and shape recognition of an object. The RS-SAN net uses spatial spreading by spreading layers, generalized inverse learning and population vector methods for the recognition of the object. The information of the object orientation and size is spread by double spreading layers which have similar tuning characteristics to spatial discrimination neurons (e.g. axis orientation neurons and size discrimination neurons) in the parietal cortex. The RS-SAN net simultaneously recognizes the size of the object irrespective of its orientation and shape, the orientation irrespective of its size and shape, and the shape irrespective of its size and orientation.

As a method of analyzing the wave scattering from a finite periodic surface, this paper introduces a periodic approach. The approach first considers the wave diffraction by a periodic surface that is a superposition of surface profiles generated by displacing the finite periodic surface by every integer multiple of the period . It is pointed out that the Floquet solution for such a periodic case becomes an integral representation of the scattered field from the finite periodic surface when the period goes to infinity. A mathematical relation estimating the scattering amplitude for the finite periodic surface from the diffraction amplitude for the periodic surface is proposed. From some numerical examples, it is concluded that the scattering cross section for the finite periodic surface can be well estimated from the diffraction amplitude for a sufficiently large .

In this paper we describe a multicast routing algorithm, which builds upon mobile multicast agents of an ad-hoc network. Mobile multicast agents (MMAs) form a virtual backbone of an ad-hoc network and they provide multicast tree discovery, multicast tree maintenance and datagram delivery. First, we construct a cluster-spine hierarchy structure for an ad-hoc network. Second, we propose a multicast routing algorithm, which is inspired by Ad-hoc On-Demand Distance Vector (AODV) routing protocol. The results show that the MMA multicast algorithm can simplify the multicast tree discovery, reduce control overhead of the network, and increase the total network throughput, in comparison with general AODV multicast operation. We also overcome the deficiency of CBRP multicast routing, which places much burden on cluster heads.

This paper proposes a measure of coefficient quantization errors for linear discrete-time state-space systems. The proposed measure of state-space systems agrees with the actual output error variance since it is derived from the exact evaluation of the output error variance due to coefficient deviation. The measure in this paper is represented by the controllability and the observability gramians and the state covariance matrix of the system. When the variance of coefficient variations is very small, the proposed measure is identical to the conventional statistical sensitivity of state-space systems. This paper also proposes a method of synthesizing minimum measure structures. Numerical examples show that the proposed measure is in very good agreement with the actual output error variance, and that minimum measure structures have a very small degradation of the frequency characteristic due to coefficient quantization.

In two- or more-dimensional systems where the components of the sample data are strongly correlated, it is not proper to divide the input space into several subspaces without considering the correlation. In this paper, we propose the usage of the method of principal component in order to uncorrelate and remove any redundancy from the input space of the adaptive neuro-fuzzy inference system (ANFIS). This leads to an effective partition of the input space to the fuzzy model and significantly reduces the modeling error. A computer simulation for two frequently used benchmark problems shows that ANFIS with the uncorrelation process performs better than the original ANFIS under the same conditions.

In [3], the decision feedback channel estimation (DFCE) for M-ary orthogonal modulation in direct sequence/code division multiple access (DS/CDMA) systems was proposed. However, the performance of the DFCE in the multiuser environment is severely degraded due to multiple access interference (MAI). In this letter, to overcome this problem, we modify the DFCE as multistage configurations using a multistage parallel interference cancellation (PIC) scheme. According to the results of our simulations, the performance of coherent demodulation using the proposed multistage DFCE is significantly improved in comparison with conventional demodulation in [3].

This paper addresses a technique for multiplexing voice streams into an IP packet for efficient VoIP transportation. The principles and distinctive schemes are presented and a comparative performance evaluation of the schemes based on a prototype is provided. In this paper, a scheme using a dynamic packet length threshold is proposed. As a conclusion, we show the scheme is beneficial for shortening packetization delay compared with the scheme in which multiple coded blocks in one voice stream are carried by an IP packet and superior with respect to reducing the header overhead and the number of generated packets.

Negative differential conductance based on lateral interband tunnel effect is demonstrated in a planar degenerate p+-n+ diode (Esaki tunnel diode). The device is fabricated with the current silicon ultralarge scale integration (Si ULSI) process, paying attention to the processing damage so as to reduce an excess tunnel current that flows over some intermediate states in the tunnel junction. I-V characteristics at a low temperature clearly show an intrinsic electron transport, indicating phonon-assisted tunneling in Si as in the case of the previous Esaki diodes fabricated by the alloying method. In addition, a simple circuit function of bistable operation is demonstrated by connecting the planar Esaki diode with conventional Si metal-oxide-semiconductor field effect transistors (MOSFETs). The planar Esaki diode will be a promising device element in the functional library for enhancing the total system performance for the coming system-on-a-chip (SoC) era.

A mobile ad hoc network (MANET) is a characterized by multi-hop wireless links, absence of any cellular infrastructure, and frequent host mobility. Existing MANET routing protocols are divided into location-aware and non-location-aware routing protocols. In a location-aware routing protocol, location information can be exploited to facilitate routing. Our protocol, namely multi-eye spiral-hopping (MESH) routing protocol, is a location-aware routing protocol. Most promising routing protocols are constructed by the route-discovery, route-reply, and route-maintenance phases. Our MESH protocol utilizes the location-information to confine the blind-flooding region in the route-discovery phase, minimize route-reply packets in the route-reply phase, and promote the routing robustness in the route-maintenance phase. Two major contributions of this paper are introduced: (1) a multi-eye scheme is presented to confine route-discovery region for reducing redundant packets, and (2) a special multi-path scheme, called as spiral-hopping scheme, is introduced to provide on-line route-recovery capability. Extensive simulations are conducted to evaluate the protocol.

In this paper, we evaluate the performance of flow control mechanisms for reliable multicast under several retransmission approaches in terms of scalability. The mechanisms examined are a window-based flow control mechanism for ACK-based retransmission approaches and a rate-based flow control mechanism for NAK-based retransmission approaches. Our simulation results show that the NAK-based flow control mechanism has better scalability and higher throughput than the ACK-based flow control mechanism, and the delay incurred by a NAK suppression mechanism does not affect the performance of multicast flow control.

For the microwave level meter based on the FM-CW radar, we analyze the spectrum correlation of beat signals and propose a measurement algorithm using the fact that there exists a peak in the spectrum correlation of beat signals when range difference is sufficiently small. This algorithm can compensate the nonlinear effect of VCO frequency sweep, making it possible to determine the range difference in a precise manner even using a practical VCO. We present some experimental results to show the validity of this algorithm.

Since each ATM virtual path (VP) contains bundles of virtual channels (VCs), a VP layer network can serve as a server layer and each VC layer network can be a client layer. Therefore the effective VC service provisioning depends completely on the reliability of the VP layer network. We propose the ATM virtual path (VP) management framework with dynamic routing and rerouting schemes in a hierarchical transport network. The routing algorithm aims to provide the globally optimal route in a hierarchical network environment from the perspectives of maximization of network resource utilization and satisfaction of the end user's QoS requirement. The rerouting algorithm guarantees network survivability in the event of network faults or performance degradations. We also propose the implementation model of the ATM virtual path network management system (VP-NMS). Lastly, we evaluate the routing and rerouting performance for a real network, the High Speed Information Network (HSIN) of Korea Telecom.

This paper proposes a novel fast algorithm for the decomposition and reconstruction of two-dimensional (2-D) signals by box splines. The authors have already proposed an algorithm to calculate the discrete box splines which enables the fast reconstruction of 2-D signals (images) from box spline coefficients. The problem still remains in the decomposition process to derive the box spline coefficients from an input image. This paper first investigates the decomposition algorithm which consists of the truncated geometric series of the inverse filter and the steepest descent method with momentum (SDM). The reconstruction process is also developed to correspond to the enlargement of images. The proposed algorithm is tested for the expansion of several natural images. As a result, the peak signal-to-noise ratio (PSNR) of the reconstructed images became more than 50 dB, which can be considered as enough high level. Moreover, the property of box splines are discussed in comparison with 2-D (the tensor product of) B-splines.

The capacity analysis of CDMA forward link is required to allocate high data-rate users. To solve this problem, we analyze the capacity of the CDMA forward link based on optimum power control. In a multi-cell environment, the intracell interference and intercell interference are derived. To show the capacity impact of high data-rate users, we introduce a location dependent factor, which is the ratio of intercell interference to intracell interference. Considering the location dependent factor, we propose a coordinated allocation scheme that can be used to allocate high data-rate users in sectorized cells. As a result, we show the capacity impact of high data-rate users according to location variations. The outage probability can be decreased when the coordinated allocation scheme is applied.