This paper proposes an energy efficient processor which can be used as a design alternative for the dynamic voltage scaling (DVS) processors in embedded system design. The processor consists of multiple PE (processing element) cores and a selective set-associative cache memory. The PE-cores have the same instruction set architecture but differ in their clock speeds and energy consumptions. Only a single PE-core is activated at a time and the other PE-cores are deactivated using clock gating and signal gating techniques. The major advantage over the DVS processors is a small overhead for changing its performance. The gate-level simulation demonstrates that our processor can change its performance within 1.5 microsecond and dissipates about 10 nano-joule while conventional DVS processors need hundreds of microseconds and dissipate a few micro-joule for the performance transition. This makes it possible to apply our multi-performance processor to many real-time systems and to perform finer grained and more sophisticated dynamic voltage control.

Design-complexity metrics, while measured from the code, have shown to be good predictors of fault-prone object-oriented programs. Some of the most often used metrics are the Chidamber and Kemerer metrics (CK). This paper discusses how to make early predictions of fault-prone object-oriented classes, using a UML approximation of three CK metrics. First, we present a simple approach to approximate Weighted Methods per Class (WMC), Response For Class (RFC) and Coupling Between Objects (CBO) CK metrics using UML collaboration diagrams. Then, we study the application of two data normalization techniques. Such study has a twofold purpose: to decrease the error approximation in measuring the mentioned CK metrics from UML diagrams, and to obtain a more similar data distribution of these metrics among software projects so that better prediction results are obtained when using the same prediction model across different software projects. Finally, we construct three prediction models with the source code of a package of an open source software project (Mylyn from Eclipse), and we test them with several other packages and three different small size software projects, using their UML and code metrics for comparison. The results of our empirical study lead us to conclude that the proposed UML RFC and UML CBO metrics can predict fault-proneness of code almost with the same accuracy as their respective code metrics do. The elimination of outliers and the normalization procedure used were of great utility, not only for enabling our UML metrics to predict fault-proneness of code using a code-based prediction model but also for improving the prediction results of our models across different software packages and projects.

Through fractional sampling (FS) it is possible to separate multipath components and achieve path diversity. However, if no path component whose delay corresponds to the sampling point, FS cannot obtain diversity gain. In this paper, a novel scheme to improve the performance with FS over a sparse multipath channel is proposed. The proposed scheme uses multiple transmit antennas and sends multiple signals with fractional delays. The performance improvement with the proposed scheme is confirmed through computer simulation. It is shown that the proposed scheme increases the capacity of a MIMO-OFDM system by a factor of 1.5 to 2 and improves the BER performance on the sparse multipath channels.

Processing structures required in sensing are designed to convert real-world information into useful information, and there are various restrictions and performance goals depending on physical restrictions and the target applications. On the other hand, network technologies are mainly designed for data exchange in the information world, as is seen in packet communications, and do not go well with sensing structures from the viewpoints of real-time properties, spatial continuity, etc. This indicates the need for understanding the architectures and restrictions of sensor technologies and network technologies when aiming to fuse these technologies. This paper clarifies the differences between these processing structures, proposes some issues to be addressed in order to achieve real fusion of them, and presents future directions toward real fusion of sensor technologies and network technologies.

Ternary Content Addressable Memory (TCAM) is a special type of memory used in routers to achieve high-speed packet forwarding and classification. Packet forwarding is done by referring to the rules written in the routing table, whereas packet classification is performed by referring to the rules in the Access Control List (ACL). TCAM uses more transistors than Random Access Memory (RAM), resulting in high power consumption and high production cost. Therefore, it is necessary to reduce the entries written in the TCAM to reduce the transistor count. In this paper, we propose a new TCAM architecture by using Range Matching Devices (RMD) integrated within the TCAM's control logic with an optimized prefix expansion algorithm. The proposed method reduces the number of entries required to express ACL rules, especially when specifying port ranges. With less than 10 RMDs, the total number of lines required to write port ranges in the TCAM can be reduced to approximately 50%.

In this paper, we investigate two receiver structures for spatially multiplexed transmission on MIMO frequency selective fading channels. Those receivers compensate the IAI (Inter-Antenna Interference) and ISI (Inter-Symbol Interference) in the time domain. We first propose the MIMO sequential equalizer in which the block of several receives symbols is processed symbol by symbol by MLD (Maximum Likelihood Detection). Next we investigate the MIMO MLSE (Maximum Likelihood Sequence Estimation) receiver in which the terminated block trellis is decoded by the Viterbi algorithm. The bit error rates of two time domain receivers are examined through computer simulations and we also compare their BER characteristics to those of the conventional MIMO SC-FDE.

Recently there has been a surge of interest in construction of low correlation zone sequences. The purpose of this paper is to survey the known results in the area and to present an interleaved construction of binary low correlation zone sequences. The interleaved construction unifies many constructions currently available in the literature. These sequences are useful in quasi-synchronous code-division multiple access (QS-CDMA) communication systems.

A new type of digital filter for removing impulsive noise in color images is proposed using interactive evolutionary computing. This filter is realized as a rule-based system containing switching median filters. This filter detects impulsive noise in color images with rules and applies switching median filters only at the noisy pixel. Interactive evolutionary computing (IEC) is adopted to optimize the filter parameters, considering the subjective assessment by human vision. In order to detect impulsive noise precisely, complicated rules with multiple parameters are required. Here, the relationship between color components and the degree of peculiarity of the pixel value are utilized in the rules. Usually, optimization of such a complicated rule-based system is difficult, but IEC enables such optimization easily. Moreover, human taste and subjective sense are highly considered in the filter performance. Computer simulations are shown for noisy images to verify its high performance.

Broadband wireless technology that enables a variety of gigabit-per-second class data services is a requirement in future wireless communication systems. Broadband wireless channels become extremely frequency-selective and cause severe inter-symbol interference (ISI). Furthermore, the average received signal power changes in a random manner because of the shadowing and distance-dependant path losses resulted from the movement of a mobile terminal (MT). Accordingly, the transmission performance severely degrades. To overcome the performance degradation, two most promising approaches are the frequency-domain equalization (FDE) and distributed antenna network (DAN). The former takes advantage of channel frequency-selectivity to obtain the frequency-diversity gain. In DAN, a group of distributed antennas serve each user to mitigate the negative impact of shadowing and path losses. This article will introduce the recent advances in FDE and DAN for the broadband single-carrier (SC) transmissions.

In clustered sensor networks, because CHs (Cluster Heads) are the collection points of data, they are likely to be compromise targets of attackers. So, they need to be changed through a CH election scheme as frequently as possible. Besides, because the compromised nodes must try to become a CH, a CH election scheme should prevent them from being a CH. This paper presents a secure CH election scheme for clustered sensor networks, which changes the CH role nodes securely by excluding the compromised nodes from CH candidates. In the proposed scheme, each node gives marks for behavior of all other nodes in the same CH election region and exchanges the mark list with them. Then, each node computes the average marks for all nodes in the region, and nodes whose average mark is less than a specific threshold are excluded from CH candidates. A CH is elected among the remaining candidates. Simulation results show that our scheme provides strong resilience against misbehavior of compromised nodes and reduces energy consumption of nodes. Another simulation results show that our scheme well operates in the environment where some packets are often lost.

We consider a distributed transmission of data packet to a sink where the distance of a sensor node to a sink is much longer than the maximum communication range of each sensor node. We give a simple modification to the transmitter, i.e., multiplication of random phase before the transmission. Thanks to Turbo Code, it is possible to extend the transmission range as the received amplitude varies symbol by symbol for our scheme while whole data packet may be lost for the conventional scheme. In this letter, we report the experimental results of our scheme equivalently developed using visible light communication.

In this paper, we propose a two-step error concealment algorithm based on an error resilient three-dimensional discrete wavelet transform (3-D DWT) video coding scheme. The proposed scheme consists of an error-resilient encoder duplicating the lowest sub-band bit-streams for dispersive grouped frames and an error concealment decoder. The error concealment method of this decoder is decomposed of two steps, the first step is replacement of erroneous coefficients in the lowest sub-band by the duplicated coefficients, and the second step is interpolation of the missing wavelet coefficients by minimum mean square error (MMSE) estimation. The proposed scheme can achieve robust transmission over unreliable channels. Experimental results provide performance comparisons in terms of peak signal-to-noise ratio (PSNR) and demonstrate increased performances compared to state-of-the-art error concealment schemes.

Recently, it is demanded to form a high performance pattern on an enlarged circuit board in a low cost in the process to produce LCD devices. In the part of upgrading the performance, the materials are reexamined such as Al or Mo to Cu. Furthermore, in the process of reexamining the materials, it is demanded that such materials are low in environmental load. Therefore, we examined if it is possible to reuse Ethylene Carbonate, a photo resist stripper, with low environmental load by decomposing dissolved photo resist using ozone gas. Furthermore, we examined if it is possible to apply Ethylene Carbonate without damaging the next generation wiring materials. As a result, we were able to identify the most efficient condition for ozone gas to recycle Ethylene Carbonate used as a photo resist stripper. Ethylene Carbonate was not only suitable for Al · Mo wiring, but was also suitable for the next generation Cu wiring. Therefore by using Ethylene Carbonate for the new and old process for stripping photo resists, it is able to reduce the environmental load and also reduce the cost for stripping.

We present self-calibration techniques for an interleaved SAR (Successive Approximation Register) ADC. The calibration technique is based on hardware corrections for linearity of single stage, gain error and mismatch errors of parallel ADCs. The 4-interleaved 11-bit ADC has been fabricated in a 0.18-µm CMOS process. Using the calibrations, measurement and calculation results show that the differences of ramp characteristic among the 4-interleaving ADC can be decresased to under 0.63 LSB.

Several papers have presented measured function to handle multi-criteria fuzzy decision-making problems based on interval-valued intuitionistic fuzzy sets. However, in some cases, the proposed function cannot give sufficient information about alternatives. Consequently, in this paper, we will overcome previous insufficient problem and provide a novel accuracy function to measure the degree of the interval-valued intuitionistic fuzzy information. And a practical example has been provided to demonstrate our proposed approach. In addition, to make computing and ranking results easier and to increase the recruiting productivity, a computer-based interface system has been developed for decision makers to make decisions more efficiently.

Ubiquitous technologies such as sensor network and RFID have enabled companies to realize more rapid and agile manufacturing and service systems. In this paper, we addresses how the huge amount of real-time events coming from these devices can be filtered and integrated to business process such as manufacturing, logistics, and supply chain process. In particular, we focus on complex event processing of sensor and RFID events in order to integrate them to business rules in business activities. We also illustrate a ubiquitous event processing system, named ueFilter, which helps to filter and aggregate sensor event, to detect event patterns from sensors and RFID by means of event pattern languages (EPL), and trigger event-condition-action (ECA) in logistics processes.

A novel approach for fast traffic classification for the high speed networks is proposed, which bases on the protocol behavior statistical features. The packet size and a new parameter named "Estimated Protocol Processing Time" are collected from the real data flows. Then a set of joint probability distributions is obtained to describe the protocol behaviors and classify the traffic. Comparing the parameters of an unknown flow with the pre-obtained joint distributions, we can judge which application protocol the unknown flow belongs to. Distinct from other methods based on traditional inter-arrival time, we use the "Estimated Protocol Processing Time" to reduce the location dependence and time dependence and obtain better results than traditional traffic classification method. Since there is no need for character string searching and parallel feature for hardware implementation with pipeline-mode data processing, the proposed approach can be easily deployed in the hardware for real-time classification in the high speed networks.

Fractional sampling (FS) and Doppler diversity equalization in OFDM receivers can achieve two types of diversity (path diversity and frequency diversity) simultaneously on time-varying multipath channels. However FS with a higher sampling rate requires the large amount of complexity in demodulation. In this paper, a novel sampling point selection (SPS) scheme with MMSE equalization in FS-OFDM receivers is proposed. On fast time-varying multipath channels, the proposed scheme selects the appropriate samples from the fractionally sampled signals. Through the computer simulation, it is demonstrated that with the proposed scheme, both path diversity gain and Doppler diversity gain can increase as compared to a conventional non-SPS scheme.

Vision sensors provide rich sources of information, but sensing images and processing them in real time would be a challenging task. This paper introduces a vision system using SoCBase platform and presents heuristic designs of SAD correlation algorithm as a component of the vision system. Simulation results show that the vision system is suitable for real-time applications and that the heuristic designs of SAD algorithm are worth utilizing since they save a considerable amount of space with little sacrificing in quality.

The need for efficient movement and precise location of robots in intelligent robot control systems within complex buildings is becoming increasingly important. This paper proposes an indoor positioning and communication platform using Fluorescent Light Communication (FLC) employing a newly developed nine-channel receiver, and discusses a new location estimation method using FLC, that involves a simulation model and coordinate calculation formulae. A series of experiments is performed. Distance errors of less than 25 cm are achieved. The enhanced FLC system yields benefits such as greater precision and ease of use.