Suitably aggregated data burst enhances link utilization and reduces data processing complexity of optical transport networks rather than just transmitting each bursty input traffic from access networks. This data burst generation method is called as a burst assembly process and has two assembly parameters, timer and threshold, for regulating burst release time and burst size. Since the traffic characteristics of data burst generated at the burst assembler may affect network performance, the decision of burst assembly parameters should be carefully designed. Thus, in this paper we study the dimensioning burst assembly process to find the burst assembly parameter values satisfying target performance. For this purpose, we first analyze timer-based and threshold-based burst assembly processes, respectively. As constraints on the dimensioning burst assembly process, we consider the following performance metrics: 1) processing delay of control packet, 2) burst loss at control plane, and 3) link utilization. Based on these constraints, a decision mechanism of the burst assembly parameters is proposed. From numerical analysis, we suggest a possible lower boundary value for the burst assembly parameters satisfying the target burst loss rate and delay time at the control plane.

We propose an accurate and efficient model of having an unbalanced differential line structure, where mode-conversion and frequency dependent loss effects are considered in above the GHz frequency range. To extract model parameters of the proposed unbalanced differential line model, we measured s-parameters of test patterns using a 2-port VNA and defined a new type of mixed-mode s-parameter. The model parameters were obtained and are described for various types of the unbalanced differential line structures. Finally, the validity of the proposed model and the model parameters were successfully confirmed by a series of time-domain measurements and a lattice diagram analysis.

We show that distributed source coding of multi-view images in camera sensor networks (CSNs) using adaptive modules can come close to the Slepian-Wolf bound. In a systematic scenario with limited node abilities, work by Slepian and Wolf suggest that it is possible to encode statistically dependent signals in a distributed manner to the same rate as with a system where the signals are jointly encoded. We considered three nodes (PN, CN and CNs), which are statistically depended. Different distributed architecture solutions are proposed based on a parent node and child node framework. A PN sends the whole image whereas a CNs/CN only partially, using an adaptive coding based on adaptive module-operation at a rate close to theoretical bound - H(CNs|PN)/H(CN|PN,CNs). CNs sends sub-sampled image and encodes the rest of image, however CN encodes all image. In other words, the proposed scheme allows independent encoding and jointly decoding of views. Experimental results show performance close to the information-theoretic limit. Furthermore, good performance of the proposed architecture with adaptive scheme shows significant improvement over previous work.

In contention-based wireless ad hoc networks, power control is an efficient way to improve the spatial reuse by allowing multiple pairs to communicate simultaneously. In this paper, we propose a game-theoretical approach for joint power and rate control in ad hoc networks, where the transmit rate of each link is maximized. Meanwhile we consider the transmit power as the cost, since higher power leads to higher interference and more energy consumption. In particular, we introduce a novel auction-like pricing algorithm in which the cost per unit power steps up until the network settles down at a Nash equilibrium, which is a feasible power and rate allocation, even when the Signal to Interference and Noise Ratio (SINR) requirements are initially infeasible. Numerical results show significant throughput improvement and energy consumption savings compared with the previously proposed algorithm that defers the link with minimum SINR.

Over the past few years, a considerable number of studies have been conducted on modeling the bargaining game using artificial agents on within-model interaction. However, very few attempts have been made at study on the interaction and co-evolutionary process among heterogeneous artificial agents. Therefore, we present two kinds of artificial agents, based on genetic algorithm (GA) and reinforcement learning (RL), which play a game on between-model interaction. We investigate their co-evolutionary processes and analyze their parameters using the analysis of variance.

The process of evaluating and selecting Commercial Off-The-Shelf (COTS) products is complicated because of conflicting priorities of the stakeholders, complex interdependences among the evaluation criteria, multiple evaluation objectives, changing system requirements, and a large number of similar COTS products with extreme capability differences. Numerous COTS evaluation and selection methods have been proposed to address the complexity of the process. Some of these methods have been successfully applied in industry. However, negotiation to resolve stakeholder conflicts is still an ad hoc process. In this paper, we present a systematic model that assists the COTS selection stakeholders in identifying conflicts, as well as in determining and evaluating conflict resolution options. Our model is facilitated by an agent-based decision support system, which has user agents that assist the stakeholders in the COTS evaluation and negotiation process. The agents utilize a hybrid of analytic and artificial intelligence techniques to identify conflicts and the corresponding agreement options. Moreover, each user agent analyzes the agreement options in detail before advising its client about which goals to optimize, and which goals to compromise in order to reach agreement with the other stakeholders. Finally, the community of agents facilitates information sharing among stakeholders in a bid to improve the quality of their COTS selection decisions.

Direction-of-arrival (DOA) estimation based on subspace methods has collected much interest over a few decades, and adaptive DOA estimation with rapidly changing parameters will be necessary for wireless communications. This paper is concerned with a new subspace tracking scheme by using an accelerated LMS and RLS algorithms for time-varying parameters. The proposed accelerated adaptive algorithms are based on the internal model principle by approximately expressing the changing parameters by an expansion of polynomial time functions. Thus its application to DOA estimation based on the MUSIC and MODE schemes is presented and the effectiveness is validated in numerical simulations.

Animation video is becoming very popular with the availability of low cost computing resources. The cell animation is a popular method, used for producing animation video. In order to efficiently encode these videos, conventional video codecs, such as AutoDesk Animation Pro FLC, Intel Indeo 5, and MPEG-4 can be used to achieve high compression. However, when cell animation videos are compressed at very low bit rate by these traditional codecs, objectionable artifacts, e.g., false color, blurred contours, and blocking artifact, are severely occurred. In this paper, we propose an efficient compression method for cell animation images. The proposed method employs hybrid coding scheme which includes intraframe and interframe coding modes. The intraframe mode consists of color quantization, adaptive differential pulse code modulation, forward classification, and Golomb-Rice coding. The interframe coding consists of block-based techniques and exploits the characteristics of motion. Simulation results show that the proposed method provides superior performance over AutoDesk Animation Pro FLC, MPEG-1, Intel Indeo 5, and MPEG-4 standards.

In each contact material (Ag, Cu, Ni, and Fe), the breaking arcs occurring between an electrical contact pair in a resistive circuit of DC42 V/10.5 A were observed with a high-speed camera (1000 frames/s). Arc voltage and arc current were also measured simultaneously. By analyzing cathode and anode bright spots in the photographs, the positions of cathode and anode bright spots on contact surfaces were plotted on the graph. As a result, cathode and anode bright spots were found to express the characteristic motion in each material. Moreover, by comparing those results with the photograph of contact surface after all operations.

The motion of arc spots of breaking arc is investigated for Ag electrical contacts in DC 42 V/10 A resistive circuit using a high-speed camera. Also, the eroded contact surfaces are observed with a microscope after each breaking operation. As results, some kinds of different films and eroded regions are distinguished. Diameters of these regions are corresponding to the widths of the cathode and anode spot regions that are obtained by using the high-speed camera. It is found that the films and eroded regions on the electrical contacts are generated at different stages of the breaking arc.

In this letter, a new computation method for the noise parameters of a linear noisy two-port network is introduced. A new error function, which considers noise figure and source admittance error simultaneously, is proposed to estimate the four noise parameters. The global optimization of the error function is searched directly by using a genetic algorithm.

Call admission control (CAC) plays a significant role in providing the efficient use of the limited bandwidth and the desired quality-of-service (QoS) in mobile multimedia communications. As efficiency is an important performance issue for CAC in the mobile networks with multimedia services, the concept of fairness among services should also be considered. Game theory provides an appropriate framework for formulating such fair and efficient CAC problem. Thus, in this paper, a framework based on game theory (both of noncooperative and cooperative games) is proposed to select fair-efficient guard bandwidth coefficients of the CAC scheme for the asymmetrical traffic case in mobile multimedia communications. The proposed game theoretic framework provides fairness and efficiency in the aspects of bandwidth utilization and QoS for multiple classes of traffic, and also guarantees the proper priority mechanism. Call classes are viewed as the players of a game. Utility function of the player is defined to be of two types, the bandwidth utilization and the weighted sum of new call accepting probability and handoff succeeding probability. The numerical results show that, for both types of the utility function, there is a unique equilibrium point of the noncooperative game for any given offered load. For the cooperative game, the arbitration schemes for the interpersonal comparisons of utility and the bargaining problem are investigated. The results also indicate that, for both types of the utility function, the Nash solution with the origin (0,0) as the starting point of the bargaining problem can achieve higher total utility than the previous CAC scheme while at the same time providing fairness by satisfying a set of fairness axioms. Since the Nash solution is determined from the domain of the Pareto boundary, the way to generate the Pareto boundary is also provided. Therefore, the Nash solution can be obtained easily.

This letter discusses the prediction of the time-varying bit error rate (BER) for a transmitting channel using recent transmissions and retransmissions. Depending on the predicted BER, we propose a maximum frame size control to improve the goodput in wireless networks. It is shown, using simulation, that when the maximum frame size is controlled relative to the time-varying BER the goodput of the network is improved.

The goal of gaze detection is to locate the position (on a monitor) where a user is looking. Previous researches use one wide view camera, which can capture the user's entire face. However, the image resolution is too low with such a camera and the fine movements of user's eye cannot be exactly detected. So, we propose the new gaze detection system with dual cameras (a wide and a narrow view camera). In order to locate the user's eye position accurately, the narrow-view camera has the functionalities of auto focusing/panning/tilting based on the detected 3D eye positions from the wide view camera. In addition, we use the IR-LED illuminators for wide and narrow view camera, which can ease the detecting of facial features, pupil and iris position. To overcome the problem of specular reflection on glasses by illuminator, we use dual IR-LED illuminators for wide and narrow view camera and detect the accurate eye position, which is not hidden by the specular reflection. Experimental results show that the gaze detection error between the computed positions and the real ones is about 2.89 cm of RMS error.

In this paper, we propose a hardware architecture of real-time JPEG encoder for 1.4 mega pixels CMOS image sensor SoC which can be applied to mobile communication devices. The proposed architecture has an efficient interface scheme with CMOS image sensor and other peripherals for real-time encoding. The JPEG encoder supports the base-line JPEG mode, and processes motion images of which resolution is up to 1280960 (CCIR601 YCrCb 4:2:2,15 fps) by real-time processing. The JPEG encoder supports 8 types of resolution, and can serve the 4 levels of image quality through quantization matrix. The proposed JPEG encoder can transfer encoded motion pictures and raw image data from CMOS image sensor to external device through USB 2.0 and a compressed still image is stored at external pseudo SRAM through SRAM interface. And proposed core can communicate parameters of encoding type with other host by I2C. The proposed architecture was implemented with VHDL and verified for the functions with Synopsys and Modelsim. The encoder proposed in this paper was fabricated in process of 0.18 µ of Hynix semiconductor Inc.

In this paper, an algorithm for anchor frame detection in news video is proposed, which consists of four steps. First, the cumulative histogram method is used to detect shot boundaries in order to segment a news video into video shots. Second, skin color information is used to detect face regions in each video shot. Third, color information of upper body regions is used to extract anchor object. Then, a graph-theoretic cluster analysis algorithm is utilized to classify the news video into anchor-person shots and non-anchor shots. Experimental results have shown the effectiveness of the proposed algorithm.

We have developed a visualization system for dialog text exchanged in e-learning virtual classrooms. In this system, text-based online discussions among learners are effectively visualized as discussions held in a virtual classroom in cyberspace. Discussion participants are displayed as avatars. The virtual classroom maintains the interest of learners because it incorporates professional camerawork and switching know-how based on rules derived from an analysis of 42 TV programs. The gestures of the CG avatar depend on the dialog text. A series of virtual classroom experiments confirmed that elementary and junior high school students maintained an interest in using the system.

We propose guidelines for LSI-chip design, taking the within-die variations into consideration, and for process quality improvement to suppress the variations. The auto-correlation length, λ, of device variation is shown to be a useful measure to treat the systematic variations in a chip. We may neglect the systematic variation in chips within the range of λ, while σ2 of the systematic variation must be added to σ2 of the random variation outside the λ. The random variations, on the other hand, exhibit complete randomness even in the closest pair transistors. The mismatch variations in transistor pairs were enhanced by 1.41(=) compared with the random variations in single transistors. This requires careful choice of gate size in designing a transistor pair with a minimum size, such as transfer gates in an SRAM cell. Poly-Si gate formation is estimated to be the most important process to ensure the spatial uniformity in transistor current and to enhance circuit performance. Large relative variations are observed for the contact to p+ diffusion, via1 (M1-M2), and via2 (M2-M3) among parameter variations in passive elements. The standard deviations for random variations in via1 and via2 are noticeably widespread, indicating the importance of the via resistance control in BEOL. The spatial frequency power spectrum for within-die random variations is confirmed experimentally, as uniform ('white') with respect to the spatial frequency. To treat the large 'white random noise,' the least-square method with a 4th-order polynomial exhibits a best efficiency as a fitting function for decomposing the raw variation data into systematic part and random part.

We report the empirically obtained conditions for the fusion splicing with photonic crystal fibers (PCF) having large mode areas. By controlling the arc-power and the arc-time of a conventional electric-arc fusion splicer, the splicing loss between two PCFs could be lowered down to 0.2 dB in average. For the splicing PCF with a conventional single mode fiber (SMF), the loss was increased due to the modal field mismatch, but still below 0.45 dB in average. The tensile strength was weakened by the splicing from 2.83 GPa down to 1.04 GPa for the PCF-PCF case and 0.89 GPa for the PCF-SMF one.

In this study, a cascade open-short-thru (COST) de-embedding procedure is proposed for the first time for on-wafer device characterization in the RF/microwave frequency regime. This technique utilizes the "open" and "short" dummy structures to de-embed the probe-pad parasitics of a device-under-test (DUT). Furthermore, to accurately estimate the input/output interconnect parasitics, including the resistive, inductive, capacitive, and conductive components, the "thru" dummy device has been characterized after probe-pad de-embedding. With the combination of transmission-line theory and cascade-configuration concept, this method can efficiently generate the scalable and repeatable interconnect parameters to completely eliminate the redundant parasitics of the active/passive DUTs of various device sizes and interconnect dimensions. Consequently, this method is very suitable for the on-wafer automatic measurement.