Abnormal IDDQ (Quiescent power supply current) is the signal to indicate the existence of physical damage which includes the between circuit lines. Using this signal, a CAD-based line pairs with bridging fault (LBFs) detection technique has been developed to enhance the manufacturing yield of advanced logic LSI with scaled-down structure and multi-metal layers. The proposed technique progressively narrows the doubtful LBFs down by logic information and layout structure. This technique, quickly handled, is applied to draw down the distribution chart of bridging fault portion on wafer, the feature of which chart is fed back to manufacturing process and layout design.

The bi-level digital video, because of its simplicity and compactness, can be utilized to provide for a quick and faithful preview of its original content. The proposed bi-level digital video compression technique exploits the context-based probabilistic estimation model towards adaptive pixel prediction which can be used towards generating residual image frames which may then be Run-Length-Rice coded. Towards promoting error-resiliency and random-access, each bi-level digital video frame may be typed into either intra- or inter- picture format. The proposed technique can be seen, in comparison to existing JBIG compression technologies in simulation runs, to provide added temporal redundancy removal.

Interval arithmetic is able to be applied when we include the ranges of various functions. When we include them applying the interval arithmetic, the serious problem that the widths of the range inclusions increase extremely exists. In range inclusion of polynomials particularly, Horner's method and Alefeld's method are well known as the conventional methods which mitigates this problem. The purpose of this paper is to propose the new methods which are able to mitigate this problem more efficiently than the conventional methods. And in this paper, we show and compare the efficiencies of the new methods by some numerical examples.

This letter presents a significant property of the mapping parameters that play a central role to represent a given signal in Fractal Interpolation Functions (FIF). Thanks to our theoretical analysis, it is derived that the mapping parameters required to represent a given signal are also applicable to represent the upsampled signal of a given one. Furthermore, the upsampled signal obtained by using the property represents the self-affine property more distinctly than the given signal. Experiments show the validity and usefulness of the significant property.

This paper investigates modified random timers based on uniform and exponentially distributed timers for feedback scalability for large groups. We observe the widely-used probability distribution functions and propose new ones that are aware of network delays. The awareness of network delays of our proposed modified p.d.fs proves to be able to achieve lower expected number of messages compared to the original ones given that the parameters are optimized for the network variables: the number of receivers, and the network delay. In our analysis we derive an equation to estimate the optimized parameter based on these network variables. We also simulate the p.d.fs for heterogenous network delays and find that each receiver only needs to be aware of its network delay.

The handoff in Mobile IP networks causes packet sequence disruption during a packet forwarding procedure and may result in performance degradation in higher layer protocols. We investigate the impact of handoff in the Mobile IPv6 networks, where an optimized routing with the smooth handoff is adopted. The impact on the packet sequence is measured by an 'unstable time period (UTP)' and a 'silence time period (STP).' The UTP explains the time duration of out-of-sequence packets while the STP reflects the blackout duration of a mobile node after the initiation of handoff procedure. With the analysis on the UTP and STP, the total transient time period (denoted as handoff time period or HTP) after the handoff initiation can be estimated. In our previous work, focusing on the UTP, the packet flow sequence under the smooth handoff is analyzed for the Mobile IPv4 networks. The proposed queuing-based analysis is extended in this work for the Mobile IPv6 networks. That is, several modifications are made to conform to Mobile IPv6 and at the same time the queuing analysis itself is improved to better model the handoff procedure. The numerical results show that the queuing delay for the handoff packets (affected by background traffic) and the involved link (or route) capacities affect the estimated UTP, STP, and HTP. In addition, two schemes such as priority queuing and buffered packet forwarding are introduced to reduce the transient period and the improvements are analyzed for comparison.

In this paper a new adaptive multi-input multi-output (MIMO) channel estimation and multiuser detection algorithm based kernel space iterative inversion is proposed. The functions of output signals are mapped from a low dimensional space to a high dimensional reproducing kernel Hilbert space. The function of the output signals is represented as a linear combination of a set of basis functions, and a Mercer kernel function is constructed by the distribution function. In order to avoid finding the function f(.) and g(.), the correlation among the output signals is calculated in the low dimension space by the kernel. Moreover, considering the practical application, the algorithm is extended to online iteration of mixture system. The computer simulation results illustrated that the new algorithm increase the performance of channel estimation, the global convergence, and the system stability.

In this paper, we propose an extension to the image transport protocol (ITP). When images are transmitted through the Internet, TCP is generally used because it ensures the reliable transmission. However, interactivity will largely affected because of its acknowledgement scheme. This becomes remarkable in the network where packet-loss rate is relatively higher like wireless LANs. For more efficient image transmission, ITP was proposed. Like UDP, in ITP transmission, packets can be transmitted without acknowledgement of the reception. This contributes to improve the interactivity, on the other hand, some of packets may lost during transmission. ITP has a mechanism that the receiver-side can control the retransmission of the lost packets to maintain the quality of the received image. However, it is a hard task for the receiver to select which packets to be retransmitted. In this paper, we propose an extension to ITP by which the server can mark the importance of each packet. This helps the receivers to select important packets for requesting retransmission for server.

Next-generation wireless/mobile networks will be IP-based cellular networks integrating Internet with the existing cellular networks. Recently, Hierarchical Mobile IPv6 (HMIPv6) was proposed by the Internet Engineering Task Force (IETF) for efficient mobility management. HMIPv6 reduces the amount of signaling and improves the performance of MIPv6 in terms of handoff latency. Although HMIPv6 is an efficient scheme, the performance of wireless networks is highly dependent on various system parameters such as user mobility model, packet arrival pattern, etc. Therefore, it is essential to analyze the network performance when HMIPv6 is deployed in IP-based cellular networks. In this paper, we develop two analytic models for the performance analysis of HMIPv6 in IP-based cellular networks, which are based on the random-walk and the fluid-flow models. Based on these analytic models, we formulate the location update cost and the packet delivery cost. Then, we analyze the impact of cell residence time and user population on the location update cost and the packet delivery cost, respectively. In addition, we study the variation of the total cost as the session-to-mobility ratio is changed and the optimal MAP domain size to minimize the total cost is also investigated.

By means of the three-dimensional (3D) finite-difference time domain (FDTD) method, we have investigated in detail the optical properties of a two-dimensional photonic crystal (PC) surface-emitting laser having a square-lattice structure. The 3D-FDTD calculation is carried out for the finite size PC slab structure. The device is based on band-edge resonance, and plural band edges are present at the corresponding band edge point. For these band edges, we calculate the mode profile in the PC slab, far field pattern (FFP) and polarization mode of the surface-emitted component, and photon lifetime. FFPs are shown to be influenced by the finiteness of the structure. Quality (Q) factor, which is a dimensionless quantity representing photon lifetime, is introduced. The out-plane radiation loss in the direction normal to the PC plane greatly influences the total Q factor of resonant mode and is closely related with the band structure. As a result, Q factors clearly differ among these band edges. These results suggest that these band edges include resonant modes that are easy to lase and resonant modes that are difficult to lase.

Fast algorithms for computing the running type-I discrete sine transform (DST-I) and type-III discrete sine transform (DST-III) are proposed. The algorithms are based on a recursive relationship between three subsequent local discrete sine spectra. The computational complexity of the algorithms is compared with that of fast DST-I and DST-III algorithms. Fast inverse algorithms for signal processing in the running discrete sine transform domains are also proposed.

This paper provides a review on the optimal design of photonic bandgap structures by inverse problem techniques. An overview of inverse problems techniques is given, with a special focus on topology design methods. A review of first applications of inverse problems techniques to photonic bandgap structures and waveguides is given, as well as some model problems, which provide a deeper insight into the structure of the optimal design problems.

As the Internet grows, various types of traffic, such as voice, video and data, are transmitted. Therefore, the Internet should provide the Quality of Service (QoS) required by each type of traffic as well as end-to-end connectivity, and routing decisions should be based on the utilization of links/routers and/or the application types of traffic. This kind of routing is called Traffic Engineering (TE), and its objective is to improve such performance factors as flow loss probability for users and the utilization of links for networks, simultaneously. Some studies claim that the Multi-Protocol Label Switching (MPLS) technique can easily implement TE. So far, some experimental results show that TE is effective on a MPLS network; however, its performance has not been theoretically and quantitatively analyzed. Thus, in this paper, we will investigate the basic and preliminary performance of MPLS networks with TE by analyzing flow loss probability and Smoothness index of link utilization in the queueing system.

This paper presents a computationally efficient subspace-based method for partially adaptive beamforming which is based on the structure of the generalized sidelobe canceller (GSC). Its auxiliary beamformer operates in an estimated interference subspace which is obtained through simple computation. The computational burden of the proposed method in terms of complex multiplication is just on O(η2M) where η and M are the numbers of interferences and the array elements, respectively. Though the subspace obtained is different from the exact interference subspace due to the presence of noise, theoretical analysis shows that the proposed beamfomer virtually attains the optimal performance for strong or sidelobe interference. Simulation results validate its effectiveness including fast convergence, even in the presence of errors in the detected number of directional signals.

We have demonstrated low-threshold two-dimensional photonic crystal lasers with self-assembled InAs/GaAs quantum dots. Coupled cavity designs of whispering gallery modes are defined in square lattice photonic crystal slabs. Our lasers showed a small 120 µW input pumping power threshold. Actual absorption power is evaluated to be less than 20 µW. Our lasers show high spontaneous emission coupling (β) factors0.1. The mode volumes are expected to be 0.7-1.2 times cubed wavelength by our modelling. Based on threshold analysis, 80 QDs are the effective number of QDs defined as the number of QDs needed to make PC cavities transparent if they are on maximum optical field points. Using the same analysis we found that single quantum dot lasing is likely to occur both by proper alignment of the single quantum dot relative to geometries of photonic crystals and by using sharp QD emission lines in high-Q localized modes.

Colloidal crystallization is one of the most promising approaches to the fabrication of photonic crystals with periodicity at the submicron length scale. Several approaches have been explored to enhance the optical quality of these materials and, at the same time, to integrate these materials in substrates of interest in current technology. In this paper we review some of the most promising advances recently made in this direction, as well as some achievements towards the creation of new colloidal structures.

In this paper, an area efficient VLSI architecture of decision feedback equalizer is derived accommodating 64/256 QAM modulators. This architecture is implemented efficiently in VLSI structure using EDA tools due to its regular structure. The method is to employ a time-multiplexed design scheme, so-called Folding, which executes multiple operation on a single functional unit. In addition, we define a new folding set by grouping the adjacent filter taps with data transfer having the same processing sequence between blocks and perform the internal data-bit optimization. By doing so, the computational complexity is reduced by performance optimization and also silicon area is reduced by using a shared operator. Moreover, through the performance and convergence time comparison of the various LMS (e.g. LMS, data signed LMS, error signed LMS, signed-signed LMS) ) coefficient updating algorithms, we identify an optimum LMS algorithm scheme suitable for the low complexity, high performance and high order (64 and 256) QAM applications for the presented Fractionally Spaced Decision Feedback Equalizer. We simulated the proposed design scheme using SYNOPSYSTM and SPWTM.

A silicon (Si) wire waveguiding system fabricated on silicon-on-insulator (SOI) substrates is one of the most promising platforms for highly-integrated, ultra-small optical circuits, or microphotonics devices. The cross-section of the waveguide's core is about 300-nm-square, and the minimum bending radius are a few micrometers. Recently, crucial problems involving propagation losses and in coupling with external circuits have been resolved. Functional devices using silicon wire waveguides are now being tested. In this paper, we describe our recent progress and future prospects on the microphotonics devices based on the silicon-wire waveguiding system.

Low-loss optical coupling structures between photonic crystal waveguides and channel waveguides were investigated. It was emphasized that impedance matching of guided modes of those waveguides, as well as field-profile matching, was essential to achieving the low-loss optical coupling. We developed an impedance matching theory for Bloch waves, and applied it to designing the low-loss optical coupling structures. It was demonstrated that the optical coupling loss between a photonic crystal waveguide and a Si-channel waveguide was reduced to as low as 0.7 dB by introducing an interface structure for impedance matching between the two waveguides.

This paper presents a new technique to implement a convolutional codec in VLSI. The code is used in the Trellis Code Modulation. The technique aims to reduce hardware complexity and increase throughput to decode the convolutional code using Viterbi algorithm. To simplify decoding algorithm and calculation, branch cost distances are pre-calculated and stored in a Distance Look Up Table (DLUT). By using the DLUT to get each branch cost in the algorithm, the hardware implementation of the algorithm does not require any calculation circuits. Furthermore, based on the trellis diagram, an Output Look-Up-Table (OLUT) is also constructed for decoding output generation. This table reduces the amount of storage in the algorithm. The use of look-up tables reduces hardware complexity and increases throughput of the decoder. Using this technique, a 16-states, radix-4 TCM codec with 2-D and 4-D was designed and implemented in both FPGA and ASIC after mathematically simulated. The tested ASIC has a core area of 1.1 mm2 in 0.18 µm CMOS technology and yields a decoding speed over 500 Mbps. Implementation results have shown that LUT can be used to decrease hardware requirement and to increase decoding speed. The designed codec can be used as an IP core to be integrated into system-on-chip applications and the technique can be explored to use to decode the turbo code.