Narimasa TAKAHASHI Kenji KAGAWA Yutaka HONDA Yo TAKAHASHI
This paper describes the modeling and the analysis methodology to evaluate Simultaneous Switching Noise (SSN) for the combined system of the package with the 4-layer Printed Circuit Board (PCB), which the 64 Simultaneous Switching Outputs (SSOs) were included using a simple IBIS model. Simulation results showed that the ground plane in both package and PCB can be used as the reference to reduce SSN more effectively than the power plane. For the source synchronous timing technique such as used in a DDR SDRAM memory bus in the model shown in this paper, the skew control circuit tequiniqe is easy to apply in the chip design instead of using embedded capacitors in the package's substrate. And also the radiated emission and eye diagram analysis were studied.
Radiation of a Hertzian dipole placed within a cylindrical cavity with narrow slots is investigated. Narrow axial and transverse slots are considered. Scattered fields are expanded in terms of eigenfunctions and boundary conditions are enforced to obtain a set of simultaneous equations. Computations are performed to check the validity of the formulation.
In many engineering problems it is required to convert a polynomial into another polynomial through a transformation. Due to its wide range of applications, the polynomial transformation has received much attention and many techniques have been developed to compute the coefficients of a transformed polynomial from those of an original polynomial. In this letter a new result is presented concerning the transformation matrix for arbitrary polynomial transformation. A simple algorithm is obtained which enables one to successively compute transformation matrices of various order.
It is essential, as bandwidths of wireless communications get wider, to evaluate the imbalances among quadrature mixer ports, in terms of carrier phase offset, IQ gain imbalance, and IQ skew. Because it is time consuming to separate skew, gain imbalance and carrier phase offset evaluation during test is often performed using a composite value, without separation of the imbalance factors. This paper describes an algorithm for enabling separation among quadrature mixer gain imbalance, carrier phase offset, and skew. Since the test time is reduced by the proposed method, it can be applied during high volume production testing.
Hasan S. M. AL-KHAFFAF Abdullah Z. TALIB Rosalina Abdul SALAM
Noise removal in engineering drawing is an important operation performed before other image analysis tasks. Many algorithms have been developed to remove salt-and-pepper noise from document images. Cleaning algorithms should remove noise while keeping the real part of the image unchanged. Some algorithms have disadvantages in cleaning operation that leads to removing of weak features such as short thin lines. Others leave the image with hairy noise attached to image objects. In this article a noise removal procedure called TrackAndMayDel (TAMD) is developed to enhance the noise removal of salt-and-pepper noise in binary images of engineering drawings. The procedure could be integrated with third party algorithms' logic to enhance their ability to remove noise by investigating the structure of pixels that are part of weak features. It can be integrated with other algorithms as a post-processing step to remove noise remaining in the image such as hairy noise attached with graphical elements. An algorithm is proposed by incorporating TAMD in a third party algorithm. Real scanned images from GREC'03 contest are used in the experiment. The images are corrupted by salt-and-pepper noise at 10%, 15%, and 20% levels. An objective performance measure that correlates with human vision as well as MSE and PSNR are used in this experiment. Performance evaluation of the introduced algorithm shows better-quality images compared to other algorithms.
This letter derives the packet error rate (PER) in terms of the retry limit and the channel error probability in wireless local area networks (WLANs), when an additional number of retries is allocated to a block of packets to be transmitted. We prove that the lower bound of the PER is the dropping probability which is defined as the probability of any given packet being dropped after its retry limit has been reached.
Youhei INOUE Toshihiko TAKAHASHI Ryo FUJIMAKI
A subdivision of a rectangle into rectangular faces with horizontal and vertical line segments is called a rectangular drawing or floorplan. It has been an open problem to determine whether there exist a polynomial time algorithm for computing R(n). We affirmatively solve the problem, that is, we introduce an O(n4)-time and O(n3)-space algorithm for R(n). The algorithm is based on a recurrence for R(n), which is the main result of the paper. We also implement our algorithm and computed R(n) for n 3000.
Masaru HARAGUCHI Tokuya OSAWA Akira YAMAZAKI Chikayoshi MORISHIMA Toshinori MORIHARA Yoshikazu MOROOKA Yoshihiro OKUNO Kazutami ARIMOTO
This paper describes new DDRx SDRAM interface architecture suitable for system-on-chip (SOC) implementation. Our test chip fabricated in a 90-nm CMOS process adopts three key schemes and achieves 960 Mb/s/pin operations with 32 bits width. One of new schemes is to suppress timing skew with rising-edge signal transmission I/O circuit and look-up table type impedance calibration circuit. DQS round-trip-time, propagation delay from rising edge of system clock in SOC to arrival of DQS at input PAD of SOC during read operation, becomes longer than one clock cycle time as for DDR2 interface and beyond. Flexible DQS round-trip-time scheme can allow wide range up to N/2 cycles in N bits burst read operation. In addition, full self loop-backed test scheme is also proposed to measure AC timing parameters without high-end tester. The architecture reported in this paper can be continuously adaptive to realize higher data-rate and cost-efficient DDRx-SDRAM interface for various kinds of SOC.
Jae-Hoon JANG Sung-Hak LEE Kyu-Ik SOHNG
The Processing of high-dynamic-range (HDR) images is embodied by a lot of algorithms. This paper takes notice of one of these algorithms which is presented using the iCAM06. iCAM06 is capable of making color appearance predictions of HDR images based on CIECAM02 color predictions and incorporating spatial process models in the human visual system (HVS) for contrast enhancement. The effect of user controllable factors of iCAM06 was investigated and the best factor which corresponds with Breneman's corresponding color data sets was found. A suggested model improves color matching predictions for the corresponding color data set in Breneman's experiment.
Eiji HIGURASHI Daisuke CHINO Tadatomo SUGA
An AuSn reflow process using hydrogen radicals as a way to avert the cleaning of flux residues was investigated for its application to solder bumping. AuSn particles (manufactured by a gas atomizer) smaller than 5 µm, which are difficult to reflow by conventional methods that use rosin mildly activated (RMA) flux, were used for the experiments. In this process, the reduction effect by the hydrogen radicals removes the surface oxides of the AuSn particles. Excellent wetting between 1-µm-diameter AuSn particles and Ni metallization occurred in hydrogen plasma. Using hydrogen radicals, 100 µm-diameter AuSn bumps without voids were successfully formed at a peak temperature of 300. The average bump shear strength was approximately 73 gf/bump. Bump inspection after shear testing showed that a fracture had occurred between the Au/Ni/Cr under bump metallurgy (UBM) and Si substrate, suggesting sufficient wetting between the AuSn bump and the UBM.
Hong Bo CHE Hyoun Soo PARK Jin Wook KIM Young Hwan KIM
The authors present R2Power, an effective approach to the realizable reduction of RC networks with independent current sources. The proposed approach is based on the entrywise perturbation theory for diagonally dominant M-matrices. The accuracy of the node voltages of the reduced network, as compared to those of the original network, is maintained on the order of the entrywise perturbation performed during reduction. R2Power can be used to reduce the size of RC networks used to model the power networks of SoCs, for efficient IR-drop analysis. Experiments showed that R2Power reduced the size of industrial examples by more than 95%, with maximum relative node voltage errors of less than 0.012%.
Seung-Jin PARK Young Hun SEO Hong-June PARK Jae-Yoon SIM
A general-purpose multi-Gbps LVDS driver is presented with a new distortion-free level conversion scheme. For high-speed transmission, a dynamic pre-emphasis scheme is also proposed with overdriving current effectively distributed in time. The proposed LVDS driver achieves supply-insensitive duty preservation with a reduction of switching noise by 50-percent.
Keiji GOTO Toru KAWANO Toyohiko ISHIHARA
We study the high-frequency asymptotic analysis methods for the scattered fields by a cylindrically curved conducting surface excited by the incident wave on the curved surface from the convex side. We first derive the novel hybrid ray-mode solution for the scattered fields near the concave surface by solving a canonical problem formulated under the assumption that the cylindrically curved conducting surface possesses only one edge. Then by applying the ray tracing technique and the idea of Keller's GTD (Geometrical Theory of Diffraction), the solutions derived for the canonical problem are extended to account for the problem of the radiation from and the scattering by the other edge of the cylindrically curved surface. We confirm the validity of the novel asymptotic representations proposed in the present study by comparing both with the numerical results obtained from the method of moment and the experimental results performed in the anechoic chamber.
Peter SURANYI Yasushi SHINJO Kazuhiko KATO
IPv4 private addresses are commonly used in local area networks (LANs). With the increasing popularity of virtual private networks (VPNs), it has become common that a user connects to multiple LANs at the same time. However, private address ranges for LANs frequently overlap. In such cases, existing systems do not allow the user to access the resources on all LANs at the same time. In this paper, we propose name-based address mapping for VPNs, a novel method that allows connecting to hosts through multiple VPNs at the same time, even when the address ranges of the VPNs overlap. In name-based address mapping, rather than using the IP addresses used on the LANs (the real addresses), we assign a unique virtual address to each remote host based on its domain name. The local host uses the virtual addresses to communicate with remote hosts. We have implemented name-based address mapping for layer 3 OpenVPN connections on Linux and measured its performance. The communication overhead of our system is less than 1.5% for throughput and less than 0.2 ms for each name resolution.
In this paper, for odd n and any k with gcd(n,k) = 1, new binary sequence families Sk of period 2n-1 are constructed. These families have maximum correlation , family size 22n+2n+1 and maximum linear span . The correlation distribution of Sk is completely determined as well. Compared with the modified Gold codes with the same family size, the proposed families have the same period and correlation properties, but larger linear span. As good candidates with low correlation and large family size, the new families contain the Gold sequences and the Gold-like sequences. Furthermore, Sk includes a subfamily which has the same period, correlation distribution, family size and linear span as the family So(2) recently constructed by Yu and Gong. In particular, when k=1, is exactly So(2).
Koji NUIDA Satoshi FUJITSU Manabu HAGIWARA Hideki IMAI Takashi KITAGAWA Kazuto OGAWA Hajime WATANABE
The code length of Tardos's collusion-secure fingerprint code is of theoretically minimal order with respect to the number of adversarial users (pirates). However, the constant factor should be further reduced for practical implementation. In this article, we improve the tracing algorithm of Tardos's code and propose a 2-secure and short random fingerprint code, which is secure against collusion attacks by two pirates. Our code length is significantly shorter than that of Tardos's code and its tracing error probability is practically small.
Most routing protocols in MANET use IP addresses as one of the most important routing information. To implement the routing protocol of MANET, the IP assignment in MANET should be solved. Allocating IP addresses is one of current key issues in the MANET, due to the absence of a centralized agent server. Previous methods require a large address space or can not use all the IP addresses of the given IP address space. For that reason, many IP addresses remain unused. To resolve this, we propose an IP address assignment protocol that uses the contiguous IP address assignment strategy without unused IP addresses. Simulations perform on ns-2 and confirm the viability of our protocol.
A trihedral corner reflector is often used for SAR polarimetric calibration. However, the scattering property of the reflector used for the calibration may not be correct if the high frequency approximation is not satisfied or if an incident angle deviates from the symmetric axis of the reflector. In order to know the conditions for precise SAR polarimetric calibration, we evaluated the polarimetric response of the reflector by a numerical simulation using the method of moment (MoM). It is found that allowable incident angle deviation is 5 degree to azimuth direction and 4 degree to elevation direction for precise SAR polarimetric calibration when the size of the reflector is 7.5 times larger than the wavelength of an incident wave.
Minimizing the residual impurity gases is a key factor for reducing temporal dark image sticking. Therefore, this paper uses a vacuum-sealing method that minimizes the residual impurity gases by enhancing the base vacuum level, and the resultant change in temporal dark image sticking is then examined in comparison to that with the conventional sealing method using 42-in. ac-PDPs with a high Xe (11%) content. As a result of monitoring the difference in the display luminance, infrared emission, and perceived luminance between the cells with and without temporal dark image sticking, the vacuum-sealing method is demonstrated to reduce temporal dark image sticking by decreasing the residual impurity gases and increasing the oxygen vacancy in the MgO layer. Furthermore, the use of a modified driving waveform along with the vacuum-sealing method is even more effective in reducing temporal dark image sticking.
Yoshihiro KOKUBO Tadashi KAWAI
A system that has an array of dielectric rods at the center of a waveguide was previously suggested for single mode propagation with a wide frequency range. However, it is difficult to introduce the wave source from a coaxial cable, due to use of the TE10-like and TE20-like modes. In this investigation, an asymmetric setup of the dielectric rods is proposed for better coupling efficiency of the TE10 mode.