Masatake HANGAI Kazuhiko NAKAHARA Mamiko YAMAGUCHI Morishige HIEDA
High-power protection switch utilizing a new stub/line selectable configuration is presented. By employing the proposed circuit topology, the insertion loss at receiving mode and the power handling capability at transmitting mode can be independently designed. Therefore, the proposed circuit is able to achieve low insertion loss at receiving mode while keeping high-power performance at transmitting mode. To verify this methodology, MMIC switch has been fabricated in Ka-band. The circuit has achieved the insertion loss of 2 dB, the isolation of 25 dB, and the power handling capability of 40 dBm at 5% bandwidth.
Weiqiang KONG Tomohiro SHIRAISHI Noriyuki KATAHIRA Masahiko WATANABE Tetsuro KATAYAMA Akira FUKUDA
State Transition Matrix (STM) is a table-based modeling language that has been frequently used in industry for specifying behaviors of systems. Functional correctness of a STM design (i.e., a design developed with STM) could often be expressed as invariant properties. In this paper, we first present a formalization of the static and dynamic aspects of STM designs. Consequentially, based on this formalization, we investigate a symbolic encoding approach, through which a STM design could be bounded model checked w.r.t. invariant properties by using Satisfiability Modulo Theories (SMT) solving technique. We have built a prototype implementation of the proposed encoding and the state-of-the-art SMT solver - Yices, is used in our experiments to evaluate the effectiveness of our approach. Two attempts for accelerating SMT solving are also reported.
Jongsun KIM Gyungsu BYUN M. Frank CHANG
One of the most difficult problems that remains to be solved in wire interconnect architectures is the achievement of lower latency and higher concurrency on a shared bus or link without increasing the power and circuit overhead. Novel improvements in short distance on- and off-chip interconnects can be provided by using a multi-band RF interconnect (RF-I) system. Unlike the conventional current- or voltage-mode square wave signaling transceivers that use binary or multilevel baseband signals, the proposed RF-I transceiver uses high-frequency modulated RF passband signals with binary phase-shift keying (BPSK) modulation. The proposed low-overhead RF-I transceiver using 0.18-µm CMOS technology achieves an aggregate data rate of 4 Gb/s/pin between four I/Os (2Tx-to-2Rx) on a shared FR4 PCB line using two carriers of 6 GHz and 12 GHz. The two transceivers occupy an area of 0.077 mm2 and dissipate a power of about 25 mW with a power efficiency of 6.25 pJ/bit.
Norimasa NAKASHIMA Mitsuo TATEIBA
This paper presents various types of iterative progressive numerical methods (IPNMs) for the computation of electromagnetic (EM) wave scattering from many objects and reports comparatively the performance of these methods. The original IPNM is similar to the Jacobi method which is one of the classical linear iterative solvers. Then the modified IPNMs are based on other classical solvers like the Gauss-Seidel (GS), the relaxed Jacobi, the successive overrelaxation (SOR), and the symmetric SOR (SSOR) methods. In the original and modified IPNMs, we repeatedly solve linear systems of equations by using a nonstationary iterative solver. An initial guess and a stopping criterion are discussed in order to realize a fast computation. We treat EM wave scattering from 27 perfectly electric conducting (PEC) spheres and evaluate the performance of the IPNMs. However, the SOR- and SSOR-type IPNMs are not subject to the above numerical test in this paper because an optimal relaxation parameter is not possible to determine in advance. The evaluation reveals that the IPNMs converge much faster than a standard BEM computation. The relaxed Jacobi-type IPNM is better than the other types in terms of the net computation time and the application range for the distance between objects.
Jaejun LEE Sungho LEE Sangwook NAM
This paper presents a circuit that improves supply noise rejection using an active inductor circuit. Compared to the conventional designs, the proposed supply noise suppression circuit has better characteristics such as low current consumption and small die size with noise rejection. The circuit was fabricated using 0.13 µm UMC CMOS technology. The experimental results showed that the supply noise was suppressed by 61% with only an increase in size of 20.0 µm 2.5 µm, and the current consumption was under 2 mA.
Shi ZHENG Weiqiang WU Qinyu ZHANG
Energy conservation is an important issue in mobile ad hoc networks (MANET), where the terminals are always supplied with limited energy. A new routing protocol is presented according to the study on the influence of low-energy nodes in ad hoc networks. The novel routing protocol (energy sensing routing protocol, ESRP) is based on the energy sensing strategy. Multiple strategy routing and substitute routing are both adopted in this paper. Referring to the level of the residual energy and the situation of energy consumption, different routes are chosen for packets transmission. The local maintenance is adopted, which can reduce packets retransmission effectively when the link breaks. We focus on the network lifetime most in all performances. The evaluation is done in comparison with other routing protocols on NS2 platform, and the simulation results show that this routing protocol can prolong the network lifetime and balance energy consumption effectively.
Lei JING Yinghui ZHOU Zixue CHENG Junbo WANG
Automatic recognition of finger gestures can be used for promotion of life quality. For example, a senior citizen can control the home appliance, call for help in emergency, or even communicate with others through simple finger gestures. Here, we focus on one-stroke finger gesture, which are intuitive to be remembered and performed. In this paper, we proposed and evaluated an accelerometer-based method for detecting the predefined one-stroke finger gestures from the data collected using a MEMS 3D accelerometer worn on the index finger. As alternative to the optoelectronic, sonic and ultrasonic approaches, the accelerometer-based method is featured as self-contained, cost-effective, and can be used in noisy or private space. A compact wireless sensing mote integrated with the accelerometer, called MagicRing, is developed to be worn on the finger for real data collection. A general definition on one-stroke gesture is given out, and 12 kinds of one-stroke finger gestures are selected from human daily activities. A set of features is extracted among the candidate feature set including both traditional features like standard deviation, energy, entropy, and frequency of acceleration and a new type of feature called relative feature. Both subject-independent and subject-dependent experiment methods were evaluated on three kinds of representative classifiers. In the subject-independent experiment among 20 subjects, the decision tree classifier shows the best performance recognizing the finger gestures with an average accuracy rate for 86.92 %. In the subject-dependent experiment, the nearest neighbor classifier got the highest accuracy rate for 97.55 %.
Takahisa KITAGAWA Miyuki HANAOKA Kenji KONO
In the face of constant malicious attacks to network-connected software systems, software vulnerabilities need to be discovered early in the development phase. In this paper, we present AspFuzz, a state-aware protocol fuzzer based on the specifications of application-layer protocols. AspFuzz automatically generates anomalous messages that exploit possible vulnerabilities. The key observation behind AspFuzz is that most attack messages violate the strict specifications of application-layer protocols. For example, they do not conform to the rigid format or syntax required of each message. In addition, some attack messages ignore the protocol states and have incorrect orders of messages. AspFuzz automatically generates a large number of anomalous messages that deliberately violate the specifications of application-layer protocols. To demonstrate the effectiveness of AspFuzz, we conducted experiments with POP3 and HTTP servers. With AspFuzz, we can discover 20 reported and 1 previously unknown vulnerabilities for POP3 servers and 25 reported vulnerabilities for HTTP servers. Two vulnerabilities among these can be discovered by the state-awareness of AspFuzz. It can also find a SIP state-related vulnerability.
Yang YANG Zejian YUAN Nanning ZHENG Yuehu LIU Lei YANG Yoshifumi NISHIO
This paper introduces an interactive expression editing system that allows users to design facial expressions easily. Currently, popular example-based methods construct face models based on the examples of target face. The shortcoming of these methods is that they cannot create expressions for novel faces: target faces not previously recorded in the database. We propose a solution to overcome this limitation. We present an interactive facial-geometric-feature animation system for generating expressions of novel faces. Our system is easy to use. By click-dragging control points on the target face, on the computer screen display, unique expressions are generated automatically. To guarantee natural animation results, our animation model employs prior knowledge based on various individuals' expressions. One model prior is learned from motion vector fields to guarantee effective facial motions. Another, different, model prior is learned from facial shape space to ensure the result has a real facial shape. Interactive animation problem is formulated in a maximum a posterior (MAP) framework to search for optimal results by combining the priors with user-defined constraints. We give an extension of the Motion Propagation (MP) algorithm to infer facial motions for novel target faces from a subset of the control points. Experimental results on different facial animations demonstrate the effectiveness of the proposed method. Moreover, one application of our system is exhibited in this paper, where users create expressions for facial sketches interactively.
Young-Uk SONG Hiroshi ISHIWARA Shun-ichiro OHMI
In order to realize stable n-type characteristics of pentacene for applying to the organic complementary metal-oxide-semiconductor field-effect transistors (CMOS), we have fabricated pentacene based MOS diodes using ultra-thin Yb layer such as 0.5-3 nm between gate insulator and pentacene. From the results of capacitance-voltage (C-V) measurements, excellent n-type C-V characteristics of the devices with 1 and 2 nm-thick Yb were observed even though the devices were measured in air. These results suggested that the n-type semiconductor characteristics of pentacene are able to be improved by the thin Yb interfacial layer. Furthermore, the improved n-type characteristics of pentacene will enable the fabrication of flexible complementary logic circuits utilizing one kind organic semiconductor.
In this paper, a soft-error-tolerant BILBO (Built-In Logic Block Observer) FF (flip-flop) is presented. The proposed FF works as a soft-error-tolerant FF in system operations and as a BILBO FF in manufacturing testing. The construction of the proposed FF is based on that of an existing soft-error-tolerant FF, namely a BISER (Built-In Soft Error Resilience) FF. The proposed FF contains a reconfigurable C-element with XNOR calculation capability, which works as a C-element for soft-error-tolerance during system operations and as an XNOR gate employed in linear feedback shift registers (LFSRs) during manufacturing testing. The evaluation results shown in this paper indicate that the area of the proposed FF is 8.5% smaller than that of a simple combination of the existing BISER and BILBO FFs. In addition, the sum of CLK-Q delay and D-CLK setup times on system operations for the proposed FF is 19.7% shorter than that for the combination.
Zhigang ZANG Keisuke MUKAI Paolo NAVARETTI Marcus DUELK Christian VELEZ Kiichi HAMAMOTO
The fabricated 1.55 µm high power superluminescent light emitting diodes (SLEDs) with 115 mW maximum output power and 3 dB bandwidth of 50 nm, using active multi-mode interferometer (MMI), showed high coupling efficiency of 66% into single-mode fiber, which resulted in maximum fiber-coupled power of 77 mW.
M.M. Hafizur RAHMAN Yukinori SATO Yasushi INOGUCHI
A Modified Hierarchical 3D-Torus (MH3DT) network is a 3D-torus network consisting of multiple basic modules, in which each basic module itself is a 3D-torus network. Inter-node communication performance has been evaluated using dimension-order routing and 2 virtual channels (VCs) under uniform traffic patterns but not under non-uniform traffic patterns. In this paper, we evaluate the inter-node communication performance of MH3DT under five non-uniform traffic patterns and compare it with other networks. We found that under non-uniform traffic patterns, the MH3DT yields high throughput and low latency, providing better inter-node communication performance compared to H3DT, TESH, mesh, and torus networks. Also, we found that non-uniform traffic patterns have higher throughput than uniform traffic in the MH3DT network.
Akio OHTA Daisuke KANME Hideki MURAKAMI Seiichiro HIGASHI Seiichi MIYAZAKI
A stacked structure consisting of ∼ 1 nm-thick MgO and ∼ 4 nm-thick HfO2 was formed on thermally grown SiO2/Si(100) by MOCVD using dipivaloymethanato (DPM) precursors, and the influences of N2 anneal on interfacial reaction and defect state density in this stacked structure were examined. The chemical bonding features of Mg atom were evaluated by using an Auger parameter independently of positive charge-up during XPS measurements. With Mg incorporation into HfO2, a slight decrease in the oxidation number of Mg was detectable. The result suggests that Mg atoms are incorporated preferentially near oxygen vacancies in the HfO2, which can be responsible for a reduction of the flat band voltage shifts observed from C-V characteristics.
Lingjiang KONG Bin ZHAO Meifang LUO Guolong CUI
Based on the reiterative maximum signal minus interference level (MSMIL) criterion and adaptive beamforming, a novel interference suppression algorithm is proposed for shared-spectrum multistatic radar that must contend with clutter. In this algorithm, two-dimensional adaptive beamformers are designed for azimuths and range cells. Numerical results show advantages of the proposed method.
QuocDinh NGUYEN Naobumi MICHISHITA Yoshihide YAMADA Koji NAKATANI
For the easy design of very small normal-mode helical antennas (NMHAs), an equation that helps determine the self-resonant structures of these antennas is developed. For this purpose, the expression for the capacitance of an NMHA is established. The accuracy of this design equation is confirmed by comparing the results obtained using the equation with the simulation results.
Kazuyuki SEO Kunio SAKAKIBARA Nobuyoshi KIKUMA
Many kinds of microstrip array antennas have been developed in the millimeter-wave band. In order to avoid feeding loss and the decrease of antenna gain by beam shift due to frequency changes, center-fed array antennas are advantageous. In this case, the element spacing around the feeding circuit of the transition from the waveguide to two microstrip lines is larger than one wavelength. Therefore, the sidelobe level grows significantly. In order to suppress the sidelobe level, we propose transitions with slot radiators. Moreover, any polarization angles can be achieved by changing the slot angle. A wide variety from 1.5% to 70% of slot radiator coupling powers can be achieved. To investigate the performance of the proposed transition, 10, 22 and 30-element center-fed microstrip comb-line antennas with the proposed transition were developed at 76.5 GHz, and measured performance was evaluated in the millimeter-wave band.
Hiroyoshi YAMADA Hiroshi SAKAI Yoshio YAMAGUCHI
High resolution direction-of-arrival (DOA) estimation algorithm for array antennas becomes popular in these days. However, there are several error factors such as mutual coupling among the elements in actual array. Hence array calibration is indispensable to realize intrinsic performance of the algorithm. In the many applications, it is preferable that the calibration can be done in the practical environment in operation. In such a case, the incident wave becomes coherent multipath wave. Calibration of array in the multipath environment is a hard problem, even when DOA of elementary waves is known. To realize array calibration in the multipath environment will be useful for some applications even if reference signals are required. In this report, we consider property of reference waves in the multipath environment and derive a new calibration technique by using the multipath coherent reference waves. The reference wave depends on not only the DOA but also complex amplitude of each elementary wave. However, the proposed technique depends on the DOA only. This is the main advantage of the technique. Simulation results confirm the effectiveness of the proposed technique.
EIRP measurement in the direction of maximum radiation has not always been valid to estimate the radiated power from radio equipments integrated with antennas, for example, integrated radiator with antennas shaped like the notebook-sized PC. Therefore, it is recommended that total radiated power (TRP) from equipment under test (EUT) should be estimated by integrating measured EIRPs on the whole surface of the unit sphere. In this paper, a conventional and some novel sampling methods for the TRP estimation, which were proposed to reduce the number of measurement points, are examined by using a measured EIRP data set and compared with each other. For a simulated radio equipment shaped like a notebook-sized PC, it is found that the equi-area and generalized spiral points methods are superior to the equi-angle method in terms of reducing the number of the measurement points and orthogonal three planes method is another candidate in terms of saving measurement time unless the pattern radiated from EUT is not so complicated.
Eun-Jun YOON Il-Soo JEON Kee-Young YOO
Autonomous objects represent active database objects which can be distributed over the Internet. This paper proposes a robust authentication scheme for the remote autonomous object based on AES (Advanced Encryption Standard) symmetric cryptosystem. Compared with related schemes, the proposed scheme not only resists various security attacks but also provides computation and communication efficiency.