Zero-knowledge arguments allows one party to prove that a statement is true, without leaking any other information than the truth of the statement. In many applications such as verifiable shuffle (as a practical application) and circuit satisfiability (as a theoretical application), zero-knowledge arguments for mathematical statements related to linear algebra are essentially used. Groth proposed (at CRYPTO 2009) an elegant methodology for zero-knowledge arguments for linear algebraic relations over finite fields. He obtained zero-knowledge arguments of the sub-linear size for linear algebra using reductions from linear algebraic relations to equations of the form z=x*'y, where x, y ∈ Fnp are committed vectors, z ∈ Fp is a committed element, and *': FnpFnpFp is a bilinear map. These reductions impose additional rounds on zero-knowledge arguments of the sub-linear size. The round complexity of interactive zero-knowledge arguments is an important measure along with communication and computational complexities. We focus on minimizing the round complexity of sub-linear zero-knowledge arguments for linear algebra. To reduce round complexity, we propose a general transformation from a t-round zero-knowledge argument, satisfying mild conditions, to a (t-2)-round zero-knowledge argument; this transformation is of independent interest.
Takenori YASUZUMI Yusuke OMOTE Tomoki UWANO Osamu HASHIMOTO
This paper presents an ultra-wideband (UWB) bandpass filter (BPF) with sharp attenuation slope characteristics. The circuit structure consists of an inter-digital finger resonator, parallel-coupled lines and phase matching line. The design of the bandwidth was described by using the even and odd mode characteristic impedances in the resonator structure. The parallel-coupled lines were also designed in the same manner. The parameters of the resonator and two parallel-coupled lines in combination as the BPF were then optimized by the simulation with HFSS. The designed BPF was experimentally fabricated and its measured performances showed the bandwidth from 3.6 to 10 GHz with the 20 dB outband rejection. For the U.S. UWB band design, the matching line was inserted between the two parallel-coupled lines. The matching at both band edges was then qualitatively analyzed on the smithchart. The HFSS simulation results of the structure realized the bandwidth from 3.1 to 10.6 GHz with sharp attenuation slope characteristics for SWR < 2.0. The measurement results agree well with the simulation results.
Satoshi IWAMOTO Yasuhiko ARAKAWA
Efficient silicon-based light sources are expected to be key devices for applications such as optical interconnection. Huge number of researches has been conducted for realizing silicon-based light sources. Most of them utilized silicon-related materials such as silicon nanostructures or germanium, not crystalline silicon, which has been considered as a poor light emitter because of its indirect electronic bandgap. Light emission properties of materials can be tailored not only by modifying the material properties directly, but also by controlling the electromagnetic environment surrounding the material. Photonic nanostructures are a powerful tool for creating the engineered environment. In this paper, we briefly review the mechanisms for improving the light emission properties of materials by photonic nanostructures and present our recent experimental results showing the enhancement of light emission from silicon by introducing photonic crystal structures.
Masaki HANADA Hidenori NAKAZATO Hitoshi WATANABE
Multimedia applications such as music or video streaming, video teleconferencing and IP telephony are flourishing in packet-switched networks. Applications that generate such real-time data can have very diverse quality-of-service (QoS) requirements. In order to guarantee diverse QoS requirements, the combined use of a packet scheduling algorithm based on Generalized Processor Sharing (GPS) and leaky bucket traffic regulator is the most successful QoS mechanism. GPS can provide a minimum guaranteed service rate for each session and tight delay bounds for leaky bucket constrained sessions. However, the delay bounds for leaky bucket constrained sessions under GPS are unnecessarily large because each session is served according to its associated constant weight until the session buffer is empty. In order to solve this problem, a scheduling policy called Output Rate-Controlled Generalized Processor Sharing (ORC-GPS) was proposed in [17]. ORC-GPS is a rate-based scheduling like GPS, and controls the service rate in order to lower the delay bounds for leaky bucket constrained sessions. In this paper, we propose a call admission control (CAC) algorithm for ORC-GPS, for leaky-bucket constrained sessions with deterministic delay requirements. This CAC algorithm for ORC-GPS determines the optimal values of parameters of ORC-GPS from the deterministic delay requirements of the sessions. In numerical experiments, we compare the CAC algorithm for ORC-GPS with one for GPS in terms of schedulable region and computational complexity.
Asymptotic expansions of the amplitudes of the direct and scattered waves in a waveguide system with an imperfection core are derived for large core number and the partial cancellation of the direct wave by the scattered wave is shown in detail. The total power of light in the cross section of a waveguide system is analytically derived and it is shown that the total power of the sum of the direct and scattered waves decreases from that of the direct wave because of the cancellation, the difference of the total power transfers to the localized wave and the total power of light is conserved.
An adaptive and iterative intertrack-interference (ITI) cancelling scheme is described for multi-track signal detection in inter-track asynchronous shingled write magnetic recording. There is write-clock frequency drift in asynchronous recording systems. Read-back signals obtained with a wide read head scanning narrow tracks thus suffer from not only intersymbol interference (ISI) but also time-variant ITI. To efficiently cope with static ISI and time-variant ITI, multi-track soft interference cancellers and two-dimensional partial-response filters are incorporated based on per-survivor processing into each trellis state defined in a one-dimensional/two-dimensional trellis-switching max-log-MAP detector. In addition, the computational complexity can be reduced based on channel interpolation and intermittent TDPR-filter control by allowing small degradation in signal detection. Computer simulation results in media-noise-dominant environments demonstrate that the proposed adaptive and iterative ITI canceller achieves bit error rates close to those obtained in a non-ITI case when the read-head off-track ratio is up to 50% in write-clock frequency difference of 0.02%.
Keijiro SAKAI Satoshi DOI Nobuyuki IWATA Hirofumi YAJIMA Hiroshi YAMAMOTO
We propose a novel technique to grow the single-walled carbon nanotubes (SWNTs) with specific chirality at the desired position using free electron laser (FEL) irradiation during growth and surface treatment. As a result, only the semiconducting SWNTs grew at the area between triangle electrodes, where the ozone treatment was done to be hydrophilic when an alcohol chemical vapor deposition (ACCVD) process was carried out with the 800 nm FEL irradiation. Although the number of possible chiral index is 22 in the SWNTs grown without the FEL irradiation, the number is much reduced to be 8 by the FEL.
Huihui WANG Hitoshi OHNUKI Hideaki ENDO Mitsuru IZUMI
Thin film glucose biosensors were fabricated with organic/inorganic hybrid films based on glucose oxidase (GOx) and Prussian Blue nano-clusters. The biosensors composed of hybrid films were characterized by the low operating potential and the advantage to interference-free detection. In this research, we employed two kinds of thin films for GOx immobilization: Langmuir-Blodgett (LB) and self-assembled monolayer (SAM). The LB film immobilizes GOx in its inside through the electrostatic force, while the SAM immobilizes GOx with the covalent bond. The sensors with LB film produced a relatively high current signal, while the non-linear behavior and a low stability were recognized. On the other hand, the sensors with SAM presented a good linear relationship and a very stable performance.
Hironori UCHIKAWA Kenta KASAI Kohichi SAKANIWA
We consider spatially-coupled protograph-based LDPC codes for the three terminal erasure relay channel. It is observed that BP threshold value, the maximal erasure probability of the channel for which decoding error probability converges to zero, of spatially-coupled codes, in particular spatially-coupled MacKay-Neal code, is close to the theoretical limit for the relay channel. Empirical results suggest that spatially-coupled protograph-based LDPC codes have great potential to achieve theoretical limit of a general relay channel.
Aldhino ANGGOROSESAR Young-Jin KIM Kee-Wook RIM
Backlight dimming techniques have been researched much to obtain high power saving on display modules, especially those which are based on LCD. The use of LED as a light source in a backlight module has opened a wider chance to perform local dimming as an improvement of a conservative global dimming approach. However, local dimming techniques are sometimes observed to obtain worse performance than global dimming ones in terms of power saving or image fidelity. We observed that even some of their results show visible artifacts. In this paper, we propose a novel backlight dimming technique called hybrid dimming, which combines local and global dimming approaches effectively. We do local dimming to obtain the initial backlight levels while calculating its SSIM index, which is a human visual system-aware image quality metric. We then make sure that these backlight levels don't exceed the ones obtained from a human visual system-aware global dimming with similar image fidelity. As a result, our proposed method can gain better power saving than a human visual system-aware global dimming and prior local dimming techniques, while making little difference in the image fidelity and suppressing visible block artifacts in the results. Experimental results showed that the proposed technique can achieve up to 14, 2.2, and 2.4 times higher power saving ratio than human visual system-aware global dimming and two well-designed local dimming techniques, respectively.
Daiki TAKEUCHI Wataru CHUJO Shin-ichi YAMAMOTO Yahei KOYAMADA
Microwave/millimeter-wave phase and amplitude characteristics of the optically controlled phased array antenna with a different SMF for each antenna feed were measured. Suitable phases for the beam steering can be realized by the adjustment of the LD wavelength independently with multiple SMFs. In addition to the phase, amplitude of each antenna feed can be controlled stably using LD current without phase variation. Furthermore, effectiveness of the calibration method of the phased array using multiple SMFs by LD wavelength adjustment is experimentally verified. Excellent microwave/millimeter-wave phase characteristics using 2- and 3-element optically controlled phased array feed were experimentally demonstrated with calibration of the phases. Phase characteristics of the array using multiple SMFs were also compared with that using a single SMF experimentally.
Kuo-Hsiung TSENG Tuo-Wen CHANG Ming-Fu HUNG
This study focused on three simplified models, namely (1) one set of single-phase DC-DC converter, (2) two sets of parallel connection single-phase DC-DC converter, and (3) two sets of series connection single-phase DC-DC converter. The purposes are: (1) to propose the simplification conditions and procedures for the three-phase AC-DC converter; (2) propose a set of new simplification steps for modeling, and present the examples of different three-phase AC-DC circuit topologies, detailed discussion on the simplification steps for modeling of a three-phase AC-DC converter is offered, to help people simplify and analyze the simplified model easily; (3) according to three types of simplified modeling in the three-phase AC-DC converter, this study established a useful reference for the design and analysis of the control systems of the three-phase AC-DC converter simply; (4) to acquire PWM control strategy beforehand based on PFC-Controlled property; (5) to reduce the switching loss for the PWM control strategy of the simplified model; (6) to maintain the original circuit topology and verify that the theory can extensively apply the knowledge of single-phase DC-DC converter to the simplified modeling of three-phase AC-DC converter.
Xuerong YE Jie DENG Qiong YU Guofu ZHAI
Generally, the failure rate of a sealed relay is regarded as a constant value, no matter where and how it is used. However, the failure processes of sealed relays won't be the same under different conditions, even for one relay, its failure rate also will be changed during operations. This paper studies the failure process of a kind of sealed relay by analyzing the variations of its time parameters. Among contact resistance and all those time parameters, it is found that closing gap time can indicate the failure process of tested relay very well. For the purpose of verifying this conclusion derived from time parameters, the contacts are observed by microscope after the tested relay failed. Both theoretical calculation result of contacts gap and photos taken by microscope show that the hypothetic failure mode derived from time parameters is reasonable. Based on the failure analysis, the paper also proposes a dynamic reliability estimation method with closing gap time.
Bum-Soo KWON Tae-Jin JUNG Kyun-Kyung LEE
A novel algorithm is presented for near-field source localization with a symmetric uniform linear array (ULA) consisting of an even number of sensors. Based on element reordering of a symmetric ULA, the steering vector is factorised with respect to the range-independent bearing parameters and range-relevant 2-D location parameters, which allows the range-independent bearing estimation with rank-reduction idea. With the estimated bearing, the range estimation for each source is then obtained by defining the 1-D MUSIC spectrum. Simulation results are presented to validate the performance of the proposed algorithm.
This paper presents pulse-coupled piecewise constant spiking oscillators (PWCSOs) consisting of two PWCSOs and a coupling method is master-slave coupling. The slave PWCSO exhibits chaos because of chaotic response of the master one. However, if the parameter varies, the slave PWCSO can exhibit the phenomena as a periodicity in the phase plane. We focus on such phenomena and corresponding bifurcation. Using the 2-D return map, we clarify its mechanism.
Yoo-mi PARK Aekyung MOON Byung-sun LEE Sangha KIM
In this paper, we propose a Network Knowledge Layer (NKL) that is a service platform overlaid onto the existing networks to provide network knowledge for user-centric services in the Next Generation Network (NGN). Most traditional networks lack capabilities for accommodating user-centric service paradigm. Taking this into consideration, the proposed NKL has capabilities to acquire contextual information from various sources, to evolve this information with legacy information into high-level knowledge, and to expose the high-level knowledge to entities outside the network. For easy knowledge exposure, we specify a set of abstracted application programming interfaces (APIs). For efficient handling of network knowledge accessed by the APIs, we design and compare the three different network knowledge models. With the proposed APIs and the three knowledge models, we accomplish the experimental performance evaluation of NKL to verify its feasibility. The results of the various tests on knowledge models and APIs give good guidelines for efficient design and exposing network knowledge in developing a user-centric service platform. Finally, we expect NKL can support the effective development and execution of user-centric services by providing rich network knowledge with the APIs.
Pichai ARUNVIPAS Chokchai SANGDAO Ravee PHROMLOUNGSRI
This paper presents novel structures of band-pass filters using two configurations of open loop ring resonators (OPLRR): a resonator with embedded quadruply-stepped impedance transmission lines (QSITL) in coupled lines, and a stepped impedance resonator (SIR). Both types of OPLRR have the capability of suppressing the second spurious response and shifting the third spurious response to a higher frequency as well. To demonstrate the performances of both proposed resonators, two sections of each structure with cascaded and crossed configurations at an operating frequency of 0.9 GHz are presented. Both methodologies are easy to design and implement. The methodology with a SIR has a better performance than the SITL. The measurement results of the proposed circuits are in full agreement with the simulated prediction results.
Hiroshi OKAZAKI Kiyomichi ARAKI
A detailed analysis of a multilayer symmetric coupler employing symmetrical broad-side coupled lines is presented. We confirm that the coupler can be designed using a well-known even-odd mode analysis of two strip lines while the coupler has four strip lines. We also confirm that the previously reported poor isolation originates from port mismatching. To verify the analysis, couplers that have different dimensions are fabricated. One example exhibits a coupling loss of 4.50.5 dB, a return loss better than 15 dB, and isolation characteristics higher than 12 dB in the 6.5 to 15.1 GHz frequency range. These results agree well with the obtained simulation results. The results show that the coupler has the potential to provide tight and ideal coupling.
Raul Ernesto MENENDEZ-MORA Ryutaro ICHISE
An ability to assess similarity lies close to the core of cognition. Its understanding support the comprehension of human success in tasks like problem solving, categorization, memory retrieval, inductive reasoning, etc, and this is the main reason that it is a common research topic. In this paper, we introduce the idea of semantic differences and commonalities between words to the similarity computation process. Five new semantic similarity metrics are obtained after applying this scheme to traditional WordNet-based measures. We also combine the node based similarity measures with a corpus-independent way of computing the information content. In an experimental evaluation of our approach on two standard word pairs datasets, four of the measures outperformed their classical version, while the other performed as well as their unmodified counterparts.
Kun-Joon LEE Tae-Hak LEE Young-Sik KIM
A dual-band patch antenna with a shorting wall and a U-shaped slot is presented in this paper. The shorted-patch is coupled with the aperture slot that is closely placed to the shorting wall for achieving good impedance matching. A U-shaped slot is embedded in the shorted-patch and is located near the radiating edge to yield a dual-band operation. By changing the side slot length of the U-shaped slot, the tunable frequency ratio of the proposed antenna is varied from 1.73 to 2.05.