This letter proposes a practical algorithm for video transmission of the scalable extension of H.264/AVC (SVC) over limited bit-rate and varying channel signal-to-noise ratio (SNR). The proposal consists of SVC source-layer dropping and layered FEC using LDPC codes to maximize the video quality. The experimental results show that the proposed method realizes better video quality than the compared unequal error protection (UEP) without source-layer dropping. This implies that the dropping of a certain number of source-layers and using the resultant bit-budget for channel coding is more effective than the other UEP case which uses all possible source-layers.

We have developed two modulator driver ICs that are based on the functional distributed circuit (FDC) topology for over 40-Gb/s optical transmission systems using InP HBT technology. The FDC topology enables both a wide bandwidth amplifier and high-speed digital functions. The none-return-to-zero (NRZ) driver IC, which is integrated with a D-type flip-flop, exhibits 2.6-Vp-p (differential output: 5.2 Vp-p) output-voltage swings with a high signal quality at 43 and 50 Gb/s. The return-to-zero (RZ) driver IC, which is integrated with a NRZ to RZ converter, produces 2.4-Vp-p (differential output: 4.8 Vp-p) output-voltage swings and excellent eye openings at 43 and 50 Gb/s. Furthermore, we conducted electro-optical modulation experiments using the developed modulator driver ICs and a dual drive LiNbO3 Mach-Zehnder modulator. We were able to obtain NRZ and RZ clear optical eye openings with low jitters and sufficient extinction ratios of more than 12 dB, at 43 and 50 Gb/s. These results indicate that the FDC has the potential to achieve a large output voltage and create high-speed functional ICs for over-40-Gb/s transmission systems.

This paper presents a low distortion 3rd-order continuous-time delta-sigma modulator for a worldwide digital TV-receiver whose peak SNDR is 69.8 dB and SNR is 70.2 dB under 1 V power supply. To enhance SNDR performance, the mechanisms to occur harmonic distortions at feedback current-steering DAC and flash ADC have been analyzed. A low power tuning system using RC-relaxation oscillator has been developed in order to achieve high yield against PVT variations. A 3rd-order modulator with modified single opamp resonator contributes to cost reduction by realizing a very compact circuit. Reduction schemes of the distortions enabled the modulator to achieve FOM of 0.18 pJ/conv-step.

Packet classification is essential for supporting advanced network services such as firewalls, quality-of-service (QoS), virtual private networks (VPN), and policy-based routing. The rules that routers use to classify packets are called packet filters. If two or more filters overlap, a conflict occurs and leads to ambiguity in packet classification. This study proposes an algorithm that can efficiently detect and resolve filter conflicts using tuple based search. The time complexity of the proposed algorithm is O(nW +s), and the space complexity is O(nW), where n is the number of filters, W is the number of bits in a header field, and s is the number of conflicts. This study uses the synthetic filter databases generated by Class-Bench to evaluate the proposed algorithm. Simulation results show that the proposed algorithm can achieve better performance than existing conflict detection algorithms both in time and space, particularly for databases with large numbers of conflicts.

Obtaining a compact representation of a large-size feature map built by mapper robots is a critical issue in recent mobile robotics. This “map compression” problem is explored from a novel perspective of dictionary-based data compression techniques in the paper. The primary contribution of the paper is the proposal of the dictionary-based map compression approach. A map compression system is presented by employing RANSAC map matching and sparse coding as building blocks. The effectiveness levels of the proposed techniques is investigated in terms of map compression ratio, compression speed, the retrieval performance of compressed/decompressed maps, as well as applications to the Kolmogorov complexity.

Monolithic integration of various kinds of optical components on a silicon wafer is the key to making silicon (Si) photonics practical technology. Applying silicon photonics to telecommunications further requires low insertion loss and polarization independence. We propose an integration concept for telecommunications based on Si and related materials and demonstrate monolithic integration of passive and dynamic functional components. This article shows the great potential of Si photonics technology for telecommunications.

Federated identity and access management (FIAM) systems enable a user to access services provided by various organizations seamlessly. In FIAM systems, service providers normally stipulate that their users show assertions issued by allied parties to use their services as well as determine user privileges based on attributes in the assertions. However, the integrity of the attributes is important under certain circumstances. In such a circumstance, all released assertions should reflect modifications made to user attributes. Despite the ability to adopt conventional certification revocation technologies, including CRL or OCSP, to revoke an assertion and request the corresponding user to obtain a new assertion, re-issuing an entirely new assertion if only one attribute, such as user location or other environmental information, is changed would be inefficient. Therefore, this work presents a self-adaptive framework to achieve consistency in federated identity and access management systems (SAFIAM). In SAFIAM, an identity provider (IdP), which authenticates users and provides user attributes, should monitor access probabilities according to user attributes. The IdP can then adopt the most efficient means of ensuring data integrity of attributes based on related access probabilities. While Internet-based services emerge daily that have various access probabilities with respect to their user attributes, the proposed self-adaptive framework significantly contributes to efforts to streamline the use of FIAM systems.

A secret broadcasting scheme deals with secure transmission of a message so that more than one privileged receiver can decrypt it. Jeong et al. proposed an efficient secret broadcast scheme using binding encryption to obtain the security properties of IND-CPA semantic security and decryption consistency. Thereafter, Wu et al. showed that the Jeong et al.'s scheme just achieves consistency in relatively weak condition and is also inefficient, and they constructed a more efficient scheme to improve the security. In this letter, we demonstrate that the Wu et al.'s scheme is also a weak decryption consistency and cannot achieve the decryption consistency if an adversary has the ability to tamper with the ciphertext. We also present an improved and more efficient secret broadcast scheme to remedy the weakness. The proposed scheme achieves decryption consistency and IND-CCA security, which can protect against stronger adversary's attacks and allows us to broadcast a digital message securely.

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%.

In this paper, we propose a new Delay PUF architecture trying to solve the major problem of existing Delay PUFs that it is easy to predict the relation between delay information and generated information. For that purpose, our architecture exploits glitches as a source of information generation that behave non-linearly from delay variation between gates and the characteristic of pulse propagation of each gate. We thus call it the Glitch PUF. We present two circuit structures of the Glitch PUF both of which have their own merits. We then provide the results of evaluation in which we first verify that the two Glitch PUFs exhibit the same characteristics, and second show the randomness and statistical properties of the Glitch PUF.

Pairings on elliptic curves over finite fields are crucial for constructing various cryptographic schemes. The ηT pairing on supersingular curves over GF(3n) is particularly popular since it is efficiently implementable. Taking into account the Menezes-Okamoto-Vanstone attack, the discrete logarithm problem (DLP) in GF(36n) becomes a concern for the security of cryptosystems using ηT pairings in this case. In 2006, Joux and Lercier proposed a new variant of the function field sieve in the medium prime case, named JL06-FFS. We have, however, not yet found any practical implementations on JL06-FFS over GF(36n). Therefore, we first fulfill such an implementation and we successfully set a new record for solving the DLP in GF(36n), the DLP in GF(36·71) of 676-bit size. In addition, we also compare JL06-FFS and an earlier version, named JL02-FFS, with practical experiments. Our results confirm that the former is several times faster than the latter under certain conditions.

Based on Tu-Deng's conjecture and the Tu-Deng function, in 2010, X. Tang et al. proposed a class of Boolean functions in even variables with optimal algebraic degree, very high nonlinearity and optimal algebraic immunity. In this corresponding, we consider the concatenation of Tang's function and another Boolean function, and study its cryptographic properties. With this idea, we propose a class of 1-resilient Boolean functions in odd variables with optimal algebraic degree, good nonlinearity and suboptimal algebraic immunity based on Tu-Deng's conjecture.

The electric field mill in our underground observation room detected a co-seismic electromagnetic signal in the vertical electrostatic field ca. 8 s after the origin time of the Niigataken Chuetsu-oki Earthquake in 2007, but ca. 30 s before the arrival time of the P-waves.

This paper presents a restoration method using several degraded observed images obtained through a technique known as microscanning. It is shown that microscanning provides sufficient spatial information for image restoration with minimal information about the original image and without knowing the interference function that causes degradation.

Traceable ring signatures, proposed at PKC'07, are a variant of ring signatures, which allow a signer to anonymously sign a message with a tag behind a ring, i.e., a group of users chosen by the signer, unless he signs two messages with the same tag. However, if a signer signs twice on the same tag, the two signatures will be linked and the identity of the signer will be revealed when the two signed messages are different. Traceable ring signatures can be applied to anonymous write-in voting without any special voting authority and electronic coupon services. The previous traceable ring signature scheme relies on random oracles at its security and the signature size is linear in the number of ring members. This paper proposes the first secure traceable ring signature schemes without random oracles in the common reference string model. In addition, the proposed schemes have a signature size of O(), where N is the number of users in the ring.

This paper proposes a differential fault analysis on the stream cipher MUGI, which uses two kinds of update functions of an intermediate state. MUGI was proposed by Hitachi, Ltd. in 2002 and is specified as ISO/IEC 18033-4 for keystream generation. Differential fault analysis (DFA) is a type of fault analysis, which is considered to be a serious threat against secure devices such as smart cards. DFA on MUGI was first proposed at ICISC 2010 [25]; however, the attack condition for the successful attack such as the position into which the fault is injected was restricted. In this paper, we extend the attack methods which are more practical, based on a one-byte and a multi-byte fault models using the relationship between two kinds of update functions that are mutually dependent. In the proposed attack, the attacker can know the position affected by the fault injection even if he has no control of the timing of the fault injection. As a result, a 128-bit secret key can be recovered using 13 pairs of correct and faulty outputs on average.

In this letter we perform an evaluation procedure of the Multi-Cluster Gaussian Scatterer Distribution Channel model. We present analytical expressions that allow to calculate the Angle of Arrival and Time of Arrival statistics directly and derive an expression to calculate the Angle Spread. The use of these expressions allows channel evaluation without the need for multiple ray simulation, thus reducing computational burden.

In the past few years, discriminant analysis and manifold learning have been widely used in feature extraction. Recently, the sparse representation technique has advanced the development of pattern recognition. In this paper, we combine both discriminant analysis and manifold learning with sparse representation technique and propose a novel feature extraction approach named sparsity preserving embedding with manifold learning and discriminant analysis. It seeks an embedded space, where not only the sparse reconstructive relations among original samples are preserved, but also the manifold and discriminant information of both original sample set and the corresponding reconstructed sample set is maintained. Experimental results on the public AR and FERET face databases show that our approach outperforms relevant methods in recognition performance.

Evaluation of addition coefficients introduced by the addition theorems for vector spherical harmonics is one of the most intractable problems in electromagnetic scattering by multi-sphere systems. The derivation of the analytical expressions for the addition coefficients is lengthy and complex while the computation of the addition coefficients is annoyingly time-consuming even with the reasonably fast computers available nowadays. This paper presents an efficient algorithm for calculating addition coefficients which is based on the recursive relations of scalar addition coefficients. Numerical results from the formulation derived in this paper agree with those of previous published results but the algorithm proposed here reduces the computational time considerably. This paper also discusses the strengths and limitations of other formulations and numerical techniques found in the literature.