A quartz-crystal-microbalance (QCM) and surface-plasmon-resonance (SPR) hybrid sensor was prepared, and the depositions of polymer electrolytes layer-by-layer (LbL) films were observed in situ. The estimated thicknesses obtained from the QCM method were different from those obtained from the SPR method. This was estimated to be caused by film swelling and water contained in the film.

The performance of multiuser multiple-input single-output (MU-MISO) systems is not only affected by small-scale multipath fading but also by large-scale fading (i.e., shadowing) and path loss. In this paper, we concentrate on the sum rate distribution of MU-MISO systems employing linear zero-forcing beamforming, accounting for both multipath fading and shadowing effects, as well as spatial correlation at the transmit and receiver sides. In particular, we consider the classical spatially correlated lognormal model and propose closed-form bounds on the distribution of the achievable sum rates in MU-MISO systems. With the help of these bounds, we derive a relationship between the interuser distance and sum rate corresponding to 10% of the cumulative distribution function under different environmental conditions. A practical conclusion from our results based on the considered system is that the effect of spatially correlated shadowing can be considered to be independent when the interuser distance is approximately five times the shadowing correlation distance. Furthermore, a detailed analysis of the effects of composite channel attenuation consisting of multipath fading and shadowing is also provided.

The fast multipole method (FMM) for N-body simulations is attracting much attention since it requires minimal communication between computing nodes. We implemented hardware pipelines specialized for the FMM on an FPGA device, the GRAPE-9. An N-body simulation with 1.6×107 particles ran 16 times faster than that on a CPU. Moreover the particle-to-particle stage of the FMM on the GRAPE-9 executed 2.5 times faster than on a GPU in a limited case.

Displacement current measurement (DCM) is widely used as a method for analyzing carrier behaviors of organic devices. Carrier behaviors are analyzed using transient currents. On the other hand, electric-field-induced optical second-harmonic generation (EFISHG) measurement is capable of directly probing carrier motions in organic devices, where the migration of electric field stemmed from carriers is measured. In this study, we employed the DCM and EFISHG measurements for analyzing interfacial carrier behaviors in Au/pentacene/polyimide (PI)/indium-tin-oxide (ITO) double layer organic devices, where interfacial accumulated charges and electric fields formed in the pentacene layer were explored.

In this paper, we propose fault-tolerant field-programmable gate array (FPGA) architectures and their design framework for intellectual property (IP) cores in system-on-chip (SoC). Unlike discrete FPGAs, in which the integration scale can be made relatively large, programmable IP cores must correspond to arrays of various sizes. The key features of our architectures are a regular tile structure, spare modules and bypass wires for fault avoidance, and a configuration mechanism for single-cycle reconfiguration. In addition, we utilize routing tools, namely EasyRouter for proposed architecture. This tool can handle various array sizes corresponding to developed programmable IP cores. In this evaluation, we compared the performances of conventional FPGAs and the proposed fault-tolerant FPGA architectures. On average, our architectures have less than 1.82 times the area and 1.11 times the delay compared with traditional island-style FPGAs. At the same time, our FPGA shows a higher fault tolerant performance.

In this paper, we consider a decentralized failure diagnosis problem for discrete event systems. For a conjunctively codiagnosable system, there exists a conjunctive decentralized diagnoser that can detect the occurrence of any failure within a uniformly bounded number of steps. We present a method for synthesizing such a conjunctive decentralized diagnoser as an online diagnoser.

An all-digital time-domain ADC, abbreviated as TAD, is presented in this paper. All-digital structure is intrinsically compatible with the scaling of CMOS technology, and can satisfy the great demand of miniaturized and low-voltage sensor interface. The proposed TAD uses an inverter-based Ring-Delay-Line (RDL) to transform the input signal from voltage domain to time domain. The voltage-modulated time information is then digitized by a composite architecture namely “4-Clock-Edge-Shift Construction” (4CKES). TAD features superior voltage sensitivity and 1st-order noise shaping, which can significantly simplify the power-hungry pre-conditioning circuits. Reconfigurable resolution can be easily achieved by applying different sampling rates. A TAD prototype is fabricated in 65nm CMOS, and consumes a small area of 0.016mm2. It achieves a voltage resolution of 82.7µV/LSB at 10MS/s and 1.96µV/LSB at 200kS/s in a narrow input range of 0.1Vpp, merely under 0.6V supply. The highest SNR of TAD prototype is 61.36dB in 20kHz bandwidth at 10MS/s. This paper also analyzes the nonideal effects of TAD and discusses the potential solutions. As the principal drawback, nonlinearity of TAD can be compensated by the differential-setup and digital calibration.

The fabrication of a grating structure formed by a solid-state electrolyte layer on a dye-TiO$_{2}$ film by the nanoimprinting technique using a polydimethylsiloxane (PDMS) stamp and its application in photoelectric conversion devices are described. The PDMS grating pattern is imprinted from blu-ray disc recordable. A silver electrode was deposited on the patterned solid-state electrolyte layers. Surface plasmon resonance (SPR) excitation was observed in the fabricated solar cells by irradiation with white light. The photoelectric conversion properties were measured to study the effect of the two types of SPR excitations, i.e., the propagating surface plasmon on the Ag grating surface and the localized surface plasmon from the Au nanoparticles on TiO$_{2}$.

This paper investigates the system-level throughput of non-orthogonal multiple access (NOMA) with a successive interference canceller (SIC) in the cellular downlink assuming proportional fair (PF)-based radio resource (bandwidth and transmission power) allocation. The purpose of this study is to examine the possibility of applying NOMA with a SIC to the systems beyond the 4G cellular system. Both the mean and cell-edge user throughput are important in a real system. PF-based scheduling is known to achieve a good tradeoff between them by maximizing the product of the user throughput among users within a cell. In NOMA with a SIC, the scheduler allocates the same frequency to multiple users simultaneously, which necessitates multiuser scheduling. To achieve a better tradeoff between the mean and cell-edge user throughput, we propose and compare three power allocation strategies among users, which are jointly implemented with multiuser scheduling. Extensive simulation results show that NOMA with a SIC with a moderate number of non-orthogonally multiplexed users significantly enhances the system-level throughput performance compared to orthogonal multiple access (OMA), which is widely used in 3.9 and 4G mobile communication systems.

This paper proposes a multiple-fault injection attack based on adaptive control of fault injection timing in embedded microcontrollers. The proposed method can be conducted under the black-box condition that the detailed cryptographic software running on the target device is not known to attackers. In addition, the proposed method is non-invasive, without the depackaging required in previous works, since such adaptive fault injection is performed by precisely generating a clock glitch. We first describe the proposed method which injects two kinds of faults to obtain a faulty output available for differential fault analysis while avoiding a conditional branch in a typical recalculation-based countermeasure. We then show that the faulty output can be obtained by the proposed method without using information from the detailed instruction sequence. In particular, the validity of the proposed method is demonstrated through experiments on Advanced Encryption Standard (AES) software with a recalculation-based countermeasure on 8-bit and 32-bit microcontrollers. We also present a countermeasure resistant to the proposed method.

With the rapid growth of high performance ICT (Information Communication Technologies) devices such as smart phones and tablet PCs, multitasking has become one of the popular ways of using mobile devices. The reasons users have adopted multitask operation are that it reduces the level of dissatisfaction regarding waiting time and makes effective use of time by switching their attention from the waiting process to other content. This is a good solution to the problem of waiting; however, it may cause another problem, which is the increase in traffic volume due to the multiple applications being worked on simultaneously. Thus, an effective method to control throughput adapted to the multitasking situation is required. This paper proposes a transmission rate control method for web browsing that takes multitasking behavior into account and quantitatively demonstrates the effect of service by two different field experiments. The main contribution of this paper is to present a service design process for a new transmission rate control that takes into account human-network interaction based on the human-centered approach. We show that the degree of satisfaction in relation to waiting time did not degrade even when a field trial using a testbed showed that throughput of the background task was reduced by 40%.

Orthogonal frequency division multiplexing (OFDM) has great advantages of high spectrum efficiency and robustness against multipath fading. When the received signal is deeply suppressed by deep fading, path loss and shadowing, the received carrier power must be increased in order to avoid degrading communication quality and provide high reliability at the cost of lower system throughput. A repetition coding is very attractive in providing the high reliability with simple configuration and the low decoding complexity of maximal ratio combining. In order to analytically confirm the effectiveness of repetition coded OFDM systems, we theoretically analyze the effect of increasing the number of repetitions (diversity branches) and acquiring both time and frequency diversity gain, and then derive a closed-form equation of average bit error rate (BER) to easily but precisely evaluate the performance.

This paper presents an efficient method for differential fault analysis (DFA) on substitution-permutation network (SPN)-based block ciphers. A combination of a permutation cancellation and an algebraic key filtering technique makes it possible to reduce the computational cost of key filtering significantly and therefore perform DFAs with new fault models injected at an earlier round, which defeats conventional countermeasures duplicating or recalculating the rounds of interest. In this paper, we apply the proposed DFA to the LED block cipher. Whereas existing DFAs employ fault models injected at the 30th round, the proposed DFA first employs a fault model injected at the 29th round. We demonstrate that the proposed DFA can obtain the key candidates with only one pair of correct and faulty ciphertexts in about 2.1h even from the 29th round fault model and the resulting key space is reduced to 24.04

Resonant scattering of flexural waves in acoustic waveguide is analysed by using the recursive transfer method (RTM). Because flexural waves are governed by a fourth-order differential equation, a localized wave tends to be induced around the scattering region and dampening wave tails from the localized wave may reach the ends of a simulation domain. A notable feature of RTM is its ability to extract the localized wave even if the dampening tail reaches the end of the simulation domain. Using RTM, the enhanced reflection caused by a localized wave is predicted and the shape of the localized wave is explored at its resonance with the incident wave.

In this paper, we propose a new cross-layer scheme Cooperation between channel Access control and TCP Rate Adaptation (CATRA) aiming to manage TCP flow contention in multi-hop ad hoc networks. CATRA scheme collects useful information from MAC and physical layers to estimate channel utilization of the station. Based on this information, we adjust Contention Window (CW) size to control the contention between stations. It can also achieve fair channel access for fair channel access of each station and the efficient spatial channel usage. Moreover, the fair value of bandwidth allocation for each flow is calculated and sent to the Transport layer. Then, we adjust the sending rate of TCP flow to solve the contention between flows and the throughput of each flow becomes fairer. The performance of CATRA is examined on various multi-hop network topologies by using Network Simulator (NS-2).

Most recent work on cooperative spectrum sensing using cognitive radios has focused on issues involving the sensing channels and seemed to ignore those involving the reporting channels. Furthermore, no research has treated the effect of correlated composite Rayleigh-lognormal fading, also known as Suzuki fading, in cognitive radio. This paper proposes a technique for reuse of shadowed CRs, discarded during the sensing phase, as amplified-and-forward (AF) diversity relays for other surviving CRs to mitigate the effects of such fading in reporting channels. A thorough analysis of and a closed-form expression for the outage probability of the resulting cooperative AF diversity network in correlated composite Rayleigh-lognormal fading channels are presented in this paper. In particular, an efficient solution to the “PDF of sum-of-powers” of correlated Suzuki-distributed random variables using moment generating function (MGF) is proposed.

A method of round addition attack on substitution-permutation network (SPN) block ciphers using differential fault analysis (DFA) is presented. For the 128-bit advanced encryption standard (AES), we show that secret keys can be extracted using one correct ciphertext and two faulty ciphertexts. Furthermore, we evaluate the success rate of a round addition DFA attack, experimentally. The proposed method can also be applied to lightweight SPN block cipher such as KLEIN and LED.

As the virtualization technology becomes the core ingredient for recent promising IT infrastructures such as utility computing and cloud computing, accurate analysis of the internal behaviors of virtual machines becomes more and more important. In this paper, we first propose a novel I/O fairness analysis tool for virtualization systems. It supports the following three features: fine-grained, multimodal and multidimensional. Then, using the tool, we observe various I/O behaviors in our experimental XEN-based virtualization system. Our observations disclose that 1) I/O fairness among virtual machines is broken frequently even though each virtual machine requests the same amount of I/Os, 2) the unfairness is caused by an intricate combination of factors including I/O scheduling, CPU scheduling and interactions between the I/O control domain and virtual machines, and 3) some mechanisms, especially the CFQ (Completely Fair Queuing) I/O scheduler that supports fairness reasonable well in a non-virtualization system, do not work well in a virtualization system due to the virtualization-unawareness. These observations drive us to design a new virtualization-aware I/O scheduler for enhancing I/O fairness. It gives scheduling opportunities to asynchronous I/Os in a controlled manner so that it can avoid the unfairness caused by the priority inversion between the low-priority asynchronous I/Os and high-priority synchronous I/Os. Real implementation based experimental results have shown that our proposal can enhance I/O fairness reducing the standard deviation of the finishing time among virtual machines from 4.5 to 1.2.

The present paper introduces a novel method for the construction of sequences that have a zero-correlation zone. For the proposed sequence set, both the cross-correlation function and the side lobe of the autocorrelation function are zero for phase shifts within the zero-correlation zone. The proposed scheme can generate a set of sequences, each of length 16n2, from an arbitrary Hadamard matrix of order n and a set of 4n trigonometric function sequences of length 2n. The proposed construction can generate an optimal sequence set that satisfies, for a given zero-correlation zone and sequence period, the theoretical bound on the number of members. The peak factor of the proposed sequence set is equal to √2.

This paper proposes to obtain high-level, domain-robust representations for cross-view face recognition. Specially, we introduce Convolutional Deep Belief Networks (CDBN) as the feature learning model, and an CDBN based interpolating path between the source and target views is built to model the correlation of cross-view data. The promising results outperform other state-of-the-art methods.