Time-of-Flight Mass Spectroscopy (TOF-MS) with superconducting detectors has two advantages over MS with conventional ion detectors. First, it is coverage for a very wide range of molecule weight over 1,000,000. Secondly, kinetic energies of accelerated molecules can be measured at impact events one by one. These unique features enable an ultimate detection efficiency of 100% for intact ions and a fragmentation analysis that is critical for top-down proteomics. Superconducting MS is expected to play a role in, for example, the detection of antigen-antibody complexes, which are important for medical diagnosis. In this paper, how superconductivity contributes to MS is described.

In this paper, theoretical properties of deinterlacer banks are analyzed. Deinterlacer banks are novel filter banks in the sense that a progressive video sequence is separated into two progressive video sequences of a half frame rate and, furthermore, interlaced sequences are produced as intermediate data. Unlike the conventional filter banks, our deinterlacer banks are constructed in a way unique to multidimensional systems by using invertible deinterlacers, which the authors have proposed before. The system is a kind of shift-varying filter banks and it was impossible to derive the optimal bit-allocation control without any equivalent parallel filter banks. This paper derives an equivalent polyphase matrix representation of the whole system and its equivalent parallel structure, and then shows the optimal rate allocation for the deinterlacer banks. Some experimental results justify the effectiveness of the optimal rate allocation through our theoretical analysis.

This paper describes an 11-Gb/s CMOS demultiplexer (DEMUX) using redundant multi-valued logic (RMVL). The proposed circuit is received to serial binary data and is converted to parallel redundant multi-valued data. The converted data are reconverted to parallel binary data. By the redundant multi-valued data conversion, the RMVL makes it possible to achieve higher operating speeds than that of a conventional binary logic. The implemented DEMUX consists of eight integrators. The DEMUX is designed with 0.35 µm standard CMOS process. The validity and effectiveness are verified through HSPICE simulation. The DEMUX is achieved to the maximum data rate of 11-Gb/s and the average power consumption of 69.43 mW. This circuit is expected to operate at higher speed than 11-Gb/s in the deep-submicron process of the high operating frequency.

This paper presents a simple but high resolution DOA estimation method using second-order differential of MUSIC spectrum. MUSIC method is paid attention as one of "Superresolution" DOA estimation methods because of their brilliant characteristics, however MUSIC also has the problem of estimation accuracy in severe environments like low SNR, small number of snapshots, or incident waves from closely-spaced angles. Especially the case of two or more incident waves from closely-spaced angles, MUSIC often fails in making spectrum peaks that leads inaccurate DOA estimation. We pay attention to the fact that the second-order differential of MUSIC spectrum makes negative peaks around the original DOAs even when MUSIC spectrum does not make peaks there. We try to estimate DOAs not by MUSIC spectrum but by the second-order differential of the MUSIC spectrum, and to find its peaks for being estimated DOAs. The performance of the present method is evaluated in compared with MUSIC and Root-MUSIC methods through computer simulations and experiments.

We report on a subsystem of electromagnetic wave radiation and propagation estimation using high-Tc superconducting (HTS) receiving filters for S band. The subsystem, comprised of HTS filters, a rubidium standard signal generator (Rb SSG), a global positioning system (GPS) unit, etc., was used to evaluate the electromagnetic-wave (EMW) intensities, frequencies, the frequency interferences and the ground positions where the EM are measured. The developed subsystem showed high frequency selectivity for S band by using the HTS filters. Furthermore, we verified that the subsystem with the HTS filters operated on the moving car.

Privacy is increasingly viewed as a key concern in multi-agent based algorithms for Distributed Constraint Satisfaction Problems (DCSP) such as the Meeting Scheduling (MS) problem. Many algorithms aim for a global objective function and as a result, incur performance penalties in computational complexity and personal privacy. This paper describes a mobile agent-based scheduling scheme called Efficient and Privacy-aware Meeting Scheduling (EPMS), which results in a tradeoff among complexity, privacy, and global utility. It also introduces a privacy loss model for collaborative computation, multiple criteria for evaluating privacy in the MS problem, and a privacy measurement metric called the Min privacy metric. We have utilized a common computational space in EPMS for reducing the complexity and the privacy loss in the MS problem. The analytical results show that EPMS has a polynomial time computational complexity. In addition, simulation results show that the obtained global utility for scheduling multiple meetings with EPMS is close to the optimal level and the resulting privacy loss is less than for those in existing algorithms.

Transmitting multimedia data requires high bandwidth and low delay of the network. Today's wireless networks satisfy these requirements in ideal situations, but in practice multiple devices including those of neighboring networks share the same physical layer channel and the desired speeds in the wireless network can not be achieved. Traffic in one network causes interference to other neighboring networks. In this paper, we evaluate end user's playback quality of video content transmitted over a wireless network. We take into account the influence of interference from a neighboring network and define a multi-layer control strategy to maintain the quality on the network. Through simulations, we have obtained acceptable improvements in video playback quality by controlling the transmission power, the number of retransmissions, and other parameters at various layers.

3-D sound using head-related transfer functions (HRTFs) is applicable to embedded systems such as portable devices, since it can create spatial sound effect without multichannel transducers. Low-order modeling of HRTF with an IIR filter is effective for the reduction of the computational load required in embedded applications. Although modeling of HRTFs with IIR filters has been studied earnestly, little attention has been paid to sound movement with IIR filters, which is important for practical applications of 3-D sound. In this paper, a practical method for sound movement is proposed, which utilizes time-varying IIR filters and variable delay filters. The computational cost for sound movement is reduced by about 50% with the proposed method, compared to conventional low-order FIR implementation. In order to facilitate efficient implementation of 3-D sound movement, tradeoffs between the subjective quality of the output sound and implementation parameters such as the size of filter coefficient database and the update period of filter coefficients are also discussed.

A direction-oriented spatial interpolation technique for image de-interlacing is presented in this letter. The experimental results demonstrate that our method achieves excellent performance in terms of both objective and subjective image quality. The proposed algorithm also has a very computationally simple structure, and proves to be a good candidate for low-cost hardware interpolator.

This paper proposes a synthesis method of all low-voltage CMOS instantaneous-companding log domain integrators. The method is based on the exhaustive search of all low-voltage CMOS instantaneous-companding log domain integrators. All the integrators are derived from a general block diagram. A function of each block can be realized by any of a family of circuits and elemental circuits chosen from such families are combined to build an integrator. It is clarified that each family contains a few circuit topologies. All topologies of integrators including new ones are obtained from combinational procedure. Comparing characteristics of all generated integrators, ones satisfying required performances are found out.

A secure and efficient route discovery protocol is proposed for ad hoc networks, where only one-way hash functions are used to authenticate nodes in the ROUTE REQUEST, while additional public-key cryptography is used to guard against active attackers disguising a node in the ROUTE REPLY.

Both mutual authentication and generation of session keys can be accomplished by an authenticated key exchange (AKE) protocol. Let us consider the following situation: (1) a client, who communicates with many different servers, remembers only one password and has insecure devices (e.g., mobile phones or PDAs) with very-restricted computing power and built-in memory capacity; (2) the counterpart servers have enormous computing power, but they are not perfectly secure against various attacks (e.g., virus or hackers); (3) neither PKI (Public Key Infrastructures) nor TRM (Tamper-Resistant Modules) is available. The main goal of this paper is to provide security against the leakage of stored secrets as well as to attain high efficiency on client's side. For those, we propose an efficient and leakage-resilient RSA-based AKE (RSA-AKE) protocol suitable for the above situation whose authenticity is based on password and another secret. In the extended model where an adversary is given access to the stored secret of client, we prove that its security of the RSA-AKE protocol is reduced tightly to the RSA one-wayness in the random oracle model. We also show that the RSA-AKE protocol guarantees several security properties (e.g., security of password, multiple sever scenario with only one password, perfect forward secrecy and anonymity). To our best knowledge, the RSA-AKE protocol is the most efficient, in terms of both computation costs of client and communication costs, over the previous AKE protocols of their kind (using password and RSA).

Two versions of Krylov subspace order reduction techniques for VLSI interconnect reductions, including structure preserving reductions approach and adjoint networks approach, will be comparatively investigated. Also, we will propose a modified structure preserving reduction algorithm to speed up the projection construction in a linear order. The numerical experiment shows the high accuracy and low computational consumption of the modified method. In addition, it will be shown that the projection subspace generated from the structure-preserving approach and those from the adjoint networks approach are equivalent. Therefore, transfer functions of both reduced networks are identical.

Next generation free electron lasers aim to generate x-ray pulses with pulse durations down to 30 fs, and possibly even sub-fs. Synchronization of various stages of the accelerator and the probe laser system to the x-ray pulses with stability on the order of the pulse width is necessary to make maximal use of this capability. We are developing an optical timing synchronization system in order to meet this challenge. The scheme is based on generating a train of short optical pulses, with a precise repetition frequency, from a mode-locked laser oscillator and distributed via length-stabilized optical fibers to points requiring synchronization. The timing information is embedded in the repetition frequency and its harmonics. A significant advantage of the optical synchronization system is that multiple mode-locked Ti:sapphire seed oscillators typically present in an accelerator facility can be replaced by the master mode-locked fiber laser. In this paper, we briefly review progress on the development of the synchronization system and then discuss the implementation of this new possibility. Several technical issues related to this approach are analyzed.

In this paper, we propose a new technique for the scattering problems of multilayered inhomogeneous columnar dielectric gratings loaded rectangular dielectric constant both TM and TE waves using the combination of improved Fourier series expansion method, the multilayer method, and the eigenvalue matrix method. Numerical results are given for the power transmission coefficients in the parameters ε 3 /ε 0 , c/p, and b/d of rectangular cylinders to obtain the basic characteristic of the power transmission coefficients and reflection coefficients switching or frequency selective devices for both TM and TE waves. The influence of the incident angle and frequency of the transmitted power are also discussed in the connection with the propagation constant β in the free mode.

Assume that each vertex of a graph G is assigned a constant number q of nonnegative integer weights, and that q pairs of nonnegative integers li and ui, 1 ≤ i ≤ q, are given. One wishes to partition G into connected components by deleting edges from G so that the total i-th weights of all vertices in each component is at least li and at most ui for each index i, 1 ≤ i ≤ q. The problem of finding such a "uniform" partition is NP-hard for series-parallel graphs, and is strongly NP-hard for general graphs even for q = 1. In this paper we show that the problem and many variants can be solved in pseudo-polynomial time for series-parallel graphs and partial k-trees, that is, graphs with bounded tree-width.

In this paper the coexistence issue between the DS-UWB systems and Wi-Max/IEEE-802.16 based Fixed Broadband Wireless Access (FBWA) systems has been investigated. The aim is to evaluate the impact that the interference resulting from a realistic UWB hot spot scenario may have on the performance of a FBWA receiver. A mathematical model is developed through which the interference power produced by the UWB hot spot can be calculated. The benchmarks against which the UWB interference is assessed are also developed using the specifications of Wi-Max/IEEE-802.16 systems. Several simulations have been done to both validate the analytical results and calculate the UWB interference. In doing so, the effects of parameters like victim receiver bandwidth, carrier frequency, activity factor, the number of users and the distance from victim receiver in a realistic hot spot scenario have been studied.

Three distortion reduction filters for radio-on-fiber systems are proposed and evaluated from the standpoint of improvements in in-band third order intermodulation (IM3) components (spurious components), insertion loss, temperature stability and so on. The basic filter configuration includes optical comb filter, RF (radiowave frequency) comb filter, and RF dual band rejection filter (DBRF). Experiments are conducted at 2 GHz band for frequency separation Δf=5 MHz and 100 MHz in the temperature range of -10 to +50. These filters can reduce IM3 components even in the saturation region, unlike conventional linearizers. An optical comb filter can reduce IM3 components more than 20 dB and noise level around 10 dB if its polarization controller is properly adjusted, but its insertion loss is large and stability against vibration is very poor. The proposed RF comb filter and RF-DBRF can reduce IM3 components by more than 20 dB and noise level by more than 3 dB. Their stability against vibration and temperature change is good, and insertion losses are 1-2 dB for Δf=100 MHz.

An electrooptic near-field mapping system based on a gain-switched distributed feedback (DFB) pulsed laser and a CdTe electrooptic crystal was used for characterizing stationary and transient near-field patterns of conventional and uniplanar compact photonic band gap (UC-PBG) patch antennas. Effect of the UC-PBG structure on reduction in surface waves in the UC-PBG patch antenna was experimentally verified by comparing stationary and transient near-field measurement of the conventional and UC-PBG patch antennas.

This paper examines a system which is inspected at equally spaced points in time. We express the observed states of the system as a discrete time Markov chain with an absorbing state. It is assumed that the true state is certainly identified through inspection. After each inspection, one of three actions can be taken: Operation, repair, or replacement. We assume that the result of repair is uncertain. If repair is taken, we decide whether to inspect the system or not. When inspection is performed after completion of repair, we select an optimal action. After replacement, the system becomes new. We study the optimal maintenance policy which minimizes the expected total discounted cost for unbounded horizon. It is shown that, under reasonable conditions on the system's deterioration and repair laws and the cost structures, a control limit policy is optimal. We derive several valid properties for finding the optimal maintenance policy numerically. Furthermore, numerical analysis is conducted to show our theoretical results could hold under weaker conditions.