A frequency-reconfigurable dipole antenna, whose dual resonant frequencies are independently controlled, is introduced. The antenna's conductor consists of radiating conductors, lumped and distributed elements, and varactors. To design the antenna, current distribution, input impedance, and radiation power including higher-order modes, are analyzed for a narrow-angle sectorial antenna embedded with passive elements. To derive the formulae used, radiation power is analyzed in two ways: using Chu's equivalent circuit and the multipole expansion method. Numerical estimations of electrically small antennas show that dual-band antennas are feasible. The dual resonant frequencies are controlled with the embedded series and shunt inductors. A dual-band antenna is fabricated, and measured input impedances agree well with the calculated data. With the configuration, an electrically small 2.5-/5-GHz dual-band reconfig-urable antenna is designed and fabricated, where the reactance values for the series and shunt inductors are controlled with varactors, each connected in series to the inductors. Varying the voltages applied to the varactors varies the measured upper and lower resonant frequencies between 2.6 and 2.9GHz and between 5.1 and 5.3GHz, where the other resonant frequency is kept almost identical. Measured radiation patterns on the H-plane are almost omni-directional for both bands.

Two plasmonic band-bass filters are analyzed: one is a grating-type filter and the other is a slit-type filter. The former shows a band-pass characteristic with a high transmission for a two-dimensional structure, while the latter exhibits a high transmission even for a three-dimensional structure with a thin metal layer.

In this paper we propose a novel classification method for the multiple k-nearest neighbor (MkNN) classifier and show its practical application to medical image processing. The proposed method performs fine classification when a pair of the spatial coordinate of the observation data in the observation space and its corresponding feature vector in the feature space is provided. The proposed MkNN classifier uses the continuity of the distribution of features of the same class not only in the feature space but also in the observation space. In order to validate the performance of the present method, it is applied to the tissue characterization problem of coronary plaque. The quantitative and qualitative validity of the proposed MkNN classifier have been confirmed by actual experiments.

In this paper, we have investigated a new structure which combines dielectric cylinders with air-hole cylinders array, and analyzed the guiding problem for periodically dielectric waveguides by arbitrary shape of dielectric constants in the middle layer. In the numerical analysis, we examined an influence of the dielectric circular cylinder along a middle layer by using the energy distribution and complex propagation constants at the first stop band region compared with hollow dielectric cylinder. In addition, we also investigated the influence of dielectric structure with equivalence cross section compared with dielectric cylinders, and clarified an influence of dielectric structures in the middle layer by energy distribution analysis for TE0 mode.

In this study, a well-shaped microelectrode array (MEA) for fabricating a high-density complementary metal-oxide semiconductor amperometric electrochemical sensor array was designed and verified. By integrating an auxiliary electrode with the well-shaped structure of the MEA, the footprint was reduced and high density and high resolution were also achieved. The results of three-dimensional electrochemical simulations confirmed the effectiveness of the proposed MEA structure and possibility of increasing the density to four times than that achieved by the conventional two-dimensional structure.

A rapid single-flux-quantum (RSFQ) 4-bit bit-slice multiplier is proposed. A new systolic-like multiplication algorithm suitable for RSFQ implementation is developed. The multiplier is designed using the cell library for AIST 10-kA/cm2 1.0-µm fabrication technology (ADP2). Concurrent flow clocking is used to design a fully pipelined RSFQ logic design. A 4n×4n-bit multiplier consists of 2n+17 stages. For verifying the algorithm and the logic design, a physical layout of the 8×8-bit multiplier has been designed with target operating frequency of 50GHz and simulated. It consists of 21 stages and 11,488 Josephson junctions. The simulation results show correct operation up to 62.5GHz.

An extended harmonic disturbance observer is designed for speed (or position) sensorless current control of DC motor subject to a biased sinusoidal disturbance and parameter uncertainties. The proposed method does not require the information on the mechanical part of the motor equation. Theoretical analysis via the singular perturbation theory is performed to verify that the feedforward compensation using the estimation can improve the robust transient performance of the closed-loop system. A stability condition is derived against parameter uncertainties. Comparative experimental results validate the robustness of the proposed method against the uncertainties.

An (≤n,≤ω)-one-time secure broadcast encryption scheme (BES) allows a sender to choose any subset of receivers so that only the designated users can decrypt a ciphertext. In this paper, we first show an efficient construction of an (≤n,≤ω)-one-time secure BES with general ciphertext sizes. Specifically, we propose a generic construction of an (≤n,≤ω)-one-time secure BES from key predistribution systems (KPSs) when its ciphertext size is equal to integer multiple of the plaintext size, and our construction includes all known constructions. However, there are many possible combinations of the KPSs to realize the BES in our construction methodology, and therefore, we show that which combination is the best one in the sense that secret-key size can be minimized. Our (optimized) construction provides a flexible parameter setup (i.e. we can adjust the secret-key sizes) by setting arbitrary ciphertext sizes based on restrictions on channels such as channel capacity and channel bandwidth.

It is known that, using just a deck of cards, an arbitrary number of parties with private inputs can securely compute the output of any function of their inputs. In 2009, Mizuki and Sone constructed a six-card COPY protocol, a four-card XOR protocol, and a six-card AND protocol, based on a commonly used encoding scheme in which each input bit is encoded using two cards. However, up until now, there are no known results to construct a set of COPY, XOR, and AND protocols based on a two-card-per-bit encoding scheme, which all can be implemented using only four cards. In this paper, we show that it is possible to construct four-card COPY, XOR, and AND protocols using polarizing plates as cards and a corresponding two-card-per-bit encoding scheme. Our protocols use a minimum number of cards in the setting of two-card-per-bit encoding schemes since four cards are always required to encode the inputs. Moreover, we show that it is possible to construct two-card COPY, two-card XOR, and three-card AND protocols based on a one-card-per-bit encoding scheme using a common reference polarizer which is a polarizing material accessible to all parties.

Considering the obvious bias of the traditional interpolation method, a novel time delay estimation (TDE) interpolation method with sub-sample accuracy is presented in this paper. The proposed method uses a generalized extended approximation method to obtain the objection function. Then the optimized interpolation curve is generated by Second-order Cone programming (SOCP). Finally the optimal TDE can be obtained by interpolation curve. The delay estimate of proposed method is not forced to lie on discrete samples and the sample points need not to be on the interpolation curve. In the condition of the acceptable computation complexity, computer simulation results clearly indicate that the proposed method is less biased and outperforms the other interpolation algorithms in terms of estimation accuracy.

We have studied ultra-low-power superconductor circuits using adiabatic quantum flux parametron (AQFP) logic. Latches, which store logic data in logic circuits, are indispensable logic elements in the realization of AQFP computing systems. Among them, feedback latches, which hold data by using a feedback loop, have advantages in terms of their wide operation margins and high stability. Their drawbacks are their large junction counts and long latency. In this paper, we propose a majority gate-based feedback latch for AQFP logic with a reduced number of junctions. We designed and fabricated the proposed AQFP latches using a standard National Institute of Advanced Industrial Science and Technology (AIST) process. The measurement results showed that the feedback latches operate with wide operation margins that are comparable with circuit simulation results.

We describe a calculation tool and modeling methods to find self and mutual inductance and current distribution in superconductive multilayer circuit layouts. Accuracy of the numerical solver is discussed and compared with experimental measurements. Effects of modeling parameter selection on calculation results are shown, and we make conclusions on the selection of modeling parameters for fast but sufficiently accurate calculations when calibration methods are used. Circuit theory for the calculation of branch impedances from the output of the numerical solver is discussed, and compensation for solution difficulties is shown through example. We elaborate on the construction of extraction models for superconductive integrated circuits, with and without resistive branches. We also propose a method to calculate current distribution in a multilayer circuit with multiple bias current feed points. Finally, detailed examples are shown where the effects of stacked vias, bias pillars, coupling, ground connection stacks and ground return currents in circuit layouts for the AIST advanced process (ADP2) and standard process (STP2) are analyzed. We show that multilayer inductance and current distribution extraction in such circuits provides much more information than merely branch inductance, and can be used to improve layouts; for example through reduced coupling between conductors.

A single-flux-quantum (SFQ) arithmetic logic unit (ALU) was designed and tested to evaluate the effectiveness of introducing dynamically reconfigurable logic gates in the design of a superconducting logic circuit. We designed and tested a bit-serial SFQ ALU that can perform six arithmetic/logic functions by using a dynamically reconfigurable AND/OR gate. To ensure stable operation of the ALU, we improved the operating margin of the SFQ AND/OR gate by employing a partially shielded structure where the circuit is partially surrounded by under- and over-ground layers to reduce parasitic inductances. Owing to the introduction of the partially shielded structure, the operating margin of the dynamically reconfigurable AND/OR gate can be improved without increasing the circuit area. This ALU can be designed with a smaller circuit area compared with the conventional ALU by using the dynamically reconfigurable AND/OR gate. We implemented the SFQ ALU using the AIST 2.5kA/cm2 Nb standard process 2. We confirmed high-speed operation and correct reconfiguration of the SFQ ALU by a high-speed test. The measured maximum operation frequency was 30GHz.

Human body segmentation has many applications in a wide variety of image processing tasks, from intelligent vehicles to entertainment. A substantial amount of research has been done in the field of segmentation and it is still one of the active research areas, resulting in introduction of many innovative methods in literature. Still, until today, a method that can overcome the human segmentation problems and adapt itself to different kinds of situations, has not been introduced. Many of methods today try to use the graph-cut framework to solve the segmentation problem. Although powerful, these methods rely on a distance penalty term (intensity difference or RGB color distance). This term does not always lead to a good separation between two regions. For example, if two regions are close in color, even if they belong to two different objects, they will be grouped together, which is not acceptable. Also, if one object has multiple parts with different colors, e.g. humans wear various clothes with different colors and patterns, each part will be segmented separately. Although this can be overcome by multiple inputs from user, the inherent problem would not be solved. In this paper, we have considered solving the problem by making use of a human probability map, super-pixels and Grab-cut framework. Using this map relives us from the need for matching the model to the actual body, thus helps to improve the segmentation accuracy. As a result, not only the accuracy has improved, but also it also became comparable to the state-of-the-art interactive methods.

Quantum key distribution (QKD), a cryptography technology providing information theoretic security based on physical laws, has moved from the research stage to the engineering stage. Although the communication distance is subject to a limitation attributable to the QKD fundamentals, recent research and development of “key relaying” over a “QKD network” is overcoming this limitation. However, there are still barriers to widespread use of QKD integrated with conventional information systems: applicability and development cost. In order to break down these barriers, this paper proposes a new solution for developing secure network infrastructure based on QKD technology to accommodate multiple applications. The proposed solution introduces 3 functions: (1) a directory mechanism to manage multiple applications hosted on the QKD network, (2) a key management method to share and to allocate the keys for multiple applications, and (3) a cryptography communication library enabling existing cryptographic communication software to be ported to the QKD network easily. The proposed solution allows the QKD network to accommodate multiple applications of various types, and moreover, realizes applicability to conventional information systems easily. It also contributes to a reduction in the development cost per information system, since the development cost of the QKD network can be shared between the multiple applications. The proposed solution was implemented with a network emulating QKD technology and evaluated. The evaluation results show that the proposed solution enables the infrastructure of a single QKD network to host multiple applications concurrently, fairly, and effectively through a conventional application programming interface, OpenSSL API. In addition, the overhead of secure session establishment by the proposed solution was quantitatively evaluated and compared.

In order to minimize packet error rate in extremely dynamic vehicular networks, a novel vehicle to vehicle (V2V) mobile content transmission scheme that jointly employs random network coding and shuffling/scattering techniques is proposed in this paper. The proposed scheme consists of 3 steps: Step 1-The original mobile content data consisting of several packets is encoded to generate encoded blocks using random network coding for efficient error recovery. Step 2-The encoded blocks are shuffled for averaging the error rate among the encoded blocks. Step 3-The shuffled blocks are scattered at different vehicle locations to overcome the estimation error of optimum transmission location. Applying the proposed scheme in vehicular networks can yield error free transmission with high efficiency. Our simulation results corroborate that the proposed scheme significantly improves the packet error rate performance in high mobility environments. Thanks to the flexibility of network coding, the proposed scheme can be designed as a separate module in the physical layer of various wireless access technologies.

In this paper, we exploit MapReduce framework and other optimizations to improve the performance of hash join algorithms on multi-core CPUs, including No partition hash join and partition hash join. We first implement hash join algorithms with a shared-memory MapReduce model on multi-core CPUs, including partition phase, build phase, and probe phase. Then we design an improved cuckoo hash table for our hash join, which consists of a cuckoo hash table and a chained hash table. Based on our implementation, we also propose two optimizations, one for the usage of SIMD instructions, and the other for partition phase. Through experimental result and analysis, we finally find that the partition hash join often outperforms the No partition hash join, and our hash join algorithm is faster than previous work by an average of 30%.

A Field Programmable Sequencer and Memory (FPSM), which is a programmable unit exclusively optimized for peripherals on a micro controller unit, is proposed. The FPSM functions as not only the peripherals but also the standard built-in memory. The FPSM provides easier programmability with a smaller area overhead, especially when compared with the FPGA. The FPSM is implemented on the FPGA and the programmability and performance for basic peripherals such as the 8 bit counter and 8 bit accuracy Pulse Width Modulation are emulated on the FPGA. Furthermore, the FPSM core with a 4K bit SRAM is fabricated in 0.18µm 5 metal CMOS process technology. The FPSM is an half the area of FPGA, its power consumption is less than one-fifth.

Maneuvering target tracking under mixed line-of-sight/non-line-of-sight (LOS/NLOS) conditions has received considerable interest in the last decades. In this paper, a hierarchical interacting multiple model (HIMM) method is proposed for estimating target position under mixed LOS/NLOS conditions. The proposed HIMM is composed of two layers with Markov switching model. The purpose of the upper layer, which is composed of two interacting multiple model (IMM) filters in parallel, is to handle the switching between the LOS and the NLOS environments. To estimate the target kinetic variables (position, speed and acceleration), the unscented Kalman filter (UKF) with the current statistical (CS) model is used in the lower-layer. Simulation results demonstrate the effectiveness and superiority of the proposed method, which obtains better tracking accuracy than the traditional IMM.

In our previous work [12], [13], we introduced generalized feed-forward shift registers (GF2SR, for short) to apply them to secure and testable scan design. In this paper, we introduce another class of generalized shift registers called generalized feedback shift registers (GFSR, for short), and consider the properties of GFSR that are useful for secure scan design. We present how to control/observe GFSR to guarantee scan-in and scan-out operations that can be overlapped in the same way as the conventional scan testing. Testability and security of scan design using GFSR are considered. The cardinality of each class is clarified. We also present how to design strongly secure GFSR as well as GF2SR considered in [13].