This paper proposes a virtual layered successive detector with adaptive transmit signal phase rotation for quadrature amplitude modulation (QAM) that enables high speed communication even in downlinks of wireless communication systems. It is shown that the detection performance is degraded when the eigenvalue of a virtual channel becomes close to the power of the additive white Gaussian noise (AWGN). Therefore, adaptive transmit signal phase rotation is introduced for the detector to improve the transmission performance. For the transmit phase rotation, three techniques to search the rotation angles are proposed, which can reduce the feedback information from the receiver to the transmitter. Among the three proposed techniques, the technique called “iterative variable step step search” is shown to achieve the best performance. Actually, it is confirmed by computer simulation that the variable step search makes the detector attain about 17 dB of a gain at the bit error rate (BER) of 10-5 in 42 multiple-input-multiple-output (MIMO) systems.

This paper presents a compact metal plate lens antenna for evaluating a wave absorber placed on ceiling of the ETC gate. The focal distance of the lens was derived to be 129 cm by the geometrical optics procedure. By arranging the lens in front of a horn antenna, the gain and beamwidth characteristics were improved from 18 dBi to 26 dBi and from 22 degrees to 7 degrees, respectively. Then the antenna characteristics were evaluated when the distance between the antenna and the lens was changed in order to miniaturize the lens antenna. As the result, the changes in beamwidth were held to within 1 dB when the lens came close to the horn antenna. Scattering, phase and electric field intensity of electromagnetic wave were evaluated to clarify the foundation of the given characteristics. It was found that the field intensity for the miniaturized lens antenna is stronger than that for GO designed one though the phase uniformity is worse. The distance between the horn antenna and lens can be reduced to 80 cm. The absorption characteristics for the arranged absorbers which have different absorptions were measured, and it was shown that the proposed method was suitable for specifying the deteriorated absorber in the ETC system.

We propose a novel dynamic hierarchical optical path network architecture that achieves efficient optical fast circuit switching. In order to complete wavelength path setup/teardown efficiently, the proposed network adaptively manages waveband paths and bundles of optical paths, which provide virtual mesh connectivity between node pairs for wavelength paths. Numerical experiments show that operational and facility costs are significantly reduced by employing the adaptive virtual waveband connections.

In this paper, we propose a novel texture analysis method capable of estimating multiple primitives, which are elements repetitively arranged to compose a texture, in multi-structured textures. The approach is based on a texture description model that uses mathematical morphology, called the “Primitive, Grain, and Point Configuration (PGPC)” texture model. The estimation of primitives based on the PGPC texture model involves searching the optimal structuring element for primitives according to a size distribution function and a magnification. The proposed method achieves the following two improvements: (1) the simultaneous estimation of a multiple number of primitives in multi-structured textures with a ranking of primitives on the basis of their significance. and (2) the introduction of flexibility in the process of magnification to obtain a higher degree of fitness of large grains. With a computational combination of different primitives, the method provides an ordered priority to denote the significance of elements. The promising performance of the proposed method is experimentally shown by a comparison with conventional methods.

In this letter, we adopt a new factor analysis of neighborhood-preserving embedding (NPE) for speaker verification. NPE aims at preserving the local neighborhood structure on the data and defines a low-dimensional speaker space called neighborhood-preserving embedding space. We compare the proposed method with the state-of-the-art total variability approach on the telephone-telephone core condition of the NIST 2008 Speaker Recognition Evaluation (SRE) dataset. The experimental results indicate that the proposed NPE method outperforms the total variability approach, providing up to 24% relative improvement.

In this letter, we present a general construction of sequence sets with low correlation zone, which is based on finite fields and the balance property of some functions. The construction is more flexible as far as the partition of parameters is concerned. A simple example is also given to interpret the construction.

The research on body-centric wireless communications (BCWCs) is becoming very hot because of numerous applications, especially the application of E-health systems. Therefore, a small multi-band and low-profile planar inverted-F antenna (PIFA) with tuning function is presented for BCWCs in this paper. In order to achieve multi-band operation, there are two branches in the antenna: the longer branch low frequency band (950–956 MHz), and the shorter branch with a varactor diode embedded for high frequency bands. By supplying different DC voltages, the capacitance of the varactor diode varies, so the resonant frequency can be tuned without changing the dimension of the antenna. While the bias is set at 6 V and 14 V, WiMAX and ISM bands can be covered, respectively. From the radiation patterns, at 950 MHz, the proposed antenna is suitable for on-body communications, and in WiMAX and ISM bands, they are suitable for both on-body and off-body communications.

Various information and communication technology (ICT) applications have been introduced for use in disaster-stricken areas. Of these, those for healthcare purposes proved useful when used for continually monitoring health conditions and easily using medical and healthcare devices, such as sphygmomanometers, which are familiar to the public. Devices that were easy to understand and use were more acceptable in the first post-disaster stage in a temporary housing community as victims were experiencing mental and physical trauma. After gaining the trust of medical/healthcare staff caring for the victims, we could move to the next stage with their support. ICT technologies are tools and are basically invisible to victims; a notion we have recognized anew. This paper introduces our activities in the area of healthcare monitoring services. The UMe-1 system and subset health check kiosk version 0 are introduced. The kiosk is simple and important for life support advisers in support centers as a tool for checking the health condition of residents. Not all those living in the target temporary housing community are currently using the kiosk due to its location within the widespread premises, but the director of a support center recognizes the utility of the kiosk and expects that a community-based kiosk and user-friendly BAN device could be used at home for mimamori (the Japanese concept of informally monitoring healthcare) because residents living far from support centers have difficulty regularly visiting the center, especially in the winter. We introduced a television-based, in-home health check kiosk and are currently working on its development. There are gaps between actually deployable technologies and research results, but it is also important to continue to address research issues concerning reducing impact through the user interface and introducing less stress to the everyday lives of disaster victims.

A 60 GHz direct conversion transceiver which employs amplitude/phase imbalance cancellation technique is newly proposed. By using the proposed technique, the receive path of the transceiver achieves less than 0.2 dB of amplitude error and less than 3 of phase error at 60 GHz bands over a 10 GHz bandwidth, which relaxes the design accuracy required for baluns used in the transceiver. It also employs a simple and fast calibration algorithm to adjust the locking range of the divide-by-3 injection locked divider in the phase locked loop. Fabricated in 90 nm CMOS technology, the transceiver achieves a low power consumption of 230 mW in transmit mode and 173 mW in receive mode. The output spectrum of 1.76 Gsps π/2-BPSK/QPSK modulation shows the excellent distortion and spurious suppression that meet the IEEE802.11ad draft standard.

This paper proposes non-coherent multiple-input multi-ple-output (MIMO) communication systems employing per transmit antenna differential mapping (PADM), which generates an independent differentially encoded sequence for each of the multiple transmit antennas by means of space-time coding and mapping. At a receiver, the proposed PADM employs adaptive maximum-likelihood detection (MLD). The features of PADM are as follows: 1) it has excellent tracking performance for fast time-varying fading channels, because it can detect transmitted data without needing channel state information (CSI); 2) it can be applied not only to transmit diversity (TD) but also to spatial multiplexing (SM). In this paper, we analyze the adaptive MLD based on pseudo matrix inversion and derive its metric for data detection. In order to satisfy requirements on multiple transmitted sequences for the adaptive MLD, this paper proposes a mapping rule for PADM. Next, this paper describes a receiver structure based on per-survivor processing (PSP), which can drastically reduce the complexity of adaptive MLD. Finally, computer simulations confirm that the proposed non-coherent MIMO communication systems employing PADM have excellent tracking capability for TD and SM on fast time-varying fading channels.

Ground truth based image segmentation evaluation paradigm plays an important role in objective evaluation of segmentation algorithms. So far, many evaluation methods in terms of comparing clusterings in machine learning field have been developed. However, most traditional pairwise similarity measures, which only compare a machine generated clustering to a “true” clustering, have their limitations in some cases, e.g. when multiple ground truths are available for the same image. In this letter, we propose utilizing an information theoretic measure, named NJMI (Normalized Joint Mutual Information), to handle the situations which the pairwise measures can not deal with. We illustrate the effectiveness of NJMI for both unsupervised and supervised segmentation evaluation.

It is becoming more and more important to make use of personal or classified information while keeping it confidential. A promising tool for meeting this challenge is secure multi-party computation (MPC). It enables multiple parties, each given a snippet of a secret s, to compute a function f(s) by communicating with each other without revealing s. However, one of the biggest problems with MPC is that it requires a vast amount of communication. Much research has gone into making each protocol (equality testing, interval testing, etc.) more efficient. In this work, we make a set of multiple protocols more efficient by transforming them into their equivalent batch processing form and propose two protocols: “Batch Logical OR” and “Batch Logical AND.” Using proposed protocols recursively, we also propose “Batch Logical OR-AND” and “Batch Logical AND-OR,” and show arbitrary formula consisting of Boolean protocols, OR gates, and AND gates can be batched. Existing logical OR and logical AND protocols consisting of t equality testing invocations have a communication complexity of O(t), where is the bit length of the secrets. Our batched versions of these protocols reduce it to O( + t). For t interval testing invocations, they reduce both communication and round complexity. Thus they can make the queries on a secret shared database more efficient. For example, the use of the proposed protocols reduces the communication complexity for a query consisting of equality testing and interval testing by approximately 70% compared to the use of the corresponding existing protocols. The concept of the proposed protocols is versatile and can be applied to logical formulae consisting of protocols other than equality testing and interval testing, thereby making them more efficient as well.

This paper addresses conjugate-gradient (CG) based pilot-assisted channel estimation and equalization in doubly selective channels for orthogonal frequency division multiplexing (OFDM) block transmissions. With the help of the discrete prolate spheroidal sequence, which shows flat mean-square error (MSE) curves for the reconstructed channels in the presence of Doppler frequency mismatch, a basis expansion model for a parsimonious channel representation over multiple OFDM blocks is developed, a system equation for the least square channel estimation under widely used pilot lattices, where the pilot symbols are irregularly placed in the subcarrier domain, is formulated by introducing carving matrices, and the standard CG method is applied to the system. Relying on the CG method again, the linear minimum mean-square error channel equalization is pursued without performing any matrix inversion, while elevating the convergence speed of the iterative algorithm with a simple preconditioner. Finally, we validate our schemes with numerical experiments on the integrated services digital broadcasting-terrestrial system in doubly-selective channels and determine the normalized MSE and uncoded bit error rate.

For maximum-likelihood (ML) estimation to jointly track carrier frequency offset (CFO) and channel impulse response (CIR) in orthogonal frequency division multiplexing (OFDM) systems, we present a finite high order approximation method utilizing the MATLAB ‘roots' command on the log-likelihood function derived from the OFDM received signal, coupled with an adaptive iteration algorithm. The tracking performance of this high order approximation algorithm is found to be excellent, and as expected, the algorithm outperforms the other existing first order approximation algorithms.

This paper proposes a cumulative DNL (CDNL) test methodology for the BIST of ADCs. It analyzes the histogram of the DNL of a predetermined k LSBs distance to determine the DNL and gain error. The advantage of this method over others is that the numbers of required code bins and required samples are significantly reduced. The simulation and measurements of a 12-bit ADC show that the proposed CDNL has an error of less than 5% with only 212 samples, which can only be achieved with 222 samples using the conventional method. It only needs 16 registers to store code bins in this experiment.

As business values pursued by today's organizations are abstract concepts, measurement of these values and their achievement is not straightforward. This paper proposes a value achievement measuring and managing framework, which recursively decomposes business values to construct a value hierarchy and then links it with the business process hierarchy. The framework makes it possible to measure value achievement, trace values to processes, and take necessary actions in response to the measured progress in value achievement.

The left-handed (LH) operation of a three-dimensional (3-D) LH material composed of wired metallic spheres is experimentally confirmed. A 15153-cell periodic structure designed to have an isotropic LH characteristics is fabricated by a 3-D printer with post plating technology, and near-field measurements of refracted waves by the negative refractive index slab lens are carried out. The dispersion characteristics measured from the near-field distributions on the surface of the LH material clearly show that the structure supports the backward waves at 12 GHz band. It is also shown experimentally that the resolution of the slab lens exceeds the diffraction limit by near field measurements with a single source and adjacent two sources. In addition, near-field measurements from the LH material near the Γ-point frequency at 12.90 GHz are carried out. A highly directive plane wave with a single point source is observed and the near-zero-index operation has been confirmed.

Non-negative matrix factorization (NMF) is widely used for music transcription because of its efficiency. However, the conventional NMF-based music transcription algorithm often causes harmonic confusion errors or time split-up errors, because the NMF decomposes the time-frequency data according to the activated frequency in its time. To solve these problems, we proposed an NMF with temporal continuity and harmonicity constraints. The temporal continuity constraint prevented the time split-up of the continuous time components, and the harmonicity constraint helped to bind the fundamental with harmonic frequencies by reducing the additional octave errors. The transcription performance of the proposed algorithm was compared with that of the conventional algorithms, which showed that the proposed method helped to reduce additional false errors and increased the overall transcription performance.

In this paper, the correspondence between the weighted line graph and the Mason signal flow graph (MSFG) has been established, which gives an interpretation of a convolutional network code (CNC) over a cyclic network from a different perspective. Furthermore, by virtue of Mason theorem, we present two new equivalent conditions to evaluate whether the global encoding kernels (GEKs) can be uniquely determined by the given complete set of local encoding kernels (LEKs) in a CNC over a cyclic network. These two new equivalent conditions turn out to be more intuitive. Moreover, we give an alternative simple proof of an existing result.

Based on a reverse converter algorithm derived from the New Chinese Remainder Theorem I, an algorithm for sign detection of RNS {2n-1, 2n, 2n+1} is presented in this paper. The hardware of proposed algorithm can be implemented using two n-bit additions and one (n+1)-bit comparator. Comparing with the previous paper, the proposed algorithm has reduced the number of additions used in the circuit. The experimental results show that the proposed circuit achieves 17.3% savings in area for small moduli and 10.5% savings in area for large moduli on an average, with almost the same speed. The power dissipations obtain 12.6% savings in average.