A new signed color distance for color-to-gray conversion is proposed. It is suited to reflect gradation and detailed color change in an input color image into an output monochrome image. Experiments show the effectiveness of the proposed distance.

To immobilize cytochrome $c$ (cyt.,$c$) on ITO electrode with keeping its direct electron transfer (DET) activity, 10-carboxydecylphosphonic acid (10-CDPA) self-assembled monolayer (SAM) film was formed on ITO electrode. After 100 times washing process with exchanging phosphate buffer saline solution in the cell to fresh one, extit{in situ} slab optical waveguide (SOWG) absorption spectral measurement proved that about 80% of cyt.,$c$ immobilized on 10-CDPA modified ITO electrode was adsorbed on ITO electrode. Additionally SOWG spectral change of cyt.,$c$ between oxidized and reduced forms was observed with setting the ITO electrode potential at 0.3 and $-$0.3,V vs. Ag/AgCl, respectively showing DET reaction between cyt.,$c$ and ITO electrode occurred. About 30% of a monolayer coverage was estimated from the coulomb amount in the surface area of oxidation and reduction peaks on cyclic voltammetry (CV) data. CV peak current maintained 84% for ITO electrode modified with 10-CDPA SAM film after 60,min continuous scan with 0.1,V/sec from 0.3 and $-$0.3,V vs. Ag/AgCl.

A workflow net (WF-net for short) is a Petri net which represents a workflow. There are two important subclasses of WF-nets: extended free choice (EFC for short) and well-structured (WS for short). It is known that most actual workflows can be modeled as EFC WF-nets; and acyclic WS is a subclass of acyclic EFC but has more analysis methods. A sound acyclic EFC WF-net may be transformed to an acyclic WS WF-net without changing the observable behavior of the net. Such a transformation is called refactoring. In this paper, we tackled a problem, named acyclic EFC WF-net refactorizability problem, that decides whether a given sound acyclic EFC WF-net is refactorable to an acyclic WS WF-net. We gave two sufficient conditions on the problem, and constructed refactoring procedures based on the conditions. Furthermore, we applied the procedures to a sample workflow, and confirmed usefulness of the procedures for the enhancement of the readability and the analysis power of acyclic EFC WF-nets.

In this letter, we establish a model of a digital clock synchronization method for power packet dispatching. The first-order control is carried out to a specified model to achieve the clock synchronization. From the experimental results, it is confirmed that power packets were recognized under autonomous synchronization.

In wireless communication, it is hard to set the optimal route between a source and a destination through relays, since for optimal relaying, the system operator should know all channel conditions from a source to a destination through relays and determine the path with all channel conditions. In this letter, a multiple relay selection strategy is proposed for the reliability of transmission. The proposed strategy establishes a relaying route to a destination and provides an efficient relay selection process regardless of all channel conditions.

This paper presents a compact orthomode junction with low pass filters for high power applications. It consists of a circular waveguide step, a matching element for a high frequency band, and coupling sections straddle the circular waveguide step. These dimensions were optimized to achieve wideband performances and to support a high power rating. The structure without rectangular to circular transition is simple and comprised of two milled layers to divide E-plane of corrugated low pass filters. It can be easily manufactured and has low losses. The fabricated Ku/Ka-band orthomode junction was measured including power handling test of 2,kW at Ku-band. The measurement results demonstrated return loss of 21,dB and loss of 0.2,dB in the Ku- and Ka- band.

In the era of IPv6, since the number of IPv6 addresses rapidly increases and the required speed is more than Giga lookups per second (GLPS), an area-efficient and high-speed IP lookup architecture is desired. This paper shows a parallel index generation unit (IGU) for memory-based IPv6 lookup architecture. To reduce the size of memory in the IGU, we use a linear transformation and a row-shift decomposition. A single-memory realization requires O(2l log k) memory size, where l denotes the length of prefix, while the realization using IGU requires O(kl) memory size, where k denotes the number of prefixes. In IPv6 prefix lookup, since l is at most 64 and k is about 340 K, the IGU drastically reduces the memory size. Also, to reduce the cost, we realize the parallel IGU by using both on-chip and off-chip memories. We show a design algorithm for the parallel IGU to store given off-chip and on-chip memories. The parallel IGU has a simple architecture and performs lookup by using complete pipelines those insert the pipeline registers in all the paths. We loaded more than 340 K IPv6 pseudo prefixes on the Xilinx Virtex 6 FPGA with off-chip DDRII+ Static RAMs (SRAMs). Its lookup speed is 1.100 giga lookups per second (GLPS) which is sufficient for the required speed for a next generation 400 Gbps link throughput. As for the normalized area and lookup speed, our implementation outperforms existing FPGA implementations.

The high efficiency video coding (HEVC) standard has significantly improved compression performance for many applications, including remote desktop and desktop sharing. Screen content video coding is widely used in applications with a high demand for real-time performance. HEVC usually introduces great computational complexity, which makes fast algorithms necessary to offset the limited computing power of HEVC encoders. In this study, a statistical analysis of several screen content sequences is first performed to better account for the completely different statistics of natural images and videos. Second, a fast coding unit (CU) splitting method is proposed, which aims to reduce HEVC intra coding computational complexity, especially in screen content coding. In the proposed scheme, CU size decision is made by checking the smoothness of the luminance values in every coding tree unit. Experiments demonstrate that in HEVC range extension standard, the proposed scheme can save an average of 29% computational complexity with 0.9% Bjøntegaard Delta rate (BD-rate) increase compared with HM13.0+RExt6.0 anchor for screen content sequences. For default HEVC, the proposed scheme can reduce encoding time by an average of 38% with negligible loss of coding efficiency.

A serial ATA PHY fabricated in a 0.15-µm CMOS process performs the serial ATA operation in an asynchronous transition by using large variation in the reference clock. This technique calibrates a transmission signal frequency by utilizing the received signal. This is achieved by calibrating the divide ratio of a spread-spectrum clock generator (SSCG). This technique enables a serial ATA PHY to use reference oscillators with a production-frequency tolerance of less than 400ppm, i.e., higher than the permissible TX frequency variations (i.e., 350ppm). The calibrated transmission signal achieved a total jitter of 3.9ps.

To represent interactive objects, we propose a choice-disjunctive declaration statement of the form $S add R$ where S, R are the (procedure or field) declaration statements within a class. This statement has the following semantics: request the user to choose one between S and R when an object of this class is created. This statement is useful for representing interactive objects that require interaction with the user.

Social recommendation systems that make use of the user's social information have recently attracted considerable attention. These recommendation approaches partly solve cold-start and data sparsity problems and significantly improve the performance of recommendation systems. The essence of social recommendation methods is to utilize the user's explicit social connections to improve recommendation results. However, this information is not always available in real-world recommender systems. In this paper, a solution to this problem of explicit social information unavailability is proposed. The existing user-item rating matrix is used to compute implicit social information, and then an ISRec (implicit social recommendation algorithm) which integrates this implicit social information and the user-item rating matrix for social recommendation is introduced. Experimental results show that our method performs much better than state-of-the-art approaches; moreover, complexity analysis indicates that our approach can be applied to very large datasets because it scales linearly with respect to the number of observations in the matrices.

Robust yet efficient techniques for detecting and tracking targets in infrared (IR) images are a significant component of automatic target recognition (ATR) systems. In our previous works, we have proposed infrared target detection and tracking systems based on sparse representation method. The proposed infrared target detection and tracking algorithms are based on sparse representation and Bayesian probabilistic techniques, respectively. In this paper, we adopt Naïve Bayes Nearest Neighbor (NBNN) that is an extremely simple, efficient algorithm that requires no training phase. State-of-the-art image classification techniques need a comprehensive learning and training step (e.g., using Boosting, SVM, etc.) In contrast, non-parametric Nearest Neighbor based image classifiers need no training time and they also have other more advantageous properties. Results of tracking in infrared sequences demonstrated that our algorithm is robust to illumination changes, and the tracking algorithm is found to be suitable for real-time tracking of a moving target in infrared sequences and its performance was quite good.

This paper proposes a novel scheme for sequential orthogonal frequency division multiplexing channel estimation on the receiver side.The scheme comprises two methods: one improves estimation accuracy and the other reduces computational complexity. Based on a state-space model, the first method appropriately considers frequency correlation in an approach that derives a narrow-band channel gain for multiple pilot subcarriers; such consideration of frequency correlation leads to an averaging effect in the frequency domain. The second method is based on the first one and forces the observation matrix into a sparse bidiagonal matrix in order to decrease the number of mathematical processes. The proposed scheme is verified by numerical analysis.

In Recent years, a paradigm of optimization algorithms referred to as “meta-heuristics” have been gaining attention as a means of obtaining approximate solutions to optimization problems quickly without any special prior knowledge of the problems. Meta-heuristics are characterized by flexibility in implementation. In practical applications, we can make use of not only existing algorithms but also revised algorithms that reflect the prior knowledge of the problems. Most meta-heuristic algorithms lack mathematical grounds, however, and therefore generally require a process of trial and error for the algorithm design and its parameter adjustment. For one of the resolution of the problem, we propose an approach to design algorithms with mathematical grounds. The approach consists of first constructing a “framework” of which dynamic characteristics can be derived theoretically and then designing concrete algorithms within the framework. In this paper, we propose such a framework that employs two following basic strategies commonly used in existing meta-heuristic algorithms, namely, (1) multipoint searching, and (2) stochastic searching with pseudo-random numbers. In the framework, the update-formula of search point positions is given by a linear combination of normally distributed random numbers and a fixed input term. We also present a stability theory of the search point distribution for the proposed framework, using the variance of the search point positions as the index of stability. This theory can be applied to any algorithm that is designed within the proposed framework, and the results can be used to obtain a control rule for the search point distribution of each algorithm. We also verify the stability theory and the optimization capability of an algorithm based on the proposed framework by numerical simulation.

Least squares error (LSE) method adopted recursively can be used to track the frequency and amplitude of signals in steady states and kinds of non-steady ones in power system. Taylor expansion is used to give another version of this recursive LSE method. Aided by variable-windowed short-time discrete Fourier transform, recursive LSEs with and without Taylor expansion converge faster than the original ones in the circumstance of off-nominal input singles. Different versions of recursive LSE were analyzed under various states, such as signals of off-nominal frequency with harmonics, signals with step changes, signals modulated by a sine signal, signals with decaying DC offset and additive Gaussian white noise. Sampling rate and data window size are two main factors influencing the performance of method recursive LSE in transient states. Recursive LSE is sensitive to step changes of signals, but it is in-sensitive to signals' modulation and singles with decaying DC offset and noise.

In this work, the differential received signal strength based localization problem is addressed. Based on the measurement model, we present the constrained weighted least squares (CWLS) approach, which is difficult to be solved directly due to its nonconvex nature. However, by performing the semidefinite relaxation (SDR) technique, the CWLS problem can be relaxed into a semidefinite programming problem (SDP), which can be efficiently solved using modern convex optimization algorithms. Moreover, the SDR is proved to be tight, and hence ensures the corresponding SDP find the optimal solution of the original CWLS problem. Numerical simulations are included to corroborate the theoretical results and promising performance.

The combination of a halogen-free solvent 1,2,4-trimethylbenzene and unmodified fullerene potentially provides a way to develop environmentally-friendly and cost-effective solution-processed organic photocells. In this paper, the thermal annealing effect on the optical absorption spectra in poly(3-hexylthiophene):unmodified-C$_{60}$ composites with various compositions is reported. It is found that the onset temperature of the absorption spectrum change is higher in the composites with higher fullerene content. It is speculated that strong interaction between the polymer main chain and C$_{60}$ tends to suppress the reorientation of polymer main chains in a composite with high C$_{60}$ content.

When Zero-Forcing (ZF) is adopted as a detector, decreasing the condition number of the channel matrix increases the BER performance. In this paper, we propose a new detection algorithm which reduces the condition number of channel matrix down to nearly 2 on average. Since the least singular value of the channel matrix is a major factor determining the condition number, we, first, project the received signal into a space spanned by singular vectors that are orthogonal to the one corresponding to the least singular value. Then, LR decomposition is performed to reduce further the condition number of the projected channel matrix. Computer simulations show that the performance of the proposed algorithm is comparable to that of the ML detector for both correlated and uncorrelated channels. And also the proposed algorithm provides an at least 2dB improvement compared to the conventional LR-based Ordered Successive Interference Cancellation (LR-OSIC) detector with a Bit Error Rate (BER) of 10-3 and a comparable computation load.