In this paper, we examine a new P2P traffic localization approach that exploits peer selection adaptation (i.e., preferring peers who are likely to provide better performance), called Netpherd. Netpherd enables peers to communicate with local domain peers by manipulating networking performance across network domains (i.e., adding an artificial delay to inter-domain traffic). Our feasibility study shows that Netpherd reduces the inter-domain traffic by influencing peer selection adaptation. Netpherd also improves download performance of the peers who know many local domain peers. We discuss one guideline to improve Netpherd based on the feasibility study and verify the guideline with evaluation results.

This paper proposes an On-Ground Polarization-Forming (GPF) technique to realize a novel polarization-tracking-free satellite communication system whose communication satellite uses linear polarizations. In this system, mobile terminals use circular polarization to realize polarization-tracking-free and simplified terminal configuration. To output circular polarization from the satellite's horizontal and vertical polarization antennas, those output signals transmitted from the satellite are controlled by the base station using the GPF technique. We fabricate a GPF transmitter to evaluate its polarization forming performance. Measured results show that the proposed technique achieves very high cross-polarization discrimination, more than 27 dB.

With the development of Global Navigation Satellite System (GNSS), the amount of related research is growing rapidly in China. A lot of accomplishments have been achieved in all branches of the satellite navigation field, especially motivated by the BeiDou Program. In this paper, the current status, technologies and developments in satellite positioning and navigation in China are introduced. Firstly, an overview and update of the BeiDou Program is presented, known as the three-step development strategy for different services. Then signal design for the BeiDou system is discussed, including the generation of pseudo-random noise (PRN) codes for currently available signal B1, and the investigation of a new signal modulation scheme for interoperability at open frequency B1C. The B1C signal should comply to Multiplexed Binary Offset Carrier (MBOC) constrains, and a modulation called Quadrature Multiplexed BOC (QMBOC) is presented, which is equivalent to time-multiplexed BOC (TMBOC) for GPS and composite BOC (CBOC) for Galileo, while overcomes the drawback of CBOC. Besides, the inter and intra system compatibility is discussed, based on the effective C/N0 proposed by International Telecommunication Union (ITU). After that, receiver technologies in challenging environments are introduced, such as weak signal acquisition and assisted GNSS (A-GNSS). Moreover, a method of ambiguity mitigation for adaptive digital beam forming (ADBF) in large spacing antenna arrays is proposed, by which interference suppression is available. Furthermore, cutting edge technologies are brought in, including seamless navigation for indoor and outdoor, and collaborative navigation. After all, GNSS applications in China for industry and daily life are shown, as well as the market prospection.

Shisen-Sho is a tile-based one-player game. The instance is a set of 136 tiles embedded on 817 rectangular grids. Two tiles can be removed if they are labeled by the same number and if they are adjacent or can be connected with at most three orthogonal line segments. Here, line segments must not cross tiles. The aim of the game is to remove all of the 136 tiles. In this paper, we consider the generalized version of Shisen-Sho, which uses an arbitrary number of tiles embedded on rectangular grids. It is shown that deciding whether the player can remove all of the tiles is NP-complete.

Microblogs are a rising social network with distinguishing features such as simplicity and convenience and has already attracted a large number of users and triggered massive information explosion concerning individuals' own statuses and opinions. While sentiment analysis of the messages in microblogs is of great value, most of present studies are on English microblogs and few are on Chinese microblogs. Compared to English, Chinese has its unique expression style, such as no spaces or other word delimiters. Furthermore, Chinese short text also has its own properties. Thus we are inspired to explore effective features for sentiment classification of Chinese short text. In this paper, we propose to study user-related sentiment classification of Chinese microblogs in terms of the statistical and semantic characteristics, and deisgn the corresponding features: ratio of positive words and negative words (PNR), position feature (POS), collocation of verbs (COL), auxiliary words (AU). Then we employ an SVM-based method to classify the sentiment. Experiments show that the features we design is effective in recognizing the sentiment of messages in microblogs.

Previous inter-domain fast authentication schemes only realize the authentication of user identity. We propose a trusted inter-domain fast authentication scheme based on the split mechanism network. The proposed scheme can realize proof of identity and integrity verification of the platform as well as proof of the user identity. In our scheme, when the mobile terminal moves to a new domain, the visited domain directly authenticates the mobile terminal using the ticket issued by the home domain rather than authenticating it through its home domain. We demonstrate that the proposed scheme is highly effective and more secure than contemporary inter-domain fast authentication schemes.

There are many web sites where net users can post and distribute their illustration images. A typical way to draw a digital illustration is first to draw rough lines on a paper and then to trace the lines on a graphics-tablet by hand. The input lines usually contain fluctuation due to hand-drawing, which limits the quality of illustration. Therefore, it is important to remove the fluctuation and to smooth the lines while maintaining sharp features such as corners. Although naive applications of moving average filters can smooth input lines, they may cause over-smoothing artifacts in which sharp features are lost by the filtering. This paper describes an improved line smoothing method using adaptive moving averages, which smoothes input lines while keeping high curvature points. The proposed method evaluates curvatures of input lines and adaptively controls the filter-size to reduce the over-smoothing artifacts. Experiments demonstrated advantages of the proposed method over the previous method in terms of achieving smoothing effect while still preserving sharp feature preservation.

Image warping is usually used to perform real-time geometric transformation of the images captured by the CMOS image sensor of video camera. Several existing look-up table (LUT)-based algorithms achieve real-time performance; however, the size of the LUT is still large, and it has to be stored in off-chip memory. To reduce latency and bandwidth due to the use of off-chip memory, this paper proposes an improved LUT (ILUT) scheme that compresses the LUT to the point that it can be stored in on-chip memory. First, a one-step transformation is adopted instead of using several on-line calculation stages. The memory size of the LUT is then reduced by utilizing the similarity of neighbor coordinates, as well as the symmetric characteristic of video camera images. Moreover, an elaborate pipeline hardware structure, cooperating with a novel 25-point interpolation algorithm, is proposed to accelerate the system and reduce further memory usage. The proposed system is implemented by a field-programmable gate array (FPGA)-based platform. Two different examples show that the proposed ILUT achieves real-time performance with small memory usage and low system requirements.

The present paper introduces a new approach to the construction of a sequence set with a zero-correlation zone (ZCZ), which is referred to as a ZCZ sequence set. The proposed sequence construction generates a ZCZ sequence set from a ZCZ sequence set. The proposed method can generate an almost optimal ZCZ sequence set, the member size of which approaches the theoretical bound, when an almost optimal ZCZ sequence is used for the sequence construction. The proposed sequence set consists of NO subsets, where a ZCZ sequence set Z(LO, NO, ZO is used in sequence construction. The correlation function of the sequences of a pair of different subsets, referred to as the inter-subset correlation function, has a ZCZ with a width that is about times that of the correlation function of sequences of the same subset (intra-subset correlation function) for integers Λ ≥ 1, T, and m ≥ 0. Wide inter-subset zero-correlation enables improved performance during application of the proposed sequence set.

For advanced mobile communication systems that adopt orthogonal frequency-division multiple access (OFDMA) technologies, intercarrier interference (ICI) significantly degrades performance when mobility is high. Standard specifications and concerns about complexity demand low-cost methods with deployment readiness and decent performance. In this paper, novel zero forcing (ZF) and minimum mean-square error (MMSE) equalizers based on per-subcarrier adaptive (PSA) processing and perturbation-based (PB) approximation are introduced. The proposed equalizers strike a good balance between implementation cost and performance; therefore they are especially suitable for OFDMA downlink receivers. Theoretical analysis and simulations are provided to verify our claims.

Histogram modification based image enhancement algorithms have been extensively used in 2-D image applications. In this letter, we apply a histogram modification framework to stereoscopic image enhancement. The proposed algorithm estimates the histogram of a stereo image pair without explicitly computing the pixel-wise disparity. Then, the histogram in the occluded regions is estimated and used to determine the target histogram of the stereo image. Experimental results demonstrate the effectiveness of the proposed algorithm.

In time-varying frequency selective channels, to obtain high-rate joint time-frequency diversity, linear dispersion coded orthogonal frequency division multiplexing (LDC-OFDM), has recently been proposed. Compared with OFDM systems, single-carrier systems may retain the advantages of lower PAPR and lower sensitivity to carrier frequency offset (CFO) effects, which motivates this paper to investigate how to achieve joint frequency and time diversity for high-rate single-carrier block transmission systems. Two systems are proposed: linear dispersion coded cyclic-prefix single-carrier modulation (LDC-CP-SCM) and linear dispersion coded zero-padded single-carrier modulation (LDC-ZP-SCM) across either multiple CP-SCM or ZP-SCM blocks, respectively. LDC-SCM may use a layered two-stage LDC decoding with lower complexity. This paper analyzes the diversity properties of LDC-CP-SCM, and provides a sufficient condition for LDC-CP-SCM to maximize all available joint frequency and time diversity gain and coding gain. This paper shows that LDC-ZP-SCM may be effectively equipped with low-complexity minimum mean-squared error (MMSE) equalizers. A lower complexity scheme, linear transformation coded SCM (LTC-SCM), is also proposed with good diversity performance.

In block transmissions, inter-block interference (IBI) due to delayed waves exceeding a cyclic prefix severely limits the performance. To suppress IBI in downlink MC-CDMA systems, this paper proposes a novel channel shortening method using a time-domain equalizer. The proposed method minimizes a cost function related to equalizer output autocorrelations without the transmission of training symbols. We prove that the method can shorten a channel and suppress IBI completely. Simulation results show that the proposed method can significantly suppress IBI using relatively less number of received blocks than a conventional method when the number of users is moderate.

In this paper, we propose a normalization method dividing the gradient vector by the sum of the diagonal and two adjoining elements of the matrix expressing the correlation between the components of the discrete Fourier transform (DFT) of the reference signal used for the identification of unknown system. The proposed method can thereby improve the estimation speed of coefficients of adaptive filter.

A solution-processed photosensitive passivation layer with a low dielectric constant (PPLD) has been developed for an a-Si thin film transistor. The PPLD has three highly important properties: a low leakage current, low water absorption, and high-transparency. In addition to providing passivation, the PPLD doubles as a planarization layer. The photoactive property of the PPLD is convenient for its adaption to LCD manufacturing process. A photoactive compound contained in the PPLD enables the formation of contact holes and patterns via a photolithography process. Meanwhile, the PPLD requires ITO workability and strong adhesion property on metal and glass substrates. Apart from the above features, an a-Si TFT must perform with extremely high reliability if it is to replace the conventional inorganic passivation layer (SiNx:H). This reliability has been achieved by an a-Si TFT and LCD panel coated with the PPLD. A reliability test was conducted under a high-temperature, high-humidity (HH) condition to examine how resistant the electronic characteristics were to change. The PPLD-coated LCD panel display view showed no defects for a test duration of HH200 hours. This high reliability was presumed to be at least partly attributable to the low water absorption rate of the passivation layer and the suppression of the increase of the TFT off-leakage current by the PPLD, a passivation layer designed to be non-polar as possible. Judging from the results of these experiments, this solution-processed passivation layer seems to be a viable substitute for the conventional inorganic passivation layer. For a larger screen LCD and higher drive frequency, the problem of RC delay has been emerged. The low dielectric constant of the PPLD will suppress the RC delay of the signal and realize both a higher pixel and a higher drive frequency.

In this letter, we propose a new 4-dimensional constellation-rotation (CR) modulation method that achieves diversity gain of 4 in Rayleigh fading channels. The proposed scheme consists of two consecutive CR operations for QAM symbols unlike the conventional 2-dimensional CR method based on only one CR operation. Computer simulation results show that the new method exhibits much better performance than the conventional one in terms of code rate and channel erasure ratio.

Recently, asymmetric zero-correlation zone (A-ZCZ) sequence sets that are composed of several sequence subsets have been proposed. In A-ZCZ sequence sets, the zero-cross-correlation zone (ZCCZ) length between different sequence subsets is larger than the zero-correlation zone (ZCZ) length in each sequence subset. However, the ZCCZ length between different sequence subsets was not precisely shown in previous studies. The present letter shows precisely the ZCCZ length between different sequence subsets. This information is useful for estimating the magnitude of inter-cell interference when designing approximately synchronized code-division multiple-access (AS-CDMA) systems.

A CMOS current-mode S-shape correction circuit with shape-adjustable control is proposed for suiting different LCD panel's characteristics from different manufactures. The correction shape is divided into three segments for easy curve-fitting using three lower order polynomials. Each segment could be realized by a corresponding current-mode circuit. The proposed circuit consists of several control points which are designed for tuning the correction shape. The S-shape correction circuit was fabricated using the 0.35 µm TSMC CMOS technology. The measured input dynamic range of the circuit is from 0 µA to 220 µA. The -3 dB bandwidth of the circuit is up to 262 MHz in a high input current region.

A scheme that modulates the training sequence is proposed to support two-layer data streams in the time domain synchronous orthogonal frequency division multiplex (TDS-OFDM) systems. A theoretical analysis and computer simulation show that the proposed scheme works well and that the two layer data streams are compatible with each other.

A laser irradiation experiment for photocurrent induced failure investigations was described. In order to focus a laser beam on a desired transistor, novel test circuit structures using selectively metal-covered transistors were proposed. Photocurrent induced upset failures were successfully observed in fabricated CMOS SRAM test cells. Results were discussed with SPICE simulations.