In H.264, the context-based adaptive variable length coding (CAVLC) is used for lossless compression. Direct table-lookup implementation requires higher cost because it employs a larger memory to produce the encoded results. In this letter, we present a more efficient technique for CAVLC implementation. Compared with those previous CAVLC chips, our design requires the lowest hardware cost.

This paper presents an advanced and extensive utilization approach of microwave resonant fields, and the applications to push-push oscillators and reconfigurable planar antennas. The excellent coherency, synchronous harmonics and the degenerative orthogonal modes of electromagnetic field built up on microwave resonators are noticeable features in this approach. Another crucial point is the resonant field controllability that is especially essential feature for reconfigurable antennas in this paper. All the features can be realized by embedding semiconductor devices and/or IC's on a microwave resonator. Push-push oscillators and reconfigurable planar antennas are described as good examples of this approach. The push-push oscillators can generate very higher frequency signals due to the selective use of the 4th harmonic up to the 8th harmonic resonant fields, suppressing undesired harmonic signals. As a result, very high frequency band oscillators up to millimeter-wave bands with good suppression of undesired harmonic signals can be easily realized at very low cost by use of commercially available active devices for low frequency bands. The reconfigurable planar antennas are also demonstrated, where the boundary condition of the resonant field on planar antennas can be purposefully controlled to realize reconfigurable antenna performances by the semiconductor devices embedded on the patch as well. The orthogonal linear polarization controllable patch, the dual-band switching patch and the continuously frequency controllable patch have been demonstrated as the successful applications of this approach.

A multiple-source system for rendering the sound pressure distribution in a target region can be modeled as a multi-input-multi-output (MIMO) system with the inputs being the source strengths and the outputs being the pressures on multiple measuring points/sensors. In this paper, we propose a target-oriented acoustic radiation generation technique (TARGET) for sound field control. For the MIMO system of a given geometry, a series of basic radiation modes, namely, target-oriented radiation modes (TORMs) can be derived using eigenvector analysis. Different TORMs have different contributions to the system control gain, which is defined as the ratio of the acoustic energy generated in the target zone to the transmitter output power. The TARGET can be effectively applied to the sound reproduction and suppression, which correspond the generations of bright and dark zone respectively. In acoustically bright zone generation and sound beamforming, the highest-gain TORM can be employed to determine the optimal source strengths. In active noise control, the strengths of the secondary sources can be derived using low-gain TORMs. Simulation results show that the proposed method has better or comparable performance than the traditional techniques.

We investigate selection transmit multi-input multi-output systems where only a single transmit antenna is selected for the transmission and multiple receive antennas are employed for maximal ratio combining. Antenna selection is performed by a generalized selection criterion based on the ordinal number of the strength of the received signal-to-noise ratio.

Multiple-access interference (MAI) limits the bit error rate (BER) performance of CDMA uplink transmission. In this paper, we propose a generalized chip-interleaved CDMA with 2-dimensional (2D) spreading using orthogonal variable spreading factor (OVSF) codes to minimize the MAI effects and achieve the maximum available time- and frequency-domain diversity gains. We present the code assignment for 2D spreading to provide users with flexible multi-rate data transmission. A computer simulation shows that by the joint use of 2D OVSF spreading and chip-interleaving, MAI-free transmission is possible for the quasi-synchronous DS- or MC-CDMA uplink, and hence the single-user frequency-domain equalization based on the MMSE criterion can be applied for signal detection. The BER performance in a time- and frequency-selective fading multiuser channel is theoretically analyzed and evaluated by both numerical computation and computer simulation.

This paper presents the design, fabrication and characterization of a low actuation voltage capacitive shunt RF-MEMS switch for microwave and millimeter-wave applications based on a corrugated electrostatic actuated bridge suspended over a concave structure of coplanar waveguide (CPW), with sputtered nickel as the structural material for the bridge and gold for CPW line, fabricated on high-resistivity silicon (HRS) substrate using IC compatible processes for modular integration in a communication devices. The residual stress is very low because having both ends corrugated structure of the bridge in concave structure. The residual stress is calculated about 3-15 MPa in corrugated bridge and 30 MPa in flat bridge. The corrugated bridge of the concave structure requires lower actuation voltages 20-80 V than 50-100 V of the flat bridge of the planar structure in 0.3 to 1.0 µm thick Ni capacitive shunt RF-MEMS switch, in insertion loss 1.0 dB, return loss 12 dB, power loss 10 dB and isolation 28 dB from 0.5 up to 40 GHz. The residual stress of the bridge material and structure is critical to lower the actuation voltage.

It has been shown that the maskless dye-diffusion technique is applicable to a conjugated polymer poly(9,9-dioctylfluorene). The introduction of Coumarin 6 and Nile red results in green and white emission, with the increased onset voltage for the both cases. It has also been confirmed that the heat treatment effect during the maskless dye diffusion technique results in not the increase but the decrease of the onset voltage, indicating that the dye plays a role of carrier trap in the polymer.

Organic field-effect transistors (OFETs) based on a composite with the same thiophene backbone were fabricated by spin coating using an annealing solution of poly(3-hexylthiophene) (PAT6) and α, ω-dihexylsexithiophene (DH-6T). The morphology of grains on the non-octadecyltrichlorosilane (OTS) treated and OTS treated gate insulators is granular and tube-like, respectively. The different morphologies of the OFETs with non-OTS treated and OTS-treated gate insulators result in the improvement of field-effect mobility. In the case of poly(ethylene naphthalate) substrate, an OFET with an 89 wt% DH-6T composite corresponding to two molecules of DH-6T per hexylthiophene repeating unit had a carrier mobility of 0.019 cm2/Vs.

We demonstrate single electron counting on an alkanethiol-protected Au nanodot in a double-barrier tunneling structure by noncontact atomic-force spectroscopy (nc-AFS). The Coulomb step width dependence on the Au nanodot diameter is observed. Evaluation of fractional charge Q0 and contact potential difference by nc-AFS reveals a Vd-independent voltage shift due to Q0.

This paper proposes a new microstrip stepped-impedance resonator (SIR) used for bandpass filters with reduced size and improved stopband characteristics. A comprehensive treatment of both ends of the resonator with loaded triangular and rectangular microstrips is described. The design concept is demonstrated by two filter examples including four-resonator parallel-coupled Chebyshev bandpass and compact four-resonator cross-coupled elliptic-type filters. These filters are not only compact size due to the slow-wave effect, but also have a wider upper stopband resulting from the resonator bandstop characteristic. The filter designs are described in details. The simulated and experimental results are demonstrated and discussed.

This paper presents a family of rate-one quasi-orthogonal space-time block codes (QO-STBCs) for any number of transmit antennas. Full diversity of the proposed QO-STBCs is achieved via the use of constellation rotation. When the number of transmit antennas is even, these codes are delay "optimal." This property along with the quasi-orthogonality one allows the codes to have low decoding complexity. Besides, by applying lookup tables into the detection methods presented in [1] and generalizing them, two low-complexity maximum-likelihood (ML) decoders for the proposed QO-STBCs and for other existing QO-STBCs, called PMLD and QMLD, are obtained. Simulation results are provided to verify the bit error rate (BER) performances and complexities of both the proposed QO-STBCs and the proposed decoders.

This paper presents the analogical conception of Chomsky normal form and Greibach normal form for linear, monadic context-free tree grammars (LM-CFTGs). LM-CFTGs generate the same class of languages as four well-known mildly context-sensitive grammars. It will be shown that any LM-CFTG can be transformed into equivalent ones in both normal forms. As Chomsky normal form and Greibach normal form for context-free grammars (CFGs) play a very important role in the study of formal properties of CFGs, it is expected that the Chomsky-like normal form and the Greibach-like normal form for LM-CFTGs will provide deeper analyses of the class of languages generated by mildly context-sensitive grammars.

We succeeded to fabricate p-n heterojunction and bulkheterojunction small-molecular-weight organic thin-film solar cells by combination of dry (p-type = zinc phthalocyanine, n-type = fullerene) and wet (p-type = tetra-tert-butyl zinc phthalocyanine, n-type = [6,6]-phenyl-C61-buteric acid methyl ester) processes. Relationship between morphologies of semiconducting layers and photovoltaic properties was investigated. The p-n heterojunction organic thin-film solar cells based on dry process, where surface roughness was approximately 2 nm, showed the highest power conversion efficiency of 1.3% in this paper.

This paper considers the optimal generator matrices of a given binary cyclic code over a binary symmetric channel with crossover probability p→0 when the goal is to minimize the probability of an information bit error. A given code has many encoder realizations and the information bit error probability is a function of this realization. Our goal here is to seek the optimal realization of encoding functions by taking advantage of the structure of the codes, and to derive the probability of information bit error when possible. We derive some sufficient conditions for a binary cyclic code to have systematic optimal generator matrices under bounded distance decoding and determine many cyclic codes with such properties. We also present some binary cyclic codes whose optimal generator matrices are non-systematic under complete decoding.

Technical terms are linguistic representations of a domain concept, and their constituents are components used to represent the concept. Technical terms are usually multi-word terms and their meanings can be inferred from their constituents. Therefore, term constituents are essential for understanding the designated meaning of technical terms. However, there are several problems in finding the correct meanings of technical terms with their term constituents. First, because a term constituent is usually a morphological unit rather than a conceptual unit in the case of Korean technical terms, we need to first identify conceptual units by chunking term constituents. Second, conceptual units are sometimes homonyms or synonyms. Moreover their meanings show domain dependency. It is therefore necessary to give information about conceptual units and their possible meanings, including homonyms, synonyms, and domain dependency, so that natural language applications can properly handle technical terms. In this paper, we propose a term constituent alignment algorithm that extracts such information from bilingual technical term pairs. Our algorithm recognizes conceptual units and their meanings by finding English term constituents and their corresponding Korean term constituents for given English-Korean term pairs. Our experimental results indicate that this method can effectively find conceptual units and their meanings with about 6% alignment error rate (AER) on manually analyzed experimental data and about 14% AER on automatically analyzed experimental data.

Network emulation system constructs a virtual network environment which has the characteristics of controllable and repeatable network conditions. This makes it possible to predict the correctness and performance of proposed new technology before deploying to Internet. In this paper we present a methodology for evaluating the correctness and performance of applications based on the PARNEM, a parallel discrete event network emulator. PARNEM employs a BSP based real-time event scheduling engine, provides flexible interactive mechanism and facilitates legacy network models reuse. PARNEM allows detailed and accurate study of application behavior. Comprehensive case studies covering bottleneck bandwidth measurement and distributed cooperative web caching system demonstrate that network emulation technology opens a wide range of new opportunities for examining the behavior of applications.

A compact representation of the Green function is proposed by applying the discrete wavelet concept in the k-domain, which can be used for the acceleration of scattered field calculations in integral equation methods. A mathematical expression of the Green function based on the discrete wavelet concept is derived and its characteristics are discussed.

This paper analyzes the steady-state properties of a CORDIC-based adaptive ARMA lattice filter. In our previous study, the convergence properties of the filter in the non-steady state were clarified; however, its behavior in the steady state was not discussed. Therefore, we develop a distinct analysis technique based on a Markov chain in order to investigate the steady-state properties of the filter. By using the proposed technique, the relationship between step size and coefficient estimation error is revealed.

In this paper a new approach for employing the digital signal processing capabilities in the design of the multi-bit continuous time (CT) Delta Sigma modulators (DSM's) is presented. It proposes the discrete time (DT) pre-filtering before the DAC for solving the known problems of the CT DSM's.

The purpose of this study is to maintain efficient backup routes for reconstructing overlay trees quickly. In most conventional methods, after a node leaves the trees, its child nodes start searching for the new parents. In this reactive approach, it takes a lot of time to find a new parent. In this paper, we propose a proactive approach to finding a next parent as the backup route node over the overlay tree before the current parent leaves. A proactive approach allows a node to find its new parent node immediately and switch to the backup route node smoothly. In our proposal, the structure of the overlay tree using a redundant degree can decide a backup route node without so much overhead. Simulations demonstrate our proactive approach can recover from node departures 2 times faster than reactive approaches, and can construct overlay trees with lower overheads than another proactive method. Additionally we carried out experiments over actual networks and their results support the effectiveness of our approach. We confirmed that our proposal achieved better streaming quality than conventional approaches.