Ball Grid Array packages in which I/O pins are arranged in a grid array pattern realize a number of connections between chips and PCB, but it takes much time in manual routing. So the demand for automation of package routing is increasing. In this paper, we give the necessary and sufficient condition that all nets can be connected by monotonic routes when a net consists of a finger and a ball and fingers are on the two parallel boundaries of the Ball Grid Array package, and propose a monotonic routing method based on this condition. Moreover, we give a necessary condition and a sufficient condition when fingers are on the two orthogonal boundaries, and propose a monotonic routing method based on the necessary condition.

Concurrency is one of the most important issues in system-level design. Interleaving among parallel processes can cause an extremely large number of different behaviors, making design and verification difficult tasks. In this work, we propose a synchronization verification method for system-level designs described in the SpecC language. Instead of modeling the design with timed FSMs and using a model checker for timed automata (such as UPPAAL or KRONOS), we formulate the timing constraints with equalities/inequalities that can be solved by integer linear programming (ILP) tools. Verification is conducted in two steps. First, similar to other software model checkers, we compute the reachability of an error state in the absence of timing constraints. Then, if a path to an error state exists, its feasibility is checked by using the ILP solver to evaluate the timing constraints along the path. This approach can drastically increase the sizes of the designs that can be verified. Abstraction and abstraction refinement techniques based on the Counterexample-Guided Abstraction Refinement (CEGAR) paradigm are applied.

In real-time multimedia processing systems a very large part of the power consumption is due to the data storage and data transfer. Moreover, the area cost is often largely dominated by the memory modules. In deriving an optimized (for area and/or power) memory architecture, memory size computation is an important step in the exploration of the possible algorithmic specifications of multimedia applications. This paper presents a novel non-scalar approach for computing exactly the memory size in real-time multimedia algorithms. This methodology uses both algebraic techniques specific to the data-flow analysis used in modern compilers and, also, more recent advances in the theory of polyhedra. In contrast with all the previous works which are only estimation methods, this approach performs exact memory computations even for applications significantly large in terms of the code size, number of scalars, and number of array references.

In this letter, we suggest a noise estimation method which can be applied for speech enhancement in various noise environments. The proposed method consists of the following two main processes to analyze and estimate efficiently the noise from the noisy speech. First, a least-squares line is used, which is obtained by applying coefficient magnitudes in node with a uniform wavelet packet transform to a least squares method. Next, a differential forgetting factor and a correlation coefficient per subband are applied, where each subband consists of several nodes with the uniform wavelet packet transform. In particular, this approach has the ability to update noise estimation by using the estimated noise at the previous frame only instead of employing the statistical information of long past frames and explicit nonspeech frames detection consisted of noise signals. In objective assessments, we observed that the performance of the proposed method was better than that of the compared methods. Furthermore, our method showed a reliable result even at low SNR.

This paper presents the characteristics and modeling of VoIP traffic for a real network. The new model, based on measured data, shows a significant difference from the previously proposed models in terms of parameters and their effects. It is found that the effects of background noise and ringing tones have essential influences on the model. The observed distributions of talkspurt and silent durations have long-tail characteristics and considerably differ from the existing models. An additional state called "Long burst", which represents the background noise at the talker's place, is added into the continuous-time Markov process model. The other three states, "Talk", "Short silence" and "Long silence", represent the normal behavior of the VoIP user. Models for conversational speech containing the communication during the dialogue are presented. In the case of the VoIP traffic aggregation, the simplified models, which neglect the conversation's interaction, are proposed. Depending on the occurrences of background noise during the speech, the model is classified as "noisy speech" or "noiseless speech". The measured data shows that the background noise typically increases the data rate by 60%. Simulation results of aggregated VoIP traffic indicate the self-similarity, which is analogous to the measured data. Results from the measurements support the fact that except the ringing duration the conversations from both the directions can be modeled in identical manner.

In this letter, efficient two-dimensional (2-D) fast algorithms for realizations of 88 forward and inverse integer transforms in H.264/AVC fidelity range extensions (FRExt) are proposed. Based on matrix factorizations with Kronecker product and direct sum operations, efficient fast 2-D 88 forward and inverse integer transforms can be derived from the one-dimensional (1-D) fast 88 forward and inverse integer transforms through matrix operations. The proposed fast 2-D 88 forward and inverse integer transform designs don't require transpose memory in hardware realizations. The fast 2-D 88 integer transforms require fewer latency delays and provide a larger throughput rate than the row-column based method. With regular modularity, the proposed fast algorithms are suitable for VLSI implementations to achieve H.264/AVC FRExt high-profile signal processing.

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.

In this paper, we propose a methodology for calculating on-chip temperature gradient and leakage power distributions. It considers the interdependence between leakage power and local temperature using a general circuit simulator as a differential equation solver. The proposed methodology can be utilized in the early stages of the design cycle as well as in the final verification phase. Simulation results proved that consideration of the temperature dependence of the leakage power is critically important for achieving reliable physical designs since the conventional temperature analysis that ignores the interdependence underestimates leakage power considerably and may overlook potential thermal runaway.

This paper presents a structural approach for synthesizing arbitrary multi-output multi-stage static CMOS circuits at the transistor level, targeting the reduction of transistor counts. To make the problem tractable, the solution space is restricted to the circuit structures which can be obtained by performing algebraic transformations on an arbitrary prime-and-irredundant two-level circuit. The proposed algorithm is guaranteed to find the optimal solution within the solution space. The circuit structures are implicitly enumerated via structural transformations on a single graph structure, then a dynamic-programming based algorithm efficiently finds the minimum solution among them. Experimental results on a benchmark suite targeting standard cell implementations demonstrate the feasibility and effectiveness of the proposed approach. We also demonstrated the efficiency of the proposed algorithm by a numerical analysis on randomly-generated problems.

A novel two-dimensional (2D) beam scanning antenna array using composite right/left-handed (CRLH) leaky-wave antennas (LWAs) is proposed. The antenna array consists of a set of CRLH LWAs and a Butler matrix (BM) feeding network. The direction of the beam can be scanned two-dimensionally in one plane by changing frequency and in the other plane by switching the input ports of the BM. A four-element antenna array in the microstrip line configuration operating at 10.5 GHz is designed with the assistance of full-wave simulations based on the method of moment (MoM) and the finite-element method (FEM). The antenna array is fabricated and radiation characteristics are measured. The wide range 2D beam scanning operation with the angle from -30 deg to +25 deg in one plane by sweeping frequency from 10.25 GHz to 10.7 GHz and with four discrete angles of -46 deg, -15 deg, +10 deg, and +35 deg in the other plane by switching the input port is achieved.

This letter proposes a novel approach for mel-cepstral analysis based on the psychoacoustic model of MPEG. A perceptual weighting function is developed by applying cubic spline interpolation on the signal-to-mask ratios (SMRs) which are obtained from the psychoacoustic model. Experiments on speaker identification and speech re-synthesis showed that the proposed method not only improved the speaker recognition performance, but also improved the speech quality of the re-synthesized speech.

We propose an elastic pipeline that can apply dynamic voltage scaling (DVS) to hardwired logic circuits. In order to demonstrate its feasibility, a hardwired H.264/AVC HDTV decoder is designed as a real-time application. An entropy decoding process is divided into context-based adaptive binary arithmetic coding (CABAC) and syntax element decoding (SED), which has advantages of smoothing workload for CABAC and keeping efficiency of the elastic pipeline. An operating frequency and supply voltage are dynamically modulated every slot depending on workload of H.264 decoding to minimize power. We optimize the number of slots per frame to enhance power reduction. The proposed decoder achieves a power reduction of 50% in a 90-nm process technology, compared to the conventional clock-gating scheme.

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.

The probability associated with population fitness in a Genetic Algorithm (GA) is studied using the concept of average Euclidean distance. Based on the probability derived from population fitness, the GA can effectively terminate its evolution operations to mitigate the total computational load. Simulation results verify the feasibility of the derived probability used for the GA's termination strategy.

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.

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.

The I/Q unbalance which is generated by a non-ideal component is an inevitable physical phenomenon and leads to performance degradation when we implement a practical two-dimensional (2-D) modulation system. In this paper, we provide an exact and general expression involving the 2-D Gaussian Q-function for the SER/BER of arbitrary 2-D signaling with I/Q amplitude and phase unbalances over an additive white Gaussian noise (AWGN) channel by using the coordinate rotation and shifting technique. Through Monte Carlo simulations we verify our expression provided here for 16-star Quadrature Amplitude Modulation (QAM).

A novel sensing system for glucose in aqueous solution based on cataluminescence(CTL) is proposed. CTL is a kind of chemiluminescence emitted in a course of catalytic oxidation of combustible substances. A sensing system consisting of a CTL-based chemical-sensor made of the γ-Al2O3 catalyst activated with Tb and an ultrasonic nebulizer is developed. CTL is emitted by injection of air containing mist of a glucose solution prepared by the nebulizer on the catalyst. The CTL intensity measured by a photomultiplier is reproducible for the repeated injection of the mist, and the system can measure glucose concentration in a range of 1-200 mg/dl.

Molecular aligned naphthacene thins films were fabricated using vacuum evaporation and the rubbing method. The attenuated total reflection (ATR) and emission light properties from surface plasmon (SP) excitation due to molecular luminescence were investigated for these films. The long axis of the rod-like molecule was estimated to align perpendicular to the rubbing direction. The ATR and emission light properties depended on the molecular orientation.

Combinatorial designs have been used to construct digital fingerprint codes. Here, a new constructive algorithm for an anticollusion fingerprint code based on group-divisible designs is presented. These codes are easy to construct and available for a large number of individuals, which is important from a business point of view. Group-divisible designs have not been used previously as a tool for fingerprint code construction.