The formal specification of design patterns is central to pattern research and is the foundation of solving various pattern-related problems. In this paper, we propose a metamodeling approach for pattern specification, in which a pattern is modeled as a meta-level class and its participants are meta-level references. Instead of defining a new metamodel, we reuse the Unified Modeling Language (UML) metamodel and incorporate the concepts of Variable and Set into our approach, which are unavailable in the UML but essential for pattern specification. Our approach provides straightforward solutions for pattern-related problems, such as pattern instantiation, evolution, and implementation. By integrating the solutions into a single framework, we can construct a pattern management system, in which patterns can be instantiated, evolved, and implemented in a correct and manageable way.

Protein complexes play important roles in integrating individual gene products to perform useful cellular functions. The increasing mount of protein–protein interaction (PPI) data has enabled us to predict protein complexes. In spite of the advances in these computational approaches and experimental techniques, it is impossible to construct an absolutely reliable PPI network. Taking into account the reliability of interactions in the PPI network, we have constructed a weighted protein–protein interaction (WPPI) network, in which the reliability of each interaction is represented as a weight using the topology of the PPI network. As overlaps are likely to have biological importance, we proposed a novel method named WN-PC (weighted network-based method for predicting protein complexes) to predict overlapping protein complexes on the WPPI network. The proposed algorithm predicts neighborhood graphs with an aggregation coefficient over a threshold as candidate complexes, and binds attachment proteins to candidate complexes. Finally, we have filtered redundant complexes which overlap other complexes to a very high extent in comparison to their density and size. A comprehensive comparison between competitive algorithms and our WN-PC method has been made in terms of the F-measure, coverage rate, and P-value. We have applied WN-PC to two different yeast PPI data sets, one of which is a huge PPI network consisting of over 6000 proteins and 200 000 interactions. Experimental results show that WN-PC outperforms the state-of-the-art methods. We think that our research may be helpful for other applications in PPI networks.

An IEEE 1588 based application scheme was proposed to achieve accurate time synchronization for a deep seafloor observatory network based on the communication topological structure of the Zhejiang University Experimental and Research Observatory. The principles of the network time protocol (NTP) and precision time protocol (PTP) were analyzed. The framework for time synchronization of the shore station, undersea junction box layer, and submarine science instrument layer was designed. NTP and PTP network signals were decoded by a PTP master clock on a shore station that receives signals from the Global Positioning System and the BeiDou Navigation Satellite System as reference time sources. These signals were remotely transmitted by a subsea optical–electrical composite cable through an Ethernet passive optical network. Accurate time was determined by time synchronization devices in each layer. Synchronization monitoring experiments performed within a laboratory environment indicated that the proposed system is valid and has the potential to realize microsecond accuracy to satisfy the time synchronization requirements of a high-precision seafloor observatory network.

This paper deals with a novel local arc length estimator for curves in gray-scale images. The method first estimates a cubic spline curve fit for the boundary points using the gray-level information of the nearby pixels, and then computes the sum of the spline segments’ lengths. In this model, the second derivatives and y coordinates at the knots are required in the computation; the spline polynomial coefficients need not be computed explicitly. We provide the algorithm pseudo code for estimation and preprocessing, both taking linear time. Implementation shows that the proposed model gains a smaller relative error than other state-of-the-art methods.

We propose an effective optimization method for generating smooth freeform surfaces for light-emitting diode (LED) non-rotational illumination based on ray targeting. This method begins with a starting design and goes through two optimization steps. An initial estimate is determined using a partial differential equation (PDE) method and a variable separation mapping. In the first optimization step the merit function is developed with ray targeting to ensure the shape of the illumination pattern. The purpose of the second optimization is to further improve the optical performance by constructing the merit function with uniformity and efficiency. Smooth freeform reflective and refractive surfaces, which can produce a uniform rectangular illumination without rotational symmetry, are designed using this method. The results show that uniform rectangular illumination is achieved and that smooth freeform surfaces are obtained. With ray targeting, the design efficiency can be significantly enhanced, and excellent optical performance can be achieved.

Spectrum sensing with multiple antennas for cognitive radio systems in microcell environments is affected by the spatial correlation among multiple antennas. To reduce the adverse effects of the spatial correlation on the spectrum sensing performance, we employ multiple dual polarization antennas at the sensing node of secondary users. The analysis of the spatial correlation is derived using the propagation characteristics of the electromagnetic wave based on the scattering patch model in a multipath microcell environment. The superiority of spectrum sensing with multiple dual polarized antennas over multiple mono-polarized antennas is shown by analyzing the false alarm and detection probabilities with the correlation among the antennas in a microcell environment.

Inverse lithography technology (ILT) is one of the promising resolution enhancement techniques, as the advanced IC technology nodes still use the 193 nm light source. In ILT, optical proximity correction (OPC) is treated as an inverse imaging problem to find the optimal solution using a set of mathematical approaches. Among all the algorithms for ILT, the level-set-based ILT (LSB-ILT) is a feasible choice with good production in practice. However, the manufacturability of the optimized mask is one of the critical issues in ILT; that is, the topology of its result is usually too complicated to manufacture. We put forward a new algorithm with high pattern fidelity called regularized LSB-ILT implemented in partially coherent illumination (PCI), which has the advantage of reducing mask complexity by suppressing the isolated irregular holes and protrusions in the edges generated in the optimization process. A new regularization term named the Laplacian term is also proposed in the regularized LSB-ILT optimization process to further reduce mask complexity in contrast with the total variation (TV) term. Experimental results show that the new algorithm with the Laplacian term can reduce the complexity of mask by over 40% compared with the ordinary LSB-ILT.

Based on the threshold-arithmetic algebraic system which has been proposed for current-mode circuit design, we propose a systematic methodology for emitter-couple logic (ECL) circuit design. Compared to the traditional methodologies and the theory of differential current switches, the proposed methodology uses the HE map and the characteristics of the internal current signals of ECL circuits to determine the external voltage signals. The operations of the HE map are direct and simple, and the current signals are easy to add or subtract, which make this methodology more flexible, direct, and effective, and make it possible to design arbitrary binary and multi-valued logic functions. Two example circuits are designed and simulated by HSPICE using 0.18 μm TSMC technology. Simulation results confirm the validity of the proposed methodology.