An all-optical network architecture

A novel photonic network, MATRIX (for multi-wavelength all-optical transparent information exchange), is proposed in this paper. The all-optical multihop network supports wavelength continuity and provides a very high network capacity. Spatial reuse of wavelengths as well as the multiplicity of fibers in optical fiber cables are exploited and enable the interconnection of N² network nodes with merely N wavelengths. The node structure is simple since neither tunable devices nor wavelength converters are required. Packets are routed through the network by photonic fast packet switching as well as by wavelength and experience a maximum hop number of two. Multiple optical paths between any pair of nodes provide a good network survivability     

Oxygen content determination of Bi2Sr2Ca2Cu4O11+x superconductor by thermogravimetric analysis

Thermogravimetric analysis of the individual, binary, ternary, and bismuth-based superconductor mixtures have been carried out to elucidate the excess oxygen content of the Bi₂Sr₂Ca₂Cu₄O_11+x . Our systematic approach eliminates the need to assume initial phase present, original oxygen content, and degree of reduction as in other TG studies. The excess oxygen content of the bismuth superconductor increases fromx=0.38 tox=0.64 after three heating cycles in oxygen atmosphere. Most of the excess oxygen is associated with the highly oxidized copper (Cu³⁺) in the superconducting phase/phases.     

Efficient algorithms for computing two nearest-neighbor problems on a rap

This paper makes an improvement of computing two nearest-neighbor problems of images on a reconfigurable array of processors (RAP) by increasing the bus width between processors. Based on a base-n system, a constant time algorithm is first presented for computing the maximum/minimum of N log N-bit unsigned integers on a RAP using N processors each with N^1/c-bit bus width, where c is a constant and c ≥ 1. Then, two basic operations such as image component labeling and border following are also derived from it. Finally, these algorithms are used to design two constant time algorithms for the nearest neighbor black pixel and the nearest neighbor component problems on an N^1/2 × N^1/2 image using N^1/2 × N^1/2 processors each with N^1/c-bit bus width, where c is a constant and c ≥ 1. Another contribution of this paper is that the execution time of the proposed algorithms is tunable by the bus width.     

Modeling of three-dimensional numerically controlled end milling operations

A computer-aided cutting simulation system was developed to model three-dimensional numerically controlled (NC) end milling operations. In the developed system, varying axial and radial depths of cut in an NC tool path were identified by a solid modeling system using constructive solid geometry and boundary representation techniques. Once the axial and radial depths of cut were calculated, the dynamic cutting force was calculated from an end milling process model. As a result, the cutting performance in three-dimensional NC end milling operations can be verified and optimized through this approach.     

Solving an algebraic path problem and some related graph problemson a hyper-bus broadcast network

The parallel computation model upon which the proposed algorithms are based is the hyper-bus broadcast network. The hyper-bus broadcast network consists of processors which are connected by global buses only. Based on such an improved architecture, we first design two O(1) time basic operations for finding the maximum and minimum of N numbers each of size O(log N)-bit and computing the matrix multiplication operation of two N×N matrices, respectively. Then, based on these two basic operations, three of the most important instances in the algebraic path problem, the connectivity problem, and several related problems are all solved in O(log N) time. These include the all-pair shortest paths, the minimum-weight spanning tree, the transitive closure, the connected component, the biconnected component, the articulation point, and the bridge problems, either in an undirected or a directed graph, respectively     

64-KByte sum-addressed-memory cache with 1.6-ns cycle and 2.6-nslatency

Address base-plus-offset summing is merged into the decode structure of this 64-KByte (512-Kbit), four-way set-associative cache. This address adder avoids time-consuming carry propagation by using an A+B=K equality test. The combined add and access operations are implemented using delayed-reset logic and a 0.25-μm process, This wave pipelined RAM achieves a 1.6-ns cycle time and 2.6-ns latency for the combined address add and cache access     

Novel single-poly EEPROM with damascene control-gate structure

A novel single-poly EEPROM using damascene control gate (CG) structure is presented in this letter. The CG is tungsten (W) line made by a damascene process, and intergate dielectric is Al/sub 2/O/sub 3/ grown by atomic layer deposition (ALD). The program and erase mechanism is the same as the one for traditional stacked-gate cell, which uses the channel hot electron injection for programming and Fowler-Nordheim tunneling for channel erasing. With the high dielectric constant (K) property of Al/sub 2/O/sub 3/, we can perform the program and erase function with a voltage less than 6.5 V, which can be handled by 3.3 V devices instead of traditional high voltage devices. In the process compatibility aspect, this new cell needs only two extra masking steps over the standard CMOS process, and the high-/spl kappa/ material is deposited in the back-end metallization steps without the contamination concerns on the front-end process. Therefore, this new technology is suitable for embedded application. In this letter, the good cell performance is demonstrated; such as, fast programming/erasing, good endurance and data retention.     

A computational situation assessment model for nuclear power plantoperations

This paper presents a computational situation assessment (SA) model and a model-based SA metric for nuclear power plant operations. The model and metric development starts with a definition of the plant operator's SA centered decision making behavior. A computational SA model and a model-based SA metric are then developed to quantify and measure operator SA. Using the SA model as a core, we further develop an integrated operator/plant model that provides for explicit representation of the operator's fundamental functions of information processing, situation assessment, and decision making in a closed-loop plant/operator simulation environment. We evaluate the model and metric in a model-based simulation of a selected emergency scenario, and a model-based analysis of a range of contemplated nuclear power plant automation/aiding options     

Load model effects on distance relay settings

The purpose of this paper is to study load model effects on distance protective relay settings in Taipower's transmission system. Five load models have been used in order to explore the effects of load characteristics on relay settings: (1) static ZIP model, (2) dynamic motor model, (3) composite model, (4) PTI IEEE model, and (5) exponential model. The major points of this study include (1) setting of impedance values for the three distance protective relay zones and the protection against loss of synchronicity in the outermost periphery, (2) exploring the effects of load models on impedance angle at the time of distance relay tripping, (3) study whether the load model will cause a malfunction in the distance relay when the system swings due to a sudden change in the power system, (4) analyze the coordination of the blocking time of the out-of-step blocking relay during system power swings, and (5) propose how to select a better load model for accuracy in relay settings.