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To harness the rich amount of information available on the web today, many organizations aggregate public (and private) data to derive knowledge repositories for real-world entities. This paper aims to build historical profiles of real-world entities by integrating temporal records collected from different sources. This problem is challenging not only because entities may change their attribute values over time, but also because information provided by the sources could be unreliable. In this paper, we present a new solution for profiling entities over time. To understand the evolution of entities, we describe a novel transition model which gives the probability that an entity will change to a particular attribute value after some time period. Next, a set of quality metrics are defined for the data sources to capture the exactness and timeliness of their provided values. The transition model and the quality metrics are then built into a source-aware temporal matching algorithm that can link temporal records to entities at the right time and augment entity profiles with correct values. Our suite of experiments demonstrate that the proposed approach is able to outperform the state-of-the-art techniques by constructing more complete and accurate profiles for entities.

Normally, a three-electrode spark-gap switch is controlled by the application of an external trigger impulse. In this paper, a novel self-breakdown sharpening switch based on the three-electrode spark-gap switch is proposed. However, in this paper, the trigger electrode is connected to ground through a resistor, with the prespark between the trigger and the main electrodes providing the electrons and ions that initiate conduction of the main gap. A prototype sharpening switch with a breakdown voltage of 116.0 kV ± 1.0 kV and a breakdown time of 3.396 μs ± 0.036 μs is described. When compared with a conventional two-electrode spark-gap sharpening switch, the novel sharpening switch has both a more stable breakdown voltage and lower jitter, and the dc breakdown and impulse breakdown characteristics of the two types of switches are presented and compared. When the impedance of the resistor connected to the trigger electrode is high, it is demonstrated that both the value of this resistor and also the type of load have little effect on the characteristics of the novel switch. However, the breakdown voltage of the novel sharpening switch was found to be sensitive to the rise time of the input pulse from the trigger generator. The prototype sharpening switch has a lifetime at least 20 000 shots and is now in use in a major pulsed power conditioning system.

When two-electrode spark gap switches are applied to main discharging circuit of pulsed power conditioning system, trigger generators will be needed. To guarantee triggering reliability and protect other key components in the pulsed power conditioning system, such as pre-ionization branch and xenon lamp, magnetic switch is needed to insulate the high triggering voltage in the main discharging circuit. In this paper, starting from the analysis of the working principle of the discharging circuit, we present the solution of Fe-based nanocrystalline alloy switch. Specifically, we provide the basis of theoretical calculation and the method of material selection for the design and realization of this magnetic switch. Via the performance tests in pulsed power conditioning system, the validity of material selection and parameter design is proved. This paper provides a reference for the engineering design and application of magnetic switches in huge pulsed power systems.

This technical note addresses the equivalent relationship between notions of generalized performance, robust stability, and quadratic stability for the feedback connection , where is the transfer matrix of a nominal system and describes the set of uncertainty. By defining the three notions in a more general setting, the conventional equivalent relationship between robust stability and quadratic stability with respect to the norm-bound uncertainty (respectively, the positive real uncertainty) and the corresponding performance (respectively, the extended strict positive realness) has been proved only special case of the results derived in the technical note. A version of the Kalman-Yakubovich-Popov lemma, which plays a crucial role in establishing the equivalence between the generalized performance and the quadratic stability, is also presented.

A miniature amplitude-shift-keying (ASK) demodulator without any passive elements, i.e., R or C, for low-frequency applications is presented in the paper. The noise margin of the envelope detector in the proposed ASK demodulator is enlarged such that any Schmitt trigger or current limiting resistor is no longer needed. It results in the number of transistors required for the ASK demodulator circuit is reduced to 12, while the area is merely 0.003025 mm2 using 0.35-mum 2P4M CMOS process. The power consumption is found to be 1.01 mW by physical measurement on silicon. The data rate is measured to be 250 kbps for 2-MHz carrier frequency and 27% modulation index.

The physical implementation of a prototypical 250-MHz CMOS 4-T SRAM is described in this paper. The proposed SRAM cell takes advantage of a negative word-line scheme to minimize the leakage current of the cell access transistors. As a result, the standby power consumption is drastically reduced. The proposed 4-kb 4-T SRAM is measured to consume 0.32 mW in the standby mode, and a 3.8-ns access time in the R/W mode. The highest operating clock rate is measured to be 263 MHz

This brief presents the design and implementation of a clock-and-data recovery (CDR) design for low-voltage differential signals (LVDS) transceiver operations. Instead of using an oversampling scheme which requires a high-speed clock generator, we adopt an interpolation scheme which relaxes the demand of a high-speed phase-locked loop with very high precision. A dual-tracking design is proposed to precisely align both edges of a data eye. Hence, the center of a data eye can be optimally sampled. A standard foundry 0.25-mum 1P5M CMOS technology is used to realize the proposed dual-tracking CDR for 7times100 (bit-MHz) LVDS signaling. The post-layout-extracted simulation reveals that the worst-case jitter of the sampling clocks is less than 450 ps (peak-to-peak) and 250 ps (rms) at all process corners

This work addresses the problem of finding boundary points in multidimensional data sets. Boundary points are data points that are located at the margin of densely distributed data such as a cluster. We describe a novel approach called BORDER (a BOundaRy points DEtectoR) to detect such points. BORDER employs the state-of-the-art database technique - the Gorder kNN join and makes use of the special property of the reverse k nearest neighbor (RkNN). Experimental studies on data sets with varying characteristics indicate that BORDER is able to detect the boundary points effectively and efficiently.

A novel low-power and small-area digital I/O cell is proposed in this work. The new input/output (I/O) cell drastically reduces the I/O power consumption, which has been considered as the major power dissipation of the whole chip. The maximum operating clock is 500 MHz given a 10-pF offchip load. On top of the power saving feature, the proposed cell occupies merely 10535.2=4167.45 (transmitter)+6367.8 (receiver) /spl mu/m/sup 2/ which is far less than any prior commercially available I/O and low-voltage differential signaling I/O cells. Physical measurements of the proposed I/O cells show that the delays of the transmitter and the receiver are 1.1 and 1.8 ns, respectively. The largest power/bandwidth of the proposed design is 38.9 /spl mu/W/MHz when transmitting.

New clinical studies suggest that narrowing of the retinal blood vessels may be an early indicator of cardiovascular diseases. One measure to quantify the severity of retinal arteriolar narrowing is the arteriolar-to-venular diameter ratio (AVR). The manual computation of AVR is a tedious process involving repeated measurements of the diameters of all arterioles and venules in the retinal images by human graders. Consistency and reproducibility are concerns. To facilitate large-scale clinical use in the general population, it is essential to have a precise, efficient and automatic system to compute this AVR. This paper describes a new approach to obtain AVR. The starting points of vessels are detected using a matched Gaussian filter. The detected vessels are traced with the help of a combined Kalman filter and Gaussian filter. A modified Gaussian model that takes into account the central light reflection of arterioles is proposed to describe the vessel profile. The width of a vessel is obtained by data fitting. Experimental results indicate a 97.1% success rate in the identification of vessel starting points, and a 99.2% success rate in the tracking of retinal vessels. The accuracy of the AVR computation is well within the acceptable range of deviation among the human graders, with a mean relative AVR error of 4.4%. The system has interested clinical research groups worldwide and will be tested in clinical studies.

A low-cost video decoder for NTSC signals is described in this paper. The proposed NTSC video decoder design employs a 2D2L comb filter, and a DDFS (direct digital frequency synthesizer)-based DCO (digital control oscillator) based on a trigonometric quadruple angle formula in a digital PLL to track and lock the demodulation clocks. The complexity of the digital video decoder is consequently drastically reduced. The overall cost of the proposed design is 7.22 mm/sup 2/ (26 K gates). The maximum power dissipation is 109.2 mW at the highest clock rate which is 21.48 MHz.

Data quality problems can arise from abbreviations, data entry mistakes, duplicate records, missing fields, and many other sources. These problems proliferate when you integrate multiple data sources in data warehousing, federated databases, and global information systems. A newly discovered class of erroneous data is spurious links, where a real-world entity has multiple links that might not be properly associated with it. The existence of such spurious links often leads to confusion and misrepresentation in the data records representing the entity. Although the data set is well known for its high-quality bibliographic information, collecting and maintaining the data from diverse sources requires enormous effort. Errors, including spurious links, are inevitable. To solve this problem, we use context information to identify spurious links. First, we identify data records that contain potential spurious links. We then determine the set of attributes that constitute each record's context. Experiments with three real-world databases have demonstrated that our approach can accurately identify spurious links. Comparing context information between data records can help solve the data quality problem of spurious links-that is, multiple links between data entries and real-world entities.

In this brief, a linear-matrix inequality (LMI) based strictly-positive-real (SPR) characterization and its application to absolute stability problem for discrete-time descriptor systems is addressed. After giving the definition of SPR, the Cayley transformation is used to establish formulas bridging the admissible descriptor form realizations for SPR and strictly-bounded-real transfer matrices. Based on these, an LMI-based necessary and sufficient condition for a descriptor system to be, simultaneously, admissible and SPR is derived. The obtained result is further applied to the absolute stability problem involving a linear time-invariant descriptor system and a memoryless time-varying nonlinearity. Numerical tractability of the results are illustrated by two examples.

This paper describes the feasibility of selecting fractal feature vector based on M-band wavelet transform to classify ultrasonic liver images-normal liver, cirrhosis, and hepatoma. The proposed feature extraction algorithm is based on the spatial-frequency decomposition and fractal geometry. Various classification algorithms based on respective texture measurements and filter banks are presented and tested. Classifications for the three sets of ultrasonic liver images reveal that the fractal feature vector based on M-band wavelet transform is trustworthy. A hierarchical classifier, which is based on the proposed feature extraction algorithm is at least 96.7% accurate in the distinction between normal and abnormal liver images and is at least 93.6% accurate in the distinction between cirrhosis and hepatoma liver images. Additionally, the criterion for feature selection is specified and employed for performance comparisons herein.

The Extensible Markup Language has become the standard for information interchange on the Web. We study the data- and document-centric uses of XML management systems (XMLMS). We want to provide XML data users with a guideline for choosing the data management system that best meets their needs. Because the systems we test are first-generation approaches, we suggest a hypothetical design for a useful XML database that could use all the expressive power of XML and XML query languages.