Phasor transformation and its application to the DC/AC analyses offrequency phase-controlled series resonant converters (SRC)

A novel modeling technique based on phasor transformation that provides a unified model of series resonant converters (SRCs) is proposed. The approach gives explicit and simple equations that provide fruitful physical insight. When the switching frequency deviates from the resonant frequency, a first-order SRC model is obtained, and in the case of resonance a second-order model is obtained. It is shown that the frequency band of the second-order model is very narrow in practice. The time constant, small-signal gains, and system order are highly dependent on the switching frequency, load resistor, and output capacitor     

Automatic Word Spacing Using Probabilistic Models Based on Character n-grams

On the Internet, information is largely in text form, which often includes such errors as spelling mistakes. These errors complicate natural language processing because most NLP applications aren't robust and assume that the input data is noise free. Preprocessing is necessary to deal with these errors and meet the growing need for automatic text processing. One kind of such preprocessing is automatic word spacing. This process decides correct boundaries between words in a sentence containing spacing errors, which are a type of spelling error. Except for some Asian languages such as Chinese and Japanese, most languages have explicit word spacing. In these languages, word spacing is crucial to increase readability and to accurately communicate a text's meaning. Automatic word spacing plays an important role not only as a spell-checker module but also as a preprocessor for a morphological analyzer, which is a fundamental tool for NLP applications. Furthermore, automatic word spacing can serve as a postprocessor for optical-character-recognition systems and speech recognition systems     

High Voltage Pulsed Power Supply Using IGBT Stacks

High voltage pulsed power supply using IGBT (insulated gate bipolar transistor) stacks and pulse transformer for plasma source ion implantation is proposed. To increase voltage rating, twelve IGBTs are used in series at each IGBT stack and a step-up pulse transformer is utilized. To increase the current rating, the proposed system makes use of synchronized three pulse generator modules composed of diodes, capacitors and IGBT stacks. The proposed pulsed power supply uses semiconductor switches as main switches. Hence, the system is compact, and has semi-infinite lifetime. In addition, it has high flexibility in parameters such as voltage magnitude (10-60 kV), pulse repetition rate (PRR) (10-2000 pps), and pulse width (2-5 muS).     

Psychopathy and nonverbal behavior in an interpersonal situation.

88 male adolescents living in a minimum security institution were judged by their counselors on a scale measuring psychopathic behavior. Two extreme groups were composed, with 25 Ss each. These Ss were questioned by a male interviewer in a face-to-face situation about their leisure activities. Trained judges analyzed videotape recordings of the Ss' and the interviewer's nonverbal and paralinguistic behavior. Global judgments of the Ss' emotional states were also requested of the judges. Results show that compared with nonpsycopaths, psychopathic Ss displayed more hand gestures and leaned forward more, thus reducing the distance between them and their partner. They also looked toward their partner's eyes for much longer periods and tended to smile less than nonpsychopaths. On the other hand, when interacting with psychopaths, the interviewer spoke significantly less than with nonpsychopaths. A number of other observed differences in emotional expression between the 2 groups are discussed. (17 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Adult age differences in the effects of goals on self-regulated sentence processing.

The authors examined age differences in adults' allocation of effort when reading text for either high levels of recall accuracy or high levels of efficiency. Participants read a series of sentences, making judgments of learning before recall. Older adults showed less sensitivity than the young to the accuracy goal in both reading time allocation and memory performance. Memory accuracy and differential allocation of effort to unlearned items were age equivalent, so age differences in goal adherence were not attributable to metacognitive factors. However, comparison with data from a control reading task without monitoring showed that learning gains among older adults across trial were reduced relative to those of the young by memory monitoring, suggesting that monitoring may be resource consuming for older learners. Age differences in the responsiveness to (information-acquisition) goals could be accounted for, in part, by independent contributions from working memory and memory self-efficacy. Our data suggest that both processing capacity ("what you have") and beliefs ("knowing you can do it") can contribute to individual differences in engaging resources ("what you do") to effectively learn novel content from text. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Fabrication and analysis of deep submicron strained-Si n-MOSFET's

Deep submicron strained-Si n-MOSFETs were fabricated on strained Si/relaxed Si_0.8Ge_0.2 heterostructures. Epitaxial layer structures were designed to yield well-matched channel doping profiles after processing, allowing comparison of strained and unstrained Si surface channel devices. In spite of the high substrate doping and high vertical fields, the MOSFET mobility of the strained-Si devices is enhanced by 75% compared to that of the unstrained-Si control devices and the state-of-the-art universal MOSFET mobility. Although the strained and unstrained-Si MOSFETs exhibit very similar short-channel effects, the intrinsic transconductance of the strained Si devices is enhanced by roughly 60% for the entire channel length range investigated (1 to 0.1 μm) when self-heating is reduced by an ac measurement technique. Comparison of the measured transconductance to hydrodynamic device simulations indicates that in addition to the increased low-field mobility, improved high-field transport in strained Si is necessary to explain the observed performance improvement. Reduced carrier-phonon scattering for electrons with average energies less than a few hundred meV accounts for the enhanced high-field electron transport in strained Si. Since strained Si provides device performance enhancements through changes in material properties rather than changes in device geometry and doping, strained Si is a promising candidate for improving the performance of Si CMOS technology without compromising the control of short channel effects     

Negative solvatochromism of merocyanine dyes: Application as water content probes for organic solvents

Two new merocyanine dyes derived from 7-hydroxycoumarin were prepared, and their signaling ability to detect water content in organic solvents was investigated. The dyes exhibited a pronounced negative solvatochromism, and dramatic changes in absorption spectra and λ_max as a function of water content were observed. Solvatochromic behavior was pronounced in regions of less than 5% water content; therefore, these dyes could be used as chromogenic probes for detecting water in common water miscible organic solvents.     

The lexicographic α‐robust knapsack problem

The knapsack problem is a classical combinatorial optimization problem used to model many industrial situations. The robust version of this problem was studied in the literature using a max–min or min–max regret criterion. In this paper, we show the drawbacks of such criteria and propose a new robustness approach, called lexicographic α‐robustness. We show that the complexity of the lexicographic α‐robust problem does not increase compared with the max–min version and present a pseudo‐polynomial algorithm in the case of a bounded number of scenarios.     

Developing and Evaluating New ICT Innovation System: Case Study of Korea's Smart Media Industry

The smart media (SM) industry has demonstrated that it has the characteristics to increase user innovative activities, enhance open innovativeness, and increase the segmentation of innovation value. This study introduces and evaluates an innovation system that reflects the characteristics of the SM industry. We categorize the SM industry into hardware, network, platform, and content industries and perform an AHP analysis (based on a survey of 96 experts) to evaluate the relative importance of the factors/factor groups affecting the creation of innovation. The results show that “collaboration activity” is a more important factor than other innovation factor groups (financial support, R&D, policy environment, human resources) in the SM industry. The results also show that the important factors/factor groups differ by industry.