Noun Sense Identification of Korean Nominal Compounds Based on Sentential Form Recovery

In a machine translation system, word sense disambiguation has an essential role in the proper translation of words when the target word can be translated differently depending on the context. Previous research on sense identification has mostly focused on adjacent words as context information. Therefore, in the case of nominal compounds, sense tagging of unit nouns mainly depended on other nouns surrounding the target word. In this paper, we present a practical method for the sense tagging of Korean unit nouns in a nominal compound. To overcome the weakness of traditional methods regarding the data sparseness problem, the proposed method adopts complement‐predicate relation knowledge that was constructed for machine translation systems. Our method is based on a sentential form recovery technique, which recognizes grammatical relationships between unit nouns. This technique makes use of the characteristics of Korean predicative nouns. To show that our method is effective on text in general domains, the experiments were performed on a test set randomly extracted from article titles in various newspaper sections.     

14 bit 50 ms/s 0.18 μm CMOS pipeline ADC based on digital error calibration

Described is a 14 bit 50 MS/s CMOS four-stage pipeline A/D converter (ADC)-based on a digital code-error calibration. The proposed calibration technique measures the capacitor mismatch errors of the front-end multiplying DAC (MDAC) with the back-end pipeline stages while the measured code errors are stored in memory and corrected in the digital domain during normal conversion. The calibration needs the increased power dissipation and chip area of 1.4 and 10.7 , respectively, compared to a 14 bit uncalibrated conventional pipeline ADC. The prototype ADC fabricated in a 0.18 um CMOS process occupies an active die area of 4.2 mm² and consumes 140 mW at 1.8 V and 50 MS/s. After calibration, the measured DNL and INL of the ADC are improved from 0.69 to 0.39 LSB and from 33.60 to 2.76 LSB, respectively.     

Controlling resonance frequencies in antennas to achieve wideband operation

A novel antenna design method for controlling resonance frequencies is presented. This method can be realised by simply inserting a spiral inductance and a gap capacitance into a conventional loop-type antenna, and this technique remarkably enhances an impedance bandwidth without increasing the antenna size. The proposed antenna has been designed to have 530 MHz (975?1505 MHz) and 150 MHz (2410?2560 MHz) dual bands (VSWR = 2.5), and can be effectively used as an internal antenna for global system for mobile communications (GSM) and Bluetooth bands. These wideband characteristics provide a critical advantage because the shift of an antenna operation frequency increases when it is near various other components.     

Estimation of thermal parameters of the enclosed electronic package system by using dynamic thermal response

A methodology for modeling and simulating the electro-thermal behavior of an enclosed electronic package is presented and validated. The electro-thermal model is constructed using system dynamics. The system model, in which the electrical and the thermal domain are combined, is presented. The developed model describes the dynamic thermal behavior system that was an electronic device in the test enclosure. An effective way to identify the thermal parameters of the system, especially the thermal contact resistance, is suggested. In detail, the new method for thermal resistance identification is based on the temperature difference behavior between the component and the air temperature inside the enclosure. Based on the proposed model, either the variation of the heat source or the ambient temperature can be estimated. Simulated results were in good agreement with the measured temperature in the transient state accompanying with the variation of the environment.     

Fault-Tolerant UAV Data Acquisition Schemes

Wireless Personal Communications - Through the use of UAV, the functional lifetime of WSN can be elongated in exchange for higher data delivery latency as the UAV replaces the multi-hop...     

Plasmonic Light Beaming Manipulation and its Detection Using Holographic Microscopy

Plasmonic off axis beaming and focusing of light by the use of asymmetric or non-periodic dielectric gratings around a metallic slit are experimentally demonstrated. The far-field probing was done by holographic microscopy. While the conventional near-field microscopes can probe only near-fields, our four-step phase-shift interferometer provides an efficient way of probing and reconstructing light paths coming out from the plasmonic devices. We hope our experimental work contributes to the practical applications of plasmonics such as optical interconnection and optical data storage.      

A step-and-repeat UV-nanoimprint lithography process using an elementwise patterned stamp

Ultraviolet-nanoimprint lithography (UV-NIL) is a promising cost-effective method for defining nanoscale structures at room temperature and low pressure. To apply a large-area stamp to a high throughput step-and-repeat process at atmospheric conditions, we proposed a new UV-NIL process that uses an elementwise patterned stamp (EPS), which consists of elements separated by channels, and additive gas pressurization. The proposed UV-NIL process required just four imprints to press an 8-in. wafer. EPS features measuring 50-80 nm were successfully transferred onto the wafers. The experiments demonstrated that a 5 × 5-in.² EPS could be used with a step-and-repeat UV-NIL process to imprint 8-in. wafers under atmospheric conditions.     

Simple Synthesis of Hollow Tin Dioxide Microspheres and Their Application to Lithium‐Ion Battery Anodes

Hollow tin dioxide (SnO₂) microspheres were synthesized by the simple heat treatment of a mixture composed of tin(IV ) tetrachloride pentahydrate (SnCl₄·5H₂O) and resorcinol–formaldehyde gel (RF gel). Because hollow structures were formed during the heat treatment, the pre‐formation of template and the adsorption of target precursor on template are unnecessary in the current method, leading to simplified synthetic procedures and facilitating mass production. Field‐emission scanning electron microscopy (FE‐SEM) images showed 1.7–2.5 μm sized hollow spherical particles. Transmission electron microscopy (TEM) images showed that the produced spherical particles are composed of a hollow inner cavity and thin outer shell. When the hollow SnO₂ microspheres were used as a lithium‐battery anode, they exhibited extraordinarily high discharge capacities and coulombic efficiency. The reported synthetic procedure is straightforward and inexpensive, and consequently can be readily adopted to produce large quantities of hollow SnO₂ microspheres. This straightforward approach can be extended for the synthesis of other hollow microspheres including those obtained from ZrO₂ and ZrO₂/CeO₂ solid solutions.     

Performance of a turbo‐coded CDMA system in a mobile satellite channel

The bit error rate (BER) performance of a turbo‐coded code‐division multiple‐access (CDMA) system operating in a satellite channel is analysed and simulated. The system performance is compared for various constituent decoders, including maximum a posteriori probability (MAP) and Max‐Log‐MAP algorithms, and the soft‐output Viterbi algorithm. The simulation results indicate that the Max‐Log‐MAP algorithm is the most promising among these three algorithms in overall terms of performance and complexity. It is also shown that, for fixed code rate, the BER performance is improved substantially by increasing the number of iterations in the turbo decoder, or by increasing the interleaver length in the turbo encoder. The results in this paper are of interest in CDMA‐based satellite communications applications. Copyright © 2005 John Wiley & Sons, Ltd.     

Laser Process Proximity Correction for Improvement of Critical Dimension Linearity on a Photomask

We report on the improvement of critical dimension (CD) linearity on a photomask by applying the concept of process proximity correction to a laser lithographic process used for the fabrication of photomasks. Rule‐based laser process proximity correction (LPC) was performed using an automated optical proximity correction tool and we obtained dramatic improvement of CD linearity on a photomask. A study on model‐based LPC was executed using a two‐Gaussian kernel function and we extracted model parameters for the laser lithographic process by fitting the model‐predicted CD linearity data with measured ones. Model‐predicted bias values of isolated space (I/S), arrayed contact (A/C) and isolated contact (I/C) were in good agreement with those obtained by the nonlinear curve‐fitting method used for the rule‐based LPC.