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991.
Inundation of roads by heavy rainfall has attracted more attention than traffic accidents, traffic congestion, and construction because it simultaneously causes travel delays and threatens driver safety. For these reasons, in this paper, we propose an inundation hazard index (IHI) of road links, which shows the possibility of inundation of road links caused by rainfall. To generate the index, we have used two key data sources, namely the digital elevation model (DEM) and past rainfall records of when inundation has occurred. IHI is derived by statistically analyzing the relationships between the normalized relative height of the road links calculated from DEM within the watershed and past rainfall records. After analyzing the practical applicability of the proposed index with a commercial car navigation system through a set of tests, we confirmed that the proposed IHI could be implemented to choose safer routes, with reduced chances of encountering roads having inundation risks.s  相似文献   
992.
Feature selection is very important for feature‐based relation classification tasks. While most of the existing works on feature selection rely on linguistic information acquired using parsers, this letter proposes new features, including probabilistic and semantic relatedness features, to manifest the relatedness between patterns and certain relation types in an explicit way. The impact of each feature set is evaluated using both a chisquare estimator and a performance evaluation. The experiments show that the impact of relatedness features is superior to existing well‐known linguistic features, and the contribution of relatedness features cannot be substituted using other normally used linguistic feature sets.  相似文献   
993.
A fully integrated small form‐factor HBT power amplifier (PA) was developed for UMTS Tx applications. For practical use, the PA was implemented with a well configured bottom dimension, and a CMOS control IC was added to enable/disable the HBT PA. By using helix‐on‐pad integrated passive device output matching, a chip‐stacking technique in the assembly of the CMOS IC, and embedding of the bulky inductive lines in a multilayer substrate, the module size was greatly reduced to 2 mm × 2.2 mm. A stage‐bypass technique was used to enhance the efficiency of the PA. The PA showed a low idle current of about 20 mA and a PAE of about15% at an output power of 16 dBm, while showing good linearity over the entire operating power range.  相似文献   
994.
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.  相似文献   
995.
Lee  K.-H. Kim  Y.-J. Kim  K.-S. Lee  S.-H. 《Electronics letters》2009,45(21):1067-1069
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.  相似文献   
996.
Choi  H. Jeon  S. Kim  S. Kim  H. 《Electronics letters》2009,45(14):716
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.  相似文献   
997.
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.  相似文献   
998.
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...  相似文献   
999.
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.   相似文献   
1000.
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.  相似文献   
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