• Title/Summary/Keyword: Filter-based technique

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A Rule-Based Analysis from Raw Korean Text to Morphologically Annotated Corpora

  • Lee, Ki-Yong;Markus Schulze
    • Language and Information
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    • v.6 no.2
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    • pp.105-128
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    • 2002
  • Morphologically annotated corpora are the basis for many tasks of computational linguistics. Most current approaches use statistically driven methods of morphological analysis, that provide just POS-tags. While this is sufficient for some applications, a rule-based full morphological analysis also yielding lemmatization and segmentation is needed for many others. This work thus aims at 〔1〕 introducing a rule-based Korean morphological analyzer called Kormoran based on the principle of linearity that prohibits any combination of left-to-right or right-to-left analysis or backtracking and then at 〔2〕 showing how it on be used as a POS-tagger by adopting an ordinary technique of preprocessing and also by filtering out irrelevant morpho-syntactic information in analyzed feature structures. It is shown that, besides providing a basis for subsequent syntactic or semantic processing, full morphological analyzers like Kormoran have the greater power of resolving ambiguities than simple POS-taggers. The focus of our present analysis is on Korean text.

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Development of Tire Lateral Force Monitoring Systems Using Nonlinear Observers (비선형 관측기를 이용한 차량의 타이어 횡력 감지시스템 개발)

  • 김준영;허건수
    • Transactions of the Korean Society of Automotive Engineers
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    • v.8 no.4
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    • pp.169-176
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    • 2000
  • Longitudinal and lateral forces acting on tires are known to be closely related to the tract-ability braking characteristics handling stability and maneuverability of ground vehicles. In thie paper in order to develop tire force monitoring systems a monitoring model is proposed utilizing not only the vehicle dynamics but also the roll motion. Based on the monitoring model three monitoring systems are developed to estimate the tire force acting on each tire. Two monitoring systems are designed utilizing the conventional estimation techniques such as SMO(Sliding Mode Observer) and EKF(Extended Kalman Filter). An additional monitoring system is designed based on a new SKFMEC(Scaled Kalman Filter with Model Error Compensator) technique which is developed to improve the performance of EKF method. Tire force estimation performance of the three monitoring systems is compared in the Matlab simulations where true tire force data is generated from a 14 DOF vehicle model with the combined-slip Magic Formula tire model. The built in our Lab. simulation results show that the SKFMEC method gives the best performance when the driving and road conditions are perturbed.

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Color Enhancement of Low Exposure Images using Histogram Specification and its Application to Color Shift Model-Based Refocusing

  • Lee, Eunsung;Kang, Wonseok;Kim, Sangjin
    • IEIE Transactions on Smart Processing and Computing
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    • v.1 no.1
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    • pp.8-16
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    • 2012
  • An image obtained from a low light environment results in a low-exposure problem caused by non-ideal camera settings, i.e. aperture size and shutter speed. Of particular note, the multiple color-filter aperture (MCA) system inherently suffers from low-exposure problems and performance degradation in its image classification and registration processes due to its finite size of the apertures. In this context, this paper presents a novel method for the color enhancement of low-exposure images and its application to color shift model-based MCA system for image refocusing. Although various histogram equalization (HE) approaches have been proposed, they tend to distort the color information of the processed image due to the range limits of the histogram. The proposed color enhancement algorithm enhances the global brightness by analyzing the basic cause of the low-exposure phenomenon, and then compensates for the contrast degradation artifacts by using an adaptive histogram specification. We also apply the proposed algorithm to the preprocessing step of the refocusing technique in the MCA system to enhance the color image. The experimental results confirm that the proposed method can enhance the contrast of any low-exposure color image acquired by a conventional camera, and is suitable for commercial low-cost, high-quality imaging devices, such as consumer-grade camcorders, real-time 3D reconstruction systems, digital, and computational cameras.

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Fin Cutting Line Detection Technique based on RANSAC for Fish Cutting Automation System (생선 가공 자동화 시스템을 위한 RANSAC 기반 지느러미 절단선 검출 기법)

  • Jang, Yonghun;Park, Changhyeon
    • Journal of KIISE
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    • v.43 no.3
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    • pp.346-352
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    • 2016
  • The fishing industry requires many workers to manually carry out the jobs of sorting and cutting fishes. There are therefore many dangerous situations in their working environment and the throughput is inefficiently low. This paper introduces an automatic fin cutting system based on RANSAC that is able to increase the throughput of fish processing jobs. The system proposed in this paper first detects the edges of a fish using a high-pass filter. The boundary lines between fin and body are then detected by adjusting parameters and the threshold of the noise filters. Finally, the optimal cutting lines are detected using RANSAC. Through an experiment with a sample of 50 fishes, this paper shows that the proposed system detects the cutting lines with about 90% accuracy.

A Precise Heave Determination System Using Time-Differenced GNSS Carrier Phase Measurements

  • Cho, MinGyou;Kang, In-Suk;Park, Chansik
    • Journal of Positioning, Navigation, and Timing
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    • v.6 no.4
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    • pp.149-157
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    • 2017
  • In this study, a system that precisely determines the heave of ship hull was designed using time-differenced GNSS carrier phase measurement, and the performance was examined. First, a technique that calculates precise position relative to the original position based on TDCP measurement for point positioning using only one receiver was implemented. Second, to eliminate the long-cycle drift error occurring due to the measurement error that has not been completely removed by time-differencing, an easily implementable high-pass filter was designed, and the optimum coefficient was determined through an experiment. In a static experiment based on the precise heave measurement system implemented using low-cost commercial GNSS receiver and PC, the heave could be measured with a precision of 2 cm standard deviation. In addition, in a dynamic experiment where it moved up and down with an amplitude of 48 cm and a cycle of 20 seconds, precise heave without drift error could be determined. The system proposed in this study can be easily used for many applications, such as the altitude correction of fish detection radar.

DTCF: A Distributed Trust Computing Framework for Vehicular Ad hoc Networks

  • Gazdar, Tahani;Belghith, Abdelfettah;AlMogren, Ahmad S.
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.11 no.3
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    • pp.1533-1556
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    • 2017
  • The concept of trust in vehicular ad hoc networks (VANETs) is usually utilized to assess the trustworthiness of the received data as well as that of the sending entities. The quality of safety applications in VANETs largely depends on the trustworthiness of exchanged data. In this paper, we propose a self-organized distributed trust computing framework (DTCF) for VANETs to compute the trustworthiness of each vehicle, in order to filter out malicious nodes and recognize fully trusted nodes. The proposed framework is solely based on the investigation of the direct experience among vehicles without using any recommendation system. A tier-based dissemination technique for data messages is used to filter out non authentic messages and corresponding events before even going farther away from the source of the event. Extensive simulations are conducted using Omnet++/Sumo in order to investigate the efficiency of our framework and the consistency of the computed trust metrics in both urban and highway environments. Despite the high dynamics in such networks, our proposed DTCF is capable of detecting more than 85% of fully trusted vehicles, and filtering out virtually all malicious entities. The resulting average delay to detect malicious vehicles and fraudulent data is showed to be less than 1 second, and the computed trust metrics are shown to be highly consistent throughout the network.

Implementation of Extended Kalman Filter for Real-Time Noncontact ECG Signal Acquisition in Android-Based Mobile Monitoring System

  • Rachim, Vega Pradana;Kang, Sung-Chul;Chung, Wan-Young;Kwon, Tae-Ha
    • Journal of Sensor Science and Technology
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    • v.23 no.1
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    • pp.7-14
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    • 2014
  • Noncontact electrocardiogram (ECG) measurement using capacitive-coupled technique is a very reliable long-term noninvasive health-care remote monitoring system. It can be used continuously without interrupting the daily activities of the user and is one of the most promising developments in health-care technology. However, ECG signal is a very small electric signal. A robust system is needed to separate the clean ECG signal from noise in the measurement environment. Noise may come from many sources around the system, for example, bad contact between the sensor and body, common-mode electrical noise, movement artifacts, and triboelectric effect. Thus, in this paper, the extended Kalman filter (EKF) is applied to denoise a real-time ECG signal in capacitive-coupled sensors. The ECG signal becomes highly stable and noise-free by combining the common analog signal processing and the digital EKF in the processing step. Furthermore, to achieve ubiquitous monitoring, android-based application is developed to process the heart rate in a realtime ECG measurement.

Improving nano gap control using frequency adaptive peak filter in Solid Immersion Lens-based plasmonic lithography (SIL 기반 플라즈모닉 리소그래피에서 주파수 적응형 필터를 이용한 나노간극 제어의 성능향상)

  • Choi, Guk-Jong;Lim, Geon;Park, No-Cheol
    • Transactions of the Society of Information Storage Systems
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    • v.10 no.1
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    • pp.1-6
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    • 2014
  • Plasmonic lithography is the latest technique to overcome diffraction limit of previous optical lithography. In the plasmonic lithography, the nano gap between nano metal wave guide and photoresist should be in sub-wavelength region. SIL-based plasmonic lithography is the one of the solutions to maintain small air gap. However, the nano gap control is so sensitive that a little disturbance is able to have a large effect on the nano gap control. So, we analyzed the characteristics of disturbance, and then modified the previous controller to suppress the disturbance. We applied two peak filters which were fixed one and adaptively changeable one. We experimentally confirmed the improvement of the nano gap control, which reduced nano gap error by 30 %. The proposed control will improve the quality of lithography pattern.

Geographical Group-based FastSLAM Algorithm for Maintenance of the Diversity of Particles (파티클 다양성 유지를 위한 지역적 그룹 기반 FastSLAM 알고리즘)

  • Jang, June-Young;Ji, Sang-Hoon;Park, Hong Seong
    • Journal of Institute of Control, Robotics and Systems
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    • v.19 no.10
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    • pp.907-914
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    • 2013
  • A FastSLAM is an algorithm for SLAM (Simultaneous Localization and Mapping) using a Rao-Blackwellized particle filter and its performance is known to degenerate over time due to the loss of particle diversity, mainly caused by the particle depletion problem in the resampling phase. In this paper, the GeSPIR (Geographically Stratified Particle Information-based Resampling) technique is proposed to solve the particle depletion problem. The proposed algorithm consists of the following four steps : the first step involves the grouping of particles divided into K regions, the second obtaining the normal weight of each region, the third specifying the protected areas, and the fourth resampling using regional equalization weight. Simulations show that the proposed algorithm obtains lower RMS errors in both robot and feature positions than the conventional FastSLAM algorithm.

Design of MMIC Diplexer using Eliptic Function Technique in InGaP/GaAs Process (InGaP/GaAs 화합물 반도체 공정을 이용한 MMIC Diplexer 설계)

  • Cho, Won-Yong;Kim, Nam-Young
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.06a
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    • pp.193-193
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    • 2008
  • In this paper, a MMIC diplexer with a low pass and high pass filter are designed and fabricated using an InGaP/GaAs process. The design of this diplexer is based on its stabilization of the low insertion loss since it is important in the in-building system (IBS). The IBS integrates wire and wireless signal between the cable television (CATV) and the personal communication system. In this design, a dual-mode operation of diplexer is fabricated with the frequency of 0 Hz to 900 MHz and 1.7 GHz to 2.2 GHz for CATV and personal communication. respectively. The topolygy of the designed diplexer is based on the L-C filter. This diplexer fabricated by nanoENS Inc. which is foundry service company, was measured by using the facilities of the Kwangwoon University RFIC center. The fabricated chip size is $1.6\times1.4mm^2$ and it has abroad frequency range from 0 Hz to 2.2 GHz.

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