• Title/Summary/Keyword: Position Identification

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A Study on Shipborne Automatic Identification System (AIS)

  • Liu, Renji;Liu, Chang
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2001.10a
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    • pp.19-25
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    • 2001
  • At present the identification of vessels is still depending on the OOW (Officer Of Wateh) in VTS (Vessel Traffic Service), which is completed by radar, and also by the combination of VHF radio and VHF direction finder. However, with the development of port transportation and economic, this conventional way of identification can't satisfy more and more request for the information that the VTS needs from the vessels. In such a case, the AIS(Automatic Identification System) precept which is based on STDMA (Self-organized Time Division Multiple Access) technique is put forward by IMO (International Maritime Organization). AIS can automatically provide the information, including own ship's identification, type, position, course, speed, and other information to the appropriately equipped coast station and other ships. At the same time it can also automatically monitor and track the nearby ships similarly fitted with AIS. On the basis of describing the whole comprising and the format of transmission information of AIS, this paper mainly studies the key communication techniques in AIS, such as STDMA protocol, net synchronization and GMSK(Gaussian Minimum Shift Keying)technique, and so on. At last this paper briefly introduces the recommendation decided by IMO on forcing the sea-going ships to fixed with AIS equipments, and it continuos with the unexploited potential of AIS if it applies in VTS.

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A Robotic Vision System for Turbine Blade Cooling Hole Detection

  • Wang, Jianjun;Tang, Qing;Gan, Zhongxue
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.237-240
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    • 2003
  • Gas turbines are extensively used in flight propulsion, electrical power generation, and other industrial applications. During its life span, a turbine blade is taken out periodically for repair and maintenance. This includes re-coating the blade surface and re-drilling the cooling holes/channels. A successful laser re-drilling requires the measurement of a hole within the accuracy of ${\pm}0.15mm$ in position and ${\pm}3^{\circ}$ in orientation. Detection of gas turbine blade/vane cooling hole position and orientation thus becomes a very important step for the vane/blade repair process. The industry is in urgent need of an automated system to fulfill the above task. This paper proposes approaches and algorithms to detect the cooling hole position and orientation by using a vision system mounted on a robot arm. The channel orientation is determined based on the alignment of the vision system with the channel axis. The opening position of the channel is the intersection between the channel axis and the surface around the channel opening. Experimental results have indicated that the concept of cooling hole identification is feasible. It has been shown that the reproducible detection of cooling channel position is with +/- 0.15mm accuracy and cooling channel orientation is with +/$-\;3^{\circ}$ with the current test conditions. Average processing time to search and identify channel position and orientation is less than 1 minute.

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Identification of English labial consonants by Korean EFL learners (한국 EFL 학습자들의 영어 순자음의 인지)

  • Cho, Mi-Hui
    • Proceedings of the Korea Contents Association Conference
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    • 2006.11a
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    • pp.788-791
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    • 2006
  • The perception of English labial consonants was investigated via experiment where 40 Korean EFL learners identified nonwords with the target labial consonants [p, b, f, v] in 4 different prosodic locations. The results showed that there was a strong positional effect since the accuracy rates of the four target consonants differed by position. Specifically, the average accuracy rate for the target consonants was higher in the stressed intervocalic position and initial onset position than in the unstressed intervocalic position and final coda position. Further, the accuracy rate for [f] is was high in all prosodic locations except the unstressed intervocalic position. This is unexpected in markedness theory given that fricatives are assumed to be more difficult to learn than stops.

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Evaluation of a multi-stage convolutional neural network-based fully automated landmark identification system using cone-beam computed tomography-synthesized posteroanterior cephalometric images

  • Kim, Min-Jung;Liu, Yi;Oh, Song Hee;Ahn, Hyo-Won;Kim, Seong-Hun;Nelson, Gerald
    • The korean journal of orthodontics
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    • v.51 no.2
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    • pp.77-85
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    • 2021
  • Objective: To evaluate the accuracy of a multi-stage convolutional neural network (CNN) model-based automated identification system for posteroanterior (PA) cephalometric landmarks. Methods: The multi-stage CNN model was implemented with a personal computer. A total of 430 PA-cephalograms synthesized from cone-beam computed tomography scans (CBCT-PA) were selected as samples. Twenty-three landmarks used for Tweemac analysis were manually identified on all CBCT-PA images by a single examiner. Intra-examiner reproducibility was confirmed by repeating the identification on 85 randomly selected images, which were subsequently set as test data, with a two-week interval before training. For initial learning stage of the multi-stage CNN model, the data from 345 of 430 CBCT-PA images were used, after which the multi-stage CNN model was tested with previous 85 images. The first manual identification on these 85 images was set as a truth ground. The mean radial error (MRE) and successful detection rate (SDR) were calculated to evaluate the errors in manual identification and artificial intelligence (AI) prediction. Results: The AI showed an average MRE of 2.23 ± 2.02 mm with an SDR of 60.88% for errors of 2 mm or lower. However, in a comparison of the repetitive task, the AI predicted landmarks at the same position, while the MRE for the repeated manual identification was 1.31 ± 0.94 mm. Conclusions: Automated identification for CBCT-synthesized PA cephalometric landmarks did not sufficiently achieve the clinically favorable error range of less than 2 mm. However, AI landmark identification on PA cephalograms showed better consistency than manual identification.

Complete Parameter Identification of Gough-Stewart platform with partial pose measurements using a new measurement device

  • Rauf, Abdul;Ryu, Je-Ha
    • 제어로봇시스템학회:학술대회논문집
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    • 2004.08a
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    • pp.825-830
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    • 2004
  • Kinematic calibration of Gough-Stewart platform using a new measurement device is presented in this paper. The device simultaneously measures components of position and orientation using commercially available gadgets. Additional kinematic parameters are defined to model the sources of inaccuracies for the proposed measurement device. Computer simulations reveal that all kinematic parameters of the Gough-Stewart platform and the additional kinematic parameters of the measurement device can be identified with the partial pose measurements of the device. Results also show that identification is robust for the initial errors and the noise in measurements. The device also facilitates the automation of easurement procedure.

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Sensitivity to Phrase-initial Tone and Laryngeal Feature Identification of Foreign Learners of Korean

  • Lee, Hye-Sook
    • Phonetics and Speech Sciences
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    • v.2 no.3
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    • pp.91-99
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    • 2010
  • This paper reports on an identification test where KFL learners identified the Korean three-way laryngeal contrast in the phrase-initial position, when the phrase-initial tone was systematically manipulated. It turns out that heritage learners have some sensitivity to phrase-initial tone and show a plain-aspirated alternation in their identification according to the phrase-initial tone, as native speakers do, whereas non-heritage students do not show such tone sensitivity. However, after a weekly prosody training, second-year non-heritage students have shown a significant improvement in their performance. This paper clearly shows that the phrase-initial tone plays a critical role in distinguishing laryngeal features of Korean obstruents, and also suggests that prosody including the tone-segment correlation should be incorporated in the KFL curriculum.

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Tracking of Person Walking Pattern and Trajectory Following with 2D Laser Scanner (레이저 스케너 센서기반 보행패턴 인식 및 경로추적)

  • Jin, Taeseok
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.67 no.7
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    • pp.903-909
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    • 2018
  • We propose laser scanner sensor system based walking pattern and tracking method of multiple human. This system uses laser scanners sensors and is applicable to wide and crowded area such as hospital and medical care center. The primary objective of this research is to promote the development of robust, repeatable and transferable software for security system that can automatically detect, track and follow people in public area. We developed the method of human identification for this system. Our method is following: 1. Best-walking pattern data are obtained by the help of human position and direction data obtained by laser scanners. 2. Human identification is conducted by calculating the correlation between the step length of walking human. It becomes possible to conduct human identification even in crowded scenes by estimating the movements of waling human' feet are periodic. In the experiment in the station, some effectiveness of this method became clear.

A Simple Method for Identifying Mechanical Parameters Based on Integral Calculation

  • Han, Sang-Heon;Yoo, Anno;Yoon, Sang Won;Yoon, Young-Doo
    • Journal of Power Electronics
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    • v.16 no.4
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    • pp.1387-1395
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    • 2016
  • A method for the identification of mechanical parameters based on integral calculation is presented. Both the moment of inertia and the friction constant are identified by the method developed here, which is based on well-known mechanical differential equations. The mechanical system under test is excited according to a pre-determined low-frequency sinusoidal motion, minimizing the distortion, and increasing the accuracy of the results. The parameters are identified using integral calculation, increasing the robustness of the results against measurement noise. Experimental data are supported by simulation, confirming the effectiveness of the proposed technique. The performance improvements shown here are of use in the design of speed and position controllers and observers. Owing to its simplicity, this method can be readily applied to commercial inverter products.

A reliability analysis of syndrome differentiation questionnaire for obesity (비만변증 설문지에 대한 신뢰도 분석)

  • Kang, Byeong-Kab;Moon, Jin-Seok;Choi, Sun-Mi
    • Korean Journal of Oriental Medicine
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    • v.13 no.1 s.19
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    • pp.109-114
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    • 2007
  • The high position condition 10 escape which the obesity person appeals. Obesity Pattern-Identification question it will yell and 243 subjects which to the obesity in the patient of 517 subjects which draw up correspond. (longitude obesity 153 person, altitude obesity 90 person) against it analyzes. In order to analyze the reliability of the items which diagnose each Pattern-Identification it used Cronbach alpha coefficient and escape it did the alpha of each item. Alpha value of each Pattern-Identification than appears more highly the item which it will be able to consider an elimination in the item which decreases a reliability. In that phlegm-retention syndrome is bigger alpha coefficient 0.784 than 'meal quantity is few'(0.787) a possibility of seeing in the item which decreases a reliability to the place where it diagnoses it puts in phlegm-retention syndrome.

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Mechanical Parameter Identification of Servo Systems using Robust Support Vector Regression (Support Vector Regression을 이용한 서보 시스템의 기계적 상수 추정)

  • Cho Kyung-Rae;Seok Jul-Ki
    • The Transactions of the Korean Institute of Power Electronics
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    • v.10 no.5
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    • pp.468-480
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    • 2005
  • The overall performance of AC servo system is greatly affected the uncertainties of unpredictable mechanical parameter variations and external load disturbances. To overcome this problem, it is necessary to know different parameters and load disturbances subjected to position/speed control. This paper proposes an on-line identification method of mechanical parameters/load disturbances for AC servo system using support vector regression(SVR). The experimental results demonstrate that the proposed SVR algorithm is appropriate for control of unknown servo systems even with time-varying/nonlinear parameters.