• Title/Summary/Keyword: navigation data

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A fundamental study about maritime training for marine engineer using PBL(Problem Based Learning) (선박기관사 해기실습교육에 PBL(문제중심학습) 활용을 위한 기초연구)

  • Lee, Sang-Il;Jeong, Woo-Lee
    • Journal of Advanced Marine Engineering and Technology
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    • v.38 no.4
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    • pp.476-485
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    • 2014
  • PBL is a student-centered pedagogy in which students learn about a subject through the experience of problem solving. Marine engineer is the expert which supports the safe navigation and solves the problems could happen in independent situation as a ship. This study executed the fundamental study on the maritime training education for marine engineers using PBL. In this study, we conducted the survey on 56 students for 6 months using PBL in H university. The result showed the improvement on ability to solve the problems, interpersonal relationship, communication skill, synthetic thinking faculty and practical use of data but some students answered the complaint of the insufficient information and unacquainted learning method of PBL. This suggested the development and improvement plans for the maritime training education using PBL based on this fundamental study.

Beam selection method for millimeter-wave-based uplink hybrid beamforming systems (밀리미터파 기반 상향링크 하이브리드 빔포밍 시스템을 위한 빔선택 방법)

  • Shin, Joon-Woo
    • Journal of Advanced Marine Engineering and Technology
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    • v.40 no.9
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    • pp.818-823
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    • 2016
  • Millimeter wave (mm-wave) communication systems provide high data rates owing to the large bandwidths available at mm-wave frequencies. Recently, analogue and digital combined beamforming, namely "hybrid beamforming" has drawn attentions owing to its ability to realize the required link margins in mm-wave systems. Taking into account the radio frequency (RF) hardware limitations, such as the analogue phase shifter gain constraint and the low resolution of the phase controller, we introduce an uplink hybrid beamforming system that includes discrete Fourier transform (DFT) based "fixed" analogue beamforming. We adopt a zero-forcing (ZF) multiple-input multiple-output (MIMO) equalizer to eliminate the uplink inter-user interferences. Moreover, to improve the sum-rate performances, we propose a transmit beam selection algorithm which makes the uplink effective channels, i.e., the beamformed channels, become near orthogonal. The effectiveness of the proposed beam selection algorithm was verified through numerical simulations.

A Study of Contents Arrangement in Conning Display (선박항법기기 화면의 배치에 관한 연구)

  • Yoon, Hoon-Yong;Kim, Kyung-Hoon
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.33 no.2
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    • pp.154-161
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    • 2010
  • The conning display which is located in the ship bridge shows the various important information such as ship position, ship speed, track data, rate of turn, thruster rpm so on, and is one of the IBSs(Integrated Bridge Systems). In this study, the survey was conducted for ten officers to find the importance and using frequency of the information which were displayed in the conning display. The results showed that the information of drift speed, ship speed, wind direction and wind force, rate of turn, sea water depth, ship position, heading, thrust rpm, alarm, rudder command and angle got high scores and it meant that these information were very important and high frequency of use during the navigation. The optimized contents arrangement in conning display was suggested based on importance and using frequency of information. The experiment using eye-tracking system was conducted to compare the performance time and error rate of nine different scenarios for suggested arrangement display and three other existing displays. The results showed that the suggested arrangement was the best in performance time and error rate. The scenario concerning the direction and speed of wind showed faster performance time and lower error rate than other scenarios. The movement of subject's eye tended to search from the center and to avoid the comer, called 'the comer effect.' It is expected that the results of this study could help for the bridge staff to grasp the sailing information easily and to cope with the given situations promptly.

Design of a Cross-obstacle Neural Network Controller using Running Error Calibration (주행 오차 보정을 통한 장애물 극복 신경망 제어기 설계)

  • Lim, Shin-Teak;Yoo, Sung-Goo;Kim, Tae-Yeong;Kim, Yeong-Chul;Chong, Kil-To
    • Journal of Institute of Control, Robotics and Systems
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    • v.16 no.5
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    • pp.463-468
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    • 2010
  • An obstacle avoidance method for a mobile robot is proposed in this paper. Our research was focused on the obstacles that can be found indoors since a robot is usually used within a building. It is necessary that the robot maintain the desired direction after successfully avoiding the obstacles to achieve a good autonomous navigation performance for the specified project mission. Sensors such as laser, ultrasound, and PSD (Position Sensitive Detector) can be used to detect and analyze the obstacles. A PSD sensor was used to detect and measure the height and width of the obstacles on the floor. The PSD sensor was carefully calibrated before measuring the obstacles to achieve better accuracy. Data obtained from the repeated experiments were used to plot an error graph which was fitted to a polynomial curve. The polynomial equation was used to navigate the robot. We also obtained a direction-error model of the robot after avoiding the obstacles. The prototypes for the obstacle and direction-error were modeled using a neural network whose inputs are the obstacle height, robot speed, direction of the wheels, and the error in direction. A mobile robot operated by a notebook computer was setup and the proposed algorithm was used to navigate the robot and avoid the obstacles. The results showed that our algorithm performed very well during the experiments.

Pronunciation Variation Patterns of Loanwords Produced by Korean and Grapheme-to-Phoneme Conversion Using Syllable-based Segmentation and Phonological Knowledge (한국인 화자의 외래어 발음 변이 양상과 음절 기반 외래어 자소-음소 변환)

  • Ryu, Hyuksu;Na, Minsu;Chung, Minhwa
    • Phonetics and Speech Sciences
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    • v.7 no.3
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    • pp.139-149
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    • 2015
  • This paper aims to analyze pronunciation variations of loanwords produced by Korean and improve the performance of pronunciation modeling of loanwords in Korean by using syllable-based segmentation and phonological knowledge. The loanword text corpus used for our experiment consists of 14.5k words extracted from the frequently used words in set-top box, music, and point-of-interest (POI) domains. At first, pronunciations of loanwords in Korean are obtained by manual transcriptions, which are used as target pronunciations. The target pronunciations are compared with the standard pronunciation using confusion matrices for analysis of pronunciation variation patterns of loanwords. Based on the confusion matrices, three salient pronunciation variations of loanwords are identified such as tensification of fricative [s] and derounding of rounded vowel [ɥi] and [$w{\varepsilon}$]. In addition, a syllable-based segmentation method considering phonological knowledge is proposed for loanword pronunciation modeling. Performance of the baseline and the proposed method is measured using phone error rate (PER)/word error rate (WER) and F-score at various context spans. Experimental results show that the proposed method outperforms the baseline. We also observe that performance degrades when training and test sets come from different domains, which implies that loanword pronunciations are influenced by data domains. It is noteworthy that pronunciation modeling for loanwords is enhanced by reflecting phonological knowledge. The loanword pronunciation modeling in Korean proposed in this paper can be used for automatic speech recognition of application interface such as navigation systems and set-top boxes and for computer-assisted pronunciation training for Korean learners of English.

Alcohol Drinking Status of Officers on a Ship and Drunk-navigation Experiments Using Ship Handling Simulator

  • Yang Chan-Su;Yang Young-Hoon;Kim Hong-Tae
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.12 no.1 s.24
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    • pp.39-45
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    • 2006
  • Based on the previous studies on alcohol effects on human behaviour and performance in transportation system such as air-plane and car driving, the alcohol exposure before and on watch of a ship has a great influence on subsequent behaviour. In this paper, to examine the drinking status of officers on board multiple choice questionnaires are circularized under instruction and surveyed for 118 officers. According to the results of the questionnaire survey on alcohol dependency (Alcoholism) that was invented by WHO, over 27 % of those surveyed represented alcohol abuse symptoms. In addition to that, the existing state and awareness for on-board-drinking was summarized to make a scenario of drink-operation with a ship handling simulator to investigate the effect of alcohol (0.08 g% blood alcohol concentrations) on ship operational performance. A main effect for alcohol was found indicating that ship operational performance was comparatively impaired by this alcohol relative to performance in the non-alcohol condition The results of this research can be applied to minimize marine accidents as basic data.

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Construction of Three Dimensional Virtual City Information Using the Web 3D (Web 3D를 이용한 3차원 가상도시공간정보 구축)

  • 유환희;조정운;이학균
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.20 no.2
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    • pp.119-126
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    • 2002
  • Recently, as advancing the technologies for Web 3D and Virtual Reality, the studies have been progressed actively to provide three dimensional information on the web. Especially, the various applications for providing urban information in 3D space have been developed using EAI(External Authoring Interface) that serves an interface between VRML(Virtual Reality Modeling Language), standard language for embodying virtual reality, and JAVA applet in HTML. In this study, as constructing 3D virtual city information using Digital Map, IKONOS satellite image, VRML and so on, we could provide users which need several information with building location and various urban living information. In addition, applying 3D skills such as texturing, panorama and navigation, users were enabled to perform various route searching and scenery analysis. Finally, to serve urban living information in real time, we designed to search information faster through interfacing database and to update data using ASP(Active Server Page) on web.

The Analysis of Road Alignement and Construction GSIS Using RTK GPS and TS (RTK-GPS와 TS를 이용한 도로선형분석 및 GSIS 구축)

  • 장상규;홍순헌;김가야
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.21 no.4
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    • pp.293-299
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    • 2003
  • In the future, the design of road should be convenient in using of high-technology information and it needs the design of alignment that is able to make the maximum vehicles inducement function appropriated for CNS(Car Navigation System). So it needs to analysis appropriately the alignment of road for the improvement design of road which is established and to make the design of road and the coordinate of the main points. Therefore, this research had acquired the road data by RTK-GPS to accurate the analysis of road alignment and compared with Total Station. As the result, we could acquire the design source of the road alignment using RTK-GPS. Also, it was estimated the accuracy after comparing the design with RTK-GPS coordinates. We made an analysis of the degree of slant or the ups and downs of surface. We made an analysis of three dimensional visual information which was included in GSIS concept and estimated the accuracy. Finally, we analyzed the earth volume calculation by comparing with Total Station.

Impact of Tropospheric Modeling Schemes into Accuracy of Estimated Ellipsoidal Heights by GPS Baseline Processing: Experimental Analysis and Results (GPS 기선해석에 의한 타원체고 추정에서 대류권 오차 보정기법이 정확도에 미치는 영향에 관한 실험적 분석)

  • Lee, Hungkyu
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.36 no.4
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    • pp.245-254
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    • 2018
  • Impact of tropospheric correction techniques on accuracy of the GPS (Global Positioning System) derived ellipsoidal heights has been experimentally assessed in this paper. To this end, 247 baselines were constructed from a total of 88 CORS (Continuously Operating Reference Stations) in Korea. The GPS measurements for seven days, acquired from the so-called integrated GNSS (Global Navigation Satellite Systems) data center via internet connection, have been processed by two baseline processing software packages with an application of the empirical models, such as Hopfield, modified Hopfield and Saastamoinen, and the estimation techniques based on the DD (Double-Differenced) measurements and the PPP (Precise Point Positioning) technique; hence a total number of the baseline processed and tested was 8,645. Accuracy and precision of the estimated heights from the various correction schemes were analyzed about baseline lengths and height differences of the testing baselines. Details of these results are summarized with a view to hopefully providing an overall guideline of a suitable selection of the modeling scheme with respect to processing conditions, such as the baseline length and the height differences.

An LED Positioning Method Using Image Sensor of a Smart Device (LED 조명과 스마트 디바이스의 이미지 센서를 이용한 실내 측위 기법)

  • Kim, Jae-Hoon;Kim, Byoung-Sup;Jeon, Hyun-Min;Kang, Suk-Yon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.40 no.2
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    • pp.390-396
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    • 2015
  • The drastic growth of mobile communication and spreading of smart phone make the significant attention on Location Based Service. The one of most important things for vitalizations of LBS is the accurate estimating position for mobile object. Focusing on an image sensor deployed in smart phone, we develop a LED based positioning estimation framework. The developed approaches can strengthen the advantages of independent indoor applicability of LED. The estimation of LED based positioning is effectively applied to any indoor environment. We put a focus especially on the algorithmic framework. of image processing of smart phone. From LED lighting, we can obtain a typical signal image which contains the unique positioning information. Furthermore test-bed based on smart phone platform is practically developed and all data have been harvested from the actual measurement of test indoor area. This can approve the practical usefulness of proposed framework.