• Journal of Positioning, Navigation, and Timing
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• 제6권1호
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• pp.17-26
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• 2017

Latency occurs in RTK, where the measured position actually outputs past position when compared to the measured time. This latency has an adverse effect on the navigation accuracy. In the present study, a system that estimates the latency of RTK and compensates the position error induced by the latency was implemented. To estimate the latency, the speed obtained from an odometer and the speed calculated from the position change of RTK were used. The latency was estimated with a modified correlator where the speed from odometer is shifted by a sample until to find best fit with speed from RTK. To compensate the position error induced by the latency, the current position was calculated from the speed and heading of RTK. To evaluate the performance of the implemented method, the data obtained from an actual vehicle was applied to the implemented system. The results of the experiment showed that the latency could be estimated with an error of less than 12 ms. The minimum data acquisition time for the stable estimation of the latency was up to 55 seconds. In addition, when the position was compensated based on the estimated latency, the position error decreased by at least 53.6% compared with that before the compensation.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2006년 창립20주년기념 정기학술대회 및 국제워크샵
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• pp.327-330
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• 2006

With the increasing requirements for the survey and development of the ocean, the demands on the of AUV(Autonomous Underwater Vehicle) technologies have been increased. Reconstruction and replay of the AUV motion on the basis of the data stored during the execution of mission, can help the development of control strategies for AUVs such as mission planning and control algorithms. While an AUV cruises for her mission, her attitude and position data are is recorded. The data can be used for visualization of the motion in off-line. However, because most of the position data gathered from acoustic sensors have long time-interval and include intermittent faulty signal, the replayed motion by the graphic simulator can not demonstrate the motion as a smooth movie. In this paper, interpolation methods are surveyed to reconstruct the AUV position data. Then, an efficient 3D visualization method for AUV motion using the interpolation method is proposed. Simulation results arc also included to verify the proposed method.

• 한국의상디자인학회지
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• 제14권4호
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• pp.127-137
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• 2012

The purpose of this study is to recognize the differences of visual evaluation by variations in width of hem line and waistline position of the flare pants. The stimuli are 9 samples: One control group, 3 variations of the width of hem line and 3 variations of the waistline position. The data has been obtained from 44 fashion students. The data has been analyzed by Factor Analysis, Anova, Scheffe's Test and the MCA method. The results of the study are as follows: The visual evaluation by the width of hem line and waistline position of flare pants are composed of 5 factors : physical characteristics, elegance, originality, comfort, and stiffness. Among these factors, the physical characteristic is evaluated to be the most important factor. As a v isual evaluation result o f changes in the width o f hern l ine, 8 4 cm in width (the narrowest width) was highly evaluated in physical characteristics, elegance, and originality factors. For the result of changes in the waistline position, high-waisted flare pants were highly effective in physical characteristics, and also evaluated well in elegance, originality and stiffness factors. The flare pants did not show any interaction between the width of hem line and waistline position. The waistline position had more influence on visual evaluation in physical characteristics, originality and comfort factors while elegance and stiffness factors were affected by the width of hem line.

• Journal of Astronomy and Space Sciences
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• 제35권4호
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• pp.287-293
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• 2018

This paper presents a satellite relative navigation strategy for formation flying, which chooses an appropriate navigation algorithm according to the operating environment. Not only global positioning system (GPS) measurements, but laser measurements can also be utilized to determine the relative positions of satellites. Laser data is used solely or together with GPS measurements. Numerical simulations were conducted to compare the relative navigation algorithm using only laser data and laser data combined with GPS data. If an accurate direction of laser pointing is estimated, the relative position of satellites can be determined using only laser measurements. If not, the combined algorithm has better performance, and is irrelevant to the precision of the relative angle data between two satellites in spherical coordinates. Within 10 km relative distance between satellites, relative navigation using double difference GPS data makes more precise relative position estimation results. If the simulation results are applied to the relative navigation strategy, the proper algorithm can be chosen, and the relative position of satellites can be estimated precisely in changing mission environments.

• 대한전자공학회논문지SP
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• 제41권6호
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• pp.187-193
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• 2004

본 논문에서는 무한원점의 특성과 단일 비젼 시스템을 이용하여 자율 주행을 위한 GPS 위치 데이터 보정법을 제안한다. 실제 도로를 약 60 km의 거리를 주행하며 제안한 방법에 적용한 주행실험 결과를 제시하였다. 제안하는 방법은 직선도로의 환경에서 GPS 위치 오차론 최소 약 53% 이상 감소시켰고, 거리로는 0.5m 이내로 추정되었다. 그러나 곡선도로와 직선이 아닌 산악도로 등의 도로환경에서 정확도를 판별하기 어려운 관계로 직선도로에서의 오차만을 제시하였다.

• 대한물리의학회지
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• 제6권3호
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• pp.247-256
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• 2011

Purpose : The purpose of this study were to determine whether changes of position might effect the chest expansion and pulmonary function of the 20s men obesity. Methods : Thirty subjects with obesity(M:30, % fat>25.0) and thirty normal subjects(M:30, % fat<24.9) were participated in experiment. Subjects were assessed according to position changes(supine position, $45^{\circ}$ lean sitting position, $90^{\circ}$ sitting position) using chest length(chest length for resting, chest expansion) and pulmonary function (Tidal volume, Inspiratory capacity, Vital capacity, Inspiratory reserve volume, Expiratory reserve volume) by the CardioTouch 3000S(BIONET, USA). Repeated measure ANOVA was used to compare each region data of chest length and pulmonary function according to changes of position with obesity and normal subjects. Results : These findings suggest that the obesity can be appear to low chest expansion and pulmonary function than normal subjects on position method. In comparison of three experimental position, supine position was more low. Conclusion : This study showed position of the obesity appear low chest expansion and function of pulmonary volume than normal subjects, and thus it indicates that the pulmonary function of the obesity will be suggest objective respiratory data through the exercise program.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.472-475
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• 2009

Nowadays, Short headway is a requirement of Signaling System applied to subway and Light Rail Transit (LRT) being constructed in Korea. To satisfy this Systematic Requirement, the accuracy of train position information on the line is one of the main element to improve ATC system safety and performance. On-board ATC system performs feasibility of Train Position as comparing data from balise installed along the track with data from tachometer installed at both axles of train.

• Asian Journal of Business Environment
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• 제4권4호
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• pp.19-26
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• 2014

Purpose - The study is primarily aimed at framing "Position Descriptions" for some key positions in the executive cadre of the testing department of CESC Limited. Research design, data, and methodology - The questionnaire, interview, and observation methods have been used for the purpose of data collection. The position descriptions are validated by superiors belonging to the respective departments. Results - It has been found that there is overlapping of job duties and job responsibilities in the department. This overlapping is quite alarming for the organization and may even become a hurdle in the path of its progress. It can be seen as a classic case of de-layering. Conclusions - The study concludes that good communication along with interpersonal and negotiation skills are absolutely essential to facilitate the performance of the day-to-day duties of a job, including handling the union, solving IR related issues, development of the subordinates, job setting, distribution and allocation, etc. Position descriptions will help in the alignment of the employee direction, and can be a useful tool to aid the communication between management and employees.

• 한국항해학회지
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• 제24권4호
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• pp.219-226
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• 2000

Ship's position data obtaining method is one of the very important factor in navigation. Nowadays, GPS(Global Positioning System) using the earth orbiting satellites are equipped and operated for the position finding. Because it provides more precise position information than other equipments and is very convenient for navigator. In this study, it is designed to develop the GPS simulator for everybody being able to practise the GPS operating skill like as navigation planning, navigation calculating etc. And also, it can be operated with personal computer without real GPS receiver. This simulation system is based on the real GPS receiver and built by the visual basic 5.0 program. And it displays the ship's position and navigating information and plots the ship's moving track on the screen in real time according as initial setup data-main engine's rpm, rudder angle, departure position and waypoint.

• 수산해양기술연구
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• 제29권2호
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• pp.109-116
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• 1993

Underwater acoustic positioning systems have been extensively used not only in surface position fixing but also in underwater position fixing. Recently, these systems have been applied in the field of installation and underwater inspection of offshore platforms etc. But in these systems are included the fixing errors as results of a signal with additive noise and irregular motion of vessel by ocean waves. To improve the accuracy of the position fixing a Kalman filter is applied to the supershort baseline (SSBL) acoustic positioning system with beacon mode in noise conditions. The position data obtained by the Kalman filter is compared with raw position data and it is confirmed in the simulation that the former is more accurate than the latter. And an indicator monitoring the filtering effect is described while ship's moving.