• Journal of Positioning, Navigation, and Timing
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• 제8권4호
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• pp.139-152
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• 2019

The design of new navigation signals is a key factor in building new satellite navigation systems and/or modernizing existing legacy systems. Navigation signal design involves selecting candidate groups and evaluating and analyzing their signal performances. This process can be easily performed through software simulation especially at the beginning of the development phase. The analytical signal performance analysis software introduced in this study is implemented based on equations between the signal design parameters of Radio Navigation Satellite Service (RNSS) and the navigation signal figures-of-merit (FoMs). Therefore, this study briefly summarizes the RNSS signal design parameters and FoMs before introducing the developed software. After that, we explain the operating sequence of the implemented software including the Graphical User Interface (GUI), and calculate the FoMs of an example scenario to verify the feasibility of the software operations.

• 한국위성정보통신학회논문지
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• 제3권2호
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• pp.32-37
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• 2008

Global Navigation Satellite System (GNSS) is been developing in many countries. The satellite navigation system has the importance in economic and military fields. For utilizing satellite navigation system properly, the technology of GNSS Ground Station is needed. GNSS Ground Station monitors the signal of navigation satellite and analyzes navigation solution. This study deals with the navigation software for GNSS Ground Station. This paper will introduce the navigation solution algorithm for GNSS Ground Station. The navigation solution can be calculated by the code-carrier smoothing method, the Kalman-filter method, the least-square method, and the weight least square method. The performance of each navigation algorithm in this paper is presented.

• 정보관리학회지
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• 제29권4호
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• pp.229-249
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• 2012

본 연구는 문헌정보학 분야에서 논의되고 있는 웹 정보 네비게이션의 개념에 대해 보다 명확한 이해를 위해 그 개념정의에 따른 핵심적인 특성들을 분석하고자 한다. 웹이 등장한 1995년을 기준으로 최근 2012년까지 문헌정보학 분야 국외 학술지에 출판된 총 32편의 웹 네비게이션 연구 논문들을 정성적 내용분석과 담론분석을 통해 웹 네비게이션 개념의 정의유형과 그 구성요소와 특징들을 조사하였다. 웹 정보 네비게이션 개념은 크게 네비게이션 행위, 네비게이션 전략, 네비게이션 디자인으로 구분되며, 행위적 특성에 따른 네비게이션 유형 비교는 네비게이션 전략과 디자인 요소들의 상호관련성을 파악하는 데 개념적 틀로 제시되었다.

• 한국항공우주학회지
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• 제45권9호
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• pp.734-745
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• 2017

달 착륙선의 항법 시스템은 자율 정밀 항법 성능을 확보하기 위해 관성측정기와 별추적기, 고도계, 속도계, 지형상대항법 카메라 등 다양한 항법용 전장부품으로 구성되는데 착륙선의 착륙 시나리오와 임무 요구 성능에 따라 적합한 성능의 항법용 전장부품 선정이 필요하다. 본 논문에서는 달 착륙선에 요구되는 항법용 전장부품의 사양을 공분산해석을 통해 분석하였다. 77차 상태변수로 구성되는 기준 시스템 오차모델과 센서의 측정모델을 정의하고 착륙선의 임무 요구 성능은 90m($3{\sigma}$) 착륙 위치 정확도를 요구하는 정밀탐사 임무와 6km($3{\sigma}$)의 착륙 오차가 허용되는 영역탐사 임무로 구분하였다. 자율항법 시작 시점에 따라 PDI(Powered descent initiation)와 DOI(Deorbit initiation) 시나리오로 나누고 항법용 전장부품의 조합과 착륙 시나리오에 따른 성능 분석을 통해 가상의 임무 요구 성능을 만족하기 위한 항법 시스템의 요구사양을 도출하였다.

• 한국군사과학기술학회지
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• 제24권6호
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• pp.577-590
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• 2021

In this paper, we theoretically analyzed the self-alignment/navigation performance in the accelerometer resonance state generated by dither motion of ring laser gyroscope in LINS and verified it through simulation. As a result of analysis, it is confirmed that the amplitude of the accelerometer measurement amplified in the accelerometer resonance state is decreased in the process of sampling per the navigation calculation period and that frequency is changed by the aliasing effect too. It was also analysed that the attitude error in self-alignment is determined by the amplitude/frequency of the accelerometer measurement, the gain of the self-alignment loop, and the velocity and position error in the navigation is determined by the amplitude/frequency/phase error of the accelerometer measurement. This analysis and simulation results show that the self-alignment and navigation performance is not be degraded only when the amplification factor of the accelerometer measurement in the accelerometer resonance state is 3 or less

• 대한인간공학회지
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• 제32권5호
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• pp.443-448
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• 2013

Objective: Purposes of this study are selecting main factors in evaluating the usability of mobile navigation and comprehending mutual importance among the factors. Background: Mobile navigation services have been more diffused than ever as the number of smartphone users sharply increased. However users are having trouble with the usage of mobile navigation services due to the lack of research in the area. Method: In order to attain results, general research on mobile navigation, 1st general survey, and 2nd comparative survey on navigation UI experts were performed. Empirical studies about the results were performed using AHP method. Results: As the result of AHP analysis, accuracy was drawn out to be the most important factor followed by accessibility and visibility. Regarding the characteristics of navigation system, the provision of accurate POI(Point of Interest) was considered to be the most important factor for the experts. And effectiveness was considered to be the most important, followed by satisfaction and efficiency. Conclusion: When evaluating the usability of mobile navigation, prior factors such as accuracy, visibility, and aesthetics should be considered in advance and general evaluation concentrated on effectiveness must be performed. Application: The results of this study are expected to be a fundamental data to mobile navigation design.

• Journal of Positioning, Navigation, and Timing
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• 제12권2호
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• pp.167-176
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• 2023

This study presents the performance analysis of real-time orbit determination and prediction for navigation message generation of Regional Navigation Satellite System (RNSS). Since the accuracy of ephemeris and clock correction in navigation message affects the positioning accuracy of the user, it is essential to construct a ground segment that can generate this information precisely when designing a new navigation satellite system. Based on a real-time architecture by an extended Kalman filter, we simulated orbit determination and prediction of RNSS satellites in order to assess the accuracy of orbit and clock prediction and signal-in-space ranging errors (SISRE). As a result of the simulation, the orbit and clock accuracy was at 0.5 m and 2 m levels for 24 hour determination and six hour prediction after the determination, respectively. From the prediction result, we verified that the SISRE of RNSS for six hour prediction was at a 1 m level.

• 패션비즈니스
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• 제4권4호
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• pp.123-133
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• 2000

The purpose of this study was to examine the usage of internet advertisement, to define the convenient dimensions of information navigation medium, and to examine the difference of convenient information navigation among advertisement types and information design methods. Thirty-four subjects were selected for the survey study and descriptive anlysis, factor analysis and ANOVA were used for the data analysis. The results of this study were: 1. the most perceived channel about the web site information was the search engine, the most preferred type of information design was the mixed type with text and image, and the most preferred medium for fashion information is the magazine. 2. the convenient dimensions of information navigation medium were information understanding, design composition, easy navigation, timely navigation, and convenient navigation. 3. the information design method is the significant factor influencing on the convenient information navigation.

• 대한인간공학회:학술대회논문집
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• 대한인간공학회 1997년도 추계학술대회논문집
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• pp.260-266
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• 1997

The Navigation Streets Map that directly supplies information for a driver plays an important role in Car Navigation System(CNS). Therefore, cause the compatibility, preference, visibility, and readability of the navigation streets map will be hold sway over driver's information acquisition, safety, and performance in CNS, it is important that designer's requirements should be analyuzed for ergonomic design of navigation streets map. Especially, there are differences between the topographical objects marking method and that of the general map in a navigation streets map. Because much information is marked in a narrow space, it is important that the text information should be done in navigation streets map. Also, because it is a important factor to mark the text format for the marking method of the topographical objects, the design requirements will be drawn out through the factor analysis for the text marking method. And when ergonomic designers are doing, this result will be basic research for developing driving simulator of CNS and it will be a ergonomic guideline of navigation streets map.

• Journal of Positioning, Navigation, and Timing
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• 제10권1호
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• pp.21-28
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• 2021

In order to develop a Korea Positioning System (KPS) as part of key national infrastructure, independent navigation signal design is essential. The designed signal candidates must coexist with existing or planned GNSS signals within the limited frequency band. This requires a RF compatibility assessment, which can be performed using the Spectral Separation Coefficient (SSC) and Effective Carrier to Noise Density Ratio (Effective C/N0), for navigation signals. Thus, in this paper, the analysis of RF compatibility between the designed signal candidates and the existing GNSS signals is carried out based on analytical and numerical techniques.