• Journal of Positioning, Navigation, and Timing
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• v.8 no.4
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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.

• Journal of Positioning, Navigation, and Timing
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• v.13 no.1
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• pp.1-13
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• 2024

In this paper, we investigate the signal design of six (USA, EU, Russia, China, Japan, and India) countries for Global Navigation Satellite Systems (GNSS). Recently, a navigation satellite system that is capable of high-precision and reliable Positioning, Navigation, Timing (PNT) services has been developed. Prior to system design, a survey of the signal design for other GNSS systems should precede to ensure compatibility and interoperability with other GNSS. The signal design includes carrier frequency, Pseudorandom Noise (PRN) code, modulation, navigation service, etc. Specifically, GNSS is allocated L1, L2, and L5 bands, with recent additions of the L6 and S bands. GNSS uses PRN code (such as Gold, Weil, etc) to distinguish satellites that transmit signals simultaneously on the same frequency band. For modulation, both Binary Phase Shift Keying (BPSK) and Binary Offset Carrier (BOC) have been widely used to avoid collision in the frequency spectrum, and alternating BOCs are adopted to distinguish pilot and data components. Through the survey of other GNSS' signal designs, we provide insights for guiding the design of new satellite navigation systems.

• Journal of Positioning, Navigation, and Timing
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• v.9 no.4
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• pp.305-317
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• 2020

The navigation message is composed of the information contained in the message and the structure for transmitting this information. In order to design a navigation message, considerations in terms of message content and message structure must be elicited. For designing a Korea Positioning System (KPS) navigation message, this paper explains performance indicators in terms of message structure and message content. Most of the performance analysis of GNSS navigation messages already in operation was performed only for Time-to-first-fix-Data (TTFFD). However, in the navigation message, the message content is composed of Clock-Ephemeris Data (CED) and additional information. So, this paper proposes a new performance indicator R_(Non-CED) that can be analyzed from the viewpoint of receiving additional information along with an explanation of TTFFD focusing on the CED reception time. This paper analyze the performance in terms of message structure using these two performance indicators. The message structures used for analysis are the packetized message protocol like GPS CNAV and the packetized and fixed pattern message protocol like GPS CNAV-2. From the results, it is possible to proffer how KPS navigation messages can have better performance than GPS navigation messages. And, these two performance indicators, TTFFD and R_Non-CED, can help to design the minimum TTFF required performance of KPS navigation messages.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2015.07a
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• pp.111-112
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• 2015

IMO established an e-Navigation Strategy Implementation Plan(SIP) in 2014 and they aim to enforce in 2019. Accordingly, korean government also prepared e-Navigation SIP as the Next Maritime Safety Comprehensive Management System in 2015. The main content is to promote R&D by putting 131 billion won over the next five years from 2016 to 2020. On the other hand still in a situation that staying at the conception level of Korean e-Navigation System, by study the architectural design requirements of the Korean e-Navigation system, so we will be able to establish future research directions.

• Journal of Positioning, Navigation, and Timing
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• v.13 no.1
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• pp.93-102
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• 2024

Global Navigation Satellite System (GNSS)/Inertial Navigation System (INS) integrated navigation systems provide highly accurate and reliable navigation solutions and are widely used as civil and military navigation systems. In order to facilitate the GNSS/INS integrated navigation system development task, a simulator can be used to provide inputs for the GNSS/INS integrated navigation system. In this paper, a simulator design using general-purpose Personal Computer (PC) and Off-The-Shelf (OTS) interface boards for a GNSS/INS integrated navigation system is proposed and implementation results are presented. Requirements of the GNSS/INS integrated navigation system simulator are presented and a design method that satisfies the requirements is described. In order to show the usefulness of the proposed design method, a simulator using a general-purpose PC and OTS interface boards for the GPS/INS integrated navigation system are implemented and verified. The implementation results show that the simulator designed by the proposed method generates the GPS L1 C/A signal and IMU data without any problems.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.9
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• pp.774-781
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• 2013

The purpose of this paper is to design a DVL-RPM based VKF (Velocity Kalman Filter) design for a performance improvement underwater integrated navigation system. The proposed approach relies on a VKF, augmented by a altitude from Echo-sounder based switching architecture to yield robust performance, even when DVL (Doppler Velocity Log) exceeds the measurement range and the measured value is unable to be valid. The proposed approach relies on two parts: 1) Indirect feedback navigation Kalman filter design, 2) VKF design. To evaluate proposed method, we compare the results of the VKF aided navigation system with simulation result from a PINS (Pure Inertial Navigation System) and conventional INS-DVL method. Simulations illustrate the effectiveness of the underwater navigation system assisted by the additional DVL-RPM based VKF in underwater environment.

• Journal of Fashion Business
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• v.4 no.4
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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.

• Archives of design research
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• v.19 no.4 s.66
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• pp.101-110
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• 2006

In this study, I suggested a new model of universal web navigation design which can enhance users' web usability. I would like to prove that when users enjoy web navigation design, they access information much more effectively. Using a survey, I suggest some types of web navigation design for users. After that, I conducted an experiment with 4 types of web navigation designs, which have been developed to reflect varying stages of comprehensibility. My survey focused on three points. First I measured the time they spent to search for information. Second, I tested whether they lost their way while searching for information and if they did lose their way, I checked whether they could recover from their errors and find their way back. Third, I investigated whether layout, location and size of the web navigation design factors affected usability. The results of my survey indicated that users spend the shortest time, have the easiest interface, and have least error incidence under the web navigation design to enhance old-aged users' web usability. Thus, developing a universal web navigation design can encourage people to be more involved with the internet.

• Archives of design research
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• v.19 no.1 s.63
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• pp.129-140
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• 2006

In this study, I would like to suggest a new model of web navigation design which can enhance old-aged users web usability. I would like to prove that when users enjoy web navigation design, older-users access information much more effectively. Using a survey, suggest some types of web navigation designed for old-aged users. After that, based on the result of the prepatory survey, I conducted an experiment with 4 types of web navigation designs, which have been developed to reflect varying stages of comprehensibility. My survey focused three points. First I tested whether they lost their way while searching for information. Secondly, if they did lose their way, I checked whether they could recover from their errors and find their way back. Thirdly, I investigated whether layout, location and size of the web navigation design factors affected usability. The results of my survey indicated that old-aged users spend the shortest time, have the easiest interface, and have least error incidence under the web navigation design to enhance old-aged users web usability.Thus, developing a web navigation design for old-aged users can encourage older people to be more involved with the internet, especially in the aging society.

• Archives of design research
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• v.19 no.5 s.67
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• pp.161-170
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• 2006

In this study, I would like to suggest an idal model of web navigation design which can enhance users' web usability. I would like to prove that when users enjoy web navigation design, they access information much more effectively. Using a survey, I suggest some types of web navigation design for users. After that, I conducted an experiment with 4 types of web navigation designs, which have been developed to reflect varying stages of comprehensibility. My survey focused on three points. First I measured the time they spent to search for information. Secondly, I tested whether they lost their way while searching for information and if they did lose their way, I checked whether they could recover from their errors and find their way back. Thirdly, I investigated whether layout, location and size of the web navigation design factors affected usability. The results of my survey indicated that users spend the shortest time, have the easiest interface, and have least error incidence under the web navigation design to enhance old-aged users' web usability. Thus, developing a universal web navigation design can encourage people to be more involved with the internet.