• Korean Journal of Computational Design and Engineering
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• v.9 no.4
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• pp.277-285
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• 2004

In this paper, a 2 DOF haptic yawing joystick for use as the navigation input device in virtual environments is introduced. The haptic yawing joystick has 360° range for yawing motion and ±100° for pitching motion. The device can support weights of up to 26N for χ axis and 10N for axis with 10kHz of sampling rate. The size of the haptic yawing joystick is so small that it can be assembled on armrest of an arm chair and has relatively larger work space than other conventional 2 DOF joysticks. For the haptic yawing joystick, an ellipse navigation algorithm using the user's velocity in the virtual navigation is proposed. The ellipse represents the velocity of the user. According to the velocity of the navigator, the ellipse size is supposed to be changed. Since the path width of navigation environments is limited, the ellipse size is also limited. The ellipse navigation algorithm is tested in 2 dimensional virtual environments. The test results show that the average velocity of the navigation with the algorithm is faster than the average navigation velocity without the algorithm.

• Management Science and Financial Engineering
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• v.3 no.2
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• pp.1-27
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• 1997

Designing effective navigation aids for customer interfaces is critical for the success of cyber shopping malls. Navigation aids can be classified into either basic ones which are based on the structure of the malls or add-ons which are not. Add-on navigation aids provide various short-cuts to promote efficient traversal in the cyber shopping malls, but too many of them would increase the complexity of the customer interface. Metaphors have been used widely for the design of add-on navigation aids, but little research evaluates their impact on the processes and outcomes of customers behavior in cyber shopping malls. This paper presents an empirical study that investigates the navigation process of customers and the subjective evaluation of their shopping experience. This research implemented two versions of a test-bed cyber shopping mall according to different metaphors used; one based on a spatial metaphor, and the other based on a non spatial metaphor. The results of the experiment indicate that navigation aids based on the spatial metaphor were used more frequently, which resulted in better understanding about the entire structure of the cyber shopping malls, which in turn led to an increased ease of finding target items and also a more pleasant shopping experience. The benefits of navigation aids based on the spatial metaphor became more evident when customers were looking for ad-hoc category items rather than common items. This paper presents plausible explanations for the results and implications to the design of navigation aids for cyber shopping malls.

• Journal of the Korean Society of Marine Environment & Safety
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• v.21 no.3
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• pp.259-265
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• 2015

It is clearly understood that e-navigation is beneficial to prevent collision and grounding of ships. The purpose of this study is to define and present a future ship operation system under the e-navigation environment in order to provide clear direction for the design of Korean e-navigation system. The future ship operation system consists of shipboard navigational system, shore supporting system and maritime communication system. To achieve the objectives of this study, the ship operation system was discussed separately into SOLAS ships and non-SOLAS ships in this study. In SOLAS ships, mariners become a system manager, choosing system presets, interpreting system output, and monitoring vessel response. In small ships and fishing vessels, mariners may enjoy their navigation by using the automatic tracking of ship's position on the portable electronic chart display. The improved bridge design, integrated and harmonized navigational system and single window reporting will reduce significantly the administrative and physical workload of mariners. Mariners can concentrate their attention more on navigational duty under the e-navigation environment. To build an effective Korean e-navigation system, the essential navigational functions and e-navigation services for small ships and fishing vessels must be identified and developed taking into account user needs.

• Journal of Positioning, Navigation, and Timing
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• v.2 no.1
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• pp.41-48
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• 2013

When the ground subsystem of Ground Based Augmentation System(GBAS) is installed at the airport, the functions and performance of subsystem should be evaluated through ground and flight testing at the pre-commissioning phase. In the case of GBAS flight testing, it can be conducted by the existing flight check aircraft, but the GBAS ground testing requires the development of specially customized equipment to perform the ground testing. Therefore, this paper describes the preliminary design of GBAS onboard test equipment which can be independently used for the GBAS ground testing and flight testing on a car and an aircraft.

• International Journal of Ocean System Engineering
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• v.3 no.1
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• pp.44-48
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• 2013

This paper describes the design and implementation of a practical underwater positioning system, which is applicable for shallow water depth conditions. In this paper, two strategies are used to enhance the navigation performance. First, a low-cost acoustic-ranging-based precise navigation solution for shallow water is designed. Then, the outlier rejection algorithm is introduced by designing a velocity gate. The acoustic-ranging-based navigation is implemented by modifying the long base line solution. To enhance the tracking precision, the outlier rejection algorithm is introduced. The performance of the developed approach is evaluated using experiments. The results demonstrate that precise shallow water depth navigation can be implemented using the suggested approaches.

• Journal of Navigation and Port Research
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• v.32 no.7
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• pp.529-535
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• 2008

As a method to reduce collision accidents of ships at sea, this paper suggests an expert system for collision avoidance and navigation (hereafter "ESCAN"). The ESCAN is designed and developed by using the theory and technology of expert system and based on the information provided by AIS and RADAR/ARPA system. In this paper the ESCAN is composed of four(4) components; Facts/Data Base in charge of preserving data from navigational equipment, Knowledge Base storing production rules of the ESCAN, Inference Engine deciding which rules are satisfied by facts or objects, User System Interface for communication between users and ESCAN. The ESCAN has the function of real--time analysis and judgment of various encountering situations between own ship and targets, and is to provide navigators with appropriate plans of collision avoidance and additional advice and recommendation This paper, as a basic study, is to introduce the basic design and function of ESCAN.

• Journal of Positioning, Navigation, and Timing
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• v.5 no.1
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• pp.37-45
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• 2016

In this paper, design and implementation issues for a network-oriented RF emitter localization system with array antenna are discussed. For hardware, the problem of array mismatch and RF/IF channel mismatch are introduced and the calibration schemes for solving those problems are also provided. For software, it is explained how to overcome the drawback of conventional MUltiple Signal Identification and Classification (MUSIC) algorithm in a point of identifying the number of received signals and problems such as Data Association Problem and Ghost Node Problem in regard to multiple emitter localization are presented with some approaches for getting around those problems. Finally, for implementation, a criterion for arranging each of sensors and a requirement for alignment of array antenna' orientation are also given.

• Journal of Navigation and Port Research
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• v.32 no.1
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• pp.37-45
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• 2008

The research on an E-Navigation(E-Nav) strategy development has recently carried out by the IMO sub-committee on safety of navigation(NAV). The design of communication system architecture is a key factor in the E-Nav strategy development and it may drive the direction of a national R&D project on future navigational and marine communication systems. This study aims at designing a standard model of E-Nav communication network architecture, which enhances navigational safety and provides additional benefits in marine transportation. To achieve this purpose, authors have suggested E-Nav services, which are divided into five categories, i.e., safety and security, maritime meteorology, distress, business, and infotainment, by analyzing the related user requirements. As results, this paper proposes the E-Nav communication network architecture that consists of the navigation and communication equipments.

• Journal of Positioning, Navigation, and Timing
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• v.1 no.1
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• pp.35-43
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• 2012

The UGV is one of the special field robot developed for mine detection, surveillance and transportation. To achieve successfully the missions of the UGV, the accurate and reliable navigation data should be provided. This paper presents design and implementation of multi-sensor-based open architecture integrated navigation for localization of UGV. The presented architecture hierarchically classifies the integrated system into four layers and data communications between layers are based on the distributed object oriented middleware. The navigation manager determines the navigation mode with the QoS information of each navigation sensor and the integrated filter performs the navigation mode-based data fusion in the filtering process. Also, all navigation variables including the filter parameters and QoS of navigation data can be modified in GUI and consequently, the user can operate the integrated navigation system more usefully. The conventional GPS/INS integrated system does not guarantee the long-term reliability of localization when GPS solution is not available by signal blockage and intentional jamming in outdoor environment. The presented integration algorithm, however, based on the adaptive federated filter structure with FDI algorithm can integrate effectively the output of multi-sensor such as 3D LADAR, vision, odometer, magnetic compass and zero velocity to enhance the accuracy of localization result in the case that GPS is unavailable. The field test was carried out with the UGV and the test results show that the presented integrated navigation system can provide more robust and accurate localization performance than the conventional GPS/INS integrated system in outdoor environments.

• Journal of Digital Contents Society
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• v.8 no.1
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• pp.93-106
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• 2007

Web Applications are rapidly increasing and the structure becomes very complicated. However, when users explore such complex Web applications, they cannot often grasp the current location and get the information that they want. Therefore, a novel approach to model the navigation of Web application contents is required. In this study, a framework has been presented for modeling adaptive context-based contents navigation of Web applications. The framework performs activities including navigation analysis, navigation design, and navigation realization. first, in navigation analysis domain is analyzed by using use case, focusing on navigation. Next, in navigation design three models have been produced: a navigation information model, a profile, and a navigation interface model. Finally, in navigation realization a Webpage navigation model and a component navigation model have been produced. In this work, several formal definitions and rules for checking validity of navigation model have also been provided.