• Journal of Korean Society of Industrial and Systems Engineering
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• v.41 no.4
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• pp.138-145
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• 2018

In the field of optimization, many studies have been performed on various types of Vehicle Routing Problem (VRP) for a long time. A variety of models have been derived to extend the basic VRP model, to consider multiple truck terminal, multiple pickup and delivery, and time windows characteristics. A lot of research has been performed to find better solutions in a reasonable time for these models with heuristic approaches. In this paper, by considering realtime traffic characteristics in Map Navigation environment, we proposed a method to manage realistic optimal path allocation for the logistics trucks and cargoes, which are dispersed, in order to realize the realistic cargo mixing allowance and time constraint enforcement which were required as the most important points for an online logistics brokerage service company. Then we developed a prototype system that can support above functionality together with delivery status monitoring on Map Navigation environment. First, through Map Navigation system, we derived information such as navigation-based travel time required for logistics allocation scheduling based on multiple terminal multiple pickup and delivery models with time constraints. Especially, the travel time can be actually obtained by using the Map Navigation system by reflecting the road situation and traffic. Second, we made a mathematical model for optimal path allocation using the derived information, and solved it using an optimization solver. Third, we constructed the prototype system to provide the proposed method together with realtime logistics monitoring by arranging the allocation results in the Map Navigation environment.

• Journal of Positioning, Navigation, and Timing
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• v.1 no.1
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• pp.29-34
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• 2012

A software GNSS signal generator for the GPS L1/L2/L5 and Galileo E1/E5 signals is proposed in this paper. And this signal generator is designed and implemented with several components by considering the reuse and expansion of components for similar GNSS signals. The characteristics of the reusability of the components are confirmed with the carrier generation and the band-pass filter components. And the functionality of the GNSS multi-band IF signal generator is validated by using the commercial software GPS L1 receiver, and the performance of signal acquisition, tracking and accuracy of horizontal position error are analyzed for this validation. As a result, the GPS L1 signal generator operates successfully and it could be expected that other signal generators also operate well because most of components are the same as those of the GPS L1 signal generator.

• Journal of Advanced Marine Engineering and Technology
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• v.35 no.5
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• pp.647-653
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• 2011

In vessels, various communication systems are now working with different vendor-specific ways, which are apt to cause the inter-operability problems. That, of course, leads to needs of standardization of communication network systems for vessels. The e-navigation system introduced by IMO also takes the standardization process as expected. In this paper, a 4S multiple media communication switching server for seamless communications among existing media for vessels is introduced, and the development of a information exchange software for the sever and its functionality verification results are presented as well.

• Journal of Internet Computing and Services
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• v.10 no.6
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• pp.191-203
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• 2009

Simulation is the work that identifies the characteristics of some problem through the simulated experiments. During the experiments it is frequently required to change or replace the simulation models, algorithms, or input/output data. Especially, in the case of the simulation works performed by replacing algorithms, if a replaceable component that implements a specific algorithm is not correct with respect to its functionality it is very difficult to carry out the simulation works successfully. In this paper, we suggest a test framework that verifies functional correctness of the replaceable component in the software-based GNSS (Global Navigation Satellite System) simulation environments. When a component is replaced, this framework enables us to properly execute the functional test for the component according to its context.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2023.11a
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• pp.192-193
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• 2023

The International Association of Navigational Aids to Navigation (IALA) utilizes the S-200 standard model and test data for product specification development and validation related to generating datasets compliant with the S-201 data format. Currently, they are focusing on improving the S-200 testbed DB performance and extending the IALA Questionnaire survey functionality. In this study, we investigate the design and implementation of features required to manage additional questionnaires in the S-200 testbed.

• Smart Structures and Systems
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• v.24 no.3
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• pp.403-414
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• 2019

Offshore drilling has become a key process for obtaining oil. Offshore platforms have many applications, including oil exploration and production, navigation, ship loading and unloading, and bridge and causeway support. However, vibration problems caused by severe environmental loads, such as ice, wave, wind, and seismic loads, threaten the functionality of platform facilities and the comfort of workers. These concerns may result in piping failures, unsatisfactory equipment reliability, and safety concerns. Therefore, the vibration control of offshore platforms is essential for assuring structural safety, equipment functionality, and human comfort. In this study, an optimal multiple tuned mass damper (MTMD) system was proposed to mitigate the excessive vibration of a three-dimensional offshore platform under ice and earthquake loadings. The MTMD system was designed to control the first few dominant coupled modes. The optimal placement and system parameters of the MTMD are determined based on controlled modal properties. Numerical simulation results show that the proposed MTMD system can effectively reduce the displacement and acceleration responses of the offshore platform, thus improving safety and serviceability. Moreover, this study proposes an optimal design procedure for the MTMD system to determine the optimal location, moving direction, and system parameters of each unit of the tuned mass damper.

• Journal of Advanced Navigation Technology
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• v.18 no.2
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• pp.128-133
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• 2014

This paper is the study of BNWAS based on TLC. The functionality of BNWAS and its operations are investigated through its international standard. But the BNWAS to be used currently in the ship have difficulty in monitoring. Several kinds of data are generated from many equipments in BNWAS, such as NMEA-0183 data or NMEA-2000. Although these data are mainly used for the safe navigation of ship, their usability may be enhanced if they are managed to control the BNWAS equipment with sensors. The purpose of this system is prevent the marine accidents on sailing voyages due to drowsiness of watchers. On Night sailing, watcher is collected the navigation information from multiple devices and he determines the safe operation of the ship through continuous monitoring.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2016.05a
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• pp.18-19
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• 2016

At Present, Korea government run the 38 points manned lighthouse, the change of Manned lighthouse that manager live is inevitable in orger to enhanced features as aids to navigation and provide a fore efficient management system. There are "Enhancing management system for Manned Lighthouses" four standards(Function of AtoN, Functionality of wide area management, National policy, Marine culture) for evaluation of Unmanned Lighthouses. After collecting these datas, analyzing it, applying AHP and Likert Scale, we choose base manned lighthouses for shorten restoration time that can manage AtoN far from regional office of Oceans & Fisheries. This paper will support efficient management system for AtoN that were scattered in sea of korea and improvement living environment for lighthouse keepers.

• The Journal of Korea Robotics Society
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• v.6 no.3
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• pp.237-246
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• 2011

Robots have been used in many fields due to its performance improvement and variety of its functionality, to the extent which robots can replace human tasks. Individual feature and better performance of robots are expected and required to be created. As their performances and functions have increased, systems have gotten more complicated. Multi mobile robots can perform complex tasks with simple robot system and algorithm. But multi mobile robots face much more complex driving problem than singular driving. To solve the problem, in this study, driving algorithm based on the energy method is applied to the individual robot in a group. This makes a cluster be in a formation automatically and suggests a cluster the automatic driving method so that they stably arrive at the target. The energy method mentioned above is applying attractive force and repulsive force to a special target, other robots or obstacles. This creates the potential energy, and the robot is controlled to drive in the direction of decreasing energy, which basically satisfies lyapunov function. Through this method, a cluster robot is able to create a formation and stably arrives at its target.

• Journal of Information Processing Systems
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• v.9 no.4
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• pp.548-566
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• 2013

The availability of technology and the abundance of experts in universities create an ample opportunity to provide a venue that allows a knowledge seeker to easily connect with and request advice from university experts. On the other hand, outsourcing provides opportunities and remains one of the emerging trends in organizations, and can very clearly observed in the Philippines. This paper describes the development of a reliable web-based approach to Knowledge Product Outsourcing (KPO) services in the Silliman Online University Learning system. The system is called an "e-Knowledge Box."It integrates Web 2.0 technologies and mechanisms, such as instant messaging, private messaging, document forwarding, video conferencing, online payments, net meetings, and social collaboration together into one system. Among the tools used are WAMP Server 2.0, PHP, BlabIM, Wordpress 3.0, Video Whisper, Red5, Adobe Dreamweaver CS4, and Virtual Box. The proposed system is integrated with the search engine in URLs, Web feeds, email links, social bookmarking, search engine sitemaps, and Web Analytics Direct Visitor Reports. The site demonstrates great web usability and has an excellent rating in functionality, language and content, online help and user guides, system and user feedback, consistency, and architectural and visual clarity. Likewise, the site was was rated as being very good for the following items: navigation navigation, user control, and error prevention and correction.