• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.5
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• pp.2103-2123
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• 2018

Ships built today are larger in scale and feature more complex structures. The ever-evolving systems used on board a ship require vast amounts of data processing. In the future, with the advent of smart ships, unmanned ships and other next-generation ships, the volumes of data to be processed will continue to increase. Yet, to date, ship data has been processed using wired networks. Placed at fixed locations, the nodes on wired networks often fail to process data from mobile devices. Despite many attempts made to use Wi-Fi on ships just as on land to create wireless networks, Wi-Fi has hardly been available due to the complex metal structures of ships. Therefore, Wi-Fi on ships has been patchy as the ship-wide total Wi-Fi coverage has not properly implemented. A new ship-wide wireless network environment is part of the technology conducive to the shipbuilding industry. The wireless network environment should not only serve the purpose of communication but also be able to manage and control multiple features in real-time: fault diagnostics, tracking, accident prevention and safety management. To better understand the characteristics of wireless frequencies for ships, this paper tests the widely used TETRA, UHF and Wi-Fi and sheds light on the features, advantages and disadvantages of each technology in ship settings. The proposed deployment of a Super Wi-Fi network leveraging the legacy UHF system of TMS generates a ship-wide wireless network environment. The experimental findings corroborate the feasibility of the proposed ship-wide Super Wi-Fi network environment.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.11 no.4
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• pp.34-50
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• 2012

This study set out to define a communication environment between an ITS center and field device required to be introduced in the nation in order to guarantee the interoperability, compatibility, and global competitiveness of communication between them in the nation. It also aimed to establish technical and policy plans for its introduction, develop an emulator for information exchange, and apply VMS by way of showing an example, thus testing its validity. First, a standard environment for information exchange between an ITS center and field device required to be introduced in the nation was defined as a dual protocol between DATEX and SNMP. The study also proposed a message definition system including meta-attribution definition and OID introduction. The study then suggested technical and policy plans for its introduction including securing enough feasibility with feedback through a model project of standard introduction, offering education and promotions for the standard in advance, providing methods to introduce and systematically manage OID, developing a hardware standard proper for the information exchange standard, and setting up an integrated management system to introduce a dual protocol.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.18 no.5
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• pp.19-33
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• 2019

There have been enormous efforts to develop an innovative public transport bus service for enhancing its operational efficiency based on Automated Vehicle(AV). However, since the vehicle operating environment in the public transport system varies with the purpose and method of mobility service, it is necessary to preferentially evaluate the current roadworthiness for an effective way to introduce the AV. Therefore, this study classified and redefined AV-based mobility service based on literature reviews. This research conducted the roadworthiness test for checking the feasibilities of the AV-based mobility services. Furthermore, we suggested some deployment strategies of the AV-based mobility service considering the Level-Of-Service (LOS) of road infrastructure based on the results of roadworthiness tests. The proposed direction would have a great potential to introduce the AV-based public transport system in the near future.

• Journal of Science and Technology Studies
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• v.18 no.3
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• pp.255-289
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• 2018

The social problem-solving R&D is different from the goal and process in comparison with research aimed at scientific excellence and industrial innovation. It pursues social values and active participation of the end-user civil society. In this study, we try to derive its characteristics by analyzing the cases that are evaluated as successful social problem solving R&D project. In order to analyse the social problem-solving R & D case, these four variables are selected; 1) social and technological planning for problem solving 2) participatory technological development 3) law, system and delivery system development for innovation deployment 4) scale-up of new R&D process. Those are important issues identified through case studies: 1) the tools and support services needed to carry out social and technical planning effectively, 2) the role of the Living Lab to coordinate opinions with experts and users, 3) the legislative and institutional improvement activities as important as technological development, 4) researcher's change through interaction with end user.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.7 no.3
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• pp.79-94
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• 1997

OMG (Object Management Group) published a security service specification, called CORBA (Common Object Request Broker Architecture) security reference model because the integration of security and object-oriented techniques was critical for successful deployment of distributed object systems. The CORBA security reference model treats access control as an implementation independent semantic concept but has incomplete semantics of the access control function. Because of such imcompleteness it is difficult for the system administrator and the CORBA security implementor to have the same understanding for the meaning of access control in the CORBA security. We propose a formal model for access control the CORBA security using the formal description language, which is called Z language based on typed set theory. The proposed model provides concrete semantics of the access control function to both the system administrator and the implementor.

• Journal of Aerospace System Engineering
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• v.16 no.6
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• pp.123-128
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• 2022

This paper proposes a non-explosive separation device for the deployable SAR antenna. This device utilises a Ni-Cr wire to restrain the antenna's belt mechanism, and joule-heating is used to minimise the impact of deployment. After the Ni-Cr wire has been cut, the device is deployed through the preload of the belt mechanism. Considering the design load(99g) and preload conditions, FEM analysis for AL7050 and Ti was performed. This analysis revealed that the amount of deformation for AL7050 was 0.256 mm with a margin of +0.09. In addition, by performing orbital thermal analysis, the temperature distribution for AL7050 in the worst cold case is confirmed as -50 to +2℃ and -10 to +90℃ in the worst hot case. This analysis confirmed that the separation device would remain stable even in the worst environment.

• International Journal of Aerospace System Engineering
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• v.9 no.2
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• pp.1-9
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• 2022

The NEA release mechanism is used to provide restraint and release functions with low shock for critical deployment operations on solar arrays after launch. The GK3 solar array consists of 2 wings and 6 hold down points per panel. The NEA SSD9103S1 is a part of the GK3 solar array hold-down and release mechanism. Each NEA unit is equipped with two Z-diodes which provide power to a NEA unit connected in series after actuation of the fuse wire. This paper presents the hot firing test results of a quadrature NEA SSD9103S1 configuration. One output powers a maximum of 4 NEA SSD9103S1 units simultaneously. The necessary actuation pulse duration has been determined to meet margin requirement for thermal energy of minimum 4. Actuation thermal energy difference is about 6.6% between each half of two fired serial NEAs. Thermal energy margin at worst case is minimum 5.9 in case of an actuation pulse duration of 500 ms. Two series Zener impedance depend on current applied has been characterized by an additional actuation after all fuse wires are open circuit. Total number of actuation commands to the GK3 NEA unit reduce drastically from 24 in case of single NEA configuration down to 8 in case of parallel and quadrature NEA configurations. It can be accommodated by the existing HP2U Pyro design without any impact.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.6
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• pp.1105-1112
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• 2022

Field data monitoring systems such as renewable energy generation and smart farm integrated control are developing from PC and server to mobile first, and various wireless communication and application services have emerged with the development of IoT technology. Low-power wide-area networks are services optimized for low-power, low-capacity, and low-speed data transmission, and data collected in the field is transmitted to designated storage servers or cloud-based data platforms, enabling data monitoring. In this paper, we implement an IoT repeater that collects field data with a single device and transmits it to a wireless carrier cloud data flat using a low-power wide-area network, and a monitoring app using it. Using this, the system configuration is simpler, the cost of deployment and operation is lower, and effective data accumulation is possible.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.928-934
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• 2009

Although the evolution and deployment of information technologies will undoubtedly play an important role in the current construction industry, many engineers are still unsure of the economic value of using these technologies. Especially for the planning of a construction project, a collaboration system to utilize the whole resources is a essential tool for the successful outcome. A detailed, authoritative, and readily accessible information model is needed to enable engineers to make cost-effective decisions among established and innovative plan alternatives. Most engineers rely on limited private experiences when they create solutions or design alternatives. Initial planning is crucial for the success of the construction project. Most construction projects are done through collaboration of engineers who have different specialized knowledge. Information technologies can dramatically enhance the performance of the collaboration. For the information delivery, we need a mediator between engineers. Object-based 3-D models are useful for the communication and decision assistance for the intelligent project design. In this paper, basic guidelines for the 3-D design according to different construction processes are suggested. Adequate interoperability of 3-D objects from any CAD system is essential for the collaboration. Basic architectures of geometry models and their information layer were established to enable interoperability for design checks, estimation and simulation. A typical international project for roadway was chosen for the pilot project. 3-D GIS model was created and bridge information models were created considering several requirements for planning and decision making of the project. From the pilot test, the integrated construction project planning using 3-D information models was discussed and several guidelines were suggested.

• Journal of Internet Computing and Services
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• v.25 no.1
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• pp.137-146
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• 2024

drones are used in a variety of fields, including business, leisure, lifesaving, and war. Various research using drones is being conducted in the military. In particular, the use of drones in 『Manned-Unmanned Complex combat performance plan』, powered by various unmanned vehicles deployed in the Army TIGER system, is expected to be a major factor realizing the Army's future combat performance that minimizes damage to ally combat troops while causing maximum damage to the enemy. As the deployment of various systems progresses, combat performance methods utilizing each system are evolving, but there is a lack of research to identify and resolve limitations in the perspective of unmanned vehicle operators. Based on the Ukrainian military's FPV drone combat case, we would like to make suggestions from the operator's perspective on overcoming perspective limitations through the introduction of FPV and the designation of military drone frequency.