• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.6
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• pp.495-504
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• 2014

Solar sail spacecrafts can gain propulsion using the momentum change through reflecting the photon packets of energy from the Sun. The sail slowly but continuously accelerates to accomplish a wide-range of potential missions. To develop the potential mission of the solar sail, the configuration, the film characteristics and the deployment devices should be carefully considered. In this paper, recent development and activities of the solar sail are introduced and design technology of the sail subsystem is investigated.

• Journal of KIISE:Information Networking
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• v.31 no.4
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• pp.384-392
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• 2004

Mobile contents service providers have some difficulties to timely and proper service deployment due to rapid development cycle of diverse portable devices with different capabilities. A way to resolve the problem is to introduce a mobile contents service paltform that can adapt original mobile contents to diverse devices dynamically and automatically. In this paper, we propose a mobile contents service platform based on active network mechanisms, called Mobile Content Adaptation Network(MobiCAN). The MobiCAN node provides effective service deployment, execution, and maintenance features and accommodates service layering and service customization capabilities for easy deployment. The basic functional units of the MobiCAN node are micro services with well-defined service interfaces and service layering features. For reliable services among the MobiCAN nodes, we design new distributed and robust Overlay Management Protocols(OMPs). As an example of practical MobiCAN applications, we finally describe Dynamic Contents Customization Proxy(DCCP) service.

• Proceedings of the Korea Information Processing Society Conference
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• 2023.05a
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• pp.101-103
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• 2023

With the recent advances in communication technology and Internet of Things (IoT) infrastructure, home automation systems have emerged as a new paradigm for providing users with convenient smart home services. The IoT ecosystem has merged digital systems with the physical world, dramatically changing the way people live and work. However, at the same time, security remains one of the most significant research issues in IoT, as the deployment and application of high-availability systems come with various security risks that cause serious threats to users. Among them, the security issues arising from the interaction among devices/applications should not be underestimated. Attackers can exploit interactions among devices/applications to hack into the user's home. In this paper, we present a survey of research on detecting various types of interactions among devices/applications in IoT.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.8
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• pp.726-736
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• 2012

This paper deals with Spin/Stall Recovery Parachute System from design to ground taxiing stage which would be deployed on the high speed taxi of turbo-prop airplane. In detail design phase, design parameters- riser length, parachute type, size, porosity, parachute canopy filling time, and deployment method- were considered based on the analytical disciplines such as aerodynamics, structures, and stability & control. Before the installation of Spin/Stall Recovery System of turbo-prop airplane, all control functions of this system were validated by the SBTB(System Breakout Test Box) in the laboratory. SBTB was used to confirm if it can detect faults, and simulate the firing of pyrotechnic devices that control the deployment and jettison of it. Once confirmed normal operation, deployment of parachute on the high speed taxiing were performed.

• Journal of Korea Multimedia Society
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• v.19 no.3
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• pp.595-602
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• 2016

With the evolution and development of many kinds of healthcare devices and techniques, u-health standards have emerged as a major issue. Yet, most legacy medical devices and systems are still being used without deployment of the standards. Therefore, it is required to support backward compatibility for u-health standard-compliant systems to communicate with legacy non-standard medical and healthcare devices. This paper proposes a new scheme to support backward compatibility of IEEE 11073 system by adding a codec module to IEEE 11073 agent. The codec converts data sent by non-standard health devices to IEEE 11073 MDER data. Plus, we implemented the proposed IEEE 11073 agent with an Intel Edison board which is one of popular open source H/W platforms. The IEEE 11073 manager of the proposed system can monitor and control legacy non-standard devices through the proposed agent system. In our experimental results, we examined the proposed system can support interoperability between u-health standard and non-standard devices and contribute to the growth and expansion of u-health services.

• International Journal of Internet, Broadcasting and Communication
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• v.12 no.3
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• pp.32-38
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• 2020

The deployment of geographically distributed wireless sensors has greatly elevated the capability of monitoring structural health in social-overhead capital (SOC) public infrastructures. This paper deals with the utilization of a distributed mobility management (DMM) approach for the deployment of wireless sensing devices in a structural health monitoring system (SHM). Then, a wireless sensing mechanism utilizing low-energy adaptive clustering hierarchy (LEACH)-based clustering algorithm for smart sensors has been analyzed to support the seamless data transmission of structural health information which is essentially important to guarantee public safety. The clustering of smart sensors will be able to provide real-time monitoring of structural health and a filtering algorithm to boost the transmission of critical information over heterogeneous wireless and mobile networks.

• Journal of electromagnetic engineering and science
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• v.10 no.4
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• pp.263-269
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• 2010

Multiple input multiple output (MIMO) has been considered one of the key enablers of broadband wireless communications. The indoor environment is known to be favorable to ensure both high rank property and high signal-to-interference/noise ratio (SINR) to fully exploit MIMO spatial multiplexing (SM) gain. In this paper, we describe several practical deployment cases where repeater links (or relay links), such as those present with an indoor distributed antenna system (DAS), can act as keyholes to degenerate the rank property of MIMO communications. In this case, we cannot exploit MIMO SM gain in indoor environment. We propose a novel MIMO communication scheme which uses simple converter in the devices in repeater links to resolve the rank degeneration issue and to ensure MIMO SM gain in highly MIMO-favorable indoor environment. MIMO SM is possible over the indoor DAS with single cable line through use of simple converters, which enables practical deployment in real fields.

• International Journal of Naval Architecture and Ocean Engineering
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• v.11 no.1
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• pp.256-273
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• 2019

Nowadays interceptors have been widely used in a vast range of high-speed crafts. In this study, the results of interceptor adeptness experiments made in Istanbul Technical University's Towing Tank are unveiled. The model was tested through three transverse locations of interceptors with six different deployment depths. For three locations, the interceptor was positioned transverse on the aft; close to chine, in the middle and close to the keel. The fourth interceptor was a full length of 13.00% LWL. The results show a significant drag reduction in benefits of 1.50%-11.30% for Fn 0.58-1.19 and the trim reduction was observed in between 1.60 and $4.70^{\circ}$. Besides, one of the most significant conclusions indicates that the effect of the interceptor decreases from keel to chine for the same blade deployment heights so the blades should be controlled separately at least in three parts from keel to chine area, if operable.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.9
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• pp.3120-3137
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• 2021

Small-sized IoT wireless sensing devices can be deployed with small aircraft such as drones, and the deployment of mobile IoT devices can be relocated to suit data collection with efficient relocation algorithms. However, the terrain may not be able to predict its shape. Mobile IoT devices suitable for these terrains are hopping devices that can move with jumps. So far, most hopping sensor relocation studies have made the unrealistic assumption that all hopping devices know the overall state of the entire network and each device's current state. Recent work has proposed the most realistic distributed network environment-based relocation algorithms that do not require sharing all information simultaneously. However, since the shortest path-based algorithm performs communication and movement requests with terminals, it is not suitable for an area where the distribution of obstacles is uneven. The proposed scheme applies a simple Monte Carlo method based on relay nodes selection random variables that reflect the obstacle distribution's characteristics to choose the best relay node as reinforcement learning, not specific relay nodes. Using the relay node selection random variable could significantly reduce the generation of additional messages that occur to select the shortest path. This paper's additional contribution is that the world's first distributed environment-based relocation protocol is proposed reflecting real-world physical devices' characteristics through the OMNeT++ simulator. We also reconstruct the three days-long disaster environment, and performance evaluation has been performed by applying the proposed protocol to the simulated real-world environment.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.10a
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• pp.261-264
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• 2008

IPv6 has been proposed and deployed to cater the shortage of IPv4 addresses. It is expected to foresee mobile phones, pocket PCs, home devices and any other kind of network capable devices to be connected to the Internet with the introduction and deployment of IPv6. This scenario will bring in more challenges to the existing network infrastructure especially in the network security area. Firewalls are the simplest and the most basic form of protection to ensure network security. Nowadays, firewalls' usage has been extended from not only to protect the whole network but also appear as software firewalls to protect each network devices. IPv6 and IPv4 are not interoperable as there are separate networking stacks for each protocol. Therefore, the existing states of the art in firewalling need to be reengineered. In our context here, we pay attention only to the IPv6 firewalls configuration anomalies without considering other factors. Pre-evaluation of security risk is important in any organization especially a large scale network deployment where an add on rules to the firewall may affect the up and running network. We proposed a new probabilistic based model to evaluate the security risks based on examining the existing firewall rules. Hence, the network administrators can pre-evaluate the possible risk incurred in their current network security implementation in the IPv6 network. The outcome from our proposed pre-evaluation model will be the possibilities in percentage that the IPv6 firewall is configured wrongly or insecurely where known attacks such as DoS attack, Probation attack, Renumbering attack and etc can be launched easily. Besides that, we suggest and recommend few important rules set that should be included in configuring IPv6 firewall rules.