• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.8
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• pp.13-18
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• 2016

In Internet of Things (IoT) environment, a variety of smart devices are connected to Internet through various network technologies such as 4G/5G, WiBro, Bluetooth, etc. in order to provide the remote monitoring service such as smart healthcare service, etc. Most standard mobility management protocols based on IETF Mobile IP may not be suitable for Internet of Things (IoT) environments due to constrained power, constrained CPU processing and memory capacity, and large signalling overhead which are inherently accompanied by various devices in IoT environments. In this article, we propose a new mobility management protocol CoMP (CoAP-based Mobility Managemenbt Protocol) for reliable mobility management in IoT environments. The architecture and algorithm to achieve both reliability and simplicity for IoT mobility management are proposed. Finally, performance has been evaluated by both mathematical analysis and simulation.

• Journal of KIISE
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• v.42 no.6
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• pp.807-816
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• 2015

The Internet of Things (IoT) has recently been showered with much attention worldwide. Various kinds of devices, communicating with each other in the IoT, demand multiple communication technologies to coexist. In this environment, mobile devices may utilize the vertical handover between different wireless radio interfaces such as Wi-Fi and Bluetooth, for efficient data transfer. In this paper, an IoT broker is implemented to support the vertical handover, which can also support and manage heterogeneous devices and communication interfaces. The handover is activated based on RSSI, Link Quality values, and real time traffic. The experimental results show that the proposed handover system substantially improves QoS in Bluetooth and reduces power consumption in mobile devices as compared with a system using only Wi-Fi.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.7 no.2
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• pp.199-208
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• 2017

IoT, Cloud, Bigdata, Mobile, AI, and 3D print, which are called as the main axis of the 4th Industrial Revolution, can be predicted to be changed when the technology is applied to the military. Especially, when I think about the purpose of battle, I think that IoT, Cloud, Bigdata, Mobile, and AI will play many role. Therefore, in this paper, Smart Military is defined as the future military that incorporates these five technologies, and the architecture is established and the appropriate information security model is studied. For this purpose, we studied the existing literature related to IoT, Cloud, Bigdata, Mobile, and AI and found common elements and presented the architecture accordingly. The proposed architecture is divided into strategic information security and tactical information security in the Smart Military environment. In the case of vulnerability, the information security is divided into strategic information security and tactical information security. If a protection system is established, it is expected that the optimum information protection can be constructed within an effective budget range.

• Annual Conference of KIPS
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• 2017.04a
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• pp.618-620
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• 2017

Currently, IoT mobile applications are growing fast in number and complexity. As a result, the applications quality issue became crucial, hence to ensure their quality a proper testing is highly required. Testing such mobile applications is always tedious, time-consuming and expensive. To cope with these issues, we propose a testing approach using activity diagram with data flow information. The main functionality of IoT applications is exposing the meaningful data obtained from the sensors to the users by doing a lot of analysis, comparison, and computation. Therefore, our focus is on identifying and selecting the most appropriate paths at which calculation is taking place and the paths at which predicate exists. In our case study, we have used a real-world IoT mobile application and identified a total of ten test paths with two predicate uses and two computation uses through an example. With applying only this four critical paths, we can adequately test the application's core functionalities while significantly reduce the testing effort and cost.

• Journal of Korea Game Society
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• v.20 no.3
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• pp.35-44
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• 2020

In this study, we propose a reliable command placement recognition algorithm using tangible commands blocks developed for our coding puzzle platform, and present its performance measurement results on an Augmented Reality testbed environment. As a result, it can recognize up to 30 tangible blocks simultaneously and their placements within 5 seconds reliably. It is successfully ported to an existing coding puzzle mobile app and can operate an IoT attached robot via bluetooth connected mobile app.

• Journal of Convergence for Information Technology
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• v.9 no.6
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• pp.13-18
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• 2019

This paper proposes efficient and secure two-way authentication protocol for binding update messages between mobile devices and home agents / correspondent nodes in IoT and Mobile IPv6 (MIPv6) environments with limited computing power and resources. Based on the MIPv6 message exchange, the proposed protocol satisfies both the authentication and the public key exchange optimized for both sides of the communication with minimum modification. In the future, we will carry out a performance analysis study by implementing the proposed protocol in detail.

• ETRI Journal
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• v.44 no.3
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• pp.389-399
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• 2022

Wireless sensor networks (WSNs) are one of the basic building blocks of Internet of Things (IoT) systems. However, the wireless sensing nodes in WSNs suffer from energy constraint issues because the replacement/recharging of the batteries of the nodes tends to be difficult. Furthermore, a number of realistic IoT scenarios, such as habitat and battlefield monitoring, contain mobile sensing elements, which makes the energy issues more critical. This research paper focuses on realistic WSN scenarios that involve mobile sensing elements with the aim of mitigating the attendant energy constraint issues using the concept of radio-frequency (RF) energy extraction. The proposed technique incorporates a cluster head election workflow for WSNs that includes mobile sensing elements capable of RF energy harvesting. The extensive simulation analysis demonstrated the higher efficacy of the proposed technique compared with the existing techniques in terms of residual energy, number of functional nodes, and network lifetime, with approximately 50% of the nodes found to be functional at the 4000th, 5000th, and 6000th rounds for the proposed technique with initial energies of 0.25, 0.5 and 1 J, respectively.

• KIPS Transactions on Computer and Communication Systems
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• v.10 no.11
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• pp.291-296
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• 2021

The development of the Internet of Things(IoT) requires large computational resources for tasks from numerous devices. Mobile Edge Computing(MEC) has attracted a lot of attention in the IoT environment because it provides computational resources geographically close to the devices. Task offloading to MEC servers is efficient for devices with limited battery life and computational capability. In this paper, we assumed an industrial IoT environment requiring high reliability. The complexity of optimization problem in industrial IoT environment with many devices and multiple MEC servers is very high. To solve this problem, the problem is divided into two. After selecting the MEC server considering the queue status of the MEC server, we propose an offloading decision algorithm that optimizes reliability and energy consumption using genetic algorithm. Through experiments, we analyze the performance of the proposed algorithm in terms of energy consumption and reliability.

• Annual Conference of KIPS
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• 2019.05a
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• pp.219-222
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• 2019

IoT 기술이 발달하면서 기기들 간의 안전한 통신을 위한 보안 시스템 탑재의 필요성이 대두되었다. 보안 시스템은 암호 키의 안전성과 밀접한 관련이 있기 때문에, 안전한 난수발생기를 통해 생성한 난수를 키로 사용하는 것이 중요하다. 그러나 제한된 리소스를 갖는 IoT 기기들의 특성으로 인해, 기존 난수발생기를 IoT 기기에 구현하기 어려운 문제가 있다. 이에 IoT 기기에서 사용 가능한 난수발생기에 대한 연구들이 진행되어 왔으며, 특히 IoT 기기들이 탑재하고 있는 각종 센서를 활용한 난수발생기의 설계 방안들이 활발히 연구되고 있다. 본 논문에서는 IoT 기기에 주로 탑재되는 센서를 5가지로 분류하고, 각각의 센서별로 난수성을 측정하는 연구들을 분석한다. 우리가 조사한 바에 따르면 이러한 센서들의 출력이 충분한 난수성을 제공하고 있으며, 본 논문에서 각 센서들을 활용하여 난수발생기를 설계한 연구들을 분류하고 특징을 살펴본다.

• Annual Conference of KIPS
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• 2021.05a
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• pp.202-204
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• 2021

다양한 IoT 기기로 구성된 모바일 IoT 환경에서는 IoT에서 수집된 데이터가 다른 IoT의 학습 데이터로 사용되는 순환 구조로 이루어져 있다. 따라서 해당 환경에서 데이터는 공유되는 자원이며 매우 중요한 요소이다. 특히 IoT 기기가 밀집된 지역에서는 많은 트래픽이 발생하기 때문에 전송지연 및 데이터 손실로 인한 시스템 성능이 저하되는 문제가 발생한다. 따라서 본 논문에서는 안전한 데이터 통신을 위한 블록체인 기반의 시스템 구조를 제안한다. 해당 시스템은 블록체인을 사용하여 IoT 기기의 이동성과 밀집도를 판별하고, 트래픽 밀집 구역이 발생하였을 경우 UAV를 활용하여 통신이 원활하게 이루어질 수 있도록 한다.