• 한국정밀공학회지
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• 제18권5호
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• pp.29-33
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• 2001

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권4호
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• pp.1941-1960
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• 2019

Unmanned aerial vehicles (UAVs), acting as mobile base stations (BSs), can be deployed in the typical fifth-generation mobile communications (5G) scenarios for the purpose of substantially enhancing the radio coverage. Meanwhile, UAV aided underlay device-to-device (D2D) communication mode can be activated for further improving the capacity of the 5G networks. However, this UAV aided D2D communication system is more vulnerable to eavesdropping attacks, resulting in security risks. In this paper, the D2D receivers work in full-duplex (FD) mode, which improves the security of the network by enabling these legitimate users to receive their useful information and transmit jamming signal to the eavesdropper simultaneously (with the same frequency band). The security communication under the UAV coverage is evaluated, showing that the system's (security) capacity can be substantially improved by taking advantage of the flexible radio coverage of UAVs. Furthermore, the closed-form expressions for the coverage probabilities are derived, showing that the cellular users (CUs)' secure coverage probability in downlink transmission is mainly impacted by the following three factors: its communication area, the relative position with UAV, and its eavesdroppers. In addition, it is observed that the D2D users or DUs' secure coverage probability is relevant to state of the UAV. The system's secure capacity can be substantially improved by adaptively changing the UAV's position as well as coverage.

• 디지털산업정보학회논문지
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• 제10권3호
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• pp.49-59
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• 2014

The Internet of Things(IoT) is a new promising technology made from a variety of technology. The IoT links the objects or people, then enabling anytime, anywhere connectivity for anything and not only for anyone. Social networking services have changed the way people communicate. Recently, new research challenges in many areas of Internet of things and social networking services are fired. In this paper, we propose things recommendation method using social relationship in social Internet of Things. We study previous researches about social network service, IoT, and social IoT. We proposed SIoT_FW(Social IoT Friendship Weight) using static and a dynamic social friendship weight. Also, our method considers four social relationships (Ownership Object Relationship, Co-Location Object Relationship, Social Object Relationship, Parental Object Relationship). We presents a music device scenario using our proposed method.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권5호
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• pp.1984-2002
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• 2020

With the appearance of wireless spectrum crisis in traditional cellular network, device-to-device (D2D) communication has been regarded as a promising solution to ease heavy traffic burden by enabling precise content delivery among mobile users. However, due to the channel sharing, the interference between D2D and cellular users can affect the transmission rate and narrow the throughput in the network. In this paper, we firstly present a weighted interference minimization cluster formation model involving both social attribute and physical closeness. The weighted-interference, which is evaluated under the susceptible-infected(SI) model, is utilized to gather user in social and physical proximity. Then, we address the cluster formation problem via spectrum clustering with iterative operation. Finally, we propose the stable matching theory algorithm in order to maximize rate oriented to accomplish the one-to-one resource allocation. Numerical results show that our proposed scheme acquires quite well clustering effect and increases the accumulative transmission rate compared with the other two advanced schemes.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권2호
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• pp.846-864
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• 2017

Software Defined Network (SDN) realizes management and control over the underlying forwarding device, along with acquisition and analysis of network topology and flow characters through south bridge protocol. Data path Identification (DPID) is the unique identity for managing the underlying device, so forged DPID can be used to attack the link of underlying forwarding devices, as well as carry out DoS over the upper-level controller. This paper proposes a dynamic defense method based on Client-Puzzle model, in which the controller achieves dynamic management over requests from forwarding devices through generating questions with multi-level difficulty. This method can rapidly reduce network load, and at the same time separate attack flow from legal flow, enabling the controller to provide continuous service for legal visit. We conduct experiments on open-source SDN controllers like Fluid and Ryu, the result of which verifies feasibility of this defense method. The experimental result also shows that when cost of controller and forwarding device increases by about 2%-5%, the cost of attacker's CPU increases by near 90%, which greatly raises the attack difficulty for attackers.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제6권3호
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• pp.886-905
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• 2012

Set-top Box (STB) has evolved from being a device just sitting on top of a TV shelf to a device providing a gateway to the Internet for a home network, receiving services from multiple content providers, and enabling and ensuring Quality of Service (QoS) for the streaming media. IP Multimedia Subsystem (IMS), with its promise to provide a converged access network for multimedia service delivery (such as Triple play & Quadruple play services), has to guarantee QoS support. To enable QoS in IMS-based networks, we have designed a set-top box which provides feedback to the service provider to ensure end-to-end QoS. Our set-top box is designed to provide virtual platforms such that it can support multiple service providers. Each service provider is able to manage its own multimedia streams and ensures the desired network performance for each flow. The set-top box also works as a Home Gateway and provides end-to-end QoS support to the client nodes.

• 한국인터넷방송통신학회논문지
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• 제24권3호
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• pp.49-53
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• 2024

해양 안전은 바다에서의 사고로부터 인명을 보호하고, 보다 안전한 해양 환경을 조성하는 데 중요한 요소다. 본 연구에서는 해양 안전을 향상시키기 위한 TPMS 디바이스를 개발하고, 이를 통해 바다에서의 사고 상황을 감지하고 신속한 대응을 가능케 하는 기술적 솔루션을 제시한다. 이를 위해 개발한 튜브 압력 측정 시스템(TPMS)을 활용하여 튜브의 팽창을 감지하고, 실시간으로 데이터를 수집하여 주변 기기와 통신함으로써 빠른 대응이 가능하도록 설계되었다. 실험 결과를 통해 TPMS(Tube Pressure Monitoring System)가 효과적으로 압력을 감지하고, Main IoT 디바이스와 통신하며 안정적인 데이터 송수신이 가능함을 확인하였다. 또한 비상 상황에 빠르게 대응할 수 있도록 비상 상황 알림 메시지를 수신하고 정보를 조회할 수 있는 모바일 앱을 개발하였다. 개발한 디바이스와 모바일 앱은 해양 안전 분야뿐만 아니라 다양한 응용 분야에서도 활용 가능한 기술을 포함하고 있으며, 향후에는 실제 현장에서의 적용 가능성을 확대할 것이다. 이러한 결과는 해양 환경의 안전성을 높이는 데 기여할 것으로 기대된다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권6호
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• pp.2104-2117
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• 2014

The propagation of smart devices and the rapid expansion of wireless mobile networks have increased the need for ubiquitous device connectivity and contents access. DLNA is currently being used as the de facto standard for connectivity of consumer devices in the digital home. The guidelines provided by DLNA are intended to facilitate device and contents discovery, management, sharing and distribution. However, consumer experience with DLNA has been rather poor and usability not up to speed. Different problems and issues in limited compatibility have been reported due to manufacturer customizations. Such compatibility issues are often difficult to identify by average consumers who are not savvy in information communications and multimedia technology. In this paper, the design and implementation of a DLNA protocol inspection tool is presented for compatibility analysis among DLNA certified devices. The tool monitors the home network and performs analysis of the underlying protocols used by DLNA. The tool can be used for diagnostics and troubleshooting, enabling the user to identify compatibility issues between devices or problems in the network.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권2호
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• pp.514-535
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• 2019

Information-centric networks operate under the assumption that all network components have built-in caching capabilities. Integrating the caching strategies of information centric networking (ICN) with wireless virtualization improves the gain of virtual infrastructure content caching. In this paper, we propose a framework for software-defined information centric virtualized wireless device-to-device (D2D) networks. Enabling D2D communications in virtualized ICN increases the spectral efficiency due to reuse and proximity gains while the software-defined network (SDN) as a platform also simplifies the computational overhead. In this framework, we propose a joint virtual resource and cache allocation solution for latency-sensitive applications in the next-generation cellular networks. As the formulated problem is NP-hard, we design low-complexity heuristic algorithms which are intuitive and efficient. In our proposed framework, different services can share a pool of infrastructure items. We evaluate our proposed framework and algorithm through extensive simulations. The results demonstrate significant improvements in terms of visiting latency, end user QoE, InP resource utilization and MVNO utility gain.

• International Journal of Internet, Broadcasting and Communication
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• 제16권3호
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• pp.212-220
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• 2024

A recently the advancement of society, AI technology has made significant strides, especially in the fields of computer vision and voice recognition. This study introduces a system that leverages these technologies to recognize users through a camera and relay commands within a vehicle based on voice commands. The system uses the YOLO (You Only Look Once) machine learning algorithm, widely used for object and entity recognition, to identify specific users. For voice command recognition, a machine learning model based on spectrogram voice analysis is employed to identify specific commands. This design aims to enhance security and convenience by preventing unauthorized access to vehicles and IoT devices by anyone other than registered users. We converts camera input data into YOLO system inputs to determine if it is a person, Additionally, it collects voice data through a microphone embedded in the device or computer, converting it into time-domain spectrogram data to be used as input for the voice recognition machine learning system. The input camera image data and voice data undergo inference tasks through pre-trained models, enabling the recognition of simple commands within a limited space based on the inference results. This study demonstrates the feasibility of constructing a device management system within a confined space that enhances security and user convenience through a simple real-time system model. Finally our work aims to provide practical solutions in various application fields, such as smart homes and autonomous vehicles.