• Proceedings of the Korean Information Science Society Conference
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• 2004.10a
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• pp.664-666
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• 2004

최근 업무에 컴퓨터를 이용하는 사례가 늘어나고, 각종 컨텐츠 서비스업계가 발전하면서 독립적인 파일 서버 기능만을 처리하도록 만든 네트워크 저장장치인 NAS(Network Attached Storage)의 이용이 점차 증가하는 추세에 있다. NAS는 기존 파일서버의 문제점을 보완하면서 이기종 플랫폼간의 파일 공유, 스토리지 확장성, 관리 용이성 등을 특징으로 한다. 그러나 NAS 시스템에 장애가 발생할 경우에는 막대한 경제적인 손실이 발생하게 된다. 따라서 본 논문에서는 NAS 시스템 장애가 발생하였을 때, 효율적으로 장애를 복구할 수 있는 HA(High Availability) NAS 시스템을 설계 및 구현하고, 다양한 장애 상황에서 NAS를 이용하는 서비스가 중단 없이 제공되는 것을 확인하였다

• Proceedings of the Korea Information Processing Society Conference
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• 2019.10a
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• pp.316-318
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• 2019

본 논문은 5G 기반의 스마트 시티를 위한 지능형 도로 안전 지원 서비스의 설계에 관한 것이다. 초저지연, 대용량, 초연결의 특성을 가지는 5G 무선 통신망은 스마트시티를 구현하기 위한 최적의 네트워크 인프라를 제공한다. 본 논문에서는 5G 기반의 스마트 시티 서비스를 제공하기 위한 에지 클라우드 컴퓨팅 인프라를 설계하고, 5G 무선 통신 기반의 지능형 CCTV 로부터 생산되는 대용량의 영상 데이터를 전송, 저장하기 위한 계층형 분산 VMS(Video Management System)의 모델을 제시하고 이를 이용하여 5G 기반의 무선 CCTV 와 디지털 투사, 재현 장치를 포함하는 스마트 가로등을 이용하여 지능형 도로 안전 지원 서비스를 제공하는 방법에 대하여 설명한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2015.10a
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• pp.1573-1576
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• 2015

최근 Full-HD보다 4배에서 16배 이상 선명한 초고화질 멀티미디어 영상을 볼 수 있는 UHD TV가 인기를 끌고 있다. 또한 휴대용 단말의 카메라를 이용하여 UHD 영상을 촬영하고 저장하고 있다. 그러나 이러한 초고화질 멀티미디어 영상을 스트리밍하고 재생하기에는 저사양 PC 단말이나 모바일 단말은 자원부족으로 서비스를 제대로 받을 수 없다. 본 논문에서는 클라우드 기반의 초고화질 멀티미디어 스트리밍 서비스 장치를 이용하여 저사양의 단말에서도 고품질 멀티미디어 스트리밍 서비스를 제공하기 위하여 클라우드 가상 데스크탑 서비스 기술을 이용하여 해결한다. 또한, 본 논문에서는 클라이언트 단말과의 네트워크 환경을 고려하여 다양한 비트율을 가진 영상으로 서비스를 제공함으로써 사용자에게 높은 QoE(Quality of Experience)를 제공하는 것을 보여준다.

• Proceedings of the Korea Information Processing Society Conference
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• 2013.11a
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• pp.124-126
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• 2013

대량의 메모리, 네트워크 장치, 저장매체, CPU 등으로 구성된 데이터 센터의 운용에 있어서 시스템 구축이나 운용을 단순화하기 위한 가상화가 고려되고 있다. 특히 금융 분야와 같이 데이터의 폭증 시대에 대응하기 위한 분산 서버 노드의 메모리 가상화 시스템을 고려할 수 있으며 본 연구에서는 이러한 메모리 가상화 시스템을 운용하는데 있어서 지연을 최소화하기 위한 인피니밴드의 활용방안에 대하여 검토한다. 인피니밴드의 메모리 접속 기능인 RDMA (Remote Direct Memory Access)를 더욱 쉽게 사용하기 위한 사용자 친화적인 라이브러리 구현 방법을 제안하며 RDMA 사용 시 발생하는 지연 현상을 분석하였다.

• Journal of Internet Computing and Services
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• v.19 no.1
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• pp.37-47
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• 2018

The number of capabilities of Internet of Things (IoT) devices will exponentially grow over the next years. These devices may generate a vast amount of time-constrained data. In the context of IoT, data management should act as a layer between the objects and devices generating the data and the applications accessing the data for analysis purposes and services. In addition, most of IoT services will be content-centric rather than host centric to increase the data availability and the efficiency of data delivery. IoT will enable all the communication devices to be interconnected and make the data generated by or associated with devices or objects globally accessible. Also, fog computing keeps data and computation close to end users at the edge of network, and thus provides a new breed of applications and services to end users with low latency, high bandwidth, and geographically distributed. In this paper, we propose Edge-Fog cloud-based Hierarchical Data Delivery ($EFcHD^2$) method that effectively and reliably delivers IoT data to associated with IoT applications with ensuring time sensitivity. The proposed $EFcHD^2$ method stands on basis of fully decentralized hybrid of Edge and Fog compute cloud model, Edge-Fog cloud, and uses information-centric networking and bloom filters. In addition, it stores the replica of IoT data or the pre-processed feature data by edge node in the appropriate locations of Edge-Fog cloud considering the characteristic of IoT data: locality, size, time sensitivity and popularity. Then, the performance of $EFcHD^2$ method is evaluated through an analytical model, and is compared to fog server-based and Content-Centric Networking (CCN)-based data delivery methods.

• Journal of Digital Contents Society
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• v.10 no.1
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• pp.1-10
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• 2009

One important issue to generalize the ubiquitous paradigm is the development of user-centralized and intelligent ubiquitous computing systems. Sharing knowledge and correct communication between users and devices are needed to be aware of continuous changed context information and infer services for which users are suited. The goal of this paper is to describe and manage effectively the meaning of services or data which each device offers for interaction between users and devices based on semantic relationships and reasoning. In this paper, we represent semantic data using OWL and design a ubiquitous based intelligent system. We propose some index structures and strategies to process queries classified by each subsystem and adopt labeling schemes to identify classes and resources in the semantic data. We can find devices which satisfies various user's requests exactly and quickly using the proposed strategies.

• The KIPS Transactions:PartD
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• v.11D no.4
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• pp.937-950
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• 2004

With growing population of internet and web applications, distributed environment is considered to be the standard architecture of application. A network management systems(NMS) is necessary to control and monitor the complex network resources for providing and sharing the heft quality service. We recognize the NMS as a standard infrastructure for supporting efficient networking and a separate commercial applications. We believe every resource including software, hardware and environment for the network management should be separated from special protocols, vendors and applications. Therefore, We need a standard network management system that is efficient and consistent because of the heterogeous network features. In regards to software development, software reuse through assembling and extending the reusable elements such as patterns and components assures to realize the best productivity and quality The component based development(CBD) methodology that can assemble black box though well defined interfaces makes it possible to develop easer and quicker applications and is proved as the best software development solution involved in construction, selection and assembly of components. In this thesis, we describe the architecture for the network management and identify, define and design the components through analysis and design in the network management domain and Identified components mapped to the component architecture. We also specify the component development and design and implement the component for developing the network management. Implemented components apply to the component repository system that register, retrieve and understand the components. We analyze, design and implement the entire network management system based on configuration, connection, performance and fault management through the pre-developed components.

• Journal of the Korea Convergence Society
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• v.13 no.4
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• pp.53-61
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• 2022

Accidents are steadily occurring due to machine defects and carelessness during LNG storage operations. In previous studies, an environmental sensor module capable of measuring pressure, temperature, gas concentration, and flow to detect danger in advance was developed and the response speed according to the amount of leaked gas was measured. This paper proposes the development of a wired and wireless communication module that transmits data measured by the environmental sensor module to embedded devices connected to wired and wireless networks of SPI, UART, and LTE. First, a data communication module capable of interworking with an environmental sensor is designed. Design a protocol between devices in the Local Control Part and wired and wireless protocols in the Local Control Part and Remote Control Part. Ethernet, WiFi, and LTE communication modules were designed, and UART and SPI channels that can be linked with embedded controllers were designed. As a result, it was confirmed through a UI (User Interface) that each embedded device transmits data measured by the environmental sensor module while simultaneously communicating on a wired and wireless basis.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.7
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• pp.900-905
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• 2016

The field of power system harmonics has been receiving a great deal of attention recently. This is primarily due to the fact that non-linear (or harmonic-producing) loads comprise an ever-increasing portion of what is handled at a typical industrial plant. The incidence rate of harmonic-related problems is low, but awareness of harmonic issues can still help increase offshore power plant system reliability. On the rare occasion that harmonics become a problem, this is either due to the magnitude of harmonics produced or power system resonance. This harmonic study used an electrical configuration for the offloading scenario of a Floating LNG (FLNG) unit, considering power load. This electrical network configuration is visible in the electrical network load flow study part of the project. This study has been carried out to evaluate the performance of an electric power system, focusing on the harmonic efficiency of an electrically driven motor system to ensure offshore plant safety. In addition, the design part of this study analyzed the electric power system of an FLNG unit to improve the safety of operation and maintenance.

• Journal of Advanced Navigation Technology
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• v.15 no.3
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• pp.412-418
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• 2011

In the airport, digital signage is used to provide the flight-related information for the passengers. Because the current digital signage is based on wired networking or storage medium, its use is limited in terms of the location and the usage of the digital signage. In order to overcome these limitation, we present a WiBro-based digital signage for the wireless broadband networking and the mobility of the digital signage. We perform comparative experiments with the WiBro-based digital signage and WLAN-based digital signage under various locations, datarate, advertisement contents. The experimental results showed that the WiBro-based digital signage is preferred when the mobility is required, while the WLAN-based digital signage has advantage in datarate.