• 한국항공우주학회지
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• 제44권10호
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• pp.895-903
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• 2016

우주용 영상센서의 비균일 출력특성 교정을 통한 영상품질향상을 목적으로 탑재교정장치가 요구된다. 탑재교정장치는 균일한 온도정보 제공을 위한 흑체를 비롯하여, 흑체로의 지향성 확보를 위하여 전개/수납 기능이 포함되는 교정 메커니즘으로 구성된다. 이 중, 교정 메커니즘은 궤도상에서 구동장치의 결함 발생 시 주광경로 확보를 위한 결함안전 기능이 요구된다. 추가적으로, 구동부에 대한 발사환경에서의 구조건전성 확보가 필수적이다. 본 논문에서는 단일장치로 발사환경 구속 및 결함안전 기능 구현이 가능한 전개수납형 교정 메커니즘을 제안하였다. 상기 제안한 메커니즘의 기능모델을 통한 동작 기능시험을 수행하여 설계의 유효성을 입증하였다.

• 한국통신학회논문지
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• 제36권5B호
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• pp.511-516
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• 2011

본 논문은 M2M의 가장 큰 활용분야인 지능형 원격검침 시스템에 대해 소개하고자 한다. 특히 지능형 원격검침 시스템을 성공적으로 구축하기 위해서는 단말의 설치, 관리, 운영이 무엇보다 중요하다. 이를 해결하기 위한 방법으로 장치관리기술에 대해 설명하고 지능형 원격검침 시스템에 적용하기 위한 방안에 대해 논의하기로 한다.

• 디지털산업정보학회논문지
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• 제15권3호
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• pp.29-36
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• 2019

With the rapid development of 5G technology, more and more network functions are interconnected and more popular. In order to effectively manage emerging network concepts, it allows any device object in the real world to be connected anywhere and at any time through the integration of device object recognition, interaction and raw data collection technologies. In addition, IP Multimedia Subsystem (IMS) is an architecture framework for transmitting IP-based information to the device object which can be represented as end user. Therefore, the Internet of Things and IP Multimedia Subsystem (IoT-IMS) communication platform can provide a convenient and fast way for user or device objects to deploy new application services effectively. In particular, in order to collect and manage the device information from IoT effectively in the IoT-IMS communication platform, an IoT Information Gateway (IIG) is proposed. Through the IoT Application Service (AS) scenario, the collected device information can be easily observed and managed in a unified way.

• Journal of Information Processing Systems
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• 제16권3호
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• pp.733-741
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• 2020

A smart dust monitoring system is useful for obtaining information on rough terrain that is difficult for humans to access. One of ways to deploy sensors to gather information in smart dust environment is to use an aircraft in the Amazon rainforest to scatter an enormous amount of small and cheap sensors (or smart dust devices), or to use an unmanned spacecraft to throw the sensors on the moon's surface. However, scattering an enormous amount of smart dust devices creates the difficulty of managing such devices as they can be scattered into inaccessible areas, and also causes problems such as bottlenecks, device failure, and high/low density of devices. Of the various problems that may occur in the smart dust environment, this paper is focused on solving the bottleneck problem. To address this, we propose and construct a three-layered hierarchical smart dust monitoring system that includes relay dust devices (RDDs). An RDD is a smart dust device with relatively higher computing/communicating power than a normal smart dust device. RDDs play a crucial role in reducing traffic load for the system. To validate the proposed system, we use climate data obtained from authorized portals to compare the system with other systems (i.e., non-hierarchical system and simple hierarchical system). Through this comparison, we determined that the transmission processing time is reduced by 49%-50% compared to other systems, and the maximum number of connectable devices can be increased by 16-32 times without compromising the system's operations.

• International Journal of Computer Science & Network Security
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• 제21권4호
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• pp.199-208
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• 2021

This is an era of technology and with the rapid growth of the Internet, networks are continuously growing. Companies are shifting from simple to more complex networks. Since networks are responsible to transmit huge data which is often sensitive and a point of concern for hackers. Despite the sizes of the networks, all networks are subject to several threats. Companies deploy several security measures to protect their networks from unauthorized access. These security measures are implemented from the device level to the network level. Every security layer adds more to the security of the company's network. Firewalls are the piece of software that provides internal and external security of the network. Firewalls aim to enhance the device level as well as network-level security. This paper aims to investigate the different types of firewalls, their architecture, and vulnerabilities of the firewall. This paper improves the understanding of firewall and its various types of architecture.

• 한국항공우주학회지
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• 제38권8호
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• pp.767-773
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• 2010

본 논문에서는 위성 본체에 장착된 탑제체를 위성으로부터 분리하기 위한 비폭발식 분리 메커니즘을 제안하였다. 작동기로서 경제적이고 신뢰성 있는 유성기어가 통합된 소형 직류모터를 채택하였다. 제안된 분리장치는 별도의 지그나 구조물 없이도 재장전이 용이 하도록 하였으며, 단순한 구조로 제작이 수월한 장점이 있다. 완성된 분리장치는 분리반응속도 측정시험, 최대분리가능하중 측정 시험, 최대발생충격 측정 시험을 통하여 그 성능을 입증하였고, 진동시험, 열진공 시험을 통하여 우주 환경에서 사용 가능함을 보여주었다. 개발된 인공위성용 비폭발식 분리장치를 통하여 그동안 사용되었던 폭발식 분리장치 등의 해외위성용 분리장치를 대체 할 수 있을 것으로 기대된다.

• 한국통신학회논문지
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• 제42권5호
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• pp.975-981
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• 2017

본 논문에서는 WSN 환경에서 플래시 장치를 사용할 때 에너지를 효율적으로 사용하기 위한 방법을 제안한다. 전형적인 플래시 장치는 높은 대기 에너지로 인해 에너지가 제한된 WSN에서 비효율적인 에너지 소모 저장 매체라는 단점을 가지고 있다. 플래시 장치를 WSN 환경에서 에너지 효율적으로 사용하기 가장 쉬운 방법은 유휴 상태일 때 플래시 장치를 끄는 것이다. 이와 관련하여 우리는 비휘발성 및 바이트 주소 지정 기능을 제공하는 새로운 메모리 기술인 NVRAM (Nonvolatile RAM)을 활용하여 높은 대기 에너지 소모 그리고 시작 지연시간을 제거함으로써 간단하지만 이상적인 접근 방식을 현실적으로 제안한다. 특히 NVRAM을 메타 데이터 저장소의 확장으로 사용하여 FTL 메타 데이터 검색 프로세스를 제거하여 앞의 두 가지 장애 요소를 해결 하고자 한다. 실험을 통해 제안하는 방법이 기존 저장장치 비해 약 1.087% 에너지 만을 사용함을 알 수 있었다.

• Journal of Communications and Networks
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• 제17권3호
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• pp.296-305
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• 2015

Coupled schemes between service-oriented architecture (SOA) and Web 2.0 have recently been researched. Web-based content providers and telecommunications company (Telecom) based Internet protocol television (IPTV) providers have struggled against each other to accommodate more three-screen service subscribers. Since the advent of Web 2.0, more abundant reproduced content can be circulated. However, because according to increasing device's resolution and content formats IPTV providers transcode content in advance, network bandwidth, storage and operation costs for content management systems (CMSs) are wasted. In this paper, we present a user centric CMS for open IPTV, which integrates SOA and Web 2.0. Considering content popularity based on a Zipf-like distribution to solve these problems, we analyze the performance between the user centric CMS and the conventional Web syndication system for normalized costs. Based on the user centric CMS, we implement a social Web TV with device-aware function, which can aggregate, transcode, and deploy content over social networking service independently.

• 조명전기설비학회논문지
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• 제28권10호
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• pp.69-74
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• 2014

With the increasing interest of energy efficiency, several buildings and factories begin to monitor energy usages with a built-in energy management system. However, the built-in energy monitoring system does not reflect the dynamics of buildings and factories energy usage. To overcome the latter, we deploy several sensors to monitor the dynamics of buildings energy usage patterns. In this paper, we are proposing a framework of a sensor based energy monitoring system. Based on our limited experiments, we can monitor power usages by a person, device and time period. As a result, we can plan a better energy usage and improve energy efficiency by the monitored energy usage profile data.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.1112-1114
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• 2005

Core position of the M2M (Machine to Machine) is device integration fusion using an emerging wireless and next internet technologies as well as IEEE 802.x, Bluetooth, Zigbee, DMB, Wibro etc. for ubiquitous environment that is complementary with IT839 strategy from Ministry of Information & Communication. This paper define and deploy about major functional requirements of M2M devices and middleware for how to it works, worldwide M2M technology trend & activities with its current & future application in manufacturing area that is called u-Manufacturing (Ubiquitous Manufacturing).