• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.10
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• pp.895-903
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• 2016

Spaceborne imaging sensors require periodic calibrations using an on-board calibration device for an image quality of observation satellites. The on-board calibration device consists of a blackbody to provide uniform radiance temperatures and calibration mechanism with a function of stow and deploy to target the blackbody during the calibration. Among these devices, the calibration mechanism is required to implement a fail-safe function to prevent blocking of the main optical path when the mechanism stops at a certain position during on-orbit calibration. In addition, structural safety of the mechanical driving part of the mechanism within the launch environment must be guaranteed. In this study, we proposed a deploy/stow-type calibration mechanism that provides launch-lock and fail-safe function. The effectiveness of the functionality of the proposed mechanism was validated through functional test using engineering model.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.5B
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• pp.511-516
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• 2011

In this paper, we present the AMI System mentioned as one of the main application areas in the M2M. To enable the AMI, it is essentially required to install, deploy and manage all the devices. Especially, Device Management technology is considered to be suitable for these AMI due to its advantages like, easy installation, remote FW/SW upgradeability. We investigate the fundamental operation of the DM and the design of the DM in the AMI is presented.

• Journal of Korea Society of Digital Industry and Information Management
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• v.15 no.3
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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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• v.16 no.3
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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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• v.21 no.4
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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.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.8
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• pp.767-773
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• 2010

This paper describes development of a non-explosive separation device which can be equipped on small satellites. The spur geared micro DC motor, which has high reliability and advantage of price, is adopted as an actuator. The proposed separation device has resettability and it does not need extra jig to reload. In addition, the simple structure makes it easy to fabricate and assemble. To verify the performance of the proposed device, the response time tests, maximum preload tests and maximum shock level tests were performed. Also, through the vibration tests and thermal vacuum tests, feasibility of the proposed separation device was shown in launching and space environments. Therefore, we expect that the proposed separation device can replace the imported separation devices in near future.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.42 no.5
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• pp.975-981
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• 2017

In this paper, we propose a method for efficient use of energy when using flash device in WSN environment. Typical Flash devices have a drawback to be an energy efficient storage media in the energy-constrained WSNs due to the high standby energy. An energy efficient approach to deploy Flash devices into WSNs is simply turning the Flash device off whenever idle. In this regard, we make the simple but ideal approach realistic by removing these two obstacles by exploiting nonvolatile RAM (NVRAM), which is an emerging memory technology that provides both non-volatility and byte-addressability. Specifically, we make use of NVRAM as an extension of metadata storage to remove the FTL metadata scanning process that mainly incurs the two obstacles. Through the implementation and evaluation in a real system environment, we verify that significant energy savings without sacrificing I/O performance are feasible in WSNs by turning off the Flash device exploiting NVRAM whenever it becomes idle. Experimental results show that the proposed method consumes only about 1.087% energy compared to the conventional storage device.

• Journal of Communications and Networks
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• v.17 no.3
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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.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.10
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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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• 2005.06a
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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).