• Journal of the Institute of Convergence Signal Processing
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• v.20 no.1
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• pp.57-62
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• 2019

In this paper, oneM2M based data monitoring and acquisition system is designed and implemented to measure and transmit the voltage, current, temperature, acceleration and vibration of the motor. The proposed system can detect electrical faults (overcurrent, reverse phase, phase loss, ground fault) and mechanical faults (MC counter, motor operation time, bearing and winding temperature, motor speed, insulation resistance). The system consists of sensor data collection, web server, php, database, wired/wireless communication system. The insulation resistance and the motor speed were measured, and the experimental results were similar for both the test resistance value and the reference input value.

• Journal of Platform Technology
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• v.12 no.2
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• pp.45-57
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• 2024

Smart cities are the product of modern urban planning that seeks to innovate information and communication technology and improve the quality of urban life. For the efficient operation of smart cities, data collected, stored, and processed in real time is a key resource. Therefore, data from smart cities collected in various fields must be managed safely, and personal information protection is paramount. In this study, a smart city data security model using blockchain technology was proposed to safely manage smart city data. The proposed model integrates IPFS into the blockchain network to distribute and store data to ensure data confidentiality and integrity, and encrypts data using CP-ABE to efficiently control access to data from users. In addition, privacy was guaranteed while enhancing the usability of data by using Homomorphic Encryption with data access control policies.

• Annual Conference of KIPS
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• 2007.11a
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• pp.1190-1193
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• 2007

최근 들어 저장장치의 획기적인 기술의 발달로 인하여 고용량의 작고 간편한 이동식 저장장치들이 많이 선보이고 있다. 그러나 이동식 저장장치는 도난이나 분실 등으로 인한 데이터에 대한 보호 및 안전성에 있어서 많은 문제를 노출한다. 본 논문에서는 이동식 저장장치 환경에서 가상 드라이브 연동, 실시간 암/복호화를 통한 보안 시스템의 설계와 구축 결과를 제시한다. 소개된 시스템은 기본적으로 저장장치에 보안영역을 설정하여 사용자 인증을 통해서 보안영역에 접근하도록 하였으며, 데이타 입출력 시 암/복호화를 통해 데이타에 무단 접근을 차단하는 방법을 사용하였다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.5
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• pp.743-754
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• 2022

This paper contains the results of the development and performance evaluation of the environmental data monitoring system for the fish farm. For the hardware development, the analogue sensor is used to collect dissolved oxygen, pH, salinity, and temperature of the fish farm water, and the digital sensor is used for collecting ambient temperature, humidity, and location information via a GPS module to be sent to cloud-based Firebase DB. A set of LoRa transmitters and receivers is used as a communication module to upload the collected data. The data stored in Firebase is retrieved as a graph on a web and mobile application to monitor the environmental data changes in real-time. A notification will be delivered if the collected data is outside the determined optimal value. To evaluate the performance of the developed system, a response time from hardware modules to web and mobile applications is ranging from 6.2 to 6.85 seconds, which indicates satisfactory results.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.4
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• pp.592-598
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• 2017

The purpose of this study is to suggest a new inspection period of ${\triangle}{\triangle}$ guided missiles by analyzing their reliability using field data. The ${\triangle}{\triangle}$ guided missile has an inspection period of five years which was determined using prediction data during its development process. However, from the analysis of its field data, it was shown that the inspection period could be extended to more than 18 years. Based on this result, a policy is proposed to reevaluate the inspection period by means of practical reliability tests.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2008.10a
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• pp.65-72
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• 2008

Mobile Collaboration is an enabling technology that makes users share information between mobile devices and various Mobile P2P platforms have been designed and implemented for it. There are, however, few research papers on application of SIP protocol to spatial data sharing on mobile devices. In this paper, SIP based real time sharing framework is proposed to compose a mobile P2P platform on which spatial data can be trans(erred. A new protocol based on WKT and WKB is defined to send and receive spatial objects with SIP MESSAGE method. Base maps such as digital maps and parcel maps can be provided by a map server that is integrated with SIP server after a new SIP session established and client agents are registered. The framework proposed based onSIP enables users to transfer spatial data such as maps and satellite images directly between mobile devices during VoIP based voice call and therefore, mobile applications can be applied in various domains such asforest management and national defense.

• Journal of KIISE:Databases
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• v.28 no.3
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• pp.484-493
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• 2001

As real-time database systems are extended to the distributed computing environment, the need to apply the existing real-time concurrency control schemes to the distributed computing environment has been made. In this paper we propose an efficient concurrency control scheme for distributed real-time database system. Our proposed scheme guarantees a transaction to commit at its maximum, reduces the restart of a transaction that is on the prepared commit phase, and minimizes the time of the lock holding. This is because it raises the priority of the transaction that is on the prepared commit phase in the distributed real-time computing environment. In addition, it reduces the waiting time of a transaction that owns borrowed data and improves the performance of the system, as a result of lending the data that the transaction with the raised priority holds. We compare the proposed scheme with DO2PL_PA(Distributed Optimistic Two-Phase Locking) and MIRROR(Managing Isolation in Replicated Real-time Object Repositories) protocol in terms of the arrival rate of transactions, the size of transactions, the write probability of transactions, and the replication degree of data in a firm-deadline real-time database system based on two-phase commit protocol. It is shown through the performance evaluation that our scheme outperforms the existing schemes.

• Proceedings of the Korea Multimedia Society Conference
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• 2002.11b
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• pp.194-197
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• 2002

본 논문은 리눅스 환경에서 IEEE1394의 동시 전송 프로토콜을 이용하는 멀티미디어 스트리밍 시스템의 구현에 대해 기술한다. 구현된 시스템은 DV 데이터의 스트리밍과 재생, 저장은 물론 로컬 재생과 장치 제어 기능을 갖는 사용자 프로그램과 dv1394 디바이스 드라이버로 구성된다. 스트리밍을 위한 메모리할당, 버퍼관리, 전송 데이터 형식 선언, IEEE1394 헤더 및 CIP 처리기능을 가진 dv1394 드라이버를 사용하여 드라이버와 OHCI1394 카드 사이의 스트리밍에 대한 투명성을 제공함으로써 기존의 스트리밍 시스템이 가졌던 응용 프로그램 개발의 복잡성을 줄였다. 이 시스템은 실시간 원격 모니터링이나 화상 회의 시스템, 그리고 비선형 비디오 편집 시스템에 응용될 수 있다.

• Proceedings of the Korea Database Society Conference
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• 2000.11a
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• pp.216-223
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• 2000

본 연구에서는 외부와 유무선 접속기능을 갖는 무인창구 자동화기기(CD, ATM, 통장정리기, 발권기, 무인자동발급기, 지하철 게이트 등)를 인터넷망에 접속하여 기기의 장애/ 이력 관련정보를 Server의 데이터 베이스에 저장하고, 인터넷에 접속되어 있는 A/S 센터에서 필요한 정보를 쉽고 효율적으로 검색, 운용할 수 있는 시스템을 구현하는 방법을 제시한다.

• The KIPS Transactions:PartB
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• v.11B no.3
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• pp.337-344
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• 2004

Most of the virtual space constructed sufficiently realistic need a lot of memory space to navigate smoothly. And this kind of virtual space also requires real-time responsibility for the navigation as well as realism. In the off-line virtual system, real-time responsibility can be resolved by using large scale if secondary memory. In the web-based online virtual system, on the other hand, real-time responsibility is highly related to the latency time of network data communication. This induces the necessity of the algorithm for fast data loading. In this paper, we propose and verify the validity of the two methodology for cell leading algorithm. According to the results of computer simulation, the algorithm using hexagonal type cell promotes the real-time responsibility over 30％ than that of the rectangular type.