센서네트워크 동작 및 센싱 알고리즘 검증을 위한 소프트웨어 프레임워크

유성은(Seong-eun Yoo) 한국산업정보학회 2012 한국산업정보학회논문지 Vol.17 No.1

대부분의 센서네트워크는 물리적인 세계에 대규모로 설치되기 때문에 일단 현장에 설치되면 디버깅이나 검증이 어렵다. 따라서 센서네트워크가 현장에 설치되기 전에 테스트베드 형태로 충분한 테스트와 검증이 이루어져야 한다. 테스트베드에서 센서네트워크를 테스트하고 검증할 때, 센서네트워크의 특성상 물리적인 세계와 상호작용을 해야 하기 때문에 물리적인 세계를 제어하여 자원제약적인 센서노드 수준에서 센서네트워크를 검증하는 것은 굉장한 비용과 시간을 필요로 한다. 본 논문에서는 센서네트워크의 네트워크 측면의 동작뿐만 아니라 응용 측면의 동작(즉, 센싱알고리즘)을 보다 효율적으로 검증하고 평가하기 위한 소프트웨어 프레임워크를 제안한다. 본 논문은 제안된 소프트웨어 프레임워크를 적용해 센서네트워크 기반의 지능형 주차장 응용을 위한 시뮬레이터를 구현하여 평가함으로써 제안된 소프트웨어 프레임워크의 가능성을 검증한다. Most of sensor networks are difficult to be debugged, verified, and upgraded once they are deployed in the fields, for they are usually deployed in real world and large scale. Therefore, before deploying the sensor networks, we should test and verify them sufficiently in realistic testbeds. However, since we need to control physical environments which interact with sensor networks, it takes much of time and cost to test and verify sensor networks at the level of resource-constrained sensor nodes in such environments. This paper proposes an efficient software framework for evaluating and verifying sensor networks in the view points of network and application operations (i.e., accuracy of sensing algorithms). Applying the proposed software framework to the development of a simulator for a smart parking application based on wireless sensor network, this paper verifies the feasibility of the proposed framework.

IEEE 802.15.4에서의 실시간 통신을 위한 스케쥴링 알고리듬

유성은(Seong-eun Yoo),김대영(Daeyoung Kim),도윤미(Yoonmee Doh),팜민롱(Minh-Long Pham),허재두(Jae-doo Huh) 한국통신학회 2005 한국통신학회 학술대회 및 강연회 Vol.2005 No.4

360도 콘텐츠 기반 식물 재테크 상거래서비스

유성현(Seong-Hyun Yoo),양건우(Gun-Woo Yang),최예찬(Yae-Chan Choi),김은지(Eun-Ji Kim),김병완(Byung-Wan Kim),이병권(Byong-Kwon Lee) 한국컴퓨터정보학회 2022 한국컴퓨터정보학회 학술발표논문집 Vol.30 No.2

건물 통합형 물 대 물 지열 히트펌프시스템 년성능 평가에 관한 연구

강은철(Eun-Chul Kang),PeterRiederer,유성연(Seong-Yeon Yoo),이의준(Euy-Joon Lee) 대한설비공학회 2012 대한설비공학회 학술발표대회논문집 Vol.2012 No.6

This paper deals with a dynamic method to evaluate the building integrated water to water geothermal heat pump (BIGHP) system seasonal performance factor (SPF) in laboratories. SPF is sometimes defined as CSPF (Cooling Seasonal Performance Factor) and HSPF (Heating Season Performance Factor). CSPF is equivalent to COPcs while HSPF is to COPhs in practice. However, the single point based COPc and COPh cannot express the annual performance of BIGHP system properly in the case of geothermal heat pumps. Therefore, a specially proposed new method which combined simulation and test with twelve testing days indicating twelve months per year from the climate weather data has been proposed to predict the CSPF and HSPF and finally the annual performance factor (APF). The purpose of this paper is to evaluate the CSPF and the HSPF and finally the APF for a climate building integrated geothermal heat pump system in Nice and Seoul. The error of the testing method is estimated to less than 3% compared to the reference (Annual simulation) for both climates, Seoul and Nice. In the future, further verifications will be carried out in order to compare this new testing method and IPMVP calibration model approach.

IoT 디바이스의 연결성 향상을 위한 동적 leaf 모드 기반의 INFRA-RPL

홍석원,유성은,Seokwon Hong,Seong-eun Yoo 대한임베디드공학회 2023 대한임베디드공학회논문지 Vol.18 No.4

RPL (IPv6 Routing Protocol for Low-power Lossy Network) is a standardized routing protocol for LLNs (Low power and Lossy Networks) by the IETF (Internet Engineering Task Force). RPL creates routes and builds a DODAG (Destination Oriented Directed Acyclic Graph) through OF (Objective Function) defining routing metrics and optimization objectives. RPL supports a leaf mode which does not allow any child nodes. In this paper, we propose INFRA-RPL which provides a dynamic leaf mode functionality to a leaf node with the mobility. The proposed protocol is implemented in the open-source IoT operating system, Contiki-NG and Cooja simulator, and its performance is evaluated. The evaluation results show that INFRA-RPL outperforms the existing protocols in the terms of PDR, latency, and control message overhead.

레이저 장비의 전송 경로 자가 교정을 위한 무선 네트워크 시스템

이준영,유성은,Lee, Junyoung,Yoo, Seong-eun 대한임베디드공학회 2020 대한임베디드공학회논문지 Vol.15 No.2

IIoT stands for Industrial Internet of Things used in manufacturing, healthcare, and transportation in networked smart factories. Recently, IIoT's environment requires an automated control system through intelligent cognition to improve efficiency. In particular, IIoT can be applied to automatic calibration of production equipment for improved management in industrial environments. Such automation systems require a wireless network for transmitting industrial data. Self-calibration systems in laser transmission paths using wireless networks can save resources and improve production quality by real-time monitoring and remote control of laser transmission path. In this paper, we propose a wireless networked system for self-calibration of laser equipment that requires a laser transmission path, and we show the results of the prototype evaluation. The self-calibration system of laser equipment measures the coordinates of the laser points with sensors and sends them to the host using the proposed application protocol. We propose a wireless network service for the wired motor controller to align the laser coordinates. Using this wireless network, the host controls the motor by sending a control command of the motor controller in an HTTP message based on the received coordinate values. Finally, we build a prototype system of the proposed design to verify the detection performance and analyze the network performance.

저전력 네트워크 기반의 확장 용이한 스마트 홈 IoT 시스템

이준영,유성은,Lee, Jun-young,Yoo, Seong-eun 대한임베디드공학회 2018 대한임베디드공학회논문지 Vol.13 No.3

There are increasing interests on smart home systems. However, most of the existing works focus on the functionality itself. In this paper, we propose an extensible smart home system based on low power networking such as CoAP, 6LoWPAN, and Zigbee. The proposed home IoT system consists of Home APP, Home Server, Home Broker, and Power Devices. Each component of the system is connected by the low-power network technologies aforementioned. As the end device, Power Device senses the current consumption of the attached appliance and controls the power to it. Power Device reports the sensing data to Home Server via Home Broker. The Home Broker enhances the scalability of the system. Home Broker extends the service area and the user's services, and it manages the connection of the underlying devices and processes, and transmits data to Home Server from Power Devices. Through the experimental evaluation, we show that the proposed system achieves the design goals such as extensibility and low power networking.

이중 블라인드 광파이프 주광 조명시스템 효율 및 조명에너지 절감량 평가 연구

강은철(Kang, Eun-Chul),유성연(Yoo, Seong-Yeon),이의준(Lee, Euy-Joo) 한국태양에너지학회 2013 한국태양에너지학회 논문집 Vol.33 No.1

A DBLP(Double blind light pipe) daylight system can be installed at a building exterior wall or roof to replace artificial light during the day time. This system was consisted of a double blind light collector, a mirror duct type light transformer and a prism light pipe distributor. The double blinds were used to track the sun"s altitude and azimuth movements to collect the sunlight throughout the day. The sunlight collected by the light collector was reflected on the first mirror and the second mirror and sent to the light pipe through the light transformer. The transformer was designed to deliver the sunlight into the light pipe efficiently. The light distributor plays a role in diffusing the sunlight coming in through the light collector to be used for indoor lighting. In this paper, a DBLP system has been designed, installed and tested at a KIER daylighting twin test cell. The DBLP daylighting system was applied to the experimental test cell which has an indoor area of 2.0m wide × 2.4m height × 3.8m length. The experiment was conducted from January 30 to February 27, 2012, under clear skies and partially cloudy skies. Data was collected from 10:00 am to16:00 pm every 2 minute and the average was calculated for every 30 minute of the data collection to obtain the system efficiency. The results indicated that the DBLP system efficiency was evaluated as 11.67%. The DBLP system indoor illumination energy reduction was predicted as 0.822kWh/day. This could replace 4 sets of a32W fluorescent lamp operating 6.4 hours per a day.

수직 분할 태스크 모델 기반의 IEEE 802.15.4 소프트웨어 구현과 성능평가

김희철(Hie Cheol Kim),유성은(Seong Eun Yoo) 한국산업정보학회 2014 한국산업정보학회논문지 Vol.19 No.1

IEEE 802.15.4의 물리계층은 저속, 저전력, 저가격 기반의 LR-WPAN(Low-Rate Wireless Personal Area Network) 의 물리계층으로 세계적으로 가장 많이 사용되고 있다. IEEE 802.15.4에 대한 기존의 많은 이론 연구들은 저전력 무선네트워크 환경에서의 에너지효율성, 전송처리율, 전송신뢰성에 대한 거시적 이해와 안목을 제공하는 중요한 결과들을 산출하고 있다. 이 논문에서는 이러한 이론연구에 실환경 요소를 보완하기 위해 MAC(Medium Access Control)소프트웨어 구조부터 실제 네트워크 기반 성능분석에 이르는 실험연구를 수행한다. 연구에서는 수직분할 모델의 네트워킹 스택의 MAC 계층 기능으로 IEEE 802.15.4 MAC 스택을 구현하고 이를 네트워킹 스택에 통합하여 시험 · 분석을 수행한다. 이 연구에서 도출한 네트워크 소프트웨어 모델과 실험결과는 향후 IEEE 802.15.4 MAC 소프트웨어의 구현과 실용적인 네트워크 스택 환경에서의 성능에 참고자료로 활용될 수 있다. IEEE 802.15.4 is one of the most widely adopted physical layer standards in the area of LR-WPAN(Low-Rate Wireless Personal Area Network). Numerous previous researches have contributed to deep insights on energy efficiency, transmission throughput, and reliability that IEEE 802.15.4 delivers to the LR-WPAN. As a research that is orthogonal and complementary to previous researches, we explore the implementation and practical performance evaluation of IEEE 802.15.4 MAC software. We implement the MAC software from the perspective of the networking stack, exploring the issues raised when the MAC software serves as a functional component in a complete networking stack consisting of MAC, network as well as application support layers. The performance is evaluated on a realistic experimental software environment integrated with operating system, networking stack, and applications.

분산 낙하 이동 모델에서의 평균 노드 거리 기반 적응적 OLSR 프로토콜

이택민,이진해,왕지현,유준혁,유성은,Lee, Taekmin,Lee, Jinhae,Wang, Jihyeun,Yoo, Joonhyuk,Yoo, Seong-eun 대한임베디드공학회 2018 대한임베디드공학회논문지 Vol.13 No.2

With the development of IT (Information Technology) technology, embedded system and network technology are combined and used in various environments such as military environment as well as everyday life. In this paper, we propose a new airdropped distributed mobility model (ADMM) modeling the dispersion falling of the direct shot of a cluster bomb, and we compare and analyze some representative MANET routing protocols in ADMM in ns-3 simulator. As a result of the analysis, we show OLSR routing protocol is promising in ADMM environment in the view points of packet delivery ratio (PDR), end to end delay, and jitter. In addition, we propose a new adaptation scheme for OLSR, AND-OLSR (Average Node Distance based adaptive-OLSR) to improve the original OLSR in ADMM environment. The new protocol calculates the average node distance, adapts the period of the control message based on the average node distance increasing rate. Through the simulation study, we show that the proposed AND-OLSR outperforms the original OLSR in PDR and control message overhead.