• Journal of Digital Convergence
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• v.14 no.8
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• pp.261-267
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• 2016

In this paper, we studied the range-free localization algorithm between sensor nodes based on the Radical Line for sensor networks. Routing in wireless sensor networks should reduce the overall energy consumption of the sensor network, or induce equivalent energy consumption of all the sensor nodes. In particular, when the amount of data to send more data, the energy consumption becomes worse. New methods have been proposed to address this. So as to allow evenly control the overall energy consumption. For this, the paper covers designing a localization algorithm that can obtain the location information of the peripheral nodes with fewer operations. For the operation of the algorithm is applicable Radical Line. The experimental environment is windows 7, the Visual C ++ 2010, MSSQL 2008. The experimental results could be localized to perform an error rate of 0.1837.

• The KIPS Transactions:PartA
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• v.14A no.7
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• pp.399-408
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• 2007

Currently various techniques for efficiently developing sensor network applications are developed. However, these techniques provide the method for developing only single sensor network application easily and rapidly. Since sensor network applications control various sensor nodes based on core components of operating system, the technique to develop applications by defining common functionalities of various applications and selecting variable functionalities according to the work flow of specific application is efficient. Accordingly, this paper presents an experimental study that identifies commonality of sensor network application domain and supports optional development according to the variability of application by applying product line approach to developing sensor network application. Through the experimental study, we describe the characteristics of sensor network application domain compared with general business domain for product line development. Also, we show the effectiveness of the proposed approach by presenting that core assets designed using the proposed variability feature model and VEADL are reused according to the functionalities of each sensor node.

• Proceedings of the Korean Information Science Society Conference
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• 2006.10b
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• pp.62-65
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• 2006

센서 네트워크는 라디오 통신으로 인해 생기는 예상치 못한 문제점을 비롯하여 제한적인 리소스 때문에 응용 개발에 어려움이 많다. 센서 네트워크가 구성된 후의 내부적인 데이터 흐름이나 네트워크에 참여하는 각 노드의 상태는 네트워크의 정보 수집을 통해 알 수 있다. 본 논문은 네트워크의 상태를 모니터링하고 실시간으로 네트워크 파라미터들을 효율적으로 설정할 수 있는 센서 네트워크 관리 시스템을 제안한다. Sensor Network Manager는 Multi-thread와 동적으로 할당 가능한 Kernel Module 기법을 지원하는 RETOS 운영체제를 기반으로 개발 되었다. 간단한 플러딩 기법을 적용하여 센서 네트워크의 상태를 모니터링 한 결과 Sensor Network Manager가 개발자에게 전반적인 네트워크에 대한 통제와 모니터링이 가능하다는 것을 검증하였다.

• Journal of KIISE:Computer Systems and Theory
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• v.35 no.1
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• pp.53-59
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• 2008

In spite of increasing complexity of wireless sensor network applications, most of the sensor node platforms still have severe resource constraints. Especially a small amount of memory and absence of a memory management unit (MMU) cause many problems in managing application thread stacks. Hence, a shared-stack was proposed, which allows several threads to share one single stack for minimizing the amount of memory wasted by fixed-size stacks. In this paper, we present the memory usage models for thread stacks by deriving the overflow probability of the fixed-size stack and the shared-stack and also show that the shared-stack is more reliable than the fixed-size stack.

• 한국정보통신설비학회:학술대회논문집
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• 2007.08a
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• pp.200-203
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• 2007

일반적으로 홈 게이트웨이는 가정 내 PC와 인터넷 가전 모두에 대해 공유 인터넷 액세스가 가능하도록 통신 서비스와 홈게이트웨이 자체의 보안 및 홈 오토메이션과 같은 서비스를 제공한다. 또한 추가로 미래에 제공되어야 할 여러 서비스를 위해서는 현재 개발되는 홈 게이트웨이는 모듈식 아키텍쳐를 기반으로 해야 할 것이다. 이와 같은 홈 게이트웨이를 구현하기 위해서는 독창적이고 확장 가능한 하드웨어 플랫폼은 물론, 운영체제 및 애플리케이션의 업그레이드와 새로운 서비스의 배치를 가능케 해주는 강건한 파일 시스템을 포함해야 한다. 따라서 본 논문에서는 위와 같은 홈 게이트웨이 기능 및 새로운 서비스 추가 및 관리에 용이한 개방형 표준인 OSGi(Open Service Gateway Initiative)를 기반으로 한 홈게이트웨이를 설계하고, 본 플랫폼을 통한 댁내 가전제어를 위해 센서네트워크와 연동하여 실제 댁내에 부착된 액추에이터 센서노드를 제어할 수 있도록 개발했다. 가전제어를 위한 S/W는 OSGi 상에서 서비스 번들로 개발하였으며 언제 어디에서든 해당 번들을 다운받아 홈 제어가 가능하다.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2006.06a
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• pp.89-90
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• 2006

무선센서 네트워크 기술은 최근 주목 받고 있는 유비쿼터스 컴퓨팅의 핵심 분야로서, 그 활용도가 다양해서 이와 관련된 많은 연구 개발이 이루어지고 있다. 본 논문에서는 무선 센서 네트워크 기술을 여러 응용 분야에 활용될 수 있는 환경 정보 모니터링 시스템에 적용시켜 보았다. 센서 노드로써 MicaZ와 그 운영체제인 TinyOS를 이용하여 온도, 조도, 습도, 가속도, 그리고 위치 등의 사용자 환경 정보를 탐지하고 처리하는 시스템을 구현하여 사용자가 원하는 환경의 조건을 유지하는데 이용될 수 있도록 하였다.

• Proceedings of the Korean Information Science Society Conference
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• 2007.10d
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• pp.398-402
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• 2007

USN은 각종 센서를 이용하여 무선으로 정보를 수집할 수 있도록 구성한 네트워크를 말한다. 센서네트워크 노드를 위하여 설계된 운영체제인 TinyOS에서 제공하는 TOSSIM 시뮬레이터를 이용하면 응용 프로그램을 개발하면서 시뮬레이션을 수행하고, 데이터를 분석하여 문제점을 미리 발견하고 이를 보완할 수 있다. TOSSIM에서는 그래픽 유저 인터페이스를 제공하는 TinyViz와 TOSSIM 스크립트 언어인 Tython을 이용하여 다양한 시뮬레이션이 가능하다. 본 논문에서는 능동적인 시뮬레이션 모델을 제공하기 위하여 Tython 스크립트 언어를 이용하여 TinyViz 플러그인으로서 PeriodicADCPlugin을 설계하였다. PeriodicADCPlugin은 그래픽 유저 인터페이스 상에서 모트들에게 다양한 센서 값을 여러 가지 방법으로 간편하게 입력하는 기능을 제공한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.4B
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• pp.184-191
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• 2008

NanoQplus, which is an embedded operating system for wireless sensor networks (WSNs) and developed by Electronics and Telecommunications Research Institute (ETRI), provides programmer-friendly preemptive multi-threading programming technique, but it has poor network protocol stack, as compared to TinyOS, one of the famous operating systems for WSNs. In this paper, we apply dynamic MANET on-demand routing (DYMO) protocol, which is being standardized in Internet Engineering Task Force (IETF), to NanoQplus. Since DYMO has been proposed for mobile ad-hoc networks (MANETs) and MANETs have less resource restrictions than WSNs, the basic DYMO protocol cannot be applied to WSNs without modifications. Moreover, coherence with MAC protocol should be considered in order to eliminate redundant data between MAC and network layers. Thus, we propose a modified version of the basic DYMO protocol for NanoQplus. The experimental results from a real sensor network test-bed show that the DYMO implementation using NanoQplus works efficiently in WSNs.

• Journal of the Korea Society for Simulation
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• v.15 no.1
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• pp.35-42
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• 2006

Sensor network, that is an infrastructure of ubiquitous computing, consists of a number of sensor nodes of which hardware is very small. The network topology and routing scheme of the network should be determined according to its purpose, and its hardware and software may have to be changed as needed from time to time. Thus, the sensor network simulator being capable of verifying its behavior and estimating performance is required for better design. Sensor network simulators currently existing have been developed for specific hardwares or operating systems, so that they can only be used for such systems and do not provide any means to estimate the amount of power consumption and program execution time which are major issues for system design. In this study, we develop the sensor network simulator that can be used to design and verify various sensor networks without regarding to types of applications or operating systems, and also has the capability of predicting the amount of power consumption and program execution time. For this purpose, the simulator is developed by using machine instruction-level discrete-event simulation scheme. As a result, the simulator can be used to analyze program execution timings and related system behaviors in the actual sensor nodes in detail. Instruction traces used as workload for simulations are executable images produced by the cross-compiler for ATmega128L microcontroller.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.1
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• pp.205-214
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• 2008

To transfer large amount of packets fast in sensor network, it is necessary that the delay between successive packet transmissions should be minimized as possible. In Sensor network, since the Operating Systems are worked on the event driven, the Timer Event is used to transfer packets successively. However, since the transferring time of packet completely is varies very much, it is very hard to set appropriate interval. If interval is too long, delay also becomes too long but if interval is too short, the fail of transfer request would increase. In this paper, we propose ESTEO which reduces the delay between successive packet transmissions by using SendDone Event which informs that a packet transmission has been completed. In ESTEO, the delay between successive packet transmissions is shortened very much since the transmission of next Packet starts at the time when the transmission of previous packet has completed, irrespective of the transmission time. Therefore ESTEO could provide high packet transmission rate given large amount of packets.