• 제목/요약/키워드: network life

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무선 센서 네트워크 기반 에너지 효율성이 개선된 MAC 프로토콜 설계 (Design by Improved Energy Efficiency MAC Protocol based on Wireless Sensor Networks)

  • 이철승
    • 한국전자통신학회논문지
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    • 제12권3호
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    • pp.439-444
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    • 2017
  • 무선 센서 네트워크 기술은 유비쿼터스 컴퓨팅 환경의 급성장중인 기술이며 다양한 분야에서 응용과 연구가 진행 되고 있다. 무선 센서 네트워크를 구성하는 센서 노드들은 분산 네트워크 환경에서 배터리를 이용하여 Life cycle을 유지하기 때문에 QoS 요구보다는 에너지 효율이 매우 중요하다. 이러한 사항을 고려하여 IEEE802.15.4의 MAC 프로토콜에서는 트래픽에 적응적인 MAC 프로토콜 연구와 무선 센서 네트워크 환경에 신뢰성과 효율성이 강조된 표준화 작업을 진행중에 있지만, 에너지 효율이 줄어든 만큼 센서 노드의 응답속도가 떨어지는 문제점을 지니고 있다. 이에 본 논문은 동기식 방식과 하이브리드 방식의 MAC 프로토콜을 분석하여 전체네트워크의 에너지 효율이 개선된 MAC 프로토콜을 설계하였다.

Research on Low-energy Adaptive Clustering Hierarchy Protocol based on Multi-objective Coupling Algorithm

  • Li, Wuzhao;Wang, Yechuang;Sun, Youqiang;Mao, Jie
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제14권4호
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    • pp.1437-1459
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    • 2020
  • Wireless Sensor Networks (WSN) is a distributed Sensor network whose terminals are sensors that can sense and check the environment. Sensors are typically battery-powered and deployed in where the batteries are difficult to replace. Therefore, maximize the consumption of node energy and extend the network's life cycle are the problems that must to face. Low-energy adaptive clustering hierarchy (LEACH) protocol is an adaptive clustering topology algorithm, which can make the nodes in the network consume energy in a relatively balanced way and prolong the network lifetime. In this paper, the novel multi-objective LEACH protocol is proposed, in order to solve the proposed protocol, we design a multi-objective coupling algorithm based on bat algorithm (BA), glowworm swarm optimization algorithm (GSO) and bacterial foraging optimization algorithm (BFO). The advantages of BA, GSO and BFO are inherited in the multi-objective coupling algorithm (MBGF), which is tested on ZDT and SCH benchmarks, the results are shown the MBGF is superior. Then the multi-objective coupling algorithm is applied in the multi-objective LEACH protocol, experimental results show that the multi-objective LEACH protocol can greatly reduce the energy consumption of the node and prolong the network life cycle.

Concrete mix design for service life of RC structures exposed to chloride attack

  • Kwon, Seung-Jun;Kim, Sang-Chel
    • Computers and Concrete
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    • 제10권6호
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    • pp.587-607
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    • 2012
  • The purpose of this research is to propose a design technique of concrete mix proportions satisfying service life through genetic algorithm (GA) and neural network (NN). For this, thirty mix proportions and the related diffusion coefficients in high performance concrete are analyzed and fitness function for diffusion coefficient is obtained considering mix components like w/b (water to binder ratio), cement content, mineral admixture (slag, flay ash and silica fume) content, sand and coarse aggregate content. Through averaging the results of 10 times GA simulations, relative errors to the previous data decrease lower than 5.0% and the simulated mix proportions are verified with the experimental results. Assuming the durability design parameters, intended diffusion coefficient for intended service life is derived and mix proportions satisfying the service life are obtained. Among the mix proportions, the most optimized case which satisfies required concrete strength and the lowest cost is selected through GA algorithm. The proposed technique would be improved with the enhancement of comprehensive data set including wider the range of diffusion coefficients.

인공생명기반의 웜 바이러스 모델링 및 시뮬레이션 방법론 (Worm Virus Modeling and Simulation Methodology Using Artificial Life.)

  • 오지연;지승도
    • 한국시뮬레이션학회:학술대회논문집
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    • 한국시뮬레이션학회 2005년도 추계학술대회 및 정기총회
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    • pp.171-179
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    • 2005
  • Computer virus modeling and simulation research has been conducted with focus on the network vulnerability analysis. However, computer virus generally shows the biological virus characters such as proliferation, reproduction and evolution. Therefore it is necessary to research the computer virus modeling and simulation using Artificial Life. The approach of computer modeling and simulation using the Artificial Life technology Provides the efficient analysis method for the effects on the network by computer virus and the behavioral mechanism of the computer virus. Hence this paper proposes the methodology of computer virus modeling and simulation using Artificial Life, which may be contribute the research on the computer virus vaccine.

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OGC 기반의 센서 네트워크 서비스 분석 연구 (The research of Sensor network service analysis based on OGC)

  • 김남훈;함종완;정회경
    • 한국정보통신학회논문지
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    • 제14권3호
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    • pp.774-780
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    • 2010
  • USN(Ubiquitous Sensor Network)은 u-city, u-health 등과 같은 영역에서의 다양한 서비스를 통해 유비쿼터스 사회에서 u-life 실현을 가능하게 하는 핵심 인프라이다. 따라서 u-Life의 핵심 기술인 USN 기술에 대한 국내 표준화 확립을 위한 연구가 필요하다. 현재 USN에 대한 표준 현황은 센서 노드 구현을 위한 기술과 센서 노드들 사이의 효율 적인 통신을 위한 프로토콜 및 기존의 망과 연동을 위한 기술 표준 및 연구가 대부분이다. 그러나, 센서 네트워크와 USN 응용을 위한 이기종 센서 네트워크의 통합관리, 센싱 데이터 관리 및 USN 데이터베이스 구조 정의 등과 같은 응용 및 미들웨어 부분에서의 표준 및 연구는 아직 까지 미약한 수준이다. 이에 본 논문에서는 국내 센서 네트워크 서비스의 표준 개발 및 센서 응용 및 미들웨어 부분에서의 표준화된 플랫폼 기술을 위해 OGC(Open Geospatial Consortium)의 SWE(Sensor Web Enablement)를 구성하는 관련 표준 분석과, 국내 TTA(Telecommunications Technology Association)관련 표준과 상호 연관성을 통하여 OGC 표준의 국내 도입 가능성에 대한 연구를 하였다.

조선족 이민자의 문화적응, 사회적 관계망과 건강 관련 삶의 질의 관계 (Acculturation, Social Network, and Health-related Quality of Life in Korean-Chinese Immigrants)

  • 이민혜;이현경;김수;장연수
    • 지역사회간호학회지
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    • 제24권4호
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    • pp.438-450
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    • 2013
  • Purpose: The purpose of this study is to identify relationships between acculturation, social network, and health-related quality of life (HRQOL) among Korean-Chinese immigrants. Methods: A cross-sectional descriptive study was conducted with 147 Korean-Chinese immigrants who were residing more than 1 year in Korea. Physical and mental dimensions of HRQOL were assessed by Short Form-12 Health Survey that consisted of a physical component summary (PCS) and a mental component summary (MCS). Data were analyzed with Pearson's correlation and multiple regression. Results: The mean PCS score was $41.14{\pm}10.72$ and the mean MCS score was $49.09{\pm}11.31$ (possible range 10-70). Depression (${\beta}$=-6.43) and Social network frequency (${\beta}$=2.44) explained 28.4% of the variance in PCS while depression (${\beta}$=-11.54) and visiting clinic/hospital (${\beta}$=-4.00) explained 34.3% of the variance in MCS. Acculturation was not significantly associated with HRQOL. Conclusion: This study confirmed that the social network frequency influences HRQOL among Korean-Chinese Immigrants. The findings suggest that social network analysis should be considered in the process of developing health intervention strategies for Korean-Chinese immigrants.

The US National Ecological Observatory Network and the Global Biodiversity Framework: national research infrastructure with a global reach

  • Katherine M. Thibault;Christine M, Laney;Kelsey M. Yule;Nico M. Franz;Paula M. Mabee
    • Journal of Ecology and Environment
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    • 제47권4호
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    • pp.219-227
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    • 2023
  • The US National Science Foundation's National Ecological Observatory Network (NEON) is a continental-scale program intended to provide open data, samples, and infrastructure to understand changing ecosystems for a period of 30 years. NEON collects co-located measurements of drivers of environmental change and biological responses, using standardized methods at 81 field sites to systematically sample variability and trends to enable inferences at regional to continental scales. Alongside key atmospheric and environmental variables, NEON measures the biodiversity of many taxa, including microbes, plants, and animals, and collects samples from these organisms for long-term archiving and research use. Here we review the composition and use of NEON resources to date as a whole and specific to biodiversity as an exemplar of the potential of national research infrastructure to contribute to globally relevant outcomes. Since NEON initiated full operations in 2019, NEON has produced, on average, 1.4 M records and over 32 TB of data per year across more than 180 data products, with 85 products that include taxonomic or other organismal information relevant to biodiversity science. NEON has also collected and curated more than 503,000 samples and specimens spanning all taxonomic domains of life, with up to 100,000 more to be added annually. Various metrics of use, including web portal visitation, data download and sample use requests, and scientific publications, reveal substantial interest from the global community in NEON. More than 47,000 unique IP addresses from around the world visit NEON's web portals each month, requesting on average 1.8 TB of data, and over 200 researchers have engaged in sample use requests from the NEON Biorepository. Through its many global partnerships, particularly with the Global Biodiversity Information Facility, NEON resources have been used in more than 900 scientific publications to date, with many using biodiversity data and samples. These outcomes demonstrate that the data and samples provided by NEON, situated in a broader network of national research infrastructures, are critical to scientists, conservation practitioners, and policy makers. They enable effective approaches to meeting global targets, such as those captured in the Kunming-Montreal Global Biodiversity Framework.