• Title/Summary/Keyword: Network Resilience

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A Preliminary Strategic Study of Resilient Plot Utilization in Rail Transit Stations in the Realm of the City Center, Guided by the Density of Three-Dimensional-Path Public Space

  • Yuan Zhu;Zixin Luo
    • International Journal of High-Rise Buildings
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    • v.13 no.1
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    • pp.57-67
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    • 2024
  • With the requirement of high quality and three-dimensional urban development, the public space areas city-center rail transit stations is expanded from the plots defined by the road network density to the plots defined by the three-dimensional public space density, covering the internal and external paths of the plots, which brings about the resilient pattern of plot utilization. This paper uses the isochronous three-dimensional influence realm model around the station areas to quantitatively analyze and compare the surrounding three-dimensional path density of public space, and initially proposes flexible use patterns of differently scaled plots under the multi-scale plots linkage, to effectively promote the overall accessibility of the station realm space.

The Evolution of the IT Service Industry in the U.S. National Capital Region: The Case of Fairfax County (미국 수도권 IT서비스산업 집적지의 진화: 페어팩스 카운티를 사례로)

  • Huh, Dongsuk
    • Journal of the Economic Geographical Society of Korea
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    • v.16 no.4
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    • pp.567-584
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    • 2013
  • This study aims to explore an evolutionary path of the IT service industry in Fairfax County using the Cluster Adaptive Cycle model in economic geography. The analysis is based on detailed historical and industrial information obtained through a variety of data sources including local archival materials, economic census, and interviews. This study also performs a shift-share analysis during the period of 1990 to 2011. Using the adaptive cycle model, the local IT service industry is indicated by a trajectory of constant cluster mutation. The evolution of the local IT service industry has been closely related to federal government policy due to the regional specificity of the National Capital Region and the proximity of the Department of Defense. Although the economic downturn of the late 2000s, the local IT service industry has been notable resilience and adapted to a changing market and technological environment. This constant mutation of the local industry is resulted from not only high resilience which is based on the large government procurement market, the reinforcement of adaptive capacity of the local firms and the network of economic agents such as firm and supporting institutions, but also high flexibility of the knowledge-based service industry to a changing business environment.

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Lessons from constructing and operating the national ecological observatory network

  • Christopher McKay
    • Journal of Ecology and Environment
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    • v.47 no.4
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    • pp.187-192
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    • 2023
  • The United States (US) National Science Foundation's (NSF's) National Ecological Observatory Network (NEON) is a continental-scale observation facility, constructed and operated by Battelle, that collects long-term ecological data to better understand and forecast how US ecosystems are changing. All data and samples are collected using standardized methods at 81 field sites across the US and are freely and openly available through the NEON data portal, application programming interface (API), and the NEON Biorepository. NSF led a decade-long design process with the research community, including numerous workshops to inform the key features of NEON, culminating in a formal final design review with an expert panel in 2009. The NEON construction phase began in 2012 and was completed in May 2019, when the observatory began the full operations phase. Full operations are defined as all 81 NEON sites completely built and fully operational, with data being collected using instrumented and observational methods. The intent of the NSF is for NEON operations to continue over a 30-year period. Each challenge encountered, problem solved, and risk realized on NEON offers up lessons learned for constructing and operating distributed ecological data collection infrastructure and data networks. NEON's construction phase included offices, labs, towers, aquatic instrumentation, terrestrial sampling plots, permits, development and testing of the instrumentation and associated cyberinfrastructure, and the development of community-supported collection plans. Although colocation of some sites with existing research sites and use of mostly "off the shelf" instrumentation was part of the design, successful completion of the construction phase required the development of new technologies and software for collecting and processing the hundreds of samples and 5.6 billion data records a day produced across NEON. Continued operation of NEON involves reexamining the decisions made in the past and using the input of the scientific community to evolve, upgrade, and improve data collection and resiliency at the field sites. Successes to date include improvements in flexibility and resilience for aquatic infrastructure designs, improved engagement with the scientific community that uses NEON data, and enhanced methods to deal with obsolescence of the instrumentation and infrastructure across the observatory.

Characterization of Ecological Networks on Wetland Complexes by Dispersal Models (분산 모형에 따른 습지경관의 생태 네트워크 특성 분석)

  • Kim, Bin;Park, Jeryang
    • Journal of Wetlands Research
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    • v.21 no.1
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    • pp.16-26
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    • 2019
  • Wetlands that provide diverse ecosystem services, such as habitat provision and hydrological control of flora and fauna, constitute ecosystems through interaction between wetlands existing in a wetlandscape. Therefore, to evaluate the wetland functions such as resilience, it is necessary to analyze the ecological connectivity that is formed between wetlands which also show hydrologically dynamic behaviors. In this study, by defining wetlands as ecological nodes, we generated ecological networks through the connection of wetlands according to the dispersal model of wetland species. The characteristics of these networks were then analyzed using various network metrics. In the case of the dispersal based on a threshold distance, while a high local clustering is observed compared to the exponential dispersal kernel and heavy-tailed dispersal model, it showed a low efficiency in the movement between wetlands. On the other hand, in the case of the stochastic dispersion model, a low local clustering with high efficiency in the movement was observed. Our results confirmed that the ecological network characteristics are completely different depending on which dispersal model is chosen, and one should be careful on selecting the appropriate model for identifying network properties which highly affect the interpretation of network structure and function.

Climate-Smart Agriculture (CSA)-Based Assessment of a Rice Cultivation System in Gimje, Korea (한국 김제의 벼 경작 시스템의 기후스마트농업 (Climate-Smart Agriculture) 기반의 평가)

  • Talucder, Mohammad Samiul Ahsan;Kim, Joon;Shim, Kyo-Moon
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.23 no.4
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    • pp.235-250
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    • 2021
  • The overarching question of this study is how a typical rice cultivation system in Gimje, Korea was keeping up with the triple-win challenge of climate-smart agriculture (CSA). To answer this question, we have employed (1) quantitative data from direct measurement of energy, water, carbon and information flows in and out of a rice cultivation system and (2) appropriate metrics to assess production, efficiency, GHG fluxes, and resilience. The study site was one of the Korean Network of Flux measurement (KoFlux) sites (i.e., GRK) located at Gimje, Korea, managed by National Academy of Agricultural Science, Rural Development Administration. Fluxes of energy, water, carbon dioxide (CO2) and methane (CH4) were directly measured using eddy-covariance technique during the growing seasons of 2011, 2012 and 2014. The production indicators include gross primary productivity (GPP), grain yield, light use efficiency (LUE), water use efficiency (WUE), and carbon uptake efficiency (CUE). The GHG mitigation was assessed with indicators such as fluxes of carbon dioxide (FCO2), methane (FCH4), and nitrous oxide (FN2O). Resilience was assessed in terms of self-organization (S), using information-theoretic approach. Overall, the results demonstrated that the rice cultivation system at GRK was climate-smart in 2011 in a relative sense but failed to maintain in the following years. Resilience was high and changed little for three year. However, the apparent competing goals or trade-offs between productivity and GHG mitigation were found within individual years as well as between the years, causing difficulties in achieving the triple-win scenario. The pursuit of CSA requires for stakeholders to prioritize their goals (i.e., governance) and to practice opportune interventions (i.e., management) based on the feedback from real-time assessment of the CSA indicators (i.e., monitoring) - i.e., a purpose-driven visioneering.

Living for the Children: Immigrant Korean Mothers' Re-creation of Family after Marital Dissolution

  • Oh, Seieun
    • Korean Journal of Adult Nursing
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    • v.26 no.4
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    • pp.479-487
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    • 2014
  • Purpose: This study was a grounded theory research aimed at generating a substantive theory that accounts for the explanatory social processes in which immigrant Korean single-mother families were engaged in the United States. Methods: In-depth interviews were conducted with 15 immigrant Korean single mothers who were living with children under 18 years of age at the time of the interviews. Data collection guided by theoretical sampling and concurrent constant comparative analysis of the transcribed data was conducted to identify the core social process. Results: The emerged core social process was "living for the children," which represented the driving process by which these women made transition to their new lives as single-mother families. The major task throughout the entire transition was re-creating their families. The women's transition involved practical and psychological transitions. The practical transition involved three stages: assuring family survival, struggling between the father role and the mother role, and stabilizing. The psychological transition involved becoming strong and settling in with a new supportive network. Conclusion: Study results added to the literature by elaborating the women's emphasis on maternal identity and the resilience-provoking nature of the women's transitions.

Adaptive QoS Management for MPEG-4 Streaming Service over Internet (인터넷 기반의 MPEG-4 스트리밍 서비스를 위한 적응적 QoS 관리)

  • 최지훈;이상조;서덕영;김현철;이명호
    • Journal of Broadcast Engineering
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    • v.5 no.2
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    • pp.227-238
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    • 2000
  • This paper, at first, provides analysis on loss pattern of Internet based on real experiments of the current Internet. Then, we propose an effective adaptive QoS management technique, in which measured loss pattern as well as PLR (Packet Loss Ratio) are used to select titrate of temporal scalability. level of FEC and retransmission This selection is also incorporated to the MPEG-4 error resilience tools and error concealment techniques. In order to minimize effect of packet loss, multimedia stream is segmented in the unit of group of Pictures (GOP) and interleaving and FEC are applied to the segment. Proposed algorithms are applied to build a VOD system.

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Microbiome-Linked Crosstalk in the Gastrointestinal Exposome towards Host Health and Disease

  • Moon, Yuseok
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.19 no.4
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    • pp.221-228
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    • 2016
  • The gastrointestinal exposome represents the integration of all xenobiotic components and host-derived endogenous components affecting the host health, disease progression and ultimately clinical outcomes during the lifespan. The human gut microbiome as a dynamic exposome of commensalism continuously interacts with other exogenous exposome as well as host sentineling components including the immune and neuroendocrine circuit. The composition and diversity of the microbiome are established on the basis of the luminal environment (physical, chemical and biological exposome) and host surveillance at each part of the gastrointestinal lining. Whereas the chemical exposome derived from nutrients and other xenobiotics can influence the dynamics of microbiome community (the stability, diversity, or resilience), the microbiomes reciprocally alter the bioavailability and activities of the chemical exposome in the mucosa. In particular, xenobiotic metabolites by the gut microbial enzymes can be either beneficial or detrimental to the host health although xenobiotics can alter the composition and diversity of the gut microbiome. The integration of the mucosal crosstalk in the exposome determines the fate of microbiome community and host response to the etiologic factors of disease. Therefore, the network between microbiome and other mucosal exposome would provide new insights into the clinical intervention against the mucosal or systemic disorders via regulation of the gut-associated immunological, metabolic, or neuroendocrine system.

Surimi Quality from Mechanically Deboned Chicken Meat as Affected by Washing Cycle, Salt Concentration, Heating Temperature and Rate

  • Min, Byung-Jin;Lee, Sung-Ki
    • Asian-Australasian Journal of Animal Sciences
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    • v.17 no.1
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    • pp.131-136
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    • 2004
  • The effects of salt concentration and heating conditions on the thermal gelation properties of surimi produced from mechanically deboned chicken meat (MDCM) were investigated. Chicken surimi was manufactured by washing (MDCM: 0.5% NaCl=1:4), standing, straining and centrifuging. The fat, water-soluble protein and heme pigment in the MDCM were removed by increasing washing cycles. The compressive force of the chicken surimi increased as the concentration of salt was increased from 0% to 5%. Total gel strength of the surimi measured by texture profile analysis showed a maximum in the range 3-5% NaCl. Microstructural analysis showed that the unfolding network structure of the surimi gel began to appear at NaCl concentrations>2%. The optimum heating condition for gelation was $90^{\circ}C$ for 40 min as this resulted in maximum values for measures of gel strength including compressive force, hardness, fracturability, adhesiveness, springiness, gumminess, chewiness and resilience. Chicken surimi gel formed by cooking at a heating rate of $1^{\circ}C/min$ to $90^{\circ}C$ showed better a texture than gels produced at $1.85^{\circ}C/min$. Our result show that a lower rate of heating improves chicken surimi gelation.

A Selective Motion Estimation Algorithm with Variable Block Sizes (다양한 블록 크기 기반 선택적 움직임 추정 알고리즘)

  • 최웅일;전병우
    • Journal of Broadcast Engineering
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    • v.7 no.4
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    • pp.317-326
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    • 2002
  • The adaptive coding schemes in H.264 standardization provide a significant ceding efficiency and some additional features like error resilience and network friendliness. The variable block size motion compensation using multiple reference frames is one of the key H.264 coding elements to provide main performance gain, but also the main culprit that increases the overall computational complexity. For this reason, this paper proposes a selective motion estimation algorithm based on variable block size for fast motion estimation in H.264. After we find the SAD(Sum of Absolute Difference) at initial points using diamond search, we decide whether to perform additional motion search in each block. Simulation results show that the proposed method is five times faster than the conventional full search in case of search range $\pm$32.