• Communications for Statistical Applications and Methods
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• 제29권4호
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• pp.487-498
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• 2022

Social network analysis (SNA) techniques have recently been developed to monitor and detect abnormal behaviors in social networks. As a useful tool for process monitoring, control charts are also useful for network monitoring. In this paper, the degree and closeness centrality measures, in which each has global and local perspectives, respectively, are applied to an exponentially weighted moving average (EWMA) chart and a multinomial cumulative sum (CUSUM) chart for monitoring undirected weighted networks. In general, EWMA charts monitor only one variable in a single chart, whereas multinomial CUSUM charts can monitor a categorical variable, in which several variables are transformed through classification rules, in a single chart. To monitor both degree centrality and closeness centrality simultaneously, we categorize them based on the average of each measure and then apply to the multinomial CUSUM chart. In this case, the global and local attributes of the network can be monitored simultaneously with a single chart. We also evaluate the performance of the proposed procedure through a simulation study.

• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2007년도 공동학술대회 논문집
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• pp.163-166
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• 2007

KMA established short period seismometer, accelerometer, and ocean bottom seismometer network to build the detail earthquake monitoring system and Tsunami monitoring system. KMA also replaced borehole seismometer and wave height meter monitoring system. The purposes of this study are to record the ambient seismic noise levels of short period seismometer and accelerometer installed in 2006 and 2007, and compare their characteristics to present the standard of site selection criteria.

• Journal of Korean Society for Atmospheric Environment
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• 제18권E1호
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• pp.21-28
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• 2002

Air quality issues in Korea rapidly changed at the beginning of the 1990s from primary to secondary pollutants starting in Seoul, the capital of Korea. The present frame of national air pollution monitoring networks was established between the end of the 1980s and the beginning of the 1990s. Background monitoring was initiated in the middle of the 1990s in response to increasing public concern about the long-range transport of air pollutants. Apart from the national monitoring, both routine and intensive measurements of fine particles have been made for research purposes since the middle of the 1990s at several background sites. However, air pollution monitoring in urban areas for other purposes was relatively scarce as national monitoring has been concentrated in these areas. Although ozone pollution has become a significant issue in major metropolitan areas every summer, only a little information on ozone precursors is available. During the past few years, the number of national monitoring stations has greatly increased. The government has a plan to gradually expand monitoring items as well as stations. It is anticipated that highly detailed information on both photochemical reactants and products will be available within the next several years. More emphasis will be placed on toxic substances based on risk assessment in monitoring for both research and policy making.

• 환경위생공학
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• 제8권2호
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• pp.25-48
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• 1993

International concern over the environmental pollution is ever increasing, and diversified countermeasures must be devised in Korea also. Global trend, damages, problems and countermeasures with respect to issues mentioned in the Rio Declaration, such as prevention of ozone layer destruction, reduction of migratory atmospheric pollution between neighboring countries, and prevention of global greenhouse effect, were discussed in this report. Conclusion of the report is summarized as follows : A. Measurement, Planning and Monitoring (1) Development and implementation of a global network for measurement and monitoring from the global aspects such factors as related to acid rain(Pioneer substances, pH, sulfate, nitrate), effect of global temperature(Air temperature, $CO_2$, $CH_4$, CFC, $N_2O$) and destruction of ozone layer($CFC_S$). (2) Establishment of network system via satellite monitoring movement of regional air mass, damage on the ozone layer and ground temperature distribution. B. Elucidation of Present State (1) Improvement and development of devices for carbon circulation capable of accurately forecasting input and output of carbon. (2) Developmental research on chemical reactions of greenhouse gas in the air. (3) Improvement and development of global circulation model(GCM) C. Impact Assessment Impact assessment on ecosystem, human body, agriculture, floodgate, land use, coastal ecology, industries, etc. D. Preventive Measures and Technology Development (1) Development and consumption of new energy (2) Development of new technology for removal of pioneer substances (3) Development of substitute matter for $CFC_S$ (4) Improvement of agriculture and forestry means to prevent the destruction of ozone layer and the greenhouse effect of the globe (5) Improvement of housing to prevent the destruction of ozone layer and the greenhouse effect of the globe (6) Development of new technology for probing underground water (7) Preservation of forest (8) Biomass 5. Policy Development (1) Development of strategy model (2) Development of long term forecast model (3) Development of penalty charge effect and expense evaluation methods (4) Feasibility study on regulations By establishing the above mentioned measures for environmentally sound and sustainable development to establish the right to live for humankind and to preserve the one and only earth.

• 한국정보통신학회논문지
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• 제16권12호
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• pp.2628-2634
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• 2012

온실가스(green house gas: GHG) 감시는 지구의 기후변화를 방지하기 위해 필수적인 수단이 되고 있다. 기존 연구에서 글로벌 인프라인 NGN(next generation network)을 통해 온실가스감시를 수행하기 위한 서비스 시나리오가 제시되었으나 추상적인 단계에 머무르고 있어서 실제로 NGN에 적용하는 데에는 어려움이 있다. 본 논문에서는 NGN 내에 탑재될 기능들을 중심으로 온실가스감시서비스 시나리오를 제시하여 실제 NGN에서 적용이 가능하게 하기 위한 기반을 제공한다.

• 한국항해항만학회지
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• 제45권4호
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• pp.181-185
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• 2021

본 연구에서는 어구의 정상 또는 유실 등의 상태 여부를 판단하기 위한 어구정보를 IoT 기반의 통신망을 이용하여 수신하고 분석하여, 어구의 현재 상태를 관리할 수 있고, 어구에 이상 상태 발생 시 이를 확인하고, 신속한 어구 회수 등의 관리를 수행할 수 있도록 지원하는 어구 부이 관리시스템을 개발하는 것에 관한 내용을 다룬다. IoT 기반의 통신망을 사용한 어구 관리 체계 및 통합 관리 구조 설계를 수행하였으며 이를 이용한 어구 부이 통합 관리 시스템을 개발하여 이에 대한 시스템 시험 및 검증을 수행하여 실효성을 확인하였다.

• 대한조선학회논문집
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• 제45권2호
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• pp.144-150
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• 2008

Ships and offshore structures are exposed to wave and engine excitation loadings during navigation and cargo/ballasting operations. These excessive loads may cause damages to hull and may result loss of life the ship. Therefore, it is important to develop a system that allow accurate measurements of global hull loads. The objective of the study is developing a fiber optic monitoring system that is capable of monitoring, recording and warning of the vessel performance. A method for measurement of global loads on a vessel, using strain measurements from a network of fiber optic strain sensors and extensive finite-element analyses(FEA) with idealistic load cases, is presented. The method has been successfully validated on the idealized ship structure model with strain sensors.

• 센서학회지
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• 제21권1호
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• pp.46-52
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• 2012

The rapid water pollution in stream, river, lake and sea in recent years raises an urgent need for continuous monitoring and policymaking to conserve the global clean environment. In particular, the increasing water pollution in coastal marine areas adds to the importance of the environmental monitoring systems. In this paper, the mobile server is designed to gathers information of the water quality at coastal areas. The obtained data by the server is transmitted from field servers to the base station via multi-hop communication in wireless sensor network. The information collected includes dissolved oxygen(DO), hydrogen ion exponent(pH), temperature, etc. By the information provided the real-time monitoring of water quality at the coastal marine area. In addition, wireless sensor network-based flooding routing protocol was designed and used to transfer the measured water quality information efficiently. Telosb sensor node is programmed using nesC language in TinyOS platform for small scale wireless sensor network monitoring from a remote server.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제17권7호
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• pp.1759-1772
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• 2023

Chinese named entity recognition (NER) is a challenging work that seeks to find, recognize and classify various types of information elements in unstructured text. Due to the Chinese text has no natural boundary like the spaces in the English text, Chinese named entity identification is much more difficult. At present, most deep learning based NER models are developed using a bidirectional long short-term memory network (BiLSTM), yet the performance still has some space to improve. To further improve their performance in Chinese NER tasks, we propose a new NER model, IDCNN-BiLSTM-Highway, which is a combination of the BiLSTM, the iterated dilated convolutional neural network (IDCNN) and the highway network. In our model, IDCNN is used to achieve multiscale context aggregation from a long sequence of words. Highway network is used to effectively connect different layers of networks, allowing information to pass through network layers smoothly without attenuation. Finally, the global optimum tag result is obtained by introducing conditional random field (CRF). The experimental results show that compared with other popular deep learning-based NER models, our model shows superior performance on two Chinese NER data sets: Resume and Yidu-S4k, The F1-scores are 94.98 and 77.59, respectively.

• Smart Structures and Systems
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• 제6권5_6호
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• pp.711-730
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• 2010

This study presents the design of autonomous smart sensor nodes for damage monitoring of tendons and girders in prestressed concrete (PSC) bridges. To achieve the objective, the following approaches are implemented. Firstly, acceleration-based and impedance-based smart sensor nodes are designed for global and local structural health monitoring (SHM). Secondly, global and local SHM methods which are suitable for damage monitoring of tendons and girders in PSC bridges are selected to alarm damage occurrence, to locate damage and to estimate severity of damage. Thirdly, an autonomous SHM scheme is designed for PSC bridges by implementing the selected SHM methods. Operation logics of the SHM methods are programmed based on the concept of the decentralized sensor network. Finally, the performance of the proposed system is experimentally evaluated for a lab-scaled PSC girder model for which a set of damage scenarios are experimentally monitored by the developed smart sensor nodes.