• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2014년도 추계학술대회
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• pp.152-153
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• 2014

이 논문에서는 XG-PON (10-Gbps-capable passive optical network) 시스템에서 ONU (optical network unit)가 전송요청을 OLT (optical line termination)에게 보내지 않는 새로운 동적대역할당 알고리즘을 제안한다. OLT는 ONU의 상향 대역폭 사용량을 monitoring하고 주기적으로 ONU에게 probe용 대역을 할당하여 ONU의 전송허가량을 추측한다.

• Tribology and Lubricants
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• 제14권3호
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• pp.74-80
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• 1998

The morphologies of the wear particles are directly indicative of wear process occuring in the machine. The analysis of wear particle morphology can therefore provide very early detection of a fault and can also ofen facilitate a dignosis. For this work, the neural network was applied to identify friction coefficient through four shape parameters (50% volumetric diameter, aspect, roundness and reflectivity) of wear debris generated from the machine. The averages of these parameters were used as inputs to the network. It is shown that collect identification of friction coefficient depends on the ranges of these shape parameters learned. The various kinds of the wear debris had a different pattern characteristics and recognized relation between the friction condition and materials very well by neural network. We discuss how the network determines difference in wear debris feature, and this approach can be applied for machine condition monitoring and fault diagnosis.

• 한국IT서비스학회지
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• 제14권1호
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• pp.159-173
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• 2015

This paper presents a study on the Internet of Things based low-power wireless sensor networks for remote monitoring of wildlife ecosystem due to climate change. Especially, it is targeting the wild vegetation communities ecological monitoring. First, we performed a pre-test and analysis for selecting the appropriate frequency for the sensor network to collect and deliver information reliably in harsh propagation environment of the forest area, and selected for sensors for monitoring wild vegetation communities on the basis of considerations for selecting the best sensor. In addition, we have presented the platform concept and hierarchical function structures for effectively monitoring, analyzing and predicting of ecosystem changes, to apply the Internet of Things in the ecological monitoring area. Based on this, this paper presents the system architecture and design of the Internet of Things based low-power wireless sensor networks for monitoring the ecosystem of the wild vegetation communities. Finally, we constructed and operated the test-bed applied to real wild trees, using the developed prototype based on the design.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2010년도 추계학술대회 논문집
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• pp.235-236
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• 2010

• Journal of Information Processing Systems
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• 제2권1호
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• pp.58-65
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• 2006

Accurate and efficient monitoring of dynamically changing environments is one of the most important requirements for ubiquitous network environments. Ubiquitous computing provides intelligent environments which are aware of spatial conditions and can provide timely and useful information to users or devices. Also, the growth of embedded systems and wireless communication technology has made it possible for sensor network environments to develop on a large scale and at low-cost. In this paper, we present the design and implementation of a monitoring system that collects, analyzes, and controls the status information of each sensor, following sensor data extracted from each sensor node. The monitoring system adopts Web technology for the implementation of a simple but efficient user interface that allows an operator to visualize any of the processes, elements, or related information in a convenient graphic form.

• 한국환경과학회지
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• 제29권8호
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• pp.847-855
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• 2020

This study presented problems and improvements in the quality control of an air monitoring network, using Gyeongnam as an example. 1) The effective utilization rate of the air monitoring was 95%, which showed good management, but the maximum of 2% was indicated by zero or detection limit among measurement data. 2) In the equivalence evaluation of PM_2.5, the slope and intercept satisfy the evaluation criteria; however, 1% of the PM_2.5/PM₁₀ ratios were outliers. 3) All air monitoring stations meet the quality control standards; however, the management status is added to the quality inspection, management system is unified and the related budget is expanded, and systematic commission management is required.

• Journal of Advanced Marine Engineering and Technology
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• 제25권4호
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• pp.869-879
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• 2001

Serial communications such as RS-232C or RS-485 have been used to control and monitor the industrial plants for a long in cooperating with a computer or microprocessor. In recent years a great deal of effort has been made to achieve these control and monitoring through Internet network. This paper proposes a microprocessor system to implement remote control and monitoring system through Internet network. The proposed system uses NE2000 compatible NIC for data link and physical layer to access Internet network The microprocessor employed in the system plays a role of interfacing NE2000 compatible NIC interpreting protocols above link layer, controlling and monitoring industrial plants simultaneously. This paper also shows MMI and experimental results which control and monitor two power plants on the computer monitor with a mouse remotely to verify the proposed.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2015년도 추계학술발표대회
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• pp.413-414
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• 2015

SDN은 네트워크 장비의 control plane과 data plane을 분리하고, 중앙의 컨트롤러를 통해 네트워크를 제어한다. 네트워크 운영에서 monitoring은 필수적인 요소이며, SDN 환경에서의 기존의 monitoring 방법인 OpenTM은 in-band network 환경을 고려하지 않았다. 본 논문은 in-band network 환경에서 hop-count와 정확도를 고려하여 높은 정확도를 유지하면서도 네트워크 부하를 줄일 수 monitoring 방법을 제안한다.

• 한국정밀공학회지
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• 제12권5호
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• pp.25-32
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• 1995

In highly automated milling process, in-process monitoring of the malfunction is indispensable to ensure efficient cutting operation. Among many malfunctions in milling process, chatter vibration deteriorates surface finish, tool life and productivity. In this study, the monitoring system of chatter vibration for face milling process is proposed and experimentally estimated. The monitoring system employs two types of sensor such as cutting force and acceleration in sensory detection state. The RMS value and band frequency energy of the sensor signals are extracted in time domain for the input patterns of neural network to reduce time delay in signal processing state. The resultes of experimental evaluation show that the system works well over a wide range of cutting conditions.

• 한국지반공학회논문집
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• 제34권9호
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• pp.19-32
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• 2018

본 연구에서는 무선센서네트워크기술(Wireless Sensor Network, WSN)의 산사태 모니터링 적용성을 연구하였다. WSN시스템은 IEEE 802.14e 표준규격을 사용하는 데이터의 수집과 전달을 위한 센서노드와 데이터를 수집 처리하고 최종 서버로 전송하는 게이트웨이로 구성하였다. 센서네트워크의 토폴로지는 유연성과 신뢰성이 높은 메쉬형을 채택하였으며, 서울시의 총 3개소에 테스트베드를 구축하였다. 산사태를 모니터링 하기 위하여 각 센서노드에는 함수비계, 모관흡수력계, 경사계, 강우량계를 설치하였다. 센서노드의 배치를 위해 산사태 위험도 해석, 임목밀도 및 지형분석을 통한 통신범위 분석을 수행하였다. 측정된 계측 데이터를 분석한 결과 네트워크의 연결은 양호하게 나타났으며, 강우에 의한 지반의 반응이 실내에서 측정한 함수비-모관흡수력과 유사한 결과를 나타났다. 따라서, 테스트베드 사례를 통해 산사태 모니터링에 적용이 가능함을 확인하였다.