• Smart Structures and Systems
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• 제17권4호
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• pp.669-690
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• 2016

Advances in sensor technologies have led to the instrumentation of sensor networks for bridge monitoring and management. For a dense sensor network, enormous amount of sensor data are collected. The data need to be managed, processed, and interpreted. Data management issues are of prime importance for a bridge management system. This paper describes a data management infrastructure for bridge monitoring applications. Specifically, NoSQL database systems such as MongoDB and Apache Cassandra are employed to handle time-series data as well the unstructured bridge information model data. Standard XML-based modeling languages such as OpenBrIM and SensorML are adopted to manage semantically meaningful data and to support interoperability. Data interoperability and integration among different components of a bridge monitoring system that includes on-site computers, a central server, local computing platforms, and mobile devices are illustrated. The data management framework is demonstrated using the data collected from the wireless sensor network installed on the Telegraph Road Bridge, Monroe, MI.

• Smart Structures and Systems
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• 제7권2호
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• pp.83-102
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• 2011

As a testbed for various structural health monitoring (SHM) technologies, a super-tall structure - the 610 m-tall Guangzhou Television and Sightseeing Tower (GTST) in southern China - is currently under construction. This study aims to explore state-of-the-art wireless sensing technologies for monitoring the ambient vibration of such a super-tall structure during construction. The very nature of wireless sensing frees the system from the need for extensive cabling and renders the system suitable for use on construction sites where conditions continuously change. On the other hand, unique technical hurdles exist when deploying wireless sensors in real-life structural monitoring applications. For example, the low-frequency and low-amplitude ambient vibration of the GTST poses significant challenges to sensor signal conditioning and digitization. Reliable wireless transmission over long distances is another technical challenge when utilized in such a super-tall structure. In this study, wireless sensing measurements are conducted at multiple heights of the GTST tower. Data transmission between a wireless sensing device installed at the upper levels of the tower and a base station located at the ground level (a distance that exceeds 443 m) is implemented. To verify the quality of the wireless measurements, the wireless data is compared with data collected by a conventional cable-based monitoring system. This preliminary study demonstrates that wireless sensing technologies have the capability of monitoring the low-amplitude and low-frequency ambient vibration of a super-tall and slender structure like the GTST.

• Membrane and Water Treatment
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• 제10권1호
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• pp.99-104
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• 2019

In Korea, nonpoint pollutants have a significant effect on rivers' water quality, and they are discharged in very different ways depending on rainfall events. Therefore, preparing an optimal countermeasure against nonpoint pollutants requires much monitoring. The present study was conducted to help prepare a method for installing an automatic nonpoint pollutant measurement system for the cost-effective monitoring of the effect of nonpoint pollutants on rivers. In the present study, monitoring was performed at six sites of a river passing through an urban area with a basin area of $454.3km^2$. The results showed that monitoring could be performed for a relatively long time interval in the upstream and downstream regions, which are mainly comprised of forests, regardless of the rainfall amount. On the contrary, in the urban region, the monitoring had to be performed at a relatively short time interval each time when the rainfall intensity changed. This was because the flow rate was significantly dependent on the rainfall's intensity. The appropriate sites for installing an automatic measurement system were found to be a site before entering the urban region, a site after passing through the urban region, and the end of a river where the effects of nonpoint pollutant sources can be well-decided. The analysis also showed that the monitoring time should be longer for the rainfall events of a higher rainfall class and for the sites closer to the river end. This is because the rainfall runoff has a longer effect on the river. However, the effect of nonpoint pollutant sources was not significantly different between the upstream and the downstream in the cases of rainfall events over 100 mm.

• Smart Structures and Systems
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• 제11권6호
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• pp.637-662
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• 2013

The Jiangyin Bridge is a suspension bridge with a main span of 1385 m over the Yangtze River in Jiangsu Province, China. Being the first bridge with a main span exceeding 1 km in Chinese mainland, it had been instrumented with a structural health monitoring (SHM) system when completed in 1999. After operation for several years, it was found with malfunction in sensors and data acquisition units, and insufficient sensors to provide necessary information for structural health evaluation. This study reports the SHM system upgrade project on the Jiangyin Bridge. Although implementations of SHM system have been reported worldwide, few studies are available on the upgrade of SHM system so far. Recognizing this, the upgrade of original SHM system for the bridge is first discussed in detail. Especially, lessons learned from the original SHM system are applied to the design of upgraded SHM system right away. Then, performance assessment of the bridge, including: (i) characterization of temperature profiles and effects; (ii) recognition of wind characteristics and effects; and (iii) identification of modal properties, is carried out by making use of the long-term monitoring data obtained from the upgraded SHM system. Emphasis is placed on the verification of design assumptions and prediction of bridge behavior or extreme responses. The results may provide the baseline for structural health evaluation.

• 한국IT서비스학회지
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• 제8권4호
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• pp.215-223
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• 2009

The workplace environment monitoring system based on IP-USN proposed in this study measures and analyzes workplace environment information so as to provide services to provide better work environment and prevent occupational accidents caused by poor, shabby labor environment. This study presents the procedures to design and develop a system that monitors noise, humidity, vibration, temperature, and sensors installed in the workplace and sounds alarm when workers enter dangerous areas or are exposed to hazards. The author actually installed the IP-USN workplace environment monitoring system in a small workplace and confirmed its effectiveness.

• 한국콘텐츠학회논문지
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• 제14권2호
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• pp.475-481
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• 2014

이 연구의 목적은 감마선 검출 시스템을 개발하여 평행구멍형 조준기와 바늘구멍 조준기를 이용하여, 각각 소동물용 감마영상 획득과 환경 방사선 검출 영상을 획득하는 것이다. 본 연구에서는 크기가 $50{\times}50mm$ 이며, 6 mm 두께의 CsI(Tl) 섬광체와 $50{\times}50mm$ 크기의 Hamamatsu H8500C 위치민감형 광전자증배관, 저항분배회로, 전치증폭기, 성형증폭기, NIM 모듈 및 아날로그 디지털 변환기로 구성된 감마카메라를 개발하였다. 또한. 바늘구멍 감마카메라와 전하결합소자 카메라를 결합하여 환경모니터링에 적용할 수 있는 장비를 개발하였다. 본 연구 결과는 평행 구멍형 조준기와 바늘구멍 조준기를 이용한 감마카메라를 각각 소동물용 감마영상 획득과 환경방사선 측정에 적용 할 수 있음을 보여주었다. 이 시스템은 소 동물전용 감마카메라와 환경방사선 측정 시스템으로 활용 될 수 있을 것이다.

• 대한환경공학회지
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• 제38권4호
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• pp.184-192
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• 2016

수심에 따른 수질 변동을 모니터링할 수 있는 수심 프로파일 모니터링시스템을 개발하여 대하천의 현장에 적용하고자 하였다. 이를 위하여 하천의 수생태 및 수환경 변화를 반영할 수 있는 핵심 항목을 도출하고, 수심별 실시간 모니터링 기법 및 시스템을 개발하였다. 모니터링 항목은 수질, 유황 및 기상 항목을 포함하도록 구성하였다. 대하천의 수심을 고려하여 1.0 m 간격으로 모니터링이 가능한 시작품을 제작하고, 한강 수질의 실시간 수심별 변동특성을 파악하기 위하여 양화선착장을 test-bed 대상지로 선정하여 모니터링시스템을 구축 운영하였다. 춘계를 대상으로 상세분석을 실시한 결과, 수온, pH, 용존산소량(DO) 및 클로로필 a 등의 항목에서 뚜렷한 일주변화 및 수심별 변화가 관찰되어 수심별 실시간 모니터링이 하천 수환경의 적절한 관리를 위한 매우 유효한 수단인 것으로 나타났다.

• Journal of Microbiology and Biotechnology
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• 제12권4호
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• pp.706-709
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• 2002

Bacterial bioluminescence has been known to be a highly valuable reporter system for its potential application as an effective and simple environmental monitoring method for toxic compounds. In this short report, we constructed a streptomycetes-Escherichia coli shuttle vector-containing bioluminescence system and evaluated its potential application for toxic compounds monitoring. The luxAB biolurninescence genes from Vibrio harveyi were cloned into a streptornycetes-E. coli shuttle vector (named pESK004) and functionally expressed in Streptomyces lividans. The recombinant S. lividans containing pESK004 exhibited an optimal biolurninescence at the optical density ($OD_{600\;nm}$) of 0.4-0.5 and aldehyde concentration of 0.005%. When the recombinant bioluminescence streptomycetes was exposed to a toxic compound such as heavy metals, chlorinated phenols, or pesticides, the bioluminescence was decreased proportionally to the concentration of toxic compound in the assay mixture. The $EC_{50}$ (effective concentration to decrease 50% of the bioluminescence prior to exposure) values in the recombinant biolurninescence streptomycetes for mercury, 2,4-dichlorophenol, and malathion were measured at 2.2 ppm, 144.0 ppm, and 82.4 ppm, respectively. The degree of sensitivity and specificity pattern toward these toxic compounds characterized in this recombinant bioluminescence streptomycetes were unique when compared with previously reported bacterial bioluminescence systems, and this revealed that a recombinant bioluminescence streptomycetes might provide an alternative or complementary system for potential environmental monitoring.

• 한국철도학회논문집
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• 제19권4호
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• pp.526-538
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• 2016

정부는 대구 지하철 대형 화재 사건을 계기로 2004년 철도안전법 제정과 동시에 철도안전 종합계획 추진을 통해 철도안전관리를 도모해 왔다. 그러나 여전히 열차 충돌, 탈선 및 화재 등 대형 인명피해로 이어질 수 있는 열차사고가 지속적으로 발생하고 있음에도 불구하고, 사후 처리 중심의 안전관리시스템이 운영되고 있는 실정이다. 따라서 본 연구에서는 기존의 분산되어 운영되고 있는 안전검지 장치 데이터를 통합하여 선제적 안전 관리를 위한 실시간 철도 안전 감시제어 시스템 개발에 대한 기본 프레임워크를 제안하고자 한다. 또한 철도 안전 감시제어 시스템의 효과적인 작동 여부를 모니터링하기 위한 안전성과모니터링지표에 대한 개발 방향을 제시하고자 한다. 제안된 프레임워크는 향후 추진될 실시간 철도 안전감시 제어시스템의 구현을 위한 기틀을 마련할 수 있을 것으로 전망된다.

• Smart Structures and Systems
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• 제11권5호
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• pp.511-531
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• 2013

Recent advances in low-cost remote monitoring systems have made it possible and practical to perform structural health monitoring (SHM) on a large scale. However, it is difficult for a single remote monitoring system to cover a wide range of SHM applications due to the amount of specialization required. For the remote monitoring system to be flexible, sustainable, and robust, this article introduces a new cost-effective, advanced remote monitoring and inspection system named DuraMote that can serve as a next generation supervisory control and data acquisition (SCADA) system for civil infrastructure systems. To evaluate the performance of DuraMote, we conduct experiments at two representative counterpart sites: a bridge and water pipelines. The objectives of this article are to improve upon the existing SCADA by integrating the remote monitoring system (i.e., DuraMote), to describe a prototype SCADA for civil engineering structures, and to validate its effectiveness with long-term field deployment results.