• 한국지하수토양환경학회지:지하수토양환경
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• 제26권6호
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• pp.186-195
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• 2021

In Korea, groundwater quality is monitored through National Groundwater Quality Monitoring Network (NGQMN) administered by Ministry of Environment. For a given contaminant, compliance to groundwater quality standards is assessed on a annual basis by monitoring the number of incidents that concentration exceeds the regulatory limit. However, this approach provides only a fractional information about groundwater quality degradation, and more crucial information such as location and severity of the contamination cannot be obtained. For better groundwater quality management on a watershed, a more spatially informative and intuitive method is required. This study presents two statistical methods to convert point-wise monitoring data into information on groundwater quality status of a watershed by using a proposed grading scale. The proposed grading system is based on readily available reference standards that classify the water quality into 4 grades. The methods were evaluated with NO₃^-, Cl^-, and total coliform data in Geum River basin. The analyses revealed that groundwater in most watersheds of Geum River basin is good for domestic or/and drinking with no treatment. But, there was notable quality degradation in Bunam seawall and So-oak downstream standard watersheds contaminated by NO₃^- and Cl^-, respectively.

• 한국통신학회:학술대회논문집
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• 한국통신학회 2006년도 하계종합학술발표회 논문 초록집
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• pp.366-366
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• 2006

• Spatial Information Research
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• 제20권2호
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• pp.25-34
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• 2012

대구지역은 주위가 산으로 둘러싸인 분지형 도시이기 때문에 대기 환경 쾌적성이 타 도시 보다 낮은 편이다. 따라서 본 연구에서는 대구지역 자동대기오염측정소의 위치를 일산화탄소(CO) 배출량 분포에 기초하여 CO를 체계적으로 관리하기위한 적합한 장소에 대해 조사하였다. 이를 위하여 현재 대구지역 CO 관리정책 수립에 기초자료를 제공하는 자동대기측정소의 위치 적절성에 대하여 평가하였다. 대구시 수치지도와 환경부에서 제공하는 CAPSS(대기정책지원시스템 ; Clean Air Policy Support System) 자료를 활용하여 배출량 지도를 작성하였다. 도로, 아파트, 공장, 소각장 4가지로 구분하여 배출량을 입력한 뒤 법정동별 평균 배출량을 산출하였다. CO 배출지역을 고 배출량 지역과 저 배출량 지역 10단계로 구분하고 현재 측정소가 어느 단계에 해당하는지 조사하였다. 결과적으로, 저 배출량 지역 보다는 CO 고 배출량 지역에 해당하는 측정소가 부족한 것으로 나타났다. 특히, 1999년부터 2007년까지 공통적으로 추가 설치가 필요하다고 나온 국우동 외 6곳에 CO 측정망이 설치된다면 보다 다양한 기초 자료의 제공으로 체계적인 CO 관리가 가능할 것으로 판단된다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.601-605
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• 2007

This paper describes the experimental method to monitor the structural integrity. The crack on structures changes the wave propagation characteristics of structures. To monitor this change, frequency dependent variation of dynamic stiffness of beam structures is obtained by using beam transfer function method, and its trends are compared to undamaged one for identifying the location and size of the crack. Piezoelectric actuators were used to generate flexural vibrations. It eliminated various restrictions of continuously measuring wave propagation characteristics and monitoring structural integrity. The structural integrity was identified with minimal number of measurements and smart structures employing PZT actuations.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.1382-1385
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• 2007

In this paper, we study about the measuring algorithm that can implement Structural Health Monitoring (SHM) more efficiently by two measurement methods using smart sensor. Through the impedance measurement method, the damage condition of structures on wide area is monitored first, and then it changes the mode to guided wave measurement mode by mode switching algorithm when impedance measurement mode detects abnormal signals. Efficient handling of the real-time data would be available by analyzing location and shape of damage through guided wave measurement.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.959-961
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• 2003

Cirrus clouds observation was conducted using a lidar system in order to measure their height, thickness and optical depth at Kwangju (35$^{\circ}$10'N, 126$^{\circ}$53'), Korea in winter, December 2002, and spring March and April 2003. Cirrus clouds at high altitude can be distinguished from atmospheric aerosols location by high depolarization ratio and high altitude. Cirrus clouds were observed at 5${\sim}$12km altitudes with a high depolarization ratio from 0.2 to 0.5. Optical depth of cirrus clouds had varied from 0.28 to 1.81. Radiative effect of observed cirrus cloud on climate system was estimated to be negative net flux from ?0.24 to ?31.04 W/m$^{2}$.

• 지구물리
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• 제7권1호
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• pp.61-72
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• 2004

실시간으로 수집된 환경방사능 데이터 및 차량위치정보를 무선통신망을 통해 전송 받아 지도 상에 표출하고 핵종별 수집시간대별 분석 및 차량 위치별 수집데이터 분석 등의 통계분석기능과 결과물의 문서출력기능을 지원하고 다수의 감시차량 관제 및 관리가 가능한 서버 클라이언트 환경의 환경방사능 감시 차량관제 시스템을 개발하였다

• 한국해양공학회지
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• 제19권4호
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• pp.21-27
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• 2005

Large welded structures, including ships and offshore structures, are normally in operation under cyclic fatigue loadings. These structures include many geometric discontinuities, as well as material discontinuities due to weld joints. The fatigue strength at these hot spots is very important for the structural performance. In the past, various Non Destructive Evaluation (NDE) techniques have been developed to detect fatigue cracks and to estimate their location and size. However, an important limitation of most of the existing NDE methods is that they are off line; the normal operation of the structure has to be interrupted, and the device often has to be disassembled. This study explores the development of a structural health monitoring system, with a special interest in applying the technique to welded structural members in ship and offshore structures. In particular, the impedance based structural health monitoring technique that employs the coupling effect of piezoceramic (PZT) materials and structures is investigated.

• 디지털산업정보학회논문지
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• 제6권4호
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• pp.67-73
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• 2010

A Wireless Sensor Network(WSN) is a promising infrastructure for the future U-healthcare system. In a WSN for the U-healthcare system, both biometric data and location data are transferred hierarchically from lots of mobile patients to the base station server and some countermeasures are made in real time if necessary. In this process, we encounter the load-balancing problem when many patients gather in a specific area. We also encounter the data duplication problem when each patient moves into an area monitored by several supervisors. The second problem is closely related to the first one. In this paper, we propose a mobile patient monitoring system with priority-based policy in load-balancing to solve the previous two problems and perform a DEVS Java-based system simulation to verify the system efficiency.

• Smart Structures and Systems
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• 제2권3호
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• pp.275-293
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• 2006

For health monitoring purpose usually the structure is instrumented with a large scale and multichannel measurement system. In case of highway bridges, operating vehicle could be utilized to reduce the number of measuring devices. First this paper presents a static damage detection algorithm of using operating vehicle load. The technique has been validated by finite element simulation and simple laboratory test. Next the paper presents an approach of using this technique to field application. Here operating vehicle load data has been used by instrumenting the bridge at single location. This approach gives an upper hand to other sophisticated global damage detection methods since it has the potential of reducing the measuring points and devices. It also avoids the application of artificial loading and interruption of any traffic flow.