• 국제학술발표논문집
• /
• The 6th International Conference on Construction Engineering and Project Management
• /
• pp.304-309
• /
• 2015

On construction sites, it is important to monitor the performance of construction equipment and workers to achieve successful construction project management; especially, vision-based detection methods have advantages for the real-time site data collection for safety and productivity analyses. Although many researchers developed vision-based detection methods with acceptable performance, there are still limitations to be addressed: 1) sensitiveness to the shape and appearance changes of moving objects in difference working postures, and 2) high computation time. To deal with the limitations, this paper proposes a detection algorithm of construction equipment based on Integral Channel Features. For validation, 16,850 frames of video streams were recorded and analyzed. The results showed that the proposed method worked in high performance in terms of accuracy and processing time. In conclusion, the developed method can help to understand useful site information including working pattern, working time and input manpower analyses.

• 방사성폐기물학회지
• /
• 제17권2호
• /
• pp.245-261
• /
• 2019

원자력이용시설에서 유출된 방사성 오염물질은 지표수나 지하수의 유동에 따라 이동할 수 있다. 이 중에 지표수에 의해 이동하는 오염물질은 비교적 감시가 용이하지만, 지하수를 따라 이동하는 오염물질은 대상 매질에서의 지하수흐름에 대한 정보를 알아야 하므로 감시가 매우 어렵다. 그러므로 지하수에 의한 오염물질의 이동을 규명하기 위해서 지질환경의 특성화가 선행되어야 한다. 본 연구에서는 연구부지에 건설된 가상의 원자력이용시설에 대한 감시공의 위치를 결정하고, 감시공에서의 심도별 감시 구간을 선정하는 방법론을 제안하였다. 감시공의 위치를 결정하기 위해 지하수유동 모델링을 수행하였고, 그 결과 지하수 흐름의 하류 지역에 감시공의 위치를 선정하였으며, 감시공에서 수행한 현장조사 결과를 바탕으로 비교적 지하수의 흐름이 빠른 구간을 대상으로 감시 구간을 선정하였다. 본 연구를 통해 개발된 모니터링 방법론은 국내 원자력 발전소를 포함한 원자력이용시설 뿐만 아니라, 유류비축시설의 오염물질, 농업 관련 지하수 오염의 감시 등 다양한 분야에서 잠재적으로 지하수에 유입될 수 있는 오염물질을 조기 감시하는 데에 활용할 수 있을 것이다.

• Journal of Forest and Environmental Science
• /
• 제32권2호
• /
• pp.219-235
• /
• 2016

Forest tree diversity inventory and its periodical monitoring are important to understand changes in tree population structure and to provide information useful for biodiversity conservation and reserve management. In a long-term forest dynamics program in Indian tropical dry evergreen forest, this communication deals with tree diversity changes at decadal interval. The initial inventory of tree diversity was carried out in 2003, in four tropical dry evergreen forest sites - (much disturbed sites Shanmuganathapuram - SP and Araiyapatti - AP and moderately disturbed sites - Karisakkadu - KR and Maramadakki - MM) on the Coromandel Coast of peninsular India, by establishing four 1ha permanent plots, one in each site. In 2013, the four plots were re-inventoried for tree diversity (${\geq}10cm\;gbh$) changes which yielded 56 species from 46 genera and 26 families. The studied forest sites are threatened by disturbance due to multiple reasons; cutting of trees inside of the forest, grazing by goats, construction of temple approach road, and some aspects cultural attachment of local people like constructing new, additional strctures of temple by denuding a portion of forest etc.. Tree species richness over a decade increased by four species in site SP, two species in site AP, and one species in site KR, but decreased by one species in site MM. Tree density decreased drastically by 480 (28.92%) and 102 (12.63%) stems $ha^{-1}$ respectively in sites SP and AP, but moderately increased by 82 (12.09%) stems $ha^{-1}$ in site KR and 26 (3.46%) stems $ha^{-1}$ in site MM. Tree basal area declined in site KR from $21.6m^2$ to $20.26m^2ha^{-1}$ and in site SP from 21.1 to $20.38m^2ha^{-1}$, but increased from $19.1m^2$ to $19.43m^2$ and from 15.5 to $18.63m^2ha^{-1}$ in sites AP and MM respectively. Three tree species (Allophylus serratus, Maytenus emarginata and Ehretia pubescens) were lost out of the 57 species recorded in 2003, and two species (Jatropha gossypiifolia and Streblus asper) were new additions in ten years. The long-term forest monitoring data will be valuable to understand forest dynamics and for conservation and management of this and similar tropical forests.

• 한국환경과학회지
• /
• 제18권9호
• /
• pp.941-952
• /
• 2009

The urban microscale wind field around the air quality monitoring station was investigated in order to check how a building complex influences it. For this study as the high density areas Jwa-dong and Yeonsan-dong monitoring sites in Busan were chosen. As the direction of inflow which is perpendicular to the building of the monitoring station was expected to cause the considerable variation of the wind field, that direction was selected. The model Envi-met was used as the diagnostic numerical model for this study. It is suitable for this investigation because Envi-met has the microscale resolution. After simulating it, on the leeward side around a building complex the decrease of flow velocity and some of vortexes or circulation area were discovered. In addition, on the edge of the top at the building and at the back of the building the upward flow was developed. If the sampling hole of monitoring site were located in this upward flow, it would be under the influence of upward flow from the near street.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2004년도 춘계학술발표회
• /
• pp.11-19
• /
• 2004

When pile foundation constructed by driving method, it is desirable to perform monitoring and estimation of pile drivability and bearing capacity using some suitable tools. Dynamic Pile Monitoring yields information regarding the hammer, driving system, and pile and soil behaviour that can be used to confirm the assumptions of wave equation analysis. Dynamic Pile Monitoring is performed with the Pile Driving Analyser. The Pile Driving Analyser (PDA) uses wave propagation theory to compute numerous variables that fully describe the condition of the hammer-pile-soil system in real time, following each hammer impact. This approach allows immediate field verification of hammer performance, driving efficiency, and an estimate of pile capacity. The PDA has been used widely as a most effective control method of pile installations. A set of PDA test was performed at the site of Donghea-1 Gas Platform Jacket which is located east of Ulsan. The drilling core sediments of location of jacket subsoil are composed of mud and sand, silt. In this case study, the results of PDA test which was applied to measurement and estimation of large diameter open ended steel pipe pile driven by underwater hydraulic hammer, MHU-800S, at the marine sediments were summarized.

• 한국전산구조공학회:학술대회논문집
• /
• 한국전산구조공학회 2002년도 가을 학술발표회 논문집
• /
• pp.330-337
• /
• 2002

The HANARO seismic monitoring system is classified as non-nuclear safety(NNS), seismic category I, and quality class T The seismic monitoring system installed at the instrument room consists of five field sensors and one monitoring cabinet. The field sensors are composed of three triaxial accelerometers which installed at base slab, free field and overhead crane support respectively, a seismic trigger and a seismic switch at base slab. The most parts of analog system except field sensors are not produced any more, the improvement of the system is to be needed. The analog system with magnetic tape recorder is not only out-of-date model but dependent upon foreign technology. So it is difficult to get the spare parts and the cost to buy them is increased. Therefore we have improved the analog seismic monitoring system into a new digital seismic monitoring analysis system(SMAS) except five field sensors. After the installation of the new SMAS, we have carried out the site acceptance test(SAT) to confirm the field functions. The results of SAT satisfy the requirements of the fabrication technical specification. This new SMAS is operating at HANARO instrument room to acquire and analyse the signal of earthquake.

• Corrosion Science and Technology
• /
• 제15권6호
• /
• pp.271-280
• /
• 2016

An approach to achieving the ambitious goal of cost effectively extending the safe operation life of energy pipeline to 100 years is the application of health monitoring and life prediction tools that are able to provide both long-term remnant pipeline life prediction and in-situ pipeline condition monitoring. A critical step is the enhancement of technological capabilities that are required for understanding and quantifying the effects of key factors influencing buried steel pipeline corrosion and environmentally assisted materials degradation, and the development of condition monitoring technologies that are able to provide in-situ monitoring and site-specific warning of pipeline damage. This paper provides an overview of our current research aimed at developing new sensors and electrochemical cells for monitoring, categorising and quantifying the level and nature of external pipeline and coating damages under the combined effects of various inter-related variables and processes such as localised corrosion, coating cracking and disbondment, cathodic shielding, transit loss of cathodic protection.

• 대한원격탐사학회:학술대회논문집
• /
• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
• /
• pp.37-37
• /
• 2003

Rice is one of the most important crop in the world and is a major export of Thailand. Optical sensors are not useful for rice monitoring, because most cultivated areas are often obscured by cloud during the growing period, especially in South East Asia. Spaceborne Synthetic Aperture Radar (SAR) such as RADARSAT, can see through regardless of weather condition which make it possible to monitor rice growth and to retrieve rice acreage, using the unique temporal signature of rice fields. This paper presents the result of a study of examining the backscatter behavior of rice using multi-temporal RADARSAT dataset. Ground measurements of paddy parameters and water and soil condition were collected. The ground truth information was also used to identify mature rice crops, orchard, road, residence, and aquaculture ponds. Land use class distributions from the RADARSAT image were analyzed. Comparison of the mean DB of each land use class indicated significant differences. Schematic representation of temporal backscatter of rice crop were plotted. Based on the study carried out in Pathum Thani Province test site, the results showed variation of sigma naught from first tillering vegatative phase until ripenning phase. It is suggested that at least, three radar data acquisitions taken at 3 stages of rice growth circle namely; those are at the beginning of rice growth when the field is still covered with water, in the ear differentiation period, and at the beginning of the harvest season, are required for rice monitoring. This pilot project was an experimental one aiming at future operational rice monitoring and potential yield predicttion.

• 한국지하수토양환경학회지:지하수토양환경
• /
• 제20권1호
• /
• pp.1-6
• /
• 2015

The objectives of this study were to calculate the radius of influence (ROI) of well for an air-sparging (AS)/soil vapor extraction (SVE) system and to evaluate the applicability of the system applied for the remediation of the petroleum contaminated rail site. For air permeability test, three monitoring wells were installed at a location of 1.3 m, 2.3 m, 3.0 m from the extraction well. And the pressure of each monitoring well was measured by extracting air from the extraction well with the pressure and flow of $(-)2,600mmH_2O$ and $1.58m^3/min$. The ROI for an extraction well was calculated as 4.31 m. Air was injected into the injection well with the pressure and flow of $3,500mmH_2O$ and $0.6m^3/min$ to estimate the radius of influence for oxygen transfer. Oxygen concentrations of air from three monitoring wells were measured. The ROI of an injection well for oxygen transfer was calculated as 3.46 m. The 28 extraction wells and 19 injection wells were installed according to the ROI calculated. The AS/SVE system was operated eight hours a day for five months. The rail site was contaminated with the petroleum and concentrations of benzene, toluene, and xylene were over the 'Worrisome Standard' of the 'Soil Environment Conservation Act'. The contaminated area was estimated as $732m^2$ and contaminants were dispersed up to (-)3 m from the ground. During the operation period, soil samples were collected from 5 points and analyzed periodically. With the AS/SVE system operation, concentrations of benzene, toluene, and xylene were decreased from 7.5 mg/kg to 2.0 mg/kg, from 32.0 mg/kg to 23.0 mg/kg, from 35.5 mg/kg to 23.0 mg/kg, respectively. The combined AS/SVE system applied to the rail site contaminated with volatile organic compounds (VOCs) exhibited a high applicability. But the concentration of contaminants in soil were fluctuated due to the heterogeneous of soil condition. Also the effect of the remediation mechanisms was not clearly identified.

• 한국지반환경공학회 논문집
• /
• 제13권10호
• /
• pp.15-23
• /
• 2012

본 연구에서는 산지 지형에서 토취장을 개발할 경우 상부의 지반 굴착으로 인한 지하수계의 변화를 현장 계측자료와 모델링을 활용하여 예측하고자 하였다. 9개소의 시추조사를 통하여 지층 분포와 수리상수를 구하고 현장 지하수위 조사를 실시하였으며, 물수지 분석에 의한 지하수 함양량을 추정한 후 Modflow 프로그램에 적용함으로써 지하수위 변화를 예측하였다. 토취장 개발로 40 El.m 이상 지역이 제거될 경우를 가정하여 부정류 모델링을 수행한 결과, 토취장 최인접 지역에서 최대 1m 정도의 지하수위 강하가 나타나는 것으로 예측되었다. 또한, 절토로 인한 상부 지형의 제거는 9.4% 및 7.0%의 지하수 함양량과 지표 유출량의 감소를 초래하는 것으로 예측되었는데, 이는 지하수위 변화를 야기하는 요인으로 평가되었다. 향후 토취장 개발이 시작되면 이와 같은 지하수위 변화를 지속적으로 파악하기 위하여 지하수 관측정을 설치 운영할 필요가 있다.