• Title/Summary/Keyword: Environmental Aging

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Geometric and structural assessment and reverse engineering of a steel-framed building using 3D laser scanning

  • Arum Jang;Sanggi Jeong;Hunhee Cho;Donghwi Jung;Young K. Ju;Ji-sang Kim;Donghyuk Jung
    • Computers and Concrete
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    • v.33 no.5
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    • pp.595-603
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    • 2024
  • In the construction industry, there has been a surge in the implementation of high-tech equipment in recent years. Various technologies are being considered as potential solutions for future construction projects. Building information modeling (BIM), which utilizes advanced equipment, is a promising solution among these technologies. The need for safety inspection has also increased with the aging structures. Nevertheless, traditional safety inspection technology falls short of meeting this demand as it heavily relies on the subjective opinions of workers. This inadequacy highlights the need for advancements in existing maintenance technology. Research on building safety inspection using 3D laser scanners has notably increased. Laser scanners that use light detection and ranging (LiDAR) can quickly and accurately acquire producing information, which can be realized through reverse engineering by modeling point cloud data. This study introduces an innovative evaluation system for building safety using a 3D laser scanner. The system was used to assess the safety of an existing three-story building by implementing a reverse engineering technique. The 3D digital data are obtained from the scanner to detect defects and deflections in and outside the building and to create an as-built BIM. Subsequently, the as-built structural model of the building was generated using the reverse engineering approach and used for structural analysis. The acquired information, including deformations and dimensions, is compared with the expected values to evaluate the effectiveness of the proposed technique.

Feasibility of Tobacco(Nicotiana tabacum L.) for Phytoremediation of Soil Contaminated with Zn and Cu (Zn 및 Cu 오염토양에서 담배에 의한 복원 탐색)

  • Lee, Sang-Gak;Kang, Byeung-Hoa
    • Korean Journal of Environmental Agriculture
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    • v.20 no.4
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    • pp.211-217
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    • 2001
  • This study was conducted to evaluate the effect of Zn and Cu on physiological responses of tobacco at the different leaf ages for the purpose of phytoremediation of heavy metal contaminated field. Plant height was significantly decreased at Zn and Cu concentrations of 1.0 mM or higher. Especially, root dry weight decreased more (50% reduced) than shoot dry weight. Zn and Cu accumulation in the shoot and root was dramatically increased after 2.0 mM treatment. The accumulation pattern was different by leaf aging in that Zn accumulated more in senescence leaf and Cu accumulated more in growing leaf. The amounts of heavy metal accumulations per plant were 146,000 mg/kg for Zn and 20,500 mg/kg for Cu at 2.0 mM treatment. The proper harvesting time would be suggested as vegetative growth stage for Zn and reproductive stage for Cu. The concentrations of other inorganic ions (Mg, Mn, Fe) were decreased when Zn and Cu concentrations were increased. Cu concentration and Zn concentration of both shoot and root were decreased in Zn treatment and Cu treatment, respectively.

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Determination of Amino Acids on Wintertime PM2.5 using HPLC-FLD (HPLC-FLD를 이용한 겨울철 PM2.5 중 아미노산 성분 분석)

  • Park, Da-Jeong;Cho, In-Hwan;Bae, Min-Suk
    • Journal of Korean Society for Atmospheric Environment
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    • v.31 no.5
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    • pp.482-492
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    • 2015
  • Ground-based measurements were conducted from January 6 to 12 of 2015 for understanding characteristics of nitrogen containing carbonaceous aerosols as 16 amino acids at the Mokpo National University, Korea. The detailed amino acid components such as Cystine ($(SCH_2CH(NH_2)CO_2H)_2$) and Methionine ($C_5H_{11}NO_2S$) and their sources were analyzed by High-Performance Liquid Chromatography with Fluorescence Detection (HPLC-FLD) for behavior of secondary products in particulate matter. In addition, organic carbon (OC) and elemental carbon (EC) based on the carbonaceous thermal distribution (CTD), which provides detailed carbon signature characteristics relative to analytical temperature, and water soluble organic carbon (WSOC) by total organic carbon (TOC) analyzer were used to understand the carbon compound behaviors. The backward trajectories were discussed for originations of carbonaceous aerosols as well. Different airmasses were classified with the amino acids and OC thermal signatures. The results can provide to understand the aging process influenced by the long-range transport from East Sea area.

Development of Tunnel-Environment Monitoring System and Its Installation I -Monitoring System and Measurement in Subway Tunnel- (터널 환경측정 시스템 개발 및 측정 I -개발 시스템 및 지하철터널 측정-)

  • Park, Won-Hee
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.12
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    • pp.8608-8615
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    • 2015
  • We developed a system that can collect and transmit real-time environmental data such as temperature, humidity, wind direction, and wind speed, and equipment performing aging tests on fire detectors. This system was installed in three representative sites of railway tunnels in South Korea such as Gumjung, Solan, Seoul Subway Line 4 tunnels. The systems showed a stable performance and collected environmental data for over a year. We analyzed environmental data collected by two of our developed systems installed in the running tunnels of Gwacheon Line of Seoul Subway Line 4. The developed system was capable of safely analyzing tunnel environments for 24 h straight using a wireless communication network, and has potential for use in a variety of fields other than tunnels.

Characteristics of Carbonaceous Aerosols Measured at Gosan - Based on Analysis of Thermal Distribution by Carbon Analyzer and Organic Compounds by GCMS (제주도 고산지역 탄소 성분의 특성 분석 - 유기탄소의 열광학적 특성 및 유기성분 중심으로)

  • Bae, Min-Suk;Park, Seung-Shik;Kim, Young Joon
    • Journal of Korean Society for Atmospheric Environment
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    • v.29 no.6
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    • pp.722-733
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    • 2013
  • Ground-based measurements were conducted from August 25 to September 8 of 2011 for understanding characteristics of carbonaceous aerosols measured at Gosan. Chemical components and their sources were discussed by analysis of organic compounds with identification of primary and secondary products in particulate matter. Thus, organic carbon (OC) and elemental carbon (EC) based on the carbonaceous thermal distribution (CTD), which provides detailed carbon signature characteristics relative to analytical temperature, was used to improve the carbon fractionation of the analytical method. In addition, organic compounds by gas chromatography technique with the backward trajectories were discussed for characteristics of carbonaceous aerosols. Different air-masses were classified related to the OC thermal signatures and the organic molecular markers such as aromatic acids and PAHs. We concluded that the aging process was influenced by the long-range transport from East Sea area.

Determining the Time of Least Water Use for the Major Water Usage Types in District Metered Areas (상수관망 블록의 대표적인 용수사용 유형에 대한 최소 용수사용 시간의 결정)

  • Park, Suwan;Jung, So-Yeon;Sahleh, Vahideh
    • Journal of Korean Society of Water and Wastewater
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    • v.29 no.3
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    • pp.415-425
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    • 2015
  • Aging water pipe networks hinder efficient management of important water service indices such as revenue water and leakage ratio due to pipe breakage and malfunctioning of pipe appurtenance. In order to control leakage in water pipe networks, various methods such as the minimum night flow analysis and sound waves method have been used. However, the accuracy and efficiency of detecting water leak by these methods need to be improved due to the increase of water consumption at night. In this study the Principal Component Analysis (PCA) technique was applied to the night water flow data of 426 days collected from a water distribution system in the interval of one hour. Based on the PCA technique, computational algorithms were developed to narrow the time windows for efficient execution of leak detection job. The algorithms were programmed on computer using the MATLAB. The presented techniques are expected to contribute to the efficient management of water pipe networks by providing more effective time windows for the detection of the anomaly of pipe network such as leak or abnormal demand.

A Study on the Medical Environmental Factor and Distinction of Medical Facilities for the Elderly in Berlin (베를린 노인의료 환경요인과 시설특성에 관한 연구)

  • Chai, Choul-Gyun
    • Journal of The Korea Institute of Healthcare Architecture
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    • v.17 no.1
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    • pp.15-22
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    • 2011
  • Nowadays, a proportion of healthcare service for the elderly has been improved due to the factors, such as a prolonged life expectancy, a growth of aging population and a change of member of family. For these factors, it is necessary for the elderly to receive treatment for multidisciplinary diseases, associated with psychological care of sociological concept. It is quite difficult in an acute-care hospital to accommodate the elderly patient because of the fact that an acute-care hospital is required to maintain a high level of medical care and technical standard. That is why specialized medical service is needed for the elderly. In the case of Germany, they are at the stage of the change from large scale facilities to specialized facilities applying the integrated concept. This paper addresses the medical environmental factor and distinction of medical facilities for the elderly through survey and analysis relating to all change in Germany. Therefore, it aims to suggest a fundamental resource for architectural planning and network of medical facilities for the elderly.

Uncertainty quantification for structural health monitoring applications

  • Nasr, Dana E.;Slika, Wael G.;Saad, George A.
    • Smart Structures and Systems
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    • v.22 no.4
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    • pp.399-411
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    • 2018
  • The difficulty in modeling complex nonlinear structures lies in the presence of significant sources of uncertainties mainly attributed to sudden changes in the structure's behavior caused by regular aging factors or extreme events. Quantifying these uncertainties and accurately representing them within the complex mathematical framework of Structural Health Monitoring (SHM) are significantly essential for system identification and damage detection purposes. This study highlights the importance of uncertainty quantification in SHM frameworks, and presents a comparative analysis between intrusive and non-intrusive techniques in quantifying uncertainties for SHM purposes through two different variations of the Kalman Filter (KF) method, the Ensemble Kalman filter (EnKF) and the Polynomial Chaos Kalman Filter (PCKF). The comparative analysis is based on a numerical example that consists of a four degrees-of-freedom (DOF) system, comprising Bouc-Wen hysteretic behavior and subjected to El-Centro earthquake excitation. The comparison is based on the ability of each technique to quantify the different sources of uncertainty for SHM purposes and to accurately approximate the system state and parameters when compared to the true state with the least computational burden. While the results show that both filters are able to locate the damage in space and time and to accurately estimate the system responses and unknown parameters, the computational cost of PCKF is shown to be less than that of EnKF for a similar level of numerical accuracy.

Distinguishing the Effects of Environmental Stress and Forest Succession on Changes in the Forest Floor

  • Arthur, Mary A.;Ruth D. Yanai
    • The Korean Journal of Ecology
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    • v.23 no.2
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    • pp.83-88
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    • 2000
  • When interpreting change over time in forest ecosystems, distinguishing the effects of forest succession from the effects of environmental stress can be difficult. The result may be a simplistic interpretation. citing a specific successional or environmental cause of forest change when both types may be occurring. We present two case studies of changes in the forest floor in northern hardwoods. First, the belief that 50% of soil organic matter is lost in the first 20 years after logging was based on a study comparing northern hardwood stands of different ages. We resampled a series of 13 such stands after an interval of 15 years, and found that the young stands were not, in fact. losing organic matter as rapidly as predicted from the original chronosequence study. The pattern of higher organic matter content in the forest floors of older stands compared to young stands could be equally well explained by changes in logging practices over the last century as by the aging of the stand. The observed pattern of forest floor organic matter as a function of stand age was previously interpreted as a successional pattern, ignoring changes in treatment history. In the second case study, observed losses of base cations from the forest floor were attributed to cation depletion caused by acid rain and declining calcium deposition. We found that young stands were gaining base cations in the forest floor; losses of base cations were restricted to older stands. Differences in litter chemistry in stands of different ages may explain some of the pattern in cation gains and losses. In this case, the contribution of successional processes to cation loss had been overlooked in favor of environmental stress as the dominant mechanism behind the observed changes. Studies of environmental stress use repeated measures over time. but often don't consider stand age as a factor. Studies of successional change often assume that environmental factors remain constant. We were able to consider both forest succession and external factors because we repeatedly sampled stands of different ages.

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Study on Establishment of the Greenhouse Environment Monitoring System for Crop Growth Monitoring (작물 생식 모니터링을 위한 온실환경 모니터링 시스템 구축연구)

  • Kim, Won-Kyung;Cho, Byeong-Hyo;Hong, Youngki;Choi, Won-Sik;Kim, Kyoung-Chul
    • Journal of the Korean Society of Industry Convergence
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    • v.25 no.3
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    • pp.349-356
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    • 2022
  • Currently, the agricultural population in Korea indicates a decreasing and aging orientation. As the population of farm labor continues to decline, so farmers are feeling the pressure to be stable crop production. To solve the problem caused by the decreasing of farm labor, it is necessary to change over to "Digital agriculture". Digital agriculture is tools that digitally collect, store, analyze, and share electronic data and/or information in agriculture, and aims to integrate the several digital technologies into crop and livestock management and other processes in agriculture fields. In addition, digital agriculture can offer the opportunity to increase crop production, save costs for farmer. Therefore, in this study, for data-based Digital Agriculture, a greenhouse environment monitoring system for crop growth monitoring based on Node-RED, which even beginners can use easily, was developed, and the implemented system was verified in a hydroponic greenhouse. Several sensors, such as temperature, humidity, atmospheric pressure, CO2, solar radiation, were used to obtain the environmental data of the greenhouse. And the environmental data were processed and visualized using Node-RED and MariaDB installed in rule.box digital. The environment monitoring system proposed in this study was installed in a hydroponic greenhouse and obtained the environmental data for almost two weeks. As a result, it was confirmed that all environmental data were obtained without data loss from sensors. In addition, the dashboard provides the names of installed sensors, real time environmental data, and changes in the last three days for each environmental data. Therefore, it is considered that farmers will be able to easily monitor the greenhouse environment using the developed system in this study.