• Toxicological Research
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• v.8 no.2
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• pp.317-329
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• 1992

Fifty chemicals are currently classified as human carcinogens based on epidemiologic and animal data. Humans are daily exposed to them from various sources of exposure via inhalation, dermal contact and oral ingestion. To reduce cancer risk to man, these human carcinogens should be appropriately regulated and monitored environmentally or biologically for routine human cancer risk assessment. A number of mathematical risk assessment models have been introduced, but any realistic and relevant model system is not available for humans. A mechanistic process for human cancer risk assessment was comprehensively reviewed and problems were also discussed. Here, a new conceptual approach using epidemiology and biological human monitoring was suggested for the most relevant method to study human cancer risk assessment.

• Journal of Sensor Science and Technology
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• v.24 no.5
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• pp.306-310
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• 2015

IoT(Internet of Things) based underground risk assessment system surrounding water pipeline enables an advanced monitoring and prediction for unexpected underground hazards such as abrupt road-side subsidence and urban sinkholes due to a leak in water pipeline. For the development of successful assessment technology, the PSU(Water Pipeline Safety Unit) which detects the leakage and movement of water pipes. Then, the IoT-based underground risk assessment system surrounding water pipeline will be proposed. The system consists of early detection tools for underground events and correspondence services, by analyzing leakage and movement data collected from PSU. These methods must be continuous and reliable, and cover certain block area ranging a few kilometers, for properly applying to regional water supply changes.

• Nuclear Engineering and Technology
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• v.52 no.11
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• pp.2638-2651
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• 2020

Nozzle corner cracks present at the intersection of reactor pressure vessels (RPVs) and inlet or outlet nozzles have been a persistent problem for a number of years. The fracture analysis of such nozzle corner cracks is very important and critical for the efficient design and assessment of the structural integrity of RPVs. This paper aims to perform an engineering critical assessment of RPVs with nozzle corner cracks subjected to several transients accompanied by pressurized thermal shocks. The critical crack size of the RPV model with nozzle corner cracks under transient loading is evaluated on failure assessment curve. In particular, the influence of cladding on the crack initiation of nozzle corner crack under thermal transients is studied. The influence of primary internal pressure and secondary thermal stress on the stress field at nozzle corner and SIF at crack front is analyzed. Finally, the influence of different crack size and crack shape on the final critical crack size is analyzed.

• Journal of Environmental Impact Assessment
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• v.22 no.6
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• pp.745-751
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• 2013

Environmental Specimen Banks (ESBs) have been established widely in the world since 1979 for monitoring long-term bio-accumulation of environmental pollutants. The ESBs perform the retrospective analysis of representative biological samples collected regularly and store them in cryogenic condition. In Korea, National Environmental Specimen Bank (NESB) was established in 2009. Since then, NESB had prepared the standard operating procedures (SOPs) for the seven kinds of specimens (Red Pine (Pinus densiflora), Common Carp (Cyprinus carpio), and etc.) for monitoring the effect of environmental pollution on the terrestrial ecosystem and river ecosystem. In 2012, NESB added Black-tailed Gull (Larus crassirostris)'s eggs to the list of the environmental specimen for monitoring marine environmental pollution. In this study, we sampled the eggs of the Black-tailed Gull on two islands (Baekryeongdo of the West Sea and Hongdo of the South Sea). Especially, we selected eggs which remained in the early stages of embryo development for certifying the consistent and stable monitoring for environmental pollutants in egg contents. However, it was not considered to classify an order of eggs per clutch in this study. It is known that the concentration variations of pollutants exist among eggs in one clutch. Therefore, it is needed to consider the positions of eggs in the laying sequences to meet the objective of bioaccumulation monitoring. We collected 30 eggs in each site but the amount may be insufficient to achieve storage target (over 2,000 g). Therefore, we need to consider an optimal sampling size.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2006.05a
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• pp.89-90
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• 2006

• Korean Journal of Remote Sensing
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• v.33 no.5_3
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• pp.799-807
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• 2017

Environmental impact assessment is a regulation that is implemented to reduce harmful environmental impacts of development projects. However, The environmental value is difficult to quantify and the uncertainty, There is a problem of objectivity and reliability of the system is consistently pointed out. Therefore, the necessity of the data-based environmental impact assessment system is gradually increasing. Especially, environmental impact assessment is highly applicable to environmental spatial information because it contains about the development of a particular area. Also with the introduction of EIA Follow-up management system, there is a demand for a system for providing and utilizing environmental information in a time series. This study derives the necessity of information provision system and analyz existing environmental information utilization system based on the institutional characteristics of environmental impact assessment. And suggest ways to provide environmental spatial information to find policy implications for improving the limit of environmental impact assessment system.

• Journal of the Korean Society for Nondestructive Testing
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• v.27 no.6
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• pp.483-500
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• 2007

Emerging sensor-based structural health monitoring (SHM) technology can play an important role in inspecting and securing the safety of aging civil infrastructure, a worldwide problem. However, implementation of SHM in civil infrastructure faces a significant challenge due to the lack of suitable sensors and reliable methods for interpreting sensor data. This paper reviews recent efforts and advances made in addressing this challenge, with example sensor hardware and software developed in the author's research center. It is proposed to integrate real-time continuous monitoring using on structure sensors for global structural integrity evaluation with targeted NDE inspection for local damage assessment.

• Nuclear Engineering and Technology
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• v.55 no.6
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• pp.2158-2165
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• 2023

Marine radioactivity monitoring is critical for taking immediate action in case of unexpected nuclear accidents at nuclear facilities located near coastal areas. Especially when the level of contamination is not predictable, mobile monitoring systems will be useful for wide-area ocean radiation survey and for determination of the level of radioactivity. Here, we used a silicon photomultiplier and a high-efficiency GAGG crystal to fabricate a compact, battery-powered gamma spectroscopy that can be used in an ocean environment. The developed spectroscopy has compact dimensions of 6.5 × 6.5× 8 cm³ and weighs 560 g. We used LoRa, a low-power wireless protocol for communication. Successful data transmission was achieved within 1.4 m water depth. The developed gamma spectroscopy was able to detect radioactivity from a ¹³⁷Cs point source (3.7 kBq) at a distance of 20 cm in water. Moreover, we demonstrated an unmanned radioactivity monitoring system in a real sea by combining unmanned surface vehicle with the developed gamma spectroscopy. A hidden ¹³⁷Cs source (3.07 MBq) was detected by the unmanned system at a distance of 3 m. After successfully testing the developed mobile spectroscopy in an ocean environment, we believe that our proposed system will be an effective solution for mobile real-time marine radioactivity monitoring.

• Smart Structures and Systems
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• v.12 no.2
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• pp.209-233
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• 2013

With an annual growth rate of about 30%, wind energy systems, such as wind turbines, represent one of the fastest growing renewable energy technologies. Continuous structural health monitoring of wind turbines can help improving structural reliability and facilitating optimal decisions with respect to maintenance and operation at minimum associated life-cycle costs. This paper presents an integrated monitoring system that is designed to support structural assessment and life-cycle management of wind turbines. The monitoring system systematically integrates a wide variety of hardware and software modules, including sensors and computer systems for automated data acquisition, data analysis and data archival, a multiagent-based system for self-diagnosis of sensor malfunctions, a model updating and damage detection framework for structural assessment, and a management module for monitoring the structural condition and the operational efficiency of the wind turbine. The monitoring system has been installed on a 500 kW wind turbine located in Germany. Since its initial deployment in 2009, the system automatically collects and processes structural, environmental, and operational wind turbine data. The results demonstrate the potential of the proposed approach not only to ensure continuous safety of the structures, but also to enable cost-efficient maintenance and operation of wind turbines.

• Structural Engineering and Mechanics
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• v.18 no.5
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• pp.609-626
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• 2004

The Land Transport Authority of Singapore has a continuing program of highway bridge upgrading, to refurbish and strengthen bridges to allow for increasing vehicle traffic and increasing axle loads. One subject of this program has been a short span bridge taking a busy highway across a coastal inlet near a major port facility. Experiment-based structural assessments of the bridge were conducted before and after upgrading works including strengthening. Each assessment exercise comprised two separate components; a strain and acceleration monitoring exercise lasting approximately one month, and a full-scale dynamic test carried out in a single day. This paper reports the application of extreme value statistics to estimate bridge live loads using strain measurements.