• International Journal of Aeronautical and Space Sciences
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• v.9 no.1
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• pp.42-47
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• 2008

One of the main cases of the desertification impact is the negative contribution of human activities that worsen environment. There are historical facts of inability and excessive activities which destroyed the civilizations. The basic difference is only in the tempo and scales of civilization collapse. Human pressure was accumulated within the centuries and millennia due to the extremely active economic activities. But today it covers only the decades. Presently the process of desertification has a global scale. There are huge factors of Earth aridization as an increase of the quantity of C02 and atmospheric dust and bloom. This process related not only to the arid areas. Obviously a comprehensive approach of development of territories, particularly arid areas is very important. The use of the satellite information and technologies of remote sensing data processing can take a significant place for decision-makers for calculation and estimation of the environment impacts.

• Korean Journal of Health Education and Promotion
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• v.33 no.3
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• pp.109-119
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• 2016

Objectives: To review policy contents which can have a direct impact on health-enhancing physical activity(PA) prevalence in Korea. Methods: The web-search and a literature was undertaken to identify reports and documents related to policy contents of PA. The web-search mainly focused on the web site of the departments and organizations relevant to PA policy and was supplemented by the literature searching. Results: The results of this study are as follows: First, the goal of PA does not match the established number of the Health Plan(HP). Second, the recommended levels of PA is not the same as levels of the year of establishment of the HP. Third, the questions of monitoring tool were inconsistent across years. Conclusions: Therefore, policy contents of physical activity should be improved to ensure accurate PA prevalence in Korea.

• Smart Structures and Systems
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• v.16 no.3
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• pp.435-457
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• 2015

The most widely known form of multifunctional aircraft structure is smart structures for structural health monitoring (SHM). The aim is to provide automated systems whose purposes are to identify and to characterize possible damage within structures by using a network of actuators and sensors. Unfortunately, environmental and operational variability render many of the proposed damage detection methods difficult to successfully be applied. In this paper, an original robust damage detection approach using output-only vibration data is proposed. It is based on independent component analysis and matrix perturbation analysis, where an analytical threshold is proposed to get rid of statistical assumptions usually performed in damage detection approach. The effectiveness of the proposed SHM method is demonstrated numerically using finite element simulations and experimentally through a conformal load-bearing antenna structure and composite plates instrumented with piezoelectric ceramic materials.

• 한국IT서비스학회:학술대회논문집
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• 2010.05a
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• pp.151-154
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• 2010

In this paper, we propose an energy monitoring and management service based on wireless sensors and a home gateway for homes and buildings. Homes and buildings have a significant energy saving potential compared with other sectors. Sensing, monitoring, and managing of the information on the energy consumption are required for an efficient energy saving service. The proposed system is composed of two main components, wireless sensor and an intelligent home gateway. Wireless sensors have the ZigBee communication interface for communication, and the intelligent home gateway is an energy portal. We expect that energy saving could be achieved with this system. As a further work, we will analyze the practical impact of the proposed service.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.05a
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• pp.1187-1192
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• 2003

The railroad noise has been considered as one of environment pollution and complaints about it have been increasing every you. Therefore, the establishment of railroad noise monitoring network is necessary. It will be designed for monitoring railroad noise, storing data of railroad noise continuously and providing the fundamental knowledge for the measures of railroad noise. For this, we investigated the actual condition of railroad noise and status of noise level by floor in apartments around the capital region, Daejeon, Daegu, Gwangju, and Busan. Additionally, we present the basic data that will be used for predicting the noise level near railroad in the environmental impact assessment

• Smart Structures and Systems
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• v.2 no.1
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• pp.25-46
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• 2006

Aging wiring in buildings, aircraft and transportation systems, consumer products, industrial machinery, etc. is among the most significant potential causes of catastrophic failure and maintenance cost in these structures. Smart wire health monitoring can therefore have a substantial impact on the overall health monitoring of the system. Reflectometry is commonly used for locating faults on wire and cables. This paper compares Time domain reflectometry (TDR), frequency domain reflectometry (FDR), mixed signal reflectometry (MSR), sequence time domain reflectometry (STDR), spread spectrum time domain reflectometry (SSTDR) and capacitance sensors in terms of their accuracy, convenience, cost, size, and ease of use. Advantages and limitations of each method are outlined and evaluated for several types of aircraft cables. The results in this paper can be extrapolated to other types of wire and cable systems.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.4
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• pp.517-525
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• 2021

Trawl fishing is a major concern worldwide, and there is considerable debate about its impact on marine ecosystems. In this study, we used the vessel monitoring system (VMS) data collected in the southwest Atlantic Ocean from 2016 to 2019 to estimate the fishing effort and trawled area. Spatial distribution of trawl activities according to the latitude and longitude and the hotspots where fishing was concentrated each year were identified. Trawling activities of the Korean vessels were mainly distributed between 40-52°S and 56-63°W. The species caught during the fishing period comprised five Cephalopoda, three Chondrichthyes, ten Osteichthyes, and other fish. The Argentine hake Merluccius hubbsi and Argentine shortfin squid Illex argentinus were the dominant species in the catch.

• Korean Journal of Remote Sensing
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• v.37 no.4
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• pp.687-698
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• 2021

We present quantitative estimations of changes in the areal extent of coral reef habitats at Weno Island, Micronesia, using high-spatial-resolution remote sensing images and field observations. Coral reef habitat maps were generated from Kompsat-2 satellite images for September 2008 and September 2010, yielding classifications with 78.6% and 72.4% accuracy, respectively, which is a relatively high level of agreement. The difference between the number of pixels occupied by each seabed type was calculated, revealing that the areal extent of living corals decreased by 8.2 percentage points between 2008 and 2010. This result is consistent with a comparison of the seabed types determined by field observations. This study can be used as a basis for remediation planning to diminish the impact of changes in coral reefs.

• Smart Structures and Systems
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• v.31 no.2
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• pp.171-181
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• 2023

Using the most up-to-date system identification methods in both time and frequency domains, the dynamic monitoring data from the reinforced concrete Egebaekvej Bridge near Holte, Denmark, is examined in this investigation. The bridge was erected in the 1960s and was still standing during test campaign before demolishing. The ARTeMIS Modal was adopted to derive the modal parameters from ambient vibration data. Several Operational Modal Analysis (OMA) approaches were applied, including Enhanced Frequency Domain Decomposition (EFDD), Curve-fit Frequency Domain Decomposition (CFDD), and Frequency Domain Decomposition (FDD). Afterward, Principal Component (SSI-PC), Unweighted Principal Component (SSI-UPC) Stochastic Subspace Identification methods were utilized. Danish engineering consulting company, COWI with the allowance of the bridge contractor BARSLUND, allow the researcher for this experimental test to demonstrate the impact of OMA applications.

• Nuclear Engineering and Technology
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• v.55 no.10
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• pp.3716-3724
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• 2023

Loose parts monitoring and detecting alarm type in real Nuclear Power Plant have challenges such as background noise, insufficient alarm data, and difficulty of distinction between alarm data that occur during start and stop. Although many signal processing methods and alarm determination algorithms have been developed, it is not easy to determine valid alarm and extract the meaning data from alarm signal including background noise. To address these issues, this paper proposes a denoising autoencoder-based majority vote classification. Training and test data are prepared by acquiring alarm data from real NPP and simulation facility for data augmentation, and noisy data is reproduced by adding Gaussian noise. Using DAEs with 3, 5, 7, and 9 layers, features are extracted for each model and classified into neural networks. Finally, the results obtained from each DAE are classified by majority voting. Also, through comparison with other methods, the accuracy and the false alarm rate are compared, and the excellence of the proposed method is confirmed.