• Journal of the Korean Society of Environmental Restoration Technology
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• v.22 no.1
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• pp.73-84
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• 2019

In this research, it is a basic study to investigate the population of birds using UAVs. The research area is Ardeidae species(ASP) habitat and has long-term monitoring. The purpose of the study is to compare the ASP populations which analyzed ground observational survey and UAVs imagery. We used DJI's Mavic pro and Phantom4 for this research. Before investigating the population of ASP, we measured the escape distance by the UAVs, and the escape distances of the two UAVs models were statistically significant. Such a result would be different in UAV size and rotor(rotary wing) noise. The population of ASP who analyzed the ground observation and UAVs imagery count differed greatly. In detail, the population(mean) on the ground observation was 174.9, and the UAVs was 247.1 ~ 249.9. As a result of analyzing the UAVs imagery, These results indicate that the lower the UAVs camera altitude, the higher the ASP population, and the lower the UAVs camera altitude, the higher the resolution of the images and the better the reading of the individual of ASP. And we confirmed analyzed images taken at various altitudes, the individuals of ASP was not statistically significant. This is because the resolution of the phantom was superior to that of mavic pro. Our research is fundamental compared to similar studies. However, long-term monitoring for ASP of South Korea's by ground observation is a barrier of the reliability of the monitoring result. We suggested how to use UAVs which can improve long-term monitoring for ASP habitat.

• Journal of Advanced Navigation Technology
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• v.28 no.1
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• pp.1-14
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• 2024

Global navigation satellite system (GNSS) providing position, navigation and timing (PNT) services consist of satellite, ground, and user systems. Monitoring stations, a key element of the ground segment, play a crucial role in continuously collecting satellite navigation signals for service provision and fault detection. These stations detect anomalies such as threats to the signal-in-space (SIS) of satellites, receiver issues, and local threats. They deliver received data and detection results to the master station. This paper introduces the main monitoring algorithms and measurement pre-processing processes for quality assessment and fault detection of received satellite signals in current satellite navigation system monitoring stations. Furthermore, it proposes a strategy for the development of components, architecture, and algorithms for the new regional navigation satellite system (RNSS) monitoring stations.

• Proceedings of the Korean Geotechical Society Conference
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• 2001.10a
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• pp.133-145
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• 2001

This paper presents quality and measure controls of Plastic Board Drains(PBD) for improvement of soft ground. Laboratory and field tests has been carried out to evaluate the quality of PBD focussing on : discharge capacity of flow area; permeability of filter sleeve; migration of fine particles; deformed shape of PBD; consolidation of clay in the close vicinity of PBD; tensile strength of PBD; long-term consolidation behavior of clay-PBD. Test results show that the quality of PBD is sufficient to perform the improvement of soft silty and clayey ground. But, geotechnical engineer must make efforts minimizings of PBD damage and ground disturbance, continuity of drainage system during construction. Adequate monitoring system should apply at ground focussing on number, location, and accuracy of geotechnical instrumentation, measurement and evaluation of data for ground behaviour.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2001.09a
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• pp.155-159
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• 2001

A study on multivariate statistical classification of ground water hydrographs was conducted. The vast data of national ground water monitoring network (78 sites of alluvium) were used. 6 factors were selected to classify the ground water level change. Factor analysis was proved to be useful tool for classifying vast hydrogeological data.

• 한국지구물리탐사학회:학술대회논문집
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• 2006.06a
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• pp.79-82
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• 2006

This paper presents to examine the ability of an electrical resistivity method to monitor the grouting effect at subsidence area. To monitor the changes in ground resistivity before and during the grout, series of electrical resistivity monitoring surveys have been conducted. Data has acquired in the form of grid making nine lines parallel to road and four lines traverse the road. Two kinds of electrode arrays modify pole-pole and dipole-dipole arrays were used during resistivity data acquisition. In this paper, the results show that electrical prospecting is an effective method to detect low resistivity imaging zone by grout during the ground reinforcement.

• Proceedings of the Korean Geotechical Society Conference
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• 1992.10a
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• pp.149-155
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• 1992

In case of construction of the final refuse disposal site on the ground where 20m soft clay layer is deposited, Sand Compaction Pile(SCP) was driven with a view to increase the strength and reduce the settlement when the reclaimed revetment intend to be constructed first in a short time. Field monitoring method is carried out in order to overcome the problems of settlement and stability in the construction of the reclaimed revetment and the assumed problems in the design of composite ground. In this paper the observed data from monitoring sections are analysed, fedback to the desigh and field, and compared with FEM analysis. Conclusions are as follow: in case of 70% replacement the use of modified soilparameters makes the FEM analysis of SCP possible. In case of 27% replacement, n(stress concentration ratio)=0.2-0.3, B(measured settleme reduction coefficient)=0.43 are evalated. Also, horizontal displacement is remarkably happened around the ground.

• Explosives and Blasting
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• v.33 no.2
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• pp.40-43
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• 2015

In this case study, a S/W optimized for ground vibration monitoring and analysis was developed. It was applied at vibrating compaction works for the ground improvement needed for the expansion of terminal 5 in Chagi International Airport in Singapore. The possible application of the new vibration analysis software to similar works like pile driving and the capability of long term and real time of the repeated wave vibration at seawalls, the vibration occurring from large structures like super tall buildings, tunnels, long cable hanging bridges, and etc were investigated.

• Proceedings of the Korean Geotechical Society Conference
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• 2003.03a
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• pp.781-788
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• 2003

It is an essential process to predict behaviors of ground and structure to seek economical efficiency and stability on the given environment. Predictions are conducted through analysis process of ground and structure. For these analyses, exact and quick acquisition of measuring data is required. But we face many difficulties in data acquisition stages due to the conditions of construction site. Therefore development of a powerful and effective monitoring system that can manage the integration of database and the implementation of measuring process in real time is strongly desired. This article shows an actual example of application of internet based monitoring system compared with the conventional monitoring system.

• Journal of Forest and Environmental Science
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• v.29 no.3
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• pp.211-218
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• 2013

This study was conducted to examine the community structure of ground beetles between coniferous- and deciduous-dominant forest in agricultural landscapes, in Miryang-si, Yeongdong-gun, Icheon-si, and Cheolwon-gun during April to October in 2009. A total of 19 species belonging to 15 genera of 9 subfamilies were identified from 6,253 collected ground beetles. Dominant species from 4 regions were Synuchus nitidus (3,715 individuals, 59.4% of total) and Synuchus cyloderus (1,783 individuals, 28.5%) respectively. Non-metric multidimensional scaling based on Bray-Curtis similarity showed that ground beetle assemblage was not different between forest stands, but it was significantly different among regions. Overall, forest stands of secondary forests may not show a different community structure of ground beetle assemblages in our study. However, monitoring on the ground beetle fauna as well as other arthropods of secondary forests in agricultural landscapes is still important for the management and conservation of biodiversity, because forests provides important habitats for many predatory arthropods, such as ground beetles, spiders and rove beetles.

• The Journal of Engineering Geology
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• v.14 no.1
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• pp.71-80
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• 2004

The failure of cut slopes frequently occurs particularly during the thawing season and the rain season in summer. This study interpreted data collected from site to which a real-monitoring system was applied in order to analyze the causes of ground behaviors and to forecast future slope failure. As for research methods, this study analyzed the size and mechanism of failure by integrating the results of field surveys and measurements. Furthermore, it analyzed data transmitted by the monitoring system installed in the a result, three times of ground displacement occurred as well as a number of partial tension cracks. The cut slope composed of sandstone and siltstone started its initial behavior as a result of torrential downpour and the loss of support of the substructure. For quantitative analysis of the characteristics of ground behavior, this study measured 5 lateral lines. According to the result of the measurement, displacement happened little in the section to which countermeasure had been applied, but displacement of maximum 400mm happened in the section to which countermeasure had not bee applied. The analysis of data on displacement and rainfall suggested a close relationship between ground behavior and rainfall. According to the result of stability interpretation along with the change of ground saturation, stability rate appeared to be less than 1.0 when ground saturation is over 55%. Although the current trend of ground behavior is at a stable stage falling within the range of tolerance, it is considered necessary to continue monitoring and data analysis because ground displacement is highly possible with the change of temperature during the winter.