• Journal of the Korean earth science society
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• v.40 no.2
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• pp.177-187
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• 2019

Several volcanic activities have continued in Mt. Baekdu since the Millennium eruption, and these phenomena have increased the need for volcanic activity surveillance. Various geophysical approaches are needed to obtain the depth and size of magma chamber that lie several kilometers below the surface. We examined the applicability of direct-current resistivity survey in this study. In order to explore the deep magma chamber of Mt. Baekdu, which has a spatial limitation due to the borderline, a large-scale survey with a length of tens of kilometers should be conducted. This type of survey requires a distributed measurement system and optimized exploration designs. Therefore, we propose survey designs taking advantage of our developed distributed acquisition system and analyze the applicability using numerical simulation. We confirmed that our designs that use single survey line with offline transmitting points show comparable results to the conventional 3D survey. It is expected that our research result can contribute to the deep geophysical exploration in Mt. Baekdu.

• Geophysics and Geophysical Exploration
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• v.17 no.4
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• pp.202-208
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• 2014

KIGAM (Korea Institute of Geoscience and Mineral Resources) and MRAM (Mineral Resources Authority of Mongolia) performed joint survey on Bayan-Onjuul W-Mo mineralized area. Following the survey, we carried out magnetic survey. W-Mo occurrences are located with keeping a certain distance from the northern boundary of granite which has higher magnetic susceptibility values. Also, the 3D imaging results of magnetic inversion show that granite bodies are extended to the W-Mo occurrence areas from the deep main body with decreasing of susceptibility. The results of magnetic data analysis are well matched with the general characteristics of ore solution involved with W mineralization. The further study about the hidden ore deposits which have similar spatial relationship between granite and known WMo occurrences are necessary to improve the economic feasibility.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.09b
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• pp.1156-1157
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• 2005

• Journal of Korean Society of Rural Planning
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• v.16 no.3
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• pp.77-85
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• 2010

The objective of this study is to analyze demands and important level of rural amenity resources information in rural development consulting. For this study, the questionnaire survey was implemented to regional development consulting companies and organizations with three parts. The first part is about the methodologies in using for the rural development consulting, particularly, the collect processes of the amenity resources information and methods to establish development strategy are included in the questionnaire. In second part, essential factors for constructing the information system of rural amenity resources are investigated. Finally, the rural development project types were classified, and performed an analysis of important level for the rural amenity resources utilizing AHP technique. According to results of this study survey, the demands from residents are the most important factor for establishing rural development plan, and the relationship among neighboring regions and the amounts of rural amenity resources are also considered as important factors. The most important rural amenity resources are different as rural development project types.

• Journal of Korean Society of Rural Planning
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• v.15 no.4
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• pp.1-10
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• 2009

Rural amenity is regarded as a breakthrough that can revitalize the rural communities. The demand for rural amenity development is also increasing since the urban people have growing incomes and leisure time. This study was implemented to survey the needs and application directions of rural amenity database. The survey questionnaires were collected from various related groups including industry, universities, administration and research institute. Two kinds of analysis of variance (ANOVA) were carried out in order to prioritize the building rural amenity resource map among four user groups and ten rural amenity resources. The result of survey showed that most of respondents had been aware of amenity resources and the industry group had the highest level of utilization in making decisions for rural development. Although the significant difference among groups was not shown in the priority, the priority in the construction of information map was shown the significant difference among 10 kinds of amenity resources. Landscape's map and traditional resource map were relatively higher priority than the other resource map.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.58 no.1
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• pp.49-58
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• 2022

In September and October 2020, combined acoustic and trawl surveys were conducted in the northwestern sea of Jeju Island. In the survey area, a region, so called Jeju region, was designated to esimate the biomass of chub mackerel and jack mackerel using a trawl survey method and frequency difference method. In the September survey, the weight ratios of jack mackerel and chub mackerel to the total catch were 24.6% and 2.8%, respectively, and in the October survey, those ratios were 24.9% and 20.7%, which were used to calculate their biomass (trawl survey). Using the frequency difference range (-8 to -3dB) corresponding to two species in 120 and 200 kHz, their biomass was estimated (frequency difference method). As a result, the biomass of two species from the trawl method was 3252.3 tons in September and 5777.0 tons in October. The estimated biomass by the frequency difference method was 4926.6 tons in September and 7521.5 tons in October. It was the first trial to estimate the biomass of two species using the trawl and frequency differencing methods in South Korea although there were some differences between two methods. In addition, horizontal distributions of acoustic backscattering strength over the entire survey area were mapped.

• 한국지구물리탐사학회:학술대회논문집
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• 2003.11a
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• pp.455-458
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• 2003

A combination of drilling, hydrogeochemical survey, geophysical survey and the numerical modelling for the flow and transport of groundwater was performed to evaluate the seawater intrusion in Baeksu-eup, Yeonggwang-gun, Korea. The survey area extends to over 24 $km^2$. Twelve wells were also drilled for the collection of geologic, geochemical, hydrologic, and geophysical logging data to delineate the degree and vertical extent of seawater intrusion. To evaluate and map the salinity in a coastal aquifer, geophysical data and hydrogeochemical results were used. Layer parameters derived from VES data, various in situ physical properties from geophysical well loggings, and the estimated equivalent NaCl concentration were used as the useful input parameters for the numerical simulation with density-dependent flow. Our multidisciplinary approach for evaluating the seawater intrusion can be considered as a valuable attempt to enhancing the utilization of various data and the reliability of numerical ground modelling.

• Geophysics and Geophysical Exploration
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• v.17 no.3
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• pp.147-154
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• 2014

For analyzing the distribution of chromite, magnetic survey was carried out on the chromium mineralized belt in Bophi Vum area, northwestern Myanmar. As a result, the magnetic susceptibility of chromite is lower than those of dunite and harzburgite, which are background rocks of chromite. Also, the locations of low magnetic anomaly zone and low magnetic susceptibility models of 3D magnetic inversion result are spatially well matched with those of chromite occurrences confirmed by the surface geological survey and trench survey. Some of low magnetic effects are expanded to the periphery area of chromite occurrences. Considering the magnetic susceptibility characteristics of various rocks in this area, the expanded low magnetic anomaly zones are estimated as the high potential areas bearing chromite. For confirming the potential area of chromite pointed by coarse magnetic survey, the additional detail exploration need to be carried out in future.

• 한국지구물리탐사학회:학술대회논문집
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• 2003.11a
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• pp.410-415
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• 2003

Ground subsidence has occurred in the downtown of Muan-eup in Korea. Integrated geophysical survey, including two-dimensional resistivity, CSMT(Controlled source magnetotelluric), magnetic, borehole logging, GPR and resistivity tomography, has been conducted to investigate the cause of subsidence and ground conditions. Since the target area is in the city downtown, there were no spaces for surface geophysical methods. To get regional geology and to facilitate the detailed geophysical interpretation in the survey area, two-dimensional resistivity, CSMT and magnetic surveys have been applied in the outer region of the downtown. From these results, we could accurately define the Gwangju fault system and estimate the geologic conditions in the downtown. For the detailed survey of the downtown area, resistivity tomography and borehole logging data have been acquired using a few tens of densely located boreholes. Among these survey results, borehole logging data provided the guide to classification of the rock type and we could define the geologic boundary of granite and limestone formations. From the resistivity tomograms of 42 sections, which are densely located enough to be interpreted in a three-dimensional manner, we could delineate the possible weak zones or cavities in the limestone formations. In particular, resistivity tomograms in the subsided area showed the real image of ground subsidence. The map of hazardous zone has been derived from the joint interpretation of these survey results and we could provide the possible reinforcement strategy in this area.

• Journal of Korean Society of Rural Planning
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• v.11 no.2 s.27
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• pp.21-34
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• 2005

The objective of this study is to suggest a planning direction for the management and conservation of a rural landscape. For suggesting the planning direction, this study was classified rural landscape resources based on spatial type to understand the assessment of rural landscape. This study examined literature reviews and site investigations for collecting the data on the resources of a rural landscape to maintain rurality. First above all, it was classified into physical and non-physical resources. Non-Physical resources include elements such as inhabitants' will, leaders' will and the software. It is also to reflect all these factors on the planning. Next, this study classified the resources of a landscape into artificial and natural resources and applied these resources to rural areas which were divided into five types: industry area, life area, natural landscape area, program area and human behavior area. The pictures obtained from this field survey were used for a questionnaire survey to understand the value of a rural landscape. The contents of questionnaire survey were divided into two parts: the presentation condition of a rural land-scape and assessment of a rural landscape. Especially, the value of a rural landscape was divided into the ecological value, socio-cultural value and holistic value.