• Geophysics and Geophysical Exploration
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• v.15 no.4
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• pp.245-248
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• 2012

Two dimensional Fourier transform can be used for the upward continuation of gravity or magnetic field data acquired at given altitude over a rectangular area. Earth's curvature is often neglected in most potential field continuations, however, it should be considered over several hundred kilometer field area. In this study, we developed a new method retaining terms of Earth's curvature to better perform the continuation of potential field on spherical patch area.

• Structural Engineering and Mechanics
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• v.15 no.4
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• pp.477-493
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• 2003

Masonry is not a simple material, the influence of mortar joints as a plane of weakness is a significant feature and this makes the numerical modelling of masonry very difficult especially when dynamic (seismic) analysis is involved. In order to develop a simple numerical model for masonry under earthquake load, an analytical model based on Distinct Element Method (DEM) is being developed. At the first stage, the model is applied to simulate the in-plane shear behaviour of an unreinforced masonry wall with and without opening where the testing results are available for comparison. In DEM, a solid is represented as an assembly of discrete blocks. Joints are modelled as interface between distinct bodies. It is a dynamic process and specially designed to model the behaviour of discontinuities. The numerical solutions obtained from the distinct element analysis are validated by comparing the results with those obtained from existing experiments and finite element modelling.

• Journal of Fisheries and Marine Sciences Education
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• v.17 no.3
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• pp.427-433
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• 2005

The study of Web GUI(Graphic User Information) system for Virtual Reality System is mainly performed on effective methodology which transform real world data to computing world data. MGIS(Marine Geographic Information System) has its own target on reliable data service by acquisition of geometric information using accurate measurement and graphical visualization. This type of raw data visualization can be built without software tools, yet is incredibly useful for interpreting and communicating data. Even simple visualizations can aid in the interpretation of complex 3D relationships that are frequently encountered in the geosciences. The Virtual Reality Modeling Language provides an easy way for geoscientists to construct complex visualizations that can be viewed with free software. This study propose a three dimensional Web GUI system using MGIS-based three dimensional data models and virtual imaging system. Finally, we design a Web GUI system integrating above data models.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.1-12
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• 2006

For advanced civil engineering structures a service life of hundred up to hundred fifty and even two hundred years is sometimes required. The prediction of the performance of concrete structures over such a long period requires accurate and reliable predictive models. Most of the presently used, mostly experience based models don't have the quality and reliability that is required for reliable long-term predictions. The models designers are searching for should be based on an accurate description of the relevant degradation mechanisms. The starting point of such models is a realistic description of the microstructure of the concrete. In this presentation the need and the role of fundamental microstructural models for predicting the performance of concrete structures will be presented. An example will be given of a microstructural model with a proven potential for long-term predictions. Besides this also the role of models in general, i.e. in the whole design and execution process of concrete structures, will be dealt with. Finally recent trends in concrete research will be presented, like the research on self-healing cement-bases systems.

• Journal of the Korean earth science society
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• v.25 no.1
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• pp.39-47
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• 2004

In the FMAS system the effect of iron on alumina solubility in orthopyroxene has been determined by experiments with crystalline starting mixtures of garnet and orthopyroxene of known initial compositions at 20 kb, 975$^{\circ}C$ and 25 kb, 1,200$^{\circ}C$. These data have been modeled to develop a thermodynamic method for the calculation of Al$_{2}$O$_{3}$ in orthopyroxene as a function of P, T and composition. The direct application of the alumina solubility data in the MAS system to natural assemblages could lead to significant overestimation of pressure, probably by about 5kb for the relatively common garnet-lherzolites with abot 25 mol per cent Ca + Fe$^{2+}$ in garnet and about 1 wt. per cent Al$_{2}$O$_{3}$ in orthopyroxene since the effect of Fe is similar to that of Ca and Cr$^{3+}$in reducing the alumina solubility in orthopyroxene in equilibrum with garnet relative to that in the MAS system.

• Journal of the Korean Geographical Society
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• v.33 no.spc
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• pp.721-728
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• 1998

UN은 1990년대를 전세계적인 자연재해 감소를 위한 10년(IDNDR)으로 지정하고 이러한 취지로 제네바에 사무국을 개설했다. 그에 대한 반응으로 국제 과학 연합회는 IGU를 통해 여러 지역에서의 지리적 연구를 지원하고 있다. IGU는 1992년에 개최된 제 27차 IGC에서 자연재해연구 분과를 개설하여 지리학에 있어서 새로운 기술을 개발하는데 강조를 두는 다양한 자연재해 프로젝트에 지리학자들을 포함시키려는 노력을 시작했다. 지리학자들은 IDNDR에 중요한 공헌을 하고 있는데, 특히 재해 관리를 위한 GIS의 영역과 지도화와 재해 평가를 위한 원격탐사, 재해 반응에 대한 GPS의 이용 등이 이에 포함된다. 지리학자들은 지도화와 재해를 경감시키려는 노력에 중요한 역할을 하고 있으며, 이미 재해를 입은 지역에 대해 복구 계획을 세우고 있다. CONAHA는 2000년에 서울에서 개최되는 제 29차 IGU에서 UN에 의해 시작된 안건을 지지하게 됨으로 그 역할을 마무리하게 될 것이다. 영구적인 공헌 중에는 1998년에 산악 재해에 관한 발간을 시작으로 자연재해에 관한 책 시리즈와 UNESCO에 의해 발간된 Life Systems 백과사전 내용 중 자연재해에 대한 부분이 포함된다는 것이다

• Journal of Energy Engineering
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• v.26 no.1
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• pp.62-67
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• 2017

Limestone is an important commodity in Philippines. Limestone has numerous uses that range from agricultural applications to building materials to medicines. Many limestone products require rock with specific physical and chemical characteristics. Most limestone is biochemical in origin meaning the calcium carbonate in the stone originated from shelled oceanic creatures. In this paper, we reported the natural sources of limestone, geological formation of limestone and the oyster shell waste in Cebu, Bantayan, Philippines were reported. Due to the mining or quarrying in Cebu, Bantayan, in a limestone area poses the threat of groundwater pollution (since limestone is a porous geologic formation with a high transmissivity). The other environmental issue is oyster shell waste. The oyster shell waste is the major source of limestone. We developed and applied appropriate technologies for the extraction of limestone from oyster shell waste and utilizes as high value added material.

• Proceedings of the KSEEG Conference
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• 2003.04a
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• pp.15-18
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• 2003

We preliminarily describe the basic characteristics of the low-sulfidation epithermal gold deposits in East China. It can be divided into granite- and alkaline rock-related types. These gold deposits are structurally controlled by caldera, craters, diatremes and related faults, hosted in volcanic rocks, and characterized by alterations of adularia, chalcedony, quartz, sericite and calcite assemblages. The ore-forming ages are within three pulses of 180-188 Ma, 135-141 Ma, and ca. 120 Ma, which are geodynamically corresponding the collision orogenic process between North China and Yangtze cratons, transformation of the tectonic regime, and delamination of the lithosphere, respectively.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.381-383
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• 2003

SAR imagery offers a reliable mode of image acquisition over tropical countries for various applications. The Philippines participated in two missions to the Pacific Rim by NASA in 1996 and 2000 that saw the deployment of the AIRSAR instrument. This paper discusses the Philippine experience in the use of polarimetric and interferometric radar datasets for diverse applications, including hazards mapping, geologic and geomorphologic mapping, and land cover mapping. The results are discussed in the light of present efforts at capacity building in remote sensing, attempts at operationalizing the use of SAR for priority applications, and future ambitions in remote sensing.

• Korean Journal of Environmental Biology
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• v.35 no.4
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• pp.604-621
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• 2017

This research was conducted to find the indigenous diatom species unrecorded in Korea from February to December 2016. The samples were taken at 28 sites of the coastal regions on the west coast of Korea and Jeju Island. Diatoms were collected mostly from sand and mud of tidal flats, including gravel, seaweed on the bottom and macrophytes floating in the seawater. Diatom specimens were observed by means of light and scanning electron microscopy. Twenty one species were discovered and added as new specimens to the Korean diatom flora, which are divided into 9 orders, 12 families, and 16 genera. The list and photographs of the species are included with the description of the morphological characteristics and distribution in Korea.