• Journal of Korean Society for Atmospheric Environment
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• v.17 no.E4
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• pp.169-181
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• 2001

To test the compatibility of differential optical absorption spectroscopy (DOAS) and conventional in-situ monitoring technique we conducted a comparative analysis of the two systems using hourly measurement data sets of three criteria pollutants including No$_{2}$O$_{3}$, and SO$_{2}$ collected in months between April and June of 2001 at Sung Man city, Kyung Gi Province, Korea. The results of our comparative analysis were useful to evaluate the various aspects of DOAS performance, of particular the level of agreement with the counterpart method through computation of percent differences and correlation analysis. Interpretation of the mixing ratio data for those chemical species was however confined in terms of explaining the differences affected by the changes in environmental conditions because measurements of important meteorological parameters were limited during most of the study period. Nevertheless, the overall results of this study strongly demonstrated that the mixing ratio of major pollutants measured by the two different systems maintain strong compatibility from various respects.

• Proceedings of the KIEE Conference
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• 1996.07b
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• pp.841-843
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• 1996

This paper presents efficient protection countermeasure against lightning and surge for the control & instrumentation equipment using TVSS(transient voltage surge suppressor) and TEC(transient earth clamp). We propose the zone protection technique with TVSS and the use of TEC for clearing potential difference between frame ground and signal ground.

• The Journal of Engineering Geology
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• v.18 no.4
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• pp.537-543
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• 2008

To effectively delineate the foundation of stone relics by GPR and seismic refraction methods, a geological engineering model was constructed with alternating layer of soil and gravel to a depth of 3 m. This study was aimed at mapping the boundaries of model ground structure and interfaces of alternating layer using the various frequency antenna in GPR survey and seismic velocities. Compared to the resolution from the high frequency antenna, the image resolution from the survey using 100 Hz antenna is the lower, but with the deeper image coverage. On the contrast, the deeper structure was not mapped in the higher frequency data due to higher absorption effect, but the shallow layered zone was distinctively resolved. Therefore subsurface images were effectively provided by integrating the data with 100 MHz and 450 MHz antennas for the deep and shallow structures, respectively. Regarding the seismic refraction data, the boundaries of the model and interface of the alternating layers were not successfully mapped due to the limit of the survey length. However, the equivalent contours of low velocity extended deep as considerable velocity contrasts with surrounding ground.

• Journal of the Korean Society of Earth Science Education
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• v.10 no.1
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• pp.38-49
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• 2017

The purpose of this study was to find out how pre-service teachers who have gone through training have thought about teaching practice. Specifically, I analyzed the relationship between college curriculum and teaching practice, and what they had felt in teaching practice. The study included 20 third grade students in teacher's college. The results of this study were as follows: First, it was found that the content knowledge and the pedagogical knowledge of the subjects taught at the university were helpful for the teaching practice. Second, they were thought that teaching practice would be helpful just to watch the class. And pre-service teachers felt that class demonstration was a necessary part of becoming a teacher. Third, pre-service teachers said that it is necessary to have a lecture in the university that can have opportunity for class demonstration for teaching practice. And also they wanted to open a lecture to learn various teaching techniques and the newest teaching methods. Fourth, pre-service teachers said that it is important to form relationships with students in order to complete the lessons through the teaching practice. And they said that they felt that the education scene was more powerful and harder than they thought. In addition, they said that through this exercise, it became a moment to feel the importance of thorough preparation and experience. In this way, teaching practice is an essential process for pre-service teachers to become teachers and it can be seen that they have many influences. Based on these results, it is necessary to review and revise the curriculum of the training colleges in relation to the teaching practice.

• Journal of the Korean Society for Precision Engineering
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• v.4 no.4
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• pp.56-71
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• 1987

Determination of navigation variables (latitude, longitude, and altitude) near the earth's surface is termed 'Terrestrial Navigation'. The quantities that are measured inertially are the total acceleration (or the integral fo this acceleration over a fixed time interval) and the total angular rate (or the integral of this angular rate over the same time interval). These measurements when suitably compensated can be manipulated to yield the navigation variables. Hence, it is essential that the initial values of position, orientation and velocity are accurately set up during the initial alignment process. Initial alignment of gimballed inertial navigation system ( GINS) is accomplished by gyrocompassing techniques. These cannot be used, in the case of strapdown inertial navigation system(SDINS), where the inertial instruments are directly strapped down to a vehicle frame. The basic objective of this paper is the development of digital method for the determination of the initial axes erection of a SDINS from vibration and sway currupted data on the launch pad.

• Journal of the Korean earth science society
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• v.33 no.1
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• pp.73-81
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• 2012

The purpose of this study was to compare characteristics of students lived in volcanic region or not while observing the igneous rocks basalt and granite. For the study we recruited 68 fifth-grade students in Jeju Island, 29 fifthgrade students in Ulleung Island and 61 fifth-grade students in inland area area. This study was conducted as follows: After observing of granite and basalt, the students wrote observations. At the end of observation they also wrote all knowledges about granite and basalt except for the observations. The results are as follows: First, igneous rocks observations did not show a statistically significant difference between regional characteristics variables. Second, the amount of knowledge that students knew about granite and basalt except for the observation facts also did not show significant differences. Third, in the results of qualitative analysis for knowledges about granite and basalt except for the observation facts, many students knew about the igneous origin and about the substance but there were few statements that reflected the characteristics of the location. This results will provide a meaningful implication that the science class must consist of the use a various examples associated with a real-life.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.10a
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• pp.330-335
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• 2005

Reliable predictions of the movement of earth retaining structures and the ground adjacent to braced walls in urban excavation are often difficult due to many variable factors. The ground settlement and the damage of adjacent structures in urban excavation has been an important issue. Therefore, the stability of the adjacent structures must be secured with the excavation support and research on the protection of adjacent structure is necessary. This study showed a countermeasure method for case of damage behavior in urban excavation.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2009.10a
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• pp.415-417
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• 2009

3점 전위 강하법을 이용하여 접지 저항을 측정하는 방법은 접지 전극과 전류 전극 그리고 전위 전극의 이격 거리 영향 관계에 따라 그 정확성이 결정된다. 하지만 실체 접지 시설을 요하는 현장에서 접지 저항을 측정하기 위한 공간 확보가 어려워 각 전극들의 정확한 위치 선정이 여의치 않는 경우가 발생할 수 있다. 이에 본 논문에서는 전위 전극의 이탈 범위와 접지 전극으로부터의 이격 거리에 따른 접지 저항 값의 오차를 측정하여 각각의 경우에 대해 통상적인 접지 저항 측정 방법에 의한 측정값과의 오차 범위를 분석해본다.

• Korean Journal of Remote Sensing
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• v.28 no.6
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• pp.671-682
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• 2012

Strong backscattering features from high-resolution Synthetic Aperture Rader (SAR) image provide useful information to analyze earth surface characteristics such as man-made objects in urban areas. The SAR image has, however, some limitations on description of detail information in urban areas compared to optical images. In this paper, we propose a new classification method using a fused SAR and Electro-Optical (EO) image, which provides more informative classification result than that of a single-sensor SAR image classification. The experimental results showed that the proposed method achieved successful results in combination of the SAR image classification and EO image characteristics.

• Journal of Korean Society for Atmospheric Environment
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• v.29 no.4
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• pp.407-438
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• 2013

Current status and future direction of air quality modeling for monitoring and forecasting air quality in East Asia were discussed in this paper. An integrated air quality modeling system, combining (1) emission processing and modeling, (2) meteorological model simulation, (3) chemistry-transport model (CTM) simulation, (4) ground-based and satellite-retrieved observations, and (5) data assimilation, was introduced. Also, the strategies for future development of the integrated air quality modeling system in East Asia was discussed in this paper. In particular, it was emphasized that the successful use and development of the air quality modeling system should depend on the active applications of the data sets from incumbent and upcoming LEO/GEO (Low Earth Orbit/Geostationary Earth Orbit) satellites. This is particularly true, since Korea government successfully launched Geostationary Ocean Color Imager (GOCI) in June, 2010 and has another plan to launch Geostationary Environmental Monitoring Spectrometer (GEMS) in 2018, in order to monitor the air quality and emissions in/around the Korean peninsula as well as over East Asia.