• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2006년도 International Symposium on GPS/GNSS Vol.2
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• pp.47-51
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• 2006

Among Solar activities' events, the geomagnetic storms are believed to cause the largest atmospheric effects. The geomagnetic storm is a complex process of solar wind/magnetospheric origin. It is well known to affect severely on the ionosphere. However, this effect of this complex process will maybe act at various altitudes in the atmosphere, even including the lower layer and the neutral middle atmosphere, particularly the stratosphere. Nowadays, the GPS-derived ZTD (zenith tropospheric delay) can be transformed into the precipitable water vapor (PWV) through a function relation, and further has been widely used in meteorology, especially in improving the precision of Numerical Weather Prediction (NWP) models. However, such geomagnetic effects on the atmosphere are ignored in GPS meteorology applications. In this paper, we will investigate the geomagnetic storms' effects on the middle atmosphere and troposphere (0-100km) by GPS observations and other data. It has found that geomagnetic storms' effect on the atmosphere also appears in the troposphere, but the mechanism to interpret correlations in the troposphere need be further studied.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2009년도 춘계 학술발표회
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• pp.640-648
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• 2009

Recently the truction of coastal reclaimation work has been extensively implemented in Korea. The Sondo New City is being established on the reclaimed land from the sea, construction companies of metro construction are planing to pull-out the sheet pile for saving the construction cost. In the case of soft marine clay, it is very difficult to pull-out the sheet pile by using the hydraulic hammer difficult. Therefore, the man of the field must be aware of vibration effect to the ground and the structure. For understanding the vibration effect to the ground during subway construction, the model was formulated with 1/25 braced-cut for subway construction. Scott and Iai(1989) proposed the law of the similarity for other experimental conditions. The laboratory model test was conducted under the vibration condition of sheet pile pulling out. The settlement on the ground surface was measured during the shaking table test. The pore water pressure was also monitored in the upper, middle, and lower layers of soil. The field settlement level and the pore water pressure can be predicted by using the results of the laboratory shaking table test.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2008년도 춘계학술대회논문집
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• pp.440-443
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• 2008

Plume radiation has been measured during ground tests of KSLV-I kick motor in order to predict the thermal load on the equipment around the kick motor at flight. The measuring positions are the kick motor base, and the measured heats were about 2${\sim}$5 w/cm$^2$. The measured heat showed a lot of shot fluctuation in their values, and the radiative heats at the latter half of time are higher than those of the first half. A plausible explanation for these phenomena was given as the variation of alumina particles with time. The radiative heats along the plume axis were also measured recently at 8 positions with 1.5m radius from plume axis, but only the initial parts of the results could be acceptable because the sensor were damaged by the accumulated heat. The strongest heat occurred at the middle of the plume, which can be explained with different view factors. Despite of the plausible explanation, it seems to need more analysis because the plume structure such as temperature, alumina particle, after burning has not been revealed until yet. The measure heat flux has been reflected in the prediction of the plume radiation at high altitude where the kick motor operates.

• Earthquakes and Structures
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• 제8권1호
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• pp.19-35
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• 2015

This study compares the seismic performances of two reinforced concrete frame specimens tested by the pseudo-dynamic procedure. The pair of 3-storey, 3-bay frames specimens are constructed with typical characteristics of older construction which is lacking seismic design. One of the specimens is a bare frame while the other is infilled with low-strength autoclave aerated concrete (AAC) block masonry. The focus of this study is to investigate the influence of low strength masonry infill walls on the seismic response of older RC frames designed for gravity loads. It is found that the presence of weak infill walls considerably reduce deformations and damage in the upper stories while their influence at the critical ground story is not all that positive. Infill walls tend to localize damage at the critical story due to a peculiar frame-infill interaction, and impose larger internal force and deformation demands on the columns and beams bounding the infills. Therefore the general belief in earthquake engineering that infills develop a second line of defence against lateral forces in seismically deficient frames is nullified in case of low-strength infill walls in the presented experimental research.

• 한국가족관계학회지
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• 제22권4호
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• pp.239-256
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• 2018

Objective: The purpose of this research is to develop an intergenerational ambivalence scale which can measure the intergenerational relationship between middle-aged married couples and their mothers/mother-in-law. Method: The initial items were selected by reviewing the previous research and literature. To test validity and reliability, 222 middle-aged married couples who were residing in Seoul or the Gyeonggi area were selected. Results: The results of the research are as follows: 1) the scale was the total of 26 items consisting of two sub-factors of 14 positives and 12 negatives from the analysis of content validity, construct validity, and convergent validity, 2) the reliability of Cronbach's ${\alpha}$ were from .90 to .94 which showed a high degree of internal consistency. Conclusions: The intergenerational ambivalence scale developed is expected to serve as a useful tool for those who study the intergenerational relationship and work on the ground to measure people's intergenerational dynamics.

• Corrosion Science and Technology
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• 제16권6호
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• pp.298-304
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• 2017

Coil spring steels from the automobile suspension part after field exposure for 10 years and those after anti-corrosion validation test in proving ground of 5,000 ~ 10,000 km were examined for corrosion damages. Partial loss of paint, accumulation of corrosion product, and cracking of paint and superficial material were observed. The surface and subsurface region of spring steels had compressive residual stress and high hardness by shot peening. The surface hardness values of the specimens were 620 ~ 670 Hv. They were 60 ~ 80 Hv higher than those of the samples taken from the middle part of the spring. The maximum compressive stress was -916 ~ -1208 MPa measured at depth of about $100{\mu}m$. Electrochemical impedance spectroscopy showed that the resistances of charge transfer and the paint layer of the spring steels ranged from several tens to millions ${\Omega}{\cdot}cm^2$. The resistance of the field samples was much higher than that of the proving ground samples used in this study, implying that the proving ground test condition would be more corrosive than the field environment.

• 조명전기설비학회논문지
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• 제15권2호
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• pp.13-20
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• 2001

본 논문은 배전선에 설치하는 내뢰설비인 가공지선과 피뢰기의 특성과 생략 방안에 대하여 언급하였다. 특히, 피뢰기의 중간 상을 생략하는 방안에 대하여 EMTP 시뮬레이션을 실시하여 생략시 나타날 수 있는 문제점과 생략 방안에 대해 기술하였으며, 가공지선은 지정된 경우에는 생략이 가능하고 피뢰기는 중간 상을 생략시 건전상의 피뢰기 용량을 재검토해야 할 것으로 생각된다.

• Journal of Forest and Environmental Science
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• 제39권4호
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• pp.203-212
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• 2023

Directional felling is a felling method practised by the Forestry Department in Peninsular Malaysia as prescribed in Field Work Manual (1997) for Selective Management Systems (SMS) in forest harvesting. Determining the direction of tree felling in Peninsular Malaysia is conducted during the pre-felling inventory 1 to 2 years before the felling operation. This study aimed to predict and analyze the direction of tree felling using the vector-based path distance back link method in Geographic Information Systems (GIS) and compare it with the felling direction observed on the ground. The study area is at Balah Forest Reserve, Kelantan, Peninsular Malaysia. A Path Distance Back Link (spatial analyst) function in ArcGIS Pro 3.0 was used in predicting tree felling direction. Meanwhile, a binary classification was used to compare the felling direction estimated using GIS and the tree felling direction observed on the ground. Results revealed that 61.3% of 31 trees predicted using the vector-based projection method were similar to the felling direction observed on the ground. It is important to note that dynamic changes of natural constraints might occur in the middle of tree felling operation, such as weather problems, wind speed, and unpredicted tree falling direction.

• 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
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• 제15권2호
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• pp.51-58
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• 2009

These days the trend of special education is changing from special school-based education to special class room based education, and from separated education to integrated education. In accordance with this change, special classes should be planned for multi purposes so that the class room can be used for the place of teaching and learning, guidance, job education. This research surveyed the special teachers working for 937 schools which have special classes(elementary 631, middle 217 high school 89). The result of this survey shows the different responses according to the level of the schools. For education activities, elementary and middle schools put emphasis on curriculum rather than guidance. High education, elementary school should have the places for teaching and learning, student management, play ground. Middle schools give priority to the places for individual learning, computer and practical training. High schools value the places for job education and practical training above for learning.

• 대한수학교육학회지:학교수학
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• 제15권1호
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• pp.15-35
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• 2013

본 연구의 목적은 중학생용 수학학습양식 판별도구를 개발하여 선호유형을 범주화하는 것이다. 개발된 수학학습양식 판별도구로 976명의 중학생을 대상으로 설문조사하여 16가지의 수학학습양식 유형이 존재하는지를 확인하였고 이를 선행 연구들과 비교 분석하였다. 또한 수학학습양식의 각 요인에 따른 양식별 남녀 학습자, 학년별 학습자의 분포에 어떠한 차이가 있는지 분석하였다. 수학학습양식 판별도구를 통해서 학습자의 인지적 정의적 학습양식을 파악함으로써 수학학습에 대한 학습자 특성을 전체적으로 파악하여 획일화된 수업형태에서 벗어나 개별화 수업으로 나아갈 수 있는 방향을 제시하고자 한다.