• 한국가정과교육학회지
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• 제23권1호
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• pp.53-71
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• 2011

본 연구는 중학교 1학년 기술 가정 교과의 '청소년의 이해' 대단원에 속한 소단원별 하위 주제의 교과 내용에 대한 남녀 학생들의 흥미도와 유용성 인식을 파악하고 이들 간의 관계를 분석하는데 목적이 있다. 이를 위해 서울 및 경기, 인천에 거주하는 중학교 1학년 남녀 학생 521명을 대상으로 설문조사를 실시하였고 빈도분석, t-test, 일원분산분석, Pearson의 적률상관관계분석을 적용하여 자료를 분석하였다. '청소년의 이해' 대단원 내용에 대한 전반적인 흥미도와 유용성 인식 경향을 보면 가장 흥미도와 유용성 인식이 높은 소단원은 '청소년의 스트레스 관리'로 나타났다. 중학생의 '청소년의 이해' 대단원의 소단원별 하위내용에 대한 흥미도는 성별, 거주지역, 모의 연령, 부모 학력, 교과 선호도에 따라 차이가 나타났으며 유용성 인식은 성별, 거주지역, 모의 연령, 모의 학력, 교과 성적, 교과 선호도에 따라 차이가 나타났다. 소단원별 교과내용에 대한 흥미도와 유용성 인식과의 상관관계는 전반적으로 어느 소단원에 대해 흥미를 많이 가질 경우 그 해당 단원뿐만 아니라 해당 단원이 속해 있는 중단원 내의 다른 단원에 대하여도 유용성을 높게 인식하는 것으로 나타났다.

• 지역연구
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• 제8권1호
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• pp.31-50
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• 1992

The aim of this paper is to define major factors influencing land development of each of major uses (residential, commercial, industrial) in the process of rapid urban expansion. The main hypothesis of this study is that land use changing patterns are directed by supply side of land managed to public policies rather than demand side. The graphic analysis is applied to relationships between urban growth and land development process of each use and between land development project managed to public policies and land development process. Public and land development projects and zonning protection seem to be major roles of land supply and main determinants of urban spatial structure. Location factors for land development of each uses are selected in 23 variables. Factor analysis is applied to test correlation between variables in 1971 and 1981. Factor structure between two years is similar, but progressive processing of functional separation is derived such as intensive land use is grouped, different location between residential and industrial use is deep. Dependent variables are standardized to logarithm of land development of each use per unit vacant land in two periods, between 1971 and 1980 year and between 1981 year. Correlation analysis between 6 dependent variables and 23 location factors in each years are applied. Major factors of each use are selected in criteria such as high correlation with dependent variables, low correlation between independent variables and common application in two periods. As the result, major factors for residential land development are Land Readjustment Project (LRP), percent of total zoned area in residential zone, residential floor space density per available area, percent of total area in industrial use; for commercial development is distance to CBD, percent of total area in commercial use, residential floor space density per available area in each year, and volumn rate of industrial use; for industrial use is percent of total area of industrial use is percent of total area of industrial use, Industrial Estate Project (IES), LRP, and distance from CBD. Land development pattern of each use between two periods are slightly different. So 6 equation is derived from appling backward method of regession. Adjusted multiple R squares of all is more than 0.5 and those equation is statistically significant and valuable to assist urban land use forecasting.

• 한국과학교육학회지
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• 제26권3호
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• pp.393-405
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• 2006

본 연구에서는 고등학교 생물 I, '유전' 단원에서 Keller의 ARCS 전략 중, 특히 "주의집중"과 "만족감" 요소를 적용한, 의미 망 프로그램(Semantic Network Program)을 활용한 수업이 학생들의 학업성취도와 학습동기 향상에 미치는 효과를 분석하는 것을 연구의 목적으로 삼았다. 연구대상은 고등학교 2학년 실험집단 및 통제집단의 124명으로 구성되었고, 사전검사로 학업성취도 검사, 학습동기검사, 그리고 의미망 형성 검사를 실시한 후, 4주간에 걸쳐 6차시 동안 실험집단에게는 ARCS 전략 중 주의집중 전략을 적용한 의미망 프로그램을 활용한 유전 수업과 만족감 전략에 따른 의미망 제작 활동을, 통제집단에게는 교과서 중심의 강의식 수업을 처치하였다. 수업 처치에 따른 사후 검사 결과 동기전략을 적용한 의미망 프로그램을 활용한 수업은 강의식 수업보다 '주의집중과 만족감'을 높여 학생들의 인지구조에 새로운 지식을 효과적으로 연결시켜 생물 학업성취도를 향상시켰고(p<.001), 학생들의 유전관련 새로운 개념 형성에도 효과적인 것으로 나타났다(p<.001). 또한 본 연구에서 적용한 수업은 학생들이 생물 개념들을 구조지식으로 조직하여 이해함으로써, 기억효과를 높여 학습내용의 파지(retention)에 효과적이었다(p>.05). 실험집단의 심층면담 결과에서는 동기전략을 적용한 의미망 프로그램을 활용한 수업은 유전과 관련된 영상자료의 연결(link)로 호기심을 유발하여 주의집중이 잘 되었고, 직접 의미망을 제작해 봄으로써, 학습내용이 오랫동안 기억에 남아 문제해결에 효과적이었다는 긍정적인 반응을 보였다. 본 연구의 결과는 앞으로 고등학교 생물 I, '유전'단원에 대한 다양한 수업 전략을 모색하는데 의미있는 시사점을 제공해 줄 수 있을 것이다.

• JSTS:Journal of Semiconductor Technology and Science
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• 제10권4호
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• pp.316-324
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• 2010

In this paper, we design a 256 kbits EEPROM for a MCU (Microcontroller unit) with the wide voltage range of 1.8 V to 5.5 V. The memory space of the EEPROM is separated into a program and data region. An option memory region is added for storing user IDs, serial numbers and so forth. By making HPWs (High-voltage P-wells) of EEPROM cell arrays with the same bias voltages in accordance with the operation modes shared in a double word unit, we can reduce the HPW-to-HPW space by a half and hence the area of the EEPROM cell arrays by 9.1 percent. Also, we propose a page buffer circuit reducing a test time, and a write-verify-read mode securing a reliability of the EEPROM. Furthermore, we propose a DC-DC converter that can be applied to a MCU with the wide voltage range. Finally, we come up with a method of obtaining the oscillation period of a charge pump. The layout size of the designed 256 kbits EEPROM IP with MagnaChip's 0.18 ${\mu}m$ EEPROM process is $1581.55{\mu}m{\times}792.00{\mu}m$.

• 산업기술연구
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• 제21권A호
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• pp.293-301
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• 2001

This paper is experimental results of investigating the efficiency of horizontal vacuum drainage system. Effects of size and shape of drain on horizontal vacuum drainage were studied. Model tests in the laboratory with soft marine clay were carried out with drain pipe of having three different diameters and PBD (Plastic Board Drain) of strip shape so that consolidation settlement of soft clay due to applied vacuum pressure, amount of discharge, ground settlement and distributions of pore pressure and undrained shear strength were measured during testing. From results of model test, amount of discharge due to vacuum pressure was increased with the diameter of pipe drain whereas the drain efficiency of pipe in per unit area of drain surface was decreased with diameter of pipe. The rate of discharge per unit time was reduced very fast with diameter of pipe. Settlement of ground surface with time was increased with diameter of pipe as a result of increase of discharge to drain pipe.

• 한국전기전자재료학회논문지
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• 제29권12호
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• pp.819-823
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• 2016

DSSC (dye-sensitized solar cell) is expected to be one of the next-generation photovoltaics because of its environment-friendly and low-cost properties. However, commercialization of DSSC is difficult because of the electrolyte leakage. We propose thermal curable base on silicon resin and apply a unit cell and large area ($200{\times}200mm$) dye-sensitized solar cell. The resin aimed at sealing of DSSC and gives a promising resolution for sealing of practical DSSC. In result, the photoelectric conversion efficiency of the unit cell and the module was 6.63% and 5.49%, respectively. In the durability test result, the photoelectric conversion efficiency of the module during 500, 1,000, 1,500 and 2,000 hours was 0.73%, 0.73%, 1.82% and 2.36% respectively. It was confirmed that the photoelectric conversion efficiency characteristics are constant. We have developed encapsulation material of thermal curing method excellent in chemical resistance. A sealing material was applied to the dye-sensitized solar cell and it solved the problem of durability the dye-sensitized solar cell. Sealing material may be applied to verify the possibility of practical application of the dye-sensitized solar cell.

• 한국철도학회논문집
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• 제9권4호
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• pp.493-498
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• 2006

In this study, two large pile load tests were performed in the deep sand gravel deposit of Nakdong river basin so that the characteristics of the load transfer was identified. The fully instrumented rectangular barrette pile in the size of $1.5\times3.0m$ and the circular bored pile of the diameter 1.5 m were placed into the ground below 50 m. Under the applied loads of 2,400 tonf and 4,000 tonf, the test results of the load transfer showed the portion of 83% and 93% of the applied loads on the barrette pile and the bored pile, respectively, were supported by the skin friction along the pile shaft. It was revealed that the most of these skin friction mobilized in sand layer underlying clay layer having N-value more than 30 and that the friction per unit area of the bored pile was larger than the friction of barrette pile. However, if embedded in the stiff sand graval layer, the both piles were proven to be sufficient for using as the friction piles.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.854-859
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• 2008

In a railway vehicle, contact between wheel and rail is a peculiar characteristic and variations of wheel and rail profile influence on the dynamic characteristics of railway vehicle. Thus the variations of the wheel and rail profile are very important in railway dynamics. Recently a research relating to active steering to improve the curving performance of vehicle is progressing actively at home and abroad. In this field, a pre-study for the wheel/rail contact geometry is needed and especially the variation of the wheel/rail contact geometry with wheel wear is the key design parameter to develop the controller of the active steering bogie. In this paper, we have experimentally studied to analyze the variation of the wheel/rail contact geometry with wheel wear as a pre-study to develop the active steering bogie for electric multiple unit (EMU). For this, we have made an experiment with EMU operating in curving area. We have measured the wear profiles of the wheel of the test vehicle and analyzed the wheel/rail contact geometry with a mileage of the test vehicle. In experiment with test vehicle, we have got the useful data to design the steering controller of the wheelset.

• 한국주조공학회지
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• 제22권1호
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• pp.26-34
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• 2002

For application of cast-forging process with Al-Si alloys, casting experiments are carried out by adding Sr and TiB to Al-Si alloys for grain refinement treatment. We experimented on the mechanical properties according to microstructural changes, forging ability test and also investigated the mechanical properties after forging. The finest microstructure could be observed respectively when 0.05 wt.%Sr and 0.1 wt.%TiB were added. In this case, tensile strength and elongation increased much more than as casting. After high temperature deformation simulation test with grain refinement specimens was carried out, about 60N per unit $area(mm^2)$ of specimen was confirmed. After hot forging, tensile strength and elongation were increased. It was considered that casting defect was removed by compressive working.

• 한국지반공학회논문집
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• 제23권12호
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• pp.5-11
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• 2007

국내에서는 조립토를 이용한 연약지반 처리공법 중 모래다짐말뚝공법이 많이 활용되고 있으나, 모래자원의 고갈과 단가상승으로 인해 적용이 제한되고 있어 대체공법이 필요한 실정이다. 본 연구에서는 육상부 현장에 시험시공된 단일쇄석다짐말뚝에 대한 정재하시험을 수행하였다. 시험시 말뚝의 직경을 700mm로 고정하구 재하판의 면적을 변화시켰으며, 치환율 20, 30, 40%에 대하여 정재하시험을 실시하였다. 그 결과를 토대로 하여 단일쇄석다짐말뚝의 지지력 증가효과를 평가하였다. 치환율이 증가할수록 침하량이 작아지는 경향을 보였다. 또한, 치환율이 고려된 단일쇄석다짐말뚝의 항복지지력 공식을 제안하였다.