• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2005년도 지반공학 공동 학술발표회
• /
• pp.601-612
• /
• 2005

In mountainous area, Two parallel tunnels have been usually recognized as a road tunnel which has benefits in aspects of cost and stability. However, Design and construction of 2-Arch road tunnel are growing recently due to environmental destruction, compensation of land and difficulty of route separation. As studies are mainly undergoing on only guaranteeing stability and developing a waterproofing-drainage system to avoid water leakage through comprehension for characteristics of 2-arch tunnel behaviors, there is a tendency to evaluate quantity of support by empirical method with a tunnel which has a complicated cross-section and lack of construction ability. In this study, therefore, we made a plan of tunnel cross-section which had shown good construction ability and developed the waterproofing-drainage system which is able to solve the water leakage problem fundamentally by analyzing precedented 2-arch tunnels and investigating their sites in and out of nation. We also determined fixed quantity of support by a large-scale model test and numerical analysis. We want to contribute to 2-arch tunnel design hereafter introducing design procedure and method applied here.

• 상하수도학회지
• /
• 제24권4호
• /
• pp.369-376
• /
• 2010

The purpose of this study is to reprocess Waste-LCD(Liquid Crystal Display), to widely increase specific surface-area by foaming agent in the process of reprocessing and to use as a substrate of water treatment which is increased the ability of biological treatment, as well as to control non-point source pollutants produced by surface run off during rainfall with using this substrate, and to improve water quality of public watershed as developing substrate for water treatment to be able to purify second treated water which is exhausted at the wastewater treatment plant. The average removal efficiency of Waste-LCD that using the foaming technology was SS 71.2%, BOD 55.7%, COD 58.4%, T-N 29.5% and T-P was 50.3%. Almost Media, early stage showed low removal efficiency of SS and BOD. However, it became high when the microorganism adhered the Media. The variation of SS removal efficiency was high by inflow concentration of SS. The reason for the Media 4 showed high SS removal efficiency is that it has wide specific surface-area, and also it has a pore. All in all, it shows floating matter treatment ability not only inside but it also works outside of the substrate.

• 대한기계학회논문집A
• /
• 제27권8호
• /
• pp.1295-1302
• /
• 2003

In order to evaluate a failure behavior of pipe with notch-type wall thinning, the present study performed full-scale pipe tests using the 102mm, Schedule 80 pipe specimen simulated notch- and circular-type thinning defects. The pipe tests were conducted under the conditions of both monotonic and cyclic bending moment at a constant internal pressure of 10 MPa. From the results. of experiment the failure mode, load carrying capacity, deformation ability, and fatigue life of a notch-type wall thinned pipe were investigated, and they were compared with those of a circular-type wall thinned pipe. The failure mode of notched pipe was similar to that of circular-type thinned pipe under the monotonic bending load. Under the cyclic bending load, however, the mode was clearly distinguished with variation in the shape of wall thinning. The load carrying capacity of a pipe containing notch-type wall thinning was about the same or slightly lower than that of a pipe containing circular-type wall thinning when the thinning area was subjected to tensile stress, whereas it was higher than that of a pipe containing circular-type thinning defect when the thinning area was subjected to compressive stress. On the other hand, the deformation ability and fatigue life of a notch-type wall thinned pipe was lower than those of a circular-type wall thinned pipe.

• Weed & Turfgrass Science
• /
• 제4권4호
• /
• pp.338-347
• /
• 2015

Reinforcement cells are used to aid grass growth and taken together, this serves to extend greenery beyond the conventional spaces of lawns, tree pits, gardens, and parks, and is advantageous to urban cities since space for greening is often limited. Drought has variable effects on plant life and the resilience of turf to drought resistance also varies with species. Changes in photosynthetic ability were more pronounced for media rather than grass species. The media of sand without organic matter was found to be least suited for drought resistance. Normalized difference vegetation index (NDVI) and digital image analysis (DIA) data were generally in favour of Zoysia species as oppose to A. compressus. In A. compressus, selective traits such as, a more extensive root system and lower specific leaf area (SLA) were not an underlying factor that assisted this grass with enhanced drought resistance. Generally, WUE was found to be strongly related to plant characterises such as overall biomass, photosynthetic features as well as the lushness indexes, and specific leaf area. This study found a strong relationship between WUE and a suite of plant characteristics. These traits should serve as useful selection criteria for species with the ability to resist water stress.

• 한국수학교육학회지시리즈A:수학교육
• /
• 제49권4호
• /
• pp.501-522
• /
• 2010

In this study, 'Instruments of the achievement attribution in mathematical learning' was develop to investigate the reasons of mathematical learning achievement by reflecting Korean middle school and high school students' psychological characters and learning context in mathematical learning. To develop the appropriate items for the achievement attribution in mathematical learning, after reviewing attribution literature thoroughly, first version of the instrument was developed and Exploratory Factor Analysis and Confirmatory Factor Analysis were conducted. Then, to reduce the effect of the gender difference and achievement level difference, Differential Item Functioning was performed. Also, using Multiple group Confirmatory Factor Analysis, this instrument was investigated to see whether this can be used for both middle school and high school. The final items for success attribution are 3 items for luck, 3 items for effort, 2 items for ability. The failure attribution were composed of 3 items for luck, 3 items for effort, 2 items for ability, and 2 items for other. The instrument was developed by using large samples and psychometric analysis. Therefore, mathematic teachers can use this instrument efficiently to make a foundation for better learning environment so students' cognitive area and affective area can be harmonized.

• 대한금속재료학회지
• /
• 제49권2호
• /
• pp.104-111
• /
• 2011

An ultrafine grained Mg-9Al-1Zn magnesium alloy with the mean grain size less than $1{\mu}m$ was produced by using high-ratio differential speed rolling. The processed alloy exhibited excellent superplasticity at relatively low temperatures. The micro-forming tests were carried out using a micro-forging apparatus with micro V-grooved shaped dies made of silicon and the micro-formability was evaluated by means of micro-formability index, $R_f$ ($=A_f/A_g$, $A_f$: formed and inflowed area into the V-groove, $A_g$: area of the V-groove). The $R_f$ value increased with temperature up to $280^{\circ}C$ and then decreased beyond $300^{\circ}C$. The decrease of the $R_f$ value at $300^{\circ}C$ was attributed to the accelerated grain coarsening. Increasing the micro-forging pressure increased the $R_f$ values. At a given die geometry, die filling ability decreased as the die position moved away from the die center to the end. FEM simulation predicted this behavior and a method of improving this problem was proposed.

• 한국정보시스템학회지:정보시스템연구
• /
• 제30권3호
• /
• pp.177-199
• /
• 2021

Purpose This study explores the development direction of the artificial intelligence curriculum as a universal education that enhances the ability of college students to flexibly use artificial intelligence these days, where artificial intelligence education is spreading, and the educational components based on this are subdivided according to the characteristics of each major. Design/methodology/approach In order to develop the educational purpose of the subject and the detailed educational curriculum suitable for the subject of education, we first analyzed domestic and foreign prior research related to artificial intelligence liberal arts education. As the main components derived by experts, the basic concept of artificial intelligence converges to literacy to read and write for everyday problem solving, as well as problem-solving ability to manipulate real data and software. Findings The results showed that In the artificial intelligence literacy module, trends and prospects of artificial intelligence and necessary competencies were checked, and cases applied to major fields were examined. In the AI utilization and application part, basic data analysis items and content composition were composed through creative thinking, logical thinking, and intelligence. In order to design the curriculum, a software development language suitable for each major area was first selected, and AI education content areas, elements, and packages were defined and designed for each major area to meet the objectives of the subject.

• Human Ecology Research
• /
• 제53권1호
• /
• pp.29-47
• /
• 2015

The purpose of this study is to conceptualize the definition of school readiness specific to the context of the Republic of Korea. The school readiness test can be used as basic data to enable early childhood educational institutes to determine the general readiness of preschoolers and provide support to fit individual characteristics. For this purpose, six stages of the school readiness development process were considered, that is, draft development, primary preliminary survey, primary expert verification, secondary expert verification, secondary preliminary survey, and main survey. In the main survey, tests were conducted using the school readiness final draft targeting 344 preschoolers living in Seoul and Gyeonggi-do. The item discrimination power analysis and factor analysis for the examination area and question area were also conducted. Consequently, a test tool was developed on the basic of the results obtained, consisting of 129 items in the five areas of knowledge, function, adaptation, tendency, and attitude. The knowledge area was divided into general, linguistic, and mathematical knowledge, and the function area into fine motor function, basic living ability, expressive function, and gross motor function. The adaptation area was classified into adaptation activity, separation anxiety, maladaptive behavior, and environment adaptation; the tendency area into learning tendency; others understanding, and individual tendency, and the attitude area into rule compliance and life habits.

• 한국콘텐츠학회논문지
• /
• 제18권2호
• /
• pp.334-343
• /
• 2018

본 연구에서는 유아의 기후변화 대응 지식 및 문제해결 능력의 전반적 경향을 살펴보고, 유아의 성별 및 연령에 따라 기후변화 대응 지식과 문제해결 능력에 차이가 있는지를 알아보고자 하였다. 이를 위해 서울 및 경기지역 어린이집에 재원 중인 만 5세 및 6세 유아 129명을 연구대상으로 선정하였다. 기후변화 대응 지식을 측정하기 위해 환경보존 지식 검사도구를 수정해 10문항을 사용하였고, 기후변화 대응 문제해결 능력을 측정하기 위해 안전문제해결능력 검사 문항을 기후변화 대응능력과 관련된 내용으로 수정하여 5가지 문제해결 상황을 사용하였다. 수집된 자료는 평균과 표준편차, 이원변량분석, 피어슨의 적률상관계수를 사용하여 분석하였다. 그 결과, 만 6세 유아의 기후변화 대응 지식과 기후변화 대응 문제해결 능력은 만 5세 유아에 비해 더 높았으나, 성별에 따른 차이는 나타나지 않았다. 또한 유아의 기후변화 대응 지식수준이 높을수록 기후변화 대응 문제해결 능력도 높은 것으로 나타났다. 이 연구의 결과는 유아의 기후변화 대응지식과 문제해결 능력 간 관련성을 확인시켜주었으며, 기후변화 대응 지식과 문제해결 능력 향상을 위한 보다 체계적인 교육과정이 유아들에게 제공될 필요가 있음을 보여주었다.

• 한국콘텐츠학회논문지
• /
• 제11권9호
• /
• pp.352-361
• /
• 2011

이 연구의 목적은 특수경비원들의 사건충격이 직무스트레스 및 대처능력에 미치는 영향을 규명하는데 있다. 이 연구는 2011년 4월 수도권(인천)소재 공항에서 재직하고 있는 특수경비원들을 모집단으로 설정한 후 판단표집법을 이용하여 최종분석에 이용된 사례 수는 총 239명이다. 연구에 사용된 설문지는 총 67문항으로 구성되었으며, SPSSWIN 18.0을 이용하여 빈도분석, 요인분석, 신뢰도분석, 회귀분석 등을 실시하였다. 설문지의 신뢰도는 Cronbach's ${\alpha}$값이 .779이상으로 나타났다. 결론은 다음과 같다. 첫째, 특수경비원들의 사건충격은 직무스트레스에 영향을 미친다. 즉, 침습이 자주 반복될수록 인간관계에 대한 스트레스는 증가한다. 또한, 과각성이 자주 반복될수록 역할에 대한 스트레스는 증가한다. 둘째, 특수경비원들의 사건충격은 대처능력에 영향을 미친다. 즉, 과각성이 자주 반복될수록 문제중심적 대처능력은 감소한다. 반면, 회피성향이 지속적으로 작용할수록 문제중심적 대처능력은 증가한다. 셋째, 특수경비원들의 직무스트레스는 대처능력에 영향을 미친다. 즉, 직무특성에 대한 무력감이 작용할수록 문제중심적 대처능력은 증가한다. 반면, 역할에 대한 모호성이 높게 작용할수록 문제중심적 대처능력, 사회적지지 추구능력은 감소한다.