• Journal of the Korea Concrete Institute
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• v.14 no.2
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• pp.223-230
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• 2002

The main intent of this research was to determine the feasibility of utilizing recycling bottom ash as CLSM (controlled low-strength material). CLSM is a cementitious material, commonly a blend of portland cement, fly ash, sand, and water, that is usually flowable and self-leveling at the time of placement. The durability characteristics of mixtures made bottom ash we compared with those of fly ash CLSM in order to evaluate the effectiveness and suitability of bottom ash as material in CLSM. A comprehensive evaluation of the bottom ash in CLSM and mix proportions indicated that the bottom ash are capable of performing as CLSM mixtures. The durability characteristic of CLSM incorporating the bottom ash under various physical and chemical causes of deterioration were investigated. Test results indicated that CLSM using bottom ash has acceptable durability performance. CLSM incorporating with bottom ash were also found to be environmentally safe.

• Journal of the Korean Society of Costume
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• v.60 no.6
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• pp.1-10
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• 2010

The cultures and traditions of Asia has the roots so deep and it is the origin of inspiration. Therefore, it is easy to find a different inspiration when designing, expecially for Western designers who are seeking European tradition and its comparison. The most distinctive feature of the Asian look is non-structural and has no clear form close to the structure of the body or mathematical ratio, but is steric with 2-Dimensional planed textiles, and has a flexible, non-structural formative characteristic related to the movable body. This is base on the vision of the universe that regards the parts as the whole. From this research, generally studying about the Asian look and its non-structural formative characteristics. The study looked closely into the aesthetic value of non-structural formative characteristics formation, with basis on the large dress regulation system of the western reasoning and rationalism and mechanism. At first, my study pointed on the dressing functionalism or Neo-classism considering emotions, Anti-Western aspect observing surrealism dressing and expressionism dressing. Second, with men and women showing similar outer shape without the equivalent element such from wearing a corset, the sexism is abolished. Finally, the designers’ inner intention of art is being delivered, from the aspect that the expression of art, size and no waste of fabric shows effort of communicating with the world, giving value to the possibility of continuance.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.6
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• pp.683-688
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• 2018

In the 21stcentury, teachers must welcome new technology to ensure the best learning in virtual classrooms, aside from the physical classroom. Google Classroom provides a vital chance to promote blended learning and professional development. The purpose of this study is to specify the procedures in problem design when employing blended problem-based learning (BPBL) and to design problems for learning the contents of the subject. The design of problems is crucial for effective BPBL. The underlying theory of BPBL is that learning is most effectively initiated and facilitated by posing and solving real-life problems that interest the learner, because working on such problems makes learning meaningful and motivates students. Ineffective problem-based learning (PBL) could affect students when acquiring sufficient domain knowledge, activating appropriate prior knowledge, and properly directing their own learning. The procedures for designing good problems are composed of the selection of educational content, figuring out the learner's characteristics, finding problems, setting up roles and situations, and writing down problems. Using these procedures, we designed five integration problems covering the contents of management subjects. Planned management subjects based on BPBL in a Mongolian university focuses on the process of designing problems.

• Journal of The Korean Society of Grassland and Forage Science
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• v.25 no.1
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• pp.57-64
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• 2005

월동기간 동안 zoysiagrass[Zoysia matrella(L.) Merr]와 creeping bentgrass(Agrostis palustris Hunds)의 저온 스트레스에 대한 탄수화물 대사 반응을 구명하기 위해 11월부터 이듬해 4월까지의 식물체내의 탄수화물 대사산물의 변화를 비교 분석하였다. Creeping bentgrass의 녹색도와 뿌리 성장은 온도변화와 거의 평행하게 변화하였으나 zoysiagrass는 뿌리 성장에 거의 변화가 없이 3월 말까지 담황색을 나타냈다. 11월부터 이듬해 1월까지 zoysiagrass에서 glucose와 sucrose 함량은 크게 높았고, 1월에서 4월까지 starch를 제외한 모든 탄수화물 화합물들의 감소의 정도가 현저하게 낮았다. Reeping bentgrass에서 fructan의 depolymerization이 2월 이후 단당류와 이당류의 감소와 일치했으나 zoysiagrass에서는 starch 가수분해가 11월부터 일찍이 시작되었다. 이상의 결과들은 creeping bentgrass와 비교 했을때 zoysisagrass 뿌리의 높은 비구조적 탄수화물의 농도가 저온 내성과 밀접한 관계가 있음을 잘 나타내어 주고 있다.

• Journal of the Korean Society of Safety
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• v.21 no.2 s.74
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• pp.143-149
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• 2006

This paper deals with the space-time finite element analysis of two-dimensional vibration problem with a single variable. The method of space-time finite elements enables the simpler solution than the usual finite element analysis with discretization in space only. We present a discretization technique in which finite element approximations are used in time and space simultaneously for a relatively large time period. The weighted residual process is used to formulate a finite element method for a space-time domain. A stability problem is described and some investigations for chosen type of rectangular space-time finite elements are carried out. Instability is caused by a too large time step of successive time steps in the traditional time-dependent problems. It has been shown that the numerical stability of time-stepping on the larger time steps is quite good. The unstructured space-time finite element not only overcomes the shortcomings of the stability in the traditional numerical methods, but it is also endowed with the features of an effective computational technique. Some numerical examples have been presented to illustrate the efficiency of the described method.

• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.3
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• pp.13-20
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• 2021

Post-installed anchor is a structural material that connects structural and non-structural members to existing concrete members. However, there are cases where rebar interception and construction error occur at the site. In that case, measures are needed to prevent performance degradation of the rear-installation anchors. In this study, in order to evaluate the performance of torsional control expandable post-installed anchors for compressive strength and effective depth of the reference concrete was tested. The results of the most commonly used tests of M10 and M20 showed that had variable coefficients within 15%, satisfying the reliability presented in KCI(2017). It was also confirmed that the depth of the buried and the strength of concrete affect the strength of the pavement. Based on the results of the existing similar studies and the results of this study, the design equation of the post-installed anchor was proposed and the results were compared with the existing design.

• Journal of Animal Environmental Science
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• v.8 no.1
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• pp.43-53
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• 2002

The aim of the study is to describe the fate and transformation of nitrogen in grassland ecosystems. In the growing season from 1987 to 1993, 2 growing farmer in south Germany were studied the yield and nutrient balance of reduced input slurry application. The study includes 3 different slurry application levels. The levels are conventional slurry application, reduced slurry application, without slurry application. These levels are studied at 2 different experimental farms. The forage yield of zero slurry application plot has 14∼44% of the conventional slurry application, while the yield in the reduced slurry plot is only 0∼14% lower than that in the conventional slurry plot. The kalium and phosphorus contents of forage were tend to decrease with reduced slurry application N-uptake was increasing with the increase of slurry application level. The N-uptake of zero slurry plots was lower 40∼65% of the conventional plot, while in the reduced plot was only 6∼16% lower than in the conventional plot. The N-balance shows negative figures on all plots. The N-uptake in experiment site A was only a little bit more than the N-fertilizer plot, while in site experiment B the N-uptake is 2 to 3 times higher than the N-application amount of slurry.

• Journal of the Korea institute for structural maintenance and inspection
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• v.15 no.4
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• pp.116-124
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• 2011

RC frames with unreinforced masonry infiledl walls are common in worldwide. Since infilled walls are normally considered as non-structural elements, their presence is often ignored by engineers. In this study, to improve the seismic performance of masonry walls, hexagonal block was developed and the influence of masonry infilled wall on the seismic performance of reinforced concrete(RC) frames that were designed in accordance with current code provisions without the consideration of earthquake loadings are investigated. Two 1/2 scale, single story, single bay, frame specimens were tested. The parameters investigated included that the strength of infilled wallls with respect to that of the lateral load history. The experimental results indicate that infilled walls can significantly improve the lateral stiffness and strength of RC frames. The lateral loads developed by the infilled frame specimen is higher than that of the bare frame. It also indicates that infilled walls can be potentially used to improve the performance of existing nonductile frames. For this purpose. methods should be developed to avoid irreparable damage and catastrophic failure.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.35 no.1
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• pp.35-44
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• 2022

It is essential to control the lateral displacement and differential axial shortening of the vertical elements in high-rise buildings. Recently, an outrigger or a mega structure system has been adopted to control the lateral displacement. Furthermore, to resolve the problems caused by differential axial shortening in high-rise buildings, analytical prediction and correction is often studied; however, the study on the comparisons of the lateral load resisting systems to address differential axial shortening is less. Therefore, in this paper, a 60-story RC residential building using an outrigger or a mega structure system is analyzed with a construction sequence. Moreover, differential axial shortening can result in an additional member force of structural members and failure of non-structural members. These problems caused by differential axial shortening affects the behaviors and can damage the important structure member in the high-rise buildings. Hence, the effects of the systems on differential axial shortening between the vertical elements in high-rise buildings are studied.

• Journal of Astronomy and Space Sciences
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• v.22 no.1
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• pp.13-20
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• 2005

Bound abrasive grinding is used for the initial fabrication phase of the precision aspheric mirrors for both space and ground based astronomical telescopes. We developed a new grinding optimization process that determines the input grinding variables for the target surface roughness, checks the grinding error magnitude in resulting surface roughnesses, and minimizes the required machining time. Using the machining data collected from the previous grinding runs and subsequently fed into the multivariable regression engine, the process has the evolving controllability that suggests the optimum set of grinding variables for each target surface roughness. The process model was then used for ten grinding experiments that resulted in the grinding accuracy of $=-0.906{\pm}3.38(\sigma)\;nm(Ra)$ for the target surface roughnesses of Zerodur substrate ranging from 96.1 nm (Ra) to 65.0 nm (Ra) The results imply that the quantitative process optimization technique developed in this study minimizes the machining time and offers the nanometric surface roughness controllability superior to the traditional, qualitative, craftsman based grinding process for the astronomical optical surfaces.