• 한국수학교육학회지시리즈D:수학교육연구
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• 제19권2호
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• pp.89-100
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• 2015

The study investigated pre-service teachers' knowledge and computational skills by using Triangular Arithmagon. Participants included 90 pre-service teachers from two schools in the United States and Taiwan. The Triangular Arithmagons Test (TAT) was used to measure pre-service teachers' performance in whole number, fractions, and decimals operations (i.e., addition, subtraction, multiplication, and division), each of which included level-1 (basic) and level-2 (advanced) tests. MANOVA analysis was performed to compare the performance between teachers from the United States and Taiwan. Results indicated that overall, pre-service teachers in Taiwan outperformed those in the United States, especially on the advanced-level tests. Pre-service teachers in the United States were found to have poor ability of solving complex operation problems. Different curriculum plans and teaching methods may lead to the performance gap between the two countries.

• 한국수학교육학회지시리즈A:수학교육
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• 제52권4호
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• pp.465-481
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• 2013

In this study, 27 pre-service teachers presented virtual mathematics instruction to develop his/her own teaching practice ability. I found several attributes in their virtual mathematics instruction such as connecting contents, asking justification, encouraging students' communication, representing variously, and using ICT etc. These will be the characteristics of the future mathematics class. When peer pre-service teachers assess presenter's instruction quantitatively, there are differences in the results between expert and pre-service teachers. Pre-service teachers didn't find the elements of student self assessment or group assessment and communication activities at the virtual instruction. When they assess peers' virtual instruction qualitatively, the results are specific or new ones compared with the quantitative assessment elements. Thus I suggested some implications for the mathematics pre-service teachers' virtual instruction in the view of teacher education.

• 한국농공학회논문집
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• 제58권6호
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• pp.71-77
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• 2016

This study was to evaluate the feasibility of pre-consolidation pressure distribution characteristic of western and southern coastal region, using correlation of unconfined compressive strength and preceding research equation. Pre-consolidation of western and southern region showed similar trends undrained shear strength and pre-consolidation pressure in proportion to unconfined compressive strength. Predicted results of U.S. NAVY. (1982) equation revealed a small error western 9.7 % and southern 0.4 %. Prediction correlation results of pre-consolidation using unconfined compressive strength revealed an error western 16.8 % and southern 0.7 %. It was reported that less than 20 percent of pre-consolidation pressure prediction result of Casagrande forecasting error. Estimates of pre-consolidation pressure are possible, before the standard consolidation test, because it was reported that less than 20 % of the forecasting errors of Casagrande.

• Structural Engineering and Mechanics
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• 제21권4호
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• pp.375-392
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• 2005

Cable supported structures offer an elegant and economical solution for bridging over long spans with resultant low material content and ease of construction. In this paper, a model of shallow cable supported footbridge with reverse profiled pre-tensioned cables is treated and its load deformation characteristics under different quasi-static loads are investigated. Effects of important parameters such as cable sag and pre-tension are also studied. Numerical results performed on a 3D model show that structural stiffness of this bridge (model) depends not only on the cable sag and cross sectional areas of the cables, but also on the pre-tension in the reverse profiled cables. The tension in the top supporting cables can be adjusted to a high level by the pre-tension in the reverse profiled bottom cables, with the total horizontal force in the bridge structure remaining reasonably constant. It is also evident that pre-tensioned horizontally profiled cables can greatly increase the lateral horizontal stiffness and suppress the lateral horizontal deflection induced by eccentric vertical loads.

• 대한정형도수물리치료학회지
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• 제12권2호
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• pp.42-51
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• 2006

The purpose of this study was effect of pilates exercise program on obesity pre-obese adult sixteen (men 3, women 13). The pilates exercise program was provided to subject for 4weeks (3 time a week) Measurements of pre and post 2weeks, and post 4weeks experiment were BMI (Body Mass Index), WHR(Waist-hip Ratio). The result were as follows: 1. The BMI was decreased in pre - exercise 2weeks, pre - exercise 4weeks but there was no statistically. There was significant difference between pre - exercise-4weeks. 2. The WHR was no significant difference between pre - exercise-2 weeks and pre - exercise-2 weeks and 2-4 weeks everybody.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1996년도 춘계학술대회 논문집
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• pp.41-46
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• 1996

In this study, unsintered and pre-sintered low purity alumina ceramics were machined with various tools to clarify the machinability, optimum tool materials and optimum cutting conditions. The main conclusions obtained were as follows. (1)In the case of dry cutting, the sintered diamond and natural diamond tools exhibit better performance in machining of the ceramic pre-sintered at lower temperature, and the tool lives of both tools in machining the ceramics pre-sintered at high temperature becomes extremely short. (2)The performance of CBN tool becomes better in dry machining of the ceramics pre-sintered at higher temperature. (3)When the pre-sintered ceramics were wet machined with sintered diamond, the tool life becomes considerably long, and higher cutting speed can be used than in the case of the CBN and ceramic tools, the tool lives becomes shorter at wet cutting than at dry cutting, especially exhibiting extremely short tool life in wet cutting with ceramic tool.

• Structural Engineering and Mechanics
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• 제59권2호
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• pp.327-341
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• 2016

This study addresses the effect of pre-stressed cables on a pre-stressed mega-braced steel frame through employing static analysis and pushover analysis. The performances of a pre-stressed mega-braced steel frame and a pure steel frame without mega-braces are compared in terms of base shear, ductility, and failure mode. The influence of the cable parameters is also analyzed. Numerical results show that cable braces can effectively improve the lateral stiffness of a pure frame. However, it reduces structural ductility and degenerates structural pre-failure lateral stiffness greatly. Furthermore, it is found that 20% fluctuation in the cable pretension has little effect on structural ultimate bearing capacity and lateral stiffness. As comparison, 20% fluctuation in the cable diameter has much greater impact.

• 디지털산업정보학회논문지
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• 제10권4호
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• pp.143-150
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• 2014

A high power amplifier(HPA) has widely been used in wireless communications. In order to have a maximum power efficiency, the HPA uses a saturation domain having nonlinear characteristics, which generates nonlinear distortions to decrease the transmission efficiency. In order to solve this problem, various methods to linearize HPA have been reported until now, and the pre-distorter method is very attractive among them. In this paper, a new enhanced adaptive pre-distorter method was proposed to be applied for compensating nonlinear distortions of HPA. Through computer simulations as well as the analytical analysis, it could be shown that it is possible for both conventional adaptive pre-distorter and proposed adaptive pre-distorter, to be applied for linearizing HPA. Also, the simulations results demonstrated that the proposed adaptive pre-distorter may have faster convergence speed and better capability of compensating the nonlinear distortion than the conventional adaptive pre-distorter with nearly equal computation complexity.

• Animal cells and systems
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• 제11권2호
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• pp.129-134
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• 2007

The initiation of eukaryotic DNA replication requires assembly of the pre-replicative complex (Pre-RC) through the concerted action of Orc, Cdc6, Cdt1 and Mcm2-7 complex during G1 phase. The pre-RC assembly licenses individual replication origins for the initiation of DNA replication and sufficient number of the pre-RC is essential for proper progression of S phase. However, it is not well known how cells recognize the completion of the pre-RC assembly before G1-S transition. In order to understand the cellular responses to the defects in pre-RC assembly, we depleted the known components of pre-RC proteins using the small interference RNAs in HeLa cells. Although the defects of pre-RC assembly by the depletion of the pre-RC proteins such as Orc2, Cdt1, Mcm2 & Mcm10 did not elicit the activation of Chk1- or Chk2-dependent checkpoint pathways, these cells still showed significant decrease in the cellular level of Cdc25A proteins. These results suggests that a novel checkpoint pathway exist in HeLa cells, which is not dependent upon Chk1 or Chk2 proteins and play essential roles in the cellular responses to the defects in the pre-RC assembly. Also, among those four proteins tested in this study, the depletion of Mcm10 and Cdt1 proteins significantly increased the apoptotic cell death in HeLa cells, suggesting that these proteins not only play roles in the pre-RC assembly, but also are involved in the checkpoint responses to the defects in the pre-RC assembly.

• 한국과학교육학회지
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• 제34권3호
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• pp.197-206
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• 2014

이 연구에서는 중등 교육과정의 실험을 수행하는 과정에서 예비과학교사의 논증구조를 분석함으로써 예비과학교사의 탐구 능력과 탐구에 대한 인식을 조사하고자 한다. 사범대학교 4학년에 재학 중인 예비과학교사 9명을 대상으로 하였으며, 중학교 1학년 과학교과서의 상태변화에 관한 실험을 수행하였다. 예비교사들의 실험 보고서는 Toulmin의 논증구조를 분석틀로 분석되었다. 또한 설문지를 통해 과학과 실험에 대한 인식조사를 하였으며, 반구조화된 면담을 실시하였다. 연구결과, 예비교사들의 논증에는 과학지식의 결핍, 탐구 능력 미흡, 오차에 대한 신념, 추가 근거자료가 영향을 미쳤다. 이러한 연구결과를 통해 예비교사들의 실험 탐구능력 수준은 미흡하며, 예비교사 교육과정을 재구성하여 교사교육 프로그램을 통해 탐구 실험을 경험할 수 있는 기회를 제공할 필요가 있다고 주장하였다.