• 한국수학교육학회지시리즈E:수학교육논문집
• /
• 제21권2호
• /
• pp.331-345
• /
• 2007

본 연구에서는 중학생들이 수학 평가 결과를 어떻게 파지하는지를 탐구하고자 하였다. 이를 위해, 측정시기, 문항 유형, 성적, 평가요소 등을 학생들이 평가결과를 파지하는데 중요한 요인이라고 보고 이 변인들과 관련된 학생들의 평가결과 파지 유형을 분류하였다. 이를 토대로, 두 명의 연구 참여자를 선정하여 심층면담을 진행함으로써 그들의 평가에서 핵심적인 역할을 하는 요소가 무엇이며 그것이 향후에 어떤 형태로 파지되어 나타나는지를 분석함으로써 중학생들의 수학과 평가 결과의 파지 유형을 분석하였다.

• Computers and Concrete
• /
• 제14권2호
• /
• pp.145-161
• /
• 2014

The article presents the statistical method of grouping the results of the compressive strength of concrete in continuous production. It describes the method of dividing the series of compressive strength results into batches of statistically stable strength parameters at specific time intervals, based on the standardized concept of "concrete family". The article presents the examples of calculations made for two series of concrete strength results, from which sets of decreased strength parameters were separated. When assessing the quality of concrete elements and concrete road surfaces, the principal issue is the control of the compressive strength parameters of concrete. Large quantities of concrete mix manufactured in a continuous way should be subject to continuous control. Standardized approach to assessing the concrete strength proves to be insufficient because it does not allow for the detection of subsets of the decreased strength results, which in turn makes it impossible to make adjustments to the concrete manufacturing process and to identify particular product or area on site with decreased concrete strength. In this article two independent methods of grouping the test results of concrete with statistically stable strength parameters were proposed, involving verification of statistical hypothesis based on statistical tests: Student's t-test and Mann - Whitney - U test.

• Wind and Structures
• /
• 제5권2_3_4호
• /
• pp.277-290
• /
• 2002

A two dimensional discrete vortex method (DIVEX) has been developed at the Department of Aerospace Engineering, University of Glasgow, to predict unsteady and incompressible flow fields around closed bodies. The basis of the method is the discretisation of the vorticity field, rather than the velocity field, into a series of vortex particles that are free to move in the flow field that the particles collectively induce. This paper gives a brief description of the numerical implementation of DIVEX and presents the results of calculations on a recent suspension bridge deck section. The results from both the static and flutter analysis of the main deck in isolation are in good agreement with experimental data. A brief study of the effect of flow control vanes on the aeroelastic stability of the bridge is also presented and the results confirm previous analytical and experimental studies. The aeroelastic study is carried out firstly using aerodynamic derivatives extracted from the DIVEX simulations. These results are then assessed further by presenting results from full time-dependent aeroelastic solutions for the original deck and one of the vane cases. In general, the results show good qualitative and quantitative agreement with results from experimental data and demonstrate that DIVEX is a useful design tool in the field of wind engineering.

• The Journal of Korean Physical Therapy
• /
• 제27권1호
• /
• pp.55-60
• /
• 2015

Purpose: The purpose of this study is to examine the effects of types of shoes and distance travelled on oxygen saturation and walk in relation to smoking. Methods: To achieve this goal, the researcher divided 20 normal male adults into two groups: a smoking group (10) and a non-smoking group (10) and used a treadmill to have them walk in intervals of 3 days, a total of 4 times. Results: By analyzing their walk, the following results were obtained: oxygen saturation showed statistically significant results in both the smoking group and the non-smoking group. The smoking group showed significant results for left pace and significant results were achieved for setting foot and shaking in both the smoking group and the non-smoking group. In comparison of oxygen saturation between groups, there were significant results for 3km sneakers walk and 3 km slippers walk. There were significant results for width in 3 km sneakers walk, left and right pace in 3 km slippers walk, and setting foot in 1 km sneakers walk. Conclusion: In conclusion, in the smoking group changes in walk occur if the shoes are more unstable and the distance travelled becomes longer.

• Computers and Concrete
• /
• 제25권3호
• /
• pp.193-204
• /
• 2020

In the study, a new, simple and alternative formula is proposed to calculate numerically crack widths of concrete on a finite element (FE) model. By considering more general tension softening behavior of concrete, the proposed expression is derived irrespective of any tension softening model given in the literature or design codes. The test results of six reinforced concrete (RC) deep beams having different geometrical and material properties selected from a recent existing experimental study of the authors are used to verify the accuracy and reliability of the proposed formula and the created numerical FE models of the specimens. Moreover, the crack width results obtained from the FE models are compared with the test results to see the performance of the proposed formula. The results of the study demonstrate that the proposed formula gives very accurate results in a comparison with the test results. The ratios of errors on the results stay commonly at an acceptable level as well. Consequently, the proposed formula is quite simple, unique, and robust to determine crack widths of RC deep beams on an FE model.

• 한국지반공학회지:지반
• /
• 제4권2호
• /
• pp.25-32
• /
• 1988

본 논문에서는 뒤채움이 사질토이고 수평면인 연직벽이 수평이동변위(ATRA)를 일으킬 때 토류벽에 작용하는 정적 주동토복을 Dubrova방법과 Dubrova방법에 Chang의 개념을 도입시킨 방법 각각으로 구하였다. 이 결과를 최근에 Fang and Ishibashi가 발표한 모형실험결과와 비교분석하였다. 또한 이미 발표한 바 있는 제(1985)의 벽체 정점과 저면을 중심으로 단전하는 정적 주동토압(AT, AB)의 경우도 상기모형실험결과와 비교분석하였다. 그 결과 다음과 같은 결론을 얻었다.

• Computers and Concrete
• /
• 제12권4호
• /
• pp.413-429
• /
• 2013

The primary aim of this study is to develop a three dimensional finite element (FE) model to predict the axial stress-strain relationship and ultimate strength of the FRP-wrapped UHPC columns by comparing experimental results. The reliability of four selected confinement models and three design codes such as ACI-440, CSA-S806-02, and ISIS CANADA is also evaluated in terms of agreement with the experimental results. Totally 6 unconfined and 36 different types of the FRP-wrapped UHPC columns are tested under monotonic axial compression. The values of ultimate strengths of FRP-wrapped UHPC columns obtained from the experimental results are compared and verified with finite element (FE) analysis results and the design codes mentioned above. The concrete damage plasticity model (CDPM) in Abaqus is utilized to represent the confined behavior of the UHPC. The results indicate that agreement between the test results and the non-linear FE analysis results is highly satisfactory. The CSA-S806-02 design code is considered more reliable than the ACI-440 and the ISIS CANADA design codes to calculate the ultimate strength of the FRP-wrapped UHPC columns. None of the selected confinement models that are developed for FRP-wrapped low and normal strength concrete columns can safely predict the ultimate strength of FRP-wrapped UHPC columns.

• Wind and Structures
• /
• 제25권6호
• /
• pp.537-549
• /
• 2017

In this study, the turbulent flow around a bluff body for different wind velocities was investigated numerically by using its two- and three-dimensional models. These models were tested to verify the validity of the simulation by being compared with experimental results which were taken from the literature. Variations of non-dimensional velocities in different positions according to the bluff body height were analysed and illustrated graphically. When the velocity distributions were examined, it was seen that the results of both two- and three-dimensional models agree with the experimental data. It was also seen that the velocities obtained from two-dimensional model matched up with the experimental data from the ground to the top of the bluff body. Particularly, compared to the front part of the bluff body, results of the upper and back part of the bluff body are better. Moreover, after comparing the results from calculations by using different models with experimental data, the effect of multidimensional models on the obtained results have been analysed for different inlet velocities. The calculation results from the two-dimensional (2D) model are in satisfactory agreement with the calculation results of the three-dimensional model (3D) for various flow situations when comparing with the experimental data from the literature even though the 3D model gives better solutions.

• 대한족부족관절학회지
• /
• 제10권2호
• /
• pp.184-189
• /
• 2006

Purpose: To evaluate surgical treatment using two-staged MIPO technique in tibial pilon fractures involving tibial shaft. Materials and Methods: Twelve patients, who underwent two-staged MIPO technique for pilon fractures involving tibial shaft between January 2003 and May 2005, were followed for more than one year. Radiographs were graded by the criteria of Anglen and ankle functions were graded by the criteria of Mast and Teipner. Ankle function, union time and postoperative complications were also analysed. Results: Clinically there were eight (67%) good results, three (25%) fair results and one (8%) poor result. At the last follow-up, the radiographic results showed seven (58%) excellent results, three (25%) good results, and two (17%) fair results. During the follow up, There was one case of nonunion Conclusion: Two-staged MIPO techinque is one of the good methods for the treatment of pilon fractures invloving tibial shaft.

• Clinics in Shoulder and Elbow
• /
• 제3권1호
• /
• pp.20-25
• /
• 2000

Purpose : To evaluate functional results and study factors influencing results after humeral hemiarthroplasty for comminuted fractures of the proximal humerus. Materials and Methods: We reviewed 12 patients with average follow-up period of 23 months(12 to 42). The proximal humeral fractures consisted of one anatomical neck fracture, five three-part and six four-part fractures or fracture-dislocations. Constant score and Compito et al' evaluation system were used for clinical assessment. Statistical analysis was done with the Wilcoxon test. Results: Six cases of anatomical neck, three-part fractures or fracture-dislocations showed 61 points on the average Constant score and three unsatisfactory results on the Compito et al' evaluation; Six of four-part fractures or fracture-dislocations showed 51 points and three unsatisfactory results. There were 59(two unsatisfactory) for five non-associated dislocation and 53(four unsatistactory) for seven associated dislocation; 66(one unsatisfactory) for three under 60 years and 41(five unsatisfactory) for nine over 60 years; 67(two unsatisfactory) for seven tuberosity union and 41(four unsatisfactory) for five tuberosity non-union or resorption; 58(four unsatisfactory) for ten early operation within two weeks and 43(all unsatisfactory) for two delayed operation; and 18(unsatisfactory) for one case of a accompanied rotator cuff tear. Conclusion: We concluded that tuberosity union was important factor influencing the results. Also, we thought that age, timing of operation and accompanied rotator cuff tear could be influenced to results.