• International Journal of Highway Engineering
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• v.8 no.3 s.29
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• pp.105-114
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• 2006

A popular alternative to extend the life of aged pavement is asphalt overlay. However, it has a very serious and inherent shortcoming in deterring a reflection crack. Although joint-rehabilitation and stress-relief techniques have been applied to deter such reflection cracks in aged pavement, the techniques had a limited success only in slowing down the progress of a reflection crack. Rubblization technique rubblizes the concrete pavement slab in situ and uses the rubblized slab as the base material. Then, pavement overlay is applied to finish off the rehabilitation of aged pavement. This rubblization technique has the advantage of solving the problem of reflection cracking completely. When rubblization technique is applied, the upper layer of aged concrete pavement is rubblized between 40mm-70mm in depth. However, the lower layer is typically rubblized more than 100mm in depth. Nevertheless, it is difficult to turn the entire concrete pavement of more than 30cm in depth into rubblized aggregate of appropriate size. Thus, a simulation experiment was carried out to find the appropriate rubblized depth, which avoids the reflection cracking and still maintains the function of subbase, by varying the depth of rubblized depth in loom increments of 0cm, 10cm, and 20cm. The result indicated the optimum rubblized depth was 10cm (Lee, 2006). Additionally, a small rubblizinge equipment was developed in order to derive the rubblization technique appropriate for thick concrete pavement. This equipment was tested out on an experimental pavement, which was constructed with the same standard and specification for the road in actual use, by varying its rubblizing head shape and energy as well as the effective area of rubblization. This experiment led to a prototype equipment for rubblization of thick concrete pavement. The prototype was put into use on a highway, undergoing a test construction and monitoring afterwards. This entire process was necessary for the validation of the proposed rubblization technique.

• Journal of Korean Society of Transportation
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• v.23 no.3 s.81
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• pp.125-136
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• 2005

The current traffic accident reduction procedure in economic feasibility study does not consider the characteristics of road and V/C ratio. For solving this problem, this paper suggests methods to be able to evaluate safety of each road in construction and improvement through developing accident Prediction model in reflecting V/C ratio Per road types and traffic characters. In this paper as primary process, model is made by tke object of urban roads. Most of all, factor effecting on accident relying on road types is selected. At this point, selecting criteria chooses data obtained from road planning procedure, traffic volume, existence or non-existence of median barrier, and the number of crossing point, of connecting road. and of traffic signals. As a result of analyzing between each factor and accident. all appear to have relatives at a significant level of statistics. In this research, models are classified as 4-categorized classes according to roads and V/C ratio and each of models draws accident predicting model through Poisson regression along with verifying real situation data. The results of verifying models come out relatively satisfactory estimation against real traffic data. In this paper, traffic accident prediction is possible caused by road's physical characters by developing accident predicting model per road types resulted in V/C ratio and this result is inferred to be used on predicting accident cost when road construction and improvement are performed. Because data using this paper are limited in only province of Jeollabuk-Do, this paper has a limitation of revealing standards of all regions (nation).

• Journal of Educational Research in Mathematics
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• v.24 no.2
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• pp.181-204
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• 2014

This research aims to have some implications for revision of curriculum and textbooks by analysing connections between the 2009 revised national curriculum and its textbooks in elementary school mathematics. The results of analyses for 3~4 grades can be summarized in four aspects: Firstly, we noticed that the reconstructed achievement criteria were reflected properly in the textbooks except for use of calculators in 'Numbers and Operations'. Secondly, the analysis of connections between unit objectives of textbooks and the reconstructed achievement criteria suggests that 10 units must receive attention. Especially, the range of decimal numbers for adding and subtracting needs to be corrected. Thirdly, mathematical terms and symbols excluding 'unit fraction' were found in the textbooks. Finally, mathematical processes were also fully reflected in the textbooks. However 'simplifying' as a strategy for problem solving was only missing. This result shows good or poor connections between the curriculum and its textbooks, therefore it is expected to be used effectively to revise the national curriculum for mathematics and its textbooks.

• Journal of Elementary Mathematics Education in Korea
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• v.15 no.1
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• pp.57-75
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• 2011

This research aimed to explore the effects of collaborative writing activities in a mathematical context, specifically pertaining to areas such as numbers and operation, geometrical figure, and measurement in Mathematics: Level 5-b, on their mathematical achievement gain and disposition among Grade 5 students. To do this, out of a total of 62 students selected from two Grade 5 classes of J Elementary School in Dalseo-gu, Daegu City, who were found to be homogenic from the tests of math performance and dispositions, an experimental group(n=31) was designed and compared to a control group (n=31). Over a six week period from October to November in 2009, the experimental group was given collaborative writing lessons in math classes while the control group was given teacher-oriented regular lessons. The results were as follows. First, there was more or less considerable, though not significant, difference in overall mathematical achievement in the students experiencing collaborative writing activities when compared with the students in the control group. However, in terms of numbers and operation, a sub-category of mathematics, there was significant difference between the two groups. Second, the students experiencing collaborative writing activities were more positively affected in all sub-categories of mathematical disposition: confidence, flexibility, determination, curiosity, reflection, and value, than those in the control group. In summing up, the exposure of collaborative writing activities to mathematics learning was found to help students not only to have a concrete and proper grasp of the relevant problem solving process, which was observed from their mathematical achievement gain especially in the sphere of numbers and operation, but also to have their mathematical disposition set towards more positive direction, which was seen in all sub-categories of mathematical disposition measurement.

• Korean Journal of Health Education and Promotion
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• v.14 no.2
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• pp.43-57
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• 1997

Educational goals of SPH were two-fold : One was to train a health professions who should take charge of a leading roles, another were to educate the researchers of public health. There were strong demands to evaluate whether these goals had been effectively achieved through the master's course of SPH or not. According to the educational goals of SPH, public health is an applied science to be applicable to health-related fields. The curriculum of SPH has to be built under this principle and be evaluated by someone regularly. Who evaluates that? The most pertinent appraiser is the graduates of public health currently working at health-related jobs. It was the purpose of the study to let the graduates evaluate their education and the curriculum that they had undertaken during master's course at SNU. If the results of the evaluation by the graduates were not satisfactory, we should find the actual causes of low scored apraisal and reform the curriculum of SPH as the process of problem solving. During September and October 1996, a postal survey was undertaken of the 293 SNU graduates of public health who had been engaged in the health related jobs. As 198 graduates answered out of 293, the response rate was 67.6%. The questionnaire was designed to ascertain how well the SNU master's course of public health had helped their practice. The SAS package was used for statistical analysis and $x^2$-test as a test of statistical significance. Major findings of the study were summarized as follows: $\cdot$ The health related abilities consisted of three categories, which were health administration abilities composed of 14 items, health education abilities composed of 5 items, health research abilities composed of 10 items. $\cdot$ The respondents had acquired 'Worldwide trends of health policy', 'evaluation concepts of health projects', 'interpersonal relationships in professional life', and 'communication through writings' moe than other detailed items in the category of health administration abilities. $\cdot$ 'Establishment of educational and learning golas' was the most acquired item of 5 detailed items of health education abilities. $\cdot$ Respondents indicated that they had acquired ability 'to search reference', ' to understand health problems', 'to establish study plannings', and 'to collect health related data' more than other detailed items in the category of health research abilities.

• The Mathematical Education
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• v.43 no.4
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• pp.419-440
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• 2004

The purpose of this paper is to know the effects on number and operation abilities of the 1st grade children of elementary school by applying teaching and learning activity throught communication. For this purpose, we have studied according to the following procedure. 1. We divised teaching and learning model through communication and applied in the actual teaching and learning activity. 2. We investigated the effects of number and operations abilities of the 1st grade children by applying teaching and learning activity through communication. To accomplish this purpose, we applied learning activity through communication to the 1st grade of 40 elementary school children for about six months(September 1, 1999 ～ February 20, 2000). In process of applying this model, we collected all sorts of cases in the children's learning activity and investigated children's response on learning activity through communication, interview with children and researcher's observation. We applied the model through communication in class and compared with the traditional learning. 1. In learning through communication, children could solve the problem in themselves with a sense of responsibility. 2. It was impossible to find out the degree of children's comprehension in the explanatory learning. But in the learning through communication, it was a great help to individualize and plan the learning because children express their ideas clearly. It has conclusion as follows. The learning activity through communication has effected on forming number and operations abilities of the 1st grade of elementary school children importantly. 1. Children have improved in the abilities through communication to express their own ideas. 2. Children have studied with a sense of responsibility not in the teacher-oriented learning but in the self-directed learning 3. Children could find out the mathematical concepts in themselves - correcting false concepts, reguiding concepts by errors, finding invisible errors, solving problems variously and knowing the easy method. 4. The activity through communication in mathematics was a base of children's individual learning and important data of next learning plan. 5. The mathematical concepts formed through communication had a high transfer of learning. 6. Children have taken pleasure of discovery and had affirmative attitude about mathematics learning. We can make sure that number and operations abilities of the 1st grade children are formed by applying teaching and learning activity through communication. However, help and control of teacher have to be with it.

• Journal of Korea Game Society
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• v.9 no.3
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• pp.23-33
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• 2009

This study aims to uncover the gamers' cognitive process during the gameplay and explore the differences between groups in the gamers' playing behavior according to their expertise: experts, intermediate players, and novices. To this end, the empirical experiment was conducted in 'World of Warcraft' game which is a good representative of MMO(Massively Multi-player Online) game currently. Verbal protocol and action protocol collected from the empirical experiment were analyzed according to the gamers' expertise. As a result of this study, we found that the different behavior patterns result from standardizing pattern of their actions for experts and forming the learning curves and the specific patterns of action for intermediate game players and novices. While three functional-actions as a collection action concentrates on the early stage of the game for experts, the novices' behavior pattern dispersedly appeared in all seven functional-action, such as search, combat, three type collections, avoid, and communication in the whole gameplay. This study represents the consistency and the difference derived from the comparison analysis between groups according to the expertise. This study is concluded with key implications to support game design guidelines according to experts, intermediate players, and novices. Consequently, the result of this study provides the basic to the development of MMO content for game novices.