• Proceedings of the Korean Geotechical Society Conference
• /
• 2008.03a
• /
• pp.932-937
• /
• 2008

The asphalt waste has been collected more than ten thousands' ton from repairing works on the road and excavation repair works, most of them are disposed on land of reclamation. Only a few percentage of wasted asphalt recycled to new one. Therefore, In this study, usage of wasted asphalt and has been done engineered characteristic test for recycling materials of sub-grade and structure. To know the characteristic of asphalt waste, tamping test, bearing-ratio test, permeability test and direct shear test was done using asphalt-sand mixture. The test results shows that, mixed asphalt materials with sand can be used for materials of subgrade-soil and structure.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2008.03a
• /
• pp.1004-1011
• /
• 2008

In this study, obtained large block sample and piston sample of marine clay in korea were performed unconfined compression and consolidation test. Soil properties of two type samples such as failure strain, between two parameter's ratio($E_{50}$ and $q_u$), and volumetric strain were used to evaluate sample disturbance. The result, large block samples show a low disturbance than piston samples. Therefore, we suggest new sample disturbance evaluated method through the relation of OCR and volumaric strain at shallow of marine clay in Korea and suggest new sample disturbance classified method by subdivided grade for failure strain of unconfined compression test.

• Journal of Korean Elementary Science Education
• /
• v.32 no.4
• /
• pp.485-494
• /
• 2013

The purpose of this study was to know that the 'Thinking Science' activities affects the enhancement of critical thinking skill by the logical thinking skill about pupils in the $5^{th}$ and $6^{th}$ grade of elementary school in Korea. The 19 activities of 'Thinking Science' as the teaching materials was implemented to 40 pupils in elementary school over 13 weeks. Results indicated that the experimental group presented statistically meaningful improvement in logical thinking skills(p<.05). Those teaching materials contributed to improve 3 logical sub-elements significantly(p<.05) as the proportional logical element, the probabilistic logical element, and combinational logical element. But, there was no significant improvement in conservational logical element, control of variable element, and correlational element(p<.05).

• Proceedings of the KSR Conference
• /
• 2007.05a
• /
• pp.1403-1407
• /
• 2007

The bogie of Rolling Stock is the basic rolling component. It operates the train body, guides the body considering various tracks and offers comfort to passengers. We can verify the safety level of bogie about all factors through the first -grade scenario of Preliminary Hazard Analysis, but especially the horizontal acceleration sensor, equipped in each power bogie and trailer bogie, is the device, which makes it possible to test bogie instability and uncomfortable body movements by the method, similar to actual train driving, and in this context the necessity of this device becomes important. This paper would classify the main functions of driving sub system and examine the reliability, availability, maintainability and safety, which are main factors of RAMS. Especially, we would realize the bogie instability sensor with a simulator and offer the content in analyzing the data by the statistical method, which are obtained through the connected test with OBCS.

• The Korean Journal of Elementary Counseling
• /
• v.7 no.1
• /
• pp.165-181
• /
• 2008

In this study, a preliminary study has been made to check the availability of examination after selecting one among the criteria to adaptation of school life, in recognition of the necessity for a tool in order to collect multi =dimensional information about children. An examination has been done with the survey target of 291 pupils in the fifth and sixth grade in an elementary school located in Incheon. And the focus group with the teachers in charge of each class was undertaken to check the availability of the examination. As the result of the examination, 37 was the average score of children diagnosed as the category of temporary maladaptation in terms of the score of 4 sub-scales of school adaptation and their total scores, and 28 was the score which corresponds to the assessment of teachers. The results of examinations and the evaluations of teachers were proved to be highly correlated. Lastly discussion is focused on the meaning of these findings and the suggestions for the further studies.

• Journal of the Korean Society for Precision Engineering
• /
• v.16 no.6
• /
• pp.14-24
• /
• 1999

In this study, the product complexity is evaluated quantitatively considering the disassembly process of the product. To evaluate complexity of the product, we analyze the characteristics of the product and the disassembly process. And we determine factors, which influence on the complexity of the product in the main-disassembly and sub-disassembly. Considering each characteristics of part and subassembly. Evaluations criteria of complexity are determined. Using evaluation criteria of the complexity can be determined the complexity grade of the product, and then we show the total complexity of the product considering the disassembly process.

• Journal of Digital Contents Society
• /
• v.10 no.3
• /
• pp.375-380
• /
• 2009

Computer programming education can improve students' logical thinking and problem-solving ability. Therefore, it is essential tool to improve algorithmic thinking ability. We study how much Dolittle and Squeak influences improving elementary students' logical thinking ability. Thus, we divided 6th grade elementary students into two classes and then taught Dorittle and Squeak programming languages for 6 weeks, respectively. We compare and analyze each logical thinking ability and its sub-classifications. The results showed that Dorritle affects significant improvement, but not Squeak.

• Journal of the Optical Society of Korea
• /
• v.12 no.2
• /
• pp.79-87
• /
• 2008

We have developed a miniature fisheye lens with $190^{\circ}$ field of view operating simultaneously in the visible and the near infrared wavelengths. The modulation transfer function characteristic for the visible wavelength is sufficient for a mega-pixel-grade image sensor. The lens also has a fair resolution in the infrared wavelength region. The calibrated $f-{\theta}$ distortion is less than 5%, and the relative illumination is over 90%. In consequence, a sharp wide-angle image can be obtained which is uniform in brightness over the entire range of field angles. The real image heights for the visible and the near infrared wavelengths have been fitted to polynomial functions of incidence angle with sub-pixel accuracies. Combined with the near equidistance projection scheme of the lens, this lens can be advantageously employed in various image-processing applications requiring a wide-angle lens.

• Structural Engineering and Mechanics
• /
• v.42 no.1
• /
• pp.1-12
• /
• 2012

In this study, Pasternak foundation model, which is a two parameter foundation model, is used to analyze the behavior of laterally loaded beams embedded in semi-infinite media. Total potential energy variation of the system is written to formulate the problem that yielded the required field equations and the boundary conditions. Shear force discontinuities are exposed within the boundary conditions by variational method and are validated by photo elastic experiments. Exact solution of the deflection of the beam is obtained. Both foundation parameters are obtained by self calibration for this particular problem and loading type in this study. It is shown that, like the first parameter k, the second foundation parameter G also depends not only on the material type but also on the geometry and the loading type of the system. On the other hand, surface deflection of the semi infinite media under singular loading is obtained and another method is proposed to determine the foundation parameters using the solution of this problem.

• Proceedings of the Korea Society for Simulation Conference
• /
• 2005.11a
• /
• pp.138-143
• /
• 2005

In order to reduce traffic accident, the interaction between drivers and roads should be studied in drivers' behaviour standpoints, and then this must be applied to the establishment of the road design standard. The K-ROADS(KICT-Road Analysis Driving Simulator) was developed to analyze and evaluate the road safety at the project HuRoSAS(Human & Road Safety Analysis System), since 2003. This has two distinct functions. One is the visual system which has 360 degree F.O.V. to reduce a dead angle on black spots as at-grade intersection. The other is the motion system which reproduce high frequency vibration made in irregular road surface and vehicle's motion. The K-ROADS has been used the study on the effect of alternatives of speed hump, and the study on the interior wall design of long tunnel to safety standpoints.