• Geomechanics and Engineering
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• v.16 no.5
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• pp.495-501
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• 2018

Geogrid application that has proved to be an effective and economic method of reinforcing particles, is widely used in geotechnical engineering. The discrete element method (DEM) has been used to investigate the micro mechanics of the geogrid deformation and also the interlocking mechanism that cannot be easily studies in laboratory tests. Two types of realistically shaped geogrid models with square and triangle apertures were developed using parallel bonds in PFC3D. The calibration test simulations have demonstrated that the precisely shaped triangular geogrid model is also able to reproduce the deformation and strength characteristics of geogrids. Moreover, the square and triangular geogrid models were also used in DEM pull-out test simulations with idealized shape particle models for validation. The simulation results have been shown to provide good predictions of pullout force as a function of displacement especially for the initial 30 mm displacement. For the granular material of size 40 mm, both the experimental and DEM results demonstrate that the triangular geogrid of size 75 mm outperforms the square geogrid of size 65 mm. Besides, the simulations have given valuable insight into the interaction between particle and geogrid and also revealed similar deformation behavior of geogrids during pullout. Therefore, the DEM provides a tool which enable to model other possible prototype geogrid and investigate their performance before manufacture.

• Journal of Korean Society of Transportation
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• v.24 no.4 s.90
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• pp.43-53
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• 2006

Pedestrian countdown signals were newly introduced to make Pedestrians feel more comfortable and safer in crossing the streets This Paper analysed pedestrian walking-speed through a before-after behavior study Data was collected from 22 sites. and the total number of pedestrians was 19,800. The results showed that the average Pedestrian walking-speed of existing pedestrian signal, an inverted triangle countdown signal and a numeric countdown signal were 1.44, 1.39 and 1.42m/sec. The difference between the three methods was statistically significant. The results showed that the distribution of the walking-speed of existing signal. an inverted triangle countdown signal and a numeric countdown signal were statistically Erlang(0.117, 10) distribution. Weibull(1.17, 3.72) distribution and Gamma(0.137, 8.18) distribution at 95% confidence level.

• Journal of the Korea Safety Management & Science
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• v.10 no.4
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• pp.105-109
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• 2008

The purpose of this study is to distinguish the causes of broken glass on doors or windows when it is originally kept among the remains on the floor in fire site - whether it was broken due to heating or outer power-through test and characteristics of the broken plane including the pattern on the plane. Addition to it, the study tries to find characteristics to judge the point and direction of breakdown through the analysis of glass broken by outer power. With two assumed causes - a) breakdown due to heating and b) breakdown due to outer power-3 pieces of glass plates ($30cm{\times}30cm{\times}5mm$) were tested for each case, getting the results as following: First, for the glass broken due to the change of temperature, the broken plane is of slow and smooth curve without any pattern. Second, for the glass broken due to outer power, with the impact point as the center, the glass shows breakdown of radial type and the side shows breakdown of near-perpendicular type. The far the broken piece is from the impact point, the bigger the size is. The broken piece at the impact point is of long triangle type and the two long planes of the triangle shows semi-arc with the center of breakdown point and the other plane shows opposite pattern. Third, when glass that is damaged by outer power is heated, damaged forms and side patterns of the glass that is damaged by outer power are heated and disappeared.

• Journal of Korean Institute of Fire Investigation
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• v.3 no.1
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• pp.12-15
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• 2003

The purpose of this study is to distinguish the causes of broken glass from doors or windows when it is found being originally kept among the remains on the floor in fire site - whether it was broken due to heating or by outer power through test and the properties of the broken plane including the pattern on the plane. Addition to it, the study tries to find characteristics for judging the point and direction of breakdown through the analysis of glass broken by outer power. With two causes assumed - a. breakdown due to heating and b. breakdown due to outer power - 3 pieces of glass plates $(30cm{\times}30cm{\times}5mm)$ for each case were tested, getting the results as following: 1. For the glass broken due to the change of temperature The broken plane is of slow curve and smooth without any pattern. 2. For the broken due to outer power With the impact point as the center, the shows breakdown of radial type and the side shows breakdown of near-perpendicular type. The far the broken piece is from the impact point, the bigger the size is. The broken piece at the impact point is of long triangle type and the two long planes of the triangle shows semi-arc with the center of breakdown point and the other plane shows opposite pattern 3. Change of the pattern and type of the glass due to outer power The pattern and type of the glass due to outer power shows change due to heatihg.

• Journal of Ocean Engineering and Technology
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• v.36 no.3
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• pp.153-160
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• 2022

Moored floating platforms have great potential in ocean engineering applications because a mooring system is necessary to keep the platform in station, which is directly related to the operational efficiency and safety of the platform. This paper briefly introduces the technical and operational details of an optical sensor for measuring the tension of mooring lines of a moored platform in waves. In order to check the performance of optical sensors, an experiment with a moored floating platform in waves is carried out in the wave tank at Changwon National University. The experiment is performed in regular waves and irregular waves with a semi-submersible and triangle platform. The performance of the optical sensor is confirmed by comparing the results of the tension of the mooring lines by the optical sensor and tension gauges. The maximum tension of the mooring lines is estimated to investigate the mooring dynamics due to the effect of the wave direction and wavelength in the regular waves. The significant value of the tension of mooring lines in various wave directions is estimated in the case of irregular waves. The results show that the optical sensor is effective in measuring the tension of the mooring lines.

• Journal of the Korean Society of Clothing and Textiles
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• v.47 no.1
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• pp.17-34
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• 2023

This study aimed to develop a fitted torso pattern with an improved fit for inverted-triangular males in their twenties. For this study, six torso patterns were collected, compared and evaluated, and a fitted torso pattern was developed using virtual fittings. The research results are as follows. First, the fitted torso pattern received a good rating as a result of the virtual fitting evaluation: waist dart set 2 of the front; the amount of comfort is set at 5 cm around the chest, 4 cm around the waist and 10 cm around the hips. Second, the evaluation of virtual fitting of the development pattern showed that fit evaluation was 4.11/5 points, ease evaluation was 6.53/7 points, and that the stress map and airgap were suitable for the human body. Third, the actual fit evaluation of the development pattern was 4.25/5 points, 6.35/7 points for ease evaluation, and 4.81/5 points for motion evaluation. Fourth, there was no significant difference between the results of the virtual and actual fitting evaluation with the objectivity test. It is therefore possible to apply a pattern developed through a virtual fitting to an actual human body and to confirm the objectivity of the pattern.

• Journal of muscle and joint health
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• v.7 no.2
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• pp.294-308
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• 2000

This study was conducted to test the effect of brisk walking & muscle strengthening exercise program on bone mineral density(BMD) of the lumbar & femur in rheumatoid arthritis women. Research design was a quasi-experimental study of non-equivalent control group pretest-posttest design(16 weeks). 14 for the experimental group and 14 for the control group were selected from the outpatients on rheumatoid arthritis clinic of Dong-A University Hospital. The experimental group underwent 16 weeks of brisk walking and muscle strengthening exercise. Bone mineral density was measured before and after 16 weeks of exercise by DXA at lumbar spine, femoral neck, Ward's triangle and trochanter. The results were summarized as follows : 1. BMD of the lumbar spine in experimental group who carried out the brisk walking and muscle strengthening exercise was not significantly increased after 16weeks and there was no significant difference between experimental and control group(U=70.00 p>.05). 2. BMD of the femoral neck in the experimental group who carried out the brisk walking and muscle strengthening exercises was significantly increased after 16 weeks(Z=-2.901 p<.01). But, there was no significant difference between experimental and control group(U=83.00 p>.05). 3. BMD of the femoral Ward's triangle in the experimental group who carried out the brisk walking and muscle strengthening exercises was significantly increased after 16 weeks (Z=-2.355 p<.05). But, there was no significant difference between experimental and control group(U=86.00 p>.05). 4. BMD of the femoral trochanter in experimental group who carried out the brisk walking and muscle strengthening exercise was not significantly increased after 16weeks and there was no significant difference between experimental and control group(U=75.00 p>.05). These results suggest that brisk walking and muscle strengthening exercise program has an effect on promoting bone mineral density of femoral neck and Ward's triangle in rheumatoid arthritis women.

• The Journal of Korean Association of Computer Education
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• v.7 no.2
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• pp.77-84
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• 2004

In this thesis, We propose the self-directed learning and test-performing abilities assessment method to evaluate the learning and the test-performing abilities in which learners can not only control their own learning abilities for themselves, but also judge objectively learning and test-performing abilities. This method shows the membership degree of learning and test-performing abilities by using both the triangle-type membership function and the fuzzy logic. In addition, it gives the fuzzy grades to each item. The final membership degrees are calculated and the fuzzy grades are decided by the operation and composition of fuzzy relations on the membership degrees of learning and test-performing abilities. In this method, which is applicable to a writing subject for information searchers, learners are asked to analyse the membership degrees of the learning and test-performing abilities and the final fuzzy grades and to adjust a learning process for themselves.

• Journal of the Korea institute for structural maintenance and inspection
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• v.14 no.6
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• pp.220-228
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• 2010

A steel wire-integrated deck plate that welds integrated triangle truss steel wires on a galvanized steel sheet is developed to reduce construction costs of a slab or formwork such as shores and supports, and it is already widely applied in many construction fields. This study selected upper and lower steel wires, lattice steel wires, span, and cutting methods of ends as variables, and conducted an experimental test by manufacturing a total of 32 full scale test bodies. According to the result, changes in final destruction types of the test bodies and cutting methods of ends didn't affect structural performance of test bodies, and for a 3.2m-span test body, there was no big problems in using ${\Phi}4.5$ of lattice steel wires.

• Korean Journal of Child Studies
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• v.26 no.5
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• pp.391-391
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• 2005

This study focused on the development and effect of children's art creativity program applying basic three shapes : square, triangle, and circle. The program consisted of 10 art activities. A total of 55 children participated the 10 week program to examine the effectiveness of this program. The experimental design included a pretest, treatment, and post-test. Results showed that the experimental group children scored significantly higher on creativity in the posttest than the control group children.