• Journal of Technologic Dentistry
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• v.35 no.3
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• pp.201-207
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• 2013

Purpose: In this study, the loosening torque test was conducted with three implant products that are produced, approved and sold in Korea, which are manufactured in different fixture and abutment tightening methods (internal submerged type, internal morse taper type, and external type) to examine the loosening torque of the screw according to the method of tightening the implant fixture and abutment. Methods: In the loosening torque test, the three types of fixtures and abutments with different tightening methods were tightened by rotating them clockwise with a $30N{\cdot}cm$ force using a driver equipped with an electric torque meter. The results of the test are as follows. Results: The loosening torque values of the internal submerged type, internal morse taper type and external type implants were $24.10{\pm}0.742N{\cdot}cm$, $29.10{\pm}1.710N{\cdot}cm$, and $26.60{\times}1.636N{\cdot}cm$, respectively. Conclusion: The screw loosening torque values of the three fixture and abutment tightening methods were analyzed via Kruskal Wallis test layout, and they were significantly different (p<0.05).

• Nuclear Engineering and Technology
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• v.53 no.6
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• pp.1878-1886
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• 2021

For industrial package (IP)-type transport containers for radioactive materials, a free drop test should be conducted under regulatory conditions. Owing to various uncertainties observed during the drop test, errors in drop angles inevitably occur. In IP-type metal transport containers in which the container directly impacts onto a rigid target without any shock absorbing materials, the error in the drop angle due to a slight misalignment makes a significant difference from the ideal drop. In particular, in a vertical drop, the error in the drop angle causes a strong secondary impact. In this paper, a numerical method is proposed to estimate the error in the drop angle occurring during the test. To determine this error, an optimization method accompanying a computational drop analysis is proposed, and a surrogate model is introduced to ensure calculation efficiency. Effectiveness of the proposed method is validated by performing the verification and comparison between the test and the analysis applied with the drop angle error.

• International Journal of Highway Engineering
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• v.19 no.3
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• pp.1-10
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• 2017

PURPOSES : This paper focuses on strength development according to the mix design with cement type and mineral admixture from laboratory and field tests in cool weather. METHODS : Two methods evaluated the mix design of concrete pavement in cool weather. Firstly, laboratory tests including slump, air contents, setting time, strength, maturity, and freezing-thawing test were conducted. Three alternatives were selected based on the tests. Secondly, a field test was conducted and the optimum mix design in cool weather was suggested. RESULTS : It is an evident from the laboratory test that a mix with type III cement showed better performance than the one with type I cement. There was a delay in strength development of a mix with mineral admixture compared to mix design without any mineral admixture. In the field test, type III cement+flyash 20% mix design proved the best performance. CONCLUSIONS : For concrete pavement in cool weather, mix design using type III cement could overcome the strength delay due to mineral admixture. Moreover, it is possible to make sure of durability of pavement. Therefore, strength and durability problems due to cool weather would decrease.

• Journal of The Korean Association For Science Education
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• v.16 no.3
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• pp.314-328
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• 1996

This study investigated the literature about science process skills' evaluation to analyse transition of evaluation objectives before and after a Scholastic Ability Test for College Entrance. In the literature survey the researcher established a 3 dimensional science assessment framework with X axis as science concept, Y axis as science process skills and Z axis as problem context. In order to analysis and compare each items the researcher selected 210 items from the 1st to the 7th trials and 138 items from the 1st to 4th Scholastic Ability Test for College Entrance and sampled 2873 science achievement test items from 10 high schools. In accordance with this taxonomy the researcher analysed and compared science process skills item forms. The following results were drawn : The items were evenly distributed in all the four areas(Earth Science, Biology, Physics and Chemistry) of the science concept domain, but they were heavily concentrated on data analysis and drawing a conclusion in science process domain. In the domain of problem context school context was the majority. In spite of distribution like this the ratio on science process skills measurement items and science achievement test items was increased after the Scholastic Ability Test for College Entrance was given. Also the ratio on item expression type was increased. Item form was almost 5 options selection type in the national level test. Although there were 4 options selection type, 5 options selection type, short answer type, essay type in school level test, rising from 33.1% to 65.5% on 5 options selection type is exhibited. This study showed that the school level item form was better various than the nation level. This point like this is the evidence for the improvement toward the science process skills test and influenced by Scholastic Ability Test for College Entrance. The ratio on the item which joined with the 3 axes had a mean of 99.3% in nation level test and mean 44.9% in school achievement test level. But the ratio in the school achievement test level increased after the Scholastic Ability Test for College Entrance was given. In view of this study we must furthermore study the item types which can evaluate valjdately science process skill's five stage each and evaluation method by the high school students' problem solving patterns and features in scientific inquiry on all science process skills elements.

• Korean Journal of Applied Biomechanics
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• v.22 no.2
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• pp.209-217
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• 2012

The purpose of this study was to develop a turn-type treatment program which applies the principle of spotting and a roll-type treatment program that induces off-vertical axis. 29 collegiate students volunteered for this study. 12-week treatment programs were applied to both 15 students for turn-type treatment group and 14 students for roll-type treatment group. As an analytic tool, eye camera was employed to verify the treatment programs for a stimulus upon a turn, recovery after a stimulus upon a turn, and nystagmus that affects a vestibular system. Two-way ANOVA with repeated measures was applied to see the significant differences between the treatment groups, and between the test periods. For Post-Hoc Test, paired t-test was used to within the group and independent t-test was used to between the groups. The results indicated that roll-type treatment training has maximized a stimulus on nystagmyus during the stimulus by a roll. Turn-type treatment training has maximized a stimulus on nystagmyus right after a stimulus by a roll and significantly decreased the intensity of nystagmyus during the recovery. Both turn and roll type treatments have reduced the recovery time which from nystagmyus to a normal status. Roll-type treatment has showed a much shorter recovery time for nystagmyus than the roll-type treatment has. Based on the results of treatment programs developed in this study, we expect the treatment programs can be applied to treat dizziness and to improve the function of vestibular system as a rehabilitation tool.

• The Research Journal of the Costume Culture
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• v.12 no.6 s.53
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• pp.953-970
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• 2004

The purpose of this study was to design men's jacket pattern for variable body types by employing the data of wearing evaluation from experimental basic bodices selected by male subjects in the 30's. As a result of sensory evaluation, functional test and clothing pressure test by each type of experimental basic bodices, the 3rd experimental basic bodice was chosen to be a basic bodice type in this research since it showed a high degree in fitness and function, but a low in the clothing pressure test. As a comparison of one item from conventional jacket and sleeve pattern with each somatotype, the type 2(the standard somatotype) indicated a great fitness in both basic bodice type and conventional jacket pattern, whereas the type 1 and the type 3 showed higher fitness and moving function in the basic bodice type. In the making of men's jacket, many corrections were made in the front interscye breadth, back interscye breadth, front and back length, and shoulder line as adapting each body type. Thus, the ease-amount of chest circumference at scye for clothes should be established differently according to the size of chest circumference at scye.

• Journal of Applied Reliability
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• v.18 no.1
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• pp.40-48
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• 2018

Purpose: This research is to develop Trailer Durability Test of towing device, in order to cover usage conditions of bike type as well as general type trailer. With the diversification of leisure activities, the population that enjoys various sports and leisure has increased rapidly, and the number of vehicles equipped with camping trailers and bike carriers is also increasing steadily. The purpose of this study is to develop a durable vehicle that has no problem in various customer conditions. Methods: We measured the input load under various conditions of the user by attaching load cell to the body fixing part and towing ball of the towing device. The load in various modes was measured, and the difference between the trailer and the bike carrier type was compared and analyzed. Results: Due to the difference in fixing method and weight between the two types, the trailer has a large longitudinal force and the bike type has a large vertical force. Therefore, it is necessary to durability test method capable of satisfying all longitudinal force and vertical force. Conclusion: We improved the durability test of the towing device by changing the test surface. The new mode has made it possible to shorten the durability test schedule by increasing test efficiency.

• Journal of Applied Reliability
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• v.12 no.3
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• pp.201-213
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• 2012

A gear type lubrication pump is an essential component of the powertrain and has a major role for supplying oil to the gears and bearings in automatic transmission with a hydraulic clutch. Therefore, the durability test code design of lubrication pump is very important to ensure the reliability of the entire transmission and the vehicle. In this study, the design process for the life testing of lubrication pump has been generalized by four steps. The four design steps of the life testing of lubrication pump consist of the configuration of load spectrum, rain flow counting and analysis of load level, the equivalent damage assessment and test code generation. In fact, the load spectrum should be obtained from the field operating condition but that kind of data is the top secret of manufacturers. This is not open to the public in general. So we could use the artificially simulated load spectrum instead of field obtained one and focused on the development of the general process for designing the life test of a gear type lubrication pump. Reliability goals for lubrication pump, pressure, torque, temperature and load spectrum, if present, as appropriate for the given test conditions, accelerated life testing for the lubrication pump can be designed by the developed design steps.

• Journal of Power System Engineering
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• v.5 no.1
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• pp.11-20
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• 2001

Super-critical type steam power plant, which operates with steam pressure above the super-critical point, has a good reputation recently and is adopted as a new standard of the Korean Electric Power Corporation. The reason for the good reputation lies in it's superior power efficiency. However, the field data of the new power plant for the verification of it's performance are still insufficient, and more empirical data are needed to acquire technologies on the effective operation of it. In this study, the authors analyzed the field test data on power efficiencies got in a super-critical type steam power plant, and evaluated the excellency of the new plant by comparing the efficiency data with the one got in a conventional sub-critical type steam power plant.

• International Journal of Highway Engineering
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• v.19 no.2
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• pp.75-85
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• 2017

PURPOSES : The purpose of this study was to determine the optimum mix design of the content of 100 % reclaimed asphalt pavement (RAP) for spray injection application with different binder types. METHODS : Literature review revealed that spray injection method is the one of the efficient and economical methods for repairing a small defective area on an asphalt pavement. The Rapid-Setting Polymer modified asphalt mixtures using two types of rapid setting polymers-asphalt emulsion and a quick setting polymer asphalt emulsion-were subjected to the following tests to determine optimum mix designs and for performance comparison: 1) Marshall stability test, 2) Retained stability test, 3) Wet track abrasion test, and 4) Dynamic stability test. RESULTS and CONCLUSIONS : Type A, B, and C emulsions were tested with different mix designs using RAP aggregates, to compare the performances and determine the optimum mix design. Performance of mixtures with Type A emulsion exceeded that of mixtures with Type B and C emulsion in all aspects. In particular, Type A binder demonstrated the highest performance for WTAT at low temperature. It demonstrated the practicality of using Type A mixture during the cold season. Furthers studies are to be performed to verify the optimum mix design for machine application. Differences in optimum mix designs for machine application and lab application will be corrected through field tests.