• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.05a
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• pp.32-33
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• 2019

This study evaluated the effect of amorphous steel fibers on the spalling characteristics of high-strength concrete. with mix proportions of polypropylene (PP) fibers of 0.15% by concrete volume, and proportions of amorphous steel fibers of 0.3% and 0.5% by concrete volume. In the range of 0.3 vol% of amorphous steel fiber, the effect of suppression of the spalling and the prevention of degradation of strength was shown, but it was evaluated to be ineffective in the suppression of the spalling due to interferences in formation of pore network in the range of 0.5 vol.%.

• Phonetics and Speech Sciences
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• v.7 no.3
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• pp.55-64
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• 2015

Previous research on syntactic processing shows that the interpretation of a syntactically ambiguous sentence is frequently strongly biased towards one meaning over another. The current study investigated the effect of bias strength on the production of disambiguating prosody for English ambiguous sentences. In Experiment 1, 40 speakers gave default readings of 18 syntactically ambiguous sentences. Questioning was used to prove intended meanings behind default readings. Intended meanings were treated as interpretation biases when a majority of speakers read a sentence with the same intended meaning. The size of the majority was used to establish bias strength. In Experiment 2, 10 speakers were instructed to use prosody to disambiguate given alternate meanings of the sentences from Experiment 1. The results indicated an effect of bias strength on disambiguating prosody: speakers used temporal juncture cues to reliably disambiguate alternate meanings for sentences with a weak interpretation bias, but not for those with a strong bias. Overall, the results indicated that interpretation biases strongly affect the production of prosody.

• Advances in concrete construction
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• v.5 no.6
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• pp.613-624
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• 2017

In this paper, an experimental investigation was carried out to study the effect of volume fraction of fiber and maximum aggregate size on mode-I fracture parameters of high strength concrete. Total of 108 beams were tested on loading frame with three point loading, the variables in the high strength concrete beams are aggregate size (20 mm, 16 mm and 10 mm) and volume fraction of fibers (0%, 0.5%, 1% and 1.5%). The fracture parameters like fracture energy, brittleness number and fracture process zone were analyzed by the size effect method (SEM). It was found that fracture energy (Gf) increases with increasing the Maximum aggregate size and also increasing the volume of fibers, brittleness number (${\beta}$) decreases and fracture process zone (CF) increases.

• The Journal of the Korea Contents Association
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• v.17 no.8
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• pp.90-97
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• 2017

This study is to explore the effect of family strength and solving skills on school adjustment of elementary school students. To attain this purpose, it utilized the data which examine 2,422 elementary students who participate in school social work in S City. The data collected is analyzed by frequency, correlation, regression with SPSS 20 program. The result of this study is as follows. Firstly, there was significant correlation among family strength, problem solving skills, school adjustment Secondly, family strength directly affected the students without the mediator variable on school adjustment. Lastly, family strength had a decisive effect on school adjustment through problem solving skills. Based on this results in the study, we need a strategy of sustainable family strength and solving skills in order to help school adjustment.

• Korean Journal of Applied Biomechanics
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• v.16 no.4
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• pp.195-203
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• 2006

The isometric rehabilitation program was applied to 47 people of the aged low back patients(man 22 people, woman 25 people) twice a week for 8weeks. The Medx was used to study an effect on a change for extended strength ratio(ESR) according to a posture change. The isometric ESR at each flexion angle ($0^{\circ}$, $12^{\circ}$, $24^{\circ}$, $36^{\circ}$, $48^{\circ}$, $60^{\circ}$, $72^{\circ})$ was measured total 3times("before excercise", "on 4th week after excercise", "8th week after excercise") and analyzed. So, we could come to a conclusion as follows. 1. The maximum extended strength measured at a range of 7 angles for an isometric excercise of 8 weeks increased than "before an excercise", including that men have an increase of 39.51% and women have 62.92% in training effect. All of men and women showed statistically significant increase in physical strength(p<.001).excercise") and analyzed. So, we could come to a conclusion as follows. 2. After an excercise of 8 weeks, man showed 62.17% at zero degree and 49.115% at 12 degree respectively in maximum extended strength. Women showed 106.6% at zero degree and 86.16% at 12 degree. In view of this, respectively man have increase rate of physical strength over 31% and women have over 46% at all angles, also have significant increase in extension angle(p<.001). 3. A change for isometric ESR have a decrease of 27.68% for men and 74.66% for women than before isometric excercise of 8 weeks statistically significantly(p<.05, p<.00l). Men showed 1.77:1 of a similar ratio in the decrease effect comparing with normal people, but women showed 225:1.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.185-188
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• 2008

Flat plate system has structural weakness such as punching shear. Punching shear resistance can be increase by using a lager column section and effective depth, higer concrete compressive strength, and more flexural reinforcement ratio. But using a shear reinforcement is most economical, enable, workable solution in flat plate. The slab with thickness smaller than 250mm can not perform effectively due to insufficient development length of shear reinforcement in the slab. In case of proposed reinforcements, since the shear reinforcements were installed between the top bar and the bottom bar, shear elements generated slip failure before they reached yield. strength. effect of anchorage strength were effective anchorage length, concrete strength, diameter of shear element and anchorage detail. considering effect of slab thickness and concrete strength, formula of K factor propose in thin flat plate slab. by considering effect of anchorage length and concrete strength, strength of shear reinforcement will be computed correctly in thin flat plate slab.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.3
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• pp.901-907
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• 2013

In this study, flexural strength properties of concrete under biaxial stress state were experimentally investigated. Tests for size effect and fatigue behaviour of concrete under biaxial stress were carried out by the ASTM C 1550 and the biaxial flexure test(BFT). The results given by the biaxial tests were compared to those by the third-point bending test. Test results showed that biaxial flexural strengths obtained from the ASTM C 1550 and the biaxial flexure test are greater than the strength by the third-point bending test. As the size increases, the uniaxial and biaxial flexural strength decreases. However, the slope of the size effect of the biaxial strength was greater than that of the uniaxial strength. Finally, the fatigue response of concrete under the biaxial stress state was similar with that for uniaxial stress state.

• The Journal of Advanced Prosthodontics
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• v.7 no.2
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• pp.98-107
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• 2015

PURPOSE. The aim of this study was to appraise the some mechanical properties of polymethyl methacrylate based denture base resin polymerized by copolymerization mechanism, and to investigate the cytotoxic effect of these copolymer resins. MATERIALS AND METHODS. 2-hydroxyethyl methacrylate (HEMA) and isobutyl methacrylate (IBMA) were added to monomers of conventional heat polymerized and injection-molded poly methyl methacrylate (PMMA) resin contents of 2%, 3%, and 5% by volume and polymerization was carried out. Three-point bending test was performed to detect flexural strength and the elasticity modulus of the resins. To determine the statistical differences between the study groups, the Kruskall-Wallis test was performed. Then pairwise comparisons were performed between significant groups by Mann-Whitney U test. Agar-overlay test was performed to determine cytotoxic effect of copolymer resins. Chemical analysis was determined by FTIR spectrum. RESULTS. Synthesis of the copolymer was approved by FTIR spectroscopy. Within the conventional heat-polymerized group maximum transverse strength had been seen in the HEMA 2% concentration; however, when the concentration ratio increased, the strength decreased. In the injection-molded group, maximum transverse strength had been seen in the IBMA 2% concentration; also as the concentration ratio increased, the strength decreased. Only IBMA showed no cytotoxic effect at low concentrations when both two polymerization methods applied while HEMA showed cytotoxic effect in the injection-molded resins. CONCLUSION. Within the limitations of this study, it may be concluded that IBMA and HEMA may be used in low concentration and at high temperature to obtain non-cytotoxic and durable copolymer structure.

• Composites Research
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• v.24 no.5
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• pp.1-8
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• 2011

This paper presents the results of theoretical analysis and experimental test to show the size effect on the fiber strength of filament would pressure vessel. First, a series of fully scaled hoop ring tests with filament would carbon-epoxy were conducted, which exhibited a remarkable size effect on the fiber strength. Next, the failure analyses using WWLM(Weibull Weakest Link Model) and the SMFM(Sequential Multi-step Failure Model) were performed and compared to the hoop ring test data, as well as to unidirectional specimens test data from the literature. It was found that the analysis results significantly underestimated the fiber strengths compared to the test data. In this study, a modified SMFM was proposed through the modification of the length size effect. The fiber strengths from modified SMFM analysis showed good agreement with the test data.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.11a
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• pp.193-194
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• 2022

The use of high-strength grout for facility foundations and bridges has recently been expanding in offshore wind farms. Offshore wind farms require a bearing capacity for horizontal loads such as wind, waves. Therefore, in this study, the strength of the high-strength grout discharged through pump pressure was measured and compared with the existing strength to secure the strength after the underwater pump pressure of the high-strength grout used in the offshore wind connection. The compressive strength measurement showed that the strength difference at each position of the core specimen was 1% higher than that of the other specimens, and there was almost no change in the strength according to the height. The strength of the core specimen decreased by 23% compared to the existing strength, which is similar to the result of this study because the strength of the core specimen decreased by approximately 25% compared to the general specimen according to related research. Therefore, it is believed that there is no decrease in strength due to underwater pumping.