• Design & Manufacturing
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• 제12권3호
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• pp.48-54
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• 2018

This paper presents a numerical study for the development of a low-noise low-vibration industrial wheel for non-pneumatic wheel to significantly reduce vibration and noise. For this, design, injection molding and performance testing were performed. Various geometric shapes and materials were taken into account. For numerical analysis, ANSYS, LS-Dyna, and ABAQUS were used to predict the behavior of the wheel under different loadings based on various design changes. Based on this, 4 prototypes were fabricated by changing the design of wheels and molds, and various vibration and noise tests were carried out. A vibration tester was developed and tested to perform the vibration noise test considering durability. A prototype and test of the final wheel was performed. In the case of the vibration test, the vibration levels were 81.16dB and 80.66dB, which were below the target 90dB. Noise levels were 53.20 dB and 52.55 dB below the target 65dB. In the case of the impact resistance test, it was confirmed that there was no change in appearance after impact. The product weight was measured to be 174g compared to the target of 190g.

• Advances in concrete construction
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• 제7권4호
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• pp.219-229
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• 2019

This paper presents an experimental study on the structural performance of an innovative ultra-high performance fiber reinforced concrete (UHPFRC) deck with coarse aggregate of composite bridge under shear force. Test parameters included curing method and shear span-to-height ratio. Test results indicated that more short fine cracks developed beside the existing cracks due to the randomly dispersed fibers, resulting in re-distributing and homogenizing of the concrete stress beside cracks and allowing for the occurrence of more cracks with small spacing compared to normal strength concrete beams. Curing methods, incorporating steam curing and natural curing, did not have obvious effect on the nominal bending cracking strength and the ultimate strength of the test specimens. Shear reinforcement need not be provided for UHPFRC decks with a fiber volume fraction of 2%. UHPFRC decks showed superior load resistance ability after the appearance of cracks and excellent post-cracking deformability. Lastly, the current shear provisions were evaluated by the test results.

• 한국건축시공학회지
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• 제22권1호
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• pp.45-55
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• 2022

초 저수축 콘크리트는 콘크리트 구조물의 건조수축 균열을 극한으로 제어할 수 있기 때문에 콘크리트 구조물의 품질 및 외관 확보에 매우 효과적이다. 본 연구에서는 초 저수축 콘크리트의 상용화를 목적으로 실내실험을 통해 최적의 팽창재 및 수축저감제 투입량을 정하였고, 콘크리트 벽체 실물대부재실험을 실시하여 초 저수축 콘크리트의 수축 특성 및 균열제어 효과 등을 검토하였다. 그 결과 벽체 시험체에는 건조수축 변형이 거의 발생하지 않았고 균열도 발생하지 않음을 확인할 수 있었다.

• Journal of Mechanical Science and Technology
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• 제16권8호
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• pp.1109-1116
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• 2002

To investigate the effect of nitriding layer on both fatigue crack initiation and fatigue life, turbine rotor steel ( IC.- 1Mo-0.25V steel) specimens were nitrided by the nitemper method and then put to a rotary bending fatigue test at room and elevated temperatures. In nitriding, temperature and time were controlled to obtain a different nitrided thickness. Microstructure analysis, micro-Victors hardness test, and scanning electron microscope observation were carried out for evaluating experiments. In results, the fatigue cracks of nitrided specimens were initiated at inclusion near the interface between nitrided layer and substrate, which showed fish-eye type appearance in fractograph. The fatigue life of nitrided specimens at every temperature was prolonged compared to that of the non-nitrided. However, there was not observable improvement in fatigue characteristics with the increase of a nitrided thickness.

• 산업기술연구
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• 제22권A호
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• pp.161-168
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• 2002

Latex modified concrete is governed by both cement hydration and polymer film formation processes in its binder phase. Such the reactions are expected to improve the polymer-cement co-matrixes themselves and the bond between the cement hydrates and aggregates, and to improve the properties of hardened latex-modified concrete. The purpose of this study was to study the strength and chemical resistance of Rapid-setting latex modified concrete(RSLMC) with the main experimental variables such as latex content(0, 5, 10, 15, 20%) and water-cement ratio(36, 38, 40%) at latex content 15%. Water absorption test was earned out to estimate water permeability resistance. Chemical resistance test was carried out to measure the weight change and to observe the appearance of RSLMC immersion in hydrochloric acid, sulfuric acid, and calcium choloride.

• 동아시아식생활학회지
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• 제18권2호
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• pp.207-213
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• 2008

This study examined the effects of added amounts of skate (Raja kenojei) flour on the physical and sensory properties, and consumer acceptability of Jook. As the level of skate flour increased the L-values and b-values decreased, and a-values increased. The Jook also had higher viscosity and lower spread ability values as the amount of skate flour increased. Sensory characteristics, such as color intensity, viscosity, nutty taste, and off-flavor increased significantly with the addition of skate flour. A consumer acceptability test indicated that the 3% skate flour group had the highest overall acceptability, appearance, flavor, and texture. In conclusion, to enhance the quality of Jook, a 3% addition of skate flour would be the useful.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1999년도 학회창립 10주년 기념 1999년도 가을 학술발표회 논문집
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• pp.147-150
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• 1999

Glossing Exposure Concrete is a high quality architectural concrete, i.e., appearance of natural stone and a marbling effect concrete to achieve high quality glassy reflective surface for outer wall of the building. In this study to obtain the conservation and durability of gloss of the "glossing exposure concrete" we developed a from practice and the best mix proportion and derived the optimistic removal time of form to bring out the durable glassy reflective surface and durable concrete. Hereby with the "glossing exposure concrete" obtained, we investigate the accelerate carbonation and accelerate durability test to evaluate the durability factor of this type of concrete.is type of concrete.

• 대한가정학회지
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• 제47권3호
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• pp.79-85
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• 2009

This study examined the effects of added amounts of Lotus root powder on the physical and sensory properties, and consumer acceptability of Jook. As the level of Lotus root powder increased, L-value decreased and a and b values increased. The Jook also had higher viscosity and lower spreadability values as the amount of Lotus root powder increased. Sensory characteristics, such as color intensity, viscosity, nutty taste, and off-flavor increased significantly with the addition of Lotus root powder. A consumer acceptability test indicated that the 25% Lotus root powder group had the highest overall acceptability, appearance, flavor, and texture. In conclusion, to enhance the quality of Jook, a 25% addition of Lotus root powder would be the most beneficial.

• 정신신체의학
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• 제3권1호
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• pp.49-57
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• 1995

To evaluate body image disturbance in Korea, the Body Image Scale(BIS) was developed and it's reliability and validity was tested. The BIS was administered to 33 subjects of normal controls and 64 patients consisting of mainly neurotic patients. The correlation coefficient, of test-retest reliability with an interval of 2 weeks was 0.88 and internal consistency coefficient Cronbach's alpha, was 0.80. Discriminant validity test indicated that there were significant differences in total BIS score between normal control group and psychiatric patients group after controlling the effects of age, sex, and educational level. Factor analysis showed two distinct dimensions, namely 'physical appearance' and 'physical health and strength'. The BIS appears to be a reliable, internally consistent and valid scale which can be used for assessing body image in Korea pupulations.

• 한국응용과학기술학회지
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• 제28권1호
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• pp.1-5
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• 2011

In this study, We investigated the properites of nano-emulsions containing hydrogenated lecithin prepared by high pressure homogenizer. The size of droplet of emulsions prepared by homogenizer at various rpm (rotation per minute) was not measured due to the unstability of emulsions, however, the size of droplet of nano-emulsions prepared by high pressure homogenizer was around 300 nm and the appearance of emulsions was bluish. The stability of emulsions with various lecithin concentration was tested against time. POV (Peroxide value) of emulsions were plotted against time. POVs of emulsions prepared with an egg lecithin and a soy lecithin were increased with time, however, POV of emulsion with Lecinol S-$10^{(R)}$ was kept constant within 60 hours and at $60^{\circ}C$. In consumer test, the nano-emulsion showed higher affinity regardless of skin type. Both of irritation scores of emulsions were similar.