• The Journal of the Convergence on Culture Technology
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• v.8 no.6
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• pp.667-674
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• 2022

In this study, the correlation between the damage type and operating conditions of the sleepers was analyzed based on the design data and visual inspection results for the concrete sleepers of the sleeper floating track (STEDEF) that have been in operation for more than 20 years. It appeared in the form of cracks, breakages, and breaks in the concrete at the center and tie bar contact and buried areas. As a result of the numerical analysis, it was analyzed that the change in the left and right spring stiffness of the sleeper resilience pad increases the maximum stress, tensile stress, compressive stress, and displacement of the concrete sleeper, and stress concentration in the concrete at the tie bar contact area. It was proved analytically that the sleeper resilience pad can affect the damage of the concrete sleeper. Therefore, damage of concrete sleepers in the sleeper floating track in urban transit could be caused by changes in spring stiffness of sleeper resilience pads. It was reviewed that preventive maintenance such as improvement and timely replacement of sleeper resilience pads was necessary.

• The Journal of Engineering Geology
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• v.33 no.4
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• pp.599-609
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• 2023

In the seismic retrofitting of harbor breakwaters in Korea, the recovery rate is often uncertain due to site conditions and site conditions, and problems continue to arise. Therefore, in this study, we analyzed the recovery rate and compressive strength of the improved material through drilling survey by grouting confirmation method after applying low-fluidity mortar injection method, and furthermore, we checked the elastic modulus by downhole test and tomography to confirm the reinforcement effect of soft ground after ground improvement. The experimental results showed that the average shear wave velocity of the ground increased from 229 m/s to 288 m/s in BH-1 and BH-3 boreholes to a depth of 28.0 m, and the average shear wave velocity of the ground to a depth of 30.0 m tended to increase from 224 m/s to 282 m/s in the downhole test. This is believed to be a result of the increased stiffness of the ground after reinforcement. The results of the tomographic survey showed that the Vs of the soft ground of the sample at Site 1 increased from 113 m/s to 214 m/s, and the Vs of the sample at Site 2 increased from 120 m/s to 224 m/s. This shows that the stiffness of the ground after seismic reinforcement is reinforced with hard soil, as the Vs value satisfies 180 m/s to 360 m/s in the classification of rock quality according to shear wave velocity.

• Journal of Hydrogen and New Energy
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• v.25 no.5
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• pp.509-515
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• 2014

At the fuel processing system (FPS) of fuel cell vehicle, hydrogen recirculation blower (HRB) is used for the recirculation of remained hydrogen after reaction. In this paper, noise and vibration improvement of HRB is studied by changing design and control. It is checked the campbell diagram and critical speed for stability of rotor, and housing stiffness is improved using simulation of frequency response function (FRF). A method is suggested that can decrease the unbalance amount of the rotor and impeller which main source of noise and vibration. In order to reduce the noise during deceleration of blower, electrical braking is applied and tested the risk impact of durability. Founded the optimum switching frequency of the motor control, and reduced the idle rpm by increasing of aerodynamic performance. The superiority of paper is proved by measurement of the improved product's noise and vibration.

• Fashion & Textile Research Journal
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• v.19 no.6
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• pp.759-767
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• 2017

This study investigates the improvement of domestic compression stockings by comparing and analyzing the characteristics of materials and fabrics of medical compression stockings developed in Korea and domestic imported compression stockings. Among imported compression stockings currently available in Korea, three brands with high sales rates are selected by countries (USA, Italy, and Germany) to measure the physical and mechanical properties of the material. Medical compression stockings to be analyzed were selected as M size pantyhose included in 20-30mmHg. As a result, the tensile elongation of medical compression stockings selected in this study was the highest in Korean products in the ankle, while the highest in the US was in the thigh, and the elasticity of Italian products was low. The recovery rate of the kidneys was similar for all four ankles. The ankle weight was the highest except for Korean products that showed the highest weight of the thigh and difference from products of other countries. US product also showed high shape stability due to high recovery of tensile strength from high value RT. Italian products showed low banding and shear values; however, shape stability was poor with good drapeability. In Germany, LT and RT values were low, but clothing comfort was considered excellent. In Korea, LT and RT values, banding and shear characteristics were high, and drapeability was poor. Stiffness was good, but recoverability was excellent.

• Journal of the Korean GEO-environmental Society
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• v.2 no.3
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• pp.57-69
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• 2001

Sand pile is widely used as a ground improvement method. Although the primary purpose of constructing sand pile is accelerating consolidation, composite ground effect also can be gained by constructing sand pile. This study was accomplished to understand composite ground effect on the ground improved by sand piles which were applied as vertical drainage material when area replacement ratio was small relatively. For determining bearing capacities of origin ground and sand piles and analysing interaction between embankment and origin ground, bearing tests and earth pressure monitoring are performed. From the results, it turned out that the contribution of sand pile as a load bearing mechanism is not substantial. However, the bearing capacity of sand pile was increased to sixty percentages when compared with origin ground. The increasement of bearing capacity could be caused the change of consolidation characteristics during the process of consolidation by overburden load. Therefore, the composite ground effects depending on stiffness increasement of sand pile would be estimated as a factor decreasing consolidation settlement.

• Journal of Fashion Business
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• v.8 no.1
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• pp.141-155
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• 2004

Chitosan, the natural biodegradable polymer derived from chitin by de- acetylation, has been widely applied to the textile finishing processes for excellent anti-microbial characteristic and handle improvement of fabric. The purpose of this study is to investigate the change of handle when cotton fabric is treated with chitosan-polyurethane mixed solution. The viscosity values of chitosan solutions were 8cps and 50cps, and the wet-pick-up% was maintained at 90%. In case of mixing with water soluble polyurethane, the mixture ratio of chitosan and polyurethane was settled on the solid content ratio of 1:0, 1:0.5, 1:1, 1:2. Also the change of physical properties by neutralization in NaOH solution was studied. The results can be summarized up as follows : 1. Extensibility(EM) and tensile energy(WT) of cotton fabric treated with chitosan are decreased, but bending rigidity(B) is remarkably increased. With the addition of polyurethane, the decrease of EM and WT is weakened and the increase of B is weakened. The case of neutralization is similar to the case of polyurethane addition. 2. By treating fabric with chitosan, FUKURAMI(Fullness and softness) is decreased, but KOSHI(Stiffness), SHARI(Crispness), HARI(Anti-drape Stiff ness) are increased. With the addition of polyurethane, the decrease of FUKURAMI is diminished and the increase of KOSHI, SHARI, HARI are diminished. 3. As the viscosity of chitosan solution increased, the air permeability value increased. The addition of polyurethane decreased the air permeability.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.47 no.1
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• pp.10-16
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• 2015

Bio-binder is well known as a promising alternative binder for SB latex because it is eco-friendly and inexpensive, compared to synthetic latex. SB latex in top coating color was substituted with starch-based bio-binder to investigate its effects on the coating color and its coated paper properties. Bio-binder contributed to the increase of coating color viscosity, and the improvement of water retention. Most optical properties except opacity were deteriorated by the increase of bio-binder dosage. It was also found that the increase of bio-binder substitution in top coating color brought about the increase of roughness, and decrease of coated paper gloss, print gloss, dry and wet pick strength. However the stiffness and the ink set-off of the bio-binder coated paper were improved. Overall, mostly adverse effects of bio-binder on the properties of coating color and its paper were observed. Therefore, it is not recommended to use bio-binder as top coating color.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.42 no.1
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• pp.41-47
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• 2010

Increasing ash content of the paper is one of the most effective methods for saving raw materials and steam consumption and improving optical properties and better print quality. However, the increase of filler loading or filler content using a conventional wet end system is limited due to severe loss in strength properties, affecting runnability and product quality. This is because the filler has no ability to make bonding with cellulosic fibers. Therefore, if the technology to give filler the bonding ability is developed, the ash content of the paper can be increased more than ever. This study was carried out to modify PCC by coating its surface with starch contributing to better bonding with fibers. To prepare the modified PCC, cationic starch was selected as a polymer and then pretreatment was done by mixing PCC and cationic starch. Consequently, the pretreated PCC contributed to higher tensile strength, stiffness and opacity than the conventional filler, such as GCC and untreated PCC. However, CIE whiteness and ISO brightness decreased slightly compared to conventional fillers.

• Journal of Sericultural and Entomological Science
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• v.27 no.2
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• pp.28-39
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• 1985

The structural and useful characteristics of silk habutae treated with silicone resin by emulsion finishing method were studied. The results were obtained through crease recovery test, water repellency test, scanning micrograph observation, amino acid analysis, X-Ray diffraction analysis, and Fourier Transform Infrared Spectroscopy. The results are summarized as follows; 1) The improvement in crease recovery of silk habutae finished with silicone resin, was observed b soaping treatment and curing conditions. 2) The higher water repellency and stiffness in silk fabrics finished with silicone resin was found by the fabric inspection and the scanning electron microscopic observation. It is suggested that silicone resin impregnated into the void of silk fibroin. 3) The polar side chains of amino acid composition were decreased, when the silicone resin was treated on silk fibroin. 4) Through Amino acid analysis of silicone resin finished fibroin, the different amounts of amino acid composition was indicated due to silk fibroin silicone polymer reaction and the structural difference of its fibroin were also proved by X-ray diffractograms. 5) The functionality of the siloxane compound may be deduced from the silicone finished silk habutae by Fourier Transform Spectroscopy. It was concluded from the above results that the useful characteristics of silk fabric can be improved by silicone resin finishing.

• Journal of the Korean Society of Clothing and Textiles
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• v.34 no.1
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• pp.138-152
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• 2010

This study investigates the actual hospital-clothes consumption experience of consumers according to gender and age. An all age survey was conducted among male and female ex-patients in Korea nationally. From data collected during April and May 2009, a total of 513 responses were analyzed using descriptive statistics, chi-square analysis, two-way ANOVA, and MANOVA using SPSS 10.1.4. The results are as follows. The hospitalization ratio was higher in the male group than in the female group and increased with age. Many hospitalizations were taken to the department of orthopedics, internal treatment, obstetrics and gynecology, and surgery. The satisfaction with patient gowns was low regarding size, fabric touch, color and pattern, Psychological comfort, and holistic satisfaction, Specifically, the stiffness of the fabric, cheerless colors, and the limited number of sizes were the main complaints; size dissatisfaction was expressed strongly by females. About 35% of respondents showed a positive attitude to wear premium patient gowns. Various medical supplies were used and different items were utilized according to gender and age of patients. Uncomfortableness of medical supplies were highly related to laundry and fabric touch.