• Journal of Biomedical Engineering Research
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• v.20 no.2
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• pp.221-230
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• 1999

A new technique for the preparation of porous polyurethane vascular prostheses was investigated. Synthetic vascular grafts with porous wall have been widely proposed, claiming that strength, suture retention, kink resistance, and other handling properties are improved over those with nonporous solid wall. Related to these facts, the control of pores and compliance match have been very important and interesting issues. Two kinds of polymer sheets were compared. One was the porous PU-sheet made at room temerature by the solvent/non-solvent exchange. And the other was the porous PU-sheet fabricated by thermal phase transition and solvent/non-solvent exchange in the thermal controlled bath. According to the result of the above experiments, polyurethane solution was injected into a mold designed for U-type graft. After freezing at low temperature, solvent was dissolved out with alcohol at < $0^{\circ}C$ and water at room temperature to form porous vessels. The average pore size and pore occupation were easily changed by changing polyurethane concentration and freezing rate. This technique can give a proper pore size for tissue ingrowth, and suitable compliances for matching with arteries and veins. In addition, the fabrication of more complicated shaped vessels such as the U-type vascular grafts is easily controlled by using a mold. This method might give a desired compliact graft for artificial implantaion with the commercially available medical polymers.

• Journal of the Korean Geotechnical Society
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• v.28 no.11
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• pp.41-52
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• 2012

Suction drain method can directly apply vacuum pressure to the soft ground through vertical drains so it can make hardening zones around them. These hardening zones make steeply lower the discharge efficiency of the pore water with decreasing permeability. This paper considered a stepped vacuum pressure to minimize a hardening zone which is one of the important parameters that can decrease discharge efficiency. A series of laboratory tests were conducted in order to examine the effect of the hardening zones and to evaluate their effects to the ground improvements with varying durations which applied stepped vacuum pressures(-20kPa, -40kPa, -60kPa and -80kPa) with Busan marine clay. According to strength(CPT), water content test and theoretical investigation indicate a size of the hardening zone within 7cm and the decreasing ratio of permeability about 2.0~4.0. Also, the total settlements are larger for the stepped vacuum pressure than the instant vacuum loading. The application time with vacuum pressure is determined considering the geotechnical properties of the interested clays. Results of numerical analysis show that consolidation behavior is appropriate to measurement for considering hardening zones.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.46 no.2
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• pp.89-103
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• 2020

A frizz hair is referred to the fly-away hairs that have become bulky or deviated from the regular hair and the cause of that is not clear known. The internal lipids are related to the physical properties of hair such as elasticity and tensile strength and interracial studies have previously conducted to relate the lipid mass and Afrikaan hair, which has a lot of frizzy hair. Although washing hair is the only way to control the hair loss without damage of hair surface, the number of washing and lipid loss are not linearly correlated. In this study, the amount of lipid hair was analyzed by washing the hair with a few different types of shampoos containing various conditioning polymers and oils of different polarities. The results confirmed that the higher the polarity of the oil, the higher the lipid content. This method was applied to Indian frizzy hair to evaluate the degree of frizziness and found that the frizzy volume was more severe for a hair with less lipids. On the other hand, the frizzy hair volume of fly-away hairs was observed more broadly for the hairs with higher lipid contents. In addition, the friction on the surface of the hair did not differ due to the oil treatment. Taken together, it was concluded that hair frizzing was affected by the amount of lipids in the hair rather than by the adhesion between the oils. Thus, this study suggests that controlling the lipid contents in hair may be an important solution in the development of hair anti-frizzy technology.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.29 no.1
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• pp.85-93
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• 2016

In this study, finite element analyses of masonry infilled frames using a general purpose FE program, ABAQUS, were conducted. Analysis models consisted of the bare frame, infilled frames with masonry wall thickness of 0.5B and 1.0B, respectively. The masonry walls were constructed using the concrete bricks which were generally used in Korea as infilled wall. The material properties of frames and masonry for the analysis were obtained from material tests. However, four times increased the tensile strength was used for 1.0B wall, which is seemingly due to the differences in locating the bricks. The force-displacement relation and development of crack from the FE analysis were very similar to those from the experiments. From the FEA results, contact force between the frame and masonry, distribution of shear force and bending moments in frame members were analyzed. Obtained contact stress shows a trianglur distribution, and the contact length for 0.5B speciment and 1.0B specimen were close to the value estimated using ASCE 41-06 equation and ASCE 41-13 equation, respectively. Obtained shear force and bending moment distribution seems to replicate actual behavior which originates from the contact stress and gap between the frame and masonry.

• Journal of the Korean Wood Science and Technology
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• v.37 no.3
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• pp.184-191
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• 2009

In the southern part of the Korean Peninsula including Jeju-island, the production amount of domestic cedar has increased gradually. However, their low qualities, expected to be caused by the low density and frequent knots, have restricted their practical utilization as the high value-added products. In this study, it is aimed to look for the new uses of domestic cedar and to examine the applicability for lamination lumbers of structural glued laminated timber (glulam). Above all, machine stress ratings for individual sawn lumbers confirmed that modulus of elasticity (MOE) of cedar lumber was lower than that of other common softwood species in Korea. On the other hand, cedar lumbers have enough stiffness to manufacture the structural glulam in accordance with Korean Industrial Standard (KS). The bonding strength and durability also met the KS limitation. Nevertheless, from the result of bending tests for cedar glulam, it was shown that the modulus of elasticity (MOE) did not meet the KS limitation. Therefore, it was concluded that additional researches were needed for reinforcing the stiffness of cedar glulam.

• Journal of Bio-Environment Control
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• v.17 no.4
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• pp.312-318
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• 2008

In a pear fruit 'Chuhwangbae' was investigated the effect of the calcium-coated double paper bag on the physical properties of the paper bag, micro meteorological phenomena, and calcium contents in quality of fruit. The calcium-coated paper bag, compared with official paper bags, did not give any effect on light transmission ratio and tensile strength. The change of the inside relative humidity of the paper bag was a little compared with conventional paper bags, but there was no difference in temperature. The contents of the accumulated calcium of the pericarp was remarkably greater than conventional paper bags during the period of 65 days to 160 days after the full bloom, but the flesh remarkably increased at 160 days. The calcium content per concentration of calcium coating greatly increased in 12% of yellow double paper bags and 9, 12% of newspaper double paper bags in case of the pericarp, and in 3% of yellow double paper bags and 6, 9, 12% of newspaper double paper bags in case of the pericarp. As a result of treatment of a radioactive isotope, the amount of accumulated calcium in the pericarp continued until 60 hours after treatment, but there was no difference in the calcium amount between the flesh and no-treatment pericarp. As to the hardness of fruits at the time of harvest, there was no difference in the concentration in case of a yellow double bags. But newspaper double paper bags 6, 12% was significantly difference. Soluble solid remarkably increased in yellow double paper bags 6, 9% and yellow double paper bags 3, 6, 9%. Also, it did not effect on changes of the pericarp, fruit weight and the color of the pericarp.

• Korean Journal of Food Science and Technology
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• v.34 no.4
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• pp.577-582
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• 2002

Effects of the addition of single or blends of konjac flour (KF), carrageenan (CN), and soy protein isolate (SPI) into the sausage formulation were determined based on the physico-chemical and textural characteristics of low-fat comminuted sausage (LFS, fat <3%). LFSs had a pH range of 6.10 to 6.16, 77-79% moisture, <3% fat, and 13-15% protein contents, whereas regular-fat sausages (RFSs) had a pH value of 6.11, 62.5% moisture, 19.4% fat, and 11.9% protein. LFSs containing fat replacers were reduced (P<0.05) cooking loss (CL, %). KF alone or mixed with other hydrocolloids slightly improved the water-holding capacity, whereas CN increased (P<0.05) the gel strength, resulting in higher hardness values. Replacement of 6% lean meat with 1.5% SPI alone increased (P<0.05) yellowness (Hunter b value) and expressible moisture (EM, %). TPA values of KF+CN+SPI were the most similar to those of RFSs. These results indicated that triple addition of KF, CN and SPI at the ratio of 1 : 1 : 3 in LFS formulation improved functional properties, as compared to the low-fat control, and had textural characteristics most similar to those with RFSs.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.2
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• pp.107-115
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• 2019

The many countries are facing the shortage of natural resources, and the supply of aggregates are being exhausted. To consider this situation a variety of studies were performed for the development of alternative resources. In particular, high density filler material was used for shielding radioactive waste, large amount of natural aggregates are required in order to produce filler material. Also, in order to improve the shielding performance of filler material, it is required to increase the density of the filler material. Therefore, in this study was carried out to provide basic data for expanding the feasibility of high density industrial waste resource as aggregate in heavyweight concrete. From the test results, OPC case, concrete strength decreased by using heavyweight waste glass as fine aggregate, however, it is improved by using mineral admixture as binder. Therefore, when the heavyweight waste glass and steel slag are applied to heavyweight concrete, it is desirable to use mineral admixture, especially to use BFS than FA. Meanwhile, when the steel slag was replaced as coarse aggregate of heavyweight concrete, elasticity of modulus and radiation shielding performance can be improved owing to high density of steel slag.

• The Journal of the Korea Contents Association
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• v.21 no.2
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• pp.85-99
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• 2021

Graphene, called the "dream material" is drawing attention as a groundbreaking new material that will lead the era of the 4th Industrial Revolution. Graphene has high strength, excellent electrical and thermal conductivity, excellent optical permeability, and excellent gas barrier properties. In this paper, as the South Korean government recently announced Green New Deal and Digital New Deal policy, we analyze graphene technology, which is also attracting attention for its application to Corona 19 biosensor, to understand its national R&D trend and knowledge structure, and to explore the possibility of its application. Firstly, 4,054 cases of national R&D project information for the last 10 years are collected from the National Science & Technology Information Service(NTIS) to analyze the trend of graphene-related R&D. Besides, projects classified as green technology are analyzed concerning the government's Green New Deal policy. Secondly, text mining analysis is conducted by collecting 500 recent graphene-related articles from e-newspapers. According to the analysis, the field with the largest number of projects was found to be high-efficiency secondary battery technology, and the proportion of total research funds was also the highest. It is expected that South Korea will lead the development of graphene technology in the future to become a world leader in diverse industries including electric vehicles, cellular phone batteries, next-generation semiconductors, 5G, and biosensors.

• The Journal of the Convergence on Culture Technology
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• v.7 no.1
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• pp.291-299
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• 2021

In 2019, SUV sales surpassed sedans in the domestic sales market with phenomenal domestic sales. The strength of SUVs around the world is expected to continue in the future. South Korea's K-company aggressively launched small SUVs in the SUV market. Its simple lineup is recognized as a brand image, not as a SUV. It is time to evaluate this. Therefore, it influences the purchasing decisions of potential customers and buyers of small SUVs through the evaluation of design images of small SUVs in Korea. Rather than the functional properties of the SUV model, it is purchased by emotional characteristics, brand symbolism, and image. Subconsciousness of the purchasing psychology of the end consumer was used by metaphor extraction techniques. Customers wanted to study the evaluation of small SUV design images that fit their needs. We wanted to see if consumers who intend to purchase or purchase small SUVs in Korea had a connection with the image of design of small SUVs in Korea. The conclusion of the study was extracted through ZMET, a metaphor extraction technique, with the latent consciousness of the primary ambiguous message from the consumer's feeling and representation of the image. Therefore, based on the results of this study, we hope that the images presented in SUVs in the future will be used as a design guide in the development of small SUVs to influence customer thinking and behavior.