• Fibers and Polymers
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• v.2 no.1
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• pp.140-143
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• 2001

To better understand the formation of necking in drawing processes of fibers, strain distributions during drawing processes have been analyzed. For simplicity, one-dimensional incompressible steady flow at a constant temperature was assumed and quasi-static model was used. To describe mechanical properties of solid polymers, non-linear visco-plastic material properties were assumed using the power law type hardening and rate-sensitive equation. The effects of various parameters on the neck formation were matematically analyzed. As material property parameters, strain-hardening parameter, visco-elastic coefficient and strain-rate sensitivity were considered and, for process parameters, the drawing ratio and the process length were considered. It was found that rate-insensitive materials do not reach a steady flow state and the rate-sensitivity plays a key role to have a steady flow. Also, the neck formation is mainly affected by material properties, especially for the quasi-static model. If the process length changes, the strain distribution was found to be proportionally re-distributed along the process line by the factor of the total length change.

• Journal of the Korean Home Economics Association
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• v.19 no.3
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• pp.21-32
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• 1981

Clothing must have the individual beauty and the function that one can do one's body movement freely. therefore, from the human engineering view point, the exact measurement of the human body and the analysis of it's results must be applied to clothing because the arm works most. In this study, the skin surface of arm was investigated by shell made of Alginate of each movement. And by sometic method the rate of expansion and contraction of each section, inter-relation among the bust girth, axillary arm girth and scye girth and between the shoulder length right and the under axilla waist length were calculate4d. With these results, cap height, breadth of a sleeve and arm hole girth of existing sleeve pattern have been compared and analysed. The results are as follows; 1) According to the developmental figures of shell, the whole area change was small but that of shape was remarkable in M 4, 9, 13. The change of the Block 1 was particular. 2) Over arm length was contracted in all movements except M6 and under arm length expanded. The changes of sections a, b, c are large, while those of sections d, e are small. 3) In terms of latitudes, change of fore-arm region was small. The rate of scye girth varied from 14.3% of M13 to-5.6% of M2. The breadth of a sleeve expanded in all movements, and especially the front region expanded more than the back. 4) The relation between the shoulder length right and under axilla waist length, in all occasions, was contracted mutually, and one contracted, the other expanded. Therefore, in clothing construction when we consider the function of the arm it is better to widen the arm hole and the breadth of a sleeve at the same time than no widen the shoulder length by lowering the upper part of the upper side seam line.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.05a
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• pp.180-181
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• 2017

This study aims to analyze the high strength mortar's fundamental properties and autogenous shrinkage properties by taking into consideration the result of the previous study in which it was found that ERBO(Biodiesel) exercises greatest effect on the expansion effect of mortar, and changing the time and rate of mixing the ERBO. A total of five levels were set as experimental variables: the three levels of the rate of ERBO, 0, 0.5, 1.0%, and the two levels of the time of mixing the ERBO: first, adding the ERBO with the mixing water and mixing it before, and second, mixing it after the mortar is completely mixed. It was found that the rate of length change decreased as the rate of ERBO increased, and the rate of length change was lower when the ERBO was mixed sooner.

• Journal of the Korean Solar Energy Society
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• v.29 no.5
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• pp.20-27
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• 2009

The effect of borehole thermal resistance on the borehole length is studied. In performing this work a new concept BLRR(borehole length reduction rate) is developed based on the line source model. The solution of line source model is shown to be valid through the comparison with the data of thermal response test. It is shown that BLRR is a function of soil thermal conductivity(k) and borehole thermal resistance($R_b$). The value of BLRR increases with increasing k, which means reducing $R_b$ is more effective when k is high. The reduction of borehole length with change of $R_b$ is easily estimated with BLRR. The validity of BLRR is also examined with EED analysis.

• Architectural research
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• v.26 no.1
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• pp.13-20
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• 2024

This study is a research investigation into the properties of bubbles that affect the characteristics of foamed concrete during its production. The study examined the properties of bubbles based on the manufacturing conditions. To investigate these properties, the selected experimental factors included bead size, the length/diameter ratio of the bubble-generating tube, and compressed air. The experimental design used a design of experiments, and the test results were analyzed using analysis of variance. The foaming agent used to generate bubbles was AES (Alcohol Ethoxy Sulfate), and the method employed for bubble manufacture was the pre-foaming method. In the test results, a significant factor affecting the foaming rate of bubbles was the bead size; the highest foaming rate was observed when using 2mm beads. Bead size also primarily influenced the volume change of the aqueous solution, while other factors did not affect the foaming rate and volume change. None of the factors affected the change in bubble size, but compressed air was considered the main factor affecting bubble size and its change. The foaming rate and volume change of the aqueous solution showed a high correlation with each other. Spherical bubbles in the early stage eventually transformed into angular bubbles. Moreover, over time, it was observed that the bubble size increased.

• Fashion & Textile Research Journal
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• v.21 no.6
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• pp.821-829
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• 2019

This study investigated the location of grading lines and grading amount for a jacket item by the target age groups (20-30, 30-40, and 40-50) for 17 women's wear brands. This study then utilized 7th SizeKorea data to analyze the increase rate of body size and to suggest the grading deviation distribution ratio of the jackets using regression analysis. The increase in neck girth of the jackets targeting aged 30-40s did not reflect the human body change rate. The shoulder length increased by 4.6%-8.1% with the bust girth increase; however, the brands produced longer shoulder length reflecting 20-35% of the bust girth increase. The armhole girth was 54.9% - 59.7% of bust circumstance increase rate. However, the 20-30 target age group brands distributed 80% of bust girth to armhole girth and the 30-40 and the 40-50 target age group brands distributed 50% of the bust girth to armhole. In particular, the 20-30 target age group brands were found to produce a large margin around the armhole. When it came to length items, the brands targeting 20-30s and the 40-50s reflected deviation distribution rate of length from underarm to waist and length from waist to hip in comparison with the overall jacket length deviation. The 30-40 target age group brands, 8 out of 20 brands distributed the jacket length deviation in the length from the back of neck to the underarm; consequently, only 22% percent should be distributed in this part.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.11
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• pp.1139-1145
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• 2011

An automated anastomotic ring-pin system consisting of both the anastomotic ring-pin system and the coupler device has eliminated the drawbacks of the suture method. High density polyethylene (HDPE), a material with outstanding biocompatibility and injection molding capability, was used in the ring. SUS316 stainless steel, Ti-6Al-4Nb, Ti-6Al-4V, and unalloyed titanium were used in FEM simulations of the micropin. The authors categorized the microvascular anastomotic ring micropins into short neck (SN) and long neck (LN) groups in order to evaluate the effect of the micropin's fillet radius and neck length on the von Mises stress. The micropins were further divided into those with and without fillet. On the basis of the fillet radius rate (FRR), which represents the rate of change in the von Mises stress with respect to the availability and shape of the fillet, and the neck length rate (NLR), which represents the rate of change in the von Mises stress with respect to changes in the length of the neck within the fillet shape, it can be concluded that the SN-3 neck design is the most stable.

• 유체기계공업학회:학술대회논문집
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• 2003.12a
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• pp.174-177
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• 2003

The automatic temperature control valve is used to control the flow rate of heating water in the large apartment complex and buildings. It is important to have simillar heating flow rate in the apartments, even though the apartment is top or bottom floors. To achieve those purposes, the automatic flow-temperature control valve was developed. The perfromance of this control valve is effected by the catridge shape and spring length. The flow capacity of this control valve is obtained with the different shape of catridges and with change of spring length.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.11a
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• pp.150-151
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• 2013

Recently, the internal space organization of the building changes to the frame construction and flat slab construction in the wall type structure. And the use of light weight panel changing the internal joint use easily is increased. Therefore, in this research, the length change characteristic that the magnesium chloride addition rate reaches to the magnesium curing body tries to be studied. It could confirm according to the length change specific result that the magnesium chloride amount of addition reaches to the magnesium oxide curing body to expand. And the thing described below was the large-scale expansion the magnesium oxide addition rate 60%. And it showed up as 50, 40, 30, 20, and order of 10s (%). It could look at to form the hydrate of the SEM picture result needle-shaped of the Hardened.

• Asian Journal of Turfgrass Science
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• v.10 no.1
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• pp.1-11
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• 1996

Fifty accessions in Zoysia species and forty-one hybrid lines were evaluated in order to detect analyze the genectic variation of Zoysiagrasses and to obtain the basic information for breeding. 1.Plant height ranged from 13 to 34.5cm, leaf length from 7 to 26cm, leaf width from 2 to 7mm, and first leaf height from 1.1 to 8.5cm 2. The correlations among plant height, leaf length and first-leaf height were high, but leaf Width was correlated only With leaf length. 3. Stolon length was varied from 10 to 108cm, number of stolons from 12 to 53, internode length from 2 to 6.1cm and coverage percentage from 10 to 90%. 4.There were correlation among stolen length, number of stolons, internode length and coverage percentage except between stolen and internode length. 5.M1J and MC2 showed the highest level in stolen length, number of stolons and coverage percentage. Therefore they will be the best breeding materials for the purpose of fast covering. 6.According to the analysis on October 26, 1995, yellow color-change rate of leaves ranged from 5 to 85%, red color-change from 0 to 75% and sum of yellow and red change from 20 to 95%. Speciallty M2M1 and FL-41 kept green color untill early December, indicating that they had the late dormancy. 7. Visual assessment of stolon length and number of stolons, showed similar tendency With actually measured data. 8. Shoot density was very high in M2M1 and S2, and showed negative correlation with leaf width. 9. It is known in Korea that the darker green color of lawngrass is, the better it looks. There were 11 lines with dark green color leaves such as J 85-10, Meyer in Z. japonira, one asacession in Z. matrella and M2M1, M2S8, JM2, 55C2 in hybrid lines.