• Design & Manufacturing
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• v.14 no.1
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• pp.1-7
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• 2020

In this study, the variation of the shrinkage in the thickness direction of the molded parts according to the gate size of the polymer core fabricated through the 3D printer using the SLS method was studied. The polymer cores are laser sintered and the powder material is nylon base PA2200. The polymer cores have lower heat transfer rate and rigidity than the metal core due to the characteristics of the material. Therefore, the injection molding test conditions are set to minimize the deformation of the core during the injection process. The resin used in the injection molding test is a PP material. The packing condition was set to 80, 90 and 100% of the maximum injection pressure for each gate size. The runner diameter used was ∅3mm, and the gates were fabricated in semicircle shapes with cross sections 1, 2, and 3 ㎟, respectively. Thickness measurement was performed for 10 points at 2.5 mm intervals from the point 2.5 mm away from the gate, and the shrinkage to thickness was measured for each point. The shrinkage rate according to the gate size tends to decrease as the cross-sectional area decreases as the maximum injection pressure increases. The average thickness shrinkage rate was close to 0% when the packing pressure was 90% for the gate area of 1mm2. When the holding pressure was set to 100%, the shrinkage was found to decrease by 3% from the standard dimension due to the over-packing phenomenon. Therefore, the smaller the gate, the more closely the molded dimensions can be molded due to the high pressure generation. It was confirmed that precise packing process control is necessary because over-packing phenomenon may occur.

• The Journal of Korean Physical Therapy
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• v.18 no.5
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• pp.13-23
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• 2006

Purpose: This study was to investigate two-point discrimination(TPD) and related factors in rural community residents. Methods: The sample consisted of 68 people who have been living in rural community in June 2005 studied. TPD was measured from the tips of the thumb, index, middle, ring, and little finger of each hand with the TPD esthesiometer. The research was designed to be a cross-sectional measured study. SAS statistical software was used for the analysis. The characteristics of the study sample were described by mean and standard deviation(SD) for continuous variables and by frequency and percentage for categorical variables. The Student's t-test and analysis of variance (ANOVA) were used to compare TPD in gender and diabetes mellitus. A Pearson's correlation analysis was conducted for relationship among values of 5 fingers. Multiple regression analysis was performed to determine the factors associated with TPD. Results: A total of 68 residents were measured, their average $age{\pm}SD$ was $54.2{\pm}23.2$ years(range: $12{\sim}88\;yr$). The mean TPD for 5 fingers tips in dominated side was 4.76mm(thumb 3.98mm, index 4.22mm, middle 4.79mm, ring 5.17mm, and little finger 5.65mm, respectively). 4.91mm for thumb finger of women was significantly higher than 3.54mm that of men's in difference between gender(p=.01l4), also women(4.39mm) was higher than men(3.71mm) in median nerver area(p=.0318). There was a statistically significant difference in age(p=.0022), which were under age of 20(3.36mm), 30 years(3.61mm), 40 years(5.38mm), 50 years(4.84mm), 60 years(5.28mm), 70 years(5.18mm), and over age of 80(5.29mm). Factors related to TPD of fiver fingers by multiple regressions were gender(${\beta}=.03$, p=.0001). Conclusions: Taken together, gender and age were significantly associated with TPD. We recommend that further research should measure TPD by using larger sample sizes and more sensitive measurement instruments.

• Journal of the Korean Society of Clothing and Textiles
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• v.32 no.5
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• pp.846-858
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• 2008

This study was designed to propose a method to draft bodice block pattern from 3D body scan data. Subjects were ten elderly women in their 60's, who wear basic size(B: 94cm, W: 82cm) garment. Scanning was done using 3D whole body scanner(WB4, Cyberware). Measurements for 3D data and cross section were attained using Auto CAD, by which a upper bodice pattern for elderly women was drawn on the basis of short measured method. The results are as following: As for most items, no significant differences were shown between measurements from Martin's anthropometry and those from 3D scan data, suggesting measurement from 3D scan data could be used to draft a pattern. The drafting equations acquired were as follows; width of pattern=B/2+5.5, width of waist=W/2+3.5cm, dart amount=8cm. Dart distributions were 23%(B.P.) : 20%(front armpit) : 17%(side seam) : 18%(back armpit) : 15%(back protruded point) : 7% (center back line). Through wearing test using 5-point Likert scale, resultant pattern was evaluated as appropriate for elderly women's pattern to get over 4 point. As a result, it might be said that 3D scanning application is effective for elderly women in that it doesn't take time so much as Martin's anthropometry and that their body shape vary compared with those of young women.

• Journal of Digital Convergence
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• v.18 no.6
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• pp.513-522
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• 2020

The purpose of this study is to analyze the auto-regression effect between the elderly's assets and depression and life satisfaction, and to approach the influence of assets and depression on the elderly's life from a longitudinal perspective. For this purpose, the data for the 9th year (2014), 11th year (2016), and 13th year (2018) of the Korea Welfare Panel were used. As a result of the analysis, First, the assets, depression and life satisfaction of the elderly have a lasting effect on the passage of time, and the assets, depression and life satisfaction of the previous point in time (B=.694, B=.725, p<.001), depression (B=.258, B=.331 and p<.001) and life satisfaction (B=.264, B=.265, p<.001). Second, cross-recursion coefficients show how the relationship between the assets of the elderly and depression and the satisfaction of life affects each other over time, and the assets of the older person at the previous point in time (B=.010, B=.011, p<.001), the assets of the older persons at previous times are subsequently satisfied with their lives (B=.128, B=.124, p<.001). Based on the results of the above analysis, it is necessary to support the elderly's asset management service and education to prevent depression, such as continuous asset utilization education.

• Proceedings of the International Union of Geodesy And Geophysics Korea Journal of Geophysical Research Conference
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• 2003.05a
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• pp.15-15
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• 2003

The first crustal refraction survey in the Korean Peninsula was carried out over the survey line connecting Seosan-Yeongdong-Kyeongiu on Dec. 15, 2002. The total length of the survey line was about 300 Km and 198 portable seismometers were deployed with approximately 1.5-km interval. The survey line itself was geologically important since it was almost normal to the so-called Sino-Korean structural trend. Two shots, one at Seosan (west end point) and the other at Yeongdong (mid-point), were exploded. They were 100-m deep drill well explosions. The Seosan shot consisted of a ton emulsion type explosive, while Youngdong consisted of 500 kg one. Both shots generated signals with good S/N ratios to the farthest receivers. Seismic signals were recorded by 195 receivers out of 198 ones. Although the originally planned Kyeongju shot (east end point) could not be exploded due to public discontent, the experiment was evaluated very successful. First breaks in all recorded traces were picked up and two preliminary analyses were carried out. The one is conventional flat layer analysis and the other was refraction tomographic analysis. The one resulted in average 32-km thick two-layer crust and the underlying mantle with 8.05-km/s P-velocity. The top crust layer with 3.86 kw/s P-velocity was 2.5-km thick and the lower crust layer with 6.0l km/s P-velocity was 29.5-km thick. The other resulted in a velocity cross-section. The confidence level of the velocity cross-section could not be evaluated at this time because only two shot were exploded. Detailed analyses such as surface wave dispersion are on going. Continuing crustal scale refraction surveys are planned in Korea.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.28 no.4
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• pp.49-63
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• 2010

This study focused on the method of separation - space organization- as one of the architectural methods that is considered by the view point of its location and arrangement of 'Byoul-seo' private garden pavilion in Honam province. As a result, the followings are conclusions; By this study, they can be found in the concept of '居敬窮理', '格物致知'. It is presumed that nature union is archived through the 'yan-sang(玩賞)' which is ultimate state of knowledge that is based on the premises of opened significance in emancipation from narrow view point in the past and cognition of value. Therefore, it is needed to know the unworldly point of space perception about the pavilion territory, furthermore to have conceptual method to distinct pavilion from the world. there are two methods in the distinct concept in this pavilion research: unworldly separation and meditative separation. It is concluded that the specific consideration of the method of separation that is applied in the Byoul-seo pavilion. And it is accomplished by the contemplation of separation method in approach and entrance of direct influence area. they could be 1) cross the hill, 2) cross over a brook, 3) lifted up in the mount, 4) penetrate the forest, and 5) narrow entrance, which could be part of location.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.sup1
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• pp.71-78
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• 2016

Printing of pictorial health warnings (PHWs) on cigarette packages became obligatory by the Vietnam Law on Prevention and Control of Tobacco Harm in May 2013. Literature from high-income countries suggests that PHWs motivate smokers to quit smoking although their long-term effects have been questioned due to reduction of impact over time. This study aimed to assess the salience of PHWs and smokers' reactions towards PHWs over time. In May 2014 and May 2015, a cross-sectional questionnaire-based household survey was administered to respectively 1,462 and 1,509 Vietnamese male smokers aged 18 to 35. The result showed that salience of the PHWs 2 years after the implementation was higher than at the point of 1 year after the implementation. The proportion of respondents who tried to avoid noting the PHWs was reduced from 35% in wave 1 to 23% in wave 2. However, "Tried to avoid looking/thinking about the PHWs" increased 1.5 times the odds of presenting quit intention compared to those respondents who did not try to avoid looking/thinking about the PHWs (OR=1.5; 95%CI: 1.2-2.0). In conclusion, avoidance regarding PHWs may not work as a barrier when aiming at a higher level of quit intention. Salience of the PHWs may increase in the period shortly after their introduction onto packs but can be expected to decrease with time. In other words, it might be advisable to change or renew PHWs after a period of implementation to maintain their beneficial effects.

• Food Science and Biotechnology
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• v.15 no.1
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• pp.33-38
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• 2006

This study was performed to provide basic rheological data of dandelion root concentrates in order to predict their processing aptitude and usefulness as functional foods material. The hot water and 70% ethanol extracts of dandelion root were concentrated at 5, 20, and 50 Brix, and their static viscosity, dynamic viscosity, and Arrhenius plots were investigated. Almost all hot water concentrates showed the typical flow properties of a pseudoplastic fluid, but evaluation using the power law model indicated that the 70% ethanol concentrates showed a flow behavior close to a Newtonian fluid. The apparent viscosity of hot water and 70% ethanol concentrates decreased with increasing temperature. Yield stresses of hot water and 70% ethanol concentrates by Herschel-Bulkley model application were in the range of 0.026 - 1.368 Pa and 0.022 - 0.238 Pa, respectively. The effect of temperature and concentration on the apparent viscosity was examined by Arrhenius equation. The activation energies of hot water and 70% ethanol concentrates were in the range of $8.762-23.778{\times}10^3\;J/mol{\cdot}kg$ and $3.217-20.384{\times}10^3\;J/mol{\cdot}kg$ with increasing concentration, respectively. Storage (G') and loss (G") moduli were generally increased with increasing frequency. For the 70% ethanol concentrates, G" predominated over G' at all applied frequencies and so they showed the typical flow behavior of a low molecular solution. However, for the hot water concentrates, G' predominated over G" at more than 1.9 rad/sec (cross-over point) and so they showed the typical flow behavior of a macromolecular solution.

• Journal of the Microelectronics and Packaging Society
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• v.25 no.4
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• pp.123-128
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• 2018

Effect of activators in flux on the printability and wettability of a solder paste was evaluated in this study. The activators in this study were dicarboxylic acids, which were oxalic acid (n = 0), malonic acid (n = 1), succinic acid (n = 2), glutaric acid (n = 3), adipic acid (n = 4), and pimelic acid (n = 5). When the solder pastes were observed with a SMT scope, solder with glutaric acid showed clean and shiny surface when it was melted. Slump ratio of the solder pastes was low when the carbon numbers of the dicarboxylic acid were 1-3. Spreadability was high when the carbon number was over 2. Zero cross time of wetting balance test was under 1 sec when the carbon number was over 3. When activator was oxalic acid or malonic acid, zero cross time was over 1 sec and maximum wetting force was low. Fluxes with the oxalic acid and malonic acid showed decomposition at the temperature close to melting point. Among the dicarboxylic acids, glutaric acid provided excellent slump, spreadability, and wettability.

• Journal of the Korean Society of Clothing and Textiles
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• v.31 no.3 s.162
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• pp.463-474
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• 2007

With rapid expansion in e-retailing of apparel business, personalized fitting model service shows the possibility as the differentiated marketing strategy in cyber shopping. According as necessity of personalized fitting model construction rises, it is tried personalized fitting model creation in several fields such as computer engineering, mechanical engineering, information engineering. But, because existent study was concentrated only on human body modeling, it does not reflect average morphological characteristics of human body properly. In this study, we wish to examine if morphing is fit for expressing characteristic of average human body shape and suggest desirable morphing. We used 3-D scan data of 254 Korean middle aged men collected by Size Korea 2004. The result of this study are as follows: Lower body types were categorized by height hip girth and lower drop(hip girth-navel girth) which were main factors of lower body shape. Then each factor was divided into 3 groups respectively, 30% in the middle, over 30%, under 30%. In 27 groups, the group which belonged to 30% in the middle of height, 30% in the middle of hip girth, 30% in the middle of lower drop was selected as a representative group. We tested geometrical figure by differ volume, tilt, position of point. And we created a representative type of men's lower bodies by morphing the representative group and analyzed it's horizontal, vertical sections. A representative type which was created by morphing reflected a real body and changed realistically at the part of hip, crotch, calf muscle and so on. A cross sections of a representative type were similar to average cross sections of the representative group in size and shape. So it was proved that morphing was successful.