• Korean Journal of Radiology
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• v.21 no.11
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• pp.1248-1255
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• 2020

Objective: To analyze long-term follow-up sonographic findings of intrathyroidal thymus in children. Materials and Methods: Among 1259 patients with congenital hypothyroidism under 15 years of age who underwent thyroid ultrasonography (US), 41 patients were diagnosed with an intrathyroidal thymus based on US criteria, i.e., hypoechoic solid lesion with punctate and linear echogenicity. In 26 patients aged one to 14 years old, the last follow-up US was performed after 6 to 132 months and compared with the initial US. The lesion was considered to decrease in size if there was a change of more than 2 mm in any dimension. The margin change was divided into well-defined and indistinct, blurred. When the echogenicity changed to a hyperechoic from a characteristic thymic echogenicity pattern, the pattern was considered a hyperechogenic. The changes in size were compared with the changes in shape, margin, and echogenicity pattern. The changes in size, shape, margin, and echogenicity were analyzed the association with the age of last follow-up. Statistical analysis was conducted using the chi-squared test and logistic regression. Results: Fifteen (57.7%) cases were stable in size, and 11 (42.3%) decreased in size, including one that disappeared. Ten (38.5%) cases changed to indistinct margins from initially well-defined margins including one case of initially indistinct margin. Six (23.1%) changed to hyperechogenic, from initially characteristic thymic echogenicity patterns. When follow-up change was compared, decreases in size were significantly associated with lesion changes to indistinct margins (p = 0.004). The age at last follow-up was significantly associated with change to hyperechogenicity (odd ratio, 2.141; 95% confidence interval, 1.144-4.010, p = 0.017). Conclusion: On follow-up US, an intrathyroidal thymus may be decreased in size, with indistinct margins, or show changes to a hyperechoic mass. Decreases in size may be associated with changing to indistinct margins, and changes to hyperechogenicity may be associated with increasing age.

• Journal of Welding and Joining
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• v.26 no.1
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• pp.63-68
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• 2008

This paper has aimed to prevent excessive heat input by controlling arc distribution and heat input capacity with pulse GTAW in order to improve weld quality in 0.08mm pressure gauge diaphragm and flange welding parts. A design of experiment was designed using Box-Behnken method to optimize a welding process. The pulse GTAW parameters such as pulse current, base current, pulse duty, frequency and welding speed were set to input variables while hydraulic pressure that represents welding characteristics in diaphragm and flange joint were set to output variables. Based on the test result, a second regression equation was obtained between input and output variables and turned out significant. Besides, an influence of parameters has been confirmed through response surface analysis using the second-order regression equation and optimum welding condition was obtained through a grid-search method. The optimum welding condition was set to pulse current 84.4(A), base current 29.6(A), pulse duty 58.8(%), frequency 10(%), and welding speed 596(mm/min). Then, decent bead shape was acquired with no excessive heat input under the $2.3kgf/cm^2$ of hydrostatic pressure.

• Journal of the Korean Society of Clothing and Textiles
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• v.36 no.6
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• pp.616-630
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• 2012

This study examines the impact of consumer knowledge and familiarity with private label brands (PLBs) on perceptions and preferences toward PLBs and patronage intentions; in addition, it examines the incremental effects of a department store image over consumer knowledge and familiarity with perceptions, preferences, and patronage intentions. This study focused on midscale department store PLBs of apparel products and middle age consumers between the ages of 30 and 50 who are the main consumer group of private label brands of apparel products. A structured questionnaire was developed and data were collected from a convenience sample of 257 female consumers between the ages of 35 and 54, living in the Southeastern United States. A factor analysis identified the dimensions of department store image constructs; in addition, a hierarchical regression and multiple regression analyses examined the hypotheses. Consumer knowledge and familiarity with PLBs at department stores is recognized as a major determinant to shape consumer perceptions of and preferences for the PLBs as well as patronage intentions. The present study reveals the significant incremental effect of a store image on consumer preferences, perceptions, and patronage intentions beyond that explained by consumer knowledge and familiarity about PLBs. The study reveals that, among four store image constructs, the store atmosphere and store service factors had significant positive effects on consumer perceptions of PLBs. Store service and atmospheric aspects also affect consumer patronage intentions toward PLBs. The price factor shows a significant and positive influence on the preference consumers have for PLBs, but not on perceptions and patronage intentions. This study has practical implications for department store executives and managers on how to allocate resources in order to increase positive consumer perceptions toward PLBs, preferences over other brands, and patronage intentions of PLBs at a store as well as how to create effective store environments to promote PLBs.

• Fashion & Textile Research Journal
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• v.21 no.6
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• pp.789-799
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• 2019

This study classified and analyzed the upper body types of 7-13 years old elementary school boys, using 3D data from the 6th Size Korea. The results of this study are as follows. Seven factors were extracted from the factorial analysis as an independent factor for a cluster analysis. The cluster analysis generated four body types. Type 1 has large ratio of front and back depth as well as circumference, with a front protrusion. In Type 2, the vertical value of upper torso is longer than average; in addition, its flatness is the largest and produces a thin body type. Type 3 has a smaller flatness in the bust, waist, abdomen and hip than other types, while also having the largest BMI. Type 4 is characterized by a greater shoulder angle than other types and its other factors are close to average. As a result of the logistic regression analysis, the prediction model used eight variables to generate and its accuracy is 88.679%. The classification of upper body types from this study can be used as basic data to improve patternmaking for each body type. The generated prediction model is also expected to be used as a method to help classify upper body types using the eight variables.

• Journal of Wetlands Research
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• v.14 no.3
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• pp.341-352
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• 2012

The purpose of this study is to statistically project future probable rainfall and to quantitatively assess a future flood vulnerability using flood vulnerability model. To project probable rainfall under non-stationarity conditions, the parameters of General Extreme Value (GEV) distribution were estimated using the 1 yr data added to the initial 30 yr base series. We can also fit a linear regression model between time and location parameters after comparing the linear relationships between time and location, scale, and shape parameters, the probable rainfall in 2030 yr was calculated using the location parameters obtained from linear regression equation. The flood vulnerability in 2030 yr was assessed inputted the probable rainfall into flood vulnerability assessment model suggested by Jang and Kim (2009). As the result of analysis, when a 100 yr rainfall frequency occurs in 2030 yr, it was projected that vulnerability will be increased by spatial average 5 % relative to present.

• Journal of Biosystems Engineering
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• v.20 no.4
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• pp.351-359
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• 1995

In pressure cooling system, produce were packed in vented box and cooled rapidly by producing a difference in air pressure on opposite faces of stacks of vented box. So, energy requirements and performance of pressure cooling system depended upon the air flow rate and the static pressure drop through packed produce in vented box. The static pressure drop across packed produce in vented box normally depended upon air flow rate, vent area of box and conditions of produce bed (depth, porosity, stacking patterns, size and shape of products) in box. The objectives of this study were to investigate the effect of vent area and air flow rate on airflow resistance of empty box and packed produce in vented box, and to investigate the relationship between the air flow resistance of packed products in vented box and sum of air flow resistance of empty box only and products in bulk only. Mandarins and tomatoes were used in the experiment. The airflow rate were in the range of 0.02~1.0$m^3$/s.$m^2$, the opening ratio of vent hole were in the range of 2.5~20% of the side area. The results were summerized as follows. 1. The pressure drops across vented box increased in proportion to superficial air velocity and decreased in proportion to opening ratio of vent hole. A regression equation to calculate airflow resistance of vented box was derived as a function of superficial air velocity and opening ratio of vent hole. 2. The pressure drops across packed produce in vented box increased in proportion to superficial air velocity and decreased in proportion to opening ratio of vent hole. 3. Because of the air velocity increase in the vicinity of vent hole in box, the airflow resistances of packed products in vented box were always higher than sum of air flow resistance of empty box only and products in bulk only. 4. Based on the airflow resistance of empty box and products in bulk, a regression equation to calculate airflow resistance of packed products in vented box was derived.

• Journal of Korea Technology Innovation Society
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• v.12 no.3
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• pp.564-581
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• 2009

The paper investigates the determinants of firm's standardization activity in the Korean manufacturing industry. Standardization variables as dependent ones are standardization management at the firm level, accreditation activity, domestic standards utilization, and international standards utilization. The independent variables include innovative activities(R&D intensity and patent application), firm size, export ratio, networks, and firm's organization characteristics. We estimated the logistic regression model, using the data from 636 Korean manufacturing firms. The empirical findings are as follows. First, R&D intensity doesn't have any influence on standardization activities, except the utilization of international standards. Second, patent application has a positive effect on standardization management at the firm level and accreditation activity, respectively. Third, the inverse U-shape hypothesis relating firm size is accepted for standardization management and accreditation, respectively. Fourth, the level of chief executive officer's interest on standardization is a very important factor in determining firms' efforts to participate standardization process, regardless of types of standardization activity.

• Research in Community and Public Health Nursing
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• v.30 no.4
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• pp.449-459
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• 2019

Purpose: The aim of this study is to explore different types of self-rated health trajectories among one-person households in Korea. Methods: We used five time-point data derived from Korea Health Panel (2011~2015). A latent growth curve modeling was used to assess the overall feature of self-rated health trajectory in one-person households, and a latent class growth modeling was used to determine the number and shape of trajectories. We then applied multinomial logistic regression on each class to explore the predicting variables. Results: We found that the overall slope of self-rated health in one-person households decreases. In addition, latent class analysis demonstrated three classes: 1) High-Decreasing class (i.e., high intercept, significantly decreasing slope), 2) Moderate-Decreasing class (i.e., average intercept, significantly decreasing slope), and 3) Low-Stable class (i.e., low intercept, flat and nonsignificant slope). The multinomial logistic regression analysis showed that the predictors of each class were different. Especially, one-person households with poor health condition early were at greater risk of being Low-Stable class compared with High-Decreasing class group. Conclusion: The findings of this study demonstrate that more attentions to one-person households are needed to promote their health status. Policymakers may develop different health and welfare programs depending on different characteristics of one-person household trajectory groups in Korea.

• Journal of Veterinary Clinics
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• v.31 no.1
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• pp.31-35
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• 2014

As with humans, overweight or obesity is a major health concern in the companion animal population. A cross-sectional questionnaire-based survey of dog owners attending primary small animal veterinary practices from different areas in Chuncheon, Kangwon province, Korea was undertaken to explore the relationships between socioeconomic and other relevant risk factors associated with canine obesity. In addition, the author was to estimate the prevalence of obesity compared to published literatures for dogs. Owners were asked about dog age, neuter status, feeding habits, dog exercise, household income and owner age. The body condition score (BCS) of the dogs was also assessed. Multivariable binary logistic regression was used to assess the association between BCS and potential risk factors controlling for confounding variables, using odds ratios (OR), 95% confidence intervals (CIs). A total of 275 dogs (136 males and 139 females) aged 1-12 years (mean age $5.6{\pm}3.7$ years) were surveyed in 2013. Of these, 46.9% of dogs (n = 129) were classed as an ideal body shape (BCS = 3), 30.9% (n = 85) were overweight (BCS = 4), 8.4% (n = 23) were obese (BCS = 5) and 13.8% (n = 38) were underweight (BCS = 1 or 2). Neutered males and spayed females had the highest prevalence of obesity (43.4% and 33.9%); intact females had the lowest prevalence of obesity (31.6%). In univariable model, risk factors associated with canine obesity are multifactorial and include owner income, owner age, age of dog, neuter status, frequency of feeding per day, frequency of snacks and consultation with veterinarian on dog's weight. In final multivariable logistic regression model, dogs whose owners reported no consultation with veterinarians for weight management were significantly more likely to be obesity than ideal (OR = 7.6, 95% CI, 4.2-13.8; p < 0.0001). This study showed a high prevalence of obesity in domestic companion dogs. Since this was a cross-sectional study with small samples, the association of canine obesity with risk factors warrants more research. To the author's best knowledge, this is the first Korean study on dog body condition and obesity.

• The Journal of Advanced Prosthodontics
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• v.10 no.5
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• pp.381-387
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• 2018

PURPOSE. Cement-retained implant prostheses can lack proper retrievability during repair, and residual cement can cause peri-implantitis. The purpose of this in vitro study was to evaluate the influence of abutment height and convergence angle on the retrievability of cement-retained implant prostheses with lingual slots, known as retrievable cement-type slots (RCS). MATERIALS AND METHODS. We fabricated six types of titanium abutments (10 of each type) with two different heights (4 mm and 6 mm), three different convergence angles ($8^{\circ}$, $10^{\circ}$, and $12^{\circ}$), a sloped shoulder margin (0.6 mm depth), a rectangular shape ($6mm{\times}6.5mm$) with rounded edges, and a rectangular ledge ($2mm{\times}1mm$) for the RCS. One monolithic zirconia crown was fabricated for each abutment using a dental computer-aided design/computer-aided manufacturing system. The abutments and crowns were permanently cemented together with dual-curing resin cement, followed by 24 hours in demineralized water at room temperature. Using a custom-made device with a slot driver and torque gauge, we recorded the torque ($N{\cdot}cm$) required to remove the crowns. Statistical analysis was conducted using multiple regression analysis and Mann-Whitney U tests (${\alpha}=.05$). RESULTS. Removal torques significantly decreased as convergence angles increased. Multiple regression analysis showed no significant interaction between the abutment height and the convergence angle (Durbin-Watson ratio: 2.186). CONCLUSION. Within the limitations of this in vitro study, we suggest that the retrievability of cement-retained implant prostheses with RCS can be maintained by adjusting the abutment height and convergence angle, even when they are permanently cemented together.