• The korean journal of orthodontics
• /
• v.38 no.2
• /
• pp.95-103
• /
• 2008

Objective: This study was performed to investigate the labio/buccal clinical crown curvatures of Korean permanent teeth and to obtain the curve-ratio data in an attempt to fabricate bracket bases fit for each individual Korean permanent tooth. Methods: Three-dimensional digital models were made from 30 sets of dental casts with normal anatomic structures. According to the FA points, horizontal and vertical reference planes were established and lines were drawn on the tooth surfaces in reference to these planes. The curvature was expressed as the coefficient of a quadratic equation. Lines mesial, distal, gingival and occlusal to the horizontal, vertical reference planes and the FA point were drawn. Results: The curvature measured for each line revealed that there are no significant differences between male and female, except for maxillary canines and maxillary second bicuspids (p > 0.05). There were notable differences in the mesio-distal or gingivo-occlusal curvatures among the mandibular lateral incisors, maxillary canines, maxillary and mandibular first and second bicuspids and first molars (p < 0.05). Conclusions: The labial & buccal crown curvatures of teeth in Korean normal occlusion were measured on the mesial and distal, gingival and occlusal sides respectively in this study. Based on these data, a SWA can be developed to fit the individual features of Korean tooth crowns.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.23 no.5
• /
• pp.345-357
• /
• 2011

Recently, as part of diversifying energy sources and earth environmental issues, technology development of new renewable energy using wave energy is actively promoted and commercialized around Europe and Japan etc. In particular, OWC(Oscillating Water Column) wave power generation system using air flow induced by vertical movement of the water surface by waves in an air-chamber within caisson is known as the most efficient wave energy absorption device and therefore, is one of the wave power generation apparatus the closest to commercialization. This study examines air flow velocity, which operates turbine(Wells turbine) directly in oscillating water column type wave power generation structure from two-and three-dimensional numerical experiments and discusses optimal shape of oscillating water column type wave power generation structure by estimating the maximum flow rate of air according to change in shape. The three-dimensional numerical wave flume was applied in interpretation for this study which is the model for the immiscible two-phase flow based on the Navier-Stokes Equation. From this, it turned out that size of optimal shape appears differently according to the incident wave period and air flow is maximized at the period where minimum reflection ratio occurs.

• Korean Journal of Social Welfare Studies
• /
• v.43 no.2
• /
• pp.207-233
• /
• 2012

The purpose of this study is to understand direct and indirect impact and the paths of community participation and social capital, which affect improvement of single mother's community participation factors, social capital, and empowerment. To accomplish this purpose structural relationships between single mother's community participation factors, social capital and empowerment have been analyzed. For the analysis 420 single mothers, who had participated various types of communities, were surveyed and structural equation modeling had been used and optical theory structure model(χ²=86.851, df=28, GFI=.958, CFI=.944), which explains the structural relationship among the factors, had been chosen. From the result, first, there was differences between empowerment and community participation levels, which is single mothers' community participation factors, of the impact on social capital and empowerment. Empowerment level of community, which was mediated by community participation level and social capital, affected empowerment, in the other hand, community participation level affected empowerment more directly than the impact of social capital. Second, single mothers' community participation factor affected more improvement of empowerment when it mediated by the accumulation of social capital. Third, single mothers' social capital directly affected the most improvement of empowerment. Based on the fact the implications of the study were presented.

• Applied Chemistry for Engineering
• /
• v.34 no.2
• /
• pp.137-143
• /
• 2023

In this study, natural surfactants were extracted from Medicago sativa L. The O/W emulsification processes with the extracted natural surfactants were optimized using central composite design model-response surface methodology (CCD-RSM) and a 95% confidence interval was used to confirm the reasonableness of the optimization. Herein, independent parameters were the ratio of saponins to total surfactant (P), amount of surfactant (W), and emulsification speed (R), whereas the reaction parameters were the emulsion stability index (ESI), mean droplet size (MDS), and viscosity (V). Using the multiple reaction, the optimal conditions for the ratio of saponins to total surfactant, amount of surfactant, and emulsification speed for O/W emulsification were 49.5%, 9.1 wt%, and 6559.5 rpm, respectively. Under these optimal conditions, the expected values of ESI, MDS, and V as the reaction parameters were 89.9%, 1058.4 nm, and 1522.5 cP, respectively. The values of ESI, MDS, and V from these expected values were 88.7%, 1026.4 nm, and 1486.5 cP, respectively, and the average experimental error for validating the accuracy was about 2.3 (± 0.4)%. Therefore, it was possible to design an optimization process for evaluating the O/W emulsion process with Medicago sativa L. using CCD-RSM.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.30 no.5B
• /
• pp.459-469
• /
• 2010

This study is to develop a grid-based daily runoff model considering seasonal vegetation canopy condition. The model simulates the temporal and spatial variation of runoff components (surface, interflow, and baseflow), evapotranspiration (ET) and soil moisture contents of each grid element. The model is composed of three main modules of runoff, ET, and soil moisture. The total runoff was simulated by using soil water storage capacity of the day, and was allocated by introducing recession curves of each runoff component. The ET was calculated by Penman-Monteith method considering MODIS leaf area index (LAI). The daily soil moisture was routed by soil water balance equation. The model was evaluated for 930 $km^2$ Yongdam watershed. The model uses 1 km spatial data on landuse, soil, boundary, MODIS LAI. The daily weather data was built using IDW method (2000-2008). Model calibration was carried out to compare with the observed streamflow at the watershed outlet. The Nash-Sutcliffe model efficiency was 0.78~0.93. The watershed soil moisture was sensitive to precipitation and soil texture, consequently affected the streamflow, and the evapotranspiration responded to landuse type.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.25 no.5
• /
• pp.335-347
• /
• 2013

In February 2008, high storm waves due to a developed atmospheric low pressure system propagating from the west off Hokkaido, Japan, to the south and southwest throughout the East Sea (ES) caused extensive damages along the central coast of Japan and along the east coast of Korea. This study consists of two parts. In the first part, we estimate extreme storm wave characteristics in the Toyama Bay where heavy coastal damages occurred, using a non-hydrostatic meteorological model and a spectral wave model by considering the extreme conditions for two factors for wind wave growth, such as wind intensity and duration. The estimated extreme significant wave height and corresponding wave period were 6.78 m and 18.28 sec, respectively, at the Fushiki Toyama. In the second part, we perform numerical experiments on wave-structure interaction in the Fushiki Port, Toyama Bay, where the long North-Breakwater was heavily damaged by the storm waves in February 2008. The experiments are conducted using a non-linear shallow-water equation model with adaptive mesh refinement (AMR) and wet-dry scheme. The estimated extreme storm waves of 6.78 m and 18.28 sec are used for incident wave profile. The results show that the Fushiki Port would be overtopped and flooded by extreme storm waves if the North-Breakwater does not function properly after being damaged. Also the storm waves would overtop seawalls and sidewalls of the Manyou Pier behind the North-Breakwater. The results also depict that refined meshes by AMR method with wet-dry scheme applied capture the coastline and coastal structure well while keeping the computational load efficiently.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.29 no.12 s.148
• /
• pp.1571-1581
• /
• 2005

In a highly competitive marketplace, U.S. retailers are challenged to attract, recruit, and retain a skilled workforce. The purpose of our research was to examine the impact of young retail employees' work experiences on their job performance, job satisfaction, and career intention using a comprehensive approach to model development. The model was developed in three phases over a four-year period using both qualitative and quantitative methodologies. During Phase 1, we conducted focus group interviews to guide the development of the questionnaire. Work experience was initially operationalized as role conflict, role ambiguity, supervisory support, and work involvement. Using a student sample(n=470) from U.S. universities, we employed multiple regression to determine the significance of relationships between their work experience, job satisfaction, and retail career intention. During Phase 2, we expanded our investigation to include retail work experiences of teens employed while they were in high school. The teen sample(n=898) was drawn from students enrolled in work-study programs in 16 U.S. high schools, and data were analyzed using structural equation modeling (hereafter SEM). During Phase 3, we expanded our model to include two new variables, job characteristics and job performance. Based on a national sample(n=803) of U.S. university students, we employed SEM to holistically determine if retail employees' work experience impacted their job performance, job satisfaction, and retail career intention. During each phase, job satisfaction consistently was the superior antecedent of retail career intention. Among the work experience variables, supervisory support had a positive impact on job satisfaction, while role conflict, role ambiguity, and work involvement exhibited inconsistent effects on job outcomes. The strong relationship between job satisfaction and retail career intention should make job satisfaction a priority for retailers.

• Journal of Agricultural Extension & Community Development
• /
• v.21 no.2
• /
• pp.29-56
• /
• 2014

This study conduct for 200 farmhouses who didn't accept new technology like mulberry Protected Cultivation. Through research model combined Innovation diffusion theory(IDT) and Technology Acceptance Model(TAM), it analysed which factors affect for new technology acceptance and diffusion. To verify relations between external factors which affect new technology acceptance and diffusion by endogenous variables such as perceived usefulness, perceived ease of use and perceived riskiness, with external factors, mothed used to analyse it. Most of adopted variables were showed positive results except for individual innovativeness and reliability. Based on the results of these analyses, we can suggest rapid. First, technique diffusion agents should have heighten the level of expertise and technology, and build up the network to solve difficulties with technique supply with mulberry farmhouses. Secondly farmhouses of mulberry outdoor cultivation showed positive attitude protected cultivation, but negative attitude it bacause of the burden of facilities investment. Thus, it is needed to capital investment for individual farmhouse hold. Finally, through cultivation technology education, field trip about mulberry protected cultivation, we can diffuse technology receive for negative farmers.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.23 no.2
• /
• pp.171-181
• /
• 2011

Recently, many studies have been attempted to save the cost of production and to build the ocean energy power generating system. The low-reflection structure with the wall-typed curtain which has a wave power generation system of OWC is known as the most effective energy conversion system. A three-dimensional numerical model was used to understand the characteristics of velocity of flows about compressed air and to estimate the pressure acting on the low-reflection structure due to the short-period waves. The three-dimensional numerical wave flume which is the model for the immiscible two-phase flow was applied in interpretation for this. The numerical simulation showed well about the changes in velocity of compressed air and the characteristics of pressure according to the change in the wave height and depth of the curtain wall. Additionally, the results found that there was the point of the maximum velocity of the compressed air when the reflection coefficient is at its lowest point.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.2
• /
• pp.353-358
• /
• 2020

The new sales method of social commerce in food service market is growing steadily. Over 50 percent of the social commerce market is food service product. Food service companies are using social commerce, which is discount sales, as a marketing tool. There are many food service companies using social commerce as a sales and marketing tool. However, little research has investigated food service customers. Thus, this study suggests how food service customer's purchasing factor affects customer's satisfaction and loyalty of the supplier and business operator. Social commerce's purchasing characteristic factors are selected based on a previous study. Purchasing factor is divided into supplier and business operator side and the impact of the relationships between its subordinate factors (price discount, offering diversity, mutual action, brand intimacy) and customer's satisfaction is analyzed. As a result, price discount and brand intimacy show higher results. Offering diversity and brand intimacy of purchasing factor on business operator side shows a higher impact on the relationship between loyalty and ?? (Ed- 'the relationship between A and B'; what is B?). The study implications are as follows. The food service industry should establish different marketing strategies to apply social commerce and compare with social commerce business operators, because the actual place where customers use food service is food service restaurants and not just social commerce websites.