• 산업경영시스템학회지
• /
• 제41권4호
• /
• pp.81-90
• /
• 2018

Modern investment theory has empirically proved that stock returns can be explained by several factors such as market risk, firm size, and book-to-market ratio. Other unknown factors affecting stock returns are also believed to still exist yet to be found. We believe that one of such factors is the operational efficiency of firms in transforming inputs to outputs, considering the fact that operations is a fundamental and primary function of any type of businesses. To support this belief, this study intends to empirically study the relationship between firm efficiency and stock price performance. Firm efficiency is measured using data envelopment analysis (DEA) with inputs and outputs obtained from financial statements. We employ cross-efficiency evaluation to enhance the discrimination power of DEA with a secondary objective function of aggressive formulation. Using the CAPM-based performance regression model, we test the performance of equally weighted portfolios of different sizes selected based upon DEA cross-efficiency scores along with a buy & hold trading strategy. For the empirical test, we collect financial data of domestic firms listed in KOSPI over the period of 2000~2016 from well-known financial databases. As a result, we find that the porfolios with highly efficient firms included outperform the benchmark market portfolio after controlling for the market risk, which indicates that firm efficiency plays a important role in explaining stock returns.

• 한국보육지원학회지
• /
• 제15권5호
• /
• pp.23-45
• /
• 2019

Objective: The purpose of this study is to identify the longitudinal reciprocal relationship between young children's vocabulary ability and physical aggression in young children. Methods: Two waves of panel data(2013/2015) from the Panel Study of Korean Children were analyzed in this study by using an adapted version of Autoregressive cross-lagged modeling. A total of 306 five-year-old and seven-year-old preschoolers, and their mothers participated in the study. Autoregressive cross-lagged modeling for multiple groups was conducted by using AMOS 24.0. Results: First, vocabulary ability and physical aggression showed stability over time. Second, young children's vocabulary ability(t) had a statistically significant effect on physical aggression(t+1). Conclusion/Implications: This study confirmed the interrelationships of young children's vocabulary ability and physical aggression by examining longitudinal data using the longitudinal analysis method. This study highlights the importance of developing interventions to support language development with aggressive children. The results of the present study can be used as a source in developing policies for aggressive children and their parents.

• 한국의류학회지
• /
• 제47권4호
• /
• pp.609-624
• /
• 2023

This study aimed to explore the effects of perceived benefits on consumers' attitudes towards cross-border online shopping websites. We also explore whether and how consumers' COVID-19 anxiety and brand familiarity weaken or strengthen the relationship between these perceived benefits and consumer attitudes. A total 319 items of data were used for the final analysis. The perceived benefits of a website were found to have only an indirect effect on purchase intentions by mediating consumers' attitudes toward the site. Competitive pricing of fashion products directly affected purchase intentions. COVID-19 anxiety was found to have a negative moderating influence on the relationship between perceived enjoyment and consumer attitudes, whereas brand familiarity had a positive moderating effect on both the relationships between perceived usefulness and consumers' attitudes toward the site and between perceived ease of use and their site attitude. This study provides useful insights for international e-tailers in developing marketing strategies that attract international consumers. Academically, we have contributed to the existing literature on the perceived benefits of global online shopping and the moderators of consumers' attitudes towards e-commerce sites.

• Structural Engineering and Mechanics
• /
• 제8권5호
• /
• pp.465-476
• /
• 1999

A structural optimization process is presented for arches with varying cross-section. The optimality criteria method is used to develop a recursive relationship for the design variables considering displacement, stresses and minimum depth constraints. The depth at the crown and at the support are taken as design variables first. Then the approach is extended by taking the depth values of each joint as design variable. The curved beam element of constant cross section is used to model the parabolic and circular arches with varying cross section. A number of design examples are presented to demonstrate the application of the method.

• International Journal of Fluid Machinery and Systems
• /
• 제9권3호
• /
• pp.222-228
• /
• 2016

Almost 70% of the earth is covered by the ocean. Extracting the power available in the ocean using a wave energy converter has been seen to be eco-friendly and renewable. This study focuses on developing a method for analyzing a wave energy device that uses a cross-flow turbine. The motion of the ocean wave causes an internal bi-directional flow of water and the cross-flow turbine is able to rotate in one direction. This device is considered of double-hull structure, and because of this structure, sea water does not come into contact with theturbine. Due to this, the problem of befouling on the turbine is avoided. This study shows specific relationship for wave length and several motions.

• 유체기계공업학회:학술대회논문집
• /
• 유체기계공업학회 2006년 제4회 한국유체공학학술대회 논문집
• /
• pp.515-516
• /
• 2006

Internal and inlet flows of a cross-flow fan have been visualized using a particle image velocimetry(PIV) to analyze a relationship with a performance of a room air conditioner(RAC). A test model which has a geometric similarity with the real RAC has been manufactured for the experiment and the flow characteristics have been analyzed with various flow rates and inlet grill angles for the cross-flow fan. The experimental results using the PIV technique have been compared with the existing numerical results. Also, a location and movement of an eccentric vortex which can affect the performance and noise of the RAC has been investigated by the PIV with various flow rates and inlet grill angles.

• Journal of Applied Biological Chemistry
• /
• 제42권2호
• /
• pp.81-84
• /
• 1999

Blood glue was prepared to reutilize porcine blood. Plasma proteins after lyophilization were treated by addition of wood flour, sodium hydroxide, sodium silicate, and hydrated lime to make blood glue with a suitable adhesivity. Characteristics of the prepared blood glue was monitored by measuring the viscosity with time, and the relationship between degree of hydrolysis of plasma proteins by addition of various amounts of sodium hydroxide and adhesivity was studied. To prevent the emission of formaldehyde during manufacturing of plywood by blood glue, the cross-linking reaction of plasma protein with formaldehyde was also examined. Fourier transform infrared, circular dichroism, and fluorescence spectroscopy study showed that blood plasma proteins react with formaldehyde, resulting in removal of formaldehyde by cross-linking reaction.

• Structural Engineering and Mechanics
• /
• 제43권2호
• /
• pp.147-161
• /
• 2012

This paper presents a curvature method for analysis of beam-columns with different materials and arbitrary cross-section shapes and subjected to combined biaxial moments and axial load. Both material and geometric nonlinearities (the p-delta effect in this case) were incorporated. The proposed method considers biaxial curvatures and uniform normal strains of discrete cross-sections of beam-columns as basic unknowns, and seeks for a solution of the column deflection curve that satisfies force equilibrium conditions. A piecewise representation of the beam-column deflection curve is constructed based on the curvatures and angles of rotation of the segmented cross-sections. The resulting bending moments were evaluated based on the deformed column shape and the axial load. The moment curvature relationship and the beam-column deflection calculation are presented in matrix form and the Newton-Raphson method is employed to ensure fast and stable convergence. Comparison with results of analytic solutions and eccentric compression tests of wood beam-columns implies that this method is reliable and effective for beam-columns subjected to eccentric compression load, lateral bracings and complex boundary conditions.

• 한국수학교육학회지시리즈D:수학교육연구
• /
• 제11권2호
• /
• pp.153-163
• /
• 2007

Utilizing the quantitative analysis methodology of questionnaire, the study explores the differences in the factors of achievement motivation, learning mathematics attitude and learning mathematics self-confidence and also the relationship between mathematics academic achievement and these factors in three areas in China. The following conclusions are drawn: 1. The subjects from different development level areas have significant differences in motivation, attitude and self-confidence in mathematics; 2. The subjects from different areas who possess the same ethnic group have significant differences. But the subjects from same area who possess different nationalities have little difference. It can be concluded that that the differences in these factors can be contributed to regional differences, rather than to ethnic differences; 3. The subjects from undeveloped areas have significant gender differences, and the levels of males are higher than those of female.

• 한국감성과학회:학술대회논문집
• /
• 한국감성과학회 2007년도 춘계학술대회 및 국제감성 심포지엄
• /
• pp.157-160
• /
• 2007

Based on Nisbett and his colleagues' theoretical model "Holistic" and "Analytic" which show the differences in cognitive style of Eastern Asian and Westerners, the author hypothesized that the differences in cognitive style of people from diverse cultural backgrounds may influence their perception and usage of webpage. An experiment was carried out and the Eye-gaze device was used to assist to explore the relationship. The results revealed the relationship between cognitive style and webpage design. different cognitive style results different viewing pattern on webpage. Chinese people are more likely to have a holistic view of the whole page first and then focus on detail, while French people tend to read the heading information first and then proceeding down the page. Chinese emphasized the background as well as the whole look and feel of the webpage more, while French noticed the independent contents and element designs more on the webpage.