• The Korean Journal of Financial Management
• /
• v.22 no.1
• /
• pp.1-36
• /
• 2005

In this study, we analyzed determinant factors of leverage ratio and debt maturity for Korean firms in the simultaneous equation system using 2SLS (two stage least square) method under assumption that two variables are jointly determined in the capital structure decision. As a result of the analysis, we found that leverage ratio and debt maturity are positively related. Also, as for determinant factors of debt maturity, agency cost hypothesis, asset maturity matching hypothesis, signalling and liquidity risk hypothesis are all generally supported, and further leverage ratio are significantly positively related with firm size, but negatively related with default risk. However, when we divided samples into groups according to bank debt level and Chaebul affiliation, with contrast to existing study which worked on similar issues with OLS, we found no evidence supporting the argument that the information asymmetry problem is less severe in firms with more bank debt, whereas information asymmetry and financial constraint problems are more severe in non-Chaebul affiliated firms.

• Korean Journal of Social Welfare
• /
• v.56 no.4
• /
• pp.215-238
• /
• 2004

The purpose of this paper is to examine the impact of conflict and nurturing factors for the divorced parent on the behavioral adaptation of their children. The participants in this study include 216 children in divorced families nationwide. Structural Equation Modeling with LISREL8 was used for statistical method. In order to achieve the purpose, researchers firstly tried to test a construct validity of conceptual variables(parental conflict, negative attitude of parental nurturing, child's belief about parental divorce, child's aggression and child's delinquence) by employing exploratory factor analysis(EFA) and confirmatory factor analysis(CFA). Result showed that all the five conceptual variables were discriminated. It was identified as the fit index of path structure was good(CFI=.955, NNFI=.947, RMSEA=.046). The specific result were as follows: 1. the parental conflict(${\xi}1$) was directly related to the negative attitude of parental nurturing(${\eta}1$) and the child's belief about parental divorce(${\eta}2$). 2. the parental conflict(${\xi}1$) was indirectly related to child's belief about parental divorce(${\eta}2$), the child's aggression(${\eta}3$) and delinquence(${\eta}4$). 3. the negative attitude of parental nurturing(${\eta}1$) was directly related to the child's belief about parental divorce(${\eta}2$). 4. the negative attitude of parental nurturing(${\eta}1$) was indirectly related to the child's aggression(${\eta}3$) and delinquence(${\eta}4$). Lastly, and, the child's belief about parental divorce(${\eta}2$) was directly related to the child's aggression(${\eta}3$) and delinquence(${\eta}4$). Researchers also identified the mediating effect of the parental nurturing between parental conflict and child's belief about parental divorce. On the basis of these results, this article provided some suggestions for promoting of children welfare.

• Journal of Korean Society of Forest Science
• /
• v.88 no.1
• /
• pp.38-46
• /
• 1999

Canopy structure conductances of a Norway spruce forest in the Solling Hills(Central Germany) and Central Forest Biosphere Reserve(320km to the north-west from Moscow) were derived from LE(latent heat flux) and H(sensible heat flux) fluxes measured(by Eddy correlation technique and energy balance method) and modelled(by one dimensional non-steady-state) SVAT(soil-vegetation-atmosphere-transfer) model(SLODSVAT) using a rearranged Penman-Monteith equation("Big-leaf" approximation) during June 1996. They were compared with canopy stomatal conductances estimated by consecutive intergrating the stomatal conductance of individual needles over the whole canopy("bottom-up" approach) using SLODSVAT model. The result indicate a significant difference between the canopy surface conductances derived from measured and modelled fluxes("top-down" approach) and the stomatal conductances modelled by the SLODSVAT("bottom-up" approach). This difference was influenced by some nonphysiological factors within the forest canopy(e.g. aerodynamic and boundary layer resistances, radiation budget, evapotranspiration from the forest understorey). In general, canopy surface conductances derived from measured and modelled fluxes exceeded canopy stomatal conductance during the whole modelled period, The contribution of the understorey's evapotranspiration to the total forest evapotranspiration was small (up to 5-9% of the total LE flux) and was not depended on total radiation balance of forest canopy. Ignoring contribution of the understorey's evapotranspiration resulted in an overestimation of the canopy surface conductance for a spruce forest up to 2mm/s(about 10-15%).

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2008.06a
• /
• pp.236-236
• /
• 2008

(Bi,La)$Ti_3O_{12}$(BLT) thin film is one of the most attractive materials for ferroelectric random access memory (FRAM) applications due to its some excellent properties such as high fatigue endurance, low processing temperature, and large remanent polarization [1-2]. The authors firstly investigated and reported the damascene process of chemical mechanical polishing (CMP) for BLT thin film capacitor on behalf of plasma etching process for fabrication of FRAM [3]. CMP process could prepare the BLT capacitors with the superior process efficiency to the plasma etching process without the well-known problems such as plasma damages and sloped sidewall, which was enough to apply to the fabrication of FRAM [2]. BLT-CMP characteristics showed the typical oxide-CMP characteristics which were related in both pressure and velocity according to Preston's equation and Hernandez's power law [2-4]. Good surface roughness was also obtained for the densification of multilevel memory structure by CMP process [3]. The well prepared BLT capacitors fabricated by CMP process should have the sufficient ferroelectric properties for FRAM; therefore, in this study the electrical properties of the BLT capacitor fabricated by CMP process were analyzed with the process parameters. Especially, the effects of CMP pressure, which had mainly affected the removal rate of BLT thin films [2], on the electrical properties were investigated. In order to check the influences of the pressure in eMP process on the ferroelectric properties of BLT thin films, the electrical test of the BLT capacitors was performed. The polarization-voltage (P-V) characteristics show a decreased the remanent polarization (Pr) value when CMP process was performed with the high pressure. The shape of the hysteresis loop is close to typical loop of BLT thin films in case of the specimen after CMP process with the pressures of 4.9 kPa; however, the shape of the hysteresis loop is not saturated due to high leakage current caused by structural and/or chemical damages in case of the specimen after CMP process with the pressures of 29.4 kPa. The leakage current density obtained with positive bias is one order lower than that with negative bias in case of 29.4 kPa, which was one or two order higher than in case of 4.9 kPa. The high pressure condition was not suitable for the damascene process of BLT thin films due to the defects in electrical properties although the better efficiency of process. by higher removal rate of BLT thin films was obtained with the high pressure of 29.4 kPa in the previous study [2].

• Korean Chemical Engineering Research
• /
• v.55 no.2
• /
• pp.201-213
• /
• 2017

Water is removed from crude oil containing water by using oil separator. This study aims to develop a three-dimensional (3D) Eulerian computational fluid dynamics (CFD) model to predict the separation efficiency of air-water-oil separator. In the incompressible, isothermal and unsteady-state CFD model, air is defined as continuous phase, and water and oil are given as dispersed phase. The momentum equation includes the drag force, lift force and resistance force of porous media. The standard k-${\varepsilon}$ model is used for turbulence flow. The exit pressures of water and oil play an important role in determining the liquid level of the oil separator. The exit pressures were identified to be 6.3 kPa and 5.1 kPa for water and oil, respectively, to keep a liquid level of 25 cm at a normal operating condition. The time evolution of volume fractions of air, water and oil was investigated. The settling velocities of water and oil along the longitudinal separator distance were analyzed, when the oil separator reached a steady-state. The oil separation efficiency obtained from the CFD model was 99.85%, which agreed well with experimental data. The relatively simple CFD model can be used for the modification of oil separator structure and finding optimal operating conditions.

• Journal of the Korea Institute of Building Construction
• /
• v.20 no.1
• /
• pp.43-51
• /
• 2020

The main purpose of protective facility for small military unit is to provide the protection of not all the weapons system but the near-miss bullet in Korean army. In particular about the small caliber bullets, especially KM80 in Korea, there were many studies that both of the experiential and structural design methods dose not reflect enough the military threat. For that reason, a new equation to calculate effective anti-piercing depths for RC slabs against small caliber bullets is proposed in earlier research with actual shooting test. But, the test only considers the strength of concrete without the thickness of concrete, types of aggregate, the angle of yaw of bullet, high-strength concrete, etc. Therefore, this study evaluated the ballistic resistance performance by thickness and proportion of magnetic aggregate of concrete. As a result, we identified two major statistical estimations that the error of piercing depth by the angle of yaw of bullet could be cancelled by barrage and the thickness and proportion of magnetic aggregate of concrete dose not effect on the protection ability of concrete structure.

• Journal of Digital Convergence
• /
• v.11 no.11
• /
• pp.397-407
• /
• 2013

The purpose of this study was to develop comprehensive model which could represent service quality, satisfaction and loyalty in ubiquitous living English experience learning center, and to analyze an influence of service quality of elementary school students attending that center on satisfaction. The variables were extracted in connection with service quality, satisfaction and loyalty in ubiquitous living English experience learning center, and relations among those variables were examined. The study verified causality and influences between variables using feasibility of variables and structural equation thru confirmatory factor analysis, based on questionnaires of 262 students who attended ubiquitous living English experience learning center. The suggestion of the study on ubiquitous living English experience learning center of elementary school students are as follows. Programs in relation with living English should run more efficiently to expand ubiquitous living English experience learning center. More important is that guidelines or orientation for students to recognize how to use the programs be needed. Also, this study shows that the educational performance and satisfaction are found to be very large, and participation in the program of that center needs to be encouraged in terms of schools.

• Journal of The Korean Astronomical Society
• /
• v.36 no.3
• /
• pp.89-95
• /
• 2003

Observations of dark matter dominated dwarf and low surface brightness disk galaxies favor density profiles with a flat-density core, while cold dark matter (CDM) N-body simulations form halos with central cusps, instead. This apparent discrepancy has motivated a re-examination of the microscopic nature of the dark matter in order to explain the observed halo profiles, including the suggestion that CDM has a non-gravitational self-interaction. We study the formation and evolution of self-interacting dark matter (SIDM) halos. We find analytical, fully cosmological similarity solutions for their dynamics, which take proper account of the collisional interaction of SIDM particles, based on a fluid approximation derived from the Boltzmann equation. The SIDM particles scatter each other elastically, which results in an effective thermal conductivity that heats the halo core and flattens its density profile. These similarity solutions are relevant to galactic and cluster halo formation in the CDM model. We assume that the local density maximum which serves as the progenitor of the halo has an initial mass profile ${\delta}M / M {\propto} M^{-{\epsilon}$, as in the familiar secondary infall model. If $\epsilon$ = 1/6, SIDM halos will evolve self-similarly, with a cold, supersonic infall which is terminated by a strong accretion shock. Different solutions arise for different values of the dimensionless collisionality parameter, $Q {\equiv}{\sigma}p_br_s$, where $\sigma$ is the SIDM particle scattering cross section per unit mass, $p_b$ is the cosmic mean density, and $r_s$ is the shock radius. For all these solutions, a flat-density, isothermal core is present which grows in size as a fixed fraction of $r_s$. We find two different regimes for these solutions: 1) for $Q < Q_{th}({\simeq} 7.35{\times} 10^{-4}$), the core density decreases and core size increases as Q increases; 2) for $Q > Q_{th}$, the core density increases and core size decreases as Q increases. Our similarity solutions are in good agreement with previous results of N-body simulation of SIDM halos, which correspond to the low-Q regime, for which SIDM halo profiles match the observed galactic rotation curves if $Q {\~} [8.4 {\times}10^{-4} - 4.9 {\times} 10^{-2}]Q_{th}$, or ${\sigma}{\~} [0.56 - 5.6] cm^2g{-1}$. These similarity solutions also show that, as $Q {\to}{\infty}$, the central density acquires a singular profile, in agreement with some earlier simulation results which approximated the effects of SIDM collisionality by considering an ordinary fluid without conductivity, i.e. the limit of mean free path ${\lambda}_{mfp}{\to} 0$. The intermediate regime where $Q {\~} [18.6 - 231]Q_{th}$ or ${\sigma}{\~} [1.2{\times}10^4 - 2.7{\times}10^4] cm^2g{-1}$, for which we find flat-density cores comparable to those of the low-Q solutions preferred to make SIDM halos match halo observations, has not previously been identified. Further study of this regime is warranted.

• Culinary science and hospitality research
• /
• v.17 no.5
• /
• pp.92-107
• /
• 2011

The purpose of this study was to understand the effect of the characteristics of coupons purchased through a social shopping site upon customer satisfaction and future behavior intention. Based on total 332 samples who had bought franchise restaurant coupons and used them before, this study reviewed reliability and fitness of the research model and verified total 4 hypotheses with AMOS and SPSS program. The hypothesized relationships among the models were tested simultaneously by using a structure equation model(SEM). The proposed model provided an adequate fit to the data, ${\chi}^2$=309.795(df=103, p<.001), CMIN/DF=3.008, RMR=.103, GFI=.912, NFI=.927, CFI=.950, RMSEA=.074. The result showed that the coupon proneness(${\beta}$=.645) and price sensitivity(${\beta}$=-.315) had a significant influence on restaurant satisfaction(p<.001) and only coupon proneness(${\beta}$=1.040) had a significant influence on coupon satisfaction(p<.001). Also, restaurant satisfaction had a positive significant influence on restaurant customers' revisit intention(${\beta}$=.603, p<.001) and coupon users' repurchase intention(${\beta}$=.335, p<.001). Furthermore, coupon satisfaction had a positive significant influence on coupon repurchase intention(${\beta}$=.353, p<.001) but had a negative significant influence on restaurant revisit intention(${\beta}$=-.263, p<.001). Limitations and future research directions were also discussed.

• Culinary science and hospitality research
• /
• v.21 no.1
• /
• pp.174-190
• /
• 2015

This study looks at a causal relationships between service quality and behavior intention(re-visiting, recommendation, loyalty) to attract customers and make them loyal customers in the context of Japanese restaurants. The study includes 250 consumers who have experience in Japanese restaurants located in Busan to conduct survey for empirical testing. To achieve the purpose of current study, frequency test, multiple/simple regression analysis, and factor analysis were conducted with SPSS 18.0 statistical program. Structure Equation Model analysis has been employed for hypothesis testing. Results showed that the service of employee has been recognized as an primary factor among elements of Japanese restaurants' service quality to satisfy customer, and employee's service is the strongest affecting factor to consumers' behavioral intention as well. In addition, the food quality identified as an the strongest factor that affects behavior intention, whereas physical environment is the lowest factor. It can be interpreted that the quality of food is very important element to make their consumers revisit or recommend the restaurant to others. In this study, especially, the service of the employee has been identified as an key factor to customer satisfaction and behavioral intention. Therefore, CEO or restaurateurs of Japanese restaurants have to consider the importance of service quality and food quality to make more patrons as well as their business success.