• Journal of Distribution Science
• /
• v.9 no.3
• /
• pp.15-23
• /
• 2011

This study examined the effects educational service elements have on the satisfaction of educational service; it also analyzed how such satisfaction influenced educational institutions' registration renewal and word-of-mouth communications about the schools. The key factors of educational services included the following four components: physical environment, education programs, instructors, and tuition fee. An investigation into how the factors of educational services in private educational institutions may affect consumer satisfaction was an additional goal of this study. Based on the cause-and-effect analysis of the above constructs, the degree of influence that each of the attributes and the component factors have on consumers' educational service selection, as well as the consumers' satisfaction, were explored. An empirical analysis was conducted on students who were taking classes in cram schools; the analysis was also conducted on the students' parents. The results indicated that the hypotheses regarding the elements of educational service, educational program, and the instructor factor were supported. Furthermore, a hypothesis concerning the effects educational service satisfaction has on re-registration and word of mouth was supported, as well. Upon aggregating the above study results, it was concluded that when determining the effects of satisfaction on educational service, the educational program, and the instructor factor played a crucial role, while physical surroundings and tuition did not. When addressing the influence of the educational services factors on educational services satisfaction, education programs and instructors had a positive effect, whereas physical environment and tuition fee had no statistically significant impact. According to the influence of educational services satisfaction on registration renewal and word-of-mouth effects, educational services satisfaction was found to be a positive influential factor for both. In addition, it was found that satisfaction of educational service had a positive effect on renewing enrollment and forming word-of-mouth recommendations. Although the research seems simple, some theoretical implications can be drawn, as follows: First, one interpretation of the findings that the programs' and instructors' factors had a positive effect on educational services satisfaction but the physical environment and tuition fee factors did not have a significant effect suggests that the greatest influence factors in educational services are educational programs and instructors. Second, increased educational services satisfaction may result in consumer behavior changing, resulting in more registration renewals and more favorable word-of-mouth comments. Third, increased educational services satisfaction may result in enhancing consumer responses, resulting in more registration renewals and more favorable word-of-mouth opinions. Further research directions should include developing an integrated model that will allow for variation over time, before and after purchases, in relation to consumers' choices of educational services.

• Anxiety and mood
• /
• v.7 no.1
• /
• pp.48-53
• /
• 2011

Objective : Korean Version of Beck-II Depression Inventory to verify the reliability and validity of the proposed standards are practical and standardized, cut-off score by establishing a baseline indicating the presence of depression and depression On in the evaluation was to evaluate the clinical usefulness. Methods : 739 patients with major depression using the SCID and normal controls were 302 study subjects. Of patients with clinically significant medical condition, or psychotic disorders, organic mental disorder, epilepsy or seizure disorder, eating disorders are associated with patients taking anti-convulsants experienced in the past, patients were excluded from the study. Results : The main findings of this study were as follows. First, with respect to the KBDI-II items, the correlation between them ranged from 0.51 to 0.74, and was 0.60 over all questions. Further, the overall correlation of the KBDI-II plates showing confidence 'normal' than it was verified that. Second, the BDIII was used in each group to examine internal consistency and thus, whether Cronbach's alpha values were greater than 0.94. Third, the principal component analysis sought to extract factors in a way consistent with the results inspected last 3 factors were extracted and the total variance explained was 47.3%. Fourth, the Cutting calculated the score on the KBDI-II for ROC (Receiver operator characteristic) analysis yielding 18 dot, with the highest sensitivity and specificity was seen. Conclusion : Based on the results of this Study, the KBDI-II cut-off point should be valid as prescribed in 18 is considered.

• The Journal of the Petrological Society of Korea
• /
• v.25 no.3
• /
• pp.169-193
• /
• 2016

In order to characterize the Neotectonic crustal deformation and current stress field in and around the Korean Peninsula and to interpret their tectonic implications, this paper synthetically analyzes the previous Quaternary fault and focal mechanism solution data and recent geotechnical in-situ stress data and examines the characteristics of crustal deformations and tectonic settings in and around East Asia after the Miocene. Most of the Quaternary fault outcrops in SE Korea occur along major inherited fault zones and show a NS-striking top-to-the-west thrust geometry, indicating that the faults were produced by local reactivation of appropriately oriented preexisting weaknesses under EW-trending pure compressional stress field. The focal mechanism solutions in and around the Korean Peninsula disclose that strike-slip faulting containing some reverse-slip component and reverse-slip faulting are significantly dominant on land and in sea area, respectively. The P-axes are horizontally clustered in ENE-WSW direction, whereas the T-axes are girdle-distributed in NNW direction. The geotechnical in-situ stress data in South Korea also indicate the ENE-trending maximum horizontal stress. The current crustal deformation in the Korean Peninsula is thus characterized by crustal contraction under regional ENE-WSW or E-W compression stress field. Based on the regional stress trajectories in and around East Asia, the current stress regime is interpreted to have resulted from the cooperation of westward shallow subduction of the Pacific Plate and collision of Indian and Eurasian continents, whereas the Philippine Sea plate have not a decisive effect on the stress-regime in the Korean Peninsula due to its high-angle subduction that resulted in dominant crust extension of the back-arc region. It is also interpreted that the Neotectonic crustal deformation and present-day tectonic setting of East Asia commenced with the change of the Pacific Plate motion during 5~3.2 Ma.

• Clean Technology
• /
• v.25 no.1
• /
• pp.91-97
• /
• 2019

Oxidative desulfurization (ODS) has received much attention in recent years because refractory sulfur compounds such as dibenzothiophenes can be oxidized selectively to their corresponding sulfoxides and sulfones, and these products can be removed by extraction and adsorption. In this work, The oxidative desulfurization of marine diesel fuel was performed in a batch reactor with hydrogen peroxide ($H_2O_2$) in the presence of various supported heteropoly acid catalysts. The catalysts were characterized by XRD, XRF, XPS and nitrogen adsorption isotherm techniques. Based on the sulfur removal efficiency of promising silica supported heteropoly acid catalysts, the ranking of catalytic activity was: $30\;H_3PW_{12}/SiO_2$ > $30\;H_3PMo_{12}/SiO_2$ > $30\;H_4SiW_{12}/SiO_2$, which appears to be related with their intrinsic acid strength. The $30\;H_3PW_{12}/SiO_2$ catalyst showed the highest initial sulfur removal efficiency of about 66% under reaction conditions of $30^{\circ}C$, $0.025g\;mL^{-1}$ (cat./oil), 1 h reaction time. However, through the recycle test of the $H_3PW_{12}/SiO_2$ catalyst, significant deactivation was observed, which was attributed to the elution of the active component $H_3PW_{12}$. By introducing cesium cation ($Cs^+$) into the $H_3PW_{12}/SiO_2$ catalyst, the stability of the catalyst was improved with changing the solubility, and the $Cs^+$ ion exchanged catalyst could be recycled for at least five times without severe elution.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.3
• /
• pp.562-569
• /
• 2019

Raman spectroscopy has been receiving increased attention as a standoff explosive detection technique. In addition, there is a growing need for a fast search method that can identify raman spectrum for measured chemical substances compared to known raman spectra in large database. By far the most simple and widely used method is to calculate and compare the Euclidean distance between the given spectrum and the spectra in a database. But it is non-trivial problem because of the inherent high dimensionality of the data. One of the most serious problems is the high computational complexity of searching for the closet spectra. To overcome this problem, we presented the MPS Sort with Sorted Variance+PDS method for the fast algorithm to search for the closet spectra in the last paper. the proposed algorithm uses two significant features of a vector, mean values and variance, to reject many unlikely spectra and save a great deal of computation time. In this paper, we present two new methods for the fast algorithm to search for the closet spectra. the PCA+PDS algorithm reduces the amount of computation by reducing the dimension of the data through PCA transformation with the same result as the distance calculation using the whole data. the Hierarchical Cluster Tree algorithm makes a binary hierarchical tree using PCA transformed spectra data. then it start searching from the clusters closest to the input spectrum and do not calculate many spectra that can not be candidates, which save a great deal of computation time. As the Experiment results, PCA+PDS shows about 60.06% performance improvement for the MPS Sort with Sorted Variance+PDS. also, Hierarchical Tree shows about 17.74% performance improvement for the PCA+PDS. The results obtained confirm the effectiveness of the proposed algorithm.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.2
• /
• pp.425-433
• /
• 2019

In this study, a simple method of calculating the passive earth pressure coefficient, which is based on the limit equilibrium method, was proposed and the calculated earth pressure coefficients were compared with those of several researchers. The angle of the linear failure surface, which is combined with the logarithmic spiral arc, to the failure surfaces of the passive zone was derived and the whole passive thrust acting on the Rankine passive zone was considered in the proposed method instead of considering the horizontal component of passive thrust. The variations of the passive earth pressure coefficients of the proposed method showed the same tendency as that of the Coulomb's passive earth pressure coefficients with an inclined angle of backfill and internal friction angle. The magnitude of passive earth pressure coefficients of the proposed method were smaller than those of the Coulomb in almost all cases. A comparison of the passive earth pressure coefficients with the wall friction angle revealed the passive earth pressure coefficients of the proposed method to be smaller than those of the Coulomb and the differences between the two values increased with increasing internal friction angle and wall friction angle. A comparison of the passive earth pressure coefficients of the proposed method with those of the existing researchers for the considered internal friction angles of $25^{\circ}$, $30^{\circ}$, $35^{\circ}$, and $40^{\circ}$ and three wall friction angles revealed the maximum percentage differences for the Kerisel and Absi method, Soubra method, Lancellotta method, $Ant\tilde{a}o$ et al. method, Kame method, and Reddy et al. method to be 4.8%, 3.8%, 31.1%, 4.0%, 20.6%, and 12.8% respectively. The passive earth pressure coefficient and existing pressures were similar in all cases.

• Korean Journal of Remote Sensing
• /
• v.34 no.6_2
• /
• pp.1165-1178
• /
• 2018

Collapse of an Antarctic ice shelf and its flow velocity changes has the potential to reduce the restraining stress to the seaward flow of the Antarctic Ice Sheet, which can cause sea level rising. In this study, variations in ice velocity from 2000 to 2017 for the Nansen Ice Shelf in East Antarctica that experienced a large-scale collapse in April 2016 were analyzed using Landsat-7 Enhanced Thematic Mapper Plus (ETM+) and Landsat-8 Operational Land Imager (OLI) images. To extract ice velocity, image matching based on orientation correlation was applied to the image pairs of blue, green, red, near-infrared, panchromatic, and the first principal component image of the Landsat multispectral data, from which the results were combined. The Landsat multispectral image matching produced reliable ice velocities for at least 14% wider area on the Nansen Ice Shelf than for the case of using single band (i.e., panchromatic) image matching. The ice velocities derived from the Landsat multispectral image matching have the error of $2.1m\;a^{-1}$ compared to the in situ Global Positioning System (GPS) observation data. The region adjacent to the Drygalski Ice Tongue showed the fastest increase in ice velocity between 2000 and 2017. The ice velocity along the central flow line of the Nansen Ice Shelf was stable before 2010 (${\sim}228m\;a^{-1}$). In 2011-2012, when a rift began to develop near the ice front, the ice flow was accelerated (${\sim}255m\;a^{-1}$) but the velocity was only about 11% faster than 2010. Since 2014, the massive rift had been fully developed, and the ice velocity of the upper region of the rift slightly decreased (${\sim}225m\;a^{-1}$) and stabilized. This means that the development of the rift and the resulting collapse of the ice front had little effect on the ice velocity of the Nansen Ice Shelf.

• Journal of Life Science
• /
• v.29 no.8
• /
• pp.895-903
• /
• 2019

The aim of the present study was to improve the cell viability of human dental papilla derived single-induced pluripotent stem cells (iPSCs) using a Rho-associated protein kinase (ROCK) inhibitor, Y-27632. The iPSCs were produced using an episomal plasmid-based reprogramming method. After cell separation using trypsin, the iPSCs were treated with 0, 0.5, 1, 2.5, 5, 7.5, or $10{\mu}M$ Y-27632 for 5 d. Cell viability increased significantly following the $5{\mu}M$ Y-27632 treatment (p<0.05). When the iPSCs were exposed to medium containing $10{\mu}M$ Y-27632 for 0, 1, 2, 3, 4, and 5 d, the cell viability rate increased significantly in accordance with the cell viability rate (p<0.05). To evaluate the effect of the Y-27632 treatment on stemness characteristics, the expression of stem cell-specific transcripts and telomerase activity were investigated in the iPSCs treated with $10{\mu}M$ Y-27632 for 5 d. The expression levels of stem cell-specific transcripts, such as OCT-4, NONOG, and SOX-2, and telomerase activity were not significantly different in the iPSCs treated with $10{\mu}M$ Y-27632 as compared with those of untreated control iPSCs (p>0.05). Taken together, the results demonstrated that cell viability can be improved by treatment with the ROCK inhibitor Y-27632, without losing iPSC stemness characteristics.

• Journal of Life Science
• /
• v.29 no.2
• /
• pp.173-180
• /
• 2019

Amyloid ${\beta}$-protein ($A{\beta}$) is the principal component of senile plaques characteristic of Alzheimer's disease (AD) and elicits a toxic effect on neurons in vitro and in vivo. Many environmental factors, including antioxidants and proteoglycans, modify $A{\beta}$ toxicity. It is worthwhile to isolate novel natural compounds that could prove therapeutic for patients with AD without causing detrimental side effects. In this study, we investigated the in vitro neuroprotective effects of the ethyl acetate fraction of methanol extract of Ophiophogon japonicas (OJEA fraction). We used an MTT reduction assay to detect protective effects of the OJEA fraction on $A{\beta}_{25-35}$-induced cytotoxicity to PC12 cells. We also used a cell-based ${\beta}$-secretase assay system to investigate the inhibitory effect of the OJEA fraction on ${\beta}$-secretase activity. In addition, we performed an in vitro lipid peroxidation assay to evaluate the protective effect of the OJEA fraction against oxidative stress induced by $A{\beta}_{25-35}$ in PC12 cells. The OJEA fraction had strong protective effects against $A{\beta}_{25-35}$-induced cytotoxicity to PC12 cells and was strongly inhibitory to ${\beta}$-secretase activity, which resulted in the attenuation of $A{\beta}$ generation. In addition, the OJEA fraction significantly decreased malondialdehyde (MDA) content, which is induced by the exposure of PC12 cells to $A{\beta}_{25-35}$. Our results suggested that the OJEA fraction contained active compounds exhibiting a neuroprotective effect on $A{\beta}$ toxicity.

• Korean Journal of Breeding Science
• /
• v.50 no.4
• /
• pp.406-414
• /
• 2018

This study was conducted to develop environmental risk assessments and biosafety guides for insect-resistant genetically modified rice in an LMO (Living Modified Organism) isolation field. In the LMO quarantine area of Kyungpook National University, the species diversities and population densities of non-target insects found on insect-resistant genetically modified rice (Bt-T), rice resistant to Cnaphalocrocis medinalis, and non-GM rice (Dongjin-byeo and Ilmi-byeo) were investigated. The Bt-T plants were, therefore, evaluated under field conditions to detect possible impacts on above ground insects and spiders. In 2016 and 2017, the study compared transgenic rice and two non-GM reference rice, namely Dongjin-byeo and Ilmi-byeo, at Gunwi. A total of 9,552 individuals from 51 families and 11 orders were collected from the LMO isolation field. From the three types of rice fields, a total of 3,042; 3,212; and 3,297 individuals from the Bt-T, Dongjin-byeo, and Ilmi-byeo were collected, respectively. There was no difference between the population densities of the non-target insect pests, natural enemies, and other insects on the Bt-T compared to non-GM rice. The data on insect species population densities were subjected to principal component analysis (PCA) without distinguishing between the three varieties, namely GM, non-GM, and reference cultivar, in all cultivation years. However, the PCA clearly separated the samples based on the cultivation years. These results suggest that insect species diversities and population densities during plant cultivation are determined by environmental factors (growing condition and seasons) rather than by genetic factors.