• Asia pacific journal of information systems
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• v.7 no.1
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• pp.25-48
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• 1997

This study examines whether expenditures in information technology (IT) are associated with increases in the Tobin's q ratios a measure of organizational performance. It uses two groups of sample, Korean and American firms that disclose IT expenditures. For the all-firms group of each country, the association between IT expenditures and Tobin's q ratios is positive and statistically significant. But the association varies among industries. For Korean firms, IT expenditures appear to increase Tobin's q ratios for the machine and equipment manufacturing industry group (SIC3-2). IT expenditure ratio of this group as a percent of total sales is highest among the industry groups. For all service industry groups(SIC4&5), the estimated coefficient of IT expenditures is positive but statistically insignificant. For American firms IT expenditures in most of the manufacturing industry groups appear to increase only a little, if at all, for the Tobin's q ratios. But IT expenditures appear to have a greater impact on Tobin's q ratios for all service industries (SIC4-7). For three service industries tested (transportation and telecommunication- SIC4, financial- SIC6, consulting and other service industry- SIC7), the estimated coefficient of IT expenditures is positive and statistically significant. The evidence from both Korean and American firms suggests that IT expenditures in service industries provide a greater impact on an organizational performance than ones in manufacturing industry. To test whether service industries use a competitive strategy utilizing IT as a core competence, the samples ore divided into two groups, service and manufacturing industry. For Korean firms, both IT and R&D expenditures in manufacturing industry are associated with increases in Tobin's q ratios. But for service industry, the estimated coefficient of only IT expenditure is positive. For American firms, the estimated coefficients of both IT and advertising and R&D (ARD) expenditures in manufacturing industry are positive but the coefficient of only ARD is statistically significant. For service industry, the estimated coefficient of only IT expenditure is positive and statistically significant. The evidence may suggest that manufacturing industry uses both R&D and IT strategies to increase a competitive advantage but uses R&D strategy as a core competence. However, service industry uses IT strategy as a core competence to increase a competitive advatage.

• Journal of dental hygiene science
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• v.14 no.1
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• pp.29-34
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• 2014

The purpose of this study was to evaluate the influence of low temperature degradation (LTD) on the bonding strength of yttria-stabilized tetragonal zirconia polycrystal (Y-TZP). The push-shear bond test method was used to investigate the core-veneer bonding strength of industrially manufactured Y-TZP core ceramic and manufacturer recommended veneering ceramic. Four groups from ceramic-zirconia specimens (n=28; n=7 per group) were assigned into four experimental aging conditions, namely storage in an autoclave at $134^{\circ}C$ for 0, 3, 5, 10 hours. Bonding strength was obtained using a universal testing machine with crosshead speed 0.5 mm/min. Data were statistically analyzed using one-way ANOVA and Tukey's test (${\alpha}=0.05$). In bonding strength test, the group which was treated with LTD showed lower bonding strength than no treated group. The ceramic-zirconia bonding strength was affected by LTD (p<0.05). Digital microscope examination of the fracture surface showed mixed failures with adhesive and cohesive types in LTD with treated Y-TZP groups.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.4
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• pp.2585-2592
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• 2015

The purpose of this study was to evaluate the shear bond strength between metal core fabricated by 3D printing and dental porcelain. Thirty metal cores were fabricated(cast 15ea, 3D printing 15ea). The porcelain for each group was builded to the metal core. Sample was loaded to shear force(crosshead speed 1mm/min) in a universal material testing machine. The fracture samples were analyzed failure aspect. The means were statistical analyzed using by Mann-whitney test(${\alpha}=0.05$). The period of experimental(metal cores fabrication, dental porcelain build up, data analysis, statistical analysis, failure aspect analysis and others) for this study took six months. The $mean{\pm}SDs$ of shear bond strength was $50.14{\pm}1.60MPa$ for the cast group, and $54.36{\pm}3.18MPa$ for the 3D printing group(p=0.035). The failure aspect showed mixed failure. As a results, metal cores fabricated by 3D printing method were clinically acceptable range.

• Physical Therapy Rehabilitation Science
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• v.11 no.2
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• pp.245-252
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• 2022

Objective: This study aimed to investigate the abdominal muscle activity difference while performing the abdominal bracing technique focusing on inspiration (abdominal bracing group), the general abdominal bracing technique (general bracing group), and the abdominal hollowing technique (abdominal hallowing group) Design: A cross-sectional study design. Methods: Thirty-three healthy participants were recruited for this study. The participants were allocated to 3 different groups; Abdominal bracing group, general bracing group, and abdominal hallowing group. The surface electromyography was placed over the rectus abdominis, external oblique, and internal oblique muscles to collect the activation of abdominal muscles during the trial. Results: The muscle activity of the abdominal bracing group and general bracing groups was significantly higher in all abdominal muscles than in the abdominal hollowing group (p<0.05) Both rectus abdominis and external oblique muscles showed higher muscle activations in the abdominal bracing group over the general bracing group (p<0.05). However, the ratio of bilateral external obliques and rectus abdominis to bilateral internal obliques was highest when the hollowing technique was applied (p<0.05). Conclusions: The results of study showed the abdominal bracing technique that emphasized inhalation rather than the abdominal hollowing technique or general abdominal bracing technique increased the activity of the abdominal muscles. Therefore, this study is considered to be a data for effective training if the abdominal bracing technique that emphasizes inhalation is applied as a method to increase the activation of the abdominal muscles.

• Journal of Technologic Dentistry
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• v.33 no.4
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• pp.299-306
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• 2011

Purpose: This study aimed to investigate the shear bond strength by manufacturing the veneering porcelain on the IPS e.max $ZirCAD^{(R)}$ zirconia core, using the layering technique and heat-pressing technique, and to evaluate the clinical stability by comparing to the conventional metal ceramic system. Methods: The Schmitz-Schulmeyer test method was used to evaluate the core-veneer shear bond strength of zirconia core ceramic(IPS e.max $ZirCAD^{(R)}$) and their manufacture recommended two veneering ceramic systems(IPS e.max $ceram^{(R)}$, IPS e. max $ZirPress^{(R)}$). A metal ceramic system(Bellabond $plus^{(R)}$, VITA $VM13^{(R)}$) was used as a control group for the two all ceramic system test groups. The maximum loading and shear bond strength was measured. The average shear strength(MPa) was analyzed with the one-way ANOVA and the Tukey's test(${\alpha}$=.05). The fracture specimens were examined using Microscope to determine the failure pattern. Results: The mean shear bond strengths(SD) in MPa were MBSB control 43.62(2.13); ZBSB 18.65(1.76); ZPSB 18.89(1.54). The shear strengths of the zirconia cores were not significantly different(P>.05). Microscope examination showed that zirconia specimens presented mixed failure, and base metal alloy specimens showed adhesive failure. Conclusion: There was no siginificant different between the layering technique and the heat pressing technique in the veneering methods on the zirconia cores. None of the zirconia core and veneering ceramics could attain the high bond strength values of the metal ceramic combination.

• Journal of the Korea Society for Simulation
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• v.31 no.1
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• pp.1-9
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• 2022

As the automobile market has grown steadily in recent years, consumer expectations have also risen. Therefore, it is necessary for automobile sales offices to create innovative customer value that is different from the past. Auto sales offices are making efforts to select salespeople who fit their management strategies, but they are having difficulties in evaluating their actual internal capabilities. Therefore, in this paper, based on the study of Spencer & Spencer (2008), we reconstruct the core competencies required for salesperson selection, and analyze the core competencies required for today's automobile salespersons by deriving the hierarchical importance between those competencies using AHP analysis. As a result, it was possible to derive the importance of core competencies different from previous studies. This is believed to be mainly due to the modern social market, the characteristics of existing car salespeople, and the tendency of recent customers. This study showed that it is possible to set selection criteria according to the ease and importance of calculating the required competency through AHP analysis. In addition, if the existing research is based on job specifications, this study is different in that it analyzed the actual group of experts.

• Journal of Korean Academy of Nursing
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• v.35 no.6
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• pp.1014-1024
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• 2005

Purpose: This study was to exam me the effects of auricular acupuncture on insomnia in Korean elderly. Method: The study design was a triangulation study. Subjects were 40 elderly who were 65 years and over in Seoul, and 10 subjects for a qualitive study who were saturated with interviews and observation. The first auricular acupuncture was applied for three days, and this was applied to subjects on a 5 times series. The quantative data was analyzed by SPSS PC+ and the qualitive data was analyzed by driving of core meaning and abstract concepts using a semi-structural interview and observation. Result: I. The experimental group had higher significant sleep scores than that of the control group (t=32.739, p=.001). 2. The experimental group had higher significant self- satisfaction scores on sleep than that of the control group (t=30.049, p=.001). 3. In the qualitive study, insomnia characteristics before application of auricular acupressure therapy were confirmed by physical dysfunction, recall of past, and psychological dysfunction. Insomnia characteristics after application of auricular acupressure therapy were confirmed by recovery of physical dysfunction, improving recall of past, and recovery of psychological dysfunction. Conclusion: Auricular acupuncture was effective on insomnia in Korean elderly.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.40 no.10
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• pp.51-58
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• 2003

In this paper, we propose a group scheduling scheme to efficiently utilize network resources for core nodes in optical burst switching networks. This scheme schedules multiple bursts utilizing an interval graph to obtain the maximum stable set using the information such as arrival times and burst lengths from the collected header packets. Simultaneous scheduling of multiple bursts in a scheduling window results in lower burst loss probability and increased channel utilization than those proposed previously using one-to-one mapping. Simulation results for both cases of variable and fixed burst sizes show that the group scheduling scheme is better than the immediate scheduling, so called Latest Available Unused Channel with Void Filling, scheme in both performance metrics above mentioned.

• Restorative Dentistry and Endodontics
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• v.9 no.1
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• pp.115-119
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• 1983

The purpose of this study was to compare the solubility of enamel and dentin to an etchant after fluoride application. Specimens were collected from extracted anterior and bicuspid and each tooth was cut into several pieces. These specimen were allocated in 7 group; 1%, 2%, 3% NaF, 1%, 8%, 20% $SnF_2$, and control group. Five specimens in each group was exposed to pre-determined fluoride solution for 3 minutes, and washed with running water. These specimens were etched by Hipol (commercial label) etchant for 30 seconds. Following are the findings obtained through S.E.M. 1. All specimens with acid etching revealed preferential removal of prism periphery leaving prism core. 2. Specimens treated with 1%, 2% NaF solution showed that the shape of prism tip was thin and sharp like a needle. The case of 3% NaF showed rather round shape at prism end. 3.1% of $SnF_2$ case showed similar findings with the control group but 8% and 20% $SnF_2$ case revealed needle shape at the prism and was less clear than NaF case. Preferential removal of prism periphery was partialy observed and un decalcified area is fused to prism forming reidge. 4. Dentine treated by fluoride compound in low concentration showed the orifice of dentinal tubule was clearly enlarged whereas in high concentration the orifice was not widened.

• Design & Manufacturing
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• v.11 no.1
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• pp.30-33
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• 2017

In this study, the mold technology for manufacturing of porous implant was investigated. Firstly, we considered the concept of insert molding technology with 3D printing of porous inert part. The part on implant was designed in the end region of the implant. And then main implant bodies were manufactured using conventional machining method. The other porous parts were designed and optimized with molding simulation. As the feature size of porous implant was so small that perfect feature of it using 3D printing technology could not be obtained. So, we proposed another scheme for manufacturing of the porous implant in the replace of the former approach. Polymer mold cores with 3D printing technology were considered. The effects of addictive manufacturing process parameters on the properties of mechanical and dimensional accuracy were investigated. Direct 3D printed polymer mold cores were designed and manufactured under the simulation of thermal and molding analysis. It was shown that 3D printed mold core with polymer could be adapted to the injection molding for porous implant.