• Journal of dental hygiene science
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• v.18 no.2
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• pp.113-123
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• 2018

The purpose of this study to review clinicians and educators on required communication education factors of dental hygienists using qualitative research by focus group interview. The participants were dentists, dental hygienists and professors. A questionnaire was developed on communication education to collect data. The collated data derived concepts related to communication education. After transferring the data, were analyzed by open coding and axial coding using computer-aided qualitative data analysis software. Focus group emphasized that higher education on communication should be preceded before they are put into the clinical field. However, the dental hygienist emphasized experiential education in the clinical field, the professor emphasized additional education for continuity of communication education even after graduation. Besides, focus group emphasized role play, and the professor required that the standardization of the dental communication training courses objectives and role play modules and the education environment infrastructure should be established to implement communication education efficiently. The categories of communication education stated in the focus group were time and method for the dental communication training courses, dental communication training courses standardization and educational environment, of evaluation of communication competency, of perception of the dental communication training courses. This study identified the communication education development to conform with the needs of the clinical field strengthen and cultivate communication competency dental hygienists based on factors of communication education emphasized in focus groups.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.12
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• pp.1-6
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• 2007

In this study, we have performed the channel modification of the conventional MHEMT (metamorphic high electron mobility transistor) to improve the breakdown characteristics. The Modified channel consists of the InxGal-xAs channel and the InP sub channel instead of the InxGa1-xAs channel. Since InP has the lower impact ionization coefficient in comparison with In0.53Ga0.47As, we have adopted the InP-composite channel in the modified MHEMT. We have investigated the breakdown mechanism and the RF characteristics for the conventional and the InP- composite channel MHEMTs. From the measurement results, we have obtained the enhanced on and off-state breakdown voltages of 2.4 and 5.7 V, respectively. Also, the increased RF characteristics have brought about the decreased output conductance for the InP-composite channel MHEMT. The cut-off frequency (fT) and the maximum oscillation frequency (fmax) for the InP-composite Channel MHEMT were 160 GHz and 230 GHz, respectively. It has been shown that the InP-composite channel MHEMT has the potential applications for the millimeter wave power device.

• Clinical and Experimental Reproductive Medicine
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• v.29 no.2
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• pp.105-115
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• 2002

Objective : To evaluate the effects of the reactive oxygen species (ROS) generated with a xanthine (X) and xanthine oxidase (XO) system on sperm function, the change of sperm characteristics, lipid peroxidation, and DNA fragmentation in bovine spermatozoa. Materials and Methods: ROS were produced using a combination of 1000 uM X and 50 mU/ml XO. The ROS scavengers: superoxide dismu tase (SOD) (200 U/ml) and catalase (500 U/ml) were also tested. Spermatozoa were incubated for 2 hours in BWW medium with a combination of X-XO supplemented with or without ROS scavengers at $37^{circ}C$ under 5% $CO_2$ incubator. Sperm movement characteristics by CASA (computer-aided sperm analysis), HOST (hypoosmotic swelling test), Caionophore induced acrosome reaction, malondialdehyde formation for the analysis of lipid peroxidation, the percentage of DNA fragmentation using the method of TdT-mediated nick end labelling (TUNEL) by flow cytometry were determined after 2 hours incubation. Results: The action of ROS on bovine spermatozoa resulted in a decreased in capacity for sperm motility, Ca-ionophore induced acrosome reaction and membrane integrity, an increased in malondialdehyde formation and the percentage of sperm with DNA fragmentation. In the effects of antioxidant, catalase completely alleviated the toxic effects induced by the ROS in terms of sperm function and characteristics, however SOD exhibited no capacity to reduce the toxic effects. Conclusion: The ROS can induce significant damages to sperm functions and characteristics. The useful ROS scavengers can minimized the defects of sperm function and various damages of spermatozoa.

• Reproductive and Developmental Biology
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• v.29 no.3
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• pp.155-162
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• 2005

The present study evaluated whether an exogenous antioxidants, taurine and $\alpha$-tocopherol, could, when added to the freezing extender, improve the post-thaw sperm characteristics, function, the level of reactive oxygen species (ROS) generation, and the level of lipid peroxidation (LPO) in frozen-thawed porcine semen. CASA (computer-aided sperm analysis), HOST (hypoos-motic swelling test), chemiluminescence using luminol and lucigenin and the detection of malondialdehyde for LPO was performed in frozen-thawed porcine sper-matozoa. The results obtained in these studies are as follows. While no beneficial effects of taurine and $\alpha$-tocopherol supplementation were visible in motility, viability, acrosome reaction, tail swelling patterns, and the generation of $O^{2-}$ of frozen-thawed porcine sper-matozoa, $H_{2}O_{2}$ was decreased by all treatments except taurine 50mM treatment. In conclusion the taurine and $\alpha$-tocopherol treatments during freezing reduced generation of reactive oxygen species and production of malondialdehyde in frozen-thawed porcine semen, and the ROS savangers may minimize various damages of spermatozoa during freezing.

• Journal of Korean Dental Science
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• v.12 no.1
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• pp.13-19
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• 2019

Purpose: The aim of this study was to compare the flexural strength of provisional fixed dental prostheses which was three-dimensional (3D) printed by several build directions. Materials and Methods: A metal jig with two abutment teeth and pontic space in the middle was fabricated. This jig was scanned with a desktop scanner and provisional restoration was designed on dental computer-aided design program. On the preprocessing software, the build angles of the restorations were arranged at $0^{\circ}$, $30^{\circ}$, $45^{\circ}$, $60^{\circ}$, and $90^{\circ}$ and support was added and resultant structure was sliced to a thickness of $100{\mu}m$. Processed restorations were printed with digital light processing type 3D printer using poly methyl meta acrylate-based resin. After washing and post-curing, compressive loading was applied at a speed of 1 mm/min on a metal jig fixed to a universal testing machine. The maximum pressure at which fracture occurred was measured. For the statistical analysis, build direction was set as the independent variable and fracture strength as the dependent variable. One-way analysis of variance and Tukey's post hoc analysis was conducted to compare fracture strength among groups (${\alpha}=0.05$). Result: The mean flexural strength of provisional restoration 3D printed with the build direction of $0^{\circ}$ was $1,053{\pm}168N$; it was $1,183{\pm}188N$ at $30^{\circ}$, $1,178{\pm}81N$ at $45^{\circ}$, $1,166{\pm}133N$ at $60^{\circ}$, and $949{\pm}170N$ at $90^{\circ}$. The group with a build direction of $90^{\circ}$ showed significantly lower flexural strength than other groups (P<0.05). The flexural strength was significantly higher when the build direction was $30^{\circ}$ than when it was $90^{\circ}$ (P<0.01). Conclusion: Among the build directions $0^{\circ}$, $30^{\circ}$, $45^{\circ}$, $60^{\circ}$, and $90^{\circ}$ set for 3D printing of fixed dental prosthesis, an orientation of $30^{\circ}$ is recommended as an effective build direction for 3D printing.

• Journal of the Korea Institute of Building Construction
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• v.20 no.6
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• pp.505-514
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• 2020

This research introduces the method of developing Korea BIM standard (KBIMS) architectural and structural element library and the methodology of converting KBIMS IFC property names with special characters. Diverse BIM tools are utilizing in project, however BIM library researches lack diversity on BIM tool selection. This research described the method to generate twelve categories and seven hundred and ninety-three elements library containing geometrical and numerical data in CATIA V6. KBIMS has its special property data naming systems which was the challenge inputting to ENOVIA IFC database. Three mapping methods for special naming characters had been developed and the ASCII code method was applied. In addition, the convertor prototype had been developed for searching and replacing the ASCII codes into the original KBIMS IFC property names. The methodology was verified by exporting 2,443 entities without data loss in the sample model conversion test. This research would provide a wider choice of BIM tool selection for applying KBIMS. Furthermore, the research would help on the reduction of data interoperability issues in projects. The developed library would be open to the public, however the continuous update and maintenance would be necessary.

• Korean Journal of Radiology
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• v.22 no.7
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• pp.1054-1065
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• 2021

Objective: We implemented a novel resectable myocardial model for mock myectomy using a hybrid method of three-dimensional (3D) printing and silicone molding for patients with apical hypertrophic cardiomyopathy (ApHCM). Materials and Methods: From January 2019 through May 2020, 3D models from three patients with ApHCM were generated using the end-diastolic cardiac CT phase image. After computer-aided designing of measures to prevent structural deformation during silicone injection into molding, 3D printing was performed to reproduce anatomic details and molds for the left ventricular (LV) myocardial mass. We compared the myocardial thickness of each cardiac segment and the LV myocardial mass and cavity volumes between the myocardial model images and cardiac CT images. The surgeon performed mock surgery, and we compared the volume and weight of the resected silicone and myocardium. Results: During the mock surgery, the surgeon could determine an ideal site for the incision and the optimal extent of myocardial resection. The mean differences in the measured myocardial thickness of the model (0.3, 1.0, 6.9, and 7.3 mm in the basal, midventricular, apical segments, and apex, respectively) and volume of the LV myocardial mass and chamber (36.9 mL and 14.8 mL, 2.9 mL and -9.4 mL, and 6.0 mL and -3.0 mL in basal, mid-ventricular and apical segments, respectively) were consistent with cardiac CT. The volume and weight of the resected silicone were similar to those of the resected myocardium (6 mL [6.2 g] of silicone and 5 mL [5.3 g] of the myocardium in patient 2; 12 mL [12.5 g] of silicone and 11.2 mL [11.8 g] of the myocardium in patient 3). Conclusion: Our 3D model created using hybrid 3D printing and silicone molding may be useful for determining the extent of surgery and planning surgery guided by a rehearsal platform for ApHCM.

• Archives of design research
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• v.18 no.4 s.62
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• pp.119-128
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• 2005

This paper presents an intuitive 3D modeling interlace based on a field study and prototype development. The process and tools of modeling were observed in workshops of professional design model making, day modeling, wood caning and glass crafting. The Spray Modeling interlace was developed from the observational analysis of the field study. It is a 3D modeling interface which combines particle spraying and day modeling in Virtual or Augmented Reality space. Virtual volume particles are sprayed on frames in Augmented Reality space as day modeling. It adopts a real air spay gun as a tangible interface device which provides coherent sound and air-force feedback. The prototype development and a user study showed that the interface supports new patterns of form development and expression. Control interfaces and requirements of auxiliary devices were found to be improved. This study examines the potential of the new interlace for designers working in 3D virtual and augmented reality. The new spraying interface is also expected to be used as an alternative interface in 3D computer workspace, games, education software and media art.

• The Journal of Information Systems
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• v.5
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• pp.115-147
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• 1996

1. Introduction The new computing era started with the various computer technologies and services having been used in communication and automation area since 1980's. We call that era information technology(IT) era. In such era, especially communication plays very important roles in every aspect. So Schoderbek named that era the ege of c2. Therefore, communition became widely used in organizations. Now the majority of organizations have computer-aided communication capabilities that facilitate access to people and information, both within and outside organization. So one objective of this study is to assess the effects of these changes in data communication on decision making. Decision making is the essence of management and is too important to organizational success. This dissertation has three basic objectives: 1)to clarify the concept of data communication, who influences on decision making, and the concept of decision types, managerial and operational, may be affected differently by data communication 2)to investigate whether the effects of data communication upon decision making may be organizational variables. 3)to verify that business and decision types may affect different impact on decision making.2. Hypotheses Four attributes are selected to make hypotheses from the information attributes presented by famous scholars. They are as follows. ①effectiveness ②routinization ③communication easiness ④timeliness Hypotheses are developed according to these attributes, which are chosen from the literature study and theory H1 : Data communication is positively related to the effectiveness of DM H2 : Data communication is positively related to the routinization of DM H3 : Data communication is positively related to the communication easiness of DM H4 : Data communication is positively related to the timeliness of information for DM3. Methodology After pilot study, data are collected from the decision makers in 200 companies located at Seoul and the metropolitan area. A random sample of 174 employees sent back their questionnaires(response rate of 87%). Among them, 151 questionnaires was useful to the analysis of this study(useful rate of 75.5%).4. Conclusion and Discussion Among four proposed hypotheses, all hypotheses are fully supported. They are as follows. 1)effectiveness 2)routinization 3)communication easiness 4)timeliness. So, first objective of this study is proved. Namely, to clarify that the effects of data communication upon DM is fully supported. But they are different from the decision types. Second one is not apparently verfied. i.e. the effect of data communication on the decision variables is not moderated by organizational variables. Third is inspected. The effects of data communication differs from the industry and decision types evidently. This study has many limitations to generalize the statistical results. Since the definition of data communication has broad meanings in reality. So allare not contained in this research. Another restrict in this study is like this. Decision types are usually divided into three types-operational, managerial, strategic DM. But in this study, strategic DM is left out.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.30 no.3
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• pp.239-248
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• 2017

According to the structure, solenoid valve can be categorized as spool valve or poppet valve. While various research on spool valve which has simple structure and fine susceptibility to contamination has been conducted, poppet valve which has less susceptibility to contamination and advantage in a long time operation still need much research because of its complicated structure. In order to design the poppet valve, various parameters such as the diameter of the poppet, the angle of the poppet, the diameter of the disk, the spring stiffness, the spring preload and flow path structure should be considered. Conventional studies on poppet valve usually take only one design parameters and did not much focused on the effect of the parameters on flow characteristics. In this paper, the change of the flow characteristics according to the design parameters of the poppet valve for 3/2Way solenoid valve is analyzed. The previous studies and the results of initial model analysis was referred for the selection of the design parameters. The effects of design parameters on maximum pressure, minimum pressure, and pressure drop was examined using analysis of means(ANOM).