• Journal of the Korea Computer Graphics Society
• /
• v.8 no.1
• /
• pp.13-20
• /
• 2002

Recently, there is a great demand for artificial teeth prostheses made of the materials which are sintered at $1500^{\circ}C$ such as zirconia ceramic. Since degree of strength of the materials is very high, however, it is very difficult for technicians to manually fabricate the prostheses for these ceramics. So the prostheses have been fabricated by using CNC(computer numerical control) machines. In doing them by using CNC, it is very important that the prostheses satisfying dentists's requirements are accurately modeled into 3D objects. In this paper, we propose an effective method for modeling single cores such as single caps and Conus cores, which are the main those of artificial teeth prostheses. And we also present the visual examples of 3D models for these single cores modeled by the proposed methods. In special, the method has used Minkowski sum and ZMap for modeling the single cores.

• Journal of the Korea Convergence Society
• /
• v.9 no.1
• /
• pp.465-471
• /
• 2018

Recently, biometric technology has begun to be used as a fusion of IT technology and financial system. Using this biometric technology, FIDO(Fast Identity Online) technology, Samsung and Apple started Samsung Pay and Apple Pay service. FIDO authentication technology replaces existing authentication methods such as passwords. Among the biometric technologies, fingerprint recognition technology is attracting attention because it can minimize the device and user rejection at a relatively low price. However, fingerprint information has a limited number of users and it can not be reused if fingerprint information is leaked by an external attacker. Therefore, in this paper, we propose a method to authenticate a user using EEG signal which is one of biometrics technologies. W propose a method to use EEG signal measurement value in FIDO system by using convenience channel by using short channel EEG device. And propose a method to utilize EEG signal when the user recognizes a specific entity by measuring the EEG signal before and after recognizing a specific entity.

• Journal of the Korea Convergence Society
• /
• v.10 no.12
• /
• pp.7-15
• /
• 2019

With the increase of employment pressure in China and the need of economic transformation, chinese government started to encourage college students to innovate and start their businesses to relieve the employment pressure. Due to the lack of entrepreneurship ability, the success rate of college students' entrepreneurship is not high. Therefore, based on the grounded theory and qualitative research methods, this paper focuses on the entrepreneurial ability of college students, selects college students who have started their own businesses in jilin university of China as interview objects, and summarizes the original data obtained in the in-depth interview for analyzing the connotation of college students' entrepreneurial ability, and puts forward the concept model of Chinese college students' entrepreneurial ability. The results show that the entrepreneurial ability of college students consists of driving force, management ability, entrepreneurial endowment, and potential ability. This study has certain guiding significance for universities to carry out entrepreneurship education.

• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.18
• /
• pp.7611-7615
• /
• 2014

Aims: To prepare 5-fluorouracil (5-Fu) nanoparticles with higher encapsulation efficiency and drug loading, and then investigate interaction with the SGC-7901 gastric cancer cell line. Materials and Methods: Prescription was optimized by orthogonal experiments, the encapsulation efficiency and loading capacity were tested by high-performance liquid chromatography, and inhibition of proliferation by 5-Fu nanoparticles and 5-Fu given to cells for 24, 48 and 72 hours was investigated by methyl thiazolyl tetrazolium assay (MTT). In addition, 5-Fu nanoparticles were labeled by fluorescein isothiocyanate (FITC), and absorption into cells was tested by flow cytometry. Results: The optimal conditions for preparation were concentrations of 5-Fu of 5mg/ml, of $CaCl_2$ of 60 mg/ml and of chitosan of 2 mg/ml. With a stirring speed of 1200rpm, encapsulation efficiency of 5-Fu nanoparticles was $55.4{\pm}1.10%$ and loading capacity was $4.22{\pm}0.14%$; gastric cancer cells were significantly inhibited by 5-Fu nanoparticles in a time and concentration dependent manner, and compared to 5-Fu with slower drug release, in a certain concentration range, inhibition with 5-Fu nanoparticles was stronger. 5-Fu nanoparticles were absorbed by the cells in line with the concentration. Conclusions: 5-Fu nanoparticles can inhibit growth of gastric cancer cells in vitro to a greater extent than with 5-Fu with good adsorption characteristics, supporting feasibility as a carrier.

• Journal of the Korean Chemical Society
• /
• v.56 no.4
• /
• pp.448-458
• /
• 2012

In order to develop alloy resistance in aggressive sulphat ion, the corrosion behavior of metallic glasses $Ni_{92{\cdot}3}Si_{4.5}B_{32}$, $Ni_{82,3}Cr_7Fe_3Si_{4.5}B_{3.2}$ and $Ni_{75.5}Cr_{13}Fe_{4.2}Si_{4.5}B_{2.8}$ (at %) at different concentrations of $H_2SO_4$ solutions was examined by electrochemical methods and Scanning Electron Microscope (SEM) and X-ray Photoelectron Microscopy (XPS) analyses. The corrosion kinetics and passivation behavior was studied. A direct proportion was observed between the corrosion rate and acid concentration in the case of $Ni_{92{\cdot}3}Si_{4.5}B_{32}$ and $Ni_{75.5}Cr_{13}Fe_{4.2}Si_{4.5}B_{2.8}$ alloys. Critical concentration was observed in the case of $Ni_{82,3}Cr_7Fe_3Si_{4.5}B_{3.2}$ alloy. The influence of the alloying element is reflected in the increasing resistance of the protective film. XPS analysis confirms that the protection film on the $Ni_{92{\cdot}3}Si_{4.5}B_{32}$ alloy was NiS which is less protective than that formed on Cr containing alloys. The corrosion rate of $Ni_{82,3}Cr_7Fe_3Si_{4.5}B_{3.2}$ and $Ni_{75.5}Cr_{13}Fe_{4.2}Si_{4.5}B_{2.8}$. alloys containing 7% and 13% Cr are $7.90-26.1{\times}10^{-3}$ mm/y which is lower about 43-54 times of the alloy $Ni_{92{\cdot}3}Si_{4.5}B_{32}$ (free of Cr). The high resistance of $Ni_{75.5}Cr_{13}Fe_{4.2}Si_{4.5}B_{2.8}$ alloy at the very aggressive media may due to thicker passive film of $Cr_2O_3$ which hydrated to hydrated chromium oxyhydroxide.

• The Journal of Advanced Prosthodontics
• /
• v.12 no.5
• /
• pp.316-321
• /
• 2020

PURPOSE. The stress distribution and microgap formation on an implant abutment structure was evaluated to determine the relationship between the direction of the load and the stress value. MATERIALS AND METHODS. Two types of three-dimensional models for the mandibular first molar were designed: bone-level implant and tissue-level implant. Each group consisted of an implant, surrounding bone, abutment, screw, and crown. Static finite element analysis was simulated through 200 N of occlusal load and preload at five different load directions: 0, 15, 30, 45, and 60°. The von Mises stress of the abutment and implant was evaluated. Microgap formation on the implant-abutment interface was also analyzed. RESULTS. The stress values in the implant were as follows: 525, 322, 561, 778, and 1150 MPa in a bone level implant, and 254, 182, 259, 364, and 436 MPa in a tissue level implant at a load direction of 0, 15, 30, 45, and 60°, respectively. For microgap formation between the implant and abutment interface, three to seven-micron gaps were observed in the bone level implant under a load at 45 and 60°. In contrast, a three-micron gap was observed in the tissue level implant under a load at only 60°. CONCLUSION. The mean stress of bone-level implant showed 2.2 times higher than that of tissue-level implant. When considering the loading point of occlusal surface and the direction of load, higher stress was noted when the vector was from the center of rotation in the implant prostheses.

• Fashion & Textile Research Journal
• /
• v.15 no.2
• /
• pp.256-267
• /
• 2013

This study is conducted to improve the fitness of Air Force winter service uniforms pants through the development of a pants pattern drafting method and automatic pattern drafting program for mass customization. The initial study pattern drafting method is formed through an analyses of 4 kinds of conventional pants pattern drafting methods for education and 3 kinds of conventional pants patterns of Air Force apparels. The initial study pattern drafting method is converted into the final study pattern drafting method after twice conducting a wearing test. To verify the final study pants pattern, a motion adaptability evaluation, an ease amount evaluation and an appearance evaluation are conducted. The results of the final study patterns were better than conventional winter service uniforms in the motion adaptability evaluation and the appearance evaluation. However, the results show similar values between the final study patterns and conventional winter service uniform patterns in the ease amount evaluation. An automatic pattern drafting program was developed based on the final study pattern drafting method. The program allowed the achievement of customized pants patterns through the placement of customer body sizes into the size input window. It also provided two kinds of ease amount and two kinds of waist belt level options.

• Korean Journal of Adult Nursing
• /
• v.24 no.6
• /
• pp.635-646
• /
• 2012

Purpose: The purpose of this study was to understand clinical nurses' level of information retrieval skill and its influence on evidence based practice (EBP). Methods: A cross-sectional design was used. Data were collected from a convenient sample of 492 nurses working at 5 university hospitals in Korea. The Data were analyzed using descriptive statistics, t-test, one-way ANOVA, and hierarchical multiple linear regression. Results: The mean score for information retrieval skill and EBP competency were respectively $2.81{\pm}0.64$ and $3.98{\pm}0.86$. Two step hierarchical regression analysis showed that attendance at academic conference (p = .036) and information retrieval skill (p<.001) were significant factors of EBP competency, information retrieval skill explained about 19% of total variance of EBP competency. Conclusion: Nurse need to increased fundamental information retrieval skill for EBP competency. Therefore, it is important to increase nurses' information retrieval skills by tailoring continuing EBP education modules. It would be also advisable to develop centralized systems for the internal dissemination of research findings for the use of nursing staff.

• Journal of Microbiology and Biotechnology
• /
• v.23 no.12
• /
• pp.1708-1716
• /
• 2013

Conventional molecular detection methods cannot distinguish between viable and dead Escherichia coli O157 cells. In this study, the loop-mediated isothermal amplification (LAMP) method combined with propidium monoazide (PMA) treatment was developed to selectively detect viable E. coli O157 cells. Four primers, including outer primers and inner primers, were specially designed for the recognition of six distinct sequences on the serogroups (O157) of the specific rfbE gene of the E. coli O157 genome. PMA selectively penetrated through the compromised cell membranes and intercalated into DNA. Amplification of DNA from dead cells was completely inhibited by $3.0{\mu}g/ml$ PMA, whereas the DNA derived from viable cells was amplified remarkably within 1 h by PMA-LAMP. Exhibiting high sensitivity and specificity, PMA-LAMP is a suitable method for evaluating the inactivation efficacy of slightly acidic electrolyzed water in broth. PMA-LAMP can selectively detect viable E. coli O157 cells. This study offers a novel molecular detection method to distinguish between viable and dead E. coli O157 cells.

• Journal of Korean society of Dental Hygiene
• /
• v.14 no.6
• /
• pp.849-857
• /
• 2014

Objectives: The aim of the study was to investigate the knowledge and attitude toward radiation safety management in dental clinic worker. Methods: A self-reported questionnaire was filled out by 294 dental clinic workers in dental hospitals and clinics in Gwangju and Jeonnam from February 17 to March 30, 2014. The questionnaire consisted of general characteristics of radiation safety(8 questions), knowledge of radiation safety(15 questions), and attitudes of radiation safety(16 questions). The survey was done by Likert 5 scale method. Results: In completion of the radiodontia courses, 84.0% of the learners were female workers. 88.0% of the learners took the theoretical and practical courses. Those who work in the university dental hospital accounted for 87.1% and those in dental clinics accounted for 83.2%. Majority of the workers took on Leaden protective clothing in order to protect the thyroid gland. Male workers had more knowledge toward the radiation safety management than the female workers. The attitude toward the radiation safety management revealed the significant differences between age, gender, academic careers, license, clinical careers and the mean number of patients per day(p<0.05). Conclusions: The radiation safety management is very important in dental clinical workers and it is necessary to enhance the attitude toward the radiation safety through continuous education.