• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.7-8
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• 2010

The surface conductive layer (SCL) of chemical vapor deposition (CVD) diamonds has attracting much interest. However, neither photoemission electron microscopic (PEEM) nor micro-spectroscopic (PEEMS) information is available so far. Since SCL retains in an ultra-high vacuum (UHV) condition, PEEM or PEEMS study will give an insight of SCL, which is the subject of the present study. The sample was made on a Ib-type HTHP diamond (001) substrate by non-doping CVD growthin a DC-plasma deposition chamber. The SCL properties of the sample in air were; a few tens K/Sq. in sheet resistance, ${\sim}180\;cm^2/vs$ in Hall mobility, ${\sim}2{\times}10^{12}/cm^2$ in carrier concentration. The root-square-mean surface roughness (Rq) of the sample was ~0.2nm as checked by AFM. A $2{\times}1$ LEED pattern and a sheet resistance of several hundreds K/Sq. in UHV were checked in a UHV chamber with an in-situ resist-meter [1]. The sample was then installed in a commercial PEEM/S apparatus (Omicron FOCUS IS-PEEM) which was composed of electro-static-lens optics together with an electron energy-analyzer. The presence of SCL was regularly monitored by measuring resistance between two electrodes (colloidal graphite) pasted on the two ends of sample surface. Figure 1 shows two PEEM images of a same area of the sample; a) is excited with a Hg-lamp and b) with a Xe-lamp. The maximum photon energy of the Hg-lamp is ~4.9 eV which is smaller that the band gap energy ($E_G=5.5\;eV$) of diamond and the maximum photon energy of the Xe-lamp is ~6.2 eV which is larger than $E_G$. The image that appear with the Hg-lamp can be due to photo-excitation to unoccupied states of the hydrogen-terminated negative electron affinity (NEA) diamond surface [2]. Secondary electron energy distribution of the white background of Figs.1a) and b) indeed shows that the whole surface is NEA except a large black dot on the upper center. However, Figs.1a) and 1b) show several features that are qualitatively different from each other. Some of the differences are the followings: the two main dark lines A and B in Fig.1b) are not at all obvious and the white lines B and C in Fig.1b) appear to be dark lines in Fig.1a). A PEEMS analysis of secondary electron energy distribution showed that all of the features A-D have negative electron affinity with marginal differences among them. These differences can be attributed to differences in the details of energy band bending underneath the surface present in SCL [3].

• The Korean Journal of Malacology
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• v.29 no.3
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• pp.251-258
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• 2013

This study aims to find out a suitable cryoprotective agent (CPA) for cryopreservation and its optimum concentration in order to conduct planned artificial seed production of Pacific oyster, Crassostrea gigas and to preserve superior sperm. For this, we tried to understand toxicity and the effect of cryopreservation by CPA type and concentrations first and then looked into cell damage of the sperm after thawing. Toxicity analysis on the sperm of Pacific oyster according to different CPA and immersion time shows that dimethyl sulfoxide (DMSO) comes first when it comes to survival rate and mobility followed by ethylene glycol (EG), glycerol and methanol. To identify the optimum CPA and its level, filtered seawater was used as a diluent before cryopreservation for 30 days. As a result, cryopreserved sperm of Pacific oyster with 15% of DMSO showed the highest survival rate and activation. Also, we observed the cryopreserved and thawed sperm with Scanning electron micrographs by CPAs and concentrations. Consequently, DSMO showed the lowest cell damage followed by EG, methanol, glycerol and the level was 15, 20, 10, 5% respectively. In a nutshell, it is proven that the optimum CPA and its level is 15% of DMSO.

• Journal of Adhesion and Interface
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• v.15 no.1
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• pp.22-30
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• 2014

Self-photoinitiating acrylate (SPIA) which can undergo self-initiation under UV irradiation was synthesized by a Michael addition in the presence of a base catalyst. The SPIA polymerizations were investigated by photo-differential scanning calorimeter (photo-DSC) and surface physical properties such as pendulum hardness and pencil hardness. The results showed that the SPIA can cure upon UV irradiation by itself without a photoinitiator. But we found out that both the curing rate and the conversion were too low for the self-curing reaction of SPIA. In order to improve the SPIA curing properties, we introduced the SPIA/cationic hybrid system and observed the effects of the addition of commercial free radical type monomer and photoinitiator on the curing behaviors. SPIA/cationic hybrid system was the best suitable to improve the SPIA curing properties. The kinetic analysis indicated that the cationic monomer and photoinitiator apparently accelerated the cure reaction and rate of the hybrid SPIA system, mostly due to the synergistic effect of cationic monomer and photoinitiator increasing the mobility of active species and the generation of reactive species (free radical, cation) during the photopolymerization process. The physical properties showed that, unlike typical free radical system, the hybrid systems did not show oxygen inhibition effect because of cationic reaction on the coating surface.

• Journal of Korean Medicine Rehabilitation
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• v.29 no.3
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• pp.35-49
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• 2019

Objectives The purpose of this research is to evaluate the effectiveness of moxibustion theraphy for frozen shoulder through systematic review and meta-analysis. Methods The effect of moxibustion for frozen shoulder was constructed as a key question to search randomized controlled trials (RCTs) in 16 databases without type of publication restriction. Results A total of 790 studies were searched and 22 RCTs were finally selected through primary and secondary selection/exclusion process. In most of the evaluation indexes used in each study, moxibustion treatment for shoulder pain was statistically significant compared with other treatments. A meta-analysis of effective rate in 10 studies comparing moxibustion with acupuncture and acupuncture showed a statistically significant effect of moxibustion treatment. And there was a significant effect on the improvement of the shoulder mobility, but the effect size of shoulder pain was no significant effect for shoulder pain reduction. In addition in the result of meta-analysis of 4 studies' effective rate comparing moxibustion with electronic acupuncture, the effect of moxibustion was significantly higher than that of electronic acupuncture in frozen shoulder. Conclusions Moxibustion therapy was effective in symptoms in patients with frozen shoulder. However because of the high risk of bias in the quality of the included studies, the applicability of this study seems to be limited. It is thought that future randomized controlled trials will need to be designed and performed by reviewing ways to minimize bias.

• 재활복지
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• v.20 no.1
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• pp.211-233
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• 2016

The purpose of this study is to figure out problems and to suggest improvement scheme by examining 31 of the disabled who used power wheelchair developed for safe moving and standing support. The results are as follows. First, standing power wheelchair that enables the disabled to sit and stand up was developed. It can also be used as means of transportation for moving in narrow space and in a short distance. In the usability test of this prototype, two groups were respectively examined in 60 evaluation items. One group consisted of 16 people with disabilities using manual wheelchairs. And the other one consisted of 15 people with disabilities using automatic wheelchairs. The entire average figure of two groups was shown to be 2.72 and standard deviation was 0.820. Specifically, the average figure of the group in manual wheelchair was 2.85 and the one of the other group in automatic wheelchair was 2.57. And both group replied that the move to stand up and sit on both types of wheelchair was the most inconvenient thing. It shows why ergonomic design for persons with under extremity disabilities to stand up and sit is needed. Second, with further study based on the results of usability test of the disabled, it will make contribution to increase the quality of people with disabilities by helping them move and do daily lives on their own.

• Journal of vocational education research
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• v.35 no.4
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• pp.47-61
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• 2016

The purpose of this study is to analyze student and university features affecting outcome in labor market after university graduates. For accomplish this, multi-level analysis modeling with HLM(Hierarchical Linear Modeling) was adopted. GOMS(Graduates Occupational Mobility Survey) 2013 data were used for this study, and we added the Information Service of Education data for university information. The result of analysis were as follows. (a) Factors affecting outcome in labor market after university graduate were both student and university features. Significant features were house income, gender, academic major, GPA, and satisfaction in view point of student level. In university level, there were significant variables likes foundation, location, education costs, school type, and satisfaction. (b) We found the different significant variables between student and school level in the participations on the university career program. Significant features were job-experience and job-exhibition in student level, but there were no significant after adding variable in school level. In the school level, there were significant in subjects related career and job, job-exhibition, and consulting.

• The Journal of Korean Academy of Prosthodontics
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• v.57 no.3
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• pp.245-253
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• 2019

Orthognathic surgery of skeletal Class III malocclusion improves oral function and facial appearance. The greater amount of skeletal discrepancy, the greater amount of teeth movement required for decompensation, and this often causes pathological changes in periodontal tissue especially in lower anterior dentition. We made a Top-Down treatment plan with personalized analysis using Face Hunter, Plane System and ARCUS Digma II, in order to resolve severe mobility and cross-bite of lower anterior teeth for 49-year-old female patient who had undergone orthognathic surgery 20 years ago due to skeletal Class III malocclusion and mandibular prognathism. Lower anterior teeth were extracted and alveoloplasty was done. After healing of the wound, immediate loading was conducted immediately after implant placement. Final restorations were fabricated Zirconia using CAD/CAM, and inserted intraorally screw-retained type. During 6-month follow-up, no abnormal episodes of restorations were observed, and obtained satisfactorily both of functional and esthetic outcomes.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.4
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• pp.489-496
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• 2019

This paper is a study on the evaluation of loss factor of damping treatment materials to reduce the noise and vibration for panels of railway vehicles and automobiles. In order to determine the modal parameters of damping materials, beam excitation tests were carried out using different type PVC coated aluminum and steel base beam specimens. The specimens were excited from 10 Hz to 1000 Hz frequency range using sinusoidal force, and transfer mobility data were measured by using an accelerometer. The loss factors were determined by using integrated program, based on theories of Half Power Method, Minimum Tangent Error Method, Minimum Angle Error Method and Phase Change Method, which enable to evaluate the parameters using modal circle fit and least squares error method. In the case of lower loss factor and data of linear characteristics, any method could be applied for evaluation of parameters, however the case of higher loss factor or data including non-linear characteristics, the minimum angle error method could reduce the loss factor evaluation. The obtained dynamic properties of the coating material could be used for application of Finite Element Method analyzing the noise control effects of complex structures such as carbody or under-floor boxes of rolling stock. The damping material will be very useful to control the structural noise, because the obtained modal loss factors of each mode show very good effect on over $2^{nd}$ mode frequency range.

• Journal of Wetlands Research
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• v.24 no.4
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• pp.213-223
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• 2022

This study was conducted to establish a Habitat Suitability index (HSI) based on literature research and field surveys on ecology and habitat of 'Hynobius leechii'. And this study will be used as basic data for qualitative evaluation of habitat environment. The survey sites were divided into natural habitats close to the prototype habitat and artificial restoration areas where Hynobius leechii was monitored. So the types of habitats were diversified. Hynobius leechii is a vulnerable species to climate change because it is affected by the microhabitat and has low mobility. HSI variables of Hynobius leechii were extracted through domestic and overseas literature, and standards were extracted from literature research and field survey. The standards were presented as a value of the physical allowable category in consideration of realization. To verify the study, an in-depth consultation was conducted by amphibians experts. HSI variables of Hynobius leechii were included 9 variables such as Overstory canopy cover(%), Understory cover(%), Water-pH, Soil-pH, Soil relative humidity(%), Leaf litter depth(cm), Rock substrates (%), Type of Coarse woody, Distance from Street or Pollutant(m).

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.32 no.1
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• pp.5-33
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• 2021

This Study seeks for a plan for promotion of smartification of digital services for improving convenience in use and user services of public libraries in smart digital environment. Thus, in this Study, a survey on awareness of a plan for revitalization of digital data and smart libraries has been conducted for the persons in charge of digital data and librarians from public libraries. The result of this Survey are as follows: first, the introduction of smart libraries was effective by first implementing them in small and medium-sized cities with high interest in in information technology, and spreading them to public libraries in metropolitan cities and special autonomous cities; second, it is analyzed that the essential factor of success in introduction of smart libraries is the contents free from the terminals and the upgrade of computer equipment of users available for the use of these services. Terminals are to be individually utilized by smartphone users but it is necessary for upgrade and introduction of 5G which can secure the mobility of users including open type Wi-Fi; third, it is discovered that the information technology the applicability of which is expected to be easy while introducing smart libraries is RFID, which has been already generalized, and bigtata technology. The introduction of IoT technology in which the stakeholders of public libraries in metropolitan cities and special self-governing cities must be considered first.