• Korean Chemical Engineering Research
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• v.43 no.4
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• pp.495-502
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• 2005

Copper was plated on the tungsten substrate by use of a direct copper electroless plating. The optimum deposition conditions were found to be with a concentration of $CuSO_4$ 7.615 g/L, EDTA of 10.258 g/L, and glyoxylic acid of 7 g/L, respectively. The solution temperature was maintained at $60^{\circ}C$. The pH was varied from 11.0 to 12.8. After the deposition, the properties of the copper film were investigated with X-ray diffractometer (XRD), Field emission secondary electron microscope (FESEM), Atomic force microscope (AFM), X-ray photoelectron spectroscope (XPS), and Rutherford backscattering spectroscope (RBS). The best deposition condition was founded to be the solution pH of 11.8. In the case of 10 min deposition at the pH of 11.8, the grain shape was spherical, Cu phase was pure without impurity peak ($Cu_2O$ peak), and the surface root mean square roughness was about 11 nm. The thickness of the film turned out to be 140 nm after deposition for 12 min and the deposition rate was found to be about 12 nm/min. Increase in pH induced a formation of $Cu_2O$ phase with a long rectangular grain shape. The pH control seems to play an important role for the orientation of Cu in electroless deposition. The deposited copper concentration was 99 atomic percent according to RBS. The resulting Cu/W film yielded a good adhesive strength, because Cu/W alloy forms during electroless deposition.

• Journal of The Korean Association of Information Education
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• v.20 no.2
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• pp.139-150
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• 2016

The development of Smart devices has become a key influence on the changes of the school system. As Smart education is integrated and institutionalized in school systems, how it is perceived and utilized by teachers should be investigated. This study is conducted to find out the perception of the teachers on characteristics of Smart education, using qualitative research method, and to analyze importance-performance, using additional quantitative analysis. To figure out the perceptions of the attributes of Smart education by teachers, related literatures were reviewed. The 8 teachers were selected and the data on their perceptions of Smart education were collected through direct observation of class and semi-structured in-depth interview. After researching, we finally drew out 16 final concepts, 6 sub-categories, and 3 categories in the open coding process. Based on the 16 concepts on teachers' perceptions on Smart education, importance-performance analysis (IPA) were conducted to identify areas that need focus and improvement. Based on the results of teachers' perceptions on importance of and the levels of use of Smart education, recommendations were provided for better practice of Smart education in school.

• Journal of Korean Academy of Nursing
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• v.24 no.3
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• pp.484-498
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• 1994

The purpose of this study was to investigate the home care needs in a rural county as a basic study to develop a Korean home care model. A stratified cluster sampling method was used to select 1, 352 household which accounted for 8.8% of Youn Cheon County population. A Standard criterias for home care subject were delineated by five nursing professors representing five different areas of nursing specialty. The developed criteria for home care subjects were as below, 1) Patients who had been discharged from hospital during the previous week. 2) Patients with special medical devices 3) Newborns and the mothers. 4) The chronically ill with poor recovery or control of disease. 5) Subjects with poor health care behavior or ability 6) Subjects with poor social support and / or family resources. 7) Subjects with health related educational needs. Three types of questionnaires were developed to screen home care subjects, one for adults, one for infants and one for the elderly. Also different questionnaire items were developed to evaluate the control and self care ability of chronically ill subjects. After training in interview methods for 2 days, 39 interviewers visited individual households for interviews. As the results of the study showed that 14.1％ of adult subjects and 76.5% of infants and child were judged as having at least one criterion related to home care need, 15.69% of adults and 53% of elderly had at least one chronic illness. The most prevalent chronic illnesses were hypertension, skeletal-neurological disease and diabetes. The prevalence of subjects with home care needs were, those with poor health care behavior(8.89%), with health-re-lated educational needs(8.71%), with poor recovery or control of disease (3.52%), and with poor social support and inadequate family resources(3.19%). There were only 0.3%, 0.37%, 0.11% who were discharged patients, patients with medical devices, or newborns respectively. Thus, the largest home care client group were those who need direct health care and health education. Seventy five percent of the subjects responded that they were willing to use and pay for home care service if it is offered in the future. It is suggested that recently discharged patients and patients with special medical devices can be cared for by hospital based home care nurses, but other home care clients can be cared for by com-munity based home care nurses.

• The korean journal of orthodontics
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• v.31 no.3 s.86
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• pp.347-355
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• 2001

Maxillary and mandibular anterior dental arches often have the problems of occlusal relation and esthetics by malformations of teeth, congenital missing, et at. Though the clinician usually use the anterior ratio to overcome this problems, he has the limitation of a direct application this ratio to the prediction of anterior occlusal relationship by the change of anterior ratio as dental arch form, intercanine width, segment depth and arch perimeter. So this study examine maxillary and mandibular anterior dental arch forms by least square method using Korean normal occlusion models(man : 20 casts, woman : 20 casts). Maxillary and mandibular anterior dental arches of Korean normal occlusion models are curve fitted to polynomial function, beta function, hyperbolic cosine function in order. And this accuracy of curve fitting is constant regardless of man/woman and maxilla/mandible. The relationships between intercanine width, segment depth, and arch perimeter based on this owe fitted dental arch form are acquired. This relationships will give the prediction of anterior dental arch form and the information of more accurate anterior ratio according to intercanine width.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.10A
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• pp.922-929
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• 2005

This paper proposes an adaptive pilot beacon equipment for mobile communication systems based on direct spread spectrum technology which generates the pilot channel for handoff between base stations by using the information acquired from the downstream wireless signal regarding the overhead channel information. Such an adaptive pilot beacon equipment will enable low power operation since among the wireless signals, only the pilot channel will be generated and transmitted. The pilot channel in the downstream link of the CDMA receiver is used to acquire time and frequency synchronization and this is used to calibrate the offset for the beacon, which implies that time synchronization using GPS is not required and any location where forward receive signal can be received can be used as the installation site. The downstream link pilot signal searching within the CDMA receiver is performed by FPGA and DSP. The FPGA is used to perform the initial synchronization for the pilot searcher and DSP is used to perform the offset correction between beacon clock and base station clock. The CDMA transmitter the adaptive pilot beacon equipment will use the timing offset information in the pilot channel acquired from the CDMA receiver and generate the downstream link pilot signal synchronized to the base station. The intermediate frequency signal is passed through the FIR filter and subsequently upconverted and amplified before being radiated through the antenna.

• Journal of the Korea Convergence Society
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• v.9 no.5
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• pp.113-119
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• 2018

The purpose of this study is to verify the effect of participating in teaching material development program using 3D printer on the recognition of universal design for learning of early childhood special education pre-service teachers. This study was conducted on 30 early childhood special education pre-service teachers who participated in teaching material development program using 3D printer. The results of this study showed that the early childhood special education pre-service teachers use of the 3D printer-based teaching material development program resulted in statistically significant differences in the 4 low rank factors of the universal design for learning. This research shows that direct experience in developing teaching material using 3D printers is very effective to improve universal design for learning awareness. In addition, the experience of developing teaching material for pre-service early childhood teachers is important for improving the instructional design ability, and they need the practice of the development of the teaching material using the latest technology for teaching students with various needs.

• Journal of the Microelectronics and Packaging Society
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• v.20 no.4
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• pp.13-16
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• 2013

A lot of various researches have been going on to use heat spreader for LED module. Nano porous aluminum anodic oxide (AAO) applied LED, which is produced from anodization, is easy and economically advantageous. Convensional LED module is consist of aluminum/adhesive/copper circuit. The polymer adhesive in this module is used as heat spreader. However the thermal emission of LED component is degraded because of low heat conductivity of polymer and also reliability of LED component is reduced. Therefore, AAO in this work was applied to heat spreader of LED module which has higher heat conductivity compare to polymer. Bonding strength between AAO and copper circuit was improved with Ti/Cu seed layer by copper sputtering process (DBC) before the bonding. And this copper circuit has been fabricated by electro plating method. Peel strength of AAO and copper circuit in this work showed range between 1.18~1.45 kgf/cm with anodizing process which is very suitable for high power LED application.

• Journal of Aquaculture
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• v.17 no.2
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• pp.115-121
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• 2004

In a series of feeding experiments using the newly established the first laboratory strain of a temperate photosynthetic ciliate, Mesodinium rubrum MR-MAL01, direct evidence was obtained for ingestion of the cultured M. rubrum cells by the bivalves like the Korean scallop, Chlamys farreri and Manila clam. Ruditapes phil-ippinarum. Each experimental Korean scallop and Manila clam removed up to 9,590 and 23,200 cells min-1, respectively. Small particles almost identical to the ruptured cells of MR-MAL01 culture were observed in the gut of the experimental bivalves, although no intact M. rubrum cell was found. In a 28 days rearing experiment, Isoshrysis galbana (KMCC H-2), a microalga, supported better growth of small Manila clam spat (0.46 mm in shell length) than MR-MAL01 strain. For the large Manila clam spat (0.84 mm in shell length), however. MR-MAL01 strain was a better prey item. Mass culture methods for this photosynthetic marine ciliate may be developed for use as live feed in aquaculture of the spat and broodstock of bivalve and small-mouthed fish larvae.

• Spatial Information Research
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• v.17 no.1
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• pp.117-129
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• 2009

South Korea has been undergoing spring drought periodically and diverse researches using vegetation index have been carried out to monitor spring droughts. The strength of the vegetation index-based drought monitoring is that the monitoring method enables efficient spatio-temporal grasp of changes in drought events. According to the development of low resolution satellite images such as MODIS, which are characterized by outstanding temporal resolution, the use of the method is expected to increase. Drought analysis using vegetation index considered only meteorological factor as a cause that affects vitality of vegetation. But many indirect and direct factors affect vegetation stress, So many uncertainties are involved in such method of analysis. To secure objectivity of drought analysis that uses vegetation index it is therefore necessary to compare the method with most representative drought analysis tools that are used for drought management. In this study, PDSI and SPI which a meteorological drought index that quantifies drought and that is used as a basic index for drought monitoring and MODIS NDVI are compared to propose correlation among them and to show usefulness of drought assessment that uses vegetation index. This study shows changing patterns of NDVI and SPI 6-month are similar and correlation between NDVI and SPI was highest in inland vegetation cover.

• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.1
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• pp.118-126
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• 2008

Dental fear is one of the main barriers to the use of dental services, leading patients to avoid periodical dental check-ups or treatments, thus making oral health worse, and sometimes becoming the reason that dental professionals fail control the behavior of patients. Therefore, a dental fear must be controlled carefully in order to promote oral health and effective dental treatment. This study was taken from 313 people 13 to 18 year olds to measure their levels of dental fear. After analyzing the characteristics of dental fear and its related factors, as well as other factors which influence dental fear, we acquired the following results. 1. The level of dental fear was high, compared with advanced countries with relatively good oral health. 2. The strongest physiological response experienced during a dental treatment was the tension of muscles. These dental fears were mainly related to anesthetic needles and drills. 3. Levels of dental fear became higher, the number of times for the dental services utilization had reduced, avoid regular dental examination and perceived oral disease symptoms increased. 4. One of the biggest influences on dental fears turns out to be direct painful experiences and beliefs about dentists.