• 한국해양학회지
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• v.22 no.3
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• pp.143-152
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• 1987

The digital data were obtained using Kennedy 9000 magnetic tape deck which was connected to the SMS960 side scan sonar during the field operations. The data of three consecutive survey tracks near Seongsan-po, Cheju were used for the development of this study. The softwares were mainly written in Fortran-77 using VAX 11/780 MINI-COMPUTER (CPU Memory; 4MB). The established mapping system consists of the pretreatment and the digital processing of seafloor image data. The pretreatment was necessary because the raw digital data format of the field magnetic tapes was not compatible to the VAX system. Therefore the raw data were read by the personal computer using the Assembler language and the data format was converted to IBM compatible, and next data were communicated to the VAX system. The digital processing includes geometrical correction for slant range, statistical analysis and cartography of the seafloor image. The sound speed in the water column was assumed 1,500 m/sec for the slant range correction and the moving average method was used for the signal trace smoothing. Histograms and cumulative curves were established for the statistical analysis, that was purposed to classify the backscattering strength from the sea-bottom. The seafloor image was displayed on the color screen of the TEKTRONIX 4113B terminal. According to the brief interpretation of the result image map, rocky and sedimentary bottoms were very well discriminated. Also it was shown that the backscattered acoustic pressurecorrelateswith the grain size and sorting of surface sediments.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.26 no.1
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• pp.24-39
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• 2000

Various methods and graft materials have been used to fill in the defect adjacent to the implants and considered as clinically acceptable. But it is not clear whether the regenerated bone increases the implant-bone contact and supports the implant. The purpose of this study is to evaluate regenerated bone surrounding implants using bone morphogenetic protein(BMP) and demineralized freeze-dried bone(DFDB), and the interfaces between implants and regenerated bone. bBMP was extracted and partially purified from the bovine bone matrix using heparine chromatography. Demineralized freeze-dried bone was made from the dog. Inactive insoluble collagenous bone matrix(IBM) of dog was used as carrier of bBMP. Interfaces of titanium coated epoxy resin implants were processed for demineralized section for transmission electron microscopy(TEM) and those of screw type implants were for nondemineralized section for light and fluoromicroscopic examination. Implants were inserted in the inferior border of mandible of adult dogs and artificial bony defects($3{\times}3{\times}4mm$) were made at the mesial and distal side of implants. Defects were filled with BMP(BMP group) and DFDB(DFDB group). For the fluoromicroscopic examination, the fluorescent dyes(oxytetracycline, calcein green, alizarin red) were injected 2, 4, 6, 8, 12 weeks after implantation. The experimental animals were sacrificed at the 6th and the 12th week and their mandible were extirpated and processed for examination with light microscopy, fluoromicroscopy and TEM. The obtained results were as follows : 1. By the light microscopic findings, the defects were filled with woven bone at the 6th week and compact bone at the 12th week, and the osseointegrations were seen in both groups. There was no histological difference between them. 2. On the basis of the histomorphometric analysis, BMP group(6th week: 40.25%, 12th week: 56.04%) had higher bony contact ratio than DFDB group(38.37%, 42.63%). There was significant difference between two groups at the 12th week(p<0.05). 3. The amount of bone formation in BMP group was more prominent than in DFDB group. Significant difference was noted among two groups at the 6th and the 8th week(p<0.05). 4. By the transmission electron microscopic findings, $0.4-2{\mu}m$ soft tissue layer was found in adjacent to the interfaces and over the collagen fibrils of bone at the 6th week. However, about 100nm amorphous layer was noted at the interface or collagen fibrils directly extended to the titanium surface at the 12th week. There was no significant difference between two groups. 5. These results suggest that BMP and DFDB can be used as good graft materials in the regeneration of bone adjacent to implant, and BMP is more valuable as a bone inducer than DFDB.

• Journal of dental hygiene science
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• v.13 no.3
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• pp.264-270
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• 2013

This research, which was conducted for dental hygienists, intended to check out what factors have an influence on their practices by knowledge and attitude on radiation safety management (RSM). This study performed a survey on such an issue from July 2 to August 30, 2012 for 220 dental hygienists who worked in Busan, Gyeongnam areas. The data was analysed using the IBM SPSS Statistics 21.0 program. The results were as follows: As a result of the knowledge according to the general characteristics and RSM, a statistically meaningful difference was found according to the education on radiation and wearing apron. As for the attitude according to the general characteristics and RSM, a statistically meaningful difference was found according to the education on radiation and wearing apron. As to the practice according to the general characteristics and RSM, a statistically meaningful difference was found according to the education on radiation, wearing thermo luminescent dosimeter and wearing apron. When the analysis of safety management practice for radiation was conducted with the independent variables such as knowledge, altitude and health concerns about radiography, it turned out that the factors having an effect on the practice were altitude and health concerns by that order.

• Journal of dental hygiene science
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• v.15 no.2
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• pp.226-231
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• 2015

The purpose of this study was to evaluate the accuracy of model according to three types of dental scanner. A maxillary acrylic model was prepared and duplicated 10 times by silicone impression materials. Corresponding working casts were formed from scannable stone and got a 3-dimensional digital models using three different scanners. The distance of each measurement region was measured using vernier calipers and the respective program. One-way ANOVA and the Tukey honestly significant difference post hoc test (${\alpha}=0.05$) was performed using IBM SPSS Statistics 21.0. Overall, the stone cast is smaller than the digital models in measurement distance. And measuring point value of laser scanner showed the most similar values and measurement points value of digital vernier calipers. Digital model of white light scanner showed similar values in the measurement points value of the blue light scanner. In conclusion, the laser scanner showed the best accuracy among the three types of dental scanner. However, the difference between the digital models and the stone cast can be accommodated in making prostheses. Thereby, three types of dental scanner are available in a clinically acceptable range.

• Journal of dental hygiene science
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• v.15 no.6
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• pp.825-835
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• 2015

The purpose of this study was to examine the relationships between depression, stress, self-esteem, oral health-related quality of life (OHIP-14) in middle-aged women. Data were as collected by self-reported questionnaires from 205 middle-age women. The instruments were the Center for Epidemiologic Studies Depression scale (CES-D), Brief Encounter Psychosocial Instrument (BEPSI), Self-Esteem Scale (SES). The data were analyzed using t-test, one-way ANOVA, Pearson correlation coefficients and multiple regression with IBM SPSS Statistics ver. 21.0. Pearson correlation coefficient analysis found that oral health impact profile (OHIP) was significantly associated with depression (r=-0.560, p<0.001), stress (r=-0.595, p<0.001), self-esteem (r=0.522, p<0.001). The OHIP was explained 39.4% by stress (${\beta}$=-0.362, p<0.001), self-esteem (${\beta}$=0.203, p=0.009) using multiple regression analysis. These results indicate that the intervention program of oral health promotion for community-middle- aged women is needed from now on.

• Journal of dental hygiene science
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• v.15 no.6
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• pp.689-695
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• 2015

The aim of this study was to examine the image for dental hygienists and career consideration in academic high school students. A self-reported questionnaire was surveyed by 199 high school students in Gwangju. The questionnaire composed subject's general characteristics, image for dental hygienists, career consideration. The data were analyzed for independent t-test or Mann-Whitney test, one-way ANOVA or Kruskal wallis test and pearson's correlation coefficient by using IBM SPSS Statistics ver. 21.0 program. The average of total image was 3.36, personal images were 3.64, occupational images were 3.47, business images were 3.42, social images were 2.83 in the five-point scale. The image of dental hygienists was higher significantly in case of having a dental practitioner in the family, treatment experience less than 1 year, and treatment in dental hospital. The participants who considered to be dental hygienist were higher significantly in occupational and social images. There were positive correlations among the personal, occupational, business, social images of dental hygienists. These results showed that general images for dental hygienists were slightly positive but among them, social image was the lowest level. It showed that most students didn't consider to be dental hygienist. Therefore, we suggested to enhance positive recognition for dental hygienists be needed.

• Proceedings of the Materials Research Society of Korea Conference
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• 2012.05a
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• pp.52-52
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• 2012

최근 선진국을 중심으로 제조기술의 산업혁명이라고 불릴 정도로 큰 파급효과가 기대되는 자기조립기반의 산업공정기술을 확보하기 위한 많은 노력과 연구들이 활발하게 진행되고 있다. 자기조립(Self-Assembly) 현상은 자연에서 일어나는 자발적인 힘으로 원자 또는 분자 단위까지 구조물을 제어하고 bottom-up 방식(상향식: 원자/분자 스케일의 나노구조를 배열/조립하여 원하는 형태의 패턴을 만들어 내는 방식)으로 원하는 구조물을 설계/제작할 수 있는 능력을 가지고 있다. 기초적인 과학으로부터 출발한 자기조립기술은 최근 자기조립 응용개발에서 많은 성과를 이루어내면서 산업화 가능성을 크게 하고, 과학계와 산업계의 많은 관심을 불러일으키고 있다. 반도체 산업기술을 예측하는 ITRS 로드맵(2005년)에 의하면 directed self-assembly 방법이 새로운 미래 패터닝 기술로 개발되어 2016년경에 사용되고, 자기조립소재로 제작된 다양한 응용소자들은 새로운 미래소자로 개발될 것으로 예상하고 있다. 이에 맞추어 국내 기업들도 diblock copolymer를 이용한 나노패터닝 기술 확보를 위한 연구를 진행하고 있다. 또한 IBM은 자기조립기술을 반도체공정에 실험적으로 적용하여 자기조립기술이 생산 공정에 부분적으로 적용될 가능성이 크다는 것을 보여주었다. 산업계와 함께 학계의 연구센터에서는 산업화를 위한 자기조립 집적화 공정(Integrated process) 개발을 이루기 위하여 체계적으로 연구를 실시하고 있다. 미국의 Northeastern 대학의 CHN(Center for high-rate Nanomanufacturing) 연구센터는 자기조립 집적화에 용이한 새로운 개념의 소자를 제안하고 이를 집적화하기 위한 다양한 공정을 개발하고 있으며, Wisconsin 대학의 NSEC(Nanosacle Science and Engineering Center) 연구센터는 diblock copolymer를 이용한 나노패터닝 기술 개발에서 획기적인 결과를 도출하여 산업계에 적용될 가능성을 높이고 있다. 이와 같은 결과들로부터 앞으로의 자기조립기술에 대한 연구는 3차원 구조물을 제작할 수 있는 집적화 공정에 집중될 것이고, 이를 위하여 새로운 개념의 단순한 구조의 응용소자개발도 함께 추진될 것으로 판단된다. 또한 실용 가능성이 큰 집적화 공정으로 개발하기 위하여 기존의 top-down 방식을 접목한 bottom-up 방식의 자기조립 집적화 공정이 개발될 것으로 예상하고 있다. 이와 함께 자기조립공정은 반복되는 구조를 쉽게 제작할 수 있는 장점을 가지고 있어 다양한 응용소자 [태양전지(solar cell), 연료전지(fuel cell), 유연성 있는 전자기기(flexible electronics), 화면표시 장치(display device)] 제작에 쉽게 이용되어 새로운 산업을 창출할 수 있는 가능성을 보이고 있다. 본 자기조립 연구 센터에서는 이와 같은 자기조립 특성을 제조공정에 적용하여 혁신적인 제조공정기술을 확보하고자 연구를 진행하고 있다. 그러므로 본 발표에서 이와 같은 연구 흐름과 함께 본 센터에서 진행하고 있는 자기조립 제조방법을 소개하고자 한다. 이와 함께 자기조립방법을 이용하여 제작된 다양한 응용소자 개발 결과를 발표하고, 이를 top-down 방식과 접목하여 집적화공정으로 개발하는 전략을 함께 소개하고자 한다.

• Journal of dental hygiene science
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• v.15 no.3
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• pp.369-376
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• 2015

The purposes of this study were to assess dental fear and anxiety level of patients attending a dental clinic using the dental fear survey (DFS) scale, to apply interventions chosen by patients for reducing dental fear and anxiety and measure their effects. This study surveyed 34 patients who visited a dental clinic in Seoul about their self-rated health and their experience of dental fear, and measured the level of dental fear using DFS. Trained dental hygienists applied interventions desired by the patients for reducing dental fear and anxiety and, for each intervention, examined the patients' satisfaction (very helpful [5 point]~not helpful at all [1 point]). Collected data were analyzed using IBM SPSS Statistics ver. 21.0 through independent t-test or one-way ANOVA for difference in level of fear according to related characteristics, and through Wilcoxon signed rank test for comparison between before and after the intervention. The subjects' mean level of fear (DFS score) was 44.53, which was an average level, and the level of dental fear was relatively high for stimulus-response (2.72). The level of dental fear was higher in those who had experienced pains or indirect dental fear from dental treatment in the past, and those whose subjectively perceived health state was poor (p<0.05). With regard to the applied dental fear intervention, 'Helpful (3.57)' was the most common answer. Overall satisfaction before and after the application of dental fear intervention was generally high as 4.37 and 4.35, respectively, but it decreased slightly after the intervention. In order to lower the level of dental fear, it is considered effective to survey not only the level of dental fear but also patients' need of dental fear interventions and to apply a suitable intervention. It is also required to educate dental workers and to develop related manuals.

• Journal of dental hygiene science
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• v.15 no.3
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• pp.287-294
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• 2015

The aim of the study was to investigate the affecting factors on National Health Insurance coverage dental scaling experience. The self-reported survey for the adults living in Seoul, Gyeonggi province and Incheon had been progressed from February 10, 2014, to February 28, 2014, after receiving informed consents. And the 238 survey results had been analysed as the data of this study. The data analysis such as frequency analysis, ${\chi}^2$-test, and multi-logistic regression (p<0.05) for all collected survey data had been processed using IBM SPSS Statistics ver. 20.0. According to multiple logistic regression analysis, regular dental check-up (odds ratio [OR], 2.63; confidence interval [CI], 1.05~6.59) and dental scaling experience (OR, 3.06; CI, 1.09~8.54), monthly income (OR, 3.55; CI, 1.01~12.56) were the factors having statistically significant influence. Therefore, in order to increase of National health insurance dental scaling experience, it is necessary to increase awareness of the new dental scaling system through the promotion and oral health education about national health insurance dental scaling, and to emphasize the importance of dental Scaling by regular dental check-up.

• Journal of dental hygiene science
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• v.15 no.1
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• pp.12-17
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• 2015

The purpose of this study was to evaluate the marginal and internal gap of metal coping fabricated using additive manufacturing (AM) group and subtractive manufacturing (SM) group by dental computer-aided design (CAD)/computer-aided manufacturing (CAM) systems. Twenty same cases of stone models of abutment teeth 16 by the universal numbering system were manufactured and scanned. Ten metal copings of control group were fabricated using SM and ten metal coping of experimental group were fabricated using AM. Marginal and internal gap of copings were measured using the silicone replica technique and digital microscope (${\times}140$). The data were analyzed using IBM SPSS 21.0 Statistical Software for independent samples t-test (${\alpha}=0.05$). Mean${\pm}$ standard deviation (SD) of marginal and internal gap total size of SM group was $101.00{\pm}40.33{\mu}m$ of AM group was $83.61{\pm}40.37{\mu}m$. Mean${\pm}$SD of marginal and internal gap total size of SM group was significantly greater than that of AM group (p<0.05). This study showed that AM metal copings had a better marginal and internal gap than SM metal copings.