• 한국결정성장학회지
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• 제6권4호
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• pp.543-551
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• 1996

단결정 표면 및 에피 증착증 표면에 대한 연구가 많아지면서 고에너지전자회절 및 반사전자현미겨의 이용도 늘고 있다. 국내에서는 아직 보편화 되지 않은 이들 두 기술을 위한 시편분비 과정을 요약하였고, 고에너지전자회절 연구시 매우 유용하게 쓰이는 연속 고에너지전자회절 패턴 지도 작성법에 대해 설명하고 그 예를 제시하였다.

• Transactions on Electrical and Electronic Materials
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• 제6권2호
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• pp.57-62
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• 2005

Using intense pulsed ion beam evaporation technique, we have succeeded in the preparation of poly crystalline silicon thin films without impurities on silicon substrate. Good crystallinity and high deposition rate have been achieved without heating the substrate by using lEE. The crystallinity of poly-Si film has been improved with the high density of the ablation plasma. The intense diffraction peaks of poly-Si thin films could be obtained by using the substrate bias system. The crystallinity and the deposition rate of poly-Si thin films were increased by applying (-) bias voltage for the substrate.

• Journal of Periodontal and Implant Science
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• 제35권3호
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• pp.789-798
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• 2005

Primary stability is a fundamental criteria of implant success. There has been various trials to increase initial stability and bone to implant contact. The objective of osteotome technique is to preserve all the existing bone by minimizing or even eliminating the drilling sequence of the surgical protocol. The bone layer adjacent to the osteotomy site is progressively compacted with various bone condensers(osteotomes) this will result in a denser bone to implant contact. This improved bone density helps to optimize primary implant stability in low density bone. The use of wide implant is one of methods to increse primary stability. They can be used in special situations in which they can increase the surface area available for implant anchorage and improve their primary stability The aim of this study was to evaluate the influence of the osteotome technique and implant width on primary stability. Osteotome technique was compared with conventional drilling method by resonance frequency measurments according to the implant fixtures diameter. The results were as follows: 1. The average of ISQ value was sightly higher in osteotome technique, but there was not statistically significant in regular and narrow implant(p <0.05). 2. Either osteotome technique or conventional technique. ISQ value was significantly higer as increasing of implant diameter(p <0.05). 3. ISQ value of drilling technique was higer than those of osteotome technique in wide implant. It was assumed to be caused by difference in final preparation diameter.

• 한국콘텐츠학회논문지
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• 제13권11호
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• pp.404-414
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• 2013

이 연구는 경호전공 대학생의 진로장벽과 진로결정효능감 및 진로준비행동의 관계를 검증하고자 한다. 이 연구는 2012년 서울, 경기도 소재 3개 대학의 경호전공 대학생을 모집단으로 설정한 다음, 유의표집법을 활용하여 최종 130명을 활용하였다. 설문지의 타당도 및 신뢰도는 확인적 요인분석과 신뢰도 분석을 통해 검증하였으며, 설문지의 타당도는 외생변수의 경우 .664, 내생변수의 경우 .787이상으로 나탔다. 이 연구에서는 신뢰도분석을 위하여 AMOS 18.0과 SPSSWIN 18.0 프로그램을 활용하여 공변량구조분석의 기법을 활용하였다. 결론은 다음과 같다. 첫째, 경호전공 대학생의 자기명확성 부족은 진로결정 효능감에 부적 영향을 미친다. 둘째, 경호전공 대학생의 자기명확성 부족은 진로준비행동에 영향을 미치지 않는다. 셋째, 경호전공 대학생의 나이문제는 진로결정효능감에 부적 영향을 미친다. 넷째, 경호전공 대학생의 나이문재는 진로준비행동에 영향을 미치지 않는다. 다섯째, 경호전공 대학생의 신체적열등감은 진로결정효능감에 영향을 미치지 않는다. 여섯째, 경호전공 대학생의 신체적열등감은 진로준비행동에 영향을 미치지 않는다. 일곱째, 경호전공 대학생의 진로결정효능감은 진로준비행동에 영향을 미친다.

• Food Science and Biotechnology
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• 제18권2호
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• pp.565-569
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• 2009

This study was conducted to evaluate the effects of different preparation methods on the recovery and quantification of ginsenosides in raw Korean ginseng (Panax ginseng C.A. Meyer). Eight major ginsenosides ($Rb_1$, $Rb_2$, $Rb_3$, Rc, Rd, Re, Rf, and $Rg_1$) were analyzed by high performance liquid chromatography (HPLC), after which the recovery and repeatability of the extraction of those ginsenosides using 3 different preparation methods were compared [A. direct extraction (DE) method, hot MeOH extraction/evaporation/direct dissolution; B. solid phase extraction (SPE) method, hot MeOH extraction/evaporation/dissolution/$C_{18}$ cartridge adsorption/MeOH elution; C. liquid-liquid extraction (LLE) method, hot MeOH extraction/evaporation/dissolution/n-BuOH fractionation]. Use of the DE method resulted in a significantly higher recovery of total ginsenosides than other methods and a relatively clear peak resolution. Use of the SPE and LLE methods resulted in clearer peak resolution, but lower ginsenoside recovery than the DE method. The LLE method showed the lowest ginsenoside recovery and repeatability among the 3 methods. Given that the DE method employed only extraction, evaporation, and a dissolution step (avoiding complicate and time consuming purification), this technique may be an effective method for the preparation and quantification of ginsenosides from raw Korean ginseng.

• Restorative Dentistry and Endodontics
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• 제25권1호
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• pp.116-122
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• 2000

On the instrumented root canal wall, amorphous, irregular smear layer can be observed with Scanning Electron Microscope(SEM). The purpose of this study was to evaluate the effect of the presence or absence of smear layer on the adhesion of Staphylococcus aureus to the dentin of the root canal. Human incisors, extracted within 7 days, with no caries, no fracture, no calcification of canal, were selected. After cutting crown portion at cemento-enamel junction, root canal preparation was done by modified crown-down technique using Profile and Gates - Glidden Drill. During canal preparation, 10ml physiologic saline solution(group1&3) or 10ml 3.5% NaOCl(group2&4) was used as irrigation solution. And 10ml physiologic saline solution(group1&3) or 10ml 0.5M EDTA(group2&4) was applicated for final flush. After vertical sectioning and ethylene oxide gas sterilization, samples(group1&2) were immersed into BHIYHM broth inoculated with Staphylococcus aureus (ATCC 31153) and incubated for 3hrs at $37^{\circ}C$. All samples were prepared for and observed with SEM(JEOL JSM840S). The data were analyzed by Mann-Whitney rank sum test. The conclusions are as follows ; 1. Smear layer covers entire root canal surface after root canal preparation. 2. Smear layer has been removed away and the entrances of dentinal tubules have opened widely, when applying 0.5M EDTA and 3.5% NaOCl. 3. A significantly higher number of bacteria were adhered to the root canal dentin without smear layer(p<0.0001). 4. Smear layer produced during root canal preparation impedes bacterial adhesion and colonization to dentin matrix, therefore inhibits canal reinfection.

• 디지털융복합연구
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• 제16권12호
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• pp.61-69
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• 2018

이 연구는 청년들의 높은 비정규직 비율과 계층 양극화의 우려 속에서 저소득층 대학생의 진로준비과정에 대해 이해하고 시사점을 구하기 위한 것이다. 이를 위하여 S 장학재단에서 장학금 지원을 받는 13명의 대학생들을 연구 대상으로 선정하였고, 6회의 인터뷰를 진행하여 그 축어록을 바탕으로 텍스트마이닝 기법을 활용한 분석을 실시하였다. 분석 결과, 대학생들은 인터뷰 과정에서 이전의 학업 경험을 회상하거나 진로를 설계할 때, 가정환경과 소득수준의 영향을 받는 것으로 보이며, 이러한 차이는 성별, 전공별로 다른 특성이 있는 것으로 나타났다. 이 연구는 질적 연구 방법으로 축적된 자료에 텍스트마이닝 기법을 융합적으로 적용하여 분석한 연구로 종래의 진로연구에 비하여 방법론적 확장을 시도했다는 의의를 갖고 있다. 그 결과, 저소득층 대학교 장학생들의 성별 및 전공별 진로준비과정의 차이를 대학생활 및 진로준비와 관련된 단어들의 관계를 통해 탐색적으로 살펴볼 수 있었다.

• BMB Reports
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• 제39권3호
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• pp.247-252
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• 2006

A rapid method for the detection of Hepatitis E Virus (HEV) was developed by utilizing nano-gold labeled oligonucleotide probes, silver stain enhancement and the microarray technique. The 5'-end -$NH_2$ modified oligonucleotide probes were immobilized on the surface of the chip base as the capture probe. The detection probe was made of the 3'-end -SH modified oligonucleotide probe and nano-gold colloid. The optimal concentrations of these two probes were determined. To test the detection sensitivity and specificity of this technique, a conservative fragment of the virus RNA was amplified by the RT-PCR/PCR one step amplification. The cDNA was hybridized with the capture probes and the detection probes on microarray. The detection signal was amplified by silver stain enhancement and could be identified by naked eyes. 100 fM of amplicon could be detected out on the microarray. As the results, preparation of nano-gold was improved and faster. Development time also was shortened to 2 min. Thus, considering high efficiency, low cost, good specificity and high sensitivity, this technique is alternative for the detection of HEV.

• 한국자원식물학회지
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• 제35권6호
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• pp.778-784
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• 2022

Wild vegetables, such as Cirsium setidens, and Aster scaber, are commonly distributed as dried materials because the wild vegetables lose their freshness quickly after harvest and distribution. Dried wild vegetables require rehydration to use as a food ingredient, and the quality of rehydrated wild vegetables is affected by pre-drying and drying methods. Here, we introduce the newly developed pre-drying and drying method, termed "micro oil sprayed thermal air (MOTA) technique". The three wild vegetables processed by the MOTA technique showed improved rehydration rate and reduced time to achieve maximum rehydration rate. Color characteristics were also improved in C. setidens. These results indicate that the MOTA technique improves the overall quality of rehydrated wild vegetables. It is expected that our findings could enhance the marketability of dried wild vegetables by improving overall quality and reducing preparation time.

• Restorative Dentistry and Endodontics
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• 제22권1호
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• pp.244-253
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• 1997

During preparation of narrow curved canals, procedural accidents such as, ledge, zipping, and transportation are frequently encountered and may lead to failure of endodontic therapy. To reduce these procedural errors and efficiently manage curved canals, various modifications in instrumentation technique and the design and flexibility of instruments have been advocated. This study compared the maintenance of the original canal curvature, cross sectional canal shape, and preparation time during instrumentation with stainless steel hand (K-Flexo) file, and nickel-titanium rotary files (Profile and Lightspeed). Thirty resin blocks with simulated curved canals of 20~25 degrees were used and divided into three groups of 10 each. In group 1, canals were instrumented using a quarter turn/pull technique with K-Flexofiles. Group 2 canals were prepared with rotary NiTi Profiles. Group 3 was prepared with rotary NiTi Lightspeed instrument. Before and after instrumentation, all canals were scanned using stereo microcope, FlexCam camera, and Photoshop 3.0 computer program. The results were as follows : 1. All groups showed some loss of canal curvature after instrumentation. Average loss of canal curvature was 8.6 degrees for K-Flexofile, 7.7 degrees for Profile, and 5.8 degrees for Lightspeed. Lightspeed exhibited significantly less curvature loss than K-Flexofile (p<0.05). 2. At the apical 1-mm level, Profile produced significantly rounder canals than Lightspeed (p<0.05). At the 3-mm level, Profile and Lightspeed exhibited significantly rounder canals than K-Flexofile (p<0.05). 3. Preparation with Lightspeed was significantly faster than Profile and K-Flexofile, and Profile was faster than K-Flexofile (p<0.05). 4. There was no significant difference in incidence of zipping between the hand K-Flexofile and rotary NiTi (Profile and Lightspeed) instruments. Most of apical canals were slightly widened near the apical foramen. As a results of this study, rotary NiTi instruments are superior to the K-Flexofile in regard to the maintenance of original canal curvature, cross-sectional shape and preparation time. But more investigations and studies should be needed to evaluate the ideal canal instrumentation.