• Journal of Periodontal and Implant Science
• /
• 제39권4호
• /
• pp.385-390
• /
• 2009

Purpose: In this study we evaluated the morphologic aspects of defects created by a piezoelectric ultrasonic scaler with scaler tip on casting gold alloy using scanning electron microscope (SEM) images and defect surface profiles. Methods: 54 blocks of type III casting gold alloy (Firmilay, Jellenko Inc, CA, USA) were scaled by a piezoelectric ultrasonic scaler (P-MAX, Satelec, France) with scaler tip (No. 1 tip) on a sledge device. 2-dimensional profiles of defects on all samples were investigated by a surface profilometer (a-Step 500, KLA-Tencor, CA, USA). The selected working parameters were lateral force (0.5 N, 1.0 N, 2.0 N), mode (P mode, S mode), and power setting (2, 4, 8). SEM images were obtained. Defect surface profiles were made on Microsoft Excel program using data obtained by a surface profilometer. Results: Among P mode samples, there were similarities on defect surface profiles and SEM images regardless of lateral force. The defects created in P mode were narrow and shallow although the depth and the width increased as power setting changed low (2) to high (8). In P mode samples, the defect depth was the greatest when lateral force of 0.5 N was applied. However all the depths were smaller than 1 m. SEM images of Lateral force of 0.5 N, S mode, power setting 2 and 4 were similar to that of P mode, but the other SEM images of S mode showed discernible changes. Defect depth of S mode samples was the greatest when lateral force of 1.0 N was applied. Conclusions: Within the limitations of this study, it can be concoluded that removing capability of piezoelectric scaler with scaler tip becomes maximized as power level becomes higher but the capability is restricted when excessive lateral force is applied on scaler tip.

• 디지털융복합연구
• /
• 제19권9호
• /
• pp.1-8
• /
• 2021

이 연구의 목적은 영어쓰기 교과목에서 자동쓰기평가(AWE) 프로그램의 사용자 만족도가 영어쓰기 자기효능감을 매개로 학습자의 학습성취감에 미치는 영향을 알아보기 위한 것이다. AWE는 쓰기 결과물에 대해 인공지능 기술에 의해 자동으로 피드백을 제공하는 프로그램이다. 영어쓰기 교과목을 수강하는 대학생을 대상으로 각 주제별로 작문을 하고 AWE 프로그램을 사용하여 피드백을 받은 후 그것을 참고하여 최종 수정본을 제출하도록 하였다. 설문지를 통해 수집된 데이터(n=99)를 SPSS, Smart PLS-SEM으로 분석하였다. 연구결과, 첫째, AWE의 사용 편의성과 유용성은 재사용 의지에 긍정적 영향을 미치는 것으로 나타났다. 둘째, AWE 사용 만족도는 영어쓰기 자기효능감에 긍정적 영향을 미치는 것으로 나타났다. 셋째, 영어쓰기 자기효능감은 언어적, 정서적 측면에서 학업 성취감에 긍정적 영향을 미치는 것으로 나타났다. 4차 산업 및 인공지능 기술 발달에 따라 영어교육에 AWE와 같은 새로운 학습재료 도입을 권장한다.

• 대한토목학회논문집
• /
• 제34권6호
• /
• pp.1807-1814
• /
• 2014

자연재해는 발생 자체를 막는데 한계가 있기 때문에 피해저감을 위해서는 예방사업을 통해 재해발생을 사전에 예방하는 것이 중요하다. 자연재해발생의 증가와 함께 자연재해와 관련된 예방사업에 대한 관심이 높아지고 있으며, 이와 관련된 투자도 증가하고 있다. 이와 함께 자연재해예방사업에 대한 투자 시, 그 파급효과 등을 검증할 수 있는 평가 역시 중요한 과제로 대두되고 있다. 자연재해예방사업과 같은 국가 공공투자사업을 평가하기 위해서 비용편익분석과 같은 정량적 분석을 통한 연구는 지속적으로 수행되고 있다. 정량적 분석방법만으로 사업의 효과를 충분히 설명하지 못한다는 문제점에도 불구하고 재해관련 분야에서 효과분석이나 평가를 위한 다양한 방법이 제시되지 못하고 있는 것이다. 본 연구에서는 정성적 분석을 통한 자연재해예방사업의 사후평가를 위해서 자연재해예방사업의 사후평가에 영향을 미치는 항목들을 도출하고, 구조방정식모델(SEM : structural equation modeling)을 통해 사후 평가항목과 사업효과 간 인과관계 분석 및 가중치를 산정하였다. 이를 바탕으로 자연재해예방 사업에 대한 사후평가지수 산정식을 제시하였다.

• 한국재료학회지
• /
• 제21권2호
• /
• pp.125-132
• /
• 2011

Fibrous chitosan membranes were fabricated as a substrate for skin applications using an electro-spinning process with different solvents and varying concentrations. Scanning electron microscopy (SEM) images confirmed that the formation of the chitosan fibrous membrane in trifluoroacetic acid was better than that in acetic acid. Fourier transform infrared spectroscopy showed that the chitosan fibers were cross-linked with glutaraldehyde, and that the cytotoxicity of the aldehyde groups was reduced by glycine and washing by NaOH and DI water. Chitosan cross-linked fibrous membranes were insoluble in water and could be washed thoroughly to wash away glycine and excess NaOH and prevent the infiltration of other water soluble bio-toxic agents using DI water. MTT assay method was employed to test the cytotoxicity of chitosan membranes during fabricating, treating and washing processes. After the dehydration of cell cultured chitosan membranes, cell attachment behavior on the material was evaluated using SEM method. Effect of the treatment processes on the biocompatibility of the chitosan membranes was shown by comparing of filopodium and lamellipodium of fibroblast cells on grown washed and unwashed chitosan fibrous membrane. The MTT assay and SEM morphology confirmed that the washed chitosan fibrous membrane increased cell attachment and cell growth, and decreased toxicity compared to results for the unwashed chitosan fibrous membrane.

• 열처리공학회지
• /
• 제21권3호
• /
• pp.144-149
• /
• 2008

It has been reported that copper and copper alloys have a large anisotropy of functional properties such as electrical, thermal and mechanical properties, which means that the texture of polycrystalline alloy should be considered to achieve better properties. In this study, the determination of grain growth orientation and texture formation in the cold-rolled, heat-treated and Ni-plated hybrid copper sheets was investigated. Grain growth direction and texture formation were analyzed by the X-ray pole figure. The influence of texture on the mechanical properties could be quantitatively confirmed by the results from the orientation distribution function and the tensile test. The heat-treated texture in the cold-rolled hybrid copper sheet is also investigated and discussed.

• 한국조리학회지
• /
• 제15권3호
• /
• pp.262-270
• /
• 2009

본 연구는 밀 배아를 0, 3, 5, 7% 첨가하여 상화병을 제조함으로써 현대인의 기호에 맞는 전통식품으로의 가능성을 제시한 것으로써 Aw, color value, SEM, 관능적 특성을 측정하였다. 수분활성도는 밀 배아 첨가량이 많아질수록 감소하여 미생물 억제 효과와는 무관하였으며, 색도는 첨가량에 상관없이 저장기간이 길어짐에 따라 명도와 황색도는 감소하는 경향을 보였으며, 적색도는 증가하는 모습을 보였다. 상화병의 관능적 특성에서 crust color, crumb color, wheat germ flavor에서 7% 첨가구가 가장 강도가 높은 것으로 평가되었고, 상화병의 기호도 평가에서는 Odor와 taste, overall acceptability 에서 밀 배아 5% 첨가구가 가장 좋은 기호도를 보여 주어 산업화의 가능성을 제시하였다.

• 패션비즈니스
• /
• 제15권3호
• /
• pp.142-155
• /
• 2011

By developing attitude transfer model, this study examined the co-marketing alliance effect between fashion and other industries (i.e., service and product brands) based upon the information integration theory. In addition, it examined the product tangibility/intangibility effects of partner brands by controlling stimuli: two alliance cases of fashion and service brands and two alliance cases of fashion and product brands. A total of 1,037 Korean women aged 20 to 39 were surveyed to compare the prior- and post- attitudes toward fashion/partner brands under four fictitious co-marketing alliance cases. Confirmatory factor analysis (CFA), multi-group CFA, structural equation modeling (SEM) analysis, and multi-group SEM analysis were conducted to test the hypotheses. The results demonstrated that the prior-attitude toward fashion brand partially affected the alliance attitude, and the co-marketing alliance was affected by prior-attitudes partner brands. The result of multi-group SEM analysis supported the significant differences between service and product brands as alliance partners, which might refer to the effect of product tangibility, existing in brand alliance contexts. The alliance evaluation affected the subsequent evaluations on each participating brands. This study empirically provides the conceptual structure of how consumer attitudes toward the participating brands interact with the attitudes toward alliance and offer practical insights. Specifically, upon employing the manipulated co-marketing alliances cases, this study demonstrates the partnering effect according to product tangibility of partner brands.

• 한국의류학회지
• /
• 제31권8호
• /
• pp.1240-1251
• /
• 2007

The purpose of this study was to examine the relationship between weight of fabrics and texture and sensibility and preference of consumers for F/W women's jacket fabrics. Structural Equation Model(SEM) using AMOS program was conducted to analyze the relationships. Then, this study aimed to provide useful information in planning designing fabrics through predicting the subjective characteristics analyzed. The main survey was developed the 7-point semantic differential scale of subjective texture, sensibility and preference. Fifty trained female panelists of 20-30 years old were participated and questionnaire method was used with 20 kind of fabric. The evaluation methods such as by the sense of sight & touch were used when fabrics were estimated subjectively. When evaluated by the sense of sight & touch, fabric's weight did not have effect directly on preference, but had effect indirectly on preference through the texture and the sensibility..

• Journal of Dental Anesthesia and Pain Medicine
• /
• 제20권3호
• /
• pp.119-127
• /
• 2020

This study was conducted to determine how precooling reduces the subjective reported pain and objective pain and to evaluate the effectiveness of precooling the injection site before administration of local anesthesia in children. Electronic databases (PubMed, Ovid SP, Cochrane Central Register of Controlled Trials) were searched for publications from 1980 to 2020. Studies were screened for titles and abstracts, followed by full-text evaluation of included reports. Six studies were included in this systematic review. The primary outcome evaluated was the pain perception or the subjective pain reported by the child receiving the injection. The secondary outcome evaluated was objective pain evaluated in each study. Among 5 studies that evaluated child reported pain scores on a visual analogue scale (VAS), 4 studies reported lower scores in the precooling group and one study reported a higher VAS score in the precooling group than in children treated with 20% benzocaine topical anesthesia. Among 6 studies that evaluated the pain reaction of children by Sound Eye Motor (SEM) score, 4 studies reported a lower SEM score in the precooling group, one study reported no significant difference between the precooling and control groups, and one study reported higher SEM scores in the precooling group than in children treated with 20% benzocaine topical anesthesia. Within the limits of this systematic review, evidence suggests that precooling the injection site with ice can be an effective adjunct to topical anesthesia in reducing both subjective and objective pain during local anesthesia administration in children.

• 한국전기전자재료학회논문지
• /
• 제24권10호
• /
• pp.844-849
• /
• 2011

Two kind of Ag-pastes were prepared for integrating the bulk Si solar cell. One is the Ag-paste with Pb-based glass frit and the other is that with Bi-based glass frit. The pastes were the mixture of 84 wt% Ag, 2 wt% glass frit, 11 wt% solvent of buthyl cabitol acetate, and 2 wt% additives. After fabricating the Ag-pastes, they was coated on a $SiN_x$/n+/p- stacks of a commercial mono-Si solar cell. The solar cell efficiency was 17.6% in the case of the Pb-based Ag-paste. However that was 16.2% in the solar cell integrated with the Bi-based Ag-paste. The lower performance in Bi-based Ag-paste was caused by the higher series resistance and the lower shunt resistance in comparison with the Pb-based Ag-paste.