• Journal of Dental Rehabilitation and Applied Science
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• v.33 no.2
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• pp.97-105
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• 2017

Purpose: The purpose of this study was comparing the efficacy of passive irrigation (PI) and passive ultrasonic irrigation (PUI) for ability to remove debriment of canals. Materials and Methods: Mandibular premolars were decoronated and standardized to 16 mm length. After root canal enlargement and half separating longitudinally, standardized groove of 4 mm length, 0.2 mm width and 0.5 mm depth were formed on the dentin wall of one half. Three depressions in the canal wall of the opposite half, 0.3 mm in diameter and 0.5 mm in depth, were formed. After each groove and depression was filled with dentin debris, two sections of each half were reassembled using impression putty material. In group 1 the canals were irrigated with 2.5% NaOCl by PI. In group 2 the canals were irrigated with 2.5% NaOCl by PUI. Before and after root canal irrigation, the root canal wall of the section was taken with a microscope and a digital camera as images. The amount of dentin debris remaining in grooves and depressions was assessed using a scoring system. Results: There was no significant difference between PI and PUI except for the middle 1/3 of the root canal (P = 0.004). Conclusion: At the middle 1/3 of the root canal, PUI removed more dentine debris than PI. But the removal efficiency of dentin debris is not significantly different between the PUI and PI at the apical area of root canal in mandibular premolars.

• Journal of Sensor Science and Technology
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• v.12 no.1
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• pp.16-23
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• 2003

Thermoluminescent properties of $Li_2B_4O_7$ single crystal grown by Czochralski method have been investigated. The high quality $Li_2B_4O_7$ single crystal without core was obtained at rotation speed of 10 rpm for seed crystal and pulling speed below $0.18\;mm{\cdot}h^{-1}$. The structure of $Li_2B_4O_7$ single crystal was classified as tetragonal by XRD analysis. The TL glow curve was composed with three overlapped peaks which can be easily deconvoluted and the TL response of $Li_2B_4O_7$ single crystal TLD to X-ray radiation is linear within the range of $50\;mGy{\sim}1.5\;Gy$. Activation energies of three TL glow peaks analyzed by the various heating rates method and PL spectrum were 0.93, 1.78 and 2.25 eV, respectively.

• Journal of the Korean Society of Clothing and Textiles
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• v.32 no.12
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• pp.1857-1865
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• 2008

The purpose of this study was to examine the importance of personal attributes as they related to developing first impressions and managing group acceptance in the context of sorority recruitment process. Specifically, we examined how certain personal characteristics of a sorority member were related to her use of a potential member's clothing and appearance as non-verbal cues during the member selection process. The characteristics identified through the literature review were materialism, fashion clothing involvement, and proximity of clothing to self. A questionnaire was distributed to members of two sorority houses at a southeastern university in the United States. A total of 140 US sorority members participated in the study. The results showed that a member's satisfaction with her chapter, her level of participation, and her length of membership in the chapter had no relation with her tendency to base her member selection on clothing and appearance. However, members' use of clothing and appearance as guiding their member selection decisions was related to other individual characteristics selected for the study(materialism, fashion clothing involvement, and proximity of clothing to self). Fashion clothing involvement and proximity of clothing to self(clothing for acceptance) were most significantly related to clothing-based member selection. Partial correlations were also produced to examine the mediating role of clothing-based impression formation.

• Safe Food
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• v.3 no.1
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• pp.13-21
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• 2008

우리나라 학교급식의 현재 성적표를 "양적 성공, 질적 실패"로 평가할 수 있다. 2003년 학교급식이 국가적 교육사업이 되어서 초 중 고 특수학교에서 전면급식이 이루어지고 10,343개교에서 704만명의 학생에게 급식을 제공하고 있다. 현재는 양질의 학교급식을 안전하고 저렴하게 공급하고, 국가식량정책과 연계하여 효율적으로 관리하여야 할 시기이다. 그러나 학교급식 소요경비 연 2조3천억원, 영양사 7,196명 등 63,145명이 종사하는 거대한 산업군이라는 규모에도 불구하고 전체 학교의 70%만이 식당시설을 갖추고 있고 급식 만족도가 학생이나 학부모의 기대에 미치지 못하고 있으며, 식중독 발생의 원흉이 되어 국민적 질책의 대상이 되고 있는 것이 현실이다. 이 문제는 1) 영양사 업무과중에 따른 시간부족, 영양사 지식정보 부족 등에 따른 식재료 및 위생관리 소홀, 2) 냉장, 냉동, 오염/비 오염 구획 등에 필요한 시설과 설비 부족, 3) 교육인적자원부의 급식위생관리의 전문성 부족과 담당 인력 및 정책적, 재정적 지원 부족을 원인으로 볼 수 있다. 학교급식 안전대책은 아래 20대 과제를 추진하여 확보하여야 할 것이다. 전략 1은 "우수한 식재료 위생관리"로서 "급식비 인상 및 현실화, 철저한 수입 농수축산물관리, 식재료 공급 및 전처리업 자유업에서 신고제, 허가제로 전환, GAP(우수농산물관리) 제도 도입, 생산이력제도(traceability) 도입, 급식원료 "품질인증 제도" 도입, 식품원료 전처리 시 세척, 소독프로그램 보급, 학교급식 식자재기준, 규격 설정, 과학적이고 쉬운 검수지침 개발 및 보급, 신속검사키트를 활용한 주기적인 미생물 검사 의무화, 위생 전문가에 의한 검수, 식재료별로 분산된 법령과 관리제도 정비(식품안전기본법), 급식식자재 공급 유통 과정의 감시 감독 강화" 등 13개 과제를 제안한다. 전략 2는 "급식위생 확보 인프라구측"으로서 "급식종사자 전문성 확보(조리/영양/위생), 급식전담기구(학교급식진흥원 /학교급식센터 등) 설치, 급식형태 다양화(위탁/직영 균형 발전), 학교급식법 재개정, 학교급식 HACCF제도 확대" 등 4개 과제를 제안한다. 전략 3은 "급식소 시설 설비 현대화 및 환경개선"으로서 "급식시설 설비 현대화 (전처리실, 냉장고, 온장고 구비 등), 급식소 환경 개선 (상수 사용 확대 및 안전강화, 지하수 소독 강화, 정화된 공기 공급 등)" 등 2개 과제를 제안한다. 전략4는 "급식위생제도 및 관리체계 개선"으로서 "전문적 단일기관 안전관리 (식품안전처)" 과제를 제안한다.

• Science of Emotion and Sensibility
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• v.21 no.3
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• pp.3-16
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• 2018

Despite the substantial changes made in the product design field to adopt light as an essential design element, there has been little effort to define how customers respond emotionally to the light design of products. Therefore, it is necessary to analyze the emotional effect of light as a new design element. However, previous research focuses solely on deriving optimal lighting conditions to achieve particular emotional effects. Therefore, this paper investigates the customers' desired emotional effects of product's light design. We studied refrigerators that utilize light as the main design element of the product. We applied mixed methods by combining close-ended questions and open-ended question to efficiently derive the desired emotion. Participants were asked to choose the most favorable refrigerator image in each of the twelve image groups and indicate why they choose that image with the short-answer survey form. Approximately one thousand terms were collected, and those terms were classified into 29 groups using thesaurus relationships. The term groups were again classified into the four big emotion categories and labelled as "abstract quality," "light property," "space perception," and "visual comfort." Also, a model of the relationship between desired light style and light properties was proposed, since we observed the light properties related to three other categories. This study used mixed methods to identify the emotional value of a new design element. We suggest that the emotional categories derived and the proposed relationship model could be used to evaluate the product's light design.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.1
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• pp.622-632
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• 2018

With the recent changes in the social environment, the growth in the so-called 'five major crimes' has been highlighted as one of the causes of anxiety in Koreans' lives. Many attempts have been made to solve this problem; however, it is still difficult to secure the location information of the socially vulnerable in emergency situations and to precisely identify the features and clothing of criminals and track them using current image analysis technology. Therefore, the development of precision positioning technology and support services along with intelligent security service technology based on spatial information has been given a high priority. This study suggested measures that could be continuously applied to link technologies and services with high linkability by analyzing technologies based on spatial information and other fields. To establish measures for linkage between intelligent security technology and other technologies and services, this study analyzed the existing technologies and research trends in intelligent security technology, and reviewed linkable services according to five criteria established to evaluate their linkability. Based on this analysis, three technologies with high linkability were ultimately selected, and measures for linkage were established. It is expected that the linkage measures derived using the objective evaluation criteria will serve as a stepping stone for promoting active technology linkage and commercialization in the future, even after the completion of this study.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.4
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• pp.197-202
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• 2018

This study was conducted to evaluate the distortion and data accuracy that may occur depending on the methods employed by the oral scanner (intra-oral scanner). Deseutap 3D models employing a plaster model used clinically as a scanner to create a standard scan data using the same model, separated by oral scanners in three different ways (AS Group, ZS group, OS group) How to scan each 5 times made the scan data for each group, it shows the 0.121 mm, 0.172 mm AS group, OS group 0.423 mm accuracy in ZS group. The ZS group showed the highest accuracy, with maximum error values of 0.113 mm, 0.169 mm and 0.246 being observed for the ZS, AS and OS group, respectively. The three scanning methods showed a clear differences in accuracy and reproducibility and also appeared to be meaningful in clinical practice.

• Journal of the Korean GEO-environmental Society
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• v.16 no.4
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• pp.41-48
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• 2015

Coffee consumption in Korea has been currently growing every year, and as a result, approximately 0.2 million tons of Spent Coffee Grounds (SCG) are being created every year. SCG, which is waste organic material, is often classified as food waste and an annual amount of 0.27 million ton is discarded while containing moisture and provoking serious environmental issue. Physico-chemical characteristics of SCG were analyzed in this study and medium and long-term growth experiments were conducted in order to evaluate its utilization potential. According to the experiment results, mixing SCG into the previous base material resulted in accelerated germination and growth in the mid-term compared to previous base material alone, despite slower germination or growth in early stage. Especially, it showed lower withering rate and decrease in various symptoms that are caused by nutrition shortage in case of discontinued sprinkling, etc., compared to the previous base material. Hence, while SCG has a feature of hindering early development due to its feature of waste organic material that is rich in nitrogen, its benefit for long-term growth coming its moisturizing ability and supply of organic matter was confirmed in the study. On balance, SCG is believed to be a material that can replace or complement the previous base materials.

• The korean journal of orthodontics
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• v.28 no.6 s.71
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• pp.905-914
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• 1998

The goals of this study were to present presurgical naso-alveolar molding (PNAM) appliance in unilateral cleft lip and palate treatment and to evaluate the effects of PNAM appliance on alveolar molding. Samples were consisted of 4 unilateral cleft lip and palate infants (3 males and 1 female, mean age=23.2 days after birth) who were treated with PNAM appliances in Department of Orthodontics, Seoul National University Dental Hospital. Average alveolar cleft gap between the greater and lesser segment was 8.27mm and average duration of alveolar molding treatment was 9.7 weeks. These patients' models were obtained at initial visit (T1) and alter successful alveolar molding (T2). Seven linear and five angular variables were measured by using photometry and digital caliper. All statistical analyses were performed by SPSS win ver. 7.5 program. Paired t-test was used to compare the mean values. 1. The posterior part of alveolar segments are the stable structures during alveolar molding treatment period in infants. 2. Forward growth of the greater segment may be hindered by the action of alveolar molding. 3. The closure of cleft gap during alveolar molding were usually due to inward and backward bending of the anterior part of the greater segment and outward bending of the whole lesser segment.

• The Journal of Korean Academy of Prosthodontics
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• v.44 no.4
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• pp.421-431
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• 2006

Statement of problem : Accurate impression is essential to success of implant prostheses. But there have been few studies about the accuracy of fixture-level impression technique in internal connection implant system. Purpose: This study evaluated the accuracy of splinted fixture-level impression technique using clinical methods and the effect of internal hex on fit of superstructure in internal connection implant system (Astra Tech). Material and method : Two metal master frameworks made from two abutments (Cast-to Abutment ST) each for parallel and divergent conditions and a corresponding. passively fitting, dental stone master cast with four future replicas (Fixture Replica ST) were fabricated. Ten dental stone casts were made with vinyl polysiloxane impressions from the master cast by acrylic resin splinted fixture-level impression technique. To evaluate the accuracy of impression technique, the fit of master frameworks for test models was evaluated using screw resistance test (SRT) and one-screw test. The results of SRT were recorded as SRT values from grade 1 to grade 5 by 1/4 turn. And to evaluate the effect of hex on fit of superstructure, the same tests were performed after removing hexes of master frameworks. Results: 1. There was only one case (2.5%) showing SRT value of test model below ade 2 in total before and after removing hexes of master frameworks. And, by removing hexes. SRT values decreased in only one test model (5%) and did not change in 17 test models (85%). 2. SRT values of the 1$^{st}$ screws were grade 2 in 80% of cases before, and grade 1 in 80% of cases after removing hexes. And, by removing hexes, SRT values decreased in 72.5% of cases. 3. SRT values of the 2$^{nd}$ screws were grade 3 in 85% of cases before, and grade 3 in 95% of cases after removing hexes. And, by removing hexes, SRT values did not change in 85% of cases. 4. There were only 2 cases regarded as acceptable fit by one-screw test, and SRT values of 2$^{nd}$ screws of both cases were grade 2. Conclusion. Within the limitations of this study, future-level impression of internal connection implant system is considered to obtain inaccurate working cast, even using acrylic resin splinted impression technique. And, it is considered to be unable improve the fit to remove the hexes of implant restoration.