• 제목/요약/키워드: Techniques

검색결과 34,461건 처리시간 0.053초

Marginal microleakage of cervical composite resin restorations bonded using etch-and-rinse and self-etch adhesives: two dimensional vs. three dimensional methods

  • Khoroushi, Maryam;Ehteshami, Ailin
    • Restorative Dentistry and Endodontics
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    • 제41권2호
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    • pp.83-90
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    • 2016
  • Objectives: This study was evaluated the marginal microleakage of two different adhesive systems before and after aging with two different dye penetration techniques. Materials and Methods: Class V cavities were prepared on the buccal and lingual surfaces of 48 human molars. Clearfil SE Bond and Single Bond (self-etching and etchand-rinse systems, respectively) were applied, each to half of the prepared cavities, which were restored with composite resin. Half of the specimens in each group underwent 10,000 cycles of thermocycling. Microleakage was evaluated using two dimensional (2D) and three dimensional (3D) dye penetration techniques separately for each half of each specimen. Data were analyzed with SPSS 11.5 (SPSS Inc.), using the Kruskal-Wallis and Mann-Whitney U tests (${\alpha}=0.05$). Results: The difference between the 2D and 3D microleakage evaluation techniques was significant at the occlusal margins of Single bond groups (p = 0.002). The differences between 2D and 3D microleakage evaluation techniques were significant at both the occlusal and cervical margins of Clearfil SE Bond groups (p = 0.017 and p = 0.002, respectively). The difference between the 2D and 3D techniques was significant at the occlusal margins of non-aged groups (p = 0.003). The difference between these two techniques was significant at the occlusal margins of the aged groups (p = 0.001). The Mann-Whitney test showed significant differences between the two techniques only at the occlusal margins in all specimens. Conclusions: Under the limitations of the present study, it can be concluded that the 3D technique has the capacity to detect occlusal microleakage more precisely than the 2D technique.

디지털 3D 텍스타일 디자인 개발 - 마리아 그라치아 치우리 작품의 텍스타일 자수 기법 분석을 중심으로 - (Development of Digital 3D Textile Design - Focusing on the analysis of textile embroidery techniques by Maria Grazia Chiuri -)

  • 만윤준;정재윤
    • 한국의상디자인학회지
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    • 제25권2호
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    • pp.123-134
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    • 2023
  • Fashion design, CAD production, and the use of digital software can shorten the time and production processes in the fashion industry, but there are still many limitations in how to similarly express textile textures. Having this awareness, how to implement the visual effects of textile texture similar to that of the real world in the virtual world is one of the major exploration tasks in the fashion industry. Therefore, this study aims to analyze examples of embroidery techniques in Christian Dior collections and explore how embroidery techniques in 3D CLO fashion design can express the texture of real clothes more similarly by creating virtual works through 3D samples and 3D CLO software. First, the analysis criteria and theoretical basis of this study were derived through a literature review on fashion textile embroidery techniques, identifying types and characteristics of embroidery techniques, and classifying them into 12 types. Second, photos of the Dior 2017-2023 SS/FW Ready-to-Wear collections were collected and analyzed through the case analysis VOGUE site. Third, it presents the production of 3D CLO works by deriving a method of implementing embroidery techniques through the design of sample textile embroidery techniques using substances 3D sample software. The study's has some limitations. First, in 3D CLO fashion design, the needle gap for embroidery must be widened to see the thread pattern. Second, by reducing the number of needles, it is necessary to imitate the actual embroidery effect. Third, it is judged that it will be effective to lengthen the thread and adjust the thickness of the thread. Fourth, the thickness of the entire embroidery pattern must be increased to enable a three-dimensional texture.

Simulation Techniques for Mid-Frequency Vibro-Acoustics Virtual Tools For Real Problems

  • Desmet, Wim;Pluymers, Bert;Atak, Onur;Bergen, Bart;Deckers, Elke;Huijssen, Koos;Van Genechten, Bert;Vergote, Karel;Vandepitte, Dirk
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2010년도 춘계학술대회 논문집
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    • pp.49-49
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    • 2010
  • The most commonly used numerical modelling techniques for acoustics and vibration are based on element based techniques, such as the nite element and boundary element method. Due to the huge computational eorts involved, the use of these deterministic techniques is practically restricted to low-frequency applications. For high-frequency modelling, probabilistic techniques such as SEA are well established. However, there is still a wide mid-frequency range, for which no adequate and mature prediction techniques are available. In this frequency range, the computational eorts of conventional element based techniques become prohibitively large, while the basic assumptions of the probabilistic techniques are not yet valid. In recent years, a vast amount of research has been initiated in a quest for an adequate solution for the current midfrequency problem. One family of research methods focuses on novel deterministic approaches with an enhanced convergence rate and computational eciency compared to the conventional element based methods in order to shift the practical frequency limitation towards the mid-frequency range. Amongst those techniques, a wave based prediction technique using an indirect Tretz approach is being developed at the K.U.Leuven - Noise and Vibration Research group. This paper starts with an outline of the major features of the mid-frequency modelling challenge and provides a short overview of the current research activities in response to this challenge. Next, the basic concepts of the wave based technique and its hybrid coupling with nite element schemes are described. Various validations on two- and threedimensional acoustic, elastic, poro-elastic and vibro-acoustic examples are given to illustrate the potential of the method and its benecial performance as compared to conventional element based methods. A closing part shares some views on the open issues and future research directions.

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소프트웨어 복제도 감정기법의 표준화 모델에 관한 연구 (A Study on the Research Model for the Standardization of Software-Similarity-Appraisal Techniques)

  • 방효근;차태원;정태명
    • 정보처리학회논문지D
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    • 제13D권6호
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    • pp.823-832
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    • 2006
  • 소프트웨어(SW) 복제도 감정의 목적은 두 프로그램 사이의 동일 또는 유사성 정도를 판단하는 것으로, 컴퓨터프로그림 저작권 관련 분쟁해결의 주요한 기술적 판단근거를 제시하는 제도라 할 수 있다. SW감정을 진행함에 있어서 중요한 점은 감정인의 주관적 판단에 편중되지 않도록 하고, 신속 객관적인 감정의 수행으로 정확한 감정결과를 도출해내는 것이다. 그러나 현재까지 체계적인 감정기법의 표준화 연구 및 개발은 미비한 상태이며, SW감정 분야별(유형별) 감정기법 조차 전문 감정인들에 따라 그 접근방법이 천차만별이어서 뚜렷한 표준안이 제시되지 못하고 있다. 또한, 기 수행되었던 감정사례에 대한 실증적 분석 결과, 기존 감정 절차 및 기법의 오류 또는 감정인의 전문지식 결여 등의 문제가 잠재하여 일부 감정결과에 대한 객관성 및 정확성에 손상이 있음을 알 수 있다. 본 논문에서는 감정인에 따라 동일한 평가 항목에 대하여 서로 다른 결과가 도출될 수 있는 오차의 허용치를 감소시키기 위한 객관적인 평가 방법과 정형화된 SW복제도 감정기법의 표준화 모델을 제시한다. 특히, 기존 감정기법의 문제점 해결 및 보완 연구를 기반으로 감정범위의 설정, 감정기준 및 방법, 단위작업 프로세스 기준의 감정영역 및 감정항목 설정, 가중치 부여, 논리적 복제도와 물리적 복제도 산출 등에 초점을 맞추어 감정기법을 분석 평가한다. 따라서 SW복제도 감정 기법의 표준화 모델은 감정인의 주관적 판단에 의한 오류의 가능성을 최소화하고, 감정결과의 객관성 및 신뢰성을 한층 제고하기 위한 도구를 제공할 것이다.

소아 흉부 CT 검사에서 재구성 기법에 따른 영상의 유용성 평가 (Evaluation of the usefulness of Images according to Reconstruction Techniques in Pediatric Chest CT)

  • 김구;곽종혁;이승재
    • 한국방사선학회논문지
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    • 제17권3호
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    • pp.285-295
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    • 2023
  • 기술의 발전으로 CT 검사에 있어 환자가 받는 피폭선량을 줄이기 위한 노력은 새로운 재구성 기법 개발과 함께 계속 진행되고 있다. 최근에는 반복적 재구성 기법의 한계를 극복하기 위해 딥러닝 재구성 기법이 개발되었다. 본 연구는 소아 흉부 CT 영상에서 재구성 기법에 따른 영상의 유용성을 평가하였다. 환자 실험은 2021년 1월 2일부터 2022년 12월 31일까지 경상남도 P 병원에서 흉부 조영 CT 검사를 받은 소아 환자 중 85명을 대상으로 연구를 진행하였다. 팬텀 실험에 사용된 팬텀은 Pediatric Whole Body Phantom PBU-70이다. 검사 후 FBP, ASIR-V(50%), DLIR(TF-Medium,High)로 영상을 재구성했고, 동일한 크기의 ROI를 설정하여 HU값, SD값을 획득하여 SNR, CNR 값을 산출하여 영상을 평가하였다. 그 결과 DLIR의 TF-H가 모든 실험에서 ASIR-V(50%)와 TF-M에 비해 잡음 값이 가장 낮았으며, SNR과 CNR의 값이 가장 높았다. 소아 흉부 CT 검사에서 DLIR이 적용된 TF 영상이 ASiR-V 영상보다 잡음이 적었고, CNR과 SNR은 높은 것으로 나타났으며 DLIR이 적용되면 기존의 재구성법에 비해 영상의 질이 더 향상될 것으로 판단된다.

Nakagami 페이딩 채널에서 MRC 다이버시티와 채널 부호화 기법을 사용한 DS/CDMA BPSK 시스템의 블록 오율 성능 개선 (Block Error Performance improvement of the DS/CDMA BPSK system with MRC Diversity and Channel coding Techniques in Nakagami Fading Channel.)

  • 강희조;노재성;조성준
    • 한국통신학회논문지
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    • 제25권3A호
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    • pp.391-398
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    • 2000
  • In this paper, MRC(Maximum Ratio Combine) diversity, (23, 12) Golay code, (7, 5) Reed-Solomon code, and (3, 1) majority selection code are employed to improve the performance of DS/CDMA BRSK in Nakagami fading channel. and MRC diversity combined with other coding techniques is suggested, with which, the performance of DS/CDMA BRSK is compared and analyzed. Also, system required Eb/N0 to meet BER=10-5 for multi user data communication is obtained according to each techniques. From the results, when each techniques is employed to DS/CDMA BRSK system. coding employed system shows better performance than diversity employed system. Especially, Golay code shows better performance than oter codes. also MRC diversity is employed, the number of multiple access user to meet data communication requirement of BER=10-5 can accomodate up to 8 users. and when each code is employed, Golay code, majority selection code, and Reed-Solomon code shows the capacity of 14, 12, and 10 user respectively. But MRC diversity combined with coding techniques can reduce restriction of multiple access user. However, it is desirable these combined technique are employed according to service types and requirements provided.

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VE 대상선정을 위한 평가항목의 가중치결정방법에 관한 연구 (A Study on the Subject Selection of VE Using Decision Weights Techniques)

  • 윤동진;신병윤;정용식;이상범
    • 한국건축시공학회지
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    • 제5권3호
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    • pp.83-90
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    • 2005
  • Was used at step space-time mainly after VE technique sponsors in domestic in the 1960s but have been expanded to design step recently. Possibility of value elevation or cost reduction must choose member that is effectively for active and effective application of VE technique. In this study, when enforce design VE examining for weight decision corrosion protection been using in weight grant composition estimation technique, target choice process wishes to suggest formality and method that can be achieved effectively Main conclusion of this study sorts valuation items step by step for weight appropriation of valuation basis and give point on article of high position point after expert which employer is included estimates article by low rank step and this presented high position method that do union item by item and establishes by item weight. Did these techniques for giving weights so that importance for weight appropriation developed estimation program, and data save of target estimation standard and target estimation standard is possible using straight sit.

물성치 적용 기법에 따른 하이브리드 풍력 블레이드 동적특성 해석에 관한 연구 (A Study on Dynamic Characteristics Analysis of Hybrid Wind Power Blades according to Material Properties Method)

  • 강병윤;한정영;홍철현;문병영
    • 한국유체기계학회 논문집
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    • 제15권2호
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    • pp.5-11
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    • 2012
  • In this paper, the heat transfer coefficient measurement techniques using TSP(temperature sensitive paint) were introduced and the results of a comparative study on the heat transfer coefficient measurement by steady state and transient TSP techniques were discussed. The distributions of heat transfer coefficient by a single $60^{\circ}$ inclined impingement jet on a flat surface were measured by both techniques. Tested Reynolds number based on the jet diameter (d) was 30,000 and the distance between jet exit and target plate (L) was fixed at 10d. Results showed that the measured Nusselt number by both techniques indicated significant difference except near the center of impingement jet. Also, the heat transfer coefficients measured by the transient TSP technique were affected by the reference temperature of the jet. Based on the measured data, characteristics of both TSP techniques were analyzed and suggestions for applying them were also given.

Spectroscopic Techniques for Nondestructive Quality Inspection of Pharmaceutical Products: A Review

  • Kandpal, Lalit Mohan;Park, Eunsoo;Tewari, Jagdish;Cho, Byoung-Kwan
    • Journal of Biosystems Engineering
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    • 제40권4호
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    • pp.394-408
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    • 2015
  • Spectroscopy is an emerging technology for the quality assessment of pharmaceutical samples, from tablet manufacturing to final quality assurance. The traditional methods for the quality management of pharmaceutical tablets are time consuming and destructive, while spectroscopic techniques allow rapid analysis in a non-destructive manner. The advantage of spectroscopy is that it collects both spatial and spectral information (called hyperspectral imaging), which is useful for the chemical imaging of pharmaceutical samples. These chemical images provide both qualitative and quantitative information on tablet samples. In the pharmaceutics, spectroscopic techniques are used for a variety of applications, such as analysis of the homogeneity of powder samples as well as determination of particle size, product composition, and the concentration, uniformity, and distribution of the active pharmaceutical ingredient in solid tablets. This review paper presents an introduction to the applications of various spectroscopic techniques such as hyperspectroscopy and vibrational spectroscopies (Raman spectroscopy, FT-NIR, and IR spectroscopy) for the quality and safety assessment of pharmaceutical solid dosage forms. In addition, various chemometric techniques that are highly essential for analyzing the spectroscopic data of pharmaceutical samples are also reviewed.