• Title/Summary/Keyword: Replicas

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AN EXPERIMENTAL STUDY ON THE MEASUREMENT OF MARGINAL LEAKAGE USING A NEUTRON ACTIVATION ANALYSIS (Neutron Activation Analysis를 이용한 Composite Resin의 변연누출 측정에 관한 실험적 연구)

  • Kim, Mi-Ja;Lee, Myung-Jong
    • Restorative Dentistry and Endodontics
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    • v.13 no.1
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    • pp.185-190
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    • 1988
  • The study was designed to establish quantitative method for assessing the marginal leakage of dental restorations. 18 Class V cavities with $45^{\circ}$ bevel joint were prepared and replicas of these teeth were made with polyethylene wax. and classified with three groups. First group was filled with Scotch bond and silux. Second group was filled with glass ionomer cement:scotchbond/silux. Third group was filled with Dentin-Adhesit/Heliosit. After finishing, all specimens were subjected manually to 100 thermal cycles at $0^{\circ}C$ and $100^{\circ}C$ Samarium nitrate solution, irradiated with flux of $6{\times}12^{12}$ neutrons/$cm^2$/sec for 11 hours, woled for 200 hours, counted with the HpGe detector and the tracer uptake was determined by comparison with a standard of samarium ($10{\mu}g$). The following results were obtained. 1) The group filled with glass ionomer cement base showed least marginal leakage. 2) The group filled with Dentin-Adhesit/Heliosit showed less marginal leakage than the group filled with scotchbond/silux.

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Clothing-Ergonomics Study on the Development of Slacks Pattern and Wearing Evaluation for the Middle-high School Girls Based on the their Lower Body Type (여중생의 하반신 유형별 슬랙스 원형설계 및 착의평가에 관한 피복인간공학적 연구)

  • 임지영;김혜경
    • Journal of the Korean Society of Clothing and Textiles
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    • v.24 no.8
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    • pp.1125-1136
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    • 2000
  • Fitness of clothes becomes a major concern in apparel industry. Development of basic patterns will enhance the fitness of clothes. But there are few slacks patterns for the middle-high school girls. So girls had difficulties to buy ready-made clothes of good fit. To solve this problem, it is necessary to develop basic slacks patterns. The purposes of this study was to develop basic slacks patterns based on the analysis of lower body types. 4 girls were selected among 402 anthropometric measurement subjects who are 13 to 15 year-old for the wearing tests. The result of this study can be summarized as follows; 1. Analysing the replicas of lower body surface by using gypsum method, slack patterns were developed. 2. Wearing test by the sensory evaluation showed that the developed slacks pattern was estimated more highly than existing patterns in the items of the comfort of front crotch and back crotch. 3. Wearing test by moire topography method represented that garment silhouette of developed slacks pattern was estimated more highly and garment space of waist, hip were significantly different among patterns.

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Proposition for Conservation of Traditional Costumes -Mainly on the Replication of Milchanggun's Jobok (복식유물의 보존을 위한 제안 -밀창군 조복의 복제를 중심으로-)

  • Chae Ok-Ja;Park Chi-Sun;Park Sung-Sil
    • Journal of the Korean Society of Clothing and Textiles
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    • v.30 no.6 s.154
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    • pp.859-869
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    • 2006
  • We proposed that the replicas be made as an alternative to achieve such reciprocal goals as the safe preservation of traditional costume relics and socio-educational realizations through exhibitions, etc., A replication was categorized for its purpose into a restoral replication: a work based on the historical research of color and shapes as they were originally made and a current state replication : a production based on a minute record of the relics as they are excavated. Then, we reported the reproduction process from the excavation to the exhibition on the excavated traditional costumes of Milchanggun's Jobok. The purpose of a replication of relics is to record the relics experiencing the change resulted from the inevitable degeneration over time as organic cultural assets together with the substitution exhibition of relics and academic researches and so on.

Co-Channel Interference Cancellation in Cellular OFDM Networks - PART I : Maximum-Likelihood Co-Channel Interference Cancellation with Power Control for Cellular OFDM Networks

  • Mohaisen, Manar;Chang, Kyung-Hi
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.32 no.5A
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    • pp.409-416
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    • 2007
  • In cellular orthogonal frequency division multiplexing (OFDM) networks, co-channel interference (CCI) leads to severe degradation in the BER performance. To solve this problem, maximum-likelihood estimation (MLE) CCI cancellation scheme has been proposed in the literature. MLE CCI cancellation scheme generates weighted replicas of the transmitted signals where weights represent the estimated channel transfer functions. The replica with the smallest Euclidean distance from the received signal is selected and data are detected. When the received power of the desired and interference signals are nearly the same, the BER performance is degraded. In this paper, we propose a closed-loop power control (PC) scheme capable of detecting the equal received power situation at the mobile station (MS) receiver by using the newly introduced parameter power ratio (PR). When this situation is detected, the MS sends a feedback to the desired base station (BS) which boosts the transmission power in the next frame. At cell edge where signal to interferer ratio (SIR) is considered to have average value between -5 dB and 10 dB, computer simulations show that the proposed CCI cancellation scheme has a gain of 7 dB at 28 Km/h.

Comparative study of photoluminescences for Zn-polar and O-polar faces of single-crystalline ZnO bulks

  • O, Dong-Cheol;Kim, Dong-Jin;Bae, Chang-Hwan;Gu, Gyeong-Wan;Park, Seung-Hwan
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2010.06a
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    • pp.39-39
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    • 2010
  • The authors have an extensive study of photoluminescences for Zn-polar and O-polar faces of single-crystalline ZnO bulks. In the photoluminescence (PL) spectra at 10 K, Zn-polar and O-polar faces show a common emission feature: neutral donor-bound excitons and their longitudinal-optical (LO) phonon replicas are strong, and free excitons are very weak. However, in the PL spectra at room temperature (RT), Zn-polar and O-polar faces show extremely different emission characteristics: the emission intensity of Zn-polar face is 30 times larger than that of O-polar face, and the band edge of Zn-polar face is 33 meV red-shifted from that of O-polar face. The temperature dependence of photoluminescence indicates that the PL spectra at RT are closely associated with free excitons and their phonon-assisted annihilation processes. As a result, it is found that the RT PL spectra of Zn-polar face is dominated by the first-order LO phonon replica of A free excitons, while that of O-polar face is determined by A free excitons. This is ascribed that Zn-polar face has larger exciton-phonon coupling strength than O-polar face.

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Comparison of the fit of cast gold crowns fabricated from the digital and the conventional impression techniques

  • Yun, Mi-Jung;Jeon, Young-Chan;Jeong, Chang-Mo;Huh, Jung-Bo
    • The Journal of Advanced Prosthodontics
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    • v.9 no.1
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    • pp.1-13
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    • 2017
  • PURPOSE. The purpose of this study was to compare the fit of cast gold crowns fabricated from the conventional and the digital impression technique. MATERIALS AND METHODS. Artificial tooth in a master model and abutment teeth in ten patients were restored with cast gold crowns fabricated from the digital and the conventional impression technique. The forty silicone replicas were cut in three sections; each section was evaluated in nine points. The measurement was carried out by using a measuring microscope and I-Soultion. Data from the silicone replica were analyzed and all tests were performed with ${\alpha}$-level of 0.05. RESULTS. 1. The average gaps of cast gold crowns fabricated from the digital impression technique were larger than those of the conventional impression technique significantly. 2. In marginal and internal axial gap of cast gold crowns, no statistical differences were found between the two impression techniques. 3. The internal occlusal gaps of cast gold crowns fabricated from the digital impression technique were larger than those of the conventional impression technique significantly. CONCLUSION. Both prostheses presented clinically acceptable results with comparing the fit. The prostheses fabricated from the digital impression technique showed more gaps, in respect of occlusal surface.

A Basic Study on the Construction of Bodice Pattern for Development Figure of Trunk Surface (상반신 체표면전개도에 의한 길원형 설계의 기초 연구)

  • 문명옥
    • Journal of the Korean Society of Costume
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    • v.45
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    • pp.17-28
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    • 1999
  • This study was to analyze factors of the body form and factors of bodice pattern through a surface developement figure for the tight bodice pattern design. Fifty replicas of the trunk surface were made by applying a surgical tape method of female subjects between 18 and 24 years old. The result was as follows: 1. The gaps between direct measurements and measurements of the surface development figure were regarded as allowances for the tight bodice pattern. 2. There are four factors of body form selected by factor analysis. The 1st factor signifies th degree of fatness in the upper body. The 2nd factor signifies the length of the upper body. The 3rd factor signifies the part of the front shoulder. The 4th factor signifies the part of the neck. 3. There are high correlations between center back line of the surface development figure and back length line side line front length line back neck depth back upper chest depth. There are high correlations between back bust line of the surface development figure and back interscye breadth line back upper chest line back armhole line. There are high correlations between front bust line of the surface development figure and front upper chest line front interscye breadth line front armhole line front neck breadth 4. The regression expressions of measurements of the surface development figure of the upper body were analyzed as(Fig. 3).

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Analytical similitudes applied to thin cylindrical shells

  • De Rosa, Sergio;Franco, Francesco
    • Advances in aircraft and spacecraft science
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    • v.2 no.4
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    • pp.403-425
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    • 2015
  • This work is focused on the definition and the analysis of both complete and incomplete similitudes for the dynamic responses of thin shells. Previous numerical and experimental investigations on both structural and structural-acoustic systems motivated this further analysis, mainly centred on the incomplete (distorted) similitudes. These similitudes and the associated scaling laws are defined by using the classical modal approach (CMA) and by invoking also the Energy Distribution Approach (EDA) in order to take into account both the cinematic and energetic items. The whole procedure is named SAMSARA: Similitude and Asymptotic Models for Structural-Acoustic Research and Applications. A brief summary of the procedure is herein given and the attention is paid to the analytical models of thin stiffened and unstiffened cylindrical shells. By using the well-known smeared model, the stiffened cylinder equations are used as general framework to analyse the possibility to define exact (replicas) or distorted similitudes (avatars). Despite the extreme simplicity of the proposed models, the results are really encouraging. The final aim is to define equivalent models to be used in laboratory measurements.

An experimental study of scale effect on the shear behavior of rock joints

  • Lee Tae-Jin;Lee Sang-Geun;Lee Chung-In;Hwang Dae-Jin
    • 한국지구물리탐사학회:학술대회논문집
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    • 2003.11a
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    • pp.156-161
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    • 2003
  • Mechanical behavior of rock joints usually can be characterized by small-scale laboratory shear tests due to economical and technical limitations, but their applicability to the behaviour of rock mass has been always questioned by a number of researchers because of scale effect. Though there have been several researches regarding the scale effect, it has been a controversial problem how to apply the result of small-scale laboratory shear test directly to field design from different conclusions among researchers. In order to grasp the trend of scale effect of shear behavior, a series of direct shear tests on replicas of natural rock joint surfaces made of gypsum cement with different size and roughness were conducted and analyzed. Result showed that as the size of the specimen increased, average peak shear displacement increased, but average shear stiffness and average peak dilation angle decreased. As for the dependency of scale on shear strength, the degree of scale effect was dependent on normal stress and roughness of rock joint. For the condition of low normal stress and high roughness, decrease of average peak shear strength with increasing size of joint was evident.

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Standardization of Surface Replication Procedures for Life Assessment of High Temperature Facilities (고온설비 수명평가를 위한 표면복제 절차의 표준화)

  • Park, Jong-Seo;Lee, Hae-Mu;Baek, Un-Bong
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.24 no.9 s.180
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    • pp.2381-2386
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    • 2000
  • Surface replication is playing an important role in the assessment of creep damage and remaining life of high temperature components. As the replication procedures, however, have not been standardized in domestic industry, its standardization is proposed in this study. For this purpose, the 2.25Cr-IMo steel was heat treated(5 min at 1,300 0C and oil quenched) to produce a simulated HAZ microstructure, and crept in air at 575 0C and under 120 MPa to produce artificial cavities. Then, the effect of surface preparation procedures on the quality of replicas was investigated using this sample. As a result, it was demonstrated that the presence of cavities may be observed readily or missed depending on the surface preparation procedures followed. Therefore it is essential to repeat three polishing/etching cycles at least in order to reveal cavitation damage accurately, even though it may be tedious or time-consuming.