• 한국재료학회지
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• 제3권4호
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• pp.336-343
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• 1993

본 연구에서는 orthorhombic결정구조를 갖는YBa/sub 2/Cu/sub 3/ O/sub 7/-x에대해[001-110-110]을 잇는 표중 ECP map을 작성하였고 이에 대한 지수를 결정하였다. 그 후, 소성가공으로 배향화시킨 산화물 추전도체의 결정입 방위분포를 개개의 결정입에 대하여 정량화할 수 있는 ECP(electron channeling pattern)법으로 해석하여 임계전류밀도(jc)와 결정배향도의관계를 조사하였다. 실온에서 압축한 tape에 대해 JC를 측정한 결과, tape의 두께감소에 따라JC는 크게 증가하였으며 이는 tape의 두께가 감소함에따라 결정립의 (001) 배향도가 높아진데 기인한 것임을 ECP로 방위해석한 결과 알 수 있었다. 또한 고온에서 50% 압축변형시킨 시료의 경우도 강한 c축배향이 나타남을 ECP로 방위해석한 결과 확인할 수 있었다. 본 연구를 통해 ECP법을 이용한 결정방위 해석법은 JC등 초전도특성이 결정방위분포에 의존하는 산화불 초전도체의 조직제어 연구 등에 유효하게 응용될 수 있다는 것을 알 수 있었으며, 특히 박막이나 tape 등 크기가 작은 시료의 방위해석에 효과적으로 이용될 수 있을 것으로 기대된다.

• Journal of Crop Science and Biotechnology
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• 제11권2호
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• pp.151-156
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• 2008

The objective of this study is to identify main-effect QTLs, epistatic QTLs, and the interactions between QTL and the environment associated with grain appearances of brown rice. A genetic linkage map was created with 172 DNA markers spanning 12 rice chromosomes based on 120 DH lines, which derived from a cross between 'Samgang'(Tongil) and 'Nagdong'(Japonica). One thousandgrain weight, length, width, length-to-width ratio, and thickness were evaluated regarding the DH population. Twenty independent QTLs and fourteen epistatic QTLs were identified in using CIM by two programs, known as WinQTLcart2.5 and QTLMAPPER. The QTLs of qgw9.1 in an interval of RM434-RM242 on chromosome 9 and qgw11.1 at a peak marker of RM287 on chromosome 11 for one thousand-grain weight, qgwi2.2 for grain width at a peak marker of RM450, qlw2.1 for length-to-width ratio flanked by RM492 and RM324, and qgt2.1 for thickness flanked by 2009 and RM492 on chromosome 2 were detected over two years, which can be considered as stable QTLs. The epistatic effect might be an important component for genetic basis of one thousand-grain weight and width. The main-effect QTLs of grain width and length to width ratio were easily influenced by environments.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 춘계학술대회논문집
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• pp.51-55
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• 2007

In this paper Statistical Energy Analysis has been considered to predict high frequency air borne interior noise. Dash panel Insulation is major part to reduce engine excitation noise. Transmission loss and absorption coefficient are considered to predict dash insulation performance. Transmission lose is derived from coupling loss factor and absorption coefficient is derived from internal damping loss factor. Material Biot properties were used to calculate each loss factors. Insulation geometry thickness distribution was hard to measure, so FeGate software was used to calculate thickness map from CAD drawing. Each predicted transmission losses between conventional insulation and light weight insulation were compared with SEA. Transmission loss measurement was performed to validate each prediction result, and it showed good correlation between prediction and measurement. Finally interior noise prediction was performed and result showed light weight insulation system can reduce 40% weight to keep similar performance with conventional insulation system, even though light weigh insulation system has lower sound transmission loss and higher absorption coefficient than conventional system.

• 한국측량학회지
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• 제34권2호
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• pp.153-159
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• 2016

Rivers refer to either natural or artificial structures whose primary functions are flood control and water conservation. Due to recent localized torrential downpours led by climate change, large amounts of eroded soil have been carried away, forming deposits downstream, which in turn degrades the capacity to fulfill these functions. To manage rivers more effectively, we need data on riverbed erosion and deposition. However, environmental factors make it challenging to take measurements in rivers, and data errors tend to prevent researchers from grasping the current state of erosions and deposits. In this context, the aim of the present study is to provide basic data required for river management. To this end, the author made annual measurements with a Real-time Kinematic-Global Positioning System (RTK-GPS) and a total station in Pats Cabin Canyon, Oregon, United States, and also prepared thematic maps of erosion and deposition thickness as well as water depth profiles based on a GIS spatial analysis. Furthermore, the author statistically analyzed the accuracy of three dimensional (3D) measurement points and only used the data that falls within two standard deviations (i.e. ±2σ). In addition, the author determined a threshold for a DEM of Difference (DoD) by installing measurement points in the rivers and taking measurements, and then estimated erosion and deposition thickness within a confidence interval of ±0.1m. Based on the results, the author established reliable data on river depth profiles and thematic maps of erosion and deposition thickness using pre-determined work flows. It is anticipated that the riverbed data can be utilized for effective river management.

• 대한치과기공학회지
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• 제45권3호
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• pp.67-73
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• 2023

Purpose: This in vitro study aimed to evaluate the clinical acceptability of precision of fit of the support thickness of Co-Cr alloy copings fabricated using selective laser melting (SLM). Methods: Thirty dental stone models of maxillary left molar abutments were manufactured, images were taken using a scanner, and a computer-aided design program was used to design the form of a conventional metal ceramic crown coping. Overall, 30 single copings were made from Co-Cr alloy using SLM and divided into three support radius groups (0.1, 0.25, and 0.35 mm) of 10 for each. Digitized data were superimposed with three-dimensional inspection software to quantitatively obtain the machinability of a ceramic crown coping, and visual differences were confirmed using a color map. The root mean square values of the ceramic crown coping group were statistically analyzed using one-way analysis of variance (α=0.05). Results: The precision of fit was superior with 0.25 mm compared with 0.1 mm and 0.35 mm, and the results exhibited significant differences (p<0.05). All specimens showed that various support thicknesses did not exceed the clinically permitted value of 120 ㎛, which mean that more than 0.1 mm and 0.35 mm of support radius for SLM was adequate. Conclusion: The support thickness of Co-Cr alloy restoration fabricated using SLM is shown to affect the adaptation.

• 한국세라믹학회지
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• 제29권4호
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• pp.293-297
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• 1992

A proper combination of complex permeability and permittivity is necessary to produce the zero-reflection microwave absorber with an impedance matching. Increasing of dielectric permittivity and development of an impedance matching was investigated in ferrite-rubber composite specimens by addition of conducting materials. Graphite powder of high dielectric constant was added to the composite specimens to increase the permittivity. The precise estimation of graphite content to produce the matched-wave-impedance absorber at a given frequency can be made by using the numerically derived solution map of impedance matching. It was suggested that permittivity adjustment is an effective technique to obtained the microwave absorber with both good absorbing properties and small thickness as well.

• 연구논문집
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• 통권23호
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• pp.45-56
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• 1993

In order to acquire more comprehensive understanding of textile composites, the processing-microstructure-performance relationships for a variety of material systems, reinforcing schemes and processing technologies should be established. In this paper, emphasis is placed on the integrated analysis of three-dimensional (3-D) 2-step braided composites. The analysis includes the geometric model of unit cells, identification of key process parameters and processing windows due to limiting geometries of yarn jamming, and prediction of elastic constants of the composite. The coordinate transformation and averaging of stiffness and compliance constants are utilized in the prediction of elastic constants. Since there are several types of unit cells in the thickness and width directions of the composites, characterization of mechanical properties is based upon the macro-cell, which occupies the entire cross-section and the unit pitch length of the sample. The performance map demonstrates that a wide range of elastic properties can be achieved by varying the geometric and process parameters.

• Tribology and Lubricants
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• 제8권1호
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• pp.63-69
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• 1992

In order to gain better understanding of wear behaviors of TiN-coated boron cast iron, tests and analyses were conducted with block-on disc type tribometer. TiN layer of thickness $2 \mu m$ and $4 \mu m$, coated by cathodic arc evaporation process, were experimentally investigated with the variation of applied load and sliding speed under dry sliding condition. Wear characteristics were expressed in terms of the three-dimentional wear map as well as the wear rate vs sliding speed and load. Comparisons of wear and friction characteristics between coated cast irons and uncoated cast irns were also made. Wear mechanism of TiN layer was explained in view of surface interaction between the mating surfaces. The thicker coating exhibited higher hardness and adhesion strength. the significance of stresses at the surface and in the subsurface was briefly discussed in relation to the wear behavior.

• 대한자기공명의과학회:학술대회논문집
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• 대한자기공명의과학회 2003년도 제8차 학술대회 초록집
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• pp.33-33
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• 2003

목적： 확산텐서영상 획득시 확산경사자장의 방향수와 FA값, 그리고 FA값의 표준편차와의 상관관계를 조사해 보고자 하였다. 대상 및 방법： 3T MR scanner에서 정상성인 10명(남자 5명, 여자 5명)을 대상으로 걸어주는 확산강조 경사자장의 수(N = 6, 11, 23, 35, 47)를 증가시키며 확산텐서영상을 획득하였다. 획득된 영상들로부터 FA map을 만들고 주요 뇌구조물(frontal GM, putamen, posterior limb of internal capsule, thalamus 등)에 관심영역을 설정하여 FA값을 측정하였으며 그 FA값의 표준편차(sd) 를 계산하였다. 이때 사용한 펄스열은 Stejskal-Tanner type의 확산강조 경사자장이 포함된 single-shot SE EPI를 사용하였으며 영상획득시 사용한 피라미터는 다음과 같다. TR/TE=8000ms/71ms, Thickness/spacing=5/2mm, FOV=240mm, Matrix=$128{\times}128$, NEX= 1, b value=1000s/$\textrm{mm}^2$.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2001년도 제34회 추계학술대회 개최
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• pp.331-340
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• 2001

Elastic-Plasitc Finite element analysis is peformed about the TiN coated medium. The normal contact is simulated by a rigid asperity pressing the surface of an elastic-plastic half-surface. The case of a surface film stiffer than the substrate is considered, and general solutions for the subsurface stress and deformation fields are presented for several coating thickness. Additionally, the critical normal loads for deformation in the substrate and coating fracture are calculated when the yield of TiN film follows the Maximum Principal Stress Theory and Von Mises Theory. The results can be subsumed in failure maps for TiN thin film on steel.