• 대한가정학회지
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• 제37권11호
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• pp.157-165
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• 1999

This study was carried out to examine the effect of clothing materials and multi-layered textiles on thermal resistance value. Cotton, polyester, wool, silk, rayon and acetate were selected for the specimens. Thermal resistance value was tested with 2 kinds of methods(thermo labo II and BK type tester). The results were as follows; 1. The effects of clothing materials for thermal resistance value were decreased by adding layers. 2. When the fabrics are measured with multiple layers, the fabric of the lowest thermal resistance value at single layer was showed the highest increasing tendency for all test methods.

• 대한금속재료학회지
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• 제49권2호
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• pp.192-196
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• 2011

The multi-layered thin film with an ITO/Ag/ITO structure was produced on PET by using magnetron reactive sputtering method. First, 30 nm of ITO thin film was coated on PET by using normal temperature process. Then 20-52 nm of the Ag thin film was coated. Lastly, 30 nm of ITO thin film was coated on Ag layer. The sample of the 20 nm Ag thin film showed more than 70% transmission and a $2.7{\Omega}/{\Box}$ sheet resistance. When compared to the existing single-layered transparent conducting thin film, multi-layered film was found to be superior with about $5{\Omega}/{\Box}$ less sheet resistance. However, since the Ag layer became thinner, the band gap energy needs to be increased to more than 3.5 eV.

• 한국전기전자재료학회논문지
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• 제29권10호
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• pp.601-607
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• 2016

Piezoelectric thick films of soft $Pb(Zr,Ti)O_3$ (PZT) based commercial material (S55) were fabricated using a conventional tape casting method. Ag-Pd electrodes were printed on the piezoelectric film at room temperature and all 5 layered films with a dimension of $12mm{\times}16mm$ were successfully laminated for a multi-layered piezoelectric ceramic actuator. The laminated specimens were co-fired at $1,100^{\circ}C$ for 1 h. A flat layered and dense microstructure was obtained for the $112{\mu}m$ thick piezoelectric actuator after sintering process. Thereafter, a prototype piezoelectric speaker was fabricated using the multi-layered piezoelectric ceramic actuator which can operate as a bimorph. Its SPL (sound pressure level) characteristic was also evaluated for speaker application. Frequency response revealed that the output SPL with a root mean square voltage of 10 V increased gradually to the highest peak of 87.5 dB for 1.5 kHz and exhibited a relatively stable behavior over the measured frequency range (${\leq}20kHz$) at a distance of 10 cm, implying that the fabricated piezoelectric speaker is potential for speaker applications.

• 보존과학회지
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• 제35권5호
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• pp.440-452
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• 2019

전통 제철 공정 중 단야공정에서 나타나는 다층구조 무늬의 선명도를 향상시키고자 재현실험을 통해 생산된 사철강(SI)과 탄소의 함량이 다른 3종류의 현대강인 경강(HS), 고탄소강(CS), 니켈탄소강(NiS)을 각각 단접한 소재 SIHS(사철강 + 경강), SICS(사철강 + 고탄소강), SINiS(사철강 + 니켈탄소강)을 대상으로 분석하였다. 사철강과 탄소의 함량이 다른 3종류의 현대강의 접합면에 대한 미세조직 관찰 결과, SINiS의 경우 다른 소재에 비해 단접면의 단접이 잘 이루어졌고 표면무늬 또한 두드러지게 관찰되었다. 결정립 크기는 소재별 큰 차이는 없었으나 경도는 SICS가 가장 높았다. 소재별 접합면에 대한 전자빔 미세분석법 측정 결과, SINiS의 경우 니켈과 탄소가 함유되어 표면무늬의 선명도가 다른 소재에 비해 높은 것으로 관찰된다. 이상의 결과를 통해 전통단접기술의 특징인 다층구조 소재에서 표현되는 표면무늬의 선명도를 높이기 위해서는 니켈이 함유된 탄소강이 가장 적합함을 확인할 수 있었다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2007년도 춘계학술대회 논문집
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• pp.257-258
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• 2007

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 추계학술대회논문집
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• pp.175-180
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• 2006

The acoustical properties of multi-layered treatments of materials used in applications, such as automotive liners, generally cannot be directly measured by a one-time test in a standing wave duct. Therefore, we have to consider predicting them by the four-pole transfer matrix method. This method requires performing TCM or TLM for measuring the transfer matrix of each layer and calculating the total transfer matrix of the whole multi-layered material. The final predicted absorption ratios and transmission losses of the multi-layered treatments strongly depend on the measured transfer matrix of each layer. All these functions have been included in a new designed acoustical software.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2005년도 춘계학술발표대회 논문집
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• pp.137-140
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• 2005

Resin transfer molding (RTM) is one of the most popular processes for producing fiber reinforced polymer composites. In the manufacture of complex thick composite structures, analysis on flow front advancement on the resin impregnating the multi-layered fiber preform is helpful for the optimization of the process. In this study, three-dimensional mold filling simulation of RTM is carried out by using CVFEM (Control Volume Finite Element Method). On the assumption of isothermal flow of Newtonian fluid, Darcy’s law and continuity equation are used as governing equations. Different permeability tensors employed in each layer are obtained by experiments. Numerically predicted flow front is compared with experimental one in order to validate the numerical results. Flow simulations are conducted in the two mold geometries, rectangular plate and hollow cylinder. Permeability tensor of each layer preform in Cartesian coordinate system is transformed to cylinder coordinates system so that the flow within the multi-layered preforms of the hollow cylinder can be calculated exactly. Our emphasis is on the three dimensional flow analysis for circular three-dimensional braided preform, which shows outstanding mechanical properties such as high impact strength and toughness compared with other conventional two-dimensional laminar-structured preforms.

• 한국의상디자인학회지
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• 제9권3호
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• pp.221-230
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• 2007

This research was focused on the changes of layered techniques in Hussein Chalayan's collections. For this purpose, the layered techniques in 134 works from Chalayan's collections, 97S/S to 06S/S, which were obtained from fashion magazines and fashion internet site, were analyzed and classified into 15 groups. Layered techniques in his works apparently expressed his philosophy about deconstruction. Multilayered feeling was given through using various techniques such as one layer clothing which was showed like multi-layered clothing. Others were multi-layer clothing which felt like one layer, breaking the stereotyped line of clothing into atypical construction and using various materials or constructive lines which made the optical feeling like one layer or multi-layer clothing, and so on. These layered techniques in Chalayan's collections were differentiated into several categories, such as techniques which were revealed in every collections, techniques which were differentiated from one another collections, techniques which were continuously showed through three collections for connection with each collection, techniques which were used only for Spring/Summer season, and techniques which were uniquely showed in early collection or recent collections.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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• pp.535-536
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• 2008

Multi-layered thin films of ZnS/$Na_3AlF_6$/ZnS/Cr were deposited on glass substrate by evaporation process. ZnS and $Na_3AlF_6$ were selected as high and low refractive index material, and additionally Cr was chosen as mid reflective layer respectively. The multi-layered thin films were prepared in terms of different optical thickness and different staking sequence and layers. The optical properties were systematically characterized with different optical thickness of $Na_3AlF_6$ especially $0.25\lambda$ and $0.5\lambda$. In order to expect the experimental result, the simulation program, the Essential Macleod Program(EMP) was adopted. Based on the results taken by spectrophotometer at viewing angle $45^{\circ}$, the ZnS/$Na_3AlF_6$/ZnS/Cr multi-layered thin film shows purple colour range in $0.25\lambda$， bluish green in $0.5\lambda$, red purple in $0.75\lambda$, and purple in $1.0\lambda$ respectively.

• Composites Research
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• 제22권3호
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• pp.66-73
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• 2009

적층 두께, 면밀도, 질량관성모우멘트는 소재의 구조-역학적 특성을 나타내는 중요한 인자들이다. 본 연구에서는 이와 같은 인자들이 다층-복합재료구조의 내충격 성능에 미치는 영향을 고찰하기 위해 높은 충격자 속도 하에서 탄자한계속도기 최대가 되는 재료-구조 최적화를 수행하였다. 세라믹복합재료, 고무, 알루미늄 그리고 알루미늄 폼으로 구성된 다층-복합재료구조의 최적화를 위해 Florence 모델과 Awerbuch-Bonder 모델을 연계한 통합 모델을 개발하였으며, 구속 조건으로써 적층 두께, 면밀도, 질량관성모우멘트를 함께 사용하였다. 결과에서 알 수 있듯이, 제안된 통합 모델을 통해 계산된 탄자한계속도는 유한표소해석에서의 탄자한계속도와 거의 유사함을 확인하였다. 통합 모델을 바탕으로 재료-구조 최적화를 통해 설정된 다층구조는 최적화를 수행하지 않은 다층구조에 비해 약 10.8%의 탄자한계속도 및 26.7%의 충격흡수에너지 향상이 나타남을 알 수 있다.