• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2011년도 제41회 하계 정기 학술대회 초록집
• /
• pp.385-385
• /
• 2011

Ion beam Sputtering (IBS)를 이용한 물질 표면의 pattern 형성은 물리적 변수 조절로 손쉽게 nano structure의 크기와 형태를 조절할 수 있어 관심을 받고 있다. 본 연구발표에서는 massless Dirac Fermion behavior로 인한 highly carrier mobility와 같은 특성으로 인해 차세대 device material로 각광받고 있는 Graphene의 layered compound (층상구조) 형태인 HOPG (Highly Ordered Pyrolysis Graphite)에 IBS (Ion beam Sputtering)를 이용해 nano structure가 형성 가능함을 보이고 그 특징에 대해 소개하려 한다. HOPG(0001)를 Sputter 했을 때, 표면에 잘 정렬된 nano ripple pattern이 형성 가능함을 확인하였으며 sputter하는 시간을 변화하면 약 10 nm에서 80 nm까지 wavelength를 조절할 수 있다. 또한 이전의 IBS를 이용한 연구들에서 확인할 수 있는 다른 물질의 곧게 뻗은 nano ripple과는 다르게 ripple의 끝에 nano swab이 생기는 것을 AFM (Atomic Force Microscope)으로 확인할 수 있었다. 이러한 Graphite에서만 나타나는 Sputter에 의한 표면의 변화의 원인을 규명하고자 Sputter가 지속됨에 따라 나타나는 mopology의 roughness와 wavelength의 시간에 따른 dynamic scaling behavior를 확인하였고 그 얼개를 알기 위해 simulation을 수행 하였다.

• Elastomers and Composites
• /
• 제58권2호
• /
• pp.87-94
• /
• 2023

Abrasion tests of an SBR compound were conducted using four different types of abrasion testers (cut and chip, Lambourn, DIN, and LAT100). The abrasion test results were analyzed in terms of size distributions and morphologies of the wear particles. Most wear particles were larger than 1000 ㎛. The wear particle size distributions tended to decrease as the particle size decreased. Except for the Lambourn abrasion test, the wear particles smaller than 212 ㎛ were rarely generated by the other three abrasion tests, implying that small wear particles were produced through friction by introducing talc powder. Shapes of the wear particles varied depending on the abrasion testers. The wear particles generated from the Lambourn abrasion tester had stick-like shapes. The cut and chip abrasion test showed a clear abrasion pattern, but the DIN abrasion test did not show any specific abrasion pattern. The Lambourn and LAT100 abrasion tests showed irregular abrasion patterns.

• 패션비즈니스
• /
• 제13권1호
• /
• pp.17-33
• /
• 2009

The purpose of this study is to find the character of Cleopatra (69 B.C-30 B.C) by analyzing materials about Cleopatra, and to figure out symbolism and costume presented in movie . Costume of the main character, Cleopatra, compound the type of Egyptian traditional clothes, the change of it, and the trend in the 1960's. And, the symbolic meaning of it is also reinforced by adding ancient Egyptian myth to it. This kind of symbol is usually represented in Cleopatra clothing, especially in weaving pattern, embroidery, and ornament. And color of the clothes not only have their on predominance, but also can have their meaning fade away by mixed with each other, and also the shape has relation with the meaning of color. To sum up, the color and pattern of ancint Egyptian Cleopatra as alive formalize the power that come from coherence with the sun god in the center, which a used to maintain the power of the king. Costume in movie also contained color and pattern as a symbol of religion to symbolize the absolute power of king. These kinds of symbols are reemerging through historical recurrences and exotic interests.

• 한국음향학회지
• /
• 제15권6호
• /
• pp.90-98
• /
• 1996

본 논문에서는 한글의 형태소 분석에 기초한 청각장애자용 수화영상 변환시스템을 제안하였다. 제안된 시스템은 입력 문자열에 대해 형태소 분석에 의한 음운성분과 접속정보를 추출한 다음, 이에 대응한 수화영상을 구축된 수화영상 데이터베이스를 통하여 정확히 출력한다. 효과적인 수화영상변환을 위해 입력문자열에 대한 형태소 분석부와 수화패턴 참조를 위한 수화언어기술부로 이루어진 언어정보기술사전을 구성하였다. 수화패턴은 중복을 피하기 위해 기본수화, 복합수화 그리고 유사수화단어로 분류하여 작성하였으며, 실험을 통해 제안된 시스템의 유용성을 확인하였다.

• 한국산학기술학회논문지
• /
• 제7권6호
• /
• pp.1167-1174
• /
• 2006

자연이미지로부터 텍스트 영역 추출은 자동차 번호판 인식 등과 같은 많은 응용프로그램에서 유용하다. 따라서 본 논문은 문자-에지 맵의 패턴 히스토그램을 이용한 텍스트 영역을 추출하는 방법을 제안한다. 16종류의 에지맵을 생성하고, 이것을 조합하여 문자 특징을 갖는 8종류 문자-에지 맵 특징을 추출한다. 문자-에지 맵의 특징을 이용하여 텍스트 후보 영역을 추출하고, 텍스트 후보 영역에 대한 검증은 문자-에지 맵의 패턴 히스토그램 및 텍스트 영역의 구조적 특징을 이용하였다. 실험결과 제안한 방법은 복잡한 배경, 다양한 글꼴, 다양한 텍스트 컬러로 구성된 자연이미지로부터 텍스트 영역을 효과적으로 추출하였다.

• PNF and Movement
• /
• 제19권1호
• /
• pp.97-104
• /
• 2021

Purpose: The human body can experience a variety of injuries. As a result, it may be difficult to directly treat the damaged area. In such a case, indirect treatment is required. Indirect treatment is typically PNF treatment. Morphological changes in muscle have been confirmed through several previous studies; however, few studies have analyzed neurological changes. Therefore, the purpose of this study was to determine how irradiation during resistance exercise using a diagonal pattern effects neurological excitability. Methods: Electromyography was performed on 13 healthy adults. A compound muscle action potential (CMAP) was obtained through a median motor nerve conduction velocity test, which was conducted before and after performing the irradiation exercise and general exercise. Results: Compared to baseline measurements, there was no significant difference in the latency of the irradiation exercise and general exercise. The amplitude of the CMAP measured after the irradiation exercise was significantly higher than after general exercise. Conclusion: Neurological excitability was high in irradiation during resistance exercise using a diagonal pattern. When clinically direct treatment is difficult, it is thought that irradiation can be used indirectly as a technique to induce nerve excitability.

• Smart Structures and Systems
• /
• 제21권4호
• /
• pp.421-433
• /
• 2018

Carbon fiber reinforced polymer (CFRP) cable has good mechanical properties and corrosion resistance. However, the anchorage of CFRP cable is a big issue due to the anisotropic property of CFRP material. In this article, a high-efficient bonding anchorage with novel configuration is developed for CFRP cables. The acoustic emission (AE) technique is employed to evaluate the performance of anchorage in the fatigue test and post-fatigue ultimate bearing capacity test. The obtained AE signals are analyzed by using a combination of unsupervised K-means clustering and supervised K-nearest neighbor classification (K-NN) for quantifying the performance of the anchorage and damage evolutions. An AE feature vector (including both frequency and energy characteristics of AE signal) for clustering analysis is proposed and the under-sampling approaches are employed to regress the influence of the imbalanced classes distribution in AE dataset for improving clustering quality. The results indicate that four classes exist in AE dataset, which correspond to the shear deformation of potting compound, matrix cracking, fiber-matrix debonding and fiber fracture in CFRP bars. The AE intensity released by the deformation of potting compound is very slight during the whole loading process and no obvious premature damage observed in CFRP bars aroused by anchorage effect at relative low stress level, indicating the anchorage configuration in this study is reliable.

• Elastomers and Composites
• /
• 제49권1호
• /
• pp.73-81
• /
• 2014

칼날형 마모 마찰 시험기를 이용하여 NR배합고무의 마모 거동을 조사하였다. 온도, 하중, 그리고 회전속도를 변화시켜 마모속도에 미치는 영향과 열화된 배합고무의 마모 현상에 대해 평가하였다. 시편의 회전속도와 수직 하중이 증가할수록 마모속도가 증가하였다. 실험온도가 증가할수록 마찰계수가 감소하였고, 마모속도도 감소하였다. 마찰에너지와 마모속도 사이에 Power-Law 관계를 나타냈으며 마모속도는 열화에 의해 급격히 증가하였다. 시편의 마모패턴은 마모조건에 의해 영향을 받았으며 특히 수직 하중을 변화시켰을 때 마모융기(ridge)간격에 큰 변화를 보였다. 배합고무의 마모속도를 결정하는데 간헐적 마모손실 무게측정 대신 칼날형 마모시험기를 이용한 연속적인 마모이동거리측정으로 대체할 수 있음을 확인하였다.

• 복식
• /
• 제53권3호
• /
• pp.51-61
• /
• 2003

1. This study is to veri(y the characteristics of gauze fabrics focused on the them found at Sukga Pagoda. The remains researched are those of the Unified Shilla Dynasty around 8∼10 century. The found textile remains seem to be used as rugs or to be used for filling in spaces, wrapping silver reliquaries, equipments preserving relics of the Buddha, a gold-plated outermost reliquary, and so on. Since other remains found inside the Sukga Pagoda are national treasures, the textile remains can be considered as the fabrics of the highest quality. 2. Seven gauze fabrics, four non-designed gauzes and three designed gauzes, are found. They are all four-end complex gauze, weaved with the complex gauze technique. Two designed gauzes out of three designed gauzes are weaved in pattern by the clamp-resist dyeing technique and one is weaved in pattern by giving some changes in weaving. 3. In addition to the characteristics peculiar to gauze fabrics, such as thinness, fineness, and sparseness, another characteristic is found. That is, the difference in thickness between wefts and warps is over two times on the average in all of the seven gauze fabrics. Some of the gauze fabrics look like laces because of the huge difference in their thickness. 4. This research verified that with their transparency, are such materials that their beauty can easily be realized without adding various colors or patterns on the fabric by painting, embroidery, stitching old foil, or compound weaving technique.

• 한국태양에너지학회 논문집
• /
• 제35권4호
• /
• pp.43-55
• /
• 2015

This paper presents the thermal hydraulic performance of a three dimensional rib-roughened solar air heater (SAH) duct with the one principal wall subjected to uniform heat flux. The SAH duct has aspect ratio of 12.0 and the Reynolds number ranges from 2000 to 12000. The roughness has relative rib height of 0.045, ratio of dimple depth to print diameter of 0.5 and rib pitch ratio of 8.0. The flow attack angle is varied from $35^{\circ}$ to $70^{\circ}$. Various turbulent flow models are used for the heat transfer and fluid flow analysis and their results are compared with the experimental results for smooth surfaces. The computational fluid dynamics (CFD) results based on the renormalization k-epsilon model are in better outcomes compared with the experimental data. This model is used to calculate heat transfer and fluid flow in SAH duct with the compound roughness of V-shaped ribs and dimples. The overall thermal performance based on equal pumping power is found to be the highest (2.18) for flow attack angle of $55^{\circ}$. The thermo-hydraulic performance for V-pattern shaped ribs combined with dimple ribs is higher than that for dimple rib shape and V-pattern rib shape air duct.