• Applied Microscopy
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• 제46권3호
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• pp.167-169
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• 2016

Solder/electroless nickel immersion gold (ENIG) joint sample which is comprised of dissimilar materials with different mechanical properties has limited the level of success in preparing thin samples for transmission electron microscopy (TEM). This short technical note reports the operation parameters for ultramicrotomy of solder joint sample and TEM analysis results. The solder joint sample was successfully sliced to 50~70 nm thick lamellae at slicing speed of 0.8~1.2 mm/s using a boat-type $45^{\circ}$ diamond knife. Ultramicrotomy can be applied as a routine sample preparation technique for TEM analysis of solder joints.

• 동력기계공학회지
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• 제2권1호
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• pp.25-30
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• 1998

In order to investigate the droplet size distribution and Sauter Mean Diameter in a ultra high pressure diesel spray, fuel was injected with ultra high pressure into the environments of high pressure and room temperature by an Electronic Hydraulic Fuel Injection System. Droplet size was measured with the immersion liquid sampling technique. The immersion liquid was used a mixture of water-methycellulose solution and ethanol. The Sauter Mean Diameter decreased with increasing injection pressure, with a decrease environmental pressure (back pressure) and nozzle diameter. Increasing the injection pressure makes the fuel density distribution of the spray more homogeneous. An empirical correlation was developed among injection pressure, air density, nozzle diameter and the Sauter Mean Diameter of spray droplets.

• Composites Research
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• 제21권6호
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• pp.1-7
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• 2008

본 연구에서는 염수환경이 고강성 탄소-에폭시 복합재의 기계적 특성에 미치는 영향을 살펴보았다. 시편은 UPN139B 탄소-에폭시 복합재로 제작하였고, 3.5% 염수에 0, 1, 3, 6, 9, 12개월 간의 침수 후 면내 인장시험과 전단시험을 수행하였다. 실험에서 온도 조절과 같이 흡수 시간을 절약하기 위한 특별한 가속방법은 사용하지 않았다. 섬유방향 및 기지방향 인장강도와 강성의 경우 12개월 동안의 침수에도 불구하고 특별한 변화를 발견할 수 없었다. 반면 12개월 침수 후 전단강도와 강성은 염수에 노출되지 않은 시편에 비해 약 10% 내외의 감소를 보였다. 본 연구를 통하여 UPN139B가 우수한 섬유방향 강성과 내부식성으로 인하여 염수환경에서 외부수압에 의한 좌굴을 지지해야 하는 구조물의 설계에 효과적으로 사용될 수 있음을 확인하였다.

• 멤브레인
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• 제15권2호
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• pp.85-104
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• 2005

Recently, membrane can be prepared by two methods, phase inversion and electrospinning techniques. Phase inversion technique is a conventional but commercially preparation membrane. The most versatile of preparation in this technique is immersion of the cast film into nonsolvent bath, causing dense top layer with a finger-like pattern in the sub layer membrane. The membrane pore size getting from phase inversion is in the range of micro or submicrometer. As a result, it can be used as microfiltration and ultrafiltration applications. A new technique, electrospinning, is introduced for membrane preparation. Nonwoven nanofibrous mat or nanofibrous membrane is obtained. In this technique, electrostatic charge is introduced to the solution jet, causing a thin fiber with high surface area; hence it can be used in the applications where high surface area-to-volume or length-to-diameter ratios are required. Moreover, the pore size can be controlled by controlling the time of electrospinning. Hence, it can be used as a filter for filtering microparticles as well as nanoparticles.

• 한국CDE학회논문집
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• 제4권1호
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• pp.12-18
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• 1999

A deformable non-Uniform Rational B-Spline (NURBS) based volume is programed for the force reflecting exoskeleton haptic device. In this work, a direct free form deformation (DFFD) technique is applied for the realistic manipulation. In order to implement the real-time deformation, a nodal mapping technique is used to connect points on the virtual object with the NURBS volume. This geometric modeling technique is ideally incorporated with the force reflecting haptic device as a virtual interface. The results in this work introduce details for the complete set-up for the realistic virtual clay modeling task with force feedback. The force reflecting exoskeleton haptic manipulator, coupled with a supporting PUMA 560 manipulator and the virtual clay model are integrated with the graphics display, and results show that the force feedback from the realistic physically based virtual environment can greately enhance the sense of immersion.

• 한국멀티미디어학회논문지
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• 제18권2호
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• pp.277-286
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• 2015

Recently, to draw the web users' attention and stay in the website for a long time to transmit information efficiently, the website designing is focused on providing emotional experience. Emotional experience is possible through the use of interactive storytelling and multimedia. Users immersion, pleasurable experience and synesthesia satisfaction is connected to the emotional experience due to the interaction operation and multimedia feedback. In this study, application of the parallax scrolling technique's possibility has been studied to induce the emotional experience of the web users that appeared in the technical development of the web. Realizing characteristics of the elements that effect emotional experience through web cases are studied and the possibility of effective emotional experience is proposed as using parallax scrolling technique on web.

• 디지털산업정보학회논문지
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• 제12권1호
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• pp.97-106
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• 2016

3D virual reality technique develop rapidly such as parts of education, health, national defense, etc. This paper implements an education contents utilizing 3D virtual reality based on HMD. In this paper, contents make up Changdeokgung Palace using to 3Dmax and Unity program, it shows on implemented Helmet Mounted Display. HMD obtain dynamic image from the target source of smart phone. Also, contents consist of service senerio through divided palace position and King's a day's journey especially. Above all, this paper indicate improving performance according to reduced cybersickness and immersion enlargement. And memory capacity reduced by various technique such that file type, compressed file, minimized resource. Proposed technique can obtain dynamic 3D image by HMD implementation at real time basis so that it is possible to use simultaneously multi-source. From the various and practical experiment, it is confirm that proposed 3D VR education system is useful for experience of virtual reality practically.

• 한국막학회:학술대회논문집
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• 한국막학회 1997년도 추계 총회 및 학술발표회
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• pp.81-82
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• 1997

1. Introduction : The growth of membrane science was initiated by the invention of asymmetric membrane which can be formed by the technique known as phase inversion. The basic procedure of phase inversion involves casting a thin film of polymer solution onto a suitable substrate followed by immersion in a coagulation bath (quench step). Therefore, events occurring during the quench period, at which time solvent-nonsolvent exchange and eventual polymer precipitation take place, can play a controlling role in the determination of ultimate membrane structure.

• 정보저장시스템학회:학술대회논문집
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• 정보저장시스템학회 2005년도 추계학술대회 논문집
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• pp.113-118
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• 2005

Small form factor optical disks for near-field optics using solid immersion lens were developed. Disk durability properties in terms of head-disk interface (HDI) properties were investigated by drag test, diamond like carbon film and lubricant film were coated on the small form factor disk to enhance HDI. Disks with glass substrates and lubricant films after heat treatment showed more durable characteristics. Coverlayers made of UV resin were uniformly coated by spin coating In which the ski-jump could not be formed by adopting outer ring technique.

• 정보저장시스템학회논문집
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• 제2권1호
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• pp.26-31
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• 2006

Small form factor optical disks for near-field optics using solid immersion lens were developed. Diamond like carbon film and lubricant film were coated on the small form factor optical disk to enhance the head-disk interface(HDI) characteristics. The disk durability properties in terms of HDI phenomena were investigated by drag test. Disks with glass substrates and the lubricant films experienced heat treatment showed more durable characteristics. Coverlayers made of UV resin were uniformly coated by spin coating in which the ski-jump could be removed by adopting outer ring technique