• Journal of Intelligence and Information Systems
• /
• v.9 no.1
• /
• pp.125-137
• /
• 2003

In eastern countries stamps have been used more commonly than signatures when approving contracts and documents. Unlike finger prints, stamp images do not share similar patterns to each other and the resolution of stamp images is determined by the input status such as pressure under which stamps are put. This paper discusses the development of a system for recognizing stamp images of Korean or Chinese characters. Recognition of stamp images consists of several steps: acquisition of stamp images from an input device, digitization, contrast stretching, noise removal, and matching. We tested the system on 50 stamp images (20 stamp images of Korean characters, 20 images of Chinese characters, and 10 similar images). There was little difference in discrimination rate between the stamp images of Korean character and those of Chinese characters. 46 stamps images out of 50 were successfully recognized, resulting in 92% discrimination rate. Orientation and pressure under which stamps are put played an important role in determining discrimination rate. Automated stamp image recognition can be made more practical and useful by extending the types of stamp images to ellipses and rectangles and by improving the discrimination rate.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2005.06a
• /
• pp.1168-1170
• /
• 2005

Nanoimprint Lithography(NIL) has increasingly been recognized as a key manufacturing technology for nanosized feature. One of the most important task for nanoimprint lithography is to provide the imprinting stamp with low price. The Stamp fabricated with Si based material by e-beam lithography, RIE is extremely expensive and its throughput is very limited and PDMS replica is too soft to hold high imprinting pressure.(>5atm) In this study, we present the imprinting stamp which can be easily replicated from original mold and is based on PVC film. Replication of original Si mold to PVC film was done by Hot embossing technique, ($120^{\circ}C$ of Temperature, 20 atm applied) As small as 100nm patterns were successfully transferred into PVC film. The size of stamp was up to 100mm in diameter.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2007.11a
• /
• pp.99-100
• /
• 2007

Transferring patterns from mold to PDMS stamp is very useful technology in micro-fabrication, complex and three-dimensional structures. First experimentation, mold's patterns wens transferred to PDMS stamp. Comparing with PDMS stamp and Mold, patterns were transferred about 97.9%. Second experimentation, PDMS stamps were made several times by only one mold, scale and distance of transferred patterns were uniform about 89.3%. We proved that transferring patterns from mold to PDMS stamp is accurate. The uniformity of stamps is the same after mold was used several times. Transferring patterns from mold to PDMS stamp has uniformity and accuracy, it will be useful technology.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2007.06a
• /
• pp.206-206
• /
• 2007

PCB기판 제작에 있어서 미세패턴을 형성하기 위한 차세대 공법으로 imprint공법을 이용하여 PCB기판제작에 대한 내용입니다. imprinting을 하기 위해서 미세때턴이 형성된 Tool-foil을 이용하여 imprinting시 Via hole을 동시 가공을 함으로서, 공정 비용 절감과 공정 프로세스 단축의 효과를 볼수 있다. 하지만 대면적(405*510size) imprint용 N-stamp제작이 쉽지 않으며, Ni-stamp가격 또한 만만치 않으며, 대면적 size일수록 이형처리 또한 쉽지 않다. 이형문제와 Stamp제작 비용을 줄이기 Cu-stamp를 제작 하여, Imprint후 이형처리 하지 않으며, Stamp제작 또한 쉬우며, 가격도 싸기 때문에 그에 따른 기대효과를 간략하게 소개 하고자 한다.

• The Journal of Society for e-Business Studies
• /
• v.7 no.2
• /
• pp.157-171
• /
• 2002

We want to find a timestamping method which improves efficient performance and have high-level security to send secured messages in the digital signature and the law of e-commerces. Our paper shows a H-binary tree of time stamp to use a time stamp protocol with high security and performance in the packets of sending messages. We implement and analyze the protocols, show to compare with previous RSA methods. Our proposed protocol has O(log n) time complexity and high-performance.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2005.06a
• /
• pp.1493-1496
• /
• 2005

In this paper, we describe a simple, precise and low cost method of fabricating PDMS stamp for UV embossing. It is important to improve the replication quality of stamp because the accuracy of fabricated structure is related to that of the stamp in UV embossing. The PDMS stamp has been fabricated by the replica molding technology with ultrasonic vibration to eliminate micro-air bubbles during the fabrication process of PDMS stamp. Also, this fabrication to use ultrasonic vibration promotes PDMS solution to fill into micro channel and edge parts. We report the fabrication of an optical core using UV embossing with fabricated PDMS stamp. This fabricated core is $7\;\mu{m}\;at\;depth,\;6\;\mu{m}\;at\;width.\;This\;measured\;value\;has\;the\;difference\;below\;1\;\mu{m}$compared to the original stamp. The surface roughness of core is about 14 nm root mean square. This is satisfactory value to use low-loss optical waveguide. Our successful demonstration of precise replica technology presents an alternative approach for the stamp of UV embossing.

• IEIE Transactions on Smart Processing and Computing
• /
• v.4 no.5
• /
• pp.340-348
• /
• 2015

The "stamp rally" is an event that participants go the round with predetermined points for the purpose of collecting stamps. They bring the stamp card to these points. They, however, sometimes leave or lose the card. In this case, they may not reach the final destination of the stamp rally. The purpose of this research is the construction of the stamp rally system which distinguishes each participant with his or her hand instead of the stamp card. We have realized our method distinguishing a hand posture by the image processing. We have also evaluated it by 30 examinees. Furthermore, we have designed the data communication between the server and the checkpoint to implement our whole system. We have also designed and implemented the process for the registering participant, the passing checkpoint and the administration.

• Proceedings of the KSME Conference
• /
• 2007.05a
• /
• pp.343-348
• /
• 2007

Molecular dynamics study of thermal NIL (Nano Imprint Lithography) process is performed to examine stamp-resist interactions. A layered structure consists of Ni stamp, poly-(methylmethacrylate) thin film resist and Si substrate was constructed for isothermal ensemble simulations. Imposing confined periodicity to the layered unit-cell, sequential movement of stamp followed by NVT simulation was implemented in accordance with the real NIL process. Both vdW and electrostatic potentials were considered in all non-bond interactions and resultant interaction energy between stamp and PMMA resist was monitored during stamping and releasing procedures. As a result, the stamp-resist interaction energy shows repulsive and adhesive characteristics in indentation and release respectively and irregular atomic concentration near the patterned layer were observed. Also, the spring back and rearrangement of PMMA molecules were analyzed in releasing process.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
• /
• v.23 no.3
• /
• pp.225-235
• /
• 2010

Background & Objective : Rejuvenate treatment with oriental medicine is popular these days. However, there are few reports about it. This study was performed to evaluate the effect of derma stamp treatment. Derma stamp is a new clinical equipment for Microneedle System. Methods : Restrospective study was conducted. Ten patients were treated for 5 weeks. Follow-up was performed after the treatment with Janus facial analysis system. Satisfaction degree was asked from the patients. Results and Conclusions : Derma stamp treatment was good for skin aging problems like pore, wrinkle, spot, sebum and porphyrin. Especially oily type had better effect than dry type.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2009.05a
• /
• pp.84-87
• /
• 2009

This paper describes a novel method for fabricating large area metallic stamp with high aspect ratio micro intaglio features. Micro machined brass master with pillar and larger width groove patterns were electroformed to form inverse structures on the large area metallic stamp. This enabled large area metallic stamp with fine micro high aspect ratio micro intaglio features which were small width groove patterns and quadrilateral hole patterns that cannot be fabricated by direct micro machining process. Fabricated large area metallic stamp with high aspect ratio micro intaglio features was measured and analyzed.