• International Journal of CAD/CAM
• /
• v.7 no.1
• /
• pp.31-40
• /
• 2007

Reverse engineering of reliefs aims to turn an existing relief superimposed on an underlying surface into a geometric model which may be applied to a different base surface. Steps in this process include segmenting the relief from the background, and describing it as an offset height field relative to the underlying surface. We have previously considered relief segmentation using a geometric snake. Here, we show how to use this initial segmentation to estimate the background surface lying under the relief, which can be used (i) to refine the segmentation and (ii) to express the relief as an offset field. Our approach fits a B-spline surface patch to the measured background data surrounding the relief, while tension terms ensure this background surface smoothly continues underneath the relief where there are no measured background data points to fit. After making an initial estimate of relief offset height everywhere within the patch, we use a support vector machine to refine the segmentation. Tests demonstrate that this approach can accurately model the background surface where it underlies the relief, providing more accurate segmentation, as well as relief height field estimation. In particular, this approach provides significant improvements for relief concavities with narrow mouths and can segment reliefs with small internal holes.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2002.08a
• /
• pp.293-296
• /
• 2002

Surface relief holograms are fabricated by means of irradiation of laser interference patterns. The diffraction efficiency and the surface relief depth depend on the writing energy and the polarization of the writing laser beam. This structure is very stable at temperatures under glass transition temperature $T_g$ and can be erased by heating above $T_g$. We proposed a new technique to control the surface relief structure. The electric charge was deposited on the surface relief grating in a corona-depositing poling setup in an oven. The first-order diffraction efficiency measured before and after corona discharge increased from about 0.24 % to about 28 %. This diffraction efficiency increase is mainly caused by the increase of the relief depth caused by the electric charge. The relief depth is increased from 20 nm to 350 nm by corona charging. .

• Proceedings of the Optical Society of Korea Conference
• /
• 2003.07a
• /
• pp.166-167
• /
• 2003

아조벤젠 그룹의 trans-cis-trans photo isomerization 특성에 의한 광배향 (photoinduced orientation) 성질을 이용하여 아조벤젠이 함유된 폴리머박막에 표면 부조 격자 (surface relief grating)를 만드는 것은 널리 알려져 있다. 특히 최근 들어, 비선형 물질의 주기적인 배열 구조를 만들기 위해서 surface relief grating을 corona poling 하는 방법들이 연구되어 지고 있다. poling된 surface relief grating은 poling 방향으로의 azo분자의 극질서가 유도되기 때문에, $C_{{\infty}v}$점대칭을 가지는 비등방 회절 격자(anisotropic grating)가 되며 2차 비선형 특성 중의 하나인 선형 전기 광학 효과를 나타낼 수 있다. (중략)

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2000.07a
• /
• pp.299-302
• /
• 2000

In this study, we have made the large holographic surface relief gratings on amorphous chalcogenide $As_{40}$$Ge_{10}$$Se_{15}$$S_{35}$ films by two beam interference using a He-Ne laser(632.8nm) light. The film thickness was about 0.6$\mu\textrm{m}$, we could magnify beam size by using beam expander. We made use $90^{\circ}$ holder which was made of reflection mirror and sample. Formed the surface relief structures were investigated using optical microscope. The diffraction efficiency was obtained by measuring +lst order intensity. In addition we investigated grating formation and diffraction efficiency as a function of polarization states which is linear or circular polarization. The results indicate that the grating was formed by linear polarized beam is better clear than that by circular polarized beam.

• Journal of Fashion Business
• /
• v.9 no.1
• /
• pp.1-20
• /
• 2005

This study is purposed to provide new idea for developing high value added fashion goods by studying relief effects of fashion design. Based on prior researches, various ways to give relief effects were searched and then modern fashion design cases were looked for which were referred to fashion-related magazines and collection-related internet sites since the late 1990s. The ways for relief effects are weaving, industrial finishing, sewing technique. Weaving techniques are about fancy yarns, variation of weaving structure, pile weave. Industrial finishing techniques which can make relief effects are embossing, heat-setting, shearing, pliss, burn out, flocking. Sewing techniques are quilting, pleats, embroidery, slash, attachment in accordance with the way to produce relief effects. The forms of relief effects are tactile pattern that cannot be seen in the distance, subtle relief pattern which is more three-dimensional than tactile pattern, rhythmical relief pattern, sculptural pattern, and deep-volumed pattern. The present research can provide practical data for design by studying techniques of relief effects and collecting and arranging design cases that have been sporadically carried out. The study on relief and unique surface effects can be a way to effectively stimulate and express emotions of modern people with various taste and individuality.

• Macromolecular Research
• /
• v.16 no.5
• /
• pp.434-440
• /
• 2008

Three-armed, star-shaped molecules containing 4-(N,N-diphenyl)amino-4'-nitroazobenzene chromophores were synthesized to study the diffraction behavior after inscribing surface relief gratings. The two molecules differed in terms of their mode of chromophore attachment to the core. In compound 5, they were bound to the core laterally through alkylene spacers, whereas the chromophores were tethered perpendicularly to the core in compound 4. Although 60 wt% of the polar azobenzene chromophores was comprised of large molecules, no aggregation behavior was observed in the absorption spectra of the thin films. The surface relief gratings were elaborated on the surface of the molecular films by the two-beam interference method. The dynamics of grating formation were studied in terms of the diffraction efficiency using two different film samples made up of two star-shaped molecules. The maximum diffraction efficiency of D-$(ENAZ)_3$, compound 4, was measured to be about 30%, which was significantly high. The mode of chromophore attachment affected the dynamic properties of the diffraction gratings.

• Journal of the Korean Graphic Arts Communication Society
• /
• v.29 no.3
• /
• pp.133-142
• /
• 2011

We produce a photosensitive convex plate to research a Nickel metal relief printing plate using galvanic process. A Method for preparing DLC convex plate that is metalized on Nickel metal relief printing plate using CVD(Chemical Vapor Deposition) process and $N_2DLC$-convex plate that is DLC metalized thin film layer of $N_2$ plasma surface treatment are comprised. DLC thin film layers on Nickel surface are fragile. The results of the research indicate that the coefficient of friction on DLC metalized thin film layer is relatively low than Nickel surface and the durability of Nickel surface coated DLC metalized thin film layer is superior to Nickel surface. A relative evaluation of three form plate wetting properties using varnish liquid-drop plate indicates superior printing aptitudes for $N_2DLC$, DLC, Nichel plate order as above.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.33 no.8
• /
• pp.793-798
• /
• 2009

In this paper, the simulation and optimization of SRH (Surface Relief Hologram) masks for printing LCD gate patterns using TIR (Total Internal Reflection) holographic lithography was investigated. A simulation and optimization algorithm based on SDTA (Scalar Diffraction Theory Analysis) method was developed. The accuracy of the algorithm was compared to that of the RCWA (Rigorous Coupled Wave Analysis) method for estimating the Fresnel diffraction pattern of Cr amplitude masks for the given system geometry. In addition, the results from the optimization algorithm were validated experimentally. It was found that one to the most important conditions for the fabrication of SRH masks is to avoid nonlinear shape distortions of the resulting grating. These distortions can be avoided by designing SRH masks with recorded gratings having small aspect ratios of width versus depth. The optimum gap size between the Cr and SRH masks was found using the optimization algorithm. A printed LCD gate pattern with a minimum line width of $1.5{\mu}m$ exposed using the optimized SRH mask was experimentally demonstrated.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.24 no.5
• /
• pp.868-873
• /
• 1987

Holographic diffraction gratings which are the core element of the optical instruments such as a spectrophotometer have been fabricated using the photoresist as a recording material. A 488nm line from an argon laser is used in making the gratings. Transmission type surface-relief phase grating and reflection type which is fabsricated by coating the aluminum on the transmission type with thickness 2000\ulcornerare fabricated, the spatical frequency of which are 1200 lines/mm. Diffraction efficiency, scattered light and wave-front aberratin are measured to test the performance of the developed gratings. A marimum diffraction efficiency is given when light is incident at the Bragg angle. Theoretical efficiency is about 80%, but measured efficiency of the transmission type and reflection type is 50% and 45%, respectively.

• Advances in nano research
• /
• v.14 no.1
• /
• pp.17-25
• /
• 2023

Gold nanoparticles have recognized a promising drug carriers in many diseases. These nanoparticles could carry anti-inflammatory drugs in the case of muscle injury and for fatigue relief. On the other hand, specific surface of this kind of nanoparticles could be critical in amount of drug they could carry. Therefore, in this study, we explore different methodology and influencing parameters on the specific surface of gold nanoparticles. After specifying the main parameters, different machine learning and artificial neural network are adopted to model the effects of different parameters. Furthermore, response surface methodology is utilized to obtain a quadrilateral relationship between different parameters and specific surface. The results indicate that concentration of the gold salt solution is the most important parameter in increasing the size of gold nanoparticle and, as a consequence, increasing specific surface. Moreover, the ability of gold nanoparticles in prolonging retention of the drugs is discussed in detail.