• 한국광학회:학술대회논문집
• /
• 한국광학회 1990년도 제5회 파동 및 레이저 학술발표회 5th Conference on Waves and lasers 논문집 - 한국광학회
• /
• pp.102-111
• /
• 1990

In this thesis, an optical bidirectional inner-product associative memory model using liquid crystal television is proposed and analyzed theoretically and realized experimentally. The LCTV is used as a SLM(spatial light modulator), which is more practical than conventional SLMs, to produce image vector in terms of computer and CCD camera. Memory and input vectors are recorded into each LCTV through the video input connectors of it by using the image board. Two multi-focus hololenses are constructed in order to perform optical inner-product process. In forward process, the analog values of inner-products are measured by photodetectors and are converted to digital values which are enable to control the weighting values of the stored vectors by changing the gray levels of the pixels of the LCTV. In backward process, changed stored vectors are used to produce output image vector which is used again for input vector after thresholding. After some iterations, one of the stored vectors is retrieved which is most similar to input vector in other words, has the nearest hamming distance. The experimental results show that the proposed inner-product associative memory model can be realized optically and coincide well with the computer simulation.

• Archives of Pharmacal Research
• /
• 제27권8호
• /
• pp.820-824
• /
• 2004

An optical purity test was indirectly performed on (S)-ibuprofen as its diastereomeric (R)-(+)-1-phenylethylamide derivative using achiral gas chromatography (GC). The method for the determination of trace (R)-ibuprofen (optical impurity), within the range 1.0 to 50 ng, from a racemic ibuprofen standard was linear (r＝0.9997) with acceptable precision (％ $RSD{\leq}5.3$) and accuracy (％ RE＝0.7~-3.9). Similar results were obtained with the method validation for the quantification of (S)-ibuprofen within the range 0.1 to 2.0 $\mu\textrm{g}$ using a (S)-ibuprofen stan-dard. When applied to seven different commercial (S)-ibuprofen products, their optical purities (98.7~99.1％) were determined with good precision (％ $RSD{\leq}4.0$).

• 펄프종이기술
• /
• 제36권1호
• /
• pp.61-66
• /
• 2004

Bleached chemithermomechanical pulp (BCTMP) was produced from CTMP of Betula maximowicziana Regel by two staged ozone-hydrogen peroxide bleaching in order to improve the optical properties of high yield pulp. This pulp was used for the evaluation of optical properties improvement, chemical characteristics of lignin in fiber and the relationship between lignin and optical properties in fiber cell wall. Hydrogen peroxide treatment improved the brightness, but the post color number (PC No.). There was little improvement on optical properties by ozone treatment, but this could be improved more by using two staged ozone-hydrogen peroxide bleaching. The hydrogen peroxide treatment did not make any change on chemical characteristics of lignin in cell wall, but by ozone treatment, it was found that the non-aromatic conjugated structure was existed in the surface of cell wall, but this could be removed by hydrogen peroxide treatment in two staged ozone-hydrogen peroxide treatment. Therefore, the optical properties was significantly improved, due to the removal of non-aromatic conjugated structure.

• 한국정보통신설비학회:학술대회논문집
• /
• 한국정보통신설비학회 2006년도 하계학술대회
• /
• pp.15-18
• /
• 2006

We have proposed a broadband analog feedforward optical transmitter using a wideband $180^{\circ}$ hybrid coupler instead of conventional frequency-sensitive phase shifter with the narrow bandwidth property using a wideband $180^{\circ}$ hybrid coupler, the wide-band linearization technique enhances the linearity of the feedforward optical transmitter. In two-tone cases, the $3^{rd}-IMD$ products was enhanced more than 10 dB in 385 MHz range(1.375$\sim$l.76 GHz).

• 산업경영시스템학회지
• /
• 제25권2호
• /
• pp.35-41
• /
• 2002

This paper describes an automatic transplantation machine of optical fiber controlled by PLC. The transplantation operations is a key operation for the optical fiber application products, such as bag, cap, and others. To transplant 200∼500 optical fibers, there are many recurrent manual operation needed with conventional process. In this paper. we propose an automatic machine that reduce transplanting time and enhance product quality. Developed machine includes transplantation, heat cutting and ultraviolet coating operation. Also proposed Machine is controlled by PLC to adjust operation parameters such as pulling length, cycle time, coating time and others. Developed Machine has been applied in the field and found to be a useful system.

• 한국응용과학기술학회지
• /
• 제23권4호
• /
• pp.340-346
• /
• 2006

The influences of fluorescence, scattering, and flocculation in turbid material by light scattering were interpreted for the scattered fluorescence intensity and wavelength, it has been studied the molecular properties by the spectroscopy of laser induced fluorescence (LIF). The effects of optical properties in scattering media have been found by the optical $parameters({\mu}_s,\;{\mu}_a,\;{\mu}_t)$. Flocculation is an important step in many solid-liquid separation processes and is widely used. When two particles approach each other, interactions of several colloid particles can come into play which may have major effect on the flocculation and LIF process, The value of scattering coefficient ${\mu}_s$ is large by means of the increasing particles of scatterer it has been found that the slope decays exponentially as a function of distance from laser source to detector. It may also aid in designing the best model for oil chemistry, biopharmaceutical products, laser medicine and application of medical engineering on LIF and coagulation in particle transport mode.

• Journal of the Optical Society of Korea
• /
• 제14권4호
• /
• pp.383-387
• /
• 2010

The stereoscopic three-dimensional (3D) display provides a 3D image by inducing binocular disparity for the observers who wear special glasses. With the rapid progress in flat panel display technologies, the stereoscopic 3D display is becoming a new benefit-model of the current display industry, and several kinds of commercial stereoscopic 3D products have been released and are attracting people. Nowadays, the motion picture quality of the 3D image becomes as important as resolution or luminance since most of the commercial 3D products are 3D televisions or 3D monitors which are required to display a clear motion 3D image. In this paper, an analysis and simulation of the motion picture quality of stereoscopic 3D image is proposed, and a comparison of the motion picture performance among the current stereoscopic 3D technologies is also provided.

• Journal of Biosystems Engineering
• /
• 제30권2호
• /
• pp.114-120
• /
• 2005

In this study, a biological reaction and measurement control system was developed to rapidly measure the insecticide imidacloprid residues in agricultural products. The biological reaction part of the system was designed to include micro-pumps and valves for fluid transport, and a polystyrene covet as a reaction chamber. The measurement control part of the system consisted of a photodiode with a light-emitting diode for optical density measurement, and a control microcomputer to implement assay. Signal output was read as the rate of change in optical density at 645 nm. The sensitivity of the system was 2.2 ng/mL ($IC_50$). The system could execute a measurement cycle in about 19 minutes. Research will be continued to develop an automatic sampler fur imidacloprid residues from agricultural products.

• Korea-Australia Rheology Journal
• /
• 제19권4호
• /
• pp.191-199
• /
• 2007

Precision injection molding process is of great importance since precision optical products such as CD, DVD and various lens are manufactured by those process. In such products, birefringence affects the optical performance while residual stress that determines the geometric precision level. Therefore, it is needed to study residual stress and birefringence that affect deformation and optical quality, respectively in precision optical product. In the present study, we tried to predict residual stress, final shrinkage and birefringence in injection molded parts in a systematic way, and compared numerical results with the corresponding experimental data. Residual stress and birefringence can be divided into two parts, namely flow induced and thermally induced portions. Flow induced birefringence is dominant during the flow, whereas thermally induced stress is much higher than flow induced one when amorphous polymer undergoes rapid cooling across the glass transition region. A numerical system that is able to predict birefringence, residual stress and final shrinkage in injection molding process has been developed using hybrid finite element-difference method for a general three dimensional thin part geometry. The present modeling attempts to integrate the analysis of the entire process consistently by assuming polymeric materials as nonlinear viscoelastic fluids above a no-flow temperature and as linear viscoelastic solids below the no-flow temperature, while calculating residual stress, shrinkage and birefringence accordingly. Thus, for flow induced ones, the Leonov model and stress-optical law are adopted, while the linear viscoelastic model, photoviscoelastic model and free volume theory taking into account the density relaxation phenomena are employed to predict thermally induced ones. Special cares are taken of the modeling of the lateral boundary condition which can consider product geometry, histories of pressure and residual stress. Deformations at and after ejection have been considered using thin shell viscoelastic finite element method. There were good correspondences between numerical results and experimental data if final shrinkage, residual stress and birefringence were compared.

• 한국안광학회지
• /
• 제14권4호
• /
• pp.1-10
• /
• 2009

목적: 이 연구는 최근 고글 및 선글라스가 공산품으로 규정되어 있어 안경원 외의 장소에서 비전문가가 판매하고 있는데, 그에 따라 안경사가 아닌 비전문가가 판매하므로써 안경테 및 안경 렌즈의 재질과 커브, A/S 사항이 현실적으로 체크가 불가능하여 국민의 안보건을 위협하고 있다. 따라서 안경원을 제외한 고글 및 선글라스의 판매인들이 얼마나 안경에 대한 지식이 있고 어떠한 서비스를 할 수 있는지 알아보기 위하여 조사연구를 하였다. 방법: 연령에 상관없이 안경원 근무자, 안경사를 제외한 고글 및 선글라스 판매인 100명과 안경원을 제외한 판매점에서 고 글 및 선글라스를 구매한 208명을 대상으로 설문 조사하였다. 결과: 대다수의 판매인들은 안경에 대한 지식 없이 판매를 하고 안경에 대한 지식이 있더라도 많이 부족한 현실이었다. 결론: 안경 렌즈와 관련된 모든 것은 안경원에서 전문적인 지식이 있는 안경사가 직접 판매하고 관리하는 방식이 필요하다. 그래서 하루 빨리 공산품으로 되어있는 고글 및 선글라스가 의료용구로 변환시키는 대책이 필요하다.