• Journal of the Korean Society of Costume
• /
• v.44
• /
• pp.104-116
• /
• 1999

This study was intended to make an inquiry into the effect of lines, shapes and colors (achromatic colors) as apparel design elements on the perceptions of facial size, brightness and shape through an empirical research based on the theories of visual perception and optical illusion that have been studied in Gestalt Psychology, which becomes the basis of apparel design principles. It was shown that the facial size was influenced by the collar size, the degree of neckline cut, and the thickness of the trimming line. The white scarf with the white jacket made the face look darkest while the black scarf with the black jacket made the face look brightest. When the neckline had the characteristic of the line contrasted with the facial shape, the oval-shaped face was perceived to be the most ideal. When the facial shape and the neckline shape were similar, the facial shape was perceived to be more highlighted.

• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.17 no.4
• /
• pp.112-118
• /
• 2008

In order to meet the optical performance in the process of the micro lens manufacturing with plastics, it is important to embody accuracy in shape and surface roughness to the intended design. Since it is difficult to machine exactly the mold core of lens fit to the designed shape, in this paper, a simple program using MATLAB is developed for shape correction of the mold core after first machining it. This program evaluates correction parameters(aspheric coefficients and curvature) and generates aspheric NC data for compensating the core surface in prior machining process. The program provides the way to manufacture plastic injection molding lens with aspheric shape of high precision, and is expected to be effective for correction and to shorten the processing time.

• 제어로봇시스템학회:학술대회논문집
• /
• 1994.10a
• /
• pp.561-565
• /
• 1994

An automatic measuring system of three dimensional shape by a projection method with grating pattern from in optical spatial modulator has been developed. The characteristics of the system were studied. This system is composed of a projector, an optical spatial modulator, a CCD camera, and computer. A liquid crystal is used as the optical spatial modulator. The grating patterns that ire projected on the surface of the object are controlled by the computer connected with the optical spatial modulator. The projector patterns are measured by the CCD camera. The data are transferred to the computer. After a transformation into line data, the data are analyzed to obtain the coordinate of the surface of the object. This system has advantages as follows. (1) It is possible to capture the surface topography without any contact. (2) The time required for the measurements is shorter than the light-section method. (3) An optical spatial modulator using a liquid crystal is possible to control the grating patterns accurately by a computer. Surfaces of a plate and a cylinder were measured. The threshold level had an influence on the measurement. It was shown that this system has adequae accuracy in the measurements.

• Korean Journal of Optics and Photonics
• /
• v.12 no.4
• /
• pp.270-275
• /
• 2001

We have studied effects of annular phase apodizer and bump shapes on the read-out signal in an optical disc system, using scalar diffraction theory. In order to detennine the optimum parameters of annular phase apodizer which will minimize the influence of spherical aberration, we defined WR as the ratio between the maximum wavefront aberration and some absolute value of wavefront aberration at any position r in the pupil. A cylindric bump, a semi-conic bump and a conic bump were$.$ also considered as different types of bump shape. As the radius and shape of bump varies, the read-out signal from an optical disc system with an annular phase apodizer was similar to that from an optical disc system without apodizer. When spherical aberration increases, the maximum read-out signal of an optical disc system with an annular phase apodizer and minimum bump radii giving read-out signal higher than 0.6 rarely varied. Especially, the optimum parameters at $W_R$ = 0.4 , 0.6 gave the most compensated effect of a spherical aberration.ration.

• Journal of Advanced Navigation Technology
• /
• v.26 no.1
• /
• pp.22-28
• /
• 2022

In order to install ultra wide band and ultra long-haul transmission link based on standard single mode fiber, optical signal distortion due to chromatic dispersion and nonlinear Kerr effect must to be compensated. In this paper, optical link consisted of dispersion management and optical phase conjugation is proposed for compensation of the distorted wavelength division multiplexed (WDM) channels. Dispersion map profile in the proposed dispersion-managed link is configured by periodic repetitive shape, and optical phase conjugator is placed at various position including the midway of total transmission length. It is confirmed from simulation results that when the residual dispersion per span (RDPS) selected in the proposed dispersion-managed link to be large, the compensation of distorted WDM channels in the non-midway OPC system is more improved than the conventional dispersion-managed link.

• Journal of the Korean Society for Nondestructive Testing
• /
• v.31 no.6
• /
• pp.601-608
• /
• 2011

This paper presents the damage assessment of a building structure by using a novel optical fiber accelerometer system. Especially, a sub-scaled building model is designed and manufactured to check up the feasibility of the optical fiber accelerometer for structural health monitoring. The novel accelerometer exploits the moir$\acute{e}$ fringe optical phenomenon and two pairs of optical fibers to measure the displacement with a high accuracy, and furthermore a pendulum to convert the displacement into acceleration. A prototype of optical fiber accelerometer system has been successfully developed that consists of a sensor head, a control unit and a signal processing unit. The building model is also designed as a 4-story building with a rectangular shape of $200{\times}300$ mm of edges. Each floor is connected to the next ones by 6 steel columns which are threaded rods. Basically, a random vibration test of the building model is done with a shaker and all of acceleration data is successfully measured at the assigned points by the optical fiber accelerometer. The experiments are repeated in the undamaged state and the damaged state. The comparison of dynamic parameters including the natural frequencies and the eigenvectors is successfully carried out. Finally, the optical fiber accelerometer is proven to be prospective to evaluate dynamic characteristics of a building structure for the damage assessment.

• Current Optics and Photonics
• /
• v.2 no.6
• /
• pp.568-575
• /
• 2018

Various techniques to measure the three-dimensional (3D) surface profile of a 3D micro- or nanostructure have been proposed. However, it is difficult to apply such techniques directly to industrial uses because most of them are relatively slow, unreliable, and expensive. The HiLo optical imaging technique, which was recently introduced in the field of fluorescence imaging, is a promising wide-field imaging technique capable of high-speed imaging with a simple optical configuration. It has not been used in measuring a 3D surface profile although confocal microscopy originally developed for fluorescence imaging has been adapted to the field of 3D optical measurement for a long time. In this paper, to the best of our knowledge, the HiLo optical imaging technique for measuring a 3D surface profile is proposed for the first time. Its optical configuration and algorithm for a precisely detecting surface position are designed, optimized, and implemented. Optical performance for several 3D microscale structures is evaluated, and it is confirmed that the capability of measuring a 3D surface profile with HiLo optical imaging technique is comparable to that with confocal microscopy.

• Proceedings of the KSME Conference
• /
• 2001.11a
• /
• pp.841-847
• /
• 2001

This study is on the precision of the optical scanner which is suitable for shape modeling and non-contact equipment, comparing with a razer scanner. The optical scanner not only has all merits that non-contact methods have but also improve a veil phenomenon which is a razer scanner's demerits. However, the optical scanner has not been used extensively because the measurements are not very precise and there are not the definite methods of measurement. Hence, this study is to find out how parameters such as camera's hight, angle, luminous intensity, distance to object, and so on have an influence on measuring using the optical scanner and to establish the methods of measuring precision.

• Proceedings of the KSME Conference
• /
• 2003.04a
• /
• pp.1332-1336
• /
• 2003

An experimental method is presented to maximize the replication quality of UV-molded micro-optical components. It is important to maximize the replication quality, because one can obtain the replicated micro-optical components with desired properties by accurate control of the shape. In the present study, a simple technique to avoid micro-air bubbles was first suggested. The effects of the UV-curing dose and the compression pressure on the replication quality of UV-molded structure were examined experimentally. Finally, as a practical application of the process design method, microlens arrays with diameters between 8 ${\mu}m$ and 96 ${\mu}m$ were fabricated by the present method, and the replication quality and the optical properties of the replicated microlens were measured and analyzed.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2003.06a
• /
• pp.1345-1348
• /
• 2003

The Ferrule for the Optical Communication Connector is the product to set the optical ares of an optical fiber very precisely. Therefore, it is required high expectations such as high dimensional precision and new including flaws. Up to new the optical instrument has been used for the defeat and shape inspection of the ferrule, but in the paper we examined the detectable defeat and expectation by using Resonant Ultrasound Spectroscopy(RUS). The RUS is the measurement which is to excite specimen and to inspect the difference at natural frequency pattern between acceptable specimen and specimen which has some defeats. We analyzed the difference of natural frequency pattern in the experiment using Spectrum Analyzer. And we compared the results in the experiment with those in the simulation from the explicit finite elements code, Nastran.