• International Journal of Precision Engineering and Manufacturing
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• v.4 no.5
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• pp.41-46
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• 2003

Electronic Speckle Pattern Interferometry (ESPI) has been recently developed and widely used because it has the advantage of being able to measure surface deformations of engineering components and materials in industrial areas without contact. The speckle patterns formed with interference and scattering phenomena can measure not only the out-of-plane but also the in-plane deformations. Digital image equipment processes the information included in the speckle patterns and displays the consequent interferogram on a computer monitor. In this study, the experimental results of a canti-levered plate using ESPI were compared with those obtained from the simple beam theory. The ESPI results of the canti-levered plate, analyzed by 4-step phase shifting method, are close to the theoretical expectation. Similarly, out-of-plane displacements of a spot welded canti-levered plate were also measured by ESPI with 4-step phase shifting technique. The phase map of the spot welded canti-levered plate is quite different from that of the canti-levered plate without spot welding.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1807-1812
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• 2007

A bulge testing system was developed to measure mechanical properties of thin film materials. A bulge pressure test system for pressurizing the bulge window of the film and a micro out-of-plane ESPI(Electronic Speckle Pattern Interferometric) system for measuring deflection of the film were included in the testing system developed. For the out-of-plane ESPI system, whole field speckle fringe pattern, corresponding to the out-of-plane deflection of the bulged film, was 3-dimensionally visualized using 4-bucket phase shifting algorithm and least square phase unwrapping algorithm. The bulge pressure for loading and unloading was controlled at a constant rate. From the pressure-deflection curve measured by this testing system, ain-plane stress-strain curve could be determined. In this study, elastic modulus of an electrolytic copper film 18 ${\mu}m$ was determined. The modulus was calculated from determining the plain-strain biaxial elastic modulus at the respective unloading slopes of the stress-strain curve and for the Poisson's ratio of 0.34.

• Transactions of the Korean Society of Mechanical Engineers
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• v.12 no.2
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• pp.359-372
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• 1988

Characteristics of twin spray ejected from two swirl spray nozzles were studied experimentally. By using a patternator for measuring volumetric flux of drop flow at various locations inside the spray, variation of the twin spray pattern along the axial direction was studied with changing the injection pressure and the distance between the nozzles. The general findings from the experiments are as follows: (i) as axial distance from the nozzles increases, the spray pattern in x-z plane which contains both nozzles changes significantly. On the other hand the spray pattern in y-z plane which passes the midpoint between two nozzles remains almost unchanged at outer region as axial distance and injection pressure vary; (ii) at the downstream of the twin spray with spray interaction, the maximum volumetric flux in y-z plane (q$_{max}$)$_{y}$, has tendency to become larger than that of x-z plane (q$_{max}$)$_{x}$, due to a characteristic(hollow cone shape) of the constituting swirl sprays, and this trend is pronounced at higher injection pressure since the cross-section of each single spray remains hollow at the longer axial distance from each nozzle with higher injection pressure; (iii) at a certain axial distance from the nozzles, the cross-sectional shape of the boundary of the twin spray tends to be circular similar to that of the single spray with twice the flow-rate, and that distance is not proportional to the distance between two nozzles; (iv) though there are some collisions between droplets from each nozzles of twin spray, in present experimental range, the flow pattern of gas including the entrainment effect plays the key role in spray interaction.n.ion.n.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.10
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• pp.1973-1979
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• 2016

As technologies evolve, diverse 3D measurement techniques using cameras and pattern projectors have been developed continuously. In 3D measurement, high accuracy, fast speed, and easy implementation are very important factors. Recently, 3D measurement using multi-frequency fringe patterns for absolute phase computation has been widely used in the fringe projection profilometry. This paper proposes an improved method to compute the object's absolute phase using the reference plane's absolute phase and phase difference between the object and the reference plane. This method finds the object's absolute phase by adding the difference between the reference plane's wrapped phase and the object's wrapped phase to the reference plane's absolute phase already obtained in the calibration stage. Through this method, there is no need to obtain multi-frequency fringe patterns about new object for the absolute phase computation. Instead, we only need the object's phase difference relative to the reference planes's phase in the measurement stage.

• Journal of the Korea Fashion and Costume Design Association
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• v.25 no.2
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• pp.97-110
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• 2023

The purpose of this study is to develop 3D pattern textile design of traditional Jogakbo motifs and fashion products using it. As a research method, first, through literature review, the three-dimensional representation of geometry on a plane with Jogakbo, design cases were examined. Second, through a survey, the purchase perception and design preference of Jogakbo cultural products was analyzed. Third, based on the results of the survey on color and print, the 3D pattern design for each type of Jogakbo is printed, and then textile fashion cultural products were developed. The results of this study are as follows. First, the reason why the public was not attracted to the purchase of cultural products was disatisfaction with practicality, unsuitable preference, price adequacy, aesthetics, and originality. Therefore, it was analyzed that quality, practicality, price, carry-on storage harmony and manageability, as well as aesthetic design were important factors for consumers. Second, the stereoscopic space on the plane expanded the two-dimensional plane space by forming a cube through the division and dissolution of geometry could be visualized using color expression of cubes of different brightness depending on the direction of light. Third, Jogakbo had eight types consisting of four detailed forms and three arrangement methods. The 3D pattern design could be developed through regular disolution and stereoscopic construction using Jogakbo's representative images for each type. In addition, it was found that it was easy to produce Jogakbo fashion products suitable for modern people through 3D pattern digital textile printing applying traditional colors.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.11
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• pp.5447-5451
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• 2012

This paper presents a pattern-switchable microstrip patch antenna with loop structure. The loop structure for switchable radiation beam pattern is connected with feeding line of the microstrip patch antenna. As changing switch on/off state, the radiation beam pattern can be changed. The target frequency is 2.4 GHz and maximum radiation gain is 3.2dBi. The proposed antenna is useful for diversity antenna and smart antenna in modern wireless communication including MIMO (Multi-Input Multi-Output) and WLAN system. The sizes of the rectangular patch and the ground plane are $28mm{\times}28mm$ and $40mm{\times}50mm$, respectively. The simulation and experimental results show that the antenna radiation pattern can be changed with switch on/off configuration.

• Journal of the Korea Fashion and Costume Design Association
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• v.12 no.2
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• pp.107-118
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• 2010

The purpose of this study is to be data and to help understanding of pattern of Korean, Chinese and Japanese traditional dress. The methods of this study are the study of academic literatures as well as practical study through the analysis of case studies about actual works. The summary of this study's results is like followings. First, standard of Pattern are nature, mam-made in motif object, Naturalistic, Geometric, Stylized, Abstract in motif express, Order, Disorder in pattern express. Second, a point of sameness of motif object in traditional dress of three nations were that nature and letter abstractive of mam-made is a lot. but motif of Japan was used in daily life motif of mam-made which was not in Korea and China Third, commonly, motif expression of three nations were developed Naturalistic, Stylized. but in Naturalistic, Korea was simple, plane, China was three-dimensional, Japan was expressed super realism. Fourth, as formative aesthetic of Pattern, Korea is natural, plane, simple and symbolic, China is gorgeous, three-dimensional, immaculacy, filling and symbolic, Japan is delicate, complicated, decoration and symbolic.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10b
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• pp.1758-1763
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• 1991

This paper describes a new method to determine the 3D-shape of objects consisting of specular planar surfaces. This method exploits a light source which is made of a diffuse plane with a grid pattern encoded in an M-sequence and uses a single image of the light source reflected by the objects to acquiring orientations and positions of the surfaces of the objects. When grid lines of the light source are reflected by a specular planar surface and perspectively projected on an image plane, a set of lines vanishing at a point are obtained on the image plane. The orientation of the specular planar surface is determined by using the vanishing point, and the position is determined by using the correspondence between lines on the image and lines on the light source, which is obtained by employing a characteristic regularity of the M-sequence. Before the vanishing points are calculated, the lines on the image are classified and correlated with the surfaces of objects by using slopes and positions of the lines and the regularity of the M-sequence. This method requires only a single image.

• The Journal of Korean Physical Therapy
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• v.10 no.1
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• pp.213-221
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• 1998

The purpose of this study was a motion analysis of proprioceptive neuromuscular facilitation patterns which is scapular and pelvis patterns, upper extremity patterns, lower extremity patterns, trunk patterns. The patterns combine motion in sagittal plane for flextion and extension, coronal or frontal plane for abduction and adduction, transverse plane for rotation. The patterns composed of mass movement pattern of the limbs and trunk muscles. Every pattern can change by changing the activity of the middle joint in the extremity patterns and changing the patient's positions.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1997.04a
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• pp.48-53
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• 1997

Electronic Speckle Pattern Interferometry(ESPI) using the Model 95 Ar laserm, a video system and an image processor was applied to the in-plane displacement measurements. Unlike traditional strain gauges or moire method, ESPI method requires no special surface preparation or attachments and can be measured in-plane displacement with no contact and real time. In this experiment wpecimen was loaded in parallel with a loadcell. The specimen was the cold rolled sdteel sheet of 2mm thickness, which was attached strain gauges. The study provides an example of how ESPI have been used to measure strain displacement in this specimen. The results measured by ESPI have been used to measure strain displacement in this specimen. The results measured by ESPI have been used to measure strain displacement in this specimen. The results measured by ESPI compare with the data which was measured by strain gauge method in tensile testing.