• Journal of the Korean Society for Precision Engineering
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• v.26 no.7
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• pp.65-72
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• 2009

Laser interferometry is widely used as a measuring system in many fields because of its high resolution and its ability to measure a broad area in real-time all at once. In conventional laser interferometry, for example out-of-plane ESPI (Electronic Speckle Pattern Interferometry), in plane ESPI, shearography and holography, it uses PZT or other components as a phase shift instrumentation to extract 3-D deformation data, vibration mode and others. However, in most cases PZT has some disadvantages, which include nonlinear errors and limited time of use. In the present study, a new type of laser interferometry using a laser diode is proposed. Using Laser Diode Sinusoidal Phase Modulating (LD-SPM) interferometry, the phase modulation can be directly modulated by controlling the laser diode injection current thereby eliminating the need for PZT and its components. This makes the interferometry more compact. This paper reports on a new approach to the LD (Laser Diode) Modulating interferometry that involves four-frame phase shift method. This study proposes a four-frame phase mapping algorithm, which was developed to have a guaranteed application, to stabilize the system in the field and to be a user-friendly GUI. In this paper, the theory for LD wavelength modulation and sinusoidal phase modulation of LD modulating interferometry is shown. Using modulating laser and research of measurement algorithm does comparison with existent ESPI measurement algorithm. Algorithm measures using GPIB communication through most LabVIEW 8.2. GPIB communication does alteration through PC. Transformation of measurement object measures through modulating laser algorithm that develops. Comparison of algorithm of modulating laser developed newly with existent PZT algorithm compares transformation price through 3-D. Comparison of 4-frame phase mapping, unwrapping, 3-D is then introduced.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.591-594
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• 2000

This paper describes a research work of developing a computer-aided design of product with bending and piercing for progressive working. An approach to the system for progressive working is based on the knowledge-based rules. Knowledge for the system is formulated from plasticity theories, experimental results and the empirical knowledge of field experts. The system has been written in AutoLISP on the AutoCAD with a personal computer and is composed of four main modules, which are input and shape treatment, flat pattern layout, strip layout and die layout module. Based on knowledge-based rules, the system is designed by considering several factors such as radius and angle of bend, material and thickness of product, complexities of blank geometry and punch profile, bending sequence, and availability of press. Strip layout drawing generated by the piercing processes with punch profiles divided into for external area is simulated in 3-D graphic forms, including bending sequences for the product with piercing and bending. Results obtained using the modules enable the manufacturer for progressive working of electronic products to be more efficient in this field.

• Journal of Broadcast Engineering
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• v.16 no.3
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• pp.483-489
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• 2011

In this paper, we propose a new antenna, which has wide bandwidth, good radiation patterns, and high-gain characteristics. We analysis the antenna using FDTD(Finite Difference Time Domain) method. And the antenna parameters are optimized to get maximum bandwidth. From the measured results, the bandwidth of the antenna is 0.839 octave, for the S11${\leq}$-10 dB. And the measured cross polarization level of the proposed antenna is less than -25 dB at the center frequency. Experimental data of the return loss and the radiation pattern of the proposed antenna are also presented, and the experimental bandwidth characteristics are relatively in good agreement with the FDTD results. The proposed antenna can be applied to MIMO, LAN, biomedical instruments, broadcasting-network system.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.4
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• pp.413-422
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• 2011

An improved split-beam transducer for a 50 kHz fish-sizing echo sounder was developed. The main objective of this study was to minimize the side lobe level in the beam pattern and the distance between acoustic centers for adjacent transducer quadrants in the geometrical arrangement of array elements while maintaining a given number of transducer elements and beam width. To achieve these goals, a 32-element planar array transducer ($6{\times}6$ array with one element in each corner missing) was designed using the Dolph-Chebyshev shading function to suppress side lobes in the array beam pattern and fabricated by arranging the inter-element spacing to be substantially equal to half the wavelength using the transducer element of 0.4 times the wavelength in diameter. The performance characteristics of this split-beam transducer were evaluated in the experimental water tank of $5m{\times}5m{\times}6m$ (length${\times}$height${\times}$width). In this study, the design goal of the beam width and side lobe level for transmitting a beam pattern was initially set at $21^{\circ}$ and -30 dB, respectively. However, the measured beam width at 3 dB was $21^{\circ}$ in both directions with side lobe levels of -24.7 dB in the horizontal plane and -25.6 dB in the vertical plane. The averaged beam width at -3 dB of the receiving beam patterns for four receiving quadrants was $31.4^{\circ}$. The transmitting voltage response was 161.5 dB (re $1{\mu}Pa$/V at 1 m) at 50.23 kHz with a bandwidth of 2.16 kHz, and the averaged receiving sensitivity for four receiving quadrants was -178.13 dB (re 1 V/${\mu}Pa$) at 49.8 kHz with a bandwidth of 2.64 kHz.

• Fashion & Textile Research Journal
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• v.12 no.6
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• pp.789-795
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• 2010

The purpose of this study was to examine the appropriate surplus of clothing for a jacket bodice pattern of middle-aged obese men by using the 3D virtual twin and virtual garment simulation system. The results were as follows ; 1. BMI rate of middle-aged males was 28.13 which was equivalent to mild obesity, whereas WHR(W/H ratio from waist to hips) rate was near 1.00 which was highly dangerous against their obesity. In case of middle-aged obese men, the WHR was significantly higher than the entire middle-aged men's average and the section shape in which their thickness was relatively more than width. 2. As a result of appearances evaluation through virtual garment simulation, the cut-off amount of the side seam and the center back was regulated accordingly. Hereby, the final tolerance range was set up at 21.15 cm at the hips, so that the appearances became better and the bilateral distribution of the cross section and space length was formed symmetrically. Especially in case of increasing the cross amount of hems to produce a natural silhouette of the waist-to-hips parts, the ease of buttocks was judged to be moderate, but it turned out that a wavy cross section was made and the silhouette was not good. Thus it was found to be not good that the ease of the hips became excessively increased in proportion as circumference of waist and belly were increased in obesity. The use of the virtual twin made it impossible to comprehend the appearances and ease correspondent to motions. In order to evaluate wearing fitness, therefore, the system should be improved so as to change arm positions and perform various motions.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.3 no.2
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• pp.110-114
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• 2002

The master pattern manufacturing process is one of the most important processes in jewelry industry because the process takes 20% of total jewelry manufacturing costs. The previous jewelry manufacturing process has many steps of "rough design${\leftrightarro}$ detailed drawing${\leftrightarro}$ wax pattern manufacturing ${\leftrightarro}$ lime soda flask mold manufacturing ${\leftrightarro}$ silver master pattern manufacturing ${\leftrightarro}$ mass production of wax pattern ${\leftrightarro}$ investment casting process ${\leftrightarro}$ final jewelry product." A novel process that reduces processing steps by using a rapid prototyping system (RP) has been suggested. The process is "3D CAD design ${\leftrightarro}$ DuraForm mold manufacturing by RP ${\leftrightarro}$ manufacturing master pattern by low melting alloy ${\leftrightarro}$ mass production of wax pattern ${\leftrightarro}$ investment casting process${\leftrightarro}$ final jewelry product." Molds are made with DuraForm powder, of which melting temperature is 19$0^{\circ}C$, by a selective laster sintering type RP. An alloy of Pb-Sn-Bi-Cd, of which melting temperature is $70^{\circ}C$, is casted in the DuraForm molds. Spheres and rings of diameter 20 mm are made by this process. The dimension deformation rate is less than 2%, and the post processing of the castings is convenient. The casting made by the suggested process can be used as a master pattern of jewelry products.of jewelry products.

• Fashion & Textile Research Journal
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• v.15 no.4
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• pp.504-513
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• 2013

This study evaluates the difference of visual effect according to pant style and geometric pattern. The researcher made 28 stimuli-combination of four pant Stiles (classic, baggy, skinny, and bell-bottom) and seven geometric pattern (large vertical stripe, small vertical stripe, large horizontal stripe, small horizontal stripe, large check, small check, and hound's tooth check). The test involved 96 female college students. The stimuli were made with the i-Designer computer program. The panels tested the computer screen images of all manikins wearing pants. A 7-point scale was used to evaluate each image. For the data analysis, ANOVA and Duncan-test were applied along with an SPSS program. The results of this study are as follows. Three factors (lower-body compensation, abdomen highlight, and length compensation) influenced the visual effect pant styles and geometric patterns. The skinny style and large vertical stripe evaluated positively in elongated height and leg length and a slimmer overall body. It was shown that the vertical stripe pattern was evaluated as more positive than the horizontal stripe pattern in the visual effect; particularly, the results showed distinct aspects in the classic pants style. The mutual influence of the visual effect (according to pants style and geometric pattern) were indicated as two factors of lower-body compensation and length compensation. A more positive visual effects resulted in a higher mutual influence on pant style and geometric pattern.

• The Research Journal of the Costume Culture
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• v.25 no.4
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• pp.476-487
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• 2017

The purpose of this study was to suggest torso patterns that fit the three main body shapes of elderly obese women. To reduce time, costs, and also the trial and error needed to make patterns, the CLO program for 3D test wear was employed. Three virtual models for aged obese women were use, with the YUKA system used to produce torso patterns. 3D simulation of test wear and corrections was done to design optimal torso patterns. The results were as follows: First, for the three models of obese women's body shapes as realized by CLO 3D, Type 1 is lower-body obesity shapes, Type 2 is abdominal obesity shapes, and Type 3 is whole-body obesity shapes. Second, to design the study patterns, actual measurement values, back waist length and waist to hip length, were used. The armhole depth (B/4-1.5), front interscye (B/6+2.3), front neck width (B/12-0.5), front neck depth (B/12+0.5), front waist measurement (W/4+ 1.5+D), front hip measurement (H/4+2+0.5), and back hip measurement (H/4+3-0.5) were calculated using formulas. Third, according to the results of test-wearing the study patterns, reduced front neck width and depth improved the neck fit and reduced armhole depth bettered loose or plunging armhole girth and also reduced the sagging of bust c.. Also, tight sidesfrom aprotruded waist and abdomen improved with the increase of surpluses in the back waist and also back and front hip c. The exterior was enhanced by displacement of back and front darts, which distributed surpluses better.

• Journal of Fashion Business
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• v.21 no.6
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• pp.66-76
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• 2017

This study used a virtual wearing system equipped with body shape data with a 3D scanner, based on a female basic bodice, to develop a modified Hanbok Jeogori with high fitness capabilities to provide basic data for the development of the modified Hanbok Jeogori pattern for the academic and industrial fields. In this study, the representative modified Hanbok design which most frequently appeared in broadcasting ads and on line was selected. The wearing test was conducted by six professionals, and three times wearing tests were implemented based on 17 evaluation items. The data for this study was processed statistically using SAS 9.0. We conducted, the F-test for significance verification, the Duncan-test for a post test, and a correlation analysis of Cronbach's alpha coefficient for a reliability test of dressing test results were implemented for each of the three tests. The pattern of the developed modified Hanbok Jeogori overcame the defects of the short length of the conventional modified hanbok, and could fix the length issue. The developed Hanbok pattern solved the overlapping problem of the shoulder, back neck point-sleeve length(Whajang), and armhole, displayed in a straight line from the Godae point of the previous modified Hanbok; it suggested the position of the Seop and neck line in the basic bodice. Based on this, the Seop width, Git form, Goreum and the width, length, and position of the string whose dimensions can differ in accordance with the trend can be applied in various forms.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.5 s.120
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• pp.503-510
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• 2007

This paper proposes the design scheme of internal triple band antenna intended for using in GSM900, DCS1800, and PCS1900 bands. The suggested folding metal plates of the two branches are mounted on a dielectric coated ground plane for size miniaturization and durability. Return losses are overlapped when length of metal branches are controlled. This is important technique for wide band operation. For the suggested antenna geometry its return loss was calculated by HFSS 9 simulator, and was shown to be -10 [dB] less within the required band. Also, gain and radiation pattern of antenna were measured using far field measurement system in an anechoic chamber. The measured peak gain is more than 3.0 [dBi], and the average gain is over -1.0 [dBi] for the triple band, which is regarded as satisfactory for the internal antenna application. Also, the radiation pattern for two frequencies shows a similar shape each other within the required band.