• Proceedings of the KIEE Conference
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• 1995.11a
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• pp.222-224
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• 1995

This paper deals with 3-dimensional missile guidance law. This presents the general optimal solution of the state equation which includes the target maneuvering as the Gauss-Markov processing. The main results ore about the transformation between the Cartesian coordinates on which both the guidance law and the filter are bused and the polar coordinates system in real missile guidance and measurement information. And the extended Kalman filter and adjustment of the estimated target acceleration by triangular functions is proposed solution to this transformation problem. It is shown that this proposed transformation is valid in real 3-dimensional guidance problem by the computer simulation.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.233-236
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• 1997

In modem industry, the accuracy and the surface-finish requirements for machined parts have been becoming ever more stringent. Optical method in measurements is playing an important role in vibration measurement, crack and defect detection and surface topography with the advent of opto-mechatronics. In this study, the principle of the general confocal microscope is introduced for surface measurement, and the advanced confocal microscope that has better measuring speed than the traditional confocal microscope is developed. A study on improving the resolution of the advanced confocal microscope is followed. Finally, Software for data acquisition and analysis of various parameters in surface geometrical features has been developed.

• Proceedings of the IEEK Conference
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• 2007.07a
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• pp.279-280
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• 2007

Airway wall thickness is an important bio-marker for evaluation of pulmonary diseases such as stenosis, bronchiectasis. Nevertheless, an image-based analysis of the airway tree can provide precise and valuable airway size information, quantitative measurement of airway wall thickness in CT images involves various sources of error and uncertainty. So we have developed an accurate airway wall measurement technique for small airways with three-dimensional (3-D) approach. To illustrate performance of these techniques, we used airway phantom that consisted of 4 acryl tubes with various inner and outer diameters. Results show that evaluation of interpolation and deconvolution methods of airways in 3-D CT images, and significant improvement over the full-width-half-maximum method for measurement of not only location of the luminal and outer edge of the airway wall but airway wall thickness.

• Fashion & Textile Research Journal
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• v.12 no.3
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• pp.354-363
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• 2010

The purpose of this study was to provide some preliminary results on application of 3D scan data of head shapes to the hat design and pattern-making. This paper defined necessary measurement items and concepts in 3-dimensional images of head shapes. And also it presented the methodology to pattern-making of 6-piece crown hat based on 3D data. It used the data of Size Korea to pick up and choose a head shape model with the average head size of Korean women in their twenties. Main results were: 1. The 3D scan data of head shape was better than the 1 dimensional measurement data. Because I could establish a hat pattern-making theory by the 3D scan data of head. 2. The 3D scan data provided the basis for conceptualization of basic measurement points and items for a better fit of hats as well as the definition of the basic hat circumference. 3. This presented a methodology for analyzing out head shape by 3D scan data, and allowed the derivation of the basic hat circumference from the maximum head circumference. 4. As the 6-piece Crown cloche hat made by this method fitted the head shape model perfectly, this methodology could suggest potential applicability to various hat design.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.781-782
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• 2010

• Journal of the Korea Fashion and Costume Design Association
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• v.11 no.2
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• pp.183-195
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• 2009

In this study, foot shapes were compared between the men in their 20's and 60's, with the application of 3-dimensional measurement data, and the classification was established in consideration of each of their features. The results are as follows: 1. The investigation into the differences between the groups for the 3-dimensional measurement items of the men in their 20's and 60's indicated that those in their 20's had larger values than those in the 60's age group for all of the length items, while those in the 60's age group had larger values for all of the angle items. 2. The analysis of the constituting factors for the feet of those in their 60's and 20's resulted in the 7 items for the 20's age group and 8 items for those in the 60's age group. 3. The comparison of foot classifications for the 60's age group and 20's age group presented 3 types each for both groups, but the features of each type was different. To examine each characteristic by each type and age group, following can be determined of the 60's age group. Type 1 had a thick instep, high malleolus position and heel and a thick formed ankle. Type 2 the entire foot was small, and the big toe was formed in such a way that it tened to bend toward the inside. When the whole size compared with similar Type 1, Type 3 had a low instep, a low heel, the big toe did not bend and ankle form was thin. The following can be determined of the 20's age group. Type 1 had narrow width a thin ankle and the big toe was formed in such a way that it bended toward the inside. Compared with length, Type 2 had wide width and a thick ankle. Type 3 had a larger overall size, thick instep and wide and the toe was big, but the characteristic of inside and outside of a malleolus position was low and the big toe's form showed no tendencies to bend.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.24 no.4
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• pp.282-288
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• 2014

Three-dimensional multimedia industry such as 3D TV, movie and broadcast has been developed vividly. For generating 3D contents with high quality, virtual auditory display, so called VAD, is being researched to offer more realistic experience to listeners. When people render VAD using headphones or two speakers, head-related transfer function(HRTF) plays a key role. The best solution is measuring all individuals' HRTFs, but it is hard to measure all listeners' HRTFs. To overcome this difficulty, many research groups have tried to construct their own measurement system and to build HRTF databases. However, some of them have not enough subjects or spatial resolution and they are mainly focused on Caucasian. There exists difference between Korean and Caucasian in a view of physical features. In other words, if Koreans hear three-dimensional sound rendered by HRTF database based on Caucasian, performance might be hindered. To verify this possibility and remedy the drawbacks, construction of new HRTF database aimed at Korean is needed. Therefore, our laboratory built HRTF measurement system which can measure HRTF of three-dimensional space with dense spatial resolution. With this system, 55 Korean males and 45 females' HRTFs were measured and Korean HRTF database was built based on these data.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.8
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• pp.2555-2560
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• 1996

Inspecting the dimensional accuracy of a car-body in assembly line is a very important process to assure high productivity. Now there exist two common inspecting methods in practice. One is to measure a sampled car-body with three dimensional measuring machine, and the other is to measure car-body with three dimensional measuring machine, and the other is to measure car-body in assembly line using many sensors fixed to a large jig frame. The formal method takes too long to inspect a sampled car-body of a same sort, and cannot therefore give an useful error trend for the whole production. On the other hand, the latter lacks flexibility and is very cost-intensive. By using industrial robots and sensors, an in-line Car-Body Measuring(CBM) system which ensured high flexiblity and sufficient accuracy was developed. This CBM cell operates in real production line and measures the check points by the non-contact type using camera and laser displacement sensor(LDS). This system can handle about 15 Measuring points within a cycle time of 40 seconds. A process computer controls whole process such as data acquisition file handling and data analysis. Robot arms changes in length due to ambient temperature fluctuation affecting the measuring accuracy. To compensate this error, a robot arm calibration process was developed.

• Journal of the Korean Society of Combustion
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• v.7 no.1
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• pp.37-43
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• 2002

Spray characteristics in the swirling flow were investigated by Stereoscopic PIV. Spatial spray structures were measured by PIV as well as PDA in order to understand stable flame stabilization. The feasibility study of Stereoscopic PIV in spray flame was also demonstrated. The size and location of recirculation flow were measured. The stereoscopic PIV could provide 3-D flow fluctuation that cannot be measured by convectional measurement systems.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.04b
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• pp.485-489
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• 1995

From the relationship between the two different views of an object with grid, the three dimensional coordinates of intersection points are determined. The images are captured and digitized with a CCD camera and a frame grabber. To find intersection points, local thresholding and line thinning operations are performed. By establishing the correspondence between the points in the two views, the three dimensional corrdinates of intersection points are calculated.