• Journal of the Semiconductor & Display Technology
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• v.9 no.3
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• pp.47-51
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• 2010

This paper presents a wafer pre-alignment system which is improved using the image of the entire wafer area. In the previous method, image acquisition for wafer takes about 80% of total pre-alignment time. The proposed system uses only one image of entire wafer area via a high-resolution CMOS camera, and so image acquisition accounts for nearly 1% of total process time. The larger FOV(field of view) to use the image of the entire wafer area worsen camera lens distortion. A camera calibration using high order polynomials is used for accurate lens distortion correction. And template matching is used to find a correct notch's position. The performance of the proposed system was demonstrated by experiments of wafer center alignment and notch alignment.

• Journal of the Semiconductor & Display Technology
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• v.9 no.1
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• pp.11-16
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• 2010

Wafer Pre-Alignment is to find the center and the orientation of a wafer and to move the wafer to the desired position and orientation. In this paper, an area camera based pre-aligning method is presented that captures 8 wafer images regularly during 360 degrees rotation. From the images, wafer edge positions are extracted and used to estimate the wafer's center and orientation using least squares circle fitting. These data are utilized for the proper alignment of the wafer. For accurate alignments, camera calibration methods using high order polynomials are used for converting pixel coordinates into real-world coordinates. A complete pre-alignment system was constructed using mechanical and optical components and tested. Experimental results show that alignment of wafer center and orientation can be done with the standard deviation of 0.002 mm and 0.028 degree, respectively.

• Transactions of The Korea Fluid Power Systems Society
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• v.8 no.3
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• pp.14-20
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• 2011

This study aims at aligning multiple wafers to reduce wafer handling time in wafer processes. We designed a multilevel structure for a prealigner which can handle multiple wafer simultaneously in a system. The system consists of gripping parts, kinematic parts, vacuum chucks, pneumatic units, hall sensors and a DSP controller. Aligning procedure has two steps: mechanical gripping and notch finding. In the first step, a wafer is aligned in XY directions using 4-point mechanical contact. The rotational error can be found by detecting a signal in a notch using hall sensors. A dual prealigner was designed for 300mm wafers and constructed for a performance test. The accuracy was monitored by checking the movement of a notch in a machine vision. The result shows that the dual prealigner has enough performance as commercial products.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.410-413
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• 2009

Wafer pre-alignment is to find the center and the orientation of a wafer and to move the wafer to the desired position and orientation. In this paper, an area camera based pre-aligning method is presented that captures 8 wafer images regularly during 360 degrees rotation. From the images, wafer edge positions are extracted and used to estimate the wafer's center and orientation using least square circle fitting. These information are utilized for the proper alignment of the wafer.

• Journal of Institute of Control, Robotics and Systems
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• v.8 no.9
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• pp.812-817
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• 2002

This paper presents a development of high accuracy aligner and describes a method to find the orientation of a substantially circular disk shaped wafer with at least one flat region on an edge thereof. In the developed system, the wafer is spun one 360 degree turn on a chuck and the edge position is measured by a linear array to obtain a set of data points at various wafer orientation. The rotation axis may differ from wafer center by an unknown eccentricity. The flat angle is found by fitting a cosine curve to the actual data to obtain a deviation. The maximum deviation is then corrected for errors due to a finite number of data points and wafer eccentricity by calculating an adjustment angle from data points on the wafer fiat. After determining the flat angle the wafer is spun to the desired orientation. The wafer eccentricity can be calculated from four of the data points located away from the flat edge region. and the wafer is then centered.

• Journal of Korean Physical Therapy Science
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• v.6 no.2
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• pp.1041-1062
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• 1999

This study is to stimulate the model of which top notch muscle stimuli physical therapy has been made on the basis of GCM. GCM has been studied on the hypermobility & hypomobility pattern on the part of spine & extremity, and the body characteristics of four body types, which is the tilting of seal scapular & ilium. The purpose of this study is to analysize the type of GCM which has been focused on the spine & extremity for the patients having dysfunctions of neuromuscular system, being analysized the movement. The result of this study is as following; 1) The First hypothesis: The hypermobility & hypomobility pattern assorted by the tilting of scapular & ilium, as does the former study analysize was claimed that it would be in line with the pattern for hypermobility hypomobility and physical characteristics according to each body type at the percentage of at least 60(p<.001). 2) The 2nd hypothesis : Stimuli therapy of muscle dealing with physical characteristics and joint hypermobility hypomobility has the important role in restoring the deformity and keeping anatomical postural plumb alignment also it would a highly effects on correcting the body even though the stimuli area was limited to four areas and it was lack of time compared with those applied by general physical therapy(p<.001). As above the result, the top-notch type for physical therapy based on hypermobility hypomobility pattern by 4 body types which has been studied on tilting of scapular & ilium is more specificed and specialized than those of general physical therapy technologies. So this study will be believed to dedicate to restoration ideal anatomical postural plumb alignment based on spinal Manipulation and the concept of whole person as well as to being simple and effective to apply.

• Journal of Advanced Navigation Technology
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• v.13 no.3
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• pp.412-418
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• 2009

This study aims to develop a system that enables 20 to 25 wafers to be automatically aligned at the position of the corresponding serial number and facilitates the checkout of wafer processing by sensing them before and after semiconductor processing. It also suggests compensation algorithm and stepper motor control algorithm that carefully align notches. This study minimizes the rate of occurrence by adopting materials of which the surface has proper coefficient of friction when wafers are rotating and that do not rarely produce particles. This study completed the development of a slip resistance apparatus and carried out performance tests through mathematical verification. This system is expected to improve semiconductor yield due to anti-pollution technology in semiconductor processing and can be selectively applied to a large size wafer over 450mm in the future.

• Journal of Biomedical Engineering Research
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• v.17 no.4
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• pp.449-458
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• 1996

Most of the conventional electrocardiowaphs foil to detect signals other than P-QRS-T due to the limited SNR and bandwidth. High-resolution electrocardiography(HRECG) provides better SNR and wider bandwidth for the detection of micro-potentials with higher frequency components such as vontricular late potentials(LP). We have developed a HRECG using uncorrected XYZ lead for the detection of LPs. The overall gain of the amplifier is 4000 and the bandwidth is 0.5-300Hz without using 60Hz notch filter. Three 16-bit A/D converters sample X, Y, and Z signals simultaneously with a sampling frequency of 2000Hz. Sampled data are transmitted to a PC via a DMA-controlled, optically-coupled serial communication channel. In order to further reduce the noise, we implemented a signal averaging algorithm that averaged many instances of aligned beats. The beat alignment was carried out through the use of a template matching technique that finds a location maximizing cross-correlation with a given beat tem- plate. Beat alignment error was reduced to $\pm$0.25ms. FIR high-pass filter with cut-off frequency of 40Hz was applied to remove the low frequency components of the averaged X, Y, and Z signals. QRS onset and end point were determined from the vector magnitude of the sigrlaIL and some parameters needed to detect the existence of LP were estimated. The entire system was designed for the easy application of the future research topics including the optimal lead system, filter design, new parameter extraction, etc. In the developed HRECG, without signal averaging, the noise level was less than 5$\mu$V$_rms RTI$. With signal averaging of at least 100 beats, the noise level was reduced to 0.5$\mu$V$_rms RTI$, which is low enough to detect LPs. The developed HRECG will provide a new advanced functionality to interpretive ECG analyzers.

• The Journal of Korean Academy of Prosthodontics
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• v.61 no.1
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• pp.18-25
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• 2023

We present the case of a 65-year-old man with maxillary and mandibular complete dentures prepared using neutral zone technique after undergoing mandibulotomy due to tonsil cancer 10 years ago. The patient had a short edentulous period; hence, there was minimal absorption of the alveolar ridge and no abnormality in the motor function of the tongue. However, the retromolar pad was located inside the hamular notch, and the posterior alveolar ridge was relatively turned inward. If the artificial teeth would have been aligned conventionally, the functional space of the tongue would have been invaded, which would have moved the tongue posteriorly thereby reducing the stability of the denture. Therefore, applying the concept of the neutral zone can be a good reference point in such cases. The neutral zone was registered using tissue conditioner, and tooth alignment was performed by making a silicone putty index. The biggest advantage of using neutral zone concept is denture stability. In this case, the neutral zone technique was applied to obtain the lingual alignment limit of the posterior teeth to avoid invasion of the tongue space by the left posterior part of the mandible. Particularly, in case of a patient in which denture stability is difficult to obtain due to absorption of the alveolar ridge, it is believed that better results can be obtained using neutral zone technique.