• The Korean Journal of Nuclear Medicine
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• v.39 no.2
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• pp.100-106
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• 2005

Non-invasive evaluation of cardiac function by nuclear medicine technologies are one of the major contribution of nuclear medicine. Gated cardiac blood pool scan was once a novel and robust technique which enabled evaluation of ventricular function. Concept of EKG gating was one of the major breakthrough in nuclear cardiology. According to the evolution of echocardiographic techniques, and as the evaluation of myocardial perfusion by perfusion SPECT became feasible, number of gated blood pool study dong in nuclear medicine laboratory is declining. And recently, evaluation of ventricular function with gated perfusion SPECT further decreased the use of gated blood pool scan. In this article, assessment of ventricular function using gated blood pool scan is discussed including some insight about the role of gated blood pool SPECT.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.2
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• pp.245-249
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• 2007

In this paper describes image enhancement technique using deconvolution processing for ultrasonic nondestructive testing. When flaws are detected fur B-scan or C-scan, blurring effect which is caused by the moving intervals of transducer degrades the quality of images. In addition, acquisited images suffer form speckle noise which is caused by the ultrasonic components reflected from the grain boundary of material (1,2). The deconvolution technique can restore sharp peak value or clean image from blurring signal or image. This processing is applied to C-scan image obtained from known specimen. Experimental results show that the deconvolution processing contributes to get improved the quality of C-scan images.

• The KIPS Transactions:PartD
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• v.15D no.4
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• pp.475-484
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• 2008

Nowadays, lots of data mining applications based on continuous and online real time are increasing by the rapid growth of the data processing technique. In order to do association rule mining in that application, we have to use new techniques to find the frequent itemsets. Most of the existing techniques to find the frequent itemsets should scan the total database repeatedly. But in the application based on the continuous and online real time, it is impossible to scan the total database repeatedly. We have to find the frequent itemsets with only one scan of the data interval for that kind of application. So in this paper we propose an approximation technique which finds the maximum size of the frequent itemsets and items included in the maximum size of the frequent itemsets for the processing of association rule mining.

• Journal of the Korean Society of Clothing and Textiles
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• v.47 no.1
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• pp.137-151
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• 2023

Stationary 3D whole-body scanners generally require 5 to 20 seconds of scanning time and cannot effectively detect armpit and crotch areas. Therefore, this study aimed to analyze the accuracy of a photogrammetric technique using a multi-camera system. First, dimensional accuracy was analyzed using a mannequin scan, comparing the differences between the scan-derived measurements and the direct measurements, with an allowable tolerance of ISO 20685-1:2018. Only 2 of 59 measurement items (ankle height and upper arm circumference, specifically) exceeded the ISO 20685-1:2018 criteria. When compared with the results of the eight stationary whole-body scanners assessed by the literature, the photogrammetric technique was found to have the advantage of scanning the top of the head, armpit, and crotch areas clearly. Second, this study found the photogrammetric technique is suitable for obtaining the body scans because it can minimize the perform scanning, resulting in a reduction of measurement errors due to breathing and uncontrolled movements. The error rate of the photogrammetry method was much lower than that of stationary 3D whole-body scanners.

• Korean Journal of Optics and Photonics
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• v.19 no.5
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• pp.376-380
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• 2008

This paper presents the Projection Moire method using a line scan camera. The high resolution feature of a line scan camera makes it possible to scan an image quickly, thus enabling a much quicker 3D profile. This method uses a high resolution line scan camera making it possible to scan an image at high speed simultaneously measuring the 3D profile of a large FOV. When using a high resolution scan camera, a full FOV is scanned, thus requiring just one movement of a projection grating. As a result, the number of grating movements is reduced drastically. The end result is a faster and more accurate 3D measurement. Moving the grating too quickly causes vibration in the imaging system, which will normally be required to apply a stitching technique when using an area scan camera. However the technique is not required when using a line scan camera. Compared with the previous techniques, it has the advantages of simple hardware without moving mechanical parts - single exposure for obtaining three-dimensional information. A method using a high resolution line scan camera can be used in mass production to measure the bump height of wafers or the bump height of package substrates.

• Journal of the Ergonomics Society of Korea
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• v.33 no.4
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• pp.299-311
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• 2014

Objective: The aim of this study was to develop a method for measuring breast size from three-dimensional (3D) body scan image data. Background: Previous bra studies established reference points by directly contacting the subject's naked skin to determine the boundary of the breast. But some subjects were uncomfortable with these types of measurements. This study examined noncontact methods of extracting breast reference points from 3D body scan data that were collected while subjects were wearing standardized soft bras. Method: 3D body scan data of 32 Korean women were analyzed. The subjects were selected from the Size Korea 2010 study. The breast landmarks were identified by graphic analyses of slicing contour lines on 3D body scan data. Results: Three methods determining bra cup size were compared. The M1 and M2 methods determined cup size by calculating the difference between bust girth and under-bust girth. The M3 method determined bra cup size by measuring breast arc length. Conclusion: The researchers proposed an anthropometric bra cup sizing system with the breast arc length (M3 method). It was measured from the geometrically defined landmarks on the 3D body scan slicing contour lines. The new bra cup size was highly correlated with breast depth. Application: The noncontact measuring method used in this study can be applied to the ergonomic studies measuring sensitive body parts.

• Proceedings of the KOSOMBE Conference
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• v.1996 no.11
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• pp.157-160
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• 1996

In this paper, reconstruction algorithms of spiral scan imaging which has been used for ultra fast magnetic resonance imaging have been reviewed, and some simulation results using two different algorithms are reported. Since the trajectory of the spiral scan in k-space is the spiral, reconstruction of the spiral scan is not as straight forward as that used in Fourier imaging technique where the sampling points are usually on the rectangular grids. Originally the reconstruction of the spiral scan imaging was based on the convolution backprojection algorithm modified with a shift term, however, some other reconstruction techniques have also been tried by remapping sampling points from spiral trajectory to Cartesian grids. Some experimental aspects of MR spiral scan imaging will also be addressed.

• Radiation Oncology Journal
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• v.1 no.1
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• pp.55-60
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• 1983

To evaluate the usefulness of computed tomography (CT) in radiotherapy treatment planning in malignant tumors of thoracic cage, the computer generated dose distributions were compared between plans based on conventional studies and those based on CT scan. 22 cases of thoracic malignancies, 15 lung cancers and 7 esophageal cancers, diagnosed and treated in Department of Therapeutic Radiology of Seoul National University Hospital from September, 1982 to April, 1983, were analyzed. In lung cancers, dose distribution in plans using AP, PA parallel opposing ports with posterior spinal cord block and in plans using box technique both based on conventional studies were compared with dose distribution using AP, PA and two oblique ports based on CT scan. In esophageal cancers, dose distribution in plans based on conventional studies and those based on CT scans, both using 3 port technique were compared. The results are as follows: 1. Parallel opposing field technique were inadequate in all cases of lung cancers, as portion of primary tumor in 13 of 15 cases and portion of mediastinum in all were out of high dose volume. 2. Box technique was inadequate in 5 of 15 lung cancers as portion of primary tumor was not covered and in every case the irradiated normal lung volume was quite large. 3. Plans based on CT scan were superior to those based on conventional studies as tumor was demarcated better with CT and so complete coverage of tumor and preservation of more normal lung volume could be made. 4. In 1 case of lung cancer, tumor localization was nearly impossible with conventional studies, but after CT scan tumor was more clearly defined and localized. 5. In 1 of 7 esophageal cancers, the radiation volume should be increased for marginal coverage after CT scan. 6. Depth dose correction for tissue inhomogeneity is possible with CT, and exact tumor dose can be calculated. As a result radiotherapy treatment planning based on CT scan has a pteat advantage over that based on conventional studies.

• The Journal of the Korea Contents Association
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• v.5 no.4
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• pp.188-196
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• 2005

This paper presents a new test data compression and low power scan test method that can reduce test time and power consumption. A proposed method can reduce the scan-in power and test data volume using a modified scan cell reordering algorithm and hybrid adaptive encoding method. Hybrid test data compression method uses adaptively the Golomb codes and run-length codes according to length of runs in test data, which can reduce efficiently the test data volume compare to previous method. We apply a scan cell reordering technique to minimize the column hamming distance in scan vectors, which can reduce the scan-in power consumption and test data. Experimental results for ISCAS 89 benchmark circuits show that reduced test data and low power scan testing can be achieved in all cases. The proposed method showed an about a 17%-26% better compression ratio, 8%-22% better average power consumption and 13%-60% better peak power consumption than that of previous method.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.8
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• pp.1709-1718
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• 2002

It is well recognized that improving capacity of positive grid in battery is one of key factors for controlling the expected long lift-time of Battery Energy Storage System(B.E.S.S). Thus it is really important to characterized material properties of positive grid which are mainly affected by fabrication process. In this study, two kinds of positive grids, which were fabricated by gravity casting and die-casting technique were used. Micro-structural observation and tensile test were conducted to investigate the effect of fabrication process of positive grid. Ultrasonic measurement based on pulse-echo method and ultrasonic C-scan technique also performed to correlate ultrasonic velocity with porosity ratio in positive grid. It was found that the porosity ratio of grid fabricated by gravity casting technique increased significantly compared to the grid fabricated by die-casting technique. It was also shown that ulrasonic technique is effective to evaluate the porosity ratio in positive grid.