• Journal of the Korean Society of Radiology
• /
• v.9 no.4
• /
• pp.235-238
• /
• 2015

The aims of this study were to evaluate the difference of renal uptake rate in $^{99m}Tc-DMSA$ scan on pediatrics by including the bladder. Phantom and Clinical studies were performed. In the phantom study, we put $^{99m}TcO_4{^-}$ (300uCi, 11 MBq) in 3cups filled with distilled water at the rate 1:1:0, 1:1:0.5, 1:1:1, 1:1:2 and were placed Lt kidney, Rt kidney and bladder position on the table. To acquire the image, we used Symbia-E gamma camera from Siemens with preset count method(400,000 counts). In quantitative analysis, the counts of drawing ROIs on the phantom were analyzed. In clinical studies, we analyzed the 20 pediatrics who were examined by $^{99m}Tc-DMSA$ scan. At first, the images were acquired with both kidney and bladder. Secondly we acquired images after shielding the bladder. And the data were compared using a pared t-test by SPSS(ver.22.0). As a result of renal phantom's experiment, we compared with average of uptake rate(%), 1:1:0 was Lt 43.32%, Rt 45.97%, 1:1:0.5 was Lt 35.79%, Rt 36.89%, 1:1:1 was Lt 29.68%, Rt 31.45% and 1:1:2 was Lt 22.89%, Rt 24.32%. There was no correlation between the zoom and uptake rate. The results of patient were that excluded bladder was $29.83{\pm}8.81%$(Lt), $24.29{\pm}6.66%$(Rt) and included bladder was $26.65{\pm}8.03%$(Lt, $21.78{\pm}6.24%$(Rt). This is deemed statistically significant (p<0.05). Renal uptake rate was undervalued because the counts of bladder were included in the total counts.

• Journal of Technologic Dentistry
• /
• v.37 no.4
• /
• pp.191-197
• /
• 2015

Purpose: The purpose of this study was to compare the accuracy of the scan data acquired by the extra-oral and intra-oral scanner. Methods: The maxillary right first molar was made of polymethyl methacrylate(PMMA) specimen. This PMMA specimen was scanned with a engineering scanner and intra-oral scanner. Meanwhile, extra-oral scanner scanned stone die duplicated from PMMA master die. Trueness and precision of scan datas was measured by 3-dimensinal inspection. Independent t-test was conduct to analysis the significant difference(a=0.05). Results: In the trueness analysis, mean of discrepancies were 13.82um for intra oral scanner and 16.84 um for extra-oral scanner. In the precision analysis, mean of discrepancies were 11.72 for inta-oral scanner and 9.2 for extra-oral scanner. Both trueness and precision showed a statistically significant difference (Table 1, p<0.05). Conclusion: Intra-oral scanner can show higher trueness than extra-oral scanner, it has lower precision.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.16 no.8
• /
• pp.1759-1764
• /
• 2012

This paper describes FPGA design and realization using the shading correction algorithm for a CCD scan image enhancement. The shading algorithm is used by LUT (Look-up Table). The image enhancement results from that the histogram minimum value and maximum with respect to all pixels of the CCD image should be extracted, and the shading LUT is constructed to keep constant histogram with offset data. The output of sensor be converted to corrected LUT image in preprocessing, and the converting system is realized by FPGA to be enabled to operate in real time. The result of the experimentation for the proposed system is showed to take the scanning time 2.4ms below. The system is presented to be based on a low speed processor system to scan enhanced images in real time and be guaranteed to be low cost.

• The Journal of Advanced Prosthodontics
• /
• v.10 no.5
• /
• pp.335-339
• /
• 2018

PURPOSE. The purpose of the present study was to compare scanning trueness and precision between an abutment impression and a stone model according to dental computer-aided design/computer-aided manufacturing (CAD/CAM) evaluation standards. MATERIALS AND METHODS. To evaluate trueness, the abutment impression and stone model were scanned to obtain the first 3-dimensional (3-D) stereolithography (STL) file. Next, the abutment impression or stone model was removed from the scanner and re-fixed on the table; scanning was then repeated so that 11 files were obtained for each scan type. To evaluate precision, the abutment impression or stone model was scanned to obtain the first 3-D STL file. Without moving it, scanning was performed 10 more times, so that 11 files were obtained for each scan type. By superimposing the first scanned STL file onto the other STL files one by one, 10 color-difference maps and reports were obtained; i.e., 10 experimental scans per type. The independent t-test was used to compare root mean square (RMS) data between the groups (${\alpha}=.05$). RESULTS. The $RMS{\pm}SD$ values of scanning trueness of the abutment impression and stone model were $22.4{\pm}4.4$ and $17.4{\pm}3.5{\mu}m$, respectively (P<.012). The $RMS{\pm}SD$ values of scanning precision of the abutment impression and stone model were $16.4{\pm}2.9$ and $14.6{\pm}1.6{\mu}m$, respectively (P=.108). CONCLUSION. There was a significant difference in scanning trueness between the abutment impression and stone model, as evaluated according to dental CAD/CAM standards. However, all scans showed high trueness and precision.

• Journal of KIISE:Databases
• /
• v.35 no.3
• /
• pp.199-207
• /
• 2008

The FP-tree(Frequency Pattern Tree) mining association rules algorithm was proposed to improve mining performance by reducing DB scan overhead dramatically, and it is recognized that the performance of it is better than that of any other algorithms based on different approaches. But the FP-tree algorithm needs a few more memory because it has to store all transactions including frequent itemsets of the DB. This paper implements a FP-tree algorithm on a general purpose UNK system and compares it with the DHP(Direct Hashing and Pruning) algorithm which uses hash tree and direct hash table from the point of memory usage and execution time. The results show surprisingly that the FP-tree algorithm is poor than the DHP algorithm in some cases even if the system memory is sufficient for the FP-tree. The characteristics of the test data are as follows. The site of DB is look, the number of total items is $1K{\sim}7K$, avenrage length of transactions is $5{\sim}10$, avergage size of maximal frequent itemsets is $2{\sim}12$(these are typical attributes of data for large-scale convenience stores).

• Proceedings of the Korean Institute of Intelligent Systems Conference
• /
• 2004.04a
• /
• pp.576-579
• /
• 2004

Eventhough the productivity has been improved remarkably by introducing automatic facilities, the 100％ inspection is necessary because the possibility to produce large amount of defective goods is also increased. Since it is extremely unreasonable that workers inspect very large amount of products as 100％ inspection, there has been many researches for the automatic inspection system. In this thesis, we develop an automatic detection system of suspension insulator's minutes cracks System The automatic detection system of suspension insulator's minute cracks： To detect the minute cracks of suspension insulators, images of the insulator are acquired with a progressive scan camera, rotating a suspension insulator on a turning table. And after the shadow and noises are eliminated by preprocessing techniques, we detect minute cracks using the features of them.

• Nuclear Engineering and Technology
• /
• v.38 no.4
• /
• pp.383-390
• /
• 2006

Having its roots in medical applications, industrial gamma ray CT has opened up new roads far investigating and modeling industrial processes. Using a line of research related to industrial gamma ray CT, the authors set up a system of single source and detector gamma transmission tomography for wood timber and a packed bed phantom. The hardware of the CT system consists of two servo motors, a data logger, a computer, a radiation source and a radiation detector. One motor simultaneously moves the source and the detector for a parallel beam scanning, whereas the other motor rotates the scan table at a preset projection angle. The image is reconstructed from the measured projections by the filtered back projection method. The phantom was designed to simulate a cross section of a packed bed with a void. The radiation source was 20mCi of Cs-137 and the detector was a 1 inch $\times$ 1 inch NaI (TI) scintillator shielded by a lead collimator. The experimental gamma ray CT image has sufficient resolution to reveal air holes and the density distribution inside the phantom. The system could possibly be applied to a packed bed column or a pipe flow in a petrochemical plant.

• Journal of Korea Spatial Information System Society
• /
• v.11 no.1
• /
• pp.127-136
• /
• 2009

This paper proposes an on-line mining algorithm of moving trajectory patterns in RFID data streams considering changing characteristics over time and constraints of single-pass data scan. Since RFID, sensor, and mobile network technology have been rapidly developed, many researchers have been recently focused on the study of real-time data gathering from real-world and mining the useful patterns from them. Previous researches for sequential patterns or moving trajectory patterns based on stream data have an extremely time-consum ing problem because of multi-pass database scan and tree traversal, and they also did not consider the time-changing characteristics of stream data. The proposed method preserves the sequential strength of 2-lengths frequent patterns in binary relationship table using the time-evolving graph to exactly reflect changes of RFID data stream from time to time. In addition, in order to solve the problem of the repetitive data scans, the proposed algorithm infers candidate k-lengths moving trajectory patterns beforehand at a time point t, and then extracts the patterns after screening the candidate patterns by only one-pass at a time point t+1. Through the experiment, the proposed method shows the superior performance in respect of time and space complexity than the Apriori-like method according as the reduction ratio of candidate sets is about 7 percent.

• The Korean Journal of Nuclear Medicine
• /
• v.24 no.1
• /
• pp.37-48
• /
• 1990

Detection of deep-seated abscesses is sometimes difficult with ultrasonogrpahy or computed tome graphy alone. Indium-111-labeled leukocyte has widely used in the localization of abscesses after introduction by Segal and Thakur in 1976. But there are some difficulties in using indium-111-oxine in our country because of hardness to get the radiopharmaceutical timely and long time for labeling leukocytes. So we peformed the indium-111-labeled leukocyte scan for establishment of the labeling procedure and clinical application. We labeled the mixed leukocytes from 36 ml of patient's blood using 4 ml of ACD solution, 7 ml of 6% hydroxyethyl starch solution $(HESPAN^{(R)})$, 1 mCi of indium-111 oxine, 5 ml of normal saline and centrifuge. It took about 2 hours for the preparation of radiolabeled leukocytes and attention for contamination was needed. The average injected dose of labeled mixed leukocytes was 465 uCi. The average number of injected leukocytes was $2.5\times10^8$ and the labeling ratio was $57{\pm}13%$ (Table 2, Fig. 5). These number and ratio were sufficient for the localization of abscess. About twenty per cent of indium was labeled to red blood cells and platelets (Fig. 6) and the half-life of injected radiolabeled leukocytes was 8.3 hours. Scan was performed in 9 patients who were suspected to have abscesses clinically or radiologically. Three patients were positive, in one patient who had abscess close to lower lumbar vertebrae was surgically drained and another 2 positive cases did not show abscess clearly on computed tomography, so only antibiotics were administrated and treated successfully. The negative 6 patients were improved without specific treatment. In conclusion, the use of indium-111 oxine labeled leukocytes for localization of abscesses were very specific and helpful in the decision of treatment considering its relatively simple labeling method, and could be easily performed providing timely supply of the radiopharmaceutical.

• Journal of the Korea Society of Computer and Information
• /
• v.12 no.2 s.46
• /
• pp.231-242
• /
• 2007

The existing pattern mining methods[1,2,3,4,5,6,11,12,13] do not use location generalization method on the set of location history data of moving object, but even so they simply do extract only frequent patterns which have no spatio-temporal constraint in moving patterns on specific space. Therefore, it is difficult for those methods to apply to frequent pattern mining which has spatio-temporal constraint such as optimal moving or scheduling paths among the specific points. And also, those methods are required more large memory space due to using pattern tree on memory for reducing repeated scan database. Therefore, more effective pattern mining technique is required for solving these problems. In this paper, in order to develop more effective pattern mining technique, we propose new location generalization method that converts data of detailed level into meaningful spatial information for reducing the processing time for pattern mining of a massive history data set of moving object and space saving. The proposed method can lead the efficient spatial moving pattern mining of moving object using by creating moving sequences through generalizing the location attributes of moving object into 2D spatial area based on $R^*$-Tree and Area Grid Hash Table(AGHT) in preprocessing stage of pattern mining.