• The Korean Journal of Nuclear Medicine Technology
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• v.13 no.3
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• pp.81-85
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• 2009

Purpose: The examination of nuclear medicine observes the change in accordance with the time elapsed in the same region purposed and there are many examinations to acquire the image during the same term. At this time, the same parameter should be applied. The hepatobiliary scan, lung scan etc, are the acquired examination in the divided time with a regular term. Pre-set time that is applied in continued next image is set in order to acquire the fixed counts. The same scan time should be applied for each image. This study will look for the rational plan and analyze the change of scan time in accordance with the time of the decision of scan time at examination that pre-set time is applied. Methods: The hapatobiliary scan that use the radio pharmaceutical $^{99m}Tc$-mebrofenin is choosed as compensation from Jan. 2009 to Mar. 2009 in the department of nuclear medicine in ASAN MEDICAL CENTER. Scan is started after 5 minutes from when 222 MBq (6 mCi) is injected to patient. We let patient stand up between both detectors, and possibly close to the front of detector. When scan time reach 10%, 25%, 50%, 75% of total scan time, we measured the expected total scan time. After finishing all of scan, we compared the total scan time and the expected total scan time, while image is acquiring. and we observed the change of scan time in accordance with radio activity by using phantom. Results: After starting scan, a difference of when scan time reach 10%, 25%, 50%, 75% of total scan time is that the biggest difference is 5 seconds on 10%. There statistically is difference between 25% (t:2.88, p<0.01) and 50% (t:2.05, p<0.01). Conclusions: When the same the scan time is applied in the examination that acquire the many frame, concluding the same scan time has a important effect on a quantitative analysis. Although method that decide the scan time after finish all of the examinations, there is a few problem to apply practical affairs. This may cause an inaccurate result on the examination that need a quantitative analysis. We think that operator should try to improve it. At least, after reach 50% of total scan time, deciding the total scan time mean that you can minimize error of a quantitative analysis caused by unmatched scan time from a gap of image.

• Proceedings of the KIEE Conference
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• 2007.04a
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• pp.23-25
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• 2007

The partial distortion elimination (PDE) scheme is used to decrease the sum of absolute difference (SAD) computational complexity, since the SAD calculation has been taken much potion of the video compression. In motion estimation (ME) based on PDE, it is ideal that the initial value of SAD in summing performance has large value. The traditional scan order methods have many operation time and high operational complexity because these adopted the division or multiplication. In this paper, we introduce the new scan order and search order by using only adder. We define the average value which is called to rough average value (RAVR). Which is to reduce the computational complexity and increase the operational speed and then we can obtain the improvement of SAD performance. And also this RAVR is used to decide the search order sequence, since the difference RAVR between the current block and candidate block is small then this candidate block has high probability to suitable candidate. Thus, our proposed algorithm combines above two main concepts and suffers the improving SAD performance and the easy hardware implementation methods.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.39 no.3
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• pp.85-97
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• 2002

STUMPS has been widely used for built-in self-test of scan design with multiple scan chains. In the STUMPS architecture, there is very high correlation between the bit sequences in the adjacent scan chains. This correlation causes circuits lower the fault coverage. In order to solve this problem, an extra combinational circuit block(phase shifter) is placed between the LFSR and the inputs of STUMPS architecture despite the hardware overhead increase. This paper introduces an efficient test pattern generation technique and built-in self-test architecture for sequential circuits with multiple scan chains. The proposed test pattern generator is not used the input of LFSR and phase shifter, hence hardware overhead can be reduced and sufficiently high fault coverage is obtained. Only several XOR gates in each scan chain are required to modify the circuit for the scan BIST, so that the design is very simple.

• Health Policy and Management
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• v.31 no.3
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• pp.261-271
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• 2021

Background: In 2018, the government increased the fee for the magnetic resonance imaging (MRI) image deciphering services of the external hospital to discourage the redundant MRI scan and to induce appropriate use of the MRI services. It is important to evaluate the effect of the policy to provide the basis for establishing other MRI-related policies. Methods: The healthcare data of the patients who had brain MRI scans were organized by episode and analyzed using the panel study in order to find out the effect of the MRI-related policy on the substitution effect and the medical expenses. Results: As a result of the increase in the fee of deciphering the MRI image, there has been an uplift in deciphering the MRI scan of the external hospital. It implies that more hospitals chose to use the MRI scan taken by other clinics or hospitals, rather than the MRI scan taken at their own facilities. Conclusion: The research results imply that a policy that facilitates the exchange of the medical image data between the hospitals is needed in order to establish an efficient management system of the healthcare resources. Such improvement is expected to reduce the social cost and contribute to the stability in the finance of national health insurance.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.7
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• pp.66-71
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• 2019

In this paper, a study was conducted on the method of using GPR data to predict rebar thickness inside a facility. As shown in the cases of poor construction, such as the use of rebars below the domestic standard and the construction of reinforcement, information on rebar thickness can be found to be essential for precision safety diagnosis of structures. For this purpose, the B-scan data of GPR was obtained by gradually increasing the diameter of rebars by making specimen. Because the B-scan data of GPR is less visible, the data was converted into the heatmap image data through migration to increase the intuition of the data. In order to compare the results of application of commonly used B-scan data and heatmap data to CNN, this study extracted areas for rebars from B-scan and heatmap data respectively to build training and validation data, and applied CNN to the deployed data. As a result, better results were obtained for the heatmap data when compared with the B-scan data. This confirms that if GPR heatmap data are used, rebar thickness can be predicted with higher accuracy than when B-scan data is used, and the possibility of predicting rebar thickness inside a facility is verified.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.4
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• pp.403-408
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• 2013

In this paper, the characteristics of ablation processing of the eagle glass by pico-second laser are investigated. The laser ablation is used to process micro forms on materials. The ablation causes little thermal effect and little burr on the surface of eagle glass. In order to examine the characteristics of panic cracks, experiments are conducted under various cutting conditions such as a frequency of 600 kHz, laser powers, scan speeds and number of scan(NS). To minimize the panic cracks, the specimens are heated at $30^{\circ}C$, $45^{\circ}C$, and $60^{\circ}C$ for ten minutes respectively and then they are broken by hands. Laser powers, NS and scan speeds have an effect on glass cutting results. The ablation depths increase with an increase in the laser power and NS whereas the panic cracks decrease with an increase in scan speed. The high temperature on processed specimens reduces the panic cracks and makes good results of laser cutting. The optimal condition for eagle glass laser cutting is found to be at 30 W of laser power, 3 mm/s of scan speed and 500 of NS, respectively.

• Transactions on Control, Automation and Systems Engineering
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• v.4 no.4
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• pp.341-346
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• 2002

When a construction company builds a high structure. many piles should be driven into the ground by a hammer whose weight is 7,000 kg in order to make the ground under the structure safe and strong. So. it is essential to determine whether a pile is penetrated into the ground enough to support the weight of the structure since ground characteristics at different locations are different each other. This paper proposes a visual measurement system for pile rebound and penetration movement including vibration using a high-speed line-scan camera and a specially designed mark to recognize two-dimensional motion parameters of the mark using only a line-scan camera. A mark stacking white and black right-angled triangles is used for the measurement, and movement information for vertical distance, horizontal distance and rotational angle is determined simultaneously. Especially- by adopting a line-scan CCD camera whose line rate is 20 ㎑. the measurement performance of dynamic characteristics of the pile at impact instant is improved dramatically.

• The Korean Journal of Nuclear Medicine
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• v.3 no.1
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• pp.59-67
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• 1969

Correlation between the blood clearance half time and findings of liver scan using the colloidal radiogold in patients of liver cirrhosis is observed through the scoring system, in which the more changes in size, shape and density in the liver scan, the more points are given (table 1). Results: 1) Within the increase in severity of hepatocellular dysfunction in liver cirrhosis, the degree and frequency of following changes in liver scan (done with colloidal radiogold) were increased in order. a) generalized hepatomegaly b) enlargement of the left lobe & reduction of the right lobe c) relatively increased radiodensity in the left lobe and 4) visualization of spleen. 2) Frequency of the normal scan in liver cirrhosis was $12{\pm}3.56%$, frequency of normal value in blood clearance half time of the radiogold was $5.0{\pm}2.34%$ and frequency of normal scan & normal blood clearance rate in liver cirrhosis was $3.6{\pm}2.06%$.

• Childhood Kidney Diseases
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• v.11 no.2
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• pp.220-228
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• 2007

Purpose : We studied the value of clinical signs, laboratory findings and $^{99m}technetium$ dime-rcaptosuccinic acid(DMSA) scan in predicting the presence of vesicoureteral reflux(VUR) in children with first febrile urinary tract infection(UTI). Methods : A retrospective analysis of 84 hospitalized children with first febrile UTI was performed. They underwent DMSA scan and voiding cystourethrography(VCUG) during the acute phase, and were divided into three groups according to the results of the VCUG: absence of VUR, mild(grade I-II) and severe VUR(grade III-V). We studied the relation of VUR to age, gender, fever duration, causative organism, white blood cell count, serum C-reactive protein and result of DMSA scan. Results : Among 84 patients, 6 had mild and 17 had severe VUR. Thirty-eight had abnormal DMSA scan. results Patients with VUR were older than those without VUR(P<0.01). There was a lower probability of infection with Escherichia coli in patients with severe VUR than in those with mild and absent VUR(P<0.01). An abnormal DMSA scan correlated with the presence and severity of VUR(P<0.05). Severe VUR was present in 10.9% of patients with normal DMSA scan. The sensitivity, specificity, positive and negative predictive values of the DMSA scan in predicting the presence of VUR were 69.6%, 63.9%, 42.1%, and 84.8%, respectively. Conclusion : An abnormal DMSA scan correlated to the presence and severity of VUR, but the sensitivity, specificity and positive predictive value of the DMSA scan were low. There-fore, patient with an abnormal DMSA scan requires a VCUG. In order to prevent missing the 10.9% of patients with severe VUR but normal DMSA scans, a VCUG should be performed in patient with normal DMSA scan.

• The Korean Journal of Nuclear Medicine
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• v.33 no.6
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• pp.493-501
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• 1999

Purpose: We conducted a comparative study to evaluate the diagnostic values of T1-201, Tc-99m MIBI and I-131 scans in the follow-up assessment after ablative I-131 therapy in differentiated thyroid cancer. Materials and Methods: The study population consisted of 20 patients who underwent surgical removal of thyroid cancer and ablative radioactive iodine therapy, and followed by one or mote times of I-131 retreatments (33 cases). In all patients, T1-201, Tc-99m MIBI, diagnostic and therapeutic I-131 scans were performed and the results were analyzed retrospectively. Also serum thyroglobulin levels were measured in all patients. The final diagnosis of recurrent or metastatic thyroid cancer was determined by clinical, biochemical, radiologic and/or biopsy findings. Results: Positive rates (PR) of Tc-99m MIBI, T1-201, diagnostic and therapeutic I-131 scans in detecting malignant thyroid tissue lesions were 70% (19/27), 54% (15/28), 35% (17/48) and 63% (30/48), respectively. The PR in the group of 20 cases (28 lesions) who underwent concomitant T1-201 and I-131 scans were in the order of therapeutic 131 scan 71%, T1-201 scan 54% and diagnostic I-131 scan 36%. There was no statistically significant difference between T1-201 and diagnostic I-131 scans (p>0.05). In the group of 20 cases (27 lesions) who underwent concomitant Tc-99m MIBI and I-131 scans, the PR were in the order of Tc-99m MIBI scan 70%, I-131 therapeutic scan 52% and I-131 diagnostic scan 33%. The PR of Tc-99m MIBI was significantly higher than that of diagnostic I-131 scan (p<0.05). Conclusion: Tc-99m MIBI scan is superior to diagnostic I-131 scan in detecting recurrent or metastatic thyroid cancer following ablation therapy in patients with differentiated thyroid cancer. T1-201 scan did not showed significantly higher positive rate than diagnostic I-131 scan. Instead of diagnostic I-131 scan before the I-131 retreatment, Tc-99m MIBI scan without discontinuing thyroid hormone replacement would be a prudent and effective approach in the management of these patients.