• Journal of radiological science and technology
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• v.42 no.1
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• pp.25-30
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• 2019

Whole Spine Scanography (WSS) using the Digital Radiography (DR) system is an examination that requires whole body X-ray exposure, which involves more exposure to radiation for patients than other general radiographies. This can affect the occurrence of breast cancer. This research measured radiation dose when breasts were shield and not shield using the Auto Exposure Control (AEC) mode. The radiation dose without a shield was 1.540 mGy, and that using a collimator was measured 0.506 mGy. Moreover, 0.733 mGy was measured when 1 shield (0.3 mm) was used, and $0.523{\mu}Gy$ when 5 of them (1.5 mm) were used. The results showed that the radiation dose with 5 shields and the radiation dose with a collimator were similar. Moreover, 0.233 mGy was measured when 8 shields (2.4 mm) were used. The standard deviation were 0.081 when using collimator and 0.014 when 5 shields were used. Also, when 8 shields were used, it was found to be 0.002. Most patients who go under a scoliosis test are children or young people who are highly sensitive to radiation. In the research results, the case where the organs sensitive to radiation, women's breasts, were shielded showed more distinct differences compared to without shields. It is considered that using shields can provide more constant shield than using a collimator and lower the risk of breast cancer caused by exposure to radiation.

• Journal of the Korean Society of Visualization
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• v.21 no.1
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• pp.80-93
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• 2023

We performed numerical simulations of blood flow in an arterial cerebral artery aneurysm to investigate the hemodynamic behavior after coil embolization. A patient-specific model was created based on CTA data. We also conducted the coil embolization simulation to obtain the coil placement within the aneurysm. Blood was assumed to be an incompressible Newtonian fluid, and both the vessel and coil were considered rigid walls. The pulsatile boundary condition was applied at the inlet, and the outflow boundary conditions were used at the outlets. Our findings demonstrated that the coil embolization significantly reduces the blood volume flowrate entering the aneurysm by effectively blocking the inflow jet, leading to a decrease in both TAWSS and WSS, especially at the systolic peak in the impingement zone. While several high OSI regions disappeared over the aneurysm surface, we observed high OSI regions with a relatively small area where the coil did not completely occlude the aneurysm. Overall, these results quantitatively analyzed the effectiveness of coil embolization by focusing on hemodynamic indicators, potentially preventing aneurysm rupture. The present work could contribute to the development of patient-specific coil embolization.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39B no.11
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• pp.779-789
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• 2014

Cognitive radio (CR) technology based on geo-location database access approach and/or wideband spectrum sensing approach is absolutely vital in order to recognize available frequency bands in white spaces (WSs), and efficiently utilize shared spectrums. This paper presents a new structure for the TVWS database access protocol implementation based on Internet Engineering Task Force (IETF) Protocol to Access WS database (PAWS). A wideband compressive spectrum sensing (WCSS) scheme using a modulated wideband converter is also proposed for the TVWS utilization. The developed database access protocol technology which is adopted in both the TV band device (TVBD) and the TVWS database operates well in the TV frequency bands. The proposed WCSS shows a stable performance in false alarm probability irrespective of noise variance estimation error as well as provides signal detection probabilities greater than 95%. This paper also investigates Federal Communications Commision (FCC) regulatory requirements of TVWS database as well as European Telecommunications Standards Institute (ETSI) policy related to TVWS database. A standardized protocol to achieve interoperability among multiple TVBDs and TVWS databases, which is currently prepared in the IETF, is discussed.

• Journal of Biomedical Engineering Research
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• v.25 no.6
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• pp.489-496
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• 2004

Insertion of cannulae into vessels may disturb the blood flow doing non-physiological load and stress on blood cells such that ADP may increase and result in hemolysis. Authors used the computational method to simulate the 3-dimensional blood flow inside of the cannula using numerical method. We limited the research to within the drainage cannulae with side holes inserted through the human vein. In this paper, 9 different cannulae with side holes categorized by the number of side holes of 4, 12, and 20, and also categorized by the array type of side holes of staggered array, in-line array, and alternative in-line array were studied and compared to the cannula with no side holes by using CFD analysis. We evaluated the flow rate, the wall shear stress, and the shear rate and compared them with one another to estimate the effect of the side holes. The flow rate is not proportional to the number of the side holes. However, larger number of side holes can reduce the mean shear rate. Both the number and the array type of side holes play an important role on the fluid dynamics of the blood flow in cannulae.

• The Journal of Korean Obstetrics and Gynecology
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• v.27 no.1
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• pp.152-166
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• 2014

Purpose: The purpose of this study is to compare with the result of experimental study about antithrombotic effect by reviewing recent oriental medicine journals that have been published since 2001' in Korea. Methods: Articles on antithrombotic effect that have been published from 2001' to 2013' in oriental medicine journals registered National Research Foundation of Korea were searched. After that, 12 articles using same 'thrombosis condition model' were selected and reviewed. Results: The results were as follows. 1. If there is no limit drug concentrations, platelet aggregation induced by adenosine diphosphate (ADP) in hyulbuchukeo-tanggamibang (HBCT) was the largest aggregation inhibitory effect and platelet aggregation induced by epinephrine in Saegeum-san (SGS), Jogan-tanggagambang (JGTG), hyulbuchukeo-tanggamibang (HBCT) had a large inhibitory effect on aggregation. 2. At the lowest concentration, Mokdan-san (MDS) of the inhibition of platelet aggregation induced by ADP and Hyunhosaik-san (HHS) of the inhibition of platelet aggregation induced by epinephrine were effective. 3. Pulmonary embolism induced by collagen and epinephrine in Neungasojeok-tang (NSJT) has the highest antithrombotic effect. 4. Pathological conditions of extravasated blood by dextran, Jogan-tanggagambang (JGTG) has the highest inhibitory effect on decrease in platelet numbers. Compared to the rest of the experimental drug, Saegeum-san (SGS), Heanggyonghonghwa-tang (HGTHHT), Wusl-san (WSS), Mokdan-san (MDS) showed significant inhibitory effect on the prothrombin time (PT) increases. Honghwadanggui-san (HDS), Saegeum-san (SGS) showed significant inhibitory effect on increase in activated partial thromboplastin time (APTT) and Jogan-tanggagambang (JGTG), Heanggyonghonghwa-tang (HGTHHT) showed significant inhibitory effect on decrease in fibrinogen. Conclusions: This result will provide useful information for the prescriptions of antithrombotic medicine in the field of Oriental medicine. We will have to carry out further studies that will compare each herb used in the diseases caused by extravasated blood.

• Journal of dental hygiene science
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• v.9 no.4
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• pp.375-380
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• 2009

The purpose of this study was to help improve oral health care planning for the elderly in an effort to promote the oral health of elderly people in preparation for aging society. The subjects in this study were 200 elderly people who were selected by random sampling from senior centers in Seoul. An interview was conducted to gather data from June to September 2008, and the data collected were analyzed.: 1. The mean number of residual tooth was 13.71. 2. Concerning connections between gender and subjective oral symptoms, gender had a statistically significant relationship to temporomandibular joint dysfunction(p=0.000), dry mouth(p=0.001) and halitosis(p=0.006). The men underwent more oral symptoms than the women. 3. As for the relationship of mastication(p=0.000), oral pain(p=0.010), temporomandibular joint dysfunction(p=0.010) and dry mouth(p=0.001) to subjective oral health state, the elderly people who were not in a good oral health suffered more oral symptoms, and the gap between them and the others was statistically significant. 4. A larger number of tooth led to less mastication difficulties, less dry mouth and more gingival diseases, and the relationship between the factors was statistically significant. A better oral health state led to less mastication difficulties, less oral pain, less dry mouth and less bad breath, and the relationship between the factors was statistically significant. Through this study the oral health the elderly people perceive wss concerned with oral symptom, and the number of residual teeth also had links to subjective oral symptoms. Therefore, to maintain original teeth of the elderly people, the management system of oral health and the education program for oral health in order to prevent disease relateded with oral and enhance the perception standard of oral state are indispensably necessary to the elderly people.