• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.5D
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• pp.877-884
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• 2006

GPS is an essential tool for applications that be required high positioning precision, for the velocity field estimation of tectonic plates. The three years data of eight GPS permanent station were analyzed to estimate crustal deformation velocities using Gipsy-oasis II software. The velocity vectors of GPS stations are estimated by linear regression method in daily solution time series. The velocities have a standard deviation of less than 0.1mm/yr and the magnitude of velocities given by the Korean GPS permanent stations were very small, ranging from 25.1 to 31.1 mm/yr. The comparison between the final solution and other sources, such as IGS velocity result calculated from SOPAC was accomplished and the results generally show good agreement for magnitude and direction in crustal motion. To evaluate the accuracy of our results, the velocities obtained from six plate motion model was compared with the final solution based on GPS observation.

• Journal of radiological science and technology
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• v.46 no.5
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• pp.401-408
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• 2023

Thyroid uptake measurements can be subject to measurement errors due to the scoping and positioning of the thyroid gland. To compensate for these limitations, the clinical utility of the thyroid simultaneous counting method as an alternative to thyroid uptake measurement was analyzed and evaluated experimentally through quantitative analysis of images acquired after thyroid scanning. Experimental data were obtained using a Gamma camera (GE infinia), a thyroid uptake system (KOROID 1), and a thyroid neck phantom. Based on the thyroid uptake rate of 1-5% according to the protocol of thyroid scan test (^99mTcO₄ - , 370 MBq) in normal results, ^99mTcO₄ - was set in the range of 3.7-18.5 MBq (Matrix: 256×256, Scan time: 1 min, collimator: pin hole, phantom-collimator distances: 7 cm). The acquired images were corrected for the attenuation of isotopes due to the set-up time and half-life by applying the Auto Region of interest (ROI) drawing system, and the significance of the experimental results was evaluated by Multiple linear regression analysis (SPSS, ver. 22, IBM). The thyroid uptake rate showed a significant correlation between the dose and the measured counts when using the thyroid uptake system equipment. Meanwhile, the quantitative analysis counts of phantom images using Gamma camera also showed a significant correlation. Thus confirmed that the correlation between these two experiments was statistically significant (P<0.05). The simultaneous counting protocol, which indirectly measures thyroid uptake from thyroid scans, is likely to be clinically relevant if complemented by additional studies with different variables in patients with thyroid disease.

• Journal of Radiation Protection and Research
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• v.48 no.3
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• pp.162-166
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• 2023

Background: Assessment of the radiation doses to which workers are exposed can differ depending on the placement of dosimeters on the body. In addition, it is affected by whether the placement is under or over a shielding apron. This study aimed to evaluate the actual positioning of personal dosimeters on the body, with or without shielding aprons, among radiation workers in Korea. Materials and Methods: We analyzed the survey data, which included demographic characteristics, such as sex, age, occupation, work history, and placement of the personal dosimeter being worn, from a cohort study of Korean radiation workers. We assessed the use of personal dosimeters among workers, stratified by sex, age, working period, starting year of work, and occupation. Results and Discussion: Overall, high compliance (89.1% to 99.0%) with the wearing of dosimeters on the chest was observed regardless of workers' characteristics, such as age, sex, occupation, and work history. However, the placement of dosimeters, either under or over the shielding aprons, was inconsistent. Overall, 40.1% of workers wore dosimeters under their aprons, while the others wore dosimeters over their aprons. This inconsistency indicates that radiation doses are possibly measured differently under the same exposure conditions solely owing to variations in the placement of worn dosimeters. Conclusion: Although a lack of uniformity in dosimeter placement when wearing a shielding apron may not cause serious harm in radiation dose management for workers, the development of detailed guidelines for dosimeter placement may improve the accuracy of dose assessment.

• Journal of Cerebrovascular and Endovascular Neurosurgery
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• v.25 no.3
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• pp.275-287
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• 2023

Objective: Flow diverting stents (FDS) are a validated device in the treatment of intracranial aneurysms, allowing for minimally invasive intervention. However, after its approval for use in the United States in 2011, post-market surveillance of adverse events is limited. This study aims to address this critical knowledge gap by analyzing the FDA Manufacturer and User Facility Device Experience (MAUDE) database for patient and device related (PR and DR) reports of adverse events and malfunctions. Methods: Using post-market surveillance data from the MAUDE database, PR and DR reports from January 2012-December 2021 were extracted, compiled, and analyzed with R-Studio version 2021.09.2. PR and DR reports with insufficient information were excluded. Raw information was organized, and further author generated classifications were created for both PR and DR reports. Results: A total of 2203 PR and 4017 DR events were recorded. The most frequently reported PR adverse event categories were cerebrovascular (60%), death (11%), and neurological (8%). The most frequent PR adverse event reports were death (11%), thrombosis/thrombus (9%) cerebral infarction (8%), decreased therapeutic response (7%), stroke/cerebrovascular accident (6%), intracranial hemorrhage (5%), aneurysm (4%), occlusion (4%), headache (4%), neurological deficit/dysfunction (3%). The most frequent DR reports were activation/positioning/separation problems (52%), break (9%), device operates differently than expected (4%), difficult to open or close (4%), material deformation (3%), migration or expulsion of device (3%), detachment of device or device component (2%). Conclusions: Post-market surveillance is important to guide patient counselling and identify adverse events and device problems that were not identified in initial trials. We present frequent reports of several types of cerebrovascular and neurological adverse events as well as the most common device shortcomings that should be explored by manufacturers and future studies. Although inherent limitations to the MAUDE database are present, our results highlight important PR and DR complications that can help optimize patient counseling and device development.

• Journal of The Korean Society of Integrative Medicine
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• v.12 no.3
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• pp.237-247
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• 2024

Purpose : This study aimed to systematically review the effectiveness of nursing interventions for patients receiving extracorporeal membrane oxygenation (ECMO). As the use of ECMO increases in critical care settings, it is important to understand how nursing interventions affect patient outcomes, survival, and complication rates. Methods : This systematic review followed the preferred reporting items for systematic reviews and meta-analysis guidelines. A literature search was performed using terms related to ECMO and nursing interventions in several international electronic databases including CINAHL, Embase, MEDLINE, and Web of Science. Studies were screened and selected according to predefined eligibility criteria, focusing on those that evaluated the impact of nursing interventions on adult. Data extraction and risk-of-bias assessment were independently performed by two researchers. Results : A total of 647 studies were identified, and seven met the inclusion criteria for qualitative analysis. The included studies demonstrated that high-quality nursing care significantly improves clinical outcomes and reduces complications in patients receiving ECMO. Effective nursing interventions included prone positioning combined with ECMO for patients with acute respiratory distress syndrome, meticulous infection control, comprehensive and continuous nursing protocols, skilled nursing, and multidisciplinary management. These interventions have been shown to improve oxygenation, reduce complications, such as bleeding, manage blood pressure, and enhance overall clinical outcomes. Conclusion : High-quality nursing interventions are critical to improve survival and reduce complications in patients receiving ECMO. Implementing a multidisciplinary approach and comprehensive nursing protocols, including infection control and psychological support, is essential for the effective management of these patients. The findings of this study provide a foundation for the development of practical guidelines and educational programs to improve the quality of care for patients undergoing ECMO, ultimately enhancing the effectiveness of ECMO treatment and patient outcomes.

• Korean Journal of Applied Biomechanics
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• v.15 no.1
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• pp.237-257
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• 2005

It was to study as a following-research of "A Case Study on Center of Gravity(COG) Analysis when Performing Uchimata(inner thigh reaping throw) by Posture and Voluntary Resistance Levels(VRL) of Uke in Judo[I]". The purpose of this study was to analyze the COG variables when performing uchimata(inner thigh reaping throw) by two postures and voluntary resistance levels(VRL) of uke(reciver) in Judo. The subjects, who were one male judoka(YH) for 1992 Barcelona Olympic Games Olympian(silver medalist), and one male trainee; Y.I.University representative member (SDK), and were filmed on two S-VHS 16mm video cameras(60fields/sec.) through 3-dimensional motion analysis methods, that postures of uke were shizenhontai (straight natural posture) and jigohontai(straight defensive posture), VRL of uke were 0% and 100%, respectively. The kinematical variable was COG variable, distance of COG, and distance of resultant COG between uke and tori(the thrower), velocity and acceleration of COG. The data of this study collection were digitized by SIMI Motion Program computed the mean values and the standard deviation calculated for each variables. When performing uchinmata according to each posture and VRL of uke and classifying. From the data analysis and discussion, the conclusions were as follows : 1. Displacement of COG Subject YH, COG was the highest in kuzushi(balance -breaking), vertical COG was low when following in tsukuri(positioning; set-up), kake(application; execution), and COG was pattern of same character each postures and resistance, respectively. Subject SDK, COG was low from kumikata(engagement positioning) to kake, and COG was that each postures and resistance were same patterns, respectively. Subject YH, SDK, each individual, postures and resistance, vertical COG was the lowest in kake phase, when performing. 2. Distance of COG between uke and tori The distance of COG between uke and tori when performing, subject YH was $0.64{\sim}0.70cm$ in kumikata, $0.19{\sim}0.28cm$ in kake, and SDK was $0.68{\sim}0.72cm$ in kumikata, $0.30{\sim}0.42\;cm$ in kake. SDK was wider than YH. 3. Distance of resultant COG between uke and tori The distance of resultant COG between uke and tori when performing, subject YH was $0.27{\sim}0.73cm$ from kumikata to kake. and SDK was $0.14{\sim}0.34cm$ in kumikata, $0.28{\sim}0.65cm$ in kake. Jigohontai(YH:$0.43{\sim}0.73cm$,SDK:$0.59{\sim}0.65cm$) was more moved than shizenhontai(YH:$0.27{\sim}0.53cm$, SDK: $0.28{\sim}\;0.34cm$). 4. Velocity of COG The velocity of COG when performing uchimata, subject YH was fast anterior-posterior direction in kuzushi, ant.-post. and vertical direction fast in tsukuri and kake. SDK was lateral, ant.-post. and vertical direction in kuzushi, ant.-post. and vertical direction in tsukuri and ant.-post. direction in take, respectively. 5. Acceleration of COG The acceleration of COG when performing uchimata, The trend of subject YH was showed fast vertical direction in kuzushi and tsukuri, ant.-post. and vertical direction fast in kake. The trends of SDK showed lateral direction in kuzushi, lateral and ant.-post. direction in tsukuri and ant.-post. direction in kake, respectively.

• Korean Journal of Remote Sensing
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• v.34 no.6_2
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• pp.1165-1178
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• 2018

Collapse of an Antarctic ice shelf and its flow velocity changes has the potential to reduce the restraining stress to the seaward flow of the Antarctic Ice Sheet, which can cause sea level rising. In this study, variations in ice velocity from 2000 to 2017 for the Nansen Ice Shelf in East Antarctica that experienced a large-scale collapse in April 2016 were analyzed using Landsat-7 Enhanced Thematic Mapper Plus (ETM+) and Landsat-8 Operational Land Imager (OLI) images. To extract ice velocity, image matching based on orientation correlation was applied to the image pairs of blue, green, red, near-infrared, panchromatic, and the first principal component image of the Landsat multispectral data, from which the results were combined. The Landsat multispectral image matching produced reliable ice velocities for at least 14% wider area on the Nansen Ice Shelf than for the case of using single band (i.e., panchromatic) image matching. The ice velocities derived from the Landsat multispectral image matching have the error of $2.1m\;a^{-1}$ compared to the in situ Global Positioning System (GPS) observation data. The region adjacent to the Drygalski Ice Tongue showed the fastest increase in ice velocity between 2000 and 2017. The ice velocity along the central flow line of the Nansen Ice Shelf was stable before 2010 (${\sim}228m\;a^{-1}$). In 2011-2012, when a rift began to develop near the ice front, the ice flow was accelerated (${\sim}255m\;a^{-1}$) but the velocity was only about 11% faster than 2010. Since 2014, the massive rift had been fully developed, and the ice velocity of the upper region of the rift slightly decreased (${\sim}225m\;a^{-1}$) and stabilized. This means that the development of the rift and the resulting collapse of the ice front had little effect on the ice velocity of the Nansen Ice Shelf.

• Geophysics and Geophysical Exploration
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• v.8 no.4
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• pp.262-269
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• 2005

Since the buried cultural relics are three-dimensional (3-D) objects in nature, 3-D survey is more preferable in archeological exploration. 3-D Ground Penetrating Radar (GPR) survey based on very dense data in principle, however, might need much higher cost and longer time of exploration than other geophysical methods commonly used for the archeological exploration, such as magnetic and electromagnetic methods. We developed a small-scale continuous data acquisition system which consists of two sets of GPR antennas and the precise positioning device tracking the moving-path of GPR antenna automatically and continuously. Since the high cost of field work may be partly attributed to establishing many profile lines, we adopted a concept of data acquisition at arbitrary locations not along the pre-established profile lines. Besides this hardware system, we also developed several software packages in order to effectively process and visualize the 3-D data obtained by the developed system and the data acquisition concept. Using the developed system, we performed 3-D GPR survey to investigate the possible historical remains of Baekje Kingdom at Buyeo city, South Korea, prior to the excavation. Owing to the newly devised system, we could obtain 3-D GPR data of this survey area having areal extent over about $17,000m^2$ within only six-hours field work. Although the GPR data were obtained at random locations not along the pre-established profile lines, we could obtain high-resolution 3-D images showing many distinctive anomalies, which could be interpreted as old agricultural lands, waterways, and artificial structures or remains. This cast: history led us to the conclusion that 3-D GPR method is very useful not only to examine a small anomalous area but also to investigate the wider region of the archeological interests.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.30 no.1
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• pp.87-96
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• 2012

The U.S. Geological Survey (USGS) announced that an earthquake of 9.0 magnitude had occurred near the east coast of Japan on March 11, 2011, resulting in a displacement of the crust of about 2.4 meters. The Korean peninsula is located on the Eurasian tectonic plate that stretches out to Japan; therefore, there is a high possibility of being affected by an earthquake. The Korean GPS CORS network operated by the National Geographic Information Institute (NGII) was processed for ten days before and after the earthquake. Both static and kinematic baseline processing were tested for the determination of crustal deformation. The static baseline processing was performed in two scenarios: 1) fixing three IGS stations in China, Mongolia and Russia; 2) fixing SUWN, one of the CORS networks in Korea, in order to effectively verify crustal deformation. All data processing was carried out using Bernese V5.0. The test results show that most of the parts of the Korean peninsula have moved to the east, ranging 1.2 to 5.6 cm, compared to the final solution of the day before the earthquake. The stations, such as DOKD and ULLE that are established on the islands closer to the epicenter, have clearly moved the largest amounts. Furthermore, the station CHJU, located on the southwestern part of Korea, presents relatively small changes. The relative positioning between CORS confirms the fact that there were internal distortions of the Korean peninsula to some extent. In addition, the 30-second interval kinematic processing of CORS data gives an indication of earthquake signals with some delays depending on the distance from the epicenter.

• Journal of the Korean earth science society
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• v.34 no.6
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• pp.588-601
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• 2013

In geophysics and geophysical exploration fields, we can use information about inclination and azimuth in various ways. These include borehole deviation logging for inversion process, real-time data acquisition system, geophysical monitoring system, and so on. This type of information is also necessarily used in the directional drilling of shale gas fields. We thus need to develop a subminiature, low-powered, multi-functional inclination and azimuth measurement system for geophysical exploration fields. In this paper, to develop real-time measurement system, we adopt the high performance low power Micro Control Unit (made with state-of-the-art Complementary Metal Oxide Semiconductor technology) and newly released Micro Electro Mechanical Systems Attitude Heading Reference System sensors. We present test results on the development of a multifunctional real-time inclination and azimuth measurement system. The developed system has an ultra-slim body so as to be installed in 42mm sonde. Also, this system allows us to acquire data in real-time and to easily expand its application by synchronizing with a depth encoder or Differential Global Positioning System.