• Progress in Medical Physics
• /
• v.25 no.2
• /
• pp.72-78
• /
• 2014

The aim of the study is to test a hypothesis that quasi-breath-hold (QBH) biofeedback improves the residual respiratory motion management in gated 3D thoracic MR imaging, reducing respiratory motion artifacts with insignificant acquisition time alteration. To test the hypothesis five healthy human subjects underwent two gated MR imaging studies based on a T2 weighted SPACE MR pulse sequence using a respiratory navigator of a 3T Siemens MRI: one under free breathing and the other under QBH biofeedback breathing. The QBH biofeedback system utilized the external marker position on the abdomen obtained with an RPM system (Real-time Position Management, Varian) to audio-visually guide a human subject for 2s breath-hold at 90% exhalation position in each respiratory cycle. The improvement in the upper liver breath-hold motion reproducibility within the gating window using the QBH biofeedback system has been assessed for a group of volunteers. We assessed the residual respiratory motion management within the gating window and respiratory motion artifacts in 3D thoracic MRI both with/without QBH biofeedback. In addition, the RMSE (root mean square error) of abdominal displacement has been investigated. The QBH biofeedback reduced the residual upper liver motion within the gating window during MR acquisitions (~6 minutes) compared to that for free breathing, resulting in the reduction of respiratory motion artifacts in lung and liver of gated 3D thoracic MR images. The abdominal motion reduction in the gated window was consistent with the residual motion reduction of the diaphragm with QBH biofeedback. Consequently, average RMSE (root mean square error) of abdominal displacement obtained from the RPM has been also reduced from 2.0 mm of free breathing to 0.7 mm of QBH biofeedback breathing over the entire cycle (67% reduction, p-value=0.02) and from 1.7 mm of free breathing to 0.7 mm of QBH biofeedback breathing in the gated window (58% reduction, p-value=0.14). The average baseline drift obtained using a linear fit was reduced from 5.5 mm/min with free breathing to 0.6 mm/min (89% reduction, p-value=0.017) with QBH biofeedback. The study demonstrated that the QBH biofeedback improved the upper liver breath-hold motion reproducibility during the gated 3D thoracic MR imaging. This system can provide clinically applicable motion management of the internal anatomy for gated medical imaging as well as gated radiotherapy.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.29 no.1
• /
• pp.95-103
• /
• 2016

In this paper, aeroelastic instability and aerodynamic damping ratio of a helical $180^{\circ}$ model which shows better aerodynamic behavior in both along-wind and crosswind responses on a super tall building was investigated by an aeroelastic model test, and the aerodynamic damping ratio was evaluated from the wind-induced responses of the model by using Random Decrement Technique. Aerodynamic damping ratios evaluated in this study were verified through comparison with previous results obtained by quasi-steady theory. As a result, the aeroelastic instability of the helical $180^{\circ}$ model in crosswind direction were not occurred for any conditions with increasing the reduced wind velocity while the square model generally encounters aeroinstability due to the vortex shedding. The aerodynamic damping in along-wind direction for the helical $180^{\circ}$ and the square model increased monotonically both with reduced wind velocity, i.e., there is no relation with modifications of building shapes. On the other hand, in crosswind direction, the characteristics of aerodynamic damping ratio with reduced wind velocity for helical $180^{\circ}$ model were quit different from those of the square model.

• The Korean Journal of Pain
• /
• v.30 no.3
• /
• pp.176-182
• /
• 2017

Background: Current evidence suggests that intravenous magnesium sulfate might be effective for reducing migraine pain. In a recent pilot study, we showed that intravenous caffeine citrate could reduce the severity of migraine headache. The objective of this study is to investigate the efficacy of intravenous caffeine citrate vs. magnesium sulfate for management of acute migraine headache. Methods: We conducted a prospective quasi-experimental study from January until May 2016 in two educational medical centers of Shahid Beheshti University of Medical Sciences (Shoahadaye Tajrish Hospital and Imam Hossein Hospital), Tehran, Iran. The study included patients who were referred to the emergency department and met the migraine diagnosis criteria of the International Headache Society. Patients were allocated into 2 groups receiving either 60 mg intravenous caffeine or 2 g intravenous magnesium sulfate. The pain scores, based on the visual analog scale, were recorded on admission, as well as one and two hours after receiving the drug. A Chi-Square test and student t-test were used for analysis of baseline characteristics. A Mann-Whitney U test and Wilcoxon singed rank test were used to analyze differences in the visual analogue scale (VAS) score between and within the groups respectively. Results: In total, 70 patients (35 patients in each group) with the mean age of $33.1{\pm}11.3years$ were included (64.3% female). For the Caffeine citrate group, the median pain score decreased from 9.0 (2.0) to 5.0 (4.0) after one hour and to 3.0 (4.0) after two hours. For the magnesium sulfate group, the pain score decreased from 8.0 (2.0) to 2.0 (2.0) after one hour and to 0.0 (1.0) after two hours. Both intravenous caffeine citrate and intravenous magnesium sulfate reduced pain scores significantly but the magnesium sulfate group showed more improvement than the Caffeine citrate group after one hour (P < 0.001) and after two hours (P < 0.001). Conclusions: It is likely that both intravenous caffeine and intravenous magnesium sulfate can reduce the severity of migraine headache. Moreover, intravenous magnesium sulfate at a dose of 2 g might be superior to intravenous caffeine citrate 60 mg for the short term management of migraine headache in emergency departments.

• Asian Pacific Journal of Cancer Prevention
• /
• v.16 no.17
• /
• pp.7789-7794
• /
• 2015

Background: This study aimed to evaluate the impact of a community-based health education and communication programme on reducing liver fluke infections caused by the consumption of uncooked fish among people in a high-risk area of Thailand. Materials and Methods: The study was quasi-experimental in nature, with three-stages. Stage 1 involved a situational and capacity analysis of designated communities in Khon Kaen province. This was followed by the development of a model for community-based health education and communication to prevent liver fluke infections among high-risk people, and, lastly, implementation and evaluation of the model were performed. Data were collected using both qualitative and quantitative methods. In total, 390 people were surveyed, and quasi-experimental and comparison groups, each with 90 people, were assessed between May 2011 and April 2012. Analysis was using statistical OR, 95 % CI, the Willcoxon matched pairs signed ranks test, the chi-square test, and the Mann-Whitney U test. Results: The findings showed that most respondents had a high level of knowledge and understanding of liver fluke disease (89.5%, 95% CI:86.0-92.4), and positive attitudes toward the prevention of the disease (94.4%, 95% CI:91.6-96.4). However, with regard to changes in consumption of uncooked fish, most respondents were still in the pre-contemplation phase (55.1%, 95% CI:50.0-60.1), followed by the contemplation phase, 22.6%. Furthermore, four factors were found to be associated with the consumption of uncooked fish - the consumption of alcohol (OR 4.16, 95% CI:1.79-9.65), gender (OR 3.17, 95% CI:1.53-6.54), smoking (OR 3.03, 95% CI:1.31-7.05), and age 40 years and above (OR 2.68, 95% CI:1.02-7.05). After nine months of the health education and communication programme using local media based on local wisdom, culture and persons, the results showed that, compared to the control group, members of the experimental group had a higher level of knowledge, a better attitude and lower levels of ill-advised consumption behaviour. Also, it was found that consumption of uncooked fish, by an assessment of the level of stage of change, was reduced. (p-value 0.002). Conclusions: The health education and communication programme developed as part of the study was effective in changing the consumption of uncooked fish. Therefore, this approach should be promoted in other high-risk areas in Thailand in the future.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.38 no.6
• /
• pp.521-531
• /
• 2020

QZSS (Quasi-Zenith Satellite System) provides the CLAS (Centimeter Level Augmentation Service) through the satellite's L6 band. CLAS provides correction messages called C-SSR (Compact - State Space Representation) for GPS (Global Positioning System), Galileo and QZSS. In this study, CLAS messages were received by using the AsteRx4 of Septentrio which is a GPS receiver capable of receiving L6 bands, and the messages were decoded to acquire C-SSR. In addition, Multi-GNSS (Global Navigation Satellite System) Code-PPP (Precise Point Positioning) was developed to compensate for GNSS errors by using C-SSR to pseudo-range measurements of GPS, Galileo and QZSS. And non-linear least squares estimation was used to estimate the three-dimensional position of the receiver and the receiver time errors of the GNSS constellations. To evaluate the accuracy of the algorithms developed, static positioning was performed on TSK2 (Tsukuba), one of the IGS (International GNSS Service) sites, and kinematic positioning was performed while driving around the Ina River in Kawanishi. As a result, for the static positioning, the mean RMSE (Root Mean Square Error) for all data sets was 0.35 m in the horizontal direction ad 0.57 m in the vertical direction. And for the kinematic positioning, the accuracy was approximately 0.82 m in horizontal direction and 3.56 m in vertical direction compared o the RTK-FIX values of VRS.

• Journal of the Korea Convergence Society
• /
• v.7 no.4
• /
• pp.51-58
• /
• 2016

The purpose of this study was to examine the effects of clinical convergence self-directedness practice learning program on self-directedness and competency in fundamental nursing skills in undergraduate nursing students. The study design was a non-equivalent pre-post quasi-experimental design. The participants were 80 nursing students in D city. The experimental and control groups were randomly assigned with 40 participants in each group. Interventions for the experimental group were visiting clinical practice, video recording and students' self-debriefing of what they did over the 5 days. Self-directedness and competency in fundamental nursing skills were measured 2 times (pre-, and post-intervention) over the 5 days. Independent t-test, Mann-Whitney U test and chi-square test were used for data analyses. There was statistically significant difference for self-directedness(t=12.93, p=.001) and competency in fundamental nursing skills(t=8.34, p=.021). Results indicate that self-debriefing method using video recording is an effective learning way to improve Self-directedness and competency in fundamental nursing skills in nursing students.

• Research in Community and Public Health Nursing
• /
• v.7 no.2
• /
• pp.333-348
• /
• 1996

The purpose of this study was to examine the effect of nursing information on the level of need fulfillment and anxiety of the emergency patient's family members. The quasi-experimental study was designed using a noneqivalent control group non-synchronized design. During the first period, 30 subjects were assigned to the control group and 25 to the experimental group at a late period. The experimental group was provided with nursing information via guide booklet designed by the researcher. The control group received only routine care. Data was collected from January 31 to April 16 in 1996 at the K hospital in Taegu and analysed by chi-square test, t-test, ANOVA and Pearson correlation with SAS program. The instruments used for this study were the Family Needs Scale developed by Jung and the State-Trait Anxiety Inventory developed by Spielberger. The results of this study were summarized as follows : 1. The first hypothesis that the family members who received nursing information will have greater need fulfillment than family members who did not receive nursing information was supported. 2. The second hypothesis that the family members who received nursing information will have lower anxiety level than family members who did not receive nursing information was not supported. 3. The third hypothesis that the more the need of family member of emergency patient was met, the lower the anxiety level, was not supported. In conclusion, it was proved that nursing information about the emergency room provides family members with more need fulfillment, but did not decrease the anxiety level.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.5
• /
• pp.532-542
• /
• 2020

This study was undertaken to identify effects of the peer group reading program (PGRP) on the tenacity, self-resilience, and adaptation to university life of new entrants to the university. This was a non-equivalence control group quasi-experimental research study design. The subjects examined were entrants at the S University. The experimental group was provided the PGRP, and the control group was provided a general program for 13 weeks. The PGRP consisted of three or four students per group. Each group read one book for one week. Subsequently, all students gathered and presented their reading reports and discussed their comments, once a week. Data were analyzed using Chi-square test and t-test to compare the differences between both groups. A total of 73 subjects were included in the study: 34 in the experimental group and 39 in the control group. There were no significant differences in the general characteristics between the groups. Furthermore, no significant differences were observed between both groups before the intervention; however, the experimental group showed improved tenacity (p<0.01) and self-resilience (p=0.020) after the intervention, which were significantly different between both groups. Our results indicate the requirement to develop and apply various reading programs for improving the personality, self-resilience, and college life adaptability of university entrants.

• Journal of Astronomy and Space Sciences
• /
• v.34 no.4
• /
• pp.271-280
• /
• 2017

This study presents the application of satellite laser ranging (SLR) to orbit determination (OD) of high-Earth-orbit (HEO) satellites. Two HEO satellites are considered: the Quasi-Zenith Satellite-1 (QZS-1), a Japanese elliptical-inclinedgeosynchronous-orbit (EIGSO) satellite, and the Compass-G1, a Chinese geostationary-orbit (GEO) satellite. One week of normal point (NP) data were collected for each satellite to perform the OD based on the batch least-square process. Five SLR tracking stations successfully obtained 374 NPs for QZS-1 in eight days, whereas only two ground tracking stations could track Compass-G1, yielding 68 NPs in ten days. Two types of station bias estimation and a station data weighting strategy were utilized for the OD of QZS-1. The post-fit root-mean-square (RMS) residuals of the two week-long arcs were 11.98 cm and 10.77 cm when estimating the biases once in an arc (MBIAS). These residuals were decreased significantly to 2.40 cm and 3.60 cm by estimating the biases every pass (PBIAS). Then, the resultant OD precision was evaluated by the orbit overlap method, yielding three-dimensional errors of 55.013 m with MBIAS and 1.962 m with PBIAS for the overlap period of six days. For the OD of Compass-G1, no station weighting strategy was applied, and only MBIAS was utilized due to the lack of NPs. The post-fit RMS residuals of OD were 8.81 cm and 12.00 cm with 49 NPs and 47 NPs, respectively, and the corresponding threedimensional orbit overlap error for four days was 160.564 m. These results indicate that the amount of SLR tracking data is critical for obtaining precise OD of HEO satellites using SLR because additional parameters, such as station bias, are available for estimation with sufficient tracking data. Furthermore, the stand-alone SLR-based orbit solution is consistently attainable for HEO satellites if a target satellite is continuously trackable for a specific period.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.15 no.10
• /
• pp.6126-6133
• /
• 2014

This study examined the effects of a simulation-based core skill program regarding emergency care on the knowledge, problem solving process and self-esteem of health related department students. A quasi-experimental non-equivalent control group pre-post test design was used. A total of 46 students, 23 students for the experimental group and 23 students for the control group, were enrolled in this study. The simulation-based core skill program included lectures, skill training, team-based practice, simulation and debriefing. This was implemented in the experimental group for 3 weeks in May, 2013. The data was analyzed using the frequency, ratio, Chi-square, and t-test by the SPSS/Win 18.0. The experimental group, who had a simulation-based core skill program, showed significantly higher clinical knowledge, problem solving process and self-esteem compared to the control group who had a traditional education. A clinical simulation-based core skill program was verified to be an effective teaching method to improve on the clinical knowledge, problem solving process and self-esteem of health-related department students.