• The Journal of Korean Society for Radiation Therapy
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• v.33
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• pp.25-33
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• 2021

Purpose : The purpose of this study is to evaluate the accuracy and usefulness of the Trigger mode for the Respiratory Gated Radiation Therapy (RGRT) Materials and methods : A QUASAR respiratory phantom that inserted a 3 mm fiducial marker (a gold marker) was used to estimate the accuracy of the Trigger mode. And the 20 bpm was used as reference respiration rate in this study. The marker that placed at the center of the phantom was contoured, and the lower threshold of a gating window was fixed at 2.0 mm using an OBI with Truebeam STx^TM. The upper threshold was measured every 0.5 mm from 1.0 mm to 3.0 mm. The respiration rates were changed every 10 bpm from 10 bpm to 60 bpm. We repeatedly measured five times to check the error rate of the trigger mode in the same condition. Result : The differences of a distance from a peak phase to upper threshold, 1.0 to 3.0 mm at a 20 bpm as a reference for 3 days in a row were 0.68±0.05 mm, 0.91±0.03 mm, 1.23±0.03 mm, 1.42±0.04 mm, and 1.66±0.06 mm, respectively. Measurement result of changes in respiratory rate compared to baseline respiratory rate in maximum absolute difference. The coefficient of determination (R2) to estimate the correlation between the respiration velocity and variation of absolute difference was on average 0.838, 0.887, 0.770, 0.850, and 0.906. The p-values of all the variables were below 0.05. Conclusion : Using Trigger mode during respiratory gated radiation therapy (RGRT), accuracy and usefulness of trigger mode at reference breathing rate were confirmed. However, inaccuracies depending on the rate of breathing it could be uncertain in case of respiration rate is faster than 20 bpm as a standard respiration rate compared to slower than 20 bpm. Consequently, when conducting a RGRT using the trigger mode, real time monitoring is required with well educated respiration.

• The korean journal of orthodontics
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• v.37 no.1 s.120
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• pp.73-84
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• 2007

The maxillary protraction headgear has been widely used in the treatment of skeletal Class III children with maxillary deficiency. A variety of treatment objectives which allow dentoalveolar movements may be established, but when only maxillary protraction without dentoalveolar movement is needed, one of the limitations in maxillary protraction with conventional tooth-borne anchorage is the loss of dental anchorage. This is because a bone remodeling occurs not only at circummaxillary sutures but also within the periodontal tissues. During protraction treatment in the mixed dentition phase, in older children or for the patient with multiple congenitally missing teeth, it is not uncommon to observe undesirable mesial movement of maxillary teeth. Such a side effect can be eliminated or minimized using absolute anchorage such as skeletal anchorage. The purpose of this case report is to introduce a new technique of the maxillary protraction headgear treatment using surgical miniplates.

• Journal of the Korea Institute of Building Construction
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• v.7 no.1 s.23
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• pp.115-121
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• 2007

Ordinary concrete uses aggregate sufficiently soaked with water, and is weighed, mixed with other materials and placed in accord with performances required in the construction field. Recently special concrete with high fluidity and durability is required but it is difficult to use top-quality concrete due to lack of high-quality aggregate, delayed transportation because of traffic jam, etc. In addition, sometimes the use of a remicon is inevitable just for small-sized concrete constructions or it is difficult for a remicon to reach remote construction places such as mountainous areas. To solve these problems, this study attempted to pack concrete materials. In other words, it is to instantize concrete. This study dried aggregate, a material of concrete, and compared the change of absorption phase of the aggregate in water and in paste in order to examine the effect of the dryness of aggregate on its absorption rate and, based on the absorption rate, decided water addition ratio necessary for the reduction of unit quantity caused by the use of dry aggregate in designing concrete mixture, and analyzed the properties of unhardened concrete according to water addition ratio in manufacturing concrete using aggregate in the state of absolute dryness and in the state of surface dryness.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.2
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• pp.438-446
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• 2009

This study aims to investigate chemotherapy-induced neutropenia, nutritional status and both relation of patients with acute myeloid leukemia during 1st consolidation chemotherapy and the therapy-related cytopenic phase in order to determine more effective nutritional support. We review medical records of total 54 cases received first consolidation chemotherapy on P hospital in Busan. The duration of neutropenia(Absolute Neutrophil Count<$1000/{\mu}{\ell}$) is mean 14.78 days, neutropenia occur on mean 10th(9.54) day of chemotherapy(D10). The nutritional parameters of total protein, body weight, BMI showed no significant interval change during chemotherapeutic cycle except albumin, cholesterol. The neutropenia wasn't dependent on general factor of gender, age, comorbidities, Body Surface Area(BSA). The correlation wasn't revealed between neutropenia and nutritional status. In conclusion, although nutritional status didn't affect neutropenia, this study provides detailed information on the neutropenic response of acute myeloid leukemia patients during induction chemotherapy.

• Biomolecules & Therapeutics
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• v.17 no.3
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• pp.318-324
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• 2009

1-Furan-2-yl-3-pyridin-2-yl-propenone (FPP-3) has recently been synthesized and characterized to have an anti-inflammatory activity through the inhibition of the production of nitric oxide. In the present study, adverse effects of FPP-3 on hepatic functions were determined in female BALB/c mice. When mice were administered with FPP-3 at 125, 250 or 500 mg/kg for 7 consecutive days orally, FPP-3 significantly increased absolute and relative weights of liver with a dose-dependent manner. In addition, FPP-3 administration dramatically increased the hepatotoxicity parameters in serum at 500 mg/kg, in association of hepatic necrosis. FPP-3 significantly induced several phase I enzyme activities. To elucidate the possible mechanism(s) involved in FPP-3 induced hepatotoxicity, we investigated the hepatic activities of free radical generating and scavenging enzymes and the level of hepatic lipid peroxidation. FPP-3 treatment significantly elevated the hepatic lipid peroxidation, measured as the thiobarbituric acid-reactive substance, and the activity of superoxide dismutase. Taken together, the present data indicated that reactive oxygen species might be involved in FPP-3-induced hepatotoxicity.

• Journal of Advanced Navigation Technology
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• v.20 no.2
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• pp.155-160
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• 2016

Recently, underwater acoustic communication (UWAC) has been studied by many scholars and researchers. In order to use UWAC, we need to estimate time difference between the two signals in underwater environment. Typically, there are major three methods to estimate the time-difference between the two signals such as estimating the arrival time of the first non-background segment and calculate the temporal difference, calculating the cross-correlation between the two signal to infer the time-lagged, and estimating the phase delay to infer the time difference. In this paper, we present calculating the cross-correlation between the two signals to infer the time-lagged to apply UWAC. We also present the experimental result of estimating the arrival time by using cross-correlation. We get EXCORR = 0.003055 second as the estimation error in mean absolute difference.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.12 no.4
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• pp.49-57
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• 1992

This study was conducted to evaluate physical property change of asphalt cement chromatograms (by HP-GPC) were experimentally obtained from 3 types of AC-20 virgin ACs, 5 and 24-hour artificially aged ACs, and naturally aged 4 ACs that were recovered from 4 different roads. Absolute viscosity, kinematic visoosity and penetration were the physical properties tested. THF was used for mobil phase and RI detector was used as a detector for Hp-GPC testing. Correlation between each physical property change and the chromatogram variation was evaluated. Each chromatogram was divided into ten-equal-time slices. The percentage areas of 10 slices and each physical property were used for statistical correlation evaluation. Statistical analysis results showed that eaoh physical property had a strong correlation with the chromatogram characteristics. Aging was identified as a mechanism of change of molecular size distribution - increasing large size molecules and reducing coresponding samll size molecules.

• Journal of Soil and Groundwater Environment
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• v.21 no.6
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• pp.146-155
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• 2016

The field feasibility tests for a phytoextraction process were performed to identify the effect of citric acid as a chelate on the uranium (U) transfer into the plant for the naturally U contaminated soil in Duckpyeongri, Korea. For the feasibility tests, lettuce and Chinese cabbage were cultivated for 49 days on four testing grounds ($1m{\times}1m{\times}0.5m$ in each) in 2016. The citric acid solution was added to two testing grounds (one for lettuce and the other for Chinese cabbage) increasing the U transfer in two crop plants and their results were compared to those without the citric acid solution. When without the citric acid solution, the U concentration of plant after the cultivation was low (< $45{\mu}g/kg$ for leaves and < $450{\mu}g/kg$ for roots). However, with the addition of 50 mM citric acid solution, the U concentration of lettuce leaves and roots increased by 24 times and 1.8 times, and the U concentration of Chinese cabbage leaves and roots increased by 86.7 times and 5.4 times. The absolute accumulated U amount (${\mu}g$) in lettuce and Chinese cabbage also increased by 8.7 times and 50 times, compared to those without citric acid solution. Less than 8% of the U amount of exchangeable/carbonate phases was removed by using the lettuce and Chinese cabbage when the citric acid solution was not applied. However 52% and 66% of the U amount in exchangeable/carbonate phases were removed by the lettuce and the Chinese cabbage when the citric acid solution was added. The effect of the citric acid on the U transfer capability into the plants was quantitatively investigated by the field feasibility test, suggesting that U existing as exchangeable/carbonate phase in soil can be successfully removed by the phytoextraction process using Chinese cabbage with citric acid.

• Bulletin of the Korean Space Science Society
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• 2008.10a
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• pp.26.3-26.3
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• 2008

This research develops a GPS-based formation-flying testbed (FFTB) for formation navigation and control. The FFTB is a simulator in which spacecraft simulation and modeling software and loop test capabilities are integrated for test and evaluation of spacecraft navigation and formation control technologies. The FFTB is composed of a GPS measurement simulation computer, flight computer, environmental computer for providing true environment data and 3D visualization computer. The testbed can be simulated with one to two spacecraft, thus enabling a variety of navigation and control algorithms to be evaluated. In a formation flying simulation, GPS measurement are generated by a GPS measurement simulator to produce pseudorange, carrier phase measurements, which are collected and exchanged by the flight processors and subsequently processed in a navigation filter to generate relative and/or absolute state estimates. These state estimates are the fed into control algorithm, which are used to generate maneuvers required to maintain the formation. In this manner, the flight processor also serves as a test platform for candidate formation control algorithm. Such maneuvers are fed back through the controller and applied to the modeled truth trajectories to close simulation loop. Currently, The FFTB has a closed-loop capability of simulating a satellite navigation solution using software based GPS measurement, we move forward to improve using SPIRENT GPS RF signal simulator and space-based GPS receiver

• Journal of Positioning, Navigation, and Timing
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• v.6 no.4
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• pp.211-221
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• 2017

Ellipsodially referenced survey (ERS) is considered as one of the challenging issues in the hydrographic surveys due to the fact that the bathymetric data collected by this technique can be readily transformed either to the geodetic or the chart datum by application of some geoscientific models. Global Navigation Satellite Systems (GNSS) is a preferred technique to determine the ellipsoidal height of a vessel reference point (RP) because it provides cost-effective and unprecedentedly accurate positioning solutions. Especially, the GNSS-derived heights include heave and dynamic draft of a vessel, so as for the reduced bathymetric solutions to be potentially free from these corrections. Although over the last few decades, differential GNSS (DGNSS) has been widely adopted in the bathymetric surveys, it only provides limited accuracy of the vertical component. This technical barrier can be effectively overcome by adopting the so-called GNSS carrier phase (CPH) based techniques, enhancing accuracy of the height solution up to few centimeters. From the positioning algorithm standpoint, the CPH-based techniques are categorized under absolute and relative positioning in post-processing mode; the former is precise point positioning (PPP) correcting errors by the global or regional models, the latter is post-processed kinematic positioning (PPK) that uses the differencing technique to common error sources between two receivers. This study has focused on assessment of achievable accuracy of the ellipsoidal heights obtained from these CPH-based techniques with a view to their applications to hydrographic surveys where project area is, especially, few tens to hundreds kilometers away from the shore. Some field trials have been designed and performed so as to collect GNSS observables on static and kinematic mode. In this paper, details of these tests and processed results are presented and discussed.