• Journal of the Korea Society of Computer and Information
• /
• v.13 no.6
• /
• pp.59-68
• /
• 2008

In this paper, we propose a method for selecting meaningful event packets from which can receive before anything else from seismograph according to allotted priority and estimate epicenter using selected packets. Event packets which received from each station will be evaluated with their onset time, signal period and SNR by statistical method and will be selected packets related with real earthquake's P-wave. And estimated epicenters using by 'Application of epicenter estimation using first P arrivals'. With local earthquakes occurred in 2007 were announced by KMA, collected event packets on earthquake happened date and selected p-wave related packets and estimated epicenter. After result of experiment, if an earthquake occurred within seismic networks, can estimate epicenter with small misfits just after event packets arrived from above 4 stations. Considering average distance of each station, in case of using all stations' data include other organization, can estimate and alert rapidly. It show this method is useful when construct a local earthquake early warning system later.

• Progress in Medical Physics
• /
• v.25 no.4
• /
• pp.248-254
• /
• 2014

The purpose of this study is to develope a control system for a small X-ray tube generator and investigate control methods for the X-ray generator. The small X-ray tube was developed for electronic brachytherapy, and thus, the new control method should be investigated, if the small X-ray tube is used for the imaging system. The Axxent S700 X-ray tube and the XF060NZZ485 high voltage generator were used to compose a X-ray imaging system and control board was developed by using AT90CAN128 MCU. The two control methods were investigated after tube voltage was set to 50 kV, one was filament current control method and the other was beam current control method. The former was subdivided into two methods according to the filament heating time, the 5 and the 10 seconds respectively. In the filament current method, the beam current did not rise up to the desired value, if the filament current had not been maintained for at least 10 seconds. The onset filament currents to generate beam current were varied from 1,300 to 1,350 mA and over 5 seconds were needed in order to reach the desired tube current value after beam current was generated. However, in the tube current control method, the beam current reached to the desired value without any time delay with the filament current of 1,500 mA. In this study, we found that the beam current control method was appropriate for the use of small X-ray tube developed for brachytherapy in the X-ray imaging system.

• Journal of Oriental Neuropsychiatry
• /
• v.12 no.2
• /
• pp.135-146
• /
• 2001

Insomnia is one of the most common symtoms of Neuropsychiatry patients. These are many approaches to treat insomnia, but it is difficult to be resolved completely. Acupuncture and Auricular acupuncture have been used for relief insomnia. But it is not sufficient to compare the effect of Acupuncture treatment and Auricular acupuncture treatment. Thus we investigate the effect of Acupuncture treatment group and Auricular acupuncture treatment group. A clinical analysis was carried out for 40 patients who was treated insomnia with Acupuncture(20 patients) and Auricular acupuncture(20 patients) in Seoul Dong-Seo Oriental Hospital. 1. Total duration of sleeping time showed $1.55{\pm}1.1574$ hours increased in Acupuncture group and $0.925{\pm}1.184$ hours increased in Aricular acupuncture group. especially Acupuncture were much more effective method than Aricular acupuncture. P-value was 0.033 (P <0.05) 2. Delaying time before the onset of sleep showed $0.7375{\pm}0.8940$ hours decreased in Acupuncture group and $0.7969{\pm}1.3298$ hours decreased in Auricular acupuncture group. (P <0.05) 3. The wake times showed $0.9167{\pm}1.7299$ times decreased in Acupuncture group and $1.2308{\pm}1.1658$ times decreased in Auricular acupuncture group in sleep maintenance insomnia. (P <0.05) 4. Change in quality of sleep showed Excellent 30%, Good 50%, Fair 15%, Poor 5% in Acupuncture group and Excellent 20%, Good 45%, Fair 30%, Poor 5% in Aruricular acupuncture group.

• Proceedings of the KOSOMBE Conference
• /
• v.1997 no.11
• /
• pp.222-227
• /
• 1997

To diagnose cardiac arrhythmia owing to reentry mechanism, cardiac conduction system was modeled by modified Hidden Markov modeled by evaluated. First, simulation of transient conduction states and output waves were made with initially assumed parametric values of cardiac muscle repolariztion time, conduction velocity and its automaticity. The output was a series of onset time and the name of the wave. Parameters determined the rate of beating, lengths of wave intervals, rate of abnormal beats, and the like. Several parameter sets were found to simulate normal sinus rhythm, supraventricular /ventricular tachycardia, atrial /vetricular extrasystole, etc. Then, utilizing the estimation theorems of Hidden Markov Model, the best conduction path was estimated given the previous output. With this modified estimation method, close matching between the simulated conduction path and the estimated one was confirmed.

• Journal of the Korean Ceramic Society
• /
• v.54 no.2
• /
• pp.108-113
• /
• 2017

The use of aluminum-based coagulants in water pretreatment is being carefully considered because aluminum exposure is a risk factor for the onset of Alzheimer's disease. Lightly burned-dolomite kiln dust (LB-DKD) was evaluated as an alternative coagulant because it contains high levels of the healthful minerals calcium and magnesium. An organic pore forming agent (OPFA) was incorporated to prepare porous granules after OPFA removal through a thermal decomposition process. A spray drying method was used to produce uniform and reproducible spherical granules with low density, since fine dolomite particles have irregular agglomeration behavior in the hydration reaction. The use of fine dolomite powder and different porosity granules led to a visible color change in raw algae (RA) containing water, from dark green to transparent colorlessness. Also, dolomite powders and granules exhibited a mean removal efficiency of 48.3% in total nitrogen (T-N), a gradual increase in the removal efficiency of total phosphorus (T-P) as granule porosity increased. We demonstrate that porous dolomite granules can improve the settling time and water quality in summer seasons for the emergent treatment of excessive algal blooms in eutrophic water.

• Journal of Preventive Medicine and Public Health
• /
• v.57 no.5
• /
• pp.443-450
• /
• 2024

Objectives: Lack of physical activity has a critical effect on the physical and mental health of adolescents. This study examined the influence of family adversities on the longitudinal changes in physical inactivity among adolescents during the coronavirus disease 2019 (COVID-19) pandemic. Methods: The study used multi-wave data from the Korean Children and Youth Panel Survey, including 2590 Korean adolescents aged 12-14 years. The longitudinal trajectory of physical inactivity among adolescents and the effects of related factors were estimated using a latent growth modeling method. Results: Our results revealed a significant increase in physical inactivity among adolescents over time. At the onset of the pandemic, approximately one-seventh of Korean middle schoolers reported a lack of physical activity. However, 3 years later, during the quarantine, nearly one-fifth of these adolescents reported a significant increase in their physical inactivity. Initially, low level parental education was predictive of adolescents' physical inactivity, but this effect diminished over time, becoming statistically insignificant by the end of the 3-year period. Moreover, the increase in physical inactivity over the 3 years was significantly influenced by parental rejection. Conclusions: These findings suggest that adolescents who experience parental rejection are more likely to report an increase in sedentary behaviors in contexts such as the COVID-19 pandemic.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.16 no.1
• /
• pp.89-98
• /
• 1994

This study was based on a series of 213 patients with facial bone fractures treated at college of Medicine, Dong-A university from Mar. 1990 to Jun. 1993. The results obtained were as follows : 1. The ratio of male to female was 8.3 : 1 and 3rd decade(34.3%) was the highest age group in incidence. 2. Monthly incidence was the highest in Jan. & Jun.(10.3%) 3. Onset time and daily incidence was the highest in pm. 9:00-12:00(21.4%), Sunday(18.8%). 4. Traffic acidents(38.5%) were the most frequent etiologic factor. 5. The most common site of fracture was zygoma & zygomatic arch(42.3%) and mandible (37.8%), maxilla (10.9%) and nasal bone(9.0%) were next in order of frequency. 6. In mandible fractures, the most frequent site was symphyseal area(43.0%) and IMF & open reduction was major method of treatment. 7. In zygoma & zygomatic arch fractures, zygoma(62.0%) was the most common fracture site and open reduction was the most frequent treatment method. 8. In maxilla fractures, the major fracture type was Le Fort I type (72.4%) and treatment was done by IMF & open reduction primarily. 9. postoperative complications were mal-union, fibrous-union, infection, osteomyelitis etc.

• Smart Structures and Systems
• /
• v.15 no.2
• /
• pp.245-258
• /
• 2015

A methodology based on distributed fiber optic sensors is proposed to detect the lateral buckling for subsea pipelines in this study. Uncontrolled buckling may lead to serious consequences for the structural integrity of a pipeline. A simple solution to this problem is to control the formation of lateral buckles among the pipeline. This firms the importance of monitoring the occurrence and evolution of pipeline buckling during the installation stage and long-term service cycle. This study reports the experimental investigations on a method for distributed detection of lateral buckling in subsea pipelines with Brillouin fiber optic sensor. The sensing scheme possesses the capability for monitoring the pipeline over the entire structure. The longitudinal strains are monitored by mounting the Brillouin optical time domain analysis (BOTDA) distributed sensors on the outer surface of the pipeline. Then the bending-induced strain is extracted to detect the occurrence and evolution of lateral buckling. Feasibility of the method was validated by using an experimental program on a small scale model pipe. The results demonstrate that the proposed approach is able to detect, in a distributed manner, the onset and progress of lateral buckling in pipelines. The methodology developed in this study provides a promising tool for assessing the structural integrity of subsea pipelines.

• Journal of Biosystems Engineering
• /
• v.39 no.4
• /
• pp.324-329
• /
• 2014

Purpose: The finite element method (FEM) is advantageous because it can save time and cost by reducing the number of samples and experiments in the effort to identify design factors. In computational problem-solving it is necessary that the exact material properties are input for achieving a reliable analysis. However, in the case of fiber boards, it is difficult to measure their cross-directional material properties because of their small thickness. In previous research studies, the Poisson's ratio was measured by analyzing ultrasonic wave velocities. Recently, the Poisson's ratio was measured using a high-speed digital camera. In this study, we measured the transverse strain of a fiber board and calculated its Poisson's ratio using a high-speed digital camera in order to apply these estimates to a FEM analysis of a fiber board, a corrugated board, and a corrugated box. Methods: Three different fiber board samples were used in a uniaxial tensile test. The longitudinal strain was measured using the Universal Testing Machine. The transverse strain was measured using an image processing method. To calculate the transverse strain, we acquired images of the fiber board before the test onset and before the fracture occurred. Acquired images were processed using the image processing program MATLAB. After the images were converted from color to binary, we calculated the width of the fiber board. Results: The calculated Poisson's ratio ranged between 0.2968-0.4425 (Machine direction, MD) and 0.1619-0.1751 (Cross machine direction, CD). Conclusions: This study demonstrates that measurement of the transverse properties of a fiber board is possible using image processing methods. Correspondingly, these processing methods could be used to measure material properties that are difficult to measure using conventional measuring methodologies that employ strain gauge extensometers.

• Journal of Society of Preventive Korean Medicine
• /
• v.3 no.1
• /
• pp.147-155
• /
• 1999

In order to investigate the effect of circulating blood and extinguishing blood stasis method on acute ischemic stroke treatment, we compared muscle weakness in two groups. Dansamhwanotang was administered to experimental group and the Sopungtang was administered to comparison group. In prospective and consecutive study, 24 patients(male 14, female 10) were admitted to hospital within 6hours(median $4.21{\pm}2.45)$ after stroke attack. All of them were diagnosed computed tomography as acute cerebral infarction. We divided that patients into two groups. The experimental group was 13, took median $4.17{\pm}1.72hrs$ to admission after stroke attack and the comparison group 11, median $4.31{\pm}2.72hrs$ to admission after stroke attack. There was no statistical difference in time consumed from stroke onset to admission(P>0.05). Muscle weakness was measured on admission and 7 days later on AMA(American Medical Association) method. In the experimental group, muscle weakness on admission was $2.23{\pm}0.51$ and $2.79{\pm}0.72$ in upper and lower extremity, respectively. In comparison group, muscle weakness on admission was $2.17{\pm}0.43$ and $2.67{\pm}0.82$ in upper and lower extremity, respectively. There was no difference in muscle weakness(P〈0.05). In 7 days after, muscle weakness was $2.31{\pm}0.35$ in upper extremity and $3.15{\pm}0.12$ in lower extremity in experimental group, and $2.27{\pm}0.74$ in upper extremity and $3.45{\pm}0.48$, lower extremity in comparison group. There was no meaningful improvement statistically in upper extremity(p<0.05) but significant evolution in lower extremity(p<0.05). The muscle weakness comparison between admission time and 7 days later was as follows. Experimental group had improvement at the degree of $0.24{\pm}0.92$, $0.42{\pm}0.82$ in upper and lower extremity, respectively and comparison group, $0.12{\pm}0.82$, $0.27{\pm}0.97$ in same part(p<0.05). So, Dansamhwanotang administered group had more good muscle weakness improvement than Sopungtang administered group(P>0.05). From the above result, I suppose that circulating blood and extinguishing blood stasis method helps recover hemiparesis caused by acute ischemic cerabral disease, in acute stage at least.