• Journal of The Korean Astronomical Society
• /
• v.42 no.3
• /
• pp.55-60
• /
• 2009

The properties of SOHO/LASCO CMEs are subjected to projection effects. Their dependence on the source position is important to be studied. Our main aim is to study the dependence of CME properties on helio-longitude and latitude using the CMEs associated with type IIs observed by Wind/WAVES spacecraft (Deca-hecta metric type IIs - DH type IIs). These CMEs were identified as a separate population of geo-effective CMEs. We considered the CMEs associated with the Wind/WAVE type IIs observed during the period January 1997 - December 2005. The source locations of these CMEs were identified using their associated GOES X-ray flares and listed online. Using their locations and the cataloged properties of CMEs, we carried out a study on the dependence of CME properties on source location. We studied the above for three groups of CMEs: (i) all CMEs, (ii) halo and non-halo CMEs, and (iii) limb and non-limb CMEs. Major results from this study can be summarized as follows. (i) There is a clear dependence of speed on both the longitude and latitude; while there is an increasing trend with respect to longitude, it is opposite in the case of latitude. Our investigations show that the longitudinal dependence is caused by the projection effect and the latitudinal effect by the solar cycle effect. (ii) In the case of width, the disc centered events are observed with more width than those occurred at higher longitudes, and this result seems to be the same for latitude. (iii) The dependency of speed is confirmed on the angular distance between the sun-center and source location determined using both the longitude and latitude. (iv) There is no dependency found in the case of acceleration. (v) Among all the three groups of CMEs, the speeds of halo CMEs show more dependency on longitude. The speed of non-halo and non-limb CMEs show more dependency on latitude. The above results may be taken into account in correcting the projection effects of geo-effective CMEs.

• Journal of IKEEE
• /
• v.22 no.3
• /
• pp.664-671
• /
• 2018

Generally, conventional solar tracking systems employ irradiance sensors to track a sun position, which enables the system to generate maximum solar energy. The usage of irradiance sensors increases system costs and deteriorates the performance of systems from sensor malfunctions. In this paper, a new solar tracking system without irradiance sensors has been proposed in which the controller capable of controlling and monitoring remotely is based on Artik platform. The proposed system tracks the sun position by comparing the amount of currents from several solar panels, resulting in removing irradiance sensors. In order to verify the performance of the proposed solar tracking method, the 12[V]-20[W] prototype system is built and implemented. Since the proposed system has remote monitoring functions through the employment of Artik as the IoT platform, more advantages in installation, maintenance and expanded functionality can be obtained compared to the conventional solar tracking system.

• Journal of Astronomy and Space Sciences
• /
• v.14 no.1
• /
• pp.136-141
• /
• 1997

To calculate the position and velocity of the artificial satellite precisely, one has to build a mathematical model concerning the perturbations by understanding and analysing the space environment correctly and then quantifying. Due to these space environment model, the total acceleration of the artificial satellite can be expressed as the 2nd order differential equation and we build an orbit propagation algorithm by integrating twice this equation by using the Cowell's method which gives the position and velocity of the artificial satellite at any given time. Perturbations important for the orbits of geostationary spacecraft are the Earth's gravitational potential, the gravitational influences of the sun and moon, and the solar radiation pressure. For precise orbit propagation in Cowell' method, 40 x 40 spherical harmonic coefficients can be applied and the JPL DE403 ephemeris files were used to generate the range from earth to sun and moon and 8th order Runge-Kutta single step method with variable step-size control is used to integrate the the orbit propagation equations.

• Journal of Digital Convergence
• /
• v.12 no.3
• /
• pp.243-248
• /
• 2014

Recently, solar energy is expanding to combination of computing in real time by tracking the position of the sun to estimate the angle of inclination and make up freshly correcting a part of the solar radiation. Solar power is need that reliably linked technology to power generation system renewable energy in order to efficient power production that is difficult to output predict based on the position of the sun rise. In this paper, we analysis of prediction model for solar power generation to estimate the predictive value of solar power generation in the development of real-time weather data. Photovoltaic power generation input the correction factor such as temperature, module characteristics by the solar generator module and the location of the local angle of inclination to analyze the predictive power generation algorithm for the prediction calculation to predict the final generation. In addition, the proposed model in real-time national weather service forecast for medium-term and real-time observations used as input data to perform the short-term prediction models.

• Journal of Preventive Medicine and Public Health
• /
• v.39 no.4
• /
• pp.359-364
• /
• 2006

Objectives: The object of this study is to assess the relationship between socioeconomic factors and the predicted 10-year risk of cardiovascular disease by using health risk appraisal of ischemic heart disease. Methods: The study population was taken from The 2001 Korea National Health and Nutrition Survey, and it consisted of 1,566 men and 1,984 women aged 30-59. We calculated 10-year risk using the risk function of ischemic heart disease as developed by Jee. The educational level and equivalized household income were dichotomized by a 12 years education period and the median income level. Occupation was dichotomized into manual/non-manual work. We stratified the population by age(10 years) and sex, and then we rated the risk differences according to socioeconomic factors by performing t-tests for each strata. Results: There were gradients of the predicted 10-year risk of ischemic heart disease with the educational level and the equivalized household income, and thet was an increasing tendency of risk differences with age. Manual workers didn't show significant risk difference from non-manual workers. Conclusions: There was definite relationship between low socioeconomic position and the predicted risk of ischemic heart disease in the future.

• Journal of Sasang Constitutional Medicine
• /
• v.14 no.2
• /
• pp.98-105
• /
• 2002

Purpose This study was carried out to investigate the correlation between Sasang constitution and lL-4 polymorphism of Atopy gene. Methods 1. We have selected 165 cases of DNA samples from individuals with proven history of Atopy symptom and Sasang constitution. 2. The lL-4 589C-T polymorphism was genotyped by PCR-restriction fragment length polymorphism analysis. Result They were divided six groups as the history of atopy and age. There is no group shown statistical correlation in the result of constitutional lL-4 polymorphism typing. Conclusion 1. In the total groups, lL-4 polymorphism(589C-T change of 5q31-33 position) were noted 0.727 on Soumin, 0.790 on Soyangin and 0.809 on Taeumin. It was larger on Taeumin, but there is no stastical difference between. 2. In the Atopy groups, lL-4 polymorphism(589C-T change of 5q31-33 position) were noted 0.682 on Soyangin, 0.750 on Taeumin and 0.807 on Soumin. It was larger on Soumin, but there is no stastical difference between constitution.

• Journal of Convergence for Information Technology
• /
• v.9 no.8
• /
• pp.53-62
• /
• 2019

This study is a descriptive study to investigate the relationship between verbal violence type, emotional response and coping in the operating room nurse. The subjects of the study were 400 nurses working in 20 general hospitals and 372 nurses in the operating room. As a result of the analysis, it was found that the perpetrators of the verbal violence experienced by the subject were physicians, direct supervisors, and more than half of the subjects were considering the transition. The most frequent cases of language violence were when the equipment was inoperable or not used during surgery, There were significant differences in verbal violence experience according to marriage, clinical career, and work style. Language violence emotional response showed significant difference with gender, position and coping, age, academic background, clinical career, and position. There was a significant correlation between experience of verbal violence and emotional response, emotional response and coping. Therefore, the results of this study will contribute to the development of coping strategies and prevention education programs.

• Archives of Orthopedic and Sports Physical Therapy
• /
• v.14 no.2
• /
• pp.1-8
• /
• 2018

Purpose: This study investigated the effect of the augmented reality (AR)-based knee joint short period exercise program and used a motion analyzer with a 3D camera to determine the range of motion and dynamic balance and further investigate the effects of therapeutic exercise on patients. Methods: This study used AR-based motion analysis and a Y-balance test to measure the range of motion (ROM) of each joint: the hip joint and the knee joint. After the measurements, an exercise program was applied to the subjects, using the knee motion program function, and the muscles of the quadriceps femoris and the hamstring were stretched or strengthened. Results: Our results showed knee joint extension at the dominant hip joint flexion position. While there was no significant difference (p>.05) at this position, there were significant differences in the non-dominant hips, unbalanced knee joint flexion, and superior knee joint flexion (p<.05). The Y-balance test using the non-dominant leg supported by the dominant legs showed that the absolute reach was $69.70{\pm}7.06cm$ before the exercise, and the absolute reach after the exercise was $77.56{\pm}6.09cm$ (p<.05). Conclusions: There was a significant difference when the movement of the lower limbs supported the superior limbs, and a significant difference was found in the ROM when the non-dominant side supported the dominant side. Therefore, the AR-based exercise program improves the balance of the human body and the range of motion of the joints, and research that aims to improve patients abilities should continue.

• Physical Therapy Korea
• /
• v.22 no.3
• /
• pp.33-40
• /
• 2015

The purpose of this study was to investigate the effect of multi joint-joint position sense (MJ-JPS) training on joint position sense, balance, and gait ability in stroke patients. A total of 18 stroke patients participated in the study. The subjects were allocated randomly into two groups: an experimental group and a control group. Participants in the experimental group received MJ-JPS training (10 min) and conventional treatment (20 min), but participants in the control group only received conventional treatment (30 min). Both groups received training for five times per week for six weeks. MJ-JPS is a training method used to increase proprioception in the lower extremities; as such, it is used, to position the lower extremities in a given space. MJ-JPS measurement was captured via video using a Image J program to calculate the error distance. Balance ability was measured using Timed Up and Go (TUG) and the Berg Balance Scale (BBS). Gait ability was measured with a 10 m walking test (10MWT) and by climbing four flights of stairs. The Shapiro-Wilk test was used to assess normalization. Within-group differences were analyzed using the paired t-test. Between-group differences were analyzed using the independent t-test. The experimental group showed a significant decrease in error distance (MJ-JPS) compared to the control group (p<.05). Both groups showed a significant difference in their BBS and 10MWT results (p<.05). The experimental group showed a significant decrease in their TUG and climbing results (p<.05), but the control group results for those two tasks were not found to be significant (p>.05). There was significant difference in MJ-JPS and by climbing four flights of stairs on variation of pre and post test in between groups (p<.05), but TUG and BBS and 10MWT was no significantly (p>.05). We suggest that the MJ-JPS training proposed in this study be used as an intervention to help improve the functional activity of the lower extremities in stroke patients.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.35 no.2C
• /
• pp.246-253
• /
• 2010

In this paper, a method of removing the space skew and cross-talk cancellation is proposed where the self-generated signals from the subject are used to obtain the subject's location. In the proposed method, the good spatial sound image is maintained even when the listener moves from the sweet spot. Two major parts of the proposed method are as follows: listener position tracking using the stimuli from the subject and removal of the space skew and cross-talk signals. Listener position tracking is achieved by estimation of the time difference of arrival (TDoA). The position of the listener is then computed using the Talyer-series estimation method. The head-related transfer functions (HRTF) are used to remove the space skew and cross-talk signals, where the direction of the HRTF is given by the one estimated from the listener position tracking. The performance evaluation is carried out on the signals from the 100 subjects that are composed of the 50 female and 50 male subjects. The positioning accuracy is achieved by 70%~90%, under the condition that the mean squared positioning error is less than $0.07m^2$. The subjective listening test is also conducted where the 27 out of the 30 subjects are participated. According to the results, 70% of the subjects indicates that the overall quality of the reproduced sound from the proposed method are improved, regardless of the subject's position.