• 대한수학회보
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• 제55권2호
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• pp.591-598
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• 2018

This paper is concerned with global existence of weak solutions to the relativistic Vlasov-Klein-Gordon system. The energy of this system is conserved, but the interaction term ${\int}_{{\mathbb{R}}^n}\;{\rho}{\varphi}dx$ in it need not be positive. So far existence of global weak solutions has been established only for small initial data [9, 14]. In two dimensions, this paper shows that the interaction term can be estimated by the kinetic energy to the power of ${\frac{4q-4}{3q-2}}$ for 1 < q < 2. As a consequence, global existence of weak solutions for general initial data is obtained.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제51권3호
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• pp.107-115
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• 2002

This parer presents the analysis of hot gas flow in puffer-type circuit breakers using FVFLIC method. For the analysis of arc-flow interaction, the flow field is analyzed from the equations of conservation for mass, momentum and energy with the assumption of local thermodynamic equilibrium state. The arc is represented as the energy source term composed of ohmic heating and radiation term in the energy conservation equation. Ohmic heating is computed by the electric field analysis only within the conducting plasma region. An approximate radiation transport model is employed for the evaluation of emission and absorption of the radiation. The analysis method was applied to the real circuit breaker model and simulation results such as pressure rise and arc voltage were compared with the experimental ones.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.41-42
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• 2006

The important factor to evaluate the running safety of a railway vehicle would be the interaction force between wheel and rail(derailment coefficient), for which is one of important factors to check the running safety of a railway vehicle that may cause a tragic accident. In this paper, analysis of coupling term between vertical load and lateral load for install load cell to wheel-set. This result is going to be utilized in formality that verify running safety of tilting vehicles.

• 한국병원경영학회지
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• 제15권4호
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• pp.27-42
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• 2010

The purpose of this study is to investigate the intention to utilize u-healthcare services in Korea. Specifically, this study attempted to identify the relationships among the intention to use u-healthcare, consumer's demographic characteristics, and personal information technology level. We conducted telephone interview and collected data from 406 householders 20 years old or older. The results showed significant differences in use intention of u-healthcare service by innovation, gender, and their interaction term. Residence area and average time of internet use had significant effect on the use intention of u-healthcare service. Also, the interaction term between innovation and education level had a significant effect on use intention. Based on the results we concluded that the consumer's characteristics and information technology level had a significant effect on the use intention of u-healthcare service.

• 대한기계학회논문집
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• 제17권12호
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• pp.3196-3207
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• 1993

A second moment turbulent closure for the turbulent heat flux near a wall is developed by modification of model constants in pressure interaction term as the variables of the turbulent Reynolds number using the universal properties of turbulent heat flux near the wall. The present model shows that model constant for the wall reflection term in pressure interaction is most important in modelling of the near wall heat flux. Fully developed pipe flows with constant wall heat flux are tested to validate the proposed model. In most of calculation region, the predicted turbulent properties agree better with the experimetal data than the results from standard algebraic heat flux model which use the uniform model constants.

• 보건행정학회지
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• 제24권4호
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• pp.380-388
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• 2014

Background: The volume of surgery has been examined as a major source of variation in outcome after surgery. This study investigated the direct effect of surgery volume to in hospitals mortality and the moderating effect of structural complexity-the level of diversity and sophistication of technology a hospital applied in patient care-to the volume outcome relationship. Methods: Discharge summary data of 11,827 cancer patients who underwent surgery and were discharged during a month period in 2010 and 2011 were analyzed. The analytic model included the independent variables such as surgery volume of a hospital, structural complexity measured by the number of diagnosis a hospital examined, and their interaction term. This study used a hierarchical logistic regression model to test for an association between hospital complexity and mortality rates and to test for the moderating effect in the volume outcome relationship. Results: As structural complexity increased the probability of in-hospital mortality after cancer surgery reduced. The interaction term between surgery volume and structural complexity was also statistically significant. The interaction effect was the strongest among the patients group who had surgery in low volume hospitals. Conclusion: The structural complexity and volume of surgery should be considered simultaneously in studying volume outcome relationship and in developing policies that aim to reduce mortality after cancer surgery.

• Archives of Pharmacal Research
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• 제18권5호
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• pp.301-307
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• 1995

In the particulate fraction obtained from PKC-down regulated K562 cells by treatment for 24 h with 200nM TPA, phosphorylation of two proteins with molecular weight, 100 kDa and 23 kDa (designated p100 and p23, respectvely) was depleted and addition of exogenous purified PKC to this fraction failed to testore their phosphorylation. However, in the soluble fraction, all of phosphoproteins abolished by long-term treatment with TPA were restored by exogenously added PKC. Phosphorylation of two proteins was increased by short-term tretment (20 min), and diminished with the persistant exposure to TPA as well as at a concentration as low as 1nM. When K562 cells were treated with 1 nM and 200 nM TPA for 24 h, phosphorylation of p100 was restored with or without exogenous PKC on 2-3day and 6day after removal of treated TPA, respectively. Two-dimensional electrophoresis of phosphoproteins revealed that phosphorylated p100 (pl=5.9) and p66 species were completely absent from the particulate fraction of K562 cells treated with 200nM TPA for 24 h. These results suggest that the interaction of sensitive endogenous substrates, p100 and p23 with the plasma membrane might be regulated by PKC-down regulation without displacement to the cytosol and the interaction of p100 with the membrane might be reveersible.

• Journal of Magnetics
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• 제3권4호
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• pp.105-111
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• 1998

The low energy excitations of spin waves (SWR) in thin films can be used for determination of the surface anisotropy constant and the nonhomogeneities of magnetization in the close-to-surface layer. The dispersion relation in SWR is sensitive on the geometry of experiment. We report on temperature dependence of surface magnetic anisotropy energy constant in magnetic semiconductor thin films of$ CdCr_{2-2x}In_{2x}Se_4$ at spin glass state. Samples were deposited by rf sputtering technique on Corning glass substrate in controlled temperature conditions. Coexistence of the infinite ferromagnetic network (IFN) and finite spin slusters (FSC) in spin glass state (SG) is know phenomena. Some behavior typical for long range magnetic ordering is expected in samples at SG state. The spin wave resonance experiment (microwave spectrometer at X-band) with excited surface modes was applied to describe the energy state of surface spins. We determined the surface magnetic anisotropy energy constant versus temperature using the surface inhomogeneities model of magnetic thin films. It was found that two components contribute to the surface magnetic anisotropy energy. One originates from the exchange interaction term due to the lack of translation symmetry for surface spin as well as from the originates from the exchange interaction term due to the lack of translation symmetry for surface spin as well as from the stray field of the surface roughness. The second one comes from the demagnetizing field of close-to surface layer with grad M. Both term linearly decrease when temperature is increased from 5 to 123 K, but dominant contribution is from the first component.

• International journal of advanced smart convergence
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• 제8권2호
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• pp.18-29
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• 2019

In the field of Human-Computer Interaction design, persuasive design has gradually been applied to the system development and design process, especially for mobile application design. However, most mobile applications have hitherto a very short using lifecycle. Especially, design features with long-term persuasive effectiveness remain to be further researched and developed. In this study, we focused on investigating and identifying the durative persuasive design characteristics through a data mining process and evaluating the durative effectiveness through a long-term observation process. Total five hundred healthcare-related mobile applications were selected from Apple iTunes Store and a mixed method was conducted to extract the most common persuasive design characteristics. Based on the results of extraction, a representative healthcare-related mobile application was selected as experimental subject. Total one hundred and twenty participants were observed during a six-months experiment and the monitoring data of app usage of all participants was collected once a week. According to the evaluation model for behavior change identification process, participants with habit formation features were proved to have a significant long-term perception level for ten persuasive design characteristics. Further interview research was performed to investigate the participant's long-term perceptions on those characteristics for the purpose of identifying the durative persuasions. The results indicated that a long-term durative effectiveness can be observed and healthcare-related apps designed with those characteristics could have durative effectiveness. This study may contribute to the improvement of future mobile application designs in user experience and durative persuasion, as well as bringing future benefits for both mobile application developers and users.

• 대한통합의학회지
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• 제9권4호
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• pp.91-103
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• 2021

Purpose : This study aimed to evaluate the effects of a cognitive enhancement brain yoga program on short-term memory and serum brain-derived neurotrophic factor (BDNF) levels according to the cognitive state in men aged 20-29 years. Methods : Thirty healthy volunteers aged 20-29 years were divided into four groups: brain yoga group, yoga group, combined exercise group, and control group. Seven people were assigned randomly per group. A single-session intervention was conducted over 50 min and consisted of three parts: warm-up, main exercise (brain yoga, yoga, combined exercise, or non-exercise), and cool-down. Serum BDNF levels were measured using enzyme-linked immunosorbent assay, and short-term memory was evaluated using the forward number span test before and after the intervention. Results : BDNF levels significantly increased within the brain yoga group after the intervention (from 28874.37±5185.57 to 34074.80±7321.12, p=.003), whereas there were no significant differences pre-and post-intervention in the other groups. The inter-group comparison showed a significant interaction between the brain yoga group and the combined exercise group (p=.036) but no significant interaction between any of the other groups. Forward number span scores were significantly increased in the brain yoga group (from 9.43±9.83 to 23±7.92, p=.012) and theyoga group after the intervention (from 13.43±9.41 to 24.14±8.45, p=.011), whereas there were no significant changes after the intervention in any other groups. Conclusion : Our findings showed that a single-session, 50-minute brain yoga exercise improved short-term memory and increased serum BDNF levels in healthy men aged 20-29 years and that yoga improved only short-term memory in healthy men of this age group.