• Title/Summary/Keyword: School Size

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A Study of Stress, Coping Behaviors and Health Problems in School Age Children (학령기 아동의 스트레스와 대처행동 및 건강문제)

  • Kim Mi-Ye
    • Child Health Nursing Research
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    • v.11 no.1
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    • pp.83-89
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    • 2005
  • Purpose: The purpose of this study was to investigate the stress level, coping behaviors and health problems of elementary school children and to compare the level of these three variables according to size of city of residence and to identify the relationship among the three variables. Method: Data were collected by questionnaire from 465 5th and 6th grade elementary school children living in Daegu and North Kyungsang Province. Data were collected between December 1 and 20, 2003 and analyzed using the SPSS program with means, standard deviation, t-test, and Pearson's correlation coefficients. Results: The stress level was significantly higher in children who lived in the big city. The coping behavior score was not significantly different according to size of city, nor was there a difference in the health problems according to size of city. There was a positive correlation among stress level, coping behaviors and health problems. Conclusion: In general, the stress level was significantly different but coping behavior scores and health problem scores were not significantly different according to size of city. Also the elementary school children used more passive coping behavior than active coping behavior. Therefore, strategies to develop active coping behaviors for these children are needed.

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Effects of Post Annealing on the Electrical Properties of ZnO Thin Films Transistors

  • Moon, Mi Ran;An, Chee-Hong;Na, Sekwon;Jeon, Haseok;Jung, Donggeun;Kim, Hyoungsub;Lee, Hoo-Jeong
    • Applied Microscopy
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    • v.42 no.4
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    • pp.212-217
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    • 2012
  • This paper reports the effects of post-annealing of ZnO thin films on their microstructure and the device performance of the transistors fabricated from the films. From X-ray diffraction and transmission electron microscopy characterization, we uncovered that the grain size increased with the annealing temperature escalating and that the film stress shifted from compressive to tensile due to the grain size increment. Electrical characterization revealed that the grain size increase damaged the device performance by drastically lifting the off-current level. By annealing the devices in an $O_2$ ambient (instead of air), we were able to suppress the off-current while improving the electron mobility.

Preparation and Characterization of Polypropylene/Waste Ground Rubber Tire Powder Microcellular Composites by Supercritical Carbon Dioxide

  • Zhang, Zhen Xiu;Lee, Sung-Hyo;Kim, Jin-Kuk;Zhang, Shu Ling;Xin, Zhen Xiang
    • Macromolecular Research
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    • v.16 no.5
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    • pp.404-410
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    • 2008
  • In order to obtain 'value added products' from polypropylene (PP)/waste ground rubber tire powder (WGRT) composites, PP/WGRT microcellular foams were prepared via supercritical carbon dioxide. The effects of blend composition and processing condition on the cell size, cell density and relative density of PP/WGRT micro-cellular composites were studied. The results indicated that the microcellular structure was dependent on blend composition and processing condition. An increased content of waste ground rubber tire powder (WGRT) and maleic anhydride-grafted styrene-ethylene-butylene-styrene (SEBS-g-MA) reduced the cell size, and raised the cell density and relative density, whereas a higher saturation pressure increased the cell size, and reduced the cell density and relative density. With increasing saturation temperature, the cell size increased and the relative density decreased, whereas the cell density initially increased and then decreased.

Preparation and Characterization of Monodispersed and Nano-sized Cu Powders

  • Kim, Tea-Wan;Lee, Hyang-Mi;Kim, Yong-Yee;Hwang, Kyu-Hong;Park, Hong-Chae;Yoon, Seog-Young
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 2006.09a
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    • pp.464-465
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    • 2006
  • Monodispersed and nano-sized Cu powders were synthesized from copper sulfate pentahydrate $(CuSO_4{\cdot}5H_2O)$ inside a nonionic polymer matrix by using wet chemical reduction process. The sucrose was used as a nonionic polymer network source. The influences of a nonionic polymer matrix on the particle size of the prepared Cu powders were characterized by means of X-ray diffraction), scanning electron microscopy), and particle size analysis). The smallen Cu powders with size of approximately 100 nm was obtained with adding of 0.04M sucrose at reaction temperature of $60\;^{\circ}C$. The particle size of the Cu powders prepared by the reduction inside polymer network was strongly dependent of the sucrose content and reaction temperature.

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A Case Report on the Therapeutic Effect of Integrated Cancer Therapy for Glioblastoma Multiforme (교모세포종에 대한 통합암치료의 치료 효과 증례보고)

  • Yang, Jin-sung;Jang, Hyuk-jun;Song, Si-yeon;Park, Ji-hye;Park, So-jung;Yoo, Hwa-seung
    • The Journal of Internal Korean Medicine
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    • v.43 no.2
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    • pp.320-325
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    • 2022
  • Objective: The purpose of this report is to present the effects of integrative cancer treatment (ICT) on a patient diagnosed with glioblastoma multiforme (GBM). Methods: A 71-year-old male GBM patient received ICT from May 14 to October 12, 2021 and concurrently received temozolomide and radiotherapy. The effect on symptoms was evaluated using a visual analog scale (VAS), and changes in tumor size were assessed using magnetic resonance imaging. Results: After treatment, the VAS score for nausea decreased from 5 to 1, and the tumor size also reduced. Conclusion: ICT could be effective in treating GBM patients by reducing the size of the tumor as well as alleviating the side effects.

Adaptive Step-size Algorithm for the AIC in the Space-time Coded DS-CDMA System (시공간부호화된 DS-CDMA 시스템에서 적응스텝크기 알고리듬을 적용한 간섭제거수신기)

  • Yi, Joo-Hyun;Lee, Jae-Hong
    • Proceedings of the IEEK Conference
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    • 2004.06a
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    • pp.265-268
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    • 2004
  • In this paper. we propose an adaptive step-size algorithm for the adaptive interference canceller (AIC) in the space-time trellis coded DS-CDMA system. In the AIC, the performance of the blind LMS algorithms that updates the tap-weight vector of the AIC is heavily dependent on the choice of step-size. To improve the performance of the fixed step-size AIC (FS-AIC), the regular adaptive step-size algorithm is extended in complex domain and applied to the joint AIC and ML decoder scheme. Simulation results show that the joint adaptive step-size AIC (AS-AIC) and ML decoder scheme using the proposed algorithm has boner performance than not only the conventional ML decoder but also the joint FS-AIC and ML decoder scheme without much increase of the decoding delay and complexity.

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Particle size distributions and concentrations above radiators in indoor environments: Exploratory results from Xi'an, China

  • Chen, Xi;Li, Angui
    • Environmental Engineering Research
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    • v.20 no.3
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    • pp.237-245
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    • 2015
  • Particulate matter in indoor environments has caused public concerns in recent years. The objective of this research is to explore the influence of radiators on particle size distributions and concentrations. The particle size distributions as well as concentrations above radiators and in the adjacent indoor air are monitored in forty-two indoor environments in Xi'an, China. The temperatures, relative humidity and air velocities are also measured. The particle size distributions above radiators at ten locations are analyzed. The results show that the functional difference of indoor environments has little impact on the particle size distributions above radiators. Then the effects of the environmental parameters (particle concentrations in the adjacent indoor air, temperatures, relative humidities and air velocities) on particle concentrations above radiators are assessed by applying multiple linear regression analysis. Three multiple linear regression models are established to predict the concentrations of $PM_{10}$, $PM_{2.5}$ and $PM_1$ above radiators.

Exports, Firm Size, and Firm Dynamics : An Empirical Study on the Korean Manufacturing Industry (기업규모, 기업성장, 그리고 수출성과 : 우리나라 제조업에 대한 실증적 연구)

  • Sung, Tae-Kyung;Park, Kwang-Seo
    • Management & Information Systems Review
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    • v.22
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    • pp.1-23
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    • 2007
  • This paper investigates the relationships between exports, firm size, and firm dynamics. It is based on a longitudinal data covering listed firms in the Korean manufacturing industry. We found the stylized fact that the probability that a firm is exporter increases with firm size. A regression model for the determinant of export/sales ratio including dynamic adjustment process is tested on a cross-section sample for the year 2001. Empirical findings suggest that there is a positive and inversely U-shaped relationship between firm size and export/sales ratio, just for basic material and capital good industry. Except for firm size, the hypotheses concerning human capital intensity, physical capital intensity, R&D intensity, and patent are rejected. Using Granger causality test, we found that the rate of growth of total sales influences the change of the export/sales ratio with time lag for medium-sized firms. Finally, some policy implications are presented.

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A Quantitative Study of Grinding Characteristics on Particle Size and Grinding Consumption Energy by Stirred Ball Mill (입자경과 분쇄소비동력의 고찰에 의한 교반볼밀 분쇄특성의 정량적 연구)

  • Choi, Hee-Kyu;Wang, Lin
    • Korean Journal of Materials Research
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    • v.17 no.10
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    • pp.532-537
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    • 2007
  • A series of wet grinding experiments have been carried out using a stirred ball mill to systematically investigate consideration of grinding characteristics. The particle size distribution and median diameter of the grinding consumption power for a given grinding time were considered. Also, the effect of grinding aids on particle size and grinding consumption energy defined as the summation of grinding power was investigated. The grinding aids had influence on the smaller products size and decrease grinding consumption energy because the function of grinding aids were to be attribute to the prevention of agglomeration and ball and grinding chamber wall coating of sample powder. The grinding process seemed to be controlled by the force of agglomeration of the ground products. It was demonstrated that the particle size and grinding consumption energy could be more decreased by the addition of grinding aids.

Photoluminescence Characteristics of Eu-doped Yttrium Oxide Submicron-sized Particles Prepared by Aerosol Pyrolysis

  • Park, Il-Woo;Park, Chang-Kyun;Lee, Deok-Jin;Yoo, Jea-Soo
    • Transactions on Electrical and Electronic Materials
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    • v.4 no.1
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    • pp.29-33
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    • 2003
  • Europium doped yttrium oxide submicron-sized particles were prepared by ultrasonic aerosol pyrolysis. To examine the size effect of submicron-sized-particle, the photoluminescence of the particles was investigated. The particle size was controlled by pH, reaction temperature, molar concentration of yttrium in precursor solution. The PL intensity of submicron-sized particles was decreased with particles size. When the particle size is above about 150 times of Bohr radius of Y$_2$O$_3$, the optical property of the particles shows the bulk characteristics.