• Title/Summary/Keyword: School Size

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Energy barrier of nanomagnet with perpendicular magnetic anisotropy

  • Song, Kyungmi;Lee, Kyung-Jin
    • Proceedings of the Korean Magnestics Society Conference
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    • 2014.05a
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    • pp.120-121
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    • 2014
  • We investigate the field-dependence of energy barrier for various cell diameters and two type of geometry through the NEB method. We find that the energy barrier can depend strongly on the cell size when the switching is governed by the domain wall motion. Moreover we also examine the cell size dependence of energy barrier for two type of cell geometry. In the presentation, we will discuss the effect of domain wall formation and more various cell size on the energy barrier in detail.

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Effect of Reaction Conditions on the Preparation of Nano-sized Ni Powders inside a Nonionic Polymer

  • Kim, Tea-Wan;Kim, Dong-Hyun;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.462-463
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    • 2006
  • Monodispersed and nano-sized Ni powders were synthesized from aqueous nickel sulfate hexahydrate $(NiSO_4{\cdot}6H_2O)$ inside nonionic polymer network by using wet chemical reduction process. The sucrose was used as a nonionic polymer network source. The effect of reaction conditions such as the amount of sucrose and a various reaction temperature, nickel sulfate hexahydrate molarity. The influence of a nonionic polymer network on the particle size of the prepared Ni powders was characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), and particle size analysis (PSA). The results showed that the obtained Ni powders were strong by dependent of the reaction conditions. In particular, the Ni powders prepared inside a nonionic polymer network had smooth spherical shape and narrow particle size distribution.

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Fundamental study on volume reduction of cesium contaminated soil by using magnetic force-assisted selection pipe

  • Nishimura, Ryosei;Akiyama, Yoko;Manabe, Yuichiro;Sato, Fuminobu
    • Progress in Superconductivity and Cryogenics
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    • v.23 no.3
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    • pp.26-31
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    • 2021
  • Advanced classification of Cs contaminated soil by using a magnetic force-assisted selection pipe was investigated. A selection pipe is a device that sort particles depending on their particle size, based on the relationship between buoyancy, drag, and gravity force acting on the particles. Radioactive cesium is concentrated in small-particle size soil components with a large specific surface area. Hence, the volume of the Cs contaminated soil can be reduced by recycling the large-particle size soil components with low radioactive concentration. One of the problems of the selection pipe was that the radioactive concentration of the stayed soil in the selection pipe exceeds 8000 Bq/kg, which is the standard value of recycling of Cs contaminated soil, due to low classification accuracy. In this study, magnetic fields were applied to the lab-scale selection pipe from upper side to improve the classification accuracy and to reduce the radioactive concentration of the stayed soil.

A Case of Multi-Organ Macronodular Tuberculosis (다기관성 대결절성 결핵 1예)

  • Lim, Kyoung-Ree;Kang, Myung-Ho;Kim, Tae-Suk;Moon, Ki-Won;Ryu, Dong-Ryeol;Lee, Hui-Young;Han, Seon-Sook
    • Tuberculosis and Respiratory Diseases
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    • v.72 no.1
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    • pp.88-92
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    • 2012
  • A 37 year old female presented with epigastric pain and weight loss over a period of 3 months. Her abdominal CT finding showed a 4.5 cm size hepatic mass and 4.3 cm size pancreatic head mass with multiple macronodules in the liver. At the same time, her chest CT revealed a 5 cm size necrotic mass in the left lower lobe of the lung with multiple bilateral pulmonary nodules. We diagnosed these lesions as tuberculosis through multiple biopsies. She was treated with anti-tuberculous medication. After taking the medications, her symptoms were improved. Twelve months later, imaging studies indicated an improvement in the patient's health. Here we report a case report of multi-organ macronodular tuberculosis in lung, liver and pancreas.

The Effects of Age, Gender and Head Size on the Cortical Thickness of Brain (연령, 성별, 머리 크기가 대뇌 피질 두께에 미치는 효과)

  • Park, Yunyoung;Kim, Siekyeong
    • Korean Journal of Biological Psychiatry
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    • v.22 no.3
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    • pp.118-127
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    • 2015
  • Objectives Standardization of head size is essential for the volume study. Cortical thickness analyses are increasingly being used in many fields of neuroscience. However, it is not established whether head size correction should be done for thickness study. Methods Using the Open Access Series of Imaging Studies data, we determined cortical thickness of 316 cognitively normal participants aged 18-94 with FreeSurfer. The association between head size and cortical thickness of whole cortical mantle and in each lobe among age tertile groups was assessed. Estimated total intracranial volume (eTIV) was calculated for determining head size. Results Across all participants, cortical thickness in whole brain except some areas in cingulate and insula decreased with aging. eTIV had positive correlation with the thickness of frontal, parietal, occipital and whole brain areas. However, the age effect was not shown in whole brain of the first tertile group and in cingulate areas of the third tertile group. eTIV had negative correlation with the thickness of cingulate in the third tertile group. Gender effects were shown in some areas in third tertile group, but it would be due to difference of head size. Conclusions These findings suggest that head size standardization might be done especially in older population and in studies of paralimbic areas.

Patch size adaptive image inpainting

  • Liu, Huaming;Lu, Guanming;Bi, Xuehui;Wang, Weilan
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.15 no.10
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    • pp.3642-3667
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    • 2021
  • Texture synthesis technology has the advantages of repairing texture and structure at the same time. However, during the filling process, the size of the patch is fixed, and the content of the filling is not fully considered. In order to be able to adaptively change the patch size, we used the exemplar-based inpainting technique as the test algorithm, considering the image structure and texture, calculated the image structure patch size and texture patch size, and comprehensively determined the image patch size. This can adaptively change the patch size according to the filling content. In addition, we use multi-layer images to calculate the priority, so that the order of image repair was more stable. The proposed repair algorithm is compared with other image repair algorithms. The experimental results showed that the proposed adaptive image repair algorithm can better repair the texture and structure of the image, which proved the effectiveness of the proposed algorithm.

Predictors of Lymph Node Metastasis in Submucosal Gastric Carcinomas (점막하 위암에서 림프절 전이에 영향을 미치는 인자)

  • Ko Seong Ju;Suh Jae Hwan;Park Heung Kyu;Lee Hoon Gyu;Cho Seung Yeon;Lee Woon Gi;Lee Jeong Nam;Lee Young Don;Cho Hyun Yee
    • Journal of Gastric Cancer
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    • v.1 no.3
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    • pp.155-160
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    • 2001
  • Purpose: Submucosal gastric carcinomas metastasize to lymph nodes more often than the intramucosal gastric carcinomas. The objectives of this study are to clarify the characteristics of submucosal gastric carcinomas, especially in reference to the status of lymph node metastasis, and to explore the possibility of a minimally invasive operation. Materials and Methods: The clinicopathologic features of 88 patients with submucosal gastric carcinoma, all of whom were treated with a $D_{2}+\alpha$ gastrectomy between January 1994 and December 1999, were examined retrospectively with respect to the status of lymph nodes. The size, depth of submucosal invasion, histologic differentiation, location,and macroscopic finding of the tumor were investigated in association with the presence or the absence of lymph node metastasis. Results: Among the 88 patients, 15 ($17.05\%$) had lymph node metastasis, and the status of metastasis was significantly correlated with tumor size and depth of submucosal invasion. The frequency of metastasis was $0\%$ (0/7) of up to 1.0 cm and $18.5\%$ (15/81) over 1.0 cm in size (p=0.034) and $6.1\%$ (2/33) of up to 1.0mm and $23.6\%$ (13/55) over 1.0 mm in depth of submucosal invasion (p=0.042). Conclusion: The tumor size and depth of submucosal invasion are useful indicators of lymph node metastasis in submucosal gastric carcinoma. A minimally invasive operation can be applied for submucosal gastric carcinoma up to 1.0 cm in size Further studies are needed to limited surgery for depth of submucosal invasion.

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Effect of Dispersant on the Characterization of Cu Powders Prepared with Wet-reduction Process (액상-환원법으로 합성된 Cu 분말의 특성에 미치는 분산제의 영향)

  • Kim, Yong-Yee;Kim, Tea-Wan;Park, Hong-Chae;Yoon, Seog-Young
    • Korean Journal of Materials Research
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    • v.17 no.1
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    • pp.50-55
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    • 2007
  • Ultra-fine Copper powder for a conductive paste in electric-electronic field have been synthesized by chemical reduction of aqueous $CuSO_4$ with hydrazine hydrate $(N_2H_4{\cdot}H_2O)$ as a reductor. The effect of reaction conditions such as dispersant and reaction temperature on the particle size and shape for the prepared Cu powders was investigated by means of XRD, SEM, TEM and TGA. Experiments showed that type of dispersant and reaction temperature were affected on the particle size and morphology of the copper powder. When the carboxymethyl cellulose (CMC) was added as a dispersant the relative mono-dispersed and spherical Cu powder was obtained. Cu powders with particle size of approximately 140nm and narrow particle size distribution were obtained from 0.3M $CuSO_4$ with adding of 0.03M CMC and 40ml $N_2H_4{\cdot}H_2O$ at a reaction temperature of $70^{\circ}C$.

The compression-shear properties of small-size seismic isolation rubber bearings for bridges

  • Wu, Yi-feng;Wang, Hao;Sha, Ben;Zhang, Rui-jun;Li, Ai-qun
    • Structural Monitoring and Maintenance
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    • v.5 no.1
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    • pp.39-50
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    • 2018
  • Taking three types of bridge bearings with diameter being 100 mm as examples, the theoretical analysis, the experimental research as well as the numerical simulation of these bearings is conducted. Since the normal compression and shear machines cannot be applied to the small-size bearings, an improved equipment to test the properties of these bearings is proposed and fabricated. Besides, the simulation of the bearings is conducted based on the explicit finite element software ANSYS/LS-DYNA, and some parameters of the bearings are modified in the finite element model to reduce the computation cost effectively. Results show that all the research methods are capable of revealing the fundamental properties of the small-size bearings, and a combined use of these methods can better catch both the integral properties and the inner detailed mechanical behaviors of the bearings.

Application of the Leak Before Break(LBB) Concept to a Heat Exchanger in a Nuclear Power Plant

  • Kwon, Jae-Do;Lee, Choon-Yeol;Lee, Yong-Son;Sul, Il-Chan
    • Journal of Mechanical Science and Technology
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    • v.15 no.1
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    • pp.10-20
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    • 2001
  • The leak before break(LBB) concept is difficult to apply to a structure with a thin tube that is immersed in a water environment. A heat exchanger in a nuclear power plant is such a structure. The present paper addresses an application of the LBB concept to a heat exchanger in a nuclear power plant. The minimum leaked coolant amount(approximately 37.9 liters) containing the radioactive material which can activate the radiation detector device installed in near the heat exchanger is assumed. A postulated initial flaw size that can not grow to a critical flaw size within the time period to activate the radiation detector is justified. In this case, the radiation detector can activate the warning signal caused by coolant leakage from initially postulated flaws of the heat exchanger. The nuclear plant can safely shutdown when this occurs. Since the postulated initial flaw size can not grow to the critical flaw size, the structural integrity of the heat exchanger is not impeded. Particularly the informational scenario presented in this paper discusses an actual nuclear plant.

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