• Title/Summary/Keyword: Non-linear contact

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Gender Differences in Trajectories of Successful Aging Indicators: Findings from Korean Longitudinal Study of Aging (다층모형 분석을 활용한 한국 노인의 성공적 노화 지표들의 변화궤적 연구: 남녀 차이 검증을 중심으로)

  • Lee, Hyunyup;Lee, Hye Soo
    • 한국노년학
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    • v.39 no.4
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    • pp.977-996
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    • 2019
  • The current study aimed to examine the gender differences in trajectories of nine successful aging indicators (chronic disease, depression, activities of daily living, instrumental activities of daily living, mini mental state examination, social activity, personal contact, health satisfaction, and general life satisfaction) with age, controlling the effect of education. The data were from the Korean Longitudinal Study of Aging, which had been conducted biennially from 2006 to 2016. The sample included 822 men and 1,236 women who responded to all of the panel surveys and were 65 years old or above in 2006. Multilevel modeling analyses showed that older men had fewer chronic diseases; lower levels of depression; higher levels of activities of daily living, cognitive function, and social activity; and better perceived health satisfaction and general life satisfaction at age 65 years compared to women. However, both men and women showed increase in the number of chronic diseases and depression level, and decrease in physical, cognitive, and social functions with age. In addition, perceived health and life satisfaction also decreased after the age of 65. The trajectories of most of the indicators were non-linear, and markedly increased or decreased around mid-70s. Study limitations and implications were further discussed.

THREE-DIMENSIONAL FINITE ELEMENT ANALYSIS OF THE PHENOMENON PRODUCED DURING RETRACTION OF FOUR MAXILLARY INCISORS (상악 4절치의 후방견인시 나타나는 현상에 관한 유한요소법적 분석)

  • Cheon, Ok-Jin;Kim, Tae-Woo;Suhr, Cheong-Hoon
    • The korean journal of orthodontics
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    • v.25 no.5 s.52
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    • pp.525-541
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    • 1995
  • This study was designed to investigate force systems and tooth movements produced by retraction archwire during retraction of four maxillary incisors after the maxillary canine retraction into the maxillary first premolar extraction space using the computer-aided three-dimensional finite element method. A three-dimensional finite element model, consisting of 2248 elements and 3194 nodes, was constructed. The model consisted of maxillary teeth and surrounding periodontal membranes, .022'$\times$.028'-slot brackets, and 5 types of retraction archwires(.019'$\times$.025' stainless steel archwire) modeled using the beam elements. The contact between the wire and the bracket slot was modeled using the gap elements because of the non-linear elastic behaviors of the contact between them. The forces and moments, End displacements produced by retraction archwire were measured at various conditions to investigate the difference according to types of loops, magnitudes of activation force, gable angle, and anterior lingual root torque. The results were expressed quantitative and visual ways in the three-dimensional method. The following conclusions can be drawn from this study.1. When the tear-drop loop archwire was activated, the mesio-distal and lingual translational movements of the teeth helped to close the extraction space, but unwanted movements of the teeth including intrusions and extrusions, and rotational movements in each direction occurred. 2. Activation of T-loop archwire compared with those of other types of retraction archwires produced the least translational movements of the teeth helped to space closure and also the least unwanted movements of the teeth. 3. Increasing amount of activation in the tear-drop archwire led not only to increase of translational movements of the teeth helped to space closure, but also to increase of unwanted movements of the teeth. 4. Addition of gable bend in the tear-drop archwire helped anterior teeth to translational movements in the mesio-distal direction, but increased unwanted movements of the teeth 5. Addition of anterior lingual root torque in the tear-drop archwire helped central and lateral incisor to improve their facio-lingual inclination, but increased unwanted movements of the teeth.

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Geochemistry of Granites in the Southern Gimcheon Area of Korea (김천남부에 분포하는 화강암류의 지구화학)

  • 윤현수;홍세선
    • The Journal of the Petrological Society of Korea
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    • v.12 no.1
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    • pp.16-31
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    • 2003
  • The granites in the southern Gimcheon area can be divided into two parts, marginal hornblende biotite granodiorite (Mgd) and central biotite granodiorite to granite (Cgd). Mgd and Cgd are gray in color and display gradational contact relations and are mainly composed of coarse-grained and medium-grained rocks, respectively. Mgd has more frequent and larger mafic enclaves than Cgd, and the two granites partly show parallel foliation at thire contact with gneisses. From representative samples of the granites, K-Ar biotite ages of 197∼207 Ma were obtained. Considering the blocking temperature of biotite, it is suggested that the emplacement age of the granitic magma was probably late Triassic. The anorthite contents of plagioclases in Mgd display less variation than those of Cgd, indicating that Mgd crystallized within a narrow range of temperatures. In the Al$\_$total/-Mg diagram, the biotites from the granites plot within the subalkaline field, and the smooth slope indicates differentiation from a single magma. All amphiboles from the granites belong to magnesio-hornblende. The linear trends of major oxides, AFM and Ba-Sr-Rb indicate that Mgd and Cgd were fractionally differentiated from a single granitic magma body crystallizing from the margin inwards. The relations of modal (Qz+Af) vs. Op, K$_2$O vs. Na$_2$O, Fe$_2$ $O_3$ vs. FeO, Fe$\^$+3/(Fe$\^$+3/+Fe$\^$+2/) and K/Rb vs. Rb/Sr show that they belong to I-type and magnetite-series granitic rocks developed by the progressive melting products of fixed sources. REE data, normalized to chondrite value, have trends of enriched LREE and depleted HREE together with weakly negative Eu anomalies.