• Title, Summary, Keyword: Escape Theory

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On the origin of escape fractions of ionizing radiation from star-forming galaxies at high redshift

  • Yoo, Taehwa;Kimm, Taysun;Rosdahl, Joakim
    • The Bulletin of The Korean Astronomical Society
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    • v.44 no.2
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    • pp.73.2-73.2
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    • 2019
  • The physical origin of low escape fractions of ionizing radiation derived from Lyman-break galaxies (LBGs) at z ~ 3 - 4 is a puzzle in the theory of reionization. We perform idealized disk galaxy simulations to investigate how galactic properties, such as metallicity and gas mass, affect the escape of Lyman continuum (LyC) photons using radiation-hydrodynamic code RAMSES-RT, with strong stellar feedback. We find that the luminosity-weighted escape fraction from a metal-poor (Z=0.002) galaxy embedded in a halo of mass Mh ~ 1011 M⊙ is 〈f3Desc〉 ~ 8%. However, when the gas metallicity is increased to Z=0.02, the escape fraction is significantly reduced to 〈f3Desc〉 ~ 1%, as young stars are enshrouded by their birth clouds for a longer period of time. On the other hand, increasing the gas mass by a factor of 5 leads to 〈f3Desc〉 ~ 4%, as LyC photons are only moderately absorbed by the thicker disk. Our experiments seem to suggest that high metallicity is primarily responsible for the low escape fractions observed from LBGs, supporting the scenario in which the escape fraction has a negative correlation with halo mass. Indeed, our simulated galaxy with the typical metallicity of LBGs (Z=0.006) shows the relative escape fraction of 8%, consistent with recent observations of galaxies with M1500 = -20.

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Structural Relationship of School Risk Factors and Suicide Ideation in Adolescence, Based on 'Escape Theory' Model ('도피이론(Escape Theory)' 모형에 기반한 학교위험요인과 청소년 자살생각의 구조적 관계)

  • Park, Jae-Sook
    • Korean Journal of Social Welfare
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    • v.63 no.3
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    • pp.5-27
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    • 2011
  • This study was based on the 'Escape Theory' model suggested by Baumeister(1990). Based on this analysis framework, this study attempted to examine that complicated direct and indirect effect of school risk factors(risk of academic scores, risk of relation with teacher and risk of peer relation) on suicide ideation in adolescence, through negative self-esteem, depression and withdrawal coping. To this end, this study used the data from the '2008 Gyeongsangbuk-Do youth crisis survey' conducted by the Youth service center in province of Gyeongsangbuk-Do. The target number of this study was 2,335 students in the age group of middle school and high school. The result of the Analysis indicate that risk of relation with teacher among school risk factors was only one which affected directly and indirectly on suicide ideation. The other side, risk of academic scores and risk of peer relation had indirect effects, via negative self-esteem, depression and withdrawal coping. In conclusion, this study confirmed that school risk factors had effects on suicide ideation directly or indirectly, they were complicatedly connected, through negative self-esteem, depression and withdrawal coping. Therefore, Prevention program for adolescence' suicide ideation or suicide risk require integrated strategies and tactics.

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Escape Theory Approach to Consumers' Belief Biases (소비자의 신념편향에 대한 도피이론적 접근)

  • Han, Woong-Hee
    • The Journal of the Korea Contents Association
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    • v.14 no.11
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    • pp.411-421
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    • 2014
  • This study investigated the effect of cognitive narrowing on the consumers' belief biases in the light of the escape theory. Current study researched the relationship between the cognitive narrowing and the consumers' belief biases. The result of this study is as below. The degree of the consumers' belief biases is higher when the degree of the cognitive narrowing is higher than lower. On the basis of this result, theoretical and practical implications were suggested and the limitations and future research were discussed.

A Study of Pathological Gaming Model in Young Adolescents from the Perspective of Escape Theory (도피이론을 통한 청소년 게임 과몰입 영향모델 분석)

  • Lee, Daeyoung;Lee, Seungje;Jeong, Eui Jun
    • Journal of Korea Game Society
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    • v.20 no.2
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    • pp.3-12
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    • 2020
  • This study examined a pathological gaming model based on escape model. With a data set collected from 825 Korean adolescents, the associations among academic stress, depression, self-esteem, self-control, and pathological gaming were tested. Academic stress increased the degree of depression while it decreased self-esteem and self-control. The declined self-control, in turn, exacerbated pathological gaming. Results and implicaitons were discussed.

Wave propagation analysis of smart strain gradient piezo-magneto-elastic nonlocal beams

  • Ebrahimi, Farzad;Barati, Mohammad Reza
    • Structural Engineering and Mechanics
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    • v.66 no.2
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    • pp.237-248
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    • 2018
  • This study presents the investigation of wave dispersion characteristics of a magneto-electro-elastic functionally graded (MEE-FG) nanosize beam utilizing nonlocal strain gradient theory (NSGT). In this theory, a material length scale parameter is propounded to show the influence of strain gradient stress field, and likewise, a nonlocal parameter is nominated to emphasize on the importance of elastic stress field effects. The material properties of heterogeneous nanobeam are supposed to vary smoothly through the thickness direction based on power-law form. Applying Hamilton's principle, the nonlocal governing equations of MEE-FG nanobeam are derived. Furthermore, to derive the wave frequency, phase velocity and escape frequency of MEE-FG nanobeam, an analytical solution is employed. The validation procedure is performed by comparing the results of present model with results exhibited by previous papers. Results are rendered in the framework of an exact parametric study by changing various parameters such as wave number, nonlocal parameter, length scale parameter, gradient index, magnetic potential and electric voltage to show their influence on the wave frequency, phase velocity and escape frequency of MEE-FG nanobeams.

Inflnuence of the Restorative Quality of Landscape on the Visiting Preference and Satisfaction for Tourist Destination - An Evaluation of Heritage Landscape of Kyongju by Americans - (경관의 치유적 특질이 관광지 방문 선호 및 만족에 미치는 영향 - 경주 유산경관에 대한 미국인의 평가를 중심으로 -)

  • Yi, Young-Kyoung
    • Journal of the Korean Institute of Landscape Architecture
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    • v.34 no.5
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    • pp.1-13
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    • 2006
  • The Attention Restoration Theory (ART) developed by Kaplan and Kaplan proposes that effortful directed attention required in normal life can be fatigued. Restoration can occur in a setting that has restorative qualities. The restorative quality described by the ART involves four concepts: being away, fascination extent, and compatibility. The purpose of this study was to investigate how the restorative quality of landscape influenced the preferences and satisfaction of visitors to an heritage landscape. Four kinds of heritage landscapes of Kyongju were used as environmental surrogates and 150 americans participated in the study. Hartig et al.'s Revised Perceived Restorativeness Scale (RPRS) was used as the psychological measure for the restorative quality, along with other measurement constructs such as cultural uniqueness and novelty. The results showed that RPRS was a reliable measurement tool for assessing the restorative quality of artificial landscapes. Factor analysis identified three valid factors: escape-fascination compatibility, anti-extent. Among the three factors, only two, escape-fascination and compatibility, were found to have important effects on visiting preference and satisfaction. Specifically, higher levels of preference and satisfaction were associated with higher levels of escape-fascination and compatibility. The results indicate that the restorative quality has a high possibility to be used as a frame of reference for assessing various types of landscapes, from natural to artificial. It was also proposed that restorative quality could better explain the experience of the landscape strongly related to specific purpose or motivation.

Structural Analysis on the Path of Problem Gambling among College Students - Using Jacob's General Theory of Addiction- (대학생의 문제도박 발달경로 구조분석 -Jacob의 중독의 일반이론 적용-)

  • Jang, Soomi
    • Korean Journal of Social Welfare
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    • v.65 no.2
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    • pp.231-254
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    • 2013
  • The growth of legal and illegal gambling industry in Korea has increased the gambling accessibility. Actually, the prevalence of gambling addiction in Korea is significantly higher than those in western countries. The problems related to gambling make negative consequences in the individual, familial and socio-economical aspect. Previous studies showed that the prevalence of problem gambling by college students was much higher than that by adolescence and adult due to the nature of psychosocial developmental stage. The purpose of this study is to explore the path of problem gambling among college students based on the Jacob's general theory of addiction. Participants are 366 male college students who have experienced on gambling behavior. The main results are as follows. First, the problem gambling prevalence of participants is 14%. Second, statistical analysis using structural equation modeling shows the significant pathway among psychological vulnerability, needs to escape and problem gambling. Instead, the physiological vulnerability is not significant on the path to problem gambling. On the basis of these findings, the implications for social welfare prevention and intervention to college students are discussed.

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A Study of MMOPRG Background Story based on Fantasy Theory (환상의 범주에 따른 MMORPG의 세계관 연구)

  • Ahn, Jin-Kyoung;Lyou, Chul-Gyun
    • Journal of Digital Contents Society
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    • v.9 no.2
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    • pp.349-356
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    • 2008
  • MMORPG which offers a utopian world that includes a different rule from the real to satisfy players' needs for escape from the real world has changed. In these days, MMORPGs which have a unique world than middle-age fantasy have appeared as a new experience field. This paper compares MMORPGs have a middle-aged fantasy background story like J.R.R. Tolkein with another types bases on fantasy theory and presents difference.

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