• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.5
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• pp.799-812
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• 2017

Backfill grouting and realistic convergence distribution were not properly considered in previous studies on 2D numerical analysis of a shield TBM tunnel. In this study, a modeling method was suggested to cope with this problem by considering a realistic convergence distribution and proper properties of backfill grouting. To this end, the influence of gap parameter and depth of rock cover on volume loss and composed of ground volume loss around tunnel excavation and surface volume loss were analyzed with a single layer of weathered soil. As a result, most of surface settlements were occurred immediately after excavation. Additional, as depth of rock cover and gap parameter increased, the influence range of surface settlement curves obtained from 2D numerical analyses became broader than a suggested theoretical equation. Therefore, it is inferred that gap parameter should be applied based on load distribution ratio and the property of backfill grouting properly considered for the estimation of the precise behavior of a shield TBM tunnel in 2D numerical analysis.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.10 no.4
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• pp.107-115
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• 2011

Since 2009 The Korean National Police Agency has been pushed "permissive left-turn" forward in order to making progress in Korean traffic operations system. Preceding researches manuals and guidelines present 6 standards(# of accidents # of lanes, pedestrian volume sight # of permissive left-turn lanes vehicle volume) as installation permissive left-turn. But in practical affairs it is most important that secure enough Gap-time between permissive left-turn vehicle and opposite through lane vehicle to make permissive left-turn vehicle move safer and more efficiently. This study suggests applying gap acceptance theory in microscopic model to permissive left-turn installation standards. Analysis methods of this study are field data survey statistical analysis and microscopic simulation analysis. This study collected field data by using AVI recording and measured permissive left-turn vehicle intersection passing time(T1) and against the opposite through lane vehicle Gap-time(T2). And statistical analysis performed about two values that measured before to predict the functionality between T1 and T2. These studies to overcome the limit of sample size carried out a microscopic simulation(VISSIM) plan and collect more samples to input statistical analysis.

• Journal of Korean Academy of Nursing
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• v.31 no.5
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• pp.871-884
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• 2001

this study was to investigate the perception gap on nursing service between consumers and providers. Method: the questionnaire founded on the SERVQUAL was developed and distributed to 300 patients and 210 nurses at the three subjected general hospitals in three provincial city, Korea during February to March, 2001. For data analysis, Cronbachs' Alpha, frequency, t-test, and paired t-test were used. Result: 1. In the gap analysis on the 20 properties constituting nursing service, providers almost all perceived higher than consumer in quality. Among them, the number of properties being statistically significant was 7 in the expectation, 18 in the important and 7 in the performance. 2. In the comparison analysis of the perception gap on the expectation-performance and the important-performance, it turned out that the subjected hospitals had to improve their equipment and facilities immediately. It was suggested a good strategy to strengthen the responsiveness factor and the assurance factor of nursing service. Conclusion: it could be concluded that nurses have to recognize the blind spot of their perception and endeavor to take away the perception gap between consumers and providers.

• The Journal of Information Systems
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• v.33 no.1
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• pp.69-90
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• 2024

Purpose In this paper, among the four information vulnerable groups(disabled, elderly, low-income, farmers and fishermen), the mediating effect of digital device usage attitudes in the effect of digital information utilization level of farmers and fishermen with a large digital information gap with the general public on life satisfaction was verified. Design/methodology/approach This study summarizes existing research related to the digital information gap between farmers and fishermen, and the empirical analysis is based on hierarchical regression analysis based on the 2022 Digital Information Gap Report (survey data on 2,200 farmers and fishermen) published by the Korea Intelligence Information Society Promotion Agency. Among the four major information vulnerable groups (the disabled, the elderly, low-income groups, and farmers and fishermen), attitudes toward using digital devices were examined in terms of the impact of the level of digital information use on life satisfaction among farmers and fishermen, who have a relatively large digital information gap with the general public. It was verified as a mediating effect. Findings As a result of the empirical analysis, attitudes toward the use of digital devices were found to play a mediating role in the impact of the level of digital information use on life satisfaction.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.5
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• pp.993-998
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• 2011

In this paper we suggest new criteria for the classification of the electrode gap between common and scan electrodes. The electrode gap is categorized as a short, middle, and long gap according to the criteria. Among these structures, we focus on the erase waveform of a mid-gap structure. we report an unstable discharge arising from the erase ramp period in a mid-gap structure. Based on the Vt close curve, we analyze the unstable discharge at various conditions. Our analysis reveals that the unstable discharge is ignited between surface electrodes and caused by un-erased wall charges accumulated on the outer edges of electrodes. By reducing the voltage level of the last sustain pulse, the problem is solved.

• Interaction and multiscale mechanics
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• v.6 no.1
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• pp.15-29
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• 2013

Phononic system composed of periodical elastic structures exhibit band gap phenomenon, and all elastic wave cannot propagate within the band gap. In this article, we consider one-dimensional binary materials which are periodically arranged as a 20-layered medium instead of infinite layered system for phononic system. The layered medium with finite dimension is subjected to a uniformly distributed sinusoidal loading at the upper surface, and the bottom surface is assumed to be traction free. The transient wave propagation in the 20-layered medium is analyzed by Laplace transform technique. The analytical solutions are presented in the transform domain and the numerical Laplace inversion (Durbin's formula) is performed to obtain the transient response in time domain. The numerical results show that when a sinusoidal loading with a specific frequency within band gap is applied, stress response will be significantly decayed if the receiver is away from the source. However, when a sinusoidal force with frequency is out of band gap, the attenuation of the stress response is not obvious as that in the band gap.

• Elastomers and Composites
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• v.30 no.3
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• pp.235-246
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• 1995

When an O-ring is installed in a high fluid pressure device, a section of the O-ring is extruded into the piston-cylinder clearance gap. Any tendency towards extrusion will induce wear in dynamic applications, leading to premature failure of the seal. In this study, the mechanism of initial extrusion of the O-ring was studied, 1.e., how much amount of the O-ring will be extruded into the clearance gap at a certain pressure. The relationship between extrusion depth and a clearance gap or fluid pressure were studied by finite element analysis (FEA). After that, Salita's experimental data were analyzed. The result is that Initial extrusion depth for an O-ring into a clearance gap was 1.11 times the product of dimensionless pressure difference $(p-p_1)/E$ and clearance gap c. The required pressure $p_1$ for zero extrusion depth was found to decrease logarithmically with increasing clearance gap.

• Journal of Labour Economics
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• v.42 no.1
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• pp.43-72
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• 2019

As a result of decomposing the wage gap between large enterprises and SMEs using Oaxaca's wage gap decomposition method, the total wage gap of supply side factors was 44.2%, and the service years and educational background were the biggest influences. and As a result of decomposing the wage gap by firm size based on demand side factors such as business performance, total wage gap was 44.9%, and the influence on wage gap was in the order of labor productivity, union and outsourcing ratio. The results of this analysis suggest that it is necessary to consider the demand side factors such as business performance and capital structure of supply side companies such as differences in human capital in order to solve wage gap by firm size.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.2
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• pp.157-166
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• 2014

A light water reactor (LWR) fuel rod consists of zirconium alloy cladding tube and uranium dioxide pellets with a slight gap between them. The modeling of heat transfer across the gap between fuel pellets and the protective cladding is essential to understanding fuel behavior under irradiated conditions. Many researchers have been developing fuel performance codes based on finite element method (FE) to calculate temperature, stress and strain for multidimensional analysis. The gap conductance model for multi-dimension is difficult issue in terms of convergence and nonlinearity because gap conductance is function of gap thickness which depends on mechanical analysis at each iteration step. In this paper, virtual link gap element (VLG) has been proposed to resolve convergence issue and nonlinear characteristic of multidimensional gap conductance. In terms of calculation accuracy and convergence efficiency, the proposed VLG model has been evaluated for variable cases.

• The Korean Journal of Franchise Management
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• v.6 no.1
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• pp.21-41
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• 2015

The purpose of the study is to review the real situations of the income-gap between urban and rural areas which is focused on as one of the biggest issues revealed in the process of Chinese economic development and to find out which factors will alleviate or deteriorate such income-gap, also to find out such factors will effect differently on the regional characteristics. To analyze it, six factors such as industrialization-ratio, urbanization-ratio, tertiary industry-ratio, the level of both governmental educational support and agricultural support, and Chinese dual-economic structure are considered as explanatory variables, and OLS regression analysis was implemented to the factor data for the period of 1986-2007 about Chinese 31 districts(castles and cities). The results of the analysis show that both industrialization factors and urbanization factors affect significantly to alleviate income-gap between urban and rural areas, and as predicted, they also shows that dual-economic structure between urban and rural areas is the most biggest factors to enlarge the above mentioned income-gap. However, in accordance to the different level of economic development in eastern, central, and western districts the study shows that such factors will affect them differently respectively. The contents are as follows; In eastern district governmental educational support factor will affect the most great influence to alleviate the income-gap, in central district industrialization factor will affect the most great influence to alleviate the gap, and western district governmental agricultural support factor will affect the most great influence to alleviate the gap. Therefore, in solving the issue of income-gap between urban and rural areas in China we recommend that it is necessary for more differential policy in considering regional characteristics than unilateral policy to Chinese whole areas.