• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.4
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• pp.121-128
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• 1996

The impact ionization rate of thethighly-doped AlGaAs/GaAs quantum well structure is calculated, which is an important parameter ot design theinfrared detector APD and the novel neural device. In conjunction with ensemble monte carlo method and quantum mechanical treatment, we analyze the effects of the parameters of quantum well structure on the impact ionization rate. Since the number of the occupied subbands increases while the energy of the subbands decreases as the width of quantum well increases, the impact ionization rate increases in the range of th esmall well width but gradually the increament slows down and is finally saturated. Due to the effect of the energy of the injected electrons into the quantum well and the tunneling through the barrier, the impact ionization rate increases for the range of the small barrier width and decreases for the range of the large barrier width. Thus, there exists a barrier width to maximize the impact ionzation rate for a mole fraction x, and the barrier width moves to the larger vaue as the mole fraction x increases. The impact ionization rate is much more sensitive to the variation of the doping density than that of the other quantum well parameters. We found that there is a limit of the doping density to confine the electronics in the quantum well effectively.

• Journal of Family Resource Management and Policy Review
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• v.10 no.4
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• pp.87-107
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• 2006

A study of 117 Korean immigrant women who had husband and(or) children in Hawaii found the relation between social networks and psychological well-being. Social networks composed supporters, support structure, and support contents. Psychological well-being examined family life satisfaction, family life stability, and women's psychological health. Results showed as followed. First, the choice of immigration place among Korean immigrant women and her family based on other family members and friends lived in there. Second, her supporters were family and relatives, Korean friends, foreign friends, religions, belonged organizations and groups, public agencies in Hawaii, and mass-media. The best supporters of them was family and relatives and they mostly provided mental health to Korean immigrant women. Family, Korean friends, foreign friends, and religions tended to support emotional assistance. Third, the level of psychological well-being was higher. Her level of psychological health was higher than the others. Fourth, the best predictors of psychological well-being were child existence, occupation, and immigration duration. Fifth, psychological well-being significantly distinguished different relations of supporters from support structure of social network. The number and support duration with foreign friends supporter and the support duration and the level of perceived useful support content highly related with psychological well-being.

• Management & Information Systems Review
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• v.33 no.4
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• pp.119-135
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• 2014

This study examines influences of personality and grateful disposition on psychological well-being in service encounter. The results follower like these. First, extroversion, conscientiousness, and grateful disposition have positive effects on psychological well-being, and neuroticism has a negative effect. Second, psychological well-being has a positive effect on prosocial behavior. Lastly, we compared the effects personality and grateful disposition on psychological well-being, and neuroticism has the most effects on psychological well-being and followed by grateful disposition and extroversion. It means grateful disposition can enhances psychological well-being as such personality.

• Journal of Soil and Groundwater Environment
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• v.19 no.3
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• pp.66-81
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• 2014

A Fortran program was developed to determine the optimal locations of an artificial recharge well. Three objective functions were considered: (1) maximizing the recovery rates, (2) maximizing the injection rates, and (3) minimizing the coefficient of variation of the increased pumping rates. We also suggested a new aggregate objective function which combined the first and the third objective functions. The model results showed that locating the injection well inside the cluster of pumping wells was desirable if either the recovery or the injection rate was taken into account. However, the injection well located outside the cluster evenly increased the pumping rates in existing pumping wells. Therefore, for clustered pumping wells, installing an injection well at the center or the upstream of the pumping wells seems beneficial. For linear arrangement of pumping wells parallel to the constant head boundary, locating the injection well in the upstream was recommended. On the contrary, in case of the linear arrangement perpendicular to the constant head boundary, the injection well installed on both sides of the central part of the pumping wells was preferable.

• Nuclear Engineering and Technology
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• v.53 no.4
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• pp.1284-1288
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• 2021

In this work, we propose and design a GaN-based diode with a p-doped GaN (p-GaN) multi-well structure for high efficiency betavoltaic (BV) cells. The short-circuit current density (J_SC) and opencircuit voltage (V_OC) of the devices were investigated with variations of parameters such as the doping concentration, height, width of the p-GaN well region, well-to-well gap, and number of well regions. The J_SC of the device was significantly improved by a wider depletion area, which was obtained by applying the multi-well structure. The optimized device achieved a higher output power density by 8.6% than that of the conventional diode due to the enhancement of J_SC. The proposed device structure showed a high potential for a high efficiency BV cell candidate.

• Stress
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• v.26 no.4
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• pp.290-295
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• 2018

Background: The aim of this study were to investigate the effect of unstable attachment on subjective well-being and to identify mediator effects of decentering and self-compassion. Methods: A total of 255 college students participated in this study by completing the following questionnaires: Experience in Close Relationship Scale, Subjective Well-being Questionnaire, Decentering Scale, and Self-Compassion Scale. Results: Mediated Regression Analysis was used for the purposes of study. The results are as the following. First, unstable attachment had significant negative correlation with subjective well-being and decentering and self-compassion. Second, decentering had a partial meditational effect on the relation between unstable attachment and subjective well-being. Third, self-compassion had completely meditational effect on the relation between unstable attachment and subjective well-being. Conclusions: These results suggested that it is important to enhance students' level of decentering and self-compassion in order to increase their subjective well-being effectively.

• Geomechanics and Engineering
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• v.24 no.1
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• pp.15-28
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• 2021

Digging well foundation has been widely used in railway bridges due to its good economy and reliability. In other instances, bridges with digging well foundation still have damage risks during earthquakes. However, there is still a lack of knowledge of lateral behavior of digging well foundation considering the soil-foundation interaction. In this study, scaled models of bridge pier-digging well foundation system are constructed for quasi-static test to investigate their lateral behaviors. The failure mechanism and responses of the soil-foundation-pier interaction system are analyzed. The testing results indicate that the digging foundations tend to rotate as a rigid body under cyclic lateral load. Moreover, the depth-width ratio of digging well foundation has a significant influence on the failure mode of the interaction system, especially on the distribution of foundation displacement and the failure of pier. The energy dissipation capacity of the interaction system is discussed by using index of the equivalent viscous damping ratio. The damping varies with the depth-width ratio changing. The equivalent stiffness of soil-digging well foundation-pier interaction system decreases with the increase of loading displacement in a nonlinear manner. The absolute values of the interaction system stiffness are significantly influenced by the depth-width ratio of the foundation.

• The Journal of Korean Society for School & Community Health Education
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• v.22 no.1
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• pp.25-35
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• 2021

Objectives: This study examined the relations among 5 personality factors, self-regulatory efficacy and subjective well-being in parents with developmental disabilities. This study also examined the mediating effect of self-regulatory efficacy on the relationship between 5 personality factors and subjective well-being in parents with developmental disabilities. Methods: The research subjects consisted of 114 parents with developmental disabilities. They completed questionnaires 5 personality factors, self-regulatory efficacy and subjective well-being by parents. The data were analyzed by SPSS 22.0 program. Results: The results of this study showed that 5 personality factors-neuroticism and extroversion-had a direct effect on subjective well-being in parents with developmental disabilities. Second, 5 personality factors-extroversion- had an indirect effect on the subjective well-being through self-regulatory efficacy in parents with developmental disabilities. Conclusions: These findings have implications for future research and practice by highlighting the importance of self-regulatory efficacy in subjective well-being in parents with developmental disabilities.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.5
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• pp.535-539
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• 2010

We present a digital dilution chip comprising a $2{\times}6$ array of wells; the chip can be employed to change the dilution ratio as well as to initiate reactions among diluted samples by using the inter-well valve around the well. In previous dilution devices, streams comprising sample and dilution solutions were merged and separated by a branched microchannel. Therefore, the dilution ratio could not be changed until the structure of the branched microchannel was changed. The present device merges and splits the wells filled with sample or dilution solution by controlling inter-well valves around the wells. Thus, it is possible to change the dilution ratio by changing the sequence in which merging and splitting sequence of each well filled with sample or dilution solution. In experiments, we found that the chip could be used to change linear or exponential dilution ratios within an error of 16.7% and to initiate reactions among the samples within a reaction error of 17.7%.

• Economic and Environmental Geology
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• v.46 no.4
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• pp.279-289
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• 2013

The most critical factor in developing coalbed methane(CBM) reservoir is absolute permeability. Both productivity and economics of the CBM depend on the absolute permeability. The methods to estimate it are core analysis and well test. However, absolute permeability determined by core analysis cannot be a good representative of CBM reservoir. Therefore, it is generally estimated by well test. In this study, well test methods applicable of CBM reservoir were classified with their characteristics. Merits and demerits of each well tests were also analyzed. Based on those parameters, design considerations and procedures of well test were derived. After each well tests was performed, the procedure of well test interpretations to estimate reservoir properties such as absolute permeability and skin factor was presented.