• Ocean Systems Engineering
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• v.9 no.2
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• pp.179-190
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• 2019

This paper deals with the problem of the global stabilization for a class of ocean structure systems. It is well known that, in general, the global asymptotic stability of the ocean structure subsystems does not imply the global asymptotic stability of the composite closed-loop system. The classical fuzzy inference methods cannot work to their full potential in such circumstances because given knowledge does not cover the entire problem domain. However, requirements of fuzzy systems may change over time and therefore, the use of a static rule base may affect the effectiveness of fuzzy rule interpolation due to the absence of the most concurrent (dynamic) rules. Designing a dynamic rule base yet needs additional information. In this paper, we demonstrate this proposed methodology is a flexible and general approach, with no theoretical restriction over the employment of any particular interpolation in performing interpolation nor in the computational mechanisms to implement fitness evaluation and rule promotion.

• The Journal of the Korea Contents Association
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• v.15 no.11
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• pp.93-103
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• 2015

In this study, it has an intention of arranging an implication based on an effective introduction of a wage peak system in Japan to settle a mandatory retirement at sixty according to a legalization of retirement age at sixty smoothly. Institutionally, retirement age guaranteed type that reduces wage from certain period before retirement is of great importance. In Japan, mainly features the extension of retirement age that focus on keeping aged employment after retirement. In the introduction of the wage peak system, Korea attaches importance to the wage cost savings, but Japan puts emphasis on using aging workforce. Korea wants to promote the aged employment for retirement age at 60, whereas Japan actively push ahead with retirement age 65 and after that time. South Korea needs to reinforce the pensionable age and the connection though the extension of retirement age via the manpower utilization, employment promotion and the stability. It is necessary to prepare a institutional plan to try not to make a gap of the pensions by guaranteeing or extending the retirement age connect to the age of pensioners though the wage peak system. To activate the wage peak system, it is necessary to acknowledge a legal improvement that concedes rational changes such as the rule of employment. An active interpretation is needed currently though, it is more necessary to review the stipulation and the rational changes of the rule of employment that is established by a precedent like the Japanese legislation case. When a disadvantageous change of works rules is made, it is able to consider establishing the provision in the Act on age Discrimination Prohibition in Employment and Aged Employment Promotion, therefore it won't be able to apply the regulation in the rational criterion that satisfies the standards, rather than amending a Article 94 of the Labor Standards Act that makes accepting the approval of the majority of workers.

• Journal of the Korean Geotechnical Society
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• v.40 no.2
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• pp.55-64
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• 2024

While shield tunneling has demonstrated stability in international cases, the new Austrian tunneling method (NATM) encounters challenges in urban environments with shallow cover, weathered ground, and high groundwater levels. This paper introduces two typical collapse scenarios observed in urban areas, specifically within weathered bedrock and uncemented sandy soil layers. The collapses are analyzed using six stability evaluation methods, and the results are synthesized to assess the excavation face stability through a hexagonal diagram. The study finds a consistent agreement between the analysis results of the two collapsed tunnel sites and the evaluation outcomes. The employment of the stability evaluation diagram, a comprehensive method that considers the ground characteristics of the target tunnel, proves crucial for ensuring barrier stability during the tunnel design stage. This method is essential for a holistic evaluation, especially when addressing challenging ground conditions in urban settings.

• Journal of Family Resource Management and Policy Review
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• v.24 no.2
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• pp.1-21
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• 2020

The purpose of this research was, first, to classify work-life satisfaction among married wage workers aged 20-59 years into several distinct types based on two dimensions of work and life, using data from the 20th(2017) wave of the Korean Labor & Income Panel Study. Second, the study aimed to assess the differences in socio-demographic characteristics (sex, age, educational level, average monthly income), and workplace-related variables (weekly working hours, full-time employment, job stability, business type, family-friendly leave policies) by work-life satisfaction type. Accordingly, four types of work-life satisfaction were identified: work-life satisfaction, work-life dissatisfaction, work satisfaction, and life satisfaction. There was a significant difference in the type of work-life satisfaction among married waged workers based on sex, age, educational level, and average monthly income. Additionally, there was a significant difference in the type of work-life satisfaction for all workplace-related variables, namely, weekly working hours, full-time employment, job stability, business type, and family-friendly leave policies. In particular, proportionally higher values of work-life satisfaction were evident among the workers in companies with family-friendly leave policies such as paid leave, menstrual leave, maternity leave, childcare leave, and family events leave, whereas there was a high rate of work-life dissatisfaction among the workers in companies without family-friendly leave policies.

• Journal of the Korean Society of Costume
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• v.61 no.8
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• pp.127-140
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• 2011

The purpose of this study is to offer the basic data regarding the career development supporting system of senior fashion students. This study investigated contents of required vocational information and vocational information seeking behavior of senior fashion students. And this study also intended to analyse vocational choice anxiety factors and its relationship with level of vocational information requirement. The subjects of this study consisted 261 senior fashion students at eleven universities in the nation. The results of the study are as follows. First, five dimensions of required vocational information of fashion students were identified by factor analysis; information related to judgement of eligibility to apply for the job & company, information of work environment, information of fashion company that has the potential to hire them, information of level of compensation, stability of employment and promotion, and information of kind of job & job roles in the fashion field. Second, the senior fashion students faced few obstacles obtaining vocational information such as insufficient online vocational information, difficulties in discovering the sources of vocational information and time restriction for job search & career indecision. Third, the fashion students perceived diverse anxieties about making vocational choices. The survey identified five categories of the anxieties; anxiety about adapting to new job environment & recruiting process of the fashion company, anxiety about too heavy workload, anxiety about stability of employment & level of compensation, anxiety about lack confidence of their ability to do the job and anxiety about ability in English & the qualification for application. And there was significant relationship between vocational choice anxiety and requirement level of vocational information. This result proved providing vocational information relieves anxiety about getting a job.

• Korea journal of population studies
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• v.35 no.2
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• pp.159-184
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• 2012

This study purports to analyze how individuals' labor market integration affect their transition to marriage. In doing so, I construct variables for job stability and continuity to represent labor market integration using labor force status and years of participation at the time of marriage and during the three years up to the point of marriage. In particular, I focus on differential effects of these labor market integration on the transition to marriage by cohorts: one for those who are likely to enter the labor market after the 1997 financial crisis and the other for those who are before the 1997 financial crisis. I used the Korean Labor and Income Panel Study and analyzed individuals aged above 18 in 2008. The main results are as follows. being currently employed and regular employment increases hazards of the first marriage for men but decreases them for women. long-term no-jobs decreases hazards of marriage for both women and men. long-term regular employment increases hazards of marriage for women but not for men at the statistically significant level. These effects vary by cohorts implying that recent economic and labor market instability deteriorated economic conditions for the youth making transitions to marriage.

• Journal of the Korea Convergence Society
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• v.13 no.5
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• pp.237-247
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• 2022

This study predicts the economic activity level of the elderly in Korea using various machine learning methods. While the previous studies mainly focused on testing the relationship between the economic activity level and the life satisfaction or the social security system, this study aims at the accurate prediction on the economic activity level of the elderly using various machine learning methods and the forecast combination. Dependent variables such as the activity rate, employment rate, etc and independent variables such as the income, average wage, etc compose the dataset in this study. Five different machine learning methods and two forecast combinations are applied to the given dataset. The prediction performances of the machine learning method and the forecast combination varied across the dependent variables and prediction intervals, but it was found that the forecast combination was relatively superior to other methods in terms of the stability of prediction. This study has significance in that it accurately predicted the economic activity level of the elderly and achieved the stability of the prediction, raising practicality from a policy perspective.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.413-413
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• 2012

Lead sulfide (PbS) Colloidal quantum dots (CQDs) are promising material for the photovoltaic device due to its various outstanding properties such as tunable band-gap, solution processability, and infrared absorption. More importantly, PbS CQDs have large exciton Bohr radius of 20 nm due to the uniquely large dielectric constants that result in the strong quantum confinement. To exploit desirable properties in photovoltaic device, it is essential to fabricate a device exhibiting stable performance. Unfortunately, the performance of PbS NQDs based Schottky solar cell is considerably degraded according to the exposure in the air. The air-exposed degradation originates on the oxidation of interface between PbS NQDS layer and metal electrode. Therefore, it is necessary to enhance the stability of Schottky junction device by inserting a passivation layer. We investigate the effect of insertion of passivation layer on the performance of Schottky junction solar cells using PbS NQDs with band-gap of 1.3 eV. Schottky solar cell is the simple photovoltaic device with junction between semiconducting layer and metal electrode which a significant built-in-potential is established due to the workfunction difference between two materials. Although the device without passivation layer significantly degraded in several hours, considerable enhancement of stability can be obtained by inserting the very thin LiF layer (<1 nm) as a passivation layer. In this study, LiF layer is inserted between PbS NQDs layer and metal as an interface passivation layer. From the results, we can conclude that employment of very thin LiF layer is effective to enhance the stability of Schottky junction solar cells. We believe that this passivation layer is applicable not only to the PbS NQDs based solar cell, but also the various NQDs materials in order to enhance the stability of the device.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.4 no.4
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• pp.509-528
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• 2010

The random access systems, with retransmission diversity (RD) employment, over large random spreading code division multiple access (CDMA) channel subject to fading is investigated, under the assumption of infinite number of users and infinite spreading gain with their ratio converging to a constant. The low bound of the signal to interference and noise ratio (SINR) is shown to converge almost surely to a constant. The throughput, spectrum efficiency and energy efficiency in the dominating systems are obtained. The analytical results are confirmed by simulations. We find that in high traffic loads the throughput with fading is higher than that without. When the energy efficiency increases, the spectrum efficiency tends to two contrary values due to SNR increases or decreases. For the ordinary stable systems, the stability region is shown to shrink as the traffic increases and enlarge with RD employment.

• Korean Journal of Occupational Health Nursing
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• v.18 no.1
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• pp.106-115
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• 2009

Purpose: Occupational stress is a determinant risk factor for cardiovascular disease and work disability. This study aims to describe occupational stress and identify its related factors among aged security guards. Methods: A random sample of 76 aged security guards were interviewed by three research assistants. The criteria of the subjects were as follows : 50 or older male with 40 or more working hours a week working with colleagues ranged from 3 to 50. The data were collected in September, 2007 and analyzed by multiple regression using SAS Version 9.1. Results: The mean score of occupational stress among aged security guards was 47.2. The mean scores of its sub-scales were 31.3(physical environment), 33.8(occupational demand), 80.8occupational control), 44.6(interpersonal conflict), 51.3 (occupational insecurity), 53.6(occupational system), 57.5(lack of reward), and 30.3(work environment). The scores of occupational control, interpersonal conflict, and occupational insecurity were higher than the scores of Korean average occupational stress sub-scales. Significant variables affecting occupational stress and its sub-scales were work place, work type, and employment type. Conclusion: In order to reduce occupational stress among security guards, sufficient occupational control and interpersonal conflict control, appropriate reward, and employment stability should be considered. Also long working hours and work shift should be improved.