• Journal of Korean Association for Spatial Structures
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• v.13 no.4
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• pp.67-74
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• 2013

The Age-adjusted effective Modulus Method(AEMM) is one of the methods adopted for the construction stage analysis of concrete structures. The AEMM uses the aging factor to consider the effects of the varying concrete stress. In the aspects of computation time and the accuracy of the results, the AEMM is considered as one of most appropriate methods for construction stage analysis of tall building structures. Previous researches proposed appropriate values of the aging factor in the forms of graphs or using very simple equations. In this paper, an equation for estimating the aging factor as a function of rebar ratio in the section, compressive strength of concrete, notional member dimension, and age of concrete at the load application. The validity of aging factor proposed in this paper were examined by the comparison with the results of step-by step method.

• Geomechanics and Engineering
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• v.28 no.1
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• pp.1-10
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• 2022

In Korea, accidents related to the collapse of deteriorated aging reservoirs occur every year. The grouting method is generally applied to reinforce an aging reservoir. However, when using this method, different reinforcing effects appear depending on the ground conditions. Thus, new construction methods and materials capable of providing consistent reinforcing effects are required. In this study, the direct shear test (DST), model test, and simulation analysis were performed to evaluate the impact of surface stabilizers, generally used to reinforce roads, rivers, and slopes of roads, applied using surface curtain walls on aging reservoirs. The DST results indicate that when the surface stabilizer was mixed with in-situ soil, the increase in cohesion was the highest at a mixing ratio of 9%. No changes in the friction angle were evident; therefore, 9% was determined to be the optimal mixing ratio. In addition, the model test and simulation analysis showed that when 9% of the surface stabilizer was mixed and applied to the aging reservoir, the seepage quantity of water and the saturated area were reduced by approximately 42% and 73%, respectively. Moreover, the comprehensive analysis of results showed that the grouting method could be completely replaced by surface stabilizers applied through surface curtain walls because the technique could secure stability by decreasing the seepage in the aging reservoir.

• Journal of the Economic Geographical Society of Korea
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• v.16 no.2
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• pp.233-246
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• 2013

This paper investigates both the spatial patterns of aging population and its formal regional structure in 2010. The results are as follows: first, aging index shows high values in remote mountainous and coastal regions while showing relatively low values in Capital Region and large provincial cities. Aging index has low negative correlation with such variables as population increasing rate, ratio of youth population, ratio of apartments, and ratio of newly built housing. However, aging index shows high positive correlation with variables including ratio of single unit house, ratio of aged peoples' house ownerships, ratio of welfare recipients, ratio of old housing, and number of public healthcare facilities. Secondly, four factors are identified from factor analysis including aging factor, welfare factor, economic vitality factor, and new town factor. The aging level of a region is negatively related to the strong level of those factors. Thirdly, cluster analysis results in four different types of formal regions including rural mountainous coastal type, rural non-capital region type, large metropolitan type, and provincial industrial city type.

• Korean Journal of Social Welfare
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• v.63 no.4
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• pp.203-224
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• 2011

This study explored the tendencies of public perception and countermeasures on an aging society by the content analysis of Korea's four major daily newspapers since 2000. Results showed distinguishing growth of the public interest on an aging society. Articles were categorized into five domains - demographic structure, family and individual domain, health domain, economic and financial domain, and social domain. Economic and financial aspects occupied the highest frequency in the total number of articles. The analysis of public perception revealed both negative and positive perspectives on an aging society. In addition, the analysis of the newspaper articles identified particular phenomenon of Korean aging society as distinct rapid aging population, declining fertility rates caused by higher educational expenses, national security problems. Consequently, when we prepare for the alternatives of the aging society, we should pay attention to more various aspects of society based on the understanding of practical problems and needs. Furthermore, researches and discussions focusing on a particular phenomenon of Korea would be required.

• Journal of the Korean Society of Propulsion Engineers
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• v.25 no.3
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• pp.26-41
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• 2021

Titanium hydride potassium perchlorate (THPP) has played an important role as initiators of the propulsion system. However, the 'aging' may cause performance degradation and even give rise to a failure in the total system. In this study, various hygrothermal aging conditions were considered and the aging effects on thermodynamic and ignition characteristics of THPP are provided via thermal analysis and ignition measurements. Also, physical-chemical changes were identified by morphological analysis. In conclusion, thermal aging led to E_α decrease-high reactivity due to oxidizer decomposition whereas hygrothermal aging gave rise to an opposite tendency by fuel oxidation.

• International Journal of Computer Science & Network Security
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• v.22 no.2
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• pp.232-240
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• 2022

To fulfill user expectations, the rapid evolution of software techniques and approaches has necessitated reliable and flawless software operations. Aging prediction in the software under operation is becoming a basic and unavoidable requirement for ensuring the systems' availability, reliability, and operations. In this paper, an improved evolutionary computing-driven extreme learning scheme (ECD-ELM) has been suggested for object-oriented software aging prediction. To perform aging prediction, we employed a variety of metrics, including program size, McCube complexity metrics, Halstead metrics, runtime failure event metrics, and some unique aging-related metrics (ARM). In our suggested paradigm, extracting OOP software metrics is done after pre-processing, which includes outlier detection and normalization. This technique improved our proposed system's ability to deal with instances with unbalanced biases and metrics. Further, different dimensional reduction and feature selection algorithms such as principal component analysis (PCA), linear discriminant analysis (LDA), and T-Test analysis have been applied. We have suggested a single hidden layer multi-feed forward neural network (SL-MFNN) based ELM, where an adaptive genetic algorithm (AGA) has been applied to estimate the weight and bias parameters for ELM learning. Unlike the traditional neural networks model, the implementation of GA-based ELM with LDA feature selection has outperformed other aging prediction approaches in terms of prediction accuracy, precision, recall, and F-measure. The results affirm that the implementation of outlier detection, normalization of imbalanced metrics, LDA-based feature selection, and GA-based ELM can be the reliable solution for object-oriented software aging prediction.

• The Korea Journal of Herbology
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• v.26 no.3
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• pp.15-21
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• 2011

Objectives : The application of polymerase chain reaction (PCR) for the discrimination of the herbal medicine Leonuri Herba (Leonurus japonicus) was evaluated by the comparison of the DNA sequence with Lamiaceae herbal medicine. Method : Genetic analysis showed that phylogenetic tree and comparing sequences through the DNA analysis of rbcL (ribulose-1, 5-bisphosphatecarboxylase) region and trnL-F (tRNA-Leu, trnL-trnF intergeni cspacer, and tRNA-Phe) region of chloroplast DNA from six Lamiaceae sold in market. And we developed IMCF and IMCR primers in order to distinction Leonuri Herba in six Lamiaceae using rbcL and trnL-F sequences. Results : Genetic analysis showed that six Lamiaceae showed individual group on phylogenetic tree. PCR amplification product of Leonuri Herba and another five Lamiaceae were developed for amplification of a 281 bp sequence and the specific PCR amplification of a 460 bp sequence that was exclusive to Leonuri Herba was designed using IMCF and IMCR primers. Conclusion : PCR analysis based on the chloroplast DNA sequences allows the discrimination of Leonuri Herba-based medicine.

• Coupled systems mechanics
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• v.3 no.1
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• pp.53-71
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• 2014

Accurate prognoses of the durability of concrete structures require a detailed description of the continuously running aging processes and a consideration of the complete load history. Therefore, in the framework of continuous porous media mechanics a model is developed, which allows a detailed analysis of the most important aging processes of concrete as well as a flexible coupling of different processes. An overview of the prediction model and the balance equations is given. The material dependent model equations, the consequences of coupling different processes and the solution scheme are discussed. In two case studies the aging of concrete due to hydration and chloride penetration are presented, which illustrate the capabilities and the characteristics of the developed model.

• Journal of Families and Better Life
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• v.25 no.2 s.86
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• pp.137-153
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• 2007

The purpose of this study was to explore the similarities and differences of elements of successful aging in Western and Korean society using a background of time and dominant values of each society. Content analysis of concepts and components of 'successful aging' was performed based on 12 Korean articles and 23 Western articles. The major findings were: (1) The studies of successful aging accomplished since 2001 and the studies that explore the elements of successful aging perceived by the elderly mentioned diverse elements as essential to successful aging. (2) There were both common and distinct components of successful aging in Western and Korean society. Some of the essential components for successful aging were commonly accepted, but others were varied and unique, reflecting the period of experience and cultural values. These results could be used to better understand unique successful aging of the Korean elderly, as well as to establish a basis of intervention that meets the specific demands of this population.

• Korean Journal of Adult Nursing
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• v.25 no.4
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• pp.464-472
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• 2013

Purpose: The purpose of this study was to identify aging anxiety and influencing factors of middle-aged adults. Methods: Descriptive correlation design was used. Three hundred and three middle-aged adults participated in the study and completed the questionnaires in the period from September 11 to October 15 of 2011. The data was analyzed using independent t-test, one-way ANOVA, Scheff$\acute{e}$ test, Pearson correlation coefficients, and hierarchial multiple regression analysis. Results: Aging anxiety of middle-aged adults was higher than a moderate level. Socio-demographic variables such as age, religion, education, economic level, perceived health status and experience of living with older adults influenced significantly on aging anxiety. In contrast, general self-efficacy, aging knowledge and attitude toward older adults were negatively correlated with aging anxiety. Hierarchial multiple regression analysis incorporating these variables showed an explanation rate of aging anxiety at 21%. And religion, perceived health status, attitude toward older adults, and general self-efficacy were statistically significant among variables that influence on aging anxiety. Conclusion: The findings of this study suggest that senior preparation programs that can enhance self-efficacy, induce positive attitude on older adults and promote health should be implemented to reduce aging anxiety of middle-aged adults.