• International Journal of Highway Engineering
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• v.12 no.4
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• pp.147-155
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• 2010

A prediction model of resilient modulus($E_R$) was developed for recycled crushed-rock-soil mixtures. The evaluation of $E_R$, using the "orthodox" repeated loading tri-axial test, is not feasible for such a large-size gravelly material. An alternative method was proposed hereby using the subtle different modulus called nonlinear dynamic modulus. The prediction model was developed by utilizing in-situ measured shear modulus($G_{max}$) and its reduction curves of modeled materials using the large free-free resonant column test. A pilot evaluation of the model parameters was carried out for recycled crushed-rock-soil-mixture at a highway construction site near Gimcheon, Korea. The values of the model parameters($A_E,\;n_E,\;{\varepsilon}_r\;and\;{\alpha}$) were proposed as 9618, 0.47, 0.0135, and 0.8, respectively.

• International Journal of Highway Engineering
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• v.2 no.2
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• pp.149-161
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• 2000

The stiffness of the subbase materials is represented by the resilient modulus, $M_R$, which are very important properties in the mechanistic design of flexible pavement system. However, the cyclic $M_R$ testing method is too complex, expensive, and time consuming to be applicable on a production basis. In this study, the alternative $M_R$ testing technique for subbase materials was developed using a free-free resonant column (FF-RC) test considering deformational characteristics of subbase materials. To estimate the deformational characteristics of subbase materials, effects of strain amplitude and mean effective stress on modulus of subbase materials were investigated. The $M_R$ values determined by alternative testing procedures matched well with those determined by standard $M_R$ test, showing the capability of the proposed methods being used in determining $M_R$ values.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.6
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• pp.1214-1221
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• 2007

Ad-hoc network is soft wireless communication network that is consisted of mobile node and clusters without helping of infrastructure. We propose a new ad hoc multicast routing protocol for based on the ontology scheme called inference network. Ontology knowledge-based is one of the structure of context-aware. Proposed structure is consisted of context awareness parameters as like distance between each nodes. The proposed architecture performs two types of routing discovery. One is Flooding Discovery Routing(FDR) for comparing analysis step and Local Discovery Routing(LDR) to compose path of node forecast(preservation) step from node's state value. The inference network structure of proposed RODMRP(Resilient Ontology-based Dynamic Multicast Routing Protocol) adopts a tree structure to enhance an efficient packet in various environment between mobile node. We will have developed an algorithm that will desist multi-hierarchy Layered networks to simulate a desired system.

• Journal of Christian Education in Korea
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• v.65
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• pp.133-161
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• 2021

This study focuses on the vulnerability of our society and environment under the Covid-19 pandemic. The medical descriptions about severe acute respiratory syndrome coronavirus disease 2019 provide the serious manifestation of the SARS-CoV-2 virus and a new resilient hope of its vaccination. Moreover, with the perspective of feminist practical theology, the author explores a resilient possibility to reconstitute an ecological relationship between our society and environment. In addition, many people's depression in the time of Covid-19 is understood in the meaningful narrative of the relationship between integrity and despair to be stressed by Erikson in the perspective of Loder. Especially, this study focuses on the main stream of designing the convergence curriculum of medicine and theology to move toward the life wellbeing of community members, overcoming their difficult circumstances such as Covid-19.

• Geomechanics and Engineering
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• v.32 no.6
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• pp.583-600
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• 2023

The resilient modulus (M_R) of various pavement materials plays a significant role in the pavement design by a mechanistic-empirical method. The M_R determination is done by experimental tests that need time and money, along with special experimental tools. The present paper suggested a novel hybridized extreme gradient boosting (XGB) structure for forecasting the M_R of modified base materials subject to wet-dry cycles. The models were created by various combinations of input variables called deep learning. Input variables consist of the number of W-D cycles (WDC), the ratio of free lime to SAF (CSAFR), the ratio of maximum dry density to the optimum moisture content (DMR), confining pressure (σ₃), and deviatoric stress (σ_d). Two XGB structures were produced for the estimation aims, where determinative variables were optimized by particle swarm optimization (PSO) and black widow optimization algorithm (BWOA). According to the results' description and outputs of Taylor diagram, M1 model with the combination of WDC, CSAFR, DMR, σ₃, and σ_d is recognized as the most suitable model, with R² and RMSE values of BWOA-XGB for model M1 equal to 0.9991 and 55.19 MPa, respectively. Interestingly, the lowest value of RMSE for literature was at 116.94 MPa, while this study could gain the extremely lower RMSE owned by BWOA-XGB model at 55.198 MPa. At last, the explanations indicate the BWO algorithm's capability in determining the optimal value of XGB determinative parameters in M_R prediction procedure.

• Journal of the Korean Geotechnical Society
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• v.24 no.4
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• pp.37-46
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• 2008

Application of resilient modulus, representing mechanical behavior of pavement materials, has become general concept for pavement design, analysis and maintenance after '86 AASHTO selected it as a basic input property of subgrade. It is known that resilient modulus of domestic subgrade soil is affected greatly by material factors, such as water content and dry weight unit, and stress components, such as deviatoric stress and confining stress, while effects of loading frequency and loading repeat were regarded negligible. If design based on resilient modulus is to be successfully implemented, design input variables of relevant models should be able to reflect local conditions. In this study, generalized mechanical model for subgrade is proposed. Model parameters are estimated from test results. Verification of the model was performed through finite element analysis using the proposed model, which showed good agreement with measured results of pavement deflections.

• The Journal of the Korea Contents Association
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• v.20 no.7
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• pp.404-416
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• 2020

Flooding is an unavoidable natural disaster for the city. Flood disasters seriously undermine the city's economy, safety, and sustained development. In the course of development and construction of waterfront space in the same city, the construction of basic disaster prevention facilities cannot be avoided completely even if huge amounts of capital are invested to reduce the economic damage of flooding. The cost of rebuilding the city after the disaster is much higher than the cost of building disaster prevention facilities. In recent years, the theory of elasticity in urban reconstruction and so on has been a subject of city problem solving, creating widespread discussion and attention in academia. In other words, how to transform the concept of elasticity into practice based on theoretical and empirical factors is a real problem facing urban disaster. Through theoretical literature on the waterfront (space) buffer zone of a city (flood-weak area) and the case study of the city's practice, this paper tries to clarify the element of 5R, the theory of elastomeric fire prevention, and present detailed measures accordingly. In addition, the following two problems are addressed while emphasizing the feasibility of implementing the urban waterfront (space) plan of the elastomeric element around the urban water buffer zone. First, the means of disaster prevention planning are used to mitigate conflicts between individual utility of urban waterfront and disaster prevention functions in waterfront buffer zones, and second, the waterfront buffer zone can respond to flood-causing problems in terms of disaster prevention as much as possible through the elastic disaster prevention plan.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.3
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• pp.165-174
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• 2017

The purpose of this study was to investigate the effect of three sub-factors of family resilience on family strength as perceived by university students. The subjects were 409 university students in G area. This study investigated the perception level of family resilience and family strength, the difference in the family strength between the resilient group and non-resilient group and the effect of family resilience on family strength. The study results were as follows: First, the students' perceptions of family resilience and family strength were moderately high. Second, the students with positive perceptions of all three family resilience sub-factors (resilient group) also had a higher perceived family strength than the non-resilient group. Third, gender was found to have an influence on family strength, with the male students having a higher perceived family strength. All three sub-factors of family resilience were statistically significant and the belief system and organizational pattern had a strong influence on the family strength. In particular, the belief system was the most powerful factor affecting the family strength. The role clarity, family cohesion and family resource of the family organizational pattern were significant factors. Moreover, collaborative problem solving and open emotional communication also had a significant influence on family strength.

• The Journal of the Korea Contents Association
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• v.20 no.1
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• pp.644-657
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• 2020

As the development of urbanization has cause some environmental problems and natural disasters such as natural earthquakes and floods have brought about impact, designers have turned their attention to the independent prevention ability of urban ecosystems in face of environmental pollution and natural disasters, as well as its ability to adapt to the future. This study introduces 'elasticity theory' to discuss the practical application of elasticity design in landscapes and to solve the problem of lack of elasticity in space, which can provide more scientific reference meaning to create economic, cultural, and social values for space. After selecting 'The High Line' as the object, this paper investigates the previous theories and practical cases, and infers ecology, sustainability, diversity, and adaptability. And then this paper applies five components and analyzes the specific application of these five components of the landscape spatial elasticity strategy, and summarizes the application characteristics and influencing factors of elasticity design in 'The High Line' landscape planning. It can be known from the research that elasticity strategy which is reflected in the design process is the systematic management of landscape space. Elasticity design itself can strengthen environment quality and satisfy the requirements of the environment to defense external shocks so as to adapt to environment changes. Therefore, the elasticity design can strengthen the sustainable development of the city and establish a periodic recycle system.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.46 no.4
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• pp.108-115
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• 2009

In this paper, we propose a novel true-motion estimation technique supporting efficient frame error concealment for error-resilient video coding. In general, it is important to accurately obtain the true-motion of objects in video sequences for effectively recovering the corrupted frame due to transmission errors. However, the conventional motion estimation (ME) technique, which minimizes a sum of absolute different (SAD) between pixels of the current block and the motion-compensated block, does not always reflect the true-movement of objects. To solve this problem, we introduce a new metric called an absolute difference of motion vectors (ADMV) which is the distance between motion vectors of the current block and its motion-compensated block. The proposed ME method can prevent unreliable motion vectors by minimizing the weighted combination of SAD and ADMV. In addition, the proposed ME method can significantly improve the performance of error concealment at the decoder since error concealment using the ADMV can effectively recover the missing motion vector without any information of the lost frame. Experimental results show that the proposed method provides similar coding efficiency to the conventional ME method and outperforms the existing error-resilient method.