• Journal of Korea Water Resources Association
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• v.57 no.6
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• pp.371-383
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• 2024

The quantification methods and definitions of resilience vary and are studied across many fields. However, this diversity can lead to gaps in interpretation regarding the meaning and indicators of resilience, potentially having a negative impact on resilience assessments. Therefore, uniform standards for defining and quantifying resilience are essential. This study presented a definition of resilience and socio-structural evaluation methods of resilience through network analysis. Furthermore, through analyzing various definitions of resilience, the definition of resilience in the context of urban flooding was presented. Distinguishing between static and dynamic resilience, an evaluation method based on common attributes was proposed. Lastly, the economic effects of introducing resilience were analyzed using an inundation trace map. Future research on the secondary effects through standardized resilience assessments is expected to be widely utilized in decision-making stages within urban flood policies.

• Smart Structures and Systems
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• v.32 no.1
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• pp.49-59
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• 2023

A bridge transportation network supplies products from various source nodes to destination nodes through bridge structures in a target region. However, recent frequent earthquakes have caused damage to bridge structures, resulting in extreme direct damage to the target area as well as indirect damage to other lifeline structures. Therefore, in this study, a surrogate model-based comprehensive framework to estimate the seismic resilience of bridge transportation networks is proposed. For this purpose, total system travel time (TSTT) is introduced for accurate performance indicator of the bridge transportation network, and an artificial neural network (ANN)-based surrogate model is constructed to reduce traffic analysis time for high-dimensional TSTT computation. The proposed framework includes procedures for constructing an ANN-based surrogate model to accelerate network performance computation, as well as conventional procedures such as direct Monte Carlo simulation (MCS) calculation and bridge restoration calculation. To demonstrate the proposed framework, Pohang bridge transportation network is reconstructed based on geographic information system (GIS) data, and an ANN model is constructed with the damage states of the transportation network and TSTT using the representative earthquake epicenter in the target area. For obtaining the seismic resilience curve of the Pohang region, five epicenters are considered, with earthquake magnitudes 6.0 to 8.0, and the direct and indirect damages of the bridge transportation network are evaluated. Thus, it is concluded that the proposed surrogate model-based framework can efficiently evaluate the seismic resilience of a high-dimensional bridge transportation network, and also it can be used for decision-making to minimize damage.

• International Journal of Highway Engineering
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• v.20 no.1
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• pp.35-45
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• 2018

PURPOSES : This study examines the performance changes of road networks according to the strength of a disaster, and proposes a method for estimating the quantitative resilience according to the road-network performance changes and damage scale. This study also selected high-influence road sections, according to disasters targeting the road network, and aimed to analyze their hazard resilience from the network aspect through a scenario analysis of the damage recovery after a disaster occurred. METHODS : The analysis was conducted targeting Sejong City in South Korea. The disaster situation was set up using the TransCAD and VISSIM traffic-simulation software. First, the study analyzed how road-network damage changed the user's travel pattern and travel time, and how it affected the complete network. Secondly, the functional aspects of the road networks were analyzed using quantitative resilience. Finally, based on the road-network performance change and resilience, priority-management road sections were selected. RESULTS : According to the analysis results, when a road section has relatively low connectivity and low traffic, its effect on the complete network is insignificant. Moreover, certain road sections with relatively high importance can suffer a performance loss from major damage, for e.g., sections where bridges, tunnels, or underground roads are located, roads where no bypasses exist or they exist far from the concerned road, including entrances and exits to suburban areas. Relatively important roads have the potential to significantly degrade the network performance when a disaster occurs. Because of the high risk of delays or isolation, they may lead to secondary damage. Thus, it is necessary to manage the roads to maintain their performance. CONCLUSIONS : As a baseline study to establish measures for traffic prevention, this study considered the performance of a road network, selected high-influence road sections within the road network, and analyzed the quantitative resilience of the road network according to scenarios. The road users' passage-pattern changes were analyzed through simulation analysis using the User Equilibrium model. Based on the analysis results, the resilience in each scenario was examined and compared. Sections where a road's performance loss had a significant influence on the network were targeted. The study results were judged to become basic research data for establishing response plans to restore the original functions and performance of the destroyed and damage road networks, and for selecting maintenance priorities.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.11
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• pp.49-58
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• 2010

In this paper, we present a methodology for fast segment restoration under multiple simultaneous link failures in mesh-type MPLS networks. The salient feature of the methodology is that both resilience and QoS constraint conditions have been taken into account for fast segment restoration. For fast restoration, a sufficient condition for testing the existence of backup segments with guaranteed-resilience has been derived for a mesh-type MPLS network. The algorithms for constructing backup segments which can meet both resilience and QoS constraint conditions are then presented with illustrating examples. Finally, simulation has been done to show the efficiency of the proposed segment restoration algorithms.

• Proceedings of the Korea Water Resources Association Conference
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• 2002.05b
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• pp.829-836
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• 2002

The paper presents a multi-objective genetic algorithm approach to the design of a water distribution network. The objectives considered are minimization of network cost and maximization of a reliability measure. In this study, a new reliability measure, called network resilience, is introduced. This measure mimics a designer's desire of providing excess power at nodes and designing reliable loops with practicable pipe diameters. The proposed method produces a set of Pareto-optimal solutions in the search space of cost and network resilience. Genetic algorithms are observed to be poor in handling constraints. To handle constraints in a better way, a constraint handling technique that does not require a penalty coefficient and applicable to water distribution systems is presented. The present model is applied to two example problems, which were widely reported. Pipe failure analysis carried out on some of the solutions obtained revealed that the network resilience based approach gave better results in terms of network reliability.

• Journal of information and communication convergence engineering
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• v.11 no.2
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• pp.69-81
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• 2013

Maintaining connectivity is essential in multi-hop wireless networks since the network topology cannot be pre-determined due to mobility and environmental effects. To maintain the connectivity, a critical point in the network topology should be identified where the critical point is the link or node that partitions the network when it fails. In this paper, we propose a new critical point identification algorithm and also present numerical results that compare the critical points of the network and H-hop sub-network illustrating how effectively sub-network information can detect the network-wide critical points. Then, we propose two localized topological control resilient schemes that can be applied to both global and local H-hop sub-network critical points to improve the network connectivity and the network resilience. Numerical studies to evaluate the proposed schemes under node and link failure network conditions show that our proposed resilient schemes increase the probability of the network being connected in variety of link and node failure conditions.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.162-162
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• 2019

Water Distribution Network (WDN) is a critical infrastructure to be maintained ensuring proper water supply to wide-spread consumers. The WDN consists of pipes, valves, pumps and tanks, and these elements interact each other to provide adequate system performance. If elements fail by internal or external interruptions, it may result in adverse impact to water service with different degree depending on the failed element. To determine an appropriate maintenance priority, the critical elements need to be identified and mapped in the network. In order to identify and prioritize the critical elements in WDN, an element-based simulation approach is proposed, in which all the elements composing the WDN are reviewed one at a time. The element-based criticality is measured using several resilience indexes that are newly developed in this study. The proposed resilience indexes are used to quantify the impacts of element failure to water service degradation. Here, three resilience indexes are developed, such as User Demand Severity, Economic Value Loss and Water Age Degradation, each of which intends to measure different aspects of consequences, such as social, economic, and water quality, respectively. For demonstration, the proposed approach is applied to a benchmark water network to identify and prioritize the critical elements.

• Journal of Internet Computing and Services
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• v.8 no.5
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• pp.21-33
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• 2007

An overlay network is a virtual network which is constructed on top of a physical computer network. A node in the overlay network is connected through virtual or logical links, where each link corresponds to a path of the links in the underlying physical network. Overlay networks are suitable for sharing heterogeneous resources in distributed environments, However, overlay networks are limited for achieving reliable communication that failure detection in overlay networks is a very important issue. In this paper, we review conditions of conventional failure detection and propose a new approach to failure detection and resilience which can be applied to HRing (Hierarchical Ring) overlay networks. The proposed method consists of the failure detection and the failure resilience phases. Because it utilizes the characteristics of the HRing overlay network for failure detection, it can reduce unnecessary network traffic and provide better scalability and flexibility. We also analyzed and evaluated the performance of the proposed approach through simulations.

• Journal of Digital Convergence
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• v.14 no.2
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• pp.31-39
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• 2016

In recent university classes, consistent effort to improve co-operative interaction and communication between student and professor utilizing SNS(Social Network Service) is being made. This research conducted survey study with 137 pre-teachers in Daejeon & Chungnam area in order to find the relationship between pre-teachers' ego resilience, level of social support and awareness of the instructional outcome in classes that incorporate SNS. According to the result, it has been found that male's class satisfaction is higher than female's class satisfaction, while significant correlations have been found between ego resilience-social support, social support-class satisfaction, social support-semester satisfaction, and class satisfaction-semester satisfaction. Also, ego resilience and social support have significant effect on awareness of the instructional outcome. From these results, a rather close attention towards students' characteristics and their adaptation in class is needed in order to successfully carry out classes that incorporate various new media.

• International Journal of Computer Science & Network Security
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• v.22 no.6
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• pp.374-381
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• 2022

The article identifies and theoretically substantiates the trends of national resilience in the context of establishing the security of the country and its civilizational subjectivity. The strategy of development of the pedagogical university in the conditions of European integration into the European educational and scientific space based on certain characterological features of the personality of the volunteer in the context of allocation of personal resilience is developed. The analysis of both external and internal challenges and threats to the civilization of the country needs to be understood in the context of economic, socio-political, legal, military-political, spiritual-cultural, educational-scientific and network-information resilience. The concepts of "national resilience" and "national security" are quite close - at first glance, even identical. However, a deeper understanding clarifies the differences: national security is a state of protection of the country identity and its very existence, the realization of its national interests. In turn, resilience is a fairly effective strategy and a fundamental guarantee of national security. At the same time, it is extremely important to understand that both national security as a state and national resilience as a strategy are only means of achieving and developing a strong and humanistic civilizational subjectivity of the country. After all, such subjectivity opens for citizens the opportunity for development, dignified self-realization and a proper life. The restructuring of the volunteer's motivational sphere is due to the dominance of such leading motives, which are focused mainly on maintaining and restoring health, which leads to distorted meaningful life goals: isolation, alienation, passivity, inertia, reduced activity, limited communication, etc. The characteristics of relatively stable human behavior include several primary and secondary properties. The primary (relevant) properties include patience, trust, hope, faith, confidence, determination, perseverance, and love; the secondary - punctuality, neatness, obedience, honesty, loyalty, justice, diligence, thrift, accuracy, conscientiousness, obligation, etc. The restructuring of the volunteer's motivational sphere is due to the dominance of such leading motives, which are focused mainly on maintaining and restoring health, which leads to distorted meaningful life goals: isolation, alienation, passivity, inertia, reduced activity, limited communication, etc. The characteristics of relatively stable human behavior include several primary and secondary properties. The primary (relevant) properties include patience, trust, hope, faith, confidence, determination, perseverance, and love; the secondary - punctuality, neatness, obedience, honesty, loyalty, justice, diligence, thrift, accuracy, conscientiousness, obligation, etc. The use of information and communication technologies in volunteering will contribute to the formation of resilience traits in the structure of personality formation. Directly to the personal traits of resilience should be included methodological competencies, which include methodological knowledge, skills and abilities (ability to define ultimate and intermediate goals, plan, conduct and analyze knowledge, establish and implement interdisciplinary links with disciplines of medical-psychological-pedagogical cycles, etc.). All these competencies form the professional resilience of the volunteer.