• Journal of the Korean Geosynthetics Society
• /
• v.18 no.4
• /
• pp.39-52
• /
• 2019

In this paper the development and implementation of an artificial intelligence (AI)-based Tunnelling Impact prediction and assessment program (SKKU-iTunnel) is presented. Program predicts tunnelling induced surface settlement and groundwater drawdown by utilizing well trained ANNs and uses these predicted values to perform the damage assessment likely to occur in nearby structures and pipelines/utilities for a given tunnel problem. Generalised artificial neural networks (ANNs) were trained, to predict the induced parameters, through databases generated by combining real field data and numerical analysis for cases that represented real field conditions. It is shown that program equipped with carefully trained ANN can predict tunnel impact assessments and perform damage assessments quiet efficiently and comparable accuracy to that of numerical analysis. This paper describes the idea and implementation details of the SKKU-iTunnel with an example for demonstration.

• ETRI Journal
• /
• v.43 no.1
• /
• pp.40-52
• /
• 2021

DNS (Domain Name System) tunnels almost obscure the true network activities of users, which makes it challenging for the gateway or censorship equipment to identify malicious or unpermitted network behaviors. An efficient way to address this problem is to conduct a temporal-spatial analysis on the tunnel traffic. Nevertheless, current studies on this topic limit the DNS tunnel to those with a single protocol, whereas more than one protocol may be used simultaneously. In this paper, we concentrate on the refined identification of two protocols mixed in a DNS tunnel. A feature set is first derived from DNS query and response flows, which is incorporated with deep neural networks to construct a regression model. We benchmark the proposed method with captured DNS tunnel traffic, the experimental results show that the proposed scheme can achieve identification accuracy of more than 90%. To the best of our knowledge, the proposed scheme is the first to estimate the ratios of two mixed protocols in DNS tunnels.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.24 no.3
• /
• pp.27-34
• /
• 2024

The direct and indirect damages caused by fires in underground utility tunnels have a great impact on society as a whole, so efforts are needed to prevent and manage them in advance. To this end, research is ongoing to prevent disasters such as fire flooding by applying digital twin technology to underground utility tunnels. A network is required to transmit the sensed signals from each sensor to the platform. In essence, it is necessary to analyze the application of wireless networks in the underground utility tunnel environments because the tunnel lacks the reception range of external wireless communication systems. Within the underground utility tunnels, electromagnetic interference caused by transmission and distribution cables, and diffuse reflection of signals from internal structures, obstacles, and metallic pipes such as water pipes can cause distortion or size reduction of wireless signals. To ensure real-time connectivity for remote surveillance and monitoring tasks through sensing, it is necessary to measure and analyze the wireless coverage in underground utility tunnels. Therefore, in order to build a wireless network environment in the underground utility tunnels. this study minimized the shaded area and measured the actual cavity environment so that there is no problem in connecting to the wireless environment inside the underground utility tunnels. We analyzed the data transmission rate, signal strength, and signal-to-noise ratio for each section of the terrain of the underground utility tunnels. The obtained results provide an appropriate wireless planning approach for installing wireless networks in underground utility tunnels.

• The KIPS Transactions:PartC
• /
• v.18C no.5
• /
• pp.339-342
• /
• 2011

This paper proposes a network-based mobility control scheme in wireless/mobile networks, which is based on the Locator-Identifier Separation Protocol (LISP). Compared to the existing LISP mobility scheme, the proposed scheme is featured by the following two points: 1) each LISP Tunnel Router (TR) is implemented at the first-hop access router that mobile nodes are attached to, and 2) for handover support, the LISP Routing Locator (RLOC) update operation is performed between Ingress TR and Egress TR. By numerical analysis, it is shown that the proposed scheme can reduce the handover latency much more than the other candidate schemes.

• Structural Engineering and Mechanics
• /
• v.77 no.4
• /
• pp.495-508
• /
• 2021

This study devises a novel approach, namely quadruple 1D convolutional neural network, for detecting connection stiffness reduction in steel truss bridge structure using experimental and numerical modal data. The method is developed based on expertise in two domains: firstly, in Structural Health Monitoring, the mode shapes and its high-order derivatives, including second, third, and fourth derivatives, are accurate indicators in assessing damages. Secondly, in the Machine Learning literature, the deep convolutional neural networks are able to extract relevant features from input data, then perform classification tasks with high accuracy and reduced time complexity. The efficacy and effectiveness of the present method are supported through an extensive case study with the railway Nam O bridge. It delivers highly accurate results in assessing damage localization and damage severity for single as well as multiple damage scenarios. In addition, the robustness of this method is tested with the presence of white noise reflecting unavoidable uncertainties in signal processing and modeling in reality. The proposed approach is able to provide stable results with data corrupted by noise up to 10%.

• Journal of KIISE:Information Networking
• /
• v.34 no.5
• /
• pp.348-359
• /
• 2007

The conventional mobile VPN services assumed the mobile communications occur between the MN in foreign networks and the CN in the home network. However, if a MN wants to communicate with another MN in a foreign network, it could degrade the performance of the mobile VPN service because of the triangular routing problem. In this paper, we propose a route optimization mechanism based on the mobile VPN using an x-HA allocated by diameter MIP in order to support the efficient communication between the mobile VPN users in foreign networks. The i-HA maintains the VPN-TIA as well as the x-HoA as the CoAs to solve the security problem and to provide an efficient route optimization simultaneously. Moreover, we proposed revised IPSec tunnel configuration to reduce the IPSec tunnel overheads at a MN when the MN communicates with several MNs in the foreign networks at the same time. The VPN server, a security management entity in the home network, notifies an additional IPSec tunnel establishment between the x-HAs where the communication peers are registered. The simulation result showed that the proposed scheme decreases the end-to-end packet delay time and improves the throughput after the handoff compared to the existing mechanism.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.16 no.3
• /
• pp.321-339
• /
• 2014

This paper concerns the development of a knowledge-based tunnel design system within the framework of artifical neural networks(ANNs). The system is aimed at expediting a routine tunnel design works such as computation of segment lining body forces and stability analysis of selected cross section. A number of sub-modules for computation of segment lining body forces and stability analysis were developed and implemented to the system. It is shown that the ANNs trained with the results of 3D numerical analyses can be generalized with a reasonable accuracy, and that the ANN based tunnel design concept is a robust tool for tunnel design optimization. The details of the system architecture and the ANNs development are discussed in this paper.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.43 no.4 s.346
• /
• pp.1-12
• /
• 2006

In this paper we propose an efficient mobile multimedia communication protocol, mobile terminal software platform and mobile VoIP application for IP-based convergence networks. The Proposed mobile multimedia communication protocol is called as ST-MRSVP (Split tunnel based Mobile Resource reServation Protocol) which integrates split tunnel based Mobile IP and RSVP in order to support hish speed mobility. Since mobile terminal platform supports QoS (Qualify of Service) with keeping seamless mobility, mobile QoS supporting modules are developed and interworked together by means of shared memory mechanism. Testbed is composed of a core-network embedding the proposed protocols and wireless LAN-based access networks. We verify functionality and performance of the proposed techniques by using various mobility test over the testbed. As a result, the proposed architecture can reduce the handover delay time with QoS support under 30% comparing with the standard mechanisms and support voice quality as good as CDMA phone.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.12 no.6
• /
• pp.229-240
• /
• 2012

The development of multimedia applications followed by development of high-speed networks has improved the performance of mobile devices with high transfer speed broadband. Mobile internet access has made possible seamless indoor and outdoor mobile multicast services. Multicasting services are used to support efficient group communications. However, mobile multicasting services have two constraints: tunnel convergence and handover latency. Many protocols and handover methods have been proposed to address these problems. The inter-LMA optimized handover model for multicasting services has previously been proposed for PMIPv6-based networks. The proposed model removes the tunnel convergence issue and reduces router processing costs. It also makes possible the performance of fast handover operations with adaptive transmission mechanisms. In addition, the proposed scheme exhibits low packet delivery costs and handover latency in comparison with existing schemes, and ensures fast handover when moving the inter-LMA domain

• KIPS Transactions on Computer and Communication Systems
• /
• v.2 no.6
• /
• pp.265-278
• /
• 2013

With the recent advancements in various wireless communication technologies, the importance of mobile multicasting is coming to the fore, in an effort to use network resources more efficiently. In the past, when various mobile IP-based multicast techniques were proposed, the focus was put on the costs needed for network delivery for providing multicast services, as well as on minimizing the multicast handover delay. For techniques using MIPv6 (Mobile IPv6), a host-based mobility management protocol, however, it is fundamentally difficult to resolve the problems of handover delay and tunnel convergence. To resolve these problems, a network-based mobility management protocol called PMIPv6 (Proxy Mobile IPv6) was standardized. Although performance is improved in PMIPv6 over MIPv6, it still suffers from the problems of handover delay and tunnel convergence. In this paper, to overcome these limitations, a technique called LFH (Low-cost and Fast Handoff) is proposed for fast and low-cost mobility management with multicasting support in PMIPv6 networks. To reduce the interactions between the complex multicast routing protocol and the multicast messages, a simplified proxy method called MLD (Multicast Listener Discovery) is implemented and modified. Furthermore, a TCR (Tunnel Combination and Reconstruction) algorithm was used in the multicast handover procedure within the LMA (Local Mobility Anchor) domain, as well as in the multicast handover procedure between domains, in order to overcome the problem of tunnel convergence. As a result, it was found that LFH has reduced multicast delay compared to other types of multicast techniques, and that it requires lower costs as well.