• Journal of Korean Society of Transportation
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• v.26 no.2
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• pp.89-100
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• 2008

In an urban network controlled by traffic signals, there is an interaction between the signal timing and the routes chosen by individual road users. This study develops a bi level programming model for traffic signal optimization in networks with path based traffic assignment. In the bi level programming model, genetic algorithm approach has been proposed to solve upper level problem for a signalized road network. Path based traffic assignment using column generation technique which is proposed by M.H. Xu, is applied at the lower-level. Genetic Algorithm provieds a feasible set of signal timings within specified lower and upper bounds signal timing variables and feeds into lower level problem. The performance of this model is investigated in numerical experiment in a sample network. In result, optimal signal settings and user equilibrium flows are made.

• The Transactions of the Korea Information Processing Society
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• v.7 no.4
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• pp.1193-1200
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• 2000

A network topology has been an important factor for an efficient network management, but data collection for the network configuration has been done manually or semi automatically by a network administrator or an expert. Requirements to generate an intro-domain network topology ar usually either all IP addresses with subne $t^ernet mask or the network identification of all IP addresses. The amounts of traffic are generally high in the semi-automatic system due to using large number of low-level protocols and commands to get rather simple data. In this paper, we propose an algorithm which can be executed with only publicly available input. It can find all IP addresses as well as the network boundary of an intra-domain by using an intelligent method developed in this algorithm. The collected data will be used to draw a network map automatically by using a proposed network topology generation algorithm.hm.

• Journal of The Institute of Information and Telecommunication Facilities Engineering
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• v.3 no.2
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• pp.81-89
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• 2004

In this paper, we describe ubiquitous environments and the trend of convergence that is an evolution path of. current telecommunication, and show the concept of broadband convergence network, service feature and evolution path. In order to converge wire and wireless communication, telecommunication and broadcasting, voice and data efficiently, broadband convergence network divides a network into service layer, control layer, transport layer, ubiquitous access and terminal layer. Broadband convergence network will be a network that can provide and control broadband multimedia services with QoS and security of different and customized level. Then we depict characteristics and types of broadband multimedia service, and describe the characteristic of broadband convergence network. Finally, we show ubiquitous network based on the broadband convert- gence network to provide ubiquitous service which is a future telecommunication service. We also describe requirements of ubiquitous network such as an intelligent and context based platform, convergence terminals, ubi- quitous computing devices, etc.

• Journal of Information Processing Systems
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• v.20 no.4
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• pp.458-476
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• 2024

To address the issue of class imbalance in network traffic data, which affects the network intrusion detection performance, a combined framework using transformers is proposed. First, Tomek Links, SMOTE, and WGAN are used to preprocess the data to solve the class-imbalance problem. Second, the transformer is used to encode traffic data to extract the correlation between network traffic. Finally, a hybrid deep learning network model combining a bidirectional gated current unit and deep neural network is proposed, which is used to extract long-dependence features. A DNN is used to extract deep level features, and softmax is used to complete classification. Experiments were conducted on the NSLKDD, UNSWNB15, and CICIDS2017 datasets, and the detection accuracy rates of the proposed model were 99.72%, 84.86%, and 99.89% on three datasets, respectively. Compared with other relatively new deep-learning network models, it effectively improved the intrusion detection performance, thereby improving the communication security of network data.

• Proceedings of the KIPE Conference
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• 1997.07a
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• pp.352-356
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• 1997

This paper present the design of a novel neural-network (NN) based pulse-width modulation (PWM) techniques for a three-level power converter of electric trains along with nonlinear mapping of essential switching patterns and fault tolerance, which are inherent characteristics of NNs. Considering the importance of safety, power factor and harmonics of electric train power converters, two-level type and three-level type of power converters using NNs are precisely investigated and compared in computer simulation. A computer simulation shows that a new current control scheme provides an improved performance over a fixed-band hysteresis current control in many aspects.

• ETRI Journal
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• v.30 no.2
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• pp.205-215
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• 2008

Many control schemes have been proposed for flow-level traffic control. However, flow-level traffic control is implemented only in limited areas such as traffic monitoring and traffic control at edge nodes. No clear solution for end-to-end architecture has been proposed. Scalability and the lack of a business model are major problems for deploying end-to-end flow-level control architecture. This paper introduces an end-to-end transport architecture and a scalable control mechanism to support the various flow-level QoS requests from applications.

• Journal of Communications and Networks
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• v.8 no.1
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• pp.106-115
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• 2006

The current trend toward the utilization of the Internet as a common means for the offer of heterogeneous services imposes to address the issues related to end-to-end service assurance in the inter-domain scenario. In this paper, we first present an architecture for service management in networks based on service level specifications (SLS). The architecture is designed to be independent both of the specific network technology adopted and of the high level service semantics. Then, we focus on a specific functionality of the proposed architecture: Resource allocation in the multi-domain scenario. A distributed admission control algorithm is introduced, its complexity is evaluated and a comparison with related solutions is provided.

• Korean Management Science Review
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• v.11 no.1
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• pp.73-90
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• 1994

Recently the recongnition of Logistics becomes important to enterpries as a means for improving their competition, but the Korea enterpries falls for far behind in management techniques for analyzing realities and problems in the Logistics compare to the advanced countries. Especially the function of inventory control which is most undeveloped in them should be improved in Korea. Inventory is very important in Logistics, but there exists trade-off between inventory level and customer in the service level. It is difficult to coordinate both the reduction in the inventory level and the enhancement in the service level. Its effective technique is a DRP system. In general, it deals with arborescent distribution network in which a given channel member has a single source of supply. This article aims to present a DRP system, and more a DRP system which is flexible and responsive in the multisourcing, multi-echelon distribution network. Related research issues are discussed. Finally, using a DRP system on logistics and the management performance. So we can help the physical distribution improvement of the Korean enterprises.

• Journal of Construction Engineering and Project Management
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• v.2 no.2
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• pp.28-35
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• 2012

Critical to project success is effective stakeholder management. This paper presents a challenge for the project manager who uses traditional approaches to manage mid-level stakeholders in an organization. Dual roles of a mid-level stakeholder (as a stakeholder of a project and as an agent of the corporate) may cause problems that would result in difficulties for project managers in identifying the stakeholder's attributes and overcoming hierarchical authority expectation. However, the dual roles of the stakeholder result in its weakness in the project-stakeholder relationship. Can a project leverage its strategic role for effective upward influence by linking project objectives to corporate strategic objectives? To address this research question, case study method was used to gain a deeper understanding of mid-level stakeholder's salience. This research proposes an upward influence strategy to embed a project-stakeholder relationship in a hierarchical stakeholder network.

• International Journal of Computer Science & Network Security
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• v.21 no.11
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• pp.119-130
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• 2021

This study aimed at Evaluate Students' Interaction and Happiness in Distance Learning Among Students with Learning-Difficulties, by identifying the level of students' interaction in distance education and differences between them, as well as its impact on their happiness to learn. To achieve the aim of the study, two scales were designed for this purpose and were applied to a sample consisting of (310) individuals. The results showed that the level of students' interaction through the e-learning platform was at a high level. The results also showed that there was no statistically significant difference between the mean scores of males and females in the scale of students' interaction through the e-learning platform. There was no statistically significant difference between them in their happiness for distance learning via the online platform. There were also no statistically significant differences related to the grade variable in the level of interaction through the electronic platform and in the happiness to learn, while there was a positive statistically significant effect of interaction through the electronic platform on students' happiness to learn.