• 한국정보통신설비학회:학술대회논문집
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• 2007.08a
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• pp.327-330
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• 2007

This article discusses a capacity planning method in QoS-guaranteed IP networks such as BcN (Broadband convergence Network). Since IP based networks have been developed to transport best-effort data traffic, the introduction of multi-service component in BcN requires fundamental modifications in capacity planning and network dimensioning. In this article, we present the key issues of the capacity planning in multi-service IP networks. To provide a foundation for network dimensioning procedure, we describe a systematic approach for classification and modeling of BcN traffic based on the QoS requirements of BcN services. We propose a capacity planning framework considering data traffic and real-time streaming traffic separately. The multi-service Erlang model, an extension of the conventional Erlang B loss model, is introduced to determine required link capacity for the call based real-time streaming traffic. The application of multi-service Erlang model can provide significant improvement in network planning due to sharing of network bandwidth among the different services.

• Journal of Communications and Networks
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• v.11 no.3
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• pp.287-296
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• 2009

Although asymptotic bounds of wireless network capacity have been heavily pursued, the answers to the following questions are still critical for network planning, protocol and architecture design: Given a three-dimensional (3D) network space with the number of active users randomly located in the space and using the wireless communication technology, what are the expected per-flow throughput, network capacity, and network transport capacity? In addition, how can the protocol parameters be tuned to enhance network performance? In this paper, we focus on the ultra wideband (UWB) based wireless personal area networks (WPANs) and provide answers to these questions, considering the salient features of UWB communications, i.e., low transmission/interference power level, accurate ranging capability, etc. Specifically, we demonstrate how to explore the spatial multiplexing gain of UWB networks by allowing appropriate concurrent transmissions. Given 3D space and the number of active users, we derive the expected number of concurrent transmissions, network capacity and transport capacity of the UWB network. The results reveal the main factors affecting network (transport) capacity, and how to determine the best protocol parameters, e.g., exclusive region size, in order to maximize the capacity. Extensive simulation results are given to validate the analytical results.

• Journal of Korea Port Economic Association
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• v.22 no.1
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• pp.175-198
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• 2006

This paper presents a network capacity model that can be used as an analytical tool for strategic planning and resource allocation for multimodal transportation systems. In the context of freight transportation, the multimodal network capacity problem (MNCP) is formulated as a mathematical model of nonlinear bi-level optimization problem. Given network configuration and freight demand for multiple origin-destination pairs, the MNCP model is designed to determine the maximum flow that the network can accommodate. To solve the MNCP, a heuristic solution algorithm is developed on the basis of a linear approximation method. A hypothetical exercise shows that the MNCP model and solution algorithm can be successfully implemented and applied to not only estimate the capacity of multimodal network, but also to identify the capacity gaps over all individual facilities in the network, including intermodal facilities. Transportation agencies and planners would benefit from the MNCP model in identifying investment priorities and thus developing sustainable transportation systems in a manner that considers all feasible modes as well as low-cost capacity improvements.

• Journal of Information Technology Applications and Management
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• v.22 no.3
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• pp.129-141
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• 2015

The purpose of this study is to provide an explanation for the association between the characteristics of a network and the type of innovation by considering the effect of absorptive capacity. To do so, this study examined the moderating effects of absorptive capacity on the characteristics of network-innovation relationship in a technical-driven venture company. In order to obtain a better understanding about consequences caused by interfirm network, information was obtained from 169 Korean IT venture companies. Results confirmed that the network diversity is positively associated with exploration. Our results also suggested that the network strength is positively associated with exploitation. Finally, we found a positive two-way interaction between absorptive capacity and the network diversity-exploration relationship. Then, we discussed implications and directions for future research.

• Journal of the Institute of Electronics and Information Engineers
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• v.49 no.9
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• pp.11-17
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• 2012

Capacity is a traditional issue in wireless network and is closely related to the service quality of network providers, therefore it is a main interest of them. Especially, when a big match of sport game or a special event are held in a place and a large crowd temporarily gathers, a need of big transmission capacity greater than usual usage in the area is required, where network providers need a scheme to temporarily expand network capacity in any specified area. This paper focuses on temporary expansion of wireless network capacity for such situations. In this paper, we first investigate maximum transmission capacity of wireless ad-hoc networks. In the investigation, we consider a network topology with regularly located nodes. For the topology, we investigate the maximum transmission capacity with RTS/CTS medium access protocol, and then we study the maximum transmission capacity without the protocol. Next, we propose a scheme to expand network capacity and analyze the performance of the proposed scheme. From the results of analysis, we see that our proposed scheme is effective for temporary expansion of wireless network capacity.

• Journal of Communications and Networks
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• v.13 no.5
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• pp.525-535
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• 2011

In this paper, we study the contribution of network coding (NC) in improving the multicast capacity of random wireless ad hoc networks when nodes are endowed with multi-packet transmission (MPT) and multi-packet reception (MPR) capabilities. We show that a per session throughput capacity of ${\Theta}$(nT$^3$(n)) can be achieved as a tight bound when each session contains a constant number of sinks where n is the total number of nodes and T(n) is the transmission range. Surprisingly, an identical order capacity can be achieved when nodes have only MPR and MPT capabilities. This result proves that NC does not contribute to the order capacity of multicast traffic in wireless ad hoc networks when MPR and MPT are used in the network. The result is in sharp contrast to the general belief (conjecture) that NC improves the order capacity of multicast. Furthermore, if the communication range is selected to guarantee the connectivity in the network, i.e., ${\Omega}$($\sqrt{log\;n/n}$)=T(n) = O(log log n / log n), then the combination of MPR and MPT achieves a throughput capacity of ${\Theta}$(log$^{\frac{3}{2}}$ n/$\sqrt{n}$) which provides an order capacity gain of ${\Theta}$(log$^2$ n) compared to the point-to-point multicast capacity with the same number of destinations.

• ETRI Journal
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• v.32 no.6
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• pp.863-870
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• 2010

In recent years, the development of multimedia devices has meant that a wider multimedia streaming service can be supported, and there are now many ways in which TV channels can communicate with different terminals. Generally, scalable video streaming is known to provide more efficient channel capacity than simulcast video streaming. Simulcast video streaming requires a large network bandwidth for all resolutions, but scalable video streaming needs only one flow for all resolutions. In previous research, scalable video streaming has been compared with simulcast video streaming for network channel capacity, in two user simulation environments. The simulation results show that the channel capacity of SVC is 16% to 20% smaller than AVC, but scalable video streaming is not efficient because of the limit of the present network framework. In this paper, we propose a new network framework with an SVC extractor. The proposed network framework shows a channel capacity 50% (maximum) lower than that found in previous research studies.

• Journal of Industrial Technology
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• v.32 no.A
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• pp.9-13
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• 2012

In this paper, we investigate maximum transmission capacity of wireless ad-hoc networks. In the investigation, we consider a network topology with regularly located nodes. For the topology, we investigate the maximum transmission capacity with RTS/CTS medium access protocol, and next, we study the maximum transmission capacity without the protocol. We see that the results of our study overall follows the result of Gupta and Kumar's research.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.10
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• pp.3761-3771
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• 2010

This study, based on social capital theory, aims to explore how social network characteristics among organization members affect the absorptive capacity which is the ability to recognize the value of new information, assimilate it, and apply it to commercial ends. This paper also empirically investigates how the absorptive capacity will have an effect on organizational innovation performances toward achieving competitive advantages in the knowledge society. According to the degree of relationship intensity, social network shows two different characteristics: strong tied network and weak tied network. As strong tied network and weak tied network have relatively different network characteristics, this study assumes that each network affects the absorptive capacity with different aspects. Furthermore, we consider the moderation effect of a social network manager's ability in the relationship between social network and absorptive capacity. We surveyed innovative project performers who are engaged in the knowledge based industries. The empirical analysis results show that both strong tied and weak tied network positively affect the absorptive capacity. Successively, the absorptive capacity also has a positive impact on innovation performances.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.1B
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• pp.24-33
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• 2009

This paper considers network competition where the subscribers experience network congestion when they use the network and the network providers determine the network price and capacity. This paper discusses the impact of the network competition on social welfare. Network provider determines the price and capacity considering this characteristics of this sensitivity to network congestion where the subscriber has different preference about the congestion. This paper shows that network provider who wants to serve the intolerable customers (who is very sensitive to the congestion) offers higher price and capacity. However, this provider prepares lower capacity than socially optimal capacity. This is because the network provider seeks to earn more profits from additional subscriber while it is desirable to invest the capacity to give the entire subscribers a non-congestion network in the view of social welfare.