• Journal of Korea Water Resources Association
• /
• v.54 no.5
• /
• pp.289-299
• /
• 2021

This study analyzes bifurcation characteristics of the Seolmacheon experimental catchment by extracting the shape variation of channel network due to variable scale of source basin or threshold area. As the area of source basin decreases, a bifurcation process of channel network occurs within the basin of interest, resulting in the elongation of channel network (increase of total channel length) as well as the expansion of channel network (increase of the source number). In the former case, the elongation of channel reaches overwhelms the generation of sources, whereas, in the latter case, the drainage path network tends to fulfill the inner space of the basin of interest reflecting the opposite trend. Therefore, scale invariance of natural channel network could be expressed to be a balanced geomorphologic feature between the elongation of channel network and the expansion of channel network due to decrease of source basin scale. The bifurcation structure of the Seolmacheon experimental catchment can be characterized by the coexistence of the elongation and scale invariance of channel network, and thus a further study is required to find out which factor is more crucial to rainfall transformation into runoff.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.10 no.8
• /
• pp.3529-3550
• /
• 2016

In heterogeneous networks (HetNets), energy saving is vital for a sustainable network development. Many techniques, such as spectrum allocation, network planning, etc., are used to improve the network energy efficiency (EE). In this paper, micro BSs utilizing cell range expansion (CRE) and spectrum allocation are considered in multi-channel heterogeneous networks to improve EE. Hotspot region is assumed to be covered by micro BSs which can ensure that the hotspot capacity is greater than the average demand of hotspot users. The expressions of network energy efficiency are derived under shared, orthogonal and hybrid subchannel allocation schemes, respectively. Particle swarm optimization (PSO) algorithm is used to solve the optimal ratio of subchannel allocation in orthogonal and hybrid schemes. Based on the results of the optimal analysis, we propose three service control strategies on the basis of large-scale user behaviors, i.e., adjust micro cell rang expansion (AmCRE), adjust micro BSs density (AmBD) and adjust micro BSs transmit power (AmBTP). Both theoretical and simulation results show that using shared subchannel allocation scheme in AmBD strategies can obtain maximal EE with a very small area ratio. Using orthogonal subchannel allocation scheme in AmCRE strategies can obtain maximal EE when area ratio is larger. Using hybrid subchannel allocation scheme in AmCRE strategies can obtain maximal EE when area ratio is large enough. No matter which service control strategy is used, orthogonal spectrum scheme can obtain the maximal hotspot user rates.

• Water for future
• /
• v.28 no.2
• /
• pp.169-180
• /
• 1995

The cost of a looped pipe network is affected by a set of loop flows. The mathematical model for optimizing the looped pipe network is expressed in the optimal set of loop flows to apply to a stochastic optimization method. Because the feasible region of the looped pipe network problem is nonconvex with multiple local optima, the Modified Stochastic Probing Method is suggested to efficiently search the feasible region. The method consists of two phase: i) a global search phase(the stochastic probing method) and ii) a local search phase(the nearest neighbor method). While the global search sequentially improves a local minimum, the local search escapes out of a local minimum trapped in the global search phase and also refines a final solution. In order to test the method, a standard test problem from the literature is considered for the optimal design of the paralled expansion of an existing network. The optimal solutions thus found have significantly smaller costs than the ones reported previously by other researchers.

• Knowledge Management Research
• /
• v.16 no.2
• /
• pp.1-27
• /
• 2015

This paper presents a knowledge-based view of platform-centered collaborations among multiple organizations. Studies of technological innovation and knowledge creation have broadened beyond their initial emphasis on internal development within an organization or simple exchange of ideas between two parties toward complex collaboration among many organizations at the level of platform-based knowledge ecosystems. Platforms serve as an interface between different groups of producers and consumers in a variety of multi-sided knowledge markets such as smartphone operating systems and video games industries. This study is an exploratory examination to offer theoretical understanding of how the organizational capabilities of platform leaders help expand a network of platform participants. The growth of platform participants is particularly important in the early stage of any platforms as the concept of network effects suggests that the platform with the largest number of participants will capture entire markets. Building upon organization studies and network economics theory on multisided markets, this paper focuses on the role of platform leaders in expanding platform-based collaboration. In our view, platform leaders develop varying levels of three organizational capabilities to discern quality of potential participants, to attract them to actually participate in collaboration, and to maintain long-term exchange relations in the ecosystem. We suggest that the capabilities of platform leaders will have a positive effect on the expansion of platform participants to secure network effects, and also examine several contextual factors that moderate the relationship between a platform leader's capacity and platform expansion.

• The Journal of Bigdata
• /
• v.2 no.2
• /
• pp.1-7
• /
• 2017

Intelligent transportation system (ITS) has been introduced to maximize the efficiency of operation and utilization of the urban traffic facilities and promote the safety and convenience of the users. With the expansion of ITS, various traffic big data such as road traffic situation, traffic volume, public transportation operation status, management situation, and public traffic use status have been increased exponentially. In this paper, we derive structural characteristics of urban traffic according to the vehicle flow by using big data network analysis. DSRC (Dedicated Short Range Communications) data is used to construct the traffic network. The results can help to understand the complex urban traffic characteristics more easily and provide basic research data for urban transportation plan such as road congestion resolution plan, road expansion plan, and bus line/interval plan in a city.

• Journal of Korea Port Economic Association
• /
• v.28 no.3
• /
• pp.215-234
• /
• 2012

Since ports play a role of gateway to the sea and hinterlands, it is essential to analyse the networks of shipping and inland when evaluating the function and development of a port. The container port of Gwangyang, starting to operate its facilities in 1998, has developed itself as a hub port. Using the data of shipping schedules of Korean ports and the measurement of centrality in sociology, this study analyses the process of world-wide shipping network expansion in Gwangyang and concludes some implications including earlier development of shipping networks due to incentives to shipping companies. Although Gwangyang port also has been expanding its inland network through developing trucking, railway transport, and coastal shipping, it has weakness in inland network as in the cases of interruption in 2004, resumption in 2009 and re-interruption in 2012 at coastal shipping. In 2000s the expansion of shipping and inland networks at the newly built container ports such as Pyungtaek, Ulsan, and Gunsan has enticed the competition among Korean ports at each hinterland. Nevertheless, the operation of Gwangyang container port is considered to affect indirectly the relocation of some manufacturers including Samsung Electronics. Studies on interrelation between development of container port and geographical demography of manufacturers are needed to assess the effects of container port on regional economy.

• Journal of the Korea Society of Computer and Information
• /
• v.9 no.4 s.32
• /
• pp.127-131
• /
• 2004

In this paper, I propose the web-based network traffic monitoring system to monitor computers running MS Windows in the small-scale PC-room. The system can support network and system operation, management, expansion, and design using network analysis and diagnosis to a network administrator. The whole system consists of two parts: analysis server for collection and analysis of the network information. and supports real-time monitoring of network traffic, and the web-based interface system. a client system shows user a graphical data that analyzed a returned result from the server. This system implements web-based technology using java and contributes to enhance the effectiveness of network administrator's management activities in PC-room by controlling and monitoring.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.27 no.4C
• /
• pp.282-294
• /
• 2002

The modern telecommunication networks are composed of various network-type and are managed by various management technologies, such as TMN, SNMP, TINA etc. Furthermore, the network user's needs of real-time multimedia services are rapidly increasing. In order to guarantee the user-requested quality-of-service(QoS) and keep the network utilization at maximum, it is required to manage the network performance continuously after the network is deployed. The performance management function should provide the useful information for the network expansion and the capacity reallocation in the future. In this paper, we propose a DPE-based performance management architecture for the integrated management of the heterogeneous network elements with TMN and SNMP. We propose an approach to provide the Intranet traffic monitoring and analysis function using layered network management concept and distributed processing technology. The proposed architecture has been designed and implemented based on multiprocess and multithread structure to support concurrent processing. To manage the traffic according to the Intranet service categories, we implemented an ITMA(Intelligent Traffic Monitoring Agent) with packet capture library. With the proposed architecture, we could measure and analyze the real Intranet traffic of Yeungnam University.

• Journal of KIBIM
• /
• v.10 no.2
• /
• pp.1-11
• /
• 2020

BIM(Building Information Modeling) is a salient technology for influential innovation in the construction industry. The patent network analysis is useful for suggesting the direction of technology development and exploring the research and development field. Therefore, the purpose of this study is to analyze the BIM technology structure and core technologies according to the convergence of BIM technology and market expansion. In this study, social network analysis was conducted by establishing a co-classification IPC network for the United States BIM patent. In particular, the characteristics of the major technical areas in the BIM technology network were identified through centrality analysis. G06F017/00, digital computing or data processing method, is a core technology field in the BIM network. Arrangements, apparatus or systems for transmission of digital information, H04L029/00 is an influential technology across the network. B25J009/00 for program controlled manipulators is an intermediary technology field and G06T019/00, manipulating 3D models or images for computer graphics, is an important field for technological development competitiveness.

• Journal of the Korean Institute of Rural Architecture
• /
• v.6 no.1
• /
• pp.32-41
• /
• 2004

Many administrative policies for regional activation have progressed the expansion and improvement of convenience institutions. Most appraisals about rural community influenced by urban life convenience are affirmative, but chasing urban life convenience is a cause of breaking out regional identity. Recently, new rising methods of theme and characteristic to imply regional identity, are ways of regional activation through neighboring network around satellite of rural community. In this study, I research and suggest applicable possible proposal of rural communities in Korea. by survey of neighboring network methods of Asan Live Museum in Japan applied ecomuseum concept for regional activation.