• Journal of the Korean Society for Railway
• /
• v.16 no.6
• /
• pp.510-518
• /
• 2013

These days, interest in radio networks for railways has increased both at home and abroad. In response to this trend, not only the existing radio networks which focus on railway control signals but also the next-generation integrated radio network that can send videos and manage mass storage data are actively being investigated. This paper proposes wireless communication methods to establish integrated radio networks for railways. The paper further suggests a candidate frequency band that could be allocated as the frequency band for railways among the frequency bands currently used in Korea. Based on this paper, we can expect that the domestic railroad will operate more efficiently and that security and convenience of the railroad will reach a superior level. In addition, the Korean integrated radio networks for railways, which cope with the changes in the global technology market, will be established.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.13 no.6
• /
• pp.2964-2985
• /
• 2019

Global data center IP traffic is expected to reach 20.6 zettabytes (ZB) by the end of 2021. Intra-data center networks (Intra-DCN) will account for 71.5% of the data center traffic flow and will be the largest portion of the traffic. The understanding of traffic distribution in IntraDCN is still sketchy. It causes significant amount of bandwidth to go unutilized, and creates avoidable choke points. Conventional transport protocols such as Optical Packet Switching (OPS) and Optical Burst Switching (OBS) allow a one-sided view of the traffic flow in the network. This therefore causes disjointed and uncoordinated decision-making at each node. For effective resource planning, there is the need to consider joining the distributed with centralized management which anticipates the system's needs and regulates the entire network. Methods derived from Kalman filters have proved effective in planning road networks. Considering the network available bandwidth as data transport highways, we propose an intelligent enhanced SDN concept applied to OBS architecture. A management plane (MP) is added to conventional control (CP) and data planes (DP). The MP assembles the traffic spatio-temporal parameters from ingress nodes, uses Kalman filtering prediction-based algorithm to estimate traffic demand. Prior to packets arrival at edges nodes, it regularly forwards updates of resources allocation to CPs. Simulations were done on a hybrid scheme (1+1) and on the centralized OBS. The results demonstrated that the proposition decreases the packet loss ratio. It also improves network latency and throughput-up to 84 and 51%, respectively, versus the traditional scheme.

• Journal of Korea Trade
• /
• v.26 no.4
• /
• pp.39-62
• /
• 2022

Purpose - Along with the growing awareness of environmental sustainability, international green entrepreneurship is expected to realize international sustainable development (ISD) by introducing ecological innovation results, using fewer resources consumption, and reducing negative environmental impacts. Building upon contingency theory and social network theory, this paper attempts to explore the role of home country-based networks (technology ties and business ties) as contingent factors that might impact the effectiveness of entrepreneurial orientation (EO) in promoting ISD among green ventures. Design/methodology - Original data were collected from 127 green ventures in China based on the random sampling technique. These green ventures mainly focus on the lower use of energy or materials, lower CO2 emissions, and higher ecological benefits located in the Fujian province, which highlights green economic growth and economic cooperation with international markets. Moderated hierarchical linear regression analysis was conducted to test our hypotheses concerning the main relationship between EO (innovativeness, proactiveness, and risk-taking) and ISD as well as the moderating effects of home country-based networks (technology ties and business ties) on the main relationship. Findings - Empirical results indicate that: first, both innovativeness and proactiveness positively affect ISD; second, both technology ties and business ties at home might significantly strengthen the positive relationship between innovativeness (or proactiveness) and ISD. However, this study did not find significant moderating effects of technology ties or business ties at home on the relationship between risk-taking and ISD. Originality/value - Since previous literature often gives more focus on the host country context of social networks, this study shifts to a home country-based network context. Therefore, our research might enrich the international green entrepreneurship literature by empirically investigating the contingent value of home country-based networks in the relationship between EO and ISD in the context of an emerging economy such as China.

• International Commerce and Information Review
• /
• v.14 no.2
• /
• pp.55-79
• /
• 2012

The previous studies based on a resource-based view of firm highlighted the role of resources within a firm in creating and sustaining competitive advantage. Recent research, however, the relational view points to the importance of inter-firm sources(or relational capital) in creating firm competitiveness. In international business field, the studies on born-global firms also states that when firms are lack of ownership-specific advantages in their internationalization process, they resort to the external partners and social networks to complement their resource scarcity. By adopting the relational view and born-global firms concept, a network-based approach needs to be applied to explain the international strategy of Korean service firms. This is because most of Korean service firms own less ownership-specific advantages than global competitors. This study proposes Korean firms' global network building and exploiting strategy to enhance their international stages of development. The network, for example, Global Korean Tourism Network, enables network members access to the valuable resources and capabilities they are lack of when undergoing internationalization process. This study's contribution is along two dimension. First, even global Korean network is emerging as a major issue in recent years, we could not figure out how to build global Korean network for service firms. This studies gives an answer. Second, we derived what benefits can be gained from the network if Global Korean Tourism Network is developed for hotel, tourism, convention firms' internationalization.

• Journal of Distribution Science
• /
• v.18 no.4
• /
• pp.97-106
• /
• 2020

Purpose: Participation of firms in Global Value Chains (GVC) has contributed significantly to the improvement of economic outcomes for firms in developing countries. However, evidence suggests that these economic outcomes are gained at the cost of labourers' poor working conditions. This research contributes to existing literature on GVCs by investigating the influence of different governance structures on economic and social upgrading of firms participating in GVCs. Furthermore, the research attempts to understand the relationship between economic and social upgrading in GVCs. Research design and methodology: Detailed qualitative primary research was carried out in the football industry of Sialkot, Pakistan. The case study approach was employed, and football firms were the unit of analysis. Semi-structured interviews with firms' representatives were conducted. Results: Findings reveal that most firms were found in captive, relational and market governance structures. Furthermore, product and process upgrading were witnessed in all firms; however, social upgrading was observed mostly in captive and relational GVCs. Moreover, social upgrading was linked to economic upgrading in captive and relational networks. Conclusions: The findings from the Sialkot football industry reflect that buyers pay higher prices and margins to their suppliers once they upgrade their products and processes.

• Journal of Korea Multimedia Society
• /
• v.18 no.9
• /
• pp.1105-1117
• /
• 2015

During the last decade, the business infrastructure has become digital with increased interconnections among products, processes, and services. Across many firms spanning different industries and sectors, digital technologies are fundanmentally transforming business stratiges, business processes, firm capabilities, productes and services, and key interfirm relationships in extended business networks. With the emergence of smartphones, the paradigm of the ICT industry is rapidly changing as the line between global and local markets are being blurred. In the changing global environment, although some game companies are accelerating the improvement of their global competitiveness and cases of successes of venture enterprises by developing biosimilar technology are being discovered, majority of ICT companies are focusing on limited marketing activities to get subcontracts or projects from large companies. Thus the aim of this study is to find out how digital ecosystems evolve and how business models and strategies have changed of individual companies according to the evolution of the digital ecosystems.

• YAKHAK HOEJI
• /
• v.59 no.3
• /
• pp.113-119
• /
• 2015

Protein phosphorylation is one of most important post-translational modifications (PTMs) and plays an important role in regulation of protein function. Here we develop a method for a global identification of phosphopeptides and phosphorylation sites using nano-LC MS/MS. We compared two separation methods, C4 and strong cation ion exchange (SCX). Before phosphopeptides enrichment with $TiO_2$, total proteins from Rat 1 cells have been separated using C4 column or tryptic peptides of proteins from the cells have been separated using SCX column. Finally, we have detected 52 phosphorylation sites on 41 proteins from SCX method and 375 phosphorylation sites on 252 proteins from C4 method, and determined the function and localization of identified phosphoproteins using DAVID software. In particular, we showed new phosphorylation sites from membrane proteins related to various cell signaling mechanisms. This method may contribute to study global signal networks induced by various signals including ligands and drugs.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.32 no.9B
• /
• pp.569-576
• /
• 2007

This paper is on the enhancement of our heuristics for GOSST problem that could apply to the design of communication networks offering graduated services. This problem hewn as one of NP-Hard problems finds a network topology meeting the G-Condition with minimum construction cost. In our prior research, we proposed two heuristics. We suggest methods of selecting G-Node and disconnections for Global or Local locating heuristic in this research. The ameliorated Local locating heuristic retrenches 17% more network construction cost saving ratio and the reformed Global locating heuristic does 14% more than our primitives.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.9 no.4
• /
• pp.733-738
• /
• 2005

The distress communication system in the maritime mobile service had almost depended on the wireless telephony or telegraphy technique. The GMDSS (Global Maritime Distress and Safety System) which was introduced in 1992 brought a lot of changes in the maritime distress communication service such as the automatic transmission of distress signals and implementation of global search and rescue networks. However, there are some deficiencies in the GMDSS distress communication system such as a lack of compatibility in the maritime distress communication between CMDSS ships and Non-GMDSS ships, increasing deceptive or false distress alerts generated by GMDSS installations, lack of understanding about the CMDSS installations for the operators. In this paper, the problems of distress communication system in the maritime mobile service are analyzed and the methods to solve or minimize these problems are suggested.

• International Journal of Fuzzy Logic and Intelligent Systems
• /
• v.8 no.4
• /
• pp.239-247
• /
• 2008

In a resource-limited wireless communication environment, various approaches to meet the ever growing application requirements in an efficient and transparent manner, are being researched and developed. Amongst many approaches, cross layer technique is by far one of the significant contributions that has undoubtedly revolutionized the way conventional layered architecture is perceived. In this paper, we propose a Universal Cross Layer Framework based on vertical layer architecture. The primary contribution of this paper is the functional architecture of the vertical layer which is primarily responsible for cross layer interaction management and optimization. The second contribution is the use of optimization cycle that comprises awareness parameters collection, mapping, classification and the analysis phases. The third contribution of the paper is the decomposition of the parameters into local and global network perspective for opportunistic optimization. Finally, we have shown through simulations how parameters' variations can represent local and global views of the network and how we can set local and global thresholds to perform opportunistic optimization.