• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.9B
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• pp.589-597
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• 2007

In this paper, a WDM metro ring consisting of access nodes with $FT-FR^n$ (Fixed Transmitter - n Fixed Receivers) is considered. A trade-off exists between node throughput and transmission fairness because the access nodes share wavelength channels. In order to eliminate the transmission unfairness and to increase throughput, the p-persistent medium access control (MAC) protocol is proposed: each node uses an empty optical slot to transmit a packet and make it available with the extraction of a transferred packet at the source access node, called source-stripping. The local empty slot can be used to transfer a head-of-line packet in the local buffer with probability p or it is used for the next downstream nodes with 1-p. The proposed MAC protocol provides better node throughput than the non-persistent protocol and exhibits better fairness index than the 1-persistent protocol in WDM ring networks. In addition, numerical analysis shows that the proposed MAC protocol maximizes the node throughput under uniform traffic conditions. For more detailed results, we use the network simulation under Poisson and self-similar traffic. Furthermore, unpredictable traffic constructed by the combination of the former and the latter is also considered. The reasonable probability of the p-persistent protocol for a given architecture can be determined through simulation.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.7
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• pp.3041-3063
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• 2018

Community search aims at finding a meaningful community that contains the query node and also maximizes (minimizes) a goodness metric. This problem has recently drawn intense research interest. However, most metric-based algorithms tend to include irrelevant subgraphs in the identified community. Apart from the user-defined metric algorithm, how can we search the natural community that the query node belongs to? In this paper, we propose a novel community search algorithm based on the concept of the k-hop and local distance dynamics model, which can naturally capture a community that contains the query node. The basic idea is to envision the nodes that k-hop away from the query node as an adaptive local dynamical system, where each node only interacts with its local topological structure. Relying on a proposed local distance dynamics model, the distances among nodes change over time, where the nodes sharing the same community with the query node tend to gradually move together, while other nodes stay far away from each other. Such interplay eventually leads to a steady distribution of distances, and a meaningful community is naturally found. Extensive experiments show that our community search algorithm has good performance relative to several state-of-the-art algorithms.

• The Journal of Information Technology
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• v.6 no.4
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• pp.135-146
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• 2003

In the era of so-called knowledge-based economy, the creation and utilization of IT and new knowledge are recognized as core factors to enforce IT industry and to increase national competitiveness. Advanced countries, therefore, have heavily invested their resources on IT sector and introduced competition into the telecommunication market. ASEAN countries are trying to make themselves informationized society through IT market liberalization and industry development. They are investing lots of resources to construct IT infrastructure such as wired and wireless network and consider informationized society promotion as top national agenda. In this effort, Korea is a benchmarking model for them. Successful entering into ASEAN market requires close analysis and correct understanding of its IT policy and infrastructure. In this paper, therefore, tried to analyse IT policy and infrastructure of three ASEAN countries, which have high potential of economic cooperation in IT with Korea. And based on the analysis, tried to find out ways to enter into ASEAN.

• Smart Structures and Systems
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• v.14 no.1
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• pp.1-16
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• 2014

In this work, we address the so-called sensor reachback problem for Wireless Sensor Networks, which consists in collecting the measurements acquired by a large number of sensor nodes into a sink node which has major computational and power capabilities. Focused on applications such as Structural Health Monitoring, we propose a cooperative communication protocol that exploits the spatio-temporal correlations of the sensor measurements in order to save energy when transmitting the information to the sink node in a non-stationary environment. In addition to cooperative communications, the protocol is based on two well-studied adaptive filtering techniques, Least Mean Squares and Recursive Least Squares, which trade off computational complexity and reduction in the number of transmissions to the sink node. Finally, experiments with real acceleration measurements, obtained from the Canton Tower in China, are included to show the effectiveness of the proposed method.

• Asian review of World Histories
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• v.2 no.1
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• pp.105-127
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• 2014

The Silk Road, a trans-Eurasian network of trade routes connecting East and Southeast Asia to Central Asia, India, Southwest Asia, the Mediterranean, and northern Europe, which flourished from roughly 100 BCE to around 1450, has enjoyed two modern eras of intense academic study. The first spanned a period of little more than five decades, from the late nineteenth century into the early1930s, when a succession of European, Japanese, and American scholar-adventurers, working primarily in Chinese Turkestan (present-day Xinjiang Uyghur Autonomous Region, which comprises China's vast northwest) and China's Gansu Province (to the immediate east of Xinjiang) rediscovered and often looted many of the ancient sites and artifacts of the Silk Road. The second era began to pick up momentum in the 1980s due to a number of geopolitical, cultural, and technological realities as well as the emergence of the New World History as a historiographical field and area of teaching. This second period of fascination with the Silk Road has resulted in not only a substantial body of both learned and popular publications as well as productions in other media but also in an ever-expanding sense among historians of the scope, reach, and significance of the Silk Road.

• Journal of Distribution Research
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• v.2 no.2
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• pp.107-134
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• 1997

The purpose of this study was to identify perception level of QR and the usage level of QR technologes and to examine the relationships between the firm characteristics and the usage level of QR technologes and QR adoption in domestic fashon industry. Using the usage levels of QR technologes and QR adoption as the dependent variables, the selected firm characteristics, as independent variables, were firm size, perception level of QR benefits, and product characteristics. The findings from the empirical analysis of this study can be summarized as follows : Firm size and perception level of QR benefits were significantly associated with the usage level of QR technologies and adoption. Product characteristics were partly associated with QR adoption. The four elements were partly associated with QR adoption. Most of the QR adopters were using the QR technologies, and will tend to have four elements. From the results of this study, the researcher expects the information from this study to contributes to the body of knowlege about the identification, adoption and utilization of component technologies for QR management systems and draws several counterproposal as follows : The advancement of domestic fashion industry is possible through the systematic adoption of QR by the collaboration of the government & the industry. Most nonadopter had financial problems as a constraint to QR adoption. Financial supports are needed from trade associations and government. The fashion industry may promote the type of smart QR. The type of smart QR means usage level of QR technologies which reflect the firm characteristics and the actual industry state in domestic fashion industry. The fashion industry may establish information technology network (i. e., EDI, POS, EOS) between relative industry such as fiber, apparel manufacturers, retailers. The related industry should make a partnership.

• Journal of Information Management
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• v.29 no.2
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• pp.1-17
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• 1998

The Inno-NET, which is based on the Internet and up-to-date information technology, is a consolidated system to provide business-related information and to solve the difficulties in business activities. In particular, the Inno-NET is an information system to integrate such business information for enterprise as start-up, financing, technology development, recruiting, site acquisition, marketing, trade and investment and so on, in order to help companies solve their problems and make up for their weak points. Accordingly, the Inno-NET will systematically connect supporting agencies and innovative enterprises, thus guaranteeing the exchange of information among them and coordinating the business. The supporting agencies will be included government offices, public organizations, research institutes, universities, and industrial associations all over the ministries. In short, Inno-NET forms a real-time decision making system among government, industries, universities and research institutes. by elt:ictronic networking on the Internet.

• Journal of the Korean Institute of Navigation
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• v.20 no.1
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• pp.27-46
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• 1996

Vessles in the world merchant fleet generally operate in either liner or bulk trade. The supply and the demand trend of general cargo ship are both on the ebb, however, those trend of tankers and containers are in slight ascension. Oil tankers are so far the largest single vessel type in the world fleet and the tanker market is often cited as a textbook example of perfect competition. Some shipping statistics in recent years show that there has been a radical fluctuation in spot charter rate under easy charterer's market. This implys that the proper scheduling of tankers under spot market fluctuation has the great potential of improving the owner's profit and economic performance of shipping. This paper aims at developing the TS-DSS(Decision Support System for Tanker Scheduling) in the context of the importance of scheduling decisions. The TS-DSS is defined as the DSS based on the optimization models for tanker scheduling. The system has been developed through the life cycle of systems analysis, design, and implementation to be user-friendly system. The performance of the system has been tested and examined by using the data edited under several tanker scheduling scenarios and thereby the effectiveness of TS-DSS is validated satifactorily. The authors conclude the paper with the comments on the need of appropriate support environment such as data-based DSS and network system for succesful implementation of the TS-DSS.

• Journal of Korea Game Society
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• v.5 no.4
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• pp.33-38
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• 2005

In the online game that thousands of participants connect to a game world by using Internet simultaneously, participants of the game world may have different hardwares and network environments, and messages of participants should be synchronization. A solution for the synchronization problem is to wait for a certain amount of time until the server processes the message. It is not easy to determine a suitable waiting period because of the trade-off between the fairness and the responsiveness. In this paper we propose a method to decide a waiting period by considering features of the MMOFPS game and the probability of interaction among participants. We implement the proposed method and perform experiments for the performance evaluation.

• Journal of Korea Port Economic Association
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• v.18 no.1
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• pp.107-134
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• 2002

Globalization of the industry induces the internationalization of any given manufacturing company's supply chain. Development of e-Commerce and Information Technology (IT) changes the logistics structure, making logistics information systems essential. Web-based connectivity and supply chains based on new technologies are becoming essential in the logistics industry. Customers are driving the implementation of systems to ensure timely, thorough, and accurate information, often with immediate access; in response, the Internet has propagated tracking and tracing systems. Value-added services are the key to successful intermediary activities. The nationwide Integrated Logistics Information System (ILIS) aimed to utilize existing and future information infrastructure and knowledge bases to build an integrated logistics information network that would provide comprehensive logistics information services for shippers and carriers in order to improve the efficiency of both inventory and information flows in their supply chains. The ILIS, as one of the seven national information networks, has provided various services, particularly services related to import/export and clearance. Though a survey concerning logistics information services shows rather positive results, shippers and carriers still require better services and reductions in EDI prices. Therefore, the role of the ILIS needs to be re-defined. Short-term plans for the ILIS contain ICD services and XML/EDI services, which are described in detail.