• Journal of Communications and Networks
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• v.10 no.4
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• pp.455-464
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• 2008

To provide network services consistently under various network failures, enterprise networks increasingly utilize path diversity through multi-homing. As a result, multi-homed non-transit autonomous systems become to surpass single-homed networks in number. In this paper, we address an inevitable problem that occurs when networks with multiple entry points deploy firewalls in their borders. The majority of today's firewalls use stateful inspection that exploits connection state for fine-grained control. However, stateful inspection has a topological restriction such that outgoing and incoming traffic of a connection should pass through a single firewall to execute desired packet filtering operation. Multi-homed networking environments suffer from this restriction and BGP policies provide only coarse control over communication paths. Due to these features and the characteristics of datagram routing, there exists a real possibility of asymmetric routing. This mismatch between the exit and entry firewalls for a connection causes connection establishment failures. In this paper, we formulate this phenomenon into a state-sharing problem among multiple fire walls under asymmetric routing condition. To solve this problem, we propose a stateful inspection protocol that requires very low processing and messaging overhead. Our protocol consists of the following two phases: 1) Generation of a TCP SYN cookie marked with the firewall identification number upon a SYN packet arrival, and 2) state sharing triggered by a SYN/ACK packet arrival in the absence of the trail of its initial SYN packet. We demonstrate that our protocol is scalable, robust, and simple enough to be deployed for high speed networks. It also transparently works under any client-server configurations. Last but not least, we present experimental results through a prototype implementation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.9A
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• pp.853-866
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• 2008

In this paper, a multi-hop relaying transmission scheme is analyzed regarding its feasibility and potentiality in the IEEE 802.22-based cognitive radio (CR) environment. Shortly, basic design issues are addressed such as relay station (RS) deployment and a frame structure of physical channel to escape inter-hop interference. This paper mainly develops a radio resource management scheme based on spectrum sensing results aggregated from CR secondary nodes and improves the opportunistic spectrum sharing efficiency. In particular, a decision rule about a channel availability is made using a distributed sensing method. Subsequently, spectrum allocation and routing path decision procedures are proposed to establish a link from source to destination with a hop-by-hop manner. Simulation results show that the proposed multi-hop relaying scheme is substantially profitable in CR environments if the number of hops and RS deployment are designed in such a way that the spectrum sharing gain is larger than spectrum division loss which is inherently induced in multi-hop relaying systems.

• The KIPS Transactions:PartC
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• v.12C no.4 s.100
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• pp.473-480
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• 2005

We can obtain useful information by deploying large scale sensor networks in various situations. Security is also a major concern in sensor networks, and we need to establish pairwise keys between sensor nodes for secure communication. In this paper, we propose new pairwise key establishment mechanism based on clustering and polynomial sharing. In the mechanism, we divide the network field into clusters, and based on the polynomial-based key distribution mechanism we create bivariate Polynomials and assign unique polynomial to each cluster. Each pair of sensor nodes located in the same cluster can compute their own pairwise keys through assigned polynomial shares from the same polynomial. Also, in our proposed scheme, sensors, which are in each other's transmission range and located in different clusters, can establish path key through their clusterheads. However, path key establishment can increase the network overhead. The number of the path keys and tine for path key establishment of our scheme depend on the number of sensors, cluster size, sensor density and sensor transmission range. The simulation result indicates that these schemes can achieve better performance if suitable conditions are met.

• Asia pacific journal of information systems
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• v.17 no.2
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• pp.1-28
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• 2007

The success of new product development is a key factor for getting competitive advantages. Marketing research has been investigating marketing capability, manufacturing technical capability, cross-functional integration, market knowledge competence, market orientation, and competitive environment as the key success factors of new product development. Recently, the role of IT infrastructure in enhancing new product advantage is assumed in the literature. However, the empirical studies on the role of IT infrastructure are lacking. The purpose of this study is to empirically exam the impacts of IT infrastructure on new product competitive advantage. In this study, IT infrastructure is conceptualized as the flexibility of IT infrastructure. Based on previous research, a conceptual model is established by incorporating the direct impact of IT infrastructure flexibility and its indirect impact through the key success factors on new product development. To empirically test the research model, data are surveyed from a pair of IS department and Marketing department of 92 consumer goods manufacturers. By employing PLS technique, the measurement reliability and reliability of research variables are tested and the path analysis is conducted to do the hypothesis testing. The path analysis shows that IT infrastructure flexibility has no direct effect on new product advantage, However, the indirect effect of IT infrastructure is found, which is mediated by marketing capability, manufacturing technical capability, cross-functional integration, and market orientation respectively. Hence, The flexible IT infrastructure increases cross-functional integration (H1), market orientation (H3), marketing capability (H5), and manufacturing technical capability (H6). All success factors of new product development excepts for competitive environment have a positive association with new product competitive advantages (from H10 to H14). Finally, the path from IT infrastructure flexibility to cross-functional integration, to market orientation, to market knowledge capability, and to new product advantage is found as the strongest path. These results indicate that the flexible IT infrastructure enhances information sharing with multiple departments and collaboration within a distributed innovation environment. The collaboration among departments positively affects the level of customer and competitor intelligence. The ability to obtain knowledge about customers and competitors makes firms to adapt to a changing environment quickly and to respond to customers' demands adequately. The flexible IT infrastructure also enhances the capability of organization to more rapidly respond to the changes in product design resulting in faster product development and reduced costs. In addition to, it enhances marketing capability by the two-way communications with customers and the analyses of various kinds of customer data. In brief, the finding of this study suggests that the flexible IT infrastructure allows many firms to pursue sustained new product competitive advantages. This study advances research on IT infrastructure in two important aspects. First, by Integrating marketing research and IS research, this study develops a conceptual model on the role of IT infrastructure in enhancing new product advantage. Second, it empirically finds the indirect impacts of IT infrastructure on new product advantage, which confirms the potential for the IS field to contribute to new product development research. The limitations of this study are also discussed to provide research directions for future research.

• Journal of Distribution Science
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• v.14 no.10
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• pp.165-178
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• 2016

Purpose - This study aims to empirically verify the impact of media richness, social presence, and prior life satisfaction on various continual usage or withdrawal behaviors of SNS users via both a positive path of satisfaction and a negative path of relative deprivation. By identifying these causal paths, we observe dynamic interactions of SNS user psychology in a balanced view, and provide some implications about design principles for SNS providers. Research design, data, and methodology - We developed 16 hypothesis based on media richness theory, social presence theory, social comparison theory, the literature about relative deprivation, and the literature about the various reactions of IS users. The rich SNS media, social presence recognition among peer SNS users, and prior life satisfaction could generate positive experience, attitude, and virtuous behavioral intentions among SNS users. At the same time, rich media, low social presence, and low prior life satisfaction could generate relative deprivation and could increase withdrawal behavioral intentions such as refusal to provide information, misrepresentation of information, and removal of uploaded information in SNS. Scenario surveys were conducted to collect data from potential SNS users. Data from 357 surveys were collected and analyzed through a PLS algorithm to test the hypotheses. Results - Media richness, social presence, and prior life satisfaction could significantly increase perceived enjoyment, satisfaction, and behavioral intention of continual usage and knowledge sharing. They also could significantly decrease refusal and misrepresentation intention. Relative deprivation is significantly decreased only by prior life satisfaction. Relative deprivation could not significantly decrease satisfaction, but it could significantly increase misrepresentation and removal intention, which could be regarded as information distortion intention. Conclusions - SNS providers should focus on developing rich media and social presence support because these two variables could impact the positive experiences of SNS users. Moreover, the positive experiences could heavily influence SNS user behavior. Some management is needed to prevent relative deprivation and its consequences of misrepresentation and removal intention. SNS providers should prevent SNS users from excessive image misrepresentation and removal as this information distortion could be the source of relative deprivation.

• The KIPS Transactions:PartD
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• v.9D no.3
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• pp.355-364
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• 2002

Recently, WWW(World Wide Web) has become a source of a large amount of information, and is now recognized not only as an information-sharing tool, but also as an information repository. Currently, the majority of documents on the web were created using HTML(Hypertext Markup Language). Although HTML is simple and easy to learn, its inherent lack of describing document structure makes it difficult to retrieve information effectively. One possible solution would be to convert such HTML documents into XML (extensible Markup Language) documents. This is a standard markup language for exchanging data on the web. It can describe a document structure freely by defining its own DTD (Document Type Definition). This makes it possible to integrate, store, and retrieve data on the web efficiently In this paper, we will propose a converter that automatically converts HTML documents with similar pattern into XML documents by analyzing the document structure and recognizing its path information.

• Journal of Distribution Science
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• v.9 no.2
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• pp.61-72
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• 2011

The object of this research is to examine the factors leading to intercompany win-win by finding the antecedents and consequences that affect a supplier's fairness perception. We assume that the antecedent factors of a supplier's fairness perception are vertical coordination, cooperation support, information sharing, and legalistic plea. We assume that the consequential factors of a supplier's fairness perception are supply chain dependence and supply chain flexibility. The object industry is an electronic parts manufacturing company. We tested our model by using the SPSS 17.0 and the LISREL 8.5. For measurement validation, we verified by using a confirmatory factor analysis and a reliability analysis. For hypothesis analysis, we did a path analysis with the LISREL 8.5. By checking the modification index and expecting parameter changes, we modified the model. First, the buyer's vertical coordination had a positive effect on the supplier's distributive fairness perception and procedural fairness perception. Second, the buyer's cooperation support had no effect on the supplier's distributive fairness perception and procedural fairness perception: we suppose that the buyer's requests were burdensome, although they cooperated with the supplier. Third, the buyer's information sharing had a positive effect on distributive fairness perception but had no direct effect on procedural fairness perception. Fourth, the buyer's legalistic plea had a negative effect on the supplier's distributive fairness perception. and a negative effect on the supplier's procedural fairness perception at a 0.1 significance level. Fifth, although procedural fairness perception had no direct effect on supply chain dependence, fairness perception had an effect on supply chain dependence and supply chain flexibility both directly and indirectly.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.31 no.4
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• pp.201-206
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• 2020

Objectives: The Journal of the Korean Academy of Child and Adolescent Psychiatry (JKACAP) has had a 31 year-long history, sharing research and reviews of children and adolescents' mental health to promote voluntary participation and communication of the members of this society. Here, we have reviewed the detailed history of the journal from the perspective of developmental progression of JKACAP and discussed the direction of further development. Methods & Results: We reviewed the journey of the journal by focusing on the effort it took to take the journal to a global standard, and discussed the future direction of progress of JKACAP, based on the opinions raised at the Editor-in-Chiefs' reunion. Conclusion: JKACAP has just stepped on the path to globalization by being indexed in Emerging Sources Citation Index, PubMed Central, and Scopus. It is time to progress to another dimension, by acknowledging and overcoming more complicated issues, such as augmenting impact of the journal, expanding domains of interdisciplinary collaboration, and more global cooperation.

• Journal of Information Processing Systems
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• v.2 no.2
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• pp.101-106
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• 2006

Grid computing is an emerging technology that enables global resource sharing. In Korea, the $K^*$Grid provides an extremely powerful research environment to both industries and academia. As part of the $K^*$Grid project, we have constructed, together with the Korea Institute of Science and Technology Information and a number of domestic universities, a supercomputer Grid test bed which connects several types of supercomputers based on the globus toolkit. To achieve efficient networking in this Grid testbed, we propose a novel method of available bandwidth measurement, called Decoupled Capacity measurement with Initial Gap (DCIG), using packet trains. DCIG can improve the network efficiency by selecting the best path among several candidates. Simulation results show that DCIG outperforms previous work in terms of accuracy and the required measurement time. We also define a new XML schema for DCIG request/response based on the schema defined by the Global Grid Forum (GGF) Network Measurement Working Group (NM-WG).

• The Journal of Korea Robotics Society
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• v.15 no.2
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• pp.100-106
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• 2020

In the agricultural field, interests in research using robots for fruit harvesting are continuously increasing. Dual arm manipulators are promising because of its abilities like task-distribution and role-sharing. To operate it efficiently, the task sequence must be planned adequately. In our previous study, a collision-free path planning method based on a genetic algorithm is proposed for dual arm manipulators doing tasks cooperatively. However, in order to simplify the complicated collision-check problem, the movement between tasks of two robots should be synchronized, and thus there is a problem that the robots must wait and resume their movement. In this paper, we propose a heuristic algorithm that can reduce the total time of the optimal solution obtained by using the previously proposed genetic algorithm. It iteratively desynchronizes the task sequence of two robots and reduces the waiting time. For evaluation, the proposed algorithm is applied to the same work as the previous study. As a result, we can obtain a faster solution having 22.57 s than that of the previous study having 24.081 s. It will be further studied to apply the proposed algorithm to the fruit harvesting.