• Proceedings of the Korean Operations and Management Science Society Conference
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• 2005.10a
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• pp.299-320
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• 2005

To rapidly respond to uncertainties in the business environment whilst remaining competitive, every organization needs to be able to successfully introduce and manage organizational change. Cognizant of the role of information systems (IS) as an enabler of organizational change, many organizations have paid attention to Enterprise Resource Planning (ERP) systems for successful organizational change primarily because of their change-driving forces across organizations. In this study, we focus attention on the role of readiness for change in the ERP systems adoption. Readiness for change described as views about the need for organizational change is posited to be and antecedent of two expectancies about the need for organizational change is posited to be an antecedent of two expectancies about the system. performance expectancy and effort expectancy, which lead to actual system use. In order to further establish th relevance of readiness for change as a determinant of two expectancies, computer self-efficacy is considered to be other key predictor as well. In addition, this study proposes that the personal characteristics of organizational commitment and perceived personal competence play roles of important determinants of readiness for change. Based on data gathered from the users of the ERP systems, structural equation analysis using LISREL provides significant support for the proposed relationships. Theoretical and practical implications are discussed along with limitations.

• Journal of Korea Society of Industrial Information Systems
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• v.12 no.2
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• pp.24-29
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• 2007

The essential factor of ubiquitous is security technology to properly prepare making possible network access, economic and convenient information exchange. This paper proposes an authentication protocol for RFID as one technology to realize such an ubiquitous. The proposed protocol used only the EXOR and the hash function operations reduces operations at RFID tag, which improves stability compared to existing protocols.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2004.05a
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• pp.564-567
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• 2004

The government has focused the national R&D investment on 6T areas - IT(Information Technology), BT(Bio Technology), NT(Nano Technology), ST(Space Technology), ET(Environment ${\cdot}$ Energy Technology), CT(Culture Technology). The paper summarizes patents and utility models in these areas which are applied in past decade. This study presents the relationship of the patent trends and the national R&D investment in 6T areas.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2004.05a
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• pp.143-146
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• 2004

With the rapid growth of e-commerce, marketers are able to observe not only purchasing behavior on what and when customers purchased, but also the individual Web usage behavior that affect purchasing. The richness of this information has the potential to provide marketers with an in-depth understanding of customer. Using commonly available Web log data, this paper examines Web usage behaviors at the individual level. By decomposing the buying process into a pattern of visits and purchase conversion at each visit, we can better understand the relationship between Web usage behavior and purchase decision. This allows us to more accurately forecast a shopper's future purchase decision at the site and hence determine the value of individual customers to the siteAccording to our research, not only information seeking behavior but also visiting duration of a customer and participative behavior such as participation in event should be considered as important predicators of purchase decision of customer in a cosmetic internet shopping mall.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2004.05a
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• pp.441-445
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• 2004

In this paper, we deal with an inventory model of a multi-stage, serial supply chain system where a single product type and nonstationary customer demand pattern are considered. The retailer and suppliers place their orders according to an echelon-stock based replenishment control policy. We assume that the suppliers can access online information on the demand history and use this information when making their replenishment decisions. Using a reinforcement learning technique, the inventory control parameters are designed to adaptively change as the customer demand pattern is altered, in order to maintain a given target service level. Through a simulation based experiment, we verified that our approach is good for maintaining the target service level.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2003.11a
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• pp.99-102
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• 2003

While information technology has been advanced impressively, the issue of system underutilization has continued. Although TAM provides a theoretical and empirical model for explaining information technology acceptance, there exist some issues: lack of focusing task and organization. The present study examines the motivational factors influencing the beliefs about the system, in terms or the extended TTF (task-technology fit) model, to address the issues. For this purpose, an exploratory case study was conducted based on the data gathered from a Web-based survey. The present research proposes five propositions, based on the results of the case study and prior study findings, which can be used as a starting point fur future research.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1991.10a
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• pp.51-65
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• 1991

This paper describes computer-integrated manufacturing (CIM) systems as strategic information systems for business which play an important role in accelerating the speed of business, and develops a measure showing a degree of business tendency to be CIM which enables the business to check on its present status as far as CIM is concerned. It is well known that the productivity of knowledge workers is lower than that of other workers. Nowadays, a great deal of effort goes into the productivity improvement of knowledge workers. In this respect, this paper also develops a quantitative model for the productivity of knowledge workers. Finally, this paper deals with following four steps which our small business should follow through its process of CIM: [Step 1] Using expert knowledge; [Step 2] Invention of technological information; [Step 3] Feedback of factory information to the management; and, [Step 4] Accelerating the speed of business.

• Journal of the Korean Operations Research and Management Science Society
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• v.18 no.2
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• pp.183-203
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• 1993

One of the most difficult and time-consuming stages in the development of the knowledge-based system is a knowledge acquisition. A splitting algorithm is developed to infer a rule-tree which can be converted to a rule-typed knowledge. A market segmentation may be performed in order to establish market strategy suitable to each market segment. As the sales data of a product market is probabilistic and noisy, it becomes necessary to prune the rule-tree-at an acceptable level while generating a rule-tree. A splitting algorithm is developed using the pruning measure based on a total amount of information gain and the measure of existing algorithms. A user can easily adjust the size of the resulting rule-tree according to his(her) preferences and problem domains. The algorithm is applied to a market segmentation problem of a medium-large computer market. The algorithm is illustrated step by step with a sales data of a computer market and is analyzed.

• Journal of Information Processing Systems
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• v.7 no.4
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• pp.691-706
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• 2011

Since security and privacy problems in RFID systems have attracted much attention, numerous RFID authentication protocols have been suggested. One of the various design approaches is to use light-weight logics such as bitwise Boolean operations and addition modulo $2^m$ between m-bits words. Because these operations can be implemented in a small chip area, that is the major requirement in RFID protocols, a series of protocols have been suggested conforming to this approach. In this paper, we present new attacks on these lightweight RFID authentication protocols by using the Gr$\ddot{o}$bner basis. Our attacks are superior to previous ones for the following reasons: since we do not use the specific characteristics of target protocols, they are generally applicable to various ones. Furthermore, they are so powerful that we can recover almost all secret information of the protocols. For concrete examples, we show that almost all secret variables of six RFID protocols, LMAP, $M^2AP$, EMAP, SASI, Lo et al.'s protocol, and Lee et al.'s protocol, can be recovered within a few seconds on a single PC.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.6
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• pp.2908-2924
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• 2019

Multiple input multiple output orthogonal frequency division multiplexing (MIMO-OFDM) is widely applied in wireless communication by virtue of its excellent properties in data transmission rate and transmission accuracy. However, as a major drawback of MIMO-OFDM systems, the high peak-to-average power ratio (PAPR) complicates the design of the power amplifier at the receiver end. Some available PAPR reduction methods such as selective mapping (SLM) suffer from high computational complexity. In this paper, a low-complexity SLM method based on active constellation extension (ACE) and joint space-time selective mapping (AST-SLM) for reducing PAPR in Alamouti STBC MIMO-OFDM systems is proposed. In SLM scheme, two IFFT operations are required for obtaining each transmission sequence pair, and the selected phase vector is transmitted as side information(SI). However, in the proposed AST-SLM method, only a few IFFT operations are required for generating all the transmission sequence pairs. The complexity of AST-SLM is at least 86% less than SLM. In addition, the SI needed in AST-SLM is at least 92.1% less than SLM by using the presented blind detection scheme to estimate SI. We show, analytically and with simulations, that AST-SLM can achieve significant performance of PAPR reduction and close performance of bit error rate (BER) compared to SLM scheme.