• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.1
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• pp.322-340
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• 2012

Orthogonal Frequency Division Multiplexing (OFDM) is usually regarded as a spectral efficient multicarrier modulation technique, yet it suffers from a high peak-to-average power ratio (PAPR) problem. Among all the existing PAPR reduction techniques in OFDM systems, side information based PAPR reduction techniques such as partial transmit sequence (PTS) and selective mapping (SLM) schemes, have attracted the most attention. However, the transmission of side information results in somewhat spectral loss and this does not significantly improve the bit error rate (BER) performance. Parallel combinatory (PC) OFDM yields higher spectral efficiency (SE) and better BER performance on Gaussian channels,while is a little but not obvious PAPR improvement over the ordinary OFDM system. This investigation aimed to design a 'perfect' OFDM system. We introduce the side information to rotate the subcarrier phases of our novel PC-OFDM system structure, and call this new system the SIPC(Side information based Parallel Combinatory)-OFDM system. The proposed system achieves better PAPR and SE performance. In addition, considering the tradeoff of system parameters, the proposed system also has the properties of a higher BER.

• International Journal of Contents
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• v.12 no.4
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• pp.23-30
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• 2016

For a library to be able provide information services and fulfill its function as a knowledge convergence center capable of responding to various information demands, the development of next-generation information systems based on the latest information and communication technology is needed. The development of mobile information services using portable devices such smart phones and tablet PCs and information systems which incorporate the concepts of cloud computing, SaaS (Software as a Service), annotation and Library2.0 is also required. This paper describes a library information system that utilizes collective intelligence and cloud computing. The information system developed for this study adopts the SaaS-based cloud computing service concept to cope with the shift in the mobile service paradigm in libraries and the explosion of electronic data. The strengths of such a conceptual model include the sharing of resources, support of multi-tenants, and the configuration and support of metadata. The user services are provided in the form of software on-demand. To test the performance of the developed system, the efficiency analysis and TTA certification test were conducted. The results of performance tests, It is encouraging that, at least up to 100MB, the job time is approximately linear and with only a moderate overhead of less than one second. The system also passed the level-3 or higher criteria in the certification test, which includes the SaaS maturity, performance and application program functions.

• Journal of Nutrition and Health
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• v.38 no.2
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• pp.180-189
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• 2005

The purposes of this study were 1) to analyze the effect of the ERP quality (system quality, information quality, service quality) on the performance (end user satisfaction, user's performance, system utilization) of business, 2) to conduct the causal-effect analysis between outcome variables (user's satisfaction, user's performance, system utilization) of ERP in the contract foodservice management company. The questionnaires were distributed to 260 end users (dietitians, foodservice management managers) in charge of managing the institutional foodservice such as the office (government agencies, factories), schools (universities, middle and high school) and hospitals which were managed by contract foodservice management company 'C' in Seoul and Kyunggi. The surveys were performed from July 26, 2004 to July 30. 2004. Two hundred and fifty (250) questionnaires were responded (response rate: 96.2%). The statistical analysis was conducted using SPSS Win (11.5). And the descriptive analysis, factor analysis, reliability test, pearson correlation, simple and multiple regression analysis were performed. The results showed that among the 3 factors (system quality, information quality, service quality), the system quality and information quality were proved to have an effect on the user's satisfaction and user's performance significantly (p < .05). The influence of ERP quality (system quality, information quality, service quality) on system utilization were testified to be statistically significant (p < .05). The user's performance were affected significantly by system utilization (p < 0.001) and end user's satisfaction (p < 0.001). As a conclusion, to improve user satisfaction, which is the ultimate performance variable of an ERP system, high quality of an ERP system is the pre-requisite. And the user satisfaction and performance of business would be higher with the better quality ERP system. When constructing ERP system for the contract foodservice management company, we should improve system utilization and user satisfaction altogether so that user's performance could be ultimately enhanced and we should make efforts to enhance the quality level of ERP. (Korean J Nutrition 38(2): 180～189, 2005)

• Proceedings of the IEEK Conference
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• 2003.11c
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• pp.41-44
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• 2003

Generally, the frequency of set makes ICI and degrades OPDM system performance. Thus, we propose a pulse shaped OFDM to give robustness against the frequency offset. The proposed OFDM system uses pulse shaping with smooth shape, instead of rectangular pulse shape, to reduce the power of ICI. The proposed scheme always gives performance gain in comparing with the convention one, when the frequency offset exists. In addition, the smoother pulse shape is employed in the proposed system, the more performance gain is obtained.

• IE interfaces
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• v.11 no.3
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• pp.41-53
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• 1998

Several performance measurement systems have been proposed and are currently being used in many organizations. However, no performance measurement system has presented a mechanism for integrating all of the information of performance measures in a way that considers the relationships between them. This paper proposes the performance information integration method (PIIM) which synthesizes all useful information of performance measures with consideration of the relationships and generates a single, global, organizational performance score. The PIIM showed good performance in the implementation in one long-term care facility. This paper provides performance measurement systems with an integration mechanism for multiple performance measures.

• Journal of the Korea Society of Computer and Information
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• v.14 no.4
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• pp.141-152
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• 2009

This research conducted research on the provision of the strategic information for the companies' financial and accounting parts among the functions that are provided by the ERP, elements related to the adoption of financial information system that influence and that supports decision-making and management performance. The results of this research are as follows. First, organization's degree of decentralization among the organization structure's characteristics and the element of information technology infrastructure among the information technology characteristics does not affect financial or non-financial performance. Second, financial information characteristics do not affect financial performance partially, Third, organization's size does not play the role of adjuster when it comes to the financial performance. Fourth, some research variables used on this research were not analyzed as important elements that influence financial performance, but the analysis showed that they mostly influence non-financial performance, which means that these are what could be considered strategically when adopting financial information system in the future.

• Journal of Korea Society of Industrial Information Systems
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• v.16 no.5
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• pp.37-44
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• 2011

Recently, as smartphones are quickly spread to the general public, there are making a difference for use of information and communication methods. In this paper, mobile-based Performance Evaluation Management System(PEMS) that can make middle and high school teachers efficiently manage tasks of performance evaluation was implemented. That were applied to the performance evaluation of teachers. As a result, the tasks of teachers in the performance evaluation was reduced and teachers are able to concentrate on the guidance for students.

• Proceedings of the IEEK Conference
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• 2003.07d
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• pp.1621-1624
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• 2003

As the entities participating Grid become larger, performance requirement for the LDAP-based GIS(Grid Information Service) goes beyond that provided by a stand-alone single LDAP server. This entails the exploration of distributed LDAP systems. This paper presents the performance evaluation respectively for a distribution-based and a replication-based LDAP model. The analysis is based on an analytic performance model for each distributed system which is obtained by applying the M/M/1 queuing model. The performance evaluation made to these analytic models reveals that the distribution-based and the replication-based model show a significant tradeoff in their performance with respect to the system size as well as the amount of system load.

• Journal of Korea Society of Industrial Information Systems
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• v.15 no.5
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• pp.221-233
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• 2010

For the education information system, evaluation of the performance have to incorporate the special characteristics od education. This paper is to develop some measures to assess the performance of Korean National Education Information System (NEIS). Performance measures are classified those into three detailed areas as the flow of value chain. which include end-users area, education process area and performance area. Research results show that the users's concern to the information system have an affirmative influence on the satisfaction of users, and attitude change of users have also a positive influence on the administration area of the information system such as task productivity, task innovation, satisfaction of the education users, activity of control process. Also, user's satisfaction for NEIS, that comes from the communication, have an affirmative influence on the better performance of education,

• Journal of Korea Society of Digital Industry and Information Management
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• v.7 no.3
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• pp.97-105
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• 2011

With the advancement of network, privacy information as well as confidential information that belongs to government and company are exposed to security incident like spreading viruses or DDoS attack. To prevent these security incident and protect information that belongs to government and company, Security system has developed such as antivirus, firewall, IPS, VPN, and other network security system. Network security systems should be selected based on purpose, usage and cost. Verification for network security product's basic features performed in a variety of ways at home and abroad, but consumers who buy these network security product, just rely on the information presented at companies. Therefore, common user doing self performance evaluation for perform Verification before buying network security product but these verification depends on inaccurate data which based on some user's criteria. On this paper, we designing methodology of network security system performance evaluation focused on Korean using other cases of performance evaluation.