• IEIE Transactions on Smart Processing and Computing
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• v.2 no.2
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• pp.77-85
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• 2013

this study examined hybrid Time of Arrival/Angle of Arrival (TOA/AOA) localization technique in a cellular network. Based on the linearized equations from the TOA and AOA measurements, the weighted least square (WLS) method is proposed to obtain the location estimation of a mobile station (MS) by analyzing the statistical properties of the error vector in Line of Sight (LOS) and Non-line of Sight (NLOS) environments, respectively. Moreover, the precise expression of the Cramer-Rao lower bound (CRLB) for hybrid TOA/AOA measurements in different LOS/NLOS conditions was derived when the LOS error is a Gaussian variable and the NLOS error is an exponential variable. The idea of cooperative localization is proposed based on the additional information from short-range communication among the MSs in fourth generation (4G) cellular networks. Therefore, the proposed hybrid TOA/AOA WLS method can be improved further with the cooperative scheme. The simulation results show that the hybrid TOA/AOA method has better performance than the TOA only method, particularly when the AOA measurements are accurate. Moreover, the performance of the hybrid TOA/AOA method can be improved further by the cooperative scheme.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.3 no.4
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• pp.385-398
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• 2009

This paper aims to find a suitable solution to joint allocation of sub-channel and transmit power for multiple users in an IEEE 802.16e OFDMA/TDD cellular system. We propose the FASA (Fairness insured Aggressive Sub-channel Allocation) algorithm, which is a dynamic channel allocation algorithm that considers all of the users' channel state information conditionally in order to maximize throughput while taking into account fairness. A dynamic power allocation algorithm, i.e., an improved CHC algorithm, is also proposed in combination with the FASA algorithm. It collects the extra downlink transmit power and re-allocates it to other potential users. Simulation results show that the joint allocation scheme with the improved CHC power allocation algorithm provides an additional increase of sector throughput while simultaneously enhancing fairness. Four frames of time delay for CQI feedback and scheduling are considered. Furthermore, by addressing the difference between uplink and downlink scheduling in an IEEE 802.16e OFDMA TDD system, we can employ the uplink channel information directly via channel sounding, resulting in more accurate uplink dynamic resource allocation.

• The Journal of Information Systems
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• v.21 no.3
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• pp.187-214
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• 2012

Supply chain management(SCM) helps firms in integrating their business by collaborating with other value chain partners to meet the unpredictable demand of the end user. Agility is the fundamental characteristic of a supply chain needed for survival in turbulent and volatile markets, which are becoming norms as product life cycles shorten and environmental forces create additional uncertainty resulting in higher risk in the supply chain management. Literature reviews reveals various factors that could affect the agility. The objective of this study is to derive interdependence, partnership, quality of information, joint problem solving, modelize the mutual influential relationship between them, and look into the influential relationship influencing the agility. To test the proposed model, we used a data set generated from survey. Date analysis was conducted using 122 respondents. We used structural equation model (SEM) implemented in partial least square(PLS). The results of this study can be summarized as follows. Interdependence had a significant impact on partnership. Partnership had a significant impact on quality of information and joint problem solving. Quality of information had a significant impact on joint problem solving. Quality of information and joint problem solving had a significant impact on agility. This study diagnoses that Inter-organizational relationship characteristics are important for supply chain agility. Inter-organizational relationship characteristics are considered as an essential factor for supply chain agility.

• Proceedings of the Korea Contents Association Conference
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• 2011.05a
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• pp.293-294
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• 2011

KISTI collects the scientific and technical articles published in Korea and builds the Korean STI database for scientists. The number of papers exceeds one million. To improve the search efficiency of the database additional processing is required. Abstracting, classification, indexing and extracting is a traditional processing method adding value to information. Indexing and classification are useful tool to assist efficient retrieval. In this paper, authors propose a method to improve information retrieval efficiency by assigning classification code and index terms to records of Korean STI database.

• The Journal of the Korea Contents Association
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• v.6 no.8
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• pp.94-104
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• 2006

Building the Public Appraisal Information System(PAIS) has been a critical issue because real estate valuation process depends on the various information and analysis. However, there has been little research in this area. As a result, there is not any comprehensive plan for the PAIS constructed by the MOCT(Ministry of Construction and Transportation), and its database quality has various Problems. Therefore, this paper investigated the database of the public appraisal information system and suggested development strategies as follow: preparing a comprehensive plan for data collection, establishment of data management standards, additional collection of the attribute and spatial data, linkage PAIS and other information system.

• The Journal of the Korea Contents Association
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• v.7 no.7
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• pp.133-143
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• 2007

The object of this study is to empirically analyze the effects of information support quality and service quality on service satisfaction of department store. To investigate the purpose of this study, literature review and survey were conducted. for statistical analysis, factor analysis, analysis of variance(ANOVA), and regression in order by the contingency grouping method were used. In conclusion of this study are as follows First, The regression analysis had effects on information support quality and service satisfaction. Second, The Analysis of variance(ANOVA) and regression had effects on information support quality and service satisfaction as service quality factors. Result, The information support accuracy and service quality had additional effect about customer relation.

• Korean Journal of Construction Engineering and Management
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• v.12 no.5
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• pp.23-34
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• 2011

Reliable progress management at construction requires integrated information of cost and schedule, and information is used as a basis for project performance measurement. However, separate handling of cost and schedule information at construction projects makes objective measurement more difficult and decreases management productivity due to additional works for breaking down bill of quantities into corresponding activities. Recently, research related to BIM addresses issues on effective progress management based on BIM with incorporation of daily progress management. Therefore, the objective of this paper is to propose information model for daily progress rate and budgeted cost of work performed by utilizing BTM-based quantity and location information.

• Proceedings of the Korea Database Society Conference
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• 2010.06a
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• pp.235-247
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• 2010

Introduction of ICE(Integrated Collaboration Environment) has a great effect on corporate performance. In particular, it is expected that information sharing and collaboration among transaction partners will be an important factor which mediates ICE and its performance. Under such a background, this research intends to identify the influence of ICE by manufacturing industry on corporate performance through role of the parameter of information sharing and collaboration. The result of this research may be summed up as follows: ICE promotes information sharing and collaboration among enterprises, it accelerates integration of supply chain network among enterprises and cooperation. In particular, ICE has a great effect on information sharing. And information sharing has a direct effect on collaboration and performance. However, when we classify corporate performance into the "performance due to introduction", which is direct performance, and the "overall performance", which is indirect performance, the result of this research is as follows: information sharing has a great effect on the performance due to introduction, but does not have a meaningful effect on indirect performance. On the other hand, collaboration does not have any effect on the performance due to introduction, but has a meaningful effect on the overall performance, which is indirect performance. It is necessary to study and analyze additional this result in future.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.6
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• pp.2377-2397
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• 2020

Human activity recognition is widely used in smart homes, health care and indoor monitor. Traditional approaches all need hardware installation or wearable sensors, which incurs additional costs and imposes many restrictions on usage. Therefore, this paper presents a novel device-free activities recognition system based on the advanced wireless technologies. The fine-grained information channel state information (CSI) in the wireless channel is employed as the indicator of human activities. To improve accuracy, both amplitude and phase information of CSI are extracted and shaped into feature vectors for activities recognition. In addition, we discuss the classification accuracy of different features and select the most stable features for feature matrix. Our experimental evaluation in two laboratories of different size demonstrates that the proposed scheme can achieve an average accuracy over 95% and 90% in different scenarios.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.2
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• pp.522-541
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• 2016

Network virtualization provides an effective way to overcome the Internet ossification problem. As one of the main challenges in network virtualization, virtual network embedding refers to mapping multiple virtual networks onto a shared substrate network. However, existing heuristic embedding algorithms evaluate the embedding potential of the nodes simply by the product of different resource attributes, which would result in an unbalanced embedding. Furthermore, ignoring the hops of substrate paths that the virtual links would be mapped onto may restrict the ability of the substrate network to accept additional virtual network requests, and lead to low utilization rate of resource. In this paper, we introduce and extend five node attributes that quantify the embedding potential of the nodes from both the local and global views, and adopt the technique for order preference by similarity ideal solution (TOPSIS) to rank the nodes, aiming at balancing different node attributes to increase the utilization rate of resource. Moreover, we propose a novel two-stage virtual network embedding algorithm, which maps the virtual nodes onto the substrate nodes according to the node ranks, and adopts a shortest path-based algorithm to map the virtual links. Simulation results show that the new algorithm significantly increases the long-term average revenue, the long-term revenue to cost ratio and the acceptance ratio.