• Journal of the Korea Society of Computer and Information
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• v.20 no.12
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• pp.15-20
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• 2015

In this paper, we propose a modified fuzzy clustering algorithm which can overcome the center deviation due to the Euclidean distance commonly used in fuzzy clustering. Among fuzzy clustering methods, Fuzzy C-Means (FCM) is the most well-known clustering algorithm and has been widely applied to various problems successfully. In FCM, however, cluster centers tend leaning to high density clusters because the Euclidean distance measure forces high density cluster to make more contribution to clustering result. Proposed is an enhanced algorithm which modifies the objective function of FCM by adding a center-scattering term to make centers not to be close due to the cluster density. The proposed method converges more to real centers with small number of iterations compared to FCM. All the strengths can be verified with experimental results.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.248-249
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• 2015

Clustering is one of the most important unsupervised learning methods that clusters data into homogeneous groups. However, cluster centers tend leaning to high density clusters because clustering is based on the distances between data points and cluster centers. In this paper, a modified clustering method forcing cluster centers to be apart by introducing a center-scattering term in the Fuzzy C-Means objective function is introduced. The proposed method converges more to real centers with small number of iterations compared to the original one. All the strengths can be verified with experimental results.

• Journal of the Korean Institute of Telematics and Electronics
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• v.10 no.1
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• pp.27-35
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• 1973

The electronic states of carrier capture centers in reverse biased point-contact germanium diodes have been investigated through the tomperature-and reverse voltage-characteristics of burst noise. The measured values of the time constants wllich represent the electronic states of the centers are extended up to greater than ten minutes, which are about 10,000 times greater than the ones obtained by other investigators. From the relation between these time constants and temperatures, the quasi-Peymi level and the activation energy of the center have been obtained.

• Journal of Information Management
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• v.33 no.4
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• pp.25-55
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• 2002

In most libraries and information centers, access versus ownership is the new dilemma facing in view of the rapidly change of information technologies, the rising costs of serials, and not equally increasing budgets. And libraries and information centers are now confronted with the fact that the more users bypass the library's resources in favor of the results they can get with an ordinary Internet search engine. The purpose of this study is to analyze a difficult problems related to information resources development in digital world with priority given to accesscentered paradigm, the grounds of an argument and fallacy of physical collection building, and limitations of electronic publication.

• IE interfaces
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• v.20 no.2
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• pp.154-161
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• 2007

When the electrical appliances such as TVs and refrigerators become obsolete, they must be collected to the recycling centers to avoid environmental damages. The obsolete home appliances are first moved to the regional collection point; and then transported to one of the recycling centers. Each recycling center has a limited capacity; and some recycling centers can process only certain types of products. For given locations of the existing collection points and recycling centers, optimally assigning the obsolete home appliances of each type from each collection point to the recycling centers can significantly reduce the total transportation cost. We formulate this problem as an LP problem. We also present an approach to determine the locations of additional recycling centers in order to alleviate the over-utilization of the current recycling centers.

• Journal of Information Management
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• v.43 no.4
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• pp.49-68
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• 2012

This study analyzes the general operations of the current services and usages, and the perceptions on the service quality and satisfaction of the 480 users of the electronic information centers (EIC) in the 5 selected university libraries in Daegu and Kyoungpook area. Each libraries provide various levels of their services. Service quality is supposed to be comprised of 3 dimensions of facilities and equipments, contents, and staff. Each of three dimensions influences statistically significantly the user satisfaction of the EIC. Users are satisfied with the facilities and equipments highly. Users in each libraries show statistically different satisfactions in the dimensions of facilities and equipments, and contents, except staff dimensions. Users of each universities show different overall satisfactions on the EICs also.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.12
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• pp.4648-4663
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• 2020

This paper proposes the Lempel-Ziv 4(LZ4) compression accelerator optimized for scale-out servers in data centers. In order to reduce CPU loads caused by compression, we propose an accelerator solution and implement the accelerator on an Field Programmable Gate Array(FPGA) as heterogeneous computing. The LZ4 compression hardware accelerator is a fully pipelined architecture and applies 16 dictionaries to enhance the parallelism for high throughput compressor. Our hardware accelerator is based on the 20-stage pipeline and dictionary architecture, highly customized to LZ4 compression algorithm and parallel hardware implementation. Proposing dictionary architecture allows achieving high throughput by comparing input sequences in multiple dictionaries simultaneously compared to a single dictionary. The experimental results provide the high throughput with intensively optimized in the FPGA. Additionally, we compare our implementation to CPU implementation results of LZ4 to provide insights on FPGA-based data centers. The proposed accelerator achieves the compression throughput of 639MB/s with fine parallelism to be deployed into scale-out servers. This approach enables the low power Intel Atom processor to realize the Hadoop storage along with the compression accelerator.

• Asia pacific journal of information systems
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• v.25 no.3
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• pp.519-539
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• 2015

Customers are now demanding ever better service from customer service representatives (CSRs) to create superior customer service. Accordingly, CSRs are required to have more specialized knowledge and abilities of customer service. This study examines the roles of accumulated customer knowledge in electronic knowledge repositories (EKRs), which a firm has developed for customer service over time to enhance CSRs' work capabilities and work performance, in the context of call centers. To test the proposed research model and hypotheses, we conducted LISREL analysis using 261 responses collected on CSRs working for inbound call centers. The key results are as follows. First, accumulated customer knowledge in EKRs enhances CSRs' knowledge utilization and service expertise during the customer contact. Second, CSRs' knowledge utilization reinforces service expertise. Finally, service quality depends on CSRs' knowledge utilization and service expertise, but it is not directly related to accumulated customer knowledge. Overall, the findings suggest that accumulated customer knowledge in EKRs enhances CSRs' knowledge utilization and service expertise, and thereby leading to superior service quality.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.6 no.2
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• pp.138-143
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• 2006

In this paper, we have presented a Sequential Agglomerative Hierarchical Nested (SAHN) algorithm-based data clustering method in fuzzy inference system to achieve optimal performance of fuzzy model. SAHN-based algorithm is used to give possible range of number of clusters with cluster centers for the system identification. The axes of membership functions of this fuzzy model are optimized by using cluster centers obtained from clustering method and the consequence parameters of the fuzzy model are identified by standard least square method. Finally, in this paper, we have observed our model's output performance using the Box and Jenkins's gas furnace data and Sugeno's non-linear process data.

• Journal of the Korean Society for Library and Information Science
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• v.37 no.1
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• pp.101-125
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• 2003

This thesis presents a step-by-step development strategy to implement electronic school libraries corresponding to level 2 among 3 levels of the school library. The implementation of electronic school libraries means the transformation of school libraries into school media centers. This thesis divides the implementation of electronic school libraries into 3 steps. The first step is the implementation of facilities, the second step the implementation of web-based information system, the third step the networking of school libraries, on the basis of the first and second steps. And this thesis presents the basic policy of educational administration aspects to support 3 steps.