• Journal of Digital Convergence
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• v.13 no.1
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• pp.227-235
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• 2015

Big data analysis is a means of organizational problem solving. For an effective problem solving, approaches to problem solving should take into account the factors such as characteristics of problem, types and availability of data, data analytic capability, and technical capability. In this article we propose three approaches: logical top-down, data driven bottom-up, and prototyping for overcoming undefined problem circumstances. In particular we look into the relationship of creative problem solving with the bottom-up approach. Based on the organizational data governance and data analytic capability, we also derive strategic issues concerning the sourcing of big data analysis.

• The KIPS Transactions:PartA
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• v.11A no.5
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• pp.373-382
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• 2004

In this paper, a register promotion technique that translates memory accesses to register accesses is presented to enhance embedded software performance. In the proposed method, a source code is profiled to generate a memory trace. From the profiling results, target functions with high dynamic call counts are selected, and the proposed register promotion technique is applied only to the target functions to save the compilation time. The memory trace of the target functions is searched for the memory accesses that result in cycle count reduction when replaced by register accesses, and they are translated to register accesses by modifying the intermediate code and allocating promotion registers. The experiments on MediaBench and DSPstone benchmark programs show that the proposed method increases the performance by 14% and 18% on the average for ARM and MCORE, respectively.

• Journal of KIISE:Databases
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• v.32 no.2
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• pp.193-203
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• 2005

XML (extensible Markup Language) is recognized as a standard of data representation and transmission on Internet. XPath is a standard for specifying parts of XML documents anda suitable language for both query processing and access control of XML. In this paper, we use the XPath expression for representing user queries and access control for XML. And we propose an access control method for XML, where we control accesses to XML documents by filtering query XPath expressions through access control XPath expressions. In the proposed method, we directly search XACT (XML Access Control Tree) for a query XPath expression and extract the access-granted parts. The XACT is our proposedstructure, where the edges are structural summary of XML elements and the nodes contain access-control information. We show the query XPath expressions are successfully filtered through the XACT by our proposed method, and also show the performance improvement by comparing the proposed method with the previous work.

• The KIPS Transactions:PartC
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• v.10C no.4
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• pp.387-396
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• 2003

Many studies have been done on secure kernel and encryption filesystem for system security. Secure kernel can protect user or system data from unauthorized and/or illegal accesses by applying various access control policy like ACL, MAC, RBAC and so on, but cannot protect user or system data from stealing backup media or disk itself. In addition to access control policy, there are many studies on encryption filesystem that encrypt file data within system level. However few studies have been done on combining access control policy and encryption filesystem. In this paper we proposed a new encryption filesystem that provides a transparency to the user by integrating encryption service into virtual filesystem layer within secure kernel that has various access control policies. Proposed encryption filesystem can provide a simple encryption key management architecture by using encryption keys based on classes of MAC policy and overcome a limit of physical data security of access control policy for stealing.

• The Transactions of the Korea Information Processing Society
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• v.7 no.11S
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• pp.3623-3632
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• 2000

Until now the XML document is allowed users to access the whole content of it However, for some applications such as those in the field of electronic commerce, there are cases that the whole content should not be delivered. Therefore, access authorization is required for XML documents in order to protect illegal accesses to some critical parts of them. In this paper. we design and implement a system which authorizes users to XML documents and controls access to them based on the access rights. We set the user group as a basic unit of the authorization subject and the element of an XML document as a basic unit of authorization object The owner of a document authorize; user groups to access the elements of it When an XML document is accessed, the access rights of the requester are checked using an access control list and only the authorized parts are delivered_ As the result, we can authorize XML documents, which has been previously impossible.

• Journal of Korea Water Resources Association
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• v.39 no.3 s.164
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• pp.253-259
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• 2006

In almost all previous hydrological studies, the standard approach adopted for nonlinear time series analysis is to perform system characterization first followed by forecasting. However, a practical inverse approach for forecasting nonlinear hydrological time series was proposed recently To investigate the applicability standard approach method and inverse approach, this study used a theoretical time series (Mackey-Glass time series) and daily streamflows of the Bear River in Idaho. To predict a theoretical time series and daily streamflow, this study used local approximation method. From chaos analysis, chaotic characteristics are found in daily streamflow of the Bear River in Idaho. Resulting from 1, 3 and 5-day prediction, inverse approach method is shown to be better than the standard approach for a theoretical chaotic time series and daily streamflow.

• Journal of KIISE:Computer Systems and Theory
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• v.28 no.11
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• pp.581-591
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• 2001

We consider some problems of remote file accesses of multiple clients in mobile computing environments. In this environment, user mobility affects file access latency. Mobile hosts have severe resource constraints in terms of limited size of non-volatile storage. Thus, the burden of computation and communication load raise file access latency. In this paper, we propose a scheme for reducing the file access latency through the file migration. The objective is to minimize of file accesses for all mobile hosts which delivering the file to clients as quickly as possible. We develope an on-demand scheme which determines when the file server should migrate files to another server, or when it should transfer files to mobile hosts. Using simulation, we examine the effects which parameters such as file access frequency, file size, mobility rate have on file system access latency. Through simulation results, we show that our proposed migration scheme is effective in reducing the access latency on the requested file of a mobile host with high access rate and low mobility.

• Korean Journal of Social Welfare Studies
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• no.37
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• pp.35-62
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• 2008

This study starts form the inequity of the spatial accessibility in social services. This study has purpose to descript and analyze the spatial accessibility of social service agencies. While analysing the spatial accessibility, this paper uses comparative method of distance and space-time measures. The results of research are as follows; It needs (1) to enhance the spatial accessibility of the aged and the disabled. (2) to facilitate the spatial accessibility of marginal area or community like rural community. (3) to recognize utilities of distance and space-time measures in the spatial accessibility.

• Journal of the Korean Society for Library and Information Science
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• v.53 no.4
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• pp.231-254
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• 2019

Library website is medium for connecting library information resources and users. However, searching and accessing methods to information resources in library websites and retrieval systems are mostly designed for users. So, the disabled users have difficulty accessing and using library information resources through library websites. Therefore, the author carried on current status study and analysis on the retrieval system of the national and public library websites in Korea. And then, the author proposes improvement plan in order to enhance satisfaction with information needs of disabled users and to use a basic study for construction of retrieval system of library websites for disabled users.

• Journal of the Korean Society for Library and Information Science
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• v.55 no.4
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• pp.67-87
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• 2021

Public library accessibility directly affects library usage, and the disproportionate distribution of accessibility is a decisive factor limiting the equitable provision of library services. In this regard, this study analyzed the spatial accessibility of public libraries in Busan and identified the factors affecting accessibility of public libraries using spatial regression analysis. As a results of the analysis, the accessibility of public libraries in the Busan showed large deviations by region. Also, spatial distribution of public libraries had no correlation with the settled population and use of public transportation, and location of public libraries was inefficient, in terms of social equity. The results of this study will assist to understand the spatial accessibility of public libraries in Busan, to identify factors that affect the accessibility. Moreover, this study is expected to be utilized as fundamental data for releasing disparities of the spatial accessibility and selecting new location of public library in Busan.