• Journal of applied mathematics & informatics
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• v.28 no.1_2
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• pp.351-361
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• 2010

The solution of large sparse linear systems is one of the most important problems in large scale scientific computing. Among the many methods developed, the preconditioned Krylov subspace methods are considered the preferred methods. Selecting a suitable preconditioner with appropriate parameters for a specific sparse linear system presents a challenging task for many application scientists and engineers who have little knowledge of preconditioned iterative methods. The prediction of ILU type preconditioners was considered in [27] where support vector machine(SVM), as a data mining technique, is used to classify large sparse linear systems and predict best preconditioners. In this paper, we apply the data mining approach to the sparse approximate inverse(SAI) type preconditioners to find some parameters with which the preconditioned Krylov subspace method on the linear systems shows best performance.

• The KIPS Transactions:PartD
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• v.13D no.1 s.104
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• pp.139-146
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• 2006

This paper describes the design and implementation details of a distributed transactional workflow monitoring system. There have been prevalent research and development trends in the workflow literature - workflow systems tend to be completely distributed architectures to support very large-scale workflow applications on object-oriented and internet-based infrastructures. That is, the active (object), distributed (architecture), system-oriented (transaction), and large-scale (application) workflow systems are the key targets in terms of the research and development aspects. While the passive, centralized, human-oriented, and small/medium scale workflow systems are the typical instances of the traditional workflow systems. Unlike in the traditional (the client-server architecture) workflow systems, the workflow monitoring features should not be easily supported in the recent (the fully distributed architecture) workflow systems. At the same time, they need a set of additional monitoring features, such as gathering and displaying statistical (or overload status) information of the workflow architectural components dispersed on the internet. We, in this paper, introduce the additional workflow monitoring features that are necessarily required for the recent workflow systems, and show how to embed those features into a web-based distributed workflow system.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.8
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• pp.2881-2894
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• 2014

In complicated environment, context information plays an important role in image segmentation/labeling. The recently proposed auto-context algorithm is one of the effective context-based methods. However, the standard auto-context approach samples the context locations utilizing a fixed radius sequence, which is sensitive to large scale-change of objects. In this paper, we present a scale invariant auto-context (SIAC) algorithm which is an improved version of the auto-context algorithm. In order to achieve scale-invariance, we try to approximate the optimal scale for the image in an iterative way and adopt the corresponding optimal radius sequence for context location sampling, both in training and testing. In each iteration of the proposed SIAC algorithm, we use the current classification map to estimate the image scale, and the corresponding radius sequence is then used for choosing context locations. The algorithm iteratively updates the classification maps, as well as the image scales, until convergence. We demonstrate the SIAC algorithm on several image segmentation/labeling tasks. The results demonstrate improvement over the standard auto-context algorithm when large scale-change of objects exists.

• Journal of Electrical Engineering and Technology
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• v.4 no.3
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• pp.301-309
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• 2009

A simple and efficient Lambda logic (${\lambda}-logic$) based algorithm is proposed for the solution of the generator constrained economic dispatch problem when the generating units having prohibited zones. The proposed method solves the economic dispatch (ED) problem that takes into account ramprate limits, transmission losses and prohibited operating zones in the power system operation. The proposed method uses a simple heuristic rule based on average power of prohibited operating zones which produces the feasibility of solution for the restricted operating units. The effectiveness of the algorithm is tested on five different test systems and the performance compared with other relevant methods reported in the literature. In all the cases, the proposed algorithm performs better than the previous existing algorithms with a less computational burden.

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.233-236
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• 1998

In this paper, we present a novel approach named a shared library as an active memory object for application software development of large-scale real-time systems. Unlike the general passive shared memory, shared library proposed in this paper can be activated as an execution object. Moreover this is not tightly coupled with application programs unlike the normal libraries. To implement this mechanism, operating system makes the shared memory as an active object and shared library realizes the indirect call structure. This mechanism enhanced the utilization of main memory and communication performance. And this is successfully applied to the HANbit ACE ATM switching system and the TDX-10 switching system.

• Journal of Korea Society of Industrial Information Systems
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• v.11 no.4
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• pp.25-31
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• 2006

With the increasing demand of foreign language education in colleges, an effective testing and study system is also needed especially for large scale classes. In this paper, 1 propose a new online system for running large scale foreign language classes which supports not only testing function but also individually customized studying and diagnosis functions. Using the proposed system enables saving of testing space and helps all students get equally good testing and study environment regardless of class size and lecturers.

• Asia pacific journal of information systems
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• v.25 no.3
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• pp.548-562
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• 2015

The growing popularity of mobile application has led to researchers and practitioners needing to understand users' mobile application download behaviors. Using large-scale transaction data obtained from a leading Korean telecommunications company, we empirically explore how application download rank, which appears to users when they decide to download a new application, affects their extended mobile application download. This terminology refers to downloading an additional application in the same category as those that they have already downloaded. We also consider IT characteristics, user characteristics, and application type that might be associated with the extended application download. The analysis generates the following result. Overall, a higher rank of a new application encourages the extended application download, but the linear relationship between the rank and the extended application download disappears when critical rank points are incorporated into the model. Further, no quadratic effect of rank is found in the extended application download. Based on the results, we suggest theoretical and managerial implications.

• Journal of Korea Multimedia Society
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• v.6 no.4
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• pp.723-735
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• 2003

This research focuses ell an approach for the building of a requirements model for the development of large-scale information systems. It will suggest a set of requirements engineering processes as a procedure of the implementation for building the requirements model. It will also emphasise the evaluation requirements model aimed to refine and complete the requirements model by the different user groups as a cross reference. This paper provides an advanced user-construction requirements within the Event Flow Diagram as a set of requirements engineering process.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.49 no.7
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• pp.370-377
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• 2000

This paper presents a decentralized compensator design procedure for large scale systems. By using a coordinate transformation method, interconnection terms in t도 subsystem are decoupled and a decentralized observer is designed independently as a form of Luenberger-type for each subsystem. And the decentralized compensator which can select the observer and controller gain independently is designed as a form of observer based controller for each subsystem. The proposed method has a simplicity and conciseness in the aspects of the determination of coordinate transformation matrices and the derivation of the separation principle which is adopted independently for each subsystem.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.37 no.6
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• pp.7-14
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• 2000

This paper describes the synthesis of robust decentralized controllers for uncertain large-scale discrete-time systems with time-delays in subsystem interconnections. Based on the Lyapunov method, a sufficient condition for robust stability, is derived in terms of a linear matrix inequality (LMI). The solutions of the LMI can be easily obtained using various efficient convex optimization techniques. A numerical example is given to illustrate the proposed method.