• Journal of Korean Institute of Industrial Engineers
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• v.34 no.1
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• pp.49-56
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• 2008

Reliability has been considered as an important design measure in various industrial systems. We discuss a reliability optimization problem with component choices (ROP-CC) subject to a budget constraint. This problem has been known as a NP-hard problem in the reliability design fields. Several researchers have been working to find the optimal solution through different heuristic methods. In this paper, we describe our development of simulated annealing (SA) and tabu search (TS) algorithms and a reoptimization procedure of the two algorithms for solving the problem. Experimental results for some examples are shown to evaluate the performance of these methods. We compare the results with the solutions of a previous study which used ant system (AS) and the global optimal solution of each example obtained through an optimization package, CPLEX 9.1. The computational results indicate that the developed algorithms outperform the previous results.

• Korean Journal of Remote Sensing
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• v.33 no.4
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• pp.445-454
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• 2017

The performance of spatial downscaling models depends on the quality of input coarse scale products. Thus, the impact of intrinsic errors contained in coarse scale satellite products on predictive performance should be properly assessed in parallel with the development of advanced downscaling models. Such an assessment is the main objective of this paper. Based on a synthetic satellite precipitation product at a coarse scale generated from rain gauge data, two synthetic precipitation products with different amounts of error were generated and used as inputs for spatial downscaling. Geographically weighted regression, which typically has very high explanatory power, was selected as the trend component estimation model, and area-to-point kriging was applied for residual correction in the spatial downscaling experiment. When errors in the coarse scale product were greater, the trend component estimates were much more susceptible to errors. But residual correction could reduce the impact of the erroneous trend component estimates, which improved the predictive performance. However, residual correction could not improve predictive performance significantly when substantial errors were contained in the input coarse scale data. Therefore, the development of advanced spatial downscaling models should be focused on correction of intrinsic errors in the coarse scale satellite product if a priori error information could be available, rather than on the application of advanced regression models with high explanatory power.

• Korean Journal Plant Pathology
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• v.13 no.1
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• pp.46-56
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• 1997

Based on the principal component analysis (PCA) of Richards' parameter estimates, ginseng field soils were grouped as the principal component 1 (PC1) and the principal component 2 (PC2). The microflora and physico-chemical characteristics of each soil group were compared to elucidate soil environmental factors affecting the disease development of root rot of ginseng seedling. Among 3 soil groups by PC1, there were differences in the populations of total fungi (TF) and Cylindrocarpon plus Fusarium (C+F), and the population ratio of Cylindrocarpon plus Fusarium to total fungi or total bacteria (C+F/TF, C+F/TB) in rhizoplane of ginseng seedlings, the population of total actinomycetes (TA) and the population ratio of total Fusarium to total actinomycetes (Fus/TA) in soil, and soil chemical properties (EC, NO3-N, K, Mn, ect.). Among 4 soil groups by PC2, there were differences in TF, C+F, TB, C+F/TF and C+F/TB in the rhizoplane, Trichoderma plus Gliocladium (T+G) in soil, and P2O5 content in soil. Especially, EC, NO3-N, K, K/Mg and Mn were positively correlated to PC1, and TA was negatively to PC1; however, TF, C+F, TB, C+F/TF and C+F/TB in the rhizoplane were significantly correlated to PC2 positively. On the other hand, microbes in the rhizoplane were not significantly correlated to the stand-missing rate (SMR), although TA and Fe/Mn were negatively correlated, and pH and Ca were positively correlated to SMR.

• The Journal of Korean Association of Computer Education
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• v.4 no.1
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• pp.27-34
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• 2001

Recently. The web-based distance education system becomes generalized so that learners can study without being under the control of time and space. This shows that it is more widely used through Internet in education field. But the previous developed methodology for distance-lecture system has some problems, on the Distance Education. It takes much time and cost. In this paper, the need of the Distance-lecture system to apply component-based developing methodology is suggested to overcome these problems. Also, you can save lots of time and cost because it has the reuse, the convenient availability, and the transplantation of distance-educaton system through component-based developing methodology.

• Journal of Korea Water Resources Association
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• v.48 no.11
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• pp.945-955
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• 2015

The technology of the SWG (Smart Water Grid) as one of most important national projects results in significant assignment that is closely associated with systematic management and effective operation. The individual component technics are required to establish directory and classification for the purpose of effectively managing their information related to research and development (R&D). The national science technology (S&T) standard classification tree which results in the representative example has been established with an intention to manage R&D information, human resource, and budget. It has been also revised every five years and then used in the various fields related to the evaluation, administration, and prediction of the national R&D projects. In addition, the standard classification system for R&D projects has been widely used in the UNESCO (United Nations Educational, Scientific and Cultural Organization) and EU (European Union) since the Frascati Manual was established in the Organization for Economic Cooperation and Development (OECD). Therefore, it is necessary for SWG techniques to develop the standard S&T classification tree for research management and evaluation. For this, it is essential to draw the core techniques for the SWG, which are incorporated with IT (Information Technology), NT (Nano Technology), and BT (Biology Technology).

• The KIPS Transactions:PartD
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• v.18D no.6
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• pp.443-450
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• 2011

Model-based Component development methodologies consider the whole system as an component and develop physical components through recursive decomposition and refinements of components in a top-down manner. We developed a model translator that can be used to formally verify interaction consistency among components, especially the interaction behavior between before- and after- refinements of components. This translator can be used to identify potential problems in the refinement process so that problems can be addressed from the early stage of development. This paper introduces our translation approach and the organization of the translator. The translator has been applied to two case studies to show its usefulness.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.7
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• pp.621-628
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• 2016

This paper presents the development of a deadweight type 6-component force/moment generator for estimating characteristics of multi-component loadcell. Several new methods in moment generation are introduced in order to produce accurate force / moment and to minimize coupling effect between each force or moment components. In order to verify the reliability of the calibration system developed, estimation of the method for generating moment components and cross measurements between force or moment components are carried out utilizing a commercial torque cell and both-ends fixed beam designed in this paper.

• Journal of Internet Computing and Services
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• v.7 no.4
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• pp.11-22
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• 2006

Software product-lines methodology is the software development paradigm to build the target system by customizing the variable part of software assets according to requirements. To attain this, the commonalities and variabilities of the system family should be modeled explicitly at early stage. Although the researches on general software product-lines are active, the researches on component-based real-time embedded software product-lines are rather inactive. In this paper a code generation system to support the functional variabilities via feature model and generate the code for synchronization via state model is proposed to increase the productivity of the development of the real-time embedded software product-lines.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.10
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• pp.1841-1861
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• 2011

The advance in Service-Oriented Architecture (SOA) and web services has led to the development of new types of a system in which heterogeneous service components can connect and compose to solve a complex business problem. In the SOA, even though these service components are valid in their functionality, there is a need to test their behaviors when those services are composited. In recent years, WS-BPEL has received a wide acceptance as a means of integrating distributed service components. To test the composite service, the existing testing techniques have been focused on the functional features based on the WS-BPEL process. However as SOA approach is applying to real-time software development, the performance of composite service becomes one of important issues. This paper proposes a technique to the performance testing of a composite service with WS-BPEL extension which combined with the concept of aspect. Our WS-BPEL extension has been made towards annotating aspect component which is measuring the response time of the composite service. This paper also explains the procedure of performance testing with on-line transaction system. Our technique can apply to choose an adequate component in service composition with considering the performance among several candidate web service components.

• Journal of Internet Computing and Services
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• v.7 no.6
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• pp.131-141
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• 2006

In many papers, item difficulty does apply to the E-Learning system for advance learning effect. But there have to need item revision difficulty for more correct item difficulty. Also, there have to support self-directed learning process which learner can make plan and operate learning progress. In this research, I developed self-directed E-Learning system using item revision difficulty. For efficiency of system development, il is implemented and composited by component based development. In the applied result, it was able to support more correct item revision difficulty to learner. And I displayed efficiency of operation the component based self-directed learning system.