• Journal of the Korea Safety Management & Science
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• v.11 no.3
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• pp.209-216
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• 2009

A development in method of evaluating the measurement precisions using approximate F tests and variance components from expected mean square (EMS) is investigated. The research proposes three-factor mixed measurement models with the fixed and random factors. Unrestricted and unconstrained design work was rarely studied, while restricted and constrained designs have been significantly discussed. The unrestricted and unconstrained designs assume to be an independence of interaction. The proposed evaluation method about the measurement precisions can be extended to four-factor random measurement model or mixed measurement model. The study also presents the three evaluation indexes of precisions such as R&RTR (Reproducibility & Repeatability-To-Total Precision Ratio), PTR (Precision-To-Tolerance Ratio), and SNR (Signal-To-Noise Ratio). Numerical examples are proposed to evaluate the approximate F tests with Satterthwaite degrees of freedom and three indexes using the measurement precisions from EMS.

• Nuclear Engineering and Technology
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• v.47 no.7
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• pp.895-906
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• 2015

Background: Mitigation of primary water stress corrosion cracking (PWSCC) is a significant issue in the nuclear industry. Advanced nickel-based alloys with lower susceptibility have been adopted, although they do not seem to be entirely immune from PWSCC during normal operation. With regard to structural integrity assessments of the relevant components, an accurate evaluation of crack growth rate (CGR) is important. Methods: For the present study, the extended finite element method was adopted from among diverse meshless methods because of its advantages in arbitrary crack analysis. A user-subroutine based on the strain rate damage model was developed and incorporated into the crack growth evaluation. Results: The proposed method was verified by using the well-known Alloy 600 material with a reference CGR curve. The analyzed CGR curve of the alternative Alloy 690 material was then newly estimated by applying the proven method over a practical range of stress intensity factors. Conclusion: Reliable CGR curves were obtained without complex environmental facilities or a high degree of experimental effort. The proposed method may be used to assess the PWSCC resistance of nuclear components subjected to high residual stresses such as those resulting from dissimilar metal welding parts.

• Journal of Information Technology Applications and Management
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• v.11 no.4
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• pp.209-225
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• 2004

This paper presents case studies on database Quality uSing an extended database Quality model developed by Korea Database Promotion Center, which shall be called KDPC2003. The model is applied to evaluate two kinds of databases ; one is an operational database, the other is an information service database. The purpose of this research is two-folded. One is to evaluate database quality and assess current status of database quality management; the other is to assess usefulness of KDPC2003 and to propose ideas for its augmentation. The findings in this study will provide basic facts to test database quality evaluation models.

• Journal of Navigation and Port Research
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• v.31 no.7
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• pp.579-587
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• 2007

Samchunpo(Sin Hyang) Harbor is located in the bay of Sa Chun, the central south coast of Korean peninsula. The harbor and coastal boundaries have been protecting by natural coastal islands and shoals. Currently, The Sin Hyang harbor needs maintenance and renovation of the sheltered structures against the weather deterioration and typhoon damages. Consequently to support this, the calculation of accurate design wave through the typhoon wave attack is necessary. In this study, calculation of incident wave condition is simulated using steady state spectrum energy wave model(wide area wave model) from 50 years return wave condition. And this simulation results in wide offshore area were used for the input of the extended mild slope wave model at the narrow coastal area. Finally, the calculation of design wave at Sin Hyang harbor entrance was induced by Boussinesq wave model(detail area wave model) simulation. The numerical model system was able to simulate wave transformations from generation scale to shoreline or harbor impact. We hope these results will be helpful to the engineers doing placement, design, orientation, and evaluation of a wide range of potential solutions in this area.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.27 no.6
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• pp.1535-1547
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• 2017

The purchase of information protection products accounts for the largest portion of corporate information protection activity budgets. However, there are no evaluation factors and evaluation models that should be applied to objectively compare information protection products, and therefore, product selection is difficult. Therefore, in this study, we study the inherent quality characteristics of information security products and select evaluation factors accordingly. The selected evaluation factors are analyzed and a quality determination model is given by weighting according to importance. The target is limited to the network information protection product and can be extended to all information protection products.

• Journal of Korean Society of Steel Construction
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• v.27 no.2
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• pp.243-250
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• 2015

An extended end-plate connection displays different behavioral properties and energy dissipation capacity based on the thickness and length of the end-plate comprising the connection in the form of a beam-to-column moment connection, the number and diameter of the high strength bolt, the gauge distance of the high strength bolt, and the size and length of the welds. Such extended end-plate is applied to beam-to-column connections in various geometric forms in the US and European regions. Currently in Korea, however, the extended end-plate beam-to-column connection is not actively applied due to the lack of proper design formulas, the evaluation of the energy dissipation capacity, and the provision of construction guidelines. Accordingly, this study was conducted to provide the basic data for the proposal of a prediction model of energy dissipation capacity by evaluating the energy dissipation capacity of unstiffened extended end-plate connections with relatively thin end plate thicknesses. To achieve this, a three-dimensional nonlinear finite element analysis has been conducted on unstiffened extended end-plate connections, with the thickness of the end plate as the set variable.

• Journal of Aerospace System Engineering
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• v.10 no.1
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• pp.21-28
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• 2016

Orbit determination problems have been interest of many researchers for long time. Due to the high nonlinearity of the equation of motion and the measurement model, it is necessary to linearize the both equations. To avoid linearization, the filter based on Fokker-Planck equation is designed. with the extended Kalman filter update mechanism, in which the associated Fokker-Planck equation was solved efficiently and accurately via discrete quadrature and the measurement update was done through the extended Kalman filter update mechanism. This filter based on the DQMOM and the EKF update is applied to the orbit determination problem with appropriate modification to mitigate the filter smugness. Unlike the extended Kalman filter, the hybrid filter based on the DQMOM and the EKF update does not require the burdensome evaluation of the Jacobian matrix and Gaussian assumption for the system, and can still provide more accurate estimations of the state than those of the extended Kalman filter especially when measurements are sparse. Simulation results indicate that the advantages of the hybrid filter based on the DQMOM and the EKF update make it a promising alternative to the extended Kalman filter for orbit estimation problems.

• Journal of Internet Computing and Services
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• v.22 no.4
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• pp.13-28
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• 2021

Reinforcement Learning (RL) is a machine learning algorithm that repeat the closed-loop process that agents perform actions specified by the policy, the action is evaluated with a reward function, and the policy gets updated accordingly. The key benefit of RL is the ability to optimze the policy with action evaluation. Hence, it can effectively be applied to developing advanced intelligent systems and autonomous systems. Conventional RL incoporates a single policy, a reward function, and relatively simple policy update, and hence its utilization was limited. In this paper, we propose an extended RL model that considers multiple instances of RL elements. We define a formal model of the key elements and their computing model of the extended RL. Then, we propose design methods for applying to system development. As a case stud of applying the proposed formal model and the design methods, we present the design and implementation of an advanced car navigator system that guides multiple cars to reaching their destinations efficiently.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.5B
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• pp.364-378
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• 2008

Data Envelopment Analysis(DEA) models can be used for performance evaluation on governmental funding projects for IT small and medium-sized enterprises associated with multiple-outputs/multiple-inputs. In order to enhance the accuracy of DEA efficiency scores, DEA models with exogenously fixed variables are required where the corporate competency is taken into account. Additionally, it is necessary to use multiple DEA basic as well as extended models so as to relax the restriction on the performance evaluation to relying on a single DEA model. In this study; 1)a DEA data structure is designed including exogenously fixed variables representing corporate asset, revenue and the number of employees at the point in time that the governmental funding project concerned is initiated; 2)DEA basic as well as extended models are established according to the DEA data structure presented abovementioned; and 3)a case study is illustrated with an empirical testbed dataset. As for the DEA basic models, CCR, BCC, Super-efficiency model are adopted. The DEA extended models are developed based on the models associated with noncontrollable and nondiscretionary variables. In the case study, it is explained a comparison of DEA models and also major numerical outcomes such as efficiency scores, ranks derived from each DEA model are integrated using Analytic Hierarchy Process(AHP) weights. Performance significance with DEA efficiency scores between technical categories are tested based not only on parametric but also nonparametric single-factor analysis of variance method.

• The Transactions of the Korea Information Processing Society
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• v.1 no.2
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• pp.194-201
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• 1994

Recently, as application fields of software is extended, relative importance of software make a gradual increase and importance of development cost is being increased. However, as former evaluation model of development cost evaluate at the functional point of view for the most part, at this paper, I intend to propose evaluation model of software development cost COSMOS-Q(COSt MOdel for Subcontract-Quality) which one evaluate also in quality as well as function. The model proposed in this paper set the goal at software orderer evaluate software cost exactly with only order specification information. At this paper, I proposed cost evaluation model and evaluated it's validity refering to review result in ISO/SC7 about a software quality feature with extraction of quality feature factor which produce change of cost and set up the evaluation measure adoptable as order condition.