• 한국연소학회지
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• 제5권2호
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• pp.9-17
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• 2000

A brief introduction is given on the conditional moment closure model for turbulent nonpremixed combustion. It is based on the transport equations derived through a rigorous mathematical procedure for the conditionally averaged quantities and appropriate modeling forms for conditional scalar dissipation rate, conditional mean velocity and reaction rate. Examples are given for prediction of NO and OR in bluffbody flames, soot distribution in jet flames and autoignition of a methane/ethane jet to predict the ignition delay with respect to initial temperature, pressure and fuel composition. Conditional averaging may also be a powerful modeling concept in other approaches involved in turbulent combustion problems in various different regimes.

• Coupled systems mechanics
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• 제7권6호
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• pp.731-753
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• 2018

The recent seismic events have led to concerns on safety and vulnerability of Reinforced Concrete Moment Resisting Frame "RC-MRF" buildings. The seismic design demands are greatly dependent on the computational tools, the inherent assumptions and approximations introduced in the modeling process. Thus, it is essential to assess the relative importance of implementing different modeling approaches and investigate the computed response sensitivity to the corresponding modeling assumptions. Many parameters and assumptions are to be justified for generation effective and accurate structural models of RC-MRF buildings to simulate the lateral response and evaluate seismic design demands. So, the present study aims to develop reliable finite element model through many refinements in modeling the various structural components. The effect of finite element modeling assumptions, analysis methods and code provisions on seismic response demands for the structural design of RC-MRF buildings are investigated. where, a series of three-dimensional finite element models were created to study various approaches to quantitatively improve the accuracy of FE models of symmetric buildings located in active seismic zones. It is shown from results of the comparative analyses that the use of a calibrated frame model which was made up of line elements featuring rigid offsets manages to provide estimates that match best with estimates obtained from a much more rigorous modeling approach involving the use of shell elements.

• 대한기계학회논문집A
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• 제21권2호
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• pp.281-287
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• 1997

In the conventional inverse modeling method for on-line modeling of the secondary path transfer function, the signal to noise ratio between the arbitrary random signal and the plant noise have to keep at -10 - -20 dB. For these reasons, the modeling can't be exactly implemented by the conventional method alone and the convergence time for modeling becomes too long. In this study, by combining the conventional inverse modeling method with an adaptive line enhancer, or with an adaptive noise canceller, a rigorous transfer functions of secondary path modeling and the control of a primary noise have been implemented simultaneously.

• 대한산업공학회지
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• 제27권1호
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• pp.37-46
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• 2001

Business process(workflow) analysis has been recognized as a core step to building information systems. However, most analysts have recognized that deriving consistent business process artifacts even in a simple business domain is very difficult, since most analysis methods give the designers narrative and/or diagrammatic tools that do not support rigorous analysis rules. This often generates inconsistent analysis results, leading to create useless information systems and resulting in tremendous budget wastes. To overcome this weakness, this paper presents a declarative business process modeling method called contract-collaboration net(cc-net), which is not only somewhat formal but also useful to the practitioners. A case study on bank domain is presented to illustrate our approach.

• Journal of Information Display
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• 제7권4호
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• pp.5-8
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• 2006

The optical structures and rigorous electromagnetic modeling of OLEDs will be discussed of first and then their applications in analyses and designs of various advanced OLED structures, e.g. microcavity OLEDs, tandem OLEDs and top-emitting OLEDs etc., will be reported.

• 한국대기환경학회지
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• 제33권5호
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• pp.521-528
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• 2017

In the combustion treatment of explosive gases with a high heating value such as $H_2$ and $NH_3$ used in semiconductor and chemical processes, the heat recovery modeling and exergy analysis of the process using the Aspen Plus simulator and its thermodynamic data were performed to examine the recovery of high temperature thermal energy. The heat recovery process was analyzed through this process modeling while the exergy results clearly confirmed that the rigorous reaction mainly occurs in the condenser and the chamber. In addition, the process modeling demonstrated that approximately 95% of the exergy is destructed on the basis of the exergies injected and the exergy being exhausted. Using the exergy technique, which can quantitatively analyze the energy, we could understand the energy flow in the process and confirm that our heat recovery process was efficiently designed.

• 품질경영학회지
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• 제46권4호
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• pp.973-982
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• 2018

Purpose: The purpose of this study is to develop an effective simulation modeling formalism for autonomous control systems, such as unmanned aerial vehicles and unmanned surface vehicles. The proposed simulation modeling formalism can be used to evaluate the quality and effectiveness of autonomous control systems. Methods: The proposed simulation modeling formalism is developed by extending the classic DEVS (Discrete Event Systems Specifications) formalism. The main advantages of the classic DEVS formalism includes its rigorous formal definition as well as its support for the specification of discrete event models in a hierarchical and modular manner. Results: Although the classic DEVS formalism has been a popular modeling tool, it has limitations in describing an autonomous control system which needs to make decisions by its own. As a result, we proposed an extended DEVS formalism which enables the effective description of internal decisions according to its conditional variables. Conclusion: The extended DEVS formalism overcomes the limitations of the classic DEVS formalism, and it can be used for the effectiveness simulation of autonomous weapon systems.

• Nuclear Engineering and Technology
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• 제50권4호
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• pp.532-541
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• 2018

Decision support systems are a key focus of research on developing control rooms to aid operators in making reliable decisions and reducing incidents caused by human errors. For this purpose, models of complex systems can be developed to diagnose causes or consequences for specific alarms. Models applied in safety systems of complex and safety-critical systems require rigorous and reliable model building and testing. Multilevel flow modeling is a qualitative and discrete method for diagnosing faults and has previously only been validated by subjective and qualitative means. To ensure reliability during operation, this work aims to synthesize a procedure to measure model performance according to diagnostic requirements. A simple procedure is proposed for validating and evaluating the concept of multilevel flow modeling. For this purpose, expert statements, dynamic process simulations, and pilot plant experiments are used for validation of simple multilevel flow modeling models of a hydrocyclone unit for oil removal from produced water.

• East Asian mathematical journal
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• 제27권4호
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• pp.471-483
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• 2011

The purpose of this study is to introduce the Common Core State Standards (CCSS) for mathematics which is released on June 2, 2010 in the U.S.A. The common core state standards are aligned with college and work expectations, and include rigorous content and application of knowledge through high-order skills. The most distinguishable differences between the CCSS standards and the NCTM standards are that the CCSS standards considers the mathematical modeling as one of the mathematical content domains such as algebra, geometry, ets, and the standards are designed by working together with school leaders of all states.

• 산업경영시스템학회지
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• 제18권34호
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• pp.185-191
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• 1995

In this research, a mathematical programming model is developed for the economic modeling of sampling plans based on two evaluation criteria : the outgoing quality and the average total inspection cost A fuzzy goal programming model and its solution procedure are proposed for the managers whose management objectives on the two evaluation criteria are not rigorous. To study the sensitivity of quality characteristic dependence on the resulting inspection plans, a numerical example is solved several times for a dependent model.