• Journal of The Korean Association For Science Education
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• v.36 no.1
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• pp.15-28
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• 2016

The purpose of this study is to investigate the changes of students' modeling ability in terms of 'meta-modeling knowledge' and 'modeling practice' through co-construction of scientific model. Co-construction of scientific model instructions about astronomy were given to 41 middle-school students. The students were given a before and after instruction modeling ability tests. The results show that students' 'meta-modeling knowledge' has changed into a more scientifically advanced thinking about models and modeling after the instruction. Students were able to be aware that 'they could express their thoughts using models', 'many models could be used to explain a single phenomena' and 'scientific models may change' through co-construction modeling process. The change in the 'modeling practice' of the students was divided into four cases (the level improving, the level lowering, the high-level maintaining, the low-level maintaining) depending on the change of pre-posttest levels. The modeling practice level of most students has improved through the instruction. These changes were influenced by co-construction process that provides opportunities to compete and compare their models to other models. Meanwhile, the modeling practice level of few students has lowered or maintained low level. Science score of these students at school was relatively high and they thought that the goal of learning is to get a higher score in exams by finding the correct answer. This means that students who were kept well under traditional instruction may feel harder to adapt to co-construction of scientific model instruction, which focuses more on the process of constructing knowledge based on evidences.

• Journal of the Korea Computer Industry Society
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• v.5 no.9
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• pp.1055-1062
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• 2004

Unified Modeling Language (UML) is a standard language for specifying, visualizing, constructing, and documenting the artifacts of software systems. On the other hand, XML, which is a meta-language, provides meta-data types for representing and string objects. It make software development easy because it can represent various information and share information about the software analysis and design between developers, In this paper, we apply BitWiz, one of automated software generation systems, to a bid application and analyse this in UML point of view. Also, we briefly introduce an XML documentation from UML products and a verification method of XML documents from UML products.

• Journal of the Korean Society for Library and Information Science
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• v.32 no.3
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• pp.143-156
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• 1998

This paper reports the GEM (Gateway to Educational Materials) project whose goal is to develop an operational framework to provide the K-12 teachers in the world with 'one-stop/any-stop' access to thousands of lesson plans, curriculum units and other Internet-based educational resources. To the IS-element Dublin Core base package, the GEM project added an 8-element, domain-specific GEM package. The GEM project employed the conceptual data modeling approach to designing the GEM database, used the Sybase relational database management system (RDBMS) to construct the backend database for storing the metadata of educational resources, and also employed the active server page (ASP) technology to provide Web interfaces to that database. The consortium members catalog lesson plans and other Internet-based educational resources using a cataloging module program that produces HTML meta tags. A harvest program collects these meta tags across the Internet and outputs an ASCII file that conforms to the standard agreed by the consortium members. A parser program processes this file to enter meta tags automatically into appropriate relational tables in the Sybase database. The conceptual/logical schemas of Dublin Core and GEM profile are presented. The advantages of conceptual modeling approach to manage metadata are discussed. A prototype system that provides access to the GEM metadata is available at http://lis.skku.ac.kr/gem/.

• Journal of the Korea Society for Simulation
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• v.30 no.2
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• pp.23-31
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• 2021

Defense M&S(Modeling & Simulation) requires weapon effectiveness index which indicates Ph(Probability of hit) and Pk(Probability of kill) values on various impact and environmental conditions. The index is usually produced by JMEM(Joint Munition Effectiveness Manual) development process, which calculates Pk based on the impact condition and circular error probable. This approach requires experts to manually adjust the index to consider the environmental factors such as terrain, atmosphere, and obstacles. To reduce expert's involvement, this paper proposes a meta-model based method to produce weapon effectiveness index. The method considers the effects of environmental factors during calculating a munition's trajectory by utilizing high-resolution weapon system models. Based on the result of Monte-Carlo simulation, logistic regression model and Gaussian Process Regression(GPR) model is respectively developed to predict Ph and Pk values of unobserved conditions. The suggested method will help M&S users to produce weapon effectiveness index more efficiently.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.10
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• pp.1509-1516
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• 2022

This paper presents a method to generate a model of the code implementation for UML state diagrams. First, it promotes the states of a state machine into objects, and then it structures the behavior model on the mechanism of a state diagram based on State design pattern. Then, it establishes the rules of generating the code implementation, and using the rules, the Java code mode is generated for the implementations of State Diagrams in Java syntax grammar. In addition, Structuring the information of the code model is necessary for generating Java code automatically. The meta information is composed of Meta-Class Model and Meta-Behavior Model, on which we could construct the automatic code generating engine for UML State Diagrams. The implementation model generation method presented in this paper could be used as a stand-alone engine, or included and integrated as a module in the UML tools.

• Smart Structures and Systems
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• v.31 no.2
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• pp.113-130
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• 2023

Hybrid simulation (HS) has attracted community attention in recent years as an efficient and effective experimental technique for structural performance evaluation in size-limited laboratories. Traditional hybrid simulations usually take deterministic properties for their numerical substructures therefore could not account for inherent uncertainties within the engineering structures to provide probabilistic performance assessment. Reliable structural performance evaluation, therefore, calls for stochastic hybrid simulation (SHS) to explicitly account for substructure uncertainties. The experimental design of SHS is explored in this study to account for uncertainties within analytical substructures. Both computational simulation and laboratory experiments are conducted to evaluate the pseudo-random Sobol sequence for the experimental design of SHS. Meta-modeling through polynomial chaos expansion (PCE) is established from a computational simulation of a nonlinear single-degree-of-freedom (SDOF) structure to evaluate the influence of nonlinear behavior and ground motions uncertainties. A series of hybrid simulations are further conducted in the laboratory to validate the findings from computational analysis. It is shown that the Sobol sequence provides a good starting point for the experimental design of stochastic hybrid simulation. However, nonlinear structural behavior involving stiffness and strength degradation could significantly increase the number of hybrid simulations to acquire accurate statistical estimation for the structural response of interests. Compared with the statistical moments calculated directly from hybrid simulations in the laboratory, the meta-model through PCE gives more accurate estimation, therefore, providing a more effective way for uncertainty quantification.

• Journal of KIISE:Software and Applications
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• v.30 no.12
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• pp.1158-1171
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• 2003

The UML is a widely accepted standard in object-oriented modeling. As the UML is semantically rich, we can describe in detail the system that will be developed, but we cannot guarantee the correctness and consistency of the designed model. Therefore, it is important to minimize the error by verifying user models in an early stage. In this paper, we propose a method for verifying the consistency of UML structural diagrams and behavioral diagrams using OCL verification rules and meta-metamodel. The consistency is a nature for checking whether the structural diagrams and behavioral diagrams are coherently designed according to a specific requirement. First we build meta-metamodels of the structural diagram and behavioral diagram that are described with the UML diagrams and the related elements, we derive rules for verifying the consistency from each meta-metamodels, and then formally specify with the language such as OCL for automatic verification. Finally, we verify the usefulness of the rule through a case study.

• The Journal of Society for e-Business Studies
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• v.12 no.3
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• pp.235-249
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• 2007

Workflow systems are software systems that control the execution of long-term processes. Members of an organization are in charge of executing processes. A work assignment policy, i.e who should perform a certain piece of process, has to be modeled and implemented in workflow systems. Organizations may have a large variety of problems in work assignment, and it may not be feasible to devise a single model to cover all problems. In this paper, we introduce generality to work assignment design problems in workflow systems We provide a meta-model based approach which enables us to define arbitrary problem oriented work assignment policies.

• Journal of Intelligence and Information Systems
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• v.26 no.1
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• pp.23-45
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• 2020

Big data is creating in a wide variety of fields such as medical care, manufacturing, logistics, sales site, SNS, and the dataset characteristics are also diverse. In order to secure the competitiveness of companies, it is necessary to improve decision-making capacity using a classification algorithm. However, most of them do not have sufficient knowledge on what kind of classification algorithm is appropriate for a specific problem area. In other words, determining which classification algorithm is appropriate depending on the characteristics of the dataset was has been a task that required expertise and effort. This is because the relationship between the characteristics of datasets (called meta-features) and the performance of classification algorithms has not been fully understood. Moreover, there has been little research on meta-features reflecting the characteristics of multi-class. Therefore, the purpose of this study is to empirically analyze whether meta-features of multi-class datasets have a significant effect on the performance of classification algorithms. In this study, meta-features of multi-class datasets were identified into two factors, (the data structure and the data complexity,) and seven representative meta-features were selected. Among those, we included the Herfindahl-Hirschman Index (HHI), originally a market concentration measurement index, in the meta-features to replace IR(Imbalanced Ratio). Also, we developed a new index called Reverse ReLU Silhouette Score into the meta-feature set. Among the UCI Machine Learning Repository data, six representative datasets (Balance Scale, PageBlocks, Car Evaluation, User Knowledge-Modeling, Wine Quality(red), Contraceptive Method Choice) were selected. The class of each dataset was classified by using the classification algorithms (KNN, Logistic Regression, Nave Bayes, Random Forest, and SVM) selected in the study. For each dataset, we applied 10-fold cross validation method. 10% to 100% oversampling method is applied for each fold and meta-features of the dataset is measured. The meta-features selected are HHI, Number of Classes, Number of Features, Entropy, Reverse ReLU Silhouette Score, Nonlinearity of Linear Classifier, Hub Score. F1-score was selected as the dependent variable. As a result, the results of this study showed that the six meta-features including Reverse ReLU Silhouette Score and HHI proposed in this study have a significant effect on the classification performance. (1) The meta-features HHI proposed in this study was significant in the classification performance. (2) The number of variables has a significant effect on the classification performance, unlike the number of classes, but it has a positive effect. (3) The number of classes has a negative effect on the performance of classification. (4) Entropy has a significant effect on the performance of classification. (5) The Reverse ReLU Silhouette Score also significantly affects the classification performance at a significant level of 0.01. (6) The nonlinearity of linear classifiers has a significant negative effect on classification performance. In addition, the results of the analysis by the classification algorithms were also consistent. In the regression analysis by classification algorithm, Naïve Bayes algorithm does not have a significant effect on the number of variables unlike other classification algorithms. This study has two theoretical contributions: (1) two new meta-features (HHI, Reverse ReLU Silhouette score) was proved to be significant. (2) The effects of data characteristics on the performance of classification were investigated using meta-features. The practical contribution points (1) can be utilized in the development of classification algorithm recommendation system according to the characteristics of datasets. (2) Many data scientists are often testing by adjusting the parameters of the algorithm to find the optimal algorithm for the situation because the characteristics of the data are different. In this process, excessive waste of resources occurs due to hardware, cost, time, and manpower. This study is expected to be useful for machine learning, data mining researchers, practitioners, and machine learning-based system developers. The composition of this study consists of introduction, related research, research model, experiment, conclusion and discussion.

• Management & Information Systems Review
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• v.1
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• pp.229-268
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• 1997

Recently, object-oriented concepts and technology are on the leading edge of programming language and database systems research, and their usefulness in those contexts has been successfully demonstrated. The adoption of object-oriented concept to the design of model bases has several benefits. From the perspectives of object-oriented approach, models in a model base are viewed as object which encapsulate their states and behaviors. This paper focuses on the design of an object-oriented model base that handles various resources of DSS(data, knowledge, models, solvers) in a unified fashion. For the design of a model base, we adopted Object Modeling Techniques(OMT). An object model of OMT can be used for the conceptual design of an overall model base schema. The object model of OMT provides several advantages over the conventional approaches in model base design. The main advantage are model reuse, hierarchical model construction, model sharing, meta-modeling, and unified model object management.