• Journal of Integrative Natural Science
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• v.13 no.4
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• pp.147-151
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• 2020

In this paper, we propose a method to detect concept drift by applying Convolutional Neural Network (CNN) in a data stream environment. Since the conventional method compares only the final output value of the CNN and detects it as a concept drift if there is a difference, there is a problem in that the actual input value of the data stream reacts sensitively even if there is no significant difference and is incorrectly detected as a concept drift. Therefore, in this paper, in order to reduce such errors, not only the output value of CNN but also the probability vector are used. First, the data entered into the data stream is patterned to learn from the neural network model, and the difference between the output value and probability vector of the current data and the historical data of these learned neural network models is compared to detect the concept drift. The proposed method confirmed that only CNN output values could be used to reduce detection errors compared to how concept drift were detected.

• The Journal of Society for e-Business Studies
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• v.19 no.3
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• pp.107-123
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• 2014

Current text mining techniques suffer from the problem that the conventional text representation models cannot express the semantic or conceptual information for the textual documents written with natural languages. The conventional text models represent the textual documents as bag of words, which include vector space model, Boolean model, statistical model, and tensor space model. These models express documents only with the term literals for indexing and the frequency-based weights for their corresponding terms; that is, they ignore semantical information, sequential order information, and structural information of terms. Most of the text mining techniques have been developed assuming that the given documents are represented as 'bag-of-words' based text models. However, currently, confronting the big data era, a new paradigm of text representation model is required which can analyse huge amounts of textual documents more precisely. Our text model regards the 'concept' as an independent space equated with the 'term' and 'document' spaces used in the vector space model, and it expresses the relatedness among the three spaces. To develop the concept space, we use Wikipedia data, each of which defines a single concept. Consequently, a document collection is represented as a 3-order tensor with semantic information, and then the proposed model is called text cuboid model in our paper. Through experiments using the popular 20NewsGroup document corpus, we prove the superiority of the proposed text model in terms of document clustering and concept clustering.

• Communications for Statistical Applications and Methods
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• v.10 no.3
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• pp.647-654
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• 2003

Bayesian probability models for finite populations are considered assuming so-called the super-population. We find the posterior distribution of population mean by a new approach, using the concept of pivotal quantity for the small sample case. A large sample theory is also treated throught the concept of asymptotically pivotal quantity.

• Journal of The Korean Association For Science Education
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• v.27 no.6
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• pp.477-487
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• 2007

Previous studies show that students have difficulties in understanding and using molecular visualization tools. This study focuses on the ways in which first year chemistry undergraduates use ball-and-stick molecular models to explain the concept of addition reaction and the difficulties that they face using the models. Video recordings of interviews with undergraduates manipulating ball-and-stick models to solve problems related to reaction mechanisms are analysed to determine if they are able to elucidate their understanding with use of models. The results showed that students have difficulties with viewing the ball-and-stick models from the proper perspective and understanding the relationship between the various structures that they have created using the models. They also find the use of ball-and-stick models tedious and prefer drawing molecular structures on paper to explain their ideas. Implications for the teaching using ball-and-stick molecular models are discussed.

• Journal of Digital Convergence
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• v.10 no.6
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• pp.141-152
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• 2012

This study is a comparatively analyzes innovation tools for developing appropriate business models according to the types of convergence. Firstly, it examines previous studies on the type of convergence, business models, and innovation tools. Based on the understanding of each topic through literature search, it introduces Convergence-Business-Innovation Tools Cube (CBI Cube) model with the concept of developing innovative business models by applying innovation tools under the condition of convergence. In order to quantify (concretize) the concept, we have compared the relative priority of innovation tools for developing business models to find component factors of CBI Cube model through the survey of an expert group by adopting DelPhi method and AHP method. From the result of this study, we expect to be able to make an easier approach to the development of innovative products, services and market as it allo ws to develop business models of value innovation beyond just benchmarking or simple imitation of existing business models.

• International Journal of High-Rise Buildings
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• v.7 no.2
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• pp.145-151
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• 2018

Newly-designed high-rise buildings, both in China and abroad, have demonstrated new innovations from the creative concept to the creative method. from the creative concept to the creative method. At the same time, digital technology has enabled more design freedom in the vertical dimension. "Twisting" has gradually become the morphological choice of many city landmark buildings in recent years. The form seems more likely to be driven by the interaction of aesthetics and structural engineering. Environmental performance is often a secondary consideration; it is typically not simulated until the evaluation phase. Based on the research results of "DigitalFUTURE Shanghai 2017 Workshop - Wind Tunnel Visualization", an approach that can be employed by architects to design environmental-performance buildings during the early stages has been explored. The integration of a dynamic form-finding approach (DFFA) and programming transforms the complex relationship between architecture and environment into a dialogue of computer language and dynamic models. It allows the design to focus on the relationship between morphology and the surrounding environment, and is not limited to the envelope form itself. This new concept of DFFA in this research consists of three elements: 1) architectural form; 2) integration of wind tunnel and dynamic models; and 3) environmental response. The concept of wind tunnel testing integrated with a dynamic model fundamentally abandons the functional definition of the traditional static environment simulation analysis. Instead it is driven by integral environmental performance as the basic starting point of morphological generation.

• Journal of the Korea Safety Management & Science
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• v.6 no.1
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• pp.257-268
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• 2004

According to the World Competitiveness Yearbook(WCY), competitiveness of nations looks how nations create and maintain an environment which sustains the competitiveness of its enterprises. To develop economics and join the ranks of the advanced countries in the global market, Korea needs to consider the national competitiveness. Consequently, in this study, first, we try to know a concept of national competitiveness. Second, we also investigate models of national competitiveness. Finally, we suggest an improvement strategy, which is based on models, as compared with many countries of Europe.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2007.05a
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• pp.54-56
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• 2007

In recent, modeling methods for fluorescent lamp are developed well in both static and dynamic state. The models help reliable ballast to be developed in more fast time. This paper reviews the concept and method for well developed models, especially, circuit oriented models using PSpice.

• Journal of the Korean Institute of Navigation
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• v.23 no.2
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• pp.11-22
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• 1999

This paper is concerned with the development of a tractable model to assist liner shipping companies in the decision-making of empty container repositioning and leasing. A hybrid methodology is presented which properly accounts for the specific characteristics of empty container management. For this mathematical models are developed based on dynamic network models, covering both land and marine segment. Then a stochastic method is presented to deal with the uncertainty of the future demand and supply. Especially, the concept of opportunity cost has been introduced in order to explain interactions between the variation of the future demand and supply and the stock level at each depot.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.2 no.4
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• pp.183-189
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• 1990

As an effort for modeling the water waves propagating in a wide range of incident angles as when waves are diffracted behind a breakwater, angular spectrum models have been developed. In this paper, the concept of the angular spectrum is illustrated and the recently developed angular spectrum models are introduced.