• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.635-639
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• 2004

In this paper, we present a novel approach for the structure of Fuzzy Neural Network(FNN) based on wavelet function and apply this network structure to the modeling of chaotic nonlinear systems. Generally, the wavelet fuzzy model(WFM) has the advantage of the wavelet transform by constituting the fuzzy basis function(FBF) and the conclusion part to equalize the linear combination of FBF with the linear combination of wavelet functions. However, it is very difficult to identify the fuzzy rules and to tune the membership functions of the fuzzy reasoning mechanism. Neural networks, on the other hand, utilize their learning capability for automatic identification and tuning. Therefore, we design a wavelet based FNN structure(WFNN) that merges these advantages of neural network, fuzzy model and wavelet transform. The basic idea of our wavelet based FNN is to realize the process of fuzzy reasoning of wavelet fuzzy system by the structure of a neural network and to make the parameters of fuzzy reasoning be expressed by the connection weights of a neural network. And our network can automatically identify the fuzzy rules by modifying the connection weights of the networks via the gradient descent scheme. To verify the efficiency of our network structure, we evaluate the modeling performance for chaotic nonlinear systems and compare it with those of the FNN and the WFM.

• 한국치위생학회지
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• 제22권6호
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• pp.495-502
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• 2022

Objectives: The purpose of this study was to analyze research trends in dental hygiene using topic modeling and semantic network analysis. Methods: A total of 261 published studies were collected 686 key words from the Research Information Sharing Service (RISS) by 2019-2021. Topic modeling and semantic network analysis were performed using Textom. Results: The most frequently and frequency-inverse document frequently key words were 'dental hygienist', 'oral health', 'elderly', 'periodontal disease', 'dental hygiene'. N-gram of key words show that 'dental hygienist-emotional labor', 'dental hygienist-elderly', 'dental hygienist-job performance', 'oral health-quality of life', 'oral health-periodontal disease' etc. were frequently. Key words with high degree centrality were 'dental hygienist (0.317)', 'oral health (0.239)', 'elderly (0.127)', 'job satisfaction (0.057)', 'dental care (0.049)'. Extracted topics were 5 by topic modeling. Conclusions: Results from the current study could be available to know research trends in dental hygiene and it is necessary to improve more detailed and qualitative analysis in follow-up study.

• 한국시뮬레이션학회논문지
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• 제3권1호
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• pp.151-165
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• 1994

Broadband network based on the Asynchronous Transfer Mode(ATM) concept are becoming the target technology for the emerging Broadband Integrated Services Digital Network(B-ISDN). Since B-ISDN is very complex and requites a great amount of investment, optimum design and performance analysis of such systems are very important. Simulation can be widely used to analyze and examine the broadband network behavior. However, for the complicated system like broadband networks it is extremely difficult and time-consuming to develop a complete model for simulation. In this paper, an object-oriented modeling approach for the broadband network simulation is presented for the effective and efficient modeling. Object-oriented approaches can provide a good structuring capability for complicated simulation models and facilitate the development of reusable and extensible simulation models. We have developed an object-oriented model which consists of object model and behavior model. In the object mode., the components of the broadband network and both constant bit rate(CBR) and variable bit rate(VBR) traffic types of call level, burst level, and cell level are modeled as object classes. In the behavior model, the dynamic features for each object class are represented using the state transition diagram. It has been shown by illustration that objectoriented modeling is an effective tool for modeling the complicated B-ISDN.

• 디지털콘텐츠학회 논문지
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• 제19권5호
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• pp.981-993
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• 2018

스마트 헬스케어는 ICT 분야와 의료서비스 분야가 융 복합 된 분야로 다양한 분야에서 학제 간 융 복합 연구가 활발히 이루어지고 있다. 본 연구는 토픽모델링(Topic Modeling)과 에고 네트워크 분석(Ego Network Analysis)을 활용하여 스마트 헬스케어 연구동향을 살피는데 그 목적이 있다. 이를 위해 2001년부터 2018년 4월까지 Scopus에 게재된 2,690편을 대상으로 텍스트 분석, 각 기간별 빈도분석, 토픽모델링, 워드 클라우드, 에고 네트워크 분석을 수행하였다. 토픽 모델링 분석 결과 8개의 주요 연구토픽이 도출되었다. 8개 주요 연구토픽은 "AI in healthcare", " Smart hospital", "Healthcare platform", " blockchain in healthcare", "Smart health data", "Mobile healthcare", "Wellness care", "Cognitive healthcare" 순으로 나타났다. 토픽모델링 결과를 보다 심도 있게 살펴보기 위해 연구토픽별 에고 네트워크 분석을 하였다. 이를 통해 스마트 헬스케어 연구동향을 파악하고, 향후 연구의 방향성을 수립하는데 시사점을 제시하고자 한다.

• 경영과학
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• 제11권1호
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• pp.59-72
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• 1994

In this paper we examine potentials of a spreadsheet program, one of the most widly available software system, as a mathematical optimization modeling tool. For an illustrative example, a shortest path problem is modeled on Lotus-123 for practical use and an implementational framework and a general guide to the spreadsheet modeling of network analysis is provided.

• 산업공학
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• 제18권3호
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• pp.277-287
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• 2005

In this paper, we deal with a new techno-economic modeling and analysis for optical access networks. In deploying the fiber-to-the-home (FTTH) architecture, network planner needs to consider the following techno-economic issues: when do we need to upgrade existing local access network to FTTH network? how much do we invest to maximize profit? In order to answer these techno-economic questions, we need to consider the impact of emerging technologies and business environment. Toward this end, we develop a new techno-economic modeling to deal with the inherent complexity of technology evolution and cost economics. In particular, the new modeling approach provides us with an techno-economic analysis of technology alternatives such as ethernet passive optical network (E-PON) and wavelength division multiplex passive optical network (WDM-PON). In this analysis, we focus on the impact of critical factors such as the cost characteristic of proposed architecture and digital subscriber line (DSL) subscriber's churn-in to FTTH service and churn-out. We develop mixed integer-programming models for finding the evolution path of local access networks to broadband network architectures.

• 한국도서관정보학회지
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• 제47권4호
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• pp.1-18
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• 2016

이 연구는 독후감 텍스트의 주제분석에 토픽모델링의 활용방안을 탐색하는 것을 목적으로 하고 있다. 텍스트의 주제분석 방안으로서 토픽모델링 분석방법을 이해하고, R에서 제공하는 "topicmodels" 패키지의 LDA 함수를 사용하여 23건의 사례 독후감 텍스트들을 대상으로 실제의 분석작업을 수행하였다 토픽모델링 분석결과 16개의 토픽들을 추출하였고 토픽과 구성 단어들의 관계에서 토픽 네트워크 사례 독후감과 토픽들의 관계에서 독후감 네트워크를 구성하였다. 이후 토픽 네트워크와 독후감 네트워크를 대상으로 중심성 분석을 수행하였으며 분석결과는 다음과 같다. 첫째 16개의 토픽들이 1개의 컴포넌트를 가지는 네트워크로 나타났다. 이것은 16개 토픽들이 상호 연관되어 있다는 것을 의미한다. 둘째, 독후감 네트워크에서는 연결정도 중심성이 높은 독후감들과 낮은 독후감들로 구분이 되었다. 전자의 독후감들은 다른 독후감들과 주제적으로 유사성을 가지며 후자의 독후감들은 다른 독후감들과 주제적으로 상이성을 가지는 것으로 해석하였다. 토픽모델링의 결과를 네트워크 분석과 결합함으로써 독후감의 주제파악에 유용한 결과들을 얻게 되었다.

• Korean Chemical Engineering Research
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• 제46권2호
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• pp.369-375
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• 2008

생태산업단지의 주요 목표인 무배출(zero-emission)을 달성하기 위해서는, 기업간의 효과적인 용수 재이용망의 구축이 요구된다. 다양한 서브시스템과 의사결정과정을 포함한 복잡한 망 구조를 이루기 때문에 생기는 모델링 부분에서의 문제점을 해결하기 위하여, 본 연구에서는 새로운 모델링 기법인 에이전트기반 모델링(agent based modeling, ABM)을 도입하였다. 에이전트기반 모델링 기법을 이용해 물질교환망 내의 기업을 에이전트화 하고 이를 토대로 전체 시스템을 모사하는 방법론을 제시하였으며, 이를 이용해 실제 산업단지 내 기업에 대한 간단한 용수교환망 설계 모델을 구축하였다. 에이전트기반 모델에 기초한 용수재이용망은 용수공급에서 35% 감소를 보이며 폐수 배출량은 약 50%가 감소하였다. 실제 산업단지 모델링 결과 에이전트기반 모델은 시스템 변동시에도 전체 시스템을 수정할 필요가 없으며, 시스템이 확장하는 경우에도 그 적용이 용이하기 때문에 생태산업단지와 같은 복잡한 시스템의 모델링과 설계시 유용한 기술로 사용될 수 있음을 보였다.

• 환경영향평가
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• 제19권3호
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• pp.315-321
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• 2010

ArcView and water network models have been integrated to develop the water network modeling system based upon GIS. To develop this system, pre, main, and post processing systems are required. GIS programming technique was adopted by using the ArcView's script language Avenue. The input data of models have been prepared by using the AutoCAD Map3D through the conversion of modeling input data to GIS data for A city. The modeling has been implemented by using EPANET, WaterCAD, InfoWorks. To develop the post processing system, the modeling results of the water network models have been analyzed by using GIS. During the application process of the developed system to B city with 300,000 population, main problems were found in the constructed GIS DB of that city. Thus, pilot study area of B city has been constructed, and pre-, main, and post-processing techniques were invented based upon GIS. Finally, the problems related to waterworks GIS projects in Korea were discussed and solutions were suggested.

• Journal of Positioning, Navigation, and Timing
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• 제8권4호
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• pp.193-200
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• 2019

The auto-encoder network which is a good candidate to handle the modeling of the signal strength attenuation is designed for denoising and compensating the distortion of the received data. It provides a non-linear mapping function by iteratively learning the encoder and the decoder. The encoder is the non-linear mapping function, and the decoder demands accurate data reconstruction from the representation generated by the encoder. In addition, the adaptive network width which supports the automatic generation of new hidden nodes and pruning of inconsequential nodes is also implemented in the proposed algorithm for increasing the efficiency of the algorithm. Simulation results show that the proposed method can improve the neural network training surface to achieve the highest possible accuracy of the signal modeling compared with the conventional modeling method.