• The Transactions of the Korea Information Processing Society
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• v.2 no.4
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• pp.603-610
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• 1995

In this paper, we present a highly efficient simulation package which supports simulation from functional level to gate level. The package consists of a set of front-end tools, a logic simulator, named HSIM(Highly efficient logic SIMulator), and an waveform analyzer. The front-end tools include a netlist compiler, functional primitive compiler and behavioral compiler. Key feature of developed simulator is that the compiled behavioral models written in C language are directly executed in the simulation engine using incremental loader. By doing so, we achieved significant speed up as compared with the interpretive functional simulator. Experimental results show that HSIM runs about 55% faster than traditional unit-delay event-driven interpretive simulator.

• Journal of Ocean Engineering and Technology
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• v.27 no.3
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• pp.1-7
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• 2013

The purpose of this study was the implementation of a simulation for a subsea production system. This subsea production system is installed under environments with high pressure and low temperature. Most of the processes for oil and gas production occur in the subsea equipment. Therefore, an understanding and study of subsea production systems is very difficult because people cannot directly observe the processes occurring in the subsea production system. A simulation system can be a useful solution for this difficult problem. In this research, information models and a 3-D graphic model of the subsea equipment were built using the object-oriented technology and 3-D CAD. The entire system was implemented with the help of simulation software, 3-DVIA Virtools. The simulation system for the subsea production system was tested using several production process scenarios. The results of the tests showed that the simulation system is very useful for understanding a subsea production system and could be a good educational tool.

• Korean Journal of Computational Design and Engineering
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• v.20 no.2
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• pp.145-158
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• 2015

ISO 15926 is an international standard for the sharing and integration of plant lifecycle information. Plant design data consist of logical configuration, equipment specifications, 2D piping and instrument diagrams (P&IDs), and 3D plant models (shape data). Although 3D computer-aided design (CAD) data is very important data across the plant lifecycle, few studies on the exchange of 3D CAD data using ISO 15926 have been conducted so far. For this, we analyze information requirements regarding plant 3D design in the process industry. Based on the analysis, ISO 15926 templates are defined for the representation of constructive solid geometry (CSG) - based 3D design data. Since system environments for 3D CAD modeling and Semantic Web technologies are different from each other, we present system architecture for processing and visualizing plant 3D design data in the Web Ontology Language (OWL) format. Through the visualization test of ISO 15926-based 3D design data for equipment with a prototype system, feasibility of the proposed method is verified.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.524-529
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• 2004

In this paper, We described the method which developed the optimal control system for air separation unit to change production rates frequently and rapidly. Control models of the process were developed from actual plant data using subspace identification method which is developed by many researchers in resent years. The model consist of a series connection of linear dynamic block and static nonlinear block (Wiener model). The model is controlled by model based predictive controller. In MPC the input is calculated by on-line optimization of a performance index based on predictions by the model, subject to possible constraints. To calculate the optimal the performance index, conditions are expressed by LMI(Linear Matrix Inequalities).In order to access at the Bailey DCS system, we applied the OPC server and developed the Client program. The OPC sever is a device which can access Bailey DCS system.The Client program is developed based on the Matlab language for easy calculation,data simulation and data logging. Using this program, we can apply the optimal input to the DCS system at real time.

• Proceedings of the Acoustical Society of Korea Conference
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• spring
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• pp.35-38
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• 2000

본 연구에서는 연속음성인식 시스템의 성능 향상을 위한 기초 연구로서 시스템에 적합한 음향모델과 언어모델을 작성하고 항공편 예약 태스크를 대상으로 인식실험을 실시한 결과 그 유효성을 확인하였다. 이를 위하여 먼저 HMM의 출력확률분포의 mixture와 파라미터의 차원에 대한 정확한 분석을 통한 음향모델을 작성하였다. 또한 반복학습법으로 특정 태스크를 대상으로 N-gram 언어모델을 적용하여 인식 시스템에 적합한 모델을 작성하였다. 인식실험에 있어서는 3인의 화자가 발성한 200문장에 대해 파라미터 차원 및 mixture의 변화에 따른 음향모델과 반복학습에 의해 작성한 언어모델에 대해 multi-pass 탐색 알고리즘을 이용하였다. 그 결과, 25차원에 대한 mixture 수가 9인 음향모델과 10회 반복 학습한 언어모델을 이용한 경우 평균 $81.0\%$의 인식률을 얻었으며, 38차원에 대한 mixture 수가 9인 음향모델과 10회 반복 학습한 언어모델을 이용한 경우 평균 $90.2\%$의 인식률을 보여 인식률 제고를 위해서는 38차원에 대한 mixture 수가 9인 음향모델과 10회 반복학습으로 작성한 언어모델을 이용한 경우가 매우 효과적임을 알 수 있었다.

• Journal of the Korean Society of Safety
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• v.30 no.4
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• pp.151-158
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• 2015

Usually risk assessment is performed for the safety of diverse industries though, many kinds of risks cannot be analyzed effectively by using classical probability models due to lack of experience data and impreciseness of human decision making. For these reasons, fuzzy risk assessment utilizing subjective judgment and experience of skillful experts has been considered as a solution. In this study, to comprehend the relationship between conventional fuzzy theory and human conceptual images on risks, linguistic variables were reviewed with reference to fuzzy membership functions, especially in the Korean language. As interviewees, about a hundred people including students as well as safety engineers voluntarily participated. The research results showed that most people were in favor of adjective expressions decorated with adverbs rather than naive expressions such as "high" or "low", and that directly translated linguistic variables were not appropriate for the Korean people in risk assessment as far. Therefore, with consideration of the selection tendency by the Korean people in linguistic variables, it could be concluded that 5 level expressions would be most favorable for linguistic variables in risk assessments in Korea.

• Journal of Korea Society of Digital Industry and Information Management
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• v.6 no.1
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• pp.91-103
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• 2010

This paper introduces efficient rule-based semantic search techniques to ontology-based knowledge commerce services. Primarily, the search techniques presented in this paper define rules of reasoning that are required for users to search using the concept of ontology, multiple characteristics, relations among concepts and data type. In addition, based on the defined rules, the rule-based reasoning techniques search ontology for knowledge commerce services. This paper explains the conversion rules of query which convert user's query language into semantic search words, and transitivity rules which enable users to search related tags, knowledge products and users. Rule-based sematic search techniques are also presented; these techniques comprise knowledge search modules that search ontology using validity examination of queries, query conversion modules for standardization and expansion of search words and rule-based reasoning. The techniques described in this paper can be applied to sematic knowledge search systems using tags, since transitivity reasoning, which uses tags, knowledge products, and relations among people, is possible. In addition, as related users can be searched using related tags, the techniques can also be employed to establish collaboration models or semantic communities.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.1
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• pp.114-130
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• 2020

Balinese calendar is defined as a unique calendar system for combining solar-based and lunar-based system and assuming local system. It is considered as guidance of Balinese societies' activities management, starting from meeting arrangement, wedding ceremony, to religious ceremonies. Practically, it has developed in the form of printed Balinese calendar and electronic Balinese calendar, either web or mobile application. The core of the function is to find out the day with its various characteristics in the Balinese Calendar. In general, society usually asks the religious leader to find out the day in detail. The technology of NLP combined with models of pattern discoveries supports the arrangement of the interaction model in searching the good day in Balinese Calendar to equip the conventional searching system in the previous applications. This study will design a dialog model with AIML method in multi-parameter basis; therefore, the users will be dynamically able to use the searching content in various ways by chatting in similar with consulting to a religious leader. This model will be applied in a chatbot basis service in telegram machine. The addition of the context recognition section into 4 paterns has been successfully improve the ability of AIML to recognize input patterns with many criteria. Based on the testing with 50 random input patterns obtained a success rate of 92.5%.

• Journal of Information Technology Services
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• v.17 no.1
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• pp.79-89
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• 2018

Sentiment analysis is a technique of text mining that extracts feelings of the person who wrote the sentence like movie review. The preliminary researches of sentiment analysis identify sentiments by using the dictionary which contains negative and positive words collected in advance. As researches on deep learning are actively carried out, sentiment analysis using deep learning model with morpheme or word unit has been done. However, this model has disadvantages in that the word dictionary varies according to the domain and the number of morphemes or words gets relatively larger than that of phonemes. Therefore, the size of the dictionary becomes large and the complexity of the model increases accordingly. We construct a sentiment analysis model using recurrent neural network by dividing input data into phoneme-level which is smaller than morpheme-level. To verify the performance, we use 30,000 movie reviews from the Korean biggest portal, Naver. Morpheme-level sentiment analysis model is also implemented and compared. As a result, the phoneme-level sentiment analysis model is superior to that of the morpheme-level, and in particular, the phoneme-level model using LSTM performs better than that of using GRU model. It is expected that Korean text processing based on a phoneme-level model can be applied to various text mining and language models.

• Journal of the Korea Convergence Society
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• v.11 no.6
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• pp.23-28
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• 2020

A comment system is essential for communication on the Internet. However, there are also malicious comments such as inappropriate expression of others by exploiting anonymity online. In order to protect users from malicious comments, classification of malicious / normal comments is necessary, and this can be implemented as text classification. Text classification is one of the important topics in natural language processing, and studies using pre-trained models such as BERT and graph structures such as GCN and GAT have been actively conducted. In this study, we implemented a comment classification system using BERT, GCN, and GAT for actual published comments and compared the performance. In this study, the system using the graph-based model showed higher performance than the BERT.