• Journal of the Korea Computer Graphics Society
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• v.18 no.2
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• pp.63-72
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• 2012

As BIM(Building Information Modeling) is widely used in the construction process the need for exploring building models realistically is also growing. In this paper, we present a 3D stereoscopic navigation method for virtual buildings considering virtual perception. We first find out factors that may cause virtual discomfort while navigating stereoscopic building models, and then develop a method for automatically adjusting the range of virtual camera separation. In addition, we measure each user's JND(Just Noticeable Difference) in depth to adjust virtual camera separation and movement. The presented method can be used for various architectural applications by creating user-customized 3D stereoscopic contents.

• Journal of electromagnetic engineering and science
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• v.16 no.1
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• pp.44-51
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• 2016

A commercial $0.25{\mu}m$ GaN process is used to implement 6-18 GHz wideband power amplifier (PA) monolithic microwave integrated circuits (MMICs). GaN HEMTs are advantageous for enhancing RF power due to high breakdown voltages. However, the large-signal models provided by the foundry service cannot guarantee model accuracy up to frequencies close to their maximum oscillation frequency ($F_{max}$). Generally, the optimum output load point of a PA varies severely according to frequency, which creates difficulties in generating watt-level output power through the octave bandwidth. This study overcomes these issues by the development of in-house large-signal models that include a thermal model and by applying distributed L-C output load matching to reactive matched amplifiers. The proposed GaN PAs have successfully accomplished output power over 5 W through the octave bandwidth.

• Korean Journal of Agricultural and Forest Meteorology
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• v.3 no.1
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• pp.16-21
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• 2001

Regression models were obtained on the base of the correlation between Phytophthora blight incidence in red pepper and the microclimate data obtained from automated weather station (AWS) during 1997 and 1998. A computer program (PEPBLIGHT) was constructed based on the model that the R2 value is highest among regression models. This computer program uses the microclimate data from more than one AWS through the common dialogue box easy and it is able provide disease forecasting information. In addition, it could be applied far other diseases and converts the microclimate data of AWS to the input data for Statical Analysis System (SAS). PEPBLIGHT was first developed for the forecasting computer system of red pepper blight in Korea. PEPBLIGHT is operated on the MS Windows, so that it is easy to use.

• Journal of the Korea Society of Computer and Information
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• v.27 no.3
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• pp.13-23
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• 2022

In this study we leveraged a probing method to evaluate how a pre-trained L2 LSTM language model represents sentences with relative and coordinate clauses. The probing experiment employed adapted models based on the pre-trained L2 language models to trace the syntactic properties of sentence embedding vector representations. The dataset for probing was automatically generated using several templates related to different sentence structures. To classify the syntactic properties of sentences for each probing task, we measured the adaptation effects of the language models using syntactic priming. We performed linear mixed-effects model analyses to analyze the relation between adaptation effects in a complex statistical manner and reveal how the L2 language models represent syntactic features for English sentences. When the L2 language models were compared with the baseline L1 Gulordava language models, the analogous results were found for each probing task. In addition, it was confirmed that the L2 language models contain syntactic features of relative and coordinate clauses hierarchically in the sentence embedding representations.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.5
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• pp.1146-1165
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• 2013

Collaborative awareness between persons with various smart multimedia devices is a new trend in the Internet of Things (IoT). Because of the mobility, randomness, and complexity of persons, it is difficult to achieve complete data awareness and data transmission in IoT. Therefore, research must be conducted on mobile-aware service models. In this work, we first discuss and quantify the social relationships of mobile nodes from multiple perspectives based on a summary of social characteristics. We then define various decision factors (DFs). Next, we construct a directed and weighted community by analyzing the activity patterns of mobile nodes. Finally, a mobile-aware service routing algorithm (MSRA) is proposed to determine appropriate service nodes through a trusted chain and optimal path tree. The simulation results indicate that the model has superior dynamic adaptability and service discovery efficiency compared to the existing models. The mobile-aware service model could be used to improve date acquisition techniques and the quality of mobile-aware service in the IoT.

• Korean Journal of Computational Design and Engineering
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• v.9 no.2
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• pp.122-132
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• 2004

Progressive mesh representation and generation have become one of the most important issues in network-based computer graphics. However, current researches are mostly focused on triangular mesh models. On the other hand, solid models are widely used in industry and are applied to advanced applications such as product design and virtual assembly. Moreover, as the demand to share and transmit these solid models over the network is emerging, the generation and the transmission of progressive solid models depending on specific engineering needs and purpose are essential. In this paper, we present a Cellular Topology-based approach to generating and transmitting progressive solid models from a feature-based solid model for internet-based design and collaboration. The proposed approach introduces a new scheme for storing and transmitting solid models over the network. The Cellular Topology (CT) approach makes it possible to effectively generate progressive solid models and to efficiently transmit the models over the network with compact model size. Thus, an arbitrary solid model SM designed by a set of design features is stored as a much coarser solid model SM/sup 0/ together with a sequence of n detail records that indicate how to incrementally refine SM/sup 0/ exactly back into the original solid model SM = SM/sup 0/.

• Proceedings of the Korean Information Science Society Conference
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• 2008.06a
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• pp.43-44
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• 2008

• Proceedings of the Korean Society of Computer Information Conference
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• 2012.01a
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• pp.245-246
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• 2012

본 논문에서는 컴퓨터 프로그래밍 수업에서 상위 수준 학습자들을 위한 맞춤형 학습 모형 사례들을 살펴본다. 동일한 학습자들에게 여러 가지 학습 모형들을 적용하였을 때 보다 효과적인 학습 유형이 어떤 것인지 탐색해보고 그 학습 효과를 검증하기 위해 이들의 성적 변화를 분석해봄으로써 상위 수준 학습자에 적합한 맞춤형 학습 모형을 탐구해가는데 본 연구의 목적이 있다.

• The Transactions of the Korea Information Processing Society
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• v.2 no.4
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• pp.477-486
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• 1995

This paper describes and constructs object-oriented analysis models using Galois-lattices that we are always studying in discrete mathematics, shows fundamental approaches to maintain the models, analyzes the construction of object-oriented analysis models through good examples. Also, we define several properties of Galois-lattices that have binary relations between class objects, propose the incremental updating algorithms that can update the Galois-lattice whenever new classes are added. This proposal shows that in case of adding new class nodes the results from simulations can implement in constant time and have linearly the incremental structures in worst cases, and in that the growth rate of lattices is proportioned to class nodes in time complexity. This results can achieve the high understandability of object-oriented analysis models and the high traceability of maintenance models. Furthermore it is possible to make more efficient performances of class reusability in advantages of object-oriented systems and support truly the class hierarchical maintenances.

• Earthquakes and Structures
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• v.4 no.5
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• pp.451-470
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• 2013

It generally accepted that most building structures shall exhibit a nonlinear response when subjected to medium-high intensity earthquakes. It is currently known, however, that this phenomenon is not properly modelled in the majority of cases, especially at the design stage, where only simple linear methods have effectively been used. Recently, as a result of the exponential progress of computational tools, nonlinear modelling and analysis have gradually been brought to a more promising level. A wide range of modelling alternatives developed over the years is hence at the designer's disposal for the seismic design and assessment of engineering structures. The objective of the study presented herein is to test some of these models in an existing structure, and observe their performance in nonlinear static and dynamic analyses. This evaluation is done by the use of two of a known range of advanced computer programs: SAP2000 and SeismoStruct. The different models will focus on the element flexural mechanism with both lumped and distributed plasticity element models. In order to appraise the reliability and feasibility of each alternative, the programs capabilities and the amount of labour and time required for modelling and performing the analyses are also discussed. The results obtained show the difficulties that may be met, not only in performing nonlinear analyses, but also on their dependency on both the chosen nonlinear structural models and the adopted computer programs. It is then suggested that these procedures should only be used by experienced designers, provided that they are aware of these difficulties and with a critical stance towards the result of the analyses.