• The Journal of Korean Association of Computer Education
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• v.10 no.2
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• pp.101-113
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• 2007

In this paper, we present an object-based modeling and language for an object-oriented spatio-temporal database system. For handling the structure of spatio-temporal objects and the spatio-temporal operators, we propose the two layers of data modeling: a spatio-temporal object model (STOM) and an spatio_temporal internal description model (STIM). We then propose STOQL, a spatio-temporal object-oriented query language. STOQL provides an integrated mechanism for the graphical display of spatial objects and the retrieval of spatio-temporal and aspatial objects.

• Journal of Electrical Engineering and Technology
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• v.10 no.3
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• pp.1138-1143
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• 2015

Effects of fabrication process variations on impedance of microelectrodes integrated on a neural probe were examined through equivalent circuit modeling and SPICE simulation. Process variation and the corresponding range were estimated based on experimental data. The modeling results illustrate that the process variation induced by metal etching process was the dominant factor in impedance variation. We also demonstrate that the effect of process variation is frequency dependent. Another process variation that was examined in this work was the thickness variation induced by deposition process. The modeling results indicate that the effect of thickness variation on impedance is negligible. This work provides a means to predict the variations in impedance values of microelectrodes on neural probe due to different process variations.

• The Journal of Society for e-Business Studies
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• v.3 no.2
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• pp.141-160
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• 1998

In order to achieve a successful introduction of CALS, an enterprise model which is a concise description of what an enterprise does is required. The enterprise model mainly consists of a process model and a data model. The process model describes processes that create, change, combine, or destroy the entities within the enterprise. Several process modeling methodologies have been proposed. Each modeling methodology requires its own modeling view point, elements, and syntax. In developing a process model for CALS, these models created at different view points are required to analyze and design a system in a broad view. This paper aims at proposing an integration methodology for a process model. Specifically, IDEF0, IDEF3, and Petri Net are considered to be integrated. An IDEF0 model describing static functions of enterprise is transformed to an IDEF3 model describing behaviour of a system with additional information. Also, the IDEF3 model is transformed to a Petri Net model. These transformations will be automatically accomplished once the additional information for the transformation is provided.

• Journal of Korean Society on Water Environment
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• v.26 no.4
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• pp.637-647
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• 2010

The Universal Soil Loss Equation (USLE)-based modeling systems have been widely used to simulate soil erosion studies. However the GIS-based USLE modeling systems have limitation in gully erosion evaluation which is one of the most important factor in soil erosion estimation. In this study, the integrated soil erosion evaluation system using with Sediment Assessment Tool for Effective Erosion Control (SATEEC) system, nLS and Unit Stream Power-based Erosion/Deposition (USPED) model was developed to simulate gully erosion. Gully head location using nLS model, USPED for gully erosion, and the SATEEC estimated sheet and rill erosion were evaluated and combined together with the integrated soil erosion evaluation system. This system was applied to the Haean-myeon watershed, annual average sediment-yield considering sheet, rill and gully erosion was simulated as 101,933 ton/year at the study watershed. if the integrated soil erosion evaluation system is calibrated and validated with the measured data, this system could be efficiently used in developing site-specific soil erosion best management system to reduce soil erosion and muddy water inflow into the receiving waterbody.

• Korean Journal of Construction Engineering and Management
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• v.13 no.2
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• pp.11-24
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• 2012

Recently, BIM (Building Information Modeling) technique is being considered as a critical delivery condition for the public projects according to the increase of best practices by practical application of BIM. However, since existing BIM studies are focused on the design and construction phases, those results are not considering the life cycle of a construction project. Therefore, this study suggests an integrated BIM operation process that enables an application of BIM for each phase of a construction project from planning to maintenance phases and develops an integrated BIM system based on the suggested methodologies. This study developed basic BIM functions and its application process by analyzing information systems in each project phase for a bridge construction project. Besides, this study performed case study and survey analysis for construction managers to verify a practical applicability of the developed system. Therefore, it is expected that the integrated BIM system is going to be utilized as a 3D-based integrated information management system considering life cycle of construction projects.

• Journal of Digital Convergence
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• v.14 no.3
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• pp.251-260
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• 2016

Knowledge map is widely used to represent knowledge in many domains. This paper presents a method of integrating the national R&D data and assists of users to navigate the integrated data via using a knowledge map service. The knowledge map service is built by using a lightweight ontology modeling method. The national R&D data is integrated with the research project as its center, i.e., the other R&D data such as research papers, patent, and project reports are connected with the research project as its outputs. The lightweight ontology is used to represent the simple relationships between the integrated data such as project-outputs relationships, document-author relationships, and document-topic relationships. Knowledge map enables us to infer the further relationships such as co-author and co-topic relationships. To extract the relationships between the integrated data, a RDB-to-Triples transformer is implemented. Lastly, we show an experiment on R&D data integration using the lightweight ontology, triples generation, and visualization and navigation of the knowledge map.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.3
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• pp.151-164
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• 2013

Multidimensional dynamic water quality model of organic matter and trophic state was applied to the Han River system. The model was calibrated using field measurement data obtained during the year of 2007. The model results showed reasonable performance in predicting temporal variations of TN, TP, Chl-a and BOD concentrations. The applied integrated modeling system can be effectively used to simulate water quality as well as hydrodynamic and water temperature for river-lake continuous system in the Han River. Utilizing the calibrated model, we analyzed the spatial and temporal distributions of TN, TP, Chl-a and BOD concentrations in the Han River system. The temporal variations of water quality at each river reach and lake were effectively simulated with the developed model and spatial distribution of water qualities in the Han River system could be compared. The multidimensional dynamic modeling system can simulate the water qualities of entire waterbody where Lake Paldang and the incoming flows are included using single modeling system. So it can be effectively used for integrated water quality management of the Han River system.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.5
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• pp.481-487
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• 2013

This paper presents an FIR (Finite Impulse Response) fixed-interval smoothing filter for fast and exact estimating state variables of a discrete nonlinear system with modeling uncertainty. Conventional IIR (Infinite Impulse Response) filter and smoothing filter can estimate state variables of a system with an exact model when the system is observable. When there is an uncertainty in the system model, however, conventional IIR filter and smoothing filter may cause large errors because the filters cannot estimate the state variables corresponding to the uncertain model exactly. To solve this problem, FIR filters that have fast estimation properties and have robustness to the modeling uncertainty have been developed. However, there is time-delay estimation phenomenon in the FIR filter. The FIR smoothing filter proposed in this paper makes up for the drawbacks of the IIR filter, IIR smoothing filter, and FIR filter. Therefore, the FIR smoothing filter has good estimation performance irrespective of modeling uncertainty. The proposed FIR smoothing filter is applied to the integrated navigation system composed of a magnetic compass based DR (Dead Reckoning) and a GPS (Global Positioning System) receiver. Even when the magnetic compass error that changes largely as the surrounding magnetic field is modeled as a random constant, it is shown that the FIR smoothing filter can estimate the varying magnetic compass error fast and exactly with simulation results.

• Korean Chemical Engineering Research
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• v.47 no.2
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• pp.248-257
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• 2009

In this paper, human exposure and risk of environmental pollutants were predicted using an emission assessment model and multimedia fate model. Eight environmental pollutants, acetaldehyde, acrylonitrile, aniline, benzene, carbon tetrachloride, dichloromethane, formaldehyde and vinyl chloride, were selected for the risk assessment in an urban and industrial area in Korea. The emission rate of target pollutants were estimated after considering a variety of point and non-point emission sources including geographical information. A spatially refined multimedia fate model was applied to predict the environmental concentration and fate of pollutants. Hazard data of target materials were obtained from the IRIS(Integrated Risk Information System) database. Using the modeling results with hazard data, the human risks were assessed. Modeling results demonstrate that the considerable risks were observed for several pollutants.

• KIEAE Journal
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• v.10 no.4
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• pp.87-100
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• 2010

The energy efficient design of the multiple stock housing is very important not only to save energy but also to increase sustainability in a whole city because the multiple stock housing type is dominated in the major residential supply markets in Korea. During the early design phase of the multiple stock housing type, the architect need convenient and accurate tools for evaluating energy consumptions based on building types rapidly. Building Information Modeling(BIM) is introduced as useful tool systems providing interoperability between 3rd dimensional modeling tools and environmental engineering analysis tools, and could reduce time and cost for unnecessary modeling works in the analysis. However, it is still hard to apply to building design practice and integrated energy simulation techniques because interoperability using industrial standard file formats such as IFC and bXML is still underdeveloped. Therefore, the purpose of this study is to perform the building energy simulations, to compare the results on typical building types in multiple stock housing based on BIM, and to clear the problems using industrial standard file formats between 3rd dimensional modeling and building energy simulation software. In addition, through comparisons with simulation results according to the typical building types such as building forms, orientations, and building stories, the interrelation ship and characteristics of BIM based building energy simulation software are analysed and evaluated.