• Proceedings of the Computational Structural Engineering Institute Conference
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• 1991.04a
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• pp.50-55
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• 1991

This paper presents database technique for an computer-integrated structural design system of buildings. Network database designed to support all the processes of structural design, such as, planning, modelling, analysis, member design and redesign processes etc. stores all information from user input and system results effectively and so provides centeral communication area between applications. The user interface wi th interactive and batch modes plays roles of building modeler including conventional pre-processor and post-processor. The concepts of 'Planar Surface Modeling' and 'Geometry Zoning' are defined for easy construction of building model. The concept presented in this paper will save the time and memory required for model generation and contribute to data consistency, thus leave a designer more time actually performing the analyses and interpreting the results. The formulation of automating the process of bulilding model ins and structural analysis is the key to study.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.1
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• pp.248-268
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• 2018

The performance of smartphone applications are usually constrained in user interactions due to resource limitation and it promises great opportunities to improve the performance by exploring the smartphone built-in and embedded sensing techniques. However, heterogeneity in techniques, semantic gap between sensor data and usable context, and complexity of contextual situations keep the techniques from seamless integration. Relevant studies mainly focus on feasibility demonstration of emerging sensing techniques, which rarely address both general architectures and comprehensive technical solutions. Based on a proposed functional model, this investigation provides a general architecture to deal with the dynamic context for context-aware automation and decision support. In order to take advantage of the built-in sensors to improve the performance of mobile applications, an ontology-based method is employed for context modelling, linguistic variables are used for heterogeneous context presentation, and semantic distance-based rule matching is employed to customise functions to the contextual situations. A case study on mobile application authentication is conducted with smartphone built-in hardware modules. The results demonstrate the feasibility of the proposed solutions and their effectiveness in improving operational efficiency.

• The Korean Journal of Applied Statistics
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• v.17 no.3
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• pp.519-533
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• 2004

In this paper, we suggest quasi-likelihood estimation (QLE) method and its robust version in estimating spatial dependence modelled through variogram used for spatial data modelling. We compare the statistical characteristics of the estimators with other popular least squares estimators of parameters for variogram model by simulation study. The QLE method for estimating spatial dependence has the advantages that it does not need the concept of lags commonly required for least squares estimation methods as well as its statistical superiority. The QLE method also shows the statistical superiority to the other methods for the tested Gaussian and non-Gaussian spatial processes.

• Journal of the Korean Institute of Telematics and Electronics
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• v.25 no.6
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• pp.591-597
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• 1988

In this paper, we have studied a channel capacity affected by noise which produces burst errors in the ISDN(approx 140Kbps) data transmission using a existing PSTN. First, a digital communication system model to apply a subscriber line to a narrow band ISDN channel is presented. Second, the decision methodology of a channel capacity limitation whether the pdf of the noise generated by a waveform synthesizer is Pisson or Laplacian is described. As a result of the simulation, we have obtained that the Poission distributed noise is approached to the Guassian rather than the Laplacian under the same SNR condition.

• Journal of Industrial Technology
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• v.26 no.A
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• pp.109-117
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• 2006

This study is an numerical study of predicting the behavior of anchor embedded in weathered rocks, subjected to uplift loads, about ultimate pullout capacity and the failure mechanism. Factors influencing the behavior of anchors were investigated by reviewing the data about in-situ anchor tests performing numerical modelling with changing the bondage length of anchor, diameter of anchor body and diameter of tenden, and by Correlations between those factors were evaluated to apply them to predict the behavior of anchors. As results of numerical analysis, a linear relationship between bondage length, diameter of anchor body and diameter of tenden with ultimate pullout capacity was obtained on the one hand, from the result of numerical analysis changing the Young's modulus of weathered rock, this parameter was found to inflence to load-displacement and ultimate pullout capacity within the range of 10%, which was mot so significant to affect.

• Proceedings of the KIEE Conference
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• 2008.10c
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• pp.177-179
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• 2008

This paper, we proposed the theoretical model which includes series resistance $R_s$ and shunt resistance $R_{sh}$ of single-crystalline PV module and used numerical method based on physics. Series resistance $R_s$ was derived from approach for p-n junction diode instead of established form obtained from the simulator with irradiance changes. Electrical output characteristics for PV modules to count the effect of $R_s$ were then studied. Finally simulation results were compared to experimental data leading to good agreement.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.249-250
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• 2015

Technological advance of power elcetronic devices using semiconductor switches in last several decades, invoke the increase of switching devices' penetration in the system like STATCOM or HVDC and also, increase the difficulty to adjust switching characteristics in the virtual simulating configuration, which are not capable of reflect the detailed phenomena. To investigate harmful effect of switching devices into the grid, detailed modeling of power electronic devices are necessary, and the first step for entire grid modelling is simulate power system in time domain model. In this paper, simple two bus system with synchronous generator and infinite bus on the other side has been compromised in two simulation environment, using PSS/E and Matlab/Simulink. Comparing the result of two simulation result will give answers to the fundamental difference between two type of simulation environment.

• Journal of Distribution Science
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• v.11 no.9
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• pp.5-15
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• 2013

Purpose - The research aim is to shed empirical light on whether quality-focused retailer brands such as Premium brand of Tesco Korea, Prime of Lotte Mart, and Best of E-Mart in the grocery market, make a contribution to developing store loyalty in the Korean market particularly. Research design, data, methodology - After developing sixconstructs, such as higher quality, stock availability, price levels, national brands, retailer brand attitudes, and store loyalty, the authors adopted exploratory factor analysis, confirmatory factor analysis, chi-square test and structural equation modelling as a research technique. Results - It was found that higher quality strongly influences the retailer brand attitude formation, and that retailer brand customers were sensitive to price levels. Buyers are, nevertheless, relatively less aware of price levels, when purchasing quality-oriented retailer brand types. Conclusions - The research implied that quality-oriented retailer brand types make a significant contribution to retailer brands attitude formation, and further, building store loyalty.

• Proceedings of the KSME Conference
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• 2000.11a
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• pp.446-451
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• 2000

In this paper, a S/W system for a structural analysis of machine tools has been suggested. The system is so designed to reduce manual interfacing effort. An object-oriented language is used for making a graphic user interface. In this system parametric modelling technique is applied to construct a FE model without much user intervention. The FE model is automatically updated when the design parameters are changed by user. Not only single FE analysis but also a trade-off analysis for calculating the sensitivity information of design variables is possible using this system. All data generated by this system are saved in the database. So it possible to retrieve the result later without another analysis. It is found that the design time can be reduced and unnecessary operation avoided using this system.

• International Journal of Fluid Machinery and Systems
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• v.10 no.3
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• pp.227-239
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• 2017

The accuracy of turbulence models for the Reynolds-Averaged Navier-Stokes (RANS) equations in rough-wall flows is evaluated using data from large-eddy simulations (LES) of boundary layers with favourable and adverse pressure gradients. Some features of the flow (such as flow reversal in the roughness sublayer) cannot be captured accurately by any model, due to the fundamental model formulation. In mild pressure gradients most RANS models are sufficiently accurate for engineering applications, but if strong favourable or adverse pressure gradients are applied (especially those leading to separation) the model performance rapidly degrades.