• Archives of design research
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• v.17 no.4
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• pp.375-384
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• 2004

The general tendency of approach to Korean Design History has been focusing its primary interest on the grand story in relation to the problems of modernization in political, economical and social aspects of Korea. In the discourse of modernization, however, there are two sides immanent in the modernization: there is the formal, institutional and authoritative modernization developed inside the capitalistic mode of production and the informal, individual and cultural modernization manifested in the mode of everyday lives. Especially, despite the viewpoint of the latter being embossed as an alternative approach in various areas including the academic world of history since the collapse of socialism, the historical recognition of the phenomena of modern design by the Korean design historians is more like the 'history from the above' that exists at the level of the discourse outside the reality rather than the 'history from the below' that exists within the ordinary life. To grant a sense of balance in such frame of historical understanding, it requires the restructuring the design history of Korea through the cultural perspectives from having the representation of mundane lives realized by the voluntary design activity of the common people as research subjects. One of the methods to acquire an answer to such problem is decoding, in the manner of 'cultural history', the life-long domestic artifact made by Madame Yang, Gap Jo (currently 87 years of age) who is a model of typical Korean mother. Through the historical rumination on the traces of unpretentious lives of the people that has been buried under the grand narrative of the Korean Design History, a new era aimed for the historical prospect of Korean design as cultural history will be possible by excavating the petit yet multi-layered meaning of Korean designs.

• Journal of Korean Society of Steel Construction
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• v.10 no.4 s.37
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• pp.691-700
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• 1998

Based on Von Karman-Donnell kinematic assumptions for laminated shells, the nonlinear vibration behaviour of antisymmetrically or asymmetrically laminated cross-ply circular cylindrical shells with clamped and simply-supported ends are studied by a multi-mode approach. A equation is formulated and satisfies the associated compatibility equation and all boundary conditions. The displacement function is assumed to take the form of the lowest linear vibration mode and to satisfy continuity of the circumferential displacement. The nonlinear vibration equation is derived by the Galerkin's method. And nonlinear frequency is obtained by using the harmonic balance method as a function of lamination parameters, material constants, aspect ratio and amplitude of vibration. The effect of initial imperfection is also included. Results of the non-linear vibration are presented for different amplitudes of initial imperfection and four sets of boundary conditions. Present results are compared well with existing analysis results.

• Journal of Biomedical Engineering Research
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• v.29 no.2
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• pp.122-131
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• 2008

For B-mode ultrasound images, we propose an image enhancement algorithm based on a multi-resolution approach, which consists of edge enhancing and noise reducing procedures. Edge enhancement processing is applied sequentially to coarse-to-fine resolution images obtained from wavelet-transformed data. In each resolution, the structural features of each pixel are examined through eigen analysis. Then, if a pixel belongs to an edge region, we perform two-step filtering: that is, directional smoothing is conducted along the tangential direction of the edge to improve continuity and directional sharpening is conducted along the normal direction to enhance the contrast. In addition, speckle noise is alleviated by proper attenuation of the wavelet coefficients of the homogeneous regions at each band. This region-based speckle-reduction scheme is differentiated from other methods that are based on the magnitude statistics of the wavelet coefficients. The proposed algorithm enhances edges regardless of changes in the resolution of an image, and the algorithm efficiently reduces speckle noise without affecting the sharpness of the edge. Hence, compared with existing algorithms, the proposed algorithm considerably improves the subjective image quality without providing any noticeable artifacts.

• Computers and Concrete
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• v.8 no.6
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• pp.735-755
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• 2011

The capability of a multi-directional fixed smeared crack constitutive model to simulate the flexural/punching failure modes of fiber reinforced concrete (FRC) laminar structures is discussed. The constitutive model is implemented in a computer program based on the finite element method, where the FRC laminar structures were simulated according to the Reissner-Mindlin shell theory. The shell is discretized into layers for the simulation of the membrane, bending and out-of-plane shear nonlinear behavior. A stress-strain softening diagram is proposed to reproduce, after crack initiation, the evolution of the normal crack component. The in-plane shear crack component is obtained using the concept of shear retention factor, defined by a crack-strain dependent law. To capture the punching failure mode, a softening diagram is proposed to simulate the decrease of the out-of-plane shear stress components with the increase of the corresponding shear strain components, after crack initiation. With this relatively simple approach, accurate predictions of the behavior of FRC structures failing in bending and in shear can be obtained. To assess the predictive performance of the model, a punching experimental test of a module of a façade panel fabricated with steel fiber reinforced self-compacting concrete is numerically simulated. The influence of some parameters defining the softening diagrams is discussed.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.2
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• pp.71.2-71.2
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• 2014

processes at the origin of the star formation in the galaxies over the last 10 billions years. While it was proposed in the past that merging of galaxies has a dominant role to explain the triggering of the star formation in the distant galaxies having high star formation rates. In the opposite, more recent studies revealed scaling laws linking the star formation rate in the galaxies to their stellar mass or their gas mass. The small dispersion of these laws seems to be in contradiction with the idea of powerful stochastic events due to interactions, but rather in agreement with the new vision of galaxy history where the latter are continuously fed by intergalactic gas. I was especially interested in one of this scaling law, the relation between the star formation (SFR) and the stellar mass (M*) of galaxies, commonly called the main sequence of star forming galaxies. I have studied this main sequence, SFR-M*, in function of the morphology and other physical parameters as the radius, the colour, the clumpiness. The goal was to understand the origin of the sequence's dispersion related to the physical processes underlying this sequence in order to identify the main mode of star formation controlling this sequence. This work needed a multi-wavelength approach as well as the use of galaxies profile simulation to distinguish between the different galaxy morphological types implied in the main sequence.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2006.04a
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• pp.922-927
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• 2006

There is a concern with worldwide deterioration of highway bridges, particularly reinforced concrete. The advantages of fibre reinforced plastic(FRP) composites over conventional materials motivate their use in highway bridges for replacement of structures. Recently, an FRP deck has been installed on a state highway, located in New York State, as an experimental project. In this paper, a systematic approach for analysis of this FRP deck bridge is presented. Multi-step linear numerical analyses have been performed using the finite element method to study the structural behavior and the possible failure mechanism of the FRP deck-superstructure system Deck's self-weight and ply orientations at the interface between steel girders and FRP deck are considered in this study. From this research, the results of the numerical analyses were corroborated with field test results. Analytical results reveal several potential failure mechanism for the FRP deck and truss bridge system The results presented in this study may be used to propose engineering design guideline for new and replacement FRP bridge deck structure.

• Journal of Mechanical Science and Technology
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• v.17 no.5
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• pp.654-667
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• 2003

This paper presents a consequence of the systematic approach to identify the aerodynamic parameters of an unmanned aerial vehicle (UAV) equipped with the automatic flight control system. A 3-2-1-1 excitation is applied for the longitudinal mode while a multi-step input is applied for lateral/directional excitation. Optimal time step for excitation is sought to provide the broad input bandwidth. A fully automated programmed flight test method provides high-quality flight data for system identification using the flight control computer with longitudinal and lateral/directional autopilots, which enable the separation of each motion during the flight test. The accuracy of the longitudinal system identification is improved by an additional use of the closed-loop flight test data. A constrained optimization scheme is applied to estimate the aerodynamic coefficients that best describe the time response of the vehicle. An appropriate weighting function is introduced to balance the flight modes. As a result, concurrent system models are obtained for a wide envelope of both longitudinal and lateral/directional flight maneuvers while maintaining the physical meanings of each parameter.

• Proceedings of the Korean Society of Crop Science Conference
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• 2005.08a
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• pp.22-46
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• 2005

Spatial and timely information on crop and filed conditions is one of the most important basics for rational and efficient planning and management in agriculture. Remote sensing, GIS, and modeling are powerful tools for such applications. This paper presents an overview of the state of the art in remote sensing of crop and field conditions with some case studies. It is also shown that a synergistic linkage between process-based models and remote sensing signatures enables us to estimate the multiple crop/ecosystem variables at a dynamic mode. Remotely sensed information can greatly reduce the uncertainty of simulation models by compensating for insufficient availability of data or parameters. This synergistic approach allows the effective use of infrequent and multi-source remote sensing data for estimating important ecosystem variables such as biomass growth and ecosystem $CO_2$ flux. This paper also shows a geo-spatial information system that enables us to integrate, search, extract, process, transform, and calculate any part of the data based on ID#, attributes, and/or by river-basin boundary, administrative boundary, or boundaries of arbitrary shape/size all over Japan. A case study using the system demonstrates that the nitrogen load from fertilizer was closely related to nitrate concentration of groundwater. The combined use of remote sensing, GIS and modeling would have great potential for various agro-ecosystem applications.

• Journal of the Korea Safety Management & Science
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• v.19 no.3
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• pp.137-150
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• 2017

Logistic enterprises want to be competitive enterprises in fierce logistic market and worry about the securement of discriminative competitiveness for it. The standards for the judgement of logistic industry's maintenance of competitiveness are not only economic feasibility of logistic costs but also the satisfaction of users because well-established service system for variety and enhancement of logistic needs. Some of the quality attributes sufficiently satisfy expectation of customers, but not guarantee high-quality satisfaction. Therefore, it's difficult to grasp quality attributes with the existing approach of perceived service quality. Quality attribute model suggested by Kano is widely used as the concept is accurate, there is high possibility to be used at the stage of product/service planning, and it can be easily applied. Kano model has a limitation that quality attributes are classified with mode and the differences between strong property of the quality attribute and week property in quality attributes were ignored. Therefore, Timko calculated customer satisfaction coefficient with the result of Kano's survey and effects of customer satisfaction and unsatisfaction through relations between satisfaction coefficient and unsatisfaction coefficient. The purposes of this study are to use ASC, the average of satisfaction coefficient and unsatisfaction, as the satisfaction of quality characteristics, decide the importance of quality characteristics with TOPSIS, a representative multi-standard decision-making method, and calculate strategy improvement propriety of logistic service quality.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.3C
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• pp.314-322
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• 2007

This paper proposes a new optimization algorithm named by GBNSGA(Goal-Pareto Based Non-dominated Sorting Genetic Algorithm) which determines the best configuration for CR(Cognitive Radio) communication systems. Conventionally, in order to select the proper radio configuration, genetic algorithm has been introduced so as to alleviate computational burden along the execution of the cognition cycle proposed by Mitola. This paper proposes a novel optimization algorithm designated as GBNSGA for cognitive engine which can be described as a hybrid algorithm combining well-known Pareto-based NSGA(Non-dominated Sorting Genetic Algorithm) as well as GP(Goal Programming). By conducting computer simulations, it will be verified that the proposed method not only satisfies the user's service requirements in the form of goals. It reveals the fast optimization capability and more various solutions rather than conventional NSGA or weighted-sum approach.