• Journal of Korean Association for Spatial Structures
• /
• v.23 no.4
• /
• pp.59-69
• /
• 2023

Recently, the occurrence frequency of earthquake has increased in Korea, and the interests for seismic reinforcement of existing school buildings have been raised. To this end, the seismic performance evaluations for school buildings that did not accomplish the seismic design are required. In particular, this study checks the eigenvalue analysis, pushover curves, maximum base shears, performance points and story drift ratios, and then analyzes the seismic performance characteristics according to bracing configuration of steel frame system reinforcement. Also, this study presents the practical field application methods through the comparison of analysis results for the seismic performance characteristics.

• Korean Journal of Computational Design and Engineering
• /
• v.12 no.5
• /
• pp.376-381
• /
• 2007

The geometric configuration in the weight-reduced structure is very required to be started from the conceptual design with low cost, high performance and quality. In this point, a structural-topological shape concerned with conceptual design of structure is important. The method used in this paper combines three optimization techniques, where the shape and physical dimensions of the structure and material distribution are hierachically optimized, with the maximum rigidity of structure and lightweight.

• Proceedings of the Korean Nuclear Society Conference
• /
• 1996.05a
• /
• pp.380-385
• /
• 1996

The genetic algorithm(GA) is applied to the design of the nuclear power control system. The reactor control system model is described in the LQR configuration. The LQR system order is increased to make the tracking system. The key parameters of the design are weighting matrices, and these are usually determined through numerous simulations in the conventional design. To determine the more objective and optimal weightings, the improved GA is applied. The results show that the weightings determined by the GA yield the better system responses than those obtained by tile conventional design method.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.36 no.9
• /
• pp.825-834
• /
• 2008

Nose chine shape optimization study has been performed to maximize the directional stability at high angle of attack supersonic flow. Various chine shapes are generated using super ellipse equation. By numerically investigating the directional stability characteristics of those shapes, the baseline configuration for the shape optimization has been selected using the three-dimensional Navier-Stokes equations. The configuration is represented by the NURBS curves which can adjust the surface geometry by the control points. The response surfaces are constructed to obtain optimum shape which has high directional stability characteristics and lift-to-drag ratio. From this study, an efficient configuration design and optimization process which utilizes the parameter-based configuration generation techniques and approximation method has been established, then 29% improvement of the directional stability by strong vortexes from chine nose is accomplished.

• Korean Institute of Interior Design Journal
• /
• v.17 no.5
• /
• pp.40-50
• /
• 2008

This article examined the applicability of spatial configuration to Escher's works through configurative logics and rules and studied the contrasting relations among the unit elements in Escher's works and their characteristics and the creative process of the characteristics. As the results of the study on the bases to maintain and create the partial elements revealed as the characteristics, it was shown that Escher's sequential transformative works demonstrated diverse expressive characteristics as a creative process of Inter-complementary contrasting relations based on the independence of the unit elements. It was also shown that the creative process of the unit elements was actualized through the maintenance base of the fixed and absolute characteristic as the logic for the creation and the creation base of the dynamic and relative characteristic. Therefore, it was interpreted that by applying the logics for creation to Escher's unit elements through the spatial interpretation of the maintenance base and the creation base as well as by configuring the units created in such a way according to the characteristics of Escher's works, spatial possibility canbe derived out from Escher's contrasting tessellation works. The process of spatial configuration is the process to make a balance between various conditions, artists own understanding of the space and his/her intention of the space. From this viewpoint, the logics for maintenance base and for creation base seem to have the potentiality as a spatial configuration to consistently meet the given conditions as well as to derive out novelty through the transformation to maintain the fixed and absolute condition(base) and the characteristics of the independent(additional) transformation arising together with the implicit relations among the transformative units.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.37 no.10
• /
• pp.984-991
• /
• 2009

In this study, transonic aeroelastic response analyses have been conducted for the DLR-F4(wing-body) aircraft configuration considering shockwave and flow separation effects. The developed fluid-structure coupled analysis system is applied for aeroelastic computations combining computational structural dynamics(CSD), finite element method(FEM) and computational fluid dynamics(CFD) in the time domain. It can give very accurate and useful engineering data on the structural dynamic design of advanced flight vehicles. For the nonlinear unsteady aerodynamics in high transonic flow region, Navier-Stokes equations using the structured grid system have been applied to wing-body configurations. In transonic flight region, the characteristics of static and dynamic aeroelastic responses have been investigated for a typical wing-body configuration model. Also, it is typically shown that the current computation approach can yield realistic and practical results for aircraft design and test engineers.

• Journal of the Korea Society for Simulation
• /
• v.19 no.3
• /
• pp.1-6
• /
• 2010

Simulation analysis may be the essential means to either evaluate performance of systems or optimize system parameters for new design. Including many variations for design and implementation, MANET (Mobile Ad-hoc NETwork) is one target area of such an analysis. Since every node, however, included in the network has mobility, one MANET could be overlapped or merged with another one which use a different transport protocol. In order to communicate among nodes in this case, the new merged network should configure paths and addresses in advance. Configuring paths and addresses generates much overheads which ultimately cause delay in communicating data. Performance analysis is required to improve the data transport performance by minimizing overheads. This paper proposes a sound address auto-configuration method which is based on an on-demand manner and then presents modeling and performance analysis of the method. NS-2 simulation results verify that the proposed method can not only alleviate overheads, which are inevitably generated for address auto-configuration processes, and but also decentralize them in time.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.12 no.2
• /
• pp.73-82
• /
• 2009

The traffic volume of Seoul is extremely high in comparison to other major cities in Korea, and the result has been harmful physical and mental exposure to pollution by Seoulites on a regular basis. The street air pollution is more important than the others, because the air pollution generated by street traffic directly impacts the health of nearby pedestrians. This problem requires urgent attention and resolution. Among the factors creating the air pollution originating from the street, is the configuration of streets, which have emerged as the most significant because it is related to air and pollutant dispersion. Therefore, this study was conducted under the assumption that street form affects the air quality. Study sites were classified by street characteristics, and air quality was analyzed in each class. Then the OSPM (Operational Street Pollution Model) was employed to simulate the relationship between street configuration and air quality of streets within the old city center and new city center in Seoul. After that this study analyzed the correlation between air pollution and the spatial configuration of urban streets (ex. street width, building height, building density, etc.) to determine their contributions to air pollution. The outcome of this study is as follows : First, the result that was derived from the correlation analysis between street configuration and air quality hewed that the air pollution of the street is influenced by the average height of building, width of the roads as well as traffic volume. On the roadside, the concentration level of $NO_2$ is mainly affected by the average height of building and the deviation of building height along the street and CO is affected by street width. The outcome of this study can be used as a basis for more sound urban design policies, and the promotion of desirable street environments for pedestrians.

• The Journal of Society for e-Business Studies
• /
• v.22 no.2
• /
• pp.99-121
• /
• 2017

Standard makers in both private and public sectors have been increasingly mandating security standards upon organizations to protect organizational digital assets. A major issue in security standardization is that standards often cannot regulate all possible security efforts by the standard maker because some efforts are unverifiable by nature. This paper studies from an analytical perspective how a standard maker should design the standard using a verifiable security control in the presence of another related unverifiable one. We compare it with two benchmark standards; $na{\ddot{i}}ve$-standard which refers to the standard maker who ignores the existence of the unverifiable control, and complete-information standard which refers to the maker sets standards on both controls. Optimal standard and benchmark standard depend critically on how the two controls are configured. Under parallel configuration, the existence of the unverifiable control induces the policy maker to set a higher standard (the complete-information standard is optimal); under serial configuration, a lower standard is applied (neither benchmark works). Under best-shot configuration and if the verifiable control is more cost-efficient, the existence of the unverifiable control has no impact on the optimal standard (the $na{\ddot{i}}ve$ standard is optimal).

• International Journal of Automotive Technology
• /
• v.7 no.5
• /
• pp.625-635
• /
• 2006

From a viewpoint of human factors, automated highway systems(AHS) can be defined as one of the newly developing human-machine systems that consist of humans(drivers and operators), machines(vehicles and facilities), and environments(roads and roadside environments). AHS will require a changed vehicle control process and driver-vehicle interface(DVI) comparing with conventional driving. This study introduces a fixed-based AHS simulator and provides questionnaire-based human factors evaluation results after three kinds of automated driving speed experiences in terms of road configuration, operation policies, information devices, and overall AHS use. In the simulator, the "shared space-at-grade" concept-based road configuration was virtually implemented on a portion of the Kyungbu highway in Korea, and heads-up display(HUD), AHS information display, and variable message signs(VMS) were installed for appropriate AHS DVI implementation. As the results, the subjects expressed positive opinions on the implemented road configuration, operation policies, and the overall use of AHS. The results of this study would be helpful in developing the road configuration and DVI design guideline as the basic human factors research for the future implementation of AHS.