• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.05a
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• pp.623-625
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• 2012

The restoration of an image corrupted by Gaussian noise is an important task in image processing. There are many kinds of filters are proposed to remove Gaussian noise such as Gaussian filter, mean filter, weighted filter, etc. However, they perform not good enough for denoising and edge preservation. Hence, in this paper we proposed an adaptive weighted filter which considers spatial distance and the estimated variance of noise. We also compared the proposed method with existing methods through the simulation and used MSE(mean squared error) as the standard of judgement of improvement effect.

• Journal of Korean Association for Spatial Structures
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• v.14 no.4
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• pp.97-104
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• 2014

Recently, a concept of damped outrigger system has been proposed for tall buildings. Structural characteristics and design method of this system were not sufficiently investigated to date. In this study, control performance of damped outrigger system for building structures subjected to seismic excitations has been investigated. And optimal design method of damped outrigger system has been proposed using multi-objective genetic algorithm. To this end, a simplified numerical model of damped outrigger system has been developed. State-space equation formulation proposed in previous research was used to make a numerical model. Multi-objective genetic algorithms has been employed for optimal design of the stiffness and damping parameters of the outrigger damper. Based on numerical analyses, it has been shown that the damped outrigger system control dynamic responses of the tall buildings subjected to earthquake excitations in comparison with a traditional outrigger system.

• Journal of Korean Association for Spatial Structures
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• v.19 no.4
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• pp.77-84
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• 2019

This study introduces a newly developed PC non-bearing wall system to prevent the damage of RC wall-type apartments that have been heavily damaged by the 2017 Pohang Earthquake. In order to evaluate the performance of the developed PC non-bearing wall system, a static cyclic test is conducted. The prototype of test specimen is from the RC wall-type apartment which has been severely damaged by the 2017 Pohang Earthquake. The specimen with the conventional non-bearing wall system showed the similar damage of RC wall type apartment suffered from the Pohang Earthquake. In case of the specimen with the developed PC non-bearing wall system, cracks and damages were not transmitted between the walls due to the seismic slit and there were almost no cracks in the non-bearing walls. Therefore, the proposed non-bearing wall system, separated from the structural walls, could prevent spreading cracks to bearing walls and make it possible to effectively control damage due to earthquake loads.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2006.06a
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• pp.382-389
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• 2006

Developing context awareness service In these day, It demands high security in context awareness service. So GEO-RBAC that provide user assignment of spatial role, assignment of permission, role schema, role instance and spatial role hierarchy to context awareness service is access control model to perfect in context awareness service. But GEO-RBAC is not considering temporal constraints that have to need context awareness environment. Consequently this paper improves the flexibleness of GEO-RBAC to consider time and period constraints notion and the time of GTRBAC that presents effective access control model. also we propose GEO-RBAC to consider temporal constraints for effective access control despite a various case.

• Journal of Korean Association for Spatial Structures
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• v.6 no.2 s.20
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• pp.115-121
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• 2006

In recent years vibration control damper made of low yield point steel is expected to play an important role in controlling structural vibration induced earthquake and wind. But their dynamic characteristics and energy dissipation effects on the whole structure model are not clarified. In this paper, firstly, we presents the results of cyclic tests on low yield steel dampers. Secondly, forced vibration tests on existence three stories steel structure model with low yield point steel dampers are presented. Lastly, it is estimated energy amount which is dissipated through the hysteresis dampers by using two types of analytical models, hysteresis model and equivalent linear model.

• Journal of Korean Association for Spatial Structures
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• v.1 no.2 s.2
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• pp.59-66
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• 2001

This paper describes three modules for development of the Space Frame Integrated Design System(SFIDS). The Control Module is implemented to control the developed system. The Model Generation Module based on PATRAN user interface enables users to generate a complicated finite element model for space frame structures. The Optimum Design Module base on a branch of combinatorial optimization techniques which can realize the optimization of a structure having a large number of members designs optimum members of a space frame after evaluating analysis results. The Control Module and the Model Generation Module Is implemented by PATRAN Command Language(PCL) while C++ language is used in the Optimum Design Module. The core of the system is PATRAN database, in which the Model Generation Module creates information of a finite element model. Then, PATRAN creates Input files needed for the analysis program from the information of the finite element model in the database, and in turn, imports output results of analysis program to the database. Finally, the Optimum Design Module processes member grouping of a space frame based on the output results, and performs optimal member selection of a space frame. This process is repeated until the desired optimum structural members are obtained.

• Journal of Korean Association for Spatial Structures
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• v.7 no.4
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• pp.79-87
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• 2007

The object of this study is to understand of the effectiveness characteristic in the field work which is controlled by the quality in the high-rise residential-commercial complex building. From the previous study, the quality improvement factors are investigated. Through the structured questionnaire, the opinions of the field engineers(University, Design firms, Construction company) are gathered in the improvement factors of construction phase. Comparing the results of questionnaire with the conception of field engineers, this study helps in revising and improving the quality control system including tangible factors and intangible factors in the frame work of the high-rise residential-commercial complex building project.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.10a
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• pp.359-362
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• 2007

According to the development of information and communication technology, a great deal of researches have been taken in image digital processing field. And for earning the standard level of images, to remove noises such as impulse noise has became a essential demand. In those algorithms which remove impulse noise effectively, the standard median (SM) filter is representative. However, it has a disadvantage to degrade the quality of overall image by occurring errors in the edge domain. Therefore, in this paper, to restore the corrupted image by impulse noise, a nonlinear spatial filter based on Min-max operation was proposed and it was compared with conventional methods through simulations.

• Proceeding of KASS Symposium
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• 2005.05a
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• pp.116-124
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• 2005

The recent large-spatial structures are frequently made from light-weight structural system and it has a good mechanical efficiency and uses new materials. The large space is made by light-weight structural system using tension members mainly, and generally it is called a soft structure. The cable dome structures which are a soft structures are very flexible, the stresses and nodal coordinates of other members are changed when we control the stress of one member. Therefore, we have to do two kind of works for effective and accurate construction of the cable dome structures. The first work is making a working scenario to complete the final objective form and the second is revising constructional errors occurred in process of the actual works. These works are called constructional analysis. At this time, we have to consider geometric nonlinearity to reflect the sensitivity by the initial stresses of cable dome structures, and constructional analysis comes down to a nonlinear problem after all. In this study, we try to approach the constructional analysis of the cable dome structures using the numerical method, and then verify it.

• The Plant Pathology Journal
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• v.32 no.6
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• pp.563-569
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• 2016

The spatial patterns for temperature distribution on crape myrtle leaves infested with sooty mold were investigated using a digital infrared thermal imaging camera. The mean temperatures of the control and sooty regions were $26.98^{\circ}C$ and $28.44^{\circ}C$, respectively. In the thermal images, the sooty regions appeared as distinct spots, indicating that the temperatures in these areas were higher than those in the control regions on the same leaves. This suggests that the sooty regions became warmer than their control regions on the adaxial leaf surface. Neither epidermal penetration nor cell wall dissolution by the fungus was observed on the adaxial leaf surface. It is likely that the high temperature of black leaves have an increased cooling load. To our knowledge, this is the first report on elevated temperatures in sooty regions, and the results show spatial heterogeneity in temperature distribution across the leaf surface.