• ETRI Journal
• /
• v.29 no.4
• /
• pp.411-420
• /
• 2007

The steady evolution of mapping technology is leading to an increasing availability of multi-sensory geo-spatial datasets, such as data acquired by single-head frame cameras, multi-head frame cameras, line cameras, and light detection and ranging systems, at a reasonable cost. The complementary nature of the data collected by these systems makes their integration to obtain a complete description of the object space. However, such integration is only possible after accurate co-registration of the collected data to a common reference frame. The registration can be carried out reliably through a triangulation procedure which considers the characteristics of the involved data. This paper introduces algorithms for a multi-primitive and multi-sensory triangulation environment, which is geared towards taking advantage of the complementary characteristics of spatial data available from the above mentioned sensors. The triangulation procedure ensures the alignment of involved data to a common reference frame. The devised methodologies are tested and proven efficient through experiments using real multi-sensory data.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.25 no.5A
• /
• pp.726-742
• /
• 2000

A novel rte control algorithm consisting of two major components, i.e. a variable encoding frame rate method and a hybrid DCT/wavelet I-frame coding scheme, is proposed in this work for low bit rate video coding. Most existing rate control algorithms for low bit rate video focus on bit allocation at the macroblock level under a constant frame rate assumption. The proposed rate control algorithm is able to adjust the encoding frame rate at the expense of tolerable time-delay. Furthermore, an R-D optimized hybrid DCT/wavelet scheme is used for effective I-frame coding. The new rate-control algorithm attempts to achieve a good balance between spatial quality and temporal quality to enhance the overall human perceptual quality at low bit rates. It is demonstrated that the rate control algorithm achieves higher coding efficiency at low bit rates with a low additional computational cost. The variable frame rate method and hybrid I-frame coding scheme are compatible with the bi stream structure of H.263+.

• Journal of Korean Association for Spatial Structures
• /
• v.10 no.4
• /
• pp.113-122
• /
• 2010

Space frame structures are included in the large spatial structures and can adopt various structure types. But, it is not easy to choose the optimal member size and shape because it depends on the structural engineer's experience and the repeated trial and error. Therefore, in this study, the final goal is to help the designer with the selection of the optimum shape. First, various space frame structures with ellipse dome and vault complex types are chosen and the shape generation method is considered to generate the nodes, coordinates and members. In optimal design process of space frame structure, each node coordinate changes according to height variation or the number of rings. Therefore, the auto generation technique of nodes and members is required in order to consider this phenomenon in optimal design process. Next, the shape generation module is created, base on the shape generation method. This module is connected with the analysis module and the optimization algorithm. Finally, the example model is presented for the evaluation of the efficiency of optimization algorithms.

• Journal of the Korean Society of Radiology
• /
• v.15 no.5
• /
• pp.731-739
• /
• 2021

This work compared the bright calibration of digital radiation with signal-to-noise ratio and basic spatial resolution according to multi frame to enable effective inspection of welding parts of structures at industrial sites. A total of 130 images were obtained by using a ⁷⁵Se radiation source for flat weld test pieces and segmenting bright calibration and multi frame prior to shooting. The study confirms that the signal-to-noise ratio improves as the number of bright calibrations and the number of multi frame increases. The basic spatial resolution satisfied the baseline for both radiographic images. It was confirmed that the number of signal-to-noise ratio was similar by comparing images taken after installing lead shielding for scattering radiation. Although signal-to-noise ratio increases as multi frame increases, it is believed that good quality digital radiographs can be obtained if appropriate radiographic techniques are devised because exposure time of radiation affects workers' exposure and work efficiency.

• Proceeding of KASS Symposium
• /
• 2008.05a
• /
• pp.212-217
• /
• 2008

This paper is concerned with the structural design of Angola Stadium. The Angola stadium is composed of a Steel moment frame system and a Cantilever steel truss roof. Whole structural analysis is necessary to ensure the stability. Considered FEM analysis, Design of Wind load & Seismic, Stand diaphragm, interaction between stand and Roof, Serviceability.

• Journal of Korean Association for Spatial Structures
• /
• v.1 no.1 s.1
• /
• pp.135-142
• /
• 2001

This paper proposes structural analysis on the World Wide Web to form a part of the architectural design project. It purposes modeling space frames and a structural analysis program on the internet only by inputting basic data for forming a shape in the whole phase of space frame analysis. The analysis data is conducted by Oracle DBMS(DataBase Management System), GUI(Graphic User Internet) by Java Applet and connection with server and database by Java Servlet respectively. The result from modeling and analysis is provided as graphic and text file forms by web browsers. Programs can be executed irrespective of user's OS by using internet and highly-secured system is constructed taking advantage of Java. Of great efficiency is maintaining and recycling data as the whole is dealt by database from the beginning to the end of program.

• Journal of Korean Association for Spatial Structures
• /
• v.15 no.1
• /
• pp.85-94
• /
• 2015

SAFE damper is a hybrid damper which is comprised of a friction damper and a metallic damper. These two dampers combine to resist external energy in stages. Under minor earthquake loads, the friction damper operates alone. However, the friction damper and metallic damper dissipate the energy together when a severe earthquake occurs. In comparison with other methods for seismic retrofitting, the SAFE damper has many advantages. The SAFE damper doesn't cause damage to façade of the building, and the construction period can be reduced when retrofitting. This paper describes experiments evaluating the structural performance of the SAFE damper. From the results, it was found that the structural performance of a conventional RC bare frame can be significantly improved by the installation of the SAFE damper.

• Journal of Korean Association for Spatial Structures
• /
• v.19 no.1
• /
• pp.37-44
• /
• 2019

Yangjindang house, which is located in Sang-ju province of South Korea, is one of the special Hanok structures dated back to Joseon dynasty. This study aims to examine structural safety of the Yangjindang wood frame building considering dynamic parameters such as the natural frequency and damping ratio. The numerical model of the wood frame building is implemented using Midas Gen, especially the wood joint where column and beam were connected. The behavior of the actual frame building was compared with the modeling results. In addition, structure responses such as shear force, axial force, flexural moment and deflections were calculated and compared with the allowable limits. Numerical results show that, generally, despite of some local members shear failure, Yangjindang's structural response does not exceed the limitation according to current standards.

• Journal of Korean Association for Spatial Structures
• /
• v.21 no.2
• /
• pp.57-66
• /
• 2021

This study develops finite element models for seismically-deficient reinforced concrete building frame retrofitted using fiber-reinforced polymer jacketing system and validates the finite element models with full-scale dynamic test for as-built and retrofitted conditions. The bond-slip effects measured from a past experimental study were modeled using one-dimensional slide line model, and the bond-slip models were implemented to the finite element models. The finite element model can predict story displacement and inter-story drift ratio with slight simulation variation compared to the measured responses from the full-scale dynamic tests.

• 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.