• Journal of the Earthquake Engineering Society of Korea
• /
• v.14 no.4
• /
• pp.49-60
• /
• 2010

The actual hysteretic behavior of structural elements and systems is smooth. Smooth hysteretic behavior is more representative of actual behavior than bi-linear or piece-wise linear stiffness degrading models. The strength reduction factor in seismic design is used to reduce the elastic strength demand to design levels. In this study, the effect of smoothness on the strength reduction factor is evaluated for several smooth hysteretic systems subjected to near-fault and far-fault earthquakes. For design purposes, a simple expression of the strength reduction factor considering hysteretic smoothness and earthquake characteristics, represented as near-fault and far-fault earthquakes, is proposed. The strength reduction factors calculated by the proposed simple formulation are more similar to the factors directly obtained from inelastic response spectrum analyses than those calculated by several existing formulas.

• Journal of KIISE:Computer Systems and Theory
• /
• v.37 no.3
• /
• pp.127-137
• /
• 2010

As large-scale computational applications in various scientific domains have been utilized over many integrated sets of grid computing resources, the difficulty of their execution management and control has been increased. It is beneficial to refer job history generated from many application executions, in order to identify application‘s characteristics and to decide selection policies of grid resource meaningfully. In this paper, we apply a statistical technique, Plackett-Burman design with fold-over (PBDF), for analyzing grid environments and execution history of applications. PBDF design identifies main factors in grid environments and applications, ranks based on how much they affect to their execution time. The effective factors are used for selecting reference job profiles and then preferable resource based on the reference profiles is chosen. An application is performed on the selected resource and its execution result is added to job history. Factor's credit is adjusted according to the actual execution time. For a proof-of-concept, we analyzed job history from an aerospace research grid system to get characteristics of grid resource and applications. We built JARS algorithm and simulated the algorithm with the analyzed job history. The simulation result shows good reliability and considerable performance in grid environment with frequently crashed resources.

• Proceedings of the Korean Institute Of Construction Engineering and Management
• /
• 2007.11a
• /
• pp.312-315
• /
• 2007

This study is aimed at developing a web-based management system of maintenance historical data, for effective maintenance performance and smooth exchange of information and communication between public facilities and public educational facilities managers. The current management state of maintenance historical data and its business process were investigated and analyzed, through interviewing with the persons in charge of managing each facility, by recognizing problems of maintenance historical data management that is able to be applied as a basis to judge facility deterioration and performance. In addition, this study suggests a maintenance historical data system of which DB may be applied to the practical business, by reflecting requests of the persons in charge of managing facilities, setting up the scope of system usage by facility, business phase and level of facility managers, and establishing a maintenance business process system.

• Journal of Korean Society of Steel Construction
• /
• v.19 no.5
• /
• pp.503-513
• /
• 2007

The seismic responses of a building are affected by the connection characteristics that have effects on structural stiffness. In this study, push-over analysis and time history analysis were performed to estimate structural behavior of 2D eight-story unbraced steel structures with partially restrained composite connections using a nonlinear dynamic analysis program. Nonlinear $M-{\theta}$characteristics of connection and material inelastic characteristics of composite beam and steel column were considered. The idealization of composite semi-rigid connection as fully rigid connection yielded an increase in initial stiffness and ultimate strength in the push-over analysis. In time history analysis, the stiffness and hysteretic behavior of connections have effects on base-shear force, maximum story-drift and maximum moment in beams and columns. For seismic waves with PGA of 0.4 g, the structure with the semi-rigid composite connections shows the maximum story-drift with less than the life safety criteria by FEMA 273 and no inelastic behavior of beam and column, whereas in the structure with rigid connections, beams and columns have experienced inelastic behaviors.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.26 no.6A
• /
• pp.935-941
• /
• 2006

The hysteretic behavior of steel structure under cyclic and dynami loading such as earthquake is different to that under static loading. Because structural steels on dynamic deformation is different to static deformation with respect with mechanical characteristics and stress-strain relationship. Therefore, to accurately predict the hysteretic behavior of steel structures such as circular steel columns under cyclic and dynamic loading, the difference of loading carrying capacity and deformation according to loading rate, assumed static and dynamic deformation state, must be investigated. In this study, numerical analyses of circular steel column using SM490 for change of loading rate and diameter-thickness ratio(D/t) were carried out by using three-dimensional elastic-plastic finite element analysis and dynamic cyclic plasticity model of SM490 developed by the authors. Characteristics of hysteretic behavior of circular steel column using SM490, load carrying capacity and energy dissipation ratio, were clarified by analysis results.

• Journal of the Korea Society for Simulation
• /
• v.32 no.4
• /
• pp.59-67
• /
• 2023

Private blockchains can apply enhanced security policies that allow only authorized users to participate in the blockchain network. In addition, when used in a career management system where the validity of an individual's career is important, it has the suitable characteristics in terms of information integrity. However, due to the excessive performance requirements of blockchain technology, identifying performance characteristics through simulation can be helpful in stable operation of the system. This paper presents research results that utilized performance evaluation results while constructing a career management system based on the Ethereum blockchain. The service not only serves as a portfolio that records personal career development activities, certification acquisition, and award results, but also provides a community function for career planning to strengthen employment competitiveness. In addition, we present how a compensation policy can be executed to encourage users to participate in career development through community activities. In particular, an appropriate compensation policy was derived by reviewing changes in performance characteristics in accordance with the transaction volume on Geth nodes.

• Journal of the Korean Magnetics Society
• /
• v.3 no.1
• /
• pp.61-64
• /
• 1993

We have constructed a hysteresis loop tracer in order to measure the magnetic properties of amorphous wires under variable tensile stress. It has a force range of 0 N to 20 N and a magnetizing frequency of 1 kHz to 20 kHz. Using the ac-hysteresis loop tracer, we can measure the magnetic properties(maximum magnetic induction $B_{max}$, residual magnetic induction $B_{r}$, coercive field strength $H_{c}$, etc.) of amorphous wires with precision of 1% under variable tensile stresses.

• Journal of the Korea Convergence Society
• /
• v.13 no.5
• /
• pp.249-259
• /
• 2022

More than a year has already passed since the Gyeongbuk Hemp Regulation Free Zone Project was implemented, and it is time to supplement and review the deficiencies in production history management for the domestic hemp industry after the Free Regulatory Zone. In this study, the current status and characteristics of cannabis history management in the Gyeongbuk Hemp Regulation Free Zone project were investigated, and problems with current history management were derived using service design tools such as pilot interviews, shadowing, and Customer journey map. The case of the cannabis production system and the CTS recommended for the legal cannabis market in Oregon, a leading country, was compared and analyzed, and the direction was to secure safety through production cycle history management suitable for growth characteristics, efficient technology application for real-time management, and history information sharing. Through this study, it is expected that it will help improve the current hemp production history management system and properly settle the history management system of domestic hemp industrialization in the future.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.27 no.6
• /
• pp.86-93
• /
• 2023

As the hysteretic behavior of reinforced concrete members under cyclic loading progresses, the energy dissipation ability decreases due to a decrease in stiffness and strength and pinching effects. However, the guideline "Nonlinear Analysis Model for Performance-Based Seismic Design of Reinforced Concrete Building Structures, 2021" requires calculating a single energy dissipation factor for each member and all histeric step, so the decrease in energy dissipation capacity according to histeric step cannot be considered. It is judged that Therefore, in this study, the energy dissipation factor according to the histeric step was examined by comparing the existing experimental results and the nonlinear time history analysis results for a general beam under cyclic loading. The energy dissipation factor was calculated as the ratio of the energy dissipation amount of the actual specimen to the energy dissipation amount of the idealized elastoplastic behavior obtained as a result of nonlinear time history analysis. In the existing experiment results, the energy dissipation factor was derived by calculating one cycle for each histeric step, and the energy dissipation factor was derived based on the nonlinear modeling process in the guidelines. In the existing experimental study, the energy dissipation factor was calculated by setting each histeric step (Y-L-R), and the energy dissipation factor was found to be 0.36 in the Y-L step and 0.28 in the L-R step, and the energy dissipation factor in the guideline was found to be 0.31. This shows that the energy dissipation factor calculation formula in the guidelines does not indicate a decrease in the energy dissipation capacity of reinforced concrete members.

• Tunnel and Underground Space
• /
• v.20 no.4
• /
• pp.292-298
• /
• 2010

The purpose of this study is to evaluate an effect of ground vibration caused by blasting on the concrete brick structure. For the purpose, dynamic response time-history of the structure assumed single degree of freedom (SDOF) system and vibration time-history directly measured from the structure were examined, using Newmark $\beta$ method based on data measured at ground. The time-history was interpreted from the measured data of ground and structure in single hole blasting. Vibration magnitude between ground vibration and structure in single hole blasting and 20 ms interval blasting was about three times and was shown larger vibration on the structure. By time-history analysis of structure dynamic response, the value was almost the same one with the data measured from the structure. It indicates that the vibration characteristics of structures may be predicted on the basis of the ground vibration data measured from the sub-ground of structure.