• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.13 no.8
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• pp.598-604
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• 2003

In this paper a general solution method is presented to obtain the unbalance response orbit from the finite element based equations of motion of a gear-coupled two-shaft rotor-bearing system, whose shafts rotate at their different speeds from each other. Particularly, are proposed analytical solutions of the maximum and minimum radii of the orbit. The method has been applied to analyze the unbalance response of a 800 refrigeration-ton turbo-chiller rotor-bearing system having a bull-pinion speed increasing gear. Bumps in the unbalance response of the driven high speed compressor rotor system have been observed at the first torsional natural frequency due to the coupling effect of lateral and torsional dynamics. Further, the proposed analytical solutions have agreed well with those obtained by a full numerical approach. The proposed analytical solutions can be generally applied to obtain the maximum and minimum radii of the unbalance response orbits of dual-shaft rotor-bearing systems coupled by bearings as well.

• Computational Structural Engineering
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• v.10 no.3
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• pp.125-131
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• 1997

Most dynamic systems have are known to various random properties in excitation and system parameters. In this paper, a procedure for response analysis is proposed for the linear dynamic system with random properties in both excitation and system parameters. The system parameters and responses with random properties are modeled by perturbation technique, and then response analysis is formulated by probabilistic and vibration theories. And probabilistic FEM is also used for the calculation of mean response which is difficult by the proposed response model. As an applicative example, the transient response is considered for systems of single degree of freedom with random mass and spring constant subjected to stationary white-noise excitation and the results are compared to those of numerical simulation.

• Journal of Korean Association for Spatial Structures
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• v.16 no.1
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• pp.95-104
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• 2016

Recently, the concept of damped outrigger system has been proposed for tall buildings. But, structural characteristics and design method of this system were not sufficiently investigated to date. In this study, the dynamic response control performance of outrigger damper has been analyzed. To this end, a simplified analysis model with outrigger damper system has been developed. Use the El Centro seismic(1940, NS) analysis was performed. Analysis results, on the top floor displacement response to the earthquake response, did not have a big effect. However, acceleration response control effect was found to be excellent. The increase of outrigger damper capacity usually results in the improved control performance. However, it is necessary to select that proper stiffness and damping values of the outrigger damper system because, the outrigger damper having large capacity is result in heavy financial burden.

• Journal of Ocean Engineering and Technology
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• v.20 no.3 s.70
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• pp.54-60
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• 2006

For optimal design of a deep-sea ocean mining collector system, based on self-propelled mining vehicle, it is imperative to develop and validate the dynamic model of a tracked vehicle traveling on soft deep seabed. The purpose of this paper is to evaluate the fidelity of the dynamic simulation model by means of response surface methodology. Various statistical techniques related to response surface methodology, such as outlier analysis, detection of interaction effect, analysis of variance, inference of the significance of design variables, and global sensitivity analysis, are examined. To obtain a plausible response surface model, maximum entropy sampling is adopted. From statistical analysis and prediction for dynamic responses of the tracked vehicle, conclusions will be drawn about the accuracy of the dynamic model and the performance of the response surface model.

• Journal of Satellite, Information and Communications
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• v.8 no.2
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• pp.56-61
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• 2013

With the rapidly increasing power demand in recent years, variety of methods have been proposed for efficient power consumption.. Among them, the most representative example is demand response system based smart grid. Demand response system is not passive, one-side power demand. This system can efficiently consume through communication between service provider and power consumer. Demand response system uses HTTP based TCP/IP. And currently, there are variety of communication application protocol. In this paper, we analyze procotol type and application for demand response system.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.9 no.3
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• pp.28-34
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• 2010

The suggested coupled system was analyzed using FRF and mode analysis. The eigen-mode of FRF analysis is consistent with that of conventional FFT in spectrum. Also, three numerical responses of second order system, which are coupled, was obtained using the Runge-Kutta Gill method. The displacement, velocity and acceleration response were calculated for the numerical analysis of coupled system and the displacement response was used for the calculation of FRF of this system. Using the mixed response of 1st and 2nd mode in example, the FRF was analysed for the analysis of mixed mode coupled system. Also, its mode shape was acquired by solving the eigen problem of coupled system.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.18 no.2
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• pp.195-206
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• 2020

Although the national radiological emergency response system has been improved by incorporating lessons from the Fukushima nuclear power plant accident and recent domestic natural disasters, it has not fully incorporated these lessons. In addition, it cannot deal with a variety of aftermath of the radiological disaster. Even for the same disaster, the national emergency response system should comply with multiple domestic laws in our country. Furthermore, there are a few discrepancies between the articles of the domestic laws that the national radiological emergency response system should address. Therefore, this study investigates the characteristics of radiological disasters, examines articles on the domestic laws related to the national radiological emergency response system, and analyses the Japanese government's responses to the Fukushima nuclear power plant accident. Based on the results of the review, suggestions for the improvement of the national radiological emergency response system in terms of response organization and framework have been proposed in this study.

• The Journal of the Korea Contents Association
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• v.7 no.2
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• pp.170-179
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• 2007

The present study purposed to establish a network for building an efficient disaster response system and for this purpose, we compared cases of disaster response in Japan and Korea. In Japan, disasters are responded jointly through the network of the central government, local self governing bodies and non governmental organizations. In Korea, however, the cooperative network among different areas is weak and this is aggravating damages caused by disasters. That is, in Korea, disaster response services have been mainly carried out by the public sector. The public sector can operate a powerful disaster management system using its extensive management resources, compelling power, and legal authorities. However, it was found that, due to the characteristics of contemporary society, efforts by the public sector including the central government and the local self government bodies have limitations in managing disasters effectively. Thus, for efficient disaster response in Korea, it is urgently required to establish a national disaster response network as well as a private sector cooperation system and to induce NGOs to participate in the disaster response system through institutional devices.

• Journal of Korean Association for Spatial Structures
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• v.17 no.2
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• pp.43-51
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• 2017

The demand for skyscrapers is increasing worldwide. Until now, various lateral resistance structures have been used for lateral displacement control of high-rise buildings. An outrigger damper system has been introduced recently to improve lateral dynamic response control performance further. However, a study of outrigger damper system is yet to be sufficiently investigated. In this study, time history analysis was performed to investigate the control performance of an outrigger damper system of high-rise building under eccentric loading. To do this, an actual scale 3-dimensional tall building model with an outrigger damper system was prepared. The control performance of the outrigger damper system was evaluated by varying stiffness and damping values. On the top floor torsional angle response to the earthquake load, was greatly affected by damping value. And the displacement response was affected greatly by the stiffness value and damping value of damper system. In conclusion, it is necessary to select the proper damping and stiffness values of the outrigger damper system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.12
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• pp.7357-7363
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• 2014

Korea had been known as safe region regarding volcanic disasters. On the other hand, Baekdu mountain experienced a large eruption one thousand years ago and the precursor phenomena for a volcanic eruption have been frequently reported these days. Therefore, a number of volcano experts, who warn of a volcanic eruption on the Korean peninsula, has increased. This paper describes the utilization plan and evolution of developing volcanic disaster response system based on spatial information and scientific modeling process for Baekdu mountain. First, the business processes for volcanic disaster response are derived based on an analysis of business system and related IT-based systems. Second, the design and development of a volcanic disaster response system are derived based on the business process. Third, a utilization plan is suggested to maximize the efficiency of the system. The application of the suggested volcanic disaster response system to NEMA, additional tests and system supplementation should be carried out. The complete volcanic disaster response system, which will be implemented based on this research, is expected to minimize the volcanic disaster damage in the area of Korea, China and Japan.