• Proceedings of the KIEE Conference
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• 2003.11b
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• pp.127-130
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• 2003

In this paper, a hypothesis in order that the impulse response of a stable linear system does not change sign is suggested. For fixed zeros of the systems, the problem of synthesizing such a system is reduced to the problem of finding a proper denominator polynomial so that the step response of the overall system will not overshoot. The hypothesis is associated with the generalized time constant by Kim[5]. Under the hypothesis, we propose several methods that allow to compose a continuous time LTI systems achieving non-negative impulse response.

• Journal of KSNVE
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• v.9 no.4
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• pp.813-821
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• 1999

This paper presents the technique using wavelet analysis to solve the seismic response of a steam turbine-generator rotor system subjected to earthquake excitations. A brief review of the wavelet transform and its discretization, time-frequency representation of the earthquake wave and the seismic response for a rotor system is presented. The Daubechies wavelet has been used for describing the time-frequency characteristics of the input and the response in case of a recorded accelerogram during 1995 Hyogoken Nanbu earthquake. Also, the results in the wavelet domain has been illustrated through comparison with the time domain simulation results.

• The KSFM Journal of Fluid Machinery
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• v.17 no.4
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• pp.70-75
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• 2014

In this paper a analysis method is presented to obtain the steady state dynamic response from the finite element based equations of a rotor-bearing system with initial deflection. The method has been applied to analyze the dynamic response of the two-shaft rotor-bearing system with rigid coupling offset in a heavy duty gas turbine-generator. Bumps in the dynamic response of each rotor system have been observed at each critical speed due to the effect of initial deflection for rigid coupling offset. And, the dynamic responses have been shown to reduce for operating condition changes from cold to hot.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2006.06b
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• pp.215-220
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• 2006

The oil on board is a major source of sea pollutions. Recently, according to increasement of Hazardous and noxious substances carrying on board. Our greatest concern is how to response HNS spread pollution, addition to response oil spill pollution. This is first aim how can take a speedy and precise response. So introduce to development of the computerized response aid system for HNS.

• Structural Engineering and Mechanics
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• v.15 no.2
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• pp.239-248
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• 2003

The dynamic response analysis of closed loop control system based on probability for the intelligent truss structures with random parameters is presented. The expressions of numerical characteristics of structural dynamic response of closed loop control system are derived by means of the mode superposition method, in which the randomness of physical parameters of structural materials, geometric dimensions of active bars and passive bars, applied loads and control forces are considered simultaneously. The influences of the randomness of them on structural dynamic response are inspected by several engineering examples and some significant conclusions are obtained.

• Journal of Korean Association for Spatial Structures
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• v.19 no.1
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• pp.53-64
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• 2019

The objective of this study is to investigate the earthquake response for the design of 100m spanned single-layer lattice dome. The plastic hinge analysis and eigenvalue buckling analysis are performed to estimate the ultimate load of single-layered lattice domes under vertical loads. In order to ensure the stability of lattice domes, it is investigated for the plastic hinge progressive status by the pushover increment analysis considering the elasto-plastic connection. One of the most effective methods to reduce the earthquake response of large span domes is to install the LRB isolation system of a dome. The authors discuss the reducing effect for the earthquake dynamic response of 100m spanned single-layered lattice domes. The LRB seismic isolation system can greatly reduce the dynamic response of lattice domes for the horizontal and vertical earthquake ground motion.

• The Korean Journal of Emergency Medical Services
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• v.22 no.2
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• pp.51-65
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• 2018

Purpose: The purpose of this study was to investigate experiences of violence with patients or family members by paramedics working at emergency rooms. Methods: A questionnaire was administered from June 1 to 31, 2017 to 225 paramedics working at 27 emergency medical centers. The collected data were analyzed with SPSS statistics ver 24.0 program. Results: Within the past year, 208(92.9%) of 224 participants experienced violence among whom 202(90.2%) experienced verbal abuse, 193(86.2%) experienced physical threat, 89(39.7%) experienced physical violence, and 52(23.2%) experienced sexual violence. The level of violence response depending on the overlapping experience of violence type showed significant difference from emotional response (p= .001), social response (p= .001), physical response (p= .004), and overall violence response (p= .001). Conclusion: In conclusion, paramedics are frequently exposed to violence in the emergency rooms, of which they mostly experience verbal abuse. In addition, because the reporting system in the event of violence and the coping process are not well-informed, paramedics are unable to sufficiently utilize the reporting system and programs established within the institution. Therefore, the support of the legal system is needed to create a safe working environment for the medical staff who work in the emergency medical centers.

• Journal of the Korean Society of Hazard Mitigation
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• v.7 no.2 s.25
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• pp.25-33
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• 2007

In most developed countries, Extreme heat alter system operates every summer and the response plan to be issued according to this system is composed of some government agencies sub-plans. The National Emergency Management Agency in Korea develops response plan but it is not composed of the definition of the heat vulnerability and the concrete agency roles. Therefore, this study analyses foreign cases in three processing: preparedness, response, recovery and reviews the status of heat response plan. As a conclusion, the study suggests two ways of Extreme heat management into Korean heat response plan such as strengthening its institutional position and complementing its context.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1994.10a
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• pp.35-39
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• 1994

One of the important characteristics of the response of nonlinear systems is the existence of subharmonic resonances. When some conditions in parameter space are satisfied. It is possible even in the presence of damping for a periodically excited nonlinear system to possess a response which is the combination of a contribution at the excitation frequency and a component at the system natural frequency. The system natural frequency being a submultiple of the excitation frequency implies that the resulting response is a subharmonic oscillation. In general, there also co-exists, for the system, a response at the excitation frequency, and initial conditions determine which of the steady-state responses is achieved in an experiment or a numerical simulation. In single-degree-of-freedom systems with harmonic excitation, depending on the type of the nonlinearity, e.g., cubic or quadratic the frequency of subharmonic response is respectively, one-third or one-half of that of the excitation frequency. Although subharmonic resonance is one of the principal characteristics of a nonlinear system the subharmonic responses of structures in the presence of internal resonances have been studied very rarely. In this work, we consider subharmonic responses in the two-mode approximation of the plate equations. It is assumed that the two modes are in one-to-one internal resonance. Constant and periodic steady-state solutions of the averaged equations are studied. Finally, the results of direct time integration of the original equations of motion are presented and compared with those obtained from the averaged equations.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.9
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• pp.1269-1275
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• 2015

Turbine-generator torsional response is caused by interaction between electrical transient air-gap torque and mechanical characteristics of turbine-generator shafts. There are various factors that affects torsional interaction such as fault, circuit breaker switching and generator mal-synchronizing, etc. Fortunately, we can easily simulate above torsional interaction phenomena by using ElectroMagnetic Transient Program (EMTP). However, conventional EMTP shows the incomplete response of super- synchronous torsional mode since it does not consider turbine blade section. Therefore, in this paper, we introduced mechanical-electrical analogy for detailed modeling of turbine-generator shaft system including low pressure turbine blade section. In addition, we derived the natural frequencies of modeled turbine-generator shaft system including turbine blade section and analyzed the characteristics of mechanical torque response at shaft coupling and turbine blade root area according to power system balanced/unbalanced faults.