• International Journal of High-Rise Buildings
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• v.10 no.2
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• pp.137-147
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• 2021

The principle of energy dissipation technology is to dissipate or absorb the seismic energy input through the deformation or velocity change of dampers installed in the main structure of high-rise buildings, so as to reduce the seismic response of the buildings. With the development of energy dissipation technology, recognized as an effective and new measurement for reducing seismic effects, its application in high-rise buildings has become more and more popular. The appropriate energy dissipation devices suitable for high-rise buildings are introduced in this paper. The effectiveness of energy-dissipation technology for reducing the seismic response of high-rise buildings with various structural forms is demonstrated with a number of actual examples of high-rise buildings equipped with various energy dissipation devices.

• Structural Engineering and Mechanics
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• v.63 no.1
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• pp.23-35
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• 2017

A nonlinear static procedure considering work-energy principle and global failure mechanism to estimate base shears of reinforced concrete (RC) frame-type structures is presented. The relative energy equation comprising of elastic vibrational energy, plastic strain energy and seismic input energy is obtained. The input energy is modified with a factor depending on damping ratio and ductility, and the energy that contributes to damage is obtained. The plastic energy is decreased with a factor to consider the reduced hysteretic behavior of RC members. Given the pre-selected failure mechanism, the modified energy balance equality is written using various approximations for modification factors of input energy and plastic energy in scientific literature. External work done by the design lateral forces distributed to story levels in accordance with Turkish Seismic Design Code is calculated considering the target plastic drift. Equating the plastic energy obtained from energy balance to external work done by the equivalent inertia forces considering, a total of 16 energy-based base shears for each frame are derived considering different combinations of modification factors. Ductility related parameters of modification factors are determined from pushover analysis. Relative input energy of multi degree of freedom (MDOF) system is approximated by using the modal-energy-decomposition approach. Energy-based design base shears are compared with those obtained from nonlinear time history (NLTH) analysis using recorded accelerograms. It is found that some of the energy-based base shears are in reasonable agreement with the mean base shear obtained from NLTH analysis.

• Korean Journal of Acupuncture
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• v.27 no.4
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• pp.49-57
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• 2010

Objectives : The aim of this study is evaluation for significance of skin meridian-acupoints energy measurement system, and is verification of principle to measure the bio-ion charge on acupoints. Methods : To check a correlation between the MEP(Meridian Energy Potential) and bio-electric charge condition, ten acupoints(left/right BL meridian : BL13, BL15, BL18, BL20, BL23) were chosen. Based on basic theory concerning the upward trend of the bio-electric charge by cupping therapy, we measured MEP change before and after 600mmHg(80kPa) Negative pressure stimulation using cupping. Results : We could identify the correlation between MEP and the condition of bio-electric charge in acupoints. Also, we checked the balance or imbalance of left/right the MEP and unusual cases. Conclusions : We confirmed significance of proposed principle and meridian energy measurement system.

• Proceedings of the KIPE Conference
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• 2006.06a
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• pp.203-205
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• 2006

This paper presents a novel soft-switching PWM utility frequency AC to high frequency AC power conversion circuit incorporating boost-half-bridge inverter topology, which is more suitable and acceptable for cost effective consumer induction heating applications. The operating principle and the operation modes are presented using the switching mode and the operating voltage and current waveforms. The performances of this high-frequency inverter using the latest IGBTs are illustrated, which includes high frequency power regulation and actual efficiency characteristics based on zero voltage soft switching (ZVS) operation ranges and the power dissipation as compared with those of the previously developed high-frequency inverter. In addition, a dual mode control scheme of this high frequency inverter based on asymmetrical pulse width modulation (PWM) and pulse density modulation (PDM) control scheme is discussed in this paper in order to extend the soft switching operation ranges and to improve the power conversion efficiency at the low power settings. The power converter practical effectiveness is substantially proved based on experimental results from practical design example.

• Smart Structures and Systems
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• v.20 no.1
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• pp.53-60
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• 2017

Reinforced concrete shear wall is one of the most common structural forms for high-rise buildings, and seismic energy dissipation techniques, which are effective means to control structural vibration response, are being increasingly used in engineering. Reinforced concrete-mild steel damper stiffness-tandem energy dissipation coupling beams are a new technology being gradually adopted by more construction projects since being proposed. Research on this technology is somewhat deficient, and this paper investigates design principles and methods for two types of mild steel dampers commonly used for energy dissipation coupling beams. Based on the conception design of R.C. shear wall structure and mechanics principle, the basic design theories and analytic expressions for the related optimization parameters of dampers at elastic stage, yield stage, and limit state are derived. The outcomes provide technical support and reference for application and promotion of reinforced concrete-mild steel damper stiffness-tandem energy dissipation coupling beam in engineering practice.

• Journal of Ocean Engineering and Technology
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• v.24 no.1
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• pp.133-139
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• 2010

From the ancient times, there are waves in the ocean. And all the moving body have energy. We have a kind of hope to convert the wave energy into electric one. Finally we can find out a power generator mechanism that mainly use the principle of pulleys. We have made drawings for this and completed the wave energy converter. This wave energy converter consists of several pulleys, rope, generator, buoys and anchors. The distance between an anchor and buoy is changed according to the hight of waves. Several sets of anchors, pulleys and buoys can make the movement of rope, and the ropes wind up a converter axis. In case of 1 meter movement of the buoy, the winding distance will be amplified 2 or 3 times if we use several moving and fixed pulleys. Based on this concept, we developed 2 kind of prototypes. One is for the test in the laboratory and the other is for the field test. Through the two test, we could confirm the usability of this mechanism.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.05a
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• pp.385-392
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• 2001

Time-dependent frequency and energy of free vibration of the Spagetti problem, that is the axially moving continuum with time-varying length, are investigated. Exact expressions for the natural frequency and time-varying vibration energy are derived by dealing with traveling waves. When the string length is increased, the vibration period increases, but the free vibration energy varies as a function of both translating velocity and boundary velocity of the continuum. However, when the string undergoes retraction, the vibration energy increases with time, String tension together with non-zero instantaneous velocity at the moving boundary results in energy variation.

• Proceedings of the IEEK Conference
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• 2002.06e
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• pp.141-144
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• 2002

Acupuncture effect principle on meridians is what physical stimulation does on general physiology so that it gets into new equilibrium from the fallen function state of human body. However, it is generally accepted that western medicine has regarded the action passageway of various kinds stimulation as nerve fluids tissue or nerve-endocrine-immune system. These regard any action for all meridians as a response to the stimulation. These are not treatments for transmission of the energy. This paper compares the change of electric potential when operator's bio-energy is passed on and when is not. As a result of it, the effect of acupuncture is different when a operator's bio-energy is passed on to meridians and it isn't. Therefore, it means that the general acupuncture is more effective than the insulation one. Moreover, we could certify that there is close relation between an operator's energy transmission and acupuncture effect.

• Journal of the Korean Solar Energy Society
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• v.24 no.3
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• pp.93-100
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• 2004

This study aims to presents the applicability of economic measures for renewable energy The basic principle and method of economic analyses were investigated and total life cycle cost considering environmental costs according to $CO_2$ generation. In case study, adaptation of new small wind power system to buildings were proved to produce a profit if it is considered the environmental cost and increment of energy prices. And so the economic measures can be used not only for the investment decisions for economic analysis but also for the comparative analysis of environmental cost and economic profits.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1994.10a
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• pp.121-128
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• 1994

A layerwise theory for the dynamic response of a laminated composite plate with integrated piezoelectric actuators and sensors subjected to both mechanical and electrical loadings is proposed. The formulation is derived form the variational principle with consideration for both total potential energy of the structures and the electrical potential energy of the piezoceramics. The governing equations of the present theory account for direct and converse effects of piezoelectrics, and layerwise variation of displacement field through the thickness of a laminate.