• Journal of Power System Engineering
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• v.3 no.2
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• pp.89-97
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• 1999

In this paper the forming simulations of ellipse bulge have been researched by using $PAM-STAMP_{TM}$ to estimate the sheet metal forming and the plastic deformation characteristic of ellipse bulge. Thin elliptical diaphragms of brass, copper, aluminum, and mild steel are bulged in elliptical dies having aspect ratios of 1.33 and 2. In order to compare the simulation results with the experiment and ellipse bulge's theory derived by using Johnson and Duncan's theory, the relations of hydraulic pressure and polar height, polar thickness strain and polar height, were compared. According to this study, the results of simulation and ellipse bulge's theory derived by using Johnson and Duncan's theory, and the bursting pressure and the bursting polar height are good agreement to the experiment. So, the results of simulation by using $PAM-STAMP_{TM}$ and the ellipse bulge's theory will give engineers good information to make assessment the formability and plastic deformation characteristic of hydraulic ellipse bulge test.

• Advances in nano research
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• v.5 no.4
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• pp.313-336
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• 2017

This article investigates vibration behavior of magneto-electro-elastic functionally graded (MEE-FG) nanobeams embedded in two-parameter elastic foundation using a third-order parabolic shear deformation beam theory. Material properties of MEE-FG nanobeam are supposed to be variable throughout the thickness based on power-law model. Based on Eringen's nonlocal elasticity theory which captures the small size effects and using the Hamilton's principle, the nonlocal governing equations of motions are derived and then solved analytically. Then the influences of elastic foundation, magnetic potential, external electric voltage, nonlocal parameter, power-law index and slenderness ratio on the frequencies of the embedded MEE-FG nanobeams are studied.

• Proceedings of the KIPE Conference
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• 2009.11a
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• pp.293-295
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• 2009

In this paper, a shunt active power filter (SAPF) has been used to eliminate the harmonic distortion and to improve the power quality of three-phase grid-connected power conditioning system (PCS). The adopted control strategy in active power filter system is based on the instantaneous reactive power theory (P-Q theory). Based on the theoretical analysis, the overall system of three-phase grid-connected with non-linear load PCS has been built and modeled using PSCAD$^{(R)}$/EMTDC$^{TM}$. The simulation results are shown to verify the high effective performance of the implemented SAPF in power system and to verify the reasonableness of the system structure.

• Wind and Structures
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• v.32 no.2
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• pp.81-87
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• 2021

The aim of the current study is to compare the performance of large 2 MW and 3 MW wind turbines operating on existing onshore wind farms using Blade Element Momentum (BEM) theory and Angular Momentum (AM) theory and illustrate the performance characteristic curves of the turbines as a function of wind speed (U∞). To achieve this, the measurement data obtained from two different Wind Energy Power Plants (WEPPs) located in the Hatay region of Turkey was used. Two different horizontal-axis wind turbines with capacities of 2 MW and 3 MW were selected for evaluation and comparison. The hub-height wind speed (UD), turbine power output (P), atmospheric air temperature (Tatm) and turbine rotational speed (Ω) data were used in the evaluation of the turbine performance characteristics. Curves of turbine power output (P), axial flow induction factor (a), turbine rotational speed (Ω), turbine power coefficient (CP), blade tip speed ratio (λ), thrust force coefficient (CT) and thrust force (T) as a function of U∞ were obtained for the 2 MW and 3 MW wind turbines and these characteristic curves were compared. Results revealed that, for the same wind speed conditions, the higher-capacity wind turbine (3 MW) was operating at higher turbine power coefficient rates, while rotating at lower rotational speed ratios than the lower-capacity wind turbine (2 MW).

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.11a
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• pp.33-48
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• 2000

Limitations of the simple single degree of freedom vibration isolation theory in real applications are discussed and a theory of multi-dimensional vibration/noise isolation by power approach is introduced. Illustrations of the application to compressor of an air-conditioner are presented together with problems caused by approximations. Then possible sources of distortions in the vibration power estimation are looked into and some relevant research topics are suggested.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.28 no.5
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• pp.553-561
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• 2015

The exponential and power law functionally graded material(FGM) theory is reformulated considering the refined shear and normal deformation theory. This theory has ability to capture the both normal deformation effect and exponential and power law function in terms of the volume fraction of the constituents for material properties through the plate thickness. Navier's method has been used to solve the governing equations for all edges simply supported plates on Pasternak elastic foundation. Numerical solutions of vibration analysis of FGM plates are presented using this theory to illustrate the effects of power law index and 3-D theory of exponential and power law function on natural frequency. The relations between 3-D and 2-D higher-order shear deformation theory are discussed by numerical results. Further, effects of (i) power law index, (ii) side-to-thickness ratio, and (iii) elastic foundation parameter on nondimensional natural frequency are studied. To validate the present solutions, the reference solutions are discussed.

• Journal of the Daesoon Academy of Sciences
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• v.18
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• pp.101-122
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• 2004

When people discuss the continental cultural elements in the ancient East Asian culture, people always attach great importance to the two major cultures of Confucianism and Taoism, but offer little explanation to the significant influence of the theory of yin and yang, the important philosophical base of the two major cultures. The theory of yin and yang, existing as the theoretical source at a profounder level, possesses philosophical connotations that are always embedded into the mainstream of thought, religions and customs, displaying its unique glamour in its unique way. Its influence is more than that, however. It has exerted far-reaching influence on and is of significant importance to the development of the ancient culture of East Asia. This article aims at exploring this field of study. After the erudite scholar of The Five Classics made a voyage to the east in the early sixth century, The Book of Changes, the most important Chinese ancient classic expounding the theory of yin and yang, started to circulate among the Japanese court, via Baiji in the Korea Peninsula. As a result, the theory of yin and yang found its way to Japan. Examining the spreading channels, we learn that the theory's dissemination was largely related to the activities of Buddhist monks. Shoutoku Prince, regent of Japan at the time, was himself an enthusiastic supporter of Buddhism and was excelled in the study of The Book of Changes and the theory of yin and yang. In the Twelve Ranks System and Seventeen-article Constitution promulgated by Shoutoku Prince, the influence of the theory of yin and yang and of the theory of the five elements can be visibly discerned. This obviously proves the sublime status of the Chinese theory of yin and yang in Japan, thanks to the victory of the political clique that adored Buddhism. In the shaping course of ancient Japanese culture, the theory of yin and yang served as an important philosophical source of its development. Mythology based on Kojiki and Nihon Shoki, two earliest Japanese books that exist today, record mythological stories about the emergence of the Japanese nation. The notion about the birth of heaven and earth and the forming of Japanese Shinto, expressed in the mythological stories, not only tell us the source and historical progress of the Japanese nation but also the nation's world outlook in the transition from barbarian period to civilized period, as well as the basis for its philosophical thinking. All these were marked with profound influence of the Chinese theory of yin and yang. The theory of yin and yang, as one of the ancient Chinese academic thoughts, was accepted asa political belief when it first spread to Japan. The emergence and establishment of both the Mikado system and the centralized regime in ancient Japan drew largely on the theory of yin and yang and adopted it as an important philosophical basis to deify and aggrandize the "imperial power" so as to protect the authority of the imperial ruling and consolidate the established regime. Following the continuous strengthening and expansion of the centralized state power, the theory of yin and yang was further employed, and gradually "hidden" in Japanese culture with the passage of time, finally becoming the edge tool of ancient Japanese Mikados in exercising political power and controlling the country.

• Proceedings of the KIPE Conference
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• 2002.11a
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• pp.152-157
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• 2002

This paper describes the implementation of 3-phase 3-wire active power filter system with a instantaneous PSD for distorted and unbalanced power conditions. The positive sequence voltage of the distorted and the unbalanced power system Is calculated by the instantaneous PSD, and phase transformation matrix of the instantaneous power theory is achieved with detected positive sequence voltage. Finally, the proposed method is experimented and tested under unbalanced nonlinear load as well as unbalanced/distorted condition in power system.

• Nuclear Engineering and Technology
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• v.52 no.4
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• pp.681-688
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• 2020

The telegrapher's theory was used to develop a new formulation for the neutron noise equation. Telegrapher's equation is supposed to demonstrate a more realistic approximation for neutron transport phenomena, especially in comparison to the diffusion theory. The physics behind such equation implies that the signal propagation speed is finite, instead of the infinite as in the case of ordinary diffusion. This paper presents the theory and results of the development of a new method for calculation of the neutron noise using the telegrapher's equation as its basis. In order to investigate the differences and strengths of the new method against the diffusion based neutron noise, a comparison was done between the behaviors of two methods. The neutron noise based on SN transport considered as a precision measuring point. The Green's function technique was used to calculate the neutron noise based on telegrapher's and diffusion methods as well as the transport. The amplitude and phase of Green's function associated with the properties of the medium and frequency of the noise source were obtained and their behavior was compared to the results of the transport. It was observed, the differences in some cases might be considerable. The effective speed of propagation for the noise perturbations were evaluated accordingly, resulting in considerable deviations in some cases.

• Korean journal of communication and information
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• v.69
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• pp.30-70
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• 2015

This paper is to show the relationship between power and communication. For this purpose, speech act theory has been introduced. Power is the capacity of some persons to produce intended effects on others. And the human being tries to get intended effects by perlocutionary acts through performing illocutionary acts, both of which belong to speech acts. Generally speaking, therefore, it can be said power is exercised through speech acts. Of course, in case of exercising physical force or violence, no speech act is needed. However, even violence is not totally unrelated with communication. Moreover, power other than violence is always in need of speech acts for its exercise. Including psychic force, power in general is in a close relationship with communication by mediation of speech acts. This paper, using speech act theory, attempts to examine that what is the relationship power and communication hold, that the exercise of power is the same as performing speech acts called perlocutionary acts, that the form of power is differentiated by kinds of illocutionary acts used for its exercise, and that morality of power is different according to illocutionary acts used for its exercise.