• The Journal of Korean Institute of Communications and Information Sciences
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• v.15 no.2
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• pp.166-175
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• 1990

The conventional FIR filters can be very expensive to implement due to the complexity of multibit multipliers. This paper presents an new type of multiplierless structure which is particularly suited to the hardware implementation of small, low cost, low power, high speed digital filters. The filter structures consisting of a transversal filter with tap coefficiented to the combination of two elements of the set {0, $\pm$$2^n$;n = integer} and cascaded with a integrator are proposed. Performance has been tested via simulation on a digital computer, and the results show that the response characteristics of presented filters are as equally good as those of conventional finitewordlength filters.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.41 no.8
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• pp.914-921
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• 1992

In this paper, we introduce a Walsh network and an LMS algorithm, and show how these can be realized as an adaptive equalizer. The Walsh network is built from a set of Walsh and Block pulse functions. In the LMS algorithm, the convergence factor is an important design parameter because it governs stability and convergence speed, which depend on the proper choice of the convergence facotr. The conventional adaptation techniques use a fixed time constant convergence factor by the method of trial and error. In this paper, we propose an optimal method in the choice of the convergence factor. The proposed algorithm depends on the received signal and the output of the Walsh network in real time.

• Advances in nano research
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• v.6 no.3
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• pp.219-242
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• 2018

In this study, static bending of an edge cracked cantilever nanobeam composed of functionally graded material (FGM) subjected to transversal point load at the free end of the beam is investigated based on modified couple stress theory. Material properties of the beam change in the height direction according to exponential distributions. The cracked nanobeam is modelled using a proper modification of the classical cracked-beam theory consisting of two sub-nanobeams connected through a massless elastic rotational spring. The inclusion of an additional material parameter enables the new beam model to capture the size effect. The new non-classical beam model reduces to the classical beam model when the length scale parameter is set to zero. The considered problem is investigated within the Euler-Bernoulli beam theory by using finite element method. In order to establish the accuracy of the present formulation and results, the deflections are obtained, and compared with the published results available in the literature. Good agreement is observed. In the numerical study, the static deflections of the edge cracked FGM nanobeams are calculated and discussed for different crack positions, different lengths of the beam, different length scale parameter, different crack depths, and different material distributions. Also, the difference between the classical beam theory and modified couple stress theory is investigated for static bending of edge cracked FGM nanobeams. It is believed that the tabulated results will be a reference with which other researchers can compare their results.

• International Journal of Fluid Machinery and Systems
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• v.2 no.4
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• pp.363-374
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• 2009

The 2D flow around 13 similar stay-vane profiles with different trailing edge geometries is investigated to determinate the main characteristics of the excitation forces for each one of them and their respective dynamic behaviors when modeled as a free-oscillating system. The main goal is avoid problems with cracks of hydraulic turbines components. A stay vane profile with a history of cracks was selected as the basis for this work. The commercial finite-volume code $FLUENT^{(R)}$ was employed in the simulations of the stationary profiles and, then, modified to take into account the transversal motion of elastically mounted profiles with equivalent structural stiffness and damping. The k-$\omega$ SST turbulence model is employed in all simulations and a deforming mesh technique used for models with profile motion. The static-model simulations were carried out for each one of the 13 geometries using a constant far field flow velocity value in order to determine the lift force oscillating frequency and amplitude as a function of the geometry. The free-oscillating stay-vane simulations were run with a low mass-damping parameter ($m^*{\xi}=0.0072$) and a single mean flow velocity value (5m/s). The structural bending stiffness of the stay-vane is defined by the Reduced Velocity parameter (Vr). The dynamic analyses were divided into two sets. The first set of simulations was carried out only for one profile with $2{\leq}Vr{\leq}12$. The second set of simulations focused on determining the behavior of each one of the 13 profiles in resonance.

• The Journal of Dong Guk Oriental Medicine
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• v.4
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• pp.189-209
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• 1995

The purpose of this study is to understand a term of 'Jangbu theory 臟腑論' in 'Dong-Eui-Su-Se-Bo-Won 東醫壽世保元'. The conclusion would be summerized as follows. 1. 'Jangbu theory 臟腑論' of 'Sa-Sang medicine 四象醫學' is based on 'Sa-Sang structure 四象構造'. 2. 'Mind 心' of 'Sa-Sang medicine 四象醫學' is recognised as the Lord of body. 3. 'four-Jang 四臟' and 'four-Bu 四腑' constitute 'Sa-Sang structure 四象構造' which is based on the deviation of 'vital energy 氣', and 'four-Jang 四臟' plays a loading role. 4. 'Sacho 四焦' explains the whole function of human body including one's heart's desire, physical constitution and the visceral physiology. 5. 'ear-eye-nose-mouth 耳目口鼻' is connected with 'the profound secrets of nature 天機' and also has a close relation with creation of 'spirit-vital energy-blood-essence 神氣血精' and spiritual fuction. 6. 'SaHae theory 四海論' of 'Dong Mu 東武' is philosophical concept set on the basis of 'nature 天性' and 'life 人命'. 7. 'spirit-vital energy-blood-essence 神機血精' doesn't have the relation of mutual transformation. It's creation and consumption lies on 'the power of ear-eye-nose-mouth 耳目口鼻之力'. 8. 'Sa-Sang medicine 四象醫學' expands its theory centering on the deviation of 'vital energy 氣' and the transversal circulation of 'SaHae 四海' According to the above result, 'Jangbu theory 臟腑論' in 'Dong-Eui-Su-Se-Bo-Won 東醫壽世保元' should be understood on the basis of 'Sacho 四焦' and 'SaHae 四海' according to 'Sa-Sang structure 四象構造', accompanying philosophical thinking focused on human and society, the centural concept of 'Jangbu theory 臟腑論' could be said as 'Mind 心' to be the Lord of body.