• Advances in concrete construction
• /
• v.10 no.4
• /
• pp.345-355
• /
• 2020

In this paper, vibration characteristics of double-walled carbon nanotubes (CNTs) is studied based upon nonlocal elastic shell theory. The significance of small scale is being perceived by developing nonlocal Love shell model. The wave propagation approach has been utilized to frame the governing equations as eigen value system. The influence of nonlocal parameter subjected to diverse end supports has been overtly analyzed. An appropriate selection of material properties and nonlocal parameter has been considered. The influence of changing mechanical parameter Poisson's ratio has been investigated in detail. The dominance of boundary conditions via nonlocal parameter is shown graphically. The results generated furnish the evidence regarding applicability of nonlocal shell model and also verified by earlier published literature.

• Structural Engineering and Mechanics
• /
• v.63 no.4
• /
• pp.439-446
• /
• 2017

This work proposes an original single variable shear deformation theory to study the buckling analysis of thick isotropic plates subjected to uniaxial and biaxial in-plane loads. This theory is built upon the classical plate theory (CPT) including the exponential function in terms of thickness coordinate to represent shear deformation effect and it involves only one governing differential equation. Efficacy of the present theory is confirmed through illustrative numerical examples. The obtained results are compared with those of other higher-order shear deformation plate theory results.

• Steel and Composite Structures
• /
• v.27 no.5
• /
• pp.599-611
• /
• 2018

In this article a four unknown quasi-3D shear deformation theory for the bending analysis of functionally graded (FG) plates is developed. The advantage of this theory is that, in addition to introducing the thickness stretching impact (${\varepsilon}_z{\neq}0$), the displacement field is modeled with only four variables, which is even less than the first order shear deformation theory (FSDT). The principle of virtual work is utilized to determine the governing equations. The obtained numerical results from the proposed theory are compared with the CPT, FSDT, and other quasi-3D HSDTs.

• Steel and Composite Structures
• /
• v.24 no.5
• /
• pp.569-578
• /
• 2017

In this research work, a simple and accurate hyperbolic plate theory for the buckling analysis of functionally graded sandwich plates is presented. The main interest of this theory is that, in addition to incorporating the thickness stretching effect (${\varepsilon}_z{\not=}0$), the displacement field is composed only of 5 unknowns as the first order shear deformation theory (FSDT), instead of 6 like in the well-known "higher order shear and normal deformation theories". Thus, the number of unknowns and governing equations for the present theory is reduced, significantly facilitating engineering analysis. Governing equations are obtained by employing the principle of minimum total potential energy. Comparison studies are performed to verify the validity of present results. A numerical investigation has been conducted considering and neglecting the thickness stretching effects on the buckling of sandwich plates with functionally graded skins. It can be concluded that the present theory is not only accurate but also simple in predicting the buckling response of sandwich plates with functionally graded skins.

• Journal of Korean Theatre Studies Association
• /
• no.40
• /
• pp.307-344
• /
• 2010

Cultural Studies built on the critical mind of New Left exposes the relationship between culture and power, and investigates how this relationship develops the cultural convention. It has achieved the new perspective that could make us to think culture and art in terms of political correctness. However, the critical voices against the theoretical premises of Cultural Studies have been increased as its heyday in 1980s was nearly over. For instance, Terry Eagleton, a former Marxist literary critic, declared in 2003 that the golden age of cultural theory is long past. This essay, therefore, intends to show the weak foundations on which the approaches of cultural studies to theatre rest and to clarify the general problem of their introduction to theatre studies. The approach of cultural studies to theatre takes the form of 'top-down inquiry' as it applies a theory to a particular play or historical period. In other word, from the theory the writer moves to the particular case. The result is not an inquiry but rather a demonstration. This circularity can destroy the point of serious intellectual investigation as the theory dictates answers. The goal-oriented narrow viewpoint as a logical consequence of 'top-down inquiry' makes the researcher to favor the plays or the parts of a play that are proper to test a theory. As a result it loses the fair judgment on the artistic value of a play, and brings about the misinterpretation. The interpreter-oriented reading is the other defect of cultural studies as it disregards the inherent meaning of the text, distorting a play. The approach of cultural studies also consists of a conventionality as it arrives at a stereotyped interpretation by using certain conventions of reasoning and rhetoric. The cultural theories are fundamentally the 'outside theories' that seek to explain not theatre but the very broad features of society and politics. Consequently their application to theatre risks the destructive criticism, disregarding the inherent experience of theatre. Most of, if not all, cultural theories, furthermore, are proven to be lack of empirical basis. The alternative method to them is a 'cognitive science' that proves scientifically our mind being influenced by bodily experience. The application of cultural materialism to Shakespeare's is one of the cases that reveal the limits of cultural studies. Jonathan Dollimore and Water Cohen provide a kind of 'canonical study' in this application that is imitated by the succeeding researchers. As a result the interpretation of has been flooded with repetitive critical remarks, revealing the problem of 'top-down inquiry' and conventional reasoning. Cultural Studies is antipodal to theatre in some respect. It is interested chiefly in the social and political reality while theatre aims to create the fiction world. The theatre studies, therefore, may have to risk the danger of destroying its own base when it adopts cultural studies uncritically. The different stance between theatre and cultural theories also occurs from the opposition of humanism vs. antihumanism. We have to introduce cultural theories selectively and properly not to destroy the inherent experience and domain of theatre.

• Journal of Korean Medical classics
• /
• v.10
• /
• pp.591-617
• /
• 1997

In the field of the theory about constitution(體質), the theory of 'Yun Qi(運氣) has close relations hip with the formation of theory of constitution. It is seen in the chapter 'Osangjungdae-ron("五常政大論")' that the theory of influenced the theory of constitution and talent by the 'Concept of Evaporation(氣化)'. In the chapter 'Yin-Yang twenty five men types' of the book the 'Ling Shu("靈樞")' the twenty five constitution types by the theory of 'Yan Qi is stated. And in the book 'Nei Ching("內經")' the constitution types of five elements' motion is described. In the theory of the 'five elements' motion and six kinds of natural factors' had such a problem that the individuals having the same born year and Qi had the same prescriptions irrespective of each other's constitution. So for the resolution of this problem the constitution theory of 'Yun Qi' had been formed by the mediation of the 'MyengRiHak(命理學)' and the theory of 'Yun Qi' in the book the 'OUnYukKiHanYeHakBoGam("五運六氣韓醫學寶鑑")'. But following problems should be resolved in chrono-inedieine. Those are the difference of men who has born in some year-day-time, each 'Yun Qi's brea king point, local time, summer time, living circumstances, twins, the concept of 'Zhung Won(中元)', etc.

• Smart Structures and Systems
• /
• v.19 no.6
• /
• pp.601-614
• /
• 2017

In this work, free vibration analysis of size-dependent functionally graded (FG) nanoplates resting on two-parameter elastic foundation is investigated based on a novel nonlocal refined trigonometric shear deformation theory for the first time. This theory includes undetermined integral variables and contains only four unknowns, with is even less than the conventional first shear deformation theory (FSDT). Mori-Tanaka model is employed to describe gradually distribution of material properties along the plate thickness. Size-dependency of nanosize FG plate is captured via the nonlocal elasticity theory of Eringen. By implementing Hamilton's principle the equations of motion are obtained for a refined four-variable shear deformation plate theory and then solved analytically. To show the accuracy of the present theory, our research results in specific cases are compared with available results in the literature and a good agreement will be demonstrated. Finally, the influence of various parameters such as nonlocal parameter, power law indexes, elastic foundation parameters, aspect ratio, and the thickness ratio on the non-dimensional frequency of rectangular FG nanoscale plates are presented and discussed in detail.

• Journal of Electrical Engineering and Technology
• /
• v.13 no.3
• /
• pp.1110-1122
• /
• 2018

This paper proposes an alternative method to evaluate the effect of wind power to the power system stability with small disturbance. Alternatively, available techniques for stability analysis of a power system based on deterministic methods are less accurate for high penetration of wind power. Numerical simulations of random behaviors are computationally expensive. A stochastic stability index (SSI) is proposed for the power system stability evaluation based on the theory of stochastic stability and energy function, specifically the stochastic derivative of the relative well-defined energy function and the critical energy. The SSI is implemented on the modified nine-bus system including wind turbines under different conditions. A doubly-fed induction generator (DFIG) wind turbine is characterized and modeled using measured wind data from several sites in Thailand. Each of the obtained wind power data is analyzed. The wind power effect is modeled considering the aggregated effect of wind turbines. With the proposed method, the system behavior is properly predicted and the stability is quantitatively evaluated with less computational effort compared with conventional numerical simulation methods.

• Sijohaknonchong
• /
• v.21
• /
• pp.207-239
• /
• 2004

Jungchull(정철) was a very famous poet of Kasa(가사), Sijo(시조) and Hansi(한시) during the middle period of the Chosun kingdom. He has been studied by modern scholars mainly as a poet of Kasa(가사). These days, however, his Sijos are being studied as an important literary achievement. The purpose of this study is to analyze the pursuit of reality and elegance expressed in Jungchull's Sijo in order to understand his Sijos more deeply. In the process of this discussion, I will take a look at some of his Kasa(가사), Hansi(한시) and biography also, and I will compare his Sijo(시조) with that of his teacher's, friend's and senior's. Jungchull considered it important to become an official in the royal court because he was a Confucian scholar who believed in jugi-theory (주기론), in which all realistic phenomena is evaluated(Confucianism is very realistic in essence), and he had a happy life in the royal household until he was ten years old. I found that characteristics of his "realistic pursuit" are represented in his Sijo by two situations: the one is when he is apart from the King, and the other when he is together with the King. In all situations, though, he pursued an official position in the royal court. When he was apart from the king, his absolute resolution to follow the King was expressed in his not being able to sleep. In his sijo, he asks the wild duck to inform him of the King's welfare. He tries to flap his wings, to be the water or the moon in order to reach the royal household where the King was living. When he recognizes it's impossible, he expresses his perfect loyalty to the King in his Sijo by using literary paradox. According to this, he describes himself as not an able scholar, but also not a flattering scholar. In his sijo, he reminisces about working for the King in the royal household, when he had a good relationship with the King. But when he was an official in the province in a good relationship with the King, he expressed his intention of coming back to the royal household in order to be with the King again. From this we can ascertain that his pursuit of reality means to occupy an official position in the royal household, to serve the King and to have political power among of the officials. His elegance, expressed in his sijo, is deeply related to his absolute political pursuit of the King. He describes two kinds of elegance: nature related elegance and drinking alcohol related elegance. Two kinds of nature related elegance were delineated in his sijo, depending upon his political situation. When he had a good relationship with the King, occupying an official position, he delineated his gladness and free-heart in harmonizing with nature. But when he lost his official position. he expressed his purity using nature, and exclusion from nature. These kinds of nature related elegance were different from that of the usual Confucian scholar, for example, contemporaries Lee Hwang Next, two kinds of drinking alcohol related elegance were delineated in his sijo depending upon his political situation. More often he depicted excitement and composure of mind in his sijo by drinking alcohol in good situations than in efforts to overcome his agony in bad situations. The tradition of overcoming one's agony by drinking alcohol in bad situation was discovered by this writer in Jungchull's teacher's, and also his junior's sijo. Lastly in my next research paper future, I will look at the reason why certain various themes are represented in Jungchull's sijo, and what their the relationships are, to understand his literary works as a whole.

• Smart Structures and Systems
• /
• v.10 no.2
• /
• pp.111-130
• /
• 2012

Satellites with flexible lightweight solar panels are sensitive to vibration that is caused by internal actuators such as reaction or momentum wheels which are used to control the attitude of the satellite. Any infinitesimal amount of unbalance in the reaction wheels rotors will impose a harmonic excitation which may interact with the solar panels structure. Therefore, quenching the solar panel's vibration is of a practical importance. In the present work, the panels are modeled as laminated composite beam using first-order shear deformation laminated plate theory which accounts for rotational inertia as well as shear deformation effects. The vibration suppression is achieved by bonding patches of piezoelectric material with suitable dimensions at selected locations along the panel. These patches are actuated by driving control voltages. The governing equations for the system are formulated and the dynamic Green's functions are used to present an exact yet simple solution for the problem. A guide lines is proposed for determining the values of the driving voltage in order to suppress the induced vibration.