• Smart Structures and Systems
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• v.9 no.3
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• pp.231-251
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• 2012

The stochastic optimal control for a piezoelectric spherically symmetric shell subjected to stochastic boundary perturbations is constructed, analyzed and evaluated. The stochastic optimal control problem on the boundary stress output reduction of the piezoelectric shell subjected to stochastic boundary displacement perturbations is presented. The electric potential integral as a function of displacement is obtained to convert the differential equations for the piezoelectric shell with electrical and mechanical coupling into the equation only for displacement. The displacement transformation is constructed to convert the stochastic boundary conditions into homogeneous ones, and the transformed displacement is expanded in space to convert further the partial differential equation for displacement into ordinary differential equations by using the Galerkin method. Then the stochastic optimal control problem of the piezoelectric shell in partial differential equations is transformed into that of the multi-degree-of-freedom system. The optimal control law for electric potential is determined according to the stochastic dynamical programming principle. The frequency-response function matrix, power spectral density matrix and correlation function matrix of the controlled system response are derived based on the theory of random vibration. The expressions of mean-square stress, displacement and electric potential of the controlled piezoelectric shell are finally obtained to evaluate the control effectiveness. Numerical results are given to illustrate the high relative reduction in the root-mean-square boundary stress of the piezoelectric shell subjected to stochastic boundary displacement perturbations by the optimal electric potential control.

• Fashion & Textile Research Journal
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• v.14 no.5
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• pp.701-712
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• 2012

This study examines the various expressions and immanent value of fashion and beauty style based on Craig Owens's Allegory theory. I analyzed four application elements of Borrow, Site Specificity, Accumulation of Strategy, and Hybridization in? Ladygaga's Music Videos. The results are as follows. 'Borrow' presents a kitsch style and playful Pop-art style, transformation of gender from Mini Mouse body suit, telephone headpiece, and can hair. 'Site specificity' presents the temporarity of fashion material through rebirth, aging, natural extinction from the chain over the black jump suit, crime scene tape, and skull-face makeup with masculine style. 'Accumulation of strategy' presents a futuristic chic fashion style from a layered style, retrospective fashion, repetition and duplication in Music Videos. It shows the physical beauty of an Asian warrior style in Poker Face. 'Hybridization' present Cyborg feminism and 'Will of Power' from iPOD LCD glasses and Pyro-Bra. The Pyro-Bra represents how the female body can be used as a weapon in the outfits of Lady Gaga. In addition, Immanent value is as follows. Textual interaction with high art is accomplished through a combination of contemporary social and cultural significance to understand the cultural code and to extend the value. Combined with high culture, popular music genre is accomplished through musical appreciation by a woman in fashion styling and sensual pleasures of the body as a tool to express a sublime advantage. Fashion style is accomplished by overcoming a self-transcendent body image representation. The way in which mutual coupling dismantling, destruction, and uncertainty is to re-launch the static, with a pluralistic context of Textuality.

• The Research Journal of the Costume Culture
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• v.25 no.2
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• pp.130-144
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• 2017

The purpose of this study is to apply iconology to discover the symbolic system of imaginary animals focused on four representative auspicious animals in Korean folk paintings. Study methods included literature review of folk paintings, iconological analytics books, and articles. A total of 16 folk paintings of four auspicious animals in the Joseon Dynasty were analyzed using Panofsky's iconology. The four auspicious animals were Yong(dragon), Bonghwang(the eastern version of the phoenix), Shingoo (divine turtle), and Kirin(one-horned combination of a dragon and horse). According to iconological analysis, Yong is a typical symbol of royal authority, a deity of water as an object of respect with a remarkable talent of transformation, and in iconographical interpretation, represents reverence for transcendent power. Bonhwang is the symbol of a king, sun worship, the emblem of nobility and integrity, and in iconographical interpretation, the psychic bing in the sky. Shingoo is fortune prophecy, longevity and immortality, an envoy of deity, and according to iconographical interpretation, the organic view of the world. Kirin is a divine benign creature, a symbol of talent and honor, mediator between sky and earth, and in iconographical interpretation, an expression of Confucian ideology. This study produced three results. First, the four auspicious animals projected the human hope to overcome human limitations through divine creatures with mythical abilities. Second, they reflected everyday common hopes and values of pursuing fortunes and happiness. Third, the four auspicious animals' iconology was not independent of each other; it seemed to be common to and combined with each other.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.6
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• pp.2595-2618
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• 2018

In this paper, we investigate secure communication with the presence of multiple eavesdroppers (Eves) in a two-tier downlink dense heterogeneous network, wherein there is a macrocell base station (MBS) and multiple femtocell base stations (FBSs). Each base station (BS) has multiple users. And Eves attempt to wiretap a macrocell user (MU). To keep Eves ignorant of the confidential message, we propose a physical-layer security scheme based on cross-layer cooperation to exploit interference in the considered network. Under the constraints on the quality of service (QoS) of other legitimate users and transmit power, the secrecy rate of system can be maximized through jointly optimizing the beamforming vectors of MBS and cooperative FBSs. We explore the problem of maximizing secrecy rate in both non-colluding and colluding Eves scenarios, respectively. Firstly, in non-colluding Eves scenario, we approximate the original non-convex problem into a few semi-definite programs (SDPs) by employing the semi-definite relaxation (SDR) technique and conservative convex approximation under perfect channel state information (CSI) case. Furthermore, we extend the frame to imperfect CSI case and use the Lagrangian dual theory to cope with uncertain constraints on CSI. Secondly, in colluding Eves scenario, we transform the original problem into a two-tier optimization problem equivalently. Among them, the outer layer problem is a single variable optimization problem and can be solved by one-dimensional linear search. While the inner-layer optimization problem is transformed into a convex SDP problem with SDR technique and Charnes-Cooper transformation. In the perfect CSI case of both non-colluding and colluding Eves scenarios, we prove that the relaxation of SDR is tight and analyze the complexity of proposed algorithms. Finally, simulation results validate the effectiveness and robustness of proposed scheme.

• Journal of the Korean Institute of Telematics and Electronics T
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• v.35T no.2
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• pp.86-92
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• 1998

In this paper, it is derived the system design parameters for the J-STD-018 of the PCS mobile station(MS) minimum performance using DS/CDMA analyzed the system performance due to the receiver components. The simulation shows the selectivity is -70.96dB at 1.25MHz frequency offset from the carrier frequency while the MS noise figure to satisfy J-STD-018 is 10dB and the input 3rd harmonics intercept point of the MS class I and MS class II-V is -9.5dBm and -14dBm respectively. When the interference power level at the receiver is small, the receiver has better performance as we increase the gain of LNA. However, when the interference level at the receiver is large, the receiver performance is decreased by the effect of the spurious. Thus, the effectiveness of LNA On/Off switching technique is proved as to reduce the effect of the spurious.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.6
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• pp.463-472
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• 2017

Inertial Navigation System Alignment is the process to determine direction cosine matrix which is the transformation matrix between the INS body frame and navigation frame. INS initial position value is necessary to INS attitude calculation, so that user should wait until he get such value to start the INS alignment. To remove the waiting time, we propose an alignment algorithm that immediately starts after the INS power on by using pseudo initial position input and then is completed with attitude error compensation by entering true position later. We analyse effect of INS sensor error on attitude in process of time and verify the performance and usefulness of the close-loop alignment algorithm which corrects attitude error from the change of initial position.

• Journal of Welding and Joining
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• v.34 no.1
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• pp.75-81
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• 2016

This study applied laser surface melting process using CW(Continuous wave) Yb:YAG laser and cold-work die steel SM45C and investigated microstructure and hardness. Laser beam speed, power and beam interval are fixed at 70 mm/sec, 2.8 kW and $800{\mu}m$ respectively. Depth of Hardening layer(Melting zone) was a minimum of 0.8 mm and a maximum of 1.0 mm that exceeds the limit of minimum depth 0.5 mm applying trimming die. In all weld zone, macrostructure was dendrite structure. At the dendrite boundary, Mn, Al, S and O was segregated and MnS and Al oxide existed. However, this inclusion didn't observe in the heat-affected zone (HAZ). As a result of interpreting phase transformation of binary diagram, MnS crystallizes from liquid. Also, it estimated that Al oxide forms by reacting with oxygen in the atmosphere. The hardness of the melting zone was from 650 Hv to 660 Hv regardless of the location that higher 60 Hv than the hardness of the HAZ that had maximum 600 Hv. In comparison with the size of microstructure using electron backscatter diffraction(EBSD), the size of microstructure in the melting zone was smaller than HAZ. Because it estimated that cooling rate of laser surface melting process is faster than water quenching.

• Korean journal of communication and information
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• v.52
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• pp.154-176
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• 2010

Rooted in the work of Pierre Bourdieu, the cultural intermediaries have recently developed as a focus of attention for the Anglo-saxon sociology of culture and cultural studies. This paper tries to critically examine the debate around the definition and role of cultural intermediaries. It also explores the applicability of the notion ‘cultural intermediaries’ to a changing digital mediascape. In the first part of the paper, I clarify the critical problematics inherent in the Bourdieusian conception which focuses on the function of cultural intermediaries for the ‘production of the belief’ in cultural goods. Consequently, I draw attention to the mediation and transformation process of ‘legitimate culture’ by critics in mass media as ‘new cultural intermediaries’. In the second part, I attempt to constitute a typology of cultural intermediaries, proposing the notion of ‘on-line cultural mediation’ and ‘on-line cultural intermediaries’. I also outline the characteristics of three different types (‘traditional’, ‘new' and 'on-line') of cultural intermediaries. I argue this new conception of cultural intermediaries can help to understand the complex power relations and their transmutation in various cultural fields under digital environment.

• Journal of the Korea Fashion and Costume Design Association
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• v.4 no.3
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• pp.43-54
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• 2002

Some factors had influence upon the grotesque image formation expressed in fashion: for instance, thanatos, religions, fin de siecle (end of the century), the aesthetics of ugliness, subculture group's resistance and technology development, etc. Those factors have formed a grotesque while exchanging influence each other, and have following features: First, the thanatos, which is destructive and aggressive instinct of the inner world of human being, creates frightening object and motif to form the images of grotesque. Second, from religious point of view, the church made the Devil a tool for maintenance of power: They manipulated physical body and give a damage to it to sublimate it in holy existence, so that they could feel catharsis. Third, there was fin de siecle (end of the century) to let people have negative life attitude, such as uneasiness on following century, eschatology, skepticism and nihilism, etc. Fourth, the ugliness having unpleasantness and disharmony occupies governing position when our society becomes corrupted and uneasy, and the aesthetics of ugliness discloses the inconsistency of ideal and beautiful life in the grotesque images. Fifth, subculture groups, i.e., the lower classes, homosexual and the youth's group, etc, form the grotesque images by political and ideological resistance, complaints and specific identity, etc concerning governing culture keeping traditional ethics consciousness. Sixth, recent technology development has destroyed a boundary between human being and machinery, and bio-technology development has created transplant operation, plastic operation and other human body transformation operations, and genome research, etc has raised human being's identity.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.7
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• pp.629-637
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• 2008

We report several experimental data capable of evaluating the amorphous-to-crystalline (a-c) phase transformation in $(Ag)_x(Ge_2Sb_2Te_5)_{1-x}$ (x = 0, 0.05, 0.1) thin films prepared by a thermal evaporation. The isothermal a-c structural phase changes were evaluated by XRD, and the optical transmittance was measured in the wavelength range of $800{\sim}3000$ nm using a UV-vis-IR spectrophotometer. A speed of the a-c transition was evaluated by detecting the reflection response signals using a nano-pulse scanner with 658 nm laser diode (power P = $1{\sim}17$ mW, pulse duration t = $10{\sim}460$ ns). The surface morphology and roughness of the films were imaged by AFM. It was found that the crystallization speed was so enhanced with an increase of Ag content. While the sheet resistance of c-phase $(Ag)_x(Ge_2Sb_2Te_5)_{1-x}$ was similar to that of c-phase $Ge_2Sb_2Te_5$ (i.e., $R_c{\sim}10{\Omega}/{\square}$), the sheet resistance of a-phase $(Ag)_x(Ge_2Sb_2Te_5)_{1-x}$ was found to be lager than that of a-phase $Ge_2Sb_2Te_5$, $R_a{\sim}5{\times}10^6{\Omega}{/\square}$. For example, the ratios of $R_a/R_c$ for $Ge_2Sb_2Te_5$ and $(Ag)_{0.1}(Ge_2Sb_2Te_5)_{0.9}$ were approximately $5{\times}10^5$ and $5{\times}10^6$, respectively.