• 한국컴퓨터그래픽스학회논문지
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• 제23권5호
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• pp.39-49
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• 2017

본 연구는 HMD 사용자와 Non-HMD 사용자가 같은 공간에서 함께 행동하면서 다양한 경험과 높은 현존감을 이끌어낼 수 있는 비대칭 가상현실(asymmetric VR) 콘텐츠의 핵심 요인과 활용 방안을 제안한다. 제안하는 asymmetric VR 콘텐츠의 핵심은 사용자들이 HMD 착용 유무에 상관없이 사용자가 콘텐츠에 참여하는 범위, 환경을 폭넓게 반영하여 모두가 가상현실에 몰입하고, 새로운 경험을 이끌어내는 것이다. 이를 위해 본 연구는 asymmetric VR 콘텐츠 제작에 필요한 핵심 요인으로 HMD 사용자와 Non-HMD 사용자의 역할관계, 사용자들에게 제시되는 시점 그리고 사용자들 간의 대화를 통한 의사소통 구조를 정의하였다. 이를 기반으로 보조형 asymmetric VR 콘텐츠와 협력형 asymmetric VR 콘텐츠를 직접 제작하는 과정을 통해 핵심 요인을 검증하였다. 마지막으로 제안한 asymmetric VR 콘텐츠에서의 현존감, 경험을 검증하고 활용 방안을 분석하기 위하여 참가자들을 대상으로 한 설문 실험을 진행하였다. 설문 결과 asymmetric VR 콘텐츠의 목적과 이를 체험하는 사용자들간의 핵심 요인들을 명확히 구분하고, 정의한다면 모든 사용자가 만족하는 현존감과 함께 콘텐츠가 제시하는 독립적인 경험을 제공받을 수 있음을 확인하였다.

• 한국기계가공학회지
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• 제10권2호
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• pp.124-129
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• 2011

The thick plate produced by rolling process is used as the basic members of a ship structure. In this paper, we present a setup model to control the asymmetric factors causing plate bending in the upper or lower direction during rolling. A series of finite element analysis are conducted to predict the relationship between various asymmetric factors and plate bending. The setup model is developed by regressing the relationship to the linear equations with several non-dimensional parameters. The setup model is verified by a pilot rolling test and applied to actual rolling conditions. Results show that the model is substantial to predict the asymmetric deformation in the plate rolling process.

• 대한기계학회논문집A
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• 제35권11호
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• pp.1437-1443
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• 2011

선박 건조를 위한 기본 자재인 후판은 압연공정을 통해 생산된다. 본 논문에서는 후판압연 중에 발생하는 폭방향 휨을 일으키는 비대칭 요인들을 제어할 수 있는 설정모델을 제시한다. 일련의 삼차원 유한요소해석을 통해서 휨과 비대칭 요인 사이의 관계를 예측한다. 그 관계를 무차원 변수로 이루어진 선형 방정식으로 수식화 시킴으로써 설정모델을 도출한다. 소재 폭방향으로 두께 편차와 온도차이가 있는 경우에 대해서 파이롯트 압연 시험으로 통해서 설정모델의 정도를 검증한다. 본 모델에 의해 예측된 휨 곡률이 각각의 비대칭 요인들에 의해 측정된 휨 곡률과 상당히 일치하는 결과를 보여 주었다.

• Journal of Power Electronics
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• 제17권6호
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• pp.1500-1511
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• 2017

The purpose of this paper is to study a high-performance control scheme for neutral-point-clamping three-level (NPC-3L) inverter fed dual three-phase permanent magnet synchronous motor (PMSM) drives by considering some asymmetric factors such as the non-identical parameters in phase windings. To implement this, the system model is analyzed for dual three-phase PMSM drives with asymmetric factors based on the vector space decomposition (VSD) principle. Based on the equivalent circuits, PI controllers with feedforward compensation are used in the d-q subspace for regulating torque, where the cut-off frequency of the PI controllers are set at the twice the fundamental frequency for compensating both the additional DC component and the second order component caused by asymmetry. Meanwhile, proportional resonant (PR) controllers are proposed in the x-y subspace for suppressing the possible unbalanced currents in the phase windings. A dual three-phase space vector modulation (DT-SVM) is designed for the drive, and the balancing factor is designed based on the numerical fitting surface for balancing the DC link capacitor voltages. Experimental results are given to demonstrate the validity of the theoretical analysis and the proposed control scheme.

• 융합보안논문지
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• 제16권6_1호
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• pp.25-32
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• 2016

비대칭전은 상대방이 효과적으로 대응할 수 없도록 상대방과 다른 성격 및 기능을 가진 수단과 방법으로 수행하는 작전이며 '이질성'과 '우월성'을 원칙으로 한다. 여기서 '이질성'이라 함은 적이 보유하고 있지 않거나 개발하지 못한 무기체계를 운용하여 적의 취약분야를 공격하거나 적의 능력을 파괴하는 것이며, '우월성'은 적보다 양적 질적 측면에서 압도하는 능력으로 대응하는 것이다. 비대칭 전략의 유형은 복잡하기 때문에 다양한 비대칭 전략의 유형분류가 가능하다. 따라서 비대칭전에 대한 여러 측면에서의 이해가 요구된다. 비대칭전의 관점에서 본다면, 고대전투에서 현대전에 이르기까지 혁신적인 방법과 전략 전술로 적을 격멸한 사례들은 비대칭전의 사례로 볼 수 있다. 전투에서 승리한 핵심요인에는 비대칭 전략 및 수단의 차별적 우월성이 반드시 존재했고 앞으로도 이러한 현상은 지속될 것이다. 한 때 창출된 비대칭은 시간이 경과함에 따라 상대편이 모방적으로 적응하여 비대칭이 소멸된다. 현대전에서 전략적 전술적 비대칭의 우위를 확보하려면 새로운 비대칭 전에 대하여 연구하고 상대방의 전략과 전술에 대응하는 방책개발을 계속해야 한다.

• 한국전산유체공학회지
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• 제13권2호
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• pp.8-13
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• 2008

A supersonic viscous flow over a five-degree half-angle cone is studied computationally with three-dimensional Navier-Stokes equations. Steady asymmetric solutions show that the asymmetric flow separation is caused by convective instability. The effects of angle of attacks, Reynolds numbers, and Mach numbers have been investigated and it is found that those factors affect the generation of the side force. The side force has the maximum value at ${\alpha}=22^{\circ}$, while over ${\alpha}=22^{\circ}$, asymmetric vortex becomes transient, which results in the unsteady shedding. At the angle of attack of 22 degrees, the side force increases with Reynolds number and decreases with Mach number. The increase of the side force stops over the critical Reynolds number for the present configuration.

• The Journal of Asian Finance, Economics and Business
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• 제8권3호
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• pp.99-110
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• 2021

This study aims to examine empirically the industry and economic fundamental factors that affect the stock prices of the leading palm oil company in Indonesia. The dynamics of stock price are analyzed using the autoregressive distribution lag (ARDL) model both for symmetric and asymmetric effects. The data used in this study are monthly data for the period from 2008:01 to 2020:03. In the long run, the company stock price moves in line with the competitor company stock price at the current time. The palm oil price has a positive effect on the stock price. Meanwhile, inflation negatively affects the stock price in the short run. The estimated equilibrium correction coefficient indicates a reasonably quick correction of the distortion of the stock price equilibrium in monthly dynamics. However, fundamental factors have asymmetric effects, especially the response of stock price when these factors decrease rather than increase in the short run. Stock prices that are responsive to declines in fundamental performance should be of particular concern to both investors and management in their strategic decision making. The results of this study will contribute to the enrichment of literature related to stock prices from the viewpoint of economic analysis on firm-level data.

• Communications for Statistical Applications and Methods
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• 제13권3호
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• pp.777-786
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• 2006

Two factorial designs with quantitative factors are called geometrically equivalent if the design matrix of one can be transformed into the design matrix of the other by row and column permutations, and reversal of symbol order in one or more columns. Clark and Dean (2001) gave a sufficient and necessary condition (which we call the 'gCD condition') for two symmetric factorial designs with quantitative factors to be geometrically equivalent. This condition is based on the absolute value of the Euclidean(or Hamming) distance between pairs of design points. In this paper we extend the gCD condition to asymmetric designs. In addition, a modified algorithm is applied for checking the equivalence of two designs.

• Structural Engineering and Mechanics
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• 제29권5호
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• pp.505-530
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• 2008

This paper proposes the application of active multiple tuned mass dampers (AMTMD) for translational and torsional response control of a simplified two-degree-of-freedom (2DOF) structure, able to represent the dynamic characteristics of general asymmetric structures, under the ground acceleration. This 2DOF structure is a generalized 2DOF system of an asymmetric structure with predominant translational and torsional responses under earthquake excitations using the mode reduced-order method. Depending on the ratio of the torsional to the translational eigenfrequency, i.e. the torsional to translational frequency ratio (TTFR), of asymmetric structures, the following three cases can be distinguished: (1) torsionally flexible structures (TTFR < 1.0), (2) torsionally intermediate stiff structures (TTFR = 1.0), and (3) torsionally stiff structures (TTFR > 1.0). The even distribution of the AMTMD within the whole width and half width of the asymmetric structure, thus leading to three cases of installing the AMTMD (referred to as the AMTMD of case 1, AMTMD of case 2, AMTMD of case 3, respectively), is taken into account. In the present study, the criterion for searching the optimum parameters of the AMTMD is defined as the minimization of the minimum values of the maximum translational and torsional displacement dynamic magnification factors (DMF) of an asymmetric structure with the AMTMD. The criterion used for assessing the effectiveness of the AMTMD is selected as the ratio of the minimization of the minimum values of the maximum translational and torsional displacement DMF of the asymmetric structure with the AMTMD to the maximum translational and torsional displacement DMF of the asymmetric structure without the AMTMD. By resorting to these two criteria, a careful examination of the effects of the normalized eccentricity ratio (NER) on the effectiveness and robustness of the AMTMD are carried out in the mitigation of both the translational and torsional responses of the asymmetric structure. Likewise, the effectiveness of a single ATMD with the optimum positions is presented and compared with that of the AMTMD.

• Molecules and Cells
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• 제39권7호
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• pp.524-529
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• 2016

Controlling the production of diverse cell/tissue types is essential for the development of multicellular organisms such as animals and plants. The Arabidopsis thaliana root, which contains distinct cells/tissues along longitudinal and radial axes, has served as an elegant model to investigate how genetic programs and environmental signals interact to produce different cell/tissue types. In the root, a series of asymmetric cell divisions (ACDs) give rise to three ground tissue layers at maturity (endodermis, middle cortex, and cortex). Because the middle cortex is formed by a periclinal (parallel to the axis) ACD of the endodermis around 7 to 14 days post-germination, middle cortex formation is used as a parameter to assess maturation of the root ground tissue. Molecular, genetic, and physiological studies have revealed that the control of the timing and extent of middle cortex formation during root maturation relies on the interaction of plant hormones and transcription factors. In particular, abscisic acid and gibberellin act synergistically to regulate the timing and extent of middle cortex formation, unlike their typical antagonism. The SHORT-ROOT, SCARECROW, SCARECROW-LIKE 3, and DELLA transcription factors, all of which belong to the plant-specific GRAS family, play key roles in the regulation of middle cortex formation. Recently, two additional transcription factors, SEUSS and GA- AND ABA-RESPONSIVE ZINC FINGER, have also been characterized during ground tissue maturation. In this review, we provide a detailed account of the regulatory networks that control the timing and extent of middle cortex formation during post-embryonic root development.