• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1996.11a
• /
• pp.799-805
• /
• 1996

In many cases, the magnetic farce model is linearized at the origin in designing the controller of a magnetic bearing system. However. this linear assumption is violated by the unmodeled nonlinear effect such as sensor dislocation and backup bearing dislocation. Therefore, a direct probe into the nonlinear magnetic force model in an active magnetic bearing system is necessary. To analyze the nonlinear magnetic force model of a magnetic bearing system, phase plot analysis which is to plot the numerical solution of the nonlinear equation in several initial points in the interested region is applied. Phase plot analysis is used to observe a nonlinear dynamic system qualitatively (not quantitatively). With this method, we can get much useful information of the nonlinear system. Among this information, a bifurcation graph that represents stability and locations of fixed points is essential. From the bifurcation graph, a stability criterion of magnetic bearing system is derived.

• Journal of Fashion Business
• /
• v.8 no.2
• /
• pp.116-125
• /
• 2004

In the history of western costume, women's hairstyle and headdress have been fluently studied but men's headgear has not. To study and manufacture headgear designs and details, which indicate varieties in forms and ornaments, can be utilized for the fashion currently in vogue. Purpose: the purpose of the study is to investigate one of the headgear, the hat in terms of shift in design and manufacturing method, and to study through manufacturing in order to do a literature review by era and to provide information as the source in new design. Study method and scope: Like previously manufactured and presented bonnet of women's headdress or headgear, the hat in the study was manufactured on the basis of literature review and portrait analysis. Target era is from the late 16th century to the early 17th century when the hat was used. The hat to be manufactured was selected by investigating the details such as hair style and hat features using literature. The pattern of the selected hat was analyzed, and velvet, silk, and wool were used as the materials as in the literature. Ornaments used similar things as in the photos.

• Structural Engineering and Mechanics
• /
• v.39 no.4
• /
• pp.465-498
• /
• 2011

Concrete structures are generally cracked in flexural tension at working loads. Concrete beams with asymmetric section details and crack patterns exhibit different flexural rigidity depending upon the sense of the applied flexural moment. In this paper, three different models, having the same natural period, of such SDOF bilinear dynamical systems have been proposed. The Model-I and Model-II have constant damping coefficient, but the latter is characterized by two stiffness coefficients depending upon the sense of vibration amplitude. The Model-III, additionally, has two damping coefficients as well. In this paper, the dynamical response of Model-III to sinusoidal loading has been investigated and compared with that of Model-II studied earlier. It has been found that Model-III exhibits regular and irregular sub-harmonics, jump phenomena and strong sensitivity to initial conditions, forcing frequency, system period as well as the sense of peak sinusoidal force. The constant sustained load has been found to affect the natural period of the dynamical system. The predictions of Model-I have been compared with those of the approximate linear model adopted in present practice. The behaviour exhibited by different models of the SDOF cracked elastic concrete structures under working loads and the theoretical and practical implications of the approach followed have been critically evaluated.

• Journal of Digital Convergence
• /
• v.10 no.11
• /
• pp.595-601
• /
• 2012

Narrative art is primarily narrative fiction realistic possibility for human figures into the contents of the work to build the core structure of the narrative, and the most important factor. Constitute the narrative structure of the story, while leading configuration is the subject of the act. Portrait of the artist's work presented in this perspective is the default attitude that gives the order to the drama itself, because it is the drama of aesthetic structure will eventually work through the people in the know. Mixture of aesthetic pleasure and aesthetic understanding of the regular drama is when you think that consciousness is through characters in his works is a shortcut to identify the writers think about the narrative structure.

• International Journal of Contents
• /
• v.11 no.2
• /
• pp.20-30
• /
• 2015

We propose a new method that specifies objective image quality factors by evaluating an image quality measurement model using random images. In other words, No-Reference variables are used to evaluate the quality of an original image without using any reference for comparison. 1000 portrait images were collected from a web gallery with votes constituting over 30 recommendation values. The bottom-up data collecting process was used to calculate the following image quality factors: total range, average, standard deviation, normalized distribution, z-score, preference percentage. A final grade is awarded out of 100 points, and this method ranks and grades the final estimated image quality preference in terms of total image quality factors. The results of the proposed image quality evaluation model consist of the specific dynamic range, skin tone R, G, B, L, A, B, and RSC contrast. We can present the total for the expected preference points as the average of the objective image qualities. Our proposed image quality evaluation model can measure the preferences for an actual image using a statistical analysis. The results indicate that this is a practical image quality measurement model that can extract a subject's preferred image quality.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.9 no.6
• /
• pp.711-717
• /
• 2014

Happiness has been studied in sociology and psychology as a matter of grave concern. In this paper the happiness model that a new second -order systems can be organized equivalently with a Spring-Damper-Mass are proposed. This model is organized a 2-dimensional model of identically type with Duffing equation. We added a nonlinear term to Duffing equation and also applied Gaussian white noise and period sine wave as external stimulus that is able to cause of happiness. Then we confirm that there are random motion, periodic motion and chaotic motion according to parameter variation in the new happiness model.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.24 no.6
• /
• pp.615-621
• /
• 2014

The Addiction problems have been became a social problem; the social efforts continue to solve these problems. One of those efforts, we need to establish a mathematical modeling for an addictive model to perform analysis of behavior by using this modeling. We need to process the research that can be judged before and after addictive status with result of the behavior analysis. We have to process an observation of transition from before to after addictive status. According to those necessary, this paper proposed the physical exercise model that is composed by novel second order system, which consisted of Spring-Damper-Mass system with equivalence in order to evolve an addictive equation for physical exercise. This paper also is analyzed by the behaviors for those the addictive equation of physical exercise.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.6 no.5
• /
• pp.709-716
• /
• 2011

Recently, there are many difficult for maintenance in the power in established sensor networks. In order to solve this problems, the power development has been interested using vibration in MEMS that insert the MEMS oscillator. In this paper, we propose the MEMS system with Duffing equation to generate vibration signal that can be use power signal in MEMS and confirm and verify the chaotic behaviors in vibration signal of MEMS by computer simulation. As a verification methods, we confirm the existence of period motion and chaotic motion by parameter variation through the time series, phase portrait, power spectrum and poincare map.

• Journal of Institute of Control, Robotics and Systems
• /
• v.6 no.1
• /
• pp.57-65
• /
• 2000

In this paper, a model reference adaptive control for the atomic force microscope (AFM) of tapping mode is investigated. The dynamics between the AFM system and al sample is mathematically modeled as a second order spring-mass-damper system with oscillatory inputs. The attractive and repulsive forces between the tip of the AFM system and the sample are derived using the Lennard-Jones potential energy. By non-dimensionalizing the displacement of the tip and the input frequency, the chaotic behavior near a resonance frequency is better depicted through the non-dimensionalized equations. Four nonlinear analysis techniques, a phase portrait, sensitive dependence on initial conditions, a power spectral density function, and a Pomcare map are investigated. Because the equations of motion derived in this paper involve unknown parameter values such as the damping effect of the air and the interaction constants between materials, the standard model reference adaptive control is adopted. Two control objectives, the prevention of chaos and the tracking of reference signal, are pursued. Simulation results are included.

• Journal of architectural history
• /
• v.23 no.2
• /
• pp.81-90
• /
• 2014

This study aims to comprehend architectural peculiarity of the hermitage as the one of Buddhist architectural type in Korea. Although it has not defined properly, it has been demanded the architectural respondence according to the environment of times since the introduction from other countries. Gimryong-sa temple, founded in 1635, and the hermitages are the most appropriate objects for analysis because there are many documents still remained. It is possible to find out that there are some architectural peculiarity after review of the document and the field survey about Geumseon-am(金仙庵=金仙臺), Hwajang-am(華藏庵), Daeseong-am(大成庵), Yangjin-am(養眞庵). In the late of Joseon Dynasty, the group of buddhist proceeded the economical development and the extension of authority based on the family culture. The hermitage functioned for the self-discipline, the meeting of family, the enshrinement of portraits, the memorial ceremony of family at this point. In response to that, the architectural space which had combined residence and rite became preferred such as Inbeopdang(因法堂). And a Large Ondol room called Daejungbang(大重房) was applied and Ru(樓)-Maru was added as the place for rest.