• Title/Summary/Keyword: a new concept of stability

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Design of Multi-input Multi-output Positive Position Feedback Controller Based on Block-inverse Technique (블록 역행렬 기법에 의한 다중입출력 양변위 되먹임제어기의 설계)

  • Kwak, Moon K.
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.15 no.9 s.102
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    • pp.1037-1044
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    • 2005
  • This paper is concerned with the active vibration control of a grid structure equipped with piezoceramic sensors and actuators. The grid structure is a replica of the solar panel commonly mounted on satellites, which contains complex natural mode shapes. The multi-input and multi-output positive position feedback controller is considered as an active vibration controller for the grid structure. A new concept, the block-inverse technique, is proposed to cope with more modes than the number of actuators and sensors. This study also deals with the stability and the spillover effect associated with the application of the multi-input multi-output positive position feedback controller based on the block-inverse technique. It was found that the theories developed in this study are capable of predicting the control system characteristics and its performance. The new multi-input multi-output positive position feedback controller was applied to the test structure using a digital signal processor and its efficacy was verified by experiments.

A Monistic Design Thought and Method (전일적 디자인사고와 디자인방법에 대한 연구)

  • 이순종
    • Archives of design research
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    • v.17 no.2
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    • pp.479-486
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    • 2004
  • We need to seek after new direction and order of design that puts more value on the spirits and culture of human beings in the 21st century, creating a new, all-inclusive value in which individual human being, the society and the environment can co-exist in a peaceful relationship by overcoming the materialistic, analytical, competitive, and differentiated values of traditional industrial society. The aim of this study, then, is to present a new method of design that can meet the demands of the 21st century in a civic age of information, knowledge and culture, by focusing on Monistic ideals derived from a deeply rooted Oriental philosophy. The concept of Monism is embodied by a mind set that treasures the benefit to others over rewards to the self, puts more importance on the spiritual life hidden behind physical phenomena, thinks more of what lacks than what exceeds, elevates the mind over the body, and seeks after beauty via a total harmony of balance and development that can be feasible only by combining all these elements. Ultimately, the new design principle based on the Monism consists of three basic elements: (1) identification of the subject and the object between things under the perception that all things are one (Unification); (2) the ability that helps things exist with appropriate beauty maintaining balance and stability (Harmony); and (3) the attitude of sharing to maintain sustainable vitality by filling up what lacks or is missing in a whole(Change).

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Ultrathin Titania Coating for High-temperature Stable $SiO_2$/Pt Nanocatalysts

  • Reddy, A. Satyanarayana;Kim, S.;Jeong, H.Y.;Jin, S.;Qadir, K.;Jung, K.;Jung, C.H.;Yun, J.Y.;Cheon, J.Y.;Joo, S.H.;Terasaki, O.;Park, Jeong-Young
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.08a
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    • pp.217-217
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    • 2011
  • Recently, demand for thermally stable metal nanoparticles suitable for chemical reactions at high temperatures has increased to the point to require a solution to nanoparticle coalescence. Thermal stability of metal nanoparticles can be achieved by adopting core-shell models and encapsulating supported metal nanoparticles with mesoporous oxides [1,2]. However, to understand the role of metal-support interactions on catalytic activity and for surface analysis of complex structures, we developed a novel catalyst design by coating an ultra-thin layer of titania on Pt supported silica ($SiO_2/Pt@TiO_2$). This structure provides higher metal dispersion (~52% Pt/silica), high thermal stability (~600$^{\circ}C$) and maximization of the interaction between Pt and titania. The high thermal stability of $SiO_2/Pt@TiO_2$ enabled the investigation of CO oxidation studies at high temperatures, including ignition behavior, which is otherwise not possible on bare Pt nanoparticles due to sintering [3]. It was found that this hybrid catalyst exhibited a lower activation energy for CO oxidation because of the metal-support interaction. The concept of an ultra-thin active metal oxide coating on supported nanoparticles opens-up new avenues for synthesis of various hybrid nanocatalysts with combinations of different metals and oxides to investigate important model reactions at high-temperatures and in industrial reactions.

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Holding Mechanism of Anchor System for Fisheries Facilities (계류기초의 파주력 산정에 관한 연구)

  • Jung, Jin-Ho;Ryu, Cheong-Ro;Kim, Jong-Gyu
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.32 no.2
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    • pp.132-147
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    • 1996
  • The optimal design of floating type fisheries facilities in the open sea is demanded considering with the severe hydrodynamic forces on floating body, mooring tension and holding force of anchor. For conserving the facilities in most effective state, design and selection of anchor system is one of the most important fundamental subject. To enhance the design procedure of anchor system the holding forces of anchor are investigated by the hydraulic model test and are compared with the typical conventional results for various anchors. Applicability of previous estimation methods of holding force are checked and holding mechanism of anchor is discussed. Using the results a new computational concept of holding force is suggested considering mainly the effects of passive soil pressure (resistance), steady soil pressure, and surface friction etc. The new estimation method is proved as a feasible one by comparing the results of hydraulic model experiments. Applicability of various anchors to the anchor system on open sea fisheries structures is comprehensively reviewed using the present model tests and previous study results in the viewpoint of economy, construction and stability etc. Using the results, fundamental anchoring system design procedures are suggested to apply huge marine ranching complex with increase of the holding capacity of anchor under the optimum cost.

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LIGHT EMITTING POLYMER MATERIALS: THE WORKING BASE FOR FLEXIBLE FULL COLOR DISPLAYS

  • Falcou, Aurelie;Becker, Heinrich;Breuning, Esther;Buesing, Arne;Heun, Susanne;Parham, Amir;Spreitzer, Hubert;Steiger, Juergen;Stoessel, Philipp
    • 한국정보디스플레이학회:학술대회논문집
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    • 2003.07a
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    • pp.1053-1056
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    • 2003
  • Progress in light emitting materials is presented. New polymers based on the Spiro concept show encouraging properties in electroluminescence performance and lifetime. The spiro-polymers can be tailor made to fit the RGB color requirements of a full color display. This class of materials showed recently very promising performance for white emission as well. They are readily soluble, show excellent thermal stability and can be processed by printing or through simple synthetic modification by photolithography technology.

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A theoretical review on the limitations of applying copyright law in the arts (예술창작에서 저작권법 적용의 한계에 대한 이론적 고찰)

  • Hong, Kiwon
    • Korean Association of Arts Management
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    • no.51
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    • pp.167-190
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    • 2019
  • Copyright law has functioned to certify the authorship and artistic identity of an artist as well as to remunerate the artist's labor in monetary terms. However, the legal stability of copyright law may be questioned and even challenged because it shares the ground with unfixed notions of the concept of art. This study is an attempt to find theoretical argument where such instability of copyright law stems from, by looking into the theories of Aesthetics and history of arts. The first argument builds up on the ambiguity of discriminating between the Aesthetic concept of expression and idea. The second argument illuminates how new conventions of creating art work and emerging ideals of making art prevents to accommodate copyright law in the fields of art. New art forms such as conceptual art and place specific art are such examples. Increasing role of public arts projects also questions the conventional adoptions of copyright law. Arts management is closely related with this phenomena since their job is to administer the complex situation of introducing artists to the knowledge of copyright law.

Development of Trenchless Tunneling Method Using Pressurizing Support and Its Field Application (가압식 지보를 이용한 비개착 터널공법 개발 및 현장적용 사례)

  • Kim, Dae-Young;Lee, Hong-Sung;Sim, Bo-Kyoung
    • Journal of the Korean Geotechnical Society
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    • v.28 no.7
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    • pp.17-30
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    • 2012
  • A new trenchless tunneling method using pressurizing support has been developed. As it overcomes shortcomings of conventional methods, it is applied to the field. The main concept of the new method is the pressurization system which, by means of pressurization bag between outer flange of steel ribs and excavated perimeter, applies the pressure corresponding to the magnitude of the relaxed earth pressure caused by excavation to the ground to prevent ground displacement. The stability of the support members and effect of displacement control of the new method were verified through several ways such as numerical tests and various model tests. The new method was applied to the construction of a 10.7 m wide, 7.9 m high and 85 m long road tunnel that passes under Yeongdong Expressway. By applying the new method, the tunnel construction was successfully completed in 13.5 months. It decreases the construction period to 35% compared to that of conventional methods, and ground displacement was almost negligible.

A Study on Fabrics Shown in Contemporary Art -Focused on Fabric Works in the Gwangju Biennale 2008- (현대미술에 나타난 패브릭에 대한 고찰 - 08 광주 비엔날레 패브릭 작품 중심으로-)

  • Jung, Hyung-Ho;Bae, Soo-Jeong
    • Journal of Fashion Business
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    • v.14 no.4
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    • pp.74-90
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    • 2010
  • The history of contemporary art in the 20th century can be said the history of changes. Today the variety of objects destroy the boundaries of each genre. This study aims to understand the relationship between fashion and art that becomes closer by examining contemporary art in the Gwangju Biennale 2008 to enlarge the range of understanding of mutual communication between contemporary art and fabrics which are the object of fashion. The research method was to investigate the characteristics and expression methods of object fabrics shown in contemporary art through the review of papers published at home and abroad, related literatures, and Internet materials. Also, the meaning, technique, and methods of fabrics were analyzed from works introduced in the Gwangju Biennale 2008. In order to achieve this purpose, fabric was examined as the object of work in Gwangju Biennale 2008. As a result, it is found that fabric plays an important role in changing environment newly with more dynamic, abundant, and comfortable and softer feeling than any other artistic materials and enlarging the boundaries of artistic materials by exploring formative possibility. Furthermore, its multi-dimensional expression characteristic presents unbounded possibility. Fabric which has long formed close relationship with human life has taken its place as one genre now. It departs from the past principles of fabric handicraft and the restriction of a classical norm and becomes characteristic of very wide-ranging selection of materials and free expression. Its soft and warm texture provides emotional stability for a human. Although the peculiarity of fabric as an active concept to human environment and new materials and technique based on the aesthetic consciousness of a human rely on the high development of industry, it is significant that artists' liberation from their concept and material sense is accompanied by the expression of freedom.

Case Study of Self-Supported Diaphragm Wall Method Using Counterfort Technique (부벽식 기법을 사용한 자립식 지하연속벽 공법의 사례 연구)

  • Jeong, Gyeong-Hwan;Park, Hun-Kook;Shin, Min-Sik;Han, Kyoung-Tae;Ryu, Ji-Young
    • Proceedings of the Korean Geotechical Society Conference
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    • 2006.03a
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    • pp.276-285
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    • 2006
  • Application of anchored or strutted wall system for the earth retention of excavation works in a populated urban area or a poor soil deposit can be limited due to various restrictions. Since the strut becomes longer in a wide excavation site, the stability of an earth retaining wall is decreased, the wall deformation is increased, and the ground settlement is also increased due to an increased buckling or bending deformation of struts. Especially, in a populated urban area, the installation of anchors can be problematic due to the property line of adjacent structures or facilities. Thus, a new concept of earth retaining system like Self-Supported diaphragm Wall can solve several problems expected to occur during excavation in the urban area. In this study, Numerical analyses of counterfort diaphragm wall was introduced and the monitored data from the site was compared with the original results of numerical analyses. Also, in the case of the deep excavation applied the counterfort diaphragm wall, numerical analyses was performed to predict the wall deformation and the reinforcement to reduce the wall deformation was suggested.

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Singapore Case Study of Self-Supported Diaphragm Wall Method Using Counterfort Technique (부벽식 기법을 사용한 자립식 지하연속벽 공법의 싱가폴사례)

  • Jeong, Gyeong-Hwan;Park, Hun-Kook;Shin, Min-Sik;Han, Kyoung-Tae;Ryu, Ji-Young
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.10a
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    • pp.605-613
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    • 2008
  • Application of anchored or strutted wall system for the earth retention of excavation works in a populated urban area or a poor soil deposit can be limited due to various restrictions. Since the strut becomes longer in a wide excavation site, the stability of an earth retaining wall is decreased, the wall deformation is increased, and the ground settlement is also increased due to an increased buckling or bending deformation of struts. Especially, in a populated urban area, the installation of anchors can be problematic due to the property line of adjacent structures or facilities. Thus, a new concept of earth retaining system like Self-Supported diaphragm Wall can solve several problems expected to occur during excavation in the urban area. Application of self-supported counterfort diaphragm wall was verified in this paper though comparing the design of self-supported counterfort diaphragm wall with the data monitored during excavation in Singapore.

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