• Title/Summary/Keyword: Fact Verification

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Semiactive Control for Structural Vibration Mitigation (구조물 진동 저감을 위한 반능동 제어)

  • Changki Mo;Jaesoo Lee
    • Journal of KSNVE
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    • v.11 no.1
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    • pp.96-103
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    • 2001
  • Past research has repeatedly demonstrated the fact that hydraulic semiactive systems, if operated Properly, can provide levels of control authority in structural vibration control systems that are comparable to a fully active hydraulic damper. The performance of the semiactive system when used to provide vibration mitigation for a laboratory test structure is described in this paper Numerical and experimental verification of the effectiveness of the proposed bistate controller which relies on a Lyapunov approach that seeks to dissipate the energy of the system is also presented. The results based on the bistate control are compared with those of two different control strategies. The work indicates that hydraulic semiactive actuator provides a reliable, and inexpensive means of achieving structural control.

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Improvement of the Startup Transient Analysis on the Liquid Rocket Engine Using the TP+GG Coupled Test Result (터보펌프+가스발생기 연계시험 결과를 이용한 액체로켓엔진 시동 과정에 대한 해석 방법의 개선)

  • Park, Soon-Young;Cho, Won-Kook;Moon, Yoon-Wan
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2011.11a
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    • pp.821-826
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    • 2011
  • The turbopump+gas generator (TP+GG) coupled test for the liquid rocket engine development was performed. By comparing the results of a engine startup transient analysis with this test results, the verification of the analysis model was performed. From this, as to the analysis of the engine startup, the method calculating the pressure ratio of the turbine during the initial stage of startup was improved. And a fact that the transient heat transfer phenomenon between the working fluid and the solid parts of turbine effects to the calculation of turbine pressure ratio and consequentially to the startup analysis was revealed.

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Verification of the Boundary Conditions Used for Generating g-functions and Development of a TRNSYS Simulation Model Using g-functions (트랜시스를 이용한 지열 응답 함수 경계 조건 검증 및 시뮬레이션 모델 개발에 관한 연구)

  • Kim, Eui-Jong
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.26 no.9
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    • pp.416-423
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    • 2014
  • To verify different boundary conditions on the borehole wall, which are commonly used for generating g-function, the well-known TRNSYS simulation model, DST (Duct STorage), is employed. By letting the fluid circulation determine the borehole wall conditions, a DST-based g-function is induced with numerical processes proposed in this work. A new TRNSYS module is also developed to accommodate g-function data and predict dynamic outlet fluid temperatures. Results showed that the modified g-function, which is different from Eskilson's original g-function, is closer to the DST-based g-function. This implies that the uniform heat transfer rates over the height can be used for good approximation. In fact, simulations with the modified g-function showed similar results as the DST model, while Eskilson g-function case deviated from the DST model as time progressed.

Particle vs. Field : The Concept of Unit Model in the Architectures of the East and the West (입자(粒子)와 장(場) : 동서양 건축에서의 단위개념)

  • Kim, Sung-Woo
    • Journal of architectural history
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    • v.14 no.1 s.41
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    • pp.151-183
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    • 2005
  • All architecture in the history were based on a certain concept of architectural unit that functioned as a base model of architectural design. As we know, such model was not the same in the East and the West, and therefore, their architectures are not the same. This paper aims to identify how and why such base model of the two cultural area are different. As one way of discussing this issue, the concept of particle and field, as two representative idea of the West and East respectively, the employed. This kind of discussion can not follow the way of scientific verification as method of argument. However, the understanding of such concept of unit model is crucial for the understanding of the architecture of the culture in general. In basic sense, the tradition of Western architecture is rooted in the model of particle, where, architecture is conceived to be as a independent unit standing on earth as if it is a box like object. While, the tradition of Eastern architecture is rooted in the model field, where, architecture is conceived to be a part of field organization. In present days, we are used to the model of particle as if it is the only possible model of architecture. But, in fact, what man need to achieve in their architecture and city, is the balance between the two models.

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Analysis of Dynamic Deformation of 4-Bar Linkage Mechanism(II) (4절 링크 기구의 동적 변형 해석 (II))

  • 조선휘;박종근;주동인
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.16 no.5
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    • pp.910-923
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    • 1992
  • Experimental verification of numerical results is conducted by measuring the dynamic strains of mid-points of the coupler and the lever for the 4-bar linkage mechanism with rigid bearing and flexible bearing, respectively. For the axial strain of lever mid-point, the numerical results including geometric stiffness almost agree with the experimental ones, however, the numerical results excluding geometric stiffness almost agree with the experimental ones for the axial strain of coupler mid-point. It is supposed that these phenomena should be caused by the fact that the motion of the coupler is more complicated than of the lever. The signals of dynamic strains of coupler and lever mid-points, measured by strain gages, are transformed into frequency domain by fast fourier transformer. From this experiment, the lst resonance frequencies of the coupler and the lever are obtained. It is made clear that the former almost agrees with the fundamental and the latter the 2nd mode natural frequency of the mechanism system calculated by numerical analysis.

Research on the Form and Symbolism of the Chinese Wedding Phoenix Crown

  • Cheng, Hui-Mei
    • Proceedings of the Korea Society of Costume Conference
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    • 2001.08a
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    • pp.59-61
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    • 2001
  • Along with the development of culture, dress of the Chinese people has also evolved over the last several thousand years, transcending its original functions of covering and protecting the body. As a result it has risen to become a complicated system of symbols full of intricate meanings. According to de Saussure's theory of "signs," signs are represented by the elements signified (meaning) (referent) and signifiant (sound) (exponent). "Phoenix crowns" were the headpieces most highly esteemed by women in ancient China. Actually, the name "phoenix crown" points to the fact that the headpiece is adorned with a phoenix design. The history and symbolism of the phoenix crown's use as a headpiece in Chinese weddings spans 1200 years in all, originating in the Qin Dynasty (241-210 BC) as a phoenix hairpin, evolving into the phoenix crown during the Song Dynasty (960-1276 AD), and continuing through the Ming and Qing Dynasties (1644-1911 AD), and the modem republic. It is not simply an ornamental headpiece, but instead represents the thousands of years or rich inner meaning the Chinese attribute to "dragons" and "phoenixes." This paper depicts the glorious past of phoenix crowns, using the metaphor and metonymy theories of semiology and semantics, and through the cross-verification of literature research archeological findings and reports, and old Chinese wedding photographs, in order to examine the inherent meanings of the phoenix crown in the Chinese culture.nings of the phoenix crown in the Chinese culture.

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Growth Characteristics of Silica Particles Using In situ Sampling from $H_2/O_2TEOS$ Diffusion Flame (수소/산소/TEOS 확산화염 중 직접포집을 이용한 실리카 입자의 성장특성에 관한 연구)

  • Jung, Chang-Hoon;Ahn, Kang-Ho;Choi, Man-Soo;Lee, Joon-Sik
    • Proceedings of the KSME Conference
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    • 2000.04b
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    • pp.404-409
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    • 2000
  • Growth characteristics of silica particles have been studied experimentally using in situ sampling technique from $H_2/O_2TEOS$ diffusion flame with carefully devised sampling probe. Verification of sampling result was done through new method and effects of flame condition and TEOS flow rate on growth characteristics of silica particles were investigated. By comparing particles sampled by thermophoretic sampling in flame with those by collector sampling after probe, particles do not change before and after probe sampling, which was clearly proved from the fact that the result of TEM image analysis makes good agreement with that of SMPS measurement. As flame temperature increases, the effect of coalescence or sintering becomes important mechanism during growth of silica particles, resulting in canceling the effect of coagulation, which makes mean diameter of silica particles increase slowly. With increase in TEOS flow rate, the number concentration of generated silica particle increases but residence time of particles in flame decreases. As a result, there exists upper limit to which the diameter of silica particle increases under same flame condition.

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A Construction Supply Chain Management Process with RFID/WSN-based Logistics Equipment

  • Shin, Tae-Hong;Yoon, Su-Won;Chin, Sangyoon
    • Journal of Construction Engineering and Project Management
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    • v.2 no.4
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    • pp.11-19
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    • 2012
  • Construction supply chain management (CSCM) has become one of the critical factors that determine the success of a construction project as it becomes increasingly complicated and mega-sized. Particularly for high-rise or mega-sized building construction, just-in-time supply chain management is required due to lack of storage space and effective logistics for construction components and materials at a construction site. Despite the fact that research and development of radio frequency identification (RFID) and wireless sensor network (WSN) technology have been performed, construction project managers still need to carry mobile devices and check material and component flow at each stage of the supply chain process. This research proposes that the equipment used in the construction supply chain process, such as movers, trailers, gates, and hoists, can become main actors in the supply chain process using RFID and WSN technologies. And the proposed equipment and process focused on a solution to the redundancy identification problem, which has been observed in operations that use RFID/WSN-based processes for construction logistics. This paper also presents issues identified through verification and validation of the research results and proposes further studies.

Experimental Verification of Variable Radius Model and Stiffness Model for Twisted String Actuators (TSAs) (줄 꼬임 구동기의 가변 반지름 모델과 강성 모델에 대한 실험적 검증)

  • Park, Jihyuk;Kim, Kyung-Soo;Kim, Soohyun
    • The Journal of Korea Robotics Society
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    • v.12 no.4
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    • pp.419-424
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    • 2017
  • Twisted string actuators (TSAs) are tendon-driven actuators that provide high transmission ratios. Twisting a string reduces the length of the string and generates a linear motion of the actuators. In particular, TSAs have characteristic properties (compliance) that are advantageous for operations that need to interact with the external environment. This compliance has the advantage of being robust to disturbance in force control, but it is disadvantageous for precise control because the modeling is inaccurate. In fact, many previous studies have covered the TSA model, but the model is still inadequate to be applied to actual robot control. In this paper, we introduce a modified variable radius model of TASs and experimentally demonstrate that the modified variable radius model is correct compared to the conventional variable radius string model. In addition, the elastic characteristics of the TSAs are discussed along with the experimental results.

Subject: A Study on the Influence of Exhibition Communication Media on a Visitor's Satisfaction and Re-visit (박물관의 전시소통매체가 방문객의 만족도와 재방문에 미치는 영향에 대한 연구)

  • Kim, Hyung-Jun
    • Journal of the Korea Safety Management & Science
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    • v.17 no.4
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    • pp.321-333
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    • 2015
  • This study empirically analyzed the influence of media on a visitor's satisfaction and re-visit by setting up 5 sorts of exhibition media as text, docent, virtual museum, website and Smartphone App based on practical exchange and communication between a visitor and an exhibition provider. The research results are as follows: First, all these 5 sorts of media suggested by this study were found to be able to have an influence on a visitor's satisfaction and re-visit. Second, it was found that the factors preferentially affecting a visitor's satisfaction and re-visit were 'Docent' and 'Website' factors. Accordingly, it is judged that it's necessary to more preferentially consider 'Docent' and 'Website' factors than the other factors in order to increase a visitor's satisfaction and re-visit. Third, it's possible to interpret that the bigger a visitor's satisfaction, the higher a visitor's intention to re-visit through the verification that a visitor's satisfaction will have a significant influence on a visitor's re-visit. The implication of this study lies in the fact that this study attempted at an integrated approach by analyzing the relative size of the influence through across-the-board suggestion of influential factors on a museum visitor's satisfaction and re-visit.