• Title/Summary/Keyword: critical means

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Fabrication and Test of a Superconducting Coil for SMES (SMES용 초전도코일 제작 및 특성)

  • 김해종;성기철;조전욱;배준한;김석환;심기덕;이언용;권영길;류경우
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.52 no.11
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    • pp.557-562
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    • 2003
  • To develop a stable and compact small-sized superconducting magnetic energy storage (SMES) system, which provides electric power with high quality to sensitive electric loads, we fabricated a SMES coil and tested it. Because such a large-sized superconducting coil quenches far away from its critical current, the recovery current is frequently used as a stability criterion in the coil fabrication. Therefore, we first investigated the recovery current characteristics of the large current conductor, which was used in our SMES coil fabrication. The test results indicate that the recovery currents measured in the conductor are nearly identical to those based on the single wire. This implies that the recovery current is affected by the conductor's cooling condition rather than its size and current capacity. In the SMES coil test the first quench occurred at 1250 A, which is equivalent to the stored energy of about 2 MJ. It corresponds to the quench current density of about $130A/mm^2$ This value is much higher in comparison with that reported in the other work. In addition, the first quench current of the coil agrees well with the measured recovery current of the conductor having similar cooling condition with it. This means that to determine the recovery current of a conductor is, first of all, important in the design and fabrication of a large-sized superconducting coil.

A Study on the Analytical Technique of Stability and Buckling Characteristics of the Single Layer Latticed Domes (단층 래티스돔의 안정해석기법 및 좌굴특성에 관한 연구)

  • Han, Sang-Eul
    • Computational Structural Engineering
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    • v.9 no.3
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    • pp.209-216
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    • 1996
  • The primary objective of this paper is to grasp many characteristics of buckling behavior of latticed spherical domes under various conditions. The Arc-Length Method proposed by E.Riks is used for the computation and evaluation of geometrically nonlinear fundamental equilibrium paths and bifurcation points. And the direction of the path after the bifurcation point is decided by means of Hosono's concept. Three different nonlinear stiffness matrices of the Slope-Deflection Method are derived for the system with rigid nodes and results of the numerical analysis are examined in regard to geometrical parameters such as slenderness ratio, half-open angle, boundary conditions, and various loading types. But in case of analytical model 2 (rigid node), the post-buckling path could not be surveyed because of Newton-Raphson iteration process being diversed on the critical point since many eigenvalues become zero simultaneously.

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A Study on the Historicism Fashion of Century-end (세기말에 나타난 역사주의(Historicism) 의상에 관한 연구)

  • Yoon-Jeong Park;Sook-Hi Yang
    • The Research Journal of the Costume Culture
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    • v.8 no.1
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    • pp.87-101
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    • 2000
  • The purpose of study is explaining the Historicism as a result of compromise, historical eclecticism, between historical things and current cultural background instead of regarding it as an imitation from the past. It means that external factors in history help internal esthetic value surface out as costume. Fashion s history is more than the classified thing according to the appearance with the changes of the times. Intrinsic cultural elements should be added in creating new fashion. One of the different features between Modernism and Post-modernism. When coming to the period of Post-modernism, it connected with the historical factors to make something new by fragmenting, magnifying, or minimizing them. This is calles 'Historicism'in the world of art. It revived the past, not the past itself, in new ways : quotation, reuse, metaphor, and mixture. To represent the image, parody, pastiche, or bricolage was usually used. In post-modernism fashion, parody is a technique for imitating the past or the preceding forms with artists'own critical points of view. This technique gives us shock or surprise by using satirical, ironical or paradoxical expressions. pastiche shares the same part with parody in imitating particular or unique style, and it can be renamed empty parody, because it doesn't have any hidden motivation or satirical impulse. bricolage is a mixture of quotations from other works. It contains fragments that deepen the image. Like the techniques uttered above, the revival of history through parody, pastiche or bricolage is historical eclecticism and it is included in Historicism.

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Thermomagnetic Characteristics of the Hard Magnetic Materials with a Fine Microstructure due to a HDDR Process

  • Kwon, H.W.;Kim, Yoon-B.;Jeung, W.Y.
    • Journal of Magnetics
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    • v.4 no.1
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    • pp.26-32
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    • 1999
  • The HDDR process can be used as an effective means of processing of the coercive Nd-Fe-B-type or the Sm2Fe17Nx materials. The HDDR (hydrogenation, disproportionation, desorption, recombination) processed materials are feartured with a very fine microstructure. The thermomagnetic characteristics of the Nd-Fe-B-type or the Sm2Fe17Nx materials with fine microstructure due to the HDDR process were investigated. It has been found that the fine-microstructured hard magnetic materials showed an unusual TMA (Thermomagnetic analysis) tracting featured with a low and constant magnetization at lower temperature range and a peak just below their Curie temperatures when a low external field is applied. This thermomagnetic characteristic was immediate particularly in the TMA with a low applied field. This thermomagnetic characteristic was interpreted in terms of the competition between two counteracting effects; the decrease in magnetication due to the thermal agitation at an elevated temperature and the increase in magnetization resulting from the rotation of magnetization of the fine grains comparable to a critical single domain size due to the decreased magnetocrystalline anisotropy at an elevated temperature.

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Regulation by Reversible S-Glutathionylation: Molecular Targets Implicated in Inflammatory Diseases

  • Shelton, Melissa D.;Mieyal, John J.
    • Molecules and Cells
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    • v.25 no.3
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    • pp.332-346
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    • 2008
  • S-glutathionylation is a reversible post-translational modification that continues to gain eminence as a redox regulatory mechanism of protein activity and associated cellular functions. Many diverse cellular proteins such as transcription factors, adhesion molecules, enzymes, and cytokines are reported to undergo glutathionylation, although the functional impact has been less well characterized. De-glutathionylation is catalyzed specifically and efficiently by glutaredoxin (GRx, aka thioltransferase), and facile reversibility is critical in determining the physiological relevance of glutathionylation as a means of protein regulation. Thus, studies with cohesive themes addressing both the glutathionylation of proteins and the corresponding impact of GRx are especially useful in advancing understanding. Reactive oxygen species (ROS) and redox regulation are well accepted as playing a role in inflammatory processes, such as leukostasis and the destruction of foreign particles by macrophages. We discuss in this review the current implications of GRx and/or glutathionylation in the inflammatory response and in diseases associated with chronic inflammation, namely diabetes, atherosclerosis, inflammatory lung disease, cancer, and Alzheimer's disease, and in viral infections.

Consumption of Visual Cues in Computer-Mediated Environments

  • CHOI, Hwanho
    • Journal of Distribution Science
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    • v.18 no.8
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    • pp.23-33
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    • 2020
  • Purpose: In the digital age, visual cues in computer-mediated environments are becoming a very popular means of communication. Therefore, it is a very critical market for marketers to utilize for marketing communication and platform providers and manufacturers of mobile devices which create and distribute the visual cues While the prevalent research on visual cue consumption focuses on the positive side, the dark side of consuming visual cues has not been investigated. Therefore, in this research, the dark side of using visual cues, such as difficulties and problems in their application, will be investigated. Research design, data, and methodology: Due to the nature of this study, a netnography approach was adopted. Twitter which the users regularly utilise visual cues in their communications was a prime source for data of this research. Results: This research suggests that visual cue users experience anxiety about the subordination of expression and suffer from the myth of an ideal practice of expression. Conclusions: As the previous research emphasised the complementary role of visual cues, has failed to recognise the problems associated with the extensive and growing dependence on visual cues. This awareness demonstrates that we need to take a careful approach to visual cue usage.

Study on the Motion Sickness Incidence in Express Buses (장거리 여행용 버스에서의 멀미발생 예측에 관한 연구)

  • 장한기;김승한;송치문;김성환;홍석인
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2003.05a
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    • pp.234-240
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    • 2003
  • This study aims to investigate dynamic properties of express buses in the very low frequencies which affect motion sickness incidence. Since passengers often use express buses for long distance traveling, it is a critical point whether a give rise to motion sickness or not. In the study accelerations at the three points on the floor of the six test vehicles were measured during the driving at constant speeds. By applying frequency weighting curves suggested in ISO 2631-1 and ISO 2631-3, physical amount of accelerations were changed into perceptual amount which determines incidence of motion sickness. Motion sickness dose values were calculated from the frequency weighted time history of accelerations, and compared between the vehicles, driving conditions, and the seat positions in the bus. During the driving on public road and high ways for 50 minutes vomiting incidence ratios ranged 0.4 to 0.8%, which were equivalent to 2.4 to 4.8% for 5 hours' driving. The value of 4.8 % means two among 45 passengers may vomit after the traveling, which is very serious situation. Considering the very smooth driving condition at which the data were collected, motion sickness dose values will increase in real situations

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Optimum Design for Frame Bracket of Electrical Panels for Improved Fatigue Strength (함정용 배전반의 피로강도 향상을 위한 프레임 브래킷의 최적설계)

  • Kim, Myung-Hyun;Choi, Jae-Young;Kang, Sung-Won;Chung, Ji-Young
    • Journal of the Society of Naval Architects of Korea
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    • v.43 no.2 s.146
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    • pp.206-212
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    • 2006
  • Structural reliability of electrical panels installed in naval vessels is of critical importance from structural performance viewpoint. The electrical panels may be exposed to vibration and fatigue loadings from internal and external sources as well as wave loadings which result into a crack and fracture due to the decrease of fatigue strength. It is also well known that welded joints including brackets within steel structures .such as vessels and bridges are vulnerable against such repeated loadings. This study introduces a preliminary result of the optimized shape of frame bracket consisting of electrical panels in navel vessels against fatigue loading and their fatigue life at brackets of electrical panels by means of hot spot stress and structural stress methods.

An Examination on the Concept of Visual Literacy as a Basis for Convergence Education Programme (융복합교육 프로그램을 위한 기반으로서 시각적 문해력(Visual Literacy) 개념 검토)

  • Park, Gun-Kyu;Kim, Won-seok
    • Journal of Digital Convergence
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    • v.14 no.12
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    • pp.397-403
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    • 2016
  • This research reviews the concept of Visual Literacy which is the critical base for performing convergence-style educational program of fine arts. The Visual Literacy means the ability to understand and properly deal with the visual information given to the agent such as the literacy to the written language. It is beyond doubt that the necessity of the Visual Literacy is raised because there is different visual information through new media for the entire life of young generation. Therefore, the Visual Literacy is the base for performing convergence-style education when it comes to performing convergence-style educational programs. It covers the communication abilities to utilize new media and exchange visual information one another.

Hand Language Translation Using Kinect

  • Pyo, Junghwan;Kang, Namhyuk;Bang, Jiwon;Jeong, Yongjin
    • Journal of IKEEE
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    • v.18 no.2
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    • pp.291-297
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    • 2014
  • Since hand gesture recognition was realized thanks to improved image processing algorithms, sign language translation has been a critical issue for the hearing-impaired. In this paper, we extract human hand figures from a real time image stream and detect gestures in order to figure out which kind of hand language it means. We used depth-color calibrated image from the Kinect to extract human hands and made a decision tree in order to recognize the hand gesture. The decision tree contains information such as number of fingers, contours, and the hand's position inside a uniform sized image. We succeeded in recognizing 'Hangul', the Korean alphabet, with a recognizing rate of 98.16%. The average execution time per letter of the system was about 76.5msec, a reasonable speed considering hand language translation is based on almost still images. We expect that this research will help communication between the hearing-impaired and other people who don't know hand language.