• Title/Summary/Keyword: boundary spanning

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Free Spanning of Offshore Pipelines by DNV 2002 (DNV 2002에 의한 해저관로의 자유경간해석)

  • Choi, Han-Suk;Joo, Joo-Kyung
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2002.10a
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    • pp.29-33
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    • 2002
  • A procedure of free span and fatigue analysis of offshore pipelines was made per DNV-RP-F105, 2002. The new method includes the axial force and deflection load in pipelines. The screening criteria were used to calculate the allowable span lengths. The screening criteria allow small amplitudes of vortex-induced vibration due to wave and current loading. However, the induced pipe stress is very small and usually below the limit stress of a typical S-N curve. A simplified method was established to calculate the fatigue damage due to long-term current distribution. The long-term current statistics was assumed with a 3-parameter Weibull distribution. The fatigue damage was estimated for the span lengths obtained from the screening criteria for various conditions. Sample calculations show the effect of axial force for various boundary conditions.

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The Selection of Measurement Positions for BEM Based NAH Using a Non-conformal Hologram to Reduce the Reconstruction Error

  • Oey, Agustinus;Ih, Jeong-Guon
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2007.11a
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    • pp.1018-1021
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    • 2007
  • This paper explores the use of BEM based NAH to reconstruct the surface vibration of a plate in a rectangular finite cavity, in which the distances between sensors and the nearest points on the source surface are not equal. In such circumstances, different degree of information on propagating and non-propagating wave components will be detected by sensors at different positions, as well as the influence of measurement noise will vary significantly from the nearest points of measurement to the farthest ones. On the other hand, the condition number of the vibro-acoustic transfer function matrix relating normal surface velocities and field pressures will becomes high, numerically indicating an increase of linear dependency between rows of transfer function matrix. The combination of poor measurement and high condition number will result inaccurate reconstruction. Therefore, one approach to be investigated in this work is to select the measurement positions in such ways that reduce measurement redundancy, as it indicated by the condition number. The improvement is found to be significant in the numerical simulations utilizing two different criterions, spanning from over-determined to under-determined cases, and in the validation experiment.

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Review of Operational Multi-Scale Environment Model with Grid Adaptivity

  • Kang, Sung-Dae
    • Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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    • v.10 no.S_1
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    • pp.23-28
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    • 2001
  • A new numerical weather prediction and dispersion model, the Operational Multi-scale Environment model with Grid Adaptivity(OMEGA) including an embedded Atmospheric Dispersion Model(ADM), is introduced as a next generation atmospheric simulation system for real-time hazard predictions, such as severe weather or the transport of hazardous release. OMEGA is based on an unstructured grid that can facilitate a continuously varying horizontal grid resolution ranging from 100 km down to 1 km and a vertical resolution from 20 -30 meters in the boundary layer to 1 km in the free atmosphere. OMEGA is also naturally scale spanning and time. In particular, the unstructured grid cells in the horizontal dimension can increase the local resolution to better capture the topography or important physical features of the atmospheric circulation and cloud dynamics. This means the OMEGA can readily adapt its grid to a stationary surface, terrain features, or dynamic features in an evolving weather pattern. While adaptive numerical techniques have yet to be extensively applied in atmospheric models, the OMEGA model is the first to exploit the adaptive nature of an unstructured gridding technique for atmospheric simulation and real-time hazard prediction. The purpose of this paper is to provide a detailed description of the OMEGA model, the OMEGA system, and a detailed comparison of OMEGA forecast results with observed data.

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Strategic Orientation of Hospitals in Korea and Their Related Characteristics (우리나라 병원들의 전략지향 및 관련 특성 분석)

  • Youn, Hye-Won;Shin, Eui-Chul;Kim, Ye-Soon;Jung, Ki-Taek
    • Journal of the Korean hospital association
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    • v.37 no.3 s.313
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    • pp.74-87
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    • 2008
  • As healthcare environment being more complex and turbulent, strategic approach of hospitals became more important. This study was to investigate strategic orientation of Korean hospitals and their related characteristics. We surveyed managers of 360 hospitals randomly selected from all hospitals in Korea. For typology of strategic orientation, we used that developed by Miles and Snow, and results are as follows. Firstly, major types of organizational strategic orientation of Korean hospitals were analyzer(42.0%) and prospector(34.0%). Secondly, characteristics affecting to hospitals' strategic orientation significantly were hospital ownership and sex of managers. Medical corporation had a high tendency of prospector strategic orientation by 2.7 times compared to personal ownership. Female managers had a low tendency of prospector strategic orientation by 0.2, which was statistically significant. Though 60+ age group (compared to twenties and thirties) and middle managers (compared to CEO) had a tendency of being more prospector strategic orientation, but insignificant. The study result that majority of strategic orientation were prospector and analyzer reflects Korean hospital environment are complex and unstable. Hospital managers need to more focus on environment and boundary spanning function for maintenance and survival of their organizations.

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Physical Topology Discovery Algorithm for Ethernet Mesh Networks (이더넷 메시 망에서의 물리 토폴로지 발견 알고리즘)

  • Son Myunghee;Kim Byungchul;Lee Jaeyong
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.42 no.4 s.334
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    • pp.7-14
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    • 2005
  • Earlier researches have typically concentrated on discovering IP network topology, which implies that the connectivity of all Ethernet devices is ignored. But automatic discovery of Physical topology Plays a crucial role in enhancing the manageability of modem Metro Ethernet mesh networks due to the benefits of Ethernet services, including: Ease of use, Cost Effectiveness and flexibility. Because of proprietary solutions targeting specific product families and related algorithm which depends on Layer 2 forwarding table information it is impossible to discover physical topology in the Ethernet mesh networks. To cope with these shortcomings, in this paper we propose a novel and practical algorithmic solution that can discover accurate physical topology in the Ethernet mesh networks. Our algorithm divides the Ethernet mesh networks into bridged networks and host networks and those bridges located in boundary are named edge bridges. Our algorithm uses the standard spanning tree protocol MIB information for the bridged networks and uses the standard Layer 2 forwarding table MIB information for the host networks. As using the standard MIB information to discover physical topology we can offer interoperability guarantee in the Ethernet mesh networks composed of the various vendors' products.

A Study on the Ethnic Minimalism Expressed in Modern Fashion - Comparing with Minimalism - (현대 복식에 나타난 에스닉 미니멀리즘에 관한 연구 - 미니멀리즘(minimalism)과의 비교 고찰을 통하여 -)

  • Chae, Hye-Sook;Chae, Keum-Suk
    • Journal of the Korean Society of Costume
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    • v.58 no.3
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    • pp.63-78
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    • 2008
  • Since 1960, minimalism has been one of the fashion phenomenon and turned out in many different ways. After postmodernism which contains negotiation and pluralism, appeared in 1980, there was a new wave of post minimalism that inherited 1960's minimalism. Minimal style which come out of 60's fashion, is marked by simplicity, minimal expression, and monochrome color, and it shows up simple style with no decoration. It opened up a young fashion period, and we saw minimal style in sports wear which utilized simplicity and function with spread of sports in the 70's. And also since 1980, Post-Modern widely influenced the idea about modern culture as well as complicated clothes getting rid of fixed concept, seeking to break the boundary between culture and life which were seek in fashion and personality as well as various characteristic, Accordingly in different ages, The style and image were borrowed from different culture and natural environment mixing the image, cultural phenomena like these appearing in complexity and expression, variety and possibility of new vision was expanded. Since 1980, Fashion has become more gradually diversity, high classed, required of each individuality. The phenomenon of fashion reappearance which was influenced by minimalism is continued to 2000. The Oriental style fashion is still attracted, so The new term "Ethic Minimalism" has appeared along with the trends which is put together. Therefore the purpose of this study is to search the concept and the characteristics of ethnic minimalism, to consider the relationship between minimalism and ethnic minimalism, and reveal the characteristic of ethnic minimalism happened to modern fashion. The study method went through literature research and practice research. The range of this study is oriental fashion spanning of from 1960 to current day. Photo records from this period show well the spirit of the oriental and the personality of minimalism. The oriental representative designer and western representative designer are centered Consequently, The formative characteristics of ethnic minimalism are simple, pure, unbalanced free style and representing the phenomena of compromise, blending oriental and western fashion. Structually, Elements of space and plane are emphasized, colors are restricted, and materials are composed mainly of natural fiber. So, minimalism based on simplicity combined with a structure of oriental spiritual depth and space, It could be called ethnic minimalism as a rational fashion.