• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.7
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• pp.936-944
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• 2019

Submarines, which have been called an invisible force, are strategic underwater weapon systems that perform missions such as anti-surface warfare, anti-submarine warfare, and high payoff target strikes with the advantage of underwater covertness. A submarine should be able to withstand the hydrostatic pressure of the deep sea. In this respect, the submarine pressure hull, as the main structural system to resist the external pressure corresponding to the submerged depth, should ensure the survivability from hazards and threats such as leakage, fires, shock, explosion, etc. To do this, the initial scantling of the submarine pressure hull must be calculated appropriately in the concept design phase. The shape of the aft transition ring varies according to its connection with the submarine aft end conical structure, pressure hull cylindrical part, and non-pressure hull of the submarine; the design of the aft transition ring should not only take into account stress flow and connectivity but also the cost increase due to the increased man-hours of its complex geometry. Therefore, trade-off studies based on the four different shapes of the aft transition ring are carried out considering both the review of the structural strength through nonlinear finite element analysis (FEA) and economic feasibility by reviewing the estimations of the manufacturing working days and material costs. Finally, the most rational structural aft transition ring shape for a submarine amongst four reviewed types was proposed.

• Tunnel and Underground Space
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• v.13 no.1
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• pp.52-63
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• 2003

Discontinuities such as faults, fractures and joints in rock mass play the dominant role in the mechanical and hydraulic properties of the rock mass. The key factors that influence on the flow of groundwater are hydraulic and geometric characteristics of discontinuities and their connectivity. In this study, a program that analyzes groundwater flow in the 3D discontinuity network was developed on the assumption that the discontinuity characteristics such as density, trace length, orientation and aperture have particular distribution functions. This program generates discontinuities in a three-dimensional space and analyzes their connectivity and groundwater flow. Due to the limited computing capacity In this study, REV was not exactly determined, but it was inferred to be greater than 25$\times$25$\times$25 ㎥. By calculating the extent of aperture that influences on the groundwater flow, it was found that the discontinuities with the aperture smaller than 30% of the mean aperture had little influence on the groundwater flow. In addition, there was little difference in the equivalent hydraulic conductivity for the the two cases when considering and not considering the boundary effect. It was because the groundwater flow was mostly influenced by the discontinuities with large aperture. Among the parameters considered in this study, the length, aperture, and orientation of discontinuities had the greatest influence on the equivalent hydraulic conductivity of rock mass in their order. In case of existence of a fault in rock mass, elements of the equivalent hydraulic conductivity tensor parallel to the fault fairly increased in their magnitude but those perpendicular to the fault were increased in a very small amount at the first stage and then converged.

• Journal of the Korean Institute of Landscape Architecture
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• v.47 no.2
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• pp.59-75
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• 2019

This study was carried out to explore the 4th Industrial Revolution technology from the perspective of the landscape industry to provide the basic data necessary to increase the virtuous circle value. The 4th Industrial Revolution, the characteristics of the landscape industry and urban regeneration were considered and the methodology was established and studied including the technical classification system suitable for systematic research, which was selected as a framework. First, the 4th Industrial Revolution technology based on digital data was selected, which could be utilized to increase the value of the virtuous circle for the landscape industry. From 'Element Technology Level', and 'Core Technology' such as the Internet of Things, Cloud Computing, Big Data, Artificial Intelligence, Robot, 'Peripheral Technology', Virtual or Augmented Reality, Drones, 3D 4D Printing, and 3D Scanning were highlighted as the 4th Industrial Revolution technology. It has been shown that it is possible to increase the value of the virtuous circle when applied at the 'Trend Level', in particular to the landscape industry. The 'System Level' was analyzed as a general-purpose technology, and based on the platform, the level of element technology(computers, and smart devices) was systematically interconnected, and illuminated with the 4th Industrial Revolution technology based on digital data. The application of the 'Trend Level' specific to the landscape industry has been shown to be an effective technology for increasing the virtuous circle values. It is possible to realize all synergistic effects and implementation of the proposed method at the trend level applying the element technology level. Smart gardens, smart parks, etc. have been analyzed to the level they should pursue. It was judged that Smart City, Smart Home, Smart Farm, and Precision Agriculture, Smart Tourism, and Smart Health Care could be highly linked through the collaboration among technologies in adjacent areas at the Trend Level. Additionally, various utilization measures of related technology applied at the Trend Level were highlighted in the process of urban regeneration, public service space creation, maintenance, and public service. In other words, with the realization of ubiquitous computing, Hyper-Connectivity, Hyper-Reality, Hyper-Intelligence, and Hyper-Convergence were proposed, reflecting the basic characteristics of digital technology in the landscape industry can be achieved. It was analyzed that the landscaping industry was effectively accommodating and coordinating with the needs of new characters, education and consulting, as well as existing tasks, even when participating in urban regeneration projects. In particular, it has been shown that the overall landscapig area is effective in increasing the virtuous circle value when it systems the related technology at the trend level by linking maintenance with strategic bridgehead. This is because the industrial structure is effective in distributing data and information produced from various channels. Subsequent research, such as demonstrating the fusion of the 4th Industrial Revolution technology based on the use of digital data in creation, maintenance, and service of actual landscape space is necessary.

• Journal of the Korean association of regional geographers
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• v.21 no.3
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• pp.427-449
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• 2015

Network governance can be defined as collaborative process to develop a new socio-political order through civil society centered networking with government and market, and the term 'collaborative governance' can be used in a sense that the basis of governance is collaborative process. In particular, it can be stressed that collaborative governance between regions need double collaborative processes, that is, collaboration between local governments and collaboration between local government and local civil society within a region. Yet, the collaboration as a core element of collaborative governance should not be seen as a pure normativity presupposing confidence and reciprocity, but as a strategy based on competition and antagonism. The normativity implied in the concept of collaborative governance may not realized in actual process, and tends to be mobilized as a rationale for justifying neoliberal strategies. In order to overcome such limits of collaborative governance, the concept of collaborative governance should be reconstructed. This paper suggests that collaborative governance can be seen as hegemonic governing process in a Gramcian sense operating in the government plus civil society, and that, radicalizing Ostrom's concept, it also can be seen as a governing process producing polycentricity by self-regulating subjects. Finally, collaborative governance between regions needs expansion of material basis for economic complementarity and construction of infrastructure as well as a discursive process in order to enhance connectivity between them.