• Journal of the Korean Recycled Construction Resources Institute
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• v.6 no.4
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• pp.252-258
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• 2018

A larger energy consumption and concentration of population induced green house gas glowing and heat island effect in the urban space. Roof green system was a effect method to reduce green house gas and heat concentration in the city. Therefore, construction of this system was increasing. Most of lightweight soil used in roof green system was perlite, but this caused dust and skin disease. So it needed to develop another new lightweight soli for roof green system. Meanwhile, a thermoelectric power plant generated bottom ash as a by-product. According to previous research, bottom ash could be used for artificial lightweight soil with 60 wt% of mixing rate. But this study was proceed to develop a artificial lightweight soil using bottom ash with higher mixing rate by 65 wt% and different organic ingredients. First, physical and chemical properties of bottom ash was investigated. Then test according to landscaping design standard was proceeded for various artificial lightweight soil mix types using bottom ash, bark, compost and coco peat. As a result, the artificial lightweight soil with 65% of bottom ash, 30% of bark and 5% of compost was suitable for low and middle range of soil standard.

• Smart Structures and Systems
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• v.17 no.5
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• pp.753-771
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• 2016

This paper addresses the free and transient responses of a SDOF linear complex stiffness system by making use of the Hilbert transform and the convolution integral. Because the second-order differential equation of motion having the complex stiffness give rise to the conjugate complex eigen values, its time-domain analysis using the standard time integration scheme suffers from the numerical instability and divergence. In order to overcome this problem, the transient response of the linear complex stiffness system is obtained by the convolution integral of a green function which corresponds to the unit-impulse free vibration response of the complex system. The damped free vibration of the complex system is theoretically derived by making use of the state-space formulation and the Hilbert transform. The convolution integral is implemented by piecewise-linearly interpolating the external force and by superimposing the transient responses of discretized piecewise impulse forces. The numerical experiments are carried out to verify the proposed time-domain analysis method, and the correlation between the real and imaginary parts in the free and transient responses is also investigated.

• Journal of Ecology and Environment
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• v.32 no.3
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• pp.207-215
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• 2009

Greenbelts were designated by the Korean government in 1971 in 14 large cities to prevent uncontrolled urban expansion. Recently, deregulation of the greenbelt system has resulted in further development, but the ecological role of greenbelts has not been fully considered when decisions about urban management are being made. We examined the ecological roles of the greenbelt system in the Seoul metropolitan area and prepared sustainable management and improvement plans based on our analysis of landscape characteristics using satellite images covering a ${\sim}30$-year period. The loss of forest cover during this period in the greenbelt areas was lower than that in the areas outside and inside of the greenbelt. Fragmentation of forest cover was correlated with the pattern of loss of forest cover. The NDVI of the greenbelt remained steady at 90% of that in outside of the GB for three decades. This suggests that the greenbelt system has performed its primary roles well. However, the remaining green space was not adequate to provide a sink for air pollutants even when the greenbelt area was included. We discuss how the negative effects of urbanization can be reduced through sustainable management and restoration to promote ecological functioning in greenbelts and urban landscapes.

• Ecology and Resilient Infrastructure
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• v.7 no.3
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• pp.199-207
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• 2020

Against the backdrop of frequent weather disasters such as floods, droughts, and heat waves worldwide, urban parks should provide functions for the safety of urban residents as well as rest, culture, and ecological functions. In this study, a classification system for urban disaster prevention parks is proposed for the safety of the urbanites with the aim of securing a complex function in a green space in response to climate changes in the city. Analytical indicators were extracted through literature research, and the classification system was verified through on-site surveys of the target sites and interviews with those involved. The large class for evaluation was divided into three types: location, spatial composition, and disaster prevention complex facilities of urban parks; the direction of improvement was proposed for problems identified through empirical analysis.

• Structural Engineering and Mechanics
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• v.74 no.3
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• pp.425-434
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• 2020

The present paper is concerned at investigating the effect of hydrostatic initial stress, gravity and magnetic field in fiber-reinforced thermoelastic solid, with variable thermal conductivity. The formulation of the problem applied in the context of the three-phase-lag model, Green-Naghdi theory with energy dissipation, as well as coupled theory. The exact expressions of the considered variables by using state-space approaches are obtained. Comparisons are performed in the absence and presence of the magnetic field as well as gravity. Also, a comparison was made in the three theories in the absence and presence of variable thermal conductivity as well as hydrostatic initial stress. The study finds applications in composite engineering, geology, seismology, control system and acoustics, exploration of valuable materials beneath the earth's surface.

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.12
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• pp.1917-1922
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• 2013

The objective of this study is developing urban farm management system based on USN for remote monitoring and control. This system makes it easy to manage urban farm and make the database of collected information for to build the best environment for growing crops. For this, we build a green house and installed several types of sensors and camera through which the remote sensing information collected. In addition, building a web page for user convenience and information in real time to enable control. We confirmed experimentally all functions related to stability for a long period of time through field tests such as collection and transfer of information, environmental control in green house. It will be convenient for farmers to grow crops by providing the time and space constraints and a lot of flexibility. In addition, factory, office, home like environment, including facilities for it will be possible to extend.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.10 no.6
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• pp.1-14
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• 2007

This study was conducted to propose the plan of creating a brooklet reflecting an water-friendly space as well as its function as the habitats of wildbird in Cheongdam Neighborhood Park in Seoul. Major fields of this study include a survey of the staus, a basic plan, a master plan, a execution; a survey of this site was focused on topography, water system, trail, existing vegetation, wildbird; a detailed plan was focused on flow plan, planting plan, facility plan. Existing vegetation was classified into 5 types; Quercus mongolica-Q. acutissima forest, Robinia pseudoacacia forest, Populus${\times}$albaglandulosa forest, artificial green space, urban area. 11 species and 49 individuals of wildbirds appeared in 2004(3~4month). The plan of creating a brooklet were divided passive-zone, eco-zone, and dynamic-zone. Environment elements of each space including a mountain stream, ecological pond, marshland, ecological landscape forest, wildbird observation trail, waterway etc. The brooklet of Cheongdam Neighborhood Park is rated high as an important space for wildbird biodiversity. Accordingly, continuous monitoring of this biotope as a urban habitat is required as the environment changes.

• Journal of Information Processing Systems
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• v.13 no.4
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• pp.876-892
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• 2017

A virtual reality is a virtual space constructed by a computer that provides users the opportunity to indirectly experience a situation they have not experienced in real life through the realization of information for virtual environments. Various studies have been conducted to realize virtual reality, in which the user interface is a major factor in maximizing the sense of immersion and usability. However, most existing methods have disadvantages, such as costliness or being limited to the physical activity of the user due to the use of special devices attached to the user's body. This paper proposes a new type of interface that enables the user to apply their intentions and actions to the virtual space directly without special devices, and test content is introduced using the new system. Users can interact with the virtual space by throwing an object in the space; to do this, moving object detectors are produced using infrared sensors. In addition, the users can control the virtual space with their own postures. The method can heighten interest and concentration, increasing the sense of reality and immersion and maximizing user's physical experiences.

• Journal of the Korea Society of Computer and Information
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• v.21 no.4
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• pp.25-30
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• 2016

We consider energy efficient transmit and receive strategy for a delay sensitive data. More specifically, we investigate an energy optimum scheduling characteristics for the 2 user interference channel where each user interferes to each other. First, we determine the optimum transmission rate region each individual user may have for optimum transmission. Next, we consider the optimum transmission region of two users together. Shortest path algorithm can be used for further reduction of search space. Eventually, we can reduce computational complexity. We then examine the performance of the optimum transmission strategy for various system environments.

• Journal of the Korean Professional Engineers Association
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• v.45 no.1
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• pp.49-53
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• 2012

It has been a common misconception that landscape architecture is a gardening, landscape gardening or planting. However, landscape architecture is entirely different from gardening, landscape gardening and planting when it comes to professional category. Landscape architecture is a interdisciplinary science to improve a quality of citizen's life through analysing social culture, psychological configuration, aesthetic characteristic and integrating them in human society. Today's landscape architecture is a interdisciplinary technology including ecological and artistic value to create most of outdoor space used by human through preserving nature and enhancing the environment. The field has been changed constantly in the flow of the period and social development as providing green network system, recreation area, ecological environment in the city.