• Proceedings of the Korean Geotechical Society Conference
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• 2006.03a
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• pp.552-561
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• 2006

The purpose of this study is to propose a pavement analysis system which considers dynamic effects resulted from the various vehicle speeds. Vehicle loading effects were estimated by loading frequency and dynamic loads under various vehicle speeds. In addition, a proposed analysis model takes the non-linear temperature using a predictive model for dynamic modulus in asphalt layer and the non-linear stress in the unbound material. To examine adequacy of existing multi-layer elastic analysis of non-linear temperature in asphalt layer and non-linear stress conditions in unbound material, this study divided layers of asphalt pavement structures with 10 layers in asphalt, 2 layers in subbase and 1 layer in subgrade. In order to verify the pavement analysis system that considers various speeds, deflections of pavement calculated using ABAQUS, a three dimensional finite element program, were compared with the results of field tests under various speeds.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.10
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• pp.1551-1558
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• 2022

We propose a two-tier cooperative computing system comprised of a mobile device and an edge server for partial offloading of multi-branch structures in Fog/Edge Computing environments in this paper. The proposed system includes an algorithm for splitting up application service processing by using reconstructive linearization techniques for multi-branch structures, as well as an optimal collaboration algorithm based on partial offloading between mobile device and edge server. Furthermore, we formulate computation offloading and CNN layer scheduling as latency minimization problems and simulate the effectiveness of the proposed system. As a result of the experiment, the proposed algorithm is suitable for both DAG and chain topology, adapts well to different network conditions, and provides efficient task processing strategies and processing time when compared to local or edge-only executions. Furthermore, the proposed system can be used to conduct research on the optimization of the model for the optimal execution of application services on mobile devices and the efficient distribution of edge resource workloads.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.7 no.2
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• pp.75-86
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• 2004

This study aims to figure out ecological characteristic of natural forests focusing on vegetation as a way of ecological renovation for the restoration of naturalness for golf courses that were constructed in the Country and to present vegetation models and appropriate tree species for the purpose. The study site is P golf club, which is located in Gapyong-gun, Kyeonggi Province. The site is within a forest where the grade from the natural ecology map is the first one and the level from the green index accounts for the eight, thus showing a typical environment for a golf course in terms of location. The location of the site explains a reason for restoration. The major substance of the study is to conduct ecological evaluation of vegetation structures around and inside the golf course and to present a vegetation model. In order to evaluate the ecological characteristics of the vegetation structures, the analysis of the study covered succession stages, multi-layer vegetation structures and species diversity. Plant communities that have high species diversity were selected for the vegetation model and proper density and species were proposed considering the number of species and individuals and distances between trees. The vegetation restoration model targets succession into an oak forest. Within a unit of 100 $m^2$, the recommended model include a tall-tree layer with 11 trees such as Quercus serrata and Quercus mongolica, a sub-tall-tree layer with 12 trees including Quercus mongolica, Quercus serrata, Prunus sargentii, Fraxinus rhynchophylla and Acer pseudo sieboldianum, a shrub layer with 32 trees from 16 species, and a grass layer with a cover rate of 45 %. The proposed vegetation restoration model needs to apply to : 1) damaged natural forests by the construction of golf courses; 2) boundaries between golf courses and surrounding forests; 3) buffer zones; 4) open spaces in between courses; and 5) areas between greens and tees where open spaces are available in a mass. In conclusion, one of the most important factors in presenting a vegetation model for the restoration of naturalness in the golf course and other damaged forests is to provide multi-layer vegetation structures that are composed of native species. As for the specific application for the site, it is recommended to manage the vegetation in such a way that the environment of the site can have a similar environment to the surrounding forest which is expected to succeed into an oaks-dominant one.

• Journal of the Korean Institute of Landscape Architecture
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• v.28 no.6
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• pp.1-15
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• 2001

The purpose of this study is to figure out the structural characteristics of urban plant community and suggest restoration model of Quercus mongolica in the case of Korean national Capital Region. The investigation areas were selected from urban area of Mt. Nam at Chung-Gu, suburban areas of Mt. Bong at Eunpyoung-GU, Mt. Sungju at Buchon City and non-urban areas of Mt. Suri at Kunpu City and Mt. Chonma t namyangju-City. After the main study field had been classified into the evaluation of the ecological characteristics and the modeling of the vegetation. We analyzed to evaluate the ecological characteristics of the forest structure -- successional stage, naturalness, multi-layer structure of the forest and species diversity, and the plant community structures. We have proposed vegetation restoration model based on the selection of proper plants, the number of individuals, diameter short area of breast height, the shortest distance between plants in non-urban area. As for successional stage, It was judged that the ecological succession may not be followed like the present stage of the surveyed areas in urban, suburban and non-ruban areas. As for the retention of naturalness and multi-layer structures of vegetation, In Quercus mongolica community, Robinia pseudo-acacia and Ailanthus altissima occurred in each layers at Mt. Nam, Mt. Bong and Mt. Sungju, and Eupatorium rugosum occurred in herbaceous layer at Mt. Nam. Consequently, the ecological restoration plan following the structure of the vegetation in Mt. Chonma seemed to be advisable in Q. mongolica community, there were less number of species and individuals in urban areas than those of non-urban areas. Planting of trees following the simulated native plant community of non-urban areas seemed to be required to promote the plants in urban areas. Considering the number of individuals up to three layers in each 400$m^2$ area, it was composed of twenty nine in canopy layer, forth nine in understory layer, 367 in shrub layer and 33.7% herbaceous ground cover in the Q.mongolica community. The suggested restoration model in this study is nan applicable model for the introduction in the cities, and this study shows that continuous experiments and field investigation on this model should be performed in the future.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.7 s.178
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• pp.1703-1711
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• 2000

Microstructural morphology of molded composites of thermotropic liquid crystalline polymer(LCP) and polyamide 6 (PA6) has been studied as a function of epoxy fraction. Injection-moulding of a thin composite plaque at a temperature below the melting point of the LCP fibrils by suing the extruded LCP/PA6 pellets produced multi-layered structures: 1) the surface skin layer with thickness of 65-120 ym exhibiting a transverse orientation, 2) the sub-skin layer with an orientation perpendicular to the surface skin, i.e. in the flow direction, 3) the core layer with arc-curved flow patterns. Similar microstructural orientations were observed in the respective layers for the composite plaques with different fractions of epoxy.

• International Journal of Automotive Technology
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• v.6 no.6
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• pp.607-613
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• 2005

In this study, a simplified approach to modeling the dynamic characteristics of passive constrained layer damping treatments in finite element models is presented. The basic concept is to represent multi-layered composite structures using an equivalent single layer. The equivalent properties are obtained by using the RKU (Ross, Kerwin and Ungar) equations. Comparisons are given between results obtained by the dynamic analysis of the simple models implemented in MSC/NASTRAN and by test measurements. Surface damping treatments are applied to automotive panels as well as simple structures. Using the proposed equivalent modeling technique, higher computational efficiency for the damped composite structures has been obtained.

• Korean Journal of Materials Research
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• v.26 no.3
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• pp.160-165
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• 2016

To increase the capacitance of an Al electrolytic capacitor, the anodic oxide film, $Al_2O_3$, was partly replaced by an $Al_2O_3-ZrO_2$ (Al-Zr) composite film prepared by the vacuum infiltration method and anodization. The microstructure and composition of the prepared samples were investigated by scanning electron microscopy and transmission electron microscopy. The coated and anodized samples showed multi-layer structures, which consisted of an inner Al hydrate layer, a middle Al-Zr composite layer, and an outer $Al_2O_3$ layer. The thickness of the coating layer could go up to 220 nm when the etched Al foil was coated 8 times. The electrical properties of the samples, such as specific capacitance, leakage current, and withstanding voltages, were also characterized after anodization at 100 V and 600 V. The capacitances of samples with $ZrO_2$ coating were 36.3% and 27.5% higher than those of samples without $ZrO_2$ coating when anodized at 100 V and 600 V, respectively.

• Earthquakes and Structures
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• v.10 no.4
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• pp.939-963
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• 2016

According to the new directives about the rational and efficient use of energy, thermal bridges in buildings have to be avoided, and the thermal insulation (TI) layer should run without interruptions all around the building - even under its foundations. The paper deals with the seismic response of multi-storeyed reinforced concrete (RC) frame building structures founded on an extruded polystyrene (XPS) layer placed beneath the foundation slab. The purpose of the paper is to elucidate the problem of buildings founded on a TI layer from the seismic resistance point of view, to assess the seismic behaviour of such buildings, and to search for the critical parameters which can affect the structural and XPS layer response. Nonlinear dynamic and static analyses were performed, and the seismic response of fixed-base (FB) and thermally insulated (TI) variants of nonlinear RC building models were compared. Soil-structure interaction was also taken into account for different types of soil. The results showed that the use of a TI layer beneath the foundation slab of a superstructure generally induces a higher peak response compared to that of a corresponding system without TI beneath the foundation slab. In the case of stiff structures located on firm soil, amplification of the response might be substantial and could result in exceedance of the superstructure's moment-rotation plastic hinge capacities or allowable lateral roof and interstorey drift displacements. In the case of heavier, slenderer, and higher buildings subjected to stronger seismic excitations, the overall response is governed by the rocking mode of oscillation, and as a consequence the compressive strength of the XPS could be insufficient. On the other hand, in the case of low-rise and light-weight buildings, the friction capacity between the layers of the applied TI foundation set might be exceeded so that sliding could occur.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2000.04b
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• pp.271-276
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• 2000

Optimal neuro-control algorithm is extended to the control of a multi-degree-of-freedom structure. An active mass driver(AMD) system on the top roof used as a controller. The control signals are made by a multi-layer perceptron(MLP) which is trained by minimizing a sub-optimal performance index. The performance index is a function of both the output responses and the control signals. Structure having nonlinear hysteretic behavior is also trained and controlled by using proposed control algorithm. Bothe the time delay effect and the dynamics of hydraulic actuator are included in the simulation. Example shows that optimal neuro-control algorithm can be applicable to the multi-degree of freedom structures.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.4
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• pp.443-447
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• 2004

In this study, we investigated the necessity of encapsulation layer to maximize flexibility of brittle indium-tin-oxide (ITO) on polymer substrates. And, Young's modulus (E) of encapsulation layer han a significant effect on external bending stress and the coefficient of thermal expansion (CTE) of that han a significant effect on internal thermal stress. To compare the magnitude of total mechanical stress including both bending stress and thermal stress, the mechanical stress of triple-layer structure (substrate / ITO / encapsulation layer or substrate / buffer layer / ITO) can be quantified and numerically analyzed through the farthest cracked island position. As a result, it should be noted that multi-layer structures with more elastic encapsulation material have small mechanical stress compared to that of buffer and encapsulation structure of large Young's modulus material when they were externally bent.