• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.8
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• pp.423-432
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• 2016

Due to the increase in the number of transfer lines and ground level connections with mixed-use high-rise buildings, the Seoul Metro suffers from loaded signage fatigue because of the presence of too many signs. The purpose of this research is to propose ways of improving the wayfinding on the Seoul subway station by examining the signage and (applying the) universal design (UD) concept. A review of the literature explored five universal design components, viz. the accessibility, safety, equitability, perception, and aesthetics. The field investigation found that the ceiling and wall type and general information boards were high on the information hierarchy. The survey respondents merely perceived universal design concept, however, most needed principle. The IPA found that the signs should be appropriately laid out, spaced and located from the perspective of accessibility, and their unity and harmony were other aspects that could be improved while general information boards should include important landmarks outside. In conclusion, this study suggests that the universal design signage concept should be applied to every station and that specific stations should have a duly sign system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.12
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• pp.614-621
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• 2019

A generalized laminated composite beam element is presented for the flexural and buckling analysis of laminated composite beams with double and single symmetric cross-sections. Based on shear-deformable beam theory, the present beam model accounts for transverse shear and warping deformations, as well as all coupling terms caused by material anisotropy. The plane stress and plane strain assumptions were used along with the cross-sectional stiffness coefficients obtained from the analytical technique for different cross-sections. Two types of one-dimensional beam elements with seven degrees-of-freedom per node, including warping deformation, i.e., three-node and four-node elements, are proposed to predict the flexural behavior of symmetric or anti-symmetric laminated beams. To alleviate the shear-locking problem, a reduced integration scheme was employed in this study. The buckling load of laminated composite beams under axial compression was then calculated using the derived geometric block stiffness. To demonstrate the accuracy and efficiency of the proposed beam elements, the results based on three-node beam element were compared with those of other researchers and ABAQUS finite elements. The effects of coupling and shear deformation, support conditions, load forms, span-to-height ratio, lamination architecture on the flexural response, and buckling load of composite beams were investigated. The convergence of two different beam elements was also performed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.3
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• pp.190-198
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• 2020

For domestic urban railways, which have a 19.7% aging rate, a performance evaluation is necessary to establish capital improvement investment plans. The performance evaluation, which was recently enacted in the relevant law, points out the excessive time and effort for acquiring data and evaluation. This study developed a performance evaluation simulation prototype using a virtual reality (VR) method to use as training contents for railway performance evaluations. The practical use of the VR technique to reduce the working time under poor environment conditions was confirmed through a literature review. A survey and consultation were conducted for urban railway experts to determine the weight of the performance evaluation items and the facility breakdown structure. This information was utilized to develop performance evaluation sheets for simulation. Based on the evaluation sheet, a training content prototype that evaluates the performance of platform safety doors was developed using VR techniques with HTC VIVE equipment. VR simulation tests were conducted for six players, and the prototype was sufficiently advantageous for a visual confirmation of the facility information. The result is expected to be useful for engineers to understand the performance evaluation process efficiently before an actual performance evaluation of urban railway facilities.

• Journal of the Korea Concrete Institute
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• v.21 no.5
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• pp.573-580
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• 2009

This paper presents the mix composition, production method, and curing condition applied to the extruded ECC(Engineered Cementitious Composite) panel which are able to exhibit multiple cracking and potential pseudo strain-hardening behavior. In addition to the production technique of extruded ECC panel, the effect of fiber distribution characteristics, which are uniquely created by applying extrusion process, on the flexural behavior of the panel is also focussed. In order to demonstrate fiber distribution, a series of experiments and analyses, including image processing/analysis and micro-mechanical analysis, was performed. The optimum mix composition of extruded ECC panel was determined in terms of water matrix ratio, the amount of cement, ECC powder, and silica powder. It was found that flexural behavior of extruded ECC panel was highly affected by the slight difference in mix composition of ECC panel. This is mainly because the difference in mix composition results in the change of micro-mechanical properties as well as fiber distribution characteristics, represented by fiber dispersion and orientation. In terms of the average fiber orientation, the fiber distribution was found to be similar to the assumption of two dimensional random distribution, irrespective of mix composition. In contrast, the probability density function for fiber orientation was measured to be quite different depending on the mix composition.

• Journal of the Korea Concrete Institute
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• v.27 no.6
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• pp.633-640
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• 2015

Polymer cement slurry (PCS) is made from organic polymer dispersion and cement has good adhesion to steel, waterproofness and acid resistance due to being of polymer films formed in cement slurry. The purpose of this study is to evaluate the bond strength of coated rebar by polymer cement slurry made of EVA and ultra high-early strength cement. The test pieces are prepared with EVA polymer dispersion and ultra high-early strength cement having four types of polymer-cement ratios, four types of coating thicknesses and four curing ages, and tested for the bond strength test. From the test results, in general, bond strength of PCS-coated rebar is better than that of uncoated rebar and epoxy-coated rebar. It is also high bond strength at curing ages of 7-day, and coating thicknesses of $75{\mu}m$ and $100{\mu}m$. The maximum bond strength of PCS-coated rebar with ultra high-early strength cement and EVA at polymer-cement ratio of 80%, and coating thickness of $100{\mu}m$ is about 1.32 and 1.38 times respectively, the strength of uncoated rebar and epoxy-coated rebar. It is apparent that the curing age, coating thickness, type of polymer and cement are very important factors to improve the bond strength of PCS-coated rebar to cement concrete. We can have basic information that PCS-coated rebar with polymer-cement ratio of 80% or 100% and coating thickness of $100{\mu}m$ at curing age of 1-day can replace epoxy-coated rebar.

• Journal of the Korean Association of Geographic Information Studies
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• v.16 no.3
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• pp.115-125
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• 2013

The systematic management of river is difficult due to various environmental factors such as season and terrain deformation. Especially, river terrain are rapidly changing by natural and anthropogenic factors such as torrential rain during the summer and river development projects. Thus in this conditions, building the advanced river management system is an essential condition to support the ongoing management of survey data and to acquire data regularly through river terrain survey in order to maintain an active river. The need to build an efficient system have been increased through the enhancement and advancement of River Management Geographic Information Systems(RIMGIS). In this study, database design system and Riverbed Change Data Management Program was developed for systematic management of new river terrain survey data and the efficient use of river data dynamic changes. The key features are construction of river survey data, cross and longitudinal section monitoring and analysis of riverbed change data. Maintenance tasks which can be utilized in river-based architecture was constructed. The expected results are to be able to manage river systematically, and utilization of river topographic survey data efficiently for river maintenance work.

• Korean Journal of Environmental Agriculture
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• v.23 no.1
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• pp.34-40
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• 2004

This study was conducted to get some vegetation information and to find out a way to conseue the ecosystem in the Dongjin River. The riparian vegetation was investigated by Zurich-Montpellier school's method from June 2001 to March 2002. The number of riparian plants were 73 families, 188 genera, 238 species, 33 varieties or 272 Taxa in Dongjin River. The characteristics of life farm spectra were 97 therophytes (35.7%), 78 hydrophytes (28.7%), 41 hemicryptophytes (15.1%) 22 geophytes (8.1%), and 12 chamaephytes (4.4%). The riparian vegetation was identified 8 plant communities (Potamogeton brechtoldii, Hydrilla verticillata, Ceratophyllum demersum, Potamogeton malaianus, Phragmites japonica, Persicaria thunbergii, Cardamine scutata, Persicaria hydropiper) in upstream, 4 plant communities (Zizania latifoliar, Phragmites communis, Persicaria thunbergii, Humulus japonicus) in midstream and 8 plant communities (Hydrocharis dubia, Ceratophyllum demersum, Trapa japonica, Zizania latifolia, Paspalum distichum, Phragmites communis, Pericaria thunbergii, Amphicarpaea edgeworthii) in downstream of the Dongjin River.

• The Journal of Engineering Geology
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• v.20 no.1
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• pp.47-60
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• 2010

This study is focused on the analysis of tunnel behavior to estimate the stability on tunnel design. An estimation method was proposed as a hybrid consideration, which contains the displacement analysis by 3D numerical simulation, the maximum displacement obtained after field measurement, and an assessment of tunnel stability using a deformation analysis proposed by Sakurai(1988, 1997). The points of case study by Sakurai(1988, 1997) were replotted considering his analysis. From the new analysis of the tunnel case study, the trend line for analyzed points is analogized, which curve is divided into stable, unstable and failure zone. To evaluate the estimation method, a special shape of railway tunnel was selected, which are the Inchon international airport rail way connected to subway line 9 in Gimpo, Korea. The point s of upper and below track on the Inchon international airport rail way were satisfied to the stability of tunnel after reinforcing. Also the points shows the higher apparent Young's modulus, which resulted from improvement on shear strength by the micro silica grouting and the supporting of umbrella method. Therefore, if new analysis used, proper tunnel reinforcing method could be selected according to tunnel strain and geological property.

• Journal of Environmental Impact Assessment
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• v.25 no.1
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• pp.15-24
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• 2016

This study was analyzed the distribution tendencies and statuses of development projects for EIA projects. According to the result of this study, in the annual analysis, a number of consultations and areas have shown increasing trend across the board. In the project type analysis, there are development project types; urban development, industrial complex, sport facility installation, resort complex development, road construction, which have a lot of developments. In the cities analysis, a number of consultations were about 53% on the top 5 cities, the areas were focused on 75%, and the development projects were concentrated in the southern distribution of Gyeong-gi province. The development axis, from 2004 to 2006, was C-type, but it was extended to O-type until 2010. Therefore, the development will expand into nature conservation zones and forest areas to the east. The development restriction area will be disappeared gradually because the development density of the surrounding Seoul city is more advanced, and we could predict that may be accelerated conurbation between the neighboring cities. Thus, when the development project is located, it would be reviewed difference in existing development project type, project size, and concentration in each city on the basis of environmental capacity.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.6 no.2
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• pp.21-26
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• 2003

The purpose of this study was to investigate morphological characteristics of 153 wild grown Poa pratensis collected from various areas of Korea and to see correlation among morphological characteristics and visual rating. Morphological characteristics such as plant height, leaf length, leaf width were measured. The collected Poa pratensis plants showed various morphological differences. The plant height of Poa pratensis ranged from 4.5 to 40.0cm. Poa pratensis leaf length ranged 3.0 to 30.2cm and leaf width ranged 1.0 to 5.0mm. The mean values of Poa pratensis height, leaf length and leaf width were 18.2cm, 13.1cm and 2.7mm respectively. The Poa pratensis plots were also visually rated 1 to 9 scale throughout the growing season for their overall characteristics as turfgrass. The height, leaf length, leaf width and visual rating had significant positive correlations. Especially the height and leaf length had a highly significant positive(r=0.74) correlation.