• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.1
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• pp.374-388
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• 2016

In Jeju-Do, there is the 1100 Road, 516 Road, and Bijarimro, which are typical mountain sight-seeing roads in Jeju. These roads are local roads that have been the location for many traffic accidents. This study focused on these roads, categorized the type of traffic accident and analyzed the accident characteristics. The major accident factors were analyzed through trip AHP analysis, Comparative analysis of the velocity distribution and the factors affecting traffic accidents were analyzed. Tourists took many trips on these roads. The mixing rate of the rental cars was 36.70%~71.60% in 1100 road and Bijarimro. Currently, these local roads are regulated by a speed limit of 60km/h. However, it might be necessary to reduce the speed limit to 40km/h considering the geometric line form of the road and the climate in these areas. The speed limit of more than 40km/h is found 87.0% on 516 Roads, 88.57% on 1100 roads, and 93.1% on Bjarimro, In these roads, the speed ratio is higher as described above. Therefore, these roads have been found to have a higher risk of traffic accidents by overspeeding driving. The overspeed driving ratio of these roads was 87.0%~93.1%, The overspeed driving enforcement method at one spot has only the effect of reducing the speed at that enforcement place; the effect cannot be expected for the other places or sections. It is necessary to introduce a section overspeed driving enforcement system utilizing the average velocity in these areas to prevent traffic accidents.

• Korean Journal of Environment and Ecology
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• v.21 no.3
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• pp.278-289
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• 2007

This study investigated species formation and their vegetation on the roadsides of 1100 Road and 5 16 Road in Hallasan National Park from August 2004 to December 2006 to provide basic data for distributional attribute of the naturalized plants. The vascular plants investigated on the roadsides of Hallasan National Park were found to be 62 families, 145 genera, 197 taxa in total, in which naturalized plants were recorded as 11 families, 29 genera, and 37 taxa. The floristic formation at 1100 Roadside was composed of Festuca arundinacea-Dactylis glomerata association, which was again divided into Trifolium pratense-Plantago lanceolata sub-association and Sasa quelpaertensis-Gleichenia japonica sub-association. The florisitic composition of the 5 16 Roadside was sorted as Festuca arundinacea-Dactylis glomerata association, Oplismenus undulatifolius-Potentilla fragarisiiforlia, elatior association, Ambrosia artemisiifolia, and etatior-Persicaria thunbergii association. Among the naturalized plants distributed at this area, the annual plant accounts for 51.4%[19 taxa] and the plant of European origin accounts for 70.3%[26 taxa]. As for the background of the introduction of these plants, the case of introduction for forage or a mixture with grain and for pasture was 35.1% and 21.6% respectively, showing higher introduction circumstances than others. As shown in the study, most of the roadsides were occupied by the naturalized plants- Festuca arundinacea and Dactylis glomerata association and various naturalized plants; thus we can assume that it's because Festuca arundinacea and Dactylis glomerata association were mostly used for re-vegetation of the destroyed areas due to road construction or expansion or road maintenance and improvement project.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.22 no.8
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• pp.1091-1100
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• 1998

Longitudinal distributions of the extinction coefficient and concentrations of hazardous gases in a long tunnel located in urban area haute been predicted theoretically. The results are compared with design criteria. It is found that the maximum concentrations of both CO and $NO_X$ in the tunnel are lower than the design criteria. However, the maximum extinction coefficient, generally considered to be a governing factor for ventilating flow rate, is shown lower than the design criterion. Therefore, it is suggested that the design criterion of the extinction coefficient should be increased to a slightly larger value.

• Journal of the Korean Society for Heat Treatment
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• v.36 no.1
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• pp.22-32
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• 2023

In general, when scrap is dissolved in an electric arc furnace, the amount of electric furnace steel dust (EAFD) generated is about 1.5% of the scrap charge amount, and the electric furnace steel dust collected by the bag filter is charged into the Rotary Kiln or Rotary Hearth Furnace (RHF), and the zinc component is recovered as crude zinc oxide, at which time a clinker of Fe-Base is generated. In this research, first, for the efficient resource conversion of electric furnace steel dust, a reduction and roasting experiment was conducted and the reaction kinetics was examined. As a result of the experiment, it was observed that the reduction and roasting reaction was actively conducted in the range of 1100~1150℃, and melting occurred in the range of 1250℃. In the past, this clinker was widely used as a roadbed material for road construction and an Fe-Source for cement production, but in recent years, it has been mainly reclaimed due to strengthening environmental standards. However, landfill treatment is by no means a desirable treatment method due to environmental pollution caused by leachate, expensive landfill costs, and waste of Fe resources. Therefore, in order to more actively recycle the Fe component in the clinker, first of all the clinker was pulverized into an optimal particle size, and anthracite and binder (starch) were added to the magnetic material obtained by specific gravity and magnetic separation for briquet. As a experimental results, it was possible to efficiently separate clinker as Fe component and other slag component by specific gravity and magnetic force. As a results of loading and dissolving the manufactured briquet clinker in an electric arc furnace, it was observed that the unit of power and production yield were clearly improved and the carbon addition effect in molten metal was also somewhat.