Formulations for simulating trajectories of the pantograph and reaction forces at nodal points of the pantograph mechanism are presented to develop the mechanism analysis program for railway pantograph with one contact strip. By comparison between the developed program and Solid Works®, commercial CAD S/W for tilting angles of the contact strip simulated during its upward motions, the accuracy of the formulations is validated. An optimal pantograph mechanism can be obtained by using the developed program which can simulate the changes of major design parameters, such as tilting angles of a contact strip and driving moments of a lower arm, as the lengths of members are changed.

Mechanical fatigue tests which consist of an alternate load and compression cycle show that droppers for 400km/h operation have cyclic mechanical strength of 300N with compression amplitude 0.05m. Numerical simulations for forces on the dropper during the passage of a train tell that dynamic forces can be varied up to 15% due to installation tolerance. Taking into account of the 15% variation, we end up with the maximum allowable peak load of 260N for the dropper. Peak value of measured forces on the dropper at the speed of 400km/h is 152N, which is less than the maximum allowable peak load of 260N. Conclusively, the possibility of fatigue fracture for the dropper is quite low.

Formulation of the finite element method(FEM) for dynamic interaction between a pantograph and contact wire, including non-linear formulation associated with contact wire stagger in the railway overhead contact line is presented. Penalty method is chosen for modelling contact between a pantograph and contact wire. The formulation is validated by comparing the simulated contact forces with measurements taken from 300 km/h KTX operation.

This study was carried out to evaluate the physicochemical properties and perform a feasibility analysis of planting material composed of topsoil from river improvement and non-improvement areas. The results showed that the physicochemical properties of topsoil from river improvement areas were on the average sandy loam~loamy sand in soil texture, 5.6~6.8 in pH, 0.01~0.06 dS/m in EC, 0.9~2.1% in OM, 0.02~0.12% in T-N, 8~14 cmol+/kg in CEC, 0.01~0.08 cmol+/kg in Ex. K+, 2.55~11.11 cmol+/kg in Ex. Ca2+, 0.34~2.06 cmol+/kg in Ex. Mg2+, and 3~396 mg/kg in Av. P2O5. And non-improvement areas showed on average sandy clay loam~sand in soil texture, 5.7~6.7 in pH, 0.02~0.08 dS/m in EC, 0.9~4.4% in OM, 0.02~0.23% in T-N, 7~18 cmol+/kg in CEC, 0.01~0.08 cmol+/kg in Ex. K+, 3.81~12.67 cmol+/kg in Ex. Ca2+, 0.60~1.95 cmol+/kg in Ex. Mg2+, and 3~171 mg/kg in Av. P2O5. Meanwhile, the results of an applied valuation of topsoil- based planting were as follows. Ex. K+ levels were low grade in all survey areas. OM was low grade in 12 improvement areas and 11 non-improvement areas. Av. P2O5 levels were low grade in 10 improvement areas and 10 non-improvement areas. T-N was low grade in six improvement areas and four non-improvement areas. Ex. Mg2+ levels were low grade in two improvement areas.

Purpose of this study was to evaluate germination characteristics of soil seed bank in rural stream topsoil using seedling emergence method in order to provide data for future ecological restoration of stream utilizing topsoil. There were 24 families, 52 genera, 61 taxa of soil seed bank flora found in topsoil from 6 rural streams. The most frequently found taxa were Compositae (12 taxa) followed by Gramineae (8 taxa), Caryophyllaceae (5 taxa), Cruciferae (4 taxa), Scrophulariaceae, Labiatae, Polygonaceae and Cyperaceae. Plant with the most number of germination was Stellaria aquatica followed by Erigeron annuus, Imperata cylindrica var. koenigii, Poa annua, Cyperus microiria and Veronica undulata. Naturalized plants found were Erigeron annuus, Rumex crispus, Oenothera odorata, Cerastium glomeratum, Bidens frondosa, Erigeron philadelphicus, etc.

This study was carried out to evaluate the physicochemical properties of topsoil from forest development area. The results of physicochemical properties of topsoil from forest development area shown on the average loamy sand~sandy clay loam in soil texture, 5.3~7.1 in pH, 0.02~0.18 dS/m in EC, 0.7~1.8% in OM, 0.03~0.11% in T-N, 11~15 cmol+/kg in CEC, 0.02~0.04 cmol+/kg in K+, 4.51~8.18 cmol+/kg in Ca2+, 0.93~2.77 cmol+/kg in Mg2+, 6~49 mg/kg in available phosphate. And the results of physicochemical properties of topsoil from forest non-development area shown on the average sandy loam~sandy clay loam in soil texture, 4.4~5.3 in pH, 0.03~0.05 dS/m in EC, 3.1~4.6% in OM, 0.13~0.23% in T-N, 14~18 cmol+/kg in CEC, 0.02~0.04 cmol+/kg in K+, 0.78~3.82 cmol+/kg in Ca2+, 0.29~1.31 cmol+/kg in Mg2+, 3~31 mg/kg in Av. P2O5. On the other hand, forest development area of topsoil sand content higher than 8~18% sand content than the forest non-development area. This trend is thought to be the absence of topsoil management development projects. Consequently, the results suggested a high potential of recycling of the topsoil from forest non-development area for planting soil. Therefore, in construction of the conservation and management of topsoil from forest non-development area is very important.