In this paper, a new mobile robot, so called a rollerbot, is presented, which has single body and rugby-ball shaped roller wheel. A rollerbot has single point contact on ground and low energy consumption in motion because of the reduced friction. By changing center of mass using a balancing weight, a rollerbot is able to get steering force. The vertical position of mass center of the rollerbot in this paper is designed to lie inside radius of the roller wheel, so that to have stable equilibrium position. Thus, the posture and the steering control of the rollerbot can be easily done by changing the center of mass. Kinematics of the rollerbot is derived by transformation of differential motion in this paper.

In this study, EL. 610 test and SHRP H-205.8 test were performed to evaluate the effects of deicing salts on concrete. According to the test results, EL. 610 chemical deicer test method was not enough to evaluate the chemical effects on concrete. On the contrary, the results of SHRP H-205.8 test method showed clear distinction between deicer type A and type B.

Blast furnace slag is recycled as high value-added material, while steel slag is difficult to recycle or is recycled as low value-added one relatively due to its expansion collapsability. It's property is caused by the high content of Free-CaO and unstable steel oxides. Currently, a technique to subdivide the process refining is introduced, can be divided into the electric furnace steel slag and reducing steel slag. In this study, Free-CaO in the electric arc furnace slag by the ethylene glycol method for the quantitative evaluation for the expansion to proceed with construction materials, electric arc furnace slag oxidation is to use.

The purpose of this study is to analyze seasonal distribution of insects, birds, fishes, and benthos for Gongji stream in Chuncheon and to explore some strategies towards creating a desirable close-to-nature stream. The number of species occurred in the study stream was 23 for butterflies and 149 for other insects, 23 for birds, 15 for fishes, and 47 for benthos. The study stream was dominated by Artogenia rapae, Polygonia caureum, Cyntia cardui for butterflies, and Passer montanus, Anas crecca, Anas platyrhynchos for birds. The dominant species were Rhynchocypris oxycephalus, Zacco platypus, Carassius auratus for fishes, and Limnodrilus sp. 2, Chironomus sp. 2, Hydropsyche KUb for benthos. Attracting insect species of higher density requires planting of host plant species and stabilization of plant coverage against disturbances. To enhance species diversity and density of birds, it is desirable to provide diverse habitats including preservation of downstream wetland and natural vegetation, creation of sand bars and islands with sand and gravel, and restriction of traffic passing and parking. Restoring fish and benthos habitats needs improvement of water quality, layout of gravels and stones on sand-dominant streambed, and use of close-to-nature revetment techniques.