Twitter tsunami early warning network : a social network analysis of Twitter information flows

In the aftermath of earthquakes, tsunamis, such as the 2011 Great East Japan Tsunami, caused enormous damage around the world. With the extreme disaster events of the past, nations improved disaster preparedness and response through sensors and tsunami early warning systems. Even with system usage, however, governments still need to warn the targeted citizens – who may be anywhere within the vulnerable areas – of predicted tsunami and ordered mass evacuations within a very limited lead time. While social media research is on the rise outside the domain of social networking, very little is written about Twitter use for tsunami early warning. In this research, therefore, we examined the utility of Twitter as a tsunami early warning network, which engages citizens and disaster management agencies in diffusing disaster information. We conducted a social network analysis of Twitter information flows among the central disaster warning agency’s Twitter followers during the 2012 Indonesia Earthquake.

Comparisons of seismic rock slope stability assessments between the Hoek-Brown and Mohr-Coulomb failure criteria

Current investigations have shown that earthquakes can trigger significant damages of equipment, property infrastructure and environment. This is a persistent cause of economic loss for any country, especially for the loss of life. The conventional method for slope stability design is to utilize limit equilibrium method (LEM) in conjunction with the pseudo-static (PS) approach. However, the LEM has a significant drawback which is to determine the slip surface before factor of safety calculation. The numerical upper and lower bound limit analysis method employed in this paper can avoid this limitation. In this study, the presented slope stability evaluations considering earthquake effects based on the finite difference method will be discussed and compared with the results from the numerical limit analysis methods.

Kenzo Tange's forgotten master plan for the reconstruction of Skopje

After the 1963 earthquake, which is said to have destroyed seventy-five per cent of the urban fabric, Skopje, capital city of the Republic of Macedonia (then in Yugoslavia) became a centre of architectural activity. The United Nations held a limited competition for the reconstruction of Skopje, inviting four foreign firms and four Yugoslavian firms to participate. Tange's submission received sixty per cent of the first prize, co-operating with Yugoslav architects to develop the design idea. What can this project tell us about modernism re-inscribed in Japan, and the kinds of internationalism that the United Nations constructed? Japanese Metabolism, of which Tange was a pioneer, heralded Japan as a new centre for innovation in architecture; a new nationalism re-oriented the suffering after Hiroshima and Nagasaki. Tange developed and realised in Skopje the striking planning ideas he began in his Tokyo Bay proposal. This article examines Tange's master plan for Skopje. It argues that his key elements, the City Wall and the City Gate, exemplify Tange's drive for a new vision in the context of destruction, and that these remain definitive elements today even in the context of a messy transition from a communist to a capitalist society.

Synthetic evaluation method for bridge priority ranking

In order to maintain the transportation operation, proper monitoring systems should be established on road structures, especially bridges. Since these systems need enormous investments, only a part of bridges should be equipped. Thus, the priorities of the bridges should be ranked. In this paper, a method based on two-level synthetic evaluation is proposed. First, the importance of each bridge is analyzed through the economic analysis. Six factors are considered for the bridges in a network, including construction cost, service duration, length, location importance coefficient, traffic volume, and reconstruction time. Second, the safety condition of the bridge is evaluated by using improved entropy method (IEM) which combines subjective weight with objective entropy weight. Five indices are incorporated in this step, i.e., design and construction condition, technical condition, level of overloading, hazard of wind and earthquake and environmental factors. Finally, the priorities of all the bridge in one network can be ranked and classified through a judge matrix. To demonstrate the effectiveness of the proposed method, a main highway including 16 bridges is taken as an illustrative example. The results show that the bridges can be ranked and classified quickly by using the proposed method.