Vorkurs Informatik Der Einstieg ins Informatikstudium
Ausgehend von Beispielen werden grundlegende Paradigmen der Informatik vermittelt. Die Schwerpunkte liegen auf dem Algorithmenbegriff, auf einer Einführung in die Programmierung auf Grundlage der Programmiersprache Java und auf objektorientierten Konzepte
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onn Kao I Chih-Wen Kan I Rong-Yuh Chen I Chien-Hsin Chang I Andreas Rosenberger I TzayChyn Shin I Pei-Ling Leu I Kai-Wen Kuo I Wen-Tzong Liang
Locating, monitoring, and characterizing typhoonlinduced landslides with real-time seismic signals
Abstract Landslides induced by typhoon Morakot during its passage across Taiwan on 7–9 Aug 2009 claimed more than 700 lives and caused heavy economic loss. Unlike earthquake monitoring, precise locations of landslides could not be determined in nearreal time because their seismic phases are difficult to identify. Here, we show that large, damaging landslide events are characterized seismically by a distinct waveform pattern of frequent intermixes of P and S waves over a time window of several tens of seconds. The predominant frequency band during these time windows ranges from 0.5 to 5Hz. The high-frequency content is clearly deficient relative to that of local earthquakes by about one to two orders. We also demonstrate that large landslide events can be located and monitored with algorithms specifically designed for real-time seismic applications. This near-real-time monitoring capability would be particularly useful for emergency responders and government organizations to coordinate effective relief-andrescue operations. Keywords Landslides and mud/debris flows . Near-real time . Source-scanning algorithm . Typhoon Introduction Landslides induced by the excessive rainfall of typhoons and/or hurricanes can be catastrophic, both in loss of human life and to the economy. Typhoon Morakot, for example, passed over Taiwan on 7–9 Aug 2009 and dumped as much as 1,800 mm of rain over most of the mid- and southern parts of the island (Fig. 1). There were at least 619 fatalities and 76 people missing; most resulted from landslides and mud/debris flows (LMDF) burying villages in the mountainous area. The agricultural loss alone is estimated to be half a billion US dollars. In addition, there was wide-spread damage to transportation networks, levees, critical infrastructures, and other facilities. Timing is the most critical factor in rescuing LMDF victims. Ideally, emergency response agencies would identify and pin-point the locations of large-scale LMDF as they occur, then dispatch rescue teams as soon as the air and ground conditions permit. In reality, however, the exact location and size of LMDF often cannot be accurately assessed until much later, when surveillance photographs from aircrafts and/or satellites become available. Avoiding such a time delay might significantly improve the efficiency of rescue operations and save hundreds of lives. Seismic studies of LMDF in the past focused primarily on the representation of equivalent sources (e.g., Brodsky et al. 2003; Dahlen 1993; Kanamori and Given 1982; Kanamori et al. 1984) and the estimation of geometrical parameters such as the mass volume, total drop height, runoff speed, and runoff distance (e.g., Berrocal et al. 1978; Deparis et al. 2008; La Rocca et al. 2004). Although the potential importance of utilizing seismic networks t
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