地震災害が地域に及ぼす経済的影響 : 直接被害額推定法の提案

The type and intensity of the effects of an earthquake disaster is influenced by the social and economic development patterns prevailing in the region. Thus, it becomes of particular relevance to evaluate the damage caused by such disasters from social and economic perspectives，that is，as part of the development process. Namely，it is important to collect and to analyze the amount of direct and indirect of socioeconomic damages caused by earthquakes for the enhancement of the seismic safety environment in the course of regional development. This study，first of all，develops an experimental equation for estimation of the total amount of direct damage caused by an earthquake in Japan. The evaluation of direct economic loss by the experimental equation is carried out through the use of statistical data “MINRYOKU” which is a database of an accumulated social and economical information in each prefectures and/or cities.1964年新潟地震が発生し、新潟市内では液状化による被害が多発した。この「液状化」現象は世界的に有名になり、地盤工学の分野で発生メカニズムの解明・対策などの技術が飛躍的に進歩した。しかし、新潟市で1,048億円(1994年換算で約1.6兆円)、新潟県で1,300意円(1994年換算で約2.0兆円)の直接被害額が発生し、この直接被害総額は1964年新潟市税収入の約40年分に相当する規模であった。しかし、このような経済的視点からの被害の考察や地震防災の必要性を指摘した事実は見当たらない。同様に、1995年阪神・淡路大震災による被害は、高架橋の横転や大規模な地震火災など、物的被害がセンセーショナルに報道された。しかし、兵庫県における直接被害総額約10兆円の被害規模や、この被害額が震災後も被災地域の社会経済活動に大きく圧し掛かっている事実を詳細に調査・研究しているとは言い難い。今まで、の地域防災計画は、地震発生直後の救急・消火、被災者への対応など救急・応急対応を主眼として構成されていた。もちろん、こうのような緊急・応急対策は重要な対策であるが、他方、地震発生後から始まる地域の復旧・復興、再建、特に、経済活動の早期立ち直りに関する具体な対策が不十分で、あったと推察される。地震後の地域再建過程で問題となるのは、地域経済を如何に速やかに再建させるかである。そのための事前の準備として、経済的被害(直接・間接被害を含む)に関する予測やそれに対する地域経済への影響予測が必要になってくる。しかし、既往の地震災害事例調査を概観すると、そのほとんどが、地震学的観点からの分析・考察、一方、工学分野では物的・人的被害発生の原因究明と対策に限定されていたと言える。物的・人的被害の軽減は地震防災に与えられた究極の課題であるが、同様に、経済的視点からの災害規模の把握・考察さらに経済的対応・対策も必要であると言える。本研究は既往の地震災害を経済的損失面から整理するとともに、直接被害額推定の開発を試みたものである。本論では、1964年以後の被害地震(7地震:表1、2参照)による直接被害額の情報収集・整理を行い、さらに地域固有の「社会経済力」の評価を民力総合指数を用いて行い、両者を対応させることで経験的な直接被害総額推定式(本論の7式)を開発した。この推定式には震度補正項と被害の直接的起因となる地震動、液状化、津波補正の3項目が考慮されている。しかし、社会経済力評価に用いた民力総合指数はストックとフローを合算した指標を用いており、元来、直接被害額とは資本ストックの被災量(額)であるから、この総合指数の中からストックに関連する指標のみを抽出し適切に評価することが重要である。今後の課題として、社会経済力評価の改善とさらに間接被害額も直接被害額と同じかあるいはそれを上回る規模になるとの報告や予測が出ており、それらを今後の研究課題とするものである

Results of the search for inspiraling compact star binaries from TAMA300's observation in 2000-2004

We analyze the data of TAMA300 detector to search for gravitational waves from inspiraling compact star binaries with masses of the component stars in the range 1-3Msolar. In this analysis, 2705 hours of data, taken during the years 2000-2004, are used for the event search. We combine the results of different observation runs, and obtained a single upper limit on the rate of the coalescence of compact binaries in our Galaxy of 20 per year at a 90% confidence level. In this upper limit, the effect of various systematic errors such like the uncertainty of the background estimation and the calibration of the detector's sensitivity are included.Comment: 8 pages, 4 Postscript figures, uses revtex4.sty The author list was correcte

Coincidence analysis to search for inspiraling compact binaries using TAMA300 and LISM data

Japanese laser interferometric gravitational wave detectors, TAMA300 and LISM, performed a coincident observation during 2001. We perform a coincidence analysis to search for inspiraling compact binaries. The length of data used for the coincidence analysis is 275 hours when both TAMA300 and LISM detectors are operated simultaneously. TAMA300 and LISM data are analyzed by matched filtering, and candidates for gravitational wave events are obtained. If there is a true gravitational wave signal, it should appear in both data of detectors with consistent waveforms characterized by masses of stars, amplitude of the signal, the coalescence time and so on. We introduce a set of coincidence conditions of the parameters, and search for coincident events. This procedure reduces the number of fake events considerably, by a factor $\sim 10^{-4}$ compared with the number of fake events in single detector analysis. We find that the number of events after imposing the coincidence conditions is consistent with the number of accidental coincidences produced purely by noise. We thus find no evidence of gravitational wave signals. We obtain an upper limit of 0.046 /hours (CL $= 90$) to the Galactic event rate within 1kpc from the Earth. The method used in this paper can be applied straightforwardly to the case of coincidence observations with more than two detectors with arbitrary arm directions.Comment: 28 pages, 17 figures, Replaced with the version to be published in Physical Review

Observation results by the TAMA300 detector on gravitational wave bursts from stellar-core collapses

We present data-analysis schemes and results of observations with the TAMA300 gravitational-wave detector, targeting burst signals from stellar-core collapse events. In analyses for burst gravitational waves, the detection and fake-reduction schemes are different from well-investigated ones for a chirp-wave analysis, because precise waveform templates are not available. We used an excess-power filter for the extraction of gravitational-wave candidates, and developed two methods for the reduction of fake events caused by non-stationary noises of the detector. These analysis schemes were applied to real data from the TAMA300 interferometric gravitational wave detector. As a result, fake events were reduced by a factor of about 1000 in the best cases. The resultant event candidates were interpreted from an astronomical viewpoint. We set an upper limit of 2.2x10^3 events/sec on the burst gravitational-wave event rate in our Galaxy with a confidence level of 90%. This work sets a milestone and prospects on the search for burst gravitational waves, by establishing an analysis scheme for the observation data from an interferometric gravitational wave detector

Stable Operation of a 300-m Laser Interferometer with Sufficient Sensitivity to Detect Gravitational-Wave Events within our Galaxy

TAMA300, an interferometric gravitational-wave detector with 300-m baseline length, has been developed and operated with sufficient sensitivity to detect gravitational-wave events within our galaxy and sufficient stability for observations; the interferometer was operated for over 10 hours stably and continuously. With a strain-equivalent noise level of $h\sim 5 \times 10^{-21} /\sqrt{\rm Hz}$, a signal-to-noise ratio (SNR) of 30 is expected for gravitational waves generated by a coalescence of 1.4 $M_\odot$-1.4 $M_\odot$ binary neutron stars at 10 kpc distance. %In addition, almost all noise sources which limit the sensitivity and which %disturb the stable operation have been identified. We evaluated the stability of the detector sensitivity with a 2-week data-taking run, collecting 160 hours of data to be analyzed in the search for gravitational waves.Comment: 5 pages, 4 figure

Stereoselective Construction of Fluorinated Quaternary Stereogenic Centers via an Organocatalytic Asymmetric exo-Selective Diels-Alder Reaction in the Presence of Water

A catalytic, asymmetric Diels-Alder reaction of α-fluoro α,β-unsaturated aldehydes and cyclopentadiene was developed using diarylprolinol silyl ether as an organocatalyst. The reaction proceeds in toluene with trifluoroacetic acid as an additive (condition A). Perchloric acid salt of diarylprolinol silyl ether also promotes the reaction using water as a reaction medium (condition B). In both cases, excellent exo-selectivity and enantioselectivity were obtained with generation of a fluorinated quaternary chiral center