Farm income,inequality, and poverty among farm families of a flood-prone area in Bangladesh: climate change vulnerability assessment     

Alamgir  Md. Shah  Furuya  Jun  Kobayashi  Shintaro  Mostafiz  Rubaiya Binte  Ahmed  Md. Rashid 《GeoJournal》2021,86(6):2861-2885

GeoJournal - This paper examines the farm income differences, income inequality of farm households, parameters of income variability that ascertain vulnerability levels, and cost-income variability...  相似文献   

Liverpool telescope 2: a new robotic facility for rapid transient follow-up     

C. M. Copperwheat  I. A. Steele  R. M. Barnsley  S. D. Bates  D. Bersier  M. F. Bode  D. Carter  N. R. Clay  C. A. Collins  M. J. Darnley  C. J. Davis  C. M. Gutierrez  D. J. Harman  P. A. James  J. H. Knapen  S. Kobayashi  J. M. Marchant  P. A. Mazzali  C. J. Mottram  C. G. Mundell  A. Newsam  A. Oscoz  E. Palle  A. Piascik  R. Rebolo  R. J. Smith 《Experimental Astronomy》2015,39(1):119-165

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Wavenumber spectra of planetary-scale disturbances in the Mars atmosphere     

Takeshi Imamura  Hiroko Kobayashi 《Icarus》2009,199(2):286-294

Wavenumber spectra of the martian atmosphere covering zonal wavenumbers s=1-6 were obtained as a function of latitude and season for the first time from the temperatures measured by the Thermal Emission Spectrometer onboard the Mars Global Surveyor. The stationary component tends to peak at s=2, where the martian topography has large amplitude, and drops rapidly at higher wavenumbers. The transient component in the middle and high latitudes tends to peak at s=1, which is lower than the most unstable wavenumber based on linear theories, and exhibits spectral slopes much flatter than the stationary component. In the equatorial region, the spectra of the transient component are almost flat, indicating that the organization of large-scale structures is less efficient in this region. The spectral shapes are similar between the 0.5 and 2.2 hPa surfaces, except that the slopes are slightly steeper at 0.5 than at 2.2 hPa, probably due to selective vertical transmission at low wavenumbers. The seasonal variation is relatively large in the middle and high latitudes, where the maximum power occurs in winter and the minimum occurs in summer, with an exception that the transient component is maximum in spring in the southern hemisphere. Intensification of s=1 transient waves is observed around the period of the initiation of global dust storms.  相似文献   

Capability of the penetrator seismometer system for lunar seismic event observation   总被引：2，自引：0，他引：2  

R. Yamada  I. Yamada  S. Tanaka  N. Kobayashi  Y. Ishihara  K. Yomogida  A. Fujimura 《Planetary and Space Science》2009,57(7):751-763

We developed a seismometer system for a hard landing “penetrator” probe in the course of the former Japanese LUNAR-A project to deploy new seismic stations on the Moon. The penetrator seismometer system (PSS) consists of two short-period sensor components, a two-axis gimbal mechanism for orientation, and measurement electronics. To carry out seismic observations on the Moon using the penetrator, the seismometer system has to function properly in a lunar environment after a hard landing (impact acceleration of about 8000 G), and requires a signal-to-noise ratio to detect lunar seismic events. We evaluated whether the PSS could satisfactorily observe seismic events on the Moon by investigating the frequency response, noise level, and response to ground motion of our instrument in a simulated lunar environment after a simulated impact test. Our results indicate that the newly developed seismometer system can function properly after impact and is sensitive enough to detect seismic events on the Moon. Using this PSS, new seismic data from the Moon can be obtained during future lunar missions.  相似文献   

Photoluminescence of baratovite and katayamalite     

Aierken Sidike  S. Kobayashi  Heng-Jiang Zhu  I. Kusachi  N. Yamashita 《Physics and Chemistry of Minerals》2010,37(10):705-710

The photoluminescence (PL) and optical excitation spectra of baratovite in aegirine syenite from Dara-i-Pioz, Tien Shan Mts., Tajikistan and katayamalite in aegirine syenite from Iwagi Islet, Ehime, Japan were obtained at 300 and 80 K. Under short wave (253.7 nm) ultraviolet light, baratovite and katayamalite exhibited bright blue-white luminescence. The PL spectrum of baratovite at 300 K consisted of a wide band with a peak at approximately 406 nm and a full width at half maximum (FWHM) of approximately 6.32k cm⁻¹. The excitation spectrum of the blue-white luminescence from baratovite at 300 K consisted of a prominent band with a peak at approximately 250 nm. The PL and excitation spectra of katayamalite were similar to those of baratovite. The luminescence from these minerals was attributed to the intrinsic luminescence from the TiO₆ center.  相似文献   

Fragmentation model dependence of collision cascades     

Hiroshi Kobayashi  Hidekazu Tanaka 《Icarus》2010,206(2):735-746

Mass depletion of bodies through successive collisional disruptions (i.e., collision cascade) is one of the most important processes in the studies of the asteroids belt, the Edgeworth-Kuiper belt, debris disks, and planetary formation. The collisional disruption is divided into two types, i.e., catastrophic disruption and cratering. Although some studies of the collision cascades neglected the effect of cratering, it is unclear which type of disruption makes a dominant contribution to the collision cascades. In the present study, we construct a simple outcome model describing both catastrophic disruption and cratering, which has some parameters characterizing the total ejecta mass, the mass of the largest fragment, and the power-law exponent of the size distribution of fragments. Using this simple outcome model with parameters, we examine the model dependence of the mass depletion time in collision cascades for neglect of coalescence of colliding bodies due to high collisional velocities. We find the cratering collisions are much more effective in collision cascades than collisions with catastrophic disruption in a wide region of the model parameters. It is also found that the mass depletion time in collision cascades is mainly governed by the total ejecta mass and almost insensitive to the mass of the largest fragment and the power-law exponent of fragments for a realistic parameter region. The total ejecta mass is usually determined by the ratio of the impact energy divided by the target mass (i.e. Q-value) to its threshold value for catastrophic disruption, as well as in our simple model. We derive a mass depletion time in collision cascades, which is determined by of the high-mass end of collision cascades. The mass depletion time derived with our model would be applicable to debris disks and planetary formation.  相似文献   

A trial for monitoring temporal variation of seismic velocity using an ACROSS system   总被引：4，自引：0，他引：4  

Koshun Yamaoka  Takahiro Kunitomo  Koji Miyakawa  Kazunori Kobayashi  Mineo Kumazawa 《Island Arc》2001,10(3-4):336-347

Abstract The temporal variation of seismic velocity near the Nojima Fault, which ruptured during the 1995 Kobe earthquake (Hyogo-ken Nanbu earthquake), was detected using an accurately controlled routine-operated seismic source (ACROSS). The source generates elastic waves by a centrifugal force of an eccentric mass rotating around an axis. The mass is driven with an AC servomotor whose angular position is accurately controlled with reference to a very accurate global positioning system (GPS) clock. The error of the mass' position is less than 0.002 radian and does not accumulate. As a result, the source generates sinusoidal waves of very narrow spectral peaks enabling their detection with an excellent signal-to-noise ratio. Although the stability of the rotation is quite excellent, a large daily variation was found, which seems to be caused by changes in atmospheric temperature. The daily variation was 10% in amplitude and 0.1 radian in phase of the signal observed at the 800 m borehole seismometer. A significant variation was found to be due to that of coupling between the rotational source and the foundation made of reinforced concrete in which the source was situated. In order to make a correction on the signal of the 800 m borehole seismometer, the vibration of the foundation was measured and modeled assuming a rigid body movement. The correction successfully reduced the daily variation by approximately 90%, resulting in a variation of 1% in amplitude and 0.01 radian in phase. The phase variation of 0.01 radian corresponds to 100 μs and less than 0.1% in velocity over 1000 m between the source and the receiver.  相似文献   

Upward longwave radiation from a non-black urban canopy     

Takahisa Kobayashi  Tamio Takamura 《Boundary-Layer Meteorology》1994,69(1-2):201-213

The longwave upward radiation was calculated for an urban canopy by using a Monte Carlo model. The effects of the urban geometry were examined in terms of the fractional roof area, the height of the buildings and the emissivity. The urban canopy consists of identically sized buildings and the ground surfaces. The model allows for the temperature differences between the buildings and the ground surface and for multiple reflections in the canyon.The Monte Carlo results show that neglect of the geometric effects causes significant errors in calculated upward radiation: calculations with area-weighting of the radiation emitted from flat homogeneous surfaces are not appropriate. The upward flux is a nonlinear function of the fractional roof area, which may be approximated by a function of the square or cube of the fractional roof area. Neglect of the reflections by non-black surfaces (emissivity<1) underestimates the upward flux by a few percent for a canopy of emissivity=0.9. Radiation effects due to multiple reflections in the canyon are parameterized by use of the view factor and the fractional roof area. The parameterization scheme yields accurate results.  相似文献   

Phase and group velocities and Q of mantle Love and Rayleigh waves of the first two modes and their azimuthal dependences for the 1963 Kurile Islands earthquake     

Yoshio Fukao  Minoru Kobayashi 《Physics of the Earth and Planetary Interiors》1983,32(1):4-35

Phase and group velocities and Q of mantle Love and Rayleigh waves from the 1963 Kurile Islands earthquake (M_w = 8.5) were determined over 37 great circle paths by a time variable filtering technique, in a period range 100–500 s for the fundamental modes and 100–275 s for the first higher modes. The preliminary reference Earth model (PREM) explains reasonably well the average dispersion results for the fundamental Love and Rayleigh waves. There exists a small, but significant inconsistency between the observation and the model for the first higher Love and Rayleigh waves. The Q structure of PREM is inconsistent with the observation for the fundamental Love waves, but explains other observations reasonably well. The dispersion of each mode shows a clear azimuthal dependence from which the four azimuthal windows were established. The phase and group velocity measurements for each window were, in general, shown to be mutually consistent. The azimuthal variations are largest for the first higher Rayleigh waves, indicating strong lateral heterogeneity in the structure of the low velocity zone. The first of the four windows is characterized by the largest fraction of Precambrian shields and the second window by the largest fraction of normal oceans. A comparison of these two windows may give some insight into deep lateral heterogeneity between continents and oceans. The observed phase and group velocities of the first window are systematically higher than those of the second window for the fundamental Love and Rayleigh waves at periods up to 400 s, and for the first higher Love and Rayleigh waves up to 175 s. Their differences are greatest for the first higher Rayleigh waves and least for the fundamental Rayleigh waves. Although the fundamental Rayleigh waves show the least velocity differences, their persistence up to a period of longer than 300 s is in striking contrast with some of the pure path phase velocities derived earlier for continents and oceans. A set of models for continents and oceans. PEM-C and PEM-O are not consistent with our observation. The third azimuthal window is characterized by trench-marginal seas and the fourth window by mountainous areas, typically the Asian high plateaus from northern China to the Middle East through Tibet. A comparison of these two windows gives some information about deep structural differences between subduction zones and continental collision zones, both belonging to plate convergence zones. For the fundamental and the first higher Love waves, the phase and group velocities for the third window are markedly low, whereas those for the fourth window are somewhat comparable to those for the second window. Slow Rayleigh waves are evident for two windows, with the fourth window apparently being the slowest for the fundamental Rayleigh above 200 s and for the first higher Rayleigh. For the fundamental Rayleigh waves, the third window is very slow below 200 s, but becomes progressively fast as the period increases and tends to be the fastest window around 400 s, suggesting a deep seated high velocity anomaly beneath trench-marginal seas. The dispersion characteristics of the fourth window indicate a thick high velocity lid with an extensive low velocity zone beneath it. The shield-like lithosphere, coupled with an extensive low velocity zone, may be a characteristic feature of continental collision zones. The particle motion of the fundamental Love waves was found not to be purely transverse to a great-circle connecting the epicenter to a station. The departure from the purely transverse motion is systematic among different periods, different G arrivals (G₂, G₃,…) and different stations, which may be interpreted as being due to lateral refraction.  相似文献   

Improvement of seismological earth models by using data weighting in waveform inversion     

Nozomu Takeuchi  Minoru Kobayashi 《Geophysical Journal International》2004,158(2):681-694

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