Vagueness ratio of storage function model parameters and its relation to the accuracy of hydrograph prediction     

Joko?SujonoEmail author  Shiomi?Shikasho  Kazuaki?Hiramatsu 《Paddy and Water Environment》2003,1(4):201-206

Fuzzy linear regression (FLR) has been applied in many areas, including several areas of engineering. For instance, it has been successfully applied in conceptual rainfall runoff modeling to identify the parameters of the storage function (SF) model. In the FLR, each model parameter is not a crisp value as found in traditional procedures but the model parameters have a fuzziness value characterized by the center () and the width (c) values. The width value could be further analyzed in terms of its contribution in the prediction accuracy. In this case, the vagueness ratio, defined as a ratio between the width value and its center value for the model parameters, is presented here as a surrogate for analyzing any possible relation to the prediction accuracy. Application of the vagueness ratio to a number of flood hydrographs at Ochohzu basin in Fukuoka, Japan, shows that the ratio is useful for assessing the accuracy of the hydrograph prediction; i.e., the higher the value of the ratio indicates the less accuracy in the prediction.  相似文献   

Correction to: Evaluation of recent drought conditions by standardized precipitation index and potential evapotranspiration over Indonesia     

Pramudya  Y.  Onishi  T.  Senge  M.  Hiramatsu  K.  Nur  Prasetyo M. R. 《Paddy and Water Environment》2019,17(3):331-338

In South Asia, an increasing population and frequent droughts have been significant factors deeply affecting water deficits in the region. In this study, recent drought conditions were evaluated by calculating the standardized precipitation index (SPI) for the period of 1991–2006, based on past data during the period from 1961 to 1990. In addition, the Thornthwaite equation was used to compute monthly potential evapotranspiration for the entire area of Indonesia. The APHRODITE data set was utilized for precipitation and temperature. Monthly rainfall data from April to September for 30 years (1961–1990) were used to obtain the gamma function for the computation of SPI values. Calculated probability of SPI for which values were < − 2 during the period from 1991 to 2006 was used to evaluate recent Indonesian drought conditions. Regarding potential soil water deficits, under the very simple assumption that the root zone is 30 cm, soil porosity is 0.4, and field capacity is 80% of soil porosity, the critical threshold of soil water deficit was set as − 96 mm. Frequency of potential water deficits < − 96 mm was counted during 1991–2006. The results of the SPI in Indonesia indicate that most parts of Indonesia have encountered severe and extreme drought for the period 1991–2006. Based on SPI interpretation, Borneo Island and West Papua are the islands that encountered the most extreme drought during the dry seasons. Borneo Island seems to have encountered extreme drought at the beginning and the middle of the dry seasons (April, May, and July). On the other hand, based on the Thornthwaite interpretation, Java and Bali Islands, and especially in Central Java and East Java, seem to have encountered the greatest soil water deficit at the middle and the end of the dry seasons (May, June, July, and September).

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Impacts of the nonlinear relationship between abundance and its index in a tuned virtual population analysis     

Midori Hashimoto  Hiroshi Okamura  Momoko Ichinokawa  Kazuhiko Hiramatsu  Takashi Yamakawa 《Fisheries Science》2018,84(2):335-347

The abundance index used in a tuned virtual population analysis (VPA) is usually assumed to be proportional to actual abundance. However, the actual abundance and abundance index do not always have a linear relationship. Such nonlinearity can cause biases in abundance estimates as well as retrospective biases arising from systematic differences in abundance estimates when more data are successively added. Severe retrospective biases can damage the reliability of stock assessments. In this study, we use an approach to estimate an additional parameter that controls the nonlinearity in a tuned VPA. A performance test using simulated data revealed that the tuned VPA was able to accurately estimate the nonlinearity parameter and thus yielded less biased abundance estimates and smaller retrospective biases. We also found that estimating the nonlinearity parameters was effective even under other model misspecification scenarios, such as disregarding historical increases in catchability and time-varying natural mortality. Moreover, we applied this approach to some Japanese fish stocks and evaluated its validity. We found that estimating the nonlinearity parameters in the tuned VPA enhances the reliability of fisheries stock assessments.  相似文献   

Dodeca-CLE peptides as suppressors of plant stem cell differentiation     

Ito Y  Nakanomyo I  Motose H  Iwamoto K  Sawa S  Dohmae N  Fukuda H 《Science (New York, N.Y.)》2006,313(5788):842-845

In plants and animals, small peptide ligands that signal in cell-cell communication have been suggested to be a crucial component of development. A bioassay of single-cell transdifferentation demonstrates that a dodecapeptide with two hydroxyproline residues is the functional product of genes from the CLE family, which includes CLAVATA3 in Arabidopsis. The dodecapeptide suppresses xylem cell development at a concentration of 10(-11) M and promotes cell division. An application, corresponding to all 26 Arabidopsis CLE protein family members, of synthetic dodecapeptides reveals two counteracting signaling pathways involved in stem cell fate.  相似文献   

Cosmological magnetic field: a fossil of density perturbations in the early universe     

Ichiki K  Takahashi K  Ohno H  Hanayama H  Sugiyama N 《Science (New York, N.Y.)》2006,311(5762):827-829

The origin of the substantial magnetic fields that are found in galaxies and on even larger scales, such as in clusters of galaxies, is yet unclear. If the second-order couplings between photons and electrons are considered, then cosmological density fluctuations, which explain the large-scale structure of the universe, can also produce magnetic fields on cosmological scales before the epoch of recombination. By evaluating the power spectrum of these cosmological magnetic fields on a range of scales, we show here that magnetic fields of 10(-18.1) gauss are generated at a 1-megaparsec scale and can be even stronger at smaller scales (10(-14.1) gauss at 10 kiloparsecs). These fields are large enough to seed magnetic fields in galaxies and may therefore have affected primordial star formation in the early universe.  相似文献   

A tetraploid hybrid plant from 4x × 2x crosses in Vitis and its origin     

Sung Min Park  Akira Wakana  Michikazu Hiramatsu  Kenji Uresino 《Euphytica》2002,126(3):345-353

To study the origin of unreduced (2n) gametes in diploid Vitis cultivars, we surveyed the occurrence of tetraploid hybrid seedlings from 40 interploid crosses with five tetraploid and seven diploid cultivars. A total of 250 seedlings from the interploid crosses were established through embryo culture and by seed sowing. In 20 2x × 4x crosses, no tetraploid hybrid seedlings were derived from 8,902pollinations. In 20 4x × 2x crosses, two tetraploid hybrid seedlings were obtained from 8,057 pollinations. Investigation of isozyme genotypes of the two tetraploid seedlings using three variable enzyme systems indicated that one of the two seedlings resulted from the union of a diploid egg with a 2n male gamete and that failure of second meiotic division resulted in the formation of the 2n male gamete. The percentage of giant pollen grains in `Muscat Bailey A', a pollen parent of the tetraploid seedling, was relatively high(about 5.9%) and 10.9% of the giant pollen grains germinated on agar medium. These results suggested that 2n pollen of diploid cultivars are useful for breeding tetraploid grape. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

Pathological studies on local tissue reactions in guinea pigs and rats caused by four different adjuvants.     

M Yamanaka  K Hiramatsu  T Hirahara  T Okabe  M Nakai  N Sasaki  N Goto 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》1992,54(4):685-692

We investigated pathological changes at the injection site in guinea pigs and rats for 16 weeks following a single intramuscular injection of one of the following oil adjuvant emulsions; oil adjuvant ISA-70, Freund's incomplete adjuvant, Freund's complete adjuvant, and aluminium phosphate gel. In the animals injected with ISA-70 emulsion prepared by manual shaking, grossly, there was partial thickening of subcutaneous tissue, discoloration of inter-muscular connective tissue, and swelling of the inguinal lymph nodes at 2 and 4 weeks post injection (PI). Histopathologically, ISA-70 injected sites revealed acute inflammatory changes at 72 hrs PI, and peak reactions consisting of macrophage accumulation around oil cysts and fibrosis were observed at 4 weeks PI. These changes were less severe and of shorter duration than those in the other three adjuvants. Guinea pigs and rats injected with materials containing inactivated Newcastle disease virus (NDV) antigen similarly showed an infiltration of plasma cells and lymphocytes in addition to the changes described above. ISA-70 containing NDV antigen induced similar hemagglutination-inhibition titer to that induced by Freund's incomplete adjuvant.  相似文献   

Earthquake source fault beneath Tokyo     

Sato H  Hirata N  Koketsu K  Okaya D  Abe S  Kobayashi R  Matsubara M  Iwasaki T  Ito T  Ikawa T  Kawanaka T  Kasahara K  Harder S 《Science (New York, N.Y.)》2005,309(5733):462-464

Devastating earthquakes occur on a megathrust fault that underlies the Tokyo metropolitan region. We identify this fault with use of deep seismic reflection profiling to be the upper surface of the Philippine Sea plate. The depth to the top of this plate, 4 to 26 kilometers, is much shallower than previous estimates based on the distribution of seismicity. This shallower plate geometry changes the location of maximum finite slip of the 1923 Kanto earthquake and will affect estimations of strong ground motion for seismic hazards analysis within the Tokyo region.  相似文献   

Atresia in temperate basses: cloning of hatching enzyme (choriolysin) homologues from atretic ovaries     

D.M. Donato  N. Hiramatsu  K.M. Arey  K. Hiramatsu  A.M. Kennedy  C.L. Morton  A. Hara  C.V. Sullivan 《Fish physiology and biochemistry》2003,28(1-4):329-330

Partial cDNAs encoding homologues of choriolysin were cloned from striped bass embryos and from atretic ovaries of white perch. Among these clones, one of the ovarian homologues may be a candidate bio-marker for detecting onset of atresia. Early detection of atresia may allow affected broodfish to be reproduced before they undergo complete reproductive failure.  相似文献   

Survey of agricultural reservoirs damaged by the July 2017 torrential rains in northern Kyushu,Japan     

Ozaki  Akinori  Hiramatsu  Kazuaki  Hama  Takehide 《Paddy and Water Environment》2019,17(2):237-246

Paddy and Water Environment - The torrential rains that hit northern Kyushu, Japan, on July 5–6, 2017, caused serious damage, especially in Asakura City, Fukuoka Prefecture, and in Hita City,...  相似文献