Yukio Yanagisawa

A critical look at accumulation analysis and related methods

Industrial quality characteristics are often measured categorically rather than numerically, such as by recording a response as “slight,” “moderate,” or “extreme.” Accumulation analysis, a method proposed by Taguchi (1974) for analyzing ordered categorical data from industrial experiments, is used in Japanese industry and is becoming popular in the United States. Nair (1986) proposed using the first two components of the accumulation analysis statistic separately, as well as using simpler alternatives, to detect location and dispersion effects, respectively. We expose some problems with accumulation analysis in the multifactor setting, which is the usual industrial setting, since it is more efficient to investigate many factors simultaneously. Our results show that accumulation analysis detects spurious factor effects and reverses the order of factor importance. Furthermore, reanalysis of data from two real experiments reveals that these problems with accumulation analysis are realized in practice. We dem...

On Data Compaction of Scanning Curves

We prove that there is no difference in the number of run lengths found for any scanning curves for completely random pictures. Simulation is used to compare the data compaction between a discrete Peano curve and a bidirectional scanning curve for 1000 randomly placed ellipses to determine whether spatial coherence favours one scanning curve. The results are analysed statistically. Both the theory and the results of the simulation show that there is no difference between the scanning curves chosen

Designs for discrimination between binary response models

Abstract We propose a test statistic for discrimination between alternative univariate binary response models which is asymptotically equivalent to the likelihood ratio statistic and Pearsons goodness of fit statistic. We propose an optimal design procedure. Under certain conditions we prove that the maximum value of the power can be obtained when the degrees of freedom of the test statistic is one. Several mathematical properties of the incomplete gamma function ratio and the non-central chi-squared distribution are required in the discussion and these are established.

Gene expression profiles in Rana pirica tadpoles following exposure to a predation threat

BackgroundRana pirica tadpoles show morphological changes in response to a predation threat: larvae of the dragonfly Aeshna nigroflava induce heightened tail depth, whereas larval salamander Hynobius retardatus induce a bulgy morphology with heightened tail depth. Although both predators induce similar tail morphologies, it is possible that there are functional differences between these tail morphs.ResultsHere, we performed a discriminant microarray analysis using Xenopus laevis genome arrays to compare tail tissues of control and predator-exposed tadpoles. We identified 9 genes showing large-scale changes in their expression profile: ELAV-like1, methyltransferase like 7A, dolichyl-phosphate mannosyltransferase, laminin subunit beta-1, gremlin 1, BCL6 corepressor-like 1, and three genes of unknown identity. A further 80 genes showed greater than 5 fold differences in expression after exposure to dragonfly larvae and 81 genes showed altered expression after exposure to larval salamanders. Predation-threat responsive genes were identified by selecting genes that reverted to control levels of expression following removal of the predator. Thirteen genes were induced specifically by dragonfly larvae, nine others were salamander-specific, and sixteen were induced by both. Functional analyses indicated that some of the genes induced by dragonfly larvae caused an increase in laminins necessary for cell adhesion in the extracellular matrix. The higher expression of gremlin 1 and HIF1a genes after exposure to dragonfly larvae indicated an in vivo hypoxic reaction, while down-regulation of syndecan-2 may indicate impairment of angiogenesis. Exposure to larval salamanders caused down-regulation of XCIRP-1, which is known to inhibit expression of adhesion molecules; the tadpoles showed reduced expression of cα(E)-catenin, small muscle protein, dystrophin, and myosin light chain genes.ConclusionThe connective tissue of tadpoles exposed to larval salamanders may be looser. The differences in gene expression profiles induced by the two predators suggest that there are functional differences between the altered tail tissues of the two groups of tadpoles.

Generalization for the distribution of hartley’S and nair’s Fmax statistics

The exact distribution of Hartley’s FmaxH statistics under heterogeneity of variances with or without unequal sample sizes is given by Yanagisawa and Shirakawa (1997). The distribution of Hartley’s FmaxH statistics is further generalized to that when follows a non-central χ2 distribution instead of a central χ2 distribution. The exact distribution of Nair’s FmaxN statistics under heterogeneity of variances with or without unequal sample sizes when follows either a central χ2 or a non-central χ2 distribution is given. These exact distributions provide new statistical tests and the power of the tests under very general conditions, such as a simultaneous statistical test for the Analysis of Variance (ANOVA). For these tests, we provide a Fortran program1 which calculates, to a high accuracy, the upper tail probabilities, probability points and probability densities for FmaxH and FmaxN statistics under very general conditions. Usually the accuracy of the calculation is 13 to 14 digits for double precision ari...

Tests for compound periodicities and estimating a non linear function

ABSTRACT We propose two tests for testing compound periodicities which are the uniformly most powerful invariant decision procedures against simple periodicities. The second test can provide an excellent estimation of a compound periodic non linear function from observed data. These tests were compared with the tests proposed by Fisher and Siegel by Monte Carlo studies and we found that all the tests showed high power and high probability of a correct decision when all the amplitudes of underlying periods were the same. However, if there are at least several different periods with unequal amplitudes, then the second test proposed always showed high power and high probability of a correct decision, whereas the tests proposed by Fisher and Siegel gave 0 for the power and 0 for the probability of a correct decision, whatever the standard deviation of pseudo normal random numbers. Overall, the second test proposed is the best of all in view of the probability of a correct decision and power.

The constant threat from a non-native predator increases tail muscle and fast-start swimming performance in Xenopus tadpoles

ABSTRACT Predator-induced phenotypic plasticity is the ability of prey to adapt to their native predator. However, owing to environmental changes, encounters with unknown predators are inevitable. Therefore, study of prey and non-native predator interaction will reveal the primary stages of adaptive strategies in prey-predator interactions in the context of evolutionary processes. Here, Xenopus tadpoles exposed to a non-native predator, a larval salamander, showed a significant increase in body weight and tail length to body length ratio. The Tmax2 test indicated a significant enhancement of the tail muscle and decrease in the relative ventral fin height in tadpoles exposed to predation risk, leading to significantly higher average swimming speeds. The analysis of muscle-related metabolites revealed that sarcosine increased significantly in tadpoles exposed to non-native predators. Multiple linear regression analysis of the fast-start swimming pattern showed that the fast-start swimming speed was determined by the time required for a tadpole to bend its body away from the threat (C-start) and the angle at which it was bent. In conclusion, morphological changes in tadpoles were functionally adaptive and induced by survival behaviors of Xenopus tadpoles against non-native predators. Summary: Xenopus tadpoles exposed to a non-native predator increase their tail length, muscle tissue and swimming speed, all of which are functionally adaptive and induced by tadpole survival behavior.

Applying soft computing for remote sensing data composite algorithms

Remote sensing of the earth’s surface using satellite-mounted sensor data is one of the most important methods for global environmental monitoring today. However, when using satellite sensor data, clouds in the atmosphere can interfere with the remote sensing, and specific land points may not be correctly monitored on any given day. In order to overcome this problem, a common alternative is to use multiple day composite data. Multiple day composite data use several consecutive days’ remote sensing data, and choose the most accurate data within the temporal dataset for the same land point. This allows the creation of a more complete dataset by patching together data which have had no cloud interference during a specified time period in order to create a clearer, more usable dataset. In this article, we propose the application of soft computing, namely fuzzy logic, in order to select the clearest data in the temporal interval to use for the composite data. Moderate resolution remote sensing data of areas in Japan were used for the evaluation, and the results were compared with previous composite methods.