bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development of a Coastal Drought Index Using Salinity Data
Authors: Conrads Paul A. , Darby Lisa S. 
Published: August 2016

Abstract
A critical aspect of the uniqueness of coastal drought is the effects on the salinity dynamics of creeks, rivers, and estuaries. The location of the freshwater–saltwater interface along the coast is an important factor in the ecological and socioeconomic dynamics of coastal communities. Salinity is a critical response variable that integrates hydrologic and coastal dynamics including sea level, tides, winds, precipitation, streamflow, and tropical storms. The position of the interface determines the composition of freshwater and saltwater aquatic communities as well as the freshwater availability for water intakes. Many definitions of drought have been proposed, with most describing a decline in precipitation having negative impacts on the water supply. Indices have been developed incorporating data such as rainfall, streamflow, soil moisture, and groundwater levels. These water-availability drought indices were developed for upland areas and may not be ideal for characterizing coastal drought. The availability of real-time and historical salinity datasets provides an opportunity for the development of a salinity-based coastal drought index. An approach similar to the standardized precipitation index (SPI) was modified and applied to salinity data obtained from sites in South Carolina and Georgia. Using the SPI approach, the index becomes a coastal salinity index (CSI) that characterizes coastal salinity conditions with respect to drought periods of higher-saline conditions and wet periods of higher-freshwater conditions. Evaluation of the CSI indicates that it provides additional coastal response information as compared to the SPI and the Palmer hydrologic drought index, and the CSI can be used for different estuary types and for comparison of conditions along coastlines.
Objective Climatological Analysis of Extreme Weather Events in Arizona during the North American Monsoon
Authors: Mazon Jeremy J. , Castro Christopher L. , Adams David K. , Chang Hsin-I , Carrillo Carlos M. , Brost John J. 
Published: August 2016

AbstractAlmost one-half of the annual precipitation in the southwestern United States occurs during the North American monsoon (NAM). Given favorable synoptic-scale conditions, organized monsoon thunderstorms may affect relatively large geographic areas. Through an objective analysis of atmospheric reanalysis and observational data, the dominant synoptic patterns associated with NAM extreme events are determined for the period from 1993 to 2010. Thermodynamically favorable extreme-weather-event days are selected on the basis of atmospheric instability and precipitable water vapor from Tucson, Arizona, rawinsonde data. The atmospheric circulation patterns at 500 hPa associated with the extreme events are objectively characterized using principal component analysis. The first two dominant modes of 500-hPa geopotential-height anomalies of the severe-weather-event days correspond to type-I and type-II severe-weather-event patterns previously subjectively identified by Maddox et al. These patterns reflect a positioning of the monsoon ridge to the north and east or north and west, respectively, from its position in the “Four Corners” region during the period of the climatological maximum of monsoon precipitation from mid-July to mid-August. An hourly radar–gauge precipitation product shows evidence of organized, westward-propagating convection in Arizona during the type-I and type-II severe weather events. This new methodological approach for objectively identifying severe weather events may be easily adapted to inform operational forecasting or analysis of gridded climate data.
Impacts of Tibetan Plateau Snow Cover on the Interannual Variability of the East Asian Summer Monsoon
Authors: Xiao Zhixiang , Duan Anmin 
Published: August 2016

AbstractThe relationship between Tibetan Plateau (TP) snow cover and the East Asian summer monsoon (EASM) has long been discussed, but the underlying mechanism remains controversial. In this paper, the snow–albedo and snow–hydrology feedbacks over the TP are investigated based on multiple sources of snow data for the period 1979–2011. The results indicate that winter snow cover plays an important role in cooling local air temperature through the snow–albedo effect; the TP surface net solar radiation in years with above-normal snow cover is approximately 18 W m−2 less than that in below-normal snow cover years. However, data analysis demonstrates that persistent effects of winter snow cover are limited to the period from winter to spring over most parts of the central and eastern TP. Therefore, the preceding snow cover over the central and eastern TP exerts little influence over either the in situ summer atmospheric heat source or the EASM, because of its limited persistence. In contrast, the effects of winter or spring snow cover anomalies over the western TP and the Himalayas can last until summer, and these anomalies further influence the EASM by modulating moisture transport to eastern China and favoring eastward-propagating synoptic disturbances that are generated over the TP. Generally, above-normal snow cover over the western TP and the Himalayas facilitates abundant summer precipitation between the Yangtze and Yellow River basins, which is confirmed by results from a regional Weather Research and Forecasting model simulation.
Estimating Minimum Detection Times for Satellite Remote Sensing of Trends in Mean and Extreme Precipitable Water Vapor
Authors: Roman Jacola , Knuteson Robert , Ackerman Steve , Revercomb Hank 
Published: August 2016

Abstract
The Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report found that changes in extreme events have occurred and the frequency of such events is expected to increase. Precipitable water vapor (PWV) is a useful measure of the moisture content of the atmosphere. This paper combines the predicted GCM trends in PWV from 2000 to 2100 with uncertainty estimates from infrared spectrometers, NASA Atmospheric Infrared Sounder (AIRS) and EUMETSAT Infrared Atmospheric Sounding Interferometer (IASI), to estimate minimum trend detection times on regional and global spatial scales. The minimum detection time (MDT) is the number of years before the multimodel GCM trend exceeds a fractional change equal to the uncertainty in the observed product, plus the width of the time window used to smooth out natural variability. Results indicate that the median value of PWV has an MDT of 15 yr or less over all scales, while extreme dry (5th) and wet (95th) PWV conditions (percentiles) have higher measurement uncertainty and corresponding larger MDTs. Product providers have done a relatively good job tuning results to the mean atmospheric state but more attention should be given to improving the satellite estimates for extreme PWV. A fractional measurement error of 3% is desirable to detect predicted climate trends within 15 years or less for the entire PDF of PWV. This paper presents an important case study for the design of observing systems directly linking the estimated uncertainty of the PWV products to the detectability of long-term trends. If there is a need to decrease detection times over the existing weather observation system then necessary changes to the climate observational system design can be understood quantitatively.
The Effect of the Kerguelen Plateau on the Ocean Circulation
Authors: Wang Jinbo , Mazloff Matthew R. , Gille Sarah T. 
Published: August 2016

AbstractThe Kerguelen Plateau is a major topographic feature in the Southern Ocean. Located in the Indian sector and spanning nearly 2000 km in the meridional direction from the polar to the subantarctic region, it deflects the eastward-flowing Antarctic Circumpolar Current and influences the physical circulation and biogeochemistry of the Southern Ocean. The Kerguelen Plateau is known to govern the local dynamics, but its impact on the large-scale ocean circulation has not been explored. By comparing global ocean numerical simulations with and without the Kerguelen Plateau, this study identifies two major Kerguelen Plateau effects: 1) The plateau supports a local pressure field that pushes the Antarctic Circumpolar Current northward. This process reduces the warm-water transport from the Indian to the Atlantic Ocean. 2) The plateau-generated pressure field shields the Weddell Gyre from the influence of the warmer subantarctic and subtropical waters. The first effect influences the strength of the Antarctic Circumpolar Current and the Agulhas leakage, both of which are important elements in the global thermohaline circulation. The second effect results in a zonally asymmetric response of the subpolar gyres to Southern Hemisphere wind forcing.
Nonparametric Testing Under Progressive Censoring*
Authors: Chatterjee Shoutir Kishore , Sen Pranab Kumar 
Published: August 2016

Summary Progressive censoring schemes (allowing a continuous monitoring of experimentation until a terminal decision is reached) are often adopted in clinical trials and life testing problems. In this paper, a general class of rank order tests for progressive censoring is proposed. Along with a basic martinga:le property and a Brownian motion approximation for a related rank order process, asymptotic distribution theory of the proposed statistics is developed. Asymptotic performance characteristics of the proposed tests (in the light of Bahadur efficiency and the stochastic smallness of the stopping variables) are studied.
Simultaneous Estimation of Proportions in a Finite Population
Authors: Mukhopadhyay N. , Chattopadhyay S. 
Published: August 2016

Sequential and multistage sampling strategies via simple random sampling without replacement, are proposed for simultaneously estimating several proportions in a finite population. Various asymptotic first-order properties are addressed, while some limited moderate sample performance have also been included. AMS (1980) Subject Classification: Primary 62L99; Secondary 62L12
A Note on a Criterion for a Block Design to be X-1­Balanced
Authors: Mohan N. R. , Janhavi J. V. 
Published: August 2016

An easy­to­verify criterion is proposed for a not necessarily connected block design to be X-1­balanced and its connection to the existing criteria is brought out. An example of a disconnected PBIBD is given which is X-1­balanced for a family of matrices X that includes a constant multiple' of identity matrix so that the PBIBD happens to be variance balanced. AMS (1990) Subject Classification: 62 K 10
Some Results on the Curse of Dimensionality and Sample Size Recommendations
Authors: Dasgupta Anirban 
Published: August 2016

Multivariate density estimation is well known to be a tremendously difficult problem due to the occurrence of phenomena commonly known as the corner effect and the curse of dimensionality. Specifically, histogram density estimation in high dimensions is plagued by the consequence that sampled observations tend to reside with high probability in low density regions of the sample space. In this article we attempt to quantify two central things: in how many dimensions, one starts to really feel the curse of dimensionality, and what sort of sample sizes are needed to do any kind of a reasonable inference in various dimensions. These questions cannot be formulated in a unique way. So the attempt is to derive a broad spectrum of results, which are then illustrated by extensive computation. A number of results may be of independent interest in combinatorics and applied probability. Our subjective conclusion after these extensive computations is that in 3 dimensions one often sees the most drastic effect relative to just one less dimension; in 5 dimensions one feels the curse of high dimensions rather strongly; in 10 dimensions, the feasibility of inference with realistic sample sizes basically vanishes. We also give a subjective minimum sample size recommendation based on the number of dimensions. These calculations are different in character from Epanechnikov(1969). AMS (2000} Subject Classification: Primary 62H05; Secondary 62G07.
Estimation for some Stochastic Partial Differential Equations Based on Discrete Observations
Authors: Rao B.L.S. Prakasa 
Published: August 2016

Stochastic partial differential equations (SPDE) are used for stochastic modelling, for instance, in the study of neuronal behaviour in neurophysiology and in building stochastic models for turbulence. Huebner, Khasminskii and Rozovskii (1993) started the investigation of the maximum likelihood estimation of the parameters involved in two types of SPDE's and extended their results for a class of parabolic SPDE's in Huebner and Rozovskii (1995). Prakasa Rao (1998,2000) obtained Bernstein - von Mises type theorems for a class of parabolic SPDE's and investigated the properties of Bayes estimators of parameters involved in such SPDE's. In all the papers cited earlier, it was assumed that a continuous observation of a random field uε( x, t) satisfying the SPDE over the region [0, 1] × [0, T] is available. It is obvious that this assumption is not tenable in practice and the problem of interest is to develop methods of estimation of parameters from the random field uε( x, t) observed at discrete times t and at discrete positions x or from the Fourier coefficients uiε( t) observed at discrete time instants. We construct consistent and asymptotically normal estimators of the parameter based on the Fourier coefficients uiε( t) observed at discrete times [Formula: see text] tends to infinity. AMS (2000) Subject classification: Primary 62 M 40; Secondary 60 H 15.
An Optimum Ordering Policy and its Estimation in a Two-Supplier Inventory Model with Uncertainties in Supply
Authors: Mitra Murari , Basu Sujit K. 
Published: August 2016

We consider a single-item one-period inventory model where the market demand is assumed to be random and the item under consideration is obtained from two suppliers who also supply random amounts with means equal to the order placed to the supplier concerned. Under new better than used in expectation (NBUE) assumption on the supply distributions, possibly different, a strategy which maximizes a minimum profit has been proposed. An estimate for this maximin order quantity whenever the (customer) demand distribution is unknown has been obtained and strong consistency of the suggested estimator established. AMS (2000) Subject Classification: Primary 90B05; Secondary 62G99, 60F15.
Convergence of a Robbins-Monro Algorithm for Recursive Estimation with Non-Monotone Weights for a Function with a Restricted Domain and Multiple Zeros
Authors: Findley David F. 
Published: August 2016

Summary Convergence properties are established for the output of a deterministic Robbins- Monro recursion whose function can have singularities and multiple zeros. Our analysis is built largely on slight adaptations of some lemmas and proofs of Fradkov published only in an untranslated Russian monograph (Derevitzkii and Fradkov , 1981). A gap in Fradkov's proof of the final lemma is fixed but only for the scalar case. Our results can be applied to results of Cantor (2001) to establish the convergence of two well-known time series model recursive estimation schemes in the case of an incorrect moving average model. For such models, it is known that maximum likelihood estimates can converge w .p.1 to a set of values rather than to a single value. When the limit set is finite, our results show that , on a given realization of the time series, the (recursive) estimates will converge to single value. This is the first result establishing that estimates of a moving average coefficient do not oscillate forever among different limit set values when there are more than one.
Mixed Level Dispersion Experiments
Authors: Chatterjee Kashinath , Fang Kai-Tai 
Published: August 2016

Summary Rosenbaum (1996) and Hedayat and Stufken (1999) considered the construction of compound orthogonal arrays for the two-level factors which are useful in the study of dispersion experiments, pioneered by Taguchi (1986). This paper provides a general method of constructing such arrays and their applications to obtain several asymmetric compound orthogonal arrays for mixed level dispersion experiments. Such arrays are also found to be universally optimal even if the model includes some more parameters.
Some Aspects of Multivariate Behrens-Fisher Problem
Authors: Park Junyong , Sinha Bimal 
Published: August 2016

In this paper we discuss the well known multivariate Behrens-Fisher problem which deals with testing the equality of two normal mean vectors under heteroscedasticity of dispersion matrices. Some existing tests are reviewed and a new test based on Roy's union-intersection principle coupled with the generalized P-value is proposed. The tests are compared with respect to size and power based on simulation, and applied to a few useful data sets. AMS (2000) Subject Classification : 62H10, 62H15.
Applications of Ranked Set Sampling in Estimating Parameters of Morgenstern Type Bivariate Logistic Distribution
Authors: Lesitha G. , Thomas P. Yageen , Chacko Manoj 
Published: August 2016

Abtsrcat In this work we apply ranked set sampling and its modi-fied version called extreme ranked set sampling to estimate the parameters of Morgenstern type bivariate logistic distribution (MTBLD). The Fisher information derived in this paper about the parameters contained in the concomitants of order statistics arising from MTBLD justies the possible advantages of applying extreme ranked set sampling. We propose estimators for some unknown parameters of MTBLD based on observations available on both of these two methods of ranked set sampling and make comparison on the efficiency of one estimator over the other.
Estimation of the Mean Vector of a Multivariate Elliptically Contoured Distribution
Authors: Saleh A.K. Md. E. , Kibria B.M. Golam 
Published: August 2016

Abtsrcat This paper deals with the estimation of the mean vector θ of a p-variate elliptically contoured distribution, Ep(θ,Σ, f) based on the sample Y1 Y2,..., YN of size N of size N when it is suspected that for a p× r known matrix B, the hypothesis θ = Bη, η∈ Rr may hold. We consider the following estimators, (i) the unrestricted estimator (UE), (ii) the restricted estimator (RE), (iii) the preliminary test estimator (PTE), (iv) the James—Stein estimator (JSE), and (v) the positive-rule Stein estimator (PRSE). The bias and the risk expressions under the squared loss function are obtained for the five estimators and compared. It is noted that the dominance properties of these estimators remain the same as under normal theory. Further, it is shown that the shrinkage factor of the Stein-type estimators is robust with respect to the mean and unknown mixing distributions.
Future Supply Uncertainty Model for Deteriorating Items Under Permissible Delay in Payment for two Suppliers
Authors: Kandpal Deepa H. , Tinani Khimya S. 
Published: August 2016

Abtsrcat This paper develops a model to determine an optimal ordering policy for deteriorating items under permissible delay of payment and allowable shortage for future supply uncertainty by suppliers. Spectral theory is used to derive explicit expression for the transition probabilities of a four state continuous time markov chain representing the state of the system. These probabilities are used to compute the average cost. Optimal solution is obtained using Newton Raphson method in R programming.
An M/M/2 Queueing System with Heterogeneous Servers Including One Vacationing Server
Authors: Krishnamoorthy A. , Sreenivasan C. 
Published: August 2016

Abtsrcat This paper analyzes an M/M/2 queueing system with het- erogeneous servers, one of which is always available but the other goes on vacation in the absence of customers waiting for service. The system is analyzed in the steady state using matrix geometric method. Busy period of the system is analyzed and mean waiting time in the stationary regime com- puted. Conditional stochastic decomposition of stationary queue length is obtained. An illustrative example is also provided.
Influence Diagnostics in Linear Regression Under Heteroscedasticity : A Different Approach
Authors: Emami Hadi , Rasekh Abdolrahman 
Published: August 2016

Abtsrcat Many procedures are available to identify a single outlier or an isolated influential point in linear regression model. But the detection of multiple outliers or subset of influential points is rarely considered under heteroscedasticity and not been studied from the point of direct procedure. In this paper, dedinition and properties of an influence statistic for one or a set of observations in linear regression under heteroscedasticity is generalized. We express this influence statistic in terms of the residuals and the leverages.We prove that this statistic has asymptotically normal distribution and is able to detect a subset of high weighted leverage-outliers that will be undetected by Cook's distance. For illustration, a simulation study has been carried out and also a real data set has been analyzed.
Statistical Analysis of Tandem Queues with Blocking
Authors: Savariappan Paul R. , Chandrasekar P. , Selvam S. , Vaidyanathan V.S. 
Published: August 2016

Abtsrcat A maximum likelihood estimator (MLE), a consistent asymp- totically normal (CAN) estimator and asymptotic condence limits for the expected number of entities in the system (LS) in a two service point tandem queue with at most one entity in between the service points and busy service point 1 are obtained. Further, for a three service point tandem queue with busy service points 1 and 2 and at most one entity in between the last two service points, the MLE, CAN estimator and asymptotic confidence limits for LS are obtained.
Bayesian Graphical Models for Epigenomic Heterogeneity
Authors: Müller Peter , Mitra Riten , Ji Yuan 
Published: August 2016

Abtsrcat Histone modifications (HMs) are an important post-translational feature. Different types of HMs are believed to co-regulate biological processes such as gene expression, and are therefore intrinsically dependent on each other. We develop inference for this complex biological network of HMs based on a graphical model for the dependence structure across HMs. We report inference on HM dependence in a case study with ChIP-Seq data from a next-generation sequencing experiment. A hierarchical model extension allow us comparison of multiple graphs corresponding to different genomic regions. The described inference is an important step towards cracking the histone code.
Non-Sufficiency Via Conditioning Arguments with Illustrations
Authors: Mukhopadhyay Vijay 
Published: August 2016

Abtsrcat We reiterate a conditioning approach to highlight that | X| may not be a sufficient statistic for θ when original data X follows certain specific well-known distributions. The approach requires one to show that the conditional distribution of X given | X| involves θ Our examples and commentaries are expected to lead to more appreciation of the notion of sufficiency (or non-sufficiency).
A Test for Generalized Behrens-Fisher Problem with an Adaptive Interim Analysis
Authors: Bandyopadhyay Uttam , Dutta Dhiman 
Published: August 2016

Abtsrcat The present paper considers a generalization of the Behrens-Fisher problem without assuming that the underlying distribution functions are continuous so that the proposed procedure is also applicable to count or ordered categorical data. The proposed test is based on a generalization of the Wilcoxon-Mann-Whitney statistic where the data correspond to sequentially observed responses from patients allocated at random to two treatments in two stages. At stage 1, patients are allocated completely at random between two treatments. At the end of stage 1, the accumulated responses corresponding to the treatments are compared. At stage 2, the patients are assigned to the treatments in such a way that the more promising treatment receives more patients. Simulation comparisons of the proposed procedure with some natural competitors show a considerably larger number of allocations to the better treatment and a smaller average sample number with a little loss in power.