bluuebunny/crossref_metadata_2025 huggingface dataset:
The steady-state compressibility of saturated fibre webs at low pressures
Authors: Vomhoff Hannes , Schmidt Armin
Published: May 2007

The steady-state compressibility of water-saturated Experimental work webs was investigated under annlied mechanical nressures between 30 Pa and 42 kPa. The we'bs were made fro a mechanical pulp, and an unbleached and a bleached chemical pulp. For each of these pulps, the relationship between mechanical pressure and bulk could be described by a power-law relationship with an r2-value higher than 0.98.
Vom Naturlehrpfad zum Nachhaltigkeitsweg -das Beispiel Arnisäge | From the Nature Trail to the Sustainability Trail. The Example of Arnisäge
Authors: Stuber Martin , Eggenberg Stefan
Published: May 2007

The sustainability trail of Arnisäge is a follow-up project to the educational nature trail of Rotiholz, which was established in the 1970s at the same place. The different concepts of the two trails demonstrate the development of the past two decades with regard to forest pedagogy, leading from the classical trail with information boards to the adventure trail. The second view point concerns the structure of the project. One of the significant characteristics is its long-term realisation in stages (1996 to 2001). Another rather unusual aspect is the co-operation of numerous local and regional participants. The third aspect comes from the concept of the sustainability trail based on a broad cultural and natural-historical forest notion with regard to the contents. This study mainly focuses on the mise en scène of this topic by means of installations, objects and indicating boards. The peculiarities of the sustainability trail of Arnisage can be correlated to the existing general literature on environmental education.
Die Gattung Salix. Eine Einführung in die Vielfalt, Biologie und Ökologie der Weiden | The Genus Salix: An Introduction to the Diversity, Biology and Ecology of Willows
Authors: Holdenrieder Ottmar , Rudow Andreas , Aas Gregor
Published: May 2007

Due to their pioneering character and their regenerative ability, willows (Salix spp.) are of special importance for nature conservation, restoration of ecosystems and biological engineering. The article provides a literature review of the systematics, morphology, biology, conservation and utilisation of willows.
Entwicklung der Finanzierung einer multifunktionalen Waldbewirtschaftung in den Forstbetrieben öffentlicher Waldeigentümer im schweizerischen Alpenraum | Development of Financing of a Multi-Functional Forest Management for Forest Enterprises of Publicly Owned Forest in the Alpine Region of Switzerland
Authors: Schmidhauser Albin , Schmithüsen Franz
Published: May 2007

With the federal forestry legislation coming into force in 1993, a multi-functional forest management has been established as the fundamental objective of national forest policy in Switzerland. This modern concept was already developed with the beginning of the federal forest policy during the second half of the last century with the effect that forest enterprises already perform extensive activities in the service sector.

For publicly owned forest enterprises in the Alpine region the payment flows clearly show at which degree multi-functional management takes effect on the corresponding financing. Services provided by forest enterprises in the sectors of protection(safe-guarding) and well-being are not only financed by the profits obtained from wood production, but also by budget positions especially established for this purpose. Since the 1980s, the sectoral financing for providing services by the forest enterprises has at least partially contributed to the off-setting of the impact caused by unfavourable economic conditions in wood production.

Due to the on-going planning process for the realisation of co-ordinated regional or cantonal policies as well as inter-country developments within the realms of the Alpine convention,the basis for the financing of public forest enterprises based on multi-functional forest management will be even more strongly differentiated in coming years. Pilot projects carried out under the new financial equalisation system between the federal and cantonal governments suggest that multifunctional forest management will form a solid basis for the development and implementation of forest enterprises strategies. On the operational level it is necessary to develop and apply suitable instruments for cost and management control.
Neue Waldbehandlungskonzepte in Zeiten der Mittelknappheit: Prinzipien einer biologisch rationellen und kostenbewussten Waldpflege | New Silvicultural Concepts in Times of Economic Constraints
Authors: Schütz Jean-Philippe
Published: May 2007

Current economic trends call for a review of the costefficiency of silvicultural systems. This article considers how ecological rationalisation can work alongside organisational and technical measures to minimize the cost of tending work.
Naturnaher Waldbau: gestern, heute, morgen | Near-Natural Silviculture: Past, Present and Future
Authors: Schütz Jean-Philippe
Published: May 2007

Semantically speaking, the term «near-natural» has found its way into the language because of a humanist approach to nature, namely, how nature relates to culture and mankind; this is in contrast to more fundamental ideologies where nature alone is the central focus.

The Swiss approach to this kind of silviculture, expounded by Schädelin and Leibundgut, has been a recognised school of thought in Switzerland for over 70 years. It advocates an all-encompassing outlook on forest management, and is a more comprehensive method than being restricted by one particular silvicultural technique. It is a liberal, pragmatic form of forest utilisation, which promotes not only renewal on a tree-by-tree basis (plentering), but also the renewal and growth of trees in discrete generations using progressive group felling; all this with the same goal in mind, that is, the creation of structured mixed forest.

The following six principles characterise this approach: use of local yield potential; silvicultural intervention combining timber use and tending goals; continual renewal; maximising the use of mixed tree populations; use of natural regeneration; and a liberal felling policy. The procedure is characterised by the liberal felling policy, which can be used on a per-situation basis to decide which felling technique should be used.

Near-natural silviculture is a direct response to new demands which consider the forest as having its own living space. However,the main challenge for Swiss forestry today lies more in resolving its economic problems rather than improving its proximity to nature. Liberalisation of trade has placed the viability of wood production in a precarious situation. Future silviculture must be more cost-efficient, and must be based on biological rationalisation. This requires a fundamental shift in silviculture towards a less intrusive policy which relies more on natural automation than in the past. It must also focus on individual trees and situative interventions, rather than focusing on a stand scale; this allows varying development potential of individual trees to be taken into consideration. In summary, real multipurpose use calls for flexible solutions, which can integrate silvicultural interventions on a much more varied scale than in the past.
Die Bedeutung der Erholungsnutzung des Waldes am Beispiel von Picknicken und Grillieren: Ergebnisse einer gesamtschweizerischen Umfrage bei Forstfachleuten und Waldeigentümern | The relevance of forest recreation exemplified by picnicking and grilling: Results of a nationwide survey aimed at forestry experts and public forest owners in Switzerland
Authors: Hegetschweiler K. Tessa , Skorupinski Antoinette , Rusterholz Hans-Peter , Baur Bruno
Published: May 2007

This study presents the results of a survey aimed at forestry officials, foresters and public forest owners carried out in April/May 2005 in Switzerland. The study points out common problems and interests as well as differences in recreation in forests of various regions and shows differences between urban and rural forests. The relevance of recreation is compared to other forest functions. Special attention is given to the activity picnicking and grilling and building fires at non-official picnic sites.
Aufschlüsselung statistischer Beziehungen zwischen dem Nadelverlust von Fichten und anderen Informationen dreier Forstmonitoring-Programme Nordrhein-Westfalens | Itemisation of statistical relationships between needle loss in spruce and other information from three forest monitoring programmes in North-Rhine Westphalia
Authors: Schröder Winfried , Grabkowsky Barbara , Schmidt Gunther
Published: May 2007

The paper is an introduction to the statistical model of Classification and Regression Trees (CART) to evaluate forest monitoring data in Germany. The advantages of this method as opposed to cluster methods are identified and illustrated on the example of spruce stands in North-Rhine Westphalia. The results confirm that age, altitude above sea level, chest-high diameter measurements and humus type are closely related to the degree of needle occurrence in spruce,and they reveal a positive correlation between Si-levels and loss of needles.
Propriété contre possession: les conflits liés aux plantations industrielles d'arbres | Property rights vs. common law possession: conflicts surrounding industrial tree plantations
Authors: Gerber Julien-François , Steppacher Rolf
Published: May 2007

This article proposes a new way of looking at social conflicts relating to industrial tree plantations by arguing that such conflicts reflect the struggle between two distinct institutional logics, i.e., property versus possession. The abstract logic of property, enhanced by credit relations and the minimization of costs, stimulates commercial plantations and tends to be detrimental to the environment. By contrast, the concrete logic of possession forces local communities to take account of complex local social and ecological interactions, and thereby encourages a sustainable use of the forest.
On sliding mode observers for systems with unknown inputs
Authors: Floquet T. , Edwards C. , Spurgeon S. K.
Published: May 2007

This paper considers the problem of designing an observer for a linear system subject to unknown inputs. This problem has been extensively studied in the literature with respect to both linear and nonlinear (sliding mode) observers. Necessary and sufficient conditions to enable a linear unknown input observer to be designed have been established for many years. One way to express these conditions is that the transfer function matrix between the unknown input and the measured output must be minimum phase and relative degree one. Identical conditions must be met in order to design a ‘classical’ sliding mode
observer for the same problem. This paper shows how the relative degree condition can be weakened if a classical sliding mode observer is combined with sliding mode exact differentiators to essentially generate additional independent output signals from the available measurements. A practical example dedicated to actuator fault detection and identification of a winding machine demonstrates the efficacy of the approach. Copyright © 2007 John Wiley & Sons, Ltd.
Workers' compensation experiences of computer users with musculoskeletal disorders
Authors: Fang Shona , Dropkin Jonathan , Herbert Robin , Triola Dushana , Landsbergis Paul
Published: May 2007

Background

Computer‐related musculoskeletal disorders (MSDs) are of concern as computer use continues to increase. While MSDs are among the most disabling conditions in the United States, the workers' compensation (WC) experiences of individuals with these occupational disorders are not well described.

Methods

We conducted a study among 149 adults with work‐related MSDs of the neck, upper back, or upper extremity related to computer use. Questionnaires were used to obtain information on subjective experiences with WC and economic issues.

Results

Seventy‐four percent filed for WC. Twenty‐five percent of all participants reported major financial difficulties after developing their MSD, though the majority filed for WC. Despite filing for WC, a large proportion relied partially on government, employer, or personal financial sources. Sixty‐two percent reported that overall satisfaction with the WC insurer was poor.

Conclusions

Findings indicate that a majority of participants filed for WC. Despite filing for WC financial difficulties after developing their MSD were considerable. Am. J. Ind. Med. 50:512–518, 2007. © 2007 Wiley‐Liss, Inc
Chemie unter höchsten Drücken: eine Herausforderung für die chemische Intuition
Authors: Grochala Wojciech , Hoffmann Roald , Feng Ji , Ashcroft Neil W.
Published: May 2007

Mithilfe von Diamantstempelzellen und Stoßwellentechniken ist es heute möglich, Materie unter Multimegabar‐Drücken (d. h. mehreren hundert GPa) zu studieren. In diesem Druckbereich sind die Eigenschaften von Materialien völlig anders als bei 1 atm (ca. 105 Pa). Um wie viel andersartig die Chemie bei hohen Drücken ist und welche Rolle die chemische Intuition für das Verständnis von Materie bei hohen Drücken spielen kann, wird in diesem Aufsatz untersucht. Wir werfen einen genauen Blick auf die hierarchische Abfolge struktureller Veränderungen, die im Zuge einer Dichtezunahme auftreten. Dazu gehören: a) Verdrängen des Van‐der‐Waals‐Raumes (bei Molekülkristallen); b) Erhöhung der Koordination; c) Verkürzung kovalenter Bindungen und Größenverkleinerung von Anionen; d) ein extremes Druckregime, in dem sich Elektronen von Atomen entfernen und neue Formen von Elektronenkorrelationen auftreten. Beispiele verblüffenden chemischen und physikalischen Verhaltens, das unter solchen extremen Bedingungen auftritt, wechseln sich in diesem Aufsatz ab mit qualitativen chemischen Überlegungen zu den beteiligten Bindungverhältnissen.
Phase separation of poly(N‐isopropylacrylamide) solutions and gels using a near infrared fiber laser
Authors: DeRosa Michael E. , DeRosa Rebecca L. , Noni Lisa M. , Hendrick Erin S.
Published: May 2007

We used a tunable near infrared fiber laser in the wavelength range of 1533–1573 nm to induce photothermal phase changes in poly(N‐isopropylacrylamide) (PNIPAM) aqueous solutions and hydrogels. The laser induces the hydrophilic to hydrophobic transition of the polymer by heating the surrounding water. We report our observations of the phase changes based on using a novel fiber backreflectance method coupled with visual cloud point measurements. At 1533 nm the phase transition was induced at the end of a single mode optical fiber with 9 mW of power at an ambient temperature of 24°C. We found that the power required to reach the lower critical solution temperature was inversely proportional to the absorption spectrum of water. In addition, phase changes in both solutions and gels occurred very rapidly (<1 s) as the laser was turned on and off. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007
Photoinitiation properties of heterocyclic hexaarylbiimidazoles with high UV‐vis absorbance
Authors: Shi Yongtao , Wang Baohu , Jiang Xuesong , Yin Jie , Kaji Makoto , Yori Hanako
Published: May 2007

Four heterocyclic hexaarylbiimidazoles, BFuTM‐HABI, BThTM‐HABI, BCTFu‐HABI, and BCTTh‐HABI, were synthesized to improve the UV‐vis absorption properties of hexaarylbiimidazoles. UV‐vis spectra, fluorescence spectra, ESR measurements, photo‐dilatometer experiments, and photo‐DSC measurements indicate that BCTFu‐HABI and BCTTh‐HABI exhibit better UV‐vis absorption abilities and photoinitiation activities for acrylate derivatives with different functionalities than BFuTM‐HABI and BThTM‐HABI, respectively. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Effect of low temperature plasma treatment on the electroless nickel plating of polyester fabric
Authors: Yuen C. W. M. , Jiang S. Q. , Kan C. W. , Tung W. S.
Published: May 2007

The present study is performed with an objective to acquire a deeper understanding of the properties of nickel‐plated polyester fabric after conducing low temperature plasma (LTP) treatment. LTP treatment with oxygen and argon gases was employed to render a hydrophilic property of woven polyester fabrics and facilitate the absorption of a palladium catalyst to provide a catalytic surface for electroless nickel plating. The properties of LTP‐induced electroless nickel‐plated polyester fabrics were evaluated by various standard testing methods in terms of both physical and chemical performances. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Accelerated ageing versus realistic ageing in aerospace composite materials. III. The chemistry of thermal ageing in bismaleimide based composites
Authors: Dao B. , Hodgkin J. , Krstina J. , Mardel J. , Tian W.
Published: May 2007

Samples of two Aerospace grade bismaleimide composites (Cytec Fiberite 5250‐4/IM7 and 5250‐4/RTM) were subject to long‐term (≈ 1‐year) thermal ageing in air at temperatures of 70, 120, 170, 200, and 250°C. The changes to the chemical and physicochemical structure of the composite were then analyzed by a range of different techniques, including gravimetric analysis, Fourier Transform infrared spectroscopy, and dynamic mechanical analysis, to compare the effects of the different ageing temperatures and to see if much simpler and more fundamental testing techniques could provide more informative forecasting information than the standard mechanical testing methods. The results emphasize the strong variation in chemistry that takes place between the surface and the interior of the composite materials at all temperatures tested. The results also confirmed the significant variations in chemical and physicochemical ageing mechanisms (e.g. glass transition temperature, Tg) that occur between the more realistic ageing temperatures encountered “in service” (∼ 120°C) and the accelerated ageing conditions often used for ageing studies (>170°C). This article highlights the lack of agreement in scientific literature on the basic chemistry of bismaleimide cure. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007
Effect of viscoelasticity in the film‐blowing process
Authors: Beaulne Michel , Mitsoulis Evan
Published: May 2007

Numerical simulations have been undertaken for the film‐blowing process of viscoelastic fluids under different operating conditions. Viscoelasticity is described by an integral constitutive equation of the K‐BKZ type with a spectrum of relaxation times, which can fit the experimental data well for the shear and extensional viscosities and the normal stresses measured in shear flow. Nonisothermal conditions are considered by applying the Morland–Lee hypothesis, which incorporates the appropriate shift factor and pseudotime into the constitutive equation. The momentum and energy equations are expressed in the machine direction only by using a quasi‐one‐dimensional approach introduced earlier by Pearson and Petrie. The resulting system of differential equations is solved using the finite element method and the Newton‐Raphson iterative scheme. The method of solution was first checked against the Newtonian and Maxwell results for various film characteristics given earlier. The simulations are compared with available experimental data and previous simulations in terms of film shape, velocity, stresses, and temperature. The present results show that the existing modeling of force balances is inadequate for quantitative agreement with the experimental studies. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007
Crosslinked poly(octadecene‐alt‐maleic anhydride) copolymers as crude oil sorbers
Authors: Atta Ayman M. , El‐Hamouly Sabrnal H. , AlSabagh Ahmed M. , Gabr Moataz M.
Published: May 2007

Crosslinked octadecene (OD) and maleic anhydride (MA) copolymer MA/OD (50 : 50 mol ratios) was prepared by condensation of the prepared linear copolymer with different glycols. Ethylene glycol and polyethylene glycols having different molecular weights were used as crosslinking agents. The crosslinked copolymers were evaluated for oil‐absorbency application. The effect of glycol type, composition; crosslinker wt % and type of oil on swelling properties of crosslinked polymers were studied through the oil absorption tests. The swelling parameters, such as the maximum oil absorbency (Qmax), characteristic oil sorbency (Q), characteristic swelling time (T), and swelling rate constant (k), were evaluated for the synthesized sorbers. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007
Synthesis and characterization of novel biodegradable polymeric prodrugs containing 5‐fluorouracil and 4‐amino‐N‐(2‐pyrimidinyl) benzene sulfonamide terminal groups
Authors: Chang Jun , Du Jie , Zheng Yubin
Published: May 2007

To develop novel biodegradable polymeric prodrugs with target‐directing and drug‐active functional groups, a series of polymeric antitumor prodrugs containing sulfadiazine and 5‐fluorouracil terminal groups were prepared via the two‐step reaction of chlorinated poly(lactic acid) or chlorinated poly(lactic acid‐co‐glycolic acid) with potassium sulfadiazine (SF‐K) and 1,3‐dihydroxymethyl‐5‐fluorouracil. The synthesized polymers were characterized by means of infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, gel permeation chromatography, viscosity measurements, differential scanning calorimetry, and ultraviolet (UV) spectroscopy. The GA/LA value was varied, so that the effects of the comonomer content on the solubility, thermal properties, and degradable behaviors were examined respectively. It was found that introducing the GA units could increase the melting temperature (Tm), the hydrolytic degradation, and the hydrophilicity, while it decreased the glass transition temperature (Tg). The drug content of 5‐FU measured by UV spectra is 56.3 in maximum. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007
A Note on an Optimality Property of the Regression Estimator
Authors: Chaubey Y. P. , Singh M. , Dwivedi T. D.
Published: May 2007

This note points out the derivation of regression estimator through an optimality consideration over a class of estimators generating Generalised Product and dual to ratio estimators.
A Method of Estimation of Change Points in Multiphasic Growth Models
Authors: Schulze U.
Published: May 2007

The least‐squares estimation (LSE) of change points and the phase parameters is considered for two growth models with piecewise continuously connected exponential and stationary phases. The calculation of a LSE is reduced to the solution of a finite number of simpler least‐squares problems for which methods of calculation are well known.
Statistical Testing for Seasonality in Data with Multiple Peaks and Troughs
Authors: Marrero O.
Published: May 2007

EDWARDS'S test for seasonality is extended to multiple peaks and troughs. It is shown how the extended statistic may be adjusted for the population at risk and for unequal lengths of time intervals in the cycle of seasons. A simulation study shows that the extended test statistic is, for sample sizes N ≧ 100, very specific in detecting the number of peaks and troughs for which it is intended. The associated method of parameter estimation is also assessed; for N ≦ 100, the amplitude of a possibly adequate simple harmonic model is estimated well, but the initial value of the phase angle is not. Estimated percentage points for the extended test statistic are tabulated, and some recommendations are offered regarding usage of this method.
Optimal Fixing of the Bandwidth‐Parameter for the Empirical Regression1,2
Authors: Schmerling S. , Peil J.
Published: May 2007

The estimator ř0(x) of the regression r(x) = E (Y | × = x) from measured points (xi, yi), i = 1(1) n, of a continuous two‐dimensional random variable (X, Y) with unknown continuous density function f(x, y) and with moments up to the second order can be made with the help of a density estimation f̌0(x, y) (see e.g. SCHMERLING and PEIL, 1980). Here f̌0(x, y) still contains free parameters (so‐called band‐width‐parameters), the values of which have to be optimally fixed in the concrete case. This fixing can be done by using a modification of the maximum‐likelihood principle including jackknife techniques. The parameter values can be also found from the estimators for r(x). Here the cross‐validation principle can be applied. Some numerical aspects of these possibilities for optimally fixing the bandwidth‐parameter are discussed by means of examples. If ř0(x) is used as a smoothing operator for time series the optimal choice of the parameter values is dependent on the purpose of application of the smoothed time series. The fixing will then be done by considering the so‐called filter‐characteristic of řC0(x).
Estimation of Covariance Matrices in Unbalanced Random and Mixed Multivariate Models
Authors: Wesolowska‐Janczarek M. T.
Published: May 2007

Three HENDERSON'S Methods of estimating the variance components are generalized from one to p variables using a compact matrix notation. These results are obtained using a generalized Kronecker product of matrices, generalized trace of order p and a generalized quadratic form.
Recursive Residuals on a Rectangular Lattice
Authors: Gleeson A. C. , McGilchrist C. A.
Published: May 2007

A set of independentN(O, ρ2) recursive residuals is obtained for a model proposed by GLEESON and McGILCHRIST (1980) to describe spatial dependence among observations on a rectangular lattice. These residuals can be used to test model adequacy in a similar fashion to Box‐Jenkins techniques for time series models.
On the Use of Various Methods of Discriminant Analysis
Authors: Eichhorn Chr.
Published: May 2007

The use of discriminant analysis for normal distributed populations with common or differing variances, and for populations with distributions of unknown type is discussed and illustrated by an example. Existing programs are mentioned. The results of the various methods of discriminant analysis are compared with each other.
The Ontogenetic Interpretation of the Growth Curve of Vertebral Organisms
Authors: Trincher K.
Published: May 2007

The growth curve of vertebral organism can be resolved into four different phases according to four different states of ontogenesis.
Estimation of the Mean in a Variance Component Model ‐ a Comparison of Estimation Procedures of ANOVA, MINQ and Sampling Theory
Authors: Trommer R.
Published: May 2007

We consider two simple estimators of the mean μ in a variance component model (one‐way classification, unbalanced case).
An Analysis of Variance of Nominal Data
Authors: Onukogu I. B.
Published: May 2007

This paper considers a common problem in analysis of variance where the responses to a set of treatments are nominal (i.e. are recorded in frequencies) with no underlying metric. Reasoning by analogy from standard analysis of variance of a two‐way classification we develop chi‐square tests for significance of treatments and interactions. Two tests are proposed for interaction and their asymptotic properties are studied.
Stereological Determination of Orientations, Second‐Order Quantities and Correlations for Random Spatial Fibre Systems
Authors: Stoyan D.
Published: May 2007

This paper presents methods for the stereological analysis of spatial fibre systems on the base of planar or thin sections. Under the assumption that the cross‐section figures of the tubular fibres can be measured, the orientation distribution of the fibre system and its line densityLvcan be determined from one section only and without distributional assumptions.

A simple way to study the degree of randomness of fibre systems consists in the statistical analysis of the point pattern of centres of intersection figures. More sophisticated methods are of stereological nature and yield the spatial reduced second moment measure. Similarly also correlations between two fibre systems can be quantified.

The methods are demonstrated by two examples concerning samples of human brain.
Estimating the Volume Density from Thin Sections
Authors: Stoyan D.
Published: May 2007

An approximation formula for the determination of the volume density from thin sections is given. It is applicable under very mild conditions on the structure studied and has a good accuracy.
Use of Growth Indices in Yield Forecast
Authors: Jain R. C. , Agrawal R. , Jha M. P.
Published: May 2007

A model has been developed for forecasting of crop yields in which growth indices of biometrical characters based on two or more periods simultaneously have been utilised. The growth indices are obtained as weighted accumulations of observations on biometrical characters in different periods, weights being respective correlation coefficients between yield and biometrical characters. This model has been found better than the models in use.
On the Parametric Approach to Survival Data Analysis I. Radiobiological Applications
Authors: Kadyrova N. O. , Yakovlev A. Yu.
Published: May 2007

Acute radiation injury and postirradiation recovery have been formalized in terms of a Markovian homogeneous process of the random walk with a finite set of states, two absorbing barriers and continuous time. The distribution of time for such a process to reach (for the first time) the upper absorbing barrier was earlier obtained by SAATY (1961) and within the proposed model it coincides with the life span distribution for irradiated animals. The possibilities of finding the maximum likelihood estimates of unknown parameters are investigated by means of simulating experiments performed with a computer assistance. On the basis of simulation results the applicability of the proposed distribution for the purposes of survival data analysis is discussed. Extension of the model to accomodate two (or more) radiation syndromes is presented.
Models of Parent‐Offspring Conflict in Small Populations
Authors: Mayo O. , Leach C. R.
Published: May 2007

FELDMAN and ESHEL (1982) have introduced a precise two locus genetical model to examine the spread of “selfish” alleles in a genetically “altruistic” population. They have shown that, with complete linkage between the gene affecting “altruism” and another determining parental “interference”, the development of “selfishness” may be prevented. Furthermore, “interference”, may allow the development of “altruism” in a “selfish” population. Small population results illustrate how a deterministic analysis may not provide a satisfactory description of how particular rare events occur. The usefulness of major gene models of this type is discussed.
The Empirical Bayes Classification Rules for Mixtures of Discrete and Continuous Variables
Authors: Wojciechowski T.
Published: May 2007

Let us consider a general population π. Each object belonging to the population π is characterized by a pair of correlated random vectors (X, Y). Both X and Y may be mixtures of discrete and continuous random variables. It will be assumed that our population π consists of k groups π1,….,πk, which depend on the value of the random vector Y. A certain object, which is an element of one of the k groups π1, …, πk, has to be classified into the correct group. The knowledge of the value of the random vector Y would permit its correct classification, but the observation of this vector is difficult or dangerous and we must assign the individual on the basis of the observation of the random vector X. The classification procedure is based on randomized decision function δ* which minimizes the risk function i.e. Bayes decision function. We give also two empirical Bayes classification rules i.e. decision functions based on the sample from population π and having property that their risks converge to Bayes risk when the sample size increases.
Numerical Results on Growth Functions
Authors: Berg L.
Published: May 2007

To given values for the weights of twelve rats and the averages of some of them there are fitted different smooth functions by the method of least squares. Piecewise polynomial approximation before and after the turning point suggests via a differential equation an approximation by exponential functions. The composition of these exponential functions leads to an implicit function, which can approximately be substituted by an inverses polynomial. Contrary to the usual growth functions, here the mass of the animals is unbounded, what is adequate to ad libitum feeding supposing immortality. The numerical results are laid down in ten tables and they are provided with comments.
Some Extensions to the Stochastic Study of the Life Table
Authors: Nair T. U.
Published: May 2007

This article discusses the application of statistical techniques in the analysis of the life table. Using a piece‐wise continuous model for the mortality pattern, the maximum likelihood estimates of the probabilities of dying, qi in a life table are obtained. From the form of the covariance matrix it is deduced that the estimates are asymptotically independent. The distribution of qi and its large sample variance are also derived.
A Note on Binary Contingency Tables
Authors: Upton Graham J. G.
Published: May 2007

This paper considers contingency tables in which the marginal frequencies for one variable are all 1. This could occur with two‐category binary data or when a continuous variable is treated in categorical fashion. Some results concerning the expectation of goodness‐of‐fit statistics are reported. In particular it is noted that the expectation of the Pearson statistic is independent of the model being fitted.
Analysis of Profiles Based on Ordinal Classification Functions and Rank Tests
Authors: Haux R.
Published: May 2007

In this article a test for the comparison of K groups of independent profiles is suggested. It is based on rank tests, in which the criterion is obtained by using a suitably chosen ordinal classification function. This function represents a specific view on the profiles. The test, which is easy to use, can be regarded as a generalisation of other well known tests and can be applied within a variety of situations. The relationships to other procedures for the analysis of profiles are described. Some properties are discussed.
Fidelity Estimation for a Hierarchical Classifier
Authors: Hufnagl P. , Voss K.
Published: May 2007

To estimate the correct classification rate of a classifier, many different methods exist (test sample, bootstrap, cross validation). The test sample is a method with very small expense. Sometimes, only a small number of objects is available (seldom diseases, high costs for experiments). When we split the sample in training set and test set, we get good or bad fidelity estimations but, unfortunately, vice versa a big or small confidence interval for the estimation. Overcoming this dilemma is only possible for simple classifiers. Such a simple classifier is investigated and a direct fidelity estimation is proposed.
Selection of the Better of Two Treatments when They May Not be Equivalent
Authors: Desu M. M. , Bristol D. R.
Published: May 2007

A procedure for selecting the better of two treatments which allows for the possibility of non‐selection when the treatments appear to be equivalent (that is, similar) is presented. The proposed procedure is a modification of the indifference zone approach. It is assumed that the treatments are compared with respect to a continuous response variable, which has a normal or a two‐parameter exponential distribution. For the normal distribution, each of the parameters is considered as the ranking parameter. For the two‐parameter exponential distribution, the guarantee time (location parameter) is the ranking parameter. The values of the estimates of the ranking parameters and the observed distance between these estimates are used in this selection procedure.
The Exact Distribution of the Anderson‐Kannemann Statistic
Authors: Küchenhoff H. , Lehmacher W.
Published: May 2007

The Anderson‐Kannemann test is a rank test for treatment effects in a randomized block design with K treatments and N blocks. In this paper, an algorithm for computing the exact distribution of the Anderson‐Kannemann test statistic under the null hypothesis is deduced. Then, the exact distribution is compared with the asymptotic χ2‐distribution, and it is shown that the exact distribution is approximated fairly well by the asymptotic distribution. Tables of the exact distribution are given for K = 3, N = 3(1)15; K = 4, N = 3(1)11; K = 5, N = 3(1)7; and K = 6, N = 3(1)5.
Spline and General Regression of Polytomous Data
Authors: Onukogu I. B.
Published: May 2007

The paper shows a formulation for a general linear regression as well as a spline regression of multinomial responses on a quantitative input variables. Application of least squares and asymptotic theory yields the F‐test for significance of coefficients and a t‐test for structural discontinuity.
Efficient Estimators for the verianoe of a Finite Population
Authors: Kaur P.
Published: May 2007

For the estimation of finite population variance of a character, DAS and TRIPATHI (1978) proposed some efficient estimators when population mean of variance of some other character (associated with main character) is known. We propose here some estimators for population variance using same information and compare with those given by DAS and TRIPATHI (1978). Some examples are given for illustration.
Confidence Estimation of an Unknown Component of the Vector of Regressor Variables in Multivariate Linear Regression
Authors: Rausch W. , Horn M.
Published: May 2007

The model used in this paper is Y = Xβ, where with magnified imageunknown x0. Estimators of x0 are derived by putting βmx0 =βm+1 regarding βm+1 as a new unknown parameter. Formally we use the model Y = X1β+ + e where β′+ = (β0, …βm+1 and magnified image Then βm+1/ βm is a point estimator of x0. Assuming normality for e and taking the random variable z=βmx0−βm+1 we get a t‐distributed variable and finally a confidence estimator of x0.

The formulas are applied in dose response relations in antibiotic assays refering to a standard. Now we can take into account not only the dependence on the dose/concentration but also on the position on the test agar plate where the test solution is filled in. As a consequence the confidence interval of the unknown dose/concentration x0 becomes shorter and by it the statements more precise.
The Decompositions for Point Symmetry Models in Two‐way Contingency Tables
Authors: Tomizawa S.
Published: May 2007

The decomposition for the complete point symmetry model in a rectangular contingency table is shown. Also the respective decompositions for the local point symmetry model and the reverse local point symmetry model in a square contingency table are given. Moreover test procedures for the decomposed models and an example are given.
Characterizations of Some Discrete Distribution Models Arising in Pollen Studies
Authors: Papageorgiou H.
Published: May 2007

Characterizations are obtained for multinomial and multiple binominal mixtures. Examples are given when the beta distribution is used as the mixing distribution. Biological applications are indicated.
Efficient Estimation of Protein Binding Constants
Authors: Connett J. , Gharrett A. , McHugh R.
Published: May 2007

Assays of cyclic AMP typically employ a Scatchard‐like data analysis to estimate the total binding protein RT and the dissociation constant Kd. The linear regression procedure employed is statistically ad hoc because the response variable (bound counts) occurs on both sides of the Scatchard equation.

The alternative analysis presented here is derived from the cyclic AMP binding reaction. The resulting data analysis, employing non‐linear least squares, results in estimators that on the basis of Monte Carlo studies have less bias and greater precision than the Scatchard method.
Nonparametric Evaluation of Repeated Measurement Designs by Point‐Symmetry Testing
Authors: Lienert G. A. , Netter Petra
Published: May 2007

It is suggested to use simultaneous point‐symmetry tests in evaluating trivariate repeated measurement designs nonparametrically. With k =3 treatments being applied to each of N individuals in randomized sequence, pairs of treatments are compared as to 3 variables or incremental sign patterns. It is shown that unifold trivariate tests preserve more information than do multifold univariate tests. The method is illustrated by an example from psychophysiological research.
Nonparametric Evaluation of ANOVA Designs by Local, Regional, and Global Contingency Testing
Authors: Havranek T. , Kohnen R. , Lienert G. A.
Published: May 2007

Nonparametric analysis of ANOVA designs is proposed to be done by simultaneous contingency testing of discretised response variables. Selected treatment‐response patterns are evaluated by predictive configural frequency analysis (local contingency). Treatment response associations are defined by regional contingencies. Total treatment‐response relation is defined by global contingency. All methods are illustrated numerically by biometrical examples.
Parameter Estimation for the Bateman Function via Moments of the Empirical Curve
Authors: Knolle H.
Published: May 2007

The parameters of the function f(t)=c(e−at‐e−bt) are related in a simple way to the moments ∞ tnf(t)dt(n=0, 1, 2). Using empirical values of f, the moments can be estimated by numerical integration. Therefrom estimates of the parameters are obtained by elementary algebra.
A New Estimation Method for Noncompartmental Pharmacokinetic Analysis
Authors: Knolle H.
Published: May 2007

The mathematical tools of Hilbert space theory and Gauß quadrature are used to derive a new method of curve fitting and calculation of statistical moments of the concentration‐time curve.
A Note on Non‐Parametric Tests for the Interaction in Two‐Way Layouts
Authors: Kubinger Klaus D.
Published: May 2007

A suggestion is given of how to prove main and interaction effects in two‐way layouts independent of each other even if the data are just ordinally scaled. Starting from HILDEBRAND'S (1980a, b) non‐parametric approach which presupposes interval‐scaled data, transformations of ranks are settled before analysis per analogy to theH‐test takes place. That is, the same formula of an asymptoticallyX2‐distributed test‐statistic results but mean ranks are used instead of mean scores in order to partialize, for instance, main effects while testing interaction effect. Finally an allusion is given of how to handle ties as well as unequal sample sizes.
Application of the Principal Components Method and the Proportional Hazards Regression Model to Analysis of Survival Data
Authors: Danielyan S. A. , Zharinov G. M. , Osipova T. T.
Published: May 2007

One of factor analysis techniques, viz. the principal components method, and the proportional hazards regression model (Cox, 1972) are applied in this work to study the significance of various factors characterizing the patient, the disease, and the method of treatment in the survival. The application of these methods to analysis of survival data for cervical cancer patients has shown, in particular, the tumor growth rate to be the crucial factor in distribution of the patients survival time and to be even more important than the therapy characteristics.
One Degree of Freedom for Non‐Additivity in a Contingency Table and Its Multivariate Extension
Authors: Onukogu Ike B.
Published: May 2007

The paper develops a chi‐square test with one degree of freedom for row‐column interaction in a contingency table. Use is made of the JOHNSON‐GRAYBILL [1972] model which is herein generalized to a twoway multiple response situation. Some of the merits of the new test over the better‐known tests for the same hypothesis are discussed.
Analysis of Triangular Diallel Table for Experiments in Block Designs
Authors: Ceranka B. , Kielczewska H.
Published: May 2007

In this paper the analysis of genotypes obtained in diallel crossing system, including one set ofF1′sand parents, arranged in triangular table is given. This analysis is presented for data obtained from the experiments laid out in block designs. The analysis of variance, estimators of general and specific combining abilities as well as statistics for testing of hypotheses concerning those parameters are given.
Bayesian Estimation in a Generalized Negative Binomial Distribution
Authors: Islam M. N. , Consul P. C.
Published: May 2007

A generalized negative binomial (GNB) distribution was introduced by JAIN and CONSUL (1971) and was modified by NELSON (1975). The probability function of the distribution is defined by the function p(x; m, β, θ)= θx (1 ‐ θ)m+βx—x for x=0, 1, …, and zero otherwise, where m>0, 0<θ<1 and β=0 or 1≦β<θ−1. The Bayes estimators for a number of parametric functions of θ when m and β are known are derived. The prior information on θ may be given by a beta distribution, B(a, b), to which no subjective significance is attached. It has been illustrated that the parameters in the prior distribution can be assigned by a computer. Comparisons are made of the Bayes estimate of P(X=k) to the corresponding ML estimate and the MVU estimate for any given sample to the order n−1 for different values of k..
Weighted Standardization—A General Data Transformation Method Proceeding Classification Procedures
Authors: Hohenegger J.
Published: May 2007

During preparatory steps of data for automatic classification routines, the amount of information contained by the character distribution is reduced by standardization of the character values. This information can be regained through special weighting schemes of standardized character values. Two weight coefficients derived from decomposition of the frequency distributions of the characters are proposed.
Elementary Analysis of Multidimensional Contingency Tables. Application to a Medical Example1/2
Authors: Enke H.
Published: May 2007

By the aid of analysing a medical example a three—step procedure for analysing multi—dimensional contingency tables is introduced. This procedure has some good properties.

Step one is due to catch the relationship structure between the variables connected by the contingency table. Hereby only so—called graphical models, a subclass of hierarchical models in regard of the parameters of the log—linear model, are admitted. The models can be generated by combination of hypotheses of pairwise conditional independence. Hereby a so‐called Extended Combination Procedure is proposed using the position of the Chain of (hierarchical) Hypotheses. A useful symbolic notation for ‘Dependence Models’ in addition to that in form of ‘Independence Models’ and ‘Minimal Sets’ is proposed. Step two analyses the significant conditional pairs in regard to the question for what attribute level combinations of the condition complexes the relations remain significant.

Step three investigates those tables recognised as significant in step two more closely to get ideas about the ‘sources’ of dependencies and possibilities of collapsing parts of the table.

The procedure is mostly used in explorative data analysis although the simple steps can be used to test hypotheses, too.
The Properties of Cell Kinetics Indicators. A Computer Simulation Study
Authors: Zorin A. V. , Yakovlev A. Yu.
Published: May 2007

The results of studying the properties of cell kinetics indicators by computer simulation methods are reported. Two problems are considered, one concerning investigation into the efficiency and robustness of the procedure earlier proposed by us (YAKOVLEV et al., 1977) for estimating the so‐called q‐index which characterizes the integral flow of cells into a given mitotic cycle phase. The other problem is substantiation of the way to form mathematical expectations of the indices of cell cycle phases. Discussion of the results of simulation experiments is preceded by analytical solutions of some of the simpler cases of such problems with the use of the theory of multitype age‐dependent branching stochastic processes.
The Structure of Ellipsoidal Distributions, II. Principal Components
Authors: Jensen D. R.
Published: May 2007

Principal‐axis rotations are informative for data from ellipsoidal distributions even without moments. The standard normal‐theory tests used in principal components analysis are shown to be identical in level and power for all ellipsoidal distributions under a specified model for sampling. This follows from basic invariance properties of distributions associated with sample dispersion matrices. Similar findings are reported for HOTELLING'S (1936) canonical analysis in Part I of this study.

AMS 1980 subject classification. Primary 62 H 25; Secondary 62 H 05.