bluuebunny/crossref_metadata_2025 huggingface dataset:
Down-regulation of FKBP12.6 and SERCA2a contributes to acute heart failure in septic shock and is related to an up-regulated endothelin signalling pathway
Authors: He Hai-Bo , Yu Feng , Dai De-Zai , Dai Yin
Published: July 2007

Acute heart failure (AHF) critically affects morbidity and mortality in patients suffering from septic shock. It is hypothesized that AHF is linked to down-regulation of FKBP12.6 (calstabin 2) and SERCA2a (sarco/endoplasmic reticulum Ca2+ ATPase 2a), which may be mediated by an activated endothelin (ET) system in the myocardium. The aim of the study was to test whether an attenuation of septic AHF can be achieved by a novel dual endothelin receptor antagonist, CPU0213, in association with up-regulation of FKBP12.6 and SERCA2a in rats. AHF in septic shock was produced by faeces leak from a surgically punctured caecum for 72 h in rats. CPU0213 (30 mg kg−1, s.c., every 12 h, for 3 days) was administered to rats 8 h after the operation. In the untreated model group, survival rate markedly decreased (P < 0.01), and the cardiac performance was seriously compromised (P < 0.01) relative to control. The AHF was characteristically associated with down-regulated mRNA and protein expressions of FKBP12.6, SERCA2a and PLB (phospholamban). Elevated ET-1 and mRNA abundances of the preproET-1, ECE (endothelin converting enzyme) and ETA and ETB receptors in the left ventricular tissue (P < 0.01) were found. All abnormalities were reversed significantly following CPU0213 administration. In conclusion, septic AHF is attributed to down-regulation of FKBP12.6 and SERCA2a, which is related to an activated ET system. An endothelin receptor antagonism of CPU0213 significantly improves the cardiac performance by blocking both ETA and ETB receptors.
Does caffeine reverse the EAC cell-induced immune suppression?
Authors: Mandal Anup , Poddar Mrinal K
Published: July 2007

The aim of this study was to investigate the effect of long-term consumption of caffeine in the development of Ehrlich ascites carcinoma (EAC) cells in adult female mice, 25–30 g, in relation to immune response. Mice were treated with caffeine (20 mg kg−1 daily, p.o.) for 22–27 consecutive days or inoculated with EAC cells (5 times 106 cells/mL, i.p.), or both. Control mice, corresponding to experimental groups, were treated with corresponding vehicles under similar conditions. The lymphocyte viability, mitogen-induced proliferating activity, cytotoxicity and DNA fragmentation from blood, spleen and thymus of both control and experimental groups were measured as immune response parameters. An immune response index, corticosterone, was also measured in adrenals and plasma under similar conditions. Results showed that development of EAC cells caused immune suppression with a reduction of lymphocyte viability, cytotoxicity and proliferative activity and induction of DNA fragmentation in those tissues, as well as an increase in plasma corticosterone. Though long-term caffeine treatment (which resulted in tolerance to caffeine) alone did not alter significantly any of the immune response parameters studied, including corticosterone status (immune biomarker), the continuation of caffeine treatment during the development of EAC cells either restored or reduced the EAC cell-induced alteration in these parameters, including the HPA axis biomarker. These results suggest that long-term caffeine intake may inhibit or reverse the EAC cell-induced immune suppression.
Incorporation of the strain-rate-sensitive constitutive relations in the analysis of sheet metal forming
Authors: Toh C H
Published: July 2007

Two forms of rate-sensitive constitutive equations, additive and multiplicative, are examined in the analysis of sheet metal forming using the finite element method. Results are obtained for hemispherical punch stretching of an AK steel sheet material with various punch speeds. The computed results in thickness strain distributions and load-displacement curves are almost identical for the two constitutive laws at a low punch speed. However, the additive law provides better agreement in the thickness strain distributions with the experimental trends for high-speed forming.
Closed-die coining – an upper bound analysis
Authors: Monaghan J M
Published: July 2007

The final stages of many forging processes involve the flow of material into corner cavities or other surface details within a die. The process at this stage is essentially a ‘coining’ operation, and is usually characterised by high forming forces and relatively little material flow. These forces can be particularly severe under closed-die cold forging conditions, as in, for example, the manufacture of specialised headed fasteners, and can lead to problems of premature tool failure or the production of faulty products. This paper presents an upper bound analysis of such a ‘coining’ stage during a cold forging process. The theoretical analysis is based on an upper-bound formulation derived previously by the author, but, as will be shown, can be extended with ease to investigate the deformation of a family of similar workpiece geometries. The upper bound predictions for mean forging pressure ratio were compared with experimental results and good agreement was obtained. In addition, the change in the workpiece geometry during forging was noted and is commented upon.
Direct determination of derivatives of holographically recorded displacement by an optical diffraction technique
Authors: Hung Y Y , Leung T P , Chau F S
Published: July 2007

This paper presents a novel technique for direct determination of derivatives of the displacement recorded by holographic interferometry. In the recording of a double exposure hologram, a set of relatively high frequency carrier fringes is coherently superimposed upon the displacement fringes by slightly changing the object beam direction, in addition to deforming the object. The resultant fringe pattern is a perturbed carrier fringe pattern, and the local fringe spacing directly determines displacement derivatives. Fringe spacing is accurately determined by measuring the separation of a pair of diffracted orders produced by a laser beam diffracted by the local carrier fringes.
Stability analysis of laminated and stiffened composite shells of revolution by the finite element method
Authors: Ding Wei , Xu Jinan
Published: July 2007

This paper presents a numerical method of analysing the elastic stability of thin laminated and longitudinally stiffened shells of revolution. The anisotropic elastic properties of composite materials are taken into account. The discrete longitudinal stiffener is dealt with as a beam-column, and its eccentricity effect is also considered. The basic elastic and geometric stiffness properties of the stiffeners are synthesized into a stiffness matrix compatible with an axisymmetric shell element by a series of transformations, to be used in conjunction with a finite element representation of a thin axisymmetric shell, where the displacements are decomposed into Fourier harmonics. Thus, the effect of the stiffeners can be rigorously accounted for in stability analysis. Examples are given to show that the results agree well with existing solutions by other analytical methods and by experiments.
Stress intensity factors for cracks at spherical inclusions by the boundary integral equation method
Authors: Tan C L , Gao Y L
Published: July 2007

In this paper, the steps in the derivation of the analytical expressions, which could be used to evaluate directly stress intensity factors for cracks from the numerical results of boundary integral equation axisymmetric fracture mechanics analysis are reviewed. These expressions have been found previously to provide an efficient means by which stress intensity factors can be obtained without unnecessarily refined mesh discretisations. They include those which could be used to analyse interface cracks between dissimilar materials. Such crack problems present modelling difficulties when using conventional procedures for obtaining the fracture parameters because of the oscillatorily singular stresses in the vicinity of the interface crack tip. Three axisymmetric problems, each involving a crack at an elastic inclusion which, is embedded in an elastic matrix, are treated in this study, and stress intensity factors are obtained for a range of crack sizes. Both mechanical and thermal loading are considered, and the effects of the mismatch of the material properties of the inclusion and the matrix are also investigated. The numerical results are of interest to the study of, for example, microcracking in particulate composites.
Digital photoelastic investigation of transient thermal stresses of two interacting defects
Authors: Wang W C , Chen T L , Lin S H
Published: July 2007

In this paper, the digital photoelastic technique was used to determine the transient thermal stresses of two interacting defects in a semi-infinite thin plate, a semi-circular edge defect, and an internal elliptic hole, when the plate edge experiences a rapid temperature change. The problem is formulated as a two-dimensional transient thermal problem in a multi-connected semi-infinite domain. A series of computer programs were developed on the digital photoelastic system to analyse the photo-thermoelastic fringe patterns. Then, the variations of locations of the maximum transient thermal stresses with time were discussed. Finally, the correlation expressions between the variations of the maximum transient thermal stresses with the time, temperature difference, and geometrical parameters of the defects were obtained by the regression procedure.
The stress distributions in shouldered shafts under axisymmetric loading
Authors: Gooyer L. E. , Overbeeke J. L.
Published: July 2007

The stress distributions in shouldered shafts in tension and in torsion were calculated by the finite element method (FEM) for notch radii that are of technical interest.

The calculated stress concentration factors Kt and relative stress gradients normal to the surface were compared with values given in a well-known handbook used by many designers, and with literature, respectively. From this comparison it appears that:

– Kt values for a shouldered shaft in tension are up to 30 percent higher than the values given in mentioned handbook;

–the relative stress gradients can, within the range of notch radii r that was investigated, be approximated by 2/ r for the tension case and 1/ r for the case of torsion.

Publication of reliable results from FEM calculations of stress concentrations are recommended in order to improve or extend the usability of the design data which are now available.
Effect of nut geometries on screw thread stress distribution: Photoelastic results
Authors: Dragoni E
Published: July 2007

The structural merits of lip-type nuts engaging with ordinary bolts are assessed experimentally by means of frozen-stress photoelasticity. Thread pitch, lip radial thickness, and lip length are selected as design variables and scanned for possible effect on the maximum stress within the connection. In this respect, the length of lip is shown to play a major role while the other parameters have no decided effect. It is found that a nut with a lip covering 60 percent of total height reduces the stress concentration in the screw by nearly 40 percent with respect to a standard nut of equal height and outside diameter. This improvement is achieved without producing higher stresses in the nut than in the screw.
Creep–fatigue crack growth in Jethete M152 at 550°C under mixed mode conditions
Authors: Hyde T H , Chambers A C
Published: July 2007

Creep–fatigue tests were carried out on Jethete M152 at 550°C under mode I, mode II, and mixed mode ( K1/ KII ≈ 1.6) conditions. The results were correlated and compared with corresponding fatigue and creep data. The results indicated that damage due to creep caused a larger increase in fatigue crack growth rate than a simple superposition model would predict. Also creep appeared to have a more dominant influence than fatigue on crack growth direction.
Free bending fatique of axially pre-loaded spiral strands
Authors: Raoof M
Published: July 2007

The response of a large diameter and a multi-layered spiral strand to an applied moment is considered in some detail for a given mean axial load. Carefully conducted large-scale experiments have cast some light on an interesting phenomenon observed in previously reported bending fatigue experiments The first wire to fail was invariably the wire which entered the socket on the bending neutral axis rather than the wires in the ‘extreme fibre’ positions, as might usually be expected.

Using a series of electrical resistance strain gauges placed on the individual wires at the mouth of the socket, the previously reported theoretical predictions that interwire slippage is greatest at the neutral axis (in terms of simple beam bending theory), and least at the extreme fibre positions, have been confirmed. In line with the theoretical predictions reported elsewhere, the test results show that, in general, the onset of deviations from no-slip interlayer shear interaction occurs at rather small levels of bending movements near the socket.

Based on the theoretical and experimental findings, which identify interlayer fretting as the primary cause of wire fractures, a newly developed parameter capable of predicting spiral strand free bending fatigue life has been proposed. Unlike the traditional extreme fibre maximum direct stress approaches, the proposed parameter takes the interwire/interlayer fretting phenomenon into account.
On the error analysis of residual stress measurements by the hole-drilling method
Authors: Zhou H , Rao M D
Published: July 2007

In this paper, an error analysis is carried out to discuss two important parameters that influence the accuracy in the measurement of residual stress by the hole-drilling technique. The first is the error associated with zero strain phenomenon that occurs for certain orientations of the strain gauges. A rigorous condition for zero strain point is given and measurement accuracy is discussed when the zero strain point phenomenon occurs. Secondly, the calculated residual stress field is affected by the methods chosen for the estimation and calibration of the relieved strain coefficients. The errors associated with the estimation of the relieved strain coefficients are also discussed along with their useful range for the calculation of the residual stress field.
Three benchmark examples for frictional contact modelling using finite element and boundary elements methods
Authors: Olukoko O A , Becker A A , Fenner R T
Published: July 2007

Three benchmark examples for two-dimensional and axisymmetric contact problems with friction are presented using the finite element and boundary element methods. The examples have relatively simple geometries and boundary conditions, and involve frictional sticking and slipping modes at the interface according to Coulomb's law of friction. Results are presented in the form of normal contact stresses, shear stresses, relative tangential displacements, and the stick-slip partitioning of the contact interface.
A specimen for determining fracture properties under combined modes, I, II, and III crack tip conditions
Authors: Hyde T H , Aksogan O
Published: July 2007

An axisymmetric, bar-type specimen, which contains conical, ‘crack-like’, external flaws, is described. The specimen can be used to obtain mixed-mode (I, II, and III) fracture data. These ‘crack-like’ flaws can be created in metallic and non-metallic materials by incorporating metal or ceramic shims in moulds used to cast the components.

Mode I and mode II crack tip conditions are created in the specimen by subjecting it to an axial load, while mode III crack tip conditions are produced by applying a torsional load. Finite element analyses are performed and results are presented which enable the KI, KII, and KIII values to be determined from the axial load, the torque, the bar diameter, the crack length, and the crack inclination.
The application of the Graham and Walles creep equation to aeroengine superalloys
Authors: Harrison G F , Homewood T
Published: July 2007

The paper briefly discusses the charcteristics of creep deformation and the requirements of any creep equation developed to quantify this behavior. It is shown how the Graham and Walles methodology (1)† fulfils the identified objectives and how the equations have been applied to simple and complex variable loading situations.

By reference to an appropriate blade alloy it will be shown that the approach can be extended to produce deformation maps and the results will be compared with theoretical creep models such as dislocation shearing of precipitate particles.

Finally it is shown how the Graham and Walles model has been applied to single crystal materials to predict creep in randomly oriented crystals.
Changes in wire curvature as a wire rope is bent over a sheave
Authors: Hobbs R E , Nabijou S
Published: July 2007

The changes in curvature in single and double helices as they are bent into circular arcs are derived from first principles. This analysis is applied to wire ropes to examine the bending strains in the wires of a frictionless rope as it is bent over a sheave. It is shown that the free bending strains in the wires in the innermost layer of a strand in a rope taken as an example are higher than those in the outer layer wires, while the second wire layer has the lowest bending strains.
Elastic—plastic finite element analysis of short flat bars with projections part 1: Shear loading
Authors: Hardy S J , Pipelzadeh M K
Published: July 2007

This paper describes the results of a study of the elastic–plastic behaviour of short flat bars with projections subjected to monotonic and cyclic shear loading using finite element analysis. Six geometries, associated with both local and remote restraints (resulting in elastic stress concentration factors in the range 1.90–7.20), are considered. Three simple bilinear elastic–plastic material models are assumed. The results have been normalized with respect to material properties so that they can be applied to geometrically similar components made from other materials which can be represented by the same materials models.
Response and cyclic strain accumulation of pressurized piping elbows under dynamic in-plane bending
Authors: Yahiaoui K , Moffat D G , Moreton D N
Published: July 2007

Eight pairs of carbon and stainless steel, long and short radius welding elbows were tested under conditions of steady internal pressure and in-plane, resonant dynamic moments that simulated seismic excitations. The elbows had an outside diameter of 60.3 mm and thicknesses of 3.91 and 5.54 mm. The material properties are reported, and the testing procedure and experimental programme fully described. The dynamic response of the comonents indicates that the stainless steel elbows behave differently from the carbon steel elbows.

The cyclic strain accumulation for each component is assessed and ratios of applied to limit moments of the elbows at onset of ratcheting are given for each material. While the gross deformation range increased with level of input in testing, no permanent overall swelling or ovalization was recorded; this is contrasted with similar results reported in the general literature.
Creep constitutive equations for a 0.5Cr–0.5Mo–0.25V ferritic steel in the temperature range 600–675°C
Authors: Perrin I J , Hayhurst D R
Published: July 2007

Constitutive equations have been developed to describe the creep behaviour of a 0.5Cr-0.5Mo-0.25V ferritic steel under uniaxial and multi-axial states of stress, as well as over the temperature range of 600–675°C. This material has widespread application as the parent steam pipe in the power generation industry. An accurate description of creep behaviour has been achieved by formulating constitutive equations that describe the physical mechanisms of deformation and rupture. To this end, two state variables were introduced to model intergranular creep cavitation and the coarsening of carbide precipitates respectively. The influence of temperature on the constitutive equations is also considered and activation energies are identified for each of the material constants that show a notable temperature dependence.

Numerical optimization methods are discussed for the determination of the material constants and of the corresponding activation energies. The constitutive equations provide a good representation of the experimental creep data. The limitations on the range of validity of the equations are explained with reference to the mechanisms of material deformation and rupture. The description of the creep behaviour is completed by the determination of the constant that defines the multi-axial stress rupture criterion of the material. It is argued that the constitutive equation set is suitable for the analysis of engineering components.
Hollow cylinder upsetting between flat platens considering unequal frictional conditions
Authors: Lin S Y
Published: July 2007

The plastic upsetting of a hollow cylinder taking into account unequal interface frictional conditions is investigated by a thermo-elastic—plastic coupling model. The flow stress of the deforming workpiece is taken as a function of strain, strain rate and temperature. The effects of various combinations of unequal interface frictions at the top and bottom die surfaces on the temperature and effective strain distributions are investigated. The non-symmetrical flow induces uneven profiles of inner and outer surfaces of the hollow cylinder and hence the variations in distributions of each strain component within the billet are also predicted. The theoretical results obtained are consistent with the observations of upsetting experiments of the hollow cylinder.
Participation, job satisfaction and decentralization: The case of Swaziland
Authors: Yoder Richard A. , Eby Scott L.
Published: July 2007

Using Swaziland's Ministry of Health as a case study this paper assesses the extent to which the empirical data supports anecdotal information and trends towards decentralized and participatory management systems. Specifically, this study measures the level of participation in decision making and assesses its impact on job satisfaction, measures the level of and analyses differences in job satisfaction by job classification, and identifies and analyses the determinants of employee job satisfaction. Data were obtained from a survey questionnaire which was constructed and administered to 447 employees of the Ministry of Health, a 42 per cent sample, at fifteen representative locations throughout the country. Simple descriptive statistics and multivariate techniques are used to analyse the data. From the analysis, policy implications are developed for designing administrative structures and systems that respond to emerging ‘quality of worklife’ needs, strengthening productivity, and improving the quality of services provided.
Introducing the urban land pooling/readjustment technique into Thailand to improve urban development and land supply
Authors: Archer R. W.
Published: July 2007

Land pooling/readjustment (LP/R) is a technique for managing the planned development of urban‐fringe lands, whereby a government agency consolidates a selected group of land parcels and then designs, services and subdivides them into a layout of streets, open spaces and serviced building plots, with the sale of some of the plots for cost recovery and the distribution of the remaining plots back to the landowners to develop or to sell for development. Widely used in Japan, South Korea and Taiwan, LP/R is being adopted in Indonesia, Nepal and Malaysia. The community benefits that the technique can provide in the Thailand situation of weak urban land‐use controls and inadequate provision of urban network infrastructure are outlined. The landowner benefits the technique can provide that make it a fully acceptable and feasible technique are identified. Pilot LP/R projects should be undertaken to demonstrate and learn the technique in the Thai context. A draft scheme for one such project, to install distributor roads and utility lines in advance of private land development, is outlined. These pilot projects would also provide the local experience for designing a law, administration and procedures for the wide use of LP/R in Thailand. The main elements of such a national LP/R system are outlined. A similar approach is recommended for the adoption of LP/R by the other developing countries of Asia.
Linking decentralization and centralization: A critique of the new development administration
Authors: Werlin Herbert
Published: July 2007

This article examines the orientation of what is here called the ‘New Development Administration’ (NDA), as put forth by Esman (1988). It does so using political elasticity theory. The article is sympathetic to the NDA's emphasis upon decentralization, community development, deregulation, privatization, minimal government, popular participation and flexible forms of foreign aid. However, it argues that these require an administrative framework to be effective, including strong leadership, effective bureaucracies, the cooperation of beneficiaries and the ability to shift from soft to hard forms of power. While the importance of a bureaucratic reorientation is generally recognized, NDA supporters seem unclear about the requisites needed. Without adequate supervision and control, NDA objectives cannot be achieved.
Performance of local councils in the collection of revenue in Bangladesh
Authors: Huque Ahmed Shafiqul
Published: July 2007

Local councils in Bangladesh have been provided with several sources of revenue that can be utilized for the maintenance of the councils, as well as the initiation of developmental projects. The union and upazila level councils have fared miserably in collection of such revenue. An examination of twelve upazilas during 1986–90 demonstrates that their performance has been affected by a lack of administrative support for the task, a dearth of adequate knowledge and skills on the part of local leaders and a failure to plan carefully on the part of the government. The Ordinances through which they have been established did not identify realistic sources of revenue nor did they provide guidelines on their utilization. Consequently, collection of revenue is done in an arbitrary and disorganized manner. It is recommended that adequate and appropriate administrative structures are developed and that proper training is provided to enhance the knowledge and skills of local leaders and to enable the councils to perform the task of revenue collection efficiently. Some suggestions are presented to utilize properly the market facilities, which appear to be highly potent sources for the generation of revenue.
Women in the Zambian civil service: A case of equal opportunities?
Authors: Pat O'connor Thomas Turner
Published: July 2007

There is a paucity of empirical microlevel studies of women in the formal sector in developing countries. This article attempts to redress this deficit and focuses on the position of women in the Zambian civil service using information from a sample of personnel records. Although women are disproportionately represented in the civil service compared with other areas of the formal economy, the current positions of males and females are significantly different. However, the results of the survey are not easily encompassed in prevailing theoretical frameworks and, rather surprisingly, it appears that it is age rather than gender that is the crucial explanatory variable. Finally, a number of possible explanations are advanced to account for our findings.
A policy framework for surface water and shallow groundwater allocation, with special reference to the Komadougou Yobe River Basin, northeast Nigeria
Authors: Carter Richard C.
Published: July 2007

The Hadejia and Jama'are rivers rise on the Basement Complex of Kano and Bauchi States, and on entering the area underlain by sedimentary rocks, they lose most of their water in their passage through Jigawa, Yobe and Borno to Lake Chad. Water resource developments on the Hadejia branch are now so far advanced that effectively the entire flow is consumed before the confluence, where the river changes name to the Yobe. These developments have taken place in the absence of a coherent, integrated water management policy, either nationally, for the river basin, or at a local level. The Jama'are tributary is so far undeveloped, although this is unlikely to remain so for much longer. In this article proposals for an analytical framework for water allocation policy in the river basin are made, together with an analysis of the characteristics of the major existing water‐using activities. The article argues, not for a particular water allocation policy, but for clarity and transparency in the development of such policy by the relevant authorities in Nigeria.
Die Höhen‐ und Zenitwinkelabhängigkeit der Energiespektren von Ultrastrahlungsteilchen
Authors: Allkofer O. C.
Published: July 2007

Die Energiespektren der kosmischen Strahlung sind von zweifacher Bedeutung. Einmal stellen sie eine wichtige „Konstante”︁ der kosmischen Strahlung dar, zum anderen lassen sich durch Vergleich der Spektren in verschiedenen Höhenbereichen der Atmosphäre stattfinden.
Die gängigen apparativen Methoden reichen zwar im allgemeinen aus, Energiespektren auf Meereshöhe stattfinden.

Die gängigen apparativen Methoden reichen zwar im allgemeinen aus, Energiespektren auf Meereshöhe zu untersuchen, sie sind jedoch in ihrem Aufbau meistens zu kompliziert und in ihren Dimensionen zu groß, um damit Messungen auf Höhenlabors oder in Flugzeugen durchführen zu können. Erst durch neue Detektortechniken ist es möglich geworden, Ultrastrahlungsspektrometer so zu konstruieren, daß auch in größeren Höhenbereichen Messungen von Spektren vorgenommen werden können. Dementsprechend ist das Material über die Höhenabhängigkeiten von Spektren im Vergleich zu den Spektren auf Meereshöhe weit dürftiger. Trotzdem gibt es ein Reihe von Untersuchungen von Spektren in in verschiedenen Höhenbereichen, die jedoch in ihren Resultaten nicht immer übereinstimmen.

Die vorliegende Arbeit faßt die Untersuchungen der Ultrastrahlungsspektren in den verschiedenen Höhenbereichen, die zum größten Teil in den letzten Jahren durchgeführt worden waren, zusammen. Eingeschlossen in diese Zusammenfassung sind auch Neigungsspektren und der Positive Exzeß.
Kollektives Kernmodell und Quasiteilchen‐Anregungen
Authors: Weller F.
Published: July 2007

A method is described which extends the usual Coriolis coupling band mixing calculations by the inclusion of rotation‐vibration interaction and quasiparticle‐phonon interaction. It is based on Bohr's collective Hamiltonian and on the rotation‐vibration interaction model of Faessler and Greiner. These collective models are described in detail. The success of the method depends on a careful treatment of the pairing correlations which have a striking influence. This is because the operators of the quasiparticle‐phonon interaction commute with the time‐reversal operator, so that their matrix elements between single‐particle states are in many cases considerably reduced by the pairing correlations. Because this interaction mixes high‐lying configurations with low‐lying ones, it is important to take the blocking effect into account. The influence of the number conservation is investigated.

Energies of nuclear states and their theoretical level structure, allowed and K‐forbidden gamma‐ray transitions in odd‐mass rare earth nuclei are calculated and compared with the experimental values. Good agreement with experimental results is obtained for M 1 transitions; K‐forbidden E 1 transitions are about an order of magnitude too fast.
Linear Symmetries of Scattering Amplitudes
Authors: Daboul Jamil
Published: July 2007

If we define, roughly, linear symmetries as those symmetries which lead to linear relationships among scattering amplitudes, we are then faced with the question whether we already know all possible types of linear symmetries or whether there are new types of symmetries which we can yet discover. We argue that for an important class of these symmetries there can be no new types of symmetries, except for one which we call scaling symmetry. We also attempt to point out all types of symmetries which other classes have. In analyzing the above question we are led to a simple and consistent formalism for describing linear symmetries which takes linearity as the starting point for dealing with these symmetries. In this approach all linear symmetries are formally treated on an equal footing. General results on linear symmetries are derived: These symmetries are then classified into three main classes, and an effort is made to discover the characteristic properties of the individual classes.
Greensche Funktionen in der Theorie der Kernmaterie
Authors: Weigel M. , Wegmann G.
Published: July 2007

The aim of this article is the representation of the theory of nuclear matter with the technique of many‐body Green functions. We have treated the theory of Green functions thoroughly in the first chapters taking support of the functional method, which offers a convenient approach to the construction of the theory. After treatment of the properties of the exact two‐point function and of the effective single‐particle potential, preconditions and properties of the approximate solutions are discussed. Results achieved todate are treated in chapter 6. Brueckner theory and allied methods are not further discussed, since these are sufficiently known. The theory of linear response, being important for the semi‐phenomenological treatment of real atomic nuclei, is presented in appendix A.
Theoretical Aspects of High Resolution Spectroscopy in the Presence of Strong Doppler Broadening
Authors: Paul H.
Published: July 2007

Some important types of spectroscopic experiments which allow to detect substructures masked by the Doppler width of the lines are discussed within a unified theoretical framework. It is pointed out that, in case of a three‐ or more‐level system, besides saturation effects also processes of Raman type play an essential role. The effect of high intensity of one (monochromatic) partial wave on the shape and width of the resonances (inverted Lamb dip) is studied in detail taking fully into account the dynamic Stark effect in addition to the power‐broadening of the holes burnt into the absorption profile.
Existence of Dressed One Electron States in a Class of Persistent Models
Authors: Fröhlich Jürg
Published: July 2007

In this paper the dynamics of a class of simple models (so called persistent models) including Nelson's model is studied. These models describe conserved, non relativistic, scalar electrons interacting with neutral, scalar bosons. Special attention is paid to the so called one particle problem: the existence of dressed one electron states – corresponding to an isolated one particle shell in the spectrum of the energy‐momentum operator (H, P) – is established for the models with massive bosons and the ones with bosons of rest mass zero and an infrared cutoff in the interaction.
Superfields as Representations
Authors: Rühl W. , Yunn B. C.
Published: July 2007

We study irreducible and reducible representations of the generalized Lie algebra of Wess and Zumino. The algebra is integrated to a group with the help of Grassmann algebras and the representations of the algebra are made into representations of the group. We construct invariant sesquilinear forms that are positive definite for the Wess‐Zumino algebra over the complex field. We define irreducible superfields for any spin J as specific realizations of such representations. All superfields appearing in the literature are either equivalent to one of these or built up out of these superfields.
Structural Stability Theory and Phase Transitions Models
Authors: de Alfaro V. , Rasetti M.
Published: July 2007

Global stability theory is introduced as a tool allowing the classification of mathematical models of phase transitions. The point of view is that a topological structure whose stability controls the transition, can be identified in the process of computation of the partition function. In particular we discuss mean field theories and the two dimensional Ising model.

Interesting features are disclosed concerning the classification of the instabilities, such as the number of parameters and possible approximations.
“Proper Time” Method Calculation of the “One Loop” Thermodynamical Potential for QED in External Electromagnetic Field
Authors: Cabo Alejandro
Published: July 2007

The extension of the “proper time” method to the statistical field theory is obtained. The procedure is used to calculate the “one loop” contribution to the thermodynamical potential in electrodynamics, when the electron positron gas is located in a combination of an inhomogeneous electrostatic field and an uniform magnetic one. Also, a “proper time” representation of the temperature Green function for this problem is given.
Using proportional hazard modelling in plant maintenance
Authors: Love Charles E. , Guo R.
Published: July 2007

The purpose of this paper is to develop a framework for the application of proportional hazard modelling to plant maintenance. Two regimes are investigated; a good‐as‐new regime where the hazard rate of the system is refreshed by either failure or preventive maintenance action, and a bad‐as‐old regime where only preventive maintenance action refreshes the hazard rate. The output of the analysis is the recommendation of optimal preventative maintenance plans under both of these regimes. Data for a local firm are used to illustrate the models. The inclusion of proportional hazard modelling is shown to yield improved maintenance plans in both regimes. A proposal for an adaptive scheme is made such that the maintenance plan can be adjusted as changing plant conditions warrant it.
Sample size determination of bogey tests without failures
Authors: Wang C. Julius
Published: July 2007

Highly reliable products that will last for a long time can result in the impracticality of conducting life testing at the designed normal usage conditions. When accelerated life tests can be applied to represent the normal product operating conditions with a shorter testing time, engineers usually terminate the accelerated life test upon successfully running to a multiple of a pre‐specified bogey without any failure. This testing philosophy is called ‘bogey test’ or ‘extended test’ in the automotive industry and is a subset of type I censored tests in standard reliability literature. This paper focuses on the determination of sample size when planning or assessing the applicability of such a bogey test. The underlying life characteristic is assumed to follow a Weibull distribution with a given shape parameter. In addition, the required reliability and confidence levels at the bogey to be demonstrated are pre‐determined.
The Al‐1 per cent Si/TiN/Ti interconnection scheme: Electromigration and reliability extrapolations
Authors: Caprile Candida , Specchiulli G. , Sala D. , Fantini F.
Published: July 2007

The electromigration performance of the Al‐1 per cent Si/TiN/Ti metal scheme is investigated both for contacts and for stripes and compared with the results for the standard Al‐1 per cent Si metallization. Statistical extrapolations at the operating conditions for a device have been performed to calculate the useful life of contacts and stripes. The results indicate that the most severe limitation to the interconnection reliability is given by the contacts without the diffusion barrier layer.
Cumulative score charts
Authors: Box George , Ramírez José
Published: July 2007

Shewhart charts are direct plots of the data and they have the potential to detect departures from statistical stability of unanticipated kinds. However, when one can identify in advance a kind of departure specifically feared, then a more sensitive detection statistic can be developed for that specific possibility.

In this paper Cuscore statistics are developed for this purpose which can be used as an adjunct to the Shewhart chart. These statistics use an idea due to Box and Jenkins which is in turn an application of Fisher's score statistic. This article shows how the resulting procedures relate to Wald‐Barnard sequential tests and to Cusum statistics which are special cases of Cuscore statistics. The ideas are illustrated by a number of examples. These concern the detection in a noisy environment of (a) an intermittent sine wave, (b) a change in slope of a line, (c) a change in an exponential smoothing constant and (d) a change from a stationary to a non‐stationary state in a process record.
Pragmatic procedure for the estimation of thin dielectric reliability
Authors: Vollertsen R.‐P.
Published: July 2007

A pragmatic procedure is developed for the reliability evaluation of thin dieletrics. It applies knowledge and plausible arguments for reasonable selection and implication of models. It is deduced that the Weibull distribution and the 1/Emodel are the best choice for reliability predictions of thin dielectrics. Uncertainties and measurement expense can be reduced if worst‐case conditions are used. The measurement procedure, including the test structure requirements, is described in detail. A complete set of simple equations is given for data evaluation and reliability prediction. The study and comparison of reliability data is simplified. The effect of a burn‐in can be considered.
Using rainbow net simulation to measure fault tolerance in a multiprocessor
Authors: Johnson Allen M. , Schoenfelder Michael A. , Lebold David J.
Published: July 2007

The Rainbow net simulation technique is applied to modelling the impact of system load and fault handling on the availability of a fault‐tolerant multiprocessor architecture. Rainbow nets are described along with the motivation for creating this modelling technique. A Rainbow net fault‐handling model is created for the fault‐tolerant multiprocessor architecture and the topology is shown to remain constant in size, independent of the number of processor, memory and I/O elements configured in the system. Simulation is performed with a varying load in terms of the number of active jobs the system must support. Results are given showing how the fault‐tolerant capability varies with load. Two new metrics for evaluating fault tolerance are introduced; namelyfull fault‐tolerability and partial fault‐tolerability.They are based on simple observations in the model.
Gamma function tables for the estimation of the mean and standard deviation of the weibull distribution
Authors: Bohoris G. A.
Published: July 2007

This paper provides tabulated numerical values for the gamma function necessary for the analytical estimation of the mean and standard deviation of the Weibull distribution. The tables produced also include estimates of the Weibull coefficient of variation, a quantity very important for maintenance optimization calculations when Glasser's charts are employed.
Making full use of taguchi's orthogonal arrays
Authors: Lin Dennis K. J.
Published: July 2007

Taguchi1has provided 18 orthogonal arrays which have been widely touted as useful frameworks for planning experiments. Thirteen of these are ‘saturated designs’, that is, they are appropriate for investigating (N‐ 1) factors inNruns, thus using the full capacity of the design. Here, the other five ‘non‐saturated’ designs are discussed. By creating additional, orthogonal columns which provide estimates of interaction effects, we can essentially wring out some additional information over and above that suggested by Taguchi, without additional cost. In particular, if only the linear effect is of interest for any specific factor, one can accommodate more factors than the number suggested by Taguchi. An example is given for illustration.
Testability consideration based on a test pattern length estimation
Authors: Takasaki Shigeru
Published: July 2007

A testability evaluation method is described based on an estimated test pattern length to obtain the desired fault coverage. The test pattern length is estimated from network attributes, i.e., No. of gates, No. of signal lines, No. of inputs/outputs, etc. The proposed method begins with modeling a fault coverage curve as a function of test patterns and a curve coefficient. The curve coefficient is described as a function of network attributes based on the previous execution data. The test patterns required to obtain the desired fault coverage can be estimated in the range of upper and lower bounds. The upper and lower bounds are obtained using the interpolation method. The proposed estimation method is evaluated from the relationships between estimated patterns and actual automatic test generation patterns.
Formal description of systolic algorithms and an analysis of the information flow
Authors: Aso Hirotome , Inagaki Yasuyoshi
Published: July 2007

Due to the development of VSLI fabrication technologies systolic algorithms are now being implemented as practical hardware. As a result, it is becoming more important to know their design methodologies and the scope of their object problems. In this paper as a basis to know the scope of the object problems we formalize systolic algorithms as mathematical objects in a strict manner. In other words, it is formalized by a triple systolic array, a data location space, and a set of timing functions. Moreover, equivalence between systolic arrays is defined. Under this formulation we define a data dependency graph as a tool for analyzing the flow of information, and show that wiring structures can be classified into several types. We give a condition that it is reduced equivalently to a simple memory‐type one. Finally, we consider the data flow processed in a systolic array and give not only an equation for data flow, but also the initial arrangement for a necessary encounter for interaction between data flows.
A model of integrated information processing mechanism for human and computer based on cooperative functional modules
Authors: Anzai Yuichiro
Published: July 2007

Combining the human and the computer to form an information processing system, an integrated model is constructed. This paper proposes, as a practical model for such an integrated information processing mechanism, a hierarchical network model composed of cooperative functional modules. As examples of such a model, a cooperative functional module model for the visual pattern recognition and symbolic inference in human problem solving, as well as the cooperative functional module model for the interactive processing of Japanese language are discussed. Then the integrated man‐computer functional module model is discussed from the viewpoint of matching/nonmatchings among various component modules.
Speaker‐independent isolated word recognition using n‐segment label histogram method
Authors: Watanuki Osaaki , Kaneko Toyohisa
Published: July 2007

A simplified version of a hidden Markov model (HMM), referred to as theN‐segment label histogram (NLH) method, is proposed for speaker‐independent isolated word recognition. The NLH method can be considered as an HMM with a uniform duration for each state. It can also be treated as a statistical pattern recognition approach using linear compander and probabilistic measures. During the training, the label histograms are computed forNequal segments of the input. The probability associated with each label is computed after normalization. During the recognition, the input is partitioned intoNequal segments, the corresponding label that maximizes the label probability of the input word determines the recognition result. Since the NLH method requires only about one‐tenth the computation of the HMM method, it is more suitable for implementation on small computers. Furthermore, it does not require alignment along the time axis as do the HMM and DP matching techniques. The utterance fluctuation along the time axis is handled statistically and is applicable to a large data set. Experimental results indicated that the NLH method rendered almost the same recognition rate as the other two methods while requiring much less computation. The linear approximation of the likelihood function enables the implementation of the proposed algorithm on the IBM PC/AT for real time speech recognition.