bluuebunny/crossref_metadata_2025 huggingface dataset:
Relations between central and local governments in Turkey: An historical perspective
Authors: Ersoy Melih
Published: July 2007

As organizers of urban development in the modem sense, municipalities go back to the mid‐19th century in Turkey. The main theme of this article is an analysis of the trends over roughly 150 years. Three main headings are used within this framework: (a) the political and administrative level; (b) the level of financial policies; (c) historical development of the relationship between the central and local governments with respect to the legal and institutional framework of urban planning. This relationship is fundamentally paternalistic and authoritarian. The study investigates the authenticity of the currently pronounced liberal policies and the subsequent implementation mechanisms devised by the present administration over the past 8 years. Although a change of government seems imminent, most of the policies implemented are considered to be irreversible. Emphasis is given to an assessment of the claim that liberal governments have introduced positive changes in this structural mechanism, rather than a normative evaluation of this structural relationship.
Introducing administrative reform through the application of computer‐based information systems: A case study in India
Authors: Madon Shirin
Published: July 2007

Administrative reform in a number of developing countries has recently been directed at achieving decentralization through the diffusion of information technology to local areas. However, despite these efforts, the main objective of improving the effectiveness of development planning and monitoring systems remains unfulfilled because of poor integration between the process of technology adoption and the context within which the technology is implemented. There is a paucity of literature that aims to make explicit the nature of this integration. This paper aims to offer a contribution in this direction by describing the case of the computerized rural information systems project (CRISP) in India. The results show that during the first few years of implementation information technology served to reinforce existing inefficiencies within the bureaucracy. Information technology was later used as a vehicle for promoting change within the administration as local administrators acquired the flexibility to direct the technology towards their own requirements.
Public policy and competition amongst foreign investment projects: A case study of the Daya Bay economic development zone in South China
Authors: Liu Yuelun
Published: July 2007

By the second half of the 1980s, economic reform in China had produced differentiated interests between regions and a decentralized authority in the country. The central government had increasingly delegated its powers over funding, foreign exchange, resources and investment to local governments, and local governments in different regions had gained more autonomy to control the resources. This situation resulted in the proliferation of power centres at local levels where independent policies were generated to protect and pursue regional interests and resist the general policies of the centre. Conflicts of interest and competition intensified and became more popular than during previous periods. This tendency particularly manifested itself in local policy making concerning the introduction of foreign investment and projects. The case of the founding and evolution of the Daya Bay economic development zone in South China indicates the extent to which the competition between different coastal regions, and between the coastal regions and the central government had been generated. In this case study, the contextual changes that created a competitive environment will be reviewed briefly; the general conditions and motivation to establish the zone will be introduced; then the focus will be on analysing a series of policy formulations surrounding the competition for foreign investment projects. The case study is concluded by an assessment of the ‘incremental’ nature of Chinese policy making.
Myanmar: Experience with aid and management development during transition
Authors: Cook Paul
Published: July 2007

This article examines the role of the UNDP's management development programme in Myanmar between 1988 and 1992. It describes the economic and political background against which technical assistance was provided to assist the transition from a centrally planned to a market‐oriented economy. It is argued that present reforms can be interpreted as part of a survival strategy. The article analyses the principal findings of the various components of assistance between these years, and reports on implementation. In particular, attention is given to problems that occur in reforming both central bureaucratic institutions and patterns of decision‐making, and to changes in these key areas. The concluding part summarizes the lessons that arise from implementation and indicates that forms of state‐led planning are likely to continue alongside attempts to embody market principles.
Managing the renewal process: The case of Vietnam
Authors: Van Arkadie Brian
Published: July 2007

This article reviews the management of Vietnam's renewal process from the viewpoint of understanding the structure of the economy. It argues that, in terms of population, income and welfare, Vietnam has been relatively more successful than other less‐developed Asian countries. At the same time, historically, its economy was only to a minor degree under central government management—in contrast to the ex‐USSR and Eastern Europe—and hence it has been capable of a more flexible response. Its human capital stock is strong but performance has been constrained by war, embargo and mistakes of strategy. Against this background, the article traces the reform process, from the brief interlude with central planning through the inauguration of 'doi moi' after cessation of western and Chinese aid. The initial stress has been on macroeconomic stabilization. The problems of achieving this and the reasons for success are advanced. The next stage of the reform encompasses additional areas where international assistance may be relevant: the legal and institutional framework for the market economy, reform of government administration and improving enterprise management. Following the new constitution of 1992, public administration reform has come to the fore—both structural as well as in relation to central‐local government relations. This article describes the machinery for reform implementation as well as its scope, which encompasses the size and staffing of the civil service, salaries, human resource management, systems and procedures, turn‐round of state enterprises and management skills development. The article continues with a review of two key multilateral assistance projects. The path‐breaking UNDP Management Development Programme has conducted training in economic management and supported the development of the legal system. The project has had an important impact on policy‐makers and on policy discussion. A successor project will provide support to public administration reform in Vietnam. In the light of the current dramatic expansion in aid to Vietnam from DAR sources, the article concludes that control and coordination of overseas assistance by the government will be vital if aid is to be fully utilized and work in total support of Vietnam's existing development effort.
Factors that impede and facilitate management careers of women in the Malaysian civil service
Authors: Yousof Janat Mohd , Siegel Gilbert B.
Published: July 2007

Female and male managers of the Malaysian civil service were surveyed in an attempt to elucidate the factors that have facilitated and hindered their careers. The emphasis in this article is on career differences between women and men. Many of the conditions which inhibit the careers of female managers elsewhere in the world were also reported by those sampled. Family requirements and resulting role conflict were evident. Many women have not married. There was some evidence of sexual harassment. There is a suggestion that women may suffer from low self‐esteem and attribute their career progress primarily to luck. On the positive side, and despite a government policy that has resulted in more public resources for higher education being awarded to men than to women, women managers have achieved career success. This is largely because of the socioeconomic status of their parents and the apparent willingness of parents to educate female offspring who were not necessarily the first‐born.
Managing development policy in Botswana: Implementing reforms for rapid change
Authors: Hope Kempe Ronald
Published: July 2007

In recent years, Botswana's international reputation as a nation with sound development management has been slightly tarnished and the country's government has become increasingly concerned about the declining performance of its development management machinery. This concern of the government has been translated into a series of reform measures designed to bring about rapid change. This article discusses and analyses those reform measures and their potential impact on the development management process in Botswana. It was determined that the reform measures were, for the most part, carefully crafted and are being purposefully implemented, showing the nation, once again, to be one with good governance.
Local government in Kyrghyzstan
Authors: Tordoff William
Published: July 2007

The Kyrghyzstan government is making the difficult transition from a command economy under Communist Party control to a market economy within a pluralist political framework. For the time being, however, the reality of firm executive, hierarchical control persists. An Akim heads the government structure at provincial (oblast) and district (raion) levels and exercises considerable power; though formally answerable for his budget and socio‐economic programme to the local parliament (kenesh), his accountability is virtually nil. Some attention is given to equalizing revenue among the provinces: Bishkek, the capital city, which has oblast status, and Chui oblast provide substantial financial underpinning for the rest of the country. In April 1995 the government accepted the main provisions of the EIPA Report prepared under the European Union's TACIS project ED/052, the effect of which should be to enhance the government's ability to promote development. President Akayev sees local administration, local self‐government and privatization as important levers of reform.
Two‐Centre Model of Meson Production
Authors: Gierula J.
Published: July 2007

The multiple meson production is described by the two‐centre model as an isotropic emission of mesons from centres moving with velocity which is neither the velocity of nucleons escaping the collision nor the velocity of the centre‐of‐mass system of colliding nucleons. There is an evidence of the formation of two or, sometimes, of one such a centre called “fire‐ball”. This evidence is based on a large statistics of observations of transverse momenta and of the shape of log tan θL distributions in cosmic ray jets. Both these quantities are Lorentz‐invariant or nearly invariant and therefore can be safely measured in the laboratory frame of reference.
The Bootstrap Approach to Strong Interaction Symmetries
Authors: Tarjanne Pekka
Published: July 2007

A review is given of the development and achievements of the bootstrap approach to elementary particle theory with special emphasis on its relation to the exact as well as broken internal symmetries and on the weaknesses of the presently used calculational techniques. The conjecture that the origin of unitary symmetry is completely dynamical leads to the discussion of several proposed mechanisms for spontaneous breakdown of this symmetry. The phenomenological octet enhancement found to exist in strong, electromagnetic as well as weak processes is studied in connection with the dynamical content of solutions with different symmetry character. In an appendix it is shown that in the superconductor model of elementary particle symmetries the octet enhancement can be the consequence of simple stability criteria.
Independent Electron Positron Pair Production Events and Energy Loss
Authors: Gilson J. G.
Published: July 2007

By defining electron positron pair production events in such a way that they are statistically independent, it is possible to introduce a graphical representation of ‘events’. This definition is then used to find the energy lost by an external field in the form of induced pairs when the induced current is a non‐linear functional of the driving field.
CP, T and CPT Invariance in Neutral Kaon Decays
Authors: Dass G. V.
Published: July 2007

A brief survey of the phenomenology (with emphasis on its present status) of CP, T and CPT invariance in neutral kaon decays is given. Existing limits on the invariances of the mass matrix of the K0−K̄0 system are stated. Also included are our new results and also those of DASS and KABIR for limits on these invariances for the decay amplitudes, obtained by using existing data, and the available information on the total mass matrix.

The CPT invariant part of amplitudes for decay to the I = 0 and I = 2, ππ channels is T (and CP) invariant, in the Eberhard phase convention, to about 0.4% and about 4% respectively; the corresponding T invariant part of these amplitudes is CPT (and CP) invariant to about 1% and about 5% respectively. A limit similar to this last one (5%) was already obtained in the literature by making a further approximation. The CP, T and CPT invariant part of the averaged ΔS = − ΔQ amplitude in K13 decay is found to be less than about 5% of the corresponding ΔS = ΔQ amplitude; the T invariant part of the difference of the averaged ΔS = ΔQ and the averaged ΔS = − ΔQ amplitudes is CPT (and CP) invariant to about 1%. A limit similar to this one (1%) was also obtained in the literature by making a further assumption about the mass matrix.

These amplitude limits are expected to have about one significant figure accuracy. Due to large experimental errors, the amplitude limits on the other non‐invariance parameters for the above channels are not very good. Difficulties in deriving corresponding parameters for the 3π channel are noted.

In certain respects, CPT invariance has been verified experimentally to a poorer accuracy than CP invariance and T invariance.
Single Particle Distributions from Veneziano Amplitudes I
Authors: Biebl K. J. , Bebel D. , Ebert D.
Published: July 2007

The single particle distribution for the inclusive reaction A + B → C + anything is calculated from the discontinuity of the Veneziano six point function in the tree approximation and investigated in different kinematical regions. Power series expansions around x = 1 and Barnes‐Mellin integral representations suitable for expansions around x = 0 are presented. For large transverse momenta the single particle distribution shows an exponential decrease in p⟂2 with an x dependent slope assuming the value 4 α′ for x = 0. For small transverse momenta the behaviour of the distribution function in the pionization region is determined by a logarithmic singularity at the unphysical point p⟂2 = −mc2. In addition single particle distributions following from two special types of Pomeron‐background modified B6 functions are studied. Most of the results are similar to those obtained with the unmodified B6 function. This applies in particular to the pionization region, where the asymptotic p⟂2‐slope 4α′ is replaced by a “background slope” 4β′.
Inertia and Gravity: a New Approach to Dynamical Theory in General Relativity
Authors: Quale Andreas
Published: July 2007

A new approach to gravitational field dynamics is proposed, as an alternative to the standard formulation of General Relativity. The spacetime metric tensor is split, into an externally fixed background geometry (inertia) and a local dynamical field (gravity); and a dynamical theory of matter and gravity in the inertial background is developed. The physical origin of inertia (Mach's Principle), and its observable properties, are discussed. The coordinate representations of inertia and gravity are found to have an internal gauge degree of freedom, due to the Equivalence Principle; the transformation properties of these fields, and the notion of covariant gauge conditions, are discussed. The dynamics of matter and gravitic fields is then investigated, using: (i) The group of motion of the inertial background, appearing as an externally fixed Lie symmetry in the matter and gravity action principles, which yields weakly conserved energy‐momentum‐like objects; and (ii) an internal symmetry gauge group, yielding strongly conserved “internal currents”. A fully covariant field‐theoretical formalism is used, in which all quantities and operations are tensorial; the well‐known difficulties of “coordinate effects” in the standard nontensorial formulation are thus avoided. The physical significance of various types of conservation laws is discussed; and a complete family of energy‐momentum tensors of gravity, covariantly conserved together with the matter energy‐momentum, is deduced from a tensorial action principle. Treating gravity as an independent dynamical interaction, on an equal footing with other (matter) interactions, we are then finally led to the conclusion that the gravitic energy‐momentum of a system is fully determined by the matter energy‐momentum; various physical implications of this are discussed in some detail.
Finite‐ and Infinite‐Dimensional Representations of the Lorentz Group
Authors: Carmeli M. , Malin S.
Published: July 2007

Finite‐ and infinite‐dimensional representations of the Lorentz group are discussed and various topics in which this group is currently in use are mentioned. The infinitesimal approach of finding representations is reviewed and all finite‐dimensional spinor representations of the Lorentz group are obtained. Infinite‐dimensional representations are then discussed, including the principal, complementary, and complete series of representations. A generalized Fourier transformation is introduced which enables one to use the global approach to representation theory so as to express infinite‐dimensional representations in terms of matrices. This method is shown to lead to a generalization of the spinor form of finite‐dimensional representation to the infinite‐dimensional case. However, whereas the usual spinor representations are nonunitary, the obtained new form describes both unitary and non‐unitary representations, depending on the choice of certain parameters appearing in the representation formula.
Testing Theories of Chiral Symmetry
Authors: Wing‐Chiu Ng.
Published: July 2007

We investigate various physical consequences of theories of chiral symmetry. Predictions of the symmetry are given for the meson electroproduction process at an on‐shell kinematical point where unknown contributions are minimized. Sum rules are derived for the corrections. Then we present a sum rule for the ∑ term in meson‐baryon scattering from the assumptions of Bjorken limit, precocious asymptopia, and finite‐mass dispersion relations. We use the commutation relations of the gluon model as input for a numerical evaluation. Next the explicit canonical structure of the light‐cone restriction of the commutator of the weak current with its divergence is considered in the interacting quark‐gluon model quantized in the infinite–momentum frame. The implications on neutrino scattering are analyzed. W4 and W5 are predicted to scale nontrivially as v−2F4(ω) and v−2F5(ω), which provides a simple test of light‐cone current algebra feasible in the near future. The ∑ term for weak currents is deduced from a causal representation near the light‐cone, and a correction is also made in the W5 – sum rule obtained by naive infinite momentum techniques. As a by‐product we obtain improved derivations of the Adler neutrino sum rules.
Realizations of the Unitary Representations of the Inhomogeneous Space‐Time Groups I. General Structure
Authors: Niederer U. H. , O'Raifeartaigh L.
Published: July 2007

The aim of these two papers (I and II) is to try to give a unified systematic description of the different quantum mechanical realization of the unitary representations of the inhomogeneous space‐time groups.

Paper I, which is more general, deals with the interrelationships between the Mackey, the Wigner and the covariant realizations of induced representations, first for general groups, and then for semi‐direct products. The Euclidean, Galilean and Poincaré groups are treated in some detail as examples.

Paper II gives a systematic treatment of the various covariant wavefunctions (Dirac, Bargmann‐Wigner, etc.) that can be used to describe a single irreducible representation of the Poincaré group. It is self‐contained and deals first with momentum space, and then with first and second quantized fields. In both papers the treatment is index‐free.
Description of Non‐Polynomial Quantum Field Theories by Superpropagator Method
Authors: Volkov M. K.
Published: July 2007

The description of superpropagator method and its applications to the mesodynamics, weak interaction, electrodynamics involving gravity and the chiral invariant field theory is given. The low‐energy behaviour of particles is described, taking into account the loop Feynman diagrams. The renormalizations of physical quantities are finite and are expressed in terms of coupling constants. Partly this work was reported at the Third International Conference on Non‐Local Quantum Field Theory in 1973 at Alushta, USSR.
Phase of a Microscopic Electromagnetic Field and Its Measurement
Authors: Paul H.
Published: July 2007

A novel approach to the quantum mechanical description of phase properties of a one‐mode low‐intensity radiation field is presented. The procedure is based upon the correspondence between Glauber states and classical waves of fixed phase ϕ and amplitude a, and, in contrast to the conventional quantum mechanical phase concepts, allows to make contact between certain operators ℰm corresponding to the classical quantities exp {imφ} (m = ± 1, ± 2, …) and realistic measurements. In the observation, a large amplification of the microscopic field by means of a linear quantum amplifier plays a decisive role. Since the amplified field is a macroscopic one, the measurement of phase is not problematic, and hence, in particular, average values «exp {imϕ}» can be determined experimentally. The main result of our analysis is that the mean values «exp {imϕ}» are equal to the quantum mechanical expectation values for the operators ℰm with respect to the field before amplification. To obtain this result it became necessary to calculate Glauber's P function for the amplified field in case of an arbitrary state for the initial field.
Construction of Covariant Bases for Two‐Particle Reactions
Authors: Tchrakian D. H.
Published: July 2007

A method for the construction of the Lorentz‐covariant bases occurring in the decomposition of spinor amplitudes (M‐functions) of four massive particle processes is given. Each particle of spin‐ is described by a spinor state of the type‐(s, 0) and/or (0, s), but the essential parts of our method apply whatever the type of spinor state used, and the necessary relations between the hitherto familiar types of spinor states are given, by means of which the relationship between the resulting sets of invariant amplitudes can be made explicit. By way of illustration four worked examples are presented.
Wave Equations on a de Sitter Fiber Bundle
Authors: Drechsler W.
Published: July 2007

A gauge theory of strong interaction is developed based on fields defined on a fiber bundle. The structural group of the bundle is taken to be the L4,1 de Sitter group. An internal variable ε, varying in the fiber over a space‐time point x, is introduced as a means to describe – with the help of a semiclassical wave function PS(x, ε) defined on the bundle space – the internal structure of extended hadrons in a framework using differential geometric techniques. Three basic nonlinear wave equations for PS(x, ε) are established which are of integro‐differential type. The nonlinear coupling terms in these de Sitter gauge invariant equations represent physically a generalized spin orbit coupling or a generalized spin spin coupling for the motion taking place in the fiber. The motivation for using a bigger space for the definition of hadronic matter wave functions as well as the implications of this geometric approach to strong interaction physics is discussed in detail, in particular with respect to the problem of hadronic constituents. The proposed fiber bundle formalism allows a dynamical description of extended structures for hadrons without implying the necessity of introducing any constituents.
Electromagnetic Interactions of High Energy Cosmic Ray Muons
Authors: Grupen C.
Published: July 2007

This paper investigates the electromagnetic interactions of muons. The various processes such as knock‐on electron‐, bremsstrahlung‐, direct electron pair production, and nuclear interactions are described in detail. The energy range concerned extends from 109 eV up to 1015 eV for primary muons and from 108 eV up to 1014 eV for energy transfers to the secondaries.

On the one hand the measurement of muon interactions represents a test of quantum electrodynamics. On the other hand the high energies available in cosmic rays would possibly lead to the measurement of new processes or the detection of new particles. One hopes to find in the high energy domain the answer to the question why the muon exists at all and if there are properties (apart from differences in mass, lifetime, and lepton number) which distinguish it from a mere heavy electron.

The different experimental techniques are described and the various experimental results on muon interactions are presented and compared with relevant QED‐theories.

Observed deviations between theory and experiment and anomalies in muon interactions are critically investigated and discussed in the light of experimental difficulties and interpretation problems. In general, agreement between theory and experiment is found, i.e. QED‐theories describe the results adequately. However, some experiments claim to have detected anomalies in muon physics in the cosmic ray beam. But the hypotheses on new processes and new particles in the high energy range do not withstand a critical analysis. It is concluded that the observed deviations can be understood in the framework of conventional theories.
Hadron Production by a Thermodynamical Quark Bootstrap
Authors: Wolf R.
Published: July 2007

The Gell‐Mann‐Zweig rule indicates how hadrons can be produced by quarks. This can be formulated in a bootstrap equation. A second equation which is necessary in order to eliminate one variable is found by a simple assumption about the behaviour of the quarks inside of the hadrons. Two models – a pure mesonic and a pure baryonic quark bootstrap – are presented in this paper.

This material is a portion of the Ph. D. thesis submitted to the department of physics of the Universität Kaiserslautern.

.
Nucleon‐Nucleon Scattering as High Energies
Authors: Kroll P.
Published: July 2007

The present status of the phenomenology of elastic and quasielastic nucleon‐nucleon and nucleon‐antinucleon scattering at high energies is reviewed. In particular the use of fixed‐t analyticity, models with rising cross‐sections and the impact parameter analysis are discussed.
Statistical Bootstrap Approach to Hadronic Matter and Multiparticle Reactions
Authors: Ilgenfritz E.‐M. , Kripfganz J. , Möhring H.‐J.
Published: July 2007

We present the main ideas behind the statistical bootstrap model and recent developments within this model related to the description of fireball cascade decay.

Mathematical methods developed in this model might be useful in other phenomenological schemes of strong interaction physics; they are described in detail.

We discuss the present status of applications of the model to various hadronic reactions.

When discussing the relations of the statistical bootstrap model to other models of hadron physics we point out possibly fruitful analogies and dynamical mechanisms which are modelled by the bootstrap dynamics under definite conditions. This offers interpretations for the critical temperature typical for the model and indicates further fields of application.
Stimulierte Resonanz‐Raman‐Streuung an angeregten und nicht angeregten Molekülen
Authors: Herrmann J.
Published: July 2007

A review of the theory of the stimulated resonance Raman scattering (SRRS) is given.

The calculation of the gains for the SRRS with the ground level (SRRS I) or an excited one (SRRS II) as initial states shows that there are some restrictions for their appearance. Due to the strong resonance absorption of the pumping wave and the disturbing influence of stimulated fluorescence the SRRS I is not observable in a Franck‐Condon excitation and in an absorption of Lorentzian line shape.

The SRRS II has a sufficiently large gain on the condition τel ≪vib (τel, τvib – transversal relaxation time of the electronic or vibronic transition). In case of a strong deviation of the wings of the absorption profile from the Lorentzian shape, however, the SRRS I is favoured rather than the two other processes.

Another possibility to avoid the resonance absorption of the pumping wave exists for the transversal excitation of the SRRS. Thereby the limit of application of the SRRS may be extended to other substances which are no saturable absorbers.

Apart from the saturable absorption and the transversal excitation the self‐induced transparency is the third possibility to generate SRRS of ultrashort light pulses.
Quantenfeldtheorie im de Sitter‐Raum
Authors: Mielke Eckehard W.
Published: July 2007

Based on well‐known concepts, groundwork is laid for a quantum field theory in the de Sitter space‐time considered as an exact soluble model of a more general theory in curved space‐time.

With respect to the horospherical coordinate system, invariant field equations for arbitrary spin are derived by means of induced representations of the symmetry group SO0(1,4). The additional terms, induced into the first order systems of relativistic wave equations by the space‐time curvature, are formally interpreted as external fields. Normalized c‐number solutions of the spin‐dependent Klein‐Gordon equation and of the Dirac equation are calculated explicitly.

The analysis of the singular functions of quantum field theory is based on generalized eigenfunction expansions and, in the case of the Feynman propagator of scalar fields, on the method of Schwinger and De Witt, as well.

An axiomatic approach to the quantization of neutral scalar fields is presented. Except for massless fields, the resulting “second quantization” is distinguished by a causal commutation function and a unique vacuum.

Recent developments in the regularization problem of the stress‐energy tensor are reviewed. With respect to the de Sitter space‐time the conclusion has been drawn that the quantum theory of “free” scalar fields is renormalizable on the one‐loop level.
Null Surface Quantization and Quantum Field Theory in Asymptotically Flat Space‐Time
Authors: Frolov V. P.
Published: July 2007

A quantum theory of the free scalar, electromagnetic and gravitational fields in a curved asymptotically flat space‐time is developed. It is shown that the Penrose conformal technique makes it possible to reformulate the null infinity quantization as a problem of the quantization on the proper null surface in the corresponding Penrose space. The Schwinger dynamical principle is exploited to derive the corresponding null surface commutation relations. The general covariant and gauge‐independent form of the commutation relations is also given. The existence of the asymptotic symmetry (BMS) group in the asymptotically flat space‐time is used to define uniquely the “in” and “out” vacuum states. The explicit expressions for the S‐matrix operator and for the S‐matrix elements in the asymptotically simple space‐time are given. The functional integration method is used to find the expression for the density matrix describing the observations at ∮+ in the weakly asymptotically simple space‐time when the information loss due to the event horizons or the existence of bare singularities is possible. The application of the developed approach to the problem of quantum evaporation of black holes (Hawking effect) is briefly discussed.
Massless Fields as Unitary Representations of the Poincaré Group
Authors: Niederer U.
Published: July 2007

Relativistic zero‐mass fields are described as manifestly covariant unitary irreducible representations of the Poincaré group. The wave‐equations, which are a necessary condition for unitarity, are constructed for spinor fields of arbitrary spin and for tensor fields of integer spin. Poincaré covariance together with causality and positive energy are used to determine the commutators of quantized fields up to a positive multiple and to prove the spin‐statistics theorem. The use of potentials for boson fields is discussed and it is shown that, at the expense of manifest covariance, potentials may be introduced as zero‐mass limits of the massive Wigner representations.
Master Equation Approach to the Hopping Transport Theory
Authors: Bányai L. , Aldea A.
Published: July 2007

The fundamentals of the hopping transport theory are analyzed within the Master equation framework, that allows a clarification of the underlying assumptions and approximations. The common nature of the approximations, inherent both in hopping and weak scattering problems, is revealed. Some of the delicate limit problems are illustrated in exactly solvable models. The dangers in applying ordinary perturbation theory to the d.c. conductivity are shown. Through the introduction of the Master equation with external sources a proof of the Miller‐Abrahams resistance‐network analogy is given. There is also a discussion of the “local equilibrium” distribution, with some reference to thermoelectric phenomena.
Invariant Forms of the Lorentz Group
Authors: Lazo‐Tueve D. , Rühl W.
Published: July 2007

We study trilinear and multilinear invariant forms for the homogeneous Lorentz group. The residues of these trilinear forms generate particular trilinear forms themselves. They appear also if we sum Taylor expansions partially into a series of expressions each of which is covariant under infinitesimal Lorentz transformations. Multilinear invariant forms are submitted to harmonic analysis in different channels. They are thus expressed by invariant functions. Invariant functions for different channels are related by integral equations involving 6χ‐symbols, 9χ‐symbols etc. as “crossing kernels”. It is shown by construction that all invariant functions and nχ‐symbols can be represented as finite sums of Barnes type integrals. As example we analyze explicitly the four‐point Schwinger function of the massless Euclidean Thirring field with arbitrary spin and dimension.
An Approximation Scheme for Constructing π°π° Amplitudes from ACU Requirements
Authors: Schwarz F.
Published: July 2007

The requirements of analyticity, crossing symmetry and unitarity (ACU) are used as input to construct amplitudes for the scattering of neutral π mesons. They are obtained explicitly as polynomials in certain conformally transformed variables which ensure the correct analyticity structure. Crossing symmetry is expressed as a set of linear relations between the expansion coefficients. The same is true for the threshold behaviour of the partial waves and the behaviour for large energies of either the partial waves and the amplitudes itself. To enforce the positivity of the partial waves (up to a certain l) a new set of variables is introduced. It is obtained by solving the system of linear inequalities expressing the positivity condition. In this way one gets explicit expressions for all amplitudes satisfying the ACU requirements to some approximation. The rigorous constraints obtained from these ACU requirements are used to test the accuracy of this construction. The properties of all amplitudes are investigated in detail. It is indicated how this approximation scheme may be improved to any degree of accuracy and how it may be generalized to the full isospin case.
On the Algebraic Structure of Globally or Locally SU(2) Invariant Lattice Field Theories
Authors: Rühl W.
Published: July 2007

The local contribution to the action of the O(3) σ model in D = 2 or pure SU(2) gauge models in D ≧ 3 dimensions are expanded and integrated on the group. There results a field of variables j, a 3nj coefficient W({j}) with n → ∞ and dynamical factors f(j, β). We prove that for the gauge models a local decomposition of W({j}) into a product of 3nj coefficients with n = 2D(D – 2) exists. We study generating functions for W({j}) or the 3nj coefficients and develop an algorithm for their computation. Some of these generating functions are explicitly calculated.
Nonexistence of Multiple‐Instanton Solution of the Massless 4D ϕ4 Theory
Authors: Actor Alfred
Published: July 2007

The massless ϕ4 theory in four Euclidean dimensions is shown not to have a multiple‐instanton solution — even though it does have a single‐instanton solution. Our criterion for a multiple‐instanton solution of this nontopological theory is that the energy‐momentum tensor of the solution be identically zero. Arguments are given that a similar result holds in any number of dimensions for a one‐component scale‐invariant scalar theory.
NN Potentials in QCD‐Motivated Quark Models
Authors: Bender I. , Dosch H. G.
Published: July 2007

We investigated nucleon‐nucleon interaction in different QCD‐inspired quark models, particularly the influence of configuration mixing. We advocate a string‐motivated model, which yields a realistic short‐range part of the nucleon‐nucleon potential.
Hermitean Oscillator‐like Realizations of Classical Algebras and Superalgebras in Hilbert Space with Positive Definite Metric
Authors: Nowicki Anatol
Published: July 2007

The hermitean oscillator‐like realizations of classical algebras in terms of bosonic and fermionic creation and annihilation operators are given. The hermitean realizations of classical superalgebras using boson‐fermion oscillators are explicitely described. The assumption of positive definite metric in a Hilbert space of the oscillators states is exploited. Due to this fact, the realizations of superalgebras in the Hilbert space can be constructed only for: the real orthosymplectic superalgebra osp (N; 2M; R); the unitary compact superalgebra su (N; M); the unitary noncompact one SU(N; K, M); and the quaternionic unitary superalgebra uuα(N; M; H).
Constant failure rate—A paradigm in transition?
Authors: McLinn James A.
Published: July 2007

As a science, reliability has now entered middle age, having achieved almost 40 years of recognized modern practice. As we move into the new decade of the 1990s it is appropriate that we review the status of modern reliability. The history of science has lessons for us to learn concerning the nature of paradigm changes. Clearly some reliability practitioners have had difficulty changing their own world views as scientific knowledge has increased and the conditions of the profession have changed.

The very first generalized model for reliability was based upon electron tube life data from the early 1950s. It was with these old types of complex and failure prone products upon which the original reliability model was developed and generalized. This first model dictated that the failure probability density of electronics follows the exponential law which implies that the electronics will show constant failure rates during their useful lives. To get to the constant failure rate period, an infant mortality was traversed and about 10 per cent failures observed. The reliability beliefs of the 1950s when combined with the product successes of the 1960s has created a reliability paradigm problem that first became apparent in the late 1970s. Improved quality and design effort with new technologies and knowledge about effective screening changed the conditions. Modern semiconductor electronic products do not follow the original electron tube reliability model. The applicability of this original model and the subsequent thinking that it led to must now be questioned. It is time to create a new and better paradigm to replace the defunct exponential law.
What is wrong with the existing reliability prediction methods?
Authors: Wong Kam L.
Published: July 2007

Inaccurate reliability predictions could lead to disasters such as in the case of the U.S. Space Shuttle failure. The question is: ‘what is wrong with the existing reliability prediction methods?’ This paper examines the methods for predicting reliability of electronics. Based on information in the literature the measured vs predicted reliability could be as far apart as five to twenty times. Reliability calculated using the five most commonly used handbooks showed that there could be a 100 times variation. The root cause for the prediction inaccuracy is that many of the first‐order effect factors are not explicitly included in the prediction methods. These factors include thermal cycling, temperature change rate, mechanical shock, vibration, power on/off, supplier quality difference, reliability improvement with respect to calendar years and ageing. As indicated in the data provided in this paper any one of these factors neglected could cause a variation in the predicted reliability by several times. The reliability vs ageing‐hour curve showed that there was a 10 times change in reliability from 1000 ageing‐hours to 10,000 ageing‐hours. Therefore, in order to increase the accuracy of reliability prediction the factors must be incorporated into the prediction methods.
A better method for verifying production reliability
Authors: Coppola Anthony
Published: July 2007

Various schemes have been created for verifying that reliability is not degraded during production. These include the periodic performance of reliability tests during production, three versions of an all‐equipment reliability test plan and Bayesian approaches. Each method has its drawbacks. The purpose of all of these is to verify that the production process is continuing to produce products of acceptable reliability, for which the long‐existing tools of statistical process control are directly applicable and advantageous. A method of verifying production reliability based on the use of a control chart for failure rate is proposed as a better way than the current standards and alternatives discussed in this paper.
Some procedures for decision making in controlling high yield processes
Authors: Xie M. , Goh T. N.
Published: July 2007

Statistical process control based on the cumulative counts of conforming items instead of occurrences of non‐conformances has proved to be useful for the manufacture of high‐quality products. In this paper we study some interesting and useful issues of using cumulative counts in practice. The general problem in the control of high‐quality products is first discussed, which leads to the calculation of the probability that a process is out of control when a single non‐conforming item is detected. A decision graph is introduced with which we can easily judge whether the process is out of control when a non‐conforming item is observed after a number of conforming ones, accompanied by the certainty level of this judgement. Next, using the equivalence of information on one non‐conforming item found in a number of inspected items to that on zero non‐conforming items in a smaller sample, we give a method for choosing a new starting point to reset the cumulative count after the detection of the non‐conforming item. The procedures are all statistically justified and have the practical merit of simplicity in actual applications.
A comparison of control charts from the viewpoint of change‐point estimation
Authors: Nishina Ken
Published: July 2007

ISO/DIS 7870 has presented the cumulative sum chart, the moving average chart, and the exponentially weighted moving average chart as control charts using accumulated data. In this paper, we compare the three control charts in terms of change‐point estimation. We show the probability distribution, the bias and the mean square error of the change‐point estimators using a Markov process and Monte Carlo simulation. These control charts have almost equivalent performances based on average run length considerations when parameters of each control chart are set appropriately. However, from the viewpoint of change‐point estimation we recommend the CUSUM chart.
Fault and cause diagnosis of casting defects: Case study no. 2
Authors: Sweeting F. B. J. , Thorpe W. R. , Pettitt A. N.
Published: July 2007

Under pressure for cost reduction, a semi‐automated grey iron foundry was experimenting with alternative supply sources of the moulding sand additives, bentonite and coal dust. During a period when increasing quantities of possible replacement materials were being blended with current supplies it was noticed that the previously high or erratic level of rejects in a small group of products was progressively improving. In the absence of a real understanding of the reason for the improvement and in an endeavour to ensure that adequate safeguards were in place to avoid any relapse, a statistical examination was undertaken of the green sand and metal subsystems.

The behaviour of the variables in these subsystems was analysed for a datum period before and after the decision to change the sources of supply. Using existing process records and applying appropriate statistical techniques a clear indication was obtained that factors outside those of bentonite and coal dust were also involved in the improvement.

The use of factorial analysis demonstrated the relative significance of the sand and metal variables and the existence of any interactions. The use of box and whisker plots gave a good indication of the desirable control limits for the key variables. Analysis of the follow‐up period revealed a reduction of 90 per cent in the level of rejects for one high volume line.
Quality‐based design by probability optimization
Authors: Parkinson D. B.
Published: July 2007

A primary requirement of quality‐based design and offline quality control methods is the determination of nominal design parameter values which are such as to minimize the risk that the resulting device or system will function inadequately, or fail, under specified operational conditions. It may also be desirable to control the degree of variability in certain properties or outputs of the device or system. Both requirements are to be satisfied, in the presence of unavoidable tolerances on component parameters, which may also have been optimized, using a cost balance criterion.

It is shown that these requirements can be expressed in terms of constrained optimization of probability contents of defined sets in the space of the design parameters and that the probabilities can be estimated using well‐established convolution methods, permitting optimization by standard numerical methods. This procedure avoids the need for simulation or the use of specialized statistical techniques based on analysis of variance, and may permit solution of such problems by non‐specialists using available computing facilities. It does, however, require a suitable probability model to be associated with the design variables of interest. Analytic and numerical examples are presented and discussed.

For those readers unfamiliar with the theoretical methods employed, Section 1.2 provides a qualitative description of the method and may be read in conjunction with the examples of Section 3.
Detecting test set hardware degradation using statistical data modelling
Authors: Potter Randall W. , Sturm George W.
Published: July 2007

In electronic device manufacturing, a significant amount of time is spent testing the product using sophisticated test sets. These test sets routinely develop hardware problems that cause disruption of the manufacturing process. This paper discusses how computerized networking of test sets can be used to systematically monitor and detect these hardware problems. A statistical methodology for modelling and analysing test set data is presented, along with a detailed specific example.