bluuebunny/crossref_metadata_2025 huggingface dataset:
Power Flow through Controlled Piezoelectric Actuators
Authors: Chandrasekaran Sriram , Lindner Douglas K.
Published: August 2002

In this paper we investigate the power requirements of a piezoelectric actuator operating in a damping augmentation loop. When the piezoelectric actuator is driven by a current amplifier, we show that acceleration feedback augments the damping of the structure without changing the stiffness. Using this controller, we determine the real and reactive power flow through the structure and actuator into the amplifier when the structure is excited with a sinusoidal disturbance force. Estimates of the real and reactive power flow in terms of the actuator parameters are given. These estimates are useful for sizing the drive amplifier for the actuator.
Resistance Welding of Carbon Fiber Reinforced Polyetherimide Composit
Authors: Yuan Qiang , Hou Meng , Mai Yiu-Wing , Ye Lin
Published: August 2002

CF/PEI laminates were joined using a resistance welding (fusion bonding) technique. The heating element has a sandwich structure consisting of two GF/PEI prepregs covering both sides of a stainless metal mesh. The mechanical properties of a flat welded panel were characterized by three-point bending, Mode II ENF interlaminar fracture, instrumented Charpy impact, and falling weight impact tests. Failure occurred mainly inside the adherent laminates adjacent to the heating element in the areas with deconsolidation that occurred during joining. The defect size and intensity could be minimized by increasing the hold pressure. The delamination area decreased with increasing hold pressure at the same impact energy level.
Mechanism-Based Phenomenological Models for the Pseudoelastic Hysteresis Behavior of Shape Memory Alloys
Authors: Malovrh Brendon , Gandhi Farhan
Published: August 2002

A hierarchy of mechanism-based phenomenological models, comprising linear, piecewise-linear, and nonlinear springs and friction elements, are presented for the pseudoelastic damping behavior of Shape Memory Alloys. The constitutive equations and a method for identifying the model parameters from experimental hysteresis cycles are presented. A three-element model (comprising a spring and friction elements in parallel, all in series with a lead-spring) is the simplest model that captures the essence of the experimentally observed hysteresis behavior. Several more advanced models that better capture the experimental hysteresis behavior are presented. The use of piecewise-linear elements is found to significantly improve the ability of the model to simulate experimental data, but the improved predictive capability comes at the expense of increased complexity and some loss of generality, since the frictional parameters now depend on the amplitude of excitation. The predictive capability of the models can be improved, without introducing amplitude dependence, through the proper use of nonlinear springs and multiple spring/friction chains.
Time Response of Shape Memory Alloy Actuators
Authors: Potapov Pavel L. , Da Silva Edson P.
Published: August 2002

Force/displacement actuators with the high output power and time response can be fabricated from shape memory wires or ribbons. Typically Ni-Ti shape memory alloys are used as an active material in such actuators. They are driven by Joule heating and air convection cooling. In the present work, the time response of various types of Ni-Ti actuators having different transformation temperatures and geometrical sizes, is studied systematically under conditions of free and forced air convection.

The simple analytical model for calculating the time response is developed which accounts for the latent heat and thermal hysteresis of transformation. For all the types of considered actuators, the calculated time response is in a good agreement with that observed experimentally. Finally, on the base of the suggested model, we present the time response of Ni-Ti actuators calculated as a function of their transformation temperature and cross section dimensions.
High Authority and Nonlinearity Issues in Active-Passive Hybrid Piezoelectric Networks for Structural Damping
Authors: Tang J. , Wang K. W.
Published: August 2002

The purpose of this research is to address the issues of high field nonlinearities in vibration control using APPN (Active-Passive Hybrid Piezoelectric Network). Experimental effort is carried out to quantify the nonlinearities in piezoelectric actuation. Based on the sliding mode theory, a robust controller is developed to compensate for the nonlinearities as uncertainties in the integrated system. The effectiveness of the proposed scheme is demonstrated by numerical and experimental analyses.
Multiaxial Characterization and Modeling of a PVC Cellular Foam
Authors: Gdoutos Emmanuel E. , Daniel Isaac M. , Wang Kuang-An
Published: August 2002

The failure behavior of a PVC closed-cell cellular foam under a multiaxial state of stress was investigated. The uniaxial compressive, tensile, and shear stress-strain curves along the in-plane and through-the-thickness directions were obtained. A series of multiaxial tests including strip, thin-wall ring and thin-wall tube specimens under combined tension/compression, torsion, and internal pressure were performed. From these tests biaxial strength results in the stress plane of the in-plane and through-the-thickness directions were obtained. The results are in good agreement with the Tsai-Wu failure criterion.
Warpage in Rotationally Molded Parts
Authors: Liu Shih-Jung , Ho Chung-Yuan
Published: August 2002

Rotational molding is one of the most important methods of manufacturing hollow plastic products. There are, however, some unsolved problems that confound the overall success of this technique. Part warpage caused by inappropriate mold design and processing conditions is one of them. An experimental study reports on the effect of processing parameters on the warpage of rotationally molded parts. Experiments were carried out on a lab-scale uniaxial rotational molding unit. After molding, the part warpage was measured by a profile-meter. A thermocouple and an air pressure transducer were employed to measure the in-mold temperature and pressure profiles respectively. It was found that in addition to the residual stress, the in-mold vacuum pressure during the cooling process might be another source of warpage formation. The experimental investigation of a rotational molding process can be used to optimize the molds and processing parameters in order to achieve a product with minimal warpage.
Finite Element Analysis of Debonded Sandwich Beams Under Axial Compression
Authors: Sankar Bhavani V. , Narayanan Manickam
Published: August 2002

A nonlinear finite element analysis was performed to simulate axial compression of sandwich beams with debonded face sheets. The load-end-shortening diagrams were generated for a variety of specimens used in a previous experimental study. The energy release rate at the crack tip was computed using the J-integral, and plotted as a function of the load. A detailed stress analysis was performed and the critical stresses in the face sheet and the core were computed. The core was also molded as an isotropic elastic-perfectly plastic material and a nonlinear post buckling analysis was performed. A Graeco-Latin factorial plan was used to study the effects of debond length, fact sheet and core thicknesses, and core density on the load carrying capacity of the sandwich composite. It has been found that a linear buckling analysis is inadequate in determining the maximum load a debonded sandwich beam can carry. A nonlinear post-buckling analysis combined with an elasto-plastic model of the core is required to predict the compression behavior of debonded sandwich beams.
ER Suspension System with Energy Generation
Authors: Kim K. S. , Choi S. B. , Cheong C. C.
Published: August 2002

This study presents a new type ER suspension with energy generator which does not require external power sources. This is accomplished by converting kinetic energy into electrical energy. In order to do this, a semi-active suspension with an appropriate size of the ER damper is manufactured. A mechanical mechanism which changes the linear motion of the ER damper to the rotary motion is then constructed. This rotary motion is amplified by gears and makes a generator produce electrical energy. The efficiency of energy generation is experimentally evaluated and the field-dependent damping force of the ER damper operated by the generated power is also investigated. Subsequently, the ER suspension system is applied to a quarter car model, and its vibration isolation is experimentally evaluated in frequency domain.
Prediction of Tensile Strength of Multilayer Knitted-Fabric-Reinforced Laminated Composites
Authors: Huang Zheng-Ming , Ramakrishna S. , Zhang Y. Z. , Tay A. A. O.
Published: August 2002

This paper deals with simulation of the tensile strength of plain weft-knitted-fabric-reinforced composite laminates having different configurations. The simulation is performed at the lamina ply level, based on the classical laminate theory and a recently developed bridging micromechanics model. Only material properties of constituent fiber and matrix as well as fabric geometric information are necessary for this simulation. The internal stress increments generated in the fiber and the matrix of each lamina are directly related to the overall applied load increment on the laminate. As long as either the fiber or the matrix attains its ultimate stress state, the corresponding lamina fails, and a stiffness discount is applied to the remaining laminate. Predicted results of [0/0/0/0] and [0/90/90/0] fabric laminates agree well with experimental data.
Structural Damage Detection Using an Iterative Neural Network
Authors: Chang C. C. , Chang T. Y. P. , Xu Y. G. , Wang M. L.
Published: August 2002

A structural damage detection method based on parameter identification using an iterative neural network (NN) technique is proposed in this study. The NN model is first trained off-line using an initial training data set that consists of assumed structural parameters as outputs and their corresponding dynamic characteristics as inputs. The structural parameters are assumed with different levels of reduction to simulate various degrees of structural damage. The concept of orthogonal array is adopted to generate the representative combinations of parameter changes, which can significantly reduce the number of training data while maintaining the data completeness. A modified back-propagation learning algorithm is proposed which can overcome possible saturation of the sigmoid function and speed up the training process. The trained NN model is used to predict the structural parameters by feeding in measured dynamic characteristics. The predicted structural parameters are then used in the FE model to calculate the dynamic characteristics. The NN model would go through a retraining process if the calculated characteristics deviate from the measured ones. The identified structural parameters are then used to infer the location and the extent of structural damages. The proposed method is verified both numerically and experimentally using a clamped-clamped T beam. The results indicate that the current approach can identify both the location and the extent of damages in the beam.
Physicochemical Changes during Date Ripening Related to Ethylene Production
Authors: Serrano M. , Pretel M. T. , Botella M. A. , Amorós A.
Published: August 2002

Some physicochemical parameters related to ripening and their relationship with ethylene were studied in date fruits ( Phoenix dactyliferaL. type Negros). Dates were harvested and classified into sixteen ripening stages according to their color, ranging from yellow-greenish to dark brown. Fruit firmness decreased through the different ripening stages, while the ripening index, expressed as the relation between soluble solids and acidity, increased. The greatest loss of fruit firmness correlated with the greatest increases in both polygalacturonase and •-galactosidase activities. In early ripening stages, a small peak in ethylene production was detected, followed by a peak in respiration rate, suggesting that a date could be considered as a climacteric fruit, with the plant hormone ethylene being responsible for changes in color, fruit firmness, soluble solids content and acidity.
QUANTUM EXPONENTIAL FUNCTION
Authors: WORONOWICZ S. L.
Published: August 2002

A special function playing an essential role in the construction of quantum "ax+b"-group is introduced and investigated. The function is denoted by Fℏ(r,ϱ), where ℏ is a constant such that the deformation parameter q2=e-iℏ. The first variable r runs over non-zero real numbers; the range of the second one depends on the sign of r: ϱ=0 for r>0 and ϱ=±1 for r<0. After the holomorphic continuation the function satisfies the functional equation [Formula: see text] The name "exponential function" is justified by the formula: [Formula: see text] where R, S are selfadjoint operators satisfying certain commutation relations and [R+S] is a selfadjoint extension of the sum R+S determined by operators ρ and σ appearing in the formula. This formula will be used in a forthcoming paper to construct a unitary operator W satisfying the pentagonal equation of Baaj and Skandalis.
RIGOROUS RESULTS IN NON-EXTENSIVE THERMODYNAMICS
Authors: NAUDTS JAN
Published: August 2002

This paper studies quantum systems with a finite number of degrees of freedom in the context of non-extensive thermodynamics. A trial density matrix, obtained by heuristic methods, is proved to be the equilibrium density matrix. If the entropic index q is larger than 1 then existence of the trial equilibrium density matrix requires that q is less than some critical value qc which depends on the rate by which the eigenvalues of the Hamiltonian diverge. Existence of a unique equilibrium density matrix is proved if in addition q < 2 holds. For q between 0 and 1, such that 2 < q + qc, the free energy has at least one minimum in the set of trial density matrices. If a unique equilibrium density matrix exists then it is necessarily one of the trial density matrices. Note that this is a finite rank operator, which means that in equilibrium high energy levels have zero probability of occupancy.
VIRTUAL KNOT GROUPS AND THEIR PERIPHERAL STRUCTURE
Authors: KIM SE-GOO
Published: August 2002

Virtual knots, defined by Kauffman, provide a natural generalization of classical knots. Most invariants of knots extend in a natural way to give invariants of virtual knots. In this paper we study the fundamental groups of virtual knots and observe several new and unexpected phenomena.

In the classical setting, if the longitude of a knot is trivial in the knot group then the group is infinite cyclic. We show that for any classical knot group there is a virtual knot with that group and trivial longitude. It is well known that the second homology of a classical knot group is trivial. We provide counterexamples of this for virtual knots.

For an arbitrary group G, we give necessary and sufficient conditions for the existence of a virtual knot group that maps onto G with specified behavior on the peripheral subgroup. These conditions simplify those that arise in the classical setting.
STATISTICAL INFERENCE FOR K INDEPENDENT, HOMOGENEOUS ARITHMETIC PROCESSES
Authors: LEUNG FRANCIS KIT-NAM
Published: August 2002

For k=1,…, K, a stochastic process {An,k, n =1, 2,…} is an arithmetic process (AP) if there exists some real number, d, so that {An,k +(n-1)d, n =1, 2,…} is a renewal process (RP). AP is a stochastically monotonic process and can be used to model a point process, i.e., point events occurring in a haphazard way in time (or space), especially with a trend. For example, the events may be failures arising from a deteriorating machine; and such a series of failures is distributed haphazardly along a time continuum. In this paper, we discuss estimation procedures for K independent, homogeneous APs. Two statistics are suggested for testing whether K given processes come from a common AP. If this is so, we can estimate the parameters d, [Formula: see text] and [Formula: see text] of the AP based on the techniques of simple linear regression, where [Formula: see text] and [Formula: see text] are the mean and variance of the first average random variable [Formula: see text], respectively. In this paper, the procedures are, for the most part, discussed in reliability terminology. Of course, the methods are valid in any area of application, in which case they should be interpreted accordingly.
GENERAL SEQUENTIAL IMPERFECT PREVENTIVE MAINTENANCE MODELS
Authors: LIN DAMING , ZUO MING J. , YAM RICHARD C. M.
Published: August 2002

This paper presents new sequential imperfect preventive maintenance (PM) models incorporating adjustment/improvement factors in hazard rate and effective age. The models are hybrid in the sense that they are combinations of the age reduction PM model and the hazard rate adjustment PM model. It is assumed that PM is imperfect: It not only reduces the effective age but also changes the hazard rate, while the hazard rate increases with the number of PMs. PM is performed in a sequence of intervals. The objective is to determine the optimal PM schedule to minimize the mean cost rate. Numerical examples for a Weibull distribution are given.
LINEAR LOW-ENERGY POSITRON DIFFRACTION (LLEPD) FOR THE Si(111)-(2×1) π-CHAIN MODEL
Authors: TONG S. Y.
Published: August 2002

We have applied the linear method to low-energy positron diffraction and low-energy electron diffraction. The linear method searches for the global minimum in a structural analysis by carrying out full dynamical calculations at atomic positions which scale linearly as the number of independent structural parameters and variations in each parameter. For the Si(111)-(2×1) π-chain system, linear low-energy electron diffraction (LLEED) is found to work adequately. However, in other systems tested, LLEED breaks down when atoms in the first and second layers are lined up along the incident-beam direction. On the other hand, the method of linear low-energy positron diffraction (LLEPD) is found to work extremely well in all systems tested. This is due to the absence of forward focusing in low-energy positron diffraction. Thus, LLEPD should be an excellent tool for locating the global minimum in complex surface-structural searches.
Si TWINNING SUPERLATTICE: GROWTH OF NEW SINGLE CRYSTAL Si
Authors: HIBINO H. , OGINO T.
Published: August 2002

Si twinning superlattices are grown on [Formula: see text] by the repeated growth of Si layers with a unit thickness and postgrowth annealing. In order to determine the growth conditions of the Si twinning superlattice, it is essential to measure the crystallographic orientations in the surface regions during growth. Reflection high-energy electron diffraction (RHEED) is very sensitive to the surface orientation. Using the technique to estimate the fraction of the twinned layers in the grown layers by RHEED, we investigate the growth process and thermal stability of the twinned epitaxial layers. The growth of the twinning superlattices is monitored by the oscillation of the twinned layer fraction as a function of the thickness.
MORPHOLOGICAL CONTROL OF GaN BUFFER LAYERS GROWN BY MOLECULAR BEAM EPITAXY ON 6H–SiC(0001)
Authors: HU CHANGWU , SMITH DAVID J. , DOAK R. B. , TSONG I. S. T.
Published: August 2002

The growth of GaN buffer layers of thickness 10–25 nm directly on 6H–SiC (0001) substrates was studied using low energy electron microscopy, atomic force microscopy and cross-sectional transmission electron microscopy. The Ga flux was supplied by an evaporative source, while the NH3 flux came from a seeded beam supersonic jet source. By monitoring the growth in situ and by suitably adjusting the Ga/NH 3 flux ratio, smooth basal-plane-oriented GaN layers were grown on hydrogen-etched SiC substrates at temperatures in the range of 600–700°C. The growth proceeds via nucleation of small flat islands at the step edges of the 6H–SiC (0001) substrate surface. The islands increase in size with a lateral-to-vertical growth ratio of ~10 and eventually coalesce into a quasicontinuous layer. A highly defective substrate surface was found to be detrimental to the growth of flat buffer layers.
TWO-DIMENSIONAL SELF-ASSEMBLY OF SUPRAMOLECULAR STRUCTURES
Authors: BÖHRINGER MATTHIAS , SCHNEIDER WOLF-DIETER , BERNDT RICHARD
Published: August 2002

We briefly review recent low temperature scanning tunneling microscopy (STM) investigations performed in our laboratory1–5 on the self-assembly of the dipolar organic molecule 1-nitronaphthalene (NN) adsorbed on the reconstructed Au(111) surface. NN becomes chiral upon planar adsorption on the gold surface. We observe several coverage-driven structural transformations which are associated with simultaneous changes in the enantiomeric composition of the self-assembled molecular structures. At low coverages almost exclusively decamers with an 8:2 ratio of the enantiomers are formed. In a medium coverage range enantiopure one-dimensional molecular double chains prevail on the surface. Subsequently, molecules with opposite handedness are admixed until at monolayer coverage racemic one- and two-dimensional structures coexist. Modeling shows that hydrogen bonding causes the observed self-assembly. A subtle interplay between the electrostatic interactions among the molecules and their interaction with the reconstructed metal surface is the origin of the observed coverage-driven chiral phase transition in two dimensions.
DOUBLE INVARIANCE: A NEW EQUILIBRIUM CONCEPT FOR TWO-PERSON DYNAMIC GAMES
Authors: CARAVANI P.
Published: August 2002

Doubly Invariant Equilibrium is introduced as an alternative concept to Nash equilibrium in dynamic games doing away with the notion of a payoff function. A subset of the state space enjoys the invariance property if the state can be kept in it by one player, regardless of the action of the opponent. A doubly invariant equilibrium obtains when each player can make his own subset invariant. Relationships to Nash equilibrium and viability theory are discussed and a necessary and sufficient condition for the existence of a doubly invariant equilibrium is given for the class of linear discrete-time games with polyhedral constraints on the state and strategy spaces.
The African‐specific CYP2D6*17 allele encodes an enzyme with changed substrate specificity
Authors: Wennerholm Agneta , Dandara Collet , Sayi Jane , Svensson Jan‐Olov , Abdi Yakoub Aden , Ingelman‐Sundberg Magnus , Bertilsson Leif , Hasler Julia , Gustafsson Lars L.
Published: August 2002

Objective

The effects of the CYP2D6*17 and *29 alleles on substrate specificity and enzyme activity were studied by correlating CYP2D6 genotype to phenotype with 4 probe drugs (codeine, debrisoquine, dextromethorphan, metoprolol) in black Tanzanians and white Swedes.

Methods

The black Tanzanian subjects represented the following 6 genotypic groups: A, (CYP2D6*1 or *2)/(*1 or *2) (n = 13); B, CYP2D6*17/*17 (n = 5); C, CYP2D6*29/*29 (n = 4); D, CYP2D6*1/*17 (n = 5); E, CYP2D6*5/*17 (n = 4); and F, various genotypes (n = 4). The white subjects were from 4 groups, as follows: A, (CYP2D6*1 or *2)/(*1 or *2) (n = 7); B, (CYP2D6*1 or *2)/(*3, *4, or *5) (n = 7); C, homozygous for defect alleles (n = 7); and D, duplicated CYP2D6 gene (n = 2).

Results

The metabolic ratios of the 4 probe drugs correlated significantly (rs = 0.69–0.92; P < .001) in both populations. Tanzanian subjects homozygous for the CYP2D6*17 allele were slower metabolizers when debrisoquine or dextromethorphan was used as the probe drug than when codeine or metoprolol was used, showing a different substrate specificity of CYP2D6.17 than of CYP2D6.1 and CYP2D6.2. This was confirmed with analysis of covariance of the different metabolic ratios for a subgroup of subjects carrying only the CYP2D6*17 mutated allele (n = 9) compared with all other subjects (n = 44). The metabolic ratios of dextromethorphan and metoprolol differed significantly among Tanzanian subjects homozygous for the CYP2D6*29 allele compared with those with CYP2D6*1 or *2 alleles.

Conclusion

We found differences in the disposition of 4 CYP2D6 probe drugs in black Tanzanians compared with Swedes. The differences were caused by the presence of CYP2D6.17 and CYP2D6.29. The results show that CYP2D6.17 exhibits altered substrate specificity compared with CYP2D6.1 and CYP2D6.2.

Clinical Pharmacology & Therapeutics (2002) 71, 77–88; doi: 10.1067/mcp.2002.120239
Comparative angiotensin II receptor blockade in healthy volunteers: The importance of dosing
Authors: Maillard Marc P. , Würzner Grégoire , Nussberger Jürg , Centeno Catherine , Burnier Michel , Brunner Hans R.
Published: August 2002

Objectives

We have reported previously that 80 mg valsartan and 50 mg losartan provide less receptor blockade than 150 mg irbesartan in normotensive subjects. In this study we investigated the importance of drug dosing in mediating these differences by comparing the AT1‐receptor blockade induced by 3 doses of valsartan with that obtained with 3 other antagonists at given doses.

Methods

Valsartan (80, 160, and 320 mg), 50 mg losartan, 150 mg irbesartan, and 8 mg candesartan were administered to 24 healthy subjects in a randomized, open‐label, 3‐period crossover study. All doses were given once daily for 8 days. The angiotensin II receptor blockade was assessed with two techniques, the reactive rise in plasma renin activity and an in vitro radioreceptor binding assay that quantified the displacement of angiotensin II by the blocking agents. Measurements were obtained before and 4 and 24 hours after drug intake on days 1 and 8.

Results

At 4 and 24 hours, valsartan induced a dose‐dependent “blockade” of AT1 receptors. Compared with other antagonists, 80 mg valsartan and 50 mg losartan had a comparable profile. The 160‐mg and 320‐mg doses of valsartan blocked AT1 receptors at 4 hours by 80%, which was similar to the effect of 150 mg irbesartan. At trough, however, the valsartan‐induced blockade was slightly less than that obtained with irbesartan. With use of plasma renin activity as a marker of receptor blockade, on day 8, 160 mg valsartan was equivalent to 150 mg irbesartan and 8 mg candesartan.

Conclusions

These results show that the differences in angiotensin II receptor blockade observed with the various AT1 antagonists are explained mainly by differences in dosing. When 160‐mg or 320‐mg doses were investigated, the effects of valsartan hardly differed from those obtained with recommended doses of irbesartan and candesartan.

Clinical Pharmacology & Therapeutics (2002) 71, 68–76; doi: 10.1067/mcp.2002.121425
Resource Triumphalism: Postindustrial Narratives of Primary Commodity Production
Authors: Bridge Gavin
Published: August 2002

It is now commonplace to assert that the contemporary discursive landscape is strewn with an abundance of environmental narratives. Yet these stories about nature seldom speak of the material geographies that link practices of postindustrial consumption to often-distant spaces of commodity supply. A postscarcity narrative in which the availability of natural resources no longer poses a limiting factor on economic growth, therefore, characterizes the current period. In this paper I examine how these narratives of ‘resource triumphalism’ construct the nature of commodities and the places that supply them. Using a range of sources, I illustrate how extractive spaces are constructed through a discursive dialectic which simultaneously erases socioecological histories and reinscribes space in the image of the commodity. The paper advances the claim that, despite their apparent marginality in narratives of postindustrialism, primary commodity-supply zones play a key role within broader narratives about modernity and social life. I draw on Hetherington's reworking of the concept of heterotopia to argue that commodity-supply zones be considered contemporary ‘badlands’, marginal spaces in and through which broader processes of sociospatial ordering are worked out. By examining the geographical imaginaries associated with mineral extraction, I demonstrate how contemporary discourses of commodity-supply space facilitate the material practices through which such ordering occurs.
The State of Training: Learning, Institutional Innovation, and Local Boards for Training and Adjustment in Ontario, Canada
Authors: Rutherford Tod D
Published: August 2002

This paper critiques the learning-region literature on two related points. The first is that the learning-region analysis of labour markets is theoretically underdeveloped, because it underestimates the difficulty of overcoming systematic skill mismatches, underinvestment, and free-rider practices which characterize unregulated labour markets. Second and relatedly, because it does not link the problematic nature of labour-market governance to the conflicts and contradictions of state policy, the learning-region literature effectively ‘depoliticizes’ policymaking. The paper draws on a case study of the development of local boards for training and adjustment in Ontario, Canada, and develops an alternative framework utilizing a critical governance perspective which stresses how knowledge and learning must be seen as part of state accumulation and hegemonic strategies. Such strategies are contingent on the representation of stakeholders, in particular business, and current attempts to develop decentralized associational networks are often part of what Jessop terms metagovernance. In the case of Canada, decentralization from the federal to provincial scales is viewed as crisis and cost driven and in many ways antithetical to stakeholder governance. Thus in Ontario, the development of a stakeholder-based form of labour-market governance has been marginalized by shifts in state-accumulation strategies and the inability and disinterest of business in representing itself in such stakeholder institutions. Furthermore, the local boards' generation of knowledge based on inclusionary networks and information is at odds with a state and business emphasis on knowledge derived from exclusive networks and geared to short-term profit maximization.
The Implications of Wal-Mart's Takeover of ASDA
Authors: Burt Steve , Sparks Leigh
Published: August 2002

Wal-Mart is the world's largest retailer. Within the United Kingdom, retailing has generally been considered as a local or national activity. Wal-Mart's purchase of ASDA in 1999 illustrates the global scale of much modern retailing. In this paper we consider the implications of Wal-Mart's takeover of ASDA. First, the key drivers of Wal-Mart's business success are analysed. Second, the impact of Wal-Mart in Canada and Germany is considered. Third, the match of Wal-Mart with ASDA is examined. Fourth, the key changes Wal-Mart is making to ASDA are reviewed. This consideration of Wal-Mart and ASDA is placed in the context of theoretical discussions of retailing and particularly the internationalisation of retailing.
Capturing the Age and Spatial Structures of Migration
Authors: Rogers Andrei , Raymer James , Willekens Frans
Published: August 2002

In this paper we model the structures found in the level (generation) and allocation (distribution) components of age-specific and origin – destination-specific migration flows. For the examples, we examine the regional migration patterns in the USA for four periods: 1955 – 60, 1965 – 70, 1975 – 80, and 1985 – 90. The age and migration structures are identified over time by using the logit model for categorical data. Just as model schedules can be used to capture the age patterns of fertility, mortality, and migration rates for use in indirect estimation, so too the models set out in this paper can be used to capture the spatial patterns exhibited by particular sets of age-specific and origin – destination-specific migration proportions. They then also can be used to impose these patterns on inaccurate, incomplete, or otherwise inadequate data.
The Shape of Space: Applying Geometric Morphometrics to Geographic Data
Authors: Wallace Robert G
Published: August 2002

Another means is proposed for displaying epistatic change in spatially structured ecologies. The approach uses techniques developed in geometric morphometrics, a relatively new discipline centered on mapping change in bone and other morphologies through evolutionary time across taxa. Warps analysis is introduced and its terms and protocols explained. An example of warps analysis as applied to geographic data is presented. The example focuses on the AIDS epidemic in two boroughs of New York City. Female adult AIDS incidence and percentage newborns exposed to HIV, by zip code for the years 1991 – 98, are used to generate annual configurations within an ecological parameter space. A warps analysis of those configurations indicates a clear shift in the relative positions of Manhattan zip codes during the 1990s. The analysis shows the relative positions of two subareas comprised of Harlem and Lower Manhattan zip codes were displaced in contrary directions in the parameter space with the introduction of antiretroviral combination therapies (HAART). In contrast, a warps analysis of the Bronx's AIDS parameter space shows few definable zip code groupings or temporal trends before or with HAART. The promises and problems in applying warps analysis to geographic data are discussed.
Social and Geographic Inequities in the Residential Property Tax: A Review and Case Study—A Commentary
Authors: Moore Jason
Published: August 2002

Any review of assessment values produced by an assessment authority for taxation purposes must use appropriate statistical methods to ensure that the assessment-to-sale price ratio analysis produces reliable results. Failure to do so can lead the reviewer to draw incorrect conclusions concerning the quality of the assessment base. It is my contention that the review of assessments in Hamilton, Ontario, Canada, conducted by Harris and Lehman and published in Environment and Planning A [“Social and geographic inequities in the residential property tax: a review and case study” 33 (5) 881 – 900] produced inaccurate conclusions because of the methodologies used to analyze assessment results. In this paper I will attempt to point out some of the more common methodological errors that are made when analyzing assessed values and demonstrate methods that should be employed to produce results that are more reliable.
How do Producer Services Affect the Location of Manufacturing Firms? The Role of Information Accessibility
Authors: Alonso-Villar Olga , Chamorro-Rivas José-María
Published: August 2002

The aim of this paper is to analyze the location decisions both of producer services and of manufacturing, exploring two main topics: how manufacturing and services location change when regions integrate, and how developments in telecommunications affect them both. We built a theoretical model consisting of two regions and three sectors (manufacturing, producer services, and agriculture). Given that producer services constitute a sector oriented towards information and knowledge, this is a factor that is taken into account in the explanation of their location. Numerical simulations are made in a general equilibrium framework. In contrast to previous works, we find that when regions integrate, specialization (producer services being in the core regions, and manufacturing in the periphery)—rather than convergence—arises. Besides, improvements in telecommunications may facilitate concentration of services in the core regions.
An Anthropological Case Study on the Relation of Space, Language, and Social Order: The Bisa of Burkina Faso
Authors: Dafinger Andreas
Published: August 2002

This paper outlines certain benefits that spatial analysis offers to anthropological research, and shows how anthropology and related linguistic research may in turn contribute to the understanding of the social determinants of spatial order. It presents a case study of spatial order in a rural West African society. Although the examples are from a particular setting, the theoretical frame is a general one: the analysis will focus on the connections between social order, language, and the perception of space.
Two Social Environments in a Working Day: Occupation and Spatial Segregation in Metropolitan Tel Aviv
Authors: Blumen Orna , Zamir Iris
Published: August 2002

The concepts of segregation and social distance have long been used to explain the social environment of stratified residential space. However, the social significance of occupation, though acknowledged, has rarely been applied spatially. In this study, we employed these three concepts to examine the social environment of the entire metropolitan employment space as defined by job location. Smallest space analysis was used to identify and compare the sociospatial segregation produced by workers' occupational distribution in employment and residential spheres. This empirical study focused on metropolitan Tel Aviv, Israel's largest urban area, using the latest available national census. Our findings show that the social milieu of employment differed from that of residence: blue-collar workers were segregated from white-collar workers; managers, clerks, and salespersons formed the core group; and gender and ethnic divisions characterised the sociospatial realm of employment. Overall, most employees changed their social environment when they went to work. The study indicates that spatial segregation, within each sphere and between the two spheres, is intrinsic to the capitalist – patriarchal order.
Manufacturing Productivity Growth across European Union States: 1978 – 94
Authors: Melachroinos Konstantinos A , Spence Nigel
Published: August 2002

This paper explores the sources of rising manufacturing output and labour productivity across thirteen European Union states between 1978 and 1994. Despite the severe deindustrialisation trends of the past two decades, manufacturing output continued to expand and thus contribute to overall economic growth. The analysis here reveals several key aspects of this process. First, the geographical distribution of the sector across Europe for the entire period is characterised by considerable stability. Contrary to some initial fears, the slow but steady integration process has not led to the wholesale migration of manufacturing activity from one member state to another. Second, total factor productivity increases seem to account for most of the recorded output and labour productivity gains. Third, there is, however, significant spatial variation in the performance of individual industrial bases. Smaller countries' growth rates appear to surpass those of the larger states, and the European South demonstrates higher growth rates than the North. Nevertheless, and this is the final point, there is an absence of clear signs of convergence. Geographical inequalities continue to hold, as the technology gap between advanced and lagging economies remains as wide as ever. Such findings raise some important issues about the role of EU regional policies and the challenges that they face at the dawn of the 21st century.
The Application of Zone-Design Methodology in the 2001 UK Census
Authors: Martin David , Nolan Abigail , Tranmer Mark
Published: August 2002

This paper reviews the automated zone-design procedures adopted for the creation of 2001 Census output geography in the United Kingdom. A microsimulation approach is used for the creation of household records to populate actual postcode and enumeration district boundaries, and a series of output area design scenarios are applied to these data, allowing the effects of the new design constraints to be evaluated. The authors identify the advantages of using an intra-area correlation measure for the maximization of social homogeneity within output areas, and explore the differences between the 1991 and 2001 approaches to output geography.
Bribing the Grantee: Asymmetric Information and the Enforcement of Local Minimum-Provision Levels through Grants-in-Aid
Authors: Van Puyenbroeckf Tom
Published: August 2002

A principal-agent approach is used to analyse the problem of a central government that wants to stimulate the provision of local public services, given that lower level governments are better informed about production costs. Specifically, the centre wants the provision level to be such that at least a minimum standard is provided. If the imposition of such a standard is constitutionally ruled out, what should an appropriate grant look like. It is explicitly recognised that the decision whether or not to accept the proposed grant scheme may vary for different types of recipients. In addition, the grant must be incentive compatible. This is achieved by including information-eliciting payments in the transfer, which in turn influences the optimal provision level: more types will be set at the minimum-provision level, relative to a perfect-information setting. The qualitative nature of the optimal grant scheme itself is profoundly influenced by just the addition of information asymmetry.
Institutional Barriers to Enterprise Support: An Empirical Study
Authors: Vyakarnam Shailendra , Adams Richard
Published: August 2002

This paper reports on empirical research amongst clients of the Government Office for the East of England, exploring levels of satisfaction in order to generate, rather than validate, understanding. As the landscape of public enterprise support in Britain changes and new institutions come on stream, this case poses searching questions about the manner in which policy for economic growth can be delivered in the English regions. Efforts to eliminate confusion and incoherence in the support infrastructure appear not to have succeeded. Findings indicate that barriers between policy ambitions and effective take-up by client communities continue to exist. Clients perceive behavioural rigidities as a barrier to the development of the most effective public-private relationships. A sometimes centralist perspective (arguably, the predisposition of the support infrastructure) is in danger of allowing the benefits of support tailored to regional need to be overlooked. The objective is by “constructively discrediting the system” (as Bowen et al suggest) to stimulate useful debate about the way in which the enterprise culture might be supported.
The Fiscal Manipulation of a Decentralized Public Sector: Macroeconomic Policy in Denmark
Authors: Blom-Hansen Jens , Pallesen Thomas
Published: August 2002

The authors challenge the conventional wisdom according to which a decentralized public sector makes it difficult to instrumentalize the public budget for macroeconomic control purposes. Although the literature has already demonstrated that the statistical relationship between decentralization and macroeconomic performance is not as straightforward as is indicated by the conventional wisdom, and that decentralization actually seems to be positively correlated with macroeconomic performance, a gap exists in the literature as to the causal relationship, that is, the exact mechanisms by which decentralization impacts on performance. The authors begin to fill that gap by investigating the workings of one decentralized public budget, namely that of Denmark.
The Private Finance Initiative and Public Sector Finance
Authors: Ball Rob , Heafey Maryanne , King David
Published: August 2002

Traditionally, when the public sector wanted more capital assets, it borrowed funds for the purpose. Under the Private Finance Initiative (PFI), private consortia borrow funds to build assets and then, in return for a charge, use them to provide services for the public sector. The authors explore the implications for the public finances of using the PFI. A widely held belief, which has been put forward by the Treasury, is that using the PFI allows investment in assets used by the public sector to grow, even within public spending limits, because PFI investments fall outside the ambit of public borrowing. However, the authors show that if a constant amount of spending is transferred every year from traditional finance to PFI finance, then the fall in public borrowing will diminish over time and may eventually wholly disappear. So, even if some PFI finance is used every year, the scope for extra investment will diminish and may eventually disappear. They also show that, if PFI finance is used, then the required tax yield for a given level of investment may be permanently higher or permanently lower. In addition, they show that, even if a switch to PFI did reduce both public borrowing and taxes, then it might not facilitate much extra investment.
Spending Efficiency of International Financing Institutions: Determinants of Efficiency and a Research Design
Authors: Zimmermann Horst , Pahl Thilo
Published: August 2002

International financing institutions (IFIs) spend more than US$50 billion each year, most of it for development, but also some for environmental and other purposes. Yet the question which of the IFIs spend a given amount in the most efficient way seems not to have been researched. Such information would help donor and recipient countries to put pressure on badly performing IFIs and to farther the better ones. The authors therefore discuss the subject of the efficient use of financial resources by IFIs. They develop a set of determinants of spending efficiency, structured by (1) the general features of an institution, such as being public or private; (2) the organisational elements of an institution; and (3) the type of problem an institution deals with. This set of determinants also constitute a research design for the comparative analysis of the spending efficiency of IFIs.
Is Urban Regeneration Good for Health? Perceptions and Theories of the Health Impacts of Urban Change
Authors: Curtis Sarah , Cave Ben , Coutts Adam
Published: August 2002

An important issue for the geography of health in urban areas concerns how urban change arising from renewal of inner-city areas relates to health of urban populations. In this paper we examine ways in which urban regeneration schemes in Britain are attempting to incorporate consideration of health impact into their planning and development. It concentrates especially on diverse ways that different stakeholders perceive the outcomes of these schemes and the significance for health. The paper is based on two case studies of urban development projects, focusing on housing improvement and training for unemployed people, in a London borough where levels of deprivation are high and various forms of social exclusion affect large numbers of people. The methods used aimed to represent the views of different types of stakeholders, by means of interviews and focus groups with a range of stakeholders in these schemes. Health impact assessment needs to be evidence based. We discuss the evidence for potential health impact of regeneration projects through effects on housing and employment as determinants of health. We focus especially on the ways in which this evidence can be viewed and used by different stakeholders, and how far their perceptions seemed to match with research findings from public health. We consider the potential and the limitations for health improvement associated with urban regeneration in view of the case studies presented here.