bluuebunny/crossref_metadata_2025 huggingface dataset:
INFORMAL HOUSING IN A COMPARATIVE PERSPECTIVE: On Squatting, Culture, and Development in a Latin American and a Middle Eastern Context
Authors: AlSayyad Nezar
Published: October 2007

The basis of this paper is the proposition that the development of squatter communities and informal housing varies throughout developing regions. Squatter developments follow distinct patterns and develop unique characteristics which are affected by regional cultural variables. The paper presents a framework for investigating how different cultural practices affect the nature of squatter development. It first presents a brief overview of prevailing trends of thought regarding the formation of and response to informal housing development. Its principal argument then emerges from a cross‐cultural comparison of cases of informal development in the Arab Middle East and Latin America. The comparison shows that there is no all‐encompassing model for processes of formation and maturation of squatter settlements. For example, while informal developments in the Middle East have a clearly depoliticized and unobtrusive character, in Latin America such settlements are rarely isolated, maintaining ties to either ruling or opposition political parties. Further analysis elaborates on the definition of culture and its importance as a variable. The argument is made that the purely political/economic circumstances of squatter populations cannot be considered without regard for the cultural contexts in which these are embedded. Finally, the paper critiques the generalized pattern that has emerged to describe the evaluation of informal housing developments in the Third World, despite the key mediating role played by culture. It concludes that a culturally grounded approach may broaden the horizons for housing acquisition by the urban poor.
THE DEVELOPMENT AND USE OF INTERREGIONAL INPUT‐OUTPUT MODELS FOR INDONESIA UNDER CONDITIONS OF LIMITED INFORMATION*
Authors: Hulu Edison , Hewings Geoffrey J.D.
Published: October 2007

Spatial development planning in developing economies has created the need for analytical frameworks that are capable of providing assessment of alternative strategies. This paper reports on the methods used to construct a set of interregional input‐output tables for a five‐region division of Indonesia under conditions of limited information for 1980 and 1985. The tables were constructed as a prelude to the development of a comparable set of interregional social accounts and the eventual construction of an interregional computable general equilibrium model. The structure of the Indonesian economy is explored and described; the fine structure is revealed through an examination of the fields of influence of some of the analytically important coefficients. Finally, a brief examination of the use of the model in an export promotion strategy is reported. The dominant positions of Sumatera and Java are revealed as is the concomitant difficulties attendant upon development strategies that attempt to encourage growth in other regions.
LOCAL ECONOMIC REVITALIZATION OR NATIONAL INDUSTRIAL GROWTH? A COMPARATIVE OVERVIEW OF SMALL BUSINESS POLICY IN JAPAN AND THE U.S.
Authors: Aoyama Yuko
Published: October 2007

Contrasts in small business policy are examined for Japan and the United States. The author argues that Japan's small business policy has been part of an industrial growth‐oriented policy, while comparatively the U.S. small business policy has been mainly part of locally‐based economic revitalization schemes. Recent trends in policy development indicate that the policies in the two countries are converging. The U.S. policymakers have become increasingly concerned with the small business sector becoming competitive in global markets, while widespread offshoring of large firms have prompted Japanese policymakers to focus on supporting small businesses in order to prevent further loss of manufacturing jobs.
THE DETERMINANTS OF RURAL INDUSTRIAL ESTATE PERFORMANCE IN KOREA
Authors: Cho Cheol‐Joo
Published: October 2007

Since the 1980s, a total of 221 small‐ and medium‐sized rural industrial estates have been established primarily to induce economic growth into the rural areas in Korea. Despite a growing interest in the performance of the rural industrial estates, it has not been closely examined. The purpose of this paper is to find the plausible factors that have a significant influence on the performance of the rural industrial estates, thereby providing a general understanding of the structural relationship between the estate performance and its determinants. An econometric modeling approach, called LISREL, is used to carry out this evaluation. Of several influential determinants distinguished, seven variables appear to be of substantial significance. They include the urbanization and industrialization of the estate host community, the accessibility of the individual estates to the major cities, the distances from the estates to the large industrial complexes, the local tax rates, and the government loans and incentives. The findings imply that more favorable are the estates constructed within the labor market boundaries of the major cities and adjacent to large industrial complexes. In addition to the location and environmental factors, financial funds and incentives will continue to remain as an influential factor for the success or failure of the estates.
ECONOMIC SYSTEM CONVERSION AND MIGRATION TRANSITION IN RUSSIA
Authors: Kumo Kazuhiro
Published: October 2007

This paper examines migration changes in Russia due to the transition of the economic system. As expected, great changes in migration patterns occurred in Russia. The correlation coefficients between federal investment and interregional migration are positive and large during the Soviet period, indicating that political incentives played a major role in migration patterns in the USSR. However, the regional development policy implemented in the Soviet era may not have been socially efficient in causing migration inflows and excess labor supply in the Far North regions. In addition, it can be said that the government could not control population flows perfectly even in the planned economy.
A REVIEW OF THE KOREAN HOUSING MARKET AND RELATED POLICIES
Authors: Son Jae‐young
Published: October 2007

Essentially an update of Renaud (1989). K.Y. Kim (1991), and K.H. Kim (1993), this paper introduces the Korean housing market and policies, but from a distinct perspective. Housing conditions in Korea have dramatically improved both in terms of quantity and quality over the past 35 years. The market has mainly accommodated buyers of new houses, while ignoring or even sacrificing needs of low income households. This is the result of government control of the market mostly by regulations on new for‐sale houses rather than by budgetary or financial resources. Both the weakness and strength of this housing supply system were clearly revealed by the price hikes in the late 1980s and by the mass production of houses, which finally stabilized the market As for major current policy problems, the suggestions put forth in this paper emphasize fewer regulations and more involvement of the private sector.
REGIONAL OFFICES IN SINGAPORE: SPATIAL AND STRATEGIC INFLUENCES IN THE LOCATION OF CORPORATE CONTROL
Authors: Perry Martin , Poon Jessie , Yeung Henry
Published: October 2007

This paper reports a postal questionnaire survey of 130 regional offices in Singapore. The survey examines location decisions, current location evaluation and business objectives of regional offices. The extent to which competition for regional offices is possible among Asian business centers and the regional development consequences of business strategy linked to regional offices are assessed. Variations among regional offices according to country of origin and year of establishment are analyzed. The survey concludes that Singapore retains its lead as a center for regional offices, but that the sources of its attractiveness are changing and that it is not gaining from any relocation of corporate control out of Hong Kong. Public policy incentives to attract regional offices in competition to Singapore may be most successful if aimed at Asian organizations. Promotion to offices from North America and Europe should emphasize the relative growth opportunities in Southeast and East Asia.
ASSESSING THE IMPACT OF THE MAQUILADORA INDUSTRY IN MEXICO: AN INTERINDUSTRY ANALYSIS
Authors: Guajardo‐Quiroga Ramón G.
Published: October 2007

Maquiladora industries, composed of assembly plants, play a central role in Mexico's development strategy. The author establishes that current low usage of domestic inputs by the maquiladora industries prevents Mexico from enginning the rest of the economy through secondary impacts to expand the national market. Furthermore, the economy is also affected, through diminished domestic linkages, from increasing the value added in Mexico and tax collection. An interindustry input‐output model for the Mexican economy with emphasis on the maquiladora industries was developed. Among the findings, it is stressed that input purchases linkages are more effective than worker spending as a way to generate secondary output, income and jobs. This implies that increasing domestic input purchases by maquiladora industries could represent important potential advantages for the Mexican economy.
FACT AND FALLACY IN LABOUR MARKET ANALYSIS: A REPLY TO MR. LANDO*
Authors: Killingsworth Charles C.
Published: October 2007

Mr. Mordechai E. Lando has devoted his entire ‘Comment’ to one paragraph in my article, ‘Full Employment and the New Economics’, which ran to 36 paragraphs. Despite this rather narrow concentration, Mr. Lando has seriously misstated my argument in that one paragraph, and he has supported his criticisms by misstatements of fact and errors in analysis. Since his criticisms go to the heart of a thesis that I have developed in some detail during the past decade, I think that I should answer them rather fully.
TECHNOLOGY GAPS BETWEEN RICH AND POOR COUNTRIES*
Authors: Streeten Paul
Published: October 2007

We have started by asking the question: why are there international income inequalities? We have ascribed them to differences in applied productive knowledge. This raised the question: why can productive knowledge be communicated and diffused within an advanced nation but not between nations or within underdeveloped nations? What are the obstacles to the international diffusion of benefits?

We have found these in two areas: obstacles to communication and absence of suitable technologies. The obstacles to communication can again be divided into those due to costs of transfer and those due to intentional restrictions or the exercise of monopoly power. But even perfect communication would not meet the need for quite different technologies from those developed in high‐income countries.

Measures that reduce the Communications Gap might make the Suitability Gap wider and vice versa, but a set of integrated actions attacking both gaps has a chance of success. Technical knowledge cannot be marketed like other products or factors because it possesses peculiar features: (i) indivisibility, (ii) inappropriatability, (iii) embodiment in other factors, (iv) uncertainty and (v) impossibility to know its full value until bought. Policies for closing the two gaps are interdependent, so that the pursuit of any one in isolation might make matters worse. What is needed is a set of integrated actions, attacking both the Communications Gap and the Suitability Gap. Transfer must be supplemented by indigenous capability; adaptation by invention and innovation.
MANAGEMENT BEHAVIOUR AND A THEORY OF DIVERSIFICATION
Authors: Sutton C. J.
Published: October 2007

This paper investigates the basis for a behavioural theory of diversification. A theory of diversification may be required (i) for full analysis of competitive processes, which include innovation and cross‐entry competition, and (ii) to understand the selection of diversification projects in individual firms. Alternative optimising and non‐optimising models are feasible. The choice between these alternatives will be considered after the non‐optimising model has been developed.

Section I outlines the basic model and the general predictions which it generates. In section II the predictions are subjected to a coarse test, which is taken to justify further investigation of the model's properties. The model is developed more fully in section III.
THE FIRST ROUND OF THE KEYNESIAN REGIONAL INCOME MULTIPLIER
Authors: Sinclair M. Thea , Sutcliffe Charles M. S.
Published: October 2007

Previous studies utilising the Keynesian regional income multiplier have paid very limited attention to the estimation of the income generation which occurs during the first round of the multiplier process. However, since the first round of income generation is of greater magnitude than that of any other round, it is particularly important that the first round effects should be estimated correctly. This paper will attempt to analyse the way in which such estimation depends upon the types and values of the propensities to withdraw which are included in the first round. These are related, in turn, to the type of income which the multiplier methodology is attempting to measure, and to the form which the injection itself takes.
A HIERARCHICAL THEORY OF THE FIRM*
Authors: SANDLER TODD , CAULEY JON
Published: October 2007

This paper provides a mathematically coherent and concise formulation of the Williamson market‐failure approach and, hence, develops models for single‐level and multilevel firms and organizations. These models optimally determine the extent of integration for each viable link on every hierarchical level, When the models are reformulated in terms of four operational parameters that determine integration, applied benefit‐cost methods can be utilized, in practice, to model a firm. Both static and dynamiclmodels‐are presented.
EFFECTIVE DEMAND, OUTWARD INVESTMENT AND THE (THEORY OF THE) TRANSNATIONAL CORPORATION: AN EMPRICAL INVESTIGATION
Authors: Pitelis Christos
Published: October 2007

Astract

That demand‐side deficiencies can provide an inducement for outward investment by transnational corporations has never acquired much currency, despite its long history and the fact that existing theories ofter have implications supportive of it. Arguably a reason for this is that the idea has never been tested empirically. In this paper we provide the first such empirical test. First we critically survey and attempt to synthesize the mainstream microeconomic or supply‐side theories of the TNC. Then we examine the case for a demand‐side perspective, link this to the supply‐side and discuss some existing indirect evidence in support of this perspective. Finally we provide a direct econometric test of the demand‐side perspective, which provides clear support for it.
HOW THEORY CAME TO ENGLISH CLASSICAL ECONOMICS*
Authors: Coleman William O.
Published: October 2007

Abstract

The confidently theoretical method of English classical economics is traced to the Enlightenment's struggle to resolve the disputes between rationalism and anti‐rationalism which had dominated the 17th century. It is argued that, in an attempt to resolve these disputes, several Enlightenment authors, including David Hume and Dugald Stewart, sought to unite empiricism with the notion of law‐like universe by arguing that economic laws are no more than general facts apparent from everyday life. This position, by denying that theory had any connection with the hypothetical, the instrumental or the abstract, blurred the distinction between theory and fact, and taught Classical economists to see their theorising as fact. This position thereby gave the Classical economists licence to pursue their theoretical speculations, free from any doubts or uncertainties about their theorising.
US FOREIGN EXCHANGE MARKET INTERVENTION SINCE 1962
Authors: Schwartz Anna J.
Published: October 2007

Abstract

The Federal Reserve has intervened in foreign exchange markets since 1962 as a partner of the Treasury's Exchange Stabilization Fund. Departing from its scripted passive role under the Bretton Woods system, the US defense of the dollar under pegged exchange rates may not appear unreasonable. Why the practice continues under a floating rate system is harder to understand. By accumulating large foreign currency balances since 1987, the US has made intervention easier. Holding larger balances does not help the authorities know what exchange rates ought to be. The US for a few years in the 1980s refrained from intervening. It can happen again if its authorities acknowledge that intervening is an exercise in futility.
Masked Popery and Pyrrhonian Uncertainty: The Early Scottish Covenanters on Arminianism
Authors: Mullan David G.
Published: October 2007

In Jacobean and Caroline Scotland there was little Arminianism to be found, whether in its Remonstrant (Dutch) or Laudian (English) versions. Nevertheless, the representation of this teaching by a few Scottish divines, its more strenuous advocacy in England, and reports of its spread in Europe unnerved those who would lead the covenanting movement after 1638.

Arminianism represented a two‐pronged threat to the Calvinist covenanting vision. Its attempt at moderation in the theological strife of the time approximated a compromise with, if not a surrender to, popery. But Arminianism also suffered from an identification with the scepticism then fermenting in European philosophy. The decay of a providential worldview undercut the national self‐image of Scotland at the forefront of resurgent Reformed religion. The significance of free will threatened the individual’s assurance of election. The loss of certainty about theological authority, accepting the individual’s right to interpret the Bible and to express his views publicly, shattered the ideal of a religiously uniform society. Thus considered, the persistent interest in Arminianism provides a useful perspective on the mind of the covenanting movement.
Quaker Schoolmasters, Toleration and the Law, 1689–1714
Authors: Wykes David L.
Published: October 2007

The 1689 Toleration Act allowed Protestant dissenters freedom to worship in public, but it was only a limited toleration and dissenters continued to suffer discrimination. This article examines the experience of Quakers in one important area, the Anglican monopoly in teaching. Although the prosecution of unlicensed teachers was patchy, localised, and dependent upon the hostility and zeal of particular individuals, few dissenters escaped harassment. Moreover, Friends appear to have suffered more severely because of the particular dislike that they still provoked and their unwillingness to compromise which often led to imprisonment. The growth in High Church feeling during Anne’s reign led to a more rigorous enforcement of the existing statutes and the passing of the Schism Act (1714). The consequences of an Anglican educational monopoly have not been properly considered by historians largely from the assumption that the Schism Act was fatally compromised by the death of Queen Anne, and because little attention has been paid to the continued harassment of dissenters after toleration who attempted to teach. The Schism Act was repealed in 1719, but freedom for Quakers and other dissenters to teach had already been achieved largely through the courts.
Non‐disjunction in trisomy 21: study of chromosomal heteromorphisms in 110 families
Authors: MIKKELSEN MARGARETA , POULSEN HANNE , GRINSTED JßRGEN , LANGE AKSEL
Published: October 2007

QM variants on chromosome 21 and silver staining of NOR regions were applied in the study of non‐disjunction in 110 families from different parts of Denmark. In 76% of the families the study was informative. Paternal failures were observed in 11 % on Funen as compared 23.5% on Zealand. In one family, crossing‐over on the short arms of chromosome 21 in the mother and mitotic non‐disjunction of chromosome 21 was observed.

Maternal first meiotic error predominates in both high maternal and low maternal age. Also in paternal non‐disjunction failures of first meiotic division predominate. Two maternally and one paternally originated cases of de novo translocations were observed.
Genetic studies on the Ticuna, an eniǵmatic tribe of Central Amazonas
Authors: NEEL JAMES V. , GERSHOWITZ HENEY , MOHRENWEISER HARVEY W. , AMOS BERNARD , KOSTYU DONNA D. , SALZANO FRANCISCO M. , MESTRINER MOACYR A. , LAWRENCE DALE , SIMOTES AGUINALDO L. , SMOUSE PETER E. , OLIVER WILLIAM J. , SPIELMAN RICHARD S. , NEEL JAMES V.
Published: October 2007

The Ticuna are an Amerindian tribe of Central Amazonas, a key location in theories of the peopling of eastern South America. The results of typing some 1760 members of the tribe with respect to 37 different genetic systems are reported, as are the results of HLA typings on a subsample of 129 persons. Salient findings include the following. (1) Except for a high frequency of the LMsallele and an unusual combination of HLA allele frequencies, there are no notable findings with respect to the commonly studied polymorphic systems. A multivariate treatment of six of the most commonly studied genetic polymorphisms accords the Ticuna an ‘average’ position among Amerindian tribes. (2) There is much less intervillage heterogeneity than usually encountered in Amerindian tribes; this is attributed to recent high rates of intervillage migration due to religious developments. (3) A thus‐far unique polymorphism of ACP1was identified, the responsible allele having a frequency of 0.111. (4) In proportion to the size of the tribe, there was a relative paucity of ‘private’ genetic variants, the ACP1 allele being the only one. This discrepancy is attributed to a relatively recent numerical expansion of the tribe; effective population size over the past several thousand years is thought to have been well below what present numbers would suggest. (5) The thesis is again advanced that ‘private variants’ (alleles not occurring as polymorphisms of wide distribution) are more common in Amerindian than in Caucasian or Japanese populations.
Exclusion mapping illustrated by the MNSs blood group
Authors: COOK P. J. L. , NOADES J. E. , LOMAS C. G. , BUCKTON K. E. , ROBSON E. B.
Published: October 2007

An exclusion mapping method is described which attempts to combine in a compact form negative information from deletion studies and studies on families segregating for existing reference markers, centromere markers and familial translocations. A meiotic map is provided for exclusion mapping. Chromosome 22 is used as a worked example of the exclusion mapping of the MNSs blood group. A particular assignment for MNSs to the q28 or q31 region of chromosome 4 is suggested by this method.
The linear programming approach to the Randić index
Authors: Pavlović Ljiljana
Published: October 2007

Let G(k, n) be the set of simple graphs (i.e. without multiple edges or loops) that have n vertices and the minimum degree of vertices is k. The Randić index of a graph G is: , where δu is the degree of vertex u and the summation extends over all edges (uv) of G. Using linear programming, we find the extremal graphs or give good bounds for this index when the number nk of vertices of degree kis n−k+t, for 0tk and kn/2. We also prove that for nkn−k, (kn/2) the minimum value of the Randić index is attained for the graph .
The Role of Human Capital in Technological Entrepreneurship
Authors: Wright Mike , Hmieleski Keith M. , Siegel Donald S. , Ensley Michael D.
Published: October 2007

This special issue addresses the role that the human capital characteristics of individuals and teams play in the complex process of technological entrepreneurship. In this article, we position the special issue on human capital and technology–based entrepreneurship within the literatures concerning academic entrepreneurship, technology transfer and innovation, and corporate spin–offs. We summarize the articles in the special issue and also outline a research agenda at the firm, entrepreneurial team, and individual entrepreneur levels. Finally, we discuss managerial and policy implications.
Private Enterprise Growth and Human Capital Productivity in India
Authors: Majumdar Sumit K.
Published: October 2007

This article examines patterns of growth in private firms and private equity investment and in the decline in state–owned firms and equity capital within the corporate sector in Indian industry over a 25–year period, 1973–1974 to 1997–1998, with some additional analysis extended to 2001–2002, to assess whether a transformation in ownership has taken place, whether the boundaries of the state as a participant in industry have significantly declined and the boundaries of private enterprise enhanced. The data cover the entire industrial population of India. The boundaries of the state as an industrial participant have shrunk significantly as a result of the growth of private entrepreneurship in India, especially in industries where agents are engaged in technological entrepreneurship. The numbers of private companies established in India have grown and the volume of equity capital being invested has risen substantially. Associated with this relative growth of private firms and shrinking of government ownership is a significant increase in human capital productivity across all ownership categories of Indian industry.
Entrepreneurship and Human Capital: Evidence of Patenting Activity from the Academic Sector
Authors: Allen Stuart D. , Link Albert N. , Rosenbaum Dan T.
Published: October 2007

This paper presents empirical evidence of the relationship between faculty entrepreneurial activity—quantified in terms of the propensity of U.S. university faculty to work directly with industry on research activities that lead to patents—and human capital, measured in terms of faculty tenure and age. Patenting reflects a unique dimension of faculty entrepreneurship, namely, collaborative activity that results in joint intellectual property. We find that faculty with tenure are more likely to engage in such activity, thus providing suggestive evidence of an externality associated with permanent employment. We also find that older faculty are more likely to engage with industry, to a point, holding tenure constant. Tenure and age proxy, respectively, what we call the “accumulated advantage” of faculty and their absorptive capacity. Because faculty patenting with industry involved both parties, our findings reflect that such faculty experience and expertise are important to industry to enter into a patenting relationship. Finally, we find that male faculty are more likely to patent with industry than female faculty.
Complementing Capital: The Role of Status, Demographic Features, and Social Capital in Founding Teams’ Abilities to Obtain Resources
Authors: Packalen Kelley A.
Published: October 2007

To investigate the extent to which founders can influence their firms, I formulate a framework that considers the interaction between three main facets of founding teams’ backgrounds, namely, industry status, entrepreneurially relevant demographic features, and social capital. As the propositions and illustrations suggest, the presence of one type of capital may reduce the dependence on or need for others. The model has applicability to a variety of industries with uncertain outcomes resulting from the commercialization of early–stage technology (e.g., biotechnology, nanotechnology, software, or hardware) or subjective quality (e.g., restaurants or movies).
A Generalized Fault Classification for Gas Turbine Diagnostics at Steady States and Transients
Authors: Loboda Igor , Yepifanov Sergiy , Feldshteyn Yakov
Published: October 2007

Gas turbine diagnostic techniques are often based on the recognition methods using the deviations between actual and expected thermodynamic performances. The problem is that the deviations generally depend on current operational conditions. However, our studies show that such a dependency can be low. In this paper, we propose a generalized fault classification that is independent of the operational conditions. To prove this idea, the probabilities of true diagnosis were computed and compared for two cases: the proposed classification and the conventional one based on a fixed operating point. The probabilities were calculated through a stochastic modeling of the diagnostic process. In this process, a thermodynamic model generates deviations that are induced by the faults, and an artificial neural network recognizes these faults. The proposed classification principle has been implemented for both steady state and transient operation of the analyzed gas turbine. The results show that the adoption of the generalized classification hardly affects diagnosis trustworthiness and the classification can be proposed for practical realization.
Supplementary Backward Equations p(h,s) for the Critical and Supercritical Regions (Region 3), and Equations for the Two-Phase Region and Region Boundaries of the IAPWS Industrial Formulation 1997 for the Thermodynamic Properties of Water and Steam
Authors: Kretzschmar H.-J. , Cooper J. R. , Gallagher J. S. , Harvey A. H. , Knobloch K. , Mareš R. , Miyagawa K. , Okita N. , Span R. , Stöcker I. , Wagner W. , Weber I.
Published: October 2007

When steam power cycles are modeled, thermodynamic properties as functions of enthalpy and entropy are required in the critical and supercritical regions (region 3 of IAPWS-IF97). With IAPWS-IF97, these calculations require cumbersome two-dimensional iteration of temperature T and specific volume v from specific enthalpy h and specific entropy s. While these calculations are not frequently required, the computing time can be significant. Therefore, the International Association for the Properties of Water and Steam (IAPWS) adopted backward equations for p(h,s) in region 3. For calculating properties as a function of h and s in the part of the two-phase region that is important for steam-turbine calculations, a backward equation Tsat(h,s) is provided. In order to avoid time-consuming iteration in determining the region for given values of h and s, equations for the region boundaries were developed. The numerical consistency of the equations documented here is sufficient for most applications in heat-cycle, boiler, and steam-turbine calculations.
Integrated in-Flight Fault Detection and Accommodation: A Model-Based Study
Authors: Rausch Randal T. , Goebel Kai F. , Eklund Neil H. , Brunell Brent J.
Published: October 2007

In-flight fault accommodation of safety-critical faults requires rapid detection and remediation. Indeed, for a class of safety-critical faults, detection within a millisecond range is imperative to allow accommodation in time to avert undesired engine behavior. We address these issues with an integrated detection and accommodation scheme. This scheme comprises model-based detection, a bank of binary classifiers, and an accommodation module. The latter biases control signals with pre-defined adjustments to regain operability while staying within established safety limits. The adjustments were developed using evolutionary algorithms to identify optimal biases off-line for multiple faults and points within the flight envelope. These biases are interpolated online for the current flight conditions. High-fidelity simulation results are presented showing accommodation applied to a high-pressure compressor fault on a commercial, high-bypass, twin-spool, turbofan engine throughout the flight envelope.
Acoustical scattering by arrays of cylinders in waveguides
Authors: Cai Liang-Wu , Dacol Dalcio K. , Calvo David C. , Orris Gregory J.
Published: October 2007

Multiple scattering of acoustic waves in a planar horizontal waveguide by finite-length cylinders is considered. Cylinder height equals the waveguide depth, and both are vertically constrained by the pressure-release boundaries. An analytically exact solution is obtained via normal mode expansion method in conjunction with the concept of the T matrix. The problem is decomposed into an infinite number of two-dimensional multiple scattering problems, modulated by waveguide mode shapes. Examples are presented for an isovelocity waveguide in which the medium is uniform and the waveguide depth is constant. It is found that, in numerical computations, including one or two evanescent modes captures the essence of the evanescent modes. Multiple scattering in the waveguide is compared with the corresponding two-dimensional case. It is concluded that, in low frequencies, the wave patterns in the two cases are very similar, with a shift in the frequency. The similarity diminishes when there are multiple propagating modes. Despite the mode mixing, some key features in the scattering as observed in the two-dimensional problem remain observable in the waveguide case.
Age-related changes in sensitivity to native phonotactics in Japanese infants
Authors: Mugitani Ryoko , Fais Laurel , Kajikawa Sachiyo , Werker Janet F. , Amano Shigeaki
Published: October 2007

Japanese infants at the ages of 6, 12, and 18months were tested on their ability to discriminate three nonsense words with different phonotactic status: canonical keetsu, noncanonical but possible keets, and noncanonical and impossible keet. The results showed that 12 and 18months olds discriminate the keets/keetsu pair, but infants in all age groups fail to discriminate the keets/keet pair. Taken together with the findings in our previous study [Kajikawa et al., J. Acoust. Soc. Am. 120(4), 2278–2284 (2006)], these results suggest that Japanese infants develop the perceptual sensitivity for native phonotactics after 6months of age, and that this sensitivity is limited to canonical patterns at this early developmental stage.
Nonlinear phenomena in the vocalizations of North Atlantic right whales (Eubalaena glacialis) and killer whales (Orcinus orca)
Authors: Tyson Reny B. , Nowacek Douglas P. , Miller Patrick J. O.
Published: October 2007

Nonlinear phenomena or nonlinearities in animal vocalizations include features such as subharmonics, deterministic chaos, biphonation, and frequency jumps that until recently were generally ignored in acoustic analyses. Recent documentation of these phenomena in several species suggests that they may play a communicative role, though the exact function is still under investigation. Here, qualitative descriptions and quantitative analyses of nonlinearities in the vocalizations of killer whales (Orcinus orca) and North Atlantic right whales (Eubalaena glacialis) are provided. All four nonlinear features were present in both species, with at least one feature occurring in 92.4% of killer and 65.7% of right whale vocalizations analyzed. Occurrence of biphonation varied the most between species, being present in 89.0% of killer whale vocalizations and only 20.4% of right whale vocalizations. Because deterministic chaos is qualitatively and quantitatively different than random or Gaussian noise, a program (TISEAN©) designed specifically to identify deterministic chaos to confirm the presence of this nonlinearity was used. All segments tested in this software indicate that both species do indeed exhibit deterministic chaos. The results of this study provide confirmation that such features are common in the vocalizations of cetacean species and lay the groundwork for future studies.
Optimal design of resonant piezoelectric buzzer from a perspective of vibration-absorber theory
Authors: Bai Mingsian R. , Chen Rong-Liang , Chuang Chung-Yuan , Yu Cheng-Sheng , Hsieh Huey-Lin
Published: October 2007

In this paper, an optimization technique is presented for the design of piezoelectric buzzers. This design technique aims at finding the optimal configuration of the coupled cavity and diaphragm structure to maximize the sound pressure output. Instead of measuring the material constants of the piezoelectric ceramic and the metal diaphragm, an “added-mass method” is developed to estimate the equivalent electromechanical parameters of the system on which an analogous circuit can be established. The electrical impedance and on-axis sound pressure level of the piezoelectric buzzer can be simulated by solving the loop equations of the electromechanoacoustical analogous circuit. An interesting finding of this research is that the nature of the piezoelectric buzzer bears remarkable resemblance to that in the dynamic vibration absorber theory. Much physical insight can be gained by exploiting this resemblance in search of the optimal configuration. According to the system characteristic equation, a design chart was devised to “lock” the critical frequency at which the system delivers the maximal output. On the basis of the analogous circuit and the vibration absorber theory, an optimal design was found with constrained optimization formalism. Experiments were conducted to justify the optimal design. The results showed that the performance was significantly improved using the optimal design over the original design. Design guidelines for the piezoelectric buzzers are summarized.
Effect of target-masker similarity on across-ear interference in a dichotic cocktail-party listening task
Authors: Brungart Douglas S. , Simpson Brian D.
Published: October 2007

Similarity between the target and masking voices is known to have a strong influence on performance in monaural and binaural selective attention tasks, but little is known about the role it might play in dichotic listening tasks with a target signal and one masking voice in the one ear and a second independent masking voice in the opposite ear. This experiment examined performance in a dichotic listening task with a target talker in one ear and same-talker, same-sex, or different-sex maskers in both the target and the unattended ears. The results indicate that listeners were most susceptible to across-ear interference with a different-sex within-ear masker and least susceptible with a same-talker within-ear masker, suggesting that the amount of across-ear interference cannot be predicted from the difficulty of selectively attending to the within-ear masking voice. The results also show that the amount of across-ear interference consistently increases when the across-ear masking voice is more similar to the target speech than the within-ear masking voice is, but that no corresponding decline in across-ear interference occurs when the across-ear voice is less similar to the target than the within-ear voice. These results are consistent with an “integrated strategy” model of speech perception where the listener chooses a segregation strategy based on the characteristics of the masker present in the target ear and the amount of across-ear interference is determined by the extent to which this strategy can also effectively be used to suppress the masker in the unattended ear.
Tomographic reconstruction of atmospheric turbulence with the use of time-dependent stochastic inversion
Authors: Vecherin Sergey N. , Ostashev Vladimir E. , Ziemann A. , Wilson D. Keith , Arnold K. , Barth M.
Published: October 2007

Acoustic travel-time tomography allows one to reconstruct temperature and wind velocity fields in the atmosphere. In a recently published paper [S. Vecherin et al., J. Acoust. Soc. Am. 119, 2579 (2006)], a time-dependent stochastic inversion (TDSI) was developed for the reconstruction of these fields from travel times of sound propagation between sources and receivers in a tomography array. TDSI accounts for the correlation of temperature and wind velocity fluctuations both in space and time and therefore yields more accurate reconstruction of these fields in comparison with algebraic techniques and regular stochastic inversion. To use TDSI, one needs to estimate spatial-temporal covariance functions of temperature and wind velocity fluctuations. In this paper, these spatial-temporal covariance functions are derived for locally frozen turbulence which is a more general concept than a widely used hypothesis of frozen turbulence. The developed theory is applied to reconstruction of temperature and wind velocity fields in the acoustic tomography experiment carried out by University of Leipzig, Germany. The reconstructed temperature and velocity fields are presented and errors in reconstruction of these fields are studied.
Effect of porosity on effective diagonal stiffness coefficients (cii) and elastic anisotropy of cortical bone at 1MHz: A finite-difference time domain study
Authors: Baron Cécile , Talmant Maryline , Laugier Pascal
Published: October 2007

Finite-difference time domain (FDTD) numerical simulations coupled to real experimental data were used to investigate the propagation of 1MHz pure bulk wave propagation through models of cortical bone microstructures. Bone microstructures were reconstructed from three-dimensional high resolution synchrotron radiation microcomputed tomography (SR-μCT) data sets. Because the bone matrix elastic properties were incompletely documented, several assumptions were made. Four built-in bone matrix models characterized by four different anisotropy ratios but the same Poisson’s ratios were tested. Combining them with the reconstructed microstructures in the FDTD computations, effective stiffness coefficients were derived from simulated bulk-wave velocity measurements. For all the models, all the effective compression and shear bulk wave velocities were found to decrease when porosity increases. However, the trend was weaker in the axial direction compared to the transverse directions, contributing to the increase of the effective anisotropy. On the other hand, it was shown that the initial Poisson’s ratio value may substantially affect the variations of the effective stiffness coefficients. The present study can be used to elaborate sophisticated macroscopic computational bone models incorporating realistic CT-based macroscopic bone structures and effective elastic properties derived from μCT-based FDTD simulations including the cortical porosity effect.
Frequency-dependent changes in absolute hearing threshold caused by perception of a previous sound
Authors: Yoshida Junji , Hasegawa Hiroshi , Kasuga Masao
Published: October 2007

This study investigated effects of a previous sound presentation at the absolute threshold of hearing. Changes in threshold were measured when a pure tone at 60dB SPL preceded a test tone in the contra- or ipsilateral ear. When the previous and test sounds both had the same frequency of 500Hz, threshold decreased approximately 2dB in the contralateral ear, and increased slightly in the ipsilateral ear. On the other hand, when the frequency of the previous sound differed from that of the test sound, the threshold was decreased slightly in the ipsilateral ear.
Low-frequency modulation of distortion product otoacoustic emissions in humans
Authors: Bian Lin , Scherrer Nicole M.
Published: October 2007

Low-frequency modulation of distortion product otoacoustic emissions (DPOAEs) was measured from the human ears. In the frequency domain, increasing the bias tone level resulted in a suppression of the cubic difference tone (CDT) and an increase in the magnitudes of the modulation sidebands. Higher-frequency bias tones were more efficient in producing the suppression and modulation. Quasi-static modulation patterns were derived from measuring the CDT amplitude at the peaks and troughs of bias tones with various amplitudes. The asymmetric bell-shaped pattern resembled the absolute value of the third derivative of a nonlinear cochlear transducer function. Temporal modulation patterns were obtained from inverse FFT of the spectral contents around the DPOAE. The period modulation pattern, averaged over multiple bias tone cycles, showed two CDT peaks each correlated with the zero-crossings of the bias tone. The typical period modulation pattern varied and the two CDT peaks emerged with the reduction in bias tone level. The present study replicated the previous experimental results in gerbils. This noninvasive technique is capable of revealing the static position and dynamic motion of the cochlear partition. Moreover, the results of the present study suggest that this technique could potentially be applied in the differential diagnosis of cochlear pathologies.
Acceptable range of speech level for both young and aged listeners in reverberant and quiet sound fields
Authors: Sato Hayato , Sato Hiroshi , Morimoto Masayuki , Ota Ryo
Published: October 2007

The speech level of verbal information in public spaces should be determined to make it acceptable to as many listeners as possible, while simultaneously maintaining maximum intelligibility and considering the variation in the hearing levels of listeners. In the present study, the universally acceptable range of speech level in reverberant and quiet sound fields for both young listeners with normal hearing and aged listeners with hearing loss due to aging was investigated. Word intelligibility scores and listening difficulty ratings as a function of speech level were obtained by listening tests. The results of the listening tests clarified that (1) the universally acceptable ranges of speech level are from 60 to 70dBA, from 56 to 61dBA, from 52 to 67dBA and from 58 to 63dBA for the test sound fields with the reverberation times of 0.0, 0.5, 1.0 and 2.0s, respectively, and (2) there is a speech level that falls within all of the universally acceptable ranges of speech level obtained in the present study; that speech level is around 60dBA.
PspA and PspC Minimize Immune Adherence and Transfer of Pneumococci from Erythrocytes to Macrophages through Their Effects on Complement Activation
Authors: Li Jie , Glover David T. , Szalai Alexander J. , Hollingshead Susan K. , Briles David E.
Published: October 2007

Pneumococcal surface protein A (PspA) and PspC are important virulence factors. Their absence has been shown to allow improved clearance of pneumococci from the blood of mice and to decrease pneumococcal virulence. In the presence of antibody and complement, pneumococci attach to erythrocytes in a process called immune adherence (IA), which facilitates their delivery to, and eventual phagocytosis by, macrophages. It is not known, however, if PspA and PspC affect IA. Using PspA and/or PspC isogenic mutants and complement-deficient mouse sera, we demonstrated that absence of PspA allows greater deposition of C1q and thus increased classical-pathway-mediated C3 deposition. In the absence of both PspA and PspC, there is also a major increase in C1q-independent C3 deposition through the alternative pathway. The latter was observed even though absence of PspC alone did not have a major effect on alternative-pathway-dependent complement deposition. The enhanced complement C3 deposition realized in the absence of PspA alone and in the absence of PspA and PspC resulted in both greatly increased IA to human erythrocytes and improved transfer of pneumococci from erythrocytes to phagocytes. These data provide new insight into how PspA and PspC act in synergy to protect pneumococci from complement-dependent clearance during invasive infection.