bluuebunny/crossref_metadata_2025 huggingface dataset:
Microsimulating the Evolution of Italian Pension Benefits: the Role of Retirement Choices and Lowest Pensions Indexing
Authors: Bianchi Carlo , Romanelli Marzia , Vagliasindi Pietro A.
Published: August 2003

A few years after the introduction of the Amato and Dini laws, a renewed debate on reforming the Italian pension system and on modifying its structure and technical parameters is taking place. The present work simulates individual reactions to systemic changes, distinguishing among the different typologies of workers the categories of dependent (private and public) and self‐employed ones. This approach allows us to perform a general micro‐analysis of the effects of past reforms on family pension income distribution and average individual pension benefits. Furthermore, it makes it possible to assess the consequences of legislator's choices such as the indexation of the lowest pensions (‘assegni sociali’ and ‘pensioni integrate al minimo’) to wages or to inflation. Finally, a Monte Carlo analysis projects future inequality and poverty trends with a remarkable accuracy and allows to verify the robustness of our results.
Early Retirement in Italy: Recent Trends
Authors: Inglese Luca
Published: August 2003

Abstract.  The analysis presented provides new statistical information on pensioners receiving seniority retirement benefits and highlights the positive effects of specific factors on their pension income.

The statistical estimates suggest that work incentives are weak and steady job exits before the normal retirement age continue, especially for civil servants.

In particular, since seniority benefits are based on a long contribution history, their corresponding level of pension income is high. This is not true for pensioners receiving old age benefits because of their incomplete work history.
Demographic Trends and Pension System in Italy: an Assessment of 1990s Reforms
Authors: Baldacci Emanuele , Tuzi Donatella
Published: August 2003

Abstract.  In the last decade the Italian pension system underwent many changes. The process has started in 1992 with three major reform laws (passed in 1992, 1995 and 1997), supplemented by many other minor changes. Among the innovations introduced in the pay‐as‐you‐go social security system, the most important one is the more explicit link between pensions and contributions, and pensions and life expectancy at retirement. The purpose of this paper is to provide an assessment of both the short‐term and the long‐term effects of the social security reforms on pension expenditure. Notwithstanding the slowdown in the growth rate of the pension expenditure/GDP ratio, the measures adopted so far will not be sufficient to eliminate the existing social security deficit in the next decades, particularly under the assumption of moderate economic performance and rapid population ageing. Reducing public pension expenditure requires the completion of the 1995 reform, a more rapid move towards a multi‐pillar pension scheme, and the implementation of the much needed growth‐enhancing structural reforms.
Social Insurance with Risk‐Reducing Investments
Authors: Anderberg Dan , Andersson Fredrik
Published: August 2003

A two‐sector model with sector‐dependent disability risks is presented. Working in the low‐risk sector requires skills that can be obtained by investments in education. Moral hazard precludes full insurance. The labour force allocation is responsive to the incentives created by a social insurance system. The rationale for intervention lies in the government's power to cross‐subsidize between the sectors, and it is demonstrated how the responsiveness of the labour force allocation limits cross‐subsidization. The second‐best policy is time‐inconsistent. The consistent equilibrium is explored and is argued to provide weak incentives to reduce risks.
Relative Price Variability and Inflation in Europe
Authors: Fielding David , Mizen Paul
Published: August 2003

The relationship between inflation and the relative variability of prices has been the subject of careful investigation in the United States using data for product groups at the city level. Yet in Europe, where the relationship could have profound effects on the viability of monetary integration, no attempt has been made to study the relationship. This paper fills the gap by examining data disaggregated to the commodity level across 10 EU countries. Evidence is found for logistic smooth transitions in the relative price variability measures within countries and within product groups. When this deterministic component isremoved, the stochastic element is not persistent and does not always have the positive relationship with inflation commonly found in US city data.
Exporting as a Signal for Product Quality
Authors: Shy Oz
Published: August 2003

I develop a dynamic asymmetric information model where a domestic producer is unable to commit to producing a high‐quality product. The domestic producer then can signal to consumers that it is producing a high‐quality product by developing the infrastructure needed to start exporting the product. This signalling may take place even if selling internationally is less profitable than selling high quality only at home in the absence of credibility problems. Thus, this paper provides another explanation for the decision to start exporting. I then analyse how and which kind of export subsidies alter a firm's incentive to sell a high‐quality product in different markets.
Union Wage Setting and Exchange Rate Policy
Authors: Lawler Philip
Published: August 2003

The performance of an optimally managed float is compared with that of a credibly fixed exchange rate in a small open‐economy framework where wages are set by a monopoly union. Two key results emerge. First, a sufficient condition for the managed float to outperform a fixed rate is that the union be no less inflation‐averse than society. Second, introducing an inflation target into the central bank's loss function ensures the superiority of the managed float regardless of the weight attached to inflation by the union. Both results reflect the sensitivity of the union mark‐up to the policy regime.
Road Accidents and Traffic Flows: An Econometric Investigation
Authors: Dickerson Andrew , Peirson John , Vickerman Roger
Published: August 2003

This paper develops an empirical model of the relationship between road traffic accidents and traffic flows. The analysis focuses on the accident externality, which is determined mainly by the difference between the marginal and average risks. The model is estimated using a new data‐set which combines hourly London traffic count data from automated vehicle recorders together with police records of road accidents. The accident‐flow relationship is seen to vary considerably between different road classes and geographical areas. More importantly, even having controlled for these and other differences, the accident externality is shown to vary significantly with traffic flows. In particular, while the accident externality is typically close to zero for low to moderate traffic flows, it increases substantially at high traffic flows.
Does Crime Affect Employment Status? The Case of Indigenous Australians
Authors: Borland Jeff , Hunter Boyd
Published: August 2003

A significant cost for individuals who have contact with the criminal justice system is the potential effect on employment status. In this study the effect of arrest on the employment status of indigenous Australians is examined using data from the 1994 National Aboriginal and Torres Strait Islander Survey. Having been arrested is found to reduce the probability of employment. The size of the effect is estimated to be between 10 % and 20 % for males, between 7 % and 17 % for females. The effect also varies according to the reason for a person's most recent arrest. Differences in arrest rates between indigenous and non‐indigenous Australians may explain about 15 % of the difference in employment–population rates between thosegroups.
Short‐term harvest planning including scheduling of harvest crews
Authors: Karlsson J. , Rönnqvist M. , Bergström J.
Published: August 2003

The problem we consider is short‐term harvesting planning for a total planning period of 4–6 weeks where we want to decide the harvest sequences or schedules for harvest crews. A schedule is an order or sequence of harvest areas assigned to each crew. The harvesting of areas is planned in order to meet industrial demand. The total cost includes harvesting, transportation, and storage. One considerable cost is due to the quality reduction of logs stored at harvest areas. There are a number of restrictions to be considered. Areas are of varying size and the composition of assortments in each area is different. Each harvest team has different skills, a different home base, and different production capacity. Another aspect is the road network. There is a cost related to road opening (restoring, snow removal). In this paper, we develop a mixed integer programming (MIP) model for the problem. The schedules are represented by 0/1 variables. With a limited number of schedules, the problem can be solved by a commercial MIP solver. We have also developed a heuristic solution approach that provides high‐quality integer solutions within a distinct time limit to be used when more schedules are used. Computational results from a major Swedish forest company are presented.
A solution approach for log truck scheduling based on composite pricing and branch and bound
Authors: Palmgren Myrna , Rönnqvist Mikael , Värbrand Peter
Published: August 2003

The logging truck scheduling problem is one of the most complex routing problems where both pick‐up and delivery operations are included. It consists in finding one feasible route for each vehicle in order to satisfy the demands of the customers and in such a way that the total transport cost is minimized. We use a mathematical formulation of the log truck scheduling problem where each column represents a feasible route. We generate a large pool of columns based on solving a transportation problem. Then we apply a composite pricing algorithm, which mainly consists of pricing the pool of columns and maintain an active set of these, for solving the LP relaxed model. A branch and price approach is used to obtain integer solutions in which we apply composite pricing to generate new columns. Numerical results from case studies at Swedish forestry companies are presented.
A role for stakeholder objectives in USDA Forest Service plan revisions: A case study on the White River National Forest
Authors: Kent B. , Kaval P. , Berry J. , Retzlaff M. , Hormaechea D. , Shields D.
Published: August 2003

In August 1999, The White River National Forest, headquartered in Glenwood Springs, Colorado, USA, released a draft revised forest plan, engendering almost immediate and widespread controversy. This paper describes steps taken prior to release of the final plan to reduce the controversy by linking stakeholder objectives to plan alternatives. Information from three surveys and public comments was analyzed to characterize stakeholder objectives. A series of public meetings was conducted to validate the objectives and provide information needed to develop an objectives hierarchy, which was used to characterize means objectives that were linked to alternative plans, using associated attributes. A key finding was that stakeholders align their objectives for forest management with one of two schools of thought; one having an ecosystem conservation orientation and the other, a human use/economic sustainability orientation. The final plan, released in June 2002 received a greater level of positive reaction in the media and elsewhere.
The Euler–Lagrange Cohomology and General Volume-Preserving Systems
Authors: Zhou Bin , Guo Han-Ying , Pan Jianzhong , Wu Ke
Published: August 2003

We briefly introduce the concept of Euler–Lagrange cohomology groups on a symplectic manifold (ℳ2n, ω) and systematically present the general form of volume-preserving equations on the manifold from the cohomological point of view. It is shown that for every volume-preserving flow generated by these equations there is an important two-form that plays the analog role with the Hamiltonian in the Hamilton mechanics. In addition, the ordinary canonical equations with Hamiltonian H are included as a special case with the two-form [Formula: see text]. The other volume preserving systems on (ℳ2n, ω) are studied. The relations between our approach and Feng–Shang's volume-preserving systems as well as the Nambu mechanics are also explored.
The Task of Problem Formulation
Authors: Eierman Michael A. , Philip George C.
Published: August 2003

Problem formulation is an important organizational task because it facilitates effective problem solving. However, it is not well understood. Past studies have examined problem formulation by examining the behavior of individuals performing problem formulation tasks. This approach has proven difficult due to differences in individual knowledge of the task domain. This study examines problem formulation by focusing on the characteristics of the task rather than on an individual performing the task. A rational model of the task of problem formulation is developed and examined for its implications on individual problem formulation behavior. An empirical investigation of individual's performing problem formulation shows limited support for the proposed model.
Strategic Response of an Incumbent Firm in IT Intensive Industry: Few Reflections
Authors: Gupta Omprakash K. , Mallikarjun M. , Cho Namjae , Jaisingh Jeevan
Published: August 2003

In this paper, an attempt has been made to look at the strategic options available for an incumbent firm in an information technology intensive industry. The traditional Stackleberg Leader Follower model fails to hold in this industry since costs decline substantially over time, and the incumbent firm cannot maintain a dominant position in the industry. This paper makes an attempt to look at few strategic options available for an incumbent firm under these circumstances.
Relationship Between Offer Strategy and Trade Ratio for k-ZI Traders in Continuous Double Auction Market
Authors: Zhan Wenjie , Wang Shouyang , Lai K. K.
Published: August 2003

Our previous experiments in a continuous double auction market with k-ZI traders have produced interesting results: (1) the number of transactions increases when parameter "k" increases and (2) different values of "k" reflect differently offer strategies for k-ZI traders. In this paper, we prove theoretically and experimentally a relationship between the trade ratio and the offer strategy for k-ZI traders in a continuous double auction market. An important implication of the relationship is that a trader's offer strategy is able to influence the performance of a continuous double auction market, such as the number of transactions. Consequently, the trader's offer strategy is an important parameter to help us to analyze the "Smith's mystery" by controlled experiments.
Decision Analysis of Statistically Detecting Distributed Denial-of-Service Flooding Attacks
Authors: Li Ming , Chi Chi-Hung , Jia Weijia , Zhao Wei , Zhou Wanlei , Cao Jiannong , Long Dongyang , Meng Qiang
Published: August 2003

There are two statistical decision making questions regarding statistically detecting sings of denial-of-service flooding attacks. One is how to represent the distributions of detection probability, false alarm probability and miss probability. The other is how to quantitatively express a decision region within which one may make a decision that has high detection probability, low false alarm probability and low miss probability. This paper gives the answers to the above questions. In addition, a case study is demonstrated.
Predicting Job Performance with a Fuzzy Rule-Based System
Authors: Craiger J. Philip , Coovert Michael D. , Teachout Mark S.
Published: August 2003

Classification problems affect all organizations. Important decisions affecting an organization's effectiveness include predicting the success of job applicants and the matching and assignment of individuals from a pool of applicants to available positions. In these situations, linear mathematical models are employed to optimize the allocation of an organization's human resources.

Use of linear techniques may be problematic, however, when relationships between predictor and criterion are nonlinear. As an alternative, we developed a fuzzy associative memory (FAM: a rule-based system based on fuzzy sets and logic) and used it to derive predictive (classification) equations composed of measures of job experience and job performance. The data consisted of two job experience factors used to predict measures of job performance for four US Air Force job families. The results indicated a nonlinear relationship between experience and performance for three of the four data sets. The overall classification accuracy was similar for the two systems, although the FAM provided better classification for two of the jobs. We discuss the apparent nonlinear relationships between experience and performance, and the advantages and implications of using these systems to develop and describe behavioral models.
Multiple Trait Selection and Classification of Genotype — A Data Mining Approach
Authors: Lin Chien-Hsiung , Liu Yi-Hsin
Published: August 2003

A set of data represented by a set of real numbers can be handled by the computer much easier than non-real valued data. This paper develops bicriteria linear program solution through a fuzzy mathematical programming approach which assigns a real number to each member of the data. This method integrates data information and the decision maker's objective opinion to construct a tool (function) of selection and classification.
Computing the Entropy of User Navigation in the Web
Authors: Levene Mark , Loizou George
Published: August 2003

Navigation through the web, colloquially known as "surfing", is one of the main activities of users during web interaction. When users follow a navigation trail they often tend to get disoriented in terms of the goals of their original query and thus the discovery of typical user trails could be useful in providing navigation assistance. Herein, we give a theoretical underpinning of user navigation in terms of the entropy of an underlying Markov chain modelling the web topology. We present a novel method for online incremental computation of the entropy and a large deviation result regarding the length of a trail to realize the said entropy. We provide an error analysis for our estimation of the entropy in terms of the divergence between the empirical and actual probabilities. We then indicate applications of our algorithm in the area of web data mining. Finally, we present an extension of our technique to higher-order Markov chains by a suitable reduction of a higher-order Markov chain model to a first-order one.
Acceptance of Internet Content Filters: An Empirical Study
Authors: Ho Susanna S. Y. , Lui S. M. , Ma Will W. K.
Published: August 2003

Content filters empower users to make choices about what can be downloaded from the World Wide Web. At home, parents can restrict what their children can and cannot see on the Internet. This can protect the young web surfers from unpleasant experiences. These tools allow the parents to understand electronic content by means of open and objective content labels. Web surfers may be unwittingly exposed to suggestive and explicit content. Many organizations across the globe, such as ICRA and GBDe, are working on content rating systems and software filters for the Internet. Generally, simple filters are bundled with common browsers. People are not motivated to buy commercial filters with more functionality. Also, there are few studies investigating a consumer's willingness and intention to adopt these tools. This paper presents an exploratory study of the acceptance of Internet content filters in publicly accessed computers. The relationship between demographic factors, such as gender and age, and perception factors, such as severity of Internet problems, are examined. Results show that the acceptance of blocking filters is significantly related to demographic factors and perceptions of the Internet. We discuss implications of the findings, from both the academic and applied perceptive.
A Multi-Agent Architecture for Electronic Payment
Authors: Guan Sheng-Uei , Hua Feng
Published: August 2003

The Internet has brought about innumerable changes to the way enterprises do business. An essential problem to be solved before the widespread commercial use of the Internet is to provide a trustworthy solution for electronic payment. We propose a multi-agent mediated electronic payment architecture in this paper. It is aimed at providing an agent-based approach to accommodate multiple e-payment schemes. Through a layered design of the payment structure and a well-defined uniform payment interface, the architecture shows good scalability. When a new e-payment scheme or implementation is available, it can be plugged into the framework easily. In addition, we construct a framework allowing multiple agents to work cooperatively to realize automation of electronic payment. A prototype has been built to illustrate the functionality of this design. Finally, we discuss the security issues.
Binding Machines
Authors: Branco António
Published: August 2003

Binding constraints form one of the most robust modules of grammatical knowledge. Despite their crosslinguistic generality and practical relevance for anaphor resolution, they have resisted full integration into grammar processing. The ultimate reason for this is to be found in the original exhaustive coindexation rationale for their specification and verification. As an alternative, we propose an approach which, while permitting a unification-based specification of binding constraints, allows for a verification methodology that helps to overcome previous drawbacks. This alternative approach is based on the rationale that anaphoric nominals can be viewed as binding machines.
Generating Referring Expressions: Boolean Extensions of the Incremental Algorithm
Authors: Deemter Kees van
Published: August 2003

This paper brings a logical perspective to the generation of referring expressions, addressing the incompleteness of existing algorithms in this area. After studying references to individual objects, we discuss references to sets, including Boolean descriptions that make use of negated and disjoined properties. To guarantee that a distinguishing description is generated whenever such descriptions exist, the paper proposes generalizations and extensions of the Incremental Algorithm of Dale and Reiter (1995).
The DOP Estimation Method Is Biased and Inconsistent
Authors: Johnson Mark
Published: August 2003

A data-oriented parsing or DOP model for statistical parsing associates fragments of linguistic representations with numerical weights, where these weights are estimated by normalizing the empirical frequency of each fragment in a training corpus (see Bod [1998] and references cited therein). This note observes that this estimation method is biased and inconsistent that is, the estimated distribution does not in general converge on the true distribution as the size of the training corpus increases.
The Influence of the Class Situations of Husbands and Wives on Class Identity, Party Preference and Attitudes Towards Redistribution: Sweden, Germany and the United States
Authors: Edlund Jonas
Published: August 2003

The influences of female employment on working couples' class-based identities, preferences towards government redistribution, and choice of political party in Sweden, Germany, and the US are analysed in this article. Two issues are of interest. The first is the unit of class composition: families (conventional approach) versus individuals (individual approach). The results indicate that the conventional approach explains more of the variation in the dependent variables than does the individual approach. However, in many cases the inclusion of female employment within the class schema increases the explanatory power of social class significantly. The second issue is cross-country variation. Based on assumptions about the post-industrial economy, a hypothesis concerning cross-country variation in class-gender patterns is tested. In contrast to the hypothesis, the data show that female employment influences are greatest in Germany, closely followed by Sweden. In the US, influences of female employment on working couples' socio-political orientations are negligible.
The Political Dynamics of a Segmented Labour Market
Authors: Rosenhek Zeev
Published: August 2003

This is a study of the dynamics of the segmented labour market in Israel over the past five decades dynamics characterized by the successive incorporation into the secondary labour market of different subordinate populations with distinct political status and under varying political and economic circumstances: Palestinian citizens of Israel during the first two decades of statehood, Palestinian non-citizens under occupation after the 1967 war, and migrant workers over the past decade. The analysis focuses on the main actors involved in the production and reproduction of the segmented labour market, their specific political and economic interests, and the changing institutional mechanisms employed by the state to constitute these populations as cheap and unprotected labour. The analysis shows that beyond the state's and employers' interests directly related to the functioning of the labour market, the varying conditions in the national conflict between Israel and the Palestinians and the changing strategies employed by the Israeli state to manage this conflict have fundamentally affected the dynamics of the segmented labour market. The study sheds light on the complex interplay between political and economic forces in the constitution of subordinate populations as cheap and unprotected labour, showing that fluid political settings related to state-building processes and the state's autonomous interests deriving from these processes, as well as the distinct political status of different subordinate populations, are factors as important as the employers' demand for cheap labour.
Sandwich Construction with Carbon Foam Core Materials
Authors: Sihn Sangwook , Rice Brian P.
Published: August 2003

To study suitability of the emerging ultralightweight carbon foams in load-carrying structures, the state-of-the-art carbon foams from various manufacturers were evaluated as core material in a sandwich construction. The carbon foams were firstly characterized by measuring compressive and shear mechanical properties. The carbon foam possessed highly anisotropic properties between in-plane and through-the-thickness directions. The foams aged at 316°C (600°F) for 100 h in air lost 0.6% of their weight and showed little degradation in the properties within the scatter range of test data. The carbon foams tested at an elevated temperature of 316°C (600°F) showed no degradation in the compressive modulus and strength as compared to the properties measured at a room temperature of 21°C (70°F). Sandwich beams with laminated composite facesheets were fabricated with a carbon foam core and tested under static and fatigue four-point bending loads. The beams under the static loadings showed nearly linear elastic behavior until the maximum failure loads, and then postfailed either in yielding or in brittle mode following the postfailure behavior of the carbon foam core. The failure occurred in the core material in a shear mode. Sandwich beams with carbon foam cores survived after a few hundred or even a few hundred thousands of cyclic loads. Both the moduli and strength of the beams remained nearly unchanged after the fatigue loads. Central displacement and strain measurements at the gauge locations matched well with the analytical solution from a sandwich-beam theory. The shear moduli and strength of the carbon foams calculated from the four-point bending tests were in good agreement with those from torsional tests. The sandwich beam test technique is useful for the determination of the foam shear properties, especially for uncoupled shear properties of only one plane.

The sandwich beams with the carbon foam cores tiled together in the middle of the beam exhibited nearly identical load-displacement behavior as well as the shear failure mode to those of the beam made with an intact core. From the modulus point of view, the hole-drilling with the high-density foams is a better way of achieving the weight reduction in the sandwich construction than using the low-density foams. If the materials were removed in the noncritically loaded area (e.g., central section of the beams under the four-point bending), the weight reduction can be achieved without sacrificing much strength property of the core materials as well.
Failure Strength of Woven Glass Fiber-Epoxy Composites Pinned Joints
Authors: Içten Bulent Murat , Okutan Buket , Karakuzu Ramazan
Published: August 2003

In this paper, mechanical behavior and damage development of pin-loaded woven glass fiber-epoxy composites have been observed numerically and experimentally. Parametric studies have been performed to evaluate the effects of joint geometry and ply orientation on the failure strength and failure mode of composite laminates with a pin-loaded hole. For this purpose, a finite element program has been developed. The failure analysis was based on Hashin and Hoffman criteria that were applied at the ply level. The results (with Hashin and Hoffman criteria) were compared to each other. To verify to the numerical predictions of mechanical behavior, a series of experiments was performed with two different material configurations ([(0/90)3]S [(45)3]S) and twenty different geometries. The numerical and experimental results were compared and discussed. A good agreement between experimental results and numerical predictions was obtained.
An Inverse Method Allowing User-Specified Layouts of Magnetized Microfibers in Solidifying Composites
Authors: Dulikravich George S. , ColaçO Marcelo J. , Martin Thomas J. , Lee Seungsoo
Published: August 2003

A new concept for controlled manufacturing of specialty composite materials has been developed. It is based on the concept of aligning magnetizable microfibers tangent to magnetic field lines of force. This paper offers a method that allows users to specify desired patterns of the magnetic lines of force that can be achieved by an appropriate positioning of magnets of various strengths along the boundaries of the composites' curing container. An improved analytical model and a numerical algorithm have been developed for the prediction of the magnetic force lines inside a flowing and solidifying melt. This analysis code was combined with a hybrid constrained optimization algorithm that minimizes a normalized sum of least square differences between the user-specified and the predicted patterns of the magnetic lines of force. This software package was used to inversely evaluate the strengths, locations, and orientations of magnets needed to generate the user-specified patterns of the magnetic lines of force in the solidifying composite thus verifying the conceptual feasibility of this novel manufacturing process.
Finite Element Based Energy Dissipation Studies of Al-SiC Composites
Authors: Srikanth Narasimalu , TUN Khine Khine , Gupta Manoj
Published: August 2003

In the present study, the damping capacity of Al-SiC composite formulations is predicted using a visco-plasticity based micro-mechanical modelling approach. The model is based on finite element analysis of an axisymmetric unit cell, which mimics a pure Al cylinder with a spherical SiC reinforcing particulate placed at the centre. The energy dissipated by the composite is numerically predicted using the unit cell by applying a harmonic load, taking into account the viscous behavior of the processing induced residual plastic strain at the matrix-reinforcement interface of the composite. The model shows that the plastic zone size increases with volume fraction of SiC added resulting in a proportional increase in damping capacity of the composite. The model was validated by comparing the numerical results against an impact based suspended beam experiment conducted at low strain amplitude on Al-SiC samples with different volume fraction of SiC particulates. In addition, an attempt has been made to study the effect of particulates' stress concentration features as well as process-induced defects on the overall damping capacity of the composite.
Numerical Simulation of Mixed-Mode Progressive Delamination in Composite Materials
Authors: Camanho P. P. , Davila C. G. , de Moura M. F.
Published: August 2003

A new decohesion element with the capability of dealing with crack propagation under mixed-mode loading is proposed and demonstrated. The element is used at the interface between solid finite elements to model the initiation and non-self-similar growth of delaminations in composite materials. A single relative displacement-based damage parameter is applied in a softening law to track the damage state of the interface and to prevent the restoration of the cohesive state during unloading. The softening law is applied in the three-parameter Benzeggagh-Kenane mode interaction criterion to predict mixed-mode delamination propagation. To demonstrate the accuracy of the predictions, steady-state delamination growth is simulated for quasi-static loading of various single mode and mixed-mode delamination test specimens and the results are compared with experimental data.
Reliability and Validity of Motivation for Sexual Health
Authors: Abel Elizabeth , Tak Sung Hee , Gortner Eva-Maria
Published: August 2003

The Health Self-Determinism Index-Sexual (HSDI-S) is a modification of the HSDI (a measure of motivation of health). Psychometric evaluation was needed to determine the usefulness of the HSDI-S as a measure of motivation of sexual health. The purpose of this study was to assess the reliability and validity of the HSDI-S. Three unique samples of HSDI-S scores were evaluated using principal component and maximum likelihood factor analyses with a Varimax rotation. Items that loaded on each of the factors were similar across all three samples. Factor analyses revealed two dimensions of the HSDI-S: self-directed and partner-directed motivation, which is discussed within the context of relationships. The ranges of internal consistency reliability coefficients across the samples were satisfactory for the HSDI-S (.74-.82) and for the two dimensions (.66-.77). Reliability and construct validity of the HSDI-S across three diverse samples was supported.
The Revised Personal Lifestyle Questionnaire for Early Adolescents
Authors: Mahon Noreen E. , Yarcheski Thomas J. , Yarcheski Adela
Published: August 2003

The purposes of this study were to revise the Personal Lifestyle Questionnaire (PLQ), a measure of positive health practices, for use with early adolescents and to provide evidence of reliability and validity for the revised PLQ instrument. The sample consisted of 224 seventh and eighth graders who responded to the revised PLQ and instruments measuring three theoretically relevant variables. Relative to the revised PLQ, content validity was established, construct validity was determined by support of three hypotheses derived from theoretical propositions, and a two factor solution was accepted in factor analysis procedures using principal components analysis with Varimax rotation. Acceptable reliabilities were obtained on the total revised PLQ and Factor 1; the reliability for Factor 2 fell slightly below the acceptable standard.
Validation of the Clinical Learning Environment Inventory
Authors: Chan Dominic S. K.
Published: August 2003

One hundred eight preregistration nursing students took part in this survey study, which assessed their perceptions of the clinical learning environment. Statistical data based on the sample confirmed the reliability and validity of the Clinical Learning Environment Inventory (CLEI), which was developed using the concept of classroom learning environment studies. The study also found that there were significant differences between students’actual and preferred perceptions of the clinical learning environments. In terms of the CLEI scales, students preferred a more positive and favorable clinical environment than they perceived as being actually present. The achievement of certain outcomes of clinical field placements might be enhanced by attempting to change the actual clinical environment in ways that make it more congruent with that preferred by the students.
Are Phenomenology and Postpositivism Strange Bedfellows?
Authors: Racher Frances E. , Robinson Steven
Published: August 2003

Researchers are advocating that a necessary condition of scholarly research is congruence between philosophical positions and research approaches. Phenomenology and postpositivism, traditionally, may appear to be situated in scientific inquiry as polar opposites and mutually exclusive paradigms. This article (a) describes the reflections of a nurse researcher and clarifies her philosophical assumptions; (b) delineates the postpositive paradigm and the interpretive paradigm, which traditionally includes phenomenology; (c) discusses phenomenology as a philosophy, an approach, and a research method; and (d) demonstrates the consistency between postpositivism and phenomenology. Nurse researchers must be aware of their philosophical assumptions and appraise the philosophical underpinnings of the methodologies, but this process should not restrict and limit their exploration of possibilities and the creativity in their efforts to address the growing challenges that await nursing science research.
Translation and Validation of a French Version of Brown’s Support Behaviors Inventory in Perinatal Health
Authors: Goulet Céline , Polomeno Viola , Laizner Andréa Maria , Marcil Isabelle , Lang Ariella
Published: August 2003

This article describes the process used for translation, testing for reliability and validity, and establishing factor structure of a French version of Brown’s Support Behaviors Inventory (SBI-Fr). The objective was to provide an adequate self-report measure of satisfaction with social support during the perinatal period for use with a Francophone population in Québec, Canada. When compared with the English version, the French version had similar qualities regarding reliability and validity, but principal component analysis (N = 271) revealed that the SBI-Fr measures two distinct subscales, perceived satisfaction with partner’s and others’support. The availability of the SBI-Fr will facilitate the inclusion of Francophone respondents in studies of satisfaction with social support during the perinatal period and permit cross-cultural comparison between Francophone and other populations in not only Canada but also other Frenchspeaking countries.
Using Multilevel Random Coefficient Modeling to Analyze Social Interaction Diary Data
Authors: Nezlek John B.
Published: August 2003

This article provides a rationale for using multilevel random coefficient modeling (MRCM) to analyze social interaction diary data, and describes how to conduct such analyses. This description includes how to examine relationships between individual differences in social interaction and other trait-level individual differences such as personality scales. Analyzing relationships among different ratings of interactions and analyzing differences among types of interactions are also described, including techniques to examine how relationships between trait-level individual differences and reactions to interaction vary across different types of interactions (e.g., interactions with different relational partners). Different types of analyses are illustrated using data from actual studies. Although this article focuses on the analysis of data collected using variants of the Rochester Interaction Record, the techniques described can be used to analyze data collected using other methods and protocols.
Accommodation Predictors of Grandparent–Grandchild Relational Solidarity in Taiwan
Authors: Lin Mei-Chen , Harwood Jake
Published: August 2003

Grounded in communication accommodation theory, this research examined Taiwanese grandchildren’s ( N= 100) and grandparents’ ( N= 108) perceptions of communication behavior in grandparent–grandchild (GP–GC) interactions. This study investigated noncommunicative and communicative predictors of communication satisfaction, liking, and emotional closeness in the relationship. Regression analyses showed that communication accommodation behaviors accounted for significant variance in GP–GC relational solidarity. For grandchildren and grandparents, the best single predictor was their perception of their own accommodative involvement with their grandparents/grandchildren. The findings also indicated that contact frequency significantly predicted GP–GC relational solidarity. Demographic variables were not particularly effective predictors. The findings are discussed in terms of cultural differences in GP–GC relationships and communication accommodation theory.
Three-Dimensional Imaging for a Very Large Excavator
Authors: Roberts Jonathan , Winstanley Graeme , Corke Peter
Published: August 2003

In this paper we describe the development of a three-dimensional (3D) imaging system for a 3500 tonne mining machine (dragline).Draglines are large walking cranes used for removing the dirt that covers a coal seam. Our group has been developing a dragline swing automation system since 1994. The system so far has been `blind' to its external environment. The work presented in this paper attempts to give the dragline an ability to sense its surroundings. A 3D digital terrain map (DTM) is created from data obtained from a two-dimensional laser scanner while the dragline swings. Experimental data from an operational dragline are presented.
Quantitative Safety Guarantees for Physical Human-Robot Interaction
Authors: Heinzmann Jochen , Zelinsky Alexander
Published: August 2003

If robots are to be introduced into the human world as assistants to aid a person in the completion of a manual task two key problems of today's robots must be solved. The human-robot interface must be intuitive to use and the safety of the user with respect to injuries inflicted by collisions with the robot must be guaranteed. In this paper we describe the formulation and implementation of a control strategy for robot manipulators which provides quantitative safety guarantees for the user of assistant-type robots. We propose a control scheme for robot manipulators that restricts the torque commands of a position control algorithm to values that comply to preset safety restrictions. These safety restrictions limit the potential impact force of the robot in the case of a collision with a person. Such accidental collisions may occur with any part of the robot and therefore the impact force not only of the robot's hand but of all surfaces is controlled by the scheme. The integration of a visual control interface and the safely con trolled robot allows the safe and intuitive interaction between a per son and the robot. As an example application, the system is pro grammed to retrieve eye-gaze-selected objects from a table and to hand them over to the user on demand.
The ANSER Project: Data Fusion Across Multiple Uninhabited Air Vehicles
Authors: Sukkarieh Salah , Nettleton Eric , Kim Jong-Hyuk , Ridley Matthew , Goktogan Ali , Durrant-Whyte Hugh
Published: August 2003

The objective of the autonomous navigation and sensing experiment research (ANSER) project is to demonstrate decentralized data fusion (DDF) and simultaneous localization and map building (SLAM) across multiple uninhabited air vehicles (UAVs). To achieve this objective, the project specifies the development of four UAVs, where each UAV houses up to two terrain sensors and an INS/GPS navigation system. The terrain sensors include a scanning radar, laser/vision and standard vision system. The DDF concept has to be shown to be effective both on a single UAV and on multiple UAVs. The proof of the concept will lie in the ability of the DDF structure to conduct multi-target tracking problems as well as SLAM. To obtain this goal, a number of subgoals are required, most of which have never been attempted before on a research level. The objective of this paper is to present these goals as an overview of the ANSER project along with some simulated and real-time results.
Constrained Initialization of the Simultaneous Localization and Mapping Algorithm
Authors: Williams Stefan B. , Durrant-Whyte Hugh , Dissanayake Gamini
Published: August 2003

In this paper we present a novel feature initialization technique for the Simultaneous Localization and Mapping (SLAM) algorithm. The initialization scheme extends previous approaches for identifying new confirmed features and is shown to improve the steady-state performance of the filter by incorporating tentative features into the filter as soon as they are observed. Constraints are then applied between multiple feature estimates when a feature is confirmed. Observations that are subsequently deemed as spurious are removed from the state vector after an appropriate timeout. It is shown that information that would otherwise be lost can therefore be used consistently in the filter. Results of this algorithm applied to data collected using a submersible vehicle are also shown.
Reactive Nonholonomic Trajectory Generation via Parametric Optimal Control
Authors: Kelly Alonzo , Nagy Bryan
Published: August 2003

There are many situations for which a feasible nonholonomic motion plan must be generated immediately based on real-time perceptual information. Parametric trajectory representations limit computation because they reduce the search space for solutions (at the cost of potentially introducing suboptimality). The use of any parametric trajectory model converts the optimal control formulation into an equivalent nonlinear programming problem. In this paper, curvature polynomials of arbitrary order are used as the assumed form of solution. Polynomials sacrifice little in terms of spanning the set of feasible controls while permitting an expression of the general solution to the system dynamics in terms of decoupled quadratures. These quadratures are then readily linearized to express the necessary conditions for optimality. Resulting trajectories are convenient to manipulate and execute in vehicle controllers and they can be computed with a straightforward numerical procedure in real time.
WorkPartner: Interactive Human-Like Service Robot for Outdoor Applications
Authors: Halme Aarne , Leppänen Ilkka , Suomela Jussi , Ylönen Sami , Kettunen Ilkka
Published: August 2003

WorkPartner is the prototype of a lightweight human-like mobile service robot designed to work interactively with humans in an outdoor environment. The tasks are similar to those a human can do and the robot may replace or work together with him/her. Mobility is based on a hybrid system, which combines the benefits of both legs and wheels to provide good terrain negotiating capability and large velocity range on variable ground. The robot is powered by a hybrid power system with electrical actuating and energy storage in the form of gasoline. The robot is equipped with a human-like two-hand manipulator. The long-term goal is to develop an adaptive and learning robot, which can carry different tools and work interactively with humans. The user or operator can be physically present on the same site as the robot and communicate with it by using speech and gestures, or he can use telepresence from a distant place and communicate via the Internet. In each case, communication takes place via a new type of user interface based on multimedia and cognition. In this paper we describe the mechatronic structure, the functional subsystems and motion control principles of the robot, as well as discuss the challenges of the development project.