bluuebunny/crossref_metadata_2025 huggingface dataset:
Work Related Stresses of Pediatric Bone Marrow Transplant Nurses
Authors: Stutzer Cynthia A.
Published: March 2007

The annual conference of the Association of Pediatric Oncology Nurses, entitled Caring: The Foundation of Pediatric Oncology Nursing, was held October 12-14, 1988, in Denver, Colorado. Our thanks to Jory Goldmann, the National Program Chairperson, and Mary Jo Cleaveland, the Local Program Chairperson, and her committee for their hospitality and a very informative meeting.

The following are abstracts of some of the clinical, education, and research presentations from this meeting.
Sexuality in Children and Adolescents With Cancer: Pediatric Oncology Nurses' Attitudes and Behaviors
Authors: Williams Holly Ann , Wilson Margaret E.
Published: March 2007

It is esssential that health professionals openly discuss how cancer may affect the developing sexuality of childhood cancer patients. This study was conducted to explore nurses' attitudes and behaviors regarding sexuality in cancer patients. Results are reported for a subset of a larger study (N = 937) from subjects who indicated that their practice included children and/or adolescents (N = 156). The Williams-Wilson Sexuality Survey was used to measure attitudes towards sexuality in cancer patients, behavior in nursing care related to the sexuality of a cancer patient, and attitudes towards sexuality in the child and/or adolescent with cancer. The majority of subjects agreed that sexuality should be a routine component of nursing care, yet less than half had actually discussed an alter ation in sexuality with an adolescent patient. More than one third said they were not comfortable in initiating such discussions. However, they were comfortable in discussing sexuality concerns when these discussions were initiated by the patient and/or family.
"As Per Your Request": A History of Business Jargon
Authors: Locker Kitty O.
Published: March 2007

Conventional phrases have existed in business letters since at least 1589, but both the number of phrases in conventional use and the phrases which consti tute jargon have changed. Texts have criticized jargon since at least 1914, but the phrases texts criticize continue to be used. Terms become conventional be cause inexperienced business writers copy existing correspondence. Jargon persists because people think that business letters should use jargon and be cause using jargon enables authors to write or dictate quickly.
Qualifications English Departments Prefer for New Teachers of Business and Technical Writing: Is it Time to Reassess our Degree Programs?
Authors: Rivers William E.
Published: March 2007

Based on a survey of English departments, this article, after predicting a con tinuing strong demand for teachers of business and technical writing in English departments, presents and analyzes the qualifications those depart ments prefer when hiring new faculty to teach business and technical writing. The response indicates that the most attractive candidates for these positions will be those who have completed degree programs that combine the study of literature and composition. These preferences suggest that some English de partments should consider making their degree programs more flexible and demanding.
Behavioral Talk-Write as a Method for Teaching Technical Editing
Authors: Gilbertsen Michael , Killingsworth M. Jimmie
Published: March 2007

Robert Zoellner's "talk-write" pedagogy suggests a method for conducting workshop sessions on stylistic editing. Teachers should narrow the focus of each class to one stylistic goal, such as preventing overuse of nominalizations. After explaining the goal and demonstrating alternatives, the instructor di vides the class into teams of two students apiece. One acts as primary editor and attempts to revise a set ofproblem sentences ; the other supervises the work as secondary editor, makes suggestions for improvement, and serves as a liai son with the instructor who circulates through the class, answering questions, resolving disputes, and approving or rejecting the finished set as presented by the secondary editor. This process-oriented method allows the teacher to apply several basic behavioral principles: to focus on individual students, to start with the students' naive repertory of responses and build from there, to work with freely emitted behavior, to insure frequent and brief responses, to reinforce quickly appropriate responses, and to achieve the desired behavior through sequential steps.
Approaches and Practices
Authors: Moore Patrick
Published: March 2007

Most case studies used in business- and technical-writing courses are unrealis tic, or "cooked." They take for granted the exact things that business and technical writers spend so much of their time developing in their jobs: the rhe torical situation, the information, and the definitions of technical terms and concepts. By using cooked cases, writing teachers ignore or undervalue impor tant skills that writers need in the workplace: initiative, the ability to plan, and the ability to get along with other people. Business- and technical-writing teachers ought to use at least one "raw" case in class to help students develop the practical skills that will serve them best on the job.
Intergroup Relations: an Abbreviated Update
Authors: Berg David N.
Published: March 2007

This is the first article in the new "Update"section of Exchange. As outlined in Volume III, Number IV (1978), this section is intended to provide teachers of OB with a summary of a major conceptual area in cluding (1) a concise introduction to the major con cepts, (2) a sense of the scope and depth of the topic, and (3) a list of some key articles or books that would provide the reader with a solid working knowledge.

This initial article is on intergroup relations. Please let me know your reactions to this article and to the ap proach we are taking. Does this meet your needs? Are there other approaches you would suggest that provide a more useful "update?" Finally, is there an article that you would like to write?
Designing and Understanding Adaptive Group Behavior
Authors: Matarić Maja J.
Published: March 2007

This article proposes the concept of basis behaviors as ubiquitous general building blocks for synthesizing artificial group behavior in multiagent systems and for analyzing group behavior in nature. We demonstrate the concept through examples implemented both in simulation and on a group of physical mobile robots. The basis behavior set we propose, consisting of avoidance, safe-wandering, following, aggregation, dispersion, and homing, is constructed from behaviors commonly observed in a variety of species in nature. The proposed behaviors are manifested spatially but have an effect on more abstract modes of interaction, including the exchange of information and cooperation. We demonstrate how basis behaviors can be combined into higher-level group behaviors commonly observed across species. The combination mechanisms we propose are useful for synthesizing a variety of new group behaviors, as well as for analyzing naturally occurring ones.
Hierarchical Map Building and Self-Positioning with MonaLysa
Authors: Donnart Jean-Yves , Meyer Jean-Arcady
Published: March 2007

This article describes how an animat endowed with the MonaLysa control architecture can build a cognitive map that merges into a hierarchical framework not only topological links between landmarks but also higher-level structures, control information, and metric distances and orientations. The article also describes how the animat can use such a map to locate itself, even if it is endowed with noisy dead-reckoning capacities. MonaLysa's mapping and self-positioning capacities are illustrated by results obtained in three different environments and four noise-level conditions. These capacities appear to be gracefully degraded when the environment grows more challenging and when the noise level increases. In the discussion, the current approach is compared to others with similar objectives, and directions for future work are outlined.
Making predictions in an uncertain world: Environmental structure and cognitive maps
Authors: Chown Eric
Published: March 2007

This article examines the relationship between environmental and cognitive structure. One of the key tasks for any agent interacting in the real world is the management of uncertainty; be cause of this the cognitive structures which interact with real environments, such as would be used in navigation, must effectively cope with the uncertainty inherent in a constantly changing world. Despite this uncertainty, however, real environments usually afford structure that can be effectively exploited by organisms. The article examines environmental characteristics and struc tures that enable humans to survive and thrive in a wide range of real environments. The rela tionsnip between these characteristics and structures, uncertainty, and cognitive structure is ex plored in the context of PLAN, a proposed model of human cognitive mapping, and R-PLAN, a version of PLAN that has been instantiated on an actual mobile robot. An examination of these models helps to provide insight into environmental characteristics which impact human perfor mance on tasks which require interaction with the world.
A Learning Model of a Periodic Locomotor Pattern by the Central Pattern Generator
Authors: Jun Nishii
Published: March 2007

Many basic locomotor patterns of living bodies are rhythmic, and oscillatory components of physical systems effectively contribute to the generation of the movement. The control signals for the basic locomotor patterns are generated by the central pattern generator (CPG), which is composed of collective neural oscillators, and the activity of the CPG is tightly synchronized with the movement of the physical systems. That is, appropriate locomotor patterns are realized by mutual synchronization between the physical system and the neural system. In this article a simple learning model is proposed to acquire an appropriate parameter set, the intrinsic fre quency of the CPG, and the interaction between the CPG and the physical system, in order to obtain a desired locomotor pattern. The performance of the proposed learning model is con firmed by computer simulations and an adaptive control experiment of a one-dimensional hop ping robot.
Evaluation of a Stratified Versus an Unstratified Universe of Cultures in Comparative Research
Authors: Greenbaum Lenora
Published: March 2007

A comparison is made between the use of a stratified universe and an unstratified universe of cultures for sampling purposes. Samples are taken from the Ethnographic Atlas (1) by selecting from culture clusters (a first level of stratification of cultures) and (2) by a random selection from the total list of cultures in the Atlas. The analysis is done regionally, for Africa and North America. A chi-square, two-sample test indicates the essential similarity of the stratified and the unstratified universes; no significant statistical difference is found among the samples.

Matched-pair, signed-ranks tests are used to determine (1) the comparative stability of successive samples taken from the stratified universe and those taken from the unstratified universe and (2) the interchangeability of cul tures within culture clusters. Results for Africa indicate no significantly greater similarity of successive samples based on culture clusters compared with successive random samples based on the totality of cultures. For North America, successive samples from culture clusters seem to be significantly more stable than random samples from the totality of cultures only in regard to Ethnographic Atlas data. General interchangeability of cultures within culture clusters is not borne out by the data examined.
Personal Names of the Maya in Oxchuc
Authors: Harman Robert C.
Published: March 2007

Findings from previous research in highland Chiapas, Mexico, are re viewed for correlations of name type with social structure, societal functions, phase of directed acculturation, and cultural complexity. Fifty-two lists of names recorded by inhabitants in the township of Oxchuc, at events oc curring between 1958 and 1971, are analyzed. Effects on naming of the federal government and Protestantism since 1948 are examined, and cor responding processes of cultural change and stability are identified.
Factors and Patterns: The Nature of Sociocultural Variation
Authors: Erickson Edwin E.
Published: March 2007

A factor analysis of selected Ethnographic Atlas variables (including re gional location), performed on a sample of 200 societies, indicates that much of the variance generated cross-culturally must be explained by processes that are less than hologeistic in their range. Certain well-estab lished universal relationships-e.g., that linking demographic size and or ganizational complexity, and those linking kin terminological systems with descent and preferred marriage patterns-do emerge in the factor structure. In contrast, however, several of the factors in the structure appear to be the result of processes that are localized in geographic distribution and historic tradition. In this latter category, most notably, is a factor linking bilateral cross-cousin marriage, balanced subsistence dependence on cul tivation and hunting, small community size, and simple sociopolitical or ganization in a regional context of South America. Collateral analysis of this pattern with ethnographic data supports the hypothesis that bilateral cross-cousin marriage serves specific adaptive functions in a well-delimited ecological zone of South America. The main significance of the analysis lies in its possible application to the development of quasi-natural tax onomies of on-the-ground social systems which interest not only the cross- cultural comparativist, but also social anthropologists.
Analysis Reliability Reports: Replication Unit Number 3
Authors: Beierlet John M. , Levinson David
Published: March 2007

This report summarizes the results of the third study of analysis re liability based on current file production at the Human Relations Area Files. A total of 1229 pages from 147 sources was replicated for this reliability test. The average level of absolute coding agreement for this replication unit is 60 percent. Major category agreement is 88 percent when absolute agreement is measured and 90 percent when mutual cross- references and adjacent categories are taken into consideration. We find certain Outline of Cultural Materials (OCM) categories to be especially difficult to apply consistently. We identify these categories and discuss the problems involved in their use.
A Bibliography for Ethnographic Research on Iceland
Authors: Bredahl-Petersen Frederik E.
Published: March 2007

What differentiates ethnographic field research in a Western European community from that done in a non-literate and non-Western community is the fact that the Western community is neither untouched, pristine or unknown but has been studied previously. The fiction of an ethnographic present remains so, and is neither an aid to description nor an acceptable perspective within which to perceive the field data collected during the research. The question of social change becomes a historical question. A community which possesses a one thousand year tradition of literacy is a community of the book. Oral traditions, day to day activities, and strategies of work rest upon a commonly known past, one made up of long estab lished institutional alignments and laws which are taken into account by members of the present community. The enormous amount of data avail able in this part of the world necessitates a long period of post field ges tation by the ethnographer before intellectual coherence is achieved in the end product, the published monograph on the community. F.E.B.-P.
Color Terms In Folk Tales: A Cross-Cultural Study
Authors: Bolton Ralph , Crisp Diane
Published: March 2007

The relative salience of color terms in folk tales from forty cultures is examined in this study. The authors test the hypothesis that a significant, positive association exists between the relative salience of color categories in folk tales and the evolutionary sequence proposed by Berlin and Kay (1969) to account for cross-cultural differences in color lexicons. The results support the hypothesis. While minor intercultural variations in basic color term salience are found, there is a strong, and possibly universal, tendency for the salience of color terms to correspond to the postulated evolutionary sequence. Additionally, it appears that the evolutionary order is related to the number of different classes of objects to which color terms are applied. We argue that the evolution of basic color lexicons is promoted by an increase in cultural complexity generally and, more specifically, by an increase in the diversity of material culture and technological development.
Analysis Reliability Reports: Replication Unit Number 4
Authors: Beierle John M.
Published: March 2007

This article summarizes the results of the fourth study of analysis re liability based on current file production at the Human Relations Area Files.1 A total of 3,190 pages from 226 sources was analyzed for this repli cation study. The average absolute coding agreement for this unit was sixty percent. Major category agreement, measured in terms of absolute agreement, was eighty-seven percent; when mutual cross-references and adjacent categories were taken into consideration, the adjusted major agree ment level reached ninety-one percent. As noted in the previous paper in this series (Beierle and Levinson 1978), a number of specific OCM cate gories have been found to be especially difficult to apply consistently. These particular categories are identified and the inherent difficulties of applying them in analysis are discussed.
Effects of Perceived Parental Warmth and Control on the Self-Evaluation of Puerto Rican Adolescent Males
Authors: Saavedra Jose M.
Published: March 2007

Self-report questionnaires are used here to measure adolescents' percep tion of their parents along the dimensions of warmth and control and their perception of self. The sample consists of 208 Puerto Rican youths ranging in age from thirteen to nineteen years. As predicted from parental ac ceptance-rejection theory, results show a significant correlation between perceived parental warmth and reported self-esteem and self-adequacy. Contrary to expectations, the data do not support the hypothesized cur vilinear relation between perceived parental control and reported self-ade quacy. The joint effects of perceived parental warmth and perceived parental control turn out to be a better predictor of self-adequacy than either perceived parental warmth or perceived parental control alone.
Extramarital Sex Norms in Cross-Cultural Perspective
Authors: Broude Gwen J.
Published: March 2007

The double standard of extramarital sex and the near universal restriction upon extramarital sex for wives are examined. The double standard is in terpreted as a reflection of both male fears of sexual betrayal and male concern over sexual adequacy. Each of these dispositions is in turn traced to a different and independent child training antecedent. Restrictive norms for wives are explained in terms of the sociobiological paradigm. Extra marital sex norms are examined in relation to other sexual attitudes and practices.
Infant Stress and Adult Stature: Research and Reactions1
Authors: Swanson Otterbein Charlotte , Otterbein Keith F.
Published: March 2007

T. K. Landauer, J. W. M. Whiting, and several associates have published a series of articles relating infant stress in humans to later physical or physiological effects. The research was originally sug gested by developmental studies of laboratory animals and includes both holocultural and case studies. The stressful infant experiences studied include those involving pain-such as piercing-and separa tion from the mother. Later effects include stature and age of menarche. We have reviewed this research, and citations to it ap pearing in scholarly literature. The research stands as a single line of investigation, rather than as a series of separate pieces of research, and has received both favorable and unfavorable citations. We found that it is rarely cited as a "package." We also noted that unfavor able reactions tend to come from anthropologists, while psychologists -especially those involved in studies of animals-tend to welcome the findings of Landauer, J. W. M. Whiting, and colleagues. We have suggested some reasons for these findings.
The Plow, Female Contribution to Agricultural Subsistence and Polygyny: A Log Linear Analysis
Authors: Burton Michael L. , Reitz Karl
Published: March 2007

Relationships among plow agriculture, female contributions to crop tending, and polygyny in the Standard Cross-Cultural Sample are examined here. Without controlling for world regions, a log-linear analysis would suggest that each of these variables is related to the other two. Introducing a control for region with a four-way contingency table, we find significant relationships between region and each of the three variables. Furthermore, the control for region eliminates the relationship between plow agriculture and the female contribution to crop tending. Theorists such as Boserup have claimed that women do less agricultural labor with intensive agriculture. This relationship is apparently not a valid one, but simply a consequence of the joint diffusion of the three variables throughout the Old World.
A Survey of Mental Health Systems and Services
Authors: Baskin David
Published: March 2007

I surveyed 42 respondents in 28 countries and compared their mental health policies as well as their awareness, evaluation, and financing of mental health care. The notable differences between respondents could not always be attributed to level of economic development.
Multivariate Modeling with Interdependent Network Data
Authors: Dow Malcolm M. , White Douglas R. , Burton Michael L.
Published: March 2007

In the recent comparative literature the problem of simultaneously modeling func tional and diffusional effects is being penetrated from two directions. One approach emphasizes the similar problem which arises in regression-based time series analysis. A second approach focuses on the difficulties of constructing more realistic formal representations of sample unit interdependencies. Both approaches have yielded important and complementary, but distinct, insights. Here, we outline some recent methodological developments which synthesize both approaches into a comprehen sive and unified analytical framework.
Cultural Diversity in the Morality of Caring: Individually Oriented Versus Duty-Based Interpersonal Moral Codes
Authors: Miller Joan G.
Published: March 2007

This article argues that there exists not one universal morality of caring contrasting with the morality of justice but, rather, alternative types of interpersonal moralities that reflect the meaning systems emphasized in different cultural groups. Both the superogatory view of interpersonal morality held by Lawrence Kohlberg and the morality-of-caring framework developed by Carol Gilligan are shown to be culturally bound. Research conducted among American and Hindu Indian populations supports the claim that an individually oriented interpersonal moral code develops among Americans, stressingpersonal freedom of choice, individual responsibility, and a dualistic view of individual motivation. In contrast, a duty-based interpersonal moral code develops among Hindu Indians, stressing broad and socially enforceable interpersonal obligations, the importance of contextual sensitivity, and a monistic view of individual motivation. Issues for future research are iden tified, and implications of these alternative interpersonal moral codes for other domains of interpersonal functioning are suggested.
Ethnic Conflict and Its Management: A Narollian Analysis of a Worldwide Problem
Authors: Ross Marc Howard
Published: March 2007

Raoul Naroll always saw social science as a crucial tool in the struggle to improve the human condition. His comparative cross-level framework for the analysis of social problems offers a powerful methodology for linking social scientific analysis and effective practice. This article draws on Naroll's comparative framework to consider ethnic conflict. His five-step approach is used to outline what is known about ethnic conflict and its management, to highlight areas in which additional research is needed, and to demon strate how Naroll's approach can lead to constructive interventions in intransigent ethnic conflicts, a highly visible and significant problem in all regions of the world today.
Constructing a Scale of Female Contributions to Agriculture: Methods for Imputing Missing Data
Authors: Burton Michael L.
Published: March 2007

Five methods are described for estimating missing data in cross-cultural codes. The reliability of these alternative methods is assessed in the context of constructing a scale of total female contributions to agriculture. Simulations are used to explore the potential effects on scale reliability of larger amounts of missing data in the same data set. The imputed scales show surprisingly high reliability, even when more than half of the original data points are missing.
The Birth of the Gods Revisited: A Partial Replication of Guy Swanson's (1960) Cross-Cultural Study of Religion
Authors: Peregrine Peter
Published: March 2007

Guy Swanson's classic study The Birth of the Gods provides a general theory and set of hypotheses about the origins of religious beliefs that have found wide acceptance in the sociological and anthropological study of religion. Although these hypotheses seem both logical and persuasive, the cross-cultural methods Swanson used to evaluate them seem less compelling. This article examines Swanson's sample and methodology, and, through a replication employing a sample of 72 native North American societies, finds several significant problems in Swanson's work. However, the rep lication also demonstrates that, despite methodological problems, Swanson's hypothesis concerning beliefs in a high god are sup ported. The implications of this partial replication, both for our interpretation of Swanson's work and for our understanding of the origins of religious beliefs, are explored.
Personal Boundaries Among Russians and Americans: A Vygotskian Approach
Authors: Searle-White Joshua
Published: March 2007

This article examines Russians'and Americans'reasoning about the boundaries of responsibility within friendships. Matched Russian and American samples were asked to resolve dilemmas concerning personal responsibility between friends. It was found that the Rus sian subjects'resolutions of the dilemmas were, in general, charac terized by being less protective of the self than those of the American subjects. However, this was not the case in all situations, suggesting that the psychological differences between the two groups are best conceptualized in terms of the ways of speaking and thinking invoked in specific situations, rather than as traits or personality styles that are common to all members of a culture. A conceptuali zation of the relationship between individual psychological process es and cultural context, based on the work of Vygotsky (1981) and Wertsch (1991), is offered to explain the results.
Anger, Envy, Fear, and Jealousy as Felt in the Body: A Five-Nation Study
Authors: Hupka Ralph B. , Zaleski Zbigniew , Otto Jürgen , Reidl Lucy , Tarabrina Nadia V.
Published: March 2007

An ongoing debate is centered on the question of whether emotions have their own pattern of autonomic nervous system activation. To determine whether individuals do perceive subjective physiological changes for different emotions, 514 university students in Germany, Mexico, Poland, Russia, and the United States indicated on a 6-point scale to what extent they felt anger, envy, fear, and jealousy in particular parts of the body and body processes. In agreement with recent studies, the pattern of sites where emotions were re ported to be felt varied for different emotions. Cross-cultural commonalities and differences were also found. The findings were
Murdock as Bridge: From Sumner to HRAF to SCCR
Authors: Goodenough Ward H.
Published: March 2007

George Peter Murdock began his anthropological career when the concerns of the cultural evolutionary and cultural historical schools both required the creation of large ethnographic databases and systematic comparative or cross-cultural research. Other kinds of newly emerging questions in behavioral, social, and cultural theory also required such research. Murdock led the way in undertaking the creation of the badly needed databases with the creation of the Cross-Cultural Survey and later with Human Relations Area Files. His pioneering use of these databases was a powerful stimulus to the growth of cross-cultural research and its methodology, culmi nating in the founding of the Society for Cross-Cultural Research.
Just Deserts: African American Judgments of Justice in Stories of Varying Cultural Relevance
Authors: Starr B. James , Sloan Lloyd R. , Kudrick Tarl R.
Published: March 2007

Several standard stories used to examine beliefs in justice in other (cross-national) settings were also used in this study. Additional stories were created to examine potential hypothesized differences in this population due to the nature of the original stimulus stories. The researchers also examined ways in which the participants made their decisions. Results suggest that determinations of justice do, indeed, have some fairly standard features, but that population- specific issues also may affect judgments. These contexting factors suggest further studies to help to account for the variability in justice judgments. Important underlying dynamics may be uncov ered by future studies focusing on the ways that participants arrive at their judgments.
Combative Sport and Warfare: A Reappraisal of the Spillover and Catharsis Hypotheses
Authors: Chick Garry , Loy John W. , Miracle Andrew W.
Published: March 2007

In his classic 1973 study, Richard Sipes used a cross-cultural sample to examine the relationship between combative sport and warfare. He found that combat sport and war tended to co-occur, thus supporting a spillover hypothesis, rather than a catharsis hypothesis. However, his sample was small (n = 20) and composed of outliers—societies that were either extremely warlike or extremely peaceful-and did not address a current concern in cross-cultural research-that is, time and place foci. In this restudy of the rela tionship between combative sport and warfare, the authors use Carol Ember and Melvin Ember's recent Standard Cross-Cultural Sample codes for warfare and other forms of violence with the authors' own new codes for combative sport.
Africa, NGOs, and the International Toxic Waste Trade
Authors: Clapp Jennifer
Published: March 2007

This article focuses on the involvement of Africa and environmental nongovernmental organizations (NGOs) in attempting to halt the interna tional toxic waste trade. It shows that in addition to states, non-state actors have been important players in the international politics of the waste trade. An Africa-NGO alliance that formed in the late 1980s was able to influence the outcome of several international waste trade conventions. Despite regu lations designed to keep waste imports out of Africa, waste traders were able to circumvent existing rules and continue their trade with the continent. In response to this persistence of the waste trade, a growing coalition of environmental NGOs and developing country states has recently been successful in bringing about a global ban on the waste trade between Organization forEconomic Cooperation and Development (OECD) countries and non-OECD countries. Whether or not this ban will be effective will depend to a great degree on the strength of the coalition of NGOs and states supporting the ban.
Review : Remyelination—A Regenerative Process in the CNS
Authors: Franklin Robin J.M.
Published: March 2007

CNS remyelination is a regenerative process that contrasts with the more widely recognized absence of regeneration characteristic of neuronal injury. This important process both restores saltatory conduction to demyelinated axons and enables the recovery of functions mediated by impulse conduction in those axons. Unfortunately, remyelination can be a fragile process that is prone to fail, contributing to the persistence of clinical deficits in patients with demyelinating disease. Despite being first described more than 30 years ago, it is only relatively recently that a clearer (though still incomplete) picture of the cellular and molecular mechanisms of remyelination has begun to emerge. These developments, in particular the role of the oli godendrocyte progenitor, have provided insights into why remyelination sometimes fails and will provide the basis for enhancing this process by means of therapeutic intervention. NEUROSCIENTIST 5:184-191, 1999
Comparison of Linear and Nonlinear Control of a Slewing Beam
Authors: Rietz Ralph W. , Inman Daniel J.
Published: March 2007

The performance of two position control systems was studied. Proportional plus derivative (PD) feedback control was considered along with PD plus position times velocity feedback. An analytical model of the plant (a single link, very flexible manipulator) was identified, and computer simulations using the two controllers were performed. The results clearly showed a decrease in control effort for the system using non linear control when compared to a similar response for the system using PD control. Experimental results on a slewing beam system verified this result. The system using the proposed nonlinear feedback control re quired significantly less energy to complete the same maneuver as the system using the standard PD feedback control. Other measures of performance (e.g., rise time, settling time, overshoot) showed marginal improve ment when the nonlinear feedback was added to the controller. The principal issue here is the control effort required by the linear versus nonlinear controller to obtain the same, or similar, response to a command.
Exact Solutions for Free Vibration of Single-Degree-of-Freedom Systems with Nonperiodically Varying Parameters
Authors: Li Q.S. , Fang J.Q. , Liu D.K.
Published: March 2007

An analysis of free vibration of single-degree-of-freedom (SDoF) systems with nonperiodically varying parameters, such as variable mass and stiffness, is presented and discussed in this paper The vari ations, relative to time, of mass and stiffness are expressed by the selection of suitable expressions such as power functions and exponential functions, and the general governing differential equation for free vi bration of SDoF systems with nonperiodically varying parameters is established. The exact solutions for free vibration of such time-varying systems are derived. The obtained solutions demonstrate that free vibra tion of several undamped systems with nonperiodically varying parameters cannot be induced by an initial disturbance.
LQG/LTR-Based Robust Control of Composite Beams with Piezoelectric Devices
Authors: Varadarajan S. , Chandrashekhara K. , Agarwal S.
Published: March 2007

The performance of an LQG/LTR-based multi-input multi-output robust vibration control system for a laminated composite beam is investigated. A finite element model based on a higher order shear defor mation theory and accounting for piezoelectric effects is developed. The model is thus applicable to both thick and thin laminated composite beams. The lateral strain is also incorporated in the model by a systematic re duction of two-dimensional plate constitutive equations. The mode superposition method is used to transform the coupled finite element equations of motion in the physical coordinates into a set of reduced uncoupled equations in the modal coordinates. The state space model of the system is obtained in the reduced-order modal coordinates. An LQG/LTR-based robust controller is designed using the reduced-order state space model of the structure. The performance of the controller is verified for various arbitrary initial conditions of the beam. The effect of structural parameter variation on the closed-loop system performance is also investi gated. The performance robustness of the linear quadratic Gaussian with loop transfer recovery (LQG/LTR) controller is compared with that of the proportional feedback controller.-
Vibrations of Steel-Concrete Composite Beams
Authors: Biscontin Gianni , Morassi Antonino , Wendel Pia
Published: March 2007

This paper is an experimental analytical investigation on the dynamic behavior of steel-concrete composite beams subject to small vibrations. A one-dimensional model of a composite beam is presented, where the elements connecting the steel beam and the reinforced concrete slab are described by means of a strain energy density function defined throughout the beam axis. The problem of small vibrations of the system is formulated and solved through an analytical procedure where a coupling between longitudinal and transver sal motions, due to the presence of the connection, takes place. The analytical model is used with a view to interpreting a series of dynamic tests performed on composite beams whose connections have different linear densities. Experimental results proved consistent with theoretical estimates and allowed the identification of some important physical parameters of the system and the characterization of the connection.
Stability Analysis and Controller Design for Polymer Sheet Extrusion
Authors: Nizami J. , Batur C.
Published: March 2007

Dimensional stability of thin extruded polymer sheets is analyzed as a function of draw ratio. It is assumed that the sheet keeps its rectangular cross section between the flat die and the chill roll and the flow is Newtonian. Through the analysis of linearized equations, it is shown that the sheet becomes unstable beyond a critical draw ratio as observed in experimental studies. The nonlinear model of sheet dynamics is then analyzed using the singular perturbation analysis to confirm the existence of a stable limit cycle. A feedback controller is designed to stabilize the sheet dynamics for draw ratios greater than the critical draw ratio.
Stiffness and Damping Ratio of Rubber-Modified Asphalt Mixes: Potential Vibration Attenuation for High-Speed Railway Trackbeds
Authors: Zeng X. , Rose J.G. , Rice J.S.
Published: March 2007

This paper presents the first phase laboratory test results of a research project at the University of Kentucky A number of resonant column tests were conducted to measure the stiffness and damping ratio of rubber-modified asphalt (RMA) samples with different rubber contents and mixed by different methods. The measurements were conducted under a wide range of confining pressures and shear strains to simulate the stress conditions that would be expected in a typical railway foundation. Data from the tests show that RMA has stiffness much higher than compacted soils while providing significantly higher damping ratio than most soils under the same strain level. Therefore, the results from this study indicate that RMA has great potential as a foundation material for high-speed railway trackbeds.
Active, Shunted, and Passive Constrained Layer Damping for the Vibration Suppression of a Flexible Four-Bar Mechanism
Authors: Ghoneim H. , Karkoub Mansour A.
Published: March 2007

Vibration suppression of a flexible four-bar mechanism is investigated. A generic four-bar mecha nism, with flexible coupler, is considered for the investigation. Passive, shunted, and active constrained layer damping techniques are adopted for the vibration suppression. The equations of motion are developed using the assumed mode method and the constrained Lagrange's equations and are manipulated and solved using Maple and Matlab. Two types of responses are investigated: the free decay response due to an initial midpoint deflection of the flexible coupler and the forced transient response due to an applied crank step torque. Effects of the application of passive, shunted, and active constrained layer damping on the responses are discussed.
Regulation and Vibration Control of an FEM-Based Single- Link Flexible Arm Using Sliding-Mode Theory
Authors: Chen Yon-Ping , Hsu Huai-Te
Published: March 2007

Compared to the assumed-mode method (AMM), the finite-element method (FEM) is not only more applicable to the modeling of various kinds of flexible structures but also better in estimating the natural frequencies. Motivated from these features and modified from the work of Yeung and Chen for an AMM-based model, the sliding-mode controller introduced in this paper is developed to deal with the regulation problem and vibration suppression of an FEM-based single-link flexible arm. This paper will focus on the issue of how to change the FEM-based model into a form similar to the AMM-based model via the Schur decomposition. A technique to measure the well-estimated state variables required for the control is also presented. Finally, numerical simulation results are given to verify the robustness of the modified sliding-mode controller against payload variation.
Estimation and Application of Correlation Dimension of Experimental Time Series
Authors: Wang W.J. , Chen J.
Published: March 2007

This paper reports the Grassberger-Procaccia algorithm and its modified version, with particular regard to how to reduce computation time, to avoid dynamic correlation, and to determine the scaling re gion. The influencing factors of correlation dimension computation of experimental data, especially the data length and noise level, are described comprehensively Results show that not theoretical consideration but the D2( m) —ln( r/r0) function should be used to determine the minimal requirement of data length of ex perimental data. In some cases, nonlinear noise reduction is necessary. Nonlinear time series analysis theory based on correlation dimension for practical application, especially for gearbox fault diagnosis, is introduced. Results show that the correlation dimension can usefully reflect the different kinematics mechanisms.
Sufficient Conditions for Minimum-Phase Second-Order Linear Systems
Authors: Lin Jong-Lick , Juang Jer-Nan
Published: March 2007

Several sufficient conditions are derived for a second-order linear system to be minimum phase. It is commonly known that a second-order linear system with collocated sensors and actuators is minimum phase. In general, this common knowledge is correct mathematically when the input influence matrix is the transpose of the output influence matrix. In this paper, we extend this knowledge to the case with noncollocated actuators and sensors. First, a conventional approach is used to prove some sufficient conditions of sensor and actuator locations for a system to be minimum phase. Second, a geometrical approach is introduced to discuss the sufficient conditions, and then used to derive other more useful sufficient conditions for a minimum-phase second-order linear system. Many illustrative examples are provided for the readers to better understand the theories developed in this paper.
Significance of Considering Nonlinear Effects in Predicting the Dynamic Behavior of Rotating Machinery
Authors: Noah Sherif T. , Sundararajan Padmanabhan
Published: March 2007

Limitations of the currently practiced linearized analysis of industrial rotating machinery are dis cussed. An appreciation of these limitations is particularly significant for the development of new generation, high performance machinery in which new materials, rotor supports, coupling components, and sophisticated control systems will be used. In the absence of adequate familiarity and experience with the new systems, vari ous complex phenomena associated with their nonlinearities, which may lead to malfunction or catastrophic failure, could be missed altogether. A uniform approach to accurate modeling and analysis of rotor-support systems will therefore be essential. The present paper provides an exposition of recently published studies in nonlinear rotordynamics and their relevance to the design, analysis, and monitoring of rotating machinery. This includes a brief discussion of available analytical/computational methods and the various techniques proposed, which seek reducing the order of rotor systems with large number of degrees of freedom. In ad dition, new results on the nonlinear behavior of fluid-film bearings are presented herein to further emphasize the importance of nonlinear effects.
Interaction of an Oblique Incident Elastic Wave With a Pair of Surface-Breaking Cracks
Authors: Ciarletta Michele , Sumbatyan Mezhlum A.
Published: March 2007

In this paper, the authors study a two-dimensional in-plane problem in the context of an oblique incident plane wave in the presence of two (parallel) surface-breaking vertical cracks. An analytical approach is developed that permits reducing the problem to a system of two integral equations with respect to the normal and tangential opening of the crack faces. The system is investigated numerically for a wide range of the frequency parameter. It is shown that with the choice of an appropriate pair of cracks it is possible to arrange the control of the free-surface vibrational amplitude.
An Experimental Investigation of Particle Dampers Under Harmonic Excitation
Authors: Papalou A. , Masri S.F.
Published: March 2007

This article presents an experimental study of the performance of particle dampers under harmonic excitation. The effects of various system parameters—including particle size, container dimensions, intensity, and frequency of excitation—were investigated using a single degree-of-freedom building model under har monic base excitation. It is shown that particle dampers, even with a small mass ratio, can be very effective in attenuating the vibrations of lightly damped structures. An approximate method is provided to estimate, with reasonable accuracy, the response of a harmonically excited structure that is equipped with a particle damper operating in the vicinity of the optimum range of its system parameters.
A Multiple-Damage Location Assurance Criterion Based on Natural Frequency Changes
Authors: Contursi T. , Messina A. , Williams E.J.
Published: March 2007

A new method for locating multiple damage sites in elastic structures is introduced. It uses only the natural frequencies for diagnosis and obviates the need to have complete experimental mode shapes. Results from three damaged structures are presented. A 2-bar truss illustrates the basis for the method, a 15-bar truss shows its use with symmetrical structures, and a redundant-bar truss is used to compare the new method with that of Pandey and Biswas. Correct predictions of the location and relative amounts of damage at multiple sites are obtained, even when low damage levels are present in the structure.
Bending Vibration Control of Cantilevers via Boundary Moment and Combined Feedback Control Laws
Authors: Librescu Liviu , Na Sungsoo
Published: March 2007

The problem of controlling the bending vibration of cantilevers modeled as closed cross-section thin-walled beams and incorporating a number of nonclassical effects, such as transverse shear, secondary warping, and heterogeneity, is investigated. The control is carried out via a bending moment applied at the tip of the structure. A combined feedback control law relating the boundary moment at the beam tip with the kinematic response variables appropriately selected is implemented, and its results on the closed-loop eigen frequencies and dynamic response are highlighted. The capabilities and efficiency of this control methodol ogy, considered in conjunction with a number of nonclassical effects featuring the structure, are illustrated, and pertinent conclusions are outlined.