bluuebunny/crossref_metadata_2025 huggingface dataset:
Interface Characteristics, Perceived Ease of Use and Intention to Use an Online Library in Malaysia
Authors: Ramayah T.
Published: April 2006

Many researches have identified that perceived ease of use will lead to the intention to use a particular technology and the intention in return will lead to actual behavior. In the context of this research the interface characteristics are classified as the external variable to the belief-intention relationship. Data was collected from 704 undergraduate and post graduate students of Universiti Sains Malaysia using a structured questionnaire through a convenience sampling technique. The findings of the study indicate that all three interface characteristics, terminology clarity (= 0.571, p< 0.01), screen design (= 0.268, p< 0.01) and navigation clarity (= 0.036, p< 0.05) were positively related perceived ease of use of the online library. Perceived ease of use (= 0.536, p< 0.01) was in turn positively related to intention to use. The R 2 was 0.287, indicating that 28.7 percent of the variations in the intention to use can be explained by perceived ease of use. Implications for developers and the university authorities are considered.
On the History of EGATIN
Authors: Voyatzaki Zoe
Published: April 2006

Twenty years ago, the first notion of a network of group-analytic institutions from many different countries was put forth. As time has shown, this has been a fruitful idea and thus came the thought to write an account of the formative years of EGATIN and how it all started – with the idea of combining the more concrete historical facts with what we call ‘myths’ – the often untold stories which are true, but are not given importance while they are happening, the small things which, however, give us the true flavor of history and complement reason.
Special Section : The Malign Transference: Dealing with the Unbearable in the Internal World of the Murderer
Authors: Jones David
Published: April 2006

The internal world of a murderer can be a complex area, characterized by pain, anger and separation. The pain of the knowledge of what has been done and the separation from this and other feelings threaten to overwhelm and annihilate the ego. The murderer has committed the ultimate crime and is in receipt of the opprobrium of society and, often, of themselves. The author looks at this phenomenon, illustrating it with clinical vignettes and considers the parallel process that can occur in therapists and staff groups. The consequences for staff dynamics are discussed.
The Virtue of Depression in the Secret Life of Shame: A Group-Analytic Perspective
Authors: Montgomery Charles
Published: April 2006

This article examines the role that shame plays in inducing and maintaining depression; the author proposes that chronic depressed states serve a function of neutralizing the painful awareness of shame. The similarities and differences between shame and guilt are discussed. It is suggested that concealed shame produces a debilitated state of mind in which feelings of rage and revenge are kept in check and blanketed by self-directed anger – depression. In this view depression has both a protective function and is a form of communication. Vignettes from an analytic therapy group illustrate how these themes can be worked with such that group members are enabled to move towards developing a clearer sense of self.
‘Flirt[ing] with Death’ but‘ Still Alive’
Authors: Ralph Michael
Published: April 2006

This article argues that the tendency in rap music to depict women as accessories and sexual servants is the partial result of a widespread attitude that women have better prospects for earning a legitimate wage than their male counterparts. The effort to devalue women—and, by extension, female labor—leads avowedly heteronormative rappers to displace intimacy onto feminized arenas, like ‘the game’ or ‘the streets’. This is one way of coping with a general sense of disappointedness that inheres in the tortured sense of masculinity whose contours I tentatively sketch here. This article closes by pinpointing one reason for this preoccupation with death, fascination with ‘bling’, and denigration of women: the experience of ‘surplus time’—the sense that, according to perceived life expectancies, these rappers should already be dead. In theorizing this predicament, I explore some social consequences of the belief these rappers have more time available than they had anticipated.
Economic Evaluation in an Age of Uncertainty
Authors: Pennisi Giuseppe , Scandizzo Pasquale L.
Published: April 2006

Enabling value judgements about policies and programmes is one of evaluation's central tasks. There is, however, little consensus on how evaluators should accomplish this task. The traditional cost–benefit approaches have been found wanting and yet valuing as promoted by checklists or qualitative stakeholder interviews is not anchored to an economic theory and thus inspires little confidence. While no single methodology is likely to be accepted by all, recent developments in economic theory support a new interpretation. This article draws on economic evaluation generally and the evaluation of development projects more specifically. The approach proposes a variant of social cost–benefit analysis (SCBA); it retains the representation of stakeholder values and avoids the more dogmatic, and even mechanical, underpinnings of traditional economic analysis. The article traces the development of this new ‘options-based’ approach and suggests a path for further research. It is argued that this approach warrants a voice in the dialogue on economic evaluation.
Evaluation Pragmatics
Authors: Bezzi Claudio
Published: April 2006

Evaluation is certainly based on social research, but each social research method and technique has its own limits and generates its own specific biases. This issue becomes critical at a fundamental evaluation point: the moment when one is required both to define the subject and mandate, and formulate the ‘evaluative questions’ which guide the whole activity. In this phase, it is important to look at every evaluation as a local issue, leaving the subject's definition to the (anthropological, organizational, professional) context, its grammar and lexicon. To be useful, an evaluation must focus on the context, i.e. on the ‘texts’ produced by the stakeholders and the meanings they give to these texts, thus helping them to contextually reduce evaluand ambiguity. In this perspective, evaluation is a learning organization's tool that helps to build social reality. Such a tool has its own mechanism, which is recognized by the stakeholders and makes possible both the intervention and the success of the programme.
Chasing a Ghost?
Authors: Forss Kim , Kruse Stein-Erik , Taut Sandy , Tenden Edle
Published: April 2006

UNESCO has high ambitions with respect to the use of evaluation. But for evaluation to flourish it has to be valued and understood in the whole organization, not only by top management and the specialized evaluation service. There are many ways to foster evaluation capacity; one approach is to involve stakeholders in evaluation processes so they can learn by doing. This essay describes how an external evaluation of UNESCO's response to the HIV/AIDS pandemic was designed to encourage capacity development through participation. Learning did occur, but not where it was expected to occur, and not to the extent hoped for. The authors found that practical issues, such as timing, skills, team composition, structure of budgets, and incentive systems, must be designed for capacity development so that the learning process becomes an explicit and realistic goal; good intentions do not suffice, as many other pressures arise during an evaluation.
Translation, adaptation, globalization
Authors: van Leeuwen Theo
Published: April 2006

The Vietnam News is an English language daily newspaper produced on behalf of the Vietnamese Government, as part of its market reform policies. Drawing on an analysis of 100 translations from the Vietnamese press and their rewrites by the paper's foreign sub-editors, as well as on interviews with sub-editors and journalist-translators working at the Vietnam News, the article documents the translation and adaptation decisions that constitute the process of globalizing the discourse of the Vietnamese press in this particular instance. Three kinds of decisions are discussed in turn: translation decisions affecting the English used, translation/adaptation decisions affecting journalistic style, and translation/adaptation decisions affecting cultural and ideological references in the source texts. The article ends by asking whether the Vietnamese press is best served by closely following the Anglo-Australian model, as it does at present, or by developing its own distinct local style.
Who buys whom: information environments and organizational boundary spanning through acquisitions
Authors: Schildt Henri A. , Laamanen Tomi
Published: April 2006

Companies extend their boundaries through acquisitions to new industries, product lines, technologies, markets and geographic locations. Diversification research has focused predominantly on boundary extensions across industries. Using data on 167 intra-industry acquisitions in the pharmaceuticals industry between 1991 and 1996, we study boundary extension in an industry, integrating existing arguments to examine how proximity in intraindustry networks, geographic location, and technological domain influences the likelihood of acquisition. As expected, the proximity of two firms in these search contexts increases the likelihood that one will acquire the other, but the contexts are partial substitutes, proximity in one search context overcoming distance in other contexts.Thus, we find that while pharmaceutical companies are more likely to acquire technologically similar foreign companies, they are more likely to acquire technologically dissimilar alliance partners. Our results contribute to an improved understanding of who buys whom and in doing so, organizational boundary spanning through acquisitions.
Allies Community Health Workers: Bridging the Gap
Authors: Friedman Amy R. , Butterfoss Frances D. , Krieger James W. , Peterson Jane W. , Dwyer Maura , Wicklund Kimberly , Rosenthal Michael P. , Smith Lilly
Published: April 2006

Allies Against Asthma coalitions each employ a community health worker (CHW) program as part of its community action plan. The structure and management of CHW programs vary in response to the resources and needs of the local community, as do the roles and characteristics of the CHWs hired. All programs utilize CHWs to provide community-based education and/or outreach to community members, primarily in their homes. Using an asthma action plan, most Allies CHW programs function as an extension of and link to the clinician, providing basic asthma education and care coordination in a supportive, family-friendly setting, context, and location. Community health workers rely heavily on relationship building and family empowerment to assist families in improving asthma control. Working within a coalition framework helps integrate the CHW program into other services and resources in the community. As participants in coalition activities, CHWs often bring an important and meaningful viewpoint to the coalition.
Collaborative Design and Implementation of a Multisite Community Coalition Evaluation
Authors: Lachance Laurie L. , Houle Christy R. , Cassidy Elaine F. , Bourcier Emily , Cohn Jennifer H. , Orians Carlyn E. , Coughey Kathleen , Geng Xin , Joseph Christine L.M. , Lyde Michael D. , Doctor Linda Jo , Clark Noreen M.
Published: April 2006

Evaluation designs assessing community coalitions must balance measures of how coalitions do their work and evidence that the coalitions are making a difference. The Allies cross-site evaluation attempts to determine the combined effects of the seven coalitions’ work at the individual, organizational, and community levels. Principal components considered are (a) contextual factors of the coalition community, (b) coalition processes and structure, (c) planning and planning products, (d) implementation actions, (e) activities and collaborations, (f) anticipated intermediate outcomes, and (g) expected asthma related health outcomes. Measurements are quantitative and qualitative, and data generated by these methods are used as ends in themselves and as a way to confirm or inform other measures. Evaluation has been an integral part of the planning and implementation phases of the Allies coalition work, with a priority of involving all of the partners in conceiving of and deciding upon the elements of assessment.
Subependymomas: An analysis of Clinical and Imaging Features
Authors: Ragel Brian T. , Osborn Anne G. , Whang Kum , Townsend Jeannette J. , Jensen Randy L. , Couldwell William T.
Published: April 2006

OBJECTIVE:

Subependymomas are slow-growing, benign tumors usually found incidentally in the fourth ventricle at autopsy. They are typically associated with the ventricular system and become apparent clinically only when symptoms of hydrocephalus or mass effect develop. We review clinical, histological, and contemporary radiographic presentations of 16 subependymomas, including 2 intraparenchymal tumors.

METHODS:

We retrospectively evaluated eight patients with pathologically proven subependymomas. Initial magnetic resonance imaging and magnetic resonance spectroscopy were reviewed when available. Imaging was also available on eight outside subependymoma cases reviewed by our radiology department.

RESULTS:

Twelve of these subependymomas were intraventricular, one was in the posterior fossa, two were intraparenchymal, and one was an intramedullary spinal cord tumor. These lesions were hypo- to hyperintense on T1- and T2-weighted magnetic resonance imaging, with minimal to moderate enhancement. Initial complaints included headache, seizures, tingling sensations, and weakness. Among our eight patients who underwent gross total resection with no adjuvant therapy, no recurrences have been noted on follow-up magnetic resonance imaging.

CONCLUSION:

Subependymomas are rare, representing only 0.51% of all central nervous system tumors operated on during an 8-year period at the University of Utah. Clinical symptoms were associated with tumor location: intracranial masses caused headaches, seizures, and neurological complaints, and spinal cord locations resulted in neurological deficit. The authors review the clinical presentation, management, and contemporary radiographic appearance of this rare tumor.
Lumbar Intramedullary Spinal Schistosomiasis Presenting as Progressive Paraparesis: Case Report
Authors: Kim Albert H. , Maher Cormac O. , Smith Edward R.
Published: April 2006

OBJECTIVE AND IMPORTANCE:

Blood fluke infection or schistosomiasis affects up to 300 million people worldwide. Although infection of the hepatic and urogenital systems commonly occurs, central nervous system involvement is rare. When presenting in the spinal cord, schistosomiasis can be difficult to diagnose because it can present as mass lesion or transverse myelitis. We describe a patient with lumbar intramedullary spinal schistosomiasis who presented to a tertiary medical center in the United States and discuss the diagnosis and treatment of this rare disease.

CLINICAL PRESENTATION:

A 25-year-old Brazilian man presented with progressive, subacute, bilateral lower extremity motor and sensory deficits and disturbances in bladder function. Magnetic resonance imaging revealed a diffusely enhancing mass expanding the region of the conus medullaris.

INTERVENTION:

Laboratory investigation disclosed serum and cerebrospinal fluid eosinophilia. Ultimately, cerebrospinal fluid serology demonstrated the presence of Schistosoma mansoni. The patient was treated with praziquantel and steroids and made a marked recovery.

CONCLUSION:

The clinical and radiographic manifestations of spinal schistosomiasis can mimic those of intra-axial spinal tumors and transverse myelitis. To avoid unnecessary surgery or delay in treatment, the clinician must have knowledge of this type of presentation. The increasing volume of international travel and high prevalence of the disease worldwide increases the possibility that the practicing neurosurgeon in the United States may encounter this rare but treatable disease.
Microwave-mediated Efficient Protection of Carbonyl Compounds as 1,3-Oxathiolanes in the Presence of Iodine under Solvent Free Condition
Authors: Bez Ghanashyam , Baruah Nabajyoti
Published: April 2006

A mild, efficient, and solvent free protocol for conversion of aldehydes and ketones into their corresponding 1,3-oxathiolanes using 2-mercaptoethanol in the presence of catalytic amount of elemental iodine is reported.
Interdependency, Competition, and the Distribution of Firm and Industry Profits
Authors: Lenox Michael J. , Rockart Scott F. , Lewin Arie Y.
Published: April 2006

Coordination of interdependencies among firms’ productive activities has been advanced as a promising explanation for sustained heterogeneity in capabilities among firms. In this paper, we extend this line of research to determine the industry structures and patterns of expected firm profits for the case when difficulty optimizing interdependent activities does, in fact, generate and sustain capability heterogeneity among firms. We combine a widely used agent-based model where firms search to discover sets of activities that complement one another (reducing overall costs or raising product quality) with traditional economic models of competition among profit-maximizing firms. The agent-based model produces a distribution of performance (interpreted as variable cost or product quality) among firms and the competition models determine resulting industry outcomes including patterns of entry, exit, and profits. The integration of economic models of competition among firms with an agent-based model of search for improvement by firms reveals a rich relationship between interdependencies in production functions and industry structure, firm profits, and industry average profitability.
Optimal Mechanisms with Finite Agent Types
Authors: Lovejoy William S.
Published: April 2006

In some mechanism design problems, finite-type spaces may be natural ones to consider, yet the current literature is dominated by analyses of continuous-type spaces. This probably derives from the intellectual dominance of the early work in this area. Here we present an analysis of the finite-state case that unifies and generalizes current understanding of these problems. We analyze general quasi-linear utility functions among asymmetric agents with an arbitrary number of finite types, in the context of incentive-compatible direct revelation games. A key part of the analysis is the relationship between expected benefit functions that feature alternative forms of supermodularity that translate into relaxations or restrictions of the original problem. The required features can be attained with a range of assumptions on the model primitives, each of which can support the results. This unified approach can suggest a range of alternative assumption combinations, often more general than their counterparts in the continuous-space literature, and each of which can reduce the problem to a more tractable form. Also, mechanism design problems with finite-type spaces can require conscious attention to how the principal handles ties, which are probability-zero events, and hence innocuous in continuous spaces.
From roots to routes: double consciousness in the Francophone Caribbean novel
Authors: Heady Margaret
Published: April 2006

A comparative treatment of two twentieth-century Francophone Caribbean novelists, Jacques-Stephen Alexis of Haiti and Simone Schwarz-Bart of Guadeloupe, demonstrates how Caribbean authors have been using the discourse of the marvellous to move toward the creation of a sense of identity
based on what Paul Gilroy calls a process of movement and mediation as opposed to a search for roots and rootedness. Alexis felt torn between what he perceived as his intellectual debt to Europe and his dedication to the development of a national Haitian literary form. His desire to transcend
European literary influences is expressed in his work through issues of authenticity. Schwarz-Bart's work reflects more recent theories of Caribbean identity by demythologizing the very concept of the authentic origin. She uses the narrative technique of magic realism as a way of bringing
together opposing discursive systems without evaluating them according to criteria of truth or authenticity. The result is a multiple voice which, like the larger voice of the Black Atlantic as a whole, can be described as a form of antiphony in which, in Gilroy's words, the original call
is becoming harder to locate.
Book Reviews
Authors: Marley Dawn , Langford Rachael , Korzeniowska Victoria B , Kelly Debra , Githire Njeri , Gallagher Mary , Chemla Yves , Redouane Rabia
Published: April 2006

Les Mots du bled. Cration contemporaine en langues maternelles, les artistes ont la parole, Dominique Caubet (ed.), (2004) Paris: L'Harmattan, 237 pp., ISBN 2-7475-6249-2 (pbk), 20

Colonial Cinema and Imperial France 19191939: White Blind Spots, Male Fantasies,
Settler Myths, David Henry Slavin (2001) Baltimore: Johns Hopkins University Press, xv + 300 pp., ISBN 0-8018-6616-2 (hbk), 32

Vietnamese Voices: Gender and Cultural Identity in the Vietnamese Francophone Novel, Nathalie Huynh Chau Nguyen (2003) DeKalb, IL: Southeast
Asia Publications, 239 pp., ISBN 1-891134-26-4 (pbk), 19.95

Francophone Postcolonial Studies: A Critical Introduction, Charles Forsdick and David Murphy (eds), (2003) London: Arnold, 305 pp., ISBN 0-340-80801-2 (hbk), 50, 0-340-80802-0 (pbk), 16.99

Of Suffocated Hearts
and Tortured Souls: Seeking Subjecthood through Madness in Francophone Women's Writing of Africa and the Caribbean, Valrie Orlando (2003) La Lanham, Lanham, Boulder, New York, Toronto, Oxford: Lexington Books, 197 pp., ISBN 0-7391-0563-9 (pbk), 25

Le Creuset des cultures:
la littrature antillaise, Jean Faustman (2004) New York: Peter Lang, 138 pp., ISBN 0-8204-6732-4 (hbk),39, 54.95, 55

Cacosme littraire. La fonction du personnage amricain dans le roman hatien partir de 1915, Jacques-Raphal Georges (2004) New York: Peter Lang, 179 pp.,
ISBN 0-8204-6196 (hbk), 36.40, 61.95, 52

Portrait du dcolonis arabo-musulman et de quelques autres, Albert Memmi (2004) Paris: Gallimard, 168 pp., ISBN 2070773779 (pbk), 15
Essai sur les essais dans la littrature des Antilles au tournant du xxe sicle
Authors: Fonkoua Romuald-Blaise
Published: April 2006

This is an article on essays in French Caribbean literature at the end of the last century. The essay is one of the ambiguous genres of French Caribbean literature. It is frequently practised in the Caribbean in journals and newspapers, autobiographies and novels, short stories and
theatre. Whether it appears collectively or individually, is written by one or various authors, the essay offers a loud and far-reaching voice and serves as Caliban's response to the questions of frustration, absence, and silence which are the consequences of slavery in the West Indies. The
main concern of the essay at the end of the twentieth century is to create and organize a new Creole reason in politics, history, and literature.
Voice and give voice: dialectics between fiction and history in narratives on the Rwandan genocide
Authors: Kerstens Paul
Published: April 2006

A considerable amount of literature has been produced on the genocide in Rwanda, from historical, political and sociological studies to testimonies, accounts and fiction. While the status of scientific texts is more or less clear, when it comes to fiction and journalism, the situation
is much more complex. Often, history and fiction merge. The character of the text's discourse and the narrator's viewpoint are not always obvious and in unison. How does the text function and how does it relate to reality and to history? Which knowledge does it seek to represent and spread?
This article examines the relations between fact and fiction in literary and journalistic texts. Each text is located on the continuum between the subjective and the objective.
Towards an integrated approach: university research management in an institutional context
Authors: Kirkland John
Published: April 2006

Universities throughout the world have become more proactive in the management of their research activity in response to an increasingly competitive global environment. Whilst the importance of robust structures is recognised, the precise mechanisms adopted vary between institutions.
Issues of particular concern are the extent to which professional research managers are able to forge effective relationships with academic departments and other administrative units of their universities, and the extent to which the strategy for research management is integrated into a wider
institutional strategy. This article, based on an intensive benchmarking study of fifteen higher education institutions from nine countries, identifies a range of approaches to address these issues, as well as highlighting specific examples of good practice that might be considered for wider
utilization.
Book Reviews
Authors: Shaw Lisa , Homewood Chris , Jones Stan , O'Leary Alan
Published: April 2006

Spanish Popular Cinema, Antonio Lzaro-Reboll and Andrew Willis (eds), (2004) Manchester: Manchester University Press, 256 pp., ISBN 0-7190-6282-9 (hbk), 49.99; ISBN 0-7190-6283-7 (pbk), 15.99

Hollywood Behind the Wall: The Cinema of East Germany, Daniela Berghahn
(2005) Manchester: Manchester University Press, ix + 294 pp., ISBN 0-7190-6172-5 (pbk), 16.99; ISBN 0-7190-6171-7 (hbk), 55.00

Von Neuseeland nach Mittelerde: Die Welt des Peter Jackson (From New Zealand to Middle Earth: The World of Peter Jackson), U. Vossen (ed.), (2003)
Marburg: Schren Verlag, 160 pp., ISBN 3-89472-349-1 (pbk), €14.90/SFr27.20

The Cinema of Nanni Moretti: Dreams and Diaries, Ewa Mazierska and Laura Rascaroli (2004) London: Wallflower Press, 178 pp., ISBN 1-903364-77-9 (pbk), 14.99
The servicelization of societies: towards new paradigms in work organization
Authors: de Almeida Paulo Pereira
Published: April 2006

This article proposes an alternative to the theoretical framework for the approaches to phenomena of the servicelization of work in complex organizational contexts. In contradiction to the models which question the industrialization processes, theoretical paradigms are presented which
highlight integration in the analyses of new concepts of work, such as co-production, the supremacy of the client/user, the evaluation of organizational performances and competence logic. Finally, a model of the service enterprise is presented with its alternative configurations in a proposal
for empirical application, some of which is now being carried out in Portugal.
Scheduling for rural and urban listeners on bilingual Radio Zimbabwe
Authors: Mano Winston
Published: April 2006

This article explores the ways in which Radio Zimbabwe (RZ) programme schedules reflect and affect Zimbabwean rural and urban daily life. Daily and weekly linkages between national radio programme schedules and national everyday life were analysed. I argue that RZ was popular because
its schedules appropriately approximated the habits of Zimbabwean national everyday life. It is the broadcasters' duty to reach audiences with relevant content at convenient times. The article is based on fieldwork in Zimbabwe, from 200003, involving interviews with RZ staff, its listeners
and observation notes. Scheduling was examined as part of the temporal and spatial aspects of RZ broadcasting, discussing how the radio service has adapted itself. Radio speaks to changed, and rapidly changing, structures of everyday life, and such change is not solely national- or mediacentric.
How differences in rural and urban structures of daily life, weekly routines and national reception contexts form part of an ongoing challenge for national radio broadcasters similar to RZ is shown.
A note on the time-non-homogeneous Johnson–Mehl tessellation
Authors: Horálek Vratislav
Published: April 2006

The main characteristics of the time-nonhomogeneous Johnson–Mehl tessellation with specified nucleation intensity α (t) = αtß, β > −1 and α > 0 being constants and t time, are investigated as functions of β.
Some properties of continuous-state branching processes, with applications to Bartoszyński’s virus model
Authors: Pakes Anthony G. , Trajstman A. C.
Published: April 2006

It is known that Bartoszyński’s model for the growth of rabies virus in an infected host is a continuous branching process. We show by explicit construction that any such process is a randomly time-transformed compound Poisson process having a negative linear drift.

This connection is exploited to obtain limit theorems for the population size and for the jump times in the rabies model. Some of these results are obtained in a more general context wherein the compound Poisson process is replaced by a subordinator.
Discounted branching random walks
Authors: Athreya K. B.
Published: April 2006

Let F(·) be a c.d.f. on [0,∞), f(s) = ∑∞0pjsi a p.g.f. with p0 = 0, < 1 < m = Σjpj < ∞ and 1 < ρ <∞. For the functional equation for a c.d.f. H(·) on [0,∞]

we establish that if 1 – F(x) = O(x–θ) for some θ > α =(log m)/(log p) there exists a unique solution H(·) to (∗) in the class C of c.d.f.’s satisfying 1 – H(x) = o(x–α).

We give a probabilistic construction of this solution via branching random walks with discounting. We also show non-uniqueness if the condition 1 – H(x) = o(x–α) is relaxed.
Random walks and periodic continued fractions
Authors: Woess Wolfgang
Published: April 2006

Nearest-neighbour random walks on the non-negative integers with transition probabilities p0,1 = 1, pk,k–1 = gk, pk,k+1 = 1– gk (0 < gk < 1, k = 1, 2, …) are studied by use of generating functions and continued fraction expansions. In particular, when (gk) is a periodic sequence, local limit theorems are proved and the harmonic functions are determined. These results are applied to simple random walks on certain trees.
The behavior of the ratio of a small-noise Markov chain to its deterministic approximation
Authors: Kaplan Norman , Darden Thomas
Published: April 2006

For eachN≧1, let {XN(t, x), t≧0} be a discrete-time stochastic process withXN(0) =x. LetFN(y)= E(XN(t +1) |XN(t) =y), and defineYN(t,x) =FN(YN(t –1,x)),t≧1 andYN(0,x) =x. Assume that in a neighborhood of the originFN(y)= mNy(l +O(y)) wheremN> 1, and define forδ> 0 andx> 0, υN(δ,x) = inf{t:xmtN>δ}. Conditions are given under which, forθ> 0 and ε> 0, there exist constantsδ> 0 andL<∞, depending on εand 0, such thatThis result together with a result of Kurtz (1970), (1971) shows that, under appropriate conditions, the time needed for the stochastic process {XN(t, 1/N),t≧0} to escape aδ-neighborhood of the origin is of order logΝδ/logmN. To illustrate the results the Wright-Fisher model with selection is considered.
Characterization problems in queueing and their stability
Authors: Kalashnikov V. V. , Rachev S. T.
Published: April 2006

The concept of a characterization and its stability for queueing models is introduced. The principle of two stages in the study of the stability property is formulated. A series of results concerning the G/G/1 model is obtained.
Asymptotic final-size distribution for some chain-binomial processes
Authors: Scalia-Tomba Gianpaolo
Published: April 2006

The classical Reed-Frost process is generalized by allowing infection probabilities to depend on current epidemic size. Such a process can be imbedded in a simple Markov process derived from i.i.d. waiting times. The final size of the epidemic has the same distribution as the time for the first crossing of a certain linear barrier of the imbedding process. The asymptotic distribution of the final size can be derived from some weak convergence results for the imbedding process. The existence of a distribution determining set of harmonic functions for these chain-binomial processes is also established.
DNA fragment mass distributions following molecular recombination
Authors: Darden Thomas A. , Resnick Michael A.
Published: April 2006

A mathematical model for the process of recombinational repair of DNA damage is presented. Based on the model, a method is proposed for analyzing fragment mass distributions from experiments designed to detect recombinational repair in cells. The procedures developed can be used to analyze experiments involving sucrose-gradient measurements of mass distributions. The model also provides a framework for discussion of various molecular models of this repair process.
A class of correlated cumulative shock models
Authors: Sumita Ushio , Shanthikumar J. George
Published: April 2006

In this paper we define and analyze a class of cumulative shock models associated with a bivariate sequence {Xn, Yn}∞n=0 of correlated random variables. The {Xn} denote the sizes of the shocks and the {Yn} denote the times between successive shocks. The system fails when the cumulative magnitude of the shocks exceeds a prespecified level z. Two models, depending on whether the size of the nth shock is correlated with the length of the interval since the last shock or with the length of the succeeding interval until the next shock, are considered. Various transform results and asymptotic properties of the system failure time are obtained. Further, sufficient conditions are established under which system failure time is new better than used, new better than used in expectation, and harmonic new better than used in expectation.
Conditional probabilities in Moran’s model
Authors: Haigh John , Lewis Richard P.
Published: April 2006

A result proved by Saunders et al. (1984) is generalised. This generalisation, and its proof, may help to explain some curiosities noted in the original result.
State space expansions and the limiting behavior of quasi-birth-and-death processes
Authors: Beuerman Steven L. , Coyle Edward J.
Published: April 2006

The notion of complete level crossing information, or LCI-completeness, is introduced for quasi-birth-death (QBD) processes. It is shown that state space expansions allow any QBD-process to be modified so that it is LCI-complete.

For any LCI-complete, QBD-process, there exists a matrix W such that , where is the vector of limiting probabilities for all states on level n of the process. When W cannot be found in closed form, it can be found via an algorithm requiring fewer than m steps, where m is the number of states on each level of the process. The result of this algorithm is always a linear matrix equation for which W is the solution.

In essentially all cases considered in this paper, the matrix W is a solution of the matrix quadratic

X2A2 + XA1 + A0 = 0.

Despite this fact, W is never equal to Neuts' rate matrix R, although the non-zero eigenvalues and the corresponding left eigenvectors of R are a subset of the eigenvalues and left eigenvectors of W. This fact leads to two methods for determining R from W.

If the transition rates of the QBD-process are level-dependent, then it is also shown that matrices W(n) exist such that .
On Littlewood's estimate for the binomial distribution
Authors: Mckay Brendan D.
Published: April 2006

We correct a theorem of J. E. Littlewood which gives an approximation for the tail of the binomial distribution. We also present several new approximations which are less accurate but have wider scope. One of them gives an estimate with relative error uniformly O(1/σ) over all values of all the parameters, where σ is the standard deviation.
Recent results on characterization of probability distributions: a unified approach through extensions of Deny&s theorem
Authors: Rao C. Radhakrishna , Shanbhag D. N.
Published: April 2006

The problem of identifying solutions of general convolution equations relative to a group has been studied in two classical papers by Choquet and Deny (1960) and Deny (1961). Recently, Lau and Rao (1982) have considered the analogous problem relative to a certain semigroup of the real line, which extends the results of Marsaglia and Tubilla (1975) and a lemma of Shanbhag (1977). The extended versions of Deny&s theorem contained in the papers by Lau and Rao, and Shanbhag (which we refer to as LRS theorems) yield as special cases improved versions of several characterizations of exponential, Weibull, stable, Pareto, geometric, Poisson and negative binomial distributions obtained by various authors during the last few years. In this paper we review some of the recent contributions to characterization of probability distributions (whose authors do not seem to be aware of LRS theorems or special cases existing earlier) and show how improved versions of these results follow as immediate corollaries to LRS theorems. We also give a short proof of Lau–Rao theorem based on Deny&s theorem and thus establish a direct link between the results of Deny (1961) and those of Lau and Rao (1982). A variant of Lau–Rao theorem is proved and applied to some characterization problems.
Stationary representation of queues. I
Authors: Szczotka Władysław
Published: April 2006

The paper deals with the asymptotic behaviour of queues for which the generic sequence is not necessarily stationary but is asymptotically stationary in some sense. The latter property is defined by an appropriate type of convergence of probability distributions of the sequences to the distribution of a stationary sequence We consider six types of convergence of to

The main result is as follows: if the sequence of the distributions converges in one of six ways then the sequence of distributions of the sequences converges in the same way, independently of initial conditions. Furthermore the limiting distribution is the same as the limiting distribution obtained by the weak convergence of the distributions Here wk and w∗k denote the waiting time of the kth unit in the queue generated by (v, u) and (v0, u0) respectively.
A simple derivation of an approximation to the transient blocking probability in a loss system
Authors: Yunus M. Naim
Published: April 2006

We present a simple derivation for an approximation to the transient blocking probability of an M/M/N loss system.
Some applications of the Stein-Chen method for proving Poisson convergence
Authors: Barbour A. D. , Holst Lars
Published: April 2006

LetWbe a sum of Bernoulli random variables andUλa Poisson random variable having the same meanλ = EW.Using the Stein-Chen method and suitable couplings, general upper bounds for the variational distance betweenWandUλare given. These bounds are applied to problems of occupancy, using sampling with and without replacement and Pólya sampling, of capture-recapture, of spacings and of matching and ménage.
On single-lane roads
Authors: Koning A. J.
Published: April 2006

A road which narrows at a bottleneck from an ∞-lane road to a one-lane road is studied with the aid of two stochastic processes. Special attention is given to headways and gaps. At the bottleneck an equilibrium headway can be viewed as the maximum of a shifted exponential random variable and a minimum headway. After the bottleneck the situation becomes far more complicated. However, limiting results are obtained for headways and gaps at a large distance from the bottleneck. The asymptotic behavior of headways and gaps is largely determined by the behavior of the desired speed distribution at the lower extreme of its support.
Non-stationaryq-dependent processes and time-varying moving-average models: invertibility properties and the forecasting problem
Authors: Hallin Marc
Published: April 2006

Thespectral factorization problemwas solved in Hallin (1984) for the class of (non-stationary)m-variate MA(q) stochastic processes, i.e. the class ofsecond-order q-dependent processes.It was shown that such a process generally admits an infinite (mq(mq+1)/2-dimensional) family of possible MA(q) representations. The present paper deals with theinvertibilityproperties and asymptotic behaviour of these MA(q) models, in connection with the problem of producingasymptotically efficient forecasts. Invertibleandborderline non-invertible modelsare characterized (Theorems 3.1 and 3.2). A criterion is provided (Theorem 4.1) by which it can be checked whether a given MA model is aWold–Cramér decompositionor not; and it is shown (Theorem 4.2) that, under mild conditions, almost every MA model is asymptotically identical with some Wold–Cramér decomposition. Theforecasting problemis investigated in detail, and it is established that the relevant invertibility concept, with respect toasymptotic forecasting efficiency,is what we define asGranger-Andersen invertibilityrather than theclassical invertibilityconcept (Theorem 5.3). The properties of this new invertibility concept are studied and contrasted with those of its classical counterpart (Theorems 5.2 and 5.4). Numerical examples are also treated (Section 6), illustrating the fact thatnon-invertible modelsmay provideasymptotically efficient forecasts,whereas invertible models, in some cases, may not. The mathematical tools throughout the paper are linear difference equations (Green's matrices,adjoint operators, dominated solutions, etc.), and a matrix generalization ofcontinued fractions.
Multistate reliability theory—a case study
Authors: Natvig Bent , Sørmo Skule , Holen Arne T. , Høgåsen Gutorm
Published: April 2006

Fortunately traditional reliability theory, where the system and the components are always described simply as functioning or failed, is on the way to being replaced by a theory for multistate systems of multistate components. However, there is a need for several convincing case studies demonstrating the practicability of the generalizations introduced. In this paper an electrical power generation system for two nearby oilrigs will be discussed. The amounts of power that may possibly be supplied to the two oilrigs are considered as system states.
A new class of markov processes for image encoding
Authors: Barnsley Michael F. , Elton John H.
Published: April 2006

A new class of iterated function systems is introduced, which allows for the computation of non-compactly supported invariant measures, which may represent, for example, greytone images of infinite extent. Conditions for the existence and attractiveness of invariant measures for this new class of randomly iterated maps, which are not necessarily contractions, in metric spaces such as , are established. Estimates for moments of these measures are obtained.

Special conditions are given for existence of the invariant measure in the interesting case of affine maps on . For non-singular affine maps on , the support of the measure is shown to be an infinite interval, but Fourier transform analysis shows that the measure can be purely singular even though its distribution function is strictly increasing.
A multiclass feedback queue in heavy traffic
Authors: Reiman Martin I.
Published: April 2006

We consider a single station queueing system with several customer classes. Each customer class has its own arrival process. The total service requirement of each customer is divided into a (possibly) random number of service quanta, where the distribution of each quantum may depend on the customer's class and the other quanta of that customer. The service discipline is round-robin, with random quanta.

We prove a heavy traffic limit theorem for the above system which states that as the traffic intensity approaches unity, properly normalized sequences of queue length and sojourn time processes converge weakly to one-dimensional reflected Brownian motion.
Processes with new better than used first-passage times
Authors: Shanthikumar J. G.
Published: April 2006

Let with Z(0) = 0 be a random process under investigation and N be a point process associated with Z. Both Z and N are defined on the same probability space. Let with R0 = 0 denote the consecutive positions of points of N on the half-line . In this paper we present sufficient conditions under which (Z, R) is a new better than used (NBU) process and give several examples of NBU processes satisfying these conditions. In particular we consider the processes in which N is a renewal and a general point process. The NBU property of some semi-Markov processes is also presented.
Quasi-input process in the M/G/1/∞ queue
Authors: Falin G. I.
Published: April 2006

We consider the flow of service starting times in the M/G/1/∞ queue and study some of its equilibrium properties.
Time-average optimal constrained semi-Markov decision processes
Authors: Beutler Frederick J. , Ross Keith W.
Published: April 2006

Optimal causal policies maximizing the time-average reward over a semi-Markov decision process (SMDP), subject to a hard constraint on a time-average cost, are considered. Rewards and costs depend on the state and action, and contain running as well as switching components. It is supposed that the state space of the SMDP is finite, and the action space compact metric. The policy determines an action at each transition point of the SMDP.

Under an accessibility hypothesis, several notions of time average are equivalent. A Lagrange multiplier formulation involving a dynamic programming equation is utilized to relate the constrained optimization to an unconstrained optimization parametrized by the multiplier. This approach leads to a proof for the existence of a semi-simple optimal constrained policy. That is, there is at most one state for which the action is randomized between two possibilities; at all other states, an action is uniquely chosen for each state. Affine forms for the rewards, costs and transition probabilities further reduce the optimal constrained policy to ‘almost bang-bang’ form, in which the optimal policy is not randomized, and is bang-bang except perhaps at one state. Under the same assumptions, one can alternatively find an optimal constrained policy that is strictly bang-bang, but may be randomized at one state. Application is made to flow control of a birth-and-death process (e.g., an M/M/s queue); under certain monotonicity restrictions on the reward and cost structure the preceding results apply, and in addition there is a simple acceptance region.
A new technique for analyzing large traffic systems
Authors: Weiss Alan
Published: April 2006

This paper presents a new technique for analyzing the frequency of a very large class of rare events in large traffic systems. The method is based on the theory of large deviations. If n is a large parameter, typically the number of potential traffic sources, then

where I is the solution to an associated variational problem. We present a new analysis of a previously solved system as well as an analysis of a previously intractable system. As by-products of our analysis, we obtain estimates of the transient behavior of the system, and show how they may be used in analyzing some flow control schemes.
Perturbation bounds for the stationary probabilities of a finite Markov chain
Authors: Haviv Moshe , Van Der Heyden Ludo
Published: April 2006

This paper discusses perturbation bounds for the stationary distribution of a finite indecomposable Markov chain. Existing bounds are reviewed. New bounds are presented which more completely exploit the stochastic features of the perturbation and which also are easily computable. Examples illustrate the tightness of the bounds and their application to bounding the error in the Simon–Ando aggregation technique for approximating the stationary distribution of a nearly completely decomposable Markov chain.
Single-server queues with impatient customers
Authors: Baccelli F. , Boyer P. , Hebuterne G.
Published: April 2006

We consider a single-server queueing system in which a customer gives up whenever his waiting time is larger than a random threshold, his patience time. In the case of aGI/GI/1 queue with i.i.d. patience times, we establish the extensions of the classicalGI/GI/1 formulae concerning the stability condition and the relation between actual and virtual waiting-time distribution functions. We also prove that these last two distribution functions coincide in the case of a Poisson input process and determine their common law.
Some comments on the simple queue
Authors: Ravichandran N. , Gravey A.
Published: April 2006

This communication provides an explicit expression for the joint probability of exactly i arrivals and j service completions in a duration of length t for the simple queue. The impossibility of a similar expression for the queue-length distribution is explained.