Two-queue polling systems with switching policy based on the queue that is not being served

We study a system of two non-identical and separate M/M/1/? queues with capacities (buffers) C₁ < ∞ and C₂ = ∞, respectively, served by a single server that alternates between the queues. The server’s switching policy is threshold-based, and, in contrast to other threshold models, is determined by the state of the queue that is not being served. That is, when neither queue is empty while the server attends Q_i (i = 1, 2), the server switches to the other queue as soon as the latter reaches its threshold. When a served queue becomes empty we consider two switching scenarios: (i) Work-Conserving, and (ii) Non-Work-Conserving. We analyze the two scenarios using Matrix Geometric methods and obtain explicitly the rate matrix R, where its entries are given in terms of the roots of the determinants of two underlying matrices. Numerical examples are presented and extreme cases are investigated.     

Globalized Hopes and Disillusions

In contrast to the common tendency to see war as the result of leadership decisions based on risk assessments, and political and economic considerations about gains or losses, we use a constructivist and institutional perspective to historicize and politicize the way “nation‐state interests” and “nation‐state preferences” even in a decision to go to war are socially constructed and culturally embedded. We maintain that with the end of the Cold War, many societies found themselves at a crossroads where they had to resolve internal conflicts in regards to neoliberal globalization. These internal conflicts and a crisis of identity, between those who supported the principle of globalization and regarded it as a promise for democracy, openness, liberty and peace, and those who saw it as a danger to their exceptionality and distinctiveness, ended in wars (either internal wars or external wars) when the objectors of neoliberal globalization succeeded in creating an institutional turn which presented war as the “efficient,” “necessary,” “legitimate”, or “desired” solution to the new threatening reality. We demonstrate the validity of this argument by using Israel as a test case, examining how institutional changes in the 1990s, arising from internal societal conflicts around the Oslo Agreements, led the state to move from the brink of peace to new wars despite exogenous objections to its policy.     

The Temporal Structure of Scientific Consensus Formation

This article engages with problems that are usually opaque: What trajectories do scientific debates assume, when does a scientific community consider a proposition to be a fact, and how can we know that? We develop a strategy for evaluating the state of scientific contestation on issues. The analysis builds from Latour's black box imagery, which we observe in scientific citation networks. We show that as consensus forms, the importance of internal divisions to the overall network structure declines. We consider substantive cases that are now considered facts, such as the carcinogenicity of smoking and the non-carcinogenicity of coffee. We then employ the same analysis to currently contested cases: the suspected carcinogenicity of cellular phones, and the relationship between vaccines and autism. Extracting meaning from the internal structure of scientific knowledge carves a niche for renewed sociological commentary on science, revealing a typology of trajectories that scientific propositions may experience en route to consensus.     

Forecasting: A hybrid approach

It has recently been shown that the Box-Jenkins approach to forecasting time series is superior to an econometric approach over a relatively short horizon. The results here support this contention. A combination of the two approaches, however, proves to be clearly superior to either one separately. By taking account of changes in economic and weather related variables in a time series model, improved forecasts are obtained.     

Social integration and dialect divergence in coastal Palestine

The history of Palestine has caused communities to be displaced and relocated, entailing that speech communities have been dismantled and created anew. The coastal cities of Jaffa and Gaza exemplify this reality. This study analyzes speakers from Jaffa, some of whom remained there and others residing in Gaza as refugees. Through an examination of three variables, (?), (AH), and (Q), we shed light on the effects of dialect contact while highlighting the link between dialect contact and identity formation and maintenance. All three variables are found to be in varied states of change as a result of contact with other varieties of Arabic, as well as with Modern Hebrew. We conclude that (Q), through its high social salience, works to create and maintain a sense of community identity for Jaffan refugees in Gaza at a time when the speech of the larger Jaffa community is undergoing substantial linguistic change.     

Limits to professional practice in decentralized systems

The decentralization of welfare systems and the introduction of “community social work” may confront social workers with tasks they were not trained for and limit their ability to function professionally. The experience of other countries may be relevant to the debate about localism in Britain. In Israel, the publicly directed local community centres have shifted their focus from leisure to welfare services. Trained social workers were employed to initiate and implement personal, group and other local services using local resources and charging fees for services. They reported having difficulties in defining local needs and wants, and in finding congruent solutions for these needs. They also found it difficult to negotiate with community politicians and work with them. This paper describes the Israeli system of community service centres and indicates some obstacles concerning the knowledge, skills, and attitudes of social workers functioning in an independent, decentralized practice. It also raises some selected issues for future social policy and service administration.     

Is a military coup possible in Israel? Israel and French-Algeria in comparative historical-sociological perspective

Theory and Society -     

Incentives to Exercise

Can incentives be effective in encouraging the development of good habits? We investigate the post‐intervention effects of paying people to attend a gym a number of times during one month. In two studies we find marked attendance increases after the intervention relative to attendance changes for the respective control groups. This is entirely driven by people who did not previously attend the gym on a regular basis. In our second study, we find improvements on health indicators such as weight, waist size, and pulse rate, suggesting the intervention led to a net increase in total physical activity rather than to a substitution away from nonincentivized ones. We argue that there is scope for financial intervention in habit formation, particularly in the area of health.     

Identifying Jewish names in Russia

SOVIET SAGA OF A JEWISH FAMILY

TYAZHELY PESOK (Heavy Sand),* by Anatoly Rybakov, in Oktyabr, nos. 7, 8, 9, 1978.

JEWS, DETENTE AND DISSENT

EXIT VISA. DETENTE, HUMAN RIGHTS AND THE JEWISH EMIGRATION MOVEMENT IN THE USSR, by Colin Shindler. London, Bachman &; Turner, 1978. 291 pp. Illus. Appendices. Bibl. Index. £7.50.

AN INTERESTING DEVELOPMENT

NASTOLNY IUDEYSKY KALENDAR NA 5739 god (Jewish Religious Calendar for 5739/1978–79), edited by S. L. Kleynman. Moscow Religious Society, 1978. 200 pp.

MINORITY NATIONALITIES IN THE USSR

L'EMPIRE ECLATE: LA REVOLTE DES NATIONS EN URSS, by Helene Carrere d'Encausse. Paris. Flammarion, 1978. 314 pp. Graphs and Tables.