Analysis of Some Queueing Models Related To N-Policy: Operations Research

This study is about the analysis of some queueing models related to N-policy.The optimal value the queue size has to attain in order to turn on a single server, assuming that the policy is to turn on a single server when the queue size reaches a certain number, N, and turn him off when the system is empty.The operating policy is the usual N-policy, but with random N and in model 2, a system similar to the one described here.This study analyses “ Tandem queue with two servers”.Here assume that the first server is a specialized one.In a queueing system,under N-policy ,the server will be on vacation until N units accumulate for the first time after becoming idle.A modified version of the N-policy for an M│M│1 queueing system is considered here.The novel feature of this model is that a busy service unit prevents the access of new customers to servers further down the line.It is deals with a queueing model consisting of two servers connected in series with a finite intermediate waiting room of capacity k.Here assume that server I is a specialized server.For this model ,the steady state probability vector and the stability condition are obtained using matrix – geometric method.

T-Policy in Reliability and Inventory

In this thesis T-policy is implemented to the inventory system with random lead time and also repair in the reliability of k-out-of-n system. Inventory system may be considered as the system of keeping records of the amounts of commodities in stock. Reliability is defined as the ability of an entity to perform a required function under given conditions for a given time interval. It is measured by the probability that an entity E can perform a required function under given conditions for the time interval. In this thesis considered k-out-of-n system with repair and two modes of service under T-policy. In this case first server is available always and second server is activated on elapse of T time units. The lead time is exponentially distributed with parameter  and T is exponentially distributed with parameter  from the epoch at which it was inactivated after completion of repair of all failed units in the previous cycle, or the moment n-k failed units accumulate. The repaired units are assumed to be as good as new. In this study , three different situations, ie; cold system, warm system and hot system. A k-out-of-n system is called cold, warm or hot according as the functional units do not fail, fail at a lower rate or fail at the same rate when system is shown as that when it is up.

Impact of Monetary Policy on Indian Economy in the Post-Reform Period

The present study was an attempt to analyze systematically the techniques of monetary control measures with its relevance and changing importance and to find out their effectiveness in the Indian context especially to achieve the thriving objectives of price stability and economic growth.There is definite and remarkable economic impact of monetary policy on Indian economy in the post-reform period. The importance of monetary policy has been increasing year after year. Its role is very relevant in attaining monetary objectives, especially in managing price stability and achieving economic growth. Along that, the use and importance of monetary weapons like Bank rate, CRR, SLR, Repo rate and Reverse Rate have increased over the years. Repo and Reverse Repo rates are the most frequently used monetary techniques in recent years. The rates are varied mainly for curtailing inflation and absorb the excess liquidity and hence to maintain price stability in the economy. Thus, this short-time objective of price stability is more successful on Indian economy rather than other long-term objectives of development.Monetary policy rules can be active or passive. The passive rule is to keep the money supply constant, which is reminiscent of Milton Friedman’s money growth rule. The second, called a price stabilization rule, is to change the money supply in response to changes in aggregate supply or demand to keep the price level constant. The idea of an active rule is to keep the price level and hence inflation in check. In India, this rule dominates our monetary policy. A stable growth is healthy growth.

Queues with postponed work under N-policy

Department of Mathematics, Cochin University of Science and Technology

ON (s,S) inventory policy with/without retrial and interruption of services/production

In this thesis we have developed a few inventory models in which items are served to the customers after a processing time. This leads to a queue of demand even when items are available. In chapter two we have discussed a problem involving search of orbital customers for providing inventory. Retrial of orbital customers was also considered in that chapter; in chapter 5 also we discussed retrial inventory model which is sans orbital search of customers. In the remaining chapters (3, 4 and 6) we did not consider retrial of customers, rather we assumed the waiting room capacity of the system to be arbitrarily large. Though the models in chapters 3 and 4 differ only in that in the former we consider positive lead time for replenishment of inventory and in the latter the same is assumed to be negligible, we arrived at sharper results in chapter 4. In chapter 6 we considered a production inventory model with production time distribution for a single item and that of service time of a customer following distinct Erlang distributions. We also introduced protection of production and service stages and investigated the optimal values of the number of stages to be protected.

Wage policy in Indian industries

India is on the threshold of industrial and economic development. The growth would be retarded if harmonious employer-employee relations are not maintained. 'Wages' plays a fundamental role in establishing this relationship. However, much controversy in the industrial sphere revolves round the question of wages. Though formerly the laissez faire doctrine prevailed, with the emergence of the welfare state ideology, notions of national economy and social justice gained prominence. The problem of wages has became one with social, political, economic, psychological and legal dimensions. Formulation of a proper wage policy is thus a riddle. Realities of the present have to be fused with perspectives about the future. With due recognition of all significant factors, a proper balance has to be struck, which should be the hard core of any wage policy. This study emphasises the need for a wage policy which may meet the requirements of rapid economic growth and stable industrial relations. The study also indicates the proper bases for the promotien of such a policy.

A key based cache replacement policy for cooperative caching in mobile ad hoc networks

Cooperative caching in mobile ad hoc networks aims at improving the efficiency of information access by reducing access latency and bandwidth usage. Cache replacement policy plays a vital role in improving the performance of a cache in a mobile node since it has limited memory. In this paper we propose a new key based cache replacement policy called E-LRU for cooperative caching in ad hoc networks. The proposed scheme for replacement considers the time interval between the recent references, size and consistency as key factors for replacement. Simulation study shows that the proposed replacement policy can significantly improve the cache performance in terms of cache hit ratio and query delay

Studies on Inventory with Positive Service Time Under Local Purchase Driven by N/T- Policy

In this thesis, certain continuous time inventory problems with positive service time under local purchase guided by N/T-policy are analysed. In most of the cases analysed, we arrive at stochastic decomposition of system states, that is, the joint distribution of the system states is obtained as the product of marginal distributions of the components. The thesis is divided into ve chapters

Innovation and Globalization Policy in Small Transition Countries ; Case study: Macedonia and Slovenia

Diese Arbeit befasst sich mit der Innovations- und Globalisierungspolitik in kleinen Transformationsländern am Beispiel Mazedoniens; diese wurde mit der Lage in Slowenien verglichen, einem Land von ungefähr gleicher Größe und mit gemeinsamer Vergangenheit als Teilrepublik der Jugoslawischen Föderation, aber mit einem wesentlich höheren ökonomischen Entwicklungsstand. Innovation wird dabei verstanden als „Herstellung, Anpassung und Ausnutzung von Neuerungen“, und sie wird durch das Umfeld, in dem sie stattfindet, beeinflusst. Anpassung und Ausnutzung sind gerade für kleine Transformationsländer von erheblicher Bedeutung, da ihre Fähigkeit zu Herstellung von Neuerungen sehr begrenzt sind. Die Rolle der Innovationspolitik besteht hierbei darin, institutionelle und organisationelle Regulierungen einzuführen, die ein günstiges Umfeld sowohl für Innovationen als auch für die Entwicklung eines nationalen Innovationssystems schaffen. Die Rolle der Politik besteht also nicht in der Innovation als solcher, sondern in der Herstellung der notwendigen Bedingungen für die Industrie und die Forschungseinrichtungen dahingehend zu schaffen, dass sie ihr Wissen, ihre Fertigkeiten und ihre praktischen Erfahrungen für innovative Tätigkeiten einsetzen können. Auf der einen Seite gibt es Institutionen und Organisationen, ohne die die Unternehmen rückständig und wenig leistungsstark wären (etwa das Patentamt oder Institutionen höherer Bildung), und auf der anderen Seite gibt es Institutionen und Organisationen, welche die Unternehmen dabei unterstützen, dass sie ihre Tätigkeit weiter unterstützen (z.B. durch Technologietransfer-Zentren und Netzwerke). Die Leistungen dieser Institutionen und Organisationen sind von großer Bedeutung für die nationalen Innovationssysteme und sollten ihrerseits durch Innovationspolitik unterstützt werden; dies bedeutet jedoch nicht, dass diese Leistungen vom Staat bereitgestellt werden, vielmehr sollte die Wirtschaftspolitik Möglichkeiten für die öffentlich/private oder sogar rein private Bereitstellung solcher Leistungen in Erwägung ziehen; dies würde nicht nur die Kosten für den Staat senken, sondern auch die Effizienz bei der Erstellung dieser Leistungen steigern. Die Arbeit kommt zu dem Schluss, dass das größte Problem der Innovationspolitik in Mazedonien darin besteht, dass es sie gar nicht gibt, und zwar nicht als Folge einer bewussten Entscheidung darüber. Tatsächlich müssen Ressourcen und Zeit für die Schaffung eines nationalen Innovationssystems eingesetzt werden mit Hilfe einer Politik, die sich auf die wesentlichen Umrisse konzentriert, wobei die Nachfrage nach Technologie im Unternehmensbereich gesteigert wird und das Wissen und das Informationsangebot restrukturiert wird. Dieses System muss offen sein, unter beständigem Verbesserungsdruck stehen und fähig sein, sich an Veränderungen anzupassen. Damit eine solche Politik erfolgreich ist, muss es einen Konsens darüber zwischen allen beteiligten Akteuren geben und darüber hinaus auch eine Kohärenz zwischen den verschiedenen politischen Institutionen. Das ist deswegen wichtig, weil der Innovationsprozess komplex ist und verschiedene Politikbereiche berührt. Ziel sollte die Schaffung eines Systems sein, das einerseits auf Autonomie und Kooperation aufbaut, andererseits aber auch Wettbewerb zwischen den beteiligten Institutionen und Organisationen fördert. Eine wichtige Bedingung für ein positives Investitionsklima im Bereich der Innovation ist die Erreichung von makroökonomischer Stabilität. Die gegenwärtige Situation ist gekennzeichnet durch Instabilität des Rechtswesens, durch Korruption und Probleme des Vertragsschutzes, die sowohl ausländische als auch inländische Akteure davon abhält, sich in wirtschaftlichen Aktivitäten in Mazedonien zu engagieren. Bei der Suche nach einem Ausweg aus diesen Problemen ist es wichtig für Mazedonien, von anderen Ländern wie Slowenien zu lernen, die ähnliche Probleme haben, aber auch schon Erfahrungen in der Problemlösung. Man muss dabei beachten, dass der Entwicklungsstand, das wirtschaftliche und das politische Umfeld in beiden Vergleichsländern sich erheblich unterscheiden, so dass die Lektionen, die Mazedonien von Slowenien lernen könnte, nicht direkt übertragen und kopiert werden können, sondern entsprechend angepasst werden müssen. Die vorliegende Arbeit liefert Einsichten in die Probleme der Innovationspolitik in Transformationsländern und liefert daher sowohl einen Anreiz als auch eine Quelle von Informationen für künftige Analysen der wirtschaftlichen Bedingungen und vor allem Innovationspolitik in Transformationsländern.

Social Inequality and Social Policy outside the OECD

Almost all Latin American countries are still marked by extreme forms of social inequality – and to an extent, this seems to be the case regardless of national differences in the economic development model or the strength of democracy and the welfare state. Recent research highlights the fact that the heterogeneous labour markets in the region are a key source of inequality. At the same time, there is a strengthening of ‘exclusive’ social policy, which is located at the fault lines of the labour market and is constantly (re-)producing market-mediated disparities. In the last three decades, this type of social policy has even enjoyed democratic legitimacy. These dynamics challenge many of the assumptions guiding social policy and democratic theory, which often attempt to account for the specificities of the region by highlighting the purported flaws of certain policies. We suggest taking a different perspective: social policy in Latin American should not be grasped as a deficient or flawed type of social policy, but as a very successful relation of political domination. ‘Relational social analysis’ locates social policy in the ‘tension zone’ constituted by the requirements of economic reproduction, demands for democratic legitimacy and the relative autonomy of the state. From this vantage point, we will make the relation of domination in question accessible for empirical research. It seems particularly useful for this purpose to examine the recent shifts in the Latin American labour markets, which have undergone numerous reforms. We will examine which mechanisms, institutions and constellations of actors block or activate the potentials of redistribution inherent in such processes of political reform. This will enable us to explore the socio-political field of forces that has been perpetuating the social inequalities in Latin America for generations.

From evolution to co-evolution – An empirical study of the role of innovation, policy and public research in industrial dynamics

In the past decades since Schumpeter’s influential writings economists have pursued research to examine the role of innovation in certain industries on firm as well as on industry level. Researchers describe innovations as the main trigger of industry dynamics, while policy makers argue that research and education are directly linked to economic growth and welfare. Thus, research and education are an important objective of public policy. Firms and public research are regarded as the main actors which are relevant for the creation of new knowledge. This knowledge is finally brought to the market through innovations. What is more, policy makers support innovations. Both actors, i.e. policy makers and researchers, agree that innovation plays a central role but researchers still neglect the role that public policy plays in the field of industrial dynamics. Therefore, the main objective of this work is to learn more about the interdependencies of innovation, policy and public research in industrial dynamics. The overarching research question of this dissertation asks whether it is possible to analyze patterns of industry evolution – from evolution to co-evolution – based on empirical studies of the role of innovation, policy and public research in industrial dynamics. This work starts with a hypothesis-based investigation of traditional approaches of industrial dynamics. Namely, the testing of a basic assumption of the core models of industrial dynamics and the analysis of the evolutionary patterns – though with an industry which is driven by public policy as example. Subsequently it moves to a more explorative approach, investigating co-evolutionary processes. The underlying questions of the research include the following: Do large firms have an advantage because of their size which is attributable to cost spreading? Do firms that plan to grow have more innovations? What role does public policy play for the evolutionary patterns of an industry? Are the same evolutionary patterns observable as those described in the ILC theories? And is it possible to observe regional co-evolutionary processes of science, innovation and industry evolution? Based on two different empirical contexts – namely the laser and the photovoltaic industry – this dissertation tries to answer these questions and combines an evolutionary approach with a co-evolutionary approach. The first chapter starts with an introduction of the topic and the fields this dissertation is based on. The second chapter provides a new test of the Cohen and Klepper (1996) model of cost spreading, which explains the relationship between innovation, firm size and R&D, at the example of the photovoltaic industry in Germany. First, it is analyzed whether the cost spreading mechanism serves as an explanation for size advantages in this industry. This is related to the assumption that the incentives to invest in R&D increase with the ex-ante output. Furthermore, it is investigated whether firms that plan to grow will have more innovative activities. The results indicate that cost spreading serves as an explanation for size advantages in this industry and, furthermore, growth plans lead to higher amount of innovative activities. What is more, the role public policy plays for industry evolution is not finally analyzed in the field of industrial dynamics. In the case of Germany, the introduction of demand inducing policy instruments stimulated market and industry growth. While this policy immediately accelerated market volume, the effect on industry evolution is more ambiguous. Thus, chapter three analyzes this relationship by considering a model of industry evolution, where demand-inducing policies will be discussed as a possible trigger of development. The findings suggest that these instruments can take the same effect as a technical advance to foster the growth of an industry and its shakeout. The fourth chapter explores the regional co-evolution of firm population size, private-sector patenting and public research in the empirical context of German laser research and manufacturing over more than 40 years from the emergence of the industry to the mid-2000s. The qualitative as well as quantitative evidence is suggestive of a co-evolutionary process of mutual interdependence rather than a unidirectional effect of public research on private-sector activities. Chapter five concludes with a summary, the contribution of this work as well as the implications and an outlook of further possible research.

Modeling the Transport Sector: The Role of Existing Fuel Taxes in Climate Policy

Existing fuel taxes play a major role in determining the welfare effects of exempting the transportation sector from measures to control greenhouse gases. To study this phenomenon we modify the MIT Emissions Prediction and Policy Analysis (EPPA) model to disaggregate the household transportation sector. This improvement requires an extension of the GTAP data set that underlies the model. The revised and extended facility is then used to compare economic costs of cap-and-trade systems differentiated by sector, focusing on two regions: the USA where the fuel taxes are low, and Europe where the fuel taxes are high. We find that the interplay between carbon policies and pre-existing taxes leads to different results in these regions: in the USA exemption of transport from such a system would increase the welfare cost of achieving a national emissions target, while in Europe such exemptions will correct pre-existing distortions and reduce the cost.