160 research outputs found

    An investigation of interoperability issues between authorisation systems within web services

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    The existing authorisation systems within the context of Web Services mainly apply two access control approaches – Role-Based Access Control (RBAC) and Attribute-Based Access Control (ABAC). The RBAC approach links an authenticated Web Service Requester to its specific access control permission through roles, but RBAC is not flexible enough to cater for some cases where extra attribute information is needed in addition to the identity. By contrast, the ABAC approach has more flexibility, as it allows a Web Service Requester to submit necessary credentials containing extra attribute information that can fulfil the policies declared by a Web Service Provider, which aims to protect the sensitive resources/services.RBAC and ABAC can only help to establish a unilateral trust relationship between two Web Services to enable a Web Service Provider to make an access control decision. Unfortunately, the nature of Web Services presents a high probability that two Web Services may not know each other. Therefore, successful authorisation may fail, if the Web Service Requester does not trust the Web Service Provider.Trust Negotiation (TN) is also an access control approach, which can provide a bilateral trust relationship between two unknown entities, so it sometimes can enable authorisation success in situations where success is not possible through RBAC or ABAC approaches. However, interoperability issues will arise between authorisation systems within Web Services, where a bilateral trust-based authorisation solution is applied. In addition, a lack of a unified approach that can address the interoperability issues remains as a research problem. This research aims to explore possible factors causing the lack of interoperability first, and then to explore an approach that can address the interoperability issues. The main contributions of this research are an improved interoperability model illustrating interoperability issues at different layers of abstraction, and a novel interoperability-solution design along with an improved TN protocol as an example of utilising this design to provide interoperability between authorisation systems within Web Services

    Cold war heritage (and) tourism: exploring heritage processes within Cold War sites in Britain

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    A thesis submitted to the University of Bedfordshire in partial fulfilment ofthe requirements for the degree of Doctor of PhilosophyFor most of the second half of the 20th century the world's political map was divided by the Cold War, a name given to the 40-year long standoff between the superpowers - the Unites States and the USSR - and their allies. Due to its geographical location and alliance with the United States, Britain was at the 'frontline' of the Cold War. As a response to increasing tensions, the British Government made arrangements by building hundreds of military sites and structures, which were often dismantled or abandoned as the technology on which they relied became rapidly ineffective. Nowadays, there is a growing (academic) recognition of Cold War sites and their new or contemporary uses, including as heritage attractions within a tourism context. This study has brought forward a constructionist approach as to investigate how heritage works as a cultural and social practice that constructs and regulates a range of values and ideologies about what constitutes Cold War heritage (and) tourism in Britain. It has done this by, firstly, exploring the dominant and professional 'authorised heritage discourse', which aims to construct mutually, agreed and shared concepts about the phenomenon of 'Cold War heritage' within a tourism context. The study identified a network of actors, values, policies and discourses that centred on the concept of 'Cold War heritage' at selected sites through which a 'material reality' of the past is constructed. Although various opposing viewpoints were identified, the actors effectively seem to privilege and naturalise certain narratives of cultural and social meanings and values through tourism of what constitutes Cold War heritage and the ways it should be manifested through material and natural places, sites and objects within society. Differences were particularly noticeable in the values, uses and meanings of Cold iii Cold War heritage (and) tourism War heritage within the contemporary context of heritage management in Britain. For some, the sites were connected with a personal 'past', a place to commemorate, celebrate or learn from the past. For others, the sites were a source of income, a tourism asset, or contrary, a financial burden as the sites were not 'old enough' or 'aesthetically pleasing' to be regarded as a monument to be preserved as heritage. Subsequently, the study also explored the (disempowered) role of visitors to the sites as passive receivers, leaving little room for individual reflections on the wider social and cultural processes of Cold War heritage. Although, most visitors believed that the stewardship and professional view of the Cold War representations at the sites should not directly be contested, this study has illustrated the idea that what makes places valuable and gives them meaning as heritage sites is not solely based on contemporary practices by a dominant heritage discourse. Despite the visitors' support for the sole ownership by site managers, and the selective representations of the Cold War and events, they did question or negotiate the idea of 'heritage' as a physical and sole subject of management practices. Despite having little prior knowledge about the Cold War era or events, by pressing the borders of the authorised parameters of 'Cold War heritage', visitors actively constructed their experiences as being, or becoming, part of their personal and collective moments of 'heritage'. By inscribing (new) memories and meaning into their identity, and therefore also changing the nature of that identity, they reflected upon the past, present and future, (some more critically than others. To conclude, understanding these discursive meanings of Cold War heritage (and) tourism, and the ways in which ideas about Cold War heritage are constructed, negotiated and contested within and between discourses also contributes to understandings about the philosophical, historical, conceptual and political barriers that exist in identifying and engaging with different forms of heritage

    How Effective is the Invisible Hand? Agricultural and Food Markets in Central and Eastern Europe

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    Since the seminal work of Adam Smith, markets have been considered an efficient tool for co-ordinating the behaviour of economic agents. The basic characteristic of a market economy is that the complex system of interaction among individuals is not centrally coordinated. Under the assumption of profit and utility maximisation (and a whole set of assumptions about the institutional framework), relative prices and their change over time provide the signals that guide, like an invisible hand, the allocation of resources, i.e., the structure of production and the intensity of input use in the various production processes. They do this by co-ordinating the activities of economic agents, i.e., of resource owners, producers, intermediaries, traders, and consumers. After system change in the former Soviet Union and in Central and Eastern Europe (CEE) central economic planning had to be replaced by other forms of co-ordination. The general direction in all transition countries was towards a market economy, but the speed and depth of reforms towards an environment in which markets can evolve differed largely between countries, sectors and between different phases during the past 15 years. IAMO Forum 2005 focuses on this development and discusses the functioning of markets, the requirements for this, and the advantages and disadvantages of other co-ordination mechanisms under different environments in the agricultural and food sectors in Central and Eastern Europe. CEE agri-food markets deserve researchers' and policy makers' attention for several reasons. Two of them regard the high demand for support to policy decisions that aim to stimulate economic and social development in the region. In most CEE countries, the significance of the agricultural and food sector is relatively high with respect to income and employment. In particular, rural areas can benefit from the development of this branch of the economy. Also, there is marked indication that agri-food markets in CEE are not ensuring exchange as frictionless as possible. This means that large benefits can be expected if potential improvements of the economic environment are implemented and if individual agents adapt optimally to that environment. Another motivation for economic research on transition countries is that we are looking at a huge region that started almost as a vacuum with regard to institutional settings. This means that a wide range of substantially different settings were introduced in the respective countries, and were only weakly confined by political rigidities or path dependencies. From a distant perspective, the repeated fundamental shifts in recent economic policies almost evoke the impression of a trial and error approach. The consequences of distinctively different options (across countries and periods) can be observed in a way almost similar to a laboratory situation. Such unique opportunity has attracted economists, particularly those interested in institutional economics, to conduct research on CEE. However, this also means that the experiences made in CEEC can enhance the general understanding of what markets can do and what the limitations of market coordination are. This volume contains selected contributions presented at IAMO Forum 2005 and gives an overview of the major topics discussed there. Partial analyses of specific economic problems usually abstract from the general economic framework which is assumed to be more or less constant as expressed in ceteris paribus clauses. Oftentimes, the set of institutional conditions is even assumed to be sufficiently well-described by the framework used in neoclassical models. Particularly for transition countries, this has frequently led to spurious results because crucial aspects of the framework actually in place were not considered, and sometimes were not even thought of. An extreme and very obvious example is the neglect of the effects of the replacement of monetary by nonmonetary exchange in phases of a barter economy. There is no generic approach to avoid unintended omission of crucial framework conditions, but it must generally be emphasised that a broad look at the various interdependent markets and at the entire socioeconomic context of a country is needed before going into detail. Descriptive analyses of the situation in various markets form part of such a broad look. The contributions of POPP, FERTÃ et al., WILKIN et al., and HEIN in the chapter Selected analyses from CEEC provide excellent examples, and focus on market developments in new EU member countries. On the one hand, the papers show the heterogeneity of problems e.g. due to largely differing farm structures. On the other hand, several common patterns can be observed: The market shares and power of large processors and retailers (hypermarkets, etc.) are increasing. Also, international (especially intra-EU) trade in commodities has increased in response to CAP-induced price harmonisation. Both tendencies weaken the market position of farmers, particularly small entities which cannot supply in volumes sufficient for large processing and trade firms. Within the food industry concentration increased as many smaller firms could not comply with EU processing standards and had to quit the market. The increased size and specialization of large producers, as well as of large processors, made many of those firms co-ordinate business with each other through long-term contractual agreements rather than by relying on spot markets. This tendency is very distinct in the fruit and vegetable sector, as WILKINâs contribution describes. Two contributions draw attention to the institutional framework itself, mainly by looking at circumstances which prevent market allocation from leading to an optimal outcome. HOBBS describes factors that impede investment and growth by drawing on transaction cost economics. Situations typical for transition countries are highlighted where e.g. transparency is not sufficient or the existence and reliable enforcement of contract or corporate law are not guaranteed. NUPPENAU stresses the need for the appropriate and precise formulation of land property rights, which should evoke a balance between governance and exclusion. The importance of appropriate and reliable institutions to avoid flaws is emphasised. But even with suitable institutions, transaction costs cannot be reduced to zero. The main reason for this is that since agents may gain form a head start of information, incentives to reveal their knowledge are quite restricted. Furthermore, some of the information required to make correct decisions is not available. This especially concerns information regarding all future contingencies. An uncertain future and the asymmetric distribution of information impose special problems when decisions have long-term effects and agents are linked together through investment decisions. This offers possibilities for opportunistic behaviour, i.e., when an agent behaves in a way that allows him to extract rents from the partners' activities. The friction induced in such situations may result in a market outcome that is biased by transaction costs. Mitigating this bias should be a goal of public policy but it is also in the interest of (at least some of the) private agents involved. This issue is discussed in more detail in the papers dealing with alternative governance structures. A number of contributions to IAMO Forum highlight approaches for measuring the well-functioning of markets. While studies that aim to directly measure transaction costs are very rare and are necessarily limited to comparing only very specific portions of transaction costs, most studies focus on indirect indicators. These usually start from the idea that in a well-functioning, competitive market any supply or demand shocks are reflected in price changes, not only in the particular market where the shock occurs but also in other, related markets, i.e., in different locations or at different stages of the production and marketing chain. Consequently, an approach for assessing the functioning of markets is to compare price differentials with processing-, marketing- or transfer-costs, or â since these costs are usually difficult to quantify â to observe price differentials over time. Accepting the assumption that the costs reflected by price differentials are more or less constant (or stationary) over the observed time span, any additional price changes or a lack of price co-movement is interpreted as an indication for insufficiently connected or insufficiently functioning markets. Three contributions in the chapter Analytical approaches for measuring market efficiency describe analyses which mainly focus on the vertical dimension, i.e., between market stages. BOJNEC, in his descriptive price analysis for several agricultural products in Slovenia since 1991, finds a heterogeneous development of the farm gate/consumer price spread: The processing and marketing margins increased for wheat and beef while they declined for grapes (processed to wine), sugar and poultry. BRÃMMER and ZORYA, as well as BAKUCS and FERTÃ, use cointegration analysis to describe the degree and nature of vertical price integration in the Ukrainian wheat market and the Hungarian pork market, respectively. Both studies find that price changes are transmitted vertically, that there is a tendency to "correct" any deviations from some underlying equilibrium price-relationship. However, such error correction mechanisms are found not to be a constant, universal force. In the Hungarian paper, it could only be found for a sub-period of the observed time span, excluding the highly volatile early 1990s. Also, equilibrium was found to be achieved by adjustment of farm gate prices only while the retail prices were found to be exogenous, i.e., not responding to any disequilibrium. The paper on Ukraine shows that adjustment processes between wheat and wheat flour prices cannot be sufficiently described by a constant error correction mechanism for the period 2000 to 2004. In fact, four different regimes of adjustment processes were found to have been in force, reflecting particular phases of largely differing market situations and political interventions. The functioning of markets depends on several crucial conditions. One of these conditions concerns the availability of information. Only if agents have perfect and complete information will the exchange lead to an outcome in which no individual can be better off without reducing the welfare of others. However, in the real world this condition regarding information is not fulfilled. Information is not perfect, since the future cannot be predicted with certainty. Incomplete information results from, first, not all information being revealed, and second, individuals not possessing the mental capacity to collect and process all information. Moreover, because of its asymmetric distribution, information can be regarded as a resource that can be exploited by agents. This means that there are incentives to hamper the diffusion of information to the public domain. In general, the more uncertain the future is and the more information is tacit, the worse markets will function, and the more beneficial become alternative mechanisms of coordination. Three papers dealing with this issue of organisational choice. HANF focuses on governance structures within supply chain networks that are appropriate for allowing an optimal flow of information between the involved individuals while retaining the necessary hierarchy for efficient implementation of strategic decisions. MAACKâs analysis shows that there is strong mutual interest between producers and processors of berry fruits to reduce marketing and procurement risk, respectively. This can be achieved by switching from spot market exchange to contractual supply agreements. A prerequisite for such agreements is that a well-balanced distribution of risks and risk premiums between the farmer and processor is implemented. This means that processors, who â facing a multitude of small producers â are used to opportunities for exerting market power, have to agree to cover part of the production risk through appropriate contractual clauses. Finally, BALINT looks at the various marketing channels used by Romanian farmers and finds that a self-enforcing dualism exists. For commercially-oriented farmers who can supply large quantities, marketing directly to traders, wholesalers and processors is most favourable and involves relatively low transaction costs. Although this form of supply-relationship is usually not based on contractual agreements, it can still be characterised by a certain stability over time. In contrast, small farmers whose production does not considerably exceed the subsistence level incur relatively high (per unit) transaction costs in selling their produce on local markets and to other farmers. Another aspect of organisational choice is the question of whether ownership of production factors is transferred or only the right to use them temporarily. The uncertainty of future developments implies that the possession of resources cannot be only regarded from the point of view of income generation at a certain point in time. With perfect foresight, there is no difference whether a factor is rented or purchased, because the remuneration would be the same. This perfect substitutability is no longer given when the future is uncertain. Income generation, then, is only one feature of ownership. Additional aspects such as insurance, wealth, and speculation as motivations for possession affect the value of ownership and thus shift the demand and supply curves of the factor. HURRELMAN picks up this issue in her analysis of the Polish land market and shows the impact of additional grounds for valuing property on the decision to rent or to buy land. Uncertainty may also affect the specialization of factor use. Allocating a factor of production to different production activities reduces the risk of income instabilities, but at the cost of specialization gains through economics of scale. Moreover, the decision on income combination is â besides risk â affected by a complex interaction of other determinants. GLAUBEN et al., analyse these interactions for the case of part-time farming in China and show how the decision of income combination is affected by household characteristics, human capital and other variables. Incomplete and imperfect information not only causes individuals to choose optimal governance modes, often it is also understood as a call for government intervention. The selected papers in the chapter on policy intervention plead for careful selection and coherent implementation of policy instruments. BENNER, as well as KUHN, highlight the significance of information diffusion and argue in favour of government intervention in this area. However, both emphasise that these interferences should be used carefully and be adjusted to specific market failures. Both argue that setting up information systems would improve the functioning of markets. BENNER also discusses possible negative impacts if governments that engage in setting up and enforcing product and process standards try, at the same time, to foster a sector like agriculture through support in marketing. The latter activity affects the governmentâs (crucial) credibility in the first activity. KUHN points to negative welfare effects and budgetary requirements of an intervention system which is implemented to increase price stability. Moreover, when a government intervenes in market allocation or intends to provide rules that should facilitate the exchange on markets, it has to take into account that the new regulation has to be implemented in a coherent manner. This requires the various policy regulations and institutional settings to be complementary and not cause frictions which hamper the functioning of the system. LERMAN and SHAGAIDA highlight this aspect in their discussion of the Russian land market, where bureaucracy and high costs for the registration of property rights can be regarded as a major cause of the low number of land transactions. However, since economic activities take place in a dynamic environment, the comparative static point of view may lead to inappropriate policy formulation. WANDEL discusses this aspect in the context of competition policy. From a comparative static point of view, market power has to be assessed negatively because of the distortions of resource allocation. However, monopoly profits are an indicator of extra rents and thus provide incentives for market entry. On the one hand, this thread may lead to special pricing schemes and/or to the accelerated development of technological change so that a monopolist can consolidate its market position. But it is possible, on the other hand, that market entry may in fact happen. In this case, one would observe structural change, which would be accompanied by an improved use of resources. This in turn means that competition policy should not be oriented towards an optimal market structure but towards the facilitation of market entry so that competition can discover market opportunities and determine the optimal structure of the market. The present volume shows the wide range of interesting and controversial topics that are concerned when looking at co-ordination, particularly on markets in CEE agri-food sectors. It remains a hope that the heterogeneity and dynamics of the developments will decrease as successful constellations of framework conditions, organisational choices and individual behaviour become more and more obvious and widespread in the region. Conversion to sustainable, balanced patterns might take place, but this cannot be taken for granted. However, chances for such development are better the more stable and balanced political developments, as well as international co-operation, become. We hope that the academic community will contribute towards such goal.Agribusiness, Community/Rural/Urban Development, Industrial Organization, International Development, Labor and Human Capital, Land Economics/Use, Political Economy,

    Advances in the sociology of trust and cooperation: theory, experiments, and field studies

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    The problem of cooperation and social order is one of the core issues in the social sciences. The key question is how humans, groups, institutions, and countries can avoid or overcome the collective good dilemmas that could lead to a Hobbesian war of all against all. Using the general set of social dilemmas as a paradigmatic example, rigorous formal analysis can stimulate scientific progress in several ways. The book, consisting of original articles, provides state of the art examples of research along these lines: theoretical, experimental, and field studies on trust and cooperation. The theoretical work covers articles on trust and control, reputation formation, and paradigmatic articles on the benefits and caveats of abstracting reality into models. The experimental articles treat lab based tests of models of trust and reputation, and the effects of the social and institutional embeddedness on behavior in cooperative interactions and possibly emerging inequalities. The field studies test these models in applied settings such as cooperation between organizations, informal care, and different kinds of collaboration networks. The book will be exemplary for rigorous sociology and social sciences more in general in a variety of ways: There is a focus on effects of social conditions, in particular different forms of social and institutional embeddedness, on social outcomes. Theorizing about and testing of effects of social contexts on individual and group outcomes is one of the main aims of sociological research. Modelling efforts include formal explications of micro-macro links that are typically easily overlooked when argumentation is intuitive and impressionistic Extensive attention is paid to unintended effects of intentional behavior, another feature that is a direct consequence of formal theoretical modelling and in-depth data-analyses of the social processe

    Advances in the Sociology of Trust and Cooperation

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    The book identifies conditions for trust and cooperation. It highlights unintended consequences of individually rational behavior, and shows how trust and cooperation change dependent on social embeddedness. Such analyses inspire experimental tests in lab conditions, but also tests through empirical applications in field studies. The results of this mixed-method approach can in turn be used to inspire further theoretical work
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