Naming and discovery in networks : architecture and economics

In less than three decades, the Internet was transformed from a research network available to the academic community into an international communication infrastructure. Despite its tremendous success, there is a growing consensus in the research community that the Internet has architectural limitations that need to be addressed in a effort to design a future Internet. Among the main technical limitations are the lack of mobility support, and the lack of security and trust. The Internet, and particularly TCP/IP, identifies endpoints using a location/routing identifier, the IP address. Coupling the endpoint identifier to the location identifier hinders mobility and poorly identifies the actual endpoint. On the other hand, the lack of security has been attributed to limitations in both the network and the endpoint. Authentication for example is one of the main concerns in the architecture and is hard to implement partly due to lack of identity support. The general problem that this dissertation is concerned with is that of designing a future Internet. Towards this end, we focus on two specific sub-problems. The first problem is the lack of a framework for thinking about architectures and their design implications. It was obvious after surveying the literature that the majority of the architectural work remains idiosyncratic and descriptions of network architectures are mostly idiomatic. This has led to the overloading of architectural terms, and to the emergence of a large body of network architecture proposals with no clear understanding of their cross similarities, compatibility points, their unique properties, and architectural performance and soundness. On the other hand, the second problem concerns the limitations of traditional naming and discovery schemes in terms of service differentiation and economic incentives. One of the recurring themes in the community is the need to separate an entity\u27s identifier from its locator to enhance mobility and security. Separation of identifier and locator is a widely accepted design principle for a future Internet. Separation however requires a process to translate from the identifier to the locator when discovering a network path to some identified entity. We refer to this process as identifier-based discovery, or simply discovery, and we recognize two limitations that are inherent in the design of traditional discovery schemes. The first limitation is the homogeneity of the service where all entities are assumed to have the same discovery performance requirements. The second limitation is the inherent incentive mismatch as it relates to sharing the cost of discovery. This dissertation addresses both subproblems, the architectural framework as well as the naming and discovery limitations

Change blindness: eradication of gestalt strategies

Arrays of eight, texture-defined rectangles were used as stimuli in a one-shot change blindness (CB) task where there was a 50% chance that one rectangle would change orientation between two successive presentations separated by an interval. CB was eliminated by cueing the target rectangle in the first stimulus, reduced by cueing in the interval and unaffected by cueing in the second presentation. This supports the idea that a representation was formed that persisted through the interval before being 'overwritten' by the second presentation (Landman et al, 2003 Vision Research 43149–164]. Another possibility is that participants used some kind of grouping or Gestalt strategy. To test this we changed the spatial position of the rectangles in the second presentation by shifting them along imaginary spokes (by ±1 degree) emanating from the central fixation point. There was no significant difference seen in performance between this and the standard task [F(1,4)=2.565, p=0.185]. This may suggest two things: (i) Gestalt grouping is not used as a strategy in these tasks, and (ii) it gives further weight to the argument that objects may be stored and retrieved from a pre-attentional store during this task

A Typology of Multilateral Treaty Obligations: Are WTO Obligations Bilateral or Collective in Nature?

An important, though oft neglected, distinction between multilateral treaty obligations separates obligations of the bilateral nature from those of the collective or erga omnes partes type. Multilateral obligations of the bilateral type can be reduced to a compilation of bilateral, state-to-state relations. They can be compared to contracts. Collective obligations, in contrast, cannot be divided into bilateral components. They are concluded in pursuit of a collective interest that transcends the individual interests of the contracting parties. The standard example of such obligations are those arising under a human rights treaty. In domestic law, collective obligations can be compared to criminal law statutes or even domestic constitutions. This essay examines the origins of the distinction between bilateral and collective obligations, as well as its major consequences, both in law of treaties and the law on state responsibility. On that basis, a wider typology of multilateral treaty obligations is suggested. In the exercise, obligations arising under the World Trade Organization are used as a case study. The argument is made that WTO obligations remain essentially of the bilateral type; they are not collective in nature

Doctor of Philosophy

dissertationThe hippocampus (HPP) plays an important role in episodic memory, or memory for an event that occurs in a specific place and time, and there is evidence to suggest that the HPP is involved in processing spatiotemporal information in order to form context;ual representations of memory events. The HPP is not a homogeneous structure, but instead is comprised of anatomically distinct subregions, including the dentate gyrus (DG), CA3, and CA1, associated with separate mnemonic processing functions that contribute to episodic memory formation. Specifically, the DG is thought to support spatial processing functions, whereas the CA1 subregion has been implicated in temporal processing. Despite considerable advances in our understanding of the unique contributions of HPP subregions to learning and memory processes, the role of the dorsal DG (dDG) in spatial processing as it relates to spatial representations is not entirely understood or agreed upon. Given the importance of spatial representations to spatial navigation and episodic memory function, the current investigation sought to further define the role of the dDG in spatial processing through a series of studies that explored the nature of spatial memory representations. The results suggest that the dDG plays a critical role in (1) the integration of multimodal information into unique representations of the spatial environment via conjunctive encoding, (2) the reduction of interference among similar spatial locations via spatial pattern separation, and (3) the formation of temporal associations among distinct spatial events via temporal integration. Taken together, the present findings provide evidence for a dynamic role for the dDG in spatial processing by demonstrating the importance of an intact dDG across a variety of spatial tasks and under a variety of learning and memory demands

Geographic Information Systems and Decision Processes for Urban Planning: A Case Study of Rough Set Analysis on the Residential Areas of the City of Cagliari, Italy

In Italy, urban planning is based on the city Masterplan. This plan identifies the future urban organization and a system of zoning rules. Land-use policies are based on these rules. The zoning rules should synthesize environmental and spatial knowledge and policy decisions concerning the possible futures, with reference to the different urban functions. In this essay, a procedure of analysis of the city Masterplan of Cagliari, the regional capital city of Sardinia (Italy), is discussed and applied. This procedure is referred to the residential areas. The procedure tries to explain the urban organization of the housing areas using a system of variables based on the integration of different branches of knowledge concerning the urban environment. The decisions on the urban futures that the zoning rules entail are critically analyzed in terms of consistency with this knowledge system. The procedure consists of two phases. In the first phase, the urban environment is analyzed and described. This is done by defining and developing a geographic information system. This system utilizes a spatial analysis approach to figure out the integration of the residential areas into the urban fabric. The second phase is inferential. Based on the geographic information system developed in the first phase, a knowledge discovery in databases (KDD) technique, the rough set analysis (RSA), is applied. This technique allows to recognize the connection patterns between the urban knowledge system and the city planning decisions. The patterns, the decision rules, which come from the RSA implementation are important starting points for further investigation on the development of decision models concerning urban planning.

Quantifying the shadow economy: measurement with theory

We construct a dynamic, general equilibrium model of tax evasion where agents choose to report some of their income. Unreported income requires using a payment method that avoids recordkeeping – cash. Trade using cash to avoid taxes is the theoretical measure of the shadow economy from our model. We then calibrate our model using money, interest rate and GDP data to back out the size of the shadow economy for a sample of 30 countries and compare our estimates to traditional ad hoc estimates. Our results generate reasonably larger estimates for the size of the shadow economy than exist in previous literature.>Informal sector (Economics) ; Taxation ; Credit

Quantitative Techniques in Participatory Forest Management

Forest management has evolved from a mercantilist view to a multi-functional one that integrates economic, social, and ecological aspects. However, the issue of sustainability is not yet resolved. Quantitative Techniques in Participatory Forest Management brings together global research in three areas of application: inventory of the forest variables that determine the main environmental indices, description and design of new environmental indices, and the application of sustainability indices for regional implementations. All these quantitative techniques create the basis for the development of scientific methodologies of participatory sustainable forest management

Improving the Use of Experimental Auctions in Africa: Theory and Evidence

Experimental auctions have not been widely used in Africa. However, auctions are important tools for evaluating new products and technologies. To increase the quality of these experiments, we explore an alternative first-price bidding mechanism that is more similar to African market exchanges and we analyze factors likely to affect bidding. Experiments with African consumers show that the proposed first-price mechanism has no advantage over conventional second-price mechanisms. Results show high and significant cash-in-hand, experimenter, and time of day effects in main rounds, and significant ordering effects in test rounds. These effects need to be carefully considered when applying the Becker-DeGroot-Marschak mechanism in Africa.Africa, BDM mechanism, experimenter effect, first-price auction, income effect, order effect, time of day effect, Research Methods/ Statistical Methods,

Securing EU neighborhood - an ideational approach to EU-neighborhood relations

This paper analyses the interrelationship between internal and external security discourses in the field of European Union's neighbourhood policy. The European Union can be observed to actively use security concepts developed in the internal policy-field of Justice and Home Affairs as guiding principles of its foreign policy. This development can be traced at least to the beginning of the enlargement process in the turn of the 1990s. The paper firstly examines how those discourses infuse the new domain of neighbourhood policy that starts to take shape in the early 2000s. It concludes that especially since the European Security Strategy (2003) started to talk of the neighbourhood as a security issue, the policy can be considered to have become an inherent part of the Union's security priorities. Secondly, the paper examines from a theoretical point of view the role of ideas for institutional identity-building. Using the empirical analysis of the neighbourhood discourses as its departure point, the paper considers what this particular type of discourse can tell about the political entity that has emitted it. The research thus rejects the rationalist assumption of separable structure and agency. Instead it subscribes to the discursive institutionalist theory according to which institutions themselves are ideational structures that cannot be treated separately from actors who constitute them. Building its argument on the theses of critical security studies, the work concludes that by conceptualising the neighbourhood in terms of security threat the Union constructs itself as a political community with societal accountability

Social and economic influences on restructuring rural landscapes for biodiversity conservation: Remnant vegetation in the West Australian wheatbelt as a case study

In Australia, biodiversity loss is a national concern, especially in agricultural landscapes such as the West Australian wheatbelt. Landscape restructuring offers a means of ameliorating such losses. If restructuring is to occur, the associated actions must match the ‘triple bottom line’, they must be economically gainful, socially adoptable and ecologically possible. This paper addresses one component of this bottom line, social influences. To further focus this discussion, remnant vegetation conservation, one important element of managing for biodiversity, is explored on private lands in the WA wheatbelt. The social influences on the landscapes of the WA wheatbelt are cultural, political and economic. History and attitudes can be considered key elements of culture. Historically, the WA wheatbelt has experienced a number of ‘waves’ of clearing of remnant vegetation, generally directed toward improving the nation’s agricultural production as well as populating rural areas. In terms of attitudes, the majority of landholders in the wheatbelt talk positively about nature conservation. Unfortunately, however, results from research in Australia and elsewhere indicates that the links between attitudes and behaviour are tenuous. In Australian agricultural areas behaviour is better predicted and influenced by landholders’ perceptions of environmental problems, the financial constraints they face, and the farming subculture to which they belong. Politically in Australia, the character of rural landscapes is predominantly influenced by state governments. In terms of economic influences, if a change is not economically viable, rural landholders will not make it. In Australia as elsewhere, governments seek to restructure rural landscapes through applying policy instruments. These are tools, generally used by government, to change how people behave. Instruments available to conserve remnant vegetation on private lands include motivational ones (eg, education, partnerships), financial (eg, subsidies), market-based (eg, tradeable rights), self-regulatory (eg, codes of practice) and regulatory (eg, regulations). Most are voluntary with current trends favouring such approaches. In particular, policy makers are interested in market-based and self-regulatory instruments, as both are perceived as righting current market failures. A question vexing policy makers and others is selecting the ‘best’ policy instrument(s) to achieve biodiversity conservation. Principles can be derived to help answer this question. Of central importance is selecting more than one instrument and making sure the instrument mix is complementary. Clearly identifying the property rights associated with remnant vegetation on private lands, and therefore who pays for and receives the associated costs and benefits, is also important. Crucial too is matching the policy instrument with the appropriate institution, whether it is Commonwealth, state or local government, industry, a community group or individual. And last, because regions and their landscapes have different legal, social and environmental features, different landscapes will require different policy mixes