Arguing satisfaction of security requirements

This chapter presents a process for security requirements elicitation and analysis, based around the construction of a satisfaction argument for the security of a system. The process starts with the enumeration of security goals based on assets in the system, then uses these goals to derive security requirements in the form of constraints. Next, a satisfaction argument for the system is constructed, using a problem-centered representation, a formal proof to analyze properties that can be demonstrated, and structured informal argumentation of the assumptions exposed during construction of the argument. Constructing the satisfaction argument can expose missing and inconsistent assumptions about system context and behavior that effect security, and a completed argument provides assurances that a system can respect its security requirements

Centralization Versus Decentralization in Credit Lending

This paper explores different organizational forms in terms of their ability to generate information about investment projects and allocate capital to these projects efficiently. A decentralized approach-with small, single-manager firms- is most likely to be attractive when information about individual projects is “non-verifiable” and cannot be credibly transmitted. Moreover, holding fixed firm size, non-verifiable information also favors flatter organizations with fewer layers of management. In contrast, large hierarchical firms with multiple layers of management are at comparative advantage when information can be costlessly “verified” and passed along within the hierarchy. As a concrete application of the theory, the paper discusses the consequences of consolidation in the banking industry. It has been documented that when large banks acquire small banks, there is a pronounced decline in lending to small businesses. To the extent that small-business lending relies heavily on non-verifiable information, this is exactly what the theory would lead one to expect.

The Anatomy and Facets of Dynamic Policies

Information flow policies are often dynamic; the security concerns of a program will typically change during execution to reflect security-relevant events. A key challenge is how to best specify, and give proper meaning to, such dynamic policies. A large number of approaches exist that tackle that challenge, each yielding some important, but unconnected, insight. In this work we synthesise existing knowledge on dynamic policies, with an aim to establish a common terminology, best practices, and frameworks for reasoning about them. We introduce the concept of facets to illuminate subtleties in the semantics of policies, and closely examine the anatomy of policies and the expressiveness of policy specification mechanisms. We further explore the relation between dynamic policies and the concept of declassification.Comment: Technical Report of publication under the same name in Computer Security Foundations (CSF) 201

Parameter analysis of copper-nickel-tungsten prepared via powder metallurgy process for electrical discharge machining of polycrystalline diamond

Polycrystalline Diamond (PCD) tools have an outstanding wear resistance. The electric conductivity of PCD caused by the conductive binding material (Cobalt) makes it possible to machine PCD tools with EDM. Electrode used in EDM of PCD must have better porosity, electrical and thermal conductivity. Therefore, this research presents the works in production of Cu-Ni-W electrode by powder metallurgy route. Production of powder metallurgy parts involve mixing of the powder with additives or lubricants, compacting the mixture and heating the green compacts in an Argon gas furnace so the particle bond to each other. Two levels of full factorial with six centre points and two replication technique was used to study the influence of main and interaction effects of the powder metallurgy parameter. There were four factors involved in this experiment. Factor A which is Type of Cu-Ni; Type A and Type B was defined as categorical factor. Factor B in which Composition of W; 5 Wt.%, 15 Wt. % and 25 Wt.%, was defined as numerical factor. Factor C which is the Compaction load; 7, 8 and 9 tonne and Factor D which is Sintering temperature; 635 ℃, 685 ℃ and 735 ℃ were also defined as numerical factor. Optical Microscope, Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray (EDX) was used to analysed the microstructure and surface morphology of Cu-Ni-W electrode. The best parameter combination to produced better porosity, electrical and thermal conductivity for both Type A and Type B was 5 Wt.% of W, compaction load at 9 tonne and sintering temperature at 735℃. The best response for Type A is 12.65% of porosity, 14.40 IACS% of electrical conductivity and 413.26 W/m.℃ of thermal conductivity. While that, the best response for Type B were 9.36% of porosity, 16.66 IACS% of electrical conductivity and 345.21W/m.℃ of thermal conductivity. From the calculation of Maxwell’s Equation, Type A and Type B had the highest electrical conductivity of 58.48 IACS% and 77.35 IACS% respectively at W content of 5Wt.%. Type A and Type B also had the highest thermal conductivity of 369.86 W/m.℃ and 310.24 W/m.℃ respectively at W content of 5 Wt.%. Besides that, thermal conductivity also increased with the temperature increased until 450℃

Motivation theories and implications for teaching and learning in the biosciences

Learning is fundamental throughout the development of human life. It is also known that motivation is a key factor to successful learning. The pre-entry attributes of the student (Terenzini & Pascarella, 1980) including their own internal attitudes and motivations, are considered important for successful integration into a university system. In addition, Tinto (1975) has maintained that pre-university schooling is important for academic and social integration of students and hence their learning and motivation as deduced from successful completion rates. A pivotal goal of higher education is for students ‘to learn how to learn.’ A variety of teaching approaches encourage students to adopt a deep approach to learning by seeking a personal understanding. Within the science domain, the recent Science and Innovation White Paper (HEFCE 2008) highlighted ‘the critical role that higher education plays in the competitiveness of the nation and the productivity of its public services’. A good supply of well-trained, talented and motivated researchers is essential for research excellence and innovation. The challenge therefore, for higher education, is to skill and motivate science students to become creative and entrepreneurial ‘lifelong learners’ in a fast changing work environment that provides better health care, ensures a cleaner, safer environment, and builds on the existing science base to ensure excellence. For the Biosciences disciplines, QAA Benchmark statements specify motivating and challenging the student with the use of a ‘skilled and balanced selection of teaching and learning techniques’ (QAA website). Blended learning is recommended through a wide range of teaching methods - including laboratory sessions, self-directed study, computer-aided learning, case studies and problem-based learning, demonstrations, active learning sets, work-based learning and/or placements, reflective practice, research project work - and assessment strategies. This paper provides an overview of theories of motivation based on the work of some motivation theorists. Some key principles are identified from the literature that link cognition, motivation and learning and which could have application in the teaching of Biosciences towards the goal of lifelong learning

Information behaviour in pre-literate societies.

This chapter arose from an exchange of ideas between a former life scientist, a former archaeologist, and a member of the Kope tribe, a remote tribe in Papua New Guinea. All three now work in fields related to information sciences. It discusses how notions of information have been dominated by text-based information sources, and considers how one group of people (the Kope) managed information in the absence of any awareness of text. The study explores how the Kopi relate to information, how they use it, and where they get it from. It summarises the findings as six information roles. These are related to contemporary situations

Echoes of power: Language effects and power differences in social interaction

Understanding social interaction within groups is key to analyzing online communities. Most current work focuses on structural properties: who talks to whom, and how such interactions form larger network structures. The interactions themselves, however, generally take place in the form of natural language --- either spoken or written --- and one could reasonably suppose that signals manifested in language might also provide information about roles, status, and other aspects of the group's dynamics. To date, however, finding such domain-independent language-based signals has been a challenge. Here, we show that in group discussions power differentials between participants are subtly revealed by how much one individual immediately echoes the linguistic style of the person they are responding to. Starting from this observation, we propose an analysis framework based on linguistic coordination that can be used to shed light on power relationships and that works consistently across multiple types of power --- including a more "static" form of power based on status differences, and a more "situational" form of power in which one individual experiences a type of dependence on another. Using this framework, we study how conversational behavior can reveal power relationships in two very different settings: discussions among Wikipedians and arguments before the U.S. Supreme Court.Comment: v3 is the camera-ready for the Proceedings of WWW 2012. Changes from v2 include additional technical analysis. See http://www.cs.cornell.edu/~cristian/www2012 for data and more inf

Design Features for the Social Web: The Architecture of Deme

We characterize the "social Web" and argue for several features that are desirable for users of socially oriented web applications. We describe the architecture of Deme, a web content management system (WCMS) and extensible framework, and show how it implements these desired features. We then compare Deme on our desiderata with other web technologies: traditional HTML, previous open source WCMSs (illustrated by Drupal), commercial Web 2.0 applications, and open-source, object-oriented web application frameworks. The analysis suggests that a WCMS can be well suited to building social websites if it makes more of the features of object-oriented programming, such as polymorphism, and class inheritance, available to non-programmers in an accessible vocabulary.Comment: Appeared in Luis Olsina, Oscar Pastor, Daniel Schwabe, Gustavo Rossi, and Marco Winckler (Editors), Proceedings of the 8th International Workshop on Web-Oriented Software Technologies (IWWOST 2009), CEUR Workshop Proceedings, Volume 493, August 2009, pp. 40-51; 12 pages, 2 figures, 1 tabl