Bi-Directional Safety Analysis for Product-Line, Multi-Agent Systems

Abstract. Safety-critical systems composed of highly similar, semi-autonomous agents are being developed in several application domains. An example of such multi-agent systems is a fleet, or “constellation ” of satellites. In constellations of satellites, each satellite is commonly treated as a distinct autonomous agent that must cooperate to achieve higher-level constellation goals. In previous work, we have shown that modeling a constellation of satellites or spacecraft as a product line of agents (where the agents have many shared commonalities and a few key differences) enables reuse of software analysis and design assets. We have also previously developed efficient safety analysis techniques for product lines. We now propose the use of Bi-Directional Safety Analysis (BDSA) to aid in system certification. We extend BDSA to product lines of multi-agent systems and show how the analysis artifacts thus produced contribute to the software’s safety case for certification purposes. The product-line approach lets us reuse portions of the safety analysis for multiple agents, significantly reducing the burden of certification. We motivate and illustrate this work through a specific application, a product-line, multi-agent satellite constellation

Novel development of distributed manufacturing monitoring systems to support high cost and complexity manufacturing

In the current manufacturing environment, characterized by diverse change sources (e.g. economical, technological, political, social) and integrated supply chains, success demands close cooperation and coordination between stakeholders and agility. Tools and systems based on software agents, intelligent products and virtual enterprises have been developed to achieve such demands but either because of: (i) focus on a single application; (ii) focus on a single product; (iii) separation between the product and its information; or (iv) focus on a single system characteristic (e.g. hardware, software, architecture, requirements) their use has been limited to trial or academic scenarios. In this thesis a reusable distributed manufacturing monitoring system for harsh environments, capable of addressing traceability and controllability requirements within stakeholders and across high cost and complexity supply chains is presented. [Continues.

Reusability in manufacturing, supported by value net and patterns approaches

The concept of manufacturing and the need or desire to create artefacts or products is very, very old, yet it is still an essential component of all modem economies. Indeed, manufacturing is one of the few ways that wealth is created. The creation or identification of good quality, sustainable product designs is fundamental to the success of any manufacturing enterprise. Increasingly, there is also a requirement for the manufacturing system which will be used to manufacture the product, to be designed (or redesigned) in parallel with the product design. Many different types of manufacturing knowledge and information will contribute to these designs. A key question therefore for manufacturing companies to address is how to make the very best use of their existing, valuable, knowledge resources. […] The research reported in this thesis examines ways of reusing existing manufacturing knowledge of many types, particularly in the area of manufacturing systems design. The successes and failures of reported reuse programmes are examined, and lessons learnt from their experiences. This research is therefore focused on identifying solutions that address both technical and non-technical requirements simultaneously, to determine ways to facilitate and increase the reuse of manufacturing knowledge in manufacturing system design. [Continues.

Intelligent decision support for maintenance: an overview and future trends

The changing nature of manufacturing, in recent years, is evident in industry’s willingness to adopt network-connected intelligent machines in their factory development plans. A number of joint corporate/government initiatives also describe and encourage the adoption of Artificial Intelligence (AI) in the operation and management of production lines. Machine learning will have a significant role to play in the delivery of automated and intelligently supported maintenance decision-making systems. While e-maintenance practice provides aframework for internet-connected operation of maintenance practice the advent of IoT has changed the scale of internetworking and new architectures and tools are needed. While advances in sensors and sensor fusion techniques have been significant in recent years, the possibilities brought by IoT create new challenges in the scale of data and its analysis. The development of audit trail style practice for the collection of data and the provision of acomprehensive framework for its processing, analysis and use should be avaluable contribution in addressing the new data analytics challenges for maintenance created by internet connected devices. This paper proposes that further research should be conducted into audit trail collection of maintenance data, allowing future systems to enable ‘Human in the loop’ interactions

The development of a rich multimedia training environment for crisis management: using emotional affect to enhance learning

PANDORA is an EU FP7-funded project developing a novel training and learning environment for Gold Commanders, individuals who carry executive responsibility for the services and facilities identified as strategically critical e.g. Police, Fire, in crisis management strategic planning situations. A key part of the work for this project is considering the emotional and behavioural state of the trainees, and the creation of more realistic, and thereby stressful, representations of multimedia information to impact on the decision-making of those trainees. Existing training models are predominantly paper-based, table-top exercises, which require an exercise of imagination on the part of the trainees to consider not only the various aspects of a crisis situation but also the impacts of interventions, and remediating actions in the event of the failure of an intervention. However, existing computing models and tools are focused on supporting tactical and operational activities in crisis management, not strategic. Therefore, the PANDORA system will provide a rich multimedia information environment, to provide trainees with the detailed information they require to develop strategic plans to deal with a crisis scenario, and will then provide information on the impacts of the implementation of those plans and provide the opportunity for the trainees to revise and remediate those plans. Since this activity is invariably multi-agency, the training environment must support group-based strategic planning activities and trainees will occupy specific roles within the crisis scenario. The system will also provide a range of non-playing characters (NPC) representing domain experts, high-level controllers (e.g. politicians, ministers), low-level controllers (tactical and operational commanders), and missing trainee roles, to ensure a fully populated scenario can be realised in each instantiation. Within the environment, the emotional and behavioural state of the trainees will be monitored, and interventions, in the form of environmental information controls and mechanisms impacting on the stress levels and decisionmaking capabilities of the trainees, will be used to personalise the training environment. This approach enables a richer and more realistic representation of the crisis scenario to be enacted, leading to better strategic plans and providing trainees with structured feedback on their performance under stress

The economics of collateral

In this paper we study how the use of collateral is evolving under the influence of regulatory reform and changing market structure. We start with a critical review of the recent empirical literature on the supply and demand of collateral which has focussed on the issue of ‘collateral scarcity’. We argue that while limited data availability does not allow a comprehensive view of the market for collateral, it is unlikely that there is an overall shortage of collateral. However, it is quite possible that there may be bottlenecks within the system which mean that available collateral is immobilized in one part of the system and unattainable by credit-worthy borrowers. We then describe how these problems sometimes can be overcome by improved information systems and collateral transformation. We discuss how collateral management techniques differ between banks and derivatives markets infrastructures including, in particular, CCPs. In order to assess the impact of alternative institutional arrangements on collateral demand, we introduce a theoretical model of an OTC derivatives market consisting of investors and banks arrayed in several regions or market segments. We simulate this model under alternative forms meant to capture the implications of moving to mandatory CCP clearing and mandatory initial margin requirements for non-cleared OTC derivatives

Supporting the grow-and-prune model for evolving software product lines

207 p.Software Product Lines (SPLs) aim at supporting the development of a whole family of software products through a systematic reuse of shared assets. To this end, SPL development is separated into two interrelated processes: (1) domain engineering (DE), where the scope and variability of the system is defined and reusable core-assets are developed; and (2) application engineering (AE), where products are derived by selecting core assets and resolving variability. Evolution in SPLs is considered to be more challenging than in traditional systems, as both core-assets and products need to co-evolve. The so-called grow-and-prune model has proven great flexibility to incrementally evolve an SPL by letting the products grow, and later prune the product functionalities deemed useful by refactoring and merging them back to the reusable SPL core-asset base. This Thesis aims at supporting the grow-and-prune model as for initiating and enacting the pruning. Initiating the pruning requires SPL engineers to conduct customization analysis, i.e. analyzing how products have changed the core-assets. Customization analysis aims at identifying interesting product customizations to be ported to the core-asset base. However, existing tools do not fulfill engineers needs to conduct this practice. To address this issue, this Thesis elaborates on the SPL engineers' needs when conducting customization analysis, and proposes a data-warehouse approach to help SPL engineers on the analysis. Once the interesting customizations have been identified, the pruning needs to be enacted. This means that product code needs to be ported to the core-asset realm, while products are upgraded with newer functionalities and bug-fixes available in newer core-asset releases. Herein, synchronizing both parties through sync paths is required. However, the state of-the-art tools are not tailored to SPL sync paths, and this hinders synchronizing core-assets and products. To address this issue, this Thesis proposes to leverage existing Version Control Systems (i.e. git/Github) to provide sync operations as first-class construct

Post-Foreclosure Community Stabilization Strategies: Case Studies and Early Lessons 2008

In the midst of all the foreclosures sweeping the country, and the turmoil on Wall Street, nonprofit housing organizations are quietly going about the work of stabilizing communities hard hit by the crisis. Most have had frontline responsibility for counseling families threatened with foreclosure. With their assistance tens of thousands of families have restructured their budgets, negotiated with servicers to modify their loans, and saved their homes. Other families, too far along in the foreclosure process to stop it from happening, have received help transitioning to new housing arrangements.While the work with distressed homeowners must continue, nonprofits are feeling increased pressure to deal with the growing foreclosed housing stock. These units are causing incalculable harm to neighborhoods, and any hope of housing recovery must ensure that these units are swiftly put back into productive use or demolished. This collection of 14 case studies outlines strategies that nonprofit organizations across the country are using to begin the process of repairing damaged communities.The stakes are enormous. Vacant housing invites vandalism, and becomes a hub for gangs and crime. Virtually all case study subjects reported that, within weeks of housing becoming vacant, thieves break into the units and strip them of their valuable copper plumbing and wiring, heedless of any destruction they leave in their wake. In Phoenix a half-finished, abandoned subdivision was used as an informal "Home Depot" as other homeowners broke in and helped themselves to fixtures and appliances. In Cleveland, vandals remove not just the copper but the aluminum siding from vacant houses. In photos these houses have a desolate, post-disaster look, like the aftermath of a hurricane. When units get demolished the vacant lots soon sprout grass and trash, adding to the community's forlorn appearance.Vacant, deteriorated units place a downward pressure on housing values that puts nearby neighbors in a bind. In order to sell their units they will have to reduce the price, as no one will pay top dollar to live in a blighted neighborhood. Yet their ability to refinance into a more affordable mortgage may be compromised by the drop in property values; in some cases this leads to additional foreclosures and the downward cycle continues.Intervening in these troubled neighborhoods is challenging. In some markets housing prices are still falling, making it hard to determine the value of the units. Bank asset managers and servicers often lack detailed knowledge of the markets, or even of the units they have in their own inventory. This leads them to overvalue their properties and hold out for more than they are worth, delaying the process of acquiring and renovating them for resale to new homebuyers. Finally, the complex ownership structure of mortgages which were rolled into collateralized debt obligations and other investment vehicles makes it very difficult to establish who owns properties and who has authority to negotiate their sale.0