Software systems are increasingly expected to address a broad range of stakeholder values representing both personal and societal values as well as values ensconced as laws and regulations. Whereas laws and regulations must be fully addressed, other human values need to be carefully analyzed and prioritized within the context of candidate architectural designs. The majority of prior work has investigated requirements engineering techniques for either regulatory compliance or for human-values, we take an integrated approach which simultaneously considers laws and regulations as well as societal and personal human values throughout the system analysis, specification, and design process. We illustrate our approach through detailed examples drawn from a multi-drone system regulated by the USA Federal Aviation Authority (FAA) and operating in a domain rich with human and societal values. We then discuss requirements engineering challenges and solutions unique to identifying analyzing, and prioritizing human, societal, and regulatory requirements, and ultimately for designing accountable software systems.

Abstract Adopting shared data resources requires scientists to place trust in the originators of the data. When shared data is later used in the development of artificial intelligence (AI) systems or machine learning (ML) models, the trust lineage extends to the users of the system, typically practitioners in fields such as healthcare and finance. Practitioners rely on AI developers to have used relevant, trustworthy data, but may have limited insight and recourse. This article introduces a software architecture and implementation of a system based on design patterns from the field of self‐sovereign identity. Scientists can issue signed credentials attesting to qualities of their data resources. Data contributions to ML models are recorded in a bill of materials (BOM), which is stored with the model as a verifiable credential. The BOM provides a traceable record of the supply chain for an AI system, which facilitates on‐going scrutiny of the qualities of the contributing components. The verified BOM, and its linkage to certified data qualities, is used in the AI scrutineer, a web‐based tool designed to offer practitioners insight into ML model constituents and highlight any problems with adopted datasets, should they be found to have biased data or be otherwise discredited.

Blockchains have been around for more than ten years, and since 2015, a plethora of systems have been launched to target more flexible use cases. More recently, several enterprise blockchain systems, such as Consensys Quorum and Hyperledger Fabric, have been launched to make blockchain simpler to apply in complex organizational configurations. In this paper, we identify a specific Department of Defense use case, extrapolate requirements, and perform a thorough assessment of the different layers of the blockchain stack to identify the existing state of the art and undertake a gap analysis of the technology for this context. We describe a platform that meets many of these challenges and show how we architected, designed, and implemented a solution for this use case for deployment at NAVAIR. This solution connects transactions from two separate blockchain systems, Consensys Quorum and Hyperledger Fabric, by using a graph-based approach that preserves privacy while enabling full transparency across the military and supplier networks.

Reproducibility can be considered as one of the basic requirements to ensure that a given research finding is accurate and acceptable. This paper presents a new layered approach that allows scientific researchers to provide a) data to fellow researchers to validate research and b) proofs of research quality to funding agencies, without revealing sensitive details associated with the same. We conclude that by integrating smart contracts, blockchain technology, and self-sovereign identity into an automated system, it is possible to assert the quality of scientific materials and validate the peer review process without the need of a central authority.

In this paper we describe our experience adopting the Research Object Bundle (RO-Bundle) format with BagIt serialization (BagIt-RO) for the design and implementation of "tales" in the Whole Tale platform. A tale is an executable research object intended for the dissemination of computational scientific findings that captures information needed to facilitate understanding, transparency, and re-execution for review and computational reproducibility at the time of publication. We describe the Whole Tale platform and requirements that led to our adoption of BagIt-RO, specifics of our implementation, and discuss migrating to the emerging Research Object Crate (RO-Crate) standard.

In this paper, we study the networked virtual machine (VM) placement problem in the edge cloud system with a two-layer star topology. Firstly, for a one-layer wireless compute cluster, we propose one optimal algorithm to minimize the total inter-node communication cost in the cluster. Secondly, for the two-layer edge cloud system, we design another algorithm to minimize the total inter-node communication cost in the system. Thirdly, we study the job placement problem under the multi-tenant scenario, which is NP-hard. A heuristic algorithm is proposed to give an efficient solution. The evaluation results validate the efficiency of our algorithms.

The act of sharing scientific knowledge is rapidly evolving away from traditional articles and presentations to the delivery of executable objects that integrate the data and computational details (e.g., scripts and workflows) upon which the findings rely. This envisioned coupling of data and process is essential to advancing science but faces technical and institutional barriers. The Whole Tale project aims to address these barriers by connecting computational, data-intensive research efforts with the larger research process—transforming the knowledge discovery and dissemination process into one where data products are united with research articles to create “living publications” or tales. The Whole Tale focuses on the full spectrum of science, empowering users in the long tail of science, and power users with demands for access to big data and compute resources. We report here on the design, architecture, and implementation of the Whole Tale environment.

In the era of Internet of Things (IoT), the concept of "cloudlet" was proposed, which can be considered as a "micro data center in a box or node" deployed at the edge of the mobile network. The integration of cloudlet and wireless mesh networks gives rise to the idea of "cloudlet mesh", which offers services to a large number of IoT applications simultaneously. With virtualized servers in each cloudlet, users issue networked VMs to run their applications, and then the cloudlet mesh broker or orchestrator decides the resource allocation. This process is known as the VM placement. In our previous work, we proposed an algorithm to determine the maximum number of accepted VMs into the cloudlet mesh. In this paper, we study the traffic-aware VM placement problem in the cloudlet mesh. Firstly, we give a review of the algorithm proposed in our previous work, which obtains the maximum number of accepted VMs into the cloudlet mesh. Secondly, we design one optimal algorithm to minimize the total inter-cloudlet communication traffic in the cloudlet mesh. Thirdly, we study the VM placement problem under the multi-tenant scenario, which we prove to be NP-hard. A heuristic algorithm is proposed to give an efficient solution. The evaluation results validate the efficiency of our algorithm.

The Cloud computing paradigm is built on the concept of virtualization, allowing multiple virtual machines to cohabit on one physical device to enable the scaling up and down of applications through elastic on-demand provisioning. More recently containers e.g. Docker, have been shown to enable a more lightweight mechanism than hypervisors and proved to be a viable alternative for virtualization, based on shared operating systems. The advent of such lightweight environments has brought a multitude of application uses in research, science and industry, enabling pre-configured operating environments to be shared, reused and instantiated on demand. The sharing of containers has currently been exposed using centralized repositories (e.g. Dockerhub), which allows containers to be shared and to form the building blocks for further development. In this paper, we take a look at the next evolution of this lifecycle and consider whether it is viable to securely share container-based applications within a decentralized group of individuals and to provide an audit trail recording exactly who has shared what, and with whom. For this purpose we consider the use of Blockchain technologies, and consequently perform a comparative analysis of Blockchain technologies for this use case. The paper provides mostly a review and taxonomy of different ledger systems, which we believe may be of interest to the SafeData Workshop participants.

We address the topology-aware job scheduling and placement problems on 3D torus-based high performance computing systems, with the objective of reducing system fragmentation. In our previous work, we proposed a job placement algorithm based on a local migration process, which aims at reducing the internal fragmentation due to using a convex prism shape for job allocation. However, HPC systems are prone to suffer from external fragmentation as well. Hence, in this paper, we majorly strive to reduce the external fragmentation brought in by the job scheduling and placement processes. Firstly, from the job scheduling aspect of view, we propose a packing-based job scheduling strategy, which reduces the external fragmentation by using the First Come First Served + backfilling strategy. Secondly, we give a review of the migration-based job placement algorithm in our previous work. Thirdly, in order to reduce the external fragmentation resulting from running jobs scattered across the system, we propose a job placement reconfiguration algorithm, which uses a global migration process to rearrange the placement of the running jobs across the system. Both local and global migration are emulated virtual processes under the off-line scenario, which have no migration overhead. However, under the on-line scenario, migration is a real process and leads to a migration delay. Therefore, we propose a buffer-based on-line scheduling model, which helps to avoid the delay of local migration. The evaluation results validate the efficiency of our approach in reducing system fragmentation and improving system utilization.

Building Information Modeling needs better strategies for schema interoperability in order to begin solving some of the problems the building industry faces including discrepancies in simulation tool data, missing or incorrect data, and gaps in data sourcing transparency. Addressing these challenges so far has often resulted in further “siloed” translation tools that only work for the few formats for which they were built. An application of Linked Data Views (or Semantic Views) is presented as part of a larger, modular, and extensible framework that provides a method to automatically query, understand, and translate BIM instances into Linked Data. This bypasses the need for individual translators in order to access the multitude of simulations tools, allows multiple data stores to be compared properly for more accurate Decision Support, and can be connected to other Linked Data for verifying, correcting, and extending our knowledge through available resources in multiple locations.

Globalization and cloud computing have allowed major strides forward in terms of communication possibilities, but it is also illuminating how many different resource options and formats exist access to which would dramatically increase the accuracy and reliability of choices made as a result of computational output. As a result, there is increasing need for methods resolving levels of data translations necessary for the effectiveness of distributed Linked Data platforms, especially in the context of the Building Information Modeling domain in which we conduct our work. The following research presents the current state of our Linked Data Platform for handling and processing Resilience and BIM data from existing and remotely located data stores and simulation models. This approach focuses on data interoperability and illustrates the functional interactions of a set of lightweight API endpoints that serve resources as requests are extensible with the HYDRA Core Vocabulary to increase data discoverability opportunities.

Large-scale applications expressed as scientific workflows are often grouped into ensembles of inter-related workflows. In this paper, we address a new and important problem concerning the efficient management of such ensembles under budget and deadline constraints on Infrastructure- as-aService (IaaS) clouds. We discuss, develop, and assess algorithms based on static and dynamic strategies for both task scheduling and resource provisioning. We perform the evaluation via simulation using a set of scientific workflow ensembles with a broad range of budget and deadline parameters, taking into account uncertainties in task runtime estimations, provisioning delays, and failures. We find that the key factor determining the performance of an algorithm is its ability to decide which workflows in an ensemble to admit or reject for execution. Our results show that an admission procedure based on workflow structure and estimates of task runtimes can significantly improve the quality of solutions.

This paper reports on original results of the Advancing Clinico-Genomic Trials on Cancer integrated project focusing on the design and development of a European biomedical grid infrastructure in support of multicentric, postgenomic clinical trials (CTs) on cancer. Postgenomic CTs use multilevel clinical and genomic data and advanced computational analysis and visualization tools to test hypothesis in trying to identify the molecular reasons for a disease and the stratification of patients in terms of treatment. This paper provides a presentation of the needs of users involved in postgenomic CTs, and presents such needs in the form of scenarios, which drive the requirements engineering phase of the project. Subsequently, the initial architecture specified by the project is presented, and its services are classified and discussed. A key set of such services are those used for wrapping heterogeneous clinical trial management systems and other public biological databases. Also, the main technological challenge, i.e. the design and development of semantically rich grid services is discussed. In achieving such an objective, extensive use of ontologies and metadata are required. The Master Ontology on Cancer, developed by the project, is presented, and our approach to develop the required metadata registries, which provide semantically rich information about available data and computational services, is provided. Finally, a short discussion of the work lying ahead is included.

Grid simulation tools provide frameworks for simulating application scheduling in various Grid infrastructures. However, while experimenting with many existing tools, we have encountered two main shortcomings: (i) there are no tools for generating workloads, resources and events ; (ii) it is difficult and time consuming to model different Grid levels, i.e. resource brokers, and local level scheduling systems. In this paper we present the Grid Scheduling Simulator (GSSIM), a framework that addresses these shortcomings and provides an easy-to-use Grid scheduling framework for enabling simulations of a wide range of scheduling algorithms in multi-level, heterogeneous Grid infrastructures. In order to foster more collaboration in the community at large, GSSIM is complemented with a portal (http://www.gssim.org) that provides a repository of Grid scheduling algorithms, synthetic workloads and benchmarks for use with GSSIM.

Abstract In this paper we describe our work on enabling dynamic access control and secure management over federated data resources, such as relational or XML databases exposed to public network infrastructures via OGSA‐DAI middleware. We have proposed some extensions to the OGSA‐DAI architecture and successfully implemented new mechanisms enabling secure communication and distributed data integrity along with fine‐grain authorization and policy enforcement to minimize the complexity of the security right management. As a proof of concept some preliminary results of various performance tests of our solutions are also presented in this paper. We then analyze our achievements and describe future work and research. Copyright © 2007 John Wiley & Sons, Ltd.

Abstract One of the goals of the HPC‐Europa project is to provide users with a single point of access (SPA) to the resources of HPC centers in Europe. To this end, the HPC‐Europa portal is being built to provide transparent, uniform, flexible and intuitive user access to HPC‐Europa resources. This portal will hide the underlying complexity and heterogeneity of these resources and the services that provide access to them. Since the computational environment of HPC‐Europa is strongly heterogeneous, even in terms of the deployed Grid middleware, we need a mechanism that maps a uniform graphical user interface to the functionality provided by services available in the institutions belonging to the HPC‐Europa consortium. In addition, accounting information has to be stored and provided on demand for both limiting resource usage and charging purposes in the HPC‐Europa infrastructure. The important goal of the SPA is also to provide the means to support user access to specific applications. This should make access to Grid infrastructures easier for end‐users. Both mechanisms (generic and application‐specific interfaces), along with additional tools, will combine to provide flexible and efficient software for building science gateways for researchers in various domains. In this paper, we describe the architecture of the SPA, which is based on the GridSphere portal framework. We present a mechanism for enabling end‐users to transparently access services available in the HPC‐Europa environment. The uniform job submission interface that uses this mechanism and is based on the Job Specification Description Language (JSDL) is presented. The mechanism supporting development of application‐specific user interfaces is also described. Finally, we discuss relevant issues and interoperability problems connected with the development of the SPA, in particular those concerning job submission, security and accounting. Copyright © 2006 John Wiley & Sons, Ltd.

This paper examines the problem of giving mobile users a possibility to access interoperability services based on ontologies and predefined concepts providing various meaningful objects and mechanisms to search, discover, invoke, compose and monitor appropriate grid-based services, applications as well as data sources in the Virtual Organization (VO) from any place in the world using mobile devices. Since mobiles as end devices are naturally used by humans to see a ’human-readable’ content, in our opinion, they should also allow them to specify ’human-readable’ queries instead of direct computer-interpretable queries to unknown remote service providers or databases. Based on the knowledge located in the interoperability space user’s requests from mobile devices can be mapped and forwarded automatically to appropriate remote interfaces to take advantages of various functionalities offered by the grid and service providers available today in the Internet. Therefore, more efficient interaction between the user and remote service provider(s) can be established. In our approach, the real ontology services are available from mobile devices via the gateway due to weaknesses of mobile devices and the complexity of the ontology layer within the grid infrastructure. In this paper we describe several grid-based services developed for mobile users as well as some core services which have been adopted to work with mobile devices. Roles of a mobile client, grid-services and gateway played in some novel scenarios of ontology usage are also described. Finally, in this paper we discuss issues related to obstacles and limitations that we have been facing while using the chosen J2ME technology, and the ways we are solving them.

Abstract In this paper we present our motivations and ideas for workflow management based on our experiences gained in two projects: GridLab and PROGRESS. In these projects we have been dealing with real use cases and end users' requirements for workflow management. Therefore, we were able to define and implement functional workflow extensions to the Grid(Lab) Resource Management System (GRMS). GRMS is a resource management system with a workflow engine that executes and manages jobs on remote Grid resources. One can submit to GRMS workflow experiments based on an XML workflow schema, defining flexible mechanisms for dynamic workflow control, including various types of precedence constraints, different locations of the final data products and executables, etc. All of these features allow end users to speed up remote workflow calculations and improve data management mechanisms. Copyright © 2005 John Wiley & Sons, Ltd.

The Testbed and Applications working group of the European Grid Forum (EGrid) is actively building and experimenting with a grid infrastructure connecting several research-based supercomputing sites located in Europe. The paper reports on our first feasibility study: running a self-migrating version of the Cactus simulation code across the European grid testbed, including "live" remote data visualization and steering from different demonstration booths at Supercomputing 2000, in Dallas, TX. We report on the problems that had to be resolved for this endeavour and identify open research challenges for building production-grade grid environments.

Scientific and other grand challenge applications are a driving force for developing the computing infrastructure of the future. Their constantly increasing computational power requirements often cannot be met by available systems (F. Gagliardi, 2000). Such a situation has led to the emergence of new platform called "Computational Grid" (I. Foster and C. Kesselman, 1999). It seems very important to identify common and reusable components that are needed and can be used in a computational grid by different applications. Such components could be the Grid information services, security mechanisms, resource management, large data set management, etc. The paper sketches the issues of one of the most important components of the grid: the resource management and scheduling component. We present our work on a multiobjective resource management system. The novelty of the approach lies in its multiobjective nature. We present the Multi-Criteria Resource Broker (MC-Broker), whose scheduling mechanisms are driven by user preferences regarding various scheduling criteria, such as computation time and cost, communication time between distributed processes, level of load balancing and others.