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With an growing number of web services available on the Internet, an increasing burden is imposed on the use and management of service repository. Service clustering has been employed to facilitate a wide range of service-oriented tasks, such as service discovery, selection, composition and recommendation. Conventional approaches have been proposed to cluster web services by using explicit features, including syntactic features contained in service descriptions or semantic features extracted by probabilistic topic models. However, service implicit features are ignored and have yet to be properly explored and leveraged. To this end, we propose a novel heuristics-based framework DeepWSC for web service clustering. It integrates deep semantic features extracted from service descriptions by an improved recurrent convolutional neural network and service composability features obtained from service invocation relationships by a signed graph convolutional network, to jointly generate integrated implicit features for web service clustering. Extensive experiments are conducted on 8,459 real-world web services. The experiment results demonstrate that DeepWSC outperforms state-of-the-art approaches for web service clustering in terms of multiple evaluation metrics.

Tangible controls-especially sliders and rotary knobs-have been explored in a wide range of interactive applications for desktop and immersive environments. Studies have shown that they support greater precision and provide proprioceptive benefits, such as support for eyes-free interaction. However, such controls tend to be expressly designed for specific applications. We draw inspiration from a bespoke controller for immersive data visualisation, but decompose this design into a simple, wireless, composable unit featuring two actuated sliders and a rotary encoder. Through these controller units, we explore the interaction opportunities around actuated sliders; supporting precise selection, infinite scrolling, adaptive data representations, and rich haptic feedback; all within a mode-less interaction space. We demonstrate the controllers' use for simple, ad hoc desktop interaction,before moving on to more complex, multi-dimensional interactions in VR and AR. We show that the flexibility and composability of these actuated controllers provides an emergent design space which covers the range of interactive dynamics for visual analysis. In a user study involving pairs performing collaborative visual analysis tasks in mixed-reality, our participants were able to easily compose rich visualisations, make insights and discuss their findings.

International audience; The design of glitch-resistant higher-order masking schemes is an important challenge in cryptographic engineering. A recent work by Moos et al. (CHES 2019) showed that most published schemes (and all efficient ones) exhibit local or composability flaws at high security orders, leaving a critical gap in the literature on hardware masking. In this paper, we first extend the simulatability framework of Belaïd et al. (EUROCRYPT 2016) and prove that a compositional strategy that is correct without glitches remains valid with glitches. We then use this extended framework to prove the first masked gadgets that enable trivial composition with glitches at arbitrary orders. We show that the resulting "Hardware Private Circuits" approach the implementation efficiency of previous (flawed) schemes. We finally investigate how trivial composition can serve as a basis for a tool that allows verifying full masked hardware implementations (e.g., of complete block ciphers) at any security order from their HDL code. As side products, we improve the randomness complexity of the best published refreshing gadgets, show that some S-box representations allow latency reductions and confirm practical claims based on implementation results.

Differential Privacy (DP) formalizes privacy in mathematical terms and provides a robust concept for privacy protection. DIfferentially Private Data Synthesis (DIPS) techniques produce and release synthetic individual-level data in the DP framework. One key challenge to develop DIPS methods is the preservation of the statistical utility of synthetic data, especially in high-dimensional settings. We propose a new DIPS approach, STatistical Election to Partition Sequentially (STEPS) that partitions data by attributes according to their importance ranks according to either a practical or statistical importance measure. STEPS aims to achieve better original information preservation for the attributes with higher importance ranks and produce thus more useful synthetic data overall. We present an algorithm to implement the STEPS procedure and employ the privacy budget composability to ensure the overall privacy cost is controlled at the pre-specified value. We apply the STEPS procedure to both simulated data and the 2000–2012 Current Population Survey youth voter data. The results suggest STEPS can better preserve the population-level information and the original information for some analyses compared to PrivBayes, a modified Uniform histogram approach, and the flat Laplace sanitizer.

Byzantine fault-tolerant (BFT) state-machine replication makes it possible to design systems that are resilient against arbitrary faults, a requirement considered crucial for an increasing number of use cases such as permissioned blockchains, firewalls, and SCADA systems. Unfortunately, the strong fault-tolerance guarantees provided by BFT replication protocols come at the cost of a high complexity, which is why it is inherently difficult to correctly implement BFT systems in practice. This is all the more true with regard to the plethora of solutions and ideas that have been developed in recent years to improve performance, availability, or resource efficiency. This survey aims at facilitating the task of building BFT systems by presenting an overview of state-of-the-art techniques and analyzing their practical implications, for example, with respect to applicability and composability. In particular, this includes problems that arise in the context of concrete implementations, but which are often times passed over in literature. Starting with an in-depth discussion of the most important architectural building blocks of a BFT system (i.e., clients, agreement protocol, execution stage), the survey then focuses on selected approaches and mechanisms addressing specific tasks such as checkpointing and recovery.

In this work a platform-aware model-driven engineering process for building component-based embedded software systems using annotated analysis models is described. The process is supported by a framework, called MICOBS, that allows working with different component technologies and integrating different tools that, independently of the component technology, enable the analysis of non-functional properties based on the principles of composability and compositionality. An actor, called Framework Architect, is responsible for this integration. Three other actors take a relevant part in the analysis process. The Component Provider supplies the components, while the Component Tester is in charge of their validation. The latter also feeds MICOBS with the annotated analysis models that characterize the extra-functional properties of the components for the different platforms on which they can be deployed. The Application Architect uses these components to build new systems, performing the trade-off between different alternatives. At this stage, and in order to verify that the final system meets the extra-functional requirements, the Application Architect uses the reports generated by the integrated analysis tools. This process has been used to support the validation and verification of the on-board application software for the Instrument Control Unit of the Energetic Particle Detector of the Solar Orbiter mission.

The human immune system is studied at different scales (molecular, cellular, tissue, organism, population) with varied granularity and spatiotemporal dimensions. Innate and adaptive immune responses to viral infections are researched in vitro, in vivo, and in silico using mathematical and computational methods. The construction of computational models is an iterative and interactive process which combines existing knowledge and hypotheses (knowledge-driven approach) with empirical datasets (data-driven approach). The resulting models should ideally provide reusability, composability, and interoperability to support system simulation. The main premises of this paper are (1) computational models can be used not only for representation of existing knowledge, but also as experimental tools to demonstrate, exemplify, create, and serve as test-beds for the analysis of empirical data;and (2) computational models should be evaluated in terms of their usability (defined as a measure of how well a specified group of users can achieve predefined goals effectively, efficiently, and satisfactorily in a specified context of use). The usability measure is specified by the context information: user characteristics, their goals, and additional constraints (e.g., data availability, temporal limitations). This paper focuses on the modelling process performed by multidisciplinary teams and the usability of models for the exploration of immune response to viral infections. (c) 2021 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the scientific committee of the Complex Adaptive Systems Conference, June 2021.

In this paper, we study Local Information Privacy (LIP). As a context-aware privacy notion, LIP relaxes the de facto standard privacy notion of local differential privacy (LDP) by incorporating prior knowledge and therefore achieving better utility. We study the relationships between LIP and some of the representative privacy notions including LDP, mutual information and maximal leakage. We show that LIP provides strong instance-wise privacy protection compared to other context-aware privacy notions. Moreover, we present some useful properties of LIP, including post-processing, linkage, composability, transferability and robustness to imperfect prior knowledge. Then we study a general utility-privacy tradeoff framework, under which we derive LIP based privacy-preserving mechanisms for both discrete and continuous-valued data. Three types of perturbation mechanisms are studied in this paper: 1) randomized response (RR), 2) random sampling (RS) and 3) additive noise (AN) (e.g., Gaussian mechanism). Our privacy mechanisms incorporate the prior knowledge into the perturbation parameters so as to enhance utility. Finally, we present a comprehensive set of experiments on real datasets to illustrate the advantage of context-awareness and compare the utility-privacy tradeoffs provided by different mechanisms.

Component-based design has received considerable attention owing to its advantages in terms of security and safety when developing modern embedded systems. To effectively allocate computing resources to components in these systems, real-time component-based scheduling theory has been studied from various perspectives. The main advantage of component-based scheduling theory is that it guarantees the schedulability of an independent component and composability of multiple components. However, the existing component scheduling theory cannot be directly applied to real hardware platform due to an impractical assumption that resource allocation must be conducted across the continuum of real numbers, whereas actual operating systems (or virtualization systems) allocate resources in units of scheduling time quantum. In this study, we proposed a new efficient resource allocation and supply mechanism for quantumized hardware platforms while using real-number-based component interface. In simulation results with randomly-generated workloads, our approach reduced the overhead of existing approaches by up to 97.1% in an individual component. In composition of multiple components, our approach has up to 0.41 better acceptance ratio than existing approaches.

The design of codes for communicating reliably over a statistically well defined channel is an important endeavor involving deep mathematical research and wide-ranging practical applications. In this work, we present the first family of codes obtained via deep learning, which significantly beats state-of-the-art codes designed over several decades of research. The communication channel under consideration is the Gaussian noise channel with feedback, whose study was initiated by Shannon; feedback is known theoretically to improve reliability of communication, but no practical codes that do so have ever been successfully constructed. We break this logjam by integrating information theoretic insights harmoniously with recurrent-neural-network based encoders and decoders to create novel codes that outperform known codes by 3 orders of magnitude in reliability. We also demonstrate several desirable properties of the codes: (a) generalization to larger block lengths, (b) composability with known codes, (c) adaptation to practical constraints. This result also has broader ramifications for coding theory: even when the channel has a clear mathematical model, deep learning methodologies, when combined with channel-specific information-theoretic insights, can potentially beat state-of-the-art codes constructed over decades of mathematical research., 24 pages, 20 figures

This paper presents a case study that demonstrates how tools from compositional verification can be used to design and analyze complex multi-agent systems operating in dynamic and uncertain environments. The case study concerns the design of an unmanned multi-aircraft system tasked to compromise an aerial encroacher by deploying countermeasures. The constituent agents, termed defenders, are fixed-wing unmanned aircraft. To successfully compromise the encroacher, at least one defender must be within a prespecified distance from the encroacher for a certain period, and the defenders must avoid collision among themselves and with the encroacher. Verifying this global property using monolithic (system-level) verification techniques is a challenging task due to the complexity of the components (defenders) and the interactions among them. To overcome these challenges, the components are designed to have a modular architecture, thereby enabling the use of component-based reasoning to simplify the task of verifying the global system property. Results from Euclidean geometry and formal methods are used to prove most component properties. For properties where analytical tools are overly conservative, focused Monte Carlo simulations are carried out. Restricting the use of simulations (or testing) to local verification of partial component properties leads to increasing the reliability of the system. National Science Foundation (NSF)National Science Foundation (NSF) [CMMI-1351640, CNS-1801611]; Center for Unmanned Aircraft Systems (C-UAS), an NSF sponsored industry/university cooperative research center (I/UCRC), under NSF [IIP-1539975, CNS-1650465]; C-UAS industry members This work was supported in part by the National Science Foundation (NSF) under Grant CMMI-1351640 and Grant CNS-1801611, and in part by the Center for Unmanned Aircraft Systems (C-UAS), an NSF sponsored industry/university cooperative research center (I/UCRC), under NSF Grant IIP-1539975 and Grant CNS-1650465, along with significant contributions from C-UAS industry members.

Posté sur BioRxiv le 4 août 2021; International audience; Mathematical modeling has become a major tool to guide the characterization and synthetic construction of cellular processes. However, models typically lose their capacity to explain or predict experimental outcomes as soon as any, even minor, modification of the studied system or its operating conditions is implemented. This limits our capacity to fully comprehend the functioning of natural biological processes and is a major roadblock for the de novo design of complex synthetic circuits. A common cause of this problem is that cell-to-cell variability creates couplings between single-cell circuits and population processes such as selection or growth. Altering the circuit may then have unforeseen consequences inside growing populations. Here we construct a yeast optogenetic differentiation system that exploits cell-to-cell variability to enable external control of the population composition. We show that a simple deterministic model can explain the dynamics of the core system. However, modifying the context of the circuit by expressing system components from plasmids leads to failure of model predictions. Subsequently, we deploy theory from stochastic chemical kinetics to construct models of the system’s components that simultaneously track single-cell and population processes and demonstrate that this allows us to quantitatively predict emerging dynamics of the plasmid-based system without any adjustment of model parameters. We conclude that carefully characterizing the dynamics of cell-to-cell variability using appropriate modeling theory may allow one to unravel the complex interplay of stochastic single-cell and population processes and to predict the functionality of complex synthetic circuits in growing populations before the circuit is constructed.

Disaggregation of resources is a datacenter strategy that aims to decouple the physical location of resources from the place where they are accessed, as opposed to physically attached devices connected to the Peripheral Component Interconnect Express (PCIe) bus. By attaching and detaching resources through a fast interconnection network, it is possible to increase the flexibility to manage datacenter infrastructures while keeping the performance of the pooled and disaggregated devices. This article introduces workload scheduling and placement policies for environments with disaggregated memories. These policies are driven by accurate prebuilt performance degradation models. We focus on the use of nonvolatile memory to store data and/or to provide memory extensions. Following a software-defined approach, persistent memories are combined to provide higher capacity and/or bandwidth devices, or used by multiple workloads to increase the number of running workloads. Different combinations of workloads and associated soft deadlines are used to evaluate the placement policies using a system simulator. When using the first-fit policy, results show that a disaggregated system can reduce missed deadlines up to 49% when compared to a physically attached system. When our proposed policy with workload awareness is enabled in a disaggregated system, missed deadlines can be reduced up to 100% (no deadlines missed). This work was supported in part by the Ministry of Economy of Spain under Contract TIN2015-65316-P, in part by the Ministry of Science under Contract PID2019-107255GBC21/AEI/10.13039/501100011033, and in part by the Generalitat de Catalunya under Contract 2014SGR1051.

Community efforts in the computational molecular sciences (CMS) are evolving toward modular, open, and interoperable interfaces that work with existing community codes to provide more functionality and composability than could be achieved with a single program. The Quantum Chemistry Common Driver and Databases (QCDB) project provides such capability through an application programming interface (API) that facilitates interoperability across multiple quantum chemistry software packages. In tandem with the Molecular Sciences Software Institute and their Quantum Chemistry Archive ecosystem, the unique functionalities of several CMS programs are integrated, including CFOUR, GAMESS, NWChem, OpenMM, Psi4, Qcore, TeraChem, and Turbomole, to provide common computational functions, i.e., energy, gradient, and Hessian computations as well as molecular properties such as atomic charges and vibrational frequency analysis. Both standard users and power users benefit from adopting these APIs as they lower the language barrier of input styles and enable a standard layout of variables and data. These designs allow end-to-end interoperable programming of complex computations and provide best practices options by default.

We propose a novel framework for composing crowdsourced wireless energy services to satisfy users' energy requirements in a crowdsourced Internet of Things (IoT) environment. A new energy service model is designed to transform the harvested energy from IoT devices into crowdsourced services. We propose a new energy service composability model that considers the spatio-temporal aspects and the usage patterns of the IoT devices. A multiple local knapsack-based approach is developed to select an optimal set of partial energy services based on the deliverable energy capacity of IoT devices. We propose a heuristic-based composition approach using the temporal and energy capacity distributions of services. Experimental results demonstrate the effectiveness and efficiency of the proposed approach., 15 pages, accepted and to be published in the IEEE Transactions on Services Computing, 2020

Current higher-order calculations heavily rely on publicly available tools. These are not necessarily computer programs, but it is anything that aids in different steps of calculations, e.g. also includes published loop-amplitudes, integrals and algorithms that eventually lead to important automatization. In these proceedings we give an overview of tools used for perturbative precision calculations. The availability, composability and hackability of such tools are what lets our field flourish. And while our field is already positively standing out in the development of such tools, we would like to stress their importance for the success of future developments.

In this paper, we propose ERGO (edge architecture for Ag-IoT), an edge-computing architecture for infrastructureless smart agriculture environments. We also develop Ag-IoT application APIs and the associated microservice infrastructure. Our implementation and evaluations show that ERGO can operate independently of cloud-backed assistance, is highly scalable, modular, and affords composability benefits to Ag-IoT systems. We also demonstrate that ERGO outperforms traditional infrastructure in response latencies and transactional throughput, on average, by over 54% and 77%, respectively.

Digital twin has the potential to be an important concept for achieving smart manufacturing. However, there remains a lot of confusion about the concept and how it can be implemented in real manufacturing systems, especially among small-to-medium-sized enterprises. This paper synthesizes the different perspectives that have been reported on the digital twin to identify the key characteristics that must be understood when developing a digital twin for a specific use case. Example applications are provided and the need for a standardized framework, such as the one under development as ISO 23247 (Digital Twin Manufacturing Framework), is motivated. This framework can enable context-dependent implementations and promote composability and reusability of digital twin components.

The microservice architecture (MSA) differs fundamentally from the monolithic, layered architecture. The use of microservices provides a high degree of autonomy, composability, scalability, and fault-tolerance. MSA is regarded by many as a promising architecture for smart-city applications; however, a number of issues remain, including (1) the management of complex call relationships among microservices; (2) ensuring the quality of the overall software system even as new microservices are added and existing ones are modified, and (3) locating existing microservices that satisfy new requirements. In this paper, we propose a novel approach to the development of microservice-based systems, referred to as GSMART (Graph-based and Scenario-driven Microservice Analysis, Retrieval and Testing). GSMART enables the automatic generation of a “Service Dependency Graph (SDG)” by which to visualize and analyze dependency relationships between microservices as well as between services and scenarios. It also enables the automatic retrieval of test cases required for system changes to reduce the time and costs associated with regression testing. A microservice retrieval method using VSM and word2vec accelerates the development of new microservices tailored specifically to the needs of users based on user-provided scenarios. Experiment results demonstrate the feasibility, effectiveness, and efficiency of all of the main features of GSMART.

Smart CPSs (S-CPSs) have been evolving beyond what was identified by the traditional definitions of CPSs. The objective of our research is to investigate the concepts and implementations of reasoning processes for S-CPSs, and more specifically, the frameworks proposed for the fuzzy front end of their reasoning mechanisms. The objectives of the paper are: (i) to analyze the framework concepts and implementations of CPS, (ii) to review the literature concerning system-level reasoning and its enablers from the points of view of the processed knowledge, building awareness, reasoning mechanisms, decision making, and adaptation. Our findings are: (i) awareness and adaptation behaviors are considered as system-level smartness of S-CPSs that are not achieved by traditional design approaches; (ii) model-based and composability approaches insufficiently support the development of reasoning mechanisms for S-CPSs; (iii) frameworks for development of reasoning in S-CPS should support compositional design. Based on the conclusions above, we argue that coping with the challenges of compositionality requires both software-level integration and holistic fusion of knowledge by means of semantic transformations. This entails the need for a multi aspect framework that is able to capture at least conceptual, functional, architectural, informational, interoperation, and behavioral aspects. It needs further investigation if a compositionality enabling framework should appear in the form of a meta-framework (abstract) or in the form of a semantically integrated (concrete) framework. Highlights Smartness in CPSs is a holistic and synergistic behavioral characteristic. Complex mental representations are compositional. Compositionality is necessary for smart CPSs. Without a rigorous unifying framework, designing synthesis reasoning remains ad hoc.

Working within the framework of Distributed Morphology (Halle and Marantz 1993, 1994), this paper offers a derivational analysis of the range of structures and the types of idiosyncrasy associated with compounding. Building on prior analysis by Harley (2009), compound structures are argued to vary according to the ways in which the head and the non-head of a compound are categorised. Specifically, if the non-head of a compound is acategorial, then the relationship between the compound head and non-head is non-decomposable. Based on data from Hebrew (Borer 2009), it is shown that this also makes the non-head inaccessible to independent syntactic-semantic operations, including coordination, and coreference with a pronoun. It is additionally shown that morphologically-conditioned allomorphy (Bobaljik 2012) may be conditioned between the compound head and a suffix, as constitutes part of a bracketing paradox (Williams 1981). Where categorisation of the head of the compound gives rise to effects of headedness, however, this allomorphy may be ‘blocked’ by the structure associated with exocentricity. The final sections of the paper consider exocentricity, and other interactions between idiosyncratic meanings and phonology, in further detail.

This perspectives article addresses risk in cyber defense and identifies opportunities to incorporate risk analysis principles into the cybersecurity field. The Science of Security (SoS) initiative at the National Security Agency seeks to further and promote interdisciplinary research in cybersecurity. SoS organizes its research into the Five Hard Problems (5HP): (1) scalability and composability; (2) policy-governed secure collaboration; (3) security-metrics-driven evaluation, design, development, and deployment; (4) resilient architectures; and (5) understanding and accounting for human behavior. However, a vast majority of the research sponsored by SoS does not consider risk and when it does so, only implicitly. Therefore, we identify opportunities for risk analysis in each hard problem and propose approaches to address these objectives. Such collaborations between risk and cybersecurity researchers will enable growth and insight in both fields, as risk analysts may apply existing methodology in a new realm, while the cybersecurity community benefits from accepted practices for describing, quantifying, working with, and mitigating risk.

Simulation models are widely used to study complex systems. Current simulation models are generally handcrafted using expert knowledge (knowledge-driven); however, this process is slow and introduces modeler bias. This article presents an approach towards data-driven simulation modeling by developing a framework that discovers simulation models in an automated way for mobile agent-based applications. The framework is comprised of three components: (1) a model space specification, (2) a search method (genetic algorithm), and (3) framework measurement metrics. The model space specification provides a formal specification for the general model structure from which various models can be generated. The search method is used to efficiently search the model space for candidate models that exhibit desired behavior patterns. The five framework measurement metrics: flexibility, comprehensibility, controllability, composability, and robustness, are developed to evaluate the overall framework. The results demonstrate that it is possible to discover a variety of interesting models using the framework.

Agent-based modeling and simulation has been proved useful in a variety of different complex adaptive systems comprised of autonomous, interacting components. To resolve the shortcoming of current agent-based modeling frameworks with respect to decomposition and modularity, this paper presents a formal hierarchical modeling and simulation framework with three–level architecture to reduce ambiguity as well as improve clarity in the model definition. The bottom level is Component Model (CM), which implements some domain-specific support functionality, such as curve motion in the physical domain, intelligent decision-making in the cognitive domain, etc. The middle level is Agent Model (AM), which describes an agent which can react to the current situation by executing a sequence of CMs. The top level is System Model (SM), which defines that a CAS model consists of several AMs and also the interactions between these AMs. In the hierarchical architecture, one SM can be built up from lower-level models, which were linked in a loosely coupled fashion via an event-driven interface. We then analyze the reusability and composability of lower-level models of this hierarchical framework in a formalized way. To demonstrate the effectiveness of the proposed solution, we develop a graphical composite modelling tool named GraphSim, and the case study concerning two social dynamics system scenarios is also presented.

With the advent of the Internet of Things (IoT), Cloud-based Cyber-Physical Systems (C2PS) are becoming more prevalent in manufacturing systems. Verifying the security of C2PS is a challenging task due to the inclusion of newer entities such as mobile phones and IoT devices. Therefore, scalable methods for verifying security properties of manufacturing systems are paramount. This paper presents an approach to guarantee security of C2PS using concepts from Communicating Sequential Processes (CSP) to describe the security properties of cloud constructs. We prove that composability is an essential property for enhancing the security of the C2PS. Furthermore, it also provides good scalability to the system. We propose formalisms required for modelling security properties in the Industrial IoT-based manufacturing system. Using this formalism and Hoares’ logic we provide conditions for composing systems. Finally, we provide strong authentication conditions among entity pairs in C2PS based manufacturing systems. We demonstrate the message exchanges, methodology, and different steps required for verifying C2PS.

Microservices-based architectures gain more and more attention in industry and academia due to their tremendous advantages such as providing resiliency, scalability, composability, etc. To benefit from these advantages, a proper architectural design is very important. The decomposition model of services into microservices and the granularity of these microservices affect the different aspects of the system such as flexibility, maintainability, performance, and security. An inappropriate service decomposition into microservices (improper granularity) may increase the attack surface of the system and lower its security level. In this paper, first, we study the probability of compromising services before and after decomposition. Then we formulate the impacts of possible service decomposition models on confidentiality, integrity, and availability attributes of the system. To do so, we provide equations for measuring confidentiality, integrity, and availability risks of the decomposed services in the system. It is also shown that the number of entry points to the decomposed services and the size of the microservices affect the security attributes of the system. As a use case, we propose three different service decomposition models for the 5G NRF (Network Repository Function) and calculate the impacts of these decomposition models on the confidentiality, integrity, and availability of the system using the provided equations.

Host-driven execution of applications on modern GPU-accelerated systems suffer from frequent host-device synchronizations, data movement and limited flexibility in scheduling user tasks. We present CharminG, a runtime system designed to run entirely on the GPU without any interaction with the host. CharminG takes inspiration from the Charm++ parallel programming system and implements processor virtualization and message-driven execution on the GPU. We evaluate the composability and preliminary performance of CharminG with a proxy application that performs the Jacobi iterative method in a two-dimensional grid, using the Lassen supercomputer at Lawrence Livermore National Laboratory.

Publisher Copyright: © 2021 IEEE. We present work on structuring robotics simulation scenarios into components. Components can comprise simulation entities with a physical counterpart such as automated guided vehicles, drones, robots and machines. Components are typically further structured into sub-components, e.g., a robot arm or a gripper, and can be used to build digital twins. Different aspects for classifying components can be distinguished; here we concentrate on composability, performance and fidelity.In this paper, we are mainly concerned with components in the robotics simulation tool Gazebo used with Robot Operating System. Several structured scenario case studies are described. We investigate how these scenarios behave in Gazebo with respect to performance and fidelity for selected cases.

Background Delivering tools for genome analysis to users is often difficult given the complex dependencies and conflicts of such tools. Container virtualization systems (such as Singularity) isolate environments, thereby helping developers package tools. However, these systems lack mutual composability, i.e., an easy way to integrate multiple tools in different containers and/or on the host. Another issue is that one may be unable to use a single container system of the same version at all the sites being used, thus discouraging the use of container systems. Results We developed LPMX, an open-source pure rootless composable container system that provides composability; i.e., the system allows users to easily integrate tools from different containers or even from the host. LPMX accelerates science by letting researchers compose existing containers and containerize tools/pipelines that are difficult to package/containerize using Conda or Singularity, thereby saving researchers’ precious time. The technique used in LPMX allows LPMX to run purely in userspace without root privileges even during installation, thus ensuring that we can use LPMX at any Linux clusters with major distributions. The lowest overhead for launching containers with LPMX gives us courage to isolate tools as much as possible into small containers, thereby minimizing the chance of conflicts. The support for the layered file system keeps the total size of container images for a single genomic pipeline modest, as opposed to Singularity, which uses mostly a flat single-layer image. Conclusions LPMX is pure rootless container engine with mutual composability, thus saving researchers’ time, and accelerating science.

In 1961, Jacob and Monod proposed the operon model of gene regulation. At the model's core was the modular assembly of regulators, operators, and structural genes. To illustrate the composability of these elements, Jacob and Monod linked phenotypic diversity to the architectures of regulatory circuits. In this review, we examine how the circuit blueprints imagined by Jacob and Monod laid the foundation for the first synthetic gene networks that launched the field of synthetic biology in 2000. We discuss the influences of the operon model and its broader theoretical framework on the first generation of synthetic biological circuits, which were predominantly transcriptional and posttranscriptional circuits. We also describe how recent advances in molecular biology beyond the operon model—namely, programmable DNA- and RNA-binding molecules as well as models of epigenetic and posttranslational regulation—are expanding the synthetic biology toolkit and enabling the design of more complex biological circuits.

Proofs in simulation-based frameworks have the greatest rigor when they are machine checked. But the level of details in these proofs surpasses what the formal-methods community can handle with existing tools. Existing formal results consider streamlined versions of simulation-based frameworks to cope with this complexity. Hence, a central question is how to abstract details from composability results and enable their formal verification.In this paper, we focus on the modeling of system communication in composable security statements. Existing formal models consider fixed communication patterns to reduce the complexity of their proofs. However, as we will show, this can affect the reusability of security statements. We propose an abstract approach to modeling system communication in Constructive Cryptography that avoids this problem. Our approach is suitable for mechanized verification and we use CryptHOL, a framework for developing mechanized cryptography proofs, to implement it in the Isabelle/HOL theorem prover. As a case study, we formalize the construction of a secure channel using Diffie-Hellman key exchange and a one-time-pad.

The concepts of information flow security and refinement are known to have had a troubled relationship ever since the seminal work of McLean. In this work we study refinements that support changes in data representation and semantics, including the addition of state variables that may induce new observational power or side channels. We propose a new epistemic approach to ignorance-preserving refinement where an abstract model is used as a specification of a system’s permitted information flows, that may include the declassification of secret information. The core idea is to require that refinement steps must not induce observer knowledge that is not already available in the abstract model. Our study is set in the context of a class of shared variable multiagent models similar to interpreted systems in epistemic logic. We demonstrate the expressiveness of our framework through a series of small examples and compare our approach to existing, stricter notions of information-flow secure refinement based on bisimulations and noninterference preservation. Interestingly, noninterference preservation is not supported “out of the box” in our setting, because refinement steps may introduce new secrets that are independent of secrets already present at abstract level. To support verification, we first introduce a “cube-shaped” unwinding condition related to conditions recently studied in the context of value-dependent noninterference, kernel verification, and secure compilation. A fundamental problem with ignorance-preserving refinement, caused by the support for general data and observation refinement, is that sequential composability is lost. We propose a solution based on relational pre-and postconditions and illustrate its use together with unwinding on the oblivious RAM construction of Chung and Pass.

Cyberinfrastructure is everywhere in diverse forms in service of applications in science, business and society. From IoT to extreme-scale computing data and computing have never been so distributed with the potential for real-time integration into these applications. The common theme to these applications, mostly composed of (big) data-integrated workloads, is their need to run in specialized environments for reasons such as on-demand or 24x7 nature of the tasks they are performing, and difficulties regarding their portability, latency, privacy, and performance optimization. Moreover, in many data-driven scientific applications, there is a need for heterogeneous integration of tasks requiring specialized computing capabilities with traditional high-throughput computing or high-performance computing tasks. Although some key middleware technologies enabled demonstration of standalone heterogeneous applications, such integration requires expertise convergence from a large group of people in very specialized settings. There are still many challenges for streamlined, scalable, repeatable, responsible, and explainable integration of data-integrated applications. Key opportunities for further innovations include intelligent systems and automated workflow management software that can compose and steer dynamic applications that can adapt to changing conditions in a data-driven fashion while integrating many tools to explore, analyze and utilize data. This talk will discuss some examples for data-integrated applications, describe emerging systems that enabled these applications, and overview our recent research to enable composable applications including a convergence application development methodology, intelligent middleware, and workflow composition.

Modern cloud computing workloads are becoming day by day more demanding, in terms of computational resources, as they feature multiple complex components, utilize heterogeneous hardware, and require tremendous amounts of memory. Such attributes of the emerging workloads disrupt the traditional design of cloud infrastructures, which are bound to decisions at the design time of the infrastructure, and mandate the dynamic composability of the next-generation cloud infrastructures.Scaling beyond the physical boundaries of the server trays, and minimizing over-provisioning of the nodes by disaggregating computational resources, such as CPUs, memory, etc., is a timely research problem. However, the prior line of research focuses on either NVM technologies or other disk-related approaches that try to relax the resource pressure induced by over-provisioning.In this work, we design, implement, and evaluate all necessary changes in the system software stack to support the dynamic allocation of disaggregated memory, depending on the needs of the workloads at hand. As a result, we can transparently increase the available memory of a system and achieve on average 57% better performance, compared to Swap, the de-facto mechanism used today for over-provisioning. Furthermore, we present a memory balancing policy that autonomously migrates memory pages across local and disaggregated memory. Our experimental results show that, even with a limited amount of local memory, memory balancing improves the performance by 41% on average, compared with using only disaggregated memory.

Detailed maps of the molecular basis of the disease are powerful tools for interpreting data and building predictive models. Modularity and composability are considered necessary network features for large-scale collaborative efforts to build comprehensive molecular descriptions of disease mechanisms. An effective way to create and manage large systems is to compose multiple subsystems. Composable network components could effectively harness the contributions of many individuals and enable teams to seamlessly assemble many individual components into comprehensive maps. We examine manually built versions of the RAS–RAF–MEK–ERK cascade from the Atlas of Cancer Signalling Network, PANTHER and Reactome databases and review them in terms of their reusability and composability for assembling new disease models. We identify design principles for managing complex systems that could make it easier for investigators to share and reuse network components. We demonstrate the main challenges including incompatible levels of detail and ambiguous representation of complexes and highlight the need to address these challenges.

We present a topology aware quantum synthesis algorithm designed to produce short circuits and to scale well in practice. The main contribution is a novel representation of circuits able to encode placement and topology using generic "gates", which allows the QFAST algorithm to replace expensive searches over circuit structures with few steps of numerical optimization. When compared against optimal depth, search based state-of-the-art techniques, QFAST produces comparable results: 1.19× longer circuits up to four qubits, with an increase in compilation speed of 3.6×. In addition, QFAST scales up to seven qubits. When compared with the state-of-the-art "rule" based decomposition techniques in Qiskit, QFAST produces circuits shorter by up to two orders of magnitude (331×), albeit 5.6× slower. We also demonstrate the composability with other techniques and the tunability of our formulation in terms of circuit depth and running time.

Robotic testbeds used for flight and research technology development are highly complicated electromechanical systems demanding large engineering effort to configure and manage safety-critical hardware. The software that interoperates with robotic testbeds needs to be robust yet flexible to accommodate rapidly changing testbed needs and other operational demands in a cost-efficient manner. The Jet Propulsion Laboratory (JPL) presents a new open-source C++ library called Fastcat for powerful and flexible EtherCAT device configuration for testbed and robotic applications. Fastcat implements a set of C drivers called ‘Just SOEM Drivers’ built on the popular Simple Open EtherCAT Master library for a small, but highly tested set of supported EtherCAT devices. Fastcat offers a rich set of capabilities such as supporting an arbitrary number of EtherCAT Masters, a YAML input configuration file, and a visualization tool ‘Fcviz’ to graph the bus topology using the open-source Graphiz library. Furthermore, a novel feature called ‘Fastcat Signals’ can efficiently route data and commands between devices to compose self-contained closed loop control systems such as heaters or joint-torque controllers with zero added latency. Abstract device types like signal generators, functions, and PID controllers and offline versions of device hardware drivers allow for powerful composability, offline-only testing, and flexible hybrid partial online – offline bus topologies. The Fastcat core library is middleware agnostic, but ROS2 wrappers are developed for ease-of-use. This paper will describe design tradeoffs, an overview of the implementation of these capabilities, and early results from the first JPL Robotic testbed use.

Logical Execution Time (LET) is a timed programming abstraction, which features predictable and composable timing. It has recently gained considerable attention in the automotive industry, where it was successfully applied to master the distribution of software applications on multi-core electronic control units. However, the LET abstraction in its conventional form is only valid within the scope of a single component. With the recent introduction of System-level Logical Execution Time (SL LET), the concept could be transferred to a system-wide scope. This article improves over a first paper on SL LET, by providing matured definitions and an extensive discussion of the concept. It also features a comprehensive evaluation exploring the impacts of SL LET with regard to design, verification, performance, and implementability. The evaluation goes far beyond the contexts in which LET was originally applied. Indeed, SL LET allows us to address many open challenges in the design and verification of complex embedded hardware/software systems addressing predictability, synchronization, composability, and extensibility. Furthermore, we investigate performance trade-offs, and we quantify implementation costs by providing an analysis of the additionally required buffers.

Representing the semantics of GUI screens and components is crucial to data-driven computational methods for modeling user-GUI interactions and mining GUI designs. Existing GUI semantic representations are limited to encoding either the textual content, the visual design and layout patterns, or the app contexts. Many representation techniques also require significant manual data annotation efforts. This paper presents Screen2Vec, a new self-supervised technique for generating representations in embedding vectors of GUI screens and components that encode all of the above GUI features without requiring manual annotation using the context of user interaction traces. Screen2Vec is inspired by the word embedding method Word2Vec, but uses a new two-layer pipeline informed by the structure of GUIs and interaction traces and incorporates screen- and app-specific metadata. Through several sample downstream tasks, we demonstrate Screen2Vec's key useful properties: representing between-screen similarity through nearest neighbors, composability, and capability to represent user tasks., Accepted to CHI Conference on Human Factors in Computing Systems (CHI 2021)

Proving the security of masked implementations in theoretical models that are relevant to practice and match the best known attacks of the side-channel literature is a notoriously hard problem. The random probing model is a promising candidate to contribute to this challenge, due to its ability to capture the continuous nature of physical leakage (contrary to the threshold probing model), while also being convenient to manipulate in proofs and to automate with verification tools. Yet, despite recent progress in the design of masked circuits with good asymptotic security guarantees in this model, existing results still fall short when it comes to analyze the security of concretely useful circuits under realistic noise levels and with low number of shares. In this paper, we contribute to this issue by introducing a new composability notion, the Probe Distribution Table (PDT), and a new tool (called STRAPS, for the Sampled Testing of the RAndom Probing Security). Their combination allows us to significantly improve the tightness of existing analyses in the most practical (low noise, low number of shares) region of the design space. We illustrate these improvements by quantifying the random probing security of an AES S-box circuit, masked with the popular multiplication gadget of Ishai, Sahai and Wagner from Crypto 2003, with up to six shares.

Since the inception of Bitcoin, a plethora of distributed ledgers differing in design and purpose has been created. While by design, blockchains provide no means to securely communicate with external systems, numerous attempts towards trustless cross-chain communication have been proposed over the years. Today, cross-chain communication (CCC) plays a fundamental role in cryptocurrency exchanges, scalability efforts via sharding, extension of existing systems through sidechains, and bootstrapping of new blockchains. Unfortunately, existing proposals are designed ad-hoc for specific use-cases, making it hard to gain confidence in their correctness and composability. We provide the first systematic exposition of cross-chain communication protocols.

Decentralized financial (DeFi) applications on the Ethereum blockchain are highly interoperable because they share a single state in a deterministic computational environment. Stakeholders can deposit claims on assets, referred to as ‘liquidity shares’, across applications producing effects equivalent to rehypothecation in traditional financial systems. We seek to understand the degree to which this practice may contribute to financial integration on Ethereum by examining transactions in ‘composed’ derivatives for the assets DAI, USDC, USDT, ETH and tokenized BTC for the full set of 344.8 million Ethereum transactions computed in 2020. We identify a salient trend for ‘composing’ assets in multiple sequential generations of derivatives and comment on potential systemic implications for the Ethereum network.

Combat system modeling generally includes two aspects: structure and behavior. Structural modeling is to build the structure of entities and their internal and external static relationships. Behavioral modeling aims at the typical working processes. The simulation modeling definition language (SMDL) of Simulation Modeling Platform (SMP2) can describe system structure well, but it is difficult to support behavioral modeling. The modeling and simulation tool named Ptolemy is able to support the description of system behavior, but it lacks effective support for structural modeling. For this reason, the goal of the paper is to explore a mechanism to combine structural and behavioral modeling, which can not only effectively support the architecture design but also support the expression of system behaviors. As a proof of concept, we extend the SMDL by adding the synchronous data flow (SDF) elements, and use this new language, namely, the extended Simulation Model Definition Language (ESMDL), to specify a radar system for both of structural and behavioral modeling.

This publication is based on our paper presented at the IEEE International Conference on Software Architecture 2019. Due to their close interconnection with the outside world, cyber-physical systems are vulnerable to information leaks. Accordingly, it is crucial for software engineers to regulate and analyze the flow of information through systems. The microservice architectural style requires engineers to refine the regulations into security policies for the constituent software components. These policies must be composable to secure the information flow from end to end. However, since security is hard to compose, a composition of secure components may lead to an insecure system. In our paper, we enable microservice architectures of cyber-physical systems to be composed securely. First, we provide engineers with a set of architectural well-formedness rules for the refinement of security policies, ensuring composability if the constituent components communicate by message passing. Second, we present a verification technique to analyze whether the real-time message passing of components adheres to their refined security policies. Since the analysis results are securely composable, we assure engineers that a composition of secure components will always lead to a secure system. We evaluated the accuracy of our contributions using an extension of the CoCoME case study.

One of the benefits of decentralized finance (DeFi) – an alternative financial system built on blockchain – is composability, which means the system’s building blocks (tokens) can freely interact with one another to form new services. One example is stablecoin, a token with fixed exchange rate, which is backed by token collaterals. While stablecoins can be used to facilitate payments and exchanges, in DeFi they can be used to earn returns (“yield farming”), potentially multiplicatively. We use transaction-level blockchain data to analyze a stablecoin’s flows between protocols and provide suggestive evidence of DeFi yield-chasing behavior. We shed light on what DeFi total value locked might really measure and highlight the complexity in DeFi analysis and market surveillance.

International audience; The probing security model is widely used to formally prove the security of masking schemes. Whenever a masked implementation can be proven secure in this model with a reasonable \emph{leakage rate}, it is also provably secure in a realistic leakage model known as the \emph{noisy leakage model}. This paper introduces a new framework for the composition of probing-secure circuits. We introduce the security notion of \emph{input-output separation} (IOS) for a refresh gadget. From this notion, one can easily compose gadgets satisfying the classical probing security notion --which does not ensure composability on its own-- to obtain a \emph{region probing secure} circuit. Such a circuit is secure against an adversary placing up to $t$ probes in each gadget composing the circuit, which ensures a tight reduction to the more realistic noisy leakage model. After introducing the notion and proving our composition theorem, we compare our approach to the composition approaches obtained with the (Strong) Non-Interference (S/NI) notions as well as the Probe-Isolating Non-Interference (PINI) notion. We further show that any uniform SNI gadget achieves the IOS security notion, while the converse is not true. We further describe a refresh gadget achieving the IOS property for any linear sharing with a quasilinear complexity $\Theta(n \log n)$ and a $O(1/\log n)$ leakage rate (for an $n$-size sharing). This refresh gadget is a simplified version of the quasilinear SNI refresh gadget proposed by Battistello, Coron, Prouff, and Zeitoun (ePrint~2016). As an application of our composition framework, we revisit the quasilinear-complexity masking scheme of Goudarzi, Joux and Rivain (Asiacrypt~2018). We improve this scheme by generalizing it to any base field (whereas the original proposal only applies to field with $n$th powers of unity) and by taking advantage of our composition approach. We further patch a flaw in the original security proof and extend it from the random probing model to the stronger region probing model. Finally, we present some application of this extended quasilinear masking scheme to AES and MiMC and compare the obtained performances.

A significant aspect of software integrity is the ability to determine whether a system is correctly showing the information it is intended to show. This work combines abstract cryptographic composability principles with automated machine learning techniques to support a new methodology for software integrity checking, particularly in the intractable domain of interface validation. A subtle but often perilously overlooked cryptographic principle is the requirement that a sender be aware of the meaning of inputs, specifically of the cleartext behind encrypted messages. We propose using computer vision to evaluate whether interfaces exhibit technical awareness of information content, enabling automated development-time and real-time integrity checking that is far more efficient and extensive than manual analysis.

A simulation System of Systems (SoS) comprised of various simulation systems may have dissimilar modeling paradigms. For performing autonomy research and development, various types of simulation systems need to be brought together to build a multi-domain virtual SoS wherein effects of autonomous entities/agents can be observed. While the distributed simulation community has solved the integrability challenge using standards like Distributed Interactive Simulation (DIS) or High Level Architecture (HLA), the model composability challenge is an open research problem. Many software/systems can now be made available as docker applications which can be readily plugged into existing simulation systems. However, the trust issues with such integration limit their usage as established systems cannot trust third party apps. This paper highlights some of the challenges with building a cloud-based simulation SoS, proposes an architecture framework using the concept of structural autonomy and leverages Modeling & Simulation as a fundamental key enabler for autonomy research.

To implement Service Oriented Architecture (SOA) in a banking company for transactional banking activity, this paper aims to overcome the problem of several related surrounding systems which has the same function in the different system by using Domain Driven Design. The paper proposes an approach to SOA using Web Services for service delivery in the area of transactional banking activities. Several systems will be connected to a BUS that will wait on and manage any request coming from other applications. To design the system then in this paper also will identify which application will consume the same function and analyze which function belongs to a certain domain. The paper finds that the implementation of an SOA system for transactional banking activities can be achieved by rapidly changing the habit of scaling up the system and application. This study shows that banking activity has a huge number of systems that should sync one and another to maintain the data integrity, availability, interoperability, and composability of the system.