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This position paper provides first, a literature survey of selected domains with significant contributions to simulation interoperability research, such as defense and healthcare simulation, including insights from academia and research organizations. Next, four main interoperability methods are reviewed, i.e., messages-oriented methods, use of information exchange models and common object models, and reference modeling, including ontological means. This review leads to the observation that successful approaches do not only rely on technical solutions but are also using conceptual alignment of the underlying models as well. The Levels of Conceptual Interoperability Model is revisited to consider how it contributed—and still contributes today—to reach meaningful interoperability between model-based solutions. Its descriptive and prescriptive use is discussed, and it is applied to the four methods to show its practical applicability. [ABSTRACT FROM AUTHOR]

Entropy can signify different things. For instance, heat transfer in thermodynamics or a measure of information in data analysis. Many entropies have been introduced, and it can be difficult to ascertain their respective importance and merits. Here, we consider entropy in an abstract sense, as a functional on a probability space, and we review how being able to handle the trivial case of non-interacting systems, together with the subtle requirement of extensivity, allows for a systematic classification of the functional form. [ABSTRACT FROM AUTHOR]

Decentralized finance (DeFi) has revolutionized the financial industry in recent years. Industries such as banking, insurance, and investment are experiencing a significant shift due to the growth of DeFi. The decentralized finance market is expanding exponentially, emphasizing the potential of digital currencies and decentralized platforms in providing an alternative to the traditional finance paradigm. It eliminates the need for costly intermediaries, reduces transaction fees, and increases accessibility to financial services for everyone, regardless of their geographic location or economic status. With the enormous increase in cryptocurrency investment, individuals and institutions have started to use DeFi. In this context, understanding the architecture and working mechanisms of different DeFi protocols becomes crucial in creating new and innovative products. This review paper explores various DeFi protocols, including derivatives, decentralized exchanges (DEX), lending and borrowing, asset management, and stablecoins. It analyses their internal structure and composability, providing insights into how these protocols can be combined to create new and innovative DeFi products and explore the potential of DeFi in providing an alternative to the traditional finance paradigm. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

In a dynamic environment, a manufacturing system should be reconfigurable to make the products with lot size of one and a high product mix in mass customization. A manufacturing system is continuously evolved to make new products at different time scales and ensure uninterrupted productions when internal or external changes occur. System evolution relates to add, remove, upgrade components, and reconfigure the system at different levels and scopes. However, scientific methods and tools are lacking to support designers in reconfiguring a system subject to given changes. This becomes a big hurdle to adopt automated solutions in small- and medium-sized enterprises. To support system reconfiguration, we propose a generic framework and methods to assess the performance of heterogeneous robotic systems or components. The proposed methods can also help 1) designers to select components for an integrated solution based on the needs and 2) robot manufacturers to identify the weaknesses of their products. [ABSTRACT FROM AUTHOR]

Refreshing algorithms are a critical ingredient for secure masking. They are instrumental in enabling sound composability properties for complex circuits, and their randomness requirements dominate the performance overheads in (very) high-order masking. In this paper, we improve a proposal of mask refreshing algorithms from EUROCRYPT 2017 that has excellent implementation properties in software and hardware, in two main directions. First, we provide a generic proof that this algorithm is secure at arbitrary orders—a problem that was left open so far. We introduce parametrized non-interference as a new technical ingredient for this purpose that may be of independent interest. Second, we use automated tools to further explore the design space of such algorithms and provide the best known parallel mask refreshing gadgets for concretely relevant security orders. Incidentally, we also prove the security of a recent proposal of mask refreshing with improved resistance against horizontal attacks from CHES 2017. [ABSTRACT FROM AUTHOR]

We present a round-efficient black-box construction of a general multi-party computation (MPC) protocol that satisfies composability in the plain model. The security of our protocol is proven in the angel-based UC framework [Prabhakaran and Sahai, STOC'04] under the minimal assumption of the existence of semi-honest oblivious transfer protocols. The round complexity of our protocol is max(O~(log2n),O(ROT)) when the round complexity of the underlying oblivious transfer protocol is ROT. Since constant-round semi-honest oblivious transfer protocols can be constructed under standard assumptions (such as the existence of enhanced trapdoor permutations), our result gives a O~(log2n)-round protocol under these assumptions. Previously, only an O(max(nϵ,ROT))-round protocol was shown, where ϵ>0 is an arbitrary constant. We obtain our MPC protocol by constructing a O~(log2n)-round CCA-secure commitment scheme in a black-box way under the assumption of the existence of one-way functions. [ABSTRACT FROM AUTHOR]

The last two decades witnessed the success of many efficient designs of concurrent data structures. A large set of them has a common base principle: each operation is split into a read-only traversal phase, which scans the data structure without locking or monitoring, and a read-write commit phase, which atomically validates the output of the traversal phase and applies the needed modifications to the data structure. In this paper we introduce Optimistic Transactional Boosting (OTB), an optimistic methodology for extending those designs in order to support the composition of multiple operations into one atomic execution by building a single traversal phase and a single commit phase for the whole atomic execution. As a result, OTB-based data structures are optimistic and composable . The former because they defer any locking and/or monitoring to the commit phase of the entire atomic execution; the latter because they allow the execution of multiple operations atomically. Additionally, in this paper we provide a theoretical model for analyzing OTB-based data structures and proving their correctness. In particular, we extended a recent approach that models concurrent data structures by including the two notions of optimism and composition of operations. [ABSTRACT FROM AUTHOR]

We show that it is possible for the so-called weak locking capacity of a quantum channel (Guha et al. in Phys Rev X 4:011016, 2014) to be much larger than its private capacity. Both reflect different ways of capturing the notion of reliable communication via a quantum system while leaking almost no information to an eavesdropper; the difference is that the latter imposes an intrinsically quantum security criterion whereas the former requires only a weaker, classical condition. The channels for which this separation is most straightforward to establish are the complementary channels of classical-quantum (cq-)channels and, hence, a subclass of Hadamard channels. We also prove that certain symmetric channels (related to photon number splitting) have positive weak locking capacity in the presence of a vanishingly small pre-shared secret, whereas their private capacity is zero. These findings are powerful illustrations of the difference between two apparently natural notions of privacy in quantum systems, relevant also to quantum key distribution: the older, naïve one based on accessible information, contrasting with the new, composable one embracing the quantum nature of the eavesdropper's information. Assuming an additivity conjecture for constrained minimum output Rényi entropies, the techniques of the first part demonstrate a single-letter formula for the weak locking capacity of complements to cq-channels, coinciding with a general upper bound of Guha et al. for these channels. Furthermore, still assuming this additivity conjecture, this upper bound is given an operational interpretation for general channels as the maximum weak locking capacity of the channel activated by a suitable noiseless channel. [ABSTRACT FROM AUTHOR]

Multi-Processor Systems-on-a-Chip (MPSoCs) provide sufficient computing power for many applications in scientific as well as embedded applications. Unfortunately, when real-time requirements need to be guaranteed, applications suffer from the interference with other applications, uncertainty of dynamic workload and state of the hardware. Composable application/architecture design and timing analysis is therefore a must for guaranteeing real-time applications to satisfy their timing requirements independent from dynamic workload. Here, Invasive Computing is used as the key enabler for compositional timing analysis on MPSoCs, as it provides the required isolation of resources allocated to each application. On the basis of this paradigm, this work proposes a hybrid application mapping methodology that combines design-time analysis of application mappings with run-time management. Design space exploration delivers several resource reservation configurations with verified real-time guarantees for individual applications. These timing properties can then be guaranteed at run-time, as long as dynamic resource allocations comply with the offline analyzed resource configurations. This article describes our methodology and presents programming, optimization, analysis, and hardware techniques for enforcing timing predictability. A case study illustrates the timing-predictable management of real-time computer vision applications in dynamic robot system scenarios. [ABSTRACT FROM AUTHOR]

Modeling and simulation is pervasive throughout many different disciplines. As computing technology has provided more capability, the systems being modeled and simulated have grown larger and more complex. Often times, these large systems are managed as interacting subsystems. When it is necessary for the simulation to allow disparate subsystems to maintain their independence, then a hybrid model of the subsystems should be used. Furthermore, to ease the burden of verification and validation of simulation results, a proven system theoretical modeling specification should be used. However, many communities have already adopted nonsystem theoretical software solutions and established a group of domain experts familiar with these tools. This paper provides two things: a formal approach to building a hybrid model, and a discussion of how to incorporate a nonsystem theoretical software implementation into a proven framework. The first is done through the implementation of a Knowledge Interchange Broker (KIB) as an Interaction Model (IM). The second is accomplished by exemplifying the use of the IM in an agent-environment hybrid model. In the hybrid model, the agent is implemented in the Discrete-event System (DEVS) specification and the environment is implemented in the Geographical Resources Analysis Support System (GRASS) using a Composable Cellular Automaton (CCA) specification. This concept has been successfully applied to both example models and an interdisciplinary research project where the interactions between human activities and landscape processes are studied. [ABSTRACT FROM AUTHOR]

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Modeling & Simulation (M&S) is making successful contributions to different areas in industry and academia. However, there are certain key issues that are preventing the field from addressing larger domains and from achieving wide-scale impact. Formulating these as grand challenges arguably focuses attention on these key issues and may bring a critical mass of effort to bear that could result in a major leap forward. This article is one of several concurrent activities aimed at reinvigorating the debate on grand challenges in M&S. These grand challenges include Big Simulation, human behavior, composability, cloud-based M&S, reproducibility in M&S research and the democratization of M&S. Two themes emerge: the need for large-scale cloud-based cyberinfrastructures for M&S and the democratized access to M&S and its outputs. [ABSTRACT FROM AUTHOR]

We present Abstract (ABortable STate mAChine replicaTion), a new abstraction for designing and reconfiguring generalized replicated state machines that are, unlike traditional state machines, allowed to abort executing a client's request if "something goes wrong." Abstract can be used to considerably simplify the incremental development of efficient Byzantine faulttolerant state machine replication (BFT) protocols that are notorious for being difficult to develop. In short, we treat a BFT protocol as a composition of Abstract instances. Each instance is developed and analyzed independently and optimized for specific system conditions. We illustrate the power of Abstract through several interesting examples. We first show how Abstract can yield benefits of a state-of-the-art BFT protocol in a less painful and errorprone manner. Namely, we develop AZyzzyva, a new protocol that mimics the celebrated best-case behavior of Zyzzyva using less than 35% of the Zyzzyva code. To cover worst-case situations, our abstraction enables one to use in AZyzzyva any existing BFT protocol. We then present Aliph, a new BFT protocol that outperforms previous BFT protocols in terms of both latency (by up to 360%) and throughput (by up to 30%). Finally, we present R-Aliph, an implementation of Aliph that is robust, that is, whose performance degrades gracefully in the presence of Byzantine replicas and Byzantine clients. [ABSTRACT FROM AUTHOR]

The adoption of Networks-on-Chip (NoCs) as the communication infrastructure for complex integrated systems is a fact, and has been promoted by the growing number of processing elements integrated in current MPSoCs. These are designed to execute several applications in parallel, with different communication requirements and distinct levels of required quality of service. To meet these restrictions, most designs customize the MPSoC at design time, using specific NoC communication services as adaptive routing algorithms, priorities, and connections. However, MPSoCs are increasingly used in embedded systems, where new applications may be added at runtime, characterizing dynamic workload scenarios. Such scenarios require adaptability at runtime, with applications having the possibility to select the most appropriate communication service according to their respective requirements. The goal of the present work is to link the hardware level of NoCs to the MPSoC application level, proposing the development of a communication API that exposes the communication services offered by the NoC to the application developer. Executing real and synthetic applications in two different MPSOCs, and using four different NoC communication services enabled to demonstrate the efficiency of the proposed approach to meet applications requirements. [ABSTRACT FROM PUBLISHER]

Today's embedded systems are powered by heterogeneous Multi-Processor Systems on Chip (MPSoCs) in order to cope with the increasing applications demands and the tight energy budget of portable devices. The complexity of these systems makes them difficult to program, which has caused academia and industry to look for alternative methodologies and models. In the particular case of multimedia and baseband processing, dataflow models are being proposed and appear to be a sensible choice to represent applications. [ABSTRACT FROM PUBLISHER]

With the prevalence of net-centric environments, Service-Oriented Architectures (SOAs) have emerged as a paradigm that greatly impacts the modeling and simulation (M&S) community. This paper has two interrelated goals. The first is to give a comprehensive review of various service-oriented simulation frameworks to help researchers select the appropriate one for their specific purpose. The second goal is to combine the common features derived from the review into one unifying framework that can describe and prescribe various specific approaches. The focus of this paper is on the common functionalities of service-oriented simulations reflected in the review and unifying framework. In particular, we emphasize the way SOAs and M&S are combined, and the interoperability and composability challenges of distributed M&S services. We describe some fundamental concepts first. Then we present a comprehensive survey of several classical frameworks, including formalism-based, model-driven, interoperability protocol based, eXtensible Modeling and Simulation Framework (XMSF), Open Grid Services Architecture (OGSA) based, and ontology-driven frameworks. Based on the review, we propose a novel three-dimensional reference model that can unify the ad hoc approaches into a common framework. The model can be used as a guideline or an analytic means to find potential and possible future directions. In particular, the model inspects the crossover between the disciplines of M&S, service-orientation, and software/systems engineering. Based on the model, we present a detailed comparison of the reviewed frameworks. Finally the significance of the paper is discussed and future directions are recommended. [ABSTRACT FROM PUBLISHER]

In this paper, we explore how component-based Modeling and Simulation can benefit from the Levels of Conceptual Interoperability Model, which is a three-level interoperation model, by proposing an ontology-based and domain-independent approach supporting composability (conceptual level) and interoperability (during execution). The proposed approach is in accordance with three standards: High-level Architecture for the implementation level, Base Object Model for the conceptual level, and meta object facility for the knowledge level. We apply this approach in implementing a normalized large-scale rescue management system by reusing existing agent-based simulators. The proposed approach is useful for modeling complex systems and facilitating interoperation between models (conceptual level) and between simulators (implementation level). [ABSTRACT FROM PUBLISHER]

Interoperation and dynamic composability of disparate simulations is a long-standing challenge within the defense modeling and simulation community. While both issues are extensively studied, a unified and coherent strategy that facilitates achieving seamless and transparent congruity among conceptual and realization spaces of simulations is still an elusive goal. In this paper, an agent-supported meta-level interoperation architecture is proposed to address these challenges. The strategy involves the introduction of an agent framework independent of the simulation infrastructure for explicit separation of interoperation protocols from the simulation environment. To this end, agent-based mediation, brokering, matchmaking, and facilitation services are suggested as critical components for interoperation and composability. The proposed approach is based on the following premises: 1) deployment of brokering protocols improves transparency and balances the workload in interoperation, 2) partial matchmaking mechanisms provide more efficient and effective model and data qualification strategies than the conventional keyword-based matching mechanism, and 3) automated mediation facilities that are deployed independently from the simulation infrastructure improve transparency and runtime extensibility. Stand-alone prototypes of the matchmaker and broker agents are developed to facilitate testing these propositions. We conclude by discussing the extension of the applicability of the proposed strategy to DoDAF architectural views and associated products. [ABSTRACT FROM PUBLISHER]

We propose a composability model to ascertain that Web services can safely be combined, hence avoiding unexpected failures at runtime. Composability is checked through a set of rules organized into four levels: syntactic, static semantic, dynamic semantic, and qualltative levels. We introduce the concepts of composability degree and τ-composability to cater for partial and total composability. We also propose a set of algorithms for checking composability. Finally, we conduct a performance study (analytical and experimental) of the proposed algorithms. [ABSTRACT FROM AUTHOR]

Model reuse is a longstanding challenge within the defense simulation modeling community. While other disciplines successfully apply component-based approach to build systems, this approach has proven difficult to apply in simulation model development. The significance of employing explicit and distinct experimental frames to support reuse is already well recognized. Yet, characterization of the original context of a model is one of the least appreciated aspects and central to reuse and composability. Methods and tools are needed to provide mechanisms for structured representation and storage of context information, effective ways for retrieving it, and the possibility to relate it to the developer's intention. To this end, the basic model-simulator-experimental frame viewpoint is revisited to assert the role of context in reuse. The significance of separating concept, content, context, and simulator is discussed under the discrete-event system specification (DEVS) framework to provide a basis and rationale for contextualized simulation models. An abstract design strategy is presented to facilitate packaging and distribution of concept and context specification objects along with simulation models to improve reuse and composability. [ABSTRACT FROM PUBLISHER]

In large organizations the administration of access privileges (such as the assignment of access rights to a user in a particular role) is handled cooperatively through distributed administrators in various different capacities. A quorum may be necessary, or a veto may be possible for such a decision. In this paper, we present two major contributions: We develop a role-based access control (RBAC) approach for specifying distributed administration requirements, and procedures between administrators, or administration teams, extending earlier work on distributed (modular) authorization. While a comprehensive specification in such a language is conceivable it would be quite tedious to evaluate, or analyze, their operational aspects and properties in practice. For this reason we create a new class of extended Petri Nets called Administration Nets (Adm-Nets) such that any RBAC specification of (cooperative) administration requirements (given in terms of predicate logic formulas) can be embedded into an Adm-Net. This net behaves within the constraints specified by the logical formulas, and at the same time, it explicitly exhibits all needed operational details such as allowing for an efficient and comprehensive formal analysis of administrative behavior. We introduce the new concepts and illustrate their use in several examples. While Adm-Nets are much more refined and (behaviorally) explicit than workflow systems our work provides for a constructive step towards novel workflow management tools as well. We demonstrate the usefulness of Adm-Nets by modeling typical examples of administration processes concerned with sets of distributed authorization rules. [ABSTRACT FROM AUTHOR]

This paper discusses ideas for improving the composability of future models and simulations developed or used by the U.S. Department of Defense. It is largely based on a much longer report requested by the Defense Modeling and Simulation Office (DMSO) as independent advice in developing a program to pursue composability issues. This paper presents many suggestions on both policies and investments that would enhance prospects for composability. [ABSTRACT FROM PUBLISHER]

The thermodynamic stability conditions (TSC) of nonadditive and composable entropies are discussed. Generally the concavity of a nonadditive entropy with respect to internal energy is not equivalent to the corresponding TSC. It is shown that both the TSC of Tsallis'entropy and that of the ?-generalized Boltzmann entropy are equivalent to the positivity of the standard heat capacity. [ABSTRACT FROM AUTHOR]

It is shown how, among a class of generalized entropies, the Tsallis entropy can uniquely be identified by the principles of thermodynamics, the concept of stability, and the axiomatic foundations. [ABSTRACT FROM AUTHOR]

The controller synthesis paradigm provides a general framework for scheduling real-time applications. Schedulers can be considered as controllers of the applications; they restrict their behavior so that given scheduling requirements are met. We study a modeling methodology based on the controller synthesis paradigm. The methodology allows to get a correctly scheduled system from timed models of its processes in an incremental manner, by application of composability results which simplify schedulability analysis. It consists in restricting successively the system to be scheduled by application of constraints defined from scheduling requirements. The latter are a conjunction of schedulability requirements that express timing properties of the processes and policy requirements about resource management. The presented methodology allows a unified view of scheduling theory and approaches based on timing analysis of models of real-time applications. [ABSTRACT FROM AUTHOR]

ASTRAL is a formal specification language for realtime systems. It is intended to support formal software development and, therefore, has been formally defined. The structuring mechanisms in ASTRAL allow one to build modularized specifications of complex systems with layering. A realtime system is modeled by a collection of state machine specifications and a single global specification. This paper discusses the rationale of ASTRAL's design. ASTRAL's specification style is illustrated by discussing a telephony example. Composability of one or more ASTRAL system specifications is also discussed by the introduction of a composition section, which provides the needed information to combine two or more ASTRAL system specifications. [ABSTRACT FROM AUTHOR]

The chemical industry and subsequent value chain of plastics are facing significant challenges from the viewpoints of resource conversion and environmental burden. Now is the time to explore the future direction of plastics, which will require an integrated scheme using resource circulation, carbon neutrality, and a social system to promote after-use treatment under the concept of a circular economy. Polylactic acid (PLA) should help reduce greenhouse gas (GHG) emissions as a biobased material and contribute to waste management after use due to its biodegradability if managed properly. That is, it will be necessary to treat biodegradable products appropriately in closed systems such as composting facilities after use and recovery. To realize the implementation of fully approved composting facilities in society, simply evaluating biodegradability in the laboratory is insufficient. In this study, a pilot-scale test using PLA under actual composting conditions was conducted in accordance with both international standards and domestic evaluation methods. The results not only confirm its biodegradability and disintegration, but also demonstrate that the presence of a biodegradable plastic product has a negligible impact on the composting process. The obtained compost did not adversely affect plant germination or growth, demonstrating its safety and high quality. Such a multifaceted perspective makes this study unique and useful for creating a social framework. [ABSTRACT FROM AUTHOR]

Many-core platforms are rapidly expanding in various embedded areas as they provide the scalable computational power required to meet the ever-growing performance demands of embedded applications and systems. However, the huge design space of possible task mappings, the unpredictable workload dynamism, and the numerous non-functional requirements of applications in terms of timing, reliability, safety, and so forth. impose significant challenges when designing many-core systems. Hybrid Application Mapping (HAM) is an emerging class of design methodologies for many-core systems which address these challenges via an incremental (per-application) mapping scheme: The mapping process is divided into (i) a design-time Design Space Exploration (DSE) step per application to obtain a set of high-quality mapping options and (ii) a run-time system management step in which applications are launched dynamically (on demand) using the precomputed mappings. This paper provides an overview of HAM and the design methodologies developed in line with it. We introduce the basics of HAM and elaborate on the way it addresses the major challenges of application mapping in many-core systems. We provide an overview of the main challenges encountered when employing HAM and survey a collection of state-of-the-art techniques and methodologies proposed to address these challenges. We finally present an overview of open topics and challenges in HAM, provide a summary of emerging trends for addressing them particularly using machine learning, and outline possible future directions. While there exists a large body of HAM methodologies, the techniques studied in this paper are developed, to a large extent, within the scope of invasive computing. Invasive computing introduces resource awareness into applications and employs explicit resource reservation to enable incremental application mapping and dynamic system management. [ABSTRACT FROM AUTHOR]