Constituent Systems Research Articles

2.2.2 Maintaining Emergence in Systems of Systems Integration: a Contractual Approach using SysML

AbstractThis paper describes a pilot study in the use of model‐based techniques in system of systems (SoS) engineering. The focus is on the derivation of specifications for new constituent systems that are to be integrated with an existing SoS. The pilot study is based on a commercial application in the home audio/video domain and illustrates the application of architectural modeling guidelines to the description of a content‐streaming SoS using SysML and the formal COMPASS Modeling Language (CML). Analysis of the models leads to the derivation of a specification sufficient for constituent systems to guarantee a key leader election property of the SoS.

Research on the Affecting Factors of Claim under Bill Quantity of Construction Works in China

Claim is an important part of the code of valuation with bill quantity, but the connotation and extension of claims are not defined in the valuation mode of Bill of Quantities. Therefore, on the basis of foreign constitute systems, this paper uses deductive reasoning method to study the presumptive constitute of cost claim research. Combined the assumption with the characteristics of BQ in China, this paper puts forward the constituent system framework of construction cost claiming in China, and conduct specific research on profit claim。

Women's Participation in Elective Politics in South Korea

The purpose of this study is to analyze the limits of women's representation in elective politics in order to provide strategies for activating women's participation in elective politics in South Korea. It appears that the percentage of elected female legislators in both the local and national assemblies is still very low compared with Western countries despite the percentage of female legislators has increased due to introduction of female quota system. In South Korea, Neo-Confucian culture, marriage and family, and problems lying inside of women are restricting women's public life in many ways. Following strategies are proposed in this study to increase elected women's representation in the legislature. First, along with regression of Neo-Confucian culture in modern Korea, gender-equality culture need be firmly established. Second, it is necessary to improve female welfare system in order to increase women's participation in elective politics. Third, women must make great efforts at the community level to participate in elective politics through the women's movement and link with related civic organizations. Forth, the female quota system in the electoral districts must be introduced as the mandatory clause. Fifth, it is necessary to change the small constituency system to the medium constituency system in order to increase elected female legislators from electoral districts. In conclusion, it is important that women have to identify themselves not simply as members of society but as part of the power structure.

DISTRIBUTIONS OF SHORT-LIVED RADIOACTIVE NUCLEI PRODUCED BY YOUNG EMBEDDED STAR CLUSTERS

Most star formation in the Galaxy takes place in clusters, where the most massive members can affect the properties of other constituent solar systems. This paper considers how clusters influence star formation and forming planetary systems through nuclear enrichment from supernova explosions, where massive stars deliver short-lived radioactive nuclei (SLRs) to their local environment. The decay of these nuclei leads to both heating and ionization, and thereby affects disk evolution, disk chemistry, and the accompanying process of planet formation. Nuclear enrichment can take place on two spatial scales: [1] Within the cluster itself ($\ell\sim1$pc), the SLRs are delivered to the circumstellar disks associated with other cluster members. [2] On the next larger scale ($\ell\sim2-10$pc), SLRs are injected into the background molecular cloud; these nuclei provide heating and ionization to nearby star-forming regions, and to the next generation of disks. For the first scenario, we construct the expected distributions of radioactive enrichment levels provided by embedded clusters. Clusters can account for the SLR mass fractions inferred for the early Solar Nebula, but typical SLR abundances are lower by a factor of $\sim10$. For the second scenario, we find that distributed enrichment of SLRs in molecular clouds leads to comparable abundances. For both the direct and distributed enrichment processes, the masses of $^{26}$Al and $^{60}$Fe delivered to individual circumstellar disks typically fall in the range $10-100pM_\odot$ (where $1pM_\odot=10^{-12}M_\odot$). The corresponding ionization rate due to SLRs typically falls in the range $\zeta_{SLR}\sim1-5\times10^{-19}$ sec$^{-1}$. This ionization rate is smaller than that due to cosmic rays, $\zeta_{CR}\sim10^{-17}$ sec$^{-1}$, but will be important in regions where cosmic rays are attenuated (e.g., disk mid-planes).

Availability assessment of railway signalling systems with uncertainty analysis using Statecharts

In this paper, we propose an original simulation approach to evaluate the availability of systems in the presence of state uncertainty which arises from incompleteness or imprecision of knowledge and data. This approach is based on a simulation method combining the belief functions theory and the Statecharts. Then we propose a Statechart model of a railway signalling system, European Rail Traffic Management System (ERTMS) Level 2 considering state uncertainty, and evaluate its availability according to the RAMS requirements defined in the railway standards. Finally we propose a sensitivity analysis to estimate the state uncertainty of which constituent system has the most significant influence on the state uncertainty of the entire ERTMS Level 2.

Measurement and correlation of thermodynamic properties for the binary and ternary mixtures containing 2-propanol, 1,3-propanediol, and water

Thermodynamic properties, such as densities, viscosities, and surface tensions of the ternary system (2-propanol+1,3-propanediol+water) at T=298.15K and its constituent binary systems (2-propanol+1,3-propanediol, 2-propanol+water, and 1,3-propanediol+water) at T=(298.15, 308.15, 318.15, and 328.15)K were measured under atmospheric pressure. Densities were determined using a vibrating-tube densimeter. Viscosities were measured with an automatic Ubbelholde capillary viscometer. Surface tensions were determined by the Wilhelmy-plate method. From these experimental data, the excess molar volumes (VE), deviations in viscosity (οη), and deviations in surface tension (οϿ) were derived. The values of binary VE and οη were correlated with the Redlich⿿Kister equation. A simple equation based on Connors and Wright was derived for the correlation of binary οϿ data. The values of ternary VE, οη, and οϿ were fitted to a variable-degree polynomial equation and compared with those predicted from binary data using the equations of Kohler, Colinet, Jacob⿿Fitzner, Scatchard et al., Tsao⿿Smith, and Toop. The values of VE and οη were used to discuss the nature of mixing behaviors between mixture components.

Liquidus Projection of the Ag-Sn-Te Ternary System

The Ag-Sn-Te ternary system is of interest to thermoelectric applications and its liquidus projection is determined in this study. Forty Ag-Sn-Te ternary alloys are prepared and their primary solidification phases are determined. These different primary solidification phase regions include three terminal solid solutions: Ag, Sn, and Te; six binary intermediate phases: SnTe, β-Ag5Te3, Ag1.9Te, Ag2Te (assuming no phase transformation), ζ-Ag4Sn, and e-Ag3Sn; and one ternary compound, AgSnTe2. These data, together with the phase diagrams of the three constituent binary systems, are employed to construct the univariant lines of the liquidus projection. The temperature-descending directions of these univariant lines are determined using thermal analysis results and mass balance concept. The types of invariant reactions and the reaction temperatures are determined from the temperature-descending directions of the univariant lines and by thermal analysis. There are two Class I reactions, five Class II reactions, and one Class III reaction. The invariant reaction with the highest reaction temperature is L + Ag = Ag2Te + e-Ag3Sn, at 992.7 ± 4 K (719.5 ± 4 °C), and that with the lowest reaction temperature is L = Sn + e-Ag3Sn + SnTe, at 494.2 ± 4 K (221 ± 2 °C).

Liquidus Projections of Sn-Co-Ni and Sn-Rich Sn-Ag-Co-Ni Systems

Alloys based on Sn and Sn-Ag are commonly used as Pb-free solders, and Ni is frequently used in barrier layers. Co has been studied as a possible alloying element in both solders and barrier layers. Thus, the Sn-Co-Ni and Sn-Ag-Co-Ni alloy systems are important for electronic soldering. Forty-nine Sn-Co-Ni alloys and 24 Sn-rich Sn-Ag-Co-Ni alloys were prepared. The primary solidification phases of these as-cast alloys were determined, and based on these results and the available phase diagrams of the constituent systems, the liquidus projections of Sn-Co-Ni ternary and Sn-Ag-Co-Ni quaternary systems at 90 at.% and 95 at.% Sn were determined. In the Sn-Co-Ni system, no ternary compound was found; (Ni,Co)3Sn2 and (Ni,Co) are continuous solid solutions, and there are eight kinds of primary solidification phases: Sn, CoSn3, CoSn2, CoSn, (Ni,Co)3Sn2, (Ni,Co), Ni3Sn, and Ni3Sn4. In the 90 at.% and 95 at.% Sn isoplethal sections of the Sn-Ag-Co-Ni liquidus projection, the primary solidification phases are CoSn2, CoSn, Ni3Sn4, and Ag3Sn.

Amorphous forming ranges of Al-Fe-Nd-Zr system predicted by Miedema and geometrical models

A method based on the semi-empirical Miedema model and a geometrical model was used to study the glass forming abilities (GFA) and the amorphous forming ranges of Al-Fe-Nd-Zr system and its constituent ternary systems. The amorphous forming composition ranges were analyzed based on different criteria such as ΔGam-ss and PHSS (PHSS=ΔHchem (ΔSC/R)(ΔSs/R)) for Al-Fe-Nd system. The predicted amorphous forming range was in good agreement with the experimental results. The results showed that the criterion of ΔGam-ss was more accurate, and agreed well with the experiment results. The Gibbs free energy difference ΔGam-ss and parameter PHSS were then used to predict the amorphous forming composition range for the rest of the constitutive ternary systems of Al-Fe-Nd-Zr. In addition, the amorphous forming composition ranges of the (Al-Fe-Zr)100-xNdx (x=50, 60, 70) systems were predicted by ΔGam-ss and the modified parameter PHSS. The Gibbs free energy of Al10(Fe1−xZrx)30Nd60 were also calculated. The GFA parameter PHSS indicated that the composition with the highest GFA was Al33.5Fe13.5Zr3Nd50 for the (Al-Fe-Zr)50Nd50 system, Al28.8Fe10Zr1.2Nd60 for the (Al-Fe-Zr)40Nd60 system and Al22.8Fe6.9Zr0.3Nd70 for the (Al-Fe-Zr)30Nd70 system, and the results suggested that those alloys with high content of Al had higher GFA. The appropriate content of neodymium and zirconium resulted in the lower value of PHSS and increased the GFA obviously.

Thermodynamic assessment of the Al–Dy, Dy–Zr and Al–Dy–Zr systems

Like Al3Sc, the Al30Dy7Zr3 compound has an L12 structure, implying that it could probably be used to improve the strength of aluminum alloys at elevated temperatures. Thus, it is extremely important to understand the phase relations of the Al–Dy–Zr system in the Al-rich corner. Firstly, the phase diagram of the Al–Dy binary system was re-assessed with the C15_Laves phase treated as a stoichiometric compound. Then, using the special quasirandom structure containing 16 atoms (SQS_16) to simulate Dy1−x Zr x (x = 0.25, 0.5, and 0.75) hcp_A3 solid solutions, their enthalpies of mixing at 0 K were calculated by the first-principles method. Based on these results and the evaluated phase diagram in literature, the Dy–Zr binary system was optimized thermodynamically. Integrating the thermodynamic descriptions of the three constituent binary systems, the phase diagram of the Al–Dy–Zr ternary system in the Al-rich corner was optimized finally by coupling the first-principles calculation with the CALculation of PHAse Diagram method. A good agreement has been reached between the calculated phase relations and the experimental results, which indicates that the current thermodynamic description is reasonable.

Isobaric vapor–liquid equilibria for the binary and ternary mixtures of 2-propanol, water, and 1,3-propanediol at P = 101.3 kPa: Effect of the 1,3-propanediol addition

Isobaric vapor–liquid equilibrium (VLE) at P=101.3kPa have been measured for the ternary system of 2-propanol+water+1,3-propanediol and its constituent binary systems of 2-propanol+water and 2-propanol+1,3-propanediol using an equilibrium still with circulation of both vapor and liquid phases. The ternary system of 2-propanol+water+1,3-propanediol was prepared with three mass fractions (0.10, 0.30, and 0.50) of 1,3-propanediol in the overall liquid mixtures. The equilibrium compositions of mixtures were analyzed by gas–liquid chromatography. The liquid activity coefficients were obtained using the modified Raoult's law. The relative volatilities of 2-propanol to water were also determined. The results showed that the azeotropic point of 2-propanol+water can be eliminated when the mass fraction of 1,3-propanediol in the liquid phase is up to 0.50. Thermodynamic consistency tests were performed for the VLE data of these two binary systems. The new binary and ternary VLE data were successfully correlated with the Wilson, non-random two-liquid (NRTL), and universal quasi-chemical activity coefficient (UNIQUAC) models. The models with their best-fitted interaction parameters of the binary systems were used to predict the ternary VLE data. A comparison of model performances was made by using the criterion of mean deviations in boiling point and in vapor-phase composition.

Sustainability of systems of systems

The purpose of this paper is to synthesise multiple worldviews of system of systems and introduce sustainability as a prerequisite for the development of the field. Fundamentally, systems of systems provide significantly greater capability than constituent systems. The enhanced capability is achieved through coordination and integration of complex systems. This research fosters sustainability to support enhanced capabilities in systems of systems. First, we establish sustainability in the context of system of systems characterisations. Second, the system of systems problem landscape and challenges is discussed in relation to sustainability. Third, the need for sustainability is transposed to three diverging perspectives in systems of systems. Fourth, two industrial cases are used to illustrate the need for sustainability. Fifth, we introduce an organising construct within which systems of systems might be developed to address sustainability and viability. The paper concludes with implications and directions for further research for sustainability in system of systems.

Stability Criteria for Cascaded Nonlinear Stochastic Systems Admitting Not Necessarily Unbounded Decay Rate

This paper considers global asymptotic stability and robustness of cascaded nonlinear stochastic systems, and presents Lyapunov-based criteria. Constituent systems are characterized in terms of dissipation inequalities almost in the form of input-to-state stability (ISS) which is popular for both stochastic and deterministic systems. As an important unique feature of stochastic systems, this paper first demonstrates that assuming ISS systems having unbounded decay rate is restrictive, which contrasts sharply with the deterministic case. This motivates the second part of the main results focusing on ISS systems with bounded decay rate as well as systems which are not ISS. With these developments, this paper proposes a framework based on integral input-to-state stability (iISS) and demonstrates its usefulness.

Dynamic Planning of System of Systems Architecture Evolution

The dynamic planning and development of a large collection of systems or a ‘System of Systems’ (SoS) pose significant programmatic challenges due to the complex interactions that exist between its constituent systems. Decisions to add, remove, or reconstitute connections between systems can result in repercussive failures across operational and developmental dimensions of an SoS. The work conducted in this research is part of a larger body of work funded by the DoD Systems Engineering Research Center (SERC) towards the development of an Analytic Workbench. This paper in particular develops a tool that adopts an operations research-based perspective to SoS level planning based on metrics of cost, performance, schedule and risk. Specifically, our work employs an Approximate Dynamic Programming approach that is well suited to address issues of computational tractability of the resulting dynamic planning optimization problem. This approach allows for identification of near-optimal multi-stage decisions in evolving SoS architectures. A Naval Warfare Scenario SoS example problem illustrates application of the method.

Fuzzy Optimization of Acknowledged System of Systems Meta-architectures for Agent based Modeling of Development

Acknowledged systems of systems (SoS) lie on a continuum between authoritarian central control and anarchy. The constituent systems are independent, with a life and purpose of their own. The systems require not only technical interfaces, but also social interactions, to create the SoS. A fuzzy optimization process may be used to select a desirable SoS configuration, but it may be unachievable due to the inability to persuade the systems to cooperate in the plan. Modeling the systems’ internal decision processes could help understand how to design better SoS architectures. This research used generic, modular modeling processes to examine two proposed SoS architectures and the impact of degree of cooperation on the suitability of the achieved SoS.

Application of Person-by-Person Equilibrium and Performance-Measure Statistics to Distributed Control of Uncertain Stochastic Large-Scale Systems with Time Delays

This paper presents a distributed control design for a class of interconnected linear systems with Markovian jumps, parametric uncertainties and time delays in both system states and control actuations. The switching of a countable number of modes associated with constituent systems is encapsulated by appropriate probability transitions. The parameter uncertainties are considered to be unknown but norm bounded. Analysis of time-delay systems is supported by Pade approximations of the first order. A general framework of multi-person nonzero-sum stochastic differential games is leveraged for distributed decision making with performance risk-aversion. Towards performance risk-aversion and reliability, self-directed controllers and/or decision makers are now capable of effectively incorporating risk-averse attitudes via performance-measure statistics into person-by-person equilibrium decisions with decentralized output feedback for distributed interactions.

Multi-agent Based Architecture for Acknowledged System of Systems

Negotiation and collaboration issues in large organizations, with centralized control, across the globe, are becoming more complex with each passing day. The Acknowledged System of Systems (SoS) is a new approach that addresses some of these issues in a systematic, efficient manner. This paper proposes a hierarchical architectural framework to support Acknowledged SoS architecting and analysis for a Department of Defense (DoD) Acquisition process. A major challenge of the successful planning and evolution of an Acknowledged SoS is the lack of understanding of the impact of presence or absence of a system and its interface with another constituent system on the overall architecture. The agent based model (ABM) structure developed here provides Acknowledged SoS manager that has both ability to address the managerial issues as well as a decision making tool for SoS architecting. This paper offers a complete integration of the techniques used to represent SoS architectures. The work illustrates the modeling approach through a domain setting.

A histogram analysis for system of systems

The problems stemming from increasing complexity continue to confound our capabilities to deal with systems. In response, many large organisations seek to integrate their existing systems to work together to accomplish capabilities that cannot be achieved by the constituent systems. The integration of these systems is often referred to as a system of systems (SoS). While much has been written about SoS and their associated phenomena, we have not found sufficient exploration to answer some of our most basic questions: where did this concept came from? And when, or has, the peak of the SoS development movement been reached? To answer these questions, this paper has constructed a histogram analysis to trace the history of SoS from 1926–2011. Five hundred different sources have been included in the analysis in an attempt to give a glimpse into the development of the SoS field through the frequency of publications.

Resilience-based System Importance Measures for System-of-Systems

Systems-of-systems (SoS) like the air transportation system and missile defense are gaining increasing attention in both the academic and practitioner communities. This research investigates one crucial aspect of SoSs: their ability to recover from disruptions, or their resilience. We develop a family of system importance measures (SIMs) that rank the constituent systems based on their impact on the overall SoS performance. The SIMs address some of the major weaknesses that have prevented researchers from identifying a single resilience metric. While trade-space analyses are standard practice in systems engineering, conducting trades on SoS resilience is difficult because, to date, no reliable and consistent metrics have been developed for SoS resilience. Some metrics have been proposed, but these measures assume homogenous networks, thus ignoring one of the key features of SoSs: the combination of heterogeneous systems (e.g., airports and aircraft) to achieve a common goal (e.g., transport). Instead of focusing on an overall metric, the set of SIMs provides designers with specific information on where an SoS is lacking resilience (or has excess resilience) and hence on where improvements are needed (or where downgrades are possible).

The Theory of Sovereignty in the Institutional Economics of John R. Commons from the Perspective of Constituent Power

We review the discussion of sovereignty in the work of John R. Commons from the perspective of constituent power. His discussion has implications for constituent power as discussed by Negri, Habermas and Arendt. Constituent power is a dynamic wherein forces inside each citizen gather and affect the exercise of power. We illustrate the following two points: First, Commons’s discussion of sovereignty overcomes the limitations discussed. He shows that working rules are constituted by communication in government organisations, namely, the commission. He also shows the possibility of the constitution existing in a sphere of the economy based on concrete procedures. In contrast to Negri and Arendt, he asserts the possibility of the constitution being present in a sphere of the economy through institutionalised procedures, namely, collective bargaining contained in the common-law method. We find this method indicates the constituent system of values and institutions. Second, Commons’s view of the constitution was shaped after his writings of 1889–1890. We learn that he acquired his view of the constitution from his experiences working with the constituent process.