Subsystem Boundaries Research Articles

Fractal subsystem symmetries, anomalies, boundaries, and effective field theory

Fractal subsystem symmetries, anomalies, boundaries, and effective field theory

Structure–function subsystem model and computational lesions of the central nervous system’s rostral sector (forebrain and midbrain)

The craniote central nervous system has been divided into rostral, intermediate, and caudal sectors, with the rostral sector containing the vertebrate forebrain and midbrain. Here, network science tools were used to create and analyze a rat hierarchical structure-function subsystem model of intrarostral sector neural connectivity between gray matter regions. The hierarchy has 109 bottom-level subsystems and three upper-level subsystems corresponding to voluntary behavior control, cognition, and affect; instinctive survival behaviors and homeostasis; and oculomotor control. As in previous work, subsystems identified based on their coclassification as network communities are revealed as functionally related. We carried out focal perturbations of neural structural connectivity comprehensively by computationally lesioning each region of the network, and the resulting effects on the network's modular (subsystem) organization were systematically mapped and measured. The pattern of changes was found to be correlated with three structural attributes of the lesioned region: region centrality (degree, strength, and betweenness), region position in the hierarchy, and subsystem distribution of region neural outputs and inputs. As expected, greater region centrality results, on average, in stronger lesion impact and more distributed lesion effects. In addition, our analysis suggests that strongly functionally related regions, belonging to the same bottom-level subsystem, exhibit similar effects after lesioning. These similarities account for coherent patterns of disturbances that align with subsystem boundaries and propagate through the network. These systematic lesion effects and their similarity across functionally related regions are of potential interest for theoretical, experimental, and clinical studies.

An integrated optimization and multi-scale input–output model for interaction mechanism analysis of energy–economic–environmental policy in a typical fossil-energy-dependent region

With the continuous development of the social giant system, the independence of subsystem boundaries has decreased under the drive of complex relationships and multiple uncertainties. Decision makers are required to consider the interactions between different systems to develop precise policy guidance. Given these challenges, an integrated optimization and multi-scale input–output (OMIO) model is proposed by integrating interval programming, chance-constrained programming, and integer programming into the input–output framework to provide comprehensive policy analysis. The optimized decision variables that carry uncertain information from energy system are identified as connection points to induce changes in economic-environmental effects. A typical fossil-energy-dependent region that mainly relies on fossil fuels, Shanxi Province, China, was used as a case study. It was found that the joint effects of energy system optimization and socioeconomic rebalance will promote the rise of the petroleum product sector, the logistics industry, and tertiary industries, as well as the popularity of electric vehicles. The increase in the use of clean energy and electric vehicles will stimulate GDP growth in the short term, and the emissions of carbon dioxide and air pollutants will be reduced to varying degrees. The study findings can provide comprehensive energy allocation strategies, socioeconomic effect analysis, and climate mitigation results to help fossil-energy-dependent regions better adapt to the requirements of sustainable development under multiple systematic uncertainties.

Coping Asynchronous Modular Product Design by Modelling a Systems-in-System

AbstractThis paper analyzes the potential of crossdisciplinary collaboration in the methodical development of Modular Design by harmonization asynchronous mechatronic system structures. Subsystem boundaries in multidisciplinary development processes are set disciplinespecific, resulting in inconsistencies in module fitting. Based on a case study, harmonization of disciplines is elaborated as a solution. This aligns discipline structures and reduces effects on the variety in system structures.This implementation shows support for modular design and enables an integrated view as a systems-in-system.

A Study of Feature Scattering in the Linux Kernel

Feature code is often scattered across a software system. Scattering is not necessarily bad if used with care, as witnessed by systems with highly scattered features that evolved successfully. Feature scattering, often realized with a pre-processor, circumvents limitations of programming languages and software architectures. Unfortunately, little is known about the principles governing scattering in large and long-living software systems. We present a longitudinal study of feature scattering in the Linux kernel, complemented by a survey with 74, and interviews with nine Linux kernel developers. We analyzed almost eight years of the kernel's history, focusing on its largest subsystem: device drivers. We learned that the ratio of scattered features remained nearly constant and that most features were introduced without scattering. Yet, scattering easily crosses subsystem boundaries, and highly scattered outliers exist. Scattering often addresses a performance-maintenance tradeoff (alleviating complicated APIs), hardware design limitations, and avoids code duplication. While developers do not consciously enforce scattering limits, they actually improve the system design and refactor code, thereby mitigating pre-processor idiosyncrasies or reducing its use.

Family-of-Origin Triangulation and Marital Quality of Chinese Couples: The Mediating Role of In-Law Relationships

Triangulation is an important subject in marriage and family therapy. Chinese family culture emphasizes consanguinity, which means that adult children have great difficulty separating from their original families and establishing clear boundaries. This results in the unique problem of family-of-origin triangulation in Chinese marriages. The current study explored the relationship between family-of-origin triangulation and the marital quality of Chinese couples, and examined the mediating role of in-law relationships. A total of 341 Chinese couples, ranging from newlyweds to those with school-aged children, participated in the survey. The results demonstrate that family-of-origin triangulation of both husbands and wives negatively predicted wives’ marital quality, whereas husbands’ marital quality was only predicted by their own family-of-origin triangulation. Moreover, family-of-origin triangulation not only predicted marital quality directly, but also indirectly by damaging the relationships with in-laws. The actor effects of family-of-origin triangulation were partially mediated by in-law relationships, whereas the partner effects of husbands’ triangulation on wives’ marital quality was fully mediated by in-law relationships. Family therapists in China should pay more attention to intergenerational relationships and reestablishing the sub-system boundaries of husband and wife, and at the same time, focus on repairing the couple’s relationships with the in-laws.

Reconceptualizing the Policy Subsystem: Integration with Complexity Theory and Social Network Analysis

The concept of the policy subsystem is an essential building block for several of the basic frameworks of policy process studies. Over time issues have become more complex, crossing subsystem boundaries, and so subsystems have escalated in their complexity as well. It is increasingly insufficient to study just one policy subsystem and so scholars have turned to studying boundary‐spanning regimes or policy networks. In this essay, we review the major contributions to developing the concept of a policy subsystem and trace its evolution into broader conceptualizations like issue and policy networks. We argue that the future for theories of the policy process is in more explicit integration of complexity theory and more effective modeling of subsystems with the utilization of social network analysis. In closing, we discuss the enduring nature of the concept of policy subsystems and highlight studies that continue using it in innovative ways.

Convergence of explicitly coupled simulation tools (co-simulations)

Abstract In engineering, it is a common desire to couple existing simulation tools together into one big system by passing information from subsystems as parameters into the subsystems under influence. As executed at fixed time points, this data exchange gives the global method a strong explicit component. Globally, such an explicit co-simulation schemes exchange time step can be seen as a step of an one-step method which is explicit in some solution components. Exploiting this structure, we give a convergence proof for such schemes. As flows of conserved quantities are passed across subsystem boundaries, it is not ensured that system-wide balances are fulfilled: the system is not solved as one single equation system. These balance errors can accumulate and make simulation results inaccurate. Use of higher-order extrapolation in exchanged data can reduce this problem but cannot solve it. The remaining balance error has been handled in past work by recontributing it to the input signal in next coupling time step, a technique labeled balance correction methods. Convergence for that method is proven. Further, the lack of stability for co-simulation schemes with and without balance correction is stated.

On Meeting Energy Balance Errors in Co-Simulations

ABSTRACT The term co-simulation denotes the coupling of some simulation tools for dynamical systems into one big system by having them exchange data at points of a fixed time grid and extrapolating the received data into the interval, while none of the steps is repeated for iteration. From the global perspective, the simulation thus has a strong explicit component. Frequently, among the data passed across subsystem boundaries there are flows of conserved quantities, and as there is no iteration of steps, system-wide balances may not be fulfilled: the system is not solved as one monolithic equation system. If these balance errors accumulate, simulation results become inaccurate. Balance correction methods which compensate these errors by adding corrections for the balances to the signal in the next coupling time step have been considered in past research. But establishing the balance of one quantity a posteriori due to the time delay in general cannot establish the balances of quantities that depend on the exchanged quantities, usually energy. In most applications from physics, the balance of energy is equivalent to stability. In this paper, a method is presented which allows users to choose the quantity that should be balanced to be that energy, and to accurately balance it. This establishes also numerical stability for many classes of stable problems.

Mapping Software Augments Engineering Design Thinking

Maps are visual design representations used by engineers to model the information behind a design. This paper evaluates the application of mapping methods supported by the Decision Rationale editor (DRed) in aerospace engineering industry. Specifically, the research investigates what DRed mapping methods are used, where engineers find them useful and why. DRed was selected because it has been formally embedded in the design processes of the partner company and all engineering staff have access to it. The tool was investigated using semistructured interviews with 14 engineers, each already trained with DRed through their work and representing diverse departments and experience levels. Nineteen use cases were collected, ranging from high-profile, multistakeholder projects to everyday individual work. Collected cases were analyzed for the methods applied, common contexts of use, and reasons for use. The results validate baseline DRed mapping methods to capture design rationale and analyze the root causes of engineering problems. Further, it provides empirical evidence for new DRed mapping methods to manage requirements, analyze functional interactions in complex systems and manage personal information. The contexts where mapping methods are most used involve: system-level information that cuts across subsystem boundaries; irregular intervals between map applications; dealing with loosely structured information; individual use or small team collaborations; and addressing on-going problems. The reasons stated by engineers for using maps focus on engineering design thinking, communication, and planning support. Using empirical evidence of its recurrent use, this research establishes that DRed is a powerful and versatile tool for engineers in industry and its mapping methods aid important and otherwise unsupported work. The range and impact of the use cases found in practice suggest that engineers need better support for work with loosely structured information. Organizations involved in the design of complex systems should make greater use of semiformal, graph-based visual tools like DRed. The understanding of mapping software gained through this research demonstrates a shift in emphasis from the enrichment of the engineering record to the provision of immediate cognitive benefits for engineers. The results also support an incremental, adaptive approach for deploying this emerging class of tools in other organizations.

Constructionist Design Methodology for Interactive Intelligences

We present a methodology for designing and implementing interactive intelligences. The constructionist design methodology (CDM) -- so called because it advocates modular building blocks and incorporation of prior work -- addresses factors that we see as key to future advances in AI, including support for interdisciplinary collaboration, coordination of teams, and large-scale systems integration. We test the methodology by building an interactive multifunctional system with a real-time perception- action loop. The system, whose construction relied entirely on the methodology, consists of an embodied virtual agent that can perceive both real and virtual objects in an augmented-reality room and interact with a user through coordinated gestures and speech. Wireless tracking technologies give the agent awareness of the environment and the user's speech and communicative acts. User and agent can communicate about things in the environment, their placement, and their function, as well as about more abstract topics, such as current news, through situated multimodal dialogue. The results demonstrate the CDM's strength in simplifying the modeling of complex, multifunctional systems that require architectural experimentation and exploration of unclear subsystem boundaries, undefined variables, and tangled data flow and control hierarchies.

Long tail distributions near the many-body localization transition

The random field S=1/2 Heisenberg chain exhibits a dynamical many body localization transition at a critical disorder strength, which depends on the energy density. At weak disorder, the eigenstate thermalization hypothesis (ETH) is fulfilled on average, making local observables smooth functions of energy, whose eigenstate-to-eigenstate fluctuations decrease exponentially with system size. We demonstrate the validity of ETH in the thermal phase as well as its breakdown in the localized phase and show that rare states exist which do not strictly follow ETH, becoming more frequent closer to the transition. Similarly, the probability distribution of the entanglement entropy at intermediate disorder develops long tails all the way down to zero entanglement. We propose that these low entanglement tails stem from localized regions at the subsystem boundaries which were recently discussed as a possible mechanism for subdiffusive transport in the ergodic phase.

Understanding the Conditions of Separation for an Integrated Organizational Setup – PSS Divisional Boundaries in the Light of Heterogeneity and Duality Theories

Determined by an integrated value proposition PSS constitute a unique organizational setup that is pivotally grounded in the co-existence of integrated but yet separate product-, service- and customer sub-systems. In order to benefit from the variety of available skills, competences and knowledge resources, PSS try to arrange sub-system boundaries most permeable, thus striving for the highest possible level of integration. At the same time, PSS decrease the level of divisional separation towards a minimum. However, the relation of integration and separation needs further analysis in the light of organizational theory. While recognizing the need for increasing integration towards product&service co-designed, customer integrated solutions, research also claims that a separation-typed setup determines the crucial resource configuration that is needed for novel problem-solving approaches in PSS. More precisely, it is said that the upholding of a minimal threshold between separated organizational elements secures sufficient tension between established organizational thought-worlds which again may initiate processes of organizational learning and renewal. The contradictory nature of decreasing while also pertaining separation under the umbrella of an integrated organizational setup raises the need for a nuanced understanding of how boundaries within PSS form an important area of operation for the dynamic balancing of divisional knowledge transfer versus identity-shaping. With reference to the organizational development process towards a fully integrated PSS this paper presents suggestions about how PSS can design minimal threshold for a mutual but fluid co-existence of product-, service- and customer sub-systems.

Entropy Analysis of Industrial Accident Data Series

Complex industrial plants exhibit multiple interactions among smaller parts and with human operators. Failure in one part can propagate across subsystem boundaries causing a serious disaster. This paper analyzes the industrial accident data series in the perspective of dynamical systems. First, we process real world data and show that the statistics of the number of fatalities reveal features that are well described by power law (PL) distributions. For early years, the data reveal double PL behavior, while, for more recent time periods, a single PL fits better into the experimental data. Second, we analyze the entropy of the data series statistics over time. Third, we use the Kullback–Leibler divergence to compare the empirical data and multidimensional scaling (MDS) techniques for data analysis and visualization. Entropy-based analysis is adopted to assess complexity, having the advantage of yielding a single parameter to express relationships between the data. The classical and the generalized (fractional) entropy and Kullback–Leibler divergence are used. The generalized measures allow a clear identification of patterns embedded in the data.

Power Law Behavior and Self-Similarity in Modern Industrial Accidents

Advances in technology have produced more and more intricate industrial systems, such as nuclear power plants, chemical centers and petroleum platforms. Such complex plants exhibit multiple interactions among smaller units and human operators, rising potentially disastrous failure, which can propagate across subsystem boundaries. This paper analyzes industrial accident data-series in the perspective of statistical physics and dynamical systems. Global data is collected from the Emergency Events Database (EM-DAT) during the time period from year 1903 up to 2012. The statistical distributions of the number of fatalities caused by industrial accidents reveal Power Law (PL) behavior. We analyze the evolution of the PL parameters over time and observe a remarkable increment in the PL exponent during the last years. PL behavior allows prediction by extrapolation over a wide range of scales. In a complementary line of thought, we compare the data using appropriate indices and use different visualization techniques to correlate and to extract relationships among industrial accident events. This study contributes to better understand the complexity of modern industrial accidents and their ruling principles.

A Stakeholder Analysis of the Disaster Risk Reduction Policy Subsystem in Mozambique

Climate change is expected to increase the frequency and magnitude of climate related hazards in many countries. Due to this, disaster risk reduction (DRR) policy has gained a lot of attention in recent years. DRR policies address complex problems that require inputs from a variety of stakeholders and hence a multi-stakeholder approach has been advocated widely. However, the practice of DRR policymaking is challenging and therefore new tools are needed to better understand the political context of DRR policymaking. This article utilizes an Advocacy Coalition Framework (ACF) approach to describe the political context of the DRR policy subsystem in Mozambique. Through a stakeholder analysis, the article seeks to empirically define subsystem boundaries and to identify belief systems and key actors therein. The results indicate that the actors can be divided into two advocacy coalitions, formed around extant approaches to DRR: disaster management and development. The article concludes with reflections on the applicability of an ACF approach to stakeholder analysis and as a tool for understanding policy disputes and coordination challenges in complex settings, such as DRR governance.

Interparental Conflicts in Dyadic and Triadic Contexts: Parental Depression Symptoms and Conflict History Predict Differences

Using a family systems approach, this study investigated differences in interparental conflict behavior in dyadic versus triadic contexts, and considered the potential moderating roles of interparental conflict history and parental depression symptoms. The community sample included 74 couples with an infant between 6 and 14 months of age. Behavioral observations were made of parents during interparental conflict resolution tasks. Parents were observed in both a dyadic context with just the two of them and in a triadic context with their infants present. Task order was counterbalanced across families. Multiple parental conflict behaviors, emotions, and resolution were coded based on the behavioral observations. Parents self-reported on their conflict history and depression symptoms. Mothers and fathers displayed less depressive conflict in their infants’ presence versus absence and mothers additionally displayed decreased constructive conflict when their infants were present, but neither parent differed in their expressions of destructive conflict across contexts, indicating an overall lack of shielding children from conflict. Both interparental conflict history and parental depression symptoms moderated associations between parents’ conflict behavior and the conflict context for fathers and mothers. Results supported family systems theory’s notions that marital subsystem boundaries can be eroded as a function of family stress, allowing interparental hostility or depression symptoms to spill over into triadic family interactions. Implications for family therapists and community parent education programs are discussed.

Software re-engineering using imperialist competitive algorithm

Maintenance is one of the important phases of the software development life cycle which contributes to the effective and long term use of any software system. It can become cumbersome and costly for software maintainers when subsystem boundaries are not clearly defined. Further, the problem gets worse due to the system evolution, lack of current documentation and lack of original design documentation. The application of clustering techniques and tools helps software maintenance programmers to recover high-level views of system designs and hence leads to better understanding and maintenance of software systems. In this paper, we have used a sociopolitical Imperialist Competitive Algorithm for software module clustering and compared it with existing evolutionary approaches. We conclude that the novel socio-political approach produces better quality clusters as compared to the earlier evolutionary genetic approaches.

Family boundary structures and child adjustment: The indirect role of emotional reactivity.

Structural and system theories propose that disruptions in family subsystem functioning increase risk for youth maladjustment. While there is growing evidence to support this proposition, studies that specifically focus on the larger family system remain relatively rare. Furthermore, the pathways that connect problems in family subsystem alliances to externalizing or internalizing problems in youth are as yet largely unexplored. This study examined youth emotional reactivity (anger and sadness) to family conflict as an indirect pathway of the association between family boundary disturbances and youth adjustment in a sample of two-parent families (N = 270). Observational coding was used to group families into Balanced, Dyadic, or Disengaged family alliance structures and to assess youth emotional reactivity, and parent-report was used to assess youth psychopathology. Structural equation modeling indicated both anger and sadness served as indirect pathways through which family boundary disturbances are linked with youth adjustment. In addition, gender was tested as a moderator and important gender differences were found. Specifically, boys were directly impacted by dyadic disturbances while girls were directly impacted by family disengagement. The findings help target goals for intervention and indicate that worthwhile objectives may include realigning family subsystem boundaries, changing family communication patterns, and improving affective coping skills for youth.

A deterministic multifunctional architecture for highly adaptive small satellites

A deterministic multifunctional architecture design approach for a highly adaptive small satellite system is proposed in this paper. It enables five levels of design customisation of all categories of highly adaptive small satellites; adaptive functional modules implement higher-level customised and reconfigurable mission functions. Each adaptive multifunctional structural unit (AMSU) supports the subsystem functions as a ‘structural and functional block’ and comes either as a baseline or hybrid. Associated functional sub subsystem components are contained in each AMSU. This removes the conventional structural and functional subsystem boundaries. A meteorology spacecraft mission using a highly adaptive nanosatellite reveals, besides more advanced mission capabilities, 0.6 kg and 1 W mass- and power-savings respectively over a conventional nanosatellite system implementation. This novelty results in adaptive, reconfigurable and multifunctional architectures with economies of scale, timely launch, system-level reliability, flexible integration and test options, cost-effective mass production, post-mission reapplication and optimal performance at the desired mission objectives.