scholarly journals Controllable and decomposable multidirectional synchronizations

2021 ◽  
Author(s):  
Gábor Bergmann
Keyword(s):  
Systems Engineering ◽  
Large Scale ◽  
Mathematical Framework ◽  
Collaborative Systems ◽  
Consistency Constraints ◽  
Restoration Mechanism ◽  
Common Goals ◽  
Access Privileges ◽  
Novel Concept ◽  
Engineering Projects

AbstractStudying large-scale collaborative systems engineering projects across teams with differing intellectual property clearances, or healthcare solutions where sensitive patient data needs to be partially shared, or similar multi-user information systems over databases, all boils down to a common mathematical framework. Updateable views (lenses) and more generally bidirectional transformations are abstractions to study the challenge of exchanging information between participants with different read access privileges. The view provided to each participant must be different due to access control or other limitations, yet also consistent in a certain sense, to enable collaboration towards common goals. A collaboration system must apply bidirectional synchronization to ensure that after a participant modifies their view, the views of other participants are updated so that they are consistent again. While bidirectional transformations (synchronizations) have been extensively studied, there are new challenges that are unique to the multidirectional case. If complex consistency constraints have to be maintained, synchronizations that work fine in isolation may not compose well. We demonstrate and characterize a failure mode of the emergent behaviour, where a consistency restoration mechanism undoes the work of other participants. On the other end of the spectrum, we study the case where synchronizations work especially well together: we characterize very well-behaved multidirectional transformations, a non-trivial generalization from the bidirectional case. For the former challenge, we introduce a novel concept of controllability, while for the latter one, we propose a novel formal notion of faithful decomposition. Additionally, the paper proposes several novel properties of multidirectional transformations.

scholarly journals Comparative Analysis of the Life-Cycle Cost of Robot Substitution: A Case of Automobile Welding Production in China

Symmetry ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 226
Author(s):  
Xuyang Zhao ◽  
Cisheng Wu ◽  
Duanyong Liu
Keyword(s):  
Life Cycle ◽  
Systems Engineering ◽  
Life Cycle Cost ◽  
Manufacturing Systems ◽  
Large Scale ◽  
Cost Allocation ◽  
Industrial Robot ◽  
Case Analysis ◽  
Industrial Robots ◽  
Analysis Model

Within the context of the large-scale application of industrial robots, methods of analyzing the life-cycle cost (LCC) of industrial robot production have shown considerable developments, but there remains a lack of methods that allow for the examination of robot substitution. Taking inspiration from the symmetry philosophy in manufacturing systems engineering, this article further establishes a comparative LCC analysis model to compare the LCC of the industrial robot production with traditional production at the same time. This model introduces intangible costs (covering idle loss, efficiency loss and defect loss) to supplement the actual costs and comprehensively uses various methods for cost allocation and variable estimation to conduct total cost and the cost efficiency analysis, together with hierarchical decomposition and dynamic comparison. To demonstrate the model, an investigation of a Chinese automobile manufacturer is provided to compare the LCC of welding robot production with that of manual welding production; methods of case analysis and simulation are combined, and a thorough comparison is done with related existing works to show the validity of this framework. In accordance with this study, a simple template is developed to support the decision-making analysis of the application and cost management of industrial robots. In addition, the case analysis and simulations can provide references for enterprises in emerging markets in relation to robot substitution.

scholarly journals On the structural connectivity of large-scale models of brain networks at cellular level

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Giuseppe Giacopelli ◽  
Domenico Tegolo ◽  
Emiliano Spera ◽  
Michele Migliore
Keyword(s):  
Large Scale ◽  
Brain Networks ◽  
Structural Connectivity ◽  
Network Models ◽  
Brain Regions ◽  
Cellular Level ◽  
Scale Model ◽  
Mathematical Framework ◽  
Underlying Mechanisms ◽  
Experimental Findings

AbstractThe brain’s structural connectivity plays a fundamental role in determining how neuron networks generate, process, and transfer information within and between brain regions. The underlying mechanisms are extremely difficult to study experimentally and, in many cases, large-scale model networks are of great help. However, the implementation of these models relies on experimental findings that are often sparse and limited. Their predicting power ultimately depends on how closely a model’s connectivity represents the real system. Here we argue that the data-driven probabilistic rules, widely used to build neuronal network models, may not be appropriate to represent the dynamics of the corresponding biological system. To solve this problem, we propose to use a new mathematical framework able to use sparse and limited experimental data to quantitatively reproduce the structural connectivity of biological brain networks at cellular level.

scholarly journals Potential Energy Implications of Connected and Automated Vehicles: Exploring Key Leverage Points through Scenario Screening and Analysis

2019 ◽  
Vol 2673 (5) ◽  
pp. 84-94 ◽  
Author(s):  
Brian Bush ◽  
Laura Vimmerstedt ◽  
Jeff Gonder
Keyword(s):  
Systems Engineering ◽  
Large Scale ◽  
Operating Cost ◽  
Dynamics Model ◽  
Transportation Service ◽  
Service Outcomes ◽  
Behavioral Parameters ◽  
Computationally Intensive ◽  
Different Levels ◽  
Selection Of

Connected and automated vehicle (CAV) technologies could transform the transportation system over the coming decades, but face vehicle and systems engineering challenges, as well as technological, economic, demographic, and regulatory issues. The authors have developed a system dynamics model for generating, analyzing, and screening self-consistent CAV adoption scenarios. Results can support selection of scenarios for subsequent computationally intensive study using higher-resolution models. The potential for and barriers to large-scale adoption of CAVs have been analyzed using preliminary quantitative data and qualitative understandings of system relationships among stakeholders across the breadth of these issues. Although they are based on preliminary data, the results map possibilities for achieving different levels of CAV adoption and system-wide fuel use and demonstrate the interplay of behavioral parameters such as how consumers value their time versus financial parameters such as operating cost. By identifying the range of possibilities, estimating the associated energy and transportation service outcomes, and facilitating screening of scenarios for more detailed analysis, this work could inform transportation planners, researchers, and regulators.

An Approach for Efficient CFD Simulations of an Ejector Air Injection System for Active Aerodynamic Compressor Stabilization

2017 ◽  
Author(s):  
Sebastian Brehm ◽  
Felix Kern ◽  
Jonas Raub ◽  
Reinhard Niehuis
Keyword(s):  
Large Scale ◽  
Armed Forces ◽  
Air Injection ◽  
Injection System ◽  
Cfd Simulations ◽  
Data Set ◽  
Numerical Effort ◽  
Enhance Efficiency ◽  
Set Up ◽  
Novel Concept

The Institute of Jet Propulsion at the University of the German Federal Armed Forces Munich has developed and patented a novel concept of air injection systems for active aerodynamic stabilization of turbo compressors. This so-called Ejector Injection System (EIS) utilizes the ejector effect to enhance efficiency and impact of the aerodynamic stabilization of the Larzac 04 two-spool turbofan engine’s LPC. The EIS design manufactured recently has been subject to CFD and experimental pre-investigations in which the expected ejector effect performance has been proven and the CFD set-up has been validated. Subsequently, optimization of the EIS ejector geometry comes into focus in order to enhance its performance. In this context, CFD parameter studies on the influence of in total 16 geometric and several aerodynamic parameters on the ejector effect are required. However, the existing and validated CFD set-up of the EIS comprises not only the mainly axisymmetric ejector geometry but also the highly complex 3D supply components upstream of the ejector geometry. This is hindering large scale CFD parameter studies due to the numerical effort required for these full 3D CFD simulations. Therefore, an approach to exploit the overall axissymmetry of the ejector geometry is presented within this paper which reduces the numerical effort required for CFD simulations of the EIS by more than 90%. This approach is verified by means of both experimental results as well as CFD predictions of the full 3D set-up. The comprehensive verification data set contains wall pressure distributions and the mass flow rates involved at various Aerodynamic Operating Points (AOP). Furthermore, limitations of the approach are revealed concerning its suitability e.g. to judge the response of the attached compressor of future EIS designs concerning aerodynamic stability or cyclic loading.

scholarly journals Challenges and Approaches to Scaling the Global Commons

2021 ◽  
Vol 4 ◽  
Author(s):  
Felix Fritsch ◽  
Jeff Emmett ◽  
Emaline Friedman ◽  
Rok Kranjc ◽  
Sarah Manski ◽  
...  
Keyword(s):  
Large Scale ◽  
Sharing Economy ◽  
Natural Habitats ◽  
Common Value ◽  
Exchange Value ◽  
Space Agency ◽  
The Commons ◽  
Common Goals ◽  
Distribution Of Power ◽  
New Generation

The re-emergence of commoning over the last decades is not incidental, but rather indicative of a large-scale transition to a more “generative” organization of society that is oriented toward the planet’s global carrying capacity. Digital commons governance frameworks are of particular importance for a new global paradigm of cooperation, one that can scale the organization of communities around common goals and resources to unprecedented levels of size, complexity and granularity. Distributed Ledger Technologies (DLTs) such as blockchain have lately given new impetus to the emergence of a new generation of authentic “sharing economy,” protected from capture by thorough distribution of power over infrastructure, that spans not only digital but also physical production of common value. The exploration of the frontiers of DLT-based commoning at the heart of this article considers three exemplary cases for this new generation of commons-oriented community frameworks: the Commons Stack, Holochain and the Commons Engine, and the Economic Space Agency. While these projects differ in their scope as well as in their relation to physical common-pool resources (CPRs), they all share the task of redefining markets so as to be more conducive to the production and sustainment of common value(s). After introducing each of them with regards to their specificities and commonalities, we analyze their capacity to foster commons-oriented economies and “money for the commons” that limit speculation, emphasize use-value over exchange-value, favor equity in human relations, and promote responsibility for the preservation of natural habitats. Our findings highlight the strengths of DLTs for a federated scaling of CPR governance frameworks that accommodates rather than obliterates cultural differences and creates webs of fractal belonging among nested communities.

scholarly journals Engagement of Contemporary Communities with the Shared Heritage Resources of the Dwindling Minorities of Central Calcutta

2021 ◽  
pp. 423-436
Author(s):  
Sohini Pyne
Keyword(s):  
Community Engagement ◽  
Large Scale ◽  
Local Population ◽  
Built Heritage ◽  
Heritage Buildings ◽  
Common Goals ◽  
Accelerated Growth ◽  
The City

The accelerated growth of Calcutta as a trading center under the British between the mid-18th and early 20th centuries brought an influx of diverse trading communities, including Armenians, Baghdadi Jews, Parsis, and Chinese, who settled in the historic bazaar nucleus of the city known today as Central Calcutta. These ethnoreligious communities erected significant heritage buildings reflecting their cultures. But with large-scale emigration and a rapidly dwindling local population, this shared built heritage is in neglect and has little or no relevance for Central Calcutta’s contemporary communities. This paper discusses the issues faced by these heritage resources and offers recommendations for enhancing community engagement, initiating co-management and developing common goals amongst contemporary communities so as to effectively safeguard this built heritage of dwindling minorities.

Energy Efficient Multi-Robotic 3D Printing for Large-Scale Construction – Framework, Challenges, and a Systematic Approach

2021 ◽  
Author(s):  
Azadeh Haghighi ◽  
Abdullah Mohammed ◽  
Lihui Wang
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
Energy Efficient ◽  
Large Scale ◽  
Systematic Approach ◽  
Smart Manufacturing ◽  
Energy Aware ◽  
Robot Positioning ◽  
Novel Concept ◽  
And Control

Abstract An emerging trend in smart manufacturing of the future is robotic additive manufacturing or 3D printing which introduces numerous advantages towards fast and efficient printing of high-quality customized products. In the case of the construction industry, and specifically in large-scale settings, multi-robotic additive manufacturing (i.e., adopting a team of 3D printer robots) has been found to be a promising solution in order to overcome the existing size limitations. Consequently, several research efforts regarding the development and control of such robotic additive manufacturing solutions have been reported in the literature. However, given the increasing environmental concerns, establishing novel methodologies for energy-efficient processing and planning of these systems towards higher sustainability is necessary. This paper presents a novel framework towards energy-efficient multi-robotic additive manufacturing and describes the overall challenges with respect to the energy efficiency. The energy module of the proposed framework is implemented in a simulation environment. In addition, a systematic approach for energy-aware robot positioning is introduced based on the novel concept of reciprocal energy map. The reciprocal energy map is established based on the original energy map calculated by the energy module and can be used for identifying the low energy zones for positioning and relocation of robots during the printing process.

Review and Brief History of Collaborative Systems

2011 ◽  
pp. 139-160
Author(s):  
Nuria Lloret Romero
Keyword(s):  
Information Systems ◽  
Large Scale ◽  
Previous Literature ◽  
Collaborative Systems ◽  
Collaborative Computing ◽  
Geographically Dispersed ◽  
Research Challenges ◽  
The Future ◽  
Collaborative Applications ◽  
History Of

E-collaboration and collaborative systems bring geographically dispersed teams together, supporting communication, coordination and cooperation. From the scientific perspective, the development of theories and mechanisms to enable building collaborative systems presents exciting research challenges across information subfields. From the applications perspective, the capability to collaborate with users and other systems is essential if large-scale information systems of the future are to assist users in finding the information they need and solving the problems they have. This chapter presents a review of research in the area of creating collaborative applications and taxonomies. The author analyzes previous literature, and examines some practice cases and research prototypes in the domain of collaborative computing. Finally the chapter provides a list of basic collaboration services, and tools are presented relating to the services they provide. All surveyed tools are then classified under categories of functional services. In conclusion, the chapter highlights a number of areas for consideration and improvement that arise when studying collaborative applications.

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