Agent and cyber-physical system based self-organizing and self-adaptive intelligent shopfloor

The increasing demand of customized production results in huge challenges to the traditional manufacturing systems. In order to allocate resources timely according to the production requirements and to reduce disturbances, a framework for the future intelligent shopfloor is proposed in this paper. The framework consists of three primary models, namely the model of smart machine agent, the self-organizing model, and the self-adaptive model. A cyber-physical system for manufacturing shopfloor based on the multiagent technology is developed to realize the above-mentioned function models. Gray relational analysis and the hierarchy conflict resolution methods were applied to achieve the self-organizing and self-adaptive capabilities, thereby improving the reconfigurability and responsiveness of the shopfloor. A prototype system is developed, which has the adequate flexibility and robustness to configure resources and to deal with disturbances effectively. This research provides a feasible method for designing an autonomous factory with exception-handling capabilities

Predicting subjective workload ratings: A comparison and synthesis of theoretical models.

Output data from a computer simulation of two air traffic control (ATC) scenarios were fit to workload ratings that ATC subject matter experts provided while observing each scenario in real time. Simulation output enabled regressions to test the assumptions of a variety of workload prediction models. The models included operational models that use observable situational and behavior variables (such as number of aircraft and communications by type) and theoretical models that use queuing and cognitive architecture variables (such as weightings of activities performed, amount of busy time, and sensory and cognitive resource usage) to predict workload. Regression results suggest models that include number of activities performed weighted by priority are best able to account for the highest amount of variance in subjective workload ratings

Think Twice Before Hitting \u27Send\u27: The Strategic Uses of Information in Marketing Channels

This dissertation examines the growing problem of information overload in the context of marketing channels. Information overload occurs when shared information requires more mental resources to process than the mental resources available to the receiver. This research offers strategies to attenuate information overload and examines the impact of information overload on channel outcomes. Strategic uses of information are proposed and conceptualized as a sender\u27s alteration of information volume, content, and/or timing to assist a receiver in processing information. Hypotheses are developed based on the normative perspective of communication from the organizational communication literature. Data from 244 salespeople are analyzed using structural equation modeling to test the hypotheses. The results suggest that information overload undermines shared understanding, while shared understanding enhances coordination and compliance, and reduces conflict. Post hoc analyses further reveal that the effectiveness of strategic uses of information on information overload is contingent on the task nature and receiver characteristics and that some strategies have a U-shaped relationship with information overload. The major contribution of this dissertation is integrating the paradigms of organizational communication and marketing channels literatures and providing an additional perspective in understanding information sharing in channel relationships. Contrary to conventional wisdom, this paper argues that more information sharing is not necessarily better

Is Our Model for Contention Resolution Wrong?

Randomized binary exponential backoff (BEB) is a popular algorithm for coordinating access to a shared channel. With an operational history exceeding four decades, BEB is currently an important component of several wireless standards. Despite this track record, prior theoretical results indicate that under bursty traffic (1) BEB yields poor makespan and (2) superior algorithms are possible. To date, the degree to which these findings manifest in practice has not been resolved. To address this issue, we examine one of the strongest cases against BEB: $n$ packets that simultaneously begin contending for the wireless channel. Using Network Simulator 3, we compare against more recent algorithms that are inspired by BEB, but whose makespan guarantees are superior. Surprisingly, we discover that these newer algorithms significantly underperform. Through further investigation, we identify as the culprit a flawed but common abstraction regarding the cost of collisions. Our experimental results are complemented by analytical arguments that the number of collisions -- and not solely makespan -- is an important metric to optimize. We believe that these findings have implications for the design of contention-resolution algorithms.Comment: Accepted to the 29th ACM Symposium on Parallelism in Algorithms and Architectures (SPAA 2017

Integrated and joint optimisation of runway-taxiway-apron operations on airport surface

Airports are the main bottlenecks in the Air Traffic Management (ATM) system. The predicted 84% increase in global air traffic in the next two decades has rendered the improvement of airport operational efficiency a key issue in ATM. Although the operations on runways, taxiways, and aprons are highly interconnected and interdependent, the current practice is not integrated and piecemeal, and overly relies on the experience of air traffic controllers and stand allocators to manage operations, which has resulted in sub-optimal performance of the airport surface in terms of operational efficiency, capacity, and safety. This thesis proposes a mixed qualitative-quantitative methodology for integrated and joint optimisation of runways, taxiways, and aprons, aiming to improve the efficiency of airport surface operations by integrating the operations of all three resources and optimising their coordination. This is achieved through a two-stage optimisation procedure: (1) the Integrated Apron and Runway Assignment (IARA) model, which optimises the apron and runway allocations for individual aircraft on a pre-tactical level, and (2) the Integrated Dynamic Routing and Off-block (IDRO) model, which generates taxiing routes and off-block timing decisions for aircraft on an operational (real-time) level. This two-stage procedure considers the interdependencies of the operations of different airport resources, detailed network configurations, air traffic flow characteristics, and operational rules and constraints. The proposed framework is implemented and assessed in a case study at Beijing Capital International Airport. Compared to the current operations, the proposed apron-runway assignment reduces total taxiing distance, average taxiing time, taxiing conflicts, runway queuing time and fuel consumption respectively by 15.5%, 15.28%, 45.1%, [58.7%, 35.3%, 16%] (RWY01, RWY36R, RWY36L) and 6.6%; gated assignment is increased by 11.8%. The operational feasibility of this proposed framework is further validated qualitatively by subject matter experts (SMEs). The potential impact of the integrated apron-runway-taxiway operation is explored with a discussion of its real-world implementation issues and recommendations for industrial and academic practice.Open Acces

QUERIES SERVICE TIME RESEARCH AND ESTIMATION DURING INFORMATION EXCHANGE IN MULTIPROCESSOR SYSTEMS WITH “UNI BUS” INTERFACE AND SHARED MEMORY

Abstract. The issues connected with estimating service time of queries (transactions) during the information exchange in multiprocessor systems with a unibus interface and shared memory are analyzed and studied in the article. The article aims at developing and making research of models based on systems and queueing networks, the "processor-memory" subsystem, as well as estimating the queries service time during the information exchange in multiprocessor systems with shared memory. The subject matter of the study is the analysis of time delays associated with conflict situations occured during the realization of interprocessor exchange when many processors turn to the exchange unibusand memory. The object of the article research is the "processor-memory" subsystem of existing multiprocessor systems and well-known versions of the architecture of this subsystem . The main task defined by the authors of the scientific article is to develop and make research of mathematical models of the "processor-memory" subsystem of the mentioned systems and to estimate the processing time of inputting queries during the information exchange in systems with shared memory. Mathematical models for carrying out queries service time research have been proposed. Equations fordetermining the main probabilistic-temporal characteristics of the "processor-memory" subsystem have been presented. The mentioned probabilistic-temporal models have been developed using the theory of queueing networks and probability theory. In conclusion the authors make the main judgements about the work done. The mathematical models studied in the article make it possible to estimate the main probabilistic-temporal characteristics of multiprocessor systems without developing real models or prototypes. As a result some effect is achieved, because it is possible to estimate thecharacteristics of new multiprocessor computer systems and choose the most optimal ones without creating a real expensive systemKeywords: simulation, analytical model, imitation model, queueing network system, transaction, read-operation, record-operation, multiprocessor system, “processor-memory” subsystem, memory architecture, memory bandwidth, memory controller, memory latency, buffer element