Dukki Chung

Lock-free data structure for multi-core processors

Real time control applications are very demanding in terms of closed loop system response. The challenge is to execute an operation in a predictable amount of time. As more control functions are needed, faster computing speed is preferred to achieve the desired control responses. The major processor manufacturers have given up trying to make processors run faster, at least for the time being. Instead, manufacturers are turning to multi-core architectures in which multiple processors (cores) communicate directly through shared hardware caches. Multi-core chips make computing more efficient by exploiting parallelism. This new paradigm is widely available and provides a new way of solving control problems. At the same time, the multi-core architecture poses a challenge because modern control systems are asynchronous: activities can be halted or delayed without warning by interrupts, preemption, and other events. In this paper, a lock-free linked-list queue is described and implemented on a multi-core ARM processor. The lock-free algorithm ensures threads that are competing for access to the queue do not have their execution indefinitely postponed by mutual exclusion; also system-wide progress is guaranteed.

Managed Complexity in An Agent-based Vent Fan Control System Based on Dynamic Re-configuration

Developments in advanced control techniques are occurring in parallel with advances in sensors, algorithms, and architectures that support next-generation condition-based maintenance systems. The emergence of Multi-agent Systems in the Distributed Artificial Intelligence arena is providing important new capabilities that can significantly improve automation system performance, survivability, adaptability, and scalability. The new capabilities provided by multi-agent systems has shifted control system research into a very challenging and complex domain. A multi-agent system approach enables us to encapsulate the fundamental behavior of intelligent devices as autonomous components. These components exhibit primitive attitudes to act on behalf of equipment or complex processes. Using this approach, we have implemented a set of cooperating systems that manage the operation of an axial vent fan.

Fault Detection and Diagnostics Using Data Mining

The purpose of data mining is to find new knowledge from databases in which complexity or the amount of data has so far been prohibitively large for human observation alone. Self-Organizing Map (SOM) is a special type of Artificial Neural Networks (ANNs) used in clustering, visualization and abstraction. In modern process automation systems, it is possible to collect and store huge amounts of measurement data. In this paper, SOM is used successfully to discover the base models from the automation system. Strategies based on data mining techniques are further developed for efficient fault detection and diagnostics. A semi-supervised anomaly detection technique is used with classification rules based on standardized data and domain experts’ analysis to construct the condition monitoring system.

Qualitative Evaluation of Manufacturing Software Units Interoperability Using ISO 25000 Quality Model

In the context of development and evolution of heterogeneous industrial systems, the quality of interoperability among manufacturing software units is a major concern. Qualitative characteristics of the interoperability such as reliability, functionality, performance, and security are necessary for the assurance of high quality of the developed manufacturing applications. The implemented interoperability among various software units of manufacturing applications often have various quality criteria. Therefore, an adequate qualitative modeling is required to satisfy the qualitative evaluation of the interoperability. This paper presents the use of quality model developed in respect of quality standard ISO 25000 series as a means to permit the comprehensive evaluation of interoperability of the applications developed regarding the ISO 16100 standard series.

A Standards-Based Approach for Interoperability Between Engineering Design and Asset Management

There is a wealth of asset information in the design environment that is necessary in the operational environment to effectively manage the asset. However, the asset design information model is typically a complex structure that requires in-depth knowledge of the model to access the necessary information. Currently, there are no well-defined methodologies to extract the relevant design information that is needed in the asset operational domain. In addition, there are no well-defined methods to define the relationships between the terms and definitions common to the design environment and the operational environment. In this paper, we will propose the use of an open technical dictionary and an information exchange approach based on ISO 18435 to organize the relevant information to achieve interoperability of applications in both design and operational environments.

Fast parallel CRC implementation in software

A cyclic redundancy check (CRC) is one of the most commonly used error detecting codes in communication and storage devices. Before a message is transferred, a transmitter calculates the CRC using the agreed upon polynomial called a generator, and attaches the resulting residue to the message. When the message is received, a receiver calculates the CRC using the same polynomial and verifies the message. If the two CRC values are different, it means an error has occurred during the data transfer. A CRC is easy to implement in hardware using linear feedback shift registers or in software using a simple polynomial evaluation, or a table lookup for a faster speed. In this paper, a fast CRC computation is presented using a software based parallelization scheme. In an ARM Cortex-A15 implementation of the proposed methodology, it achieves 2.6 times faster speed compared to a conventional table lookup CRC computation.

A Contribution to Software Interoperability Verification of Manufacturing Application

With an increasing number of distributed heterogeneous manufacturing systems, interoperability is becoming more and more critical for the reliability, performance, and security of working applications. In order to control the development and evolution of applications interoperability, crucial decisions should be made at the earliest stages of development. These decisions need to be incorporated in the detailed design of the components that make up the application in order to accomplish a reliable and efficient solution at the implementation level. For a complete solution the application architecture must be designed using a methodology that can be verified. The components used in the implementation must be verified against the evolving application requirements. These components need to be checked for coherency of the design as the application evolves to meet new application requirements. The two checking types, in conjunction with an integrated approach, constitute the main goal of interoperability verification. This paper presents elements of an integrated modeling of interoperability verification. The implemented model is designed to develop automatic interactive tools which facilitate the tasks of interoperability verification.