Improving software development efficiency and reusability of existing programs is an important topic for industrial automation. Recently, modern software paradigms have been introduced into the automation domain such ...
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ISBN:
(纸本)9781479938414
Improving software development efficiency and reusability of existing programs is an important topic for industrial automation. Recently, modern software paradigms have been introduced into the automation domain such as object-oriented programming using the IEC 61131-3 standard and component-based design based on the IEC 61499 standard. In this paper, another software paradigm - service-oriented architecture is applied to the software design for automation programs. The proposed SOA pattern is based on a multilayered structure with enhanced reusability and flexibility. A case study of water heating system is implemented to prove the concept of SOA paradigm.
Calling context provides important information for a large range of applications, such as event logging, profiling, debugging, anomaly detection, and performance optimization. While some techniques have been proposed ...
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ISBN:
(纸本)9781450326704
Calling context provides important information for a large range of applications, such as event logging, profiling, debugging, anomaly detection, and performance optimization. While some techniques have been proposed to track calling context efficiently, they lack a reliable and precise decoding capability; or they work only under restricted conditions, that is, small programs without object-oriented programming or dynamic component loading. These shortcomings have limited the application of calling context tracking in practice. We propose an encoding technique without those limitations: it provides precise and reliable decoding, supports large-sized programs, both procedural and objected-oriented ones, and can cope with dynamic class/library loading. The technique thus enables calling context tracking in a wide variety of scenarios. The evaluation on SPECjvm shows that its efficiency is comparable with that of the state-of-the-art approach while our technique provides precise decoding and demonstrates scalability and flexibility.
The notion of spreading activation over a semantic network is one of the most frequently used approaches to several important problems in artificial intelligence. We first argue that spreading activation subsumes not ...
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The notion of spreading activation over a semantic network is one of the most frequently used approaches to several important problems in artificial intelligence. We first argue that spreading activation subsumes not only marker-passing systems, but also local connectionist and recent 'hybrid' models. We then suggest that spreading activation reduces to the passing of messages between concurrent objects. We argue therefore in favor of the concurrent and object-oriented nature of a general architecture for spreading activation. Concurrency is required for massive parallelism; object-orientedness, for the mechanisms it readily provides for semantic modeling. We then overview an object-oriented framework for spreading activation, which we have implemented in both Smalltalk and ABCL/1. The fundamental characteristic of this implementation is that it is programmable, and thus can accommodate most of the existing spreading activation models.< >
More and more, developers use reusable components like libraries to produce high quality software systems. These systems need to satisfy not only the initial demands of their stakeholders, but they need to also offer ...
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ISBN:
(纸本)9781605580869
More and more, developers use reusable components like libraries to produce high quality software systems. These systems need to satisfy not only the initial demands of their stakeholders, but they need to also offer support for future, changing requirements. While several studies have looked at the cost of modifying systems, there exists no work verifying if libraries evolve differently than applications. This study attempts to do so *** this paper, we define design changes metrics to estimate the amount of high-level change required of individual classes and use metrics to describe their structure. These measures are then used as inputs in models capable of predicting code change. We used machine learning techniques to build these models and tested them on the evolution of industrial open-source systems. Two of the systems were libraries, and two were standalone *** found that while design changes are systematically correlated with code changes, structure metrics are better predictors of code change in libraries with well developed class hierarchies. With the two applications without this characteristic, structure alone was a poor predictor.
Over the past decades, group-based control has become one of the most popular signal technologies being applied in many cities around the world. LHOVRA control is one of such group-based controls widely employed in Sc...
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ISBN:
(纸本)9781479960798
Over the past decades, group-based control has become one of the most popular signal technologies being applied in many cities around the world. LHOVRA control is one of such group-based controls widely employed in Scandinavian countries. While several previous studies showed that group-based control outperforms stage-based control in many aspects, implementation and evaluation of signal controllers are complicated in a real application. In addition, little effort has been put in optimizing such group-based controllers in traffic management practice. This study implements generic group-based control in an object-oriented software framework, while a software-in-the-loop simulation is developed to integrate the signal controller with an open-source traffic simulator, SUMO. Also, stochastic optimization is applied to generate optimal signal parameters according to different settings of objective. In particular, part of the study is to improve the computational performance of the optimization process by parallelized simulation runs. Test-based experiments are finally carried out to evaluate traffic and optimize its impact on a small traffic network in Stockholm.
Adaptability, i.e. the ability of a system to adapt dynamically to changes in its execution environment, is considered as an important property of computer systems. Scaling directory replication in name servers and lo...
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Adaptability, i.e. the ability of a system to adapt dynamically to changes in its execution environment, is considered as an important property of computer systems. Scaling directory replication in name servers and load balancing are well known examples. However, adaptability in today's systems, if present at all, generally is burnt in and dedicated to singular properties of the execution environment. The authors discuss a more universal approach to adaptability. The approach is based on the/spl minus/in some cases artificial/spl minus/separation of nonfunctional properties from the functionality of application systems. The scheme provides full control over nonfunctional properties while preserving transparency for the application programs. To study that approach, reflection has been incorporated into the BirliX object model and its implementation. It has been used to experiment with some nonfunctional properties such as migration and protection. The authors motivate the need for a universal adaptability scheme, revisit reflection as used in programming language systems and discuss design decisions for reflective systems, describe the resulting reflective BirliX model and its implementation and finally describe applications.< >
Java had a long period of little change in its features: between Java 5 in 2004 and Java 9 in 2017, lambda functions were the only major addition to the language. However, Java's development pace has suddenly quic...
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ISBN:
(纸本)9781450394338
Java had a long period of little change in its features: between Java 5 in 2004 and Java 9 in 2017, lambda functions were the only major addition to the language. However, Java's development pace has suddenly quickened, and not just in version numbers: by the time Java 17 was released in September 2021, new features in the language since Java 9 included record types, switch expressions, sealed classes, var declaration types, text blocks and pattern-matching instanceof. More new features are also on the horizon. Java remains one of the most popular languages for teaching in high-school and university/college, but many educators will not have had the time to learn these new features, let alone consider whether they should adjust their teaching to include any of these features. In this in-person workshop we will explain the new features to attendees and then facilitate discussion on whether the features should be incorporated into Java teaching at the introductory or advanced level, if at all.
INTRODUCTION object-oriented programming is proving to be quite useful in many areas which have not been served well by more conventional *** fact,any real world object can be modeled in an objectoriented *** real-wo...
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INTRODUCTION object-oriented programming is proving to be quite useful in many areas which have not been served well by more conventional *** fact,any real world object can be modeled in an objectoriented *** real-world objects may exist and do things concurrently,object-oriented systems also show great potential for exploiting concurrence/*** many object-oriented languages currently in use are sequential(such as C++,Smalltalk-80, Eiffel).How to implement object-oriented languages on parallel systems is still a promising research topic.
The cooperation of alliance needs a powerful agent to coordinate each other's activities. The broker agent who holds the structural holes position usually initiate this kind of governance because of the advantage ...
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The cooperation of alliance needs a powerful agent to coordinate each other's activities. The broker agent who holds the structural holes position usually initiate this kind of governance because of the advantage of information and control. This paper tied to turn the focus from sharing the cake to making a bigger cake: exploring the relationship between governance and performance of triple alliance. Basing on two dimension of external environment complex and exploration capability, we design four situations. Using the simulation experiment we extend the Aggarwal's model and explore how the governance initiated by broker agent affects the triple alliance's performance. The results show that except for the extreme case of high complex and low capability governance will lead to different performance level. The final performance depends on the reasonable matching among complex, capability and governance. At the end we discuss the contribution and the possibility of extension in the future.
Cyber Physical Systems (CPSs) are a category of systems of systems (SoS) that integrate physical and computational elements. Such systems have existed for some time, but rigorous design methodologies for CPSs are scar...
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Cyber Physical Systems (CPSs) are a category of systems of systems (SoS) that integrate physical and computational elements. Such systems have existed for some time, but rigorous design methodologies for CPSs are scarce. The typical design process of a CPS makes use of a large number of models to help answer the wide range of design questions that arise in development. In other words, the design process produces models that describe the various crucial aspects, scopes and system components on different level of detail and abstraction. These partial models can potentially be coupled for effective information propagation across the different modeling perspectives to increase design reliability. However, they are usually expressed in different specialized tools and programming languages as a consequence of the system heterogeneity and the preference of the numerous designers involved. This paper therefore proposes generating abstractions of detailed sub-models, and then embedding those abstractions into system-wide models formulated in other formalisms.
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