Using the technologies of the Internet on a local Intranet can provide a cost-effective method of improving integration on the plant floor. While third-party retrofits can make these features available, equipment buil...
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Using the technologies of the Internet on a local Intranet can provide a cost-effective method of improving integration on the plant floor. While third-party retrofits can make these features available, equipment builders will probably take the lead in this area. Although many new controllers may include some of these features, a complete redesign of a controller by the equipment builder is expensive. The retrofit techniques, combined with relatively minor modification of existing controllers, are an easy way to provide additional features directly from the machine. The original equipment manufacturer (OEM) can offer embedded Web pages for troubleshooting and maintenance, adding value for the customer.
Algorithms need clear and formal representations to be implemented as computer programs. The Object-Process Methodology (OPM) has been shown to successfully describe the structure and behavior of systems by combining ...
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Algorithms need clear and formal representations to be implemented as computer programs. The Object-Process Methodology (OPM) has been shown to successfully describe the structure and behavior of systems by combining objects and processes within an integrated, coherent set of object-process diagrams (OPDs). However, OPDs lack control-flow constructs for explicit specification of the entire process sequence, which is essential for algorithm implementation. In this article we augment the OPD notation to explicitly mark the necessary execution order among processes by introducing four basic control-flow mechanisms - sequence, branch, loop, and recursion - as well as other means, such as process ownership, to support current object-oriented design and programming concepts. The explicit representation of an algorithm also makes it possible to automatically generate the program code from the OPD set and reverse engineer existing complex code to an OPD set to enhance code understandability, maintenance, and reuse.
This paper explores technical issues in the design of programming tools, development environments, simulations, code examples, user interface frameworks and pedagogies for a university-level course on object-oriented ...
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This paper explores technical issues in the design of programming tools, development environments, simulations, code examples, user interface frameworks and pedagogies for a university-level course on object-oriented software development. The course, M206 `Computing: An Object-oriented Approach' has been specifically developed for distance learning, and is enrolling over 5,000 students per year (average age 37) in the UK, Europe and Singapore. The course introduces computing via an object-oriented approach. M206 is substantial in extent, representing one sixth of a degree. It embodies a practical, industry-oriented view of computing and includes programming, analysis, design, and group working. Considerable effort has been invested in making the simplicity, consistency and power of object technology accessible to and capable of being applied by beginners. A diverse set of educational media, such as CD-ROMs, TV and the Web, have been deployed as learning resources. The paper describes the agenda for the course, its object-oriented pedagogy and our strategy for delivery. We explain measures taken to avoid misconceptions about objects, our analysis and design method, and the Smalltalk programming environment we have developed specifically for learners and which is crucial to our approach. The paper outlines how our adherence to the separation of view and domain model leads to technical innovations. Concluding remarks reflect on the benefits a reflexive strategy, both in education and training.
All elements of the user interface communicate information from a computer system to the user. This includes design aspects of the interface such as online help and system status and error messages. Although technical...
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ISBN:
(纸本)0780357094
All elements of the user interface communicate information from a computer system to the user. This includes design aspects of the interface such as online help and system status and error messages. Although technical communicators may be employed on system documentation, often these skills are overlooked in respect of these user interface design aspects. The result is online help and error messages written by programmers that subsequently fail the user because they do not communicate the intended message effectively. Recent Australian research sought to determine if, through the contribution of a technical communicator, the quality of electronic information delivered to users was improved. A series of case studies involving 20 information systems, (both when involving a technical communicator and when not), explored the effectiveness of online user information. This paper reports on the results of that research. The involvement of a technical communicator does improve the quality of online user information.
In Ada95 with the controlled types, an abstraction of safe pointers for which dereferencing will inevitably raise Constraint_Error, is provided. Safe pointers work like access types while keeping track of all pointers...
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In Ada95 with the controlled types, an abstraction of safe pointers for which dereferencing will inevitably raise Constraint_Error, is provided. Safe pointers work like access types while keeping track of all pointers to an object. So the maximum set of operations to be provided comprises of: a null pointer [null];assignment;equality;allocation [new];deallocation [Unchecked_Deallocation];dereferencing [all];and referencing [`[Unchecked_]Access]. A generic child unit providing a safe pointer type designing objects of a definite type is presented.
Exploring lower bound of scheduling is an important problem in high-level synthesis. In this paper, we address the problem of computing lower bound on the general minimal resource interval scheduling problem, called n...
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Exploring lower bound of scheduling is an important problem in high-level synthesis. In this paper, we address the problem of computing lower bound on the general minimal resource interval scheduling problem, called n-n-MRIS, in which arbitrary component selections are allowed in stead of the traditional uni-component selection. The problem of n-n-MRIS is proved to be strongly NP hard. An efficient ILP model and a surrogate relaxation technique are proposed to produce a lower bound for the n-n-MRIS problem.
Ubiquitous computing began in the Electronics and Imaging Laboratory of the Xerox Palo Alto Research Center. The evolution of ubiquitous computing from computer walls to calm computing is discussed.
Ubiquitous computing began in the Electronics and Imaging Laboratory of the Xerox Palo Alto Research Center. The evolution of ubiquitous computing from computer walls to calm computing is discussed.
Programmable logic, long revered for the flexibility it brings to system design, is taking the next step in ease-of-use. In system reprogramming (ISR), the ability to truly reprogram a device in-system without the pin...
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Programmable logic, long revered for the flexibility it brings to system design, is taking the next step in ease-of-use. In system reprogramming (ISR), the ability to truly reprogram a device in-system without the pinout or timing changes, simplifies multiple stages of the process. In-system prototyping and field upgrades are viable options when a CPLD with an ISR architecture is used. The time and money savings promised by in system programming (ISP) are delivered by ISR.
In this paper, a unified methodology is introduced for the computation of modular multiplication and reduction operations, which are fundamental to numerous public-key cryptography systems. First, a general theory is ...
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In this paper, a unified methodology is introduced for the computation of modular multiplication and reduction operations, which are fundamental to numerous public-key cryptography systems. First, a general theory is presented which aides the construction of arbitrary most-significant-digit first and least-significant-digit first iterative modular reduction methods. Utilizing this foundation, new methods are presented which are not premised in division techniques. The resultant class of algorithmic techniques, which we dub iterative residue accumulation (IRA) methods, are robust, accommodating general radixes. Furthermore, forms supporting both most-significant-digit or least-significant-digit first evaluation are presented. Significantly, in comparison to earlier methods, IRA effectively replaces quotient-digit evaluation and quotient-modulus multiplication steps encountered in techniques such as Montgomery's method with a single-step residue evaluation, thereby permitting efficiency improvements. Forms suitable for either lookup or multiplication-based evaluation are explored. Precomputation overhead is minimal and the methods are suitable for VLSI implementation.
We show a technique for consistent dynamic exchange of different aspects of implementations of abstract data types, in particular data structure representations and algorithms. Previous work showed how one single aspe...
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We show a technique for consistent dynamic exchange of different aspects of implementations of abstract data types, in particular data structure representations and algorithms. Previous work showed how one single aspects implementation can be exchanged dynamically without running into robustness problems if other aspects are guaranteed to be fixed. The present work generalizes this idea in the sense that all aspects implementations may be exchanged arbitrarily at run time where robustness is preserved. We use finite state machines where each state represents a combination of the different implementations and each transition an exchange of exactly one aspects implementation. We use these state machines to check for the robustness of a class within a certain application context.
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