Maes, P. & Nardi, D. (1988), Meta-Level Architectures and Reflection, Elsevier Science Inc., NY, USA.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....different i and j) This is all fine when we just want to represent incoherent beliefs. But what do we do with them if we really want to use them and act upon them We may view this as more generally as a problem of reflection in meta level reasoning. In metalevel reasoning architectures (e.g. [MN88]) one may reflect information from one level to another: for instance, one may reflect meta level information of the provability of some assertion to the information that that assertion is true on the object level. Thus we may see the above problem with defaults with conflicting outcomes in this ....

P. Maes & D. Nardi (eds.), Meta-Level Architectures and Reflection, North-Holland, Amsterdam, 1988.

....of base level objects. Class M I M1 M2 C2 Class C Objects Object classes Metaobjects Metaobject classes Base level is of is reflected into B : b0 B : b1 Attr B A : a0 A a1 Attr A Figure 4. 6: Behavioral Reflection Behavioral reflection is characterized by the following properties [MN88, Lis95, Cam97, MCP98] Individuality Each object at the base level can be associated with a metaobject at the metalevel independently of this other objects. So, it is possible to involve some objects of the same class, and not all of them, in the reflection mechanism; Class separation A ....

....control newly created relationship links involving an already existing ordinary object by defining new metaobjects and associating them to it. 5.3.2 Refining the Send Message Primitive The second change is to modify message passing control for behavioral reflection. A new send message primitive [MN88, Fer89] must be added to the Clos kernel. We do that through the definition of a primitive call as described below. Since this primitive extends the system behavior, it must be defined at the root of the class hierarchy Lisp is introduced in Appendix A; Clos is described in Appendix C and ....

P. Maes and D. Nardi, editors. Meta-level architectures and reflection. North-Holland, 1988.

....methods and information that can be used to analyze the analysis techniques and their relationships with the data [1] and the use of those techniques by the analyst, in the expectation of improving future analyses. This kind of computational reflection makes a computing system much more flexible [40] [22] 28] Problem Solving Methods can be viewed as problem paradigms in our sense, and we believe that something is gained by doing so, because we treat not only the method that addresses the problem at hand, but also the strategies for finding and using appropriate methods. 2.1 Analysis by ....

....to integration are the uniformities of the first two features: the uniformity of treating everything in the system as resources, and the uniformity of treating everything that happens in the system as problem study. The most important algorithmic simplification is the Computational Re flection [40] [22] 28] provided by treating the PMs as resources themselves: we explicitly make the entire system reflective by considering these programs that process the wrappings to be resources also, and wrapping them, so that all of our integration support processes apply to themselves, too. It is this ....

Pattie Maes, D. Nardi (eds.), Meta-Level Architectures and Reflection, Proceedings of the Workshop on Meta-Level Architectures and Reflection, 27-30 October 1986.

....recent AI research the term reflective system is used to identify a class of systems which in some way or other have knowledge about themselves and which are able to reason about and act upon themselves. In this view reflective systems are closely related, but not identical to meta level systems [Maes Nardi, 1988]. Maes [Maes, 1987] defines a reflective system as a computational system which has not only knowledge and data about some part of the external world, the object domain, enabling it to reason about and sometimes act upon that domain, but which also has the ability to reason and act upon itself. ....

P. Maes and D. Nardi, editors. Meta-Level Architectures and Reflection, Amsterdam, 1988. North-Holland.

....the lessons learnt from this work, we briefly address the benefits of reflection in other layers of a system for dependability issues. 1. Introduction and Related Work Reflection is the property of a system by which its structure and operation can be controlled and updated from outside itself [12]. This definition introduces the notion of metainformation that correspond to a selfrepresentation of a component that is visible and manageable from outside the component. This information can be used to model the component operation at an upper layer, called metalevel. A reflective component ....

P. Maes and D. Nardi, "Meta-Level Architectures and Reflection," , Elsevier Science Pub., 1988.

....or self referencing) systems have long been considered in many branches of logic and computer science, and more recently in their intersection area named computational logic or logic programming. Their importance and usefulness in logic [55, 56] and in theorem proving [38] in computer science [30, 51, 60], and in logic programming [7, 40, 47] has been generally recognised (see also [1, 11, 13, 32, 57] for snapshots of research) The common intuitive notion of reflection in such different areas is that of an access relationship between theories or programs at the object level and theories or ....

P. Maes and D. Nardi, editors. Meta-Level Architectures and Reflection. NorthHolland, Amsterdam, 1988.

....reasoning about logical consequence; Ginsberg, 1986] describes a meta level framework for the construction of knowledge base refinement systems; Haggith, 1995] describes a framework for reasoning about conflicts in knowledge bases. Many other systems using explicit meta knowledge do exist (cf. [Maes and Nardi, 1988]) This illustrates the availability of meta knowledge in knowledge based systems. Of particular interest to us is work on using meta knowledge for competence assessment [Vo et al. 1990] as this is directly related to capability retrieval. One of their aims was to develop a system that knows ....

Pattie Maes and Daniele Nardi, editors. Meta-Level Architectures and Reflection. North-Holland, Amsterdam, The Netherlands, 1988.

....of computer science. In programming languages, it has been used as a tool in the study of interpreters [3, 16, 18, 33] the design of extensible programming languages [13] and polymorphism [26] In A.I. reflection has been used to study programs that must explain their own reasoning strategy [4, 15]. In databases, Stemple et al. 25] applied reflection in the dynamic creation of data types in database programming languages. A very rough definition of reflection is that programs can be treated as data and vice versa. The meta programming facilities of languages like LISP provide a simple and ....

P. Maes and D. Nardi, editors. Meta-Level Architectures and Reflection. North-Holland, 1988. 30

.... implementations, which led to ORB extensions for dealing with specific aspects such as real time [19] group communication [20] and fault tolerance [20] Our goal, on the other hand, is to provide a generic skeleton in which different kinds of customizations can be performed using reflection [21] There exist some implementations of small footprint CORBA ORBs such as e ORB (http: www.vertel.com corba default.asp) which is targetted to the telecommunication market and is used for example in optical switches, and eBus which is a general purpose ORB intended to be used in appliances. ....

P. Maes, D.N., Meta-Level Architectures and Reflection. 1987: North-Holland.

....separation of communication strategy from problem level program Communication strategy changes the behavior of an agent by using a history that is a measure almost independent of a problem level program. Thus we think deciding communication structures should be a kind of computational reflection [20]. This means communication strategy could be separated from problem level programs and would be a metal level description of program solving agents. This separation has two merits: i) Programming is divided into two independent subtasks: building communication strategy and writing ....

Pattie Maes and Daniele Nardi, editors. Meta-Level Architectures and Reflection. North-Holland, 1988.

....resolution based theorem prover we developed in COMMON LISP, we found that general, domain independent reasoning methods 8 were insufficient for imposing a clear conceptual structure on the reasoning process. As a solution to this problem, we have investigated the use of a meta level architecture [27]. In our COMMON LISP theorem proving program, a knowledge base consists of two levels: an objectlevel containing the declarative domain knowledge from HEPAR, and a meta level containing domain specific control primitives. The actual application of inference rules at the object level is controlled ....

P. Maes, D. Nardi, Metalevel Architectures and Reflection, (North-Holland, Amsterdam, 1987).

....is alimitation on dynita adaptability that we can give to the software systems beforehan4 Thus, the mechanW# that realizesdynize adaptability must be con W)k#q# flexibly,an must be able to chan depen 5 on the states ofrun timeen vironSS ts. We can satisfy suchrequiremen t byusin reflection [4] [5]. We propose a software model withdyn)D5 adaptability called DASan itsdescription lancrip LEAD . A software system basedon the DAS model forms a meta level architecture [5] an the mechanS fordynW q adaptability is basedon procedures. It chan54 procedurein vocation dynn)k zq depen)S on the ....

....be able to chan depen 5 on the states ofrun timeen vironSS ts. We can satisfy suchrequiremen t byusin reflection [4] 5] We propose a software model withdyn)D5 adaptability called DASan itsdescription lancrip LEAD . A software system basedon the DAS model forms a meta level architecture [5],an the mechanS fordynW q adaptability is basedon procedures. It chan54 procedurein vocation dynn)k zq depen)S on the states ofrun timeen viron 4 ts, an realizes the dynSDW adaptability in reflective way. Tocon4 4)k the model, we haddesignD implemen ted the lan guage LEAD # [6] an we ....

P. Maes and D. Nardi, eds., "Meta-level Architecture and Reflection," Elsevier Science Publishers B.V., 1988.

....message (automatic receive) ffl Secretary Object The Secretary object is a component of a CST object. It is used to control incoming messages. An incoming message is handled before the method called by it is executed. That is, the Secretary object plays the role of Meta Object as in 3 KRS[Maes 88] or ABCL R[Watanabe 88] 2.1.4 Implementation of CST The Virtual Machine(VM) of CST was written in the C language, and runs on Sun3, Sparc station, and Sony News. However, it is not easy to port the VM to machines such as Macintosh, because the source code must be changed according to its ....

P. Maes and D. Nardi, editors. Meta-Level Architectures and Reflection. North-Holland, 1988.

....a longstanding tradition in both logic and ai. See (Feferman, 1936) for some of the early work in logic on reflective systems, Weyrauch, 1980) and (Smith, 1984) for some early reflective systems in ai, Giunchiglia Smaill, 1989) for a good introduction to the terminology and the literature, and (Maes Nardi, 1988) for a collection of some recent work in this area. Two aspects are crucial to the construction of such pairs of object meta theories. The first one concerns naming: as mentioned before, terms of M will need to refer to formulae of O. Such terms in M are called names of the formulae in O. The ....

Maes, P. and Nardi, D., editors (1988). Meta-Level Architectures and Reflection, Amsterdam. North-Holland.

....if we wish to regard the meta theory as an object theory and introduce a meta meta theory to contain statements about the encodings of meta theory statements. 1. 3 Meta level architectures A meta level architecture defines a computational system in terms of an object system and a meta system (Maes and Nardi, 1988). The object system contains a model for reasoning about the world to solve problems; the meta system contains a representation of the objectsystem, which it reasons about. The object system and its meta system representation are causally connected, meaning that any change in one causes a change ....

Maes, P. and Nardi, D., eds. (1988). Meta-Level Architectures and Reflection, Amsterdam: North-Holland.

....File: csts 94 meta sok hkb. Submit to CSTS conf. January 1994, Blacksburg, VA. 1 Introduction We have four broad purposes in this paper: 1. To clarify the concept of meta level reasoning (MLR) This concept has been discussed fairly much in the literature and has a series of different senses [8, 13, 21, 24, 25, 27]. In this paper we wish to make a clear presentation of what MLR is, and we will do so in terms of first order vs second order system functionality. Our discussion of this topic begins in x2. 2. To say clearly what inference meta level or not is and why it is needed for computer aided ....

Maes, Patti, and D. Nardi, eds., Meta-Level Architectures and Reflection, North-Holland, New York, New York, 1988.

.... should support late dynamic binding and allow executable code to be manipulated as data (like in Lisp, Smalltalk, or Prolog) This is necessary to make it possible to dynamically reason upon, manipulate, and interpret a model ( code ) e.g. represented by reified classes and meta classes [MN88] This is needed if we want to describe the software process as a single, integrated model. Therefore, most process support environments with highly diverse process modeling languages rely on such techniques to achieve model flexibility during enactment. ffl Schema evolution and ....

Patty Maes and Daniele Nardi, editors. Meta-Level Architectures and Reflection. North Holland, 1988.

....with this information We believe that with a fixed workflow meta model this is not possible. A fixed meta model can only support a fixed set of meta data and there could always be a situation where this is not sufficient. Instead, we propose to build WFMSs according to a meta level architecture [Maes and Nardi, 1988] discriminating between an object level and a meta level (see Figure 8) The workflow modelling and workflow execution processes are running on the object level. The meta level defines an explicitly represented and dynamic meta model that provides the semantics for the object level processes. ....

....meta plans contain meta operations such as plan, replan, check consistency, notify agent, or the sensor actions mentioned earlier. With the proposed declarative representation of the meta level the system is able to do introspective meta reasoning. As in other AI meta level architectures (see [Maes and Nardi, 1988]) both levels of this architecture are linked via so called reflection mechanisms. This enables computations on the meta level to control the execution of object level processes. RELATED WORK There have already been several attempts to extend WFMSs with failure handling features. Most of them ....

Maes, P. and Nardi, D., editors (1988). Meta-Level Architectures and Reflection. North-Holland, Amsterdam.

....the meta language works with the reified components of the object language (formulas, theorems, axioms, 2 etc. to build up proof plans that help the prover of the object level language to find the solution. The application of reflection techniques to KBS has been widely used in the recent past [13,21]. These techniques are used with different representation goals: implementation of non monotonic reasoning patterns [18,19] declaration of inference methods [20] architecture description [5] In general, reflection mechanisms can be understood, in this context, as a clear separation between ....

....reasoning patterns [18,19] declaration of inference methods [20] architecture description [5] In general, reflection mechanisms can be understood, in this context, as a clear separation between domain and control knowledge. Few systems have clear semantics, among which we can find OMEGA [13] and BMS [18,19] Due to the need in AI of dealing many times with uncertain and or imprecise information, a number of models for representing uncertainty and imprecision have been largely studied within the AI community. In order to have such a possibility of explicitly representing uncertainty, ....

Maes P., Nardi D (1988): Meta-level Architectures and Reflection, North-Holland, Amsterdam.

No context found.

Maes, P. & Nardi, D. (1988), Meta-Level Architectures and Reflection, Elsevier Science Inc., NY, USA.

No context found.

P. Maes and D. Nardi, editors. Meta-Level Architectures and Reflection. North-Holland, 1988.

No context found.

P. Maes and D. Nardi. Meta-Level Architectures and Reflection. North-Holland, 1988.

No context found.

Maes, P., Nardi, D., eds.: Meta-Level Architectures and Reflection, Amsterdam, North-Holland (1988)

No context found.

Pattie Maes and Daniele Nardi. Meta-Level Architectures and Reflection. North-Holland, 1988.

No context found.

Maes, P. and Nardi, D., (eds.), Meta-level Architectures and Reflection, North-Holland, 1988.

First 50 documents

Online articles have much greater impact   More about CiteSeer.IST   Add search form to your site   Submit documents   Feedback  

CiteSeer.IST - Copyright Penn State and NEC