Probabilistic Temporal Network for Numeric and Symbolic Time Information

2011 ◽  
pp. 67-86
Author(s):  
Malek Mouhoub ◽  
Jia Liu
Keyword(s):  
Branch And Bound ◽  
Real World ◽  
Possible Worlds ◽  
Constraint Satisfaction Problem ◽  
Constraint Propagation ◽  
Branch And Bound Algorithm ◽  
Temporal Constraints ◽  
Robust Solution ◽  
The Real ◽  
Interval Algebra

We propose a probabilistic extension of Allen’s Interval Algebra for managing uncertain temporal relations. Although previous work on various uncertain forms of quantitative and qualitative temporal networks have been proposed in the literature, little has been addressed to the most obvious type of uncertainty, namely the probabilistic one. More precisely, our model adapts the probabilistic Constraint Satisfaction Problem (CSP) framework in order to handle uncertain symbolic and numeric temporal constraints. In a probabilistic CSP, each constraint C is given a probability of its existence in the real world. There is thus more than one CSP to solve as opposed to the traditional CSP where no such uncertainties exist. In a probabilistic temporal CSP, since we use the Interval Algebra where a constraint is a disjunction of Allen primitives, the probability is assigned to each of these Allen primitives rather than to the temporal constraint. This means that a probabilistic temporal CSP involves many possible temporal CSPs, each with a probability of its existence. Solving a probabilistic temporal CSP consists of finding a scenario that has the highest probability to be the solution for the real world. This is an optimization problem that we solve using a branch and bound algorithm we propose and involving constraint propagation. Experimental study conducted on randomly generated temporal problems demonstrates the efficiency in time of our solving method. In the case of uncertain numeric constraints, our TemPro framework for handling numeric and symbolic temporal constraints is extended to handle uncertain domains. An algorithm for dividing domains into non-overlapping areas is proposed. This algorithm guarantees that the generated possible worlds do not intersect. Probable worlds are then constructed by combining these areas. A new branch and bound algorithm, we propose, is finally applied to find the most robust solution.

AN EFFICIENT LOTOS-BASED FRAMEWORK FOR DESCRIBING AND SOLVING (TEMPORAL) CSPs

2009 ◽  
Vol 19 (06) ◽  
pp. 765-789
Author(s):  
SAMIRA SADAOUI ◽  
MALEK MOUHOUB ◽  
BO CHEN
Keyword(s):  
Constraint Satisfaction Problem ◽  
Combinatorial Problem ◽  
Experimental Tests ◽  
Search Space ◽  
Constraint Propagation ◽  
Combinatorial Problems ◽  
Temporal Constraints ◽  
Transition Systems ◽  
Time Performance ◽  
Novel Approach

Simulation of complex Lotos specifications is not always efficient due to the space explosion problem of their corresponding transition systems. To overcome this difficulty in practice, we present in this paper a novel approach which integrates constraint propagation techniques into the Lotos specifications. These solving techniques are used to reduce the size of the search space before and during the search for a solution to a given combinatorial problem under constraints. In order to do that, we first tackle the challenging task of describing combinatorial problems in Lotos using the Constraint Satisfaction Problem (CSP) framework. In this regard, we provide two generic Lotos templates for describing CSPs and temporal CSPs (CSPs involving temporal constraints). To evaluate the time performance of the framework we propose, we have conducted several experimental tests on instances of the N-Queens, the machine scheduling and randomly generated CSPs. The results of these experiments are promising and demonstrate the efficiency of Lotos simulation when CSP techniques are integrated.

Possible Worlds of History

2018 ◽  
Vol 12 (1) ◽  
pp. 164-182
Author(s):  
Ilkka Lähteenmäki
Keyword(s):  
Real World ◽  
Possible Worlds ◽  
Philosophy Of History ◽  
Historical Writing ◽  
The Real ◽  
Metaphorical Interpretation

Abstract The theory of possible worlds has been minimally employed in the field of theory and philosophy of history, even though it has found a place as a tool in other areas of philosophy. Discussion has mostly focused on arguments concerning counterfactual history’s status as either useful or harmful. The theory of possible worlds can, however be used also to analyze historical writing. The concept of textual possible worlds offers an interesting framework to work with for analyzing a historical text’s characteristics and features. However, one of the challenges is that the literary theory’s notion of possible worlds is that they are metaphorical in nature. This in itself is not problematic but while discussing about history, which arguably deals with the real world, the terminology can become muddled. The latest attempt to combine the literary and philosophical notions of possible worlds and apply it to historiography came from Lubomír Doležel in his Possible Worlds of Fiction and History: The Postmodern Stage (2010). I offer some criticism to his usage of possible worlds to separate history and fiction, and argue that when historiography is under discussion a more philosophical notion of possible worlds should be prioritized over the metaphorical interpretation of possible worlds.

scholarly journals A NEUTROSOPHIC DESCRIPTION LOGIC

2008 ◽  
Vol 04 (03) ◽  
pp. 273-290
Author(s):  
HAIBIN WANG ◽  
ANDRÉ ROGATKO ◽  
FLORENTIN SMARANDACHE ◽  
RAJSHEKHAR SUNDERRAMAN
Keyword(s):  
Real World ◽  
Description Logic ◽  
Description Logics ◽  
Constraint Propagation ◽  
The Real ◽  
Neutrosophic Logic ◽  
Structured Knowledge

Description Logics (DLs) are appropriate, widely used, logics for managing structured knowledge. They allow reasoning about individuals and concepts, i.e. set of individuals with common properties. Typically, DLs are limited to dealing with crisp, well defined concepts. That is, concepts for which the problem whether an individual is an instance of it is a yes/no question. More often than not, the concepts encountered in the real world do not have a precisely defined criteria of membership: we may say that an individual is an instance of a concept only to a certain degree, depending on the individual's properties. The DLs that deal with such fuzzy concepts are called fuzzy DLs. In order to deal with fuzzy, incomplete, indeterminate and inconsistent concepts, we need to extend the capabilities of fuzzy DLs further. In this paper, we will present an extension of fuzzy [Formula: see text], combining Smarandache's neutrosophic logic with a classical DL. In particular, concepts become neutrosophic (here neutrosophic means fuzzy, incomplete, indeterminate and inconsistent), thus, reasoning about such neutrosophic concepts is supported. We will define its syntax, its semantics, describe its properties and present a constraint propagation calculus for reasoning.

scholarly journals A partition-based branch-and-bound algorithm for the project duration problem with partially renewable resources and general temporal constraints

OR Spectrum ◽  
2021 ◽  
Author(s):  
Kai Watermeyer ◽  
Jürgen Zimmermann
Keyword(s):  
Exact Solution ◽  
Branch And Bound ◽  
Renewable Resources ◽  
State Of The Art ◽  
Branch And Bound Algorithm ◽  
Time Lags ◽  
Temporal Constraints ◽  
New Approach ◽  
Project Duration ◽  
Partially Renewable Resources

AbstractThe concept of partially renewable resources provides a general modeling framework that can be used for a wide range of different real-life applications. In this paper, we consider a resource-constrained project duration problem with partially renewable resources, where the temporal constraints between the activities are given by minimum and maximum time lags. We present a new branch-and-bound algorithm for this problem, which is based on a stepwise decomposition of the possible resource consumptions by the activities of the project. It is shown that the new approach results in a polynomially bounded depth of the enumeration tree, which is obtained by kind of a binary search. In a comprehensive experimental performance analysis, we compare our exact solution procedure with all branch-and-bound algorithms and state-of-the-art heuristics from the literature on different benchmark sets. The results of the performance study reveal that our branch-and-bound algorithm clearly outperforms all exact solution procedures. Furthermore, it is shown that our new approach dominates the state-of-the-art heuristics on well known benchmark instances.

scholarly journals A DYSTOPIAN READING OF THE PRESENT TIME IN DAVID MITCHELL'S NUMBER 9 DREAM

2018 ◽  
Vol 6 (12) ◽  
pp. 12-22
Author(s):  
Alireza Farahbakhsh ◽  
Soulmaz Kakaee
Keyword(s):  
Science Fiction ◽  
Present Article ◽  
Real World ◽  
Possible Worlds ◽  
The Novel ◽  
The Real ◽  
Narrative Style ◽  
Critical Engagement ◽  
Genre Criticism ◽  
The Given

With the intention to study the implications and their affinity with and deviation from reality, the present study will analyze Number9Dream (2001) in terms of its narrative style, ontological qualities, and certain conventions which lead to the particular genre of dystopian science fiction. It tends to settle the following questions: are the implications and contributions of categorizing Number9Dream as a dystopian science fiction significant in any way? What is the role and ontological significance of setting in the novel? Narratological approach and genre criticism are applied to the novel to analyze it from the perspective of its critical engagement with dystopia. It traces science fictional elements and then continues to examine their utopian or dystopian nature and the different functions of those elements. It also refers to the connection between the given ontologies and reality. The present article shows that the novel provides a range of multiple possible worlds through two layers of internal and external ontology which are the representations of the real world. Dystopian narrative and science fiction conventions are exploited to address today's world issues. Through a detached view toward the present societies, Mitchell gives the opportunity to criticize what is not otherwise visible. The novel warns about human's isolation, alienation, and dehumanization and calls people to action accordingly. It briefly refers to the reconciliation of past/ present and nature/ science as a solution.

scholarly journals Subversive Humor as Art and the Art of Subversive Humor

2020 ◽  
Vol 1 (1) ◽  
pp. 153-180
Author(s):  
Chris A. Kramer
Keyword(s):  
Real World ◽  
Emotional Response ◽  
Possible Worlds ◽  
Aesthetic Experience ◽  
Thought Experiments ◽  
Consciousness Raising ◽  
The Real ◽  
Marginalized Communities ◽  
The Third ◽  
Narrative Thought

Abstract This article investigates the relationships between forms of humor that conjure up possible worlds and real-world social critiques. The first part of the article will argue that subversive humor, which is from or on behalf of historically and continually marginalized communities, constitutes a kind of aesthetic experience that can elicit enjoyment even in adversarial audiences. The second part will be a connecting piece, arguing that subversive humor can be constructed as brief narrative thought experiments that employ the use of fictionalized scenarios to facilitate an open, playful attitude, encouraging a space for collaborative interpretation. This interaction between humorist and audience is an aesthetic experience that is enjoyable in and of itself, as the feelings of mirth are intrinsically valuable. But connected to the “Ha-ha!” experience of these sorts of humorous creations is an “Aha!” or potentially revelatory experience that is a mixture of cognitive comprehension and motivated (emotional) response. The third part of the article will attempt to go beyond the consciousness-raising element with an account of how such possible worlds created in the realm of imagination through subversive humor can bleed into the real world of flesh and blood people. Finally, an example of subversive humor will be analysed.

The dynamics of sheep welfare in Norway – between idealised images and practical realities

2017 ◽  
Vol 119 (4) ◽  
pp. 952-966 ◽  
Author(s):  
Virginie Amilien ◽  
Unni Kjærnes
Keyword(s):  
Product Quality ◽  
Animal Welfare ◽  
Real World ◽  
Public Discourse ◽  
Possible Worlds ◽  
Meat Industry ◽  
Possible World ◽  
Content Type ◽  
The Real ◽  
Convention Theory

Purpose This paper is based on three social scientific studies of animal welfare and local food products in Norway, of which two focussed on sheep in particular. It addresses the widespread belief that Norwegian sheep farming is “the best” but is confronted with a meat industry that emphasises economic efficiency. A few years after a new Norwegian law on animal welfare acknowledged animals as sentient beings came into force in 2010 (LOVdata, 2009), the purpose of this paper is to better understand ongoing debates on the welfare of sheep by exploring how sheep welfare is understood and regulated in Norway. Design/methodology/approach The theoretical framework draws on convention theory, especially referring to the four “possible worlds of production” (Salais and Storper, 1993). The authors argue that animal welfare may be analysed in parallel to product quality, focussing on three major perspectives of sheep welfare: animal treatment, product quality, and an abstract conceptualisation in public discourse. The empirical analysis is based on interviews with key players in the sector and central documents. Findings Convention theory points to several general difficulties in reaching an agreement on what is “good quality” and welfare. First, the authors find difficulty in how to implement new regulatory conceptualisations with dominant ways of understanding welfare within the industry. Second, the idealised images of sheep welfare of an immaterial possible world dominating public discourse have very little interaction with the real world of farms and abattoirs. Originality/value This paper suggests that rather than addressing and handling the potential tension between the legal recognition of animal as sentient being and the economic demands of the industry, key actors keep the potentially conflicting understandings apart in different “worlds of production” (Salais and Storper, 1993). Nevertheless, the authors observe that interactions between possible worlds, as well as translation from one possible world to another, not only could be promising but would be fundamental to concretise improvements in the real world.

A Multi-Agent Temporal Constraint Satisfaction System Based on Allen's Interval Algebra and Probabilities

2011 ◽  
pp. 56-76
Author(s):  
Elhadi Shakshuki ◽  
André Trudel ◽  
Yiqing Xu
Keyword(s):  
Distributed System ◽  
Constraint Satisfaction ◽  
Real World ◽  
Constraint Satisfaction Problem ◽  
Local Constraints ◽  
Temporal Interval ◽  
Interval Algebra ◽  
Multi Agent ◽  
The Given ◽  
Execution Order

Many real-world problems can be viewed and represented as a constraint satisfaction problem (CSP). In addition, many of these problems are distributed in nature. To this end, we combine agents with a special type of CSP called an Interval Algebra network (IA network). An IA network is a graph where each node represents an interval. Directed edges in the network are labelled with temporal interval relations. A probabilistic IA network has probabilities associated with the relations on the edges that can be used to capture preferences. A probabilistic IA agent (PIA-Agent) is assigned a probabilistic IA network. PIA-Agent’s networks are connected via edges. The overall goal is to make each PIA-Agent’s network consistent and optimal. Each PIA-Agent is independent and has sole control over its network. But, it must communicate and coordinate with other PIA-Agents when modifying or updating edges that are shared between two PIA-Agents. We present an algorithm which allows the PIA-Agents to collaboratively solve and recommend a temporal schedule. At the agent level, this schedule is optimal under the given local constraints. Although the global solution may not be optimal, we try to generate near optimal ones. Note that our distributed system is not centrally controlled. Our algorithm decides which PIA-Agent should be given an opportunity to update the solution next. Also, when a conflict is detected, the algorithm modifies the PIA-Agent execution order in order to deal with the inconsistency.

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