Translations and similarity-based logic programming

In order to provide approximate reasoning capabilities, in Gerla G, Sessa MI (1999) Chen G, Ying M, Cai K-Y (Eds) Fuzzy Logic and Soft computing, 19–31, Kluwer Academic Publishers, Boston an extension of Logic Programming has been proposed. Logic programs on function-free languages are considered, and approximate and imprecise information are represented by introducing a similarity relation ? in the set of predicate names and object names of the language. The inference system exploits the classical resolution rule of the Logic Programming paradigm. Moreover, the notion of fuzzy least Herbrand model is also provided. In this paper, by introducing the general notion of structural translation of languages, we generalize these results to the case of logic programs with function symbols. Some properties of the similarity relations are also proven.     

Likelog for flexible query answering

 Starting from unification based on similarity, a logic programming language, called LIKEness in LOGic (Likelog) is derived, thorougly relying on similarity. An operational semantics and a fix-point semantics of the language are defined, using an extension principle for fuzzy operators. The two approaches are proved to be related and a fuzzy extension of the least Herbrand model is given. One of the principal feature of such a logic programming language is to allow flexible query answering to deductive databases, which we show through an example. Moreover, we describe a system for web information retrieval through Likelog. I want to thank Ferrante Formato with whom I started and I continued this research and Prof. Giangiacomo Gerla for his great support and contribution given to this field.     

The Traveling Agent Problem

 This paper considers a sequencing problem which arises naturally in the scheduling of software agents. We are given n sites at which a certain task might be successfully performed. The probability of success is p _i at the ith site and these probabilities are independent. Visiting site i and trying the task there requires time (or some other cost metric) t _i whether successful or not. Latencies between sites i and j are l _ij, that is, the travel time between those two sites. Should the task be successfully completed at a site then any remaining sites do not need to be visited. The Traveling Agent Problem is to find the sequence which minimizes the expected time to complete the task. The general formulation of this problem is NP-Complete. However, if the latencies are constant we show that the problem can be solved in polynomial time by sorting the ratios t _i/p _i according to increasing value and visiting the sites in that order. This result then leads to an efficient algorithm when groups of sites form subnets in which latencies within a subnet are constant but can vary across subnets. We also study the case when there are deadlines for solving the problem in which case the goal is to maximize probability of success subject to satisfying the deadlines. Applications to mobile and intelligent agents are described. Date received: February 10, 1998. Date revised: November 16, 1999.     

Patterns of Mobile Interaction

The design of systems for mobile scenarios covers a wide range of issues, ranging from mobile networking to user interface design for mobile devices. Mobile applications often run distributed on several connected devices, used by many users simultaneously. Considering all issues related to mobile scenarios, a designer might be overwhelmed. As a solution, we propose a specific kind of design patterns which we call mobility patterns, derived from successful mobile applications. They allow a designer to re-use design elements as building blocks in their own designs. After describing the idea of mobility patterns, we give a brief overview of patterns we have identified so far. Two patterns are described in more detail with the help of our research platforms QuickStep and Pocket DreamTeam.     

移动Agent系统Ajanta的分析与研究

文章详细地分析了Ajanta系统的运行环境、体系结构、安全性与实现中的一些关键技术，并对该系统中存在的不足与可改进的方案进行了讨论。     

Maps and isometries between indistinguishability operators

 In this paper, some geometric aspects of indistinguishability operators are studied by using the concept of morphism between them. Among all possible types of morphisms, the paper is focused on the following cases: Maps that transform a T-indistinguishability operator into another of such operators with respect to the same t-norm T and maps that transform a T-indistinguishability operator into another one of such operators with respect to a different t-norm T ^′. The group of isometries of a given T-indistinguishability operator is also studied and it is determined for the case of one-dimensional operators, in particular for the natural indistinguishability operators E _T on [0, 1]. Finally, the indistinguishability operators invariant under translations on the real line are characterized.     

Customizing Graphics for Tiny Displays of Mobile Devices

Advances in mobile devices and wireless telecommunication infrastructure already provide mobile users with access to online information sources and services. Compared to the PC world, however, mobile access is still quite restricted, especially with regard to the display of graphical representations, such as images, drawings, diagrams, maps and logos. Since graphical representations are increasingly used in the World Wide Web for the purpose of information presentation, the adaptation of graphics for tiny displays is a challenge that should not be neglected. The current contribution discusses several transformation approaches which might be employed to accomplish this adaptation task.     

Fuzzy e-negotiation agents

 The paper presents a prototype of Fuzzy e-Negotiation Agents (FeNAs) for autonomous multi-issue negotiation in e-commerce. It considers negotiation as a form of distributed decision making in the presence of limited common knowledge and imprecise/soft constraints that can be modeled as a distributed fuzzy constraint satisfaction problem (DFCSP). FeNAs incorporate the principles of utility theory within DFCSPs and use fuzzy constraint-based reasoning in order to find a consensus that maximizes the agent's utility and the level of its fuzzy constraint satisfaction subject to its acceptability by other agents. The paper presents aspects of problem representation and negotiation mechanisms used by FeNAs in the context of DFCSPs. An overview of FeNAs is provided and some capabilities for automated multi-issue negotiation are illustrated with two scenarios of e-commerce trading.     

A human-centered agent-based architecture for electronic brokerage

 Electronic brokerage, envisioning brokers acting on customers' behalf to locate required products and services at the best available price, is a promising technique to solve a specific problem of electronic commerce business relations, i.e. the identification of the goods and services satisfying the user requirements to the highest possible degree. In this paper we describe a electronic brokerage system based on a human-centered layered architecture that allows the broker to proceed seamlessly from the user's vision of the market, based on a nominal scale, to ordinal and interval based representations suitable for intelligent search agents exploiting fuzzy techniques.     

Context Awareness and Mobile Phones

This paper investigates some aspects of how context-awareness can support users of mobile phones, in particular the calling party. The use of mobile and stationary phones is discussed in relation to situational properties of a phone conversation, especially with regards to who might benefit from context-awareness in this context. An initial hypothesis is that mobile phone users communicate context information to each other (verbally) to a much higher degree than do stationary phone users. Mobile phone users could benefit much from context awareness technology, in particular when about to make a call, if they can receive context information regarding the person they are trying to reach prior to establishing the call. We argue that such technology should require low amounts of explicit user interaction, and could lead to less disrupting calls in inappropriate moments, as well as less frustration for the calling party when a call is not answered.     

The Mobile Phone: An Identity on the Move

This paper analyses the shifting identity of the mobile phone in the light of research carried out in 1996 on a representative population sample from five major European countries: Italy, UK, France, Germany and Spain. A total of 6609 people were interviewed by means of a telephone survey. The mobile phone emerged as a charismatic technology compared to other mobile technologies (laptop and car phone) and as a leading technology that, in just a few years, has appropriated 11% of total telephone traffic. It has “dragged” its widespread presence and amount of use from the workplace to the domestic sphere, although in Italy, where it has had greatest success, its widespread use has been detached from its use in the workplace. Another emerging result is that the use of the mobile phone is not correlated to strong residential mobility in individuals.     

Overcoming the Lack of Screen Space on Mobile Computers

One difficulty for interface design on mobile computers is lack of screen space caused by their small size. This paper describes a small pilot study and two formal experiments that investigate the usability of sonically-enhanced buttons of different sizes. The underlying hypothesis being that presenting information about the buttons in sound would increase their usability and allow their size to be reduced. An experimental interface was created that ran on a 3Com Palm III mobile computer and used a simple calculator-style interface to enter data. The buttons of the calculator were changed in size between 4×4, 8×8 and 16×16 pixels and used a range of different types of sound from basic to complex. Results showed that sounds significantly improved usability for both standard and small button sizes – more data could be entered with sonically-enhanced buttons and subjective workload reduced. More sophisticated sounds that presented more information about the state of the buttons were shown to be more effective than the standard Palm III sounds. The results showed that if sound was added to buttons then they could be reduced in size from 16×16 to 8×8 pixels without much loss in quantitative performance. This reduction in size, however, caused a significant increase in subjective workload. Results also showed that when a mobile device was used in a more realistic situation (whilst walking outside) usability was significantly reduced (with increased workload and less data entered) than when used in a usability laboratory. These studies show that sound can be beneficial for usability and that care must be taken to do testing in realistic environments to get a good measure of mobile device usability.     

Visual computing within environment of self-explanatory components

 A visual language and a multimedia environment supporting the language are considered. The language is explained through describing a visual program for solving partial differential equations by a multigrid method. The environment is based on a database of self-explanatory components in a “film” format and a film management system for searching, editing, composing and other manipulations with components. The visual program presented is only one view of a self-explanatory component. In fact, it can also be watched in dynamics and from other points of view for better understanding the method features. The goal of the visual program example is to show that visual programs can be physically much smaller than the text they replace and much easier for understanding and modifying.     

An entropy construction inspired by fuzzy sets

 Fuzzy dynamics is considered as a model of a general algebraic scheme based on two binary operations fulfilling a very weak distributive law. The main result is the existence of the limit defining the entropy of the general dynamical system. Present address: Katedra matematiky Fakulty prírodnych vied UMB, Tajovského 40, SK-97 401 Banská Bystrica, Slovakia E-mail: riecan@fpv.umb.sk Dedicated to Prof. Ján Jakubík on the occasion of his 80th birthday Supported by grant VEGA 1/9056/02.     

An fMUX architecture: data modularization and mixed-mode system modeling

 In this study, we introduce a concept of a fuzzy multiplexer (fMUX) generalizing a well-known idea of multiplexers existing in two-valued logic and digital systems. A generic topology of the fMUX is presented and its functional behavior studied. We show that a design process with fMUXs is concerned with their supervised learning. A detailed learning scheme is discussed. Numerical illustration is included. It is shown that fMUX support an idea of mixed-mode modeling in which we encounter data-information granules quite often exhibiting variable granularity and this diversity lends itself to a modular way of model development.     

Configuring the Mobile User: Sociological and Industry Views

This article considers the role of the consumer in the diffusion of mobile telecommunications technologies. There is presently little research on the consumption and use of mobile technologies, and the aim of the present paper is to facilitate discussion about the way consumer behaviour is currently understood in industry and academia. The paper considers key themes in social science research on mobile ICTs, and understandings of the consumer held by those in the mobile industry. Bringing these understandings together, we reiterate the now well attested view that the diffusion and consumption of mobile telephony and computing cannot be understood without investigating the contexts and processes of their use in everyday life.     

Negotiating Use: Making Sense of Mobile Technology

This paper is based on a study of the ways in which a group negotiated the use of a new mobile technology. The group was made up of ski instructors who, during a one-week ski trip, were equipped with a mobile awareness device called the Hummingbird. The group was studied using ethnomethodologically inspired qualitative methods, with the focus on the group members’ different views of the Hummingbird’s intended use. Negotiations of use occurred using two methods: talk and action. The users negotiated issues such as where and when to use the technology, and whether to consider the Hummingbird a work tool or a gadget for social events. Further, the empirical results clearly show how negotiations of new, mobile technology differ from stationary technology.     

Fuzzy closure operators II: induced relations,representation, and examples

 Closure operators (and related structures) are investigated from the point of view of fuzzy set theory. The paper is a follow up to [7] where fundamental notions and result have been established. The present approach generalizes the existing approaches in two ways: first, complete residuated lattices are used as the structures of truth values (leaving the unite interval [0,1] with minimum and other t-norms particular cases); second, the monotony condition is formulated so that it can reflect also partial subsethood (not only full subsethood as in other approaches). In this paper, we study relations induced by fuzzy closure operators (fuzzy quasiorders and similarities); factorization of closure systems by similarities and by so-called decrease of logical precision; representation of fuzzy closure operators by (crisp) closure operators; relation to consequence relations; and natural examples illustrating the notions and results. Supported by grant no. 201/99/P060 of the GA ČR and by NATO Advanced Fellowship B for 2000. The author would like to thank to Professor G. Gerla for helpful comments. Part of the paper written during author's research visit at the Center for Intelligent Systems, State University of New York at Binghamton. Support by the Center and by its director, Professor G.J. Klir, is gratefully acknowledged.     

Multiobjective fuzzy linear programming for sustainable irrigation planning: an Indian case study

 Multiobjective fuzzy linear programming (MOFLP) irrigation planning model is formulated for the evaluation of management strategy for the case study of Jayakwadi irrigation project, Maharashtra, India. Three conflicting objectives net benefits, agricultural production and labour employment are considered in the irrigation planning scenario. All three criteria are to be maximised and the last two are sustainability related. All three objective functions are quantified by linear membership functions in a fuzzy multi objective framework. It is observed from MOFLP solution that net benefits, agricultural production and labour employment are 2.031×10⁹ Rupees, 2.1186×10⁶ tons, 3.5858×10⁷ man-days respectively with degree of truth (λ) 0.5715. Analysis of results indicated that net benefits, agricultural production, labour employment have decreased by 4.13, 5.39 and 3.4% as compared to ideal values in the crisp linear programming (LP) model. Present address: Department of Civil Engineering, Birla Institute of Technology and Science, Pilani, Rajasthan, India E-mail: ksraju@bits-pilani.ac.in