Performance assessment of a system for reasoning under uncertainty

From the early developments of machines for reasoning and decision making in higher-level information fusion, there was a need for a systematic and reliable evaluation of their performance. Performance evaluation is important for comparison and assessment of alternative solutions to real-world problems. In this paper we focus on one aspect of performance assessment for reasoning under uncertainty: the accuracy of the resulting belief (prediction or estimate). We propose a framework for assessment based on the assumption that the system under investigation is uncertain only due to stochastic variability (randomness), which is partially known. In this context we formulate a distance measure between the “ground truth” and the output of an automated system for reasoning in the framework of one of the non-additive uncertainty formalisms (such as imprecise probability theory, belief function theory or possibility theory). The proposed assessment framework is demonstrated with a simple numerical example.     

An interactional view of social presence: Making the virtual other “real”

In IS research, social presence is generally defined as the perceived capacity of a communication medium to convey contextual cues normally available in face‐to‐face settings. However, theorizing social presence as a property of the technology has been challenged for decades. The objective of this paper is to develop a more contemporary, interactional view of social presence. To this end, this paper develops a new conceptualization of how participants form the sense that each other is present. We characterize the development of this sense as a skilful accomplishment that entails interactants' joint construction of each other as “real.” Viewing social presence as contingent on social practice, we seek to answer the following research question: “How is social presence accomplished in virtual environments?” To explicate how virtual others are perceived as becoming socially present, that is, emotionally and psychologically “real” to someone interacting with them, we draw from Goffman's work, particularly his concepts of involvement and involvement obligation. Detailing two examples of social interaction in the virtual world Second Life, our analysis highlights the key role that this moral obligation, intrinsic to everyday social interaction, plays in virtual others becoming perceived as psychoemotionally “there.” By outlining a model of how the sense of a virtual other as “real” is produced in and through social interaction, our work contributes a sociological perspective to the construct of social presence and underscores some of the material and social conditions necessary for users to perceive virtual others as present.     

Constructivist foundations of modeling—A Kantian perspective

By linking Knowledge Engineering to Kantian Philosophy, this paper attempts to elaborate a potential theoretical foundation for understanding the nature of expertise and the processes of modeling. The established way of modeling is criticized for presuming the relation between the real objective world and the AI software models being a “mapping” (abstraction, copy, representation, etc.) relation. The paper argues that this aspect of the foundations of modeling in Knowledge Engineering could be improved by employing the standpoint presented in Kant's Critique of Pure Reason. Two hypotheses and ten principles of a constructivist modeling paradigm based on Kant's work are proposed. The term Constructivist here refers to the hypothesis that a model cannot “correspond to” reality but merely be “viable in” (i.e., “fit into”) reality. © John Wiley & Sons, Inc.     

A privacy self-assessment framework for online social networks

During our digital social life, we share terabytes of information that can potentially reveal private facts and personality traits to unexpected strangers. Despite the research efforts aiming at providing efficient solutions for the anonymization of huge databases (including networked data), in online social networks the most powerful privacy protection “weapons” are the users themselves. However, most users are not aware of the risks derived by the indiscriminate disclosure of their personal data. Moreover, even when social networking platforms allow their participants to control the privacy level of every published item, adopting a correct privacy policy is often an annoying and frustrating task and many users prefer to adopt simple but extreme strategies such as “visible-to-all” (exposing themselves to the highest risk), or “hidden-to-all” (wasting the positive social and economic potential of social networking websites). In this paper we propose a theoretical framework to i) measure the privacy risk of the users and alert them whenever their privacy is compromised and ii) help the users customize semi-automatically their privacy settings by limiting the number of manual operations. By investigating the relationship between the privacy measure and privacy preferences of real Facebook users, we show the effectiveness of our framework.     

Book Reviews

As the results of man-engineered experiments with social design, social “revolution”, socialist “architectures”, and other feats of “social engineering”, are crumbling down, they are causing large-scale human suffering through their failures. There is a renewed awareness that self-organizing and spontaneous properties of complex social systems are much too powerful (and much too vulnerable at the same lime) to respond or be exposed to the endless, reductionistic “tinkering” of policy “makers”, “scientists” of the artificial, and “engineers of human souls”.? ? Geoffrey Vickers, in his Human Systems are Different²⁶ ends up expressing a similar awareness: “It [his book] does not offer a blueprint for the design of human societies. I hope it will weaken the contemporary urge to regard such activities as akin to engineering rather than (at most) to gardening.” View all notes The mankind is again ready to learn how to “trigger”, “catalyze”, “sustain” and “lead-manage” a spontaneous process of social self-organization; it is becoming less inclined to design another “central super-controller”, “information-processing command system”, or “World Brain”.

The purpose of this paper is to show: (1) that theories dealing with “spontaneous social orders” have deep historical roots and (2) that systems sciences are in a good position (better than economics, engineering or sociology) to build upon these roots and expand the theories into useful, practical methodologies. For example, modern theories of autopoiesis and order through fluctuations, especially their rich, computer-based simulation experiments, provide a good and solid point of departure.     

A simulation framework for crisis management: Design and use

A perennial simulation framework is proposed within the domain of crisis management simulation. Motivated by a need for establishing information superiority through decision-support analysis, the framework is designed to use symbiotic simulation and is also suitable for the hindsight and foresight studies that drive crisis-related preparedness exercises. The framework provides a novel feature of incorporating Human in the Loop simulations using virtual reality as a part of the symbiotic simulation. We coin the term perennial simulation to refer to our framework being enduring (the simulation working symbiotically with the real system), and recurring (performing “what-if?” simulations and continually providing feedback to the real system).Three case studies examine the application of the framework to crisis-related scenarios. The framework is shown to be useful and capable of dealing with crisis situations and adding value to existing expert advice, forming a symbiotic feedback loop that aids crisis management.     

Representation of interrelationships among binary variables under dempster–shafer theory of belief functions

This paper presents an algorithm for developing models under Dempster–Shafer theory of belief functions for categorical and “uncertain” logical relationships among binary variables. We illustrate the use of the algorithm by developing belief‐function representations of the following categorical relationships: “AND,” “OR,” “exclusive OR (EOR)” and “not exclusive OR (NEOR),” and “AND‐NEOR” and of the following uncertain relationships: “discounted AND,” “conditional OR,” and “weighted average.” Such representations are needed to fully model and analyze a problem with a network of interrelated variables under Dempster–Shafer theory of belief functions. In addition, we compare our belief‐function representation of the “weighted average” relationship with the “weighted average” representation developed and used by Shenoy and Shenoy (in Belief Functions in Business Decisions, edited by R. P. Srivastava and T. Mock; Heidelberg, Germany: Physica‐Verlag; 2002; pp 316–332). We find that Shenoy and Shenoy representation of the weighted average relationship is an approximation and yields significantly different values under certain conditions. © 2009 Wiley Periodicals, Inc.     

ICT for socio-economic development: A citizens’ perspective

There is a widespread belief that information and communication technologies (ICTs) can play a significant role in the socio-economic development of a developing country. ICT has the potential to affect many aspects of economic and societal activities such as GDP growth, employment, productivity, poverty alleviation, quality of life, education, and healthcare. While the literature provides a myriad of definitions and elements of socio-economic development, the focus tends to be on theoretical conceptualizations from various disciplines and impacts from isolated individual projects. In particular, the impact of ICT on socio-economic development has not been carefully examined from the viewpoint of the ultimate stakeholder, the citizens of a country, who are the final consumers of the technology. This study fills this gap by focusing on the citizens’ view in describing ICT-driven socio-economic development in a developing country. A theoretical framework influenced by the “capabilities approach” was developed to guide this research, and the interpretive stance was used to conduct the study. More specifically, the narrative research method, which is seldom used in IS research but is appropriate for this study, was used. Narratives allow deeper and profound insights into social representations and participants' beliefs about the role of ICT in socio-economic development. Using this methodology, a model of the impact dimensions of socio-economic development is presented.     

Multiaspect‐based opinion classification model for tourist reviews

Tourist reviews on social media websites reflect the tourist's opinions concerning various aspects of a tourist place or service (e.g., “comfortable room” and “terrible service” in hotel reviews). Extracting these aspects from reviews is a challenging task in opinion mining. Therefore, aspect‐based opinion mining has emerged as a new area of social review mining. Existing approaches in this area focus on extracting explicit aspects and classification of opinions around these aspects. However, the implicit and coreferential aspects during aspect extraction are often neglected, and the classification of multiaspect opinions is relatively less emphasized in prior art. In this paper, we propose a model, namely, “enhanced multiaspect‐based opinion classification” that addresses existing challenges by automatically extracting both explicit and implicit aspects and classifying the multiaspect opinions. In this model, first, a probabilistic co‐occurrence‐based method is proposed that utilizes the co‐occurrence between aspects and sentiment words to identify the coreferential aspects and merge them into groups. Second, an implicit aspect extraction method is proposed that associates the sentiment words with suitable aspects to build an aspect‐sentiment hierarchy. Third, a multiaspect opinion classification approach is proposed that employs multilabel classification algorithms to classify opinions into different polarity classes. The effectiveness of the proposed model is evaluated by conducting experiments on benchmark and real‐world datasets. The experimental results revealed the supremacy of multilabel classifiers by achieving 90% accuracy per label on classification when extracting 87% domain‐relevant aspects. A state‐of‐the‐art performance comparison is conducted that also verifies the advantages of the proposed model.     

Lightweight Bytecode Verification

In this paper, we provide a theoretical foundation for and improvements to the existing bytecode verification technology, a critical component of the Java security model, for mobile code used with the Java “micro edition” (J2ME), which is intended for embedded computing devices. In Java, remotely loaded “bytecode” class files are required to be bytecode verified before execution, that is, to undergo a static type analysis that protects the platform's Java run-time system from so-called type confusion attacks such as pointer manipulation. The data flow analysis that performs the verification, however, is beyond the capacity of most embedded devices because of the memory requirements that the typical algorithm will need. We propose to take a proof-carrying code approach to data flow analysis in defining an alternative technique called “lightweight analysis” that uses the notion of a “certificate” to reanalyze a previously analyzed data flow problem, even on poorly resourced platforms. We formally prove that the technique provides the same guarantees as standard bytecode safety verification analysis, in particular that it is “tamper proof” in the sense that the guarantees provided by the analysis cannot be broken by crafting a “false” certificate or by altering the analyzed code. We show how the Java bytecode verifier fits into this framework for an important subset of the Java Virtual Machine; we also show how the resulting “lightweight bytecode verification” technique generalizes and simulates the J2ME verifier (to be expected as Sun's J2ME “K-Virtual machine” verifier was directly based on an early version of this work), as well as Leroy's “on-card bytecode verifier,” which is specifically targeted for Java Cards.     

Enabling openness of valuable information resources: Curbing data subtractability and exclusion

In this paper we investigate how data openness can be made possible in communal settings. We adopt a utility perspective that foregrounds the use value of data, conceptualizing them as “goods.” On the basis of this conceptualization we explore 2 key goods' attributes: subtractability and exclusion. Our theoretical basis is built upon concepts from the theory of the commons, power theorizing, and notions related to data and information. Empirically, we investigate openness in the genetics domain through a longitudinal study of the evolving communal infrastructure for data related to 2 genes influencing women's susceptibility to breast and ovarian cancer (BRCA1 and BRCA2). We follow the continuously shifting “topology” of the BRCA information infrastructure and trace the multiple repositories that are put in place and the different arrangements for data collection, curation/quality assurance, access, and control that are tried out. In our analysis, we illustrate the actors' strategies for curbing the subtractability and exclusion attributes of data. We then propose a theoretically informed and empirically grounded framework that can guide understanding and action taking to enable data openness.     

Real user evaluation of a POMDP spoken dialogue system using automatic belief compression

This article describes an evaluation of a POMDP-based spoken dialogue system (SDS), using crowdsourced calls with real users. The evaluation compares a “Hidden Information State” POMDP system which uses a hand-crafted compression of the belief space, with the same system instead using an automatically computed belief space compression. Automatically computed compressions are a way of introducing automation into the design process of statistical SDSs and promise a principled way of reducing the size of the very large belief spaces which often make POMDP approaches intractable. This is the first empirical comparison of manual and automatic approaches on a problem of realistic scale (restaurant, pub and coffee shop domain) with real users. The evaluation took 2193 calls from 85 users. After filtering for minimal user participation the two systems were compared on more than 1000 calls.     

On the analysis of time-aware protocols in universal composability framework

We consider the analysis of time-aware cryptographic protocols in the universal composability (UC) framework (Canetti in 2000). The tasks we consider are the timeliness of messages within an instance as well as the time of validity of cryptographic credentials where the lifetime of time stamps overlaps lots of instances. We point out that the UC analysis of time-aware protocols with global access to real time clock cannot be carried out directly within the standard model. For the resolution of the corresponding problem, we considered two ways: one is the introduction of an auxiliary timing oracle into the ideal system, while the other consists of two time models: a quantized real time source and an abstract “random-time” source, and we show an essential equivalence between them. The time models provide not only theoretical but also practical benefits.     

The Paradox of Mobility in the Kenyan ICT Ecosystem: An Ethnographic Case of How the Youth in Kibera Slum Use and Appropriate the Mobile Phone and the Mobile Internet

The Kenyan ICT ecosystem has attracted vast global media and policy attention because of notable mobile phone adoption in the country. However, empirical research of how Kenyans use and appropriate new media and ICTs in the diverse contexts within the country remains limited. In order to contribute to the emerging literature on Sub-Saharan Africa ICT ecosystems as well as the Mobility discussions within Mobiles for Development M4D and Information and Communication Technologies for Development ICT4D, this paper discusses an empirical case of how the youth of Kibera use and appropriate the mobile phone and the mobile Internet. The purpose of this critical realist ethnographic research article is to explicate the events in the historical development of the Kenyan ICT ecosystem as well as the components of social and physical structure in Kibera slum along with the relationships between them. This paper argues that the mobile phone eases communication and strengthens existent social ties for the youth of Kibera. However, it cannot bypass the hierarchical nature of Kenya where “class and place of residence are distinctive social markers in the process of social networking” [Wallis, C. (2011). Mobile phones without guarantees: The promises of technology and the contingencies of culture. New Media & Society, 13(3), 471–485. Wallis, C. (2013). Technomobility in China: Young migrant women and mobile phones. New York, NY: New York University Press]. Therefore, the young Kiberans predominantly use and appropriate the mobile phone to network with those in the same lower income strata. This is because they are widely perceived in Kenyan society as the “other and what does not belong” because they are slum residents [Hall, S. (2013). The spectacle of the other. In S. Hall, J. Evans, & S. Nixon (Eds.), Representation: Cultural representations and signifying practices (2nd ed., pp. 223–283). Sage. p. 257].     

IFSs and Interactive Image Synthesis

Deterministic Fractal geometry provides a framework for describing both the geometry of man-made structures and the geometry of nature. Certain deterministic Fractals which exist in the plane may be “partitioned” into a number of “tiles” equivalent to the whole under some geometric mapping. We term such Fractals self-tiling images. We describe a scheme called Iterated Function Systems (IFSs) which an represent self-tiling images. IFSs make explicit the mappings which take a self-tiling image into its tiles. We show how a self-tiling image exists as the limit of both random and deterministic processes based upon its associated IFS, and exploit massive SIMD parallelism in image generation on the AMT DAP. We also attempt to answer the question: “Can one synthesise images by the interactive graphical manipulation of a representation of IFSs?”, and present our interactive system for image synthesis (ISIS).     

Construction method of shop-floor digital twin based on MBSE

Digital twin (DT) technology is essential for achieving the fusion of virtual-real cyber-physical systems. Academics and companies have made great strides in the theoretical research and case studies of constructing the shop-floor digital twin (SDT), which is the premise of applying DT technology on the shop floor. A shop floor is a large complex system that involves many elements including people, machines, materials, methods, and the environment and processes, such as the technical flow, business process, logistics, and control flow. However, most of the developed cases lack a hierarchical, structured and modularized implementation framework for the development of an SDT system, which leads to problems such as a low reuse rate of the system blocks, lack of scalability, and high upgrade and maintenance costs. In response to these issues, we propose a construction method of the DT for the shop floor based on model-based systems engineering from the perspective of the system. In this method, a comprehensive DT model for the shop floor is gradually constructed by using system modeling language, the modeling method “MagicGrid,” and the “V model” of systems engineering. The model includes four dimensions of the shop-floor requirements, structure, behavior, and parameters, as well as three stages (the problem domain, solution domain, and implementation domain), and connects nine steps of the “V model,” including the system requirements, system architecture, subsystem implementation, subsystem integration, and system verification. Then, based on an example of a real NC machining shop floor, subsystems including a visualization system, synchronization system, and simulation system, are discussed. Finally, the functions of the integrated systems are verified based on the requirements, including the real-time synchronization of “man, machine, material, and method” and the transient simulation in real time. The numerical indicators of the integrated system are verified, including the model completeness and synchronization timeliness.     

WSNs deployment framework based on the theory of belief functions

Deployment is a fundamental issue in Wireless Sensor Networks (WSNs). Indeed, the number and locations of sensors determine the topology of the WSN, which will further influence its performance. Usually, the sensor locations are precomputed based on a “perfect” sensor coverage model. However, in reality, there is an inherent uncertainty and imprecision associated with sensor readings. This issue impinges upon the success of any WSN deployment, and it is therefore important to consider it at the design stage. In contrast to existing work, this paper investigates the belief functions theory to design a unified approach for robust uncertainty-aware WSNs deployment. Specifically, we address the issue of handling uncertainty and information fusion for an efficient WSNs deployment by exploiting the belief functions reasoning framework. We present a flexible framework for target/event detection within the transferable belief model. Using this framework, we propose uncertainty-aware deployment algorithms that are able to determine the minimum number of sensors as well as their locations in such a way that full area coverage is provided. Related issues, such as connectivity, preferential coverage, challenging environments and sensor reliability, are also discussed. Simulation results, based on both synthetic data set and data traces collected in a real deployment for vehicle detection, are provided to demonstrate the ability of our approach to achieve an efficient WSNs deployment by exploiting a collaborative target/event detection scheme. Using the devised approach, we successfully deploy an experimental testbed for motion detection. The obtained results are reported, supported by comparison with other works.     

北京新机场跑道构型设计方案比较

为满足北京地区快速增长的旅客航空需求, 开展北京新机场建设工作。本期规划机场跑道数量4条, 有“3＋1”和“4＋0”两种跑道构型备选方案。首先从机场、空管和航空公司三个角度定性分析, 确定跑道构型方案比较的评价指标, 分别是跑道容量、地面滑行时间和航班延误, 再采用数学方法计算两种方案下跑道的理论容量, 最后用Simmod软件对两种方案进行仿真分析。根据评价指标比较仿真结果, 可知“3＋1”跑道构型方案较优。同时该结果也可以作为北京新机场跑道构型设计方案比选等相关问题研究的参考。