A TOPSIS-based QoE model for adapted content selection of slide documents

Multimedia Tools and Applications - In certain platforms, such as Google Docs, documents are adapted for specific mobile device types, and the installation of their applications is required....     

QoE prediction model for mobile video telephony

Interactive online video applications, such as video telephony, are known for their vulnerability to network condition. With the increasing usage of hand-held wireless mobile devices, which are capable of capturing and processing good quality videos, combined with the flexibility in an end-user movements have added new challenging factors for application providers and network operators. These factors affect the perceived video quality of mobile video telephony applications, unlike conventional video telephony over desktop computers. We investigate this impact on video quality of mobile video telephony in varying network conditions and end-users movement scenarios. Based on 312 live traces, we quantitatively derive the correlation between the perceived video quality and the network Quality of Service (QoS) and user mobility. With the results, we develop a Quality of Experience (QoE) prediction model for mobile video telephony using Support Vector Regression techniques. The prediction models display ≈ 0.8 pearson correlation with experimental data. Our methodology and findings can be used to guide the video telephony application providers and network operators to work towards satisfying end-user experience.     

QoE assessment model for multimedia streaming services using QoS parameters

This paper proposes a video QoE (Quality of Experience) assessment model which can assess video quality of experience with only QoS (Quality of Service) parameters and their relative importance at network layer. Since network or service providers can forecast whether to provide multimedia services above a certain level of service quality using the proposed model, they can offer and maintain optimum network environment for multimedia service such as IPTV. Through an experiment of video quality comparison we show that our QoS/QoE correlation model is closely related with video quality degradation patterns to network environmental change.     

Design and experiments on a personal robotic assistant

The design and development of the 'personal robot, i.e. a robot capable of living together with and assisting human beings, is perhaps the main challenge for robotics research and technology in the third Millennium. One of the most intriguing issues in the design of such robot is the definition and implementation of adequate schemes for human-robot interaction. In fact, achieving this goal requires multidisciplinary efforts, and the integration of engineering analysis with psychological, anthropological, ethological and product design considerations. In this paper, the basic concepts to be followed in the design of human-robot interaction are discussed. with reference to a concrete example: the MOVAID personal robot for assistance to disabled and elderly people at home. The MOVAID system was designed taking into careful account as a primary design goal the need for interaction with the human user. A prototype of the MOVAID system has been developed and then successfully validated with disabled end-users. The results of these tests indicate that a personal robot is technically feasible, and is acceptable to users in terms of helpfulness, easiness of use and pleasure of interaction.     

A goal-oriented trust model for virtual organization creation

Virtual organization (VO) is a main organizational paradigm for enterprises to collaborate in the rapidly changing environment. Advances in information and communication technologies are accelerating collaboration among enterprises in different domains as well as unknown enterprises. In this environment, an enterprise faces more chances to cooperate with other enterprises through the internet. Trust is a key concept in many kinds of interactions, allowing an enterprise to act under uncertainty and with the risk of negative consequences. To minimize the operating risk and guarantee the success of a VO, trust evaluation of potential partners should be considered during the partner selection process. However, trust evaluation methods in the literature have limitations in applying them to small and medium enterprises because they are based on evaluation of human experts. In this paper, a goal-oriented trust model is proposed to evaluate the trust values of enterprises. In the context, trust is the probability that a trustee satisfies the goals when it completes assigned tasks. This paper introduces the concept of a goal-oriented trust model with the core constructs of a goal, a project, a task, and a capability. It further addresses an example of applying the proposed model to the partner selection process of a project-based VO creation.     

A virtual competition auction model for perishable products

Online auctions for perishable products have tremendous potentials. However, the current forms of online auctions do not take full advantages of information technology enabled online auctions, and are ineffective for online auctions for perishable products. This study proposes a virtual competition auction model for perishable products. In virtual competition auctions, the bidder is provided with auction historical data, and the bidder’s decision is represented by a demand curve that is composed of a series of bids. A preliminary laboratory experiment based on a prototype of virtual competition auction system is reported. The preliminary laboratory experiment result shows that the virtual competition auction model for perishable products is more effective than the ordinary open-cry auction model.     

A nonparametric regression model for virtual humans generation

In this paper, we propose a novel nonparametric regression model to generate virtual humans from still images for the applications of next generation environments (NG). This model automatically synthesizes deformed shapes of characters by using kernel regression with elliptic radial basis functions (ERBFs) and locally weighted regression (LOESS). Kernel regression with ERBFs is used for representing the deformed character shapes and creating lively animated talking faces. For preserving patterns within the shapes, LOESS is applied to fit the details with local control. The results show that our method effectively simulates plausible movements for character animation, including body movement simulation, novel views synthesis, and expressive facial animation synchronized with input speech. Therefore, the proposed model is especially suitable for intelligent multimedia applications in virtual humans generation.     

A standard manufacturing information model to support design for manufacturing in virtual enterprises

Manufacturing enterprises are being forced into greater collaboration with customers and suppliers in order to produce quality products in smaller batches, shorter lead times and with greater variety. Consequently, the design-for-manufacturing task must be conducted in these virtual and distributed enterprises across traditional organizational boundaries. This paper proposes the use of standard information models to support the product realization process. While extensive work has been performed in developing product data models little effort has been performed in developing a manufacturing model. The design-for-manufacturing stages are identified with their requisite information requirements. Different approaches used to model various aspects of manufacturing processes are reviewed and found inadequate for supporting the entire design-for-manufacturing task. The development of a standard manufacturing systems information model written in EXPRESS and based upon the modelling me thodology adhered to by standard for the exchange of product (STEP) is proposed to fill the void. Initial developments in this area are discussed, the model is illustrated with an example, and the potential benefits to manufacturing are reviewed.     

一种基于QoE效用函数的资源分配算法

针对多用户MIMO-OFDM系统,立足业务体验方,给出了一种最大化用户QoE的资源分配算法.通过设计QoE效用函数,将用户QoE与系统QoS参数关联起来,在发送功率和目标误码率的约束条件下,以最大化用户平均QoE为目标,通过QoE效用函数获取用户当前时刻QoE增量,据此确定用户时频资源分配优先级,进而进行注水功率分配.仿真结果表明,该算法能够充分利用系统资源,有效提高用户平均QoE.     

A new approach to model virtual channels in interconnection networks

Dealing with virtual channels has always been a critical issue in developing analytical performance models for interconnection networks. Almost all previous studies relied on a method proposed by Dally to capture the effect of virtual channels multiplexing in the performance of interconnection networks. This paper presents a new method to model the effect of virtual channel multiplexing in high-speed wormhole-switched interconnection networks. Dally's method loses its accuracy as the traffic load increases due to blocking nature of wormhole-switched networks. Our new method is based on a finite capacity queue, M/G/1/V and comparing to Dally's method achieves a higher degree of accuracy under low, moderate and high traffic loads. Furthermore, its simplicity eases its employment under different network conditions and setup. The presented model is validated by means of an event driven simulator and a detailed comparison with Dally's method is presented.     

A probabilistic measure for model purposiveness in identification for control

The question of whether the identified process model will lead to a stable closed loop is of practical relevance during iterative identification and controller design. It is known that, in the case of overly demanding closed-loop requirements, the model resulting from the iterative procedure might conflict with prior knowledge about the process. Nevertheless, in many cases the violation of the plausibility of the identified models does not necessarily violate its purposiveness. Therefore, it is a matter of practical importance to have a confident indication as to whether the given model will result in a stable closed-loop design or not. If not, the iterative identification and controller design should be stopped, that is more appropriate model structures should be chosen. In this paper, a probabilistic measure is proposed which relies on the estimated model error obtainable by the stochastic embedding technique. The idea behind it is to estimate the probability that the critical point ( -1,0) will not be encircled by the Nyquist curve of the return ratio transfer function of the true system. The results obtained from experiments on a motor-generator laboratory set-up show that the proposed probabilistic measure provides a reliable indication of the stability of the designed closed loop.     

A user model neural network for a personal news service

User modelling has been widely applied to pedantic situations, where we are attempting to infer the user's knowledge. In teaching it is important to know that the user has mastered the elementary concepts before proceeding with the advanced topics. However, the application of user modelling to information retrieval demands a quite different type of user model. Here we construct a user model for browsing, where the user is uncertain of exactly which information he desires. This requires a more inexact and robust user model, that can quickly give guidance to the system. We propose a user model based on neural networks that can be constructed incrementally. Performance of the model shows some promise for this approach. We discuss the advantages and limitations of the approach and its implications for user modelling.     

一种虚拟人追逐过程中的情绪博弈模型

追逐行为在人类社会生活中十分常见,模拟追逐过程中的情绪变化,有助于揭示情绪和运动的关系.在借鉴博弈论的基础上,研究了虚拟人围绕障碍物追逐的情绪博弈模型,依据追逐的剧情,拟定了虚拟人的情绪强度公式,定量描述了虚拟人的速度和体力的变化,提出了追逐过程中虚拟人情绪博弈策略.采用OpenSceneGraph图形库实现了虚拟人追逐动画,实验结果表明,该模型能很好地模拟追逐中虚拟人情绪的变化规律.     

DMM:A dynamic memory mapping model for virtual machines

Memory virtualization is an important part in the design of virtual machine monitors(VMM).In this paper,we proposed dynamic memory mapping(DMM) model,a mechanism that allows the VMM to change the mapping between a virtual machine's physical memory and the underlying hardware resource while the virtual machine is running.By utilizing DMM,the VMM can implement many novel memory management policies,such as Demand Paging,Swapping,Ballooning,Memory Sharing and Copy-On-Write,while preserving compatibility with va...     

Complementary machine intelligence and human intelligence in virtual teaching assistant for tutoring program tracing

This study proposes a virtual teaching assistant (VTA) to share teacher tutoring tasks in helping students practice program tracing and proposes two mechanisms of complementing machine intelligence and human intelligence to develop the VTA. The first mechanism applies machine intelligence to extend human intelligence (teacher answers) to evaluate the correctness of student program tracing answers, to locate student errors, and to generate hints to indicate errors. The second mechanism applies machine intelligence to reuse human intelligence (previous hints that the teacher gave to other students in a similar error situation) to provide program-specific hints. Two evaluations were conducted with 85 and 64 participants, respectively. The evaluation results showed that the system helped above 89% of students correct their errors. The error-indicating hints generated by the first mechanism help students correct more than half of errors. Each teacher-generated hint was reused averagely three times by the second mechanism. The results also revealed that some error situations occurred frequently and occupied a major occurred percentage of student error situations. In sum, the VTA and these two mechanisms reduce teacher tutoring load and reduce the complexity of developing machine intelligence.     

QoE management for video conferencing applications

We introduce a framework for managing the QoE of videos coded with the H.264 codec and transmitted by video conferencing applications through limited bandwidth networks. We focus our study on the medium-motion videos with QCIF, CIF, and VGA resolutions, the most pervasive video formats used by video conferencing applications across the Internet and cellular telephony systems. Using subjective tests for measuring the level of video quality perceived by end users, we expose the relation between the main influential video parameters and the quality experienced by end users. Furthermore, after investigating the effect of different frame rates and compression levels on video streaming bit rate, and consequently on QoE, we propose a QoE control mechanism for limited-bandwidth situations. A congestion control technique is also introduced in this paper and used in simulations for verifying the efficiency of the proposed QoE management algorithm and to implement this algorithm for practical applications.     

A global virtual team model to improve software development collaboration project

Information Systems and e-Business Management - Increasingly, universities across the globe are involved in collaborations at both national and international levels. In a nutshell, the...     

Logistics tool selection with two-phase fuzzy multi criteria decision making: A case study for personal digital assistant selection

Efficient logistics and supply chain management are enabled through the use of efficient information technologies (IT). The mobile logistics tools represent the IT interface in the supply chain. This paper aims to aid decision makers to identify the most appropriate mobile logistics tools and to achieve this aim, several evaluation criteria are identified to evaluate logistics tools, and a fuzzy axiomatic design (FAD) based group decision-making method is adopted to perform the evaluation in two phases. In the first phase of pre-assessment, alternatives that cannot meet basic requirements and the defined threshold are eliminated. In the second phase of selection, the remaining alternatives are more meticulously evaluated. Criteria weights are determined using fuzzy analytic hierarchy process (AHP) and another fuzzy multi-criteria decision-making (MCDM) technique, namely fuzzy technique for order preference by similarity to ideal solution (TOPSIS), is applied in the second phase to compare the outcome of FAD. A case study is provided in order to demonstrate the potential of the proposed methodology. Personal digital assistants (PDAs) with integrated barcode scanner that are available in the Turkish market are evaluated.     

A model of a virtual memory system

Summary We present a queueing network model of a virtual memory computer system including the effect of memory sharing among processes. Page fault and file request system overheads are explicitly taken into account. The fact that some memory pages have to be saved in the secondary memory at the moment of a page fault, is also taken into consideration. We obtain an approximate solution using an equivalence and decomposition approach. The effect of system and program behavior parameters (primary memory size, drum and disk characteristics, program locality, input-output rates and different pages ratios) as well as that of the total number of processes, are examined for two different system organizations. In the first one, all the processes share real core; in the second, processes having issued a file request lose their memory space until the I/O is performed.