A web-based platform for the simulation–optimization of industrial problems

This study presents a platform for industrial, real-world simulation–optimization based on web techniques. The design of the platform is intended to be generic and thereby make it possible to apply the platform in various problem domains. In the implementation of the platform, modern web techniques, such as Ajax, JavaScript, GWT, and ProtoBuf, are used. The platform is tested and evaluated on a real industrial problem of production optimization at Volvo Aero Corporation, a company that develops and manufactures high-technology components for aircraft and gas turbine engines. The results of the evaluation show that while the platform has several benefits, implementing a web-based system is not completely straightforward. At the end of the paper, possible pitfalls are discussed and some recommendations for future implementations are outlined.     

Levels of incomplete information in group decision models – A comprehensive simulation study

We present a comprehensive computational study on the effects of providing different forms of incomplete preference information in additive group decision models. We consider different types of information on individual preferences, and on weights of the group members, and study their effects on conclusiveness, efficiency and fairness of outcomes at the group level. Furthermore, we analyze possible violations of the axiom of independence of irrelevant alternatives (IIA) as well as the impact of problem characteristics, in particular initial agreement between group members. Our results indicate that providing information in the form of a ranking of differences between consecutive alternatives comes close to providing exact cardinal preference information in several outcome dimensions. However, group decision procedures based on incomplete preference information also show a significant amount of violations of the IIA axiom.     

MNPBEM – A Matlab toolbox for the simulation of plasmonic nanoparticles

MNPBEM is a Matlab toolbox for the simulation of metallic nanoparticles (MNP), using a boundary element method (BEM) approach. The main purpose of the toolbox is to solve Maxwell?s equations for a dielectric environment where bodies with homogeneous and isotropic dielectric functions are separated by abrupt interfaces. Although the approach is in principle suited for arbitrary body sizes and photon energies, it is tested (and probably works best) for metallic nanoparticles with sizes ranging from a few to a few hundreds of nanometers, and for frequencies in the optical and near-infrared regime. The toolbox has been implemented with Matlab classes. These classes can be easily combined, which has the advantage that one can adapt the simulation programs flexibly for various applications.Program summaryProgram title: MNPBEMCatalogue identifier: AEKJ_v1_0Program summary URL: http://cpc.cs.qub.ac.uk/summaries/AEKJ_v1_0.htmlProgram obtainable from: CPC Program Library, Queen?s University, Belfast, N. IrelandLicensing provisions: GNU General Public License v2No. of lines in distributed program, including test data, etc.: 15 700No. of bytes in distributed program, including test data, etc.: 891 417Distribution format: tar.gzProgramming language: Matlab 7.11.0 (R2010b)Computer: Any which supports Matlab 7.11.0 (R2010b)Operating system: Any which supports Matlab 7.11.0 (R2010b)RAM: ?1 GByteClassification: 18Nature of problem: Solve Maxwell?s equations for dielectric particles with homogeneous dielectric functions separated by abrupt interfaces.Solution method: Boundary element method using electromagnetic potentials.Running time: Depending on surface discretization between seconds and hours.     

A contribution to the real-time simulation of coupled finite element models of machine tools – A numerical comparison

In this paper the real-time simulation of finite element (FE) models of machine tools on a multi-processor architecture is presented. The simulation model is based on several FE component models that are connected by non-linear couplings. These couplings allow relative motions of the components in a wide range. The coupled linear FE models are decomposed at the non-linear coupling nodes and each component is solved locally. The linear structure of the components can be used for efficient simulation methods and the components can be distributed to several processors for a parallel computation. Methods that differ in numerical accuracy and stability, computational effort and real-time capacity will be presented. By means of a complex example, it will be illustrated that a parallel, stable computation can be realized time-deterministically.     

A spatial system dynamic model for regional desertification simulation – A case study of Ordos,China

A spatial system dynamic (SSD) model for simulating desertification was developed by integrating climate, soil water, population, economy, pasturage, and land use. Net Primary Production (NPP) was selected as an intermediate variable to measure the impacts of driving forces and desertification grades. Ordos in China was selected to test the model. Ten scenarios were designed to simulate desertification dynamics in Ordos from 2011 to 2030. The results showed that the SSD model was reliable, and the overall accuracy of desertification degree was approximately 83%. Climate factors had relatively higher sensitivities than other parameters. Although humid climate and sustainable development strategy would reduce desertified land area and desertification degree before 2025, the rapid increase in pasturage pressure would offset this trend. Arid climate and unsustainable development strategy would accelerate desertification expansion. For local government, it is necessary to persist in the present desertification prevention policy and completely banned grazing after 2025.     

Is neglected heterogeneity really an issue in binary and fractional regression models? A simulation exercise for logit, probit and loglog models

Theoretical and simulation analysis is performed to examine whether unobserved heterogeneity independent of the included regressors is really an issue in logit, probit and loglog models with both binary and fractional data. It is found that unobserved heterogeneity has the following effects. First, it produces an attenuation bias in the estimation of regression coefficients. Second, although it is innocuous for logit estimation of average sample partial effects, it may generate biased estimation of those effects in the probit and loglog models. Third, it has much more deleterious effects on the estimation of population partial effects. Fourth, it is only for logit models that it does not substantially affect the prediction of outcomes. Fifth, it is innocuous for the size of Wald tests for the significance of observed regressors but, in small samples, it substantially reduces their power.     

Systems, control models, and codec for collaborative observation of remote environments with an autonomous networked robotic camera

Networked robotic cameras are becoming popular in remote observation applications such as natural observation, surveillance, and distance learning. Equipped with a high optical zoom lens and agile pan-tilt mechanisms, a networked robotic camera can cover a large region with various resolutions. The optimal selection of camera control parameters for competing observation requests and the on-demand delivery of video content for various spatiotemporal queries are two challenges in the design of such autonomous systems. For camera control, we introduce memoryless and temporal frame selection models that effectively enable collaborative control of the camera based on the competing inputs from in-situ sensors and users. For content delivery, we design a patch-based motion panorama representation and coding/decoding algorithms (codec) to allow efficient storage and computation. We present system architecture, frame selection models, user interface, and codec algorithms. We have implemented the system and extensively tested our design in real world applications including natural observation, public surveillance, distance learning, and building construction monitoring. Experiment results show that our frame selection models are robust and effective and our on-demand content delivery codec can satisfy a variety of spatiotemporal queries efficiently in terms of computation time communications bandwidth.

YaDiV��an open platform for 3D visualization and?3D?segmentation of medical data

In this work, we present the concept, design and implementation of a new software to visualize and segment 3-dimensional medical data. The main goal was to create a platform that would allow trying out new approaches and ideas while staying independent from hardware and operating system, being especially useful for interdisciplinary research groups. A special focus will be given on fast and interactive volume visualization, and a survey on the use of Virtual Reality (VR) and especially haptic/force feedback in medical applications will be provided.     

Customer participation,value co-creation and customer loyalty – A case of airline online check-in system

Information communication technologies and self-service technologies, such as self-check-in kiosks or online check-in systems, are widely used in the air transport industry. This study proposes a conceptual model to investigate the relationships among customer participation, co-created values and customer loyalty in an air transport context, and empirically tests the model by using questionnaire survey data collected from Taiwanese airline passengers. In particular, three perceived values (i.e. enjoyment value, economic value and relational value) are specified to represent the passengers' co-created values. The empirical results support the following hypotheses. Customer participation in using an online check-in system is positively related to all three values, which further lead to satisfaction with respect to the system. System satisfaction is also related to satisfaction with respect to the company, and both system satisfaction and company satisfaction have positive effects on customer loyalty.     

DCworms – A tool for simulation of energy efficiency in distributed computing infrastructures

In the recent years, energy-efficiency of computing infrastructures has gained a great attention. For this reason, proper estimation and evaluation of energy that is required to execute data center workloads became an important research problem. In this paper we present a Data Center Workload and Resource Management Simulator (DCworms) which enables modeling and simulation of computing infrastructures to estimate their performance, energy consumption, and energy-efficiency metrics for diverse workloads and management policies. We discuss methods of power usage modeling available in the simulator. To this end, we compare results of simulations to measurements of real servers. To demonstrate DCworms capabilities we evaluate impact of several resource management policies on overall energy-efficiency of specific workloads executed on heterogeneous resources.     

QSIA – a Web-based environment for learning,assessing and knowledge sharing in communities

This paper describes a Web-based and distributed system named QSIA that serves as an environment for learning, assessing and knowledge sharing. QSIA – Questions Sharing and Interactive Assignments – offers a unified infrastructure for developing, collecting, managing and sharing of knowledge items. QSIA enhances collaboration in authoring via online recommendations and generates communities of teachers and learners. At the same time, QSIA fosters individual learning and might promote high-order thinking skills among its users. QSIA's community, conceptual architecture, structure overview and implementations are discussed.     

A subject-specific software solution for the modeling and the visualization of muscles deformations

Today, to create and to simulate a virtual anatomical version of a subject is useful in the decision process of surgical treatments. The muscular activity is one of the factors which can contribute to abnormal movements such as in spasticity or static contracture. In this paper, we propose a numerical solution, based on the Finite Element (FE) method, able to estimate muscles deformations during contraction. Organized around a finite element solver and a volumetric environment, this solution is made of all the modeling and simulation processes from the discretization of the studied domain to the visualization of the results. The choices of materials and properties of the FE model are also presented such as the hyperelasticity, the contention model based on inter-meshes neighboring nodes pairing, and the estimation of nodal forces based on the subject-specific muscular forces and action lines.

Aesthetic design of e-commerce web pages – Webpage Complexity,Order and preference

This study was conducted to understand the perceptual structure of e-commerce webpage visual aesthetics and to provide insight into how physical design features of web pages influence users’ aesthetic perception of and preference for web pages. Drawing on the environmental aesthetics, human–computer interaction, and psychology literature, we identify webpage visual Complexity and Order as two salient webpage aesthetic features and investigate the moderating role of the e-commerce customer’s motivational orientation on his/her preference for web aesthetic features. Two independent samples were recruited and presented with images of 24 homepages varying across six levels of Complexity and four levels of Order. The results of this study suggested significant influences of webpage Complexity and Order on customer’s preference for the web pages and a moderating effect of customer’s shopping motivational orientation on his/her preference for webpage Complexity. However, no moderating effect of motivational orientation was found on the preference for webpage Order.     

The Virtual Laboratory Environment – An operational framework for multi-modelling,simulation and analysis of complex dynamical systems

The cross-disciplinary activity of modelling and simulation is the core of the scientific activities addressing the complexity of nature. In this context, we need reliable computational environments to integrate heterogeneous representations coming from different scientific fields. Therefore, such environments must be able to integrate heterogeneous formalisms in the same model and assist the modeller for the design and implementation of models, the definition of the experimental frames and the analysis of simulation results. The aim of this article is to introduce a tool supporting all these features, the Virtual Laboratory Environment (VLE). VLE is a software and an API which supports multi-modelling, simulation and analysis. It addresses the reliability issue by using recent developments in the theory of modelling and simulation proposed by Zeigler. We present VLE in the context of the modelling and simulation cycle and show the effectiveness of the tool with a multi-model of fireman fighting a fire spread.     

Automatic generation of fabrication drawings for façade mullions and transoms through BIM models

Fabrication drawings are essential for manufacturing, design evaluation and inspection of building components, especially for building façade structural components. In order to clearly represent the physical characteristics of the façade structural components, a large number of section views need to be produced, which is very time-consuming and labor intensive. Therefore, automatic generation of fabrication drawings for building façade components (such as mullions and transoms) is of paramount importance. In this paper, attempts have been made to develop an efficient framework in order to automatically generate fabrication drawings for building façade structural components, including mullions and transoms. To represent the complex physical characteristics (such as holes and notches) on mullions and transoms using minimum number of drawing views, a computational algorithm based on graph theory is developed to eliminate duplicated section views. Another methodology regarding the generation of breaks for top views is also proposed to further improve the quality of drawing layouts. The obtained drawing views are then automatically arranged using a developed approach. In addition, primary dimensions of the drawing views focusing on the physical features are also generated. Furthermore, in order to maintain the consistency of drawing formats across multiple drawings, a methodology is proposed to determine the scaling factors of the drawings by using clustering technique. In an illustrative example, the proposed framework is used to generate the fabrication drawings for a typical BIM model containing façade structural components, and saving in time is observed.     

Design of review systems – A strategic instrument to shape online reviewing behavior and economic outcomes

As online reviews play a decisive role in consumers’ purchase decisions, e-commerce platforms are using review systems strategically to obtain a competitive advantage. However, the strategic potential can only be leveraged if the review system is designed appropriately. Research on the design of review systems and the effects of design choices has not yet been summarized or synthesized in a review article. We aim to close this gap by providing a scoping review. In our synthesis we posit that the design of review systems moderates the impact of online reviews on economic outcomes and the factors that drive the formation of reviews. After reviewing current research findings, we identify gaps and provide a research agenda covering three key themes: Design features, environments, and devices.