scholarly journals Evaluating the Factors Affecting QoE of 360-Degree Videos and Cybersickness Levels Predictions in Virtual Reality

Electronics ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1530
Author(s):  
Muhammad Shahid Anwar ◽  
Jing Wang ◽  
Sadique Ahmad ◽  
Asad Ullah ◽  
Wahab Khan ◽  
...  
Keyword(s):  
Virtual Reality ◽  
Prediction Models ◽  
Safety Concern ◽  
Prediction Method ◽  
Perceptual Quality ◽  
Camera Motion ◽  
End User ◽  
Content Type ◽  
Factors Affecting ◽  
Subjective Experiment

360-degree Virtual Reality (VR) videos have already taken up viewers’ attention by storm. Despite the immense attractiveness and hype, VR conveys a loathsome side effect called “cybersickness” that often creates significant discomfort to the viewers. It is of great importance to evaluate the factors that induce cybersickness symptoms and its deterioration on the end user’s Quality-of-Experience (QoE) when visualizing 360-degree videos in VR. This manuscript’s intent is to subjectively investigate factors of high priority that affect a user’s QoE in terms of perceptual quality, presence, and cybersickness. The content type (fast, medium, and slow), the effect of camera motion (fixed, horizontal, and vertical), and the number of moving targets (none, single, and multiple) in a video can be the factors that may affect the QoE. The significant effect of such factors on end-user QoE under various stalling events (none, single, and multiple) is evaluated in a subjective experiment. The results from subjective experiments show a notable impact of these factors on end-user QoE. Finally, to label the viewing safety concern in VR, we propose a neural network-based QoE prediction method that can predict the degree of cybersickness influenced by 360-degree videos under various stalling events in VR. The performance accuracy of the proposed method is then compared against well-known Machine Learning (ML) algorithms and existing QoE prediction models. The proposed method achieved a 90% prediction accuracy rate and performed well against existing models and other ML methods.

Fluid flow effects on CO2 corrosion: a review of applications of rotating cage methodology

2019 ◽  
Vol 66 (4) ◽  
pp. 507-519
Author(s):  
Jhonatan Jair Arismendi Florez ◽  
Jean Vicente Ferrari
Keyword(s):  
Prediction Models ◽  
Electrochemical Techniques ◽  
Flow Simulation ◽  
Co2 Corrosion ◽  
Salting Out ◽  
Content Type ◽  
Factors Affecting ◽  
Flow Effects ◽  
Steel Flow ◽  
Hydrodynamic Stresses

Purpose Among the many influencing effects that the medium has on the CO2 corrosion of carbon steel, flow is one of the most important because it can determine the formation of corrosion product scales and its stabilisation, thus influencing the attack morphology and corrosion rate. This paper aims to summarise some factors affecting aqueous CO2 corrosion and the laboratory methodologies to evaluate one of the most important, the flow, with an emphasis on less costly rotating cage (RC) laboratory methodology. Design/methodology/approach Regarding the key factors affecting CO2 corrosion, both well-established factors and some not well addressed in current corrosion prediction models are presented. The wall shear stress (WSS) values that can be obtained by laboratory flow simulation methodologies in pipelines and its effects over iron carbonate (FeCO3) scales or inhibition films are discussed. In addition, promising applications of electrochemical techniques coupled to RC methodology under mild or harsh conditions are presented. Findings More studies could be addressed that also consider both the salting-out effects and the presence of oxygen in CO2 corrosion. The RC methodology may be appropriate to simulate a WSS close to that obtained by laboratory flow loops, especially when using only water as the corrosive medium. Originality/value The WSS generated by the RC methodology might not be able to cause destruction of protective FeCO3 scales or inhibition films. However, this may be an issue even when using methodologies that allow high-magnitude hydrodynamic stresses.

scholarly journals End-user involvement in rehabilitation virtual reality implementation research

2019 ◽  
Vol 13 (2) ◽  
pp. 92-100 ◽  
Author(s):  
Rachel Proffitt ◽  
Stephanie Glegg ◽  
Danielle Levac ◽  
Belinda Lange
Keyword(s):  
Virtual Reality ◽  
Research Design ◽  
Implementation Research ◽  
User Involvement ◽  
End Users ◽  
Lessons Learned ◽  
End User ◽  
Content Type ◽  
End User Involvement ◽  
Design And Methods

Purpose Despite increasing evidence for the effectiveness of off-the-shelf and rehabilitation-specific active video games (AVGs) and virtual reality (VR) systems for rehabilitation, clinical uptake remains poor. A better match between VR/AVG system capabilities and client/therapist needs, through improved end-user involvement (UI) in VR/AVG implementation research, may increase uptake of this technology. The purpose of this paper is to review four case examples from the authors’ collective experience of including end users in VR/AVG research to identify common benefits, challenges and lessons learned. Design/methodology/approach The authors apply knowledge and lessons learned from the four cases to make recommendations for subsequent user-engaged research design and methods, including evaluation of the impact of end UI. Findings A better match between VR/AVG system capabilities and client/therapist needs leads to improved end UI in all stages of VR/AVG implementation research. There are common benefits of increasing buy-in and soliciting early on the knowledge and skills of therapists as well as input from the ultimate end users: people participating in rehabilitation. Most settings have the challenges of balancing the technology requirements with the needs and goals of the practice setting and of the end users. Research limitations/implications Increasing end UI in VR/AVG implementation research may address issues related to poor clinical uptake. In the VR/AVG context, end users can be therapists, clients or technology developers/engineers. This paper presented four case scenarios describing the implementation of different VR/AVG systems and involving a variety of populations, end users and settings. Originality/value The set of recommendations for subsequent user-engaged research design and methods span the process of development, research and implementation. The authors hope that these recommendations will foster collaborations across disciplines, encourage researchers and therapists to adopt VR/AVGs more readily, and lead to efficacious and effective treatment approaches for rehabilitation clients.

scholarly journals A Subjective Study on User Perception Aspects in Virtual Reality

2019 ◽  
Vol 9 (16) ◽  
pp. 3384 ◽  
Author(s):  
Huyen T. T. Tran ◽  
Nam P. Ngoc ◽  
Cuong T. Pham ◽  
Yong Ju Jung ◽  
Truong Cong Thang
Keyword(s):  
Virtual Reality ◽  
Perceptual Quality ◽  
Affecting Factors ◽  
Head Mounted Display ◽  
Number Of Factors ◽  
Significant Difference ◽  
Subjective Experiment ◽  
The Difference ◽  
Subjective Study

Three hundred and sixty degree video is becoming more and more popular on the Internet. By using a Head-Mounted Display, 360-degree video can render a Virtual Reality (VR) environment. However, it is still a big challenge to understand Quality of Experience (QoE) of 360-degree video since user experience during watching 360-degree video is a very complex phenomenon. In this paper, we aim to investigate four QoE aspects of 360-degree video, namely, perceptual quality, presence, cybersickness, and acceptability. In addition, four key QoE-affecting factors of encoding parameters, content motion, rendering device, and rendering mode are considered in our study. To the best of our knowledge, this is the first work that covers a large number of factors and QoE aspects of 360-degree video. In this study, a subjective experiment is conducted using 60 video versions generated from three original 360-degree videos. Based on statistical analysis of the obtained results, various findings on the impacts of the factors on the QoE aspects are provided. In particular, regarding the impacts of encoding parameters, it is found that the difference of QoE is negligible between video versions encoded at 4 K and 2.5 K resolutions. Also, it is suggested that 360-degree video should not be encoded at HD resolution or lower when watching in VR mode using Head Mounted Display. In addition, the bitrate for good QoE varies widely across different video contents. With respect to the content motion factor, its impact is statistically significant on the perceptual quality, presence, and cybersickness. In a comparison of two rendering device sets used in this study, there is no statistically significant difference found for the acceptability and cybersickness. However, the differences of the perceptual quality and presence are indicated to be statistically significant. Regarding the rendering mode, a comparison between VR and non-VR modes is also conducted. Although the non-VR mode always achieves higher perceptual quality scores and higher acceptability rates, more than a half of the viewers prefer the VR mode to the non-VR mode when watching versions encoded at the resolutions of fHD or higher. By contrast, the non-VR mode is preferred at the HD resolution.

Fitting and forecasting of nonlinear Taylor rule in China

2015 ◽  
Vol 5 (4) ◽  
pp. 402-420 ◽  
Author(s):  
Guobing Wu ◽  
Hao Zhang ◽  
Ping Chen
Keyword(s):  
Monetary Policy ◽  
Exchange Rate ◽  
Prediction Accuracy ◽  
Prediction Models ◽  
Taylor Rule ◽  
Prediction Method ◽  
Monetary Policies ◽  
Content Type ◽  
Taylor Rules ◽  
Non Linear

Purpose – In this paper, six forms of non-linear Taylor rule have been applied to compare the fitting and prediction of response function of monetary policy of China, in an attempt to figure out a form of non-linear Taylor rule that accords with Chinese practices. The paper aims to discuss this issue. Design/methodology/approach – In this paper, the authors will conduct in-sample fitting and out-of-sample prediction on the response function of monetary policy of China by introducing the factor of exchange rate and by applying forward-looking, backward-looking and within-quarters non-linear Taylor rule with data from the first quarter of 1994 to the second quarter of 2011, with a view to provide reference for formulation and implementation of monetary policies of China. Findings – By analyzing the experimental data, the authors find that first, after introducing the factor of exchange rate, both the implementation effect and prediction ability of the monetary policies improve. Exchange rate has a relatively greater influence on the effect of the monetary policies during low inflation period. Introduction of exchange rate can improve the prediction accuracy of our monetary policies significantly. Second, as the implementation effect of monetary policy under different macro-background varies greatly, the situation should be correctly appraised when formulating and implementing monetary policies. According to the empirical results, the monetary policies have obvious non-linear characteristics, and transit smoothly with the change of inflation rate. On the two sides of inflation rate of 2.174 percent, there is an asymmetry response. Research limitations/implications – Surely, the conclusions are reached on the basis of quarterly data and one-step prediction method. It is no doubt that use of frequency mixing data including quarterly and monthly data will provide more sample information for studying relevant issues. And the use of multiple-step prediction method may cause a dynamic change of prediction indicators of models, which will help choose more appropriate prediction models. That is what the authors will study next. Originality/value – First, by introducing exchange rate, this paper will extend non-linear Taylor rules and test its applicability and fitting effect in China. Second, figure out a non-linear Taylor rule that conforms to Chinese practices with data. In this paper, multiple forms of non-linear Taylor rules and actual macro date will be adopted for fitting and finding out a non-linear Taylor rule that fits Chinese practices. Third, empirical basis will be provided for further perfecting monetary policies prediction models. As there are few studies in connection with the prediction accuracy of non-linear Taylor rules so far, this paper will compare and study the prediction accuracy of non-linear Taylor rules by utilizing multiple advanced prediction techniques, so as to offer a beneficial thinking for predicting and formulating monetary policies by the central bank.

Mobile communication service income prediction method based on grey buffer operator theory

2014 ◽  
Vol 4 (2) ◽  
pp. 250-259 ◽  
Author(s):  
Pinpin Qu
Keyword(s):  
Mobile Communication ◽  
Operator Theory ◽  
Prediction Models ◽  
Prediction Method ◽  
Grey System Theory ◽  
Telecommunication Service ◽  
Communication Service ◽  
Content Type ◽  
Model Based ◽  
The Future

Purpose – The mobile communication industry in China is vulnerable to competition, industry regulation, macroeconomy and so on, which leads to service income's volatility and non-stationarity. Traditional income prediction models fail to take account of these factors, thus resulting in a low precision. The purpose of this paper is to to set up a new mobile communication service income prediction model based on grey system theory to overcome the inconformity between traditional models and qualitative analysis. Design/methodology/approach – At first, mobile telecommunication service income is divided into number of users (NU) and average revenue per user (ARPU) prediction, respectively. Then, grey buffer operators are introduced to preprocess the time series according to their features and tendencies to eliminate the effect of shock disturbance. As a result, two grey models based on GM(1, 1) are constructed to forecast NU and ARPU, and thus the service income is obtained. At last, a case on Zhujiang mobile communication company is studied. The result proves that the proposed method is not only more accurate, but also could discover the turning point of income. Findings – The results are convincing: it is more effective and accurate to employ grey buffer operator theory to predict the mobile communication service income compared with other methods. Besides, this method is applicable to cases with less data samples and faster development. Practical implications – It's common to come across a system with less data and poor information. At this case, the grey prediction method exposed in the paper can be used to forecast the future trend which will give the predictors advice to achieve fine outcomes. Buffer operators can reduce the effect of shock disturbance and the GM(1, 1) model has the advantages of exploiting information using only a couple of data. Originality/value – Considering the fast development of China's mobile communication in recent years, only limited data can be acquired to predict the future, which will definitely reduce the prediction precision using traditional models. The paper succeeds in introducing GM(1, 1) model based on grey buffer operators into the income prediction and the outcome proves that it has higher prediction precision and extensive application.

A Literature Review of Rail Defect Causal Factors

2018 ◽  
Author(s):  
Daniel Milo ◽  
Liana Principe ◽  
Jieyi Deng ◽  
Kang Zhou ◽  
Xiang Liu
Keyword(s):  
Risk Factors ◽  
Prediction Models ◽  
Safety Concern ◽  
Statistical Prediction ◽  
Economic Losses ◽  
Factors Affecting ◽  
Railway Systems ◽  
Explanatory Factors ◽  
Potential Risk Factors ◽  
The Impact

Rail defects are a significant safety concern for the world’s railway systems. Broken rails may lead to the catastrophic derailment of vehicles and have severe consequences including death, injury and economic losses. Precise estimation of the impact of descriptive factors on the occurrence of rail fatigue defects is of great significance for the development of rail defect statistical prediction models. Meanwhile, improvement of prediction models will assist railroads in allocating inspection maintenance resources efficiently. Thus, this paper focuses on reviewing principal risk factors affecting the occurrence of rail defects. A better understanding of the influence of rail defect explanatory factors could aid in model improvement. Previous data collection and analysis in rail defects are highlighted in this review in order to improve the understanding of the impact of potential risk factors. The overview of rail defects aims to aid researchers in improving their understanding of what factors affect the occurrence of rail fatigue defects and how to analyze these factors during the processing of statistical models.

scholarly journals Imperceptible manipulation of lateral camera motion for improved virtual reality applications

2020 ◽  
Vol 39 (6) ◽  
pp. 1-14
Author(s):  
Ana Serrano ◽  
Daniel Martin ◽  
Diego Gutierrez ◽  
Karol Myszkowski ◽  
Belen Masia
Keyword(s):  
Virtual Reality ◽  
Camera Motion

scholarly journals Understanding employee turnover in humanitarian organizations

2016 ◽  
Vol 48 (4) ◽  
pp. 208-214 ◽  
Author(s):  
Rameshwar Dubey ◽  
Angappa Gunasekaran ◽  
Nezih Altay ◽  
Stephen J Childe ◽  
Thanos Papadopoulos
Keyword(s):  
Employee Turnover ◽  
Factor Loading ◽  
Personal Factors ◽  
Related Factors ◽  
Content Type ◽  
Factors Affecting ◽  
Work Related ◽  
Humanitarian Organizations ◽  
Using Data ◽  
High Level

Purpose – At a time when the number and seriousness of disasters seems to be increasing, humanitarian organizations find that besides their challenging work they are faced with problems caused by a high level of turnover of staff. The paper aims to discuss these issues. Design/methodology/approach – Based on the 24 variables leading to employee turnover identified by Cotton and Tuttle (1986) the authors analyse the work-related, external and personal factors affecting employee turnover in humanitarian organizations, using a survey of members of the Indian National Institute of Disaster Management. Findings – Results indicated that the three factors are present. Of the external factors, only employment perception had a factor loading over 0.7; of the work-related factors, all were significant; of the personal factors, biographical information, marital status, number of dependants, aptitude and ability and intelligence had the highest loadings. It was also shown that behavioural intentions and net expectation were not significant. Originality/value – Only a few studies reported on employee turnover and its reasons are not well understood in the context of humanitarian organizations. To address this need, the aim of this paper is to explore the personal reasons impacting employee turnover in humanitarian organizations. In the study the authors have adopted 24 variables used in Cotton and Tuttle (1986) and classified into constructs to explain turnover, and further tested the model using data gathered from humanitarian organizations.

scholarly journals Understanding consumer loyalty to technology-based self-services with credence qualities

2015 ◽  
Vol 29 (6/7) ◽  
pp. 522-532 ◽  
Author(s):  
Lisa Schuster ◽  
Judy Proudfoot ◽  
Judy Drennan
Keyword(s):  
Professional Services ◽  
Content Type ◽  
Consumer Responses ◽  
Factors Affecting ◽  
Behavioral Loyalty ◽  
Behavioral Domain ◽  
Continued Use ◽  
Self Service ◽  
The Impact ◽  
Goal Directed Behavior

Purpose – This paper aims to use the Model of Goal-Directed Behavior (MGB) to examine the factors affecting consumers’ continued use of emerging technology-based self-services (TBSSs) with credence qualities. Professional services, which traditionally require specialized knowledge and high levels of interpersonal interaction to produce owing to their credence qualities, are increasingly delivered via self-service technologies. Health services delivered via mobile devices, for example, facilitate self-care without direct involvement from health professionals. Design/methodology/approach – A mental health service delivered via the Internet and mobile phone, myCompass, was selected as the research context. Twenty interviews were conducted with users of myCompass and the data were thematically analyzed. Findings – The findings of the study showcase the unique determinants of consumers’ continued use of TBSSs with credence qualities relative to the more routine services which have been the focus of extant research. The findings further provide support for the utility of the MGB in explaining service continuance, although the importance of distinguishing between extrinsic and intrinsic motivational components of behavioral desire and capturing the impact of social influence beyond subjective norms is also highlighted. Originality/value – This study contributes to recent research examining differences in consumer responses across TBSSs and behavioral loyalty to these services. It also provides empirical evidence for broadening and deepening the MGB within this behavioral domain.

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