Analyzing the effect of tcp and server population on massively multiplayer games

Many Massively Multiplayer Online Role-Playing Games (MMORPGs) use TCP flows for communication between the server and the game clients. The utilization of TCP, which was not initially designed for (soft) real-time services, has many implications for the competing traffic flows. In this paper we present a series of studies which explore the competition between MMORPG and other traffic flows. For that aim, we first extend a source-based traffic model, based on player’s activities during the day, to also incorporate the impact of the number of players sharing a server (server population) on network traffic. Based on real traffic traces, we statistically model the influence of the variation of the server’s player population on the network traffic, depending on the action categories (i.e., types of in-game player behaviour). Using the developed traffic model we prove that while server population only modifies specific action categories, this effect is significant enough to be observed on the overall traffic. We find that TCP Vegas is a good option for competing flows in order not to throttle the MMORPG flows and that TCP SACK is more respectful with game flows than other TCP variants, namely, Tahoe, Reno, and New Reno. Other tests show that MMORPG flows do not significantly reduce their sending window size when competing against UDP flows. Additionally, we study the effect of RTT unfairness between MMORPG flows, showing that it is less important than in the case of network-limited TCP flows

Analyzing the Effect of TCP and Server Population on Massively Multiplayer Games

Many Massively Multiplayer Online Role-Playing Games (MMORPGs) use TCP flows for communication between the server and the game clients. The utilization of TCP, which was not initially designed for (soft) real-time services, has many implications for the competing traffic flows. In this paper we present a series of studies which explore the competition between MMORPG and other traffic flows. For that aim, we first extend a source-based traffic model, based on player’s activities during the day, to also incorporate the impact of the number of players sharing a server (server population) on network traffic. Based on real traffic traces, we statistically model the influence of the variation of the server’s player population on the network traffic, depending on the action categories (i.e., types of in-game player behaviour). Using the developed traffic model we prove that while server population only modifies specific action categories, this effect is significant enough to be observed on the overall traffic. We find that TCP Vegas is a good option for competing flows in order not to throttle the MMORPG flows and that TCP SACK is more respectful with game flows than other TCP variants, namely, Tahoe, Reno, and New Reno. Other tests show that MMORPG flows do not significantly reduce their sending window size when competing against UDP flows. Additionally, we study the effect of RTT unfairness between MMORPG flows, showing that it is less important than in the case of network-limited TCP flows

Content of Total Phenolics, Flavan-3-Ols and Proanthocyanidins, Oxidative Stability and Antioxidant Capacity of Chocolate During Storage

Antioxidant (AO) capacity of chocolates with 27, 44 and 75 % cocoa was assessed after production and during twelve months of storage by direct current (DC) polarographic assay, based on the decrease of anodic current caused by the formation of hydroxo-perhydroxyl mercury(II) complex (HPMC) in alkaline solutions of hydrogen peroxide at potentials of mercury oxidation, and two spectrophotometric assays. Relative antioxidant capacity index (RACI) was calculated by taking the average value of the AO assay (the sample mass in all assays was identical). Oxidative stability of chocolate fat was determined by differential scanning calorimetry. Measured parameters and RACI were correlated mutually and with the content of total phenols (Folin-Ciocalteu assay), flavan-3-ols (vanillin and p-dimethylaminocinnamaldehyde assay) and proanthocyanidins (modified Bate-Smith assay). During storage, the studied functional and health-related characteristics remained unchanged. Amongst applied AO assays, the DC polarographic one, whose validity was confirmed by two-way ANOVA and F-test, correlated most significantly with oxidative stability (oxidation onset temperature and induction time). In addition, principal component analysis was applied to characterise chocolate types

Antioxidant Activity of Pea Protein Hydrolysates Produced by Batch Fermentation with Lactic Acid Bacteria

Nine Lactobacillus strains known for surface proteinase activity were chosen from our collection and tested for their ability to grow in pea seed protein-based medium, and to hydrolyze purified pea proteins in order to produce peptides with antioxidant (AO) activity. Two strains, Lactobacillus rhamnosus BGT10 and Lactobacillus zeae LMG17315, exhibited strong proteolytic activity against pea proteins. The AO activity of the pea hydrolysate fraction, MW lt 10 kDa, obtained by the fermentation of purified pea proteins with Lactobacillus rhamnosus BGT10, was tested by standard spectrophotometric assays (DPPH, ABTS, Fe3+-reducing capacity) and the recently developed direct current (DC) polarographic assay. The low molecular weight fraction of the obtained hydrolysate was separated using ion exchange chromatography, while the AO activity of eluted fractions was determined by means of a sensitive DC polarographic assay without previous concentration of samples. Results revealed that the fraction present in low abundance that contained basic peptides possessed the highest antioxidant activity. Based on the obtained results, it can be concluded that Lactobacillus rhamnosus BGT10 should be further investigated as a candidate strain for large-scale production of bioactive peptides from legume proteins

QUALINET white paper on definitions of Immersive Media Experience (IMEx)

With the coming of age of virtual/augmented reality and interactive media, numerous definitions, frameworks, and models of immersion have emerged across different fields ranging from computer graphics to literary works. Immersion is oftentimes used interchangeably with presence as both concepts are closely related. However, there are noticeable interdisciplinary differences regarding definitions, scope, and constituents that are required to be addressed so that a coherent understanding of the concepts can be achieved. Such consensus is vital for paving the directionality of the future of immersive media experiences (IMEx) and all related matters. The aim of this white paper is to provide a survey of definitions of immersion and presence which leads to a definition of immersive media experience (IMEx). The Quality of Experience (QoE) for immersive media is described by establishing a relationship between the concepts of QoE and IMEx followed by application areas of immersive media experience. Influencing factors on immersive media experience are elaborated as well as the assessment of immersive media experience. Finally, standardization activities related to IMEx are highlighted and the white paper is concluded with an outlook related to future developments

Lu-Lu: A framework for collaborative decision making games

This paper proposes Lu-Lu as an add-on architecture to open MMOGs and social network games, which has been developed to utilise a key set of ingredients that underline collaborative decision making games as reported within the research literature: personalisation, team matching, non-optimal decision making, leading, decisiveness index, scoring, levelling, and multiple stages. The implementation of Lu-Lu is demonstrated as an add-on to the classic supply chain beer game, including customisation of Lu-Lu to facilitate information exchange through the Facebook games platform, e.g., Graph API and Scores API. Performance assessment of Lu-Lu using Behaviour-Driven Development suggests a successful integration of all key ingredients within Lu-Lu's architecture, yielding autonomous behaviour that improves both player enjoyment and decision making

Technological competence is a precondition for effective implementation of virtual reality head mounted displays in human neuroscience:A technological review and meta-analysis

International audienceImmersive virtual reality (VR) emerges as a promising research and clinical tool. However, several studies suggest that VR induced adverse symptoms and effects (VRISE) may undermine the health and safety standards, and the reliability of the scientific results. In the current literature review, the technical reasons for the adverse symptomatology are investigated to provide suggestions and technological knowledge for the implementation of VR head-mounted display (HMD) systems in cognitive neuroscience. The technological systematic literature indicated features pertinent to display, sound, motion tracking, navigation, ergonomic interactions, user experience, and computer hardware that should be considered by the researchers. Subsequently, a meta-analysis of 44 neuroscientific or neuropsychological studies involving VR HMD systems was performed. The meta-analysis of the VR studies demonstrated that new generation HMDs induced significantly less VRISE and marginally fewer dropouts. Importantly, the commercial versions of the new generation HMDs with ergonomic interactions had zero incidents of adverse symptomatology and dropouts. HMDs equivalent to or greater than the commercial versions of contemporary HMDs accompanied with ergonomic interactions are suitable for implementation in cognitive neuroscience. In conclusion, researchers' technological competency, along with meticulous methods and reports pertinent to software, hardware, and VRISE, are paramount to ensure the health and safety standards and the reliability of neuroscientific results

Fantasy and reality : design for dementia

The subject of this thesis is the medical condition of dementia in its relation to the architecture of care facilities. The world’s population is increasing and with this comes an increase in the proportion of elderly people, and in age-related degenerative diseases. The question of how to accommodate the elderly and frail has become increasingly important in all societies. This project examines the nature of the disease and the way in which occupational therapy and treatment theory has influenced the design of dementia facilities. The process of exploration considers ways in which elements of theory can be integrated into design to create an environment that mitigates disorientations in time and place, and that reduces the personal impacts of dementia. The selection of a suitable site has been influenced by the ideas of a type of therapy known as Reality Orientation (RO), and by the importance in current theory of maintaining a relationship between dementia sufferers and their social context. Consequently the architectural focus of the thesis question has been developed to engage with a design programme that proposes the integration of a care facility for dementia patients in an urban location. Proposed site: Mount Eden Valley section of Dominion Road, Auckland, bound by Valley Road, Dominion Road and Carrick Place