Virtual User Research Articles

Оцінювання якості проектування інтерфейсу користувача віртуальної лабораторії для технічних спеціальностей

Оцінювання якості проектування інтерфейсу користувача віртуальної лабораторії для технічних спеціальностей

Low‐Cost Multisensor Integrated System for Online Walking Gait Detection

A three‐dimensional motion capture system is a useful tool for analysing gait patterns during walking or exercising, and it is frequently applied in biomechanical studies. However, most of them are expensive. This study designs a low‐cost gait detection system with high accuracy and reliability that is an alternative method/equipment in the gait detection field to the most widely used commercial system, the virtual user concept (Vicon) system. The proposed system integrates mass‐produced low‐cost sensors/chips in a compact size to collect kinematic data. Furthermore, an x86 mini personal computer (PC) running at 100 Hz classifies motion data in real‐time. To guarantee gait detection accuracy, the embedded gait detection algorithm adopts a multilayer perceptron (MLP) model and a rule‐based calibration filter to classify kinematic data into five distinct gait events: heel‐strike, foot‐flat, heel‐off, toe‐off, and initial‐swing. To evaluate performance, volunteers are requested to walk on the treadmill at a regular walking speed of 4.2 km/h while kinematic data are recorded by a low‐cost system and a Vicon system simultaneously. The gait detection accuracy and relative time error are estimated by comparing the classified gait events in the study with the Vicon system as a reference. The results show that the proposed system obtains a high accuracy of 99.66% with a smaller time error (32 ms), demonstrating that it performs similarly to the Vicon system in the gait detection field.

Who is in the Room? Notification for Intrusions While in Virtual Reality

The development of head-mounted display virtual reality systems (e.g., Oculus Rift, HTC Vive) has resulted in an increasing need to represent the physical world while immersed in the virtual. Current research has focused on representing static objects in the physical room, but there has been little research into notifying VR users of changes in the environment. This study investigates how different sensory modalities affect noticeability and comprehension of notifications designed to alert head-mounted display users when a person enters his/her area of use. In addition, this study investigates how the use of an orientation type notification aids in perception of alerts that manifest outside a virtual reality users’ visual field. Results of a survey indicated that participants perceived the auditory modality as more effective regardless of notification type. An experiment corroborated these findings for the person notifications; however, the visual modality was in practice more effective for orientation notifications.

A Study on the Strategies of Developing the Autonomous Human Social Behavior of Virtual Users Based on Psychological Interpretation in an Atypical Architectural Shape

A Study on the Strategies of Developing the Autonomous Human Social Behavior of Virtual Users Based on Psychological Interpretation in an Atypical Architectural Shape

A QoS Ensuring Two-Layered Multi-Attribute Auction Mechanism to Mitigate DDoS Attack

Incentives are very important to be employed in any defensive mechanism against DDoS attack. Incentive is a major concept abandoned by most of the defensive mechanisms that have been proposed so far. It is a tool that can motivate users to send data wisely into the network. Therefore, in this paper, we have proposed a two layered multi-attribute auction mechanism for incentivising users by imposing payment schemes as well as by providing rewards. Apart from this, we have developed a reputation assessment procedure to identify malicious user by monitoring his credibility score calculated through his marginal utility. Identified malicious users are then mapped to different levels of suspiciousness. Identified legitimate users are forwarded towards first level of auction in which virtual users have been added by service provider to increase the competition among users. Critical values are computed for every user and the users satisfying the criteria are moved towards the second level. In second level, greedy method is utilized for resource allocation. Extensive simulations have been conducted on MatLab to check the validity of the proposed model. Rate of social welfare degradation and user’s satisfaction are utilized to check the appropriateness and validity of the model. Results from experimentation have shown that proposed model is able to generate enough revenue for the service provider and is able to provide acceptable QoS to identified legitimate users when there is an increase in number of malicious users.

On Coded Caching With Private Demands

Caching is an efficient way to reduce network traffic congestion during peak hours by storing some content at the user’s local cache memory without knowledge of later demands. For the shared-link caching model, Maddah-Ali and Niesen (MAN) proposed a two-phase ( placement and delivery ) coded caching strategy, which is order optimal within a constant factor. However, in the MAN coded caching scheme, each user can obtain the information about the demands of other users, i.e., the MAN coded caching scheme is inherently prone to tampering and spying the activity/demands of other users. In this paper, we formulate an information-theoretic shared-link caching model with private demands, where there are ${\mathsf K}$ cache-aided users (which can cache up to ${\mathsf M}$ files) connected to a central server with access to ${\mathsf N}$ files. Each user requests ${\mathsf L}$ files. Our objective is to design a two-phase private caching scheme with minimum load while preserving the information-theoretic privacy of the demands of each user with respect to other users. A trivial solution is the uncoded caching scheme which lets each user recover all the ${\mathsf N}$ files, referred to as baseline scheme . For this problem we propose two novel schemes which achieve the information-theoretic privacy of the users’ demands while also achieving a non-trivial caching gain over the baseline scheme. The general underlying idea is to satisfy the users’ requests by generating a set of coded multicast messages that is symmetric with respect to the library files, such that for each user k, the mutual information between these messages and the demands of all other users given the cache content and the demand of user k is zero. In the first scheme, referred to as virtual-user scheme, we introduce a number of virtual users such that each ${\mathsf L}$ -subset of files is demanded by ${\mathsf K}$ real or virtual (effective) users and use the MAN delivery to generate multicast messages. From the viewpoint of each user, the set of multicast messages is symmetric over all files even if each single multicast message is not. This scheme incurs in an extremely large sub-packetization. Then, we propose a second scheme, referred to as MDS-based scheme, based on a novel MDS-coded cache placement. In this case, we generate multicast messages where each multicast message contains one MDS-coded symbol from each file in the library and thus is again symmetric over all the files from the viewpoint of each user. The sub-packetization level of the MDS-based scheme is exponentially smaller than that needed by the virtual-user scheme. Compared with the existing shared-link coded caching converse bounds without privacy, the virtual-user scheme is proved to be order optimal with a constant factor when ${\mathsf N}\leq {\mathsf L} {\mathsf K} $ , or when ${\mathsf N}\geq {\mathsf L} {\mathsf K} $ and ${\mathsf M}\geq {\mathsf N}/ {\mathsf K}$ . In addition, when ${\mathsf M}\geq {\mathsf N}/2$ , both of the virtual-user scheme and the MDS-based scheme are order optimal within a factor of 2.

Effects of Human Behavior Simulation on Usability Factors of Social Sustainability in Architectural Design Education

While the social sustainability of built environments is an essential aspect of architectural design education, systemic experiments still lack empirical pedagogy. Therefore, factors of social sustainability are hardly reflected in students’ projects seamlessly. To overcome such limitations, this study investigates the applicability and effectiveness of human behavior simulation. To ensure authentic architectural design, the projects were equipped with autonomous, rational anthropomorphic computer agents called virtual users (VUsers). This study compared the performance scores on social sustainability factors, assessed by the students who conducted design projects both before (without) and after (with) using the simulation. A one-way analysis of variance indicated that human behavior simulation promoted the performance of projects with respect to the parameters of accessibility and safety, ergonomic usability for heterogeneous users and supportability of social interactions. However, the simulation was not found to be effective in promoting the physical attractiveness of built environments and in ensuring the completeness of design solutions. Based on previous studies, the present study interpreted the reasons why the operability of VUsers and built environments, representations of emerging interactions of VUsers and whole-and-part analytics promoted explicit experimentation, but the factors of physical attractiveness and completeness were irrelevant to the rational examinations in the use of the simulation.

Preference relation based collaborative filtering with graph aggregation for group recommender system

Most of the group recommender systems (GRS) apply some aggregation strategy to the ratings given by the group members for generating recommendations. But this can be highly influenced by a few members of the group, which can lead to poor group recommendation. Further, rating based aggregation strategies do not provide efficient ranking of items. Keeping these things in mind, this paper proposes a preference relation (PR) based GRS, that uses matrix factorization (MF) for predicting unknown PRs for group members. The aggregation of preferences is done using a novel virtual user based weight aggregation strategy. The weight aggregation concept is derived from the graph aggregation process. The advantage of this process is that it does not ignore weak preferences and also contributes towards group recommendation. The proposed model is evaluated and compared using standard ranking measures for MovieLens and NetFlix datasets. Experimental results obtained using Top-K recommendation task indicates the superiority of the proposed GRS method over the others. The proposed GRS model provides the best performance when we balance the number of member in a group and the number of recommended items.

Escala de Conductas Parentales Ante el Uso de Tecnología en Adolescentes

El uso de la tecnología se ha incrementado alrededor del mundo, en México hay 71.3 millones de usuarios, siendo niños y adolescentes, el segundo grupo que más accede a Internet, a su vez se originan diversos peligros y riesgos. Por lo tanto, la familia es un factor protector que permite regular, supervisar y guiar el contenido virtual. El objetivo del presente estudio fue confirmar la estructura factorial psicométrica de la escala de conductas parentales ante el uso de tecnología en adolescentes. Participaron 594 adolescentes de la Ciudad de México. Los resultados indicaron que el modelo pertinente a las prácticas de la mamá mostró índices de ajuste aceptables: CFI = .930; IFI = .931; NFI = .897 y RMSA = .056; al igual que el del papá: CFI = .961; IFI = .961; NFI = .943 y RMSA = .059. Se cumplieron criterios de normalidad, asimismo, los reactivos tuvieron estimaciones paramétricas arriba de .50, y presentaron índices de consistencia interna Alpha de Cronbach arriba de .70. Se concluye que la escala cumple con las propiedades psicométricas aceptables y permite evaluar la percepción de los adolescentes, sobre el comportamiento de sus padres frente al uso de internet.

Energy Efficiency and User Capacity Optimization of Cognitive MIMO Systems Via the SCMA-Based Nonorthogonal Time Slot Allocation

This paper investigates the energy-efficient communications and user capacity in the cognitive multiple input multiple output (MIMO) symmetric system of underlay mode. The advantage of the improved energy efficiency provided by the orthogonal slot allocation for time division multiple access (TDMA) has a side effect of restricting the number of users accessing the system. To tackle the above problem, this paper proposes a nonorthogonal time resource allocation method with sparse code multiple access (SCMA), which allows one to convert the orthogonal slot units of TDMA into non-orthogonal shared slot units for multiple secondary users (SUs). The method of adding virtual users is adopted, wherein each SU is treated as multiple SUs who occupy a shared unit, to facilitate the packet access. Finally, the greedy algorithm is applied to optimize the time slot allocation of unoccupied shared slot units. The simulation results show that SCMA-based nonorthogonal slot allocation can reduce not only the energy consumption by nearly 40%, but also the average power interference from SUs to primary users by nearly 2 dB if their number is relatively high. Moreover, in the case of satisfying the rate requirement of the users, the system user capacity increased by more than 50%.

Developing an autonomous psychological behaviour of virtual user to atypical architectural geometry

ABSTRACT In order to meet increasing social demand for atypical buildings and spaces, architects must be able to design an atypically shaped building. However, such design outcomes and processes often ignore the central element of architecture—namely, the human factor. In this context, virtual users (VUsers) are regarded as a suitable solution to this problem. In the previous field research, we investigated users' behaviors in atypical architectural spaces and the psychological reasons of behaviors. In this study, we focused on the computerization and systematic integration of the results of the previous research in order to develop a technology that automatically creates a space where user behavior can be expressed in atypical architectural designs and where VUsers can exhibit psychologically appropriate behaviors. This study suggests how to create the appropriate trigger spots, trigger viewpoints, and behavioral areas which guide VUsers' autonomous behavior in the virtual environment. We also integrated the results of this study into ActoViz, a user-behavior simulation system. Based on this study, further research will advance ActoViz, a human behavior simulation system based on intelligent agents which can behave freely within the designed atypical architectural geometry.

Transformation of University Libraries During the Digital Era

The paper considers the transition period of society development, based on the use of digital information and communication technologies. Now the digital economy covers all the spheres of society, so the question of its study is relevant. The transition to a new digital economy model contributes to improving the life quality of the population. In higher education institutions educational paths are changing, a rapid transition from physical to virtual reality is observed. However, the educational environment lags far behind the pace of industrial production based on modern technologies. In such situation, approaches to modernizing the training system need to be developed. This case university strategies, aimed at creating a full environment for the development of education and science, information and knowledge from the intellectual global environment, are being developed. In the context of the transition to digital technologies in education, the library, as one of the main structural divisions of the university, should also become digital. The paper reveals the different viewpoints of the library community that show the strategy and direction of library development for the digital environment. Libraries are now actively developing information and communications technology providing services to their users, while maintaining traditional forms and methods of working with readers. This symbiosis meets the needs of different groups of readers and users. On the basis of theoretical research of formation processes and development of electronic library, problems of transition period are considered, strategy of digital library development is identified, technologies of creation and introduction of information resources into university educational environment are determined. The purpose of the research was to study the activity of using information resources in the educational process and research activities, in order to improve the quality of service to library users. It will identify the attitudes of students towards information resources and library services. The relevance and importance of the transition to the digital library is noted, the impact of this process on the development of all library activities is analysed, while maintaining the continuity of its main functional purpose. In addition, the emergence of new social and technological tasks is indicated, the specifics of working with digital users are distinguished. The library works with both virtual users and real readers. Book loan and electronic resources to users are analyzed. The library’s activities are covered in educational and leisure activities with university students and teachers. In the article, the recommendations presented will improve the efficiency of the library

Physics-related companies report mostly mild economic symptoms from COVID-19

Most makers of research tools for physical scientists report stable business. Some of their products are being used in the fight against the novel coronavirus.

Virtual user pairing based non‐orthogonal multiple access in downlink coordinated multipoint transmissions

In this study, joint transmission coordinated multi-point (JT-CoMP) is integrated with virtual user pairing based non-orthogonal multiple access (VP-NOMA), termed as JT-CoMP VP-NOMA. JT-CoMP is a multi-cell coordination scheme, where base stations of neighbouring cells coordinate with each other to improve the performance of their common cell edge users (CEUs). On the other hand, VP-NOMA is a one-to-many user pairing scheme in non-orthogonal multiple access (NOMA), where one cell centre user (CCU) within a cell can be paired/multiplexed with multiple CEUs for better spectrum utilisation. The proposed scheme combines both VP-NOMA for enhancing ergodic sum capacity (ESC) within a cell and JT-CoMP for mitigating inter-cell interference (ICI) between neighbouring cells. To demonstrate the achieved performance gains, ESC of a three-cell scenario is analysed as a key performance metric, where each cell contains two users; a CCU and a CEU. Closed-form expressions for ESC of the considered system are derived, and validated through simulations. Furthermore, the analytical and simulation results of JT-CoMP VP-NOMA are compared with orthogonal multiple access, NOMA, and VP-NOMA to show the achieved performance gains. It is shown that the proposed JT-CoMP VP-NOMA outperforms the other schemes in the viewpoint of ESC.

Random group recommendation model based on fuzzy clustering

The group recommendation system is a viral requirement for the Internet service provider to provide recommendation services for all the users in a group. Due to the shared or different interests among users in the group, it is difficult for traditional personal recommendation algorithms to predict items that can meet the requirements of all the users in the group. In this paper, a random group recommendation model is proposed to recommend the top K most appealing items for all the users in a random group. By analyzing item ratings of all the users in the group, the recommendation model can abstract the group as a virtual user. Then a personal recommendation algorithm is applied to suggest the top K most appealing items for the virtual user. And the preference score and fuzzy clustering algorithm based on multiclass are applied to optimize the recommendation result of the group recommendation model. Finally, the MovieLens-100K dataset is applied to verify the efficiency of the recommendation model. The experimental results show that the items recommended by the proposed group recommendation model are more popular for all the users in the group than the items recommended by traditional group recommendation algorithms.

Nebengin: Android-based Collaborative Transportation Application

Online transportation services are transportation services that take advantage of advances in information technology. In Indonesia, several online transportation service providers have grown, such as Gojek, Grab and several other startup startups. In addition to the many benefits and conveniences that have been provided, the service price factor is still felt expensive for the community, especially the lower classes. One solution is to build a Collaborative Transportation Application that utilizes the Collaborative Transportation Management (CTM) interaction method. The main features contained in the application, namely the feature of finding driver routes in the direction of the consumer route, online chat, and route management by utilizing the Android mobile application based on Google Map API and Firebase Cloud Messaging. Performance testing using JMeter from a total of 300 virtual users performs 6 HTTP requests resulting in an average response time of 0.852 alias tolerated according to Apdex standards. Based on the results of testing of 15 respondents obtained the results that this application is easy to use, supports traveling activities, fast response time when used, features provided are quite complete, an accurate position tracking system, unidirectional route search is very compatible with consumer routes, and the process of coordination and driver collaboration is very good so that the travel costs borne by consumers become more economical..

System of scientific and information support of agricultural complex of Ukraine

The article analyzes the current state of information resources formed at different levels of government. The characteristics of the national system of scientific and technical information on agriculture are presented. It is stated that the main users of scientific and technical information in the field of agriculture are the following three categories, selected according to the nature of activity: scientists; commodity producers; executives, managers. Features of their information support are given. It is noted that among the sectoral information systems, information systems play an important role in the development of the agro-industrial complex of the country: the Ministry of Economy, Trade and Agriculture of Ukraine, Ministry of Education and Science of Ukraine, National Academy of Agrarian Sciences of Ukraine and the systems of their subordinate organizations and institutions, as well as agricultural libraries, advisory services, UkrINTEI, State Enterprise "Ukrainian Research and Training Center for Standardization, Certification and Quality", the State Statistics Committee, industry associations, information portals and others. Together, they form an integrated information system. Effective and high-quality provision of information needs of agricultural specialists is impossible without the information resources, which are traditionally handled by the agricultural libraries headed by the National Scientific Agricultural Library (NSAL) of the National Academy of Sciences of Ukraine. The main priority of the latter is the disclosure and presentation of existing documents, as well as access to a wide range of physical and virtual users. In this direction, the active creation of its own electronic database "online catalog Ukragroteka" is active, with a total volume of more than 550 thousand records, of which 52 thousand — full-text publications. The tasks for the creation of the national agricultural bibliography, presented by 13 biobibliographic series, are successfully implemented. Since 1999 the systematic quarterly abstract journal "Agroindustrial Complex of Ukraine" has been published quarterly.

Non-orthogonal multiple access in downlink coordinated multipoint transmissions

In this paper, a joint transmission coordinated multi-point based non-orthogonal multiple access (JT-CoMP NOMA) combined with spatial modulation (SM), termed as JT-CoMP NOMA-SM, is proposed to enhance capacity. User capacity and ergodic sum capacity (ESC) of K coordinated multi-point base stations (CoMP BSs) within N number of cells are analyzed by considering imperfect successive interference cancellation (SIC) and imperfect channel state information (CSI). The performances of the proposed system are compared with orthogonal multiple access (OMA), non-orthogonal multiple access (NOMA), and joint transmission coordinated multi-point combined with virtual user pairing based non-orthogonal multiple access (JT-CoMP VP-NOMA) through both simulation and analysis. The results show that the proposed system has the same cell center user (CCU) capacity compared to JT-CoMP VP-NOMA and a higher cell edge user (CEU) capacity than the other schemes. ESC of the proposed system outperforms the other schemes due to enhancing CEU capacity. Imperfect SIC and imperfect CSI may degrade capacity. To achieve an optimal capacity, the power allocated for CCU should be increased if the transmit signal-to-noise ratio (SNR) is reduced. The proposed system can maintain CEU capacity better than the other schemes if the number of cells is increased. It happens because SM works beyond Shannon upper bounds, which can mitigate inter-cell interference (ICI).

Simulation Framework for Evaluation of Indoor Navigation Systems

In this paper, we introduce the first simulation framework that provides cost-effective means to evaluate indoor navigation systems for different user groups (e.g., users with visual impairment), various positioning techniques, and navigation instructions algorithms. The simulation engine uses the Unity game engine, which tracks the virtual user interaction and motion in a virtual environment that represents the physical environment in which the user navigates. The framework includes the following modules that will be defined by the indoor navigation system developers: 1) Positioning module which simulates indoor localization techniques and their observed accuracy; 2) Indoor navigation algorithm module that generates the navigation instructions using natural language phrases, and 3) Virtual user model (VUM) that includes human perception and information processing that can understand navigation instructions, perceive the surrounding environment, and act based on this information. The framework also includes a performance analysis module that evaluates the indoor navigation system performance in terms of navigation success rate and route similarity.

Smart library: Need of 21st Century

Today technology had made an impact on all sectors. Not any sector of the world can be run without technology, as it reduced human efforts and work smoothly. We can find and access information from wherever we are and whenever we want. “The term “Smart Library” has recently been used more frequently, for labelling a vision of libraries of the future, in particular as part of the so called “Smart City” concept. This concept addresses the integration of digital processes and informational feedback loops in the public infrastructure and claims this integration to be a desirable state, in which cities become “smarter”, i.e. more efficiently organized, resource-friendly, flexible, sustainable, green, and socially inclusive”1. “The concept “smart library” appears in various contexts, as a synonym for the concept “intellectual library”. Such phrases as “digital library” and “virtual library” can also be found. The term “smart” means “flexible, adaptive, extendible, acknowledging and human”. Smart library is a hardware and software complex with a wide range of opportunities for searching and providing necessary information to virtual users according to their inquiries and requirements. Smart libraries make the user available of access to library information from mobile devices. The services of smart libraries are delivered to the user via smart phones, internet and other handheld gadgets. Smart libraries have to focus on innovation of library services to reach all library users through mobile devices. Smart libraries provide advanced services such as computer-aided design, hypertext services, knowledge mining services, and personalized services, cross-media services which make the library more active, professional and intelligent. In this descriptive approach of the paper authors highlights the smart concept of smart library architecture, IoT based library services which included Cloud computing, RFID, Magic Mirrors, and Pressure pad sensors services and ICT based library services in presents scenario in-consist with Digital Library, Institutional Repository services, Library 2.0 and Reprographic, Micrographic & Digital Scanning Service.