DOI: 10.3897/jucs.108446

Authors: Shanshan Jia, Gaukhar A. Kamalova, Dmytro Mykhalevskiy

Abstract: The importance of the topic under investigation stems from the burgeoning prominence of the Internet of Things (IoT) paradigm and the consequent imperative to devise and institute an efficacious methodology for neighbour detection that facilitates supplementary connections to mobile nodes. This research primarily aims to elucidate a mobile handover technique aligning with the neighbour discovery paradigm inherent in 6LoWPAN. The methodological framework employed herein amalgamates a systematic analysis of the foundational tenets governing 6LoWPAN communication standards over the IPv6 protocol in the context of IEEE 802.15.4aa personal wireless networks, supplemented with empirical evaluation of message propagation dynamics among discrete nodes of a designated personal wireless network. The findings of this investigation underscore the pre-eminence of the 6LoWPAN networking standard as a prime vehicle for bolstering the dependable communication of IoT's remote entities, contingent upon the utilization of the IPv6 communication protocol. This iteration of the Internet protocol is superior, particularly in surveillance contexts, given its expansive address capacity (128 bits) juxtaposed against its antecedent, the IPv4 protocol (32 bits). The inherent adaptability of this network connection augments the quality of mobile handover, especially when one considers the real-world application of 6LoWPAN's neighbour discovery auxiliary communication standard. The tangible implications of these findings beckon their potential utility in satiating the demands of IoT system users and actualizing the network collaboration ethos intrinsic to the 6LoWPAN communication standard.

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DOI: 10.3897/jucs.90663

Authors: Venilton FalvoJr, Anderson da Silva Marcolino, Nemésio Freitas Duarte Filho, Edson OliveiraJr, Ellen Francine Barbosa

Abstract: The popularity of mobile devices in all social classes has motivated the development of mobile learning (m-learning) applications. The existing applications, even having many benefits and facilities in relation to the teaching-learning process, still presents problems and challenges, es- pecially regarding the development, reuse and architectural standardization. Particularly, there is a growing adoption of the Software Product Line (SPL) concept, in view of research that investigates these gaps. This paradigm enables organizations to explore the similarities and variabilities of their products, increasing the reuse of artifacts and, consequently, reducing costs and development time. In this context, we discuss how systematic reuse can improve the development of solutions in the m-learning domain. Therefore, this work presents the design, development and experimental evaluation of M-SPLearning, an SPL created to enable the systematic production of m-learning applications. Specifically, the conception of M-SPLearning covers from the initial study for an effective domain analysis to the implementation and evaluation of its functional version. In this regard, the products have been experimentally evaluated by industry software developers, pro- viding statistical evidence that the use of our SPL can speed up the time-to-market of m-learning applications, in addition to reducing their respective number of faults.

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DOI: 10.3217/jucs-025-10-1221

Authors: K. Shankar, Mohamed Elhoseny

Abstract: In wireless communication, Mobile Ad Hoc Network (MANET) consists of a number of mobile nodes which are communicated with each other without any base station. One of the security attacks in MANETs is Packet forwarding misbehaviour attack; this makes MANETs weak by showing message loss behavior. For securing message transmission in MANET, the work proposes Energy Efficient Clustering Protocol (EECP) with Radial Basis Function (RBF) based CH is elected for formed Clusters. Moreover, here some Network measures are considered to detect the malicious nodes and CH model that is speed, mobility, trust and so on. The trust value of the node is computed from the neighbor node which helps in further location to find a malicious node in the network to avail message drop and energy consumption (EC). After detecting malicious nodes, Multi secure Protocols that is Secure Efficient Distance Vector Routing (SEDV) and Secure Link State Routing Protocol (SLSP) with encryption technique used for message security. If the" HELLO" message sending by the sender, its encrypted and decrypted triples in receiver end to get the plain message, this technique is Triple Data Encryption Standard (TDES). Finally, the implementation results are evaluated to analyze the message security level of the proposed system in MANET in terms, of Packet to Delivery Ratio (PDR, Network Life Time (NLT) and some other important Measures.

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DOI: 10.3217/jucs-024-03-0277

Authors: Yuanyuan Qiao, Yan Wu, Yaobin He, Libo Hao, Wenhui Lin, Jie Yang

Abstract: We are facing an era of Online With Offline (OWO) in the smart city - almost everyone is using various online services to connect friends, watch videos, listen to the music, download resources, and so on. Our online behaviors are separated by different domains, which may cause serious problem in the area of cross-domain recommendation, advertising, and criminal tracking in online and offline world, since it is a very challenging task to link user online behaviors belonging to the same natural person. Existing methods usually tackle user online behavior linkage problem by estimating the profile content similarity between two different online services. However, the profile contents in heterogeneous online services are unreliable or misaligned, and the proposed methods are always limited to several services in a specific domain. In order to link individual's online behavior across domains, in this paper, we propose user Online Behavior Linkage across Domains (OBLD), a novel hybrid model, to link user online behavior across domains with Internet traffic. It derives several signifficant attributes from users' online behaviors, such as user digital identity, various fingerprints of terminals and browsers, spatio-temporal behavior of users, and leverages a supervised classi_cation method to discover the relationship between users' online behaviors. Also, the proposed model has unsupervised setting for dataset with non or few label data if a certain percentage of user digital identities can be extracted from original dataset. By using real-world network traffic collected from two large provinces in China, we evaluate the OBLD model and the linkage precision achieves 89% and 97.9% for two datasets respectively. Especially, the inputs of OBLD, i.e., network traffic flows, cover all online behavior of users who connect with Internet through monitored networks, which makes it possible to link online behaviors of users in whole online world.

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DOI: 10.3217/jucs-024-02-0108

Authors: Bibeg Limbu, Halszka Jarodzka, Roland Klemke, Fridolin Wild, Marcus Specht

Abstract: Augmented reality and sensor technologies have been analysed extensively in several domains including education and training. Although, varieties of use cases and applications exist, these studies were conducted in controlled laboratory environments. This paper reports on the first user study of augmented reality prototype developed to support students to learn from trainers in professional domains using augmented reality and sensors. The prototype records the performance of trainers in the first phase to support students by making it available during practice in the second phase. The performance data is made available to both the students and trainers in the third phase for reflection. A total of 142 participants which included trainers and students from three professional domains, namely 1) aircraft maintenance 2) medical imaging and 3) astronaut training, evaluated the prototype. The trainers used the prototype to record their performance while the students used the prototype to learn from the recorded performance. Participants from the three professional domains evaluated the usability of the prototype by means of a questionnaire. Randomly selected participants were also interviewed to collect their opinions and suggestion for further usability improvement. Furthermore, they also evaluated the implementation of the instructional design methods, which were identified prior in a literature review, with a brief questionnaire. The questionnaire was designed to measure the acceptance of the implementation of instructional design methods and to evaluate its adherence to the authors definition. The results of this study show that the usability of the prototype is below expected standard acceptable level. The results of the questionnaire on the implementation of the instructional design methods varied show above average acceptance levels by both the trainers and the students in the three professional domains. To conclude, the prototype shows potential to be used in different domains to support expertise development.

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DOI: 10.3217/jucs-023-12-1147

Authors: Edgar Marçal, Rossana Maria de Castro Andrade, Windson Viana

Abstract: While field trips promote the scientific spirit of students by increasing their ability of observation and discovery in various areas of knowledge, the introduction of ubiquitous technologies, such as sensors and actuators, during the field trips, improves students' motivation and learning. However, the development of systems for this purpose implies to deal with the seamless treatment of the devices heterogeneity, absence of fixed communication infrastructure, dynamics of the computational elements of the environment, and support for user mobility. This paper presents then the development and evaluation of a system, called Ubiquitous Field Classes Inventor (UFC-Inventor), which aims to promote the use of mobile and ubiquitous technologies in field trips. The UFC-Inventor evaluation is performed in two stages: first, with five teachers of natural sciences; and later, during a field trip with seventeen students. Two of the teachers were from higher education (Geology and Animal Science) and three of them from high school (two in Geography and one in Biology). The seventeen students who participated in the case study were undergraduate students in the third year of their Geology course. The results suggest a good acceptance of UFC-Inventor and indicate that its execution occurred correctly.

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DOI: 10.3217/jucs-022-08-1123

Authors: Guilherme Melo e Maranhão, Renato Bulcão-Neto

Abstract: A great challenge in context-aware computing is dealing with the heterogeneity and volume of sensors data. A problem regarding that scenario is to notify context-aware applications, which have distinct interests of context events in terms of volume, semantic and complexity, in an efficient and relevant manner. Aiming to solve this problem, this research focuses on a new approach for filtering semantic context towards supporting context dissemination. This mechanism is to be aligned with the reasoning capabilities of a context-aware solution and also be maintainable and extensible to efficiently support changes in an ontological model. A performance evaluation is carried out in a simulated scenario of vital signs monitoring in Intensive Care Units and wards. Hermes Interpreter's behaviour is analysed when dealing with filters of different complexities and also an increasing number of subscribers per vital sign. Results demonstrate the high cost of the semantic filtering mechanism in comparison with pure context reasoning activities.

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DOI: 10.3217/jucs-021-07-0959

Authors: Andreea Molnar, Cristina Muntean

Abstract: When using mobile phones for learning purpose, video content is considered to be the preferred type of multimedia content. However, the video file has a big size in comparison to text or audio and might lead to a high delivery cost when transmitted over a mobile network, a cost that not all users are willing to pay. Concerns regarding the monetary cost for accessing data content through mobile networks have been raised by various researchers. A solution that considers the user preference for trading off between video quality and price in order to reduce the content delivery cost is presented. This paper also evaluates the proposed solution and presents the results of an experimental study that assesses the video content adaptation impact on information assimilation. The results show that although video quality is reduced information assimilation is not negatively affected by the adaptation. This holds true regardless of the mobile device used in the study.

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DOI: 10.3217/jucs-020-12-1649

Authors: Jorge Luis Victória Barbosa, Débora Nice Ferrari Barbosa, Jezer De Oliveira, Solon Andrade Rabello Jr.

Abstract: This article proposes a decentralized infrastructure for ubiquitous learning environments called Global. The two main contributions of Global are its decentralized strategy and its extensible architecture based on software agents. Global can be specialized to create ubiquitous learning environments through the extension of its agents or through the addition of new agents. The article presents the infrastructure architecture, describing the agents and auxiliary components. Moreover, the article approaches the implementation and evaluation of Global through two applications dedicated to education. The evaluation showed that the infrastructure could be used for the development of decentralized learning systems, supporting specifically the characteristics considered as strategic for ubiquitous learning.

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DOI: 10.3217/jucs-020-01-0039

Authors: Christian Haintz, Karin Pichler, Martin Ebner

Abstract: Question-driven Audience Response Systems (ARSs) are in the focus of research since the 1960s. Since then, the technology has changed and therefore systems have evolved too. This work is about conception and implementation of the web-based ARS RealFeedback which uses the principle of bring your own device (BYOD). A state-of-the-art analysis compares the features of existing web-based ARSs. The most important findings are used for the conception and the implementation of the system. Thinking-aloud tests, and the first usages during lectures confirm that the chosen requirements are very significant and valuable for lecturers.

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DOI: 10.3217/jucs-019-17-2598

Authors: Juan Mateu, Xavier Alamán

Abstract: Nowadays, one of the hot issues in the agenda is, undoubtedly, the concept of Sustainable Computing. There are several technologies in the intersection of Sustainable Computing and Ambient Intelligence. Among them we may mention "Human-Centric Interfaces for Ambient Intelligence" and "Collaborative Smart Objects" technologies. In this paper we present our efforts in developing these technologies for "Mixed Reality", a paradigm where Virtual Reality and Ambient Intelligence meet. Cubica is a mixed reality educational application that integrates virtual worlds with tangible interfaces. The application is focused on teaching computer science, in particular "sorting algorithms". The tangible interface is used to simplify the abstract concept of array, while the virtual world is used for delivering explanations. This educational application has been tested with students at different educational levels in secondary education, having obtained promising results in terms of increased motivation for learning and better understanding of abstract concepts.

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DOI: 10.3217/jucs-019-09-1219

Authors: Antonio Jara, David Fernandez, Pablo Lopez, Miguel Zamora, Antonio Skarmeta, Leandro Marin

Abstract: Bluetooth Low Energy (BLE) is extending Bluetooth technology to devices with lower communication requirements and higher constraints in terms of memory capabilities and power autonomy. Thereby, BLE makes feasible the wireless transmission of information from smart objects such as wearable clinical devices, ambient sensors and actuators. These smart objects are starting to be internet-enabled devices, reaching the so denominated Internet of Things (IoT). Our research work is focused on analyze the capabilities of these technologies for continuous data transmission and integration of clinical sensors in home-care and Ambient Assisted Living environments. For this purpose, this work analyses exhaustively the capabilities from BLE and compare this with the capabilities from Bluetooth 2.1. In addition, it has been considered the communications requirements from different clinical devices such as an electrocardiogram (ECG) and a capnograph. It is concluded that the performance from BLE is lower than Bluetooth Classic (Bluetooth 2.1) for continuous communications, since BLE is based on attributes (datapoints) transfer instead of offering a communication session where can be transmitted as much packets as required, without any size constraint. Therefore, it is necessary to perform data compression/aggregation when the amount of data to send is too large to be stored in a BLE attribute. This work also presents how to apply pre-processing techniques that greatly reduces the transmission overload (performs signal compression) in order to allow the continuous transmission of the ECG and capnograph signal through BLE making so feasible the integration of continuous clinical devices via BLE.

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DOI: 10.3217/jucs-018-15-2165

Authors: Davinia Hernández-Leo, Raul Nieves, Ernesto Arroyo, Andrea Rosales, Javier Melero, Josep Blat

Abstract: Carrying out collaborative learning activities (supported by technologies or not) typically involves the coordination of multiple participants, in their dynamic assignment to groups and roles and in the distribution of resources and tools to specific group or individuals. While the mechanisms required to address these coordination aspects in digital educational spaces have been largely studied, less research has been conducted on orchestration support for facilitating this coordination in (technology-enhanced) physical spaces, such as the classroom or the playground. This paper presents the Signal Orchestration System (SOS), a system that augments the physical environment with digital signals indicating orchestration aspects. The SOS facilitates its integration with digital educational spaces to allow transitioning activities from digital to physical spaces. The paper describes the SOS system and its underlying architecture through a functional prototype that has been developed to show its feasibility and to enable its evaluation in authentic situations. The main components of the prototype include a Manager, where orchestration visual and auditory signals are configured, changed on the fly and transmitted, and three different designs of Wearable Signaling Devices, which are carried by participants and render the orchestration signals. The prototype has been used in two different experiments in the context of a real course applying adaptations of the well-known Jigsaw collaborative learning flow pattern. The results show that the SOS enables a flexible dynamic orchestration of the collaborative activities.

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DOI: 10.3217/jucs-017-02-0332

Authors: Carlos Hurtado, Luis Guerrero

Abstract: Computer Supported Collaborative Learning could highly impact education around the world if the proper Collaborative Learning tools are set in place. In this paper we describe the design of a collaborative learning activity for teaching Chemistry to Chilean students. We describe a PDA-based software tool that allows teachers to create workgroups in their classrooms in order to work on the activity. The developed software tool has three modules: one module for teachers, which runs on a PC and lets them create the required pedagogical material; second, there is a PDA module for students which lets them execute the activity; finally, a third module allows the teacher set workgroups and monitor each workgroup during the activity.

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DOI: 10.3217/jucs-016-12-1556

Authors: Roc Messeguer, Leandro Navarro, Pedro Damian-Reyes, Jesus Favela

Abstract: In Collaborative Learning, groups of students work together using traditional and computer-based tools or applications. Participants are continuously moving and reorganizing in groups as tasks develop and the contextual information about the physical arrangement of people within groups determines the context of each sub-activity. The electronic environment needs to be in sync with the physical arrangement of the groups, but providing group context information to computer-based tools cannot effectively be done manually. This paper explores and addresses the problem of automating group awareness in CSCL applications by estimating group arrangements from location sensors and the history of interaction. We derive from case studies the requirements for context-awareness in collaborative learning, focusing on the Jigsaw technique supported by mobile devices. In our prototype system with real users, groups are detected from the location of the students within the classroom. However, this information needs filtering to avoid disturbing interruptions caused by uncertain location measures. A three-phase filtering strategy is proposed to manage uncertain contextual information by identifying sources of uncertainty, representing uncertain information, and determining how to proceed. Validation with experimental data shows the usefulness of introducing mobile devices with group-supporting applications that incorporate automatic group awareness. Results show that by managing uncertainty in the estimation of location, group membership information becomes reliable enough to satisfy the need for supporting collaborative learning with applications that are automatically group-aware, without introducing extra burdens or interruptions.

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DOI: 10.3217/jucs-015-09-1833

Authors: Nelson Baloian, Gustavo Zurita

Abstract: Nowadays, we are experiencing a rapid development in mobile computing because of the sinking prices of the mobile devices and the availability of wireless networks that can connect them. The ability of many of these devices to set up ad-hoc networks by proximity allows face-to-face interaction combined with mobility. However, mobile devices are much weaker in computing power compared with desktop or laptop computing. Therefore, a key aspect to ensure success of an application supporting mobile learning is whether mobility is really needed for the activity it supports and if mobile devices do really represent an added value compared with the same application implemented on non-mobile devices. This work presents MCI-Supporter, an application supporting collaborative learning practises in the classroom. MCI-Supported was conceived by first analyzing the best known collaborative learning practices trying to find out which are the real needs for mobility and face-to-face interaction and then designing the application supporting learning activities where mobile computing does really represents an added value compared to the desktop computing scenario.

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