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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
781

The technology and operational readiness of students for mobile learning at a South African Higher Education Institution

Naicker, Nalindren Kistasamy 10 1900 (has links)
Recent accessibility drives and price wars between the major South African (SA) cell phone companies suggest that the landscape for the adoption of mobile learning (m-learning) at the Higher Education Institution (HEI) level may be changing. As such, there is a need to gauge the current mobile readiness of students for m-learning. Mobile technology readiness refers to the extent to which students have access to mobile devices (not only handsets), and can afford data bundles that meet or exceed the requirements of a base set of currently available m-learning applications (Naicker and Van der Merwe 2012). Mobile operational readiness refers to students’ awareness of, attitude towards, support and training that is required for m-learning. This study conducted an assessment of the technology and operational readiness of students at a SA HEI. An in-depth literature survey was undertaken to delineate technology and operational readiness of students for m-learning. For technology readiness, an investigation was conducted on m- learning applications that are currently available and the technology requirements of these mobile applications. This was undertaken to determine the extent that the current student mobile handset profile match these requirements. The literature review also included a search for mobile opeeratratiioonnaall ffaactorctorss ssuuchch aass ssttuuddeennttss’’ aawwaarenerenessss ooff aanndd aattttiittuuddee ttoowwaarrddss mm--lleaearrnininngg as well as m-learning support and training that students require. The philosophical underpinning of this study was based on Activity Theory. The strategy of inquiry employed was a case study approach. Data was collected from students at the Durban University of Technology, a resident based SA HEI. A mixed methods data collection strategy was employed. The researcher used a field survey questionnaire as the primary research instrument to assess mobile technology and operational readiness. Focus group interviews were used as a secondary data gathering tool to triangulate and strengthen the results. The results were presented using descriptive and inferential statistics and were analyzed using the lens of activity theory. In terms of technology readiness, despite a high level of ownership and reasonable compliance with application requirements, data costs remain prohibitive. In assessing operational readiness, despite a positive attitude, the majority of the students require awareness, ongoing support and training. Several recommendations based on the findings are offered. For example, one of the findings showed that mobile connectivity affordability was low amongst students and it is recommended that the HEI work around exorbitant connectivity costs by combining m-learning technologies to form meaningful m-learning approaches at a minimum v cost. Another finding showed low awareness of m-learning at the HEI. A recommendation advanced to combat this finding is for the HEI to encourage and support dialogue among key stakeholders. This study concludes that any m-learning endeavour to implement m-learning at this HEI is bound to fail as only a small percentage of students are aware of m-learning and can afford data bundles to implement m-learning in its true sense. As an implication of this study to other HEI’s, the researcher suggests that regular mobile readiness surveys be conducted. / Science and Technology Education / M. A. (Information Systems)
782

Evaluation of usability and user experience of an m-learning environment, custom-designed for a tertiary educational context

Harpur, Patricia-Ann 12 November 2013 (has links)
Undergraduate software engineering learners demonstrate a lack of motivation with face-to-face classroom education. Limited access to the Internet via PCs and laptops, hinders effective communication and collaboration. However, the majority of learners enrolled for studies in tertiary education, have cellphones and are proficient in the use of digital technology. A technology-enhanced m-learning solution is indicated. This research project evaluates the usability and user experience of an m-learning environment, custom-designed for a tertiary educational context and delivered by mobile handheld devices, features a synthesized framework of categories and criteria, and determines the nature and scope of an emergent digital divide. A design-based research model suited to the context of the study is implemented, gathering quantitative and qualitative data from experts and learners by survey questionnaires. Analysis of data highlights usability and UX problems, provides insight into an emergent digital divide and suggests guidelines specific to the design of m-learning implementations. / Educational Studies / M. Sc. (Information Systems)
783

TD產業的發展對標準必要專利在中國大陸之影響——以華為 VS InterDigital案及高通反壟斷案為例 / The influence of developing of Telecommunication Development industry to Standard essential patents in mainland China —— the study of antitrust case in Huawei vs InterDigital and qualcomm

王玉宇 Unknown Date (has links)
中國國內移動通信企業對於標準必要專利與美國移動通信產業知名NPE——InterDigital的初次交鋒就使得InterDigital付出了2000萬元人民幣的代價。而後,發改委對於就高通濫用標準必要專利的反壟斷調查更是開出了60.88億元的天文數字罰款單。 事實上,這些數字不僅起到了吸睛的作用,將人們的目光分分聚焦到中國的移動通信產業,同時,也因為案件發生的時間點而使得很多業界參與者猜測這樣的判決結果很可能是政府發展中國移動通信產業的政策手段。畢竟,自2000年TD-SCDMA成為世界公認的第三代移動通信標準之一以後,中國政府就打著TD產業的發展口號開始著力關注起中國移動通信市場的發展。自2008年奧運會以後,不管是銀行的放款額度還是產業政策的保護力度,都更加凸顯中國發展移動通信產業的決心。 另外,再加上近年來,各大通信巨頭在世界移動通信產業上掀起了大規模的專利戰爭,也使得人們對於專利的關注熱情愈發高漲。尤其是在移動通信產業中起到關鍵作用的標準必要專利,其價值地位也吸引了越來越多的目光。 本文試圖通過梳理TD產業政策演進的過程,來總結出中國自TD產業概念產生之後,移動通信產業發展的各階段產業狀況。再輔以華為VS InterDigital以及高通兩宗反壟斷案來探究產業政策的背後,案件結果究竟對中國移動通信市場的標準必要專利運作模式起到了怎樣的作用。 關鍵字:TD產業、標準必要專利、中國移動通信產業政策、濫用標準必要專利的制約 / For the first time that the Chinese mobile communication enterprise had a confrontation with the famous American NPE in mobile industry——Interdigital, it ended up with the result that Interdigital paid the composition of 20 million RMB. Moreover, China Development and Reform Commission gave Qualcomm a ticket of Six billion after the antitrust investigation of its abuse of Standard Essential Patents. All these numbers not only attracted public concern to the Chinese mobile communication industry, but also make some related participants thought the time of cases happened showed the sentences might be the policy methods to develop the Chinese own mobile communication industry. Since TD-SCDMA became one of the global certificated 3rd Generation Standard, Chinese government has made great efforts to develop the Chinese mobile communication under the banner of development of TD industry. After the Beijing Olympic Games in 2008, Chinese government’s determination in developing the Chinese mobile communication became greater. The evidences were the increase of banks loans and the protection of industrial methods in related filed. Furthermore, the communication giants’ pattern wars in the field of the global communication industry during recent years also raised public attention to the patterns, especially the standard essential patents which played a critical role in communication industry. This thesis attempts to reveal the industrial situations of different stages in the development of communication industry after the rise of Chinese TD industrial concept by sorting out the evaluation of TD industrial policies. Moreover, two antirust cases of HUAWEI VS InterDigital and Qualcomm shows how the sentences affected the operating mode of standard essential patents in Chinese mobile communication industry behind the industrial policies.
784

應急行動通訊系統設計 / Design of contingency cellular network

黃智賢, Huang, Jyh-Shyan Unknown Date (has links)
當大型災害來臨,通訊系統對救災效益具有不可或缺的重要性。然而,一般公眾通訊系統,如行動通訊網路等,常因各種不同因素導致系統攤瘓,使得協調大批非組織的救災志工,顯得異常困難。現存多個緊急通訊系統的佈建,需仰頼良好的交通運輸。不幸的是,部分道路和橋樑常因大型災害而斷裂或變型,導致災區對外交通運輸中斷,無法快速的將緊急通訊系統的網路元件,運送至災區佈建。我們提出應急行動通訊系統(Contingency Cellular Network, CCN) 以提供災區救災工作的緊急通訊。部分行動基地台雖然結構完整,但因失去與核心網路連線能力或電力供應,而無法提供服務,成為孤立基地台。應急行動通訊網路(CCN) 搭配無線通訊與衛星通訊技術建置一多重跳接無線網路,以恢復孤立基地台與核心網路連線能力;並配備發電機,提供電力,使孤立基地台可提供有限的服務。救災志工和災民無需使用特殊手持設備或額外的訓練,只需使用原有的手機,即可使用CCN的應急通訊服務。CCN可於第一時間,提供大批救災志工和災民通訊服務,以提高救災效益,因而拯救更多寶貴的生命。 本論文主要聚焦在應急行動通訊系統設計所衍生出的相關議題,如 應急網路需求分析、系統架構設計、網路拓樸規劃、網路頻寬規劃、佈署行程規劃等議題。本論文針對網路拓樸規劃、網路頻寬規劃、佈署行程規劃問題以數學模式進行塑模並證明這些問題為NP-Hard問題。因網路拓樸規劃、網路頻寬規劃、佈署行程規劃需緊急完成,我們也提出啟發式算法快速解決這些規劃問題。實驗結果顯示,這些啟發式算法均具良好的效能。 / Communication system is crucial to the efficiency of disaster response operation in the large-scale disaster. However, communication systems, such as cellular networks, usually crashed due to various causes making coordination among disorganized disaster responders extremely difficult. Unfortunately, rapid deployment of many existing emergency communication systems relies on a good transportation system, which is usually not available in a catastrophic natural disaster. We proposed a Contingency Cellular Network (CCN) for emergency communication by connecting disconnected base stations together with wireless links to construct a wireless multi-hop cellular network. CCN can support existing mobile phone users with reduced capability. Such a system can support a large number of disaster responders in the early hours of a catastrophic natural disaster, thus save many lives. Our research addresses the design issues of the network topology of CCN, such as network topology planning, bandwidth management, deployment scheduling and etc., and we take the degree of emergency and population of each stricken area as the priority measure as well as the available resources as the constraint to determine the network topology. Mathematical models of these design issues are proposed and proved as NP-Hard problems. Since the network topology, bandwidth management, deployment scheduling are needed in urgent, we propose heuristic algorithms to solve these problems quickly. Finally, we evaluated the proposed algorithms by simulation. A significant improvement in resiliency is reached.
785

Cidade instantânea (IC) / Instant city (IC)

Maia, Marcelo Reis 22 April 2013 (has links)
Sugere-se a hipótese de uma Cidade Instantânea identificada no cotidiano em situações condicionadas por tecnologias de comunicação e informação, e especialmente a computação ubíqua, também conhecida como computação pervasiva ou computação ambiente. A investigação aponta para o entendimento de uma Cidade Instantânea que emerge em coletivos sem escala, sem localização e com fronteiras e limites extremamente frágeis, fluidos e temporários. A Cidade Instantânea se infiltra em todas as formas de cidades existentes sem anulá-las; substituí-las. A Cidade Instantânea não tem um objetivo traçado, ela é pura subjetividade que ganha força e presença nas multidões de indivíduos conectados. / We suggest the hypothesis of an Instant City identified in everyday situations conditioned by information and communication technologies, especially the ubiquitous computing, also known as pervasive computing or ambient computing. The research points to the understanding of an Instant City that emerges in collectives without a precise scale or location, with extremely fragile, fluid and temporary boundaries and limits. The Instant City joins and infiltrate in all forms of existing cities without dismiss them; replace them. The Instant City is pure subjectivity that gains strength and presence in the crowds of connected individuals.
786

Antenas de microfita dupla-faixa para aplicações em estações rádio-base de telefonia móvel celular

Farias, Roger Lorenzoni 08 September 2014 (has links)
Submitted by Sandro Camargo (sandro.camargo@unipampa.edu.br) on 2015-05-09T22:22:57Z No. of bitstreams: 1 126110018.pdf: 3775876 bytes, checksum: 4a58f20709bf7c39682924a84079246d (MD5) / Made available in DSpace on 2015-05-09T22:22:58Z (GMT). No. of bitstreams: 1 126110018.pdf: 3775876 bytes, checksum: 4a58f20709bf7c39682924a84079246d (MD5) Previous issue date: 2014-09-08 / Neste trabalho, são apresentadas diferentes técnicas que possibilitam a obtenção de característica dupla-faixa para antenas de microfita especificamente voltadas para aplicações em estações rádio-base de telefonia móvel celular no Brasil. As faixas de frequência de interesse encontram-se no intervalo de 0,824 GHz a 0,960 GHz para a banda inferior e 1,710 GHz a 2,165 GHz para a banda superior. Além de atender as especificações técnicas de faixa de passagem, devem ser atendidos os requisitos de coeficiente de reflexão, polarização, ganho, largura de feixe de irradiação e impedância de entrada na faixa de interesse. Primeiramente, para obtenção de antenas de microfita com característica multibanda, descreve-se a técnica em que são dispostas fendas nos elementos irradiadores, onde são estudadas três topologias de antenas, explicando-se os princípios de funcionamento e destacando-se as particularidades de cada geometria. As três antenas são analisadas e projetadas com o auxílio do software comercial de simulação eletromagnética Ansoft Designer ® , visando levantar os parâmetros elétricos através de diversos estudos paramétricos em função da variação das dimensões das antenas para compreender melhor o comportamento de cada estrutura simulada. A antena com elemento irradiador em forma de H foi a única que cumpriu os requisitos em termos de faixa de passagem e diagramas de irradiação para operação em sistemas de telefonia móvel celular. No entanto, esta geometria resultou em dimensões físicas consideráveis, pois necessita da utilização de múltiplas camadas dielétricas, acarretando em um protótipo de volume considerável e de elevado custo de produção. Outra técnica estudada foi a sobreposição de elementos irradiadores, porém a mesma não é investigada detalhadamente em função de o custo de produção da antena ser mais elevado em comparação a topologias coplanares. Em seguida, uma técnica com irradiadores em fenda anelar e dupla alimentação é proposta. A antena é projetada considerando-se duas portas independentes, uma para cada banda de operação, formando uma antena de dois acessos altamente isolados. Simulações com o software HFSS TM mostraram que é possível satisfazer as especificações para operação em estações rádio-base de telefonia móvel celular. A grande vantagem desta estrutura é a possibilidade de utilização de apenas um laminado de micro-ondas, o que reduz o custo de produção em comparação a outras topologias. Protótipos foram construídos e caracterizados experimentalmente para validar o projeto realizado no simulador eletromagnético. Constatou-se a presença de discrepâncias entre os resultados simulados e medidos. Após simulações paramétricas, verificou-se que o processo de construção alterou a geometria do protótipo em relação ao modelo de simulação. Após a inclusão das imperfeições do processo construtivo no modelo, foi possível estimar as mudanças necessárias no protótipo. Após os devidos ajustes realizados em bancada, os resultados medidos exibiram boa concordância com a previsão teórica. Por fim, realizou-se um estudo de viabilidade da utilização da antena em fenda anelar dupla-faixa para composição de uma rede de antenas para estações rádio-base. A análise teve como principal objetivo verificar a possibilidade de síntese de diagramas de irradiação em forma de cossecante ao quadrado em ambas as bandas de operação. Excelente resultado foi obtido para a banda inferior, enquanto que algumas limitações foram encontradas na banda superior. / In this work we present different techniques for achieving the dual-band feature for microstrip antennas aimed to be used in the mobile communication base stations of Brazil. The focused frequency range for lower and higher bands is in the 0.824-0.960 GHz and 1.710-2.165 GHz intervals, respectively. In addition to comply with the technical specifications, the solution is also supposed to meet the requirements of return loss, polarization, gain, beamwidth radiation and input impedance in the focused frequency range. Initially, in order to obtain microstrip antennas with dual-band characteristic, we describe the technique in which slots are placed in the irradiating elements. Three antenna topologies are analyzed in its operation principles, emphasizing the particularities of each geometry. The antennas are designed with support of Ansoft Designer ® , a commercial software that simulates electromagnetic features, in order to find out the electrical parameters through parametric studies and to better understand the behavior of each simulated structure. These studies considered the variation in the dimensions of antennas. The H-shaped microstrip antenna was the only one able to fulfill the requirements of bandwidth and irradiation diagrams for operation in mobile communication. However, this geometry originated an antenna of considerable physical dimensions, because it requires the use of multiple dielectric layers, resulting in a prototype of considerable volume and high production cost. Another technique studied was the stacking of irradiating elements. However it isn’t investigated in detail because of the production cost of the antenna, which is higher than the ones of coplanar topologies. After all that, we propose a technique based in annular-slot antennas and double feed. The antenna is designed considering two independent ports, one for each band of operation, making an antenna of two highly insulated accesses. Simulations by the HFSS TM software have shown that it’s possible to comply with the specifications for operation in base stations of the mobile communication. The biggest advantage of this structure over other topologies is that it may be made of only one microwave laminate, reducing the production cost. Prototypes were built and measured to validate the design in the electromagnetic simulator. It was noted the discrepancies between the simulated and measured results. After running parametric simulations, we found out that the building process of the prototype changed the geometry of the simulation model. We included these imperfections in the model and it was possible to estimate the necessary changes in the prototype. After inclusion of the adjustments, the measured results behaved just alike the theoretical prediction. Finally, we’ve done a feasibility study on the use of the dual-band annular slot antenna for making an array of antennas for base stations. The study aimed to verify the suitability of synthetizing squared-cosecant shaped pattern in both operation bands. We got excellent results for the lower band, although some limitations were found for the higher band.
787

Quadri-dimensional approach for data analytics in mobile networks

Minerve, Mampaka Maluambanzila 10 1900 (has links)
The telecommunication market is growing at a very fast pace with the evolution of new technologies to support high speed throughput and the availability of a wide range of services and applications in the mobile networks. This has led to a need for communication service providers (CSPs) to shift their focus from network elements monitoring towards services monitoring and subscribers’ satisfaction by introducing the service quality management (SQM) and the customer experience management (CEM) that require fast responses to reduce the time to find and solve network problems, to ensure efficiency and proactive maintenance, to improve the quality of service (QoS) and the quality of experience (QoE) of the subscribers. While both the SQM and the CEM demand multiple information from different interfaces, managing multiple data sources adds an extra layer of complexity with the collection of data. While several studies and researches have been conducted for data analytics in mobile networks, most of them did not consider analytics based on the four dimensions involved in the mobile networks environment which are the subscriber, the handset, the service and the network element with multiple interface correlation. The main objective of this research was to develop mobile network analytics models applied to the 3G packet-switched domain by analysing data from the radio network with the Iub interface and the core network with the Gn interface to provide a fast root cause analysis (RCA) approach considering the four dimensions involved in the mobile networks. This was achieved by using the latest computer engineering advancements which are Big Data platforms and data mining techniques through machine learning algorithms. / Electrical and Mining Engineering / M. Tech. (Electrical Engineering)
788

The impact of integrating smartphone technology on Grade 10 learners’ achievement in Algebra

Mhlanga, Tendayi 21 October 2019 (has links)
Smartphone technology can be integrated in mathematics education, since most learners immerse in this technology. Teachers should be facilitators of confined learning in traditional classrooms, including digital facilitators. The aim of the study was to determine the effect of integrating smartphone technology on Grade 10 learners’ achievement in algebra. The study focused on two Grade 10 classes from different township schools in the Gauteng Province. The study was conducted during the first term of 2016. A quasi-quantitative experimental research design was used. Smartphones were integrated in algebra teaching and learning, using the Microsoft Math online application: https://www.math.microsoft.com. Despite challenges encountered during the study, the results indicated a positive impact on learners’ achievements in algebra, amongst experimental group learners. A need exists for future research in integrating smartphone technology in mathematics education. / Mathematics Education / M. Ed. (Mathematics Education)
789

A framework for mobile digital literacy skills of educators using mobile technology in rural formal education

Jahoor, Farshida 01 1900 (has links)
Information and communication technology (ICT) is considered a vital enabler in the quest to reduce the disparities between the developed and developing world. Developments in mobile technology have dramatically changed the ICT landscape. Mobile cellular technologies have flourished and proliferated more rapidly than any previous technology hitherto and is thus considered, at this time, the most pervasive technology in the world. However, the introduction of mobile ICT in rural formal education is faced with many challenges and ways in which to maximise its usage is still being explored. This research explores mobile digital literacy skills required by a rural educator to successfully integrate mobile technology into the classroom. This exploration used the ICT for rural education development (ICT4RED) project as its case study and added dimensions to the project through the development of a framework for mobile digital literacy skills. ICT4RED was an appropriate case for the exploration as it met the following criteria: educators were using mobile technologies in the classroom, educators had been part of the Teacher Professional Development (TPD) course offered by the ICT4RED project and educators were based in a rural resource-constrained area in South Africa. Questionnaires were used to gain insight into which skills educators rated as most important, and least important, as based on their teaching experience using mobile technologies in the classroom. The work is grounded on an interpretivist research philosophy and followed an inductive reasoning approach. Additionally, the research employed a qualitative method of analysis with a single case study, comprising of two units, facilitating a perspective of the phenomenon. Framework development was enabled through a literature review which assisted in theorising the mobile digital literacy skills. An expert review, followed by a questionnaire driven survey for educators, was conducted. The qualitative analysis revealed that most of the mobile digital literacy skills from literature were important and should be employed. The majority of educators and experts felt that the skills could not be categorised as, due to the lack of resources, most are considered very important. The lack of stable internet connection/s were also considered a major (if not the major) hindrance to successful mobile integration in rural areas. The main research question answered by this study is: How can a framework for educators’ mobile digital literacy skills support educators using mobile technology in formal rural education? The findings of this research should be significant to developers of mobile technology training programmes, as well as educators trying to successfully integrate mobile technology into their classrooms. The framework will enable both trainers and educators to prioritise skills and channel resources into the acquisition of those skills which have been identified as important by this research work. / School of Computing / M. Sc. (Computing)
790

A Dynamic Security And Authentication System For Mobile Transactions : A Cognitive Agents Based Approach

Babu, B Sathish 05 1900 (has links)
In the world of high mobility, there is a growing need for people to communicate with each other and have timely access to information regardless of the location of the individuals or the information. This need is supported by the advances in the technologies of networking, wireless communications, and portable computing devices with reduction in the physical size of computers, lead to the rapid development in mobile communication infrastructure. Hence, mobile and wireless networks present many challenges to application, hardware, software and network designers and implementers. One of the biggest challenge is to provide a secure mobile environment. Security plays a more important role in mobile communication systems than in systems that use wired communication. This is mainly because of the ubiquitous nature of the wireless medium that makes it more susceptible to security attacks than wired communications. The aim of the thesis is to develop an integrated dynamic security and authentication system for mobile transactions. The proposed system operates at the transactions-level of a mobile application, by intelligently selecting the suitable security technique and authentication protocol for ongoing transaction. To do this, we have designed two schemes: the transactions-based security selection scheme and the transactions-based authentication selection scheme. These schemes use transactions sensitivity levels and the usage context, which includes users behaviors, network used, device used, and so on, to decide the required security and authentication levels. Based on this analysis, requisite security technique, and authentication protocols are applied for the trans-action in process. The Behaviors-Observations-Beliefs (BOB) model is developed using cognitive agents to supplement the working of the security and authentication selection schemes. A transaction classification model is proposed to classify the transactions into various sensitivity levels. The BOB model The BOB model is a cognitive theory based model, to generate beliefs over a user, by observing various behaviors exhibited by a user during transactions. The BOB model uses two types of Cognitive Agents (CAs), the mobile CAs (MCAs) and the static CAs (SCAs). The MCAs are deployed over the client devices to formulate beliefs by observing various behaviors of a user during the transaction execution. The SCA performs belief analysis, and identifies the belief deviations w.r.t. established beliefs. We have developed four constructs to implement the BOB model, namely: behaviors identifier, observations generator, beliefs formulator, and beliefs analyser. The BOB model is developed by giving emphasis on using the minimum computation and minimum code size, by keeping the resource restrictiveness of the mobile devices and infrastructure. The knowledge organisation using cognitive factors, helps in selecting the rational approach for deciding the legitimacy of a user or a session. It also reduces the solution search space by consolidating the user behaviors into an high-level data such as beliefs, as a result the decision making time reduces considerably. The transactions classification model This model is proposed to classify the given set of transactions of an application service into four sensitivity levels. The grouping of transactions is based on the operations they perform, and the amount of risk/loss involved if they are misused. The four levels are namely, transactions who’s execution may cause no-damage (level-0), minor-damage (level-1), significant-damage (level-2) and substantial-damage (level-3). A policy-based transaction classifier is developed and incorporated in the SCA to decide the transaction sensitivity level of a given transaction. Transactions-based security selection scheme (TBSS-Scheme) The traditional security schemes at application-level are either session or transaction or event based. They secure the application-data with prefixed security techniques on mobile transactions or events. Generally mobile transactions possesses different security risk profiles, so, empirically we may find that there is a need for various levels of data security schemes for the mobile communications environment, which face the resource insufficiency in terms of bandwidth, energy, and computation capabilities. We have proposed an intelligent security techniques selection scheme at the application-level, which dynamically decides the security technique to be used for a given transaction in real-time. The TBSS-Scheme uses the BOB model and transactions classification model, while deciding the required security technique. The selection is purely based on the transaction sensitivity level, and user behaviors. The Security techniques repository is used in the proposed scheme, organised under three levels based on the complexity of security techniques. The complexities are decided based on time and space complexities, and the strength of the security technique against some of the latest security attacks. The credibility factors are computed using the credibility module, over transaction network, and transaction device are also used while choosing the security technique from a particular level of security repository. Analytical models are presented on beliefs analysis, security threat analysis, and average security cost incurred during the transactions session. The results of this scheme are compared with regular schemes, and advantageous and limitations of the proposed scheme are discussed. A case study on application of the proposed security selection scheme is conducted over mobile banking application, and results are presented. Transactions-based authentication selection scheme (TBAS-Scheme) The authentication protocols/schemes are used at the application-level to authenticate the genuine users/parties and devices used in the application. Most of these protocols challenges the user/device to get the authentication information, rather than deploying the methods to identify the validity of a user/device. Therefore, there is a need for an authentication scheme, which intelligently authenticates a user by continuously monitoring the genuinity of the activities/events/ behaviors/transactions through out the session. Transactions-based authentication selection scheme provides a new dimension in authenticating users of services. It enables strong authentication at the transaction level, based on sensitivity level of the given transaction, and user behaviors. The proposed approach intensifies the procedure of authentication by selecting authentication schemes by using the BOB-model and transactions classification models. It provides effective authentication solution, by relieving the conventional authentication systems, from being dependent only on the strength of authentication identifiers. We have made a performance comparison between transactions-based authentication selection scheme with session-based authentication scheme in terms of identification of various active attacks, and average authentication delay and average authentication costs are analysed. We have also shown the working of the proposed scheme in inter-domain and intra-domain hand-off scenarios, and discussed the merits of the scheme comparing it with mobile IP authentication scheme. A case study on application of the proposed authentication selection scheme for authenticating personalized multimedia services is presented. Implementation of the TBSS and the TBAS schemes for mobile commerce application We have implemented the integrated working of both the TBSS and TBAS schemes for a mo-bile commerce application. The details on identifying vendor selection, day of purchase, time of purchase, transaction value, frequency of purchase behaviors are given. A sample list of mobile commerce transactions is presented along with their classification into various sensitivity levels. The working of the system is discussed using three cases of purchases, and the results on trans-actions distribution, deviation factor generation, security technique selection, and authentication challenge generation are presented. In summary, we have developed an integrated dynamic security and authentication system using, the above mentioned selection schemes for mobile transactions, and by incorporating the BOB model, transactions classification model, and credibility modules. We have successfully implemented the proposed schemes using cognitive agents based middleware. The results of experiments suggest that incorporating user behaviors, and transaction sensitivity levels will bring dynamism and adaptiveness to security and authentication system. Through which the mobile communication security could be made more robust to attacks, and resource savvy in terms of reduced bandwidth and computation requirements by using an appropriate security and authentication technique/protocol.

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