Search results for "Access"

Security and privacy in the Internet of Things: Current status and open issues

2014

The Internet of Things at large will foster billions of devices, people and services to interconnect and exchange information and useful data. As IoT systems will be ubiquitous and pervasive, a number of security and privacy issues will arise. Credible, economical, efficient and effective security and privacy for IoT are required to ensure exact and accurate confidentiality, integrity, authentication, and access control, among others. In this paper, the IoT vision, existing security threats, and open challenges in the domain of IoT are discussed. The current state of research on IoT security requirements is discussed and future research directions with respect to IoT security and privacy ar…

A Survey on Privacy in Decentralized Online Social Networks

2018

Decentralized Online Social Networks (DOSNs) have recently captured the interest of users because of the more control given to them over their shared contents. Indeed, most of the user privacy issues related to the centralized Online Social Network (OSN) services (such as Facebook or Google+) do not apply in the case of DOSNs because of the absence of the centralized service provider. However, these new architectures have motivated researchers to investigate new privacy solutions that allow DOSN’s users to protect their contents by taking into account the decentralized nature of the DOSNs platform. In this survey, we provide a comprehensive overview of the privacy solutions adopted by…

To Share or Not to Share: Supporting the User Decision in Mobile Social Software Applications

2007

User's privacy concerns represent one of the most serious obstacles to the wide adoption of mobile social software applications. In this paper, we introduce a conceptual model which tackles the problem from the perspective of trade-off between privacy and trust, where the user takes the decision with minimal privacy loss. To support the user decision, we introduce the Mobile Access Control List (Macl), a privacy management mechanism which takes into account the user attitude towards mobile sharing, his communication history and social network relationships.

Trust-enhanced intelligent security model

2012

In this paper we propose a trust-enhancement of access control to protect both integrity and confidentiality based on trustworthiness of users performing operations and documents' content analysis. We propose to utilize trustworthiness opinions from subjective logic and express levels of integrity as levels of trustworthiness. We assign confidentiality levels based on contents of documents and use opinions to express trustworthiness of such assignments.

Self-service Ad-hoc Querying Using Controlled Natural Language

2016

The ad-hoc querying process is slow and error prone due to inability of business experts of accessing data directly without involving IT experts. The problem lies in complexity of means used to query data. We propose a new natural language- and semistar ontology-based ad-hoc querying approach which lowers the steep learning curve required to be able to query data. The proposed approach would significantly shorten the time needed to master the ad-hoc querying and to gain the direct access to data by business experts, thus facilitating the decision making process in enterprises, government institutions and other organizations.

Improving Collective I/O Performance Using Non-volatile Memory Devices

2016

Collective I/O is a parallel I/O technique designed to deliver high performance data access to scientific applications running on high-end computing clusters. In collective I/O, write performance is highly dependent upon the storage system response time and limited by the slowest writer. The storage system response time in conjunction with the need for global synchronisation, required during every round of data exchange and write, severely impacts collective I/O performance. Future Exascale systems will have an increasing number of processor cores, while the number of storage servers will remain relatively small. Therefore, the storage system concurrency level will further increase, worseni…

Institucionālo repozitoriju nozīme un izveides teorētiskie aspekti

2011

Joint Distribution of Polarization-Multiplexed UWB and WiMAX Radio in PON

2009

[EN] In this paper, the feasibility of the joint distribution of ultra-wideband (UWB) and WIMAX wireless using polarization multiplexing as a coexistence technique is proposed and experimentally demonstrated within the framework of passive optical networks (PON). Four single- and orthogonal-polarization multiplexing schemes are studied targeting to reduce the mutual interference when UWB and WiMAX are distributed jointly through standard single-mode fiber (SSMF) without transmission impairments compensation techniques and amplification. Experimental results indicate successful transmission up to 25 km, in SSMF exceeding the range in typical PON deployments. The radio link penalty introduced…

Performance Study of Non-beaconed and Beacon-Enabled Modes in IEEE 802.15.4 under Bluetooth Interference

2008

The IEEE 802.15.4 protocol is a flexible technology with great potential for wireless sensor networks applications. The standard distinguishes two network modes; beacon-enabled and nonbeacon-enabled. In this paper, the performance study of beaconed and non-beaconed modes of IEEE 802.15.4 is evaluated using on site PER measurements. The tests are carryout in an urban outdoor environment with commercial available equipment. Likewise, the impact of Bluetooth interference over IEEE 802.15.4 modes is evaluated. The results show that Bluetooth interference and the mode selected have effects over the PER. Furthermore, for distances between 3 to 10 meters the PER doesn't show significance distance …

An Experimental Testbed and Methodology for Characterizing IEEE 802.11 Network Cards

2006

It has been observed that IEEE 802.11 commercial cards produced by different vendors show a different behavior in terms of perceived throughput or access delay. Performance differences are evident both when the cards contend alone to the channel, and when heterogeneous cards contend together. Since the performance misalignment does not disappear by averaging the environmental factors (such as propagation conditions, laptop models, traffic generators, etc), it is evident that the well known throughput-fairness property of the DCF protocol is not guaranteed in actual networks. In this paper we propose a methodological approach devised to experimentally characterize the IEEE 802.11 commercial …