46,334 research outputs found

    Low velocity impact response of rc beam with artificial polyethylene aggregate as concrete block infill

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    In structural design, an ideal situation for saving materials would be to reduce the weight of the structure without having to compromise on its strength and serviceability. A new lightweight composite reinforced concrete section was developed with a novel use of a lightweight concrete block as infill utilizing Artificial Polyethylene Aggregate (APEA and MAPEA). The concrete near the neutral axis acts as a stress transfer medium between the compression and tension zones. Partial replacement of the concrete near the neutral axis could create a reduction in weight and savings in the use of materials. In this experimental work, APEA and MAPEA were utilized as replacement for normal aggregates (NA) at percentages of 0%, 3%, 6%, and 9%, 12%, and 100% in the concrete mix. In this study, the concrete block infill uses the 100% MAPEA as a replacement for coarse aggregate. A total of sixteen beams were prepared measuring 170 mm × 250 mm × 1000 mm, in which four specimens were used as control samples (NRC) and twelve specimens were the reinforced concrete beam incorporated with different size of concrete block infill (RCAI) consisting of 100% MAPEA. All beams were tested with 100 kg steel weight dropped vertically from a height of 0.6 m and 1.54 m, which was equivalent to 3.5 m/s and 5.5 m/s respectively. Based on the experimental results, the impact force, displacement and crack patterns were affected by the impact load. For RCAI specimens, the impact force was larger but smaller displacement value was observed, compared to the NRC specimens. Furthermore, the width of the cracks generated in the RCAI specimens near the mid-span was less than that on the NRC specimen. All experiment results were validated against FEM. The transient impact force histories, displacement and crack patterns obtained from FEM matched reasonably well with the experiment results. The error reported a range of 1% to 15%. The results showed that the proposed use of concrete block infill produced desirable results under the impact loads. The main advantages of the concrete block infill that utilized MAPEA from waste plastic bags due to the weight reduction about 6% in the concrete beams

    Developing strategic learning alliances: partnerships for the provision of global education and training solutions

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    The paper describes a comprehensive model for the development of strategic alliances between education and corporate sectors, which is required to ensure effective provision of education and training programmes for a global market. Global economic forces, combined with recent advances in information and communication technologies, have provided unprecedented opportunities for education providers to broaden the provision of their programmes both on an international scale and across new sectors. Lifelong learning strategies are becoming increasingly recognized as an essential characteristic of a successful organization and therefore large organizations have shown a preparedness to invest in staff training and development. The demands for lifelong learning span a wide range of training and educational levels from school-level and vocational courses to graduate-level training for senior executive

    Improvement of speed response in four-phase DC–DC converter switching using two shunt voltage-source

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    This study proposes a technique that is able to improve the speed response of a four-phase DC–DC converter switching. The basic concept of the proposed technique is the inclusion of two shunt-connected voltage sources in series to the converter system. Using a higher input voltage to drive the load, a higher current per microsecond output system will be obtained and reverts to its nominal input upon obtaining desired references. Thus, the transient response observed when using this proposed technique is found to be much faster when compared to the conventional converter. Moreover, this technique is easily implemented as it requires only an additional voltage source, power switch, and power diode. The integrated model of the two shunt voltage-source in a four-phase DC–DC converter was simulated in MATLAB/Simulink and validated against the experimental results of a laboratory prototype, 600 W four-phase DC–DC converter. The novelty of this proposed technique is its ability to provide faster operations for critical loads applications, lower output capacitor and lower operating frequency

    Beginner's Guide for Cybercrime Investigators

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    In the real world there are people who enter the homes and steal everything they find valuable. In the virtual world there are individuals who penetrate computer systems and "steal" all your valuable data. Just as in the real world, there are uninvited guests and people feel happy when they steal or destroy someone else's property, the computer world could not be deprived of this unfortunate phenomenon. It is truly detestable the perfidy of these attacks. For if it can be observed immediately the apparent lack of box jewelry, penetration of an accounting server can be detected after a few months when all clients have given up the company services because of the stolen data came to competition and have helped it to make best deals. Cybercrime is a phenomenon of our time, often reflected in the media. Forensic investigation of computer systems has a number of features that differentiate it fundamentally from other types of investigations. The computer itself is the main source of information for the investigator. CONTENTS: Computing systems and storage media - Computing devices - - Peripheral devices - - External drives for media storage - Typology of data stored on specific supports – File systems - - Program that allows working with ” inactive” space - Information that can be obtained from the computing system environment Computer networks - Copper wire in computer networks - Optical fibers - Wireless LAN - Internet and Intranet Software and services - Client/server architecture - Protocols and Standards - Internet Services - - e-Mail - - - Spam - - HTTP - - Web address - URL - - Web browsers - - - Browser cookies - - Working with web pages - - - Choosing your favorite web pages - - - Keeping track of visited web pages - - - Saving web pages - - Proxy servers - - Privacy on the Internet - FTP - Instant Messaging - Peer-to-peer networks Vulnerabilities - The first attacks on the Internet - Cybercrime - - Typologies of cyber attackers - - - Classification of cyber attackers according to their skills and objectives - Classification of risks and incidents in cyberworld - - Classification as a list of terms - - List of categories - - Categories of results - - Empirical lists - Events, attacks and incidents - Online security events, actions, and targets - - Actions - - Targets - Attacks - - Tools - - Vulnerabilities - - Unauthorized results Cybercrime laws - The concept of "cybercrime" Investigations - Computer forensic investigations - Digital evidence - Digital sampling during investigations - The suspect - Witnesses in cybercrime - Transporting of samples in laboratory - Analysis of samples - Preparing team members - Computer tools Convention on Cybercrime - Preamble - Chapter I – Use of terms - Chapter II – Measures to be taken at the national level - - Section 1 – Substantive criminal law - - - Title 1 – Offences against the confidentiality, integrity and availability of computer data and systems - - - Title 2 – Computer-related offences - - - Title 3 – Content-related offences - - - Title 4 – Offences related to infringements of copyright and related rights - - - Title 5 – Ancillary liability and sanctions - - Section 2 – Procedural law - - - Title 1 – Common provisions - - - Title 2 – Expedited preservation of stored computer data - - - Title 3 – Production order - - - Title 4 – Search and seizure of stored computer data - - - Title 5 – Real-time collection of computer data - - Section 3 – Jurisdiction - Chapter III – International co-operation - - Section 1 – General principles - - - Title 1 – General principles relating to international co-operation - - - Title 2 – Principles relating to extradition - - - Title 3 – General principles relating to mutual assistance - - - Title 4 – Procedures pertaining to mutual assistance requests in the absence of applicable international agreements - - Section 2 – Specific provisions - - - Title 1 – Mutual assistance regarding provisional measures - - - Title 2 – Mutual assistance regarding investigative powers - - - Title 3 – 24/7 Network - Chapter IV – Final provisions Recommendation No. R (95) 13 - Appendix to Recommendation No. R (95) 13 - - I. Search and seizure - - II. Technical surveillance - - III. Obligations to co-operate with the investigating authorities - - IV. Electronic evidence - - V. Use of encryption - - VI. Research, statistics and training - - VII. International co-operation Rules for obtaining digital evidence by police officers Standards in the field of digital forensics Principles in digital evidence Procedures model for the forensic examination - Hard disk examination Code of Ethics Sources and references About - Nicolae Sfetcu - - By the same author - - Contact Publishing House - MultiMedia Publishin

    Service Platform for Converged Interactive Broadband Broadcast and Cellular Wireless

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    A converged broadcast and telecommunication service platform is presented that is able to create, deliver, and manage interactive, multimedia content and services for consumption on three different terminal types. The motivations of service providers for designing converged interactive multimedia services, which are crafted for their individual requirements, are investigated. The overall design of the system is presented with particular emphasis placed on the operational features of each of the sub-systems, the flows of media and metadata through the sub-systems and the formats and protocols required for inter-communication between them. The key features of tools required for creating converged interactive multimedia content for a range of different end-user terminal types are examined. Finally possible enhancements to this system are discussed. This study is of particular interest to those organizations currently conducting trials and commercial launches of DVB-H services because it provides them with an insight of the various additional functions required in the service provisioning platforms to provide fully interactive services to a range of different mobile terminal types

    Digital archiving of manuscripts and other heritage items for conservation and information retrieval

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    Expression of cultural heritage looking from the informatics angle falls into text, images, video and sound categories. ICT can be used to conserve all these heritage items like; the text information consisting of palm leaf manuscripts, stone tablets, handwritten paper documents, old printed records, books, microfilms, fiche etc, images including paintings, drawings, photographs and the like, sound items which includes musical concerts, poetry recitations, chanting of mantras, talks of important persons etc, and video items like archival films historical importance. To retrieve required information from such a large mass of materials in different formats and to transmit them across space and time, there are several limitations. Digital technology allows hitherto unavailable facilities for durable storage and speedy and efficient transmission / retrieval of information contained in all the above formats. Hypertext and hypermedia features of digital media enable integrating text with graphics, sound, video and animation. This paper discusses the international and national efforts for digitizing heritage items, digital archiving solutions available, the possibilities of the media, and the need to follow standards prescribed by organizations like UNESCO to enable easy exchange and pooling of information and documents generated in digital archiving systems at national and international level. The need to develop language technology for local scripts for organizing and preserving our cultural heritage is also stressed

    Distributed multimedia systems

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    Multimedia systems will allow professionals worldwide to collaborate more effectively and to travel substantially less. But for multimedia systems to be effective, a good systems infrastructure is essential. In particular, support is needed for global and consistent sharing of information, for long-distance, high-bandwidth multimedia interpersonal communication, greatly enhanced reliability and availability, and security. These systems will also need to be easily usable by lay computer users. \ud In this paper we explore the operating system support that these multimedia systems must have in order to do the job properly

    Systems for the Nineties - Distributed Multimedia Systems

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    We live at the dawn of the information age. The capabilities of computers to store and look up information are only just beginning to be exploited. As little as ten years ago, practically all the information stored in computers was entered and retrieved in the form of text. Today, we are just starting to use other means of communicating information between people and machines -- computers can now scan images, they can record sound, they can produce synthesized speech, and they can show two- and three-dimensional images of spatial data. The realization that we are still at the beginning of the information age comes when we notice the vast difference between the way in which people interact with each other and the way in which people can interact with (or through) machines. When people communicate, they tend to use speech, gestures, touch, even smell; they draw pictures on the white board, they use text, pictures, photos, graphs, sometimes even video presentations. nterpersonal communication is truly multimedia communication in that it makes use of all our senses
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