Algorithms for advance bandwidth reservation in media production networks

Media production generally requires many geographically distributed actors (e.g., production houses, broadcasters, advertisers) to exchange huge amounts of raw video and audio data. Traditional distribution techniques, such as dedicated point-to-point optical links, are highly inefficient in terms of installation time and cost. To improve efficiency, shared media production networks that connect all involved actors over a large geographical area, are currently being deployed. The traffic in such networks is often predictable, as the timing and bandwidth requirements of data transfers are generally known hours or even days in advance. As such, the use of advance bandwidth reservation (AR) can greatly increase resource utilization and cost efficiency. In this paper, we propose an Integer Linear Programming formulation of the bandwidth scheduling problem, which takes into account the specific characteristics of media production networks, is presented. Two novel optimization algorithms based on this model are thoroughly evaluated and compared by means of in-depth simulation results

A look at cloud architecture interoperability through standards

Enabling cloud infrastructures to evolve into a transparent platform while preserving integrity raises interoperability issues. How components are connected needs to be addressed. Interoperability requires standard data models and communication encoding technologies compatible with the existing Internet infrastructure. To reduce vendor lock-in situations, cloud computing must implement universal strategies regarding standards, interoperability and portability. Open standards are of critical importance and need to be embedded into interoperability solutions. Interoperability is determined at the data level as well as the service level. Corresponding modelling standards and integration solutions shall be analysed

RFCs, MOOs, LMSs: Assorted Educational Devices\ud

This paper discusses implicit social consequences of four basic internet protocols. The results are then related to the field of computer-assisted teaching. An educational on-line community is described and compared to the emerging standard of web-based learning management.\u

Identifying Complex Cultural Interactions in the Instructional Design Process: A Case Study of a Cross-Border, Cross-Sector Training for Innovation Program

The purpose of this research is to identify complex cultural dynamics in theinstructional design process of a cross-sector, cross-border training environment by applying Young’s (2009) Culture-Based Model (CBM) as a theoretical framework and taxonomy for description of the instructional design process under the conditions of one case. The guiding question of this study is: How does culture, as defined by Young’s (2009) CBM framework, interact with the instructional design process in this case of a cross-sector, cross-border training program? This research uses the qualitative approach of case study and applies a cultural design framework to examine the process of instructional design by a team of designers-by-assignment in a NASA/university consortium program to train applied research and development teams for an education software company headquartered in India. Fifteen representative participants were chosen to reflect each role involved in the training program and instructional design process, including management, instructors and students. In over two years of engagement with participants, data was gathered at a NASA space center and in Mumbai, India through interviews, observation and artifact analysis. Data was analyzed to identify where components of the design process, decisions of the design team, and perceptions of the stakeholders overlap with culture as defined by Young’s CBM framework. The findings indicate that at least twenty-three distinguishable elements of culture interact across the design process in the: 1) goals and funding decisions of the client; 2) goals and design decisions of the design team; 3) perceptions of the training program of all stakeholders; and 4) the observable outcomes of the training program. The findings also offer insight into what stakeholders do or do not consciously attribute to culture. By empirically illuminating the pervasive presence of cultural interactions across the instructional design process, this study advocates for culture to be recognized as a construct of importance in our field and demonstrates the powerful capabilities of using a comprehensive descriptive model as a lens for exploring cultural dynamics in the instructional design process

AES-CBC Software Execution Optimization

With the proliferation of high-speed wireless networking, the necessity for efficient, robust and secure encryption modes is ever increasing. But, cryptography is primarily a computationally intensive process. This paper investigates the performance and efficiency of IEEE 802.11i approved Advanced Encryption Standard (AES)-Rijndael ciphering/deciphering software in Cipher Block Chaining (CBC) mode. Simulations are used to analyse the speed, resource consumption and robustness of AES-CBC to investigate its viability for image encryption usage on common low power devices. The detailed results presented in this paper provide a basis for performance estimation of AES cryptosystems implemented on wireless devices. The use of optimized AES-CBC software implementation gives a superior encryption speed performance by 12 - 30%, but at the cost of twice more memory for code size.Comment: 8 pages, IEEE 200

Autonomous support for microorganism research in space

A preliminary design for performing on orbit, autonomous research on microorganisms and cultured cells/tissues is presented. An understanding of gravity and its effects on cells is crucial for space exploration as well as for terrestrial applications. The payload is designed to be compatible with the Commercial Experiment Transporter (COMET) launch vehicle, an orbiter middeck locker interface, and with Space Station Freedom. Uplink/downlink capabilities and sample return through controlled reentry are available for all carriers. Autonomous testing activities are preprogrammed with in-flight reprogrammability. Sensors for monitoring temperature, pH, light, gravity levels, vibrations, and radiation are provided for environmental regulation and experimental data collection. Additional experimental data acquisition includes optical density measurement, microscopy, video, and film photography. On-board full data storage capabilities are provided. A fluid transfer mechanism is utilized for inoculation, sampling, and nutrient replenishment of experiment cultures. In addition to payload design, representative experiments were developed to ensure scientific objectives remained compatible with hardware capabilities. The project is defined to provide biological data pertinent to extended duration crewed space flight including crew health issues and development of a Controlled Ecological Life Support System (CELSS). In addition, opportunities are opened for investigations leading to commercial applications of space, such as pharmaceutical development, modeling of terrestrial diseases, and material processing