Computing infrastructure issues in distributed communications systems : a survey of operating system transport system architectures

The performance of distributed applications (such as file transfer, remote login, tele-conferencing, full-motion video, and scientific visualization) is influenced by several factors that interact in complex ways. In particular, application performance is significantly affected both by communication infrastructure factors and computing infrastructure factors. Several communication infrastructure factors include channel speed, bit-error rate, and congestion at intermediate switching nodes. Computing infrastructure factors include (among other things) both protocol processing activities (such as connection management, flow control, error detection, and retransmission) and general operating system factors (such as memory latency, CPU speed, interrupt and context switching overhead, process architecture, and message buffering). Due to a several orders of magnitude increase in network channel speed and an increase in application diversity, performance bottlenecks are shifting from the network factors to the transport system factors.This paper defines an abstraction called an "Operating System Transport System Architecture" (OSTSA) that is used to classify the major components and services in the computing infrastructure. End-to-end network protocols such as TCP, TP4, VMTP, XTP, and Delta-t typically run on general-purpose computers, where they utilize various operating system resources such as processors, virtual memory, and network controllers. The OSTSA provides services that integrate these resources to support distributed applications running on local and wide area networks.A taxonomy is presented to evaluate OSTSAs in terms of their support for protocol processing activities. We use this taxonomy to compare and contrast five general-purpose commercial and experimental operating systems including System V UNIX, BSD UNIX, the x-kernel, Choices, and Xinu

Investment prospects of fish farming in the Jos-Plateau, Nigeria

The investment prospects of fish farming in the Jos-Plateau, Nigeria, strategically located in about the centre of the country are discussed with special reference to its numerous abandoned mine lakes and the tripartite role of government, universities and individuals. In the Jos-Plateau, about 17.0 km super(2) is covered by these disused mine lakes, making up about 20-30% of the area covered. In such enterprise, problems commonly encountered, like population growth and government planning policies, fish demand and supply, manpower, feed and seed availability, preservation, processing and marketing are discussed. Inspite of these, prospects still abound with regards to land-use of these numerous disused mine lakes and feed availability based on the principles of using both industrial and farm by-products for fish culture, processing and marketing. These potentials, if properly harnessed, will help to supplement the protein insufficiency in the diet of the populace. In this regard, proposals on the economics of production and sales, strategies for achieving these development goals, cost-benefit analysis and their implications in further development of fish culture are discusse

Special Libraries, May-June 1958

Volume 49, Issue 5https://scholarworks.sjsu.edu/sla_sl_1958/1004/thumbnail.jp

Rethinking Dalian New International Airport: The Exploration of a Net-Zero Airport Powered by Tidal Power Energy on an Artificial Island.

Fossil fuel is still the number one energy resource in China, and among the fossil fuel, coal is the primary resource to generate electricity and heat during heating days. Fossil fuel will result in global warming, sea level rising, but we may not perceive these because of the relatively subtle changes. Nevertheless, China got the punishment from the natural in recent years, most of the mainland China is experiencing the terrible smog, which gets worse in the winter. The cause of the smog is same to London, a huge amount of coal has been consumed in last few decades. To stop the smog spreading in China, the energy resource transformation is imperative. Oceans cover almost 70% of the earth’s surface which have a tremendous amount of energy in the form of a wave, tidal, ocean current, thermal resources and salinity gradients. Ocean energy is one of the renewable energy that human ancho’s their hope on, and researchers are seeking approaches to capture that energy and convert it to electricity more and more efficiently. As buildings consuming about 40% of global energy consumption, the architects need to emphasize more on energy saving aspect compare to the past. Dalian has sea area about 29000 square kilometers. It is reasonable to invest and develop on ocean energy. Among different types of ocean energy, tidal energy, which is created by the gravitational forces of the moon and the sun and the rotation of the moon, is one of the most predictable efficient and developed ocean energy. The New Dalian Airport locates in Jinzhou Bay Area, which provides more opportunities for integrating the tidal power to generate energy on site. With the thought of incorporating tidal energy, this thesis will develop a proposal for Dalian Jinzhou Bay International Airport, which aims at being a sustainable, educational, and Net-Zero airport on an artificial island that powered by tidal energy

Development of novel adenoviral vectors to overcome challenges observed with HAdV-5 based constructs

Recombinant vectors based on human adenovirus serotype 5 (HAdV-5) have been extensively studied in pre-clinical models and clinical trials over the last two decades. However, the thorough understanding of the HAdV-5 interaction with human subjects has uncovered major concerns about its product applicability. High vector-associated toxicity and widespread pre-existing immunity have been shown to significantly impede the effectiveness of HAdV-5 mediated gene transfer. It is therefore that the in depth knowledge attained working on HAdV-5 is currently being used to develop alternative vectors. Here, we provide a comprehensive overview of data obtained in recent years disqualifying the HAdV-5 vector for systemic gene delivery as well as novel strategies being pursued to overcome the limitations observed with particular emphasis on the ongoing vectorization efforts to obtain vectors based on alternative serotypes

Spartan Daily, March 6, 1990

Volume 94, Issue 27https://scholarworks.sjsu.edu/spartandaily/7957/thumbnail.jp

Challenges and success factors of railway megaprojects in Ethiopia

In this days project management knowledge and practices becomes very essential due to the fact that managing projects have been emerged complex and challenging from time to time. However, in Ethiopia, very little is studied about critical project success factors, measuring criteria, project management knowledge areas, tools and techniques. The aim of this study is to assess the critical success factors and challenges of the overall railway construction project success in Ethiopia. The study design was explanatory. Mixed approach was used and both primary and secondary data were collected using questionnaires. A sample of 79 respondents was selected from a population of 264. The study findings show that project success factors such as: leadership effectiveness, project team, Contractors. Competency, cost Management, communication management, time management, quality management, risk management, and stakeholder participation respectively are found to be critical factors to the project success. The study also concluded that the major challenging failure factors were: investment cost, skilled manpower in the sector, project integration and stakeholder management, contract administration, and land topography. Thus, it is recommended that participation of relevant stakeholders such as: a farmer on the road sides, people to be displaced and others that may be affected by the project is very essential for successful completion of projects. The Ethiopian Railway Corporation should give emphasis on improving contract administration practices, integration project activities, and improving the project quality management activities. In addition to this, Success factors that have significant effect on the overall success of the railway project should be managed selectively according to their effects.Keywords: Project success, Railway projects, Challenges and Ethiopi

A Logic Programming Approach to Knowledge-State Planning: Semantics and Complexity

We propose a new declarative planning language, called K, which is based on principles and methods of logic programming. In this language, transitions between states of knowledge can be described, rather than transitions between completely described states of the world, which makes the language well-suited for planning under incomplete knowledge. Furthermore, it enables the use of default principles in the planning process by supporting negation as failure. Nonetheless, K also supports the representation of transitions between states of the world (i.e., states of complete knowledge) as a special case, which shows that the language is very flexible. As we demonstrate on particular examples, the use of knowledge states may allow for a natural and compact problem representation. We then provide a thorough analysis of the computational complexity of K, and consider different planning problems, including standard planning and secure planning (also known as conformant planning) problems. We show that these problems have different complexities under various restrictions, ranging from NP to NEXPTIME in the propositional case. Our results form the theoretical basis for the DLV^K system, which implements the language K on top of the DLV logic programming system.Comment: 48 pages, appeared as a Technical Report at KBS of the Vienna University of Technology, see http://www.kr.tuwien.ac.at/research/reports

The natural resources of Carpinteria Marsh: their status and future

The purpose of this report is: 1) to document the natural resources of Carpinteria Marsh, 2) outline the uses those resources receive, 3) enumerate the problems and conflicts of use that affect those resources, and 4) recommend measures that will protect and enhance the marsh and its resources. It is intended as a guide for citizens, planners and administrators of all private and public entities interested in the status and future of the marsh. This report has been prepared under contract to and fully funded by the Office of Biological Services of the U.S. Fish and Wildlife Service. The goals and purpose of this federal office are to review the impact on fish and wildlife resources of land, mineral and water development practices, such as offshore oil and gas exploration, development and production; construction of inshore pipeline canals and refineries; power plant construction/operation and urban development. This report, and five other southern California reports, covering Agua Hedionda (San Diego County), Anaheim Bay-Huntington Harbor (Orange County), Mugu Lagoon (Ventura County), the Northern Santa Barbara County Coastal Wetlands and the Nipomo Dunes and Wetlands (San Luis Obispo County), are scheduled to be part of the Department's "Coastal Wetland Series" that includes reports on the natural resources of Upper Newport Bay (Orange County), Goleta Slough (Santa Barbara county), Bolinas Lagoon (Marin County), Elkhorn Slough (Monterey County), San Diego Bay and Los Penasquitos Lagoon (San Diego County), Morro Bay (San Luis Obispo County), Humboldt Bay and the Eel River Delta (Humboldt County), Lake Earl and the Smith River Delta (Del Norte County) and Bodega Harbor (Sonoma County). (103pp.

Washington University Record, April 10, 1986

https://digitalcommons.wustl.edu/record/1371/thumbnail.jp