Observations of the relationship between sprite morphology and in-cloud lightning processes

[1] During a thunderstorm on 23 July 2003, 15 sprites were captured by a LLTV camera mounted at the observatory on Pic du Midi in the French Pyrénées. Simultaneous observations of cloud-to-ground (CG) and intracloud (IC) lightning activity from two independent lightning detection systems and a broadband ELF/VLF receiver allow a detailed study of the relationship between electrical activity in a thunderstorm and the sprites generated in the mesosphere above. Results suggest that positive CG and IC lightning differ for the two types of sprites most frequently observed, the carrot- and column-shaped sprites. Column sprites occur after a short delay (<30 ms) from the causative +CG and are associated with little VHF activity, suggesting no direct IC action on the charge transfer process. On the other hand, carrot sprites are delayed up to about 200 ms relative to their causative +CG stroke and are accompanied by a burst of VHF activity starting 25–75 ms before the CG stroke. While column sprites associate with short-lasting (less than 30 ms) ELF/VLF sferics, carrot sprites associate with bursts of sferics initiating at the time of the causative +CG discharge and persisting for 50 to 250 ms, indicating extensive in-cloud activity. One carrot event was found to be preceded by vigorous IC activity and a strong, long-lived cluster of ELF/VLF sferics but lacking a +CG. The observations of ELF/VLF sferic clusters associated with lightning and sprites form the basis for a discussion of the reliability of lightning detection systems based on VHF interferometry.Peer ReviewedPostprint (published version

Survey on Multimedia Technologies for Mobile Learning Applications

Mobile technologies are developing very fast. This paper presents a survey on multimedia technologies for mobile learning applications, focusing on multimedia programming techniques for Windows Mobile, Symbian, and Java ME.multimedia, mobile devices, mobile applications, mobile learning

Searching for effects caused by thunderstorms in midlatitude sporadic E layers

Possible thunderstorm - sporadic E (Es) layer coupling effects are investigated during two measurement periods, one in 2013 and one in 2014. The analysis was based on ionospheric observations obtained from a Digisonde at Pruhonice, the Czech Republic, an ionosonde at Nagycenk, Hungary, and a 3.59 MHz five-point continuous HF Doppler system located in the western part of the Czech Republic. The latter is capable of detecting ionospheric wave-like variations caused by neutral atmospheric waves generated by thunderstorms. The present study searches for possible impacts on Es layers caused by the presence of two active thunderstorms: one passing across the Czech Republic on June 20, 2013 (19:00 - 01:00 LT), and one through Hungary on July 30, 2014 (11:00 - 01:00 LT). During these two time periods, presence and parameters of Es layer were inferred from ionograms, recorded every minute at Pruhonice and every two minutes at Nagycenk, whereas concurrent lightning activity was monitored by the LINET detection network. In addition, transient luminous events (TLEs) were also observed during both nights from Sopron, Hungary and from Nydek, the Czech Republic. A noticeable fact was the reduction and disappearance of the ongoing Es layer activity during part of the time in both of the traversing thunderstorms. The analysis indicated that the critical frequency foEs dropped below ionosonde detection levels in both cases, possibly because of thunderstorm activity effects. This option, however, needs more case studies in order to be further substantiated

Operating-system support for distributed multimedia

Multimedia applications place new demands upon processors, networks and operating systems. While some network designers, through ATM for example, have considered revolutionary approaches to supporting multimedia, the same cannot be said for operating systems designers. Most work is evolutionary in nature, attempting to identify additional features that can be added to existing systems to support multimedia. Here we describe the Pegasus project's attempt to build an integrated hardware and operating system environment from\ud the ground up specifically targeted towards multimedia

RAID-2: Design and implementation of a large scale disk array controller

We describe the implementation of a large scale disk array controller and subsystem incorporating over 100 high performance 3.5 inch disk drives. It is designed to provide 40 MB/s sustained performance and 40 GB capacity in three 19 inch racks. The array controller forms an integral part of a file server that attaches to a Gb/s local area network. The controller implements a high bandwidth interconnect between an interleaved memory, an XOR calculation engine, the network interface (HIPPI), and the disk interfaces (SCSI). The system is now functionally operational, and we are tuning its performance. We review the design decisions, history, and lessons learned from this three year university implementation effort to construct a truly large scale system assembly

Interfacing a high performance disk array file server to a Gigabit LAN

Our previous prototype, RAID-1, identified several bottlenecks in typical file server architectures. The most important bottleneck was the lack of a high-bandwidth path between disk, memory, and the network. Workstation servers, such as the Sun-4/280, have very slow access to peripherals on busses far from the CPU. For the RAID-2 system, we addressed this problem by designing a crossbar interconnect, Xbus board, that provides a 40MB/s path between disk, memory, and the network interfaces. However, this interconnect does not provide the system CPU with low latency access to control the various interfaces. To provide a high data rate to clients on the network, we were forced to carefully and efficiently design the network software. A block diagram of the system hardware architecture is given. In the following subsections, we describe pieces of the RAID-2 file server hardware that had a significant impact on the design of the network interface

Measuring integrated rural tourism.

If the concept of integrated rural tourism, as developed in the SPRITE project, is to be used as an operational tool to assess the all-round value of tourism in rural areas, there needs to be a means of measuring the value of tourism, and changes in it. Statistical, 'objective' methods of achieving this are critiqued. This paper describes the development of an alternative methodology for assessing the changes in the value of tourism witnessed by different groups of stakeholders in the study areas across Europe between 1992 and 2002. The methodology allows for a holistic view of the extent to which rural tourism is integrated into the local economies and cultures. Differences in perceptions regarding change in the value of tourism between actor groups and countries are noted. Illustrative examples are given of specific events and forms of rural tourism that are perceived as being of high value. It is concluded that while tourism is now better integrated than it was ten years ago, further improvements can be made in identifiable areas and dimensions and for particular actor groups

Accessing files in an Internet: The Jade file system

Jade is a new distribution file system that provides a uniform way to name and access files in an internet environment. It makes two important contributions. First, Jade is a logical system that integrates a heterogeneous collection of existing file systems, where heterogeneous means that the underlying file systems support different file access protocols. Jade is designed under the restriction that the underlying file system may not be modified. Second, rather than providing a global name space, Jade permits each user to define a private name space. These private name spaces support two novel features: they allow multiple file systems to be mounted under one directory, and they allow one logical name space to mount other logical name spaces. A prototype of the Jade File System was implemented on Sun Workstations running Unix. It consists of interfaces to the Unix file system, the Sun Network File System, the Andrew File System, and FTP. This paper motivates Jade's design, highlights several aspects of its implementation, and illustrates applications that can take advantage of its features

Дослідження управління багатонаціональною корпорацією, на прикладі компаніїb "Кока-Кола"

The main purpose of this research paper is to investigate system of management of multinational corporations and to give recommendations as for system of management at Coca-Cola Company. The main tasks of master research paper are the following: - To ascertain whether the multinational corporation are social responsible. - To ascertain whether the MNC in Nigeria have any contribution to the economic advancement of the nation. - To ascertain whether they contribute to the technological development of the countries. - To determine the environmental factors that influences the operations of the Multinationals Corporation Coca-Cola Company. - To give recommendations as for improvement of activity os Coca-Cola Company and industry of beverages.Master’s research paper critically evaluates the challenges Coca-Cola Company experiences while managing its operations in geographical and culturally diverse contexts. An overview of Coca-Cola Company and brief analysis of the global contemporary landscape is initially examined. A critical evaluation is conducted of the Global competitive, Political-Legal, Economic, Socio-cultural and Ethical challenges experienced by Coca-Cola Company. Ways to improve Coca-Cola's operations in the African markets were proposed.Introduction. 1. The theoretical framework and study of Multinational Corporation 1.1 Meanings and definition of Multinational Corporation 1.2 The managerial functions in international business 1.3 Important finding in managing Multinational Corporation 2. Research and analysis of Coca-Cola Company 2.1 Introduction to Coca-Cola Company 2.2 SWOT-analysis of the industrial and economic activity of Coca-Cola Company 2.3 Analysis of the system of management at Coca-Cola Company 3. Recommendations in management for Coca-Cola Company that operates in different geographical and cultural contexts 3.1 Recommendations as for the corporate social responsibly at Coca-Cola company 3.2 Recommendations as for using stevia in producing beverages at Coca-Cola Company 3.3 Recommendations as for strategic issues that Coca-Cola Company is facing today 4. Special part 4.1 Current trends in the field of Coca-Cola Company 4.2 Activities of multinational corporations in the development of Nigeria 5. Rationale for recommendations 5.1 Statement for recommendations at Coca-Cola Company 5.2 Recommendations as for using stevia in producing beverages at Coca-Cola Company 6. Occupational health and safety in emergencies 6.1 Safety and health for Coca-Cola Company 6.2 Protection against specific risks in safety and health 7. Environmental issues 7.1 Environmental impact of products in Coca-Cola Company 7.2 Coca-Cola sustainability plan Conclusions References Appendice