Space Technology

This is a seminar given in various countries and universities across the world on the past history of space flight as well as the future technologies of spaceflight. The seminar clearly shows how the various milestones across the space programs were achieved and what awaits the future of space programs. The moon missions and the space shuttle is also discussed in detail.For further information on space technologies contact drguven@live.com

In this study the empirical detection of ways of generating semantic maps using navigational data and data driven approaches is addressed. It is hypothesized that the hypertextual structure of distributed environments could encourages the construction of personal semantic ...

Water is one of the most important elements for sustaining-life. Despite water’s abundance, good quality water is available in a very limited quantity. Water quality describes water’s condition, including physical, chemical, biological and radiological-characteristics, usually with respect to its suitability for a particular purpose such as drinking, swimming and irrigation. Many factors can reduce quality of water such as water-pollution which is the contamination of water-bodies, usually resulting from human-activities. Poor water quality poses a health-risk for people and ecosystems. Water quality is measured by several factors, examples of which are the dissolved-oxygen, salinity, turbidity, pH, temperature. Water quality is a complex issue and requires large amounts of diverse accurate data in a timely manner. Collection of water quality measurement data by traditional method can be quite difficult and resource intensive especially in the remote-areas. Therefore, there is a nee...

Multimodality often exhibits synergistic effects: each modality compliments and compensates for other modalities in transferring coherent, unambiguous, and enriched information for higher interaction efficiency and improved sense of presence. In this paper, we explore one such phenomenon: a positive interaction among the geometric field of view, proprioceptive interaction, and tactile feedback. We hypothesize that, with proprioceptive interaction and tactile feedback,

ABSTRACT Free Space Optics (FSO) and E-band links operating in parallel are investigated. In contrast to previous work in this field equal transmission rate of the two is assumed- 1 Gbit/sec in existing systems with a likely increase in the near future. Propagation characteristics are briefly presented. It is shown that practical difficulties preclude microwave backup to FSO links. Equal transmission rate leads to the possible application of parallel MIMO techniques. Outage capacity based on that is determined regarding for both binary and quaternary modulation and both Direct Detection (DD) and heterodyne techniques in the FSO link. The unexpected conclusion is that it is more the FSO link that serves as backup to the E-band link than the converse.

ABSTRACT In this paper we apply linear and nonlinear dimensionality reduction methods to speech produced by a number of differ-ent speakers in an effort to yield low dimensional features capable of discriminating between speakers. The classical linear dimensionality ...

Most CSCW and groupware systems focus the activities of distributed teams involved in large projects by means of tools for communication and awareness. The activities of small collocated teams are often neglected. Analyzing preliminary requirements of small teams, it is possible to observe the need of tools to help the elaboration of project documentation. This paper presents a multi-agent system

Extended Surfaces (Fins) are widely used in the engineering field for enhancement of heat transfer rate by increasing surface area with additional material attachment. In many applications like heat exchangers, for economizer, cooling reactor core, electrical transformer and motors, automobile applications, rectifier, etc fins are used for better heat transfer. This paper is about an overview of various types of fins, their classification, their geometries, materials used for it, design considerations and applications with some case studies of thermal simulation and some special applications.

The WISE project is a NASA-funded medium- class Explorer mission to map the entire sky in four infrared bands during the course of a 6-month survey. Because of the mission's limited financial resources, a traditional robustness strategy of full block-redundancy was not feasible. By leveraging aspects of the mission design that tend to reduce the risk associated with certain failures, the project has been able to adopt a robustness strategy of mitigating high-risk failures, while accepting the risk of low-impact faults or unlikely faults in heritage equipment with proven reliability. The resulting WISE flight system design is primarily single-string with some select functional- and block-redundancy and includes fault tolerance measures targeted at achieving the most cost- effective risk reduction possible for the system design. The fault protection team has been challenged with balancing the risk of faults, cost, and down-time with Ground Segment capabilities, heritage, and effectively designed fault mitigations. Faults were identified via a collection of analyses, and a criticality rating was applied to each fault to assess its impact to the mission. Taking into consideration each fault's impact and time criticality, mitigations to each possible fault were considered in areas such as on-board autonomy, the addition or use of functional and block redundancy, and ground system detection. Through this exercise, the project has realized a robust and reliable system design in line with the project's risk posture and cost constraints.

Abstract— This paper describes the results of piloting an online - mobile phone environment -ViCaDiS – Virtual Campus for Digital Students, as a co-operation between 6 universities from European Union to develop a common online learning environment enhanced with web ...

Recent technological developments in the e-communications sector have lowered the threshold for users of information and communication technology (ICT) to enter the virtual domains of the Internet and to start playing other roles in society. ICT users have shifted their role from passive receivers of information and media content towards an active role in becoming producers, like in user generated content, or owners of infrastructure components, like in WiFi hotspots. The end user is not 'just' end user anymore. The trend in technological innovations undoubtedly will encourage this role shifting even further. This raises policy issues such as for the governance of privately held components of publicly accessible infrastructures and such as issues of privacy and security in virtual worlds. These policy issues have a decentralized character that escapes formerly successful central policy arrangements. We claim that policy arrangements should explicitly include a role for end user participation and take the role for technology into account. Coordination mechanisms in Open Software Development are presented as a first starting point towards innovative policy arrangements.

This technote summarizes various key relationships in rega rds to continuous time and discrete time passivesystems. It includes relationships for both the linear time invariant case and th e non linear case. For the linear time invariant case we speci fically discuss relationships between minimal causal positive real strictly-positive real extended strictly-p ositive realsystems andpassive systems. Index Terms passivitytheory, positive real , strictly-positive real , extended strictly-positive real , digital control systems, passivesystems, strictly-output passivesystems,strictly-input passivesystems ISIS TECHNICAL REPORT ISIS-2008-002, “NOVEMBER” 2008 1 Time Domain and Frequency Domain Conditions For Passivity

While differentiated services (DiffServ) offer a suitable technology support for quality-of-service (QoS) in multi-service networks, there is a lack of appropriate and technically feasible pricing schemes which would mainly provide an incentive for customers to choose efficiently among various service classes. This paper presents the basics of an implementation of recent developments in the area of charging differentiated services, in detail an Internet charge calculation and accounting system (ICCAS), including its modular architecture, components, open interfaces and databases. Finally, the explicit application of the newly developed cumulus pricing scheme (CPS) onto the ICCAS and DiffServ is discussed as a suitable example use

In selecting a reduced parametric representation of a process, it is desirable to utilize any a priori knowledge available. The authors propose a general partitioning scheme that can utilize such knowledge in a local enhancement of the process model. By partitioning the observation space, or a transform thereof, into disjoint subspaces, alternative possibly conflicting constraints can be applied to each region. The optimal subspace partitioning is found using a dynamic programming algorithm minimizing a mean-least-square error criterion derived from a rational (ARMA) innovations model.<<ETX>>

Solar System Exploration (SSE) to the Outer Planets requires internal power sources, since external power generation, relying on solar power, is not very effective or practical. One of the scientifically interesting destinations in this region is Jupiter's moon Europa, where a lander would require internal power sources, such as batteries or radioisotope power systems (RPS) to achieve mission success. This paper discusses a Europa lander concept as a potential adjunct element to NASA's proposed Jupiter Icy Moons Orbiter (JIMO) mission. The lander would operate on the surface for 3 to 14 days, performing astrobiology, geophysics and geological-compositional measurements as defined by the JIMO Science Definition Team (SDT). The power system trade study for this concept compares small-RPSs up to /spl sim/50 We against primary batteries. Additional SSE destinations are also outlined, where small-RPSs provide a viable option to accomplish science and mission objectives.

This paper identifies breakpoints for various power and propulsion technologies, with a special focus on fission-based sources in support of NASA's Mars exploration program. Transportation, orbital, and surface missions are addressed through an assessment architecture developed for this study. This architecture is based on three key considerations; decomposition of generic Mars missions into phases, a lumped parameter approach, and a bounding case analysis. With these simplifications breakpoints are identified beyond which new technologies, such as nuclear fission power, are required to achieve mission objectives. It is found that in-space propulsion and power generation are sized by launch vehicle delivery limits and trajectory options. Similarly, power levels for surface-based reactors are affected by transportation system and EDL limits imposed by current technologies. After summarizing the breakpoints for today's state of the art, development targets are identified to enable space-based nuclear power and propulsion systems to perform at their full potential.

In this article, we present our investigations on the radiation of the power-line communication (PLC) system. Power line communication or power line carrier is a technology for carrying data on a conductor usually dedicated to electric power transmission. At high frequency, the power lines, whose are dimensioned and adjusted for electrical energy transfer, not to carry high frequency (HF) data signal, act then as radiating antennas.

An array antenna system requires the same number of RF circuit sections as that of the antennas. This paper presents the novel concept of "space hopping" scheme which requires only "one" RF circuit to enable the array antenna system at very low cost. The scheme also shows excellent BER characteristics for the array antenna system. We focus on the improvement of BER in the array antenna configuration in the short range Rician distribution multipath fading environment. A multipath simulation bench is studied and designed to evaluate the space hopping performance. Several simulations are made to confirm the expected performance of the space hopping scheme and to obtain a good configuration of the array antenna.

Sketching leverages human skills for various purposes. In-Place Augmented Reality Sketching experiences build on the intuitiveness and flexibility of hand sketching for tasks like content creation. In this paper we explore the design space of In-Place Augmented Reality Sketching, with particular attention to content authoring in games. We propose a contextual model that offers a framework for the exploration of this design space by the research community. We describe a sketch-based AR racing game we developed to ...

The paper proposes a model to design collaboration supports in pervasive environments through the notion of community. As in human communities, the degree of participation of a member can dynamically change in relation both to her physical location and to her position in the logical space of the applications the community uses to cooperate. The paper shows how this approach

Nowadays, the world of interactive applications is growing due to the users' needs that expect increasingly complex scenarios under a high level of interactivity. The explosive growth of interactive multimedia applications creates the need for advanced methods of content management and the reusability aspects of interactive multimedia content. Digital media technology is becoming an integral part of our daily activities, and using multimedia objects in building rich and interactive content for ITV (interactive TV) is a complex task. This is basically due to the fact that there is a lack of production chain tools such as authoring tools that are needed to perform the content production activities. Another issue is that there is no convergence of standards in terms of methodologies and multimedia representation. This is also true for the application level. Another way in which the user can freely interact with those multimedia objects makes the applications needs to know how to a...

Abstract— A general hierarchical methodology for control distribution in highly redundant system is presented. The new method makes use of distribution functions to approximate the feasible solution set and to keep in check the “curse of dimensionality”. To improve the ...

Introduction We are interested in robotic task domains involving intermittent dynamical environ-ments, and this article considers a simple representative from a range of robotic tasks associated with dexterous capabilities that might be grouped under the general rubric of “ ...

In this overview, reasons are provided on why we do need to place multimodal, multi-band single and multiple pass POLinSAR monitoring platforms into air and space. The questions" on what POLinSAR monitoring can provide that POL-SAR and INSAR by themselves cannot accomplish " is assessed; whereupon facts and justifications on placing POL-IN-BISAR satellite clusters into space are presented. Reasons for this technology becoming a basic requirement for current, near-future and much more so for future all-day & night year around monitoring of the terrestrial covers are analyzed in view of the un-abating and uncontrollable terrestrial population explosion, which has, does and for ever will result in unavoidable conflicts deteriorating unfortunately at times into terrorism. The pertinent questions on how to reduce the exorbitant cost for initiating this "home-globe security protection"technology are therefore also broached, and the expected benefits are laid out. The p...

Abstract : ELECTRONIC FILE CHARACTERISTICS: 1,028 files; Adobe Acrobat (.PDF) and Reader. PHYSICAL DESCRIPTION: 1 computer laser optical disc (CD-ROM); 4 3/4 in.; 418 MB. SYSTEMS DETAIL NOTE: IBM-clone PC-compatible. ABSTRACT: AP2000 - Millennium Conference on Antennas & Propagation - was held in Davos, Switzerland, 9-14 April 2000, and was organized by the European Space Agency (ESA). AP2000 combined with ICAP (International Conference on Antennas and Propagation) organized by the IEE (UK) and JINA (Journees Internationales de Nice sur les Antennes) organised by CNET (F) & SEE (F) together with ESA and COST (European Cooperation in the field of Scientific and Technical Research) traditional Workshops on antennas and propagation. Conference topics include: millimeter and sub-millimeter wave antennas and propagation, photonic band-gap substrates, MEMS, smart antennas, indoor propagation, concurrent microwave and optical sensing. With the explosion of wireless multimedia communications and of new terrestrial and space applications of microwave, antennas and propagation have a bright future. Their intimate association with complex signal processing and with new integrated microwave, millimeter wave, optical as well as micro-mechanical technologies opens up multidisciplinary challenges and perspectives.