An efficient and provably secure key agreement scheme for satellite communication systems.

Satellite communication has played an important part in many different industries because of its advantages of wide coverage, strong disaster tolerance and high flexibility. The security of satellite communication systems has always been the concern of many scholars. Without authentication, user should not obtain his/her required services. Beyond that, the anonymity also needs to be protected during communications. In this study, we design an efficient and provably secure key agreement scheme for satellite communication systems. In each session, we replace user's true identity by a temporary identity, which will be updated for each session, to guarantee the anonymity. Because the only use of lightweight algorithms, our proposed scheme has high performance. Furthermore, the security of the proposed scheme is proved in the real-or-random model and the performance analysis shows that the proposed scheme is more efficient than some other schemes for satellite communication systems.

Developing Future Deep-Space Telecommunication Architectures: A Historical Look at the Benefits of Analog Research on the Development of Solar System Internetworking for Future Human Spaceflight.

Exploration analog field tests, missions, and deployments enable the integration and validation of new and experimental concepts and/or technologies through strategic experimental design. The results of these operations often create new capabilities for exploration and increase confidence in, and credibility of, emerging technologies, usually at very low cost and risk to the test subjects involved. While these experiments resemble missions 10-30 years into the future, insights obtained are often of immediate value. Knowledge gained in the field translates into strategic planning data to assist long-range exploration planners, and planners influence the experimental design of field deployments, creating a synergistic relationship. The Biologic Analog Science Associated with Lava Terrains (BASALT) communication architecture is a high-fidelity analog program that emulates conditions impacting future explorers on the martian surface. This article provides (1) a brief historical review of past analog operations that deliberately used elements of a flight-like telecommunication infrastructure to add fidelity to the test, (2) samples of the accomplishments made through analog operations, and (3) potentially significant deep-space telecommunication insights gained from the BASALT program in support of future extravehicular activity exploration of Mars. This article is paired with and complements Miller et al. in this issue which focuses on the telecommunication infrastructure utilized by the BASALT team during the field deployment.

Multi-Year Mapping of Major Crop Yields in an Irrigation District from High Spatial and Temporal Resolution Vegetation Index.

Crop yield estimation is important for formulating informed regional and national food trade policies. The introduction of remote sensing in agricultural monitoring makes accurate estimation of regional crop yields possible. However, remote sensing images and crop distribution maps with coarse spatial resolution usually cause inaccuracy in yield estimation due to the existence of mixed pixels. This study aimed to estimate the annual yields of maize and sunflower in Hetao Irrigation District in North China using 30 m spatial resolution HJ-1A/1B CCD images and high accuracy multi-year crop distribution maps. The Normalized Difference Vegetation Index (NDVI) time series obtained from HJ-1A/1B CCD images was fitted with an asymmetric logistic curve to calculate daily NDVI and phenological characteristics. Eight random forest (RF) models using different predictors were developed for maize and sunflower yield estimation, respectively, where predictors of each model were a combination of NDVI series and/or phenological characteristics. We calibrated all RF models with measured crop yields at sampling points in two years (2014 and 2015), and validated the RF models with statistical yields of four counties in six years. Results showed that the optimal model for maize yield estimation was the model using NDVI series from the 120th to the 210th day in a year with 10 days' interval as predictors, while that for sunflower was the model using the combination of three NDVI characteristics, three phenological characteristics, and two curve parameters as predictors. The selected RF models could estimate multi-year regional crop yields accurately, with the average values of root-mean-square error and the relative error of 0.75 t/ha and 6.1% for maize, and 0.40 t/ha and 10.1% for sunflower, respectively. Moreover, the yields of maize and sunflower can be estimated fairly well with NDVI series 50 days before crop harvest, which implicated the possibility of crop yield forecast before harvest.

Applications of Space Technologies to Global Health: Scoping Review.

BACKGROUND: Space technology has an impact on many domains of activity on earth, including in the field of global health. With the recent adoption of the United Nations' Sustainable Development Goals that highlight the need for strengthening partnerships in different domains, it is useful to better characterize the relationship between space technology and global health. OBJECTIVE: The aim of this study was to identify the applications of space technologies to global health, the key stakeholders in the field, as well as gaps and challenges. METHODS: We used a scoping review methodology, including a literature review and the involvement of stakeholders, via a brief self-administered, open-response questionnaire. A distinct search on several search engines was conducted for each of the four key technological domains that were previously identified by the UN Office for Outer Space Affairs' Expert Group on Space and Global Health (Domain A: remote sensing; Domain B: global navigation satellite systems; Domain C: satellite communication; and Domain D: human space flight). Themes in which space technologies are of benefit to global health were extracted. Key stakeholders, as well as gaps, challenges, and perspectives were identified. RESULTS: A total of 222 sources were included for Domain A, 82 sources for Domain B, 144 sources for Domain C, and 31 sources for Domain D. A total of 3 questionnaires out of 16 sent were answered. Global navigation satellite systems and geographic information systems are used for the study and forecasting of communicable and noncommunicable diseases; satellite communication and global navigation satellite systems for disaster response; satellite communication for telemedicine and tele-education; and global navigation satellite systems for autonomy improvement, access to health care, as well as for safe and efficient transportation. Various health research and technologies developed for inhabited space flights have been adapted for terrestrial use. CONCLUSIONS: Although numerous examples of space technology applications to global health exist, improved awareness, training, and collaboration of the research community is needed.

The evolution of eLearning background, blends and blackboard....

This review of eLearning is divided into three sections: the first charts the evolution of eLearning from early correspondence courses to the current computer mediated approaches to distributed learning. The second section deals with the concept of blended learning; combining best practice in face-to-face and online learning. The final section focuses on current platform technologies in eLearning and outlines the strengths and weaknesses of learning management systems such as Blackboard.

Simulações da SAR na cabeça e antenas planares para telefones móveis / SAR simulations and planar antennas for mobile phones

A Taxa de Absorção Específica (SAR) na cabeça dos usuários de telefones móveis é simulada utilizando o método das Diferenças Finitas no Domínio do Tempo (FDTD) quando antenas tipo monopolo convencionais e quando antenas diretivas planares são utilizadas. São também resumidos o projeto de antenas tipo patch retangular em microstrip, suas características de desempenho esperadas e medidas são apresentadas. São calculados entre outros, a taxa de onda estacionária e a largura de banda simuladas no software Ensemble®, o diagrama de irradiação no plano horizontal e o campo na região próxima, claculado em simulação em três dimensões - 3D com algoritmo baseado em FDTD. Medidas da taxa de Onda Estacionária VSWR e dos diagramas de irradiação horizontal são mostradas. Verifica-se uma excelente correlação entre os resultados das medidas e os obtidos com o método FDTD em simulações com plano de terra finito e sem aterramento efetivo. Observa-se que este tipo de antena pode ser utilizado em uma nova geração de telefones móveis, constituindo-se em uma alternativa conveniente para melhorar o desempenho destes transcetores, diminuindo também os riscos à saúde dos usuários

Impacts for medicine of global monitoring.

In his 1998 Turing Award speech, Jim Gray described a number of research goals including those of building what he referred to as a Personal Memex and a World Memex. The Personal Memex is a system for recording everything one saw, heard, or read, while the World Memex is a system to contain all professionally produced information. In this paper we discuss the consequences to medicine of an additional type of monitoring, that of movement and position via GPS devices. The paper argues that such devices will be incorporated into hand-helds, telephones, and wristwatches, and that a World Memex will (with appropriate permissions) monitor and record all personal movement. The motivation for such a development is the many uses to which the system can be put. The paper restricts itself to discussing those uses that apply to physical safety and medical research studies. Examples relating to safety include the detection of, and notification of emergency authorities about, accidents involving unusual motion, such as occur e.g. in car accidents or when people fall off ladders. Examples of medical research studies include those that involve the effects of exercise, or exposure to different environmental conditions. Precise quantitative statistics can be gathered, providing answers to such questions as what the optimum amounts of exercise are for various health-related conditions. The paper discusses these among other such applications.

New tools: potential medical applications of data from new and old environmental satellites.

The last 40 years, beginning with the first TIROS (television infrared observational satellite) launched on 1 April 1960, has seen an explosion of earth environmental satellite systems and their capabilities. They can provide measurements in globe encircling arrays or small select areas, with increasing resolutions, and new capabilities. Concurrently there are expanding numbers of existing and emerging infectious diseases, many distributed according to areal patterns of physical conditions at the earth's surface. For these reasons, the medical and remote sensing communities can beneficially collaborate with the objective of making needed progress in public health activities by exploiting the advances of the national and international space programs. Major improvements in applicability of remotely sensed data are becoming possible with increases in the four kinds of resolution: spatial, temporal, radiometric and spectral, scheduled over the next few years. Much collaborative research will be necessary before data from these systems are fully exploited by the medical community.

Consortia arrangements and educational telecommunication.

Revolutionary and rapid changes are required in nursing programs and products to fit with the developing health care system. Many present-day nurses and nursing faculty will require changes in their areas of expertise. Nursing colleges that have faculty qualified in the areas of greatest need should explore the use of consortia for delivering distance education. In this way, quality can be controlled, and the conflict of interest involved in schools trying to change the preparation of their own faculty can be reduced or resolved. Organizing consortia is complex, with problem areas in administration, personnel, and resources. Selected television satellite networks are offered as examples of how to manage the problem areas or as possible vehicles for course delivery.

Satellite-delivered continuing medical education in Europe.

There is increasing recognition of the need for continuing medical education in the medical profession. There are now many ways of delivering medical education including conferences, books, journals amongst others. This paper describes a novel method of delivering medical education using satellite transmission. This medium allows live medical education programmes to be broadcast to over 150 receiver sites in Europe. It also enables two-way live satellite links to be made between countries during the broadcast. EuroTransMed has an editorial board, in much the same way as a journal, which is representative of the differing medical societies in Europe. As the barriers between the various countries fall, EuroTransMed is an ideal medium to promote high quality, easily accessible, continuing medical education at a pan-European level.

Remotely sensed surrogates of meteorological data for the study of the distribution and abundance of arthropod vectors of disease.

This paper gives an overview of how certain meteorological data used in studies of the population dynamics of arthropod vectors of disease may be predicted using remotely sensed, satellite data. Details are given of the stages of processing necessary to convert digital data arising from satellite sensors into ecologically meaningful information. Potential sources of error in these processing steps are also highlighted. Relationships between ground-measured meteorological variables (saturation deficit, ground temperature and rainfall) and data from both the National Oceanic and Atmospheric Administration's, polar-orbiting, meteorological satellites and the geostationary, Meteosat satellite are defined and examples detailed for Africa. Finally, the current status of existing satellite platforms and future satellite missions are reviewed and potential data availability discussed. How such satellite-based predictions have proved valuable in understanding the distribution of tsetse fly species in Côte d'Ivoire and Burkina Faso will be the subject of a future review.

The state of solid state.

This talk about future communications technology is all well and good, but what about the things we already have? What's going on with current technology? And if things are going to change, what will the transition be like? For an overview, JEMS talked to a group of EMS communications experts: Bruce Jackson, president of EMSAT: Advanced Technology for EMS, in the Los Angeles area; Mark Johnson, chief of Alaska's EMS Section, chairman of the National Association of State EMS Directors' Communications Committee; and Steven Buckley, communications and facilities planning manager of the Warner Group, a public safety communications consulting company in Woodland Hills, Calif. The following summarizes their views on current issues and their projections for the near future.

Telescience and microgravity impact on future facilities, ground segments and operations.

Scientific activities related to experimentation in long duration microgravity missions can only be accomplished by the implementation of the Telescience Concept. Telescience is in fact the logical answer to the need of an intelligent interactive conduct of experiments, to the lack (or very little availability) of crew time on board of the Segments of the Columbus project and to the PIs demand for decentralized operations. Telescience could also be seen as the preparative phase for the ultimate, future exploitation of Microgravity by means of Expert Systems that will utilize AI and Robotics for routine operations (Data Factories, Space Productions and Commercial Enterprises). The implications of Telescience on future Space Activities is reviewed with reference to the Principal Investigator Activities, Crew Members Roles and Facilities. The possibilities offered by newly designed Facilities to be operated in Telescience are pointed out with reference to the scientific objectives that would not be achieved otherwise. Diagnostic facilities (mainly non invasive) that provide digital measurements to be inputted (in real time) into numerical codes for computation of field parameters are being considered. Ground Segment Structure, User Support Centers Organization and Test Bedding activities will be discussed as essential factors of the Telescience Scenario of the Multiuser, permanent platform Facilities for the Microgravity disciplines (Material, Fluid, Life and Engineering Science).