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1.
Having dedicated prior research to identifying a range of methods for detecting the hierarchical layers of language, which also incorporates unsupervised learning toolkits and a Corpus that represents the entire ‘Human Chorus’, this paper outlines the concepts behind providing the last piece in the jigsaw. This particular piece, which ultimately will provide the ability to decipher meaning without an exhaustive crib or primer, poses the perplexing problem of dealing with the seemingly arbitrary nature of this linguistic ‘veneer’. Techniques that, if perfected, will also have a profound impact on developing a universal translator for everyday translation issues and cryptopalaeography. 相似文献
2.
On February 7, 1994, four Canadian Astronauts were sealed off in a hyperbaric chamber at the Canadian Government's Defense and Civil Institute for Environmental Medicine in Toronto, Canada. This space lab training mission lasted seven days and was the first to be conducted with astronauts outside of Russia. The objective of this mission was to give Canadian astronauts, space scientists and the staff of the Canadian Space Agency (CSA), the opportunity to gain first hand experience on preparational and operational aspects of a typical space mission. Twenty-one scientific experiments involving six countries from several disciplines were involved in this mission. This paper describes the goals and preliminary results of a psychological experiment/training program that used the CAPSULS mission as a test bed for its application in the manned space flight environment. The objective of this project was to enhance the understanding of small group behaviour with a view to maximizing team effectiveness and task accomplishment in teams living and working in isolation under difficult and confined conditions. The application of this model in the light of future missions is a key thesis in this paper. 相似文献
3.
Pletser et al. performed a seismic-refraction survey on Devon Island with the goal of assessing the feasibility of astronauts carrying out such operations on Mars to detect subsurface water. We demonstrate that the seismic analysis is fundamentally flawed. The survey performed in this test will likely bear little resemblance to future crewed geophysical surface operations, and better methods exist to detect subsurface water. 相似文献
4.
In September 2011, the European Space Agency (ESA) and the German Space Agency (DLR) organized the first European SpaceTweetup during the German Aerospace day. One of the authors was one of 60 participants at this SpaceTweetup in Cologne and experienced the concept of a Tweetup and the engagement of the participants from the inside view. 相似文献
5.
A CubeSat mission to study the impact of flow incidence angle, surface material and surface roughness on gas–surface interactions on spacecraft in low Earth orbits has been designed. To accomplish this scientific goal the CubeSat deploys a variable geometry aerofoil capable of exposing different surfaces to the flow at different incident angles. By using the on-board GPS measurements and an orbit determination technique the drag experienced by the CubeSat can be estimated. The CubeSat has been designed to be part of the QB50 mission, and hence it carries a sensor that can take in-situ measurements of the atmosphere. This is then used to estimate the atmospheric density and hence to extract information on the drag coefficient. To minimise any bias present in the measurement chain a differential approach is used. Therefore no absolute drag coefficients are estimated, instead, ratios of drag coefficients are computed. This allows direct comparisons of the drag coefficients of different materials, different surface roughness or different incident angles. Simulations indicate that this CubeSat mission will be able to obtain drag coefficient ratios with an uncertainty level of less than 5%. 相似文献
6.
A process is well underway in which the scientific, technical and cultural information vital to our society is stored in digital form within a limited number of computer facilities. This practice is vulnerable to a variety of catastrophes which would destroy our knowledge base in addition to the losses they caused to population and structures. The Alliance to Rescue Civilization (ARC) proposes that a staffed data backup facility be constructed in a secure location, with the Moon as the site of choice. If Earth's population were destroyed entirely, the lunar sanctuary could serve to repopulate the planet. 相似文献
7.
The feasible rendezvous, flyby and sample return mission scenario to different spectral-type asteroids for the 2015–2025 are investigated. The emphasis is put on the potential target selection and the design of preliminary interplanetary transfer trajectory in this paper. First, according to different scientific motivations, some potential targets with different spectral-type and physical property are selected. Then, some optimal rendezvous and sample return opportunities for different spectral-type asteroids are presented by using pork-chop plots method and Sequential Quadratic-Programming (SQP) algorithm. In order to reduce the launch energy and total velocity increments for sample return mission, the Earth swingby strategy is used. In addition, the feasible trajectory profiles of flyby and rendezvous with two different spectral-type asteroids in one mission are discussed. A hybrid optimization method combing the Differential Evolution (DE) algorithm and SQP algorithm is introduced as a trajectory design method for the mission. Finally, some important parameters of transfer trajectory are analyzed, which would have a direct impact on the design of spacecraft subsystem, such as communication, power and thermal control subsystem. 相似文献
8.
Cosmogenic argon isotopes are produced in feldspars via nuclear reactions between cosmic rays and Ca and K atoms within the lattice. These cosmogenic isotopes can be used as proxies for K and Ca, much like nuclear reactor-derived 39Ar and 37Ar are used as proxies for K and Ca, respectively, in 40Ar/ 39Ar geochronology. If Ca and K are uniformly distributed, then the ratio of radiogenic 40Ar ( 40Ar ?) to cosmogenic 38Ar or 36Ar ( 38Ar cos or 36Ar cos) is proportional to the difference between the radioisotopic and exposure ages, as well as the K/Ca ratio of the degassing phase. Thus cosmogenic, radiogenic, and trapped Ar isotopes, all of which can be measured remotely and are stable over geologic time, are sufficient to generate an isochron-like diagram from which the isotopic composition of the trapped component may be inferred. Such data also provide a means to assess the extent to which the system has remained closed with respect to 40Ar ?, thereby mitigating otherwise unquantifiable uncertainties that complicate the conventional K–Ar dating method. 相似文献
9.
Under constrained budgets and rigid schedules, NASA and industry have greatly increased their utilization of small satellites to conduct low-cost planetary investigations. Recent failed small planetary science spacecraft such as Mars Polar Lander (MPL) and Mars Climate Orbiter (MCO), and impaired missions such as Mars Global Surveyor (MGS) have fueled the ongoing debate on whether NASA's “Faster, Better, Cheaper” (FBC) approach is working. Several noteworthy failures of earth-orbiting missions have occurred as well including Lewis and the Wide-field Infrared Experiment (WIRE). While recent studies have observed that FBC has resulted in lower costs and shorter development times, these benefits may have been achieved at the expense of lowering probability of success. One question remaining to be answered is when is a mission “too fast and too cheap” that it is prone to failure? This paper assesses NASA FBC missions in terms of a complexity index measured against development time and spacecraft cost. A comparison of relative failure rates of recent planetary and earth-orbiting missions are presented, and conclusions regarding dependence on system complexity are drawn. 相似文献
10.
The beauty of the view from the office of a spacewalking astronaut gives the impression of simplicity, but few beyond the astronauts, and those who train them, know what it really takes to get there. Extravehicular Activity (EVA) training is an intense process that utilizes NASA’s Neutral Buoyancy Laboratory (NBL) to develop a very specific skill set needed to safely construct and maintain the orbiting International Space Station. To qualify for flight assignments, astronauts must demonstrate the ability to work safely and efficiently in the physically demanding environment of the space suit, possess an acute ability to resolve unforeseen problems, and implement proper tool protocols to ensure no tools will be lost in space. Through the insights and the lessons learned by actual EVA astronauts and EVA instructors, this paper will take you on a journey through an astronaut’s earliest experiences working in the space suit, termed the Extravehicular Mobility Unit (EMU), in the underwater training environment of the NBL. This work details an actual Suit Qualification NBL training event, outlines the numerous challenges the astronauts face throughout their initial training, and the various ways they adapt their own abilities to overcome them. The goal of this paper is to give everyone a small glimpse into what it is really like to work in a space suit. 相似文献
13.
Since the beginning space was an exclusive domain of public organizations, the role of privates is becoming more and more important, and not only in commercial activities. However, the main international treaties dealing with this subject are still based on the assumption that space activities are mostly reserved to states. In the last decade the idea that the role of privates could include the management of space infrastructures and launch vehicles gained support and now private launch services are a reality. An even wider role of privates is now advocated and private exploration and exploitation missions are discussed. This requires that space activity in general can generate an attractive return and those business models are identified. 相似文献
14.
A method for determination of internal gravity wave (IGW) parameters from a single vertical temperature or density profile measurement in the Earth’s atmosphere has been developed. This method may be used for the analysis of profiles measured by any techniques in which the accuracy is enough to measure small (∼1%) amplitudes of the temperature or density fluctuations in the atmosphere. The criterion for the IGW identification has been formulated and argued. In the case when this criterion is satisfied then analyzed fluctuations can be considered as wave-induced. The method is based upon the analysis of relative amplitude thresholds of the temperature or density wave field and upon linear IGW saturation theory in which amplitude thresholds are restricted by dynamical instability processes in the atmosphere. In order to approbate the method we have used data of simultaneous radiosonde measurements of the temperature and wind velocity in the Earth’s stratosphere where the saturated IGW propagation has been detected. It is shown that the application of the method to radio occultation temperature data gives the possibility to identify IGWs in the Earth’s lower stratosphere and to determine values of key wave parameters. 相似文献
16.
The particular mineralogy formed in the acidic conditions of the Río Tinto has proven to be a first-order analogue for the acid-sulfate aqueous environments of Mars. Therefore, studies about the formation and preservation of biosignatures in the Río Tinto will provide insights into equivalent processes on Mars. We characterized the biomolecular patterns recorded in samples of modern and old fluvial sediments along a segment of the river by means of an antibody microarray containing more than 200 antibodies (LDCHIP200, for Life Detector Chip) against whole microorganisms, universal biomolecules, or environmental extracts. Samples containing 0.3-0.5?g of solid material were automatically analyzed in situ by the Signs Of LIfe Detector instrument (SOLID2), and the results were corroborated by extensive analysis in the laboratory. Positive antigen-antibody reactions indicated the presence of microbial strains or high-molecular-weight biopolymers that originated from them. The LDCHIP200 results were quantified and subjected to a multivariate analysis for immunoprofiling. We associated similar immunopatterns, and biomolecular markers, to samples with similar sedimentary age. Phyllosilicate-rich samples from modern fluvial sediments gave strong positive reactions with antibodies against bacteria of the genus Acidithiobacillus and against biochemical extracts from Río Tinto sediments and biofilms. These samples contained high amounts of sugars (mostly polysaccharides) with monosaccharides like glucose, rhamnose, fucose, and so on. By contrast, the older deposits, which are a mix of clastic sands and evaporites, showed only a few positives with LDCHIP200, consistent with lower protein and sugar content. We conclude that LDCHIP200 results can establish a correlation between microenvironments, diagenetic stages, and age with the biomarker profile associated with a sample. Our results would help in the search for putative martian biomarkers in acidic deposits with similar diagenetic maturity. Our LDCHIP200 and SOLID-like instruments may be excellent tools for the search for molecular biomarkers on Mars or other planets. 相似文献
17.
This paper presents the results of a mission concept study for an autonomous micro-scale surface lander also referred to as PANIC – the Pico Autonomous Near-Earth Asteroid In Situ Characterizer. The lander is based on the shape of a regular tetrahedron with an edge length of 35 cm, has a total mass of approximately 12 kg and utilizes hopping as a locomotion mechanism in microgravity. PANIC houses four scientific instruments in its proposed baseline configuration which enable the in situ characterization of an asteroid. It is carried by an interplanetary probe to its target and released to the surface after rendezvous. Detailed estimates of all critical subsystem parameters were derived to demonstrate the feasibility of this concept. The study illustrates that a small, simple landing element is a viable alternative to complex traditional lander concepts, adding a significant science return to any near-Earth asteroid (NEA) mission while meeting tight mass budget constraints. 相似文献
18.
Cosmic Research - A distinctive feature of the Jovian magnetosphere is a powerful disklike current system—the current disk. There are several models of the magnetic field of this current... 相似文献
19.
Cosmic Research - An Erratum to this paper has been published: https://doi.org/10.1134/S0010952521120029 相似文献
20.
The results of numerical modeling of thinning process in the Earth’s magnetotail current sheet are compared with the model of an anisotropic current sheet in collisionless space plasma. Stability of the current sheet during its evolution is investigated. In the evolution one can distinguish three basic stages: 1) transformation of the initial two-dimensional “isotropic” equilibrium that is well described within the MHD-approximation into a relatively thin current structure; 2) further kinetic evolution, as a result of which the virtually one-dimensional, extremely thin current sheet is formed; 3) relaxation of the system into a new equilibrium that can be stable or unstable. A substorm scenario of transformation of the magnetospheric tail and its transition into the unstable state is suggested. The spontaneously appearing tearing disturbance favors a current sheet disruption. It is shown that the estimate of a tearing mode wavelength, obtained from the model, is in accordance with experimental observations during the explosive phase of substorms. 相似文献
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