Locally optimal and suboptimal signal detection in transformationnoise

The efficacy of the optimal detector of a known vanishingly small signal in additive nonwhite transformation noise is compared with that of some eleven structurally simpler suboptimal detectors. Simulation is done under various signal choices, marginal densities, and correlation functions. The block g_lo and the block combination g followed by R_v^-1 in the optimal detector structure are found to be important for good performance in constant and oscillating signals, respectively. Two suboptimal detectors with these block structures, D₈ and D₁₀, are found to perform well consistently in all situations considered. A structurally simple suboptimal detector D₂ is found to be good in the cases with less correlated noise     

A coupled finite-element state-space approach for synchronousgenerators. I. model development

Presented here is the development of a time stepping coupled finite-element state-space (CFE-SS) modeling environment, totally within the natural time domain ABC flux-linkage frame of reference, to predict the steady-state machine parameters and performance characteristics, including laminated iron core losses, of salient-pole synchronous machines. The time stepping CFE-SS model allows one to rigorously account for the full synergistic impact of space harmonics and time harmonics on the machine parameters and performance characteristics     

声发射技术在复合材料结构无损检测中的应用

简述了复合材料AE技术的发展概况、AE特性和破坏类型;讨论了几种不同破坏机理的AE判据;着重介绍了AE技术在复合材料压力容器无损检测中的应用及压力容器水压试验时应注意的某些问题。     

The prospects for enhanced international polar-orbiting satellite cooperation

With robust polar satellite missions demonstrated and/or operational in the USA, Europe, Japan, China, Russia, India, and Brazil, and with other nations also likely to develop such capability, this paper examines the prospects for as well as the potential challenges to closer and perhaps more formal international polar satellite cooperation. In suggesting that now is the time to explore the development of a coordinated polar observing system, the present paper identifies potential contributors, assesses the relevance of existing space-based Earth observation international coordination mechanisms, and considers three potential models for a future system.     

Progress of Protection of the Environment and Resources in the United States - A Historical Survey

State and Federal legislative actions intended to improve and to preserve the quality of our environment and to conserve our natural resources were developed and implemented in a logical sequence, synchronized with our own social development and awareness of the need for specific legislative, punitive, or constructive actions. At all times, the desired legislation was developed through a consensus of opinions, needs, and costs that were to be incurred by the affected parties. In some cases, the Federal Government found it necessary to increase its budget allocations in areas where an immediate relief was needed and large losses were anticipated.     

Improved adaptive clutter cancellation through data-adaptivetraining

Adaptive array algorithms based on sample matrix inversion (SMI) require the availability of a secondary data set to “train” the adaptive filter. Numerous data-independent rules have been proposed for selecting this training data. However, such rules often perform poorly in inhomogeneous environments. We present data-adaptive methodologies for selecting the training data. The techniques, called “Power Selected Training” and “Power Selected Deemphasis”, use measurements of the interference environment to select training data. This work describes these algorithms and their performance on recorded radar data     

Techniques for the selection of spectral intervals for multispectral survey of the earth's resources from space

A solution has been proposed for the problem of optimal selection of spectral intervals for multispectral survey of the Earth's resources from space. The problem of planning multipurpose experiments on remote sensing of environment and natural resources has been considered.     

Field and wave measurements aboard the Aureol-3 spacecraft

In the Soviet-French Arcad-3 project, 3 experiments TBF-ONCH, TRAC and ISOPROBE are carried out on board the Aureol-3 satellite to measure the AC and DC electric and magnetic fields and waves. Several modes of telemetry, real time and memory regimes are available for data transmission. TBF-ONCH is devoted to the measurement of 3 components of the DC electric field, 2 electric and 3 magnetic components of the waves. In one mode of the real time telemetry these 5 components are transmitted simultaneously in the frequency range 10 Hz-1.5 kHz in order to be able to determine the wave normal directions of natural emissions and to localize their sources. In the second mode, morphological studies of saucers, chorus, hiss and triggered emissions can be undertaken using the wide band transmission (70 Hz-16 kHz) of any one of these 5 components with the possibility of periodically changing the transmitted component every 4 seconds or keeping the same one during all the pass. TRAC makes use of the on board 3 axis flux gate magnetometer to perform a fine measurement of the magnetic effects of the currents flowing in the vicinity of the spacecraft either in the ionosphere or along the magnetic field lines, with a resolution of ～ 12 nT and in the frequency range from DC to ～ 20 Hz. One component of the HF electric field (0.1–10 Mhz) is measured by ISOPROBE (see companion paper). Examples of inflight measurements from the above instruments and their presentation on microfiches are shown. Some new phenomena are emphasized and briefly discussed.