Special Array Research Articles

Ungewöhnliche Tubuli im Endoplasmatischen Retikulum von Schilddrüsentumorzellen

An unique tubular configuration of the endoplasmic reticulum was discovered electronmicroscopically in a canine thyroid carcinoma. The striking round tubules are aligned parallel to one another and have a regular diameter of about 45 nm. Mostly a number of 3–7 tubules are present in one cisterna of the endoplasmic reticulum, forming a bundle with rather straight course. Longitudinally, a length of up to 5 μm can be traced in thin sections. Continuity of the tubular membranes with those of the endoplasmic reticulum is well established, whereas free endings obviously do not exist. Most of the tubules reveal an internal structure consisting of 1–7 longitudinally oriented filaments. It is suggested that the tubules represent a partial modification of the endoplasmic reticulum. Their relation to well known special arrays of the endoplasmic reticulum is discussed.

Mesoscale Weather Systems within an Occlusion

Abstract Precipitation systems within a mature extratropical cyclone are related to the mesoscale thermal and circulation fields aloft using data from Project Stormy Spring conducted by the Air Force Cambridge Research Laboratories. Precipitation systems were analyzed using radars and recording raingages, including a special mesoscale array; upper-air structures were deduced from a 10-site mesoscale rawinsonde network including serial soundings at 90-min intervals. Results show that most of the widespread precipitation, in conjunction with the cyclonic-scale vertical motions in frontal baroclinic zones, occurs in bands and groups of showers. A sub-synoptic core of cold dry air in the middle troposphere ahead of the surface occlusion was found to be subsiding and surpressing wide-spread cloudiness, while it was furnishing a large amount of potential instability. The cyclone-scale ascending motions then released the potential instability around this cold core and also above the warm frontal stable layer. Th...

Analysis of an Integral Equation Arising from the Investigation of Vertical Directivity of Sea Noise

An integral equation relates the single frequency vertical distribution of ambient ocean noise to the measured array output when the noise power at the array arises from the superposition of uncorrelated plane waves. This integral equation has an infinite number of solutions. However, from the physical viewpoint, there is one solution, referred to as the “principal solution,” which is the most plausible representation of the true noise field. The “principal solution,” is precisely defined, and then classical Hilbert space theory is used to determine this solution from a finite number of array measurements. The number of measurements required depends only on the interelement spacings of the array. In selecting this finite number of steering angles to make the array measurements, any choice that yields independent samples for a certain finite sequence of trigometric functions is sufficient. Not surprisingly, these measurements contain all the information available in the observed distribution, the array output, and an explicit expression is given for the observed distribution. Special array configurations are exhibited for which the “principal solution” is a partial sum in the Fourier expansion of the true noise field.

A NOTE ON THE USE OF MICROSEISMS IN DETERMINING THE SHALLOW STRUCTURES OF THE EARTH’S CRUST

In the VELA UNIFORM Special Issue I of Geophysics, M. N. Toksöz presented the result of his attempt at determining the shallow structures of the earth’s crust from the phase velocity of microseisms. He stated that his attempt resulted only in partial success on account of the fact that the microseisms arrived from more than one direction at the same time with comparable strength. He also concluded that there was no way of improving the results by the use of special arrays because, according to him, there were two unknown parameters, direction and phase velocity, and without the knowledge of one the other cannot be found. I thought this problem was already solved in my paper (Aki, 1957), in which a statistical theory of determining the phase velocity of random waves was given with a successful application to microseisms in Tokyo in the frequency range of 5 to 15 cps. Since Toksöz’s conclusion might have given a pessimistic view on the use of microseisms, I feel it is necessary to report a brief summary of my old paper published in a Japanese journal which might not be well circulated in the United States.

Blocking in 3-Stage "Folded" Switching Arrays

Following a brief consideration of multistage switching arrays in general, with particular emphasis on the advantages of 3-stage switching systems, this paper discusses the blocking properties of "folded" vs. "nonfolded" 3-stage switching arrays. Conditions under which a "folded" array will be nonblocking are stipulated. A comprehensive series of formulas are given for determining the internal blocking of any "folded" 3-stage array which does not satisfy the conditions for nonblocking. Included also are tables (based on certain of these formulas) for quickly finding the blocking in any "symmetrical" 3-stage "folded" array, and for determining the "dimensions" of symmetrical arrays required to carry any given density of traffic at any given maximum allowable blocking. Additional information and formulas are included, covering the use of "multiple-linkage" in special arrays intended for register access. The derivation of certain of these blocking formulas is given in the Appendix. It should be noted that the formulas given in this paper are all based on the assumption that the distribution of telephone traffic offered to the arrays will conform to the Exponential Binomial Probability Distribution (Bernoulli); this is the usual assumption made in American practice.