Showing papers by "Florida Atlantic University published in 1985"
TL;DR: In this article, the authors considered a class of M/G/1 queueing models with a server who is unavailable for occasional intervals of time and showed that the stationary number of customers present in the system at a random point in time is distributed as the sum of two or more independent random variables.
Abstract: This paper considers a class of M/G/1 queueing models with a server who is unavailable for occasional intervals of time. As has been noted by other researchers, for several specific models of this type, the stationary number of customers present in the system at a random point in time is distributed as the sum of two or more independent random variables, one of which is the stationary number of customers present in the standard M/G/1 queue i.e., the server is always available at a random point in time. In this paper we demonstrate that this type of decomposition holds, in fact, for a very general class of M/G/1 queueing models. The arguments employed are both direct and intuitive. In the course of this work, moreover, we obtain two new results that can lead to remarkable simplifications when solving complex M/G/1 queueing models.
664 citations
TL;DR: This paper examined the influence of sentence constraint and cue validity on the processing of expected and unexpected congruous sentence completions, and found that more featural restrictions are generated as sentence constraints and cues increase.
202 citations
TL;DR: For instance, the authors found that children in Grades 3, 5, 7, and 9 were more apt to use associative relations to begin category clusters than were younger children or adults.
122 citations
TL;DR: It was concluded that sexual dimorphism can be detected by metrical analysis from the teens to the 70s and thisDimorphism increases with age.
Abstract: Although there have been a number of radiological studies of the entire anterior thorax, no attempt has been made to establish a method of sex determination based on direct metrical analysis of an isolated rib. The present study attempts to determine sex from the sternal end of the fourth rib. The sample (144 males, 86 females) was obtained from individuals of known age, sex, and race autopsied at a medical examiner's office. Three measurements (height, width, and sternal articular pit depth) were taken from each bone. The sample was divided into three groups: young, old, and the combined total and analyzed by means of stepwise discriminant function statistics. It was found that the accuracy of sex determination varied from 82% in the young and 89% in the old groups to 83% for the combined group. However, when a discriminant function formula developed for a different age group was used the accuracy of correct assessment diminished considerably. It was, therefore, concluded that sexual dimorphism can be detected by metrical analysis from the teens to the 70s and this dimorphism increases with age.
118 citations
TL;DR: The refractive index of snow at 0°C was calculated for different snow types and microwave frequencies for the sake of completeness, and the refractive indices of water and ice were also calculated for the same frequencies.
Abstract: A systematic procedure for calculating the refractive index of snow at microwave frequencies is presented. The refractive index of snow at 0°C was calculated for different snow types (classified in terms of snow wetness as dry, most, wet, and watery) and microwave frequencies. For the sake of completeness, the refractive indices of water and ice were also calculated for the same frequencies.
53 citations
TL;DR: A recent decomposition result of Fuhrmann and Cooper for the M/G/1 queue with server vacations is applied to obtain mean waiting times for the following two cyclic queueing models: Model 1 describes token-ring polling in certain computer-communication networks; Model 2 has been used to describe mail pickup and delivery systems.
Abstract: We apply a recent decomposition result of Fuhrmann and Cooper for the M/G/1 queue with server vacations to obtain mean waiting times for the following two cyclic queueing models: The server scans at a constant velocity (1) serving work as it is encountered, or (2) collecting work that it serves at the end of each cycle. Model 1 describes token-ring polling in certain computer-communication networks; Model 2 has been used to describe mail pickup and delivery systems.
47 citations
TL;DR: An in vitro flow circulation system is used to more closely simulate the physiological conditions and finds that the blood resistivity change contribution is strong enough (21.5 percent of the arterial volume change contribution) to change the morphology of the impedance pulse.
Abstract: An impedance pulse, recorded noninvasively, has contributions due to both the change in blood volume of the arteries and to the change in the blood resistivity. Other researchers have tried to quantify the relative contributions and have either underestimated or overestimated the contributions since they did not simulate the physiological conditions. We have used an in vitro flow circulation system to more closely simulate the physiological conditions and quantify the two contributions. We find that the blood resistivity change contribution is strong enough (21.5 percent of the arterial volume change contribution) to change the morphology of the impedance pulse. There is, however, a phase difference between the two contributions. As a result of this, the blood resistivity change contribution to the height of the impedance pulse will be less than 5.5 percent.
44 citations
TL;DR: Through a combination of behavioral and anatomical adaptations, phalaropes and avocets evidently are able to rid their prey of most adherent lake water and thereby largely avoid the problems of salt-loading and the ingestion of harmful ions.
Abstract: Wilson’s Phalaropes (Phalaropus tricolor) and American Avocets (Recurvirostra americana) occur in large numbers at hypersaline and alkaline lakes. Comparing birds from three lakes of different salinity and alkalinity in the Great Basin of western North America, we found no evidence of salt-loading: blood hematocrit, pH, osmolality, and sodium concentration were not elevated; stomach osmolality and sodium concentration were only slightly higher than the body fluids of the birds’ hypo-osmotic prey (brine shrimp and brine flies); salt glands were not enlarged and averaged a relatively low percentage of body weight (0.02%). Through a combination of behavioral and anatomical adaptations, phalaropes and avocets evidently are able to rid their prey of most adherent lake water and thereby largely avoid the problems of salt-loading and the ingestion of harmful ions. Both species occupy hypersaline habitats for long periods and probably derive most of their water needs from the body fluids of their prey. Their use of fresh water is sporadic and may not be required for osmoregulatory balance. Alkaline and hypersaline lakes, despite being harsh physical environments, are prime habitats for a few species of resident (e.g., flamingos) and a somewhat larger number of migratory waterbirds. Mono Lake, California, a large hypersaline (2’ 12 x the concentration of sea water) and alkaline (pH x 10) lake at the eastern base of the Sierra Nevada, attracts large numbers of a few of these species each year. Approximately 45,000 California Gulls (Larus californicus) nest there; in summer and in fall, tens of thousands of Wilson’s (Phalaropus tricolor) and Red-necked (P. lobatus) phalaropes stop over on their southward migration (Jehl 198 l), and hundreds of thousands of Eared Grebes (Podiceps nigricollis) stage there (Storer and Jehl 1985). American Avocets (Recurvirostra americana) are also common at hypersaline lakes, although at Mono Lake only a few pairs breed and flocks of several hundred occur in autumn. Hypersaline lakes are attractive to these birds because they typically lack fish, which allows the few invertebrates that can occupy them to attain great abundances. These, in turn, serve as food for the birds. At Mono Lake, brine shrimp (Artemia sp.) and brine flies (Ephydru hians) become super-abundant at some seasons. Birds feeding on these invertebrates, either by pecking them from the surface of the water or by catching them while driving, might be expected to ingest large amounts of lake water and thereby incur deleterious salt loads. Yet, our previous studies of California Gulls (Mahoney and Jehl 1985a) and Eared Grebes (Mahoney and Jehl 1985b) at Mono Lake, where salinities have varied from 72 to 90 ppt (2,160-2,700 mOsm/kg) in 1982-l 984, have shown that this is not the case. These species seem to have no special anatomical or physiological adaptations for dealing with high salt loads. Instead, they largely avoid osmoregulatory problems behaviorally, by ridding their food of adherent lake water before swallowing it. Gulls and grebes differ markedly in their use of fresh water. Gulls visit freshwater streams to drink and bathe several times each day, whereas grebes, although they may remain continuously at Mono Lake for as long as six months (Jehl, unpubl. data), never visit fresh water. Wilson’s Phalaropes and American Avocets (Fig. 1) have intermediate patterns of water use; both visit fresh water regularly, though probably not daily. If phalaropes and avocets ingest large quantities of Mono Lake water and its attendant osmotic and ionic load, they could be expected to show changes in blood chemistry, hydration state, and salt gland size. In order to determine how great a salt load these birds incur while feeding at the lake, we made the following measurements: blood pH and hematocrit; serum osmolality, sodium, and potassium; composition and osmolality of stomach contents, prey body fluids, and lake water; body water content; and salt gland weights. We then compared these values from Mono Lake birds to those
43 citations
TL;DR: In this paper, the authors argue that quality is too important a factor to be left solely to quality control personnel or planners and is a fundamental part of the chief executive's responsibility for the development of strategy.
40 citations
TL;DR: A model which covers the important stages of environmental analysis: scanning, assessment and prediction is introduced, which includes a new classification system for external variables and an outline for analyzing these variables.
38 citations
TL;DR: In this article, the optimum thickness distribution of unconstrained viscoelastic damping layer treatments for plates was investigated. And the results indicated that the system loss factor can be increased by as much as 100%, or more, by optimizing the thickness distribution.
01 Jan 1985
TL;DR: In this paper, a random process is introduced as a multiplicative factor to deterministic laws, which is assumed to be a train of randomly arriving pulses with random amplitudes, permitting simple computation of the statistical properties of the fatigue crack size at any given time.
Abstract: Deterministic fatigue crack propagation models, such as the Paris-Erdogan model, cannot account for random variability of time-histories observed in experiments. Therefore, more realistic models are proposed in which a random process is introduced as a multiplicative factor to deterministic laws. This factor is assumed to be a train of randomly arriving pulses with random amplitudes, permitting simple computation of the statistical properties of the fatigue crack size at any given time. Approximate probability distributions can then be calculated using a general scheme called cumulant-neglect closure. Results obtained from retaining only the first two cumulants are compared with available experimental data and with previously calculated distributions when the crack size was treated as a Markov process.
TL;DR: This article examined the record of enforcement by state campaign finance agencies since their inception following Watergate and found that only four of the sixteen states that have established enforcement records that meet minimal standards have sought to administer substantial penalties and other civil remedies with consistency and vigor.
Abstract: This study examines the record of enforcement by state campaign finance agencies since their inception following Watergate. These boards and commissions exist in twenty-six states, although ten of them do not engage in substantial efforts to enforce the campaign finance laws. The remaining sixteen have established enforcement records that meet minimal standards, but only four have sought to administer substantial penalties and other civil remedies with consistency and vigor. Each of the four is subjected to separate analysis as to structure, level of fines, administration of other sanctions, and judicial experiences.
TL;DR: LetG be an (r+2)-connected graph in which every vertex has degree at leastd and which has at least 2d-r vertices and for any pathQ of lengthr and vertexy not onQ, there is a cycle of length at least2d- r containing bothQ andy.
Abstract: LetG be an (r+2)-connected graph in which every vertex has degree at leastd and which has at least 2d-r vertices. Then, for any pathQ of lengthr and vertexy not onQ, there is a cycle of length at least 2d-r containing bothQ andy.
TL;DR: In this paper, a conceptual framework from which intangible attributes can be "tagged" to tangible signs is proposed, based on Kelly's notion of personal constructs (Kelly 1963), which are at the core of consumers' determination of the degree to which attributes exist within phenomenon.
Abstract: Marketing services requires identification of consumer's perceptions of salient attributes for positioning. Personal constructs (Kelly 1963) are at the core of consumers' determination of the degree to which attributes exist within phenomenon. Using Kelly's notion of personal constructs, this paper proposes a conceptual framework from which intangible attributes can be “tagged” to tangible signs.
TL;DR: The results of the study indicated that there was a decrease in the accuracy of racial classification from 80% to 77% in males and 84% to 75% in females, and decreases were not significant.
TL;DR: This article examined change in occupational goals and values among young adults who enter postsecondary education and found that the influence of variation in college characteristics on extrinsic and intrinsic value of education was significant.
Abstract: This study examines change in occupational goals and values among young adults who enter postsecondary education. The influence of variation in college characteristics on extrinsic and intrinsic va...
TL;DR: In this article, Littman showed that the estimate ∫ ∫ (¦▽(t)¦ p + ¦u t (t) ¦ p ) dx ⩽ C(t), ∫∫ ¦□u¦p dx dt cannot hold for all solutions of the wave equation □u = 0 in R n x R ; all t ϵ R ; some function C: R → R.
TL;DR: In this article, a lifestyle approach was used to explore variations in homicide rates for Dade County, Florida, and found that four individual characteristics and six residential characteristics are implicated in the explanation of variations in homicides among census tracts.
TL;DR: The effect of practice on catch trials was not accompanied by changes in speed of category-level vs. specific-level identification predicted from level-of-identification explanations of the category effect.
Abstract: Two experiments involved searching for digit or letter targets in displays of letters. On a catch trial following between-category search (for a digit among letters), a digit other than the target was presented in the display. The occurrence of incorrect target-present responses and slow, correct target-absent responses on this catch-trial decreased as the amount of preceding practice increased. This practice effect was not accompanied by shifts in decision criteria predicted from explanations of the category effect that stress between- and within-category differences in physical resemblance. Also, the effect of practice on catch trials was not accompanied by changes in speed of category-level vs. specific-level identification predicted from level-of-identification explanations of the category effect. An alternative explanation was proposed. It distinguished between attention to attributes shared by members of the target’s category (resulting in the catch-trial effect) and attention to attributes specific to the target (resulting in its elimination as a function of practice).
TL;DR: In this article, the internal paradoxes in the quantum measurement scheme related to violation of conservation laws, changes in entropy, absence of a dynamic description of collapse, Wigner's friend, as well as the paradox of violation of causality in the EPR experiment are shown to be partially circumvented in the measurement scheme of stochastic quantum mechanics.
Abstract: The internal paradoxes in the quantum measurement scheme related to violation of conservation laws, changes in entropy, absence of a dynamic description of collapse, Wigner's friend, as well as the paradox of violation of causality in the EPR experiment are shown to be partially circumvented in the measurement scheme of stochastic quantum mechanics.
TL;DR: It is shown that substantial savings in computation can be obtained by coarse quantization of the sequences and then performing the autocorrelations, and that this causes relatively insignificant loss of the usable input SNR range.
Abstract: An exclusive time-domain solution has been suggested for estimating the frequency of a single-frequency sinusoid embedded in broad-band noise. The coherent component, viz. the sinusoid is enhanced by repeated or iterated autocorrelation. It is shown that substantial savings in computation can be obtained by coarse quantization of the sequences and then performing the autocorrelations, and that this causes relatively insignificant loss of the usable input SNR range. Various quantization schemes are suggested and the resulting tradeoffs are discussed. Results of a detailed computer simulation experiment conducted to study the performance of the schemes are also given.
TL;DR: In this paper, a large amplitude oscillation in the vertical column abundance of atmospheric OH was observed in ground-based spectroscopic absorption measurements from Fritz Peak Observatory, Colorado (105°W, 40°N) during and after the partial solar eclipse of May 30, 1984.
Abstract: A large amplitude oscillation in the vertical column abundance of atmospheric OH has been observed in ground-based spectroscopic absorption measurements from Fritz Peak Observatory, Colorado (105°W, 40°N) during and after the partial solar eclipse of May 30, 1984. An initial OH reduction during the eclipse was followed by an underdamped oscillation having a period of about one hour; the OH abundances returned to normal values two hours after the eclipse termination. This is believed to be the first observation of a "ringing" response of any atmospheric constituent to a solar eclipse.
TL;DR: It is shown how information and information gain as well as efficiency (in the sense defined in this paper) can be measured directly.
Abstract: In this section we wish to further elaborate on the results of the preceding chapter. There we have shown that we may split the joint probability distribution function P(ξ u , ξ s ) which refers to the order parameters, ξ u , and enslaved-mode amplitudes, ξ s , into a product of the form
$$P\left( {{\xi _u},{\xi _s}} \right)\prod\limits_s {{P_s}\left( {{\xi _s}\left| {{\xi _u}} \right.} \right)f\left( {{\xi _u}} \right)}$$
(7.1)
.
TL;DR: In this article, the authors explored a strategy for improving service allocation decisions in the aging services area. But they did not identify the perceptions of key decision makers about the variable service needs of different aging risk groups and the results indicated that such distinctions can be made and can provide the basis of improving several aspects of the allocation process.
TL;DR: This article examined the degree to which scores on different formats are correlated after disattenuation, and found that the corrected correlations ranged from.7 to above 1.00, and several cautionary statements were made regarding the interpretation of the results.
Abstract: It was noted that format comparisons for performance rating scales rarely report the most critical statistic in terms of assessing score comparability; i.e., the disattenuated correlation of scores between formats. This study examined the degree to which scores on different formats are correlated after disattenuation. Corrected correlations ranged from .7 to above 1.00. While it appears the scales are measuring essentially the same thing, several cautionary statements are made regarding the interpretation of the results. The failure to consider the purpose for data collection in these studies was one major problem cited.
TL;DR: A new and simpler proof of Hartman's theorem that the cycles of length at least d + 1 generate the cycle space of G, unless d is odd and G ≅ K d +1 .
TL;DR: A species formerly thought to be in a monotypic genus, Petrogenia repens I. M. Johnston, is found to be congeneric with Bonamia, which is interpreted as being an endemic triad in the Chihuahuan Desert Region.
Abstract: A species formerly thought to be in a monotypic genus,Petrogenia repens I. M. Johnston, is found to be congeneric withBonamia. The new combinationBonamia repens (I. M. Johnston) Austin a Staples is made. This species, with two others, we interpret as being an endemic triad in the Chihuahuan Desert Region. Possible relationships, ecology, palynology, cotyledon structure, and morphology are discussed.
01 Jan 1985
TL;DR: In this article, the molybdenum-iron protein (MoFe protein) contains the FeMoco cofactor (FeMoco), which is generally recognized as the enzymic N2-reducing site (Hawkes et al, 1984) two such cofactors are contained within the MoFe protein, each of which accounts for one Mo ca 50% (6−8 atoms) of the Fe and probably 8−9 S atoms.
Abstract: The larger of the two component proteins of nitrogenase, the molybdenum-iron protein (MoFe protein), contains the iron-molybdenum cofactor (FeMoco), which is generally recognized as the enzymic N2-reducing site (Hawkes et al, 1984) Two such cofactors are contained within the MoFe protein,each of which accounts for one Mo ca 50% (6–8 atoms) of the Fe and probably 8–9 S atoms (Shah, Brill, 1977; Yang et al, 1982; Nelson et al, 1983), arranged in a cluster so far unrecognized elsewhere in biology Many on-going syntheses of Mo-Fe-S cluster compounds to simulate the structure or duplicate the chemical properties of FeMoco (Holm, 1981; Coucouvanis, 1981; Averill, 1983), although interesting in their own right, have yet to produce a close chemical model Additional redox and compositional probes of FeMoco, extruded from Azotobacter vinelandii nitrogenase, have been undertaken recently to gain added insight into this entity and to produce guidelines for the bioinorganic chemist in his quest for the successful synthesis of FeMoco These probes cover the application of physical techniques as well as successful attempts to perform chemistry on the natural cluster