Showing papers by "Purdue University published in 1978"

Technical Note-A General Inner Approximation Algorithm for Nonconvex Mathematical Programs

Abstract: Inner approximation algorithms have had two major roles in the mathematical programming literature. Their first role was in the construction of algorithms for the decomposition of large-scale mathematical programs, such as in the Dantzig-Wolfe decomposition principle. However, recently they have been used in the creation of algorithms that locate Kuhn-Tucker solutions to nonconvex programs. Avriel and Williams' Avriel, M., A. C. Williams. 1970. Complementary geometric programming. SIAM J. Appl. Math.19 125-141. complementary geometric programming algorithm, Duffin and Peterson's Duffin, R. J., E. L. Peterson. 1972. Reversed geometric programs treated by harmonic means. Indiana Univ. Math. J.22 531-550. reversed geometric programming algorithms, Reklaitis and Wilde's Reklaitis, G. V., D. J. Wilde. 1974. Geometric programming via a primal auxiliary problem. AIIE Trans.6 308-317. primal reversed geometric programming algorithm, and Bitran and Novaes' Bitran, G. R., A. G. Novaes. 1973. Linear programming with a fractional objective function. Opns. Res.21 22-29. linear fractional programming algorithm are all examples of this class of inner approximation algorithms. A sequence of approximating convex programs are solved in each of these algorithms. Rosen's Rosen, J. B. 1966. Iterative solution of nonlinear optimal control problems. SIAM J. Control4 223-244. inner approximation algorithm is a special case of the general inner approximation algorithm presented in this note.

The Operational Analysis of Queueing Network Models

Abstract: Queueing network models have proved to be cost effectwe tools for analyzing modern computer systems. This tutorial paper presents the basic results using the operational approach, a framework which allows the analyst to test whether each assumption is met in a given system. The early sections describe the nature of queueing network models and their apphcations for calculating and predicting performance quantitms The basic performance quantities--such as utilizations, mean queue lengths, and mean response tunes--are defined, and operatmnal relationships among them are derwed Following this, the concept of job flow balance is introduced and used to study asymptotic throughputs and response tunes. The concepts of state transition balance, one-step behavior, and homogeneity are then used to relate the proportions of time that each system state is occupied to the parameters of job demand and to dewce charactenstms Efficmnt methods for computing basic performance quantities are also described. Finally the concept of decomposition is used to stmphfy analyses by replacing subsystems with equivalent devices. All concepts are illustrated liberally with examples

Determination of catecholamines in rat brain parts by reverse-phase ion-pair liquid chromatography

Abstract: — An improved method for the measurement of catecholamines in brain parts has been developed, based on reverse-phase ion-pair chromatography. The new method offers the advantages of high efficiency microparticulate liquid chromatography packings and the flexibility of ion-pair chromatography. By this approach norepinephrine and dopamine (DA) have been measured in the hypothalamus and corpus striatum of the rat brain during various stages of development (15, 21, 30 days). Data are reported on the basis of the whole part and per weight of tissue. For the adult animals, the following concentrations (ng/g wet tissue) were observed for the hypothalamus: NE = 2261 ± 274, DA = 440 ± 103, and for the corpus striatum: DA = 11,888 ± 1840. The overall precision of the method was ±5.6% relative s.d. The absolute recovery was 60 ± 5% relative s.d. and was constant over the range of 1 ng to 1 μg of dopamine or norepinephrine per tissue sample. The relative retention behavior of 18 neurologically important catechol derivatives is reported for reverse-phase chromatography with octyl sulfate as the stationary phase modifier.

A free calcium wave traverses the activating egg of the medaka, Oryzias latipes.

Abstract: Aequorin-injected eggs of the medaka (a fresh water fish) show an explosive rise in free calcium during fertilization, which is followed by a slow return to the resting level. Image intensification techniques now show a spreading wave of high free calcium during fertilization. The wave starts at the animal pole (where the sperm enters) and then traverses the egg as a shallow, roughly 20 degrees-wide band which vanishes at the antipode some minutes later. The peak free calcium concentration within this moving band is estimated to be about 30 microM (perhaps 100-1,000 times the resting level). Eggs activated by ionophore A23187 may show multiple initiation sites. The resulting multiple waves never spread through each other; rather, they fuse upon meeting so as to form spreading waves of compound origin. The fertilization wave is nearly independent of extracellular calcium because it is only slightly slowed (by perhaps 15%) in a medium containing 5 mM ethylene glycol-bis[beta-aminoethyl ether]N,N9-tetraacetic acid (EGTA) and no deliberately added calcium. It is also independent of the large cortical vesicles, which may be centrifugally displaced. Normally, however, it distinctly precedes the well-known wave of cortical vesicle exocytosis. We conclude that the fertilization wave in the medaka egg is propagated by calcium-stimulated calcium release, primarily from some internal sources other than the large cortical vesicles. A comparison of the characteristics of the exocytotic wave in the medaka with that in other eggs, particularly in echinoderm eggs, suggests that such a propagated calcium wave is a general feature of egg activation.

Descartes: The Project of Pure Enquiry

Abstract: Descartes has often been called the 'father of modern philosophy'.His attempts to find foundations for knowledge, and to reconcile the existence of the soul with the emerging science of his time, are among the most influential and widely studied in the history of philosophy. This is a classic and challenging introduction to Descartes by one of the most distinguished modern philosophers. Bernard Williams not only analyzes Descartes' project of founding knowledge on certainty, but uncovers the philosophical motives for his search. With acute insight, he demonstrates how Descartes' Meditations are not merely a description but the very enactment of philosophical thought and discovery. Williams covers all of the key areas of Descartes' thought, including God, the will, the possibility of knowledge, and the mind and its place in nature. He also makes profound contributions to the theory of knowledge, metaphysics and philosophy generally. This is essential reading for any student of philosophy. This reissue includes a new foreword by John Cottingham.

Foundation of a Communicator Style Construct.

Abstract: The foundation of a communicator style construct is presented in this paper. The construct is stipulated to include communication variables which reflect the “way one verbally and paraverbally interacts to signal how literal meaning should be taken, interpreted, filtered, or understood.” Nine independent variables (dominant, dramatic, animated, open, contentious, relaxed, friendly, attentive, and impression leaving) and one dependent variable (communicator image) operationally define the construct. Two independent samples, the first with 80 subjects and 102 items and the second with 1,086 subjects and 51 items, are analyzed in terms of (1) how the variables cluster, (2) what dimensionality is embedded in the structure of intercorrelations, and (3) which variables best predict communicator image. Potentially, the construct provides a context for other communication variables, relates to perceptual processes, and explains interpersonal consequents.

Prenatal development of the cerebellar system in the rat. I. Cytogenesis and histogenesis of the deep nuclei and the cortex of the cerebellum

Abstract: Prenatal cerebellar development was investigated with three approaches. In normal embryos sectioned in three planes morphological and cytological changes were determined at daily intervals beginning on embryonic day 13 (E13). A similar series of X-irradiated embryos was used to study changes in neuroepithelial organization and in the location of primitive (radiosensitive) or differentiated cells. Finally, to quantify the time of origin of different classes of cerebellar neurons with the progressively delayed labelling procedure, we used autoradiograms from adult rats whose mothers were injected with two successive daily doses of 3H-thymidine on overlapping days from day E13 on. The cerebellar anlage was delineated in the dorsal metencephalon by the collapse of its ventricular lining after X-irradiation. This “collapsing neuroepithelium” was located laterally on day E13, then it spread medially and reached the midline on day E16. Deep nuclear neurons began to differentiate on day E13, with two-thirds forming on day E14; Purkinje cell formation peaked on day E15, with a few cells still forming on day E16. It was postulated that the deep nuclear neurons settled first in the superficial “nuclear zone,” and that the Purkinje cells gathered temporarily in the underlying “transitory zone,” adjacent to the collapsing neuroepithelium. In the next period of cerebellar development four major events were recognized. (1) Beginning on day E17 the cells of the nuclear and transitory zones became intermingled. It was postulated that the Purkinje cells were migrating radially through the ranks of the stationary deep nuclear neurons and assembled under the spreading canopy of a fibrous plexus and the external germinal layer. (2) It was also on day E17 that the external germinal layer began to form as one of the prongs of the “germinal trigone” in the posteroventral aspect of the cerebellum. On the succeeding days the external germinal layer spread over the surface of the cerebellum; in the vermis in a rostral direction. (3) Two cell types destined to settle in the future granular layer, the pale cells and the Golgi cells, began to form at a relatively slow rate on day E19. Chronological considerations suggested that they were generated in the regressing, noncollapsing neuroepithelium of the cerebellar ventricle. (4) From the beginning (day E17) of its genesis posteroventrally, the primitive cerebellar cortex bridged the midline. As the fused cortex spread rostrally, the vertical ventricular cleft separating the underlying portions of the cerebellum became shallower and then disappeared; the process was completed in the anterior cerebellum by day E22. By the time of birth the maturation of the neurons of the deep nuclei appeared advanced but the maturation of the prenatally produced neurons of the cortex does not start until after birth when a new class of neurons is generated in the external germinal layer.

Antixenosis–A New Term Proposed to Define Painter's “Nonpreference” Modality of Resistance

Abstract: Much of the wide acceptance and popularity of Reginald Painter's classification of the mechanisms of plant resistance to insect pests stems not only from its simplicity and apparent generality, but also because it accurately describes insect and plant responses. Based on some of his own previous work (Painter 1936, 1941), Painter in his classical book “Insect Resistance in Crop Plants” (1951) proposed that plant resistance, as observed in the field, could be explained by three fundamental mechanisms which he named: (a) nonpreference, (b) antibiosis, and (c) tolerance. Painter and many subsequent workers have stressed the fact that these mechanisms are most frequently interrelated although they may also operate independently.

Kinematic control equations for simple manipulators

Abstract: The basis for all advanced manipulator control is a relationship between the cartesian coordinates of the end-effector and the manipulator joint coordinates. A direct method for assigning link coordinate systems and obtaining the end effector position, and Jacobian, in terms of joint coordinates is reviewed. Techniques for obtaining the solution to these equations for kinematically simple manipulators, which includes all commercially available manipulators, is presented. Finally the inverse Jacobian is developed from the solution.

Synthesis and deposition of zein in protein bodies of maize endosperm.

Abstract: The origin of protein bodies in maize (Zea mays L.) endosperm was investigated to determine whether they are formed as highly differentiated organelles or as protein deposits within the rough endoplasmic reticulum. Electron microscopy of developing maize endosperm cells showed that membranes surrounding protein bodies were continuous with rough endoplasmic reticulum membranes. Membranes of protein bodies and rough endoplasmic reticulum both contained cytochrome c reductase activity indicating a similarity between these membranes. Furthermore, the proportion of alcohol-soluble protein synthesized by polyribosomes isolated from protein body or rough endoplasmic reticulum membranes was similar, and the alcohol-soluble or -insoluble proteins showed identical [(14)C]leucine labeling. These results demonstrated that protein bodies form simply as deposits within the rough endoplasmic reticulum.Messenger RNA that directed synthesis of only the smaller molecular weight zein subunit was separated from mRNA that synthesized both subunits by sucrose gradient centrifugation. This result demonstrated that separate but similar sized mRNAs synthesize the major zein components. In vitro translation products of purified mRNAs or polyribosomes were approximately 2,000 daltons larger than native zein proteins, suggesting that the proteins are synthesized as zein precursors. When intact rough endoplasmic reticulum was placed in the in vitro protein synthesis system, proteins corresponding in molecular weight to the native zein proteins were obtained.

A spread-spectrum technique for high-capacity mobile communications

Abstract: A spread-spectrum technique for cellular high-capacity mobile communications is described and some results from an analytic study are summarized. The technique uses a very large set of frequency-hopped signals which are designed for minimal mutual interference. No synchronization of the mobile units is required, and each user is permanently assigned his own signal, which serves as an identifying signal and as a carrier for the biphase-modulated digital message. The spectral efficiency of the spread-spectrum system is analyzed and compared with the efficiencies of developmental FM/channel reuse schemes currently under construction in the U.S. and Japan. It is concluded that even with relatively simple speech digitization schemes, the efficiency of the spread-spectrum scheme may exceed those of the narrow-band schemes by a factor of almost five. More ambitious bit-rate-reducing speech digitization methods could improve still further on these figures. Additional benefits of the spread-spectrum scheme include immunity from fading and interference, more consistent speech quality, simpler system control algorithms, and more flexible blocking properties under overload conditions.

A Strategic Model of the U.S. Brewing Industry: 1952-1971

Abstract: Quantitative models of business strategy can be developed upon the key relationship between a firm's objectives, its strategy and the environment in which it operates. To be meaningful, this paper ...

Development of the diencephalon in the rat. I. Autoradiographic study of the time of origin and settling patterns of neurons of the hypothalamus

Abstract: Groups of pregnant rats were injected with two successive daily doses of 3H-thymidine from gestational day 13 (E13+14) until the day before birth (E21+22). This double labelling procedure was combined with an injection schedule of a single day delay between groups (E13+14; E14+15; E15+16. .I. The two injections assured the comprehensive labelling of prac- tically all neurons of a given structure prior to the onset of their differentiation (comprehensive labelling), whereas the progressive daily delay in injections made it possible to estimate the proportion of neurons formed in various regions of the hypothalamus on a single day. Hypothalamic areas or nuclei were assigned into four classes on the basis of their cytogenetic isochronicity. Struc- tures composed of the earliest arising (class 1) neurons constitute a lateral tier that includes the lateral preoptic and lateral hypothalamic areas, and the later- al mammillary nucleus. Structures composed of early arising (class 2) neurons form a heterogeneous collection of nuclear systems, including the paraventricu- lar, internuclear and supraoptic magnocellular neurons, and several intermedi- ate tier nuclei of the anterior and posterior hypothalamus. The late arising (class 3) and latest arising (class 4) nuclei constitute a periventricular system anteriorly and a more extensive region posteriorly. The latter two nuclear sys- tems may constitute the hypophysiotropic area of the hypothalamus. The nuclei of the mammillary system, which are produced sequentially, are distinguished from other hypothalamic structures by their more rapid generation time. Inter- nuclear labelling gradients were used to infer the neuroepithelial site of origin and settling pattern of neurons. Common sites of origin were indicated for the following structures: the magnocellular neurohypophysial neurons; the neu- rons of the dorsomedial and ventromedial nuclei; and the neurons of the tuberomammillary and arcuate nuclei. The sites of origin of these groups of nu- clei were related to specialized ventricular linings in the mature hypothalamus.

Rhythmic spacing and origin of pools and riffles

Abstract: Quantitative analysis of the spacing of pools in bedrock and alluvial stream channels in California, Indiana, Virginia, and North Carolina suggest that the tendency for streams to meander in the vertical (or third) dimension, as in the horizontal plane, is a fundamental characteristic of many streams that is independent of material type. Simple linear-regression and correlation models reveal that approximately 70% of the variability of the spacing of pools can be explained by the variability of channel width. Analysis of the spacing of 251 pools in eleven streams, utilizing the Kolmogorov-Smirnov goodness of fit test and one-way analysis of variance suggests that the hypothesis that the data from bedrock and alluvial channels are from the same population cannot be rejected at the 0.05 level of significance. Morphologic maps and field observations of stream channels incised in sandstone, limestone, metavolcanic rock, and syenite suggest that although these streams have much in common with alluvial stream channels, there exist considerable differences in certain aspects of channel morphology. This results because bedrock control of morphology locally may be more significant than the effects of general processes that tend to produce rhythmic channel forms such as pools and riffles. However, local controls tend to mask rather than destroy the effects of more general processes that produce the third dimension of meandering streams.

Analysis of Laminate Strength and Its Distribution

Abstract: A failure criterion for a laminated composite is presented. A salient nature of this criterion is the use of "in situ shear strength" measured in the form of cross-ply laminate. Then by statistical consideration, the model was further modified to incorporate probabilistic nature of composite fail ure. Rigorous mathematical development of probability was simply re placed by Monte Carlo simulation. As a result, the proposed model was proved simple and effective in predicting failure in both deterministic and probabilistic sense.

A Sentence-to-Sentence Clustering Procedure for Pattern Analysis

Abstract: Cluster analysis for patterns represented by sentences is investigated. The similarity between patterns is expressed in terms of the distance between their corresponding sentences. A weighted distance between two strings is defined and its probabilistic interpretation given. The class membership of an input pattern (sentence) is determined according to the nearest neighbor or k-nearest neighbor rule. A clustering procedure on a sentence-to-sentence basis is proposed. A set of English characters is used to illustrate the proposed metric and clustering procedure.

A Behavioral Process Approach to Information Acquisition in Nondurable Purchasing

Abstract: A behavioral process method was used to explore the relationship of individual difference factors to consumer information acquisition behavior. Findings included: (1) the mean proportion of availab...

Spread spectrum apparatus for cellular mobile communication systems

Abstract: An apparatus is disclosed for a cellular mobile communication system utilizing a spread spectrum. A plurality of fixed base stations is connected with a central processor so that calls originating in any cell can terminate in any other cell. The available frequency spectrum is divided such that one-half is used for mobile-to-base station transmission and the other one-half is used for base station-to-mobile unit transmission. A power control/mobile locator system and method is utilized in all mobile units to compensate for changes in signal level and to maintain the average received signal level at the base station constant regardless of the location of the mobile unit within the cell. In addition, each mobile unit has a unique set of time-frequency coded waveforms that are used for both transmission and reception. The waveforms have large time-bandwidth products so that interfering signals are well suppressed, and which provide a large set of signals so that each user can be assigned a unique set of waveforms. Message modulation is accomplished by digitizing the speech and encoding the resulting binary sequences into the set of waveforms available to the user, while detection is accomplished by a demodulation system and method in which the phases of each received waveform are compared with those of the preceding waveform.

A Simultaneous Equation Model of Corporate Strategy

Abstract: Over the past decade strategy has become a concept of value to management as it relates the firm to the threats and opportunities of an increasingly turbulent environment. However, empirical tests of the validity of the strategy construct have been limited, as have been the managerial applications of the models used to test the construct. Early research efforts, both analytical and empirical, have shown that quantitative modeling of strategy could be a tool of value in helping top management achieve the goal is of the firm [Gershefski, George W. 1969. Building a corporate financial model. Harvard Business Rev. July--August 61--72; Guth, W. D. 1972. Product differentiation and concentration in the brewing industry. J. Business Policy.2 3 31--36.]. Prior research has been limited to single equation models linking strategy and environment to only one performance goal, profitability. While there is some controversy about it, complex organizations set multiple, and sometimes conflicting goals, creating a need for models that car; encompass more than a single performance goal. Moreover, the interactive effects of strategic variables governing the efficiency of daily operations, suggests that single equation models of strategy cannot capture the complexity of the modern firm. This research explores the use of a simultaneous equation model of corporate strategy as a means of overcoming the multiple performance goal problem, while capturing the complex patterns of the strategic, operating, and environmental variables that influence goal achievement. The difficulties of estimating the model, including the problems of sample heterogeneity so important to this type of work, are identified and discussed using data and results taken from the U.S. brewing industry.

Prenatal development of the cerebellar system in the rat. II. Cytogenesis and histogenesis of the inferior olive, pontine gray, and the precerebellar reticular nuclei.

Abstract: Aspects of the prenatal development of the inferior olive, lateral reticular nucleus, nucleus reticularis tegmenti pontis, and of the pontine gray were investigated in the rat. The material used was the same as in the preceding study of cerebellar development, including histological preparations from normal and x-irradiated embryos at daily intervals (days E13 to E22), and autoradiograms from adult rats injected with two successive doses of 3H-thymidine on overlapping days from days E13 + 14 on. Neurons of the inferior olive form on days E13 and 14: those settling rostrally in the principal nucleus somewhat ahead of those settling in the medial accessory nucleus caudally. The olivary neurons are generated in the neuroepithelium of the lateral recess of the fourth ventricle, migrate ventrally by way of the olivary migratory stream, split into two branches and provide cells to the olivary complex from its lateral and medial aspect. The migrating cells are differentiated, radioresistant elements. It was postulated that since the olivary migratory path and the course of olivary fibers (the inferior cerebellar peduncle) are on the same trajectory, climbing fibers could reach the surface of the cerebellum before the arrival of the radially migrating Purkinje cells. Neurons of the lateral reticular nucleus form predominantly on days E13 and 14, of the nucleus reticularis tegmenti pontis on days E15–17, and of the pontine gray on days E17–19. The pontine neurons originate several days after but at the same site as the olivary neurons. The cells migrating in the pontine migratory stream are undifferentiated elements and follow a course different to that of their prospective axons in the middle cerebellar peduncle. The earliest forming pontine neurons settle near the pyramidal tract, the later arriving cells form cap-like shells around this core. Axonogenesis of pontine cells begins after the settling of the perikarya on day E19. The middle cerebellar peduncle appeared to approach the cerebellum on day E22, suggesting that pontine mossy fibers do not establish contact with cerebellar elements before the perinatal period, by which time the external germinal layer and the Purkinje cells have formed a cortical mantle over the entire cerebellum. In an attempt to correlate the chronology of cytogenesis in some of the precerebellar nuclei with cell production and maturation in the cerebellum, it was hypothesized that mossy fibers of reticular origin exert influence on Purkinje cell dendrites in the lower parts of the molecular layer, whereas mossy fibers of pontine origin influence the upper parts of Purkinje cell dendrites. Reference is made to behavioral results indicating the mediation of dissociable functions by elements of the lower and upper molecular layer.

Signal Processing of Broadband Pulsed Ultrasound: Measurement of Attenuation of Soft Biological Tissues

Abstract: In this paper we will discuss the measurement of attenuation of soft tissues using broadband pulsed ultrasound. While all the methods presented here may be used for measuring the attenuation coefficient of single layers, some of the methods can also be used for measuring integrated attenuation of composite layers of soft tissue. These latter methods do not require knowledge of reflection coefficients at tissue interfaces and are well suited to generating projection data for computerized attenuation tomography of soft tissues.

Solute movement in the soil-root system

Abstract: Solute Movement in the Soil-Root System. By P. H. Nye & P. B. Tinker. Pp.542. (Blackwell Scientific: Oxford, 1977.) £12.80.

Glass transition temperatures for simple molecular liquids and their binary solutions

Abstract: Glass transition temperatures have been measured at 20 mol % intervals in 55 binary molecular liquid systems and the results used as a basis for (a) estimating by extrapolations the glass transition temperatures of many common organic liquids which do not vitrify in the pure state and thereby (b) identifying the various structural features of a molecule which collectively determine the magnitude of its T/sub g/. In most cases, simple linear composition dependences are observed for T/sub g/. The thermodynamic significance of dT/sub g//dx is discussed. In the case of cyclohexanol T/sub g/ estimated for the liquid exceeds the known value of ''T/sub g/'' for the plastic crystal phase by some 10/sup 0/C. The T/sub g/ estimated for CCl/sub 4/ and CHCl/sub 4/ exceed by large intervals the T/sub g/ values reported for vapor-deposited amorphous phases of these substances. 3 figures, 1 table.

Consumer Research: How valid and useful are all our consumer behavior research findings?: A State of the Art Review1

Abstract: W HETHER one does, sells, and/or buys consumer research, it stands to reason one should be able to critically evaluate and distinguish that which is acceptable from that which is junk. However, judging from papers· which continue to be published in our most prestigious journals and from research reports which often form the basis for important marketing management and public policy decisions, it is all too apparent that too large a proportion of the consumer (including marketing) research literature is not worth the paper it is printed on or the time it takes to read. Nearly a decade ago, Kollat et al. wrote: The consumer behavior literature has doubled during the last five years. This constitutes a remarkable achievement by almost any standard. Unfortunately, however, it would not be surprising if 90% of the findings and lack of findings prove to be wrong ...2

Scheduling Policies for Automatic Warehousing Systems: Simulation Results

Abstract: This paper examines and extends previous analytical work on the scheduling of stacker cranes in automatic warehousing systems. In particular, the following are examined by means of a computer simulation: (1) The performance of the closest-open-location rule compared to random storage assignment; (2) The dynamic behavior of the system under stochastic conditions, using various crane and rack utilization levels; (3) The actual versus predicted reduction in crane travel time due to improved scheduling rules; (4) The effect of imperfect information concerning the length of stay of an incoming pallet on system performance. The results of our experiments provide evidence in support of the proposed analytical models. Most important, the experiments demonstrate the value of previously-proposed scheduling rules in a dynamic, stochastic environment operating with imperfect information.