Showing papers by "Purdue University published in 1991"
TL;DR: In this paper, a factor analysis of survey data from 127 employees' supervisors supported the distinction between in-role behaviors and two forms of OCBs, and hierarchical regression analysis found two job cognitions variables (intrinsic and extrinsic) to be differentially related to the two types OCB.
5,343 citations
01 Jun 1991
TL;DR: The subjects of tree structure design, feature selection at each internal node, and decision and search strategies are discussed, and the relation between decision trees and neutral networks (NN) is also discussed.
Abstract: A survey is presented of current methods for decision tree classifier (DTC) designs and the various existing issues. After considering potential advantages of DTCs over single-state classifiers, the subjects of tree structure design, feature selection at each internal node, and decision and search strategies are discussed. The relation between decision trees and neutral networks (NN) is also discussed. >
3,176 citations
TL;DR: The introduction of the glycine kinker into fusion proteins allows for the cleavage of the fusion proteins while they are attached to the affinity resin resulting in a single step purification of the recombinant protein.
1,761 citations
TL;DR: The authors showed that the physical attractiveness stereotype established by studies of person perception is not as strong or general as suggested by the often-used summary phrase what is beautiful is good, and that the average magnitude of this beauty-is-good effect was moderate, and the strength of the effect varied considerably from study to study Consistent with their implicit personality theory framework, a substantial portion of this variation was explained by the specific content of the inferences that subjects were asked to make.
Abstract: This review demonstrates that the physical attractiveness stereotype established by studies of person perception is not as strong or general as suggested by the often-used summary phrase what is beautiful is good. Although subjects in these studies ascribed more favorable personality traits and more successful life outcomes to attractive than unattractive targets, the average magnitude of this beauty-is-good effect was moderate, and the strength of the effect varied considerably from study to study Consistent with our implicit personality theory framework, a substantial portion of this variation was explained by the specific content of the inferences that subjects were asked to make: The differences in subjects* perception of attractive and unattractive targets were largest for indexes of social competence; intermediate for potency, adjustment, and intellectual competence; and near zero for integrity and concern for others. The strength of the physical attractiveness stereotype also varied as a function of other attributes of the studies, including the presence of individuating information.
1,688 citations
TL;DR: A general neural-network (connectionist) model for fuzzy logic control and decision systems is proposed, in the form of feedforward multilayer net, which avoids the rule-matching time of the inference engine in the traditional fuzzy logic system.
Abstract: A general neural-network (connectionist) model for fuzzy logic control and decision systems is proposed. This connectionist model, in the form of feedforward multilayer net, combines the idea of fuzzy logic controller and neural-network structure and learning abilities into an integrated neural-network-based fuzzy logic control and decision system. A fuzzy logic control decision network is constructed automatically by learning the training examples itself. By combining both unsupervised (self-organized) and supervised learning schemes, the learning speed converges much faster than the original backpropagation learning algorithm. The connectionist structure avoids the rule-matching time of the inference engine in the traditional fuzzy logic system. Two examples are presented to illustrate the performance and applicability of the proposed model. >
1,476 citations
TL;DR: It is found that a small amount of sulfamate suppresses color production by a 20-fold excess of some neutral sugars without substantial sacrifice of the sensitive detection of uronic acids by the diphenyl reagent.
1,198 citations
TL;DR: The authors examines the relationship between strategic management and economics and provides a guide to the eight papers contained in the special issue, and offers the guest editors viewpoints on the contributions of each discipline to the other.
Abstract: This essay examines the relationship between strategic management and economics It introduces the special issue on this same topic by providing a guide to the eight papers contained in the special issue, and it offers the guest editors viewpoints on the contributions of each discipline to the other The essay notes the major contribution from economics has been primarily from the industrial organization literature, with promises of important gains to be made from the ‘new’ economics as it breaks away from the neoclassical theory of the firm Contributions from strategic management to economics are noted Areas for further research utilizing the relationship between strategic management and economics are also indicated
949 citations
TL;DR: A 32-item questionnaire on smoking urges was administered to 230 daily cigarette smokers assigned to one of three levels of cigarette deprivation and factor analyses showed that a two-factor solution best described the item structure for each of the three deprivation levels and for the entire sample.
Abstract: A 32-item questionnaire on smoking urges was administered to 230 daily cigarette smokers assigned to one of three levels of cigarette deprivation (0, 1 or 6 hours) Factor analyses showed that a two-factor solution best described the item structure for each of the three deprivation levels and for the entire sample Factor scales of 15 and 11 items derived from rotation to simple structure were highly reliable, 095 and 093, respectively, and moderately correlated (r = 071) Average scores on both scales increased significantly with level of deprivation, and the Factor 1 scale was significantly higher than the Factor 2 scale at all levels Factor 1 scale items reflected primarily intention and desire to smoke, and anticipation of pleasure from smoking Factor 2 scale items were comprised primarily of anticipation of relief from negative affect and nicotine withdrawal, and urgent and overwhelming desire to smoke
927 citations
TL;DR: Godzilla is a fault-based technique that uses algebraic constraints to describe test cases designed to find particular types of faults and has been integrated with the Mothra testing system.
Abstract: A novel technique for automatically generating test data is presented. The technique is based on mutation analysis and creates test data that approximate relative adequacy. It is a fault-based technique that uses algebraic constraints to describe test cases designed to find particular types of faults. A set of tools (collectively called Godzilla) that automatically generates constraints and solves them to create test cases for unit and module testing has been implemented. Godzilla has been integrated with the Mothra testing system and has been used as an effective way to generate test data that kill program mutants. The authors present an initial list of constraints and discuss some of the problems that have been solved to develop the complete implementation of the technique. >
824 citations
TL;DR: The Osmoregulated Genes and Genes of E. coli and S. coli: A chronology of key discoveries and inhibitors, as well as some of the mechanisms behind their development, are described.
Abstract: INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . .. .. . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 570 MECHANISMS UNDERLYING OSMOREGULATORY RESPONSES.... . . .. .. . . . . . .. .. 571 Homeostasis vs Adaptation to Change. . . . . . . . . . . ... . . . . . . . . . . . . . . . . . . 571 Examination of Possible Signals . . . . . ...... . . . . . . . . . : 573 PHYSIOLOGY OF OSMOTIC REGULATION . . . . .. .. . . . . . . . .... . . . . . . . . . . . . . . . . . . . . . . . . . . .. . 581 Compatible Solutes Synthesized and/or Transported . . . . . . . . . . . . . . . . . 581 Osmoregulation of the Periplasm . . . . . . . . ... . . . . . . . .... . . . . . . . ..... . . . . . . . .. . . . . 588 GENES AND PROTEINS . . . . . . . . . . . . . . . . .. .. . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . ... . . . . . 588 The EnvZ/OmpR-Dependent Expression of the ompF and ompC Genes of E. coli K-12 .. . . . . . . . ..... .. . .. ....... . . . . . ....... . . . . . . ..... . . . 589 The kdpABC operon of E. coli . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 592 The proU Operon of E. coli and S. typhimurium . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . 593 Other Osmoregulated Genes. . ......... 597
818 citations
TL;DR: A unified presentation, a synthesis, and an evaluation of the methods employed in the estimation of heritability in plants are presented, discussing the use of both collateral and lineal relatives and the biases present in the estimators.
Abstract: A unified presentation, a synthesis, and an evaluation of the methods employed in the estimation of heritability in plants are presented. Asexual, cross‐fertilizing, and self‐fertilizing diploid species, as well as annual and perennial ones, are considered. All broad‐ and narrow‐sense heritabilities are defined on individual and family bases for prediction of response to selection for a target population of environments in space and time. Narrow‐sense heritabilities are defined in cross‐fertilizing species for expected response to variations of mass, half‐sib, and full‐sib family selection for the next generation and the long term, and similarly in self‐fertilizing species. The use of both collateral and lineal relatives to estimate heritability is discussed, and the biases present in the estimators are given. Many departures and variations of the common procedures are discussed. The standard errors of heritability estimators and confidence intervals are presented.
TL;DR: In this article, the emergence of male and female leaders in initially leaderless groups is reviewed and a review on the role of gender in leader selection and selection is presented. But,
Abstract: In this article, research is reviewed on the emergence of male and female leaders in initially leaderless groups
TL;DR: A meta-analytic review as discussed by the authors showed that the sexes typically differ in a variety of social behaviors, including aggression, helping, nonverbal behavior, and various aspects of interaction in task-oriented groups.
Abstract: Recent meta-analytic reviews have documented that the sexes typically differ in a variety of social behaviors, including aggression, helping, nonverbal behavior, and various aspects of inter-action in task-oriented groups. In general, these findings are consistent with a social-role theory of sex differences, which emphasizes the causal impact of gender roles-that is, of people's beliefs about the behavior that is appropriate for each sex. To move beyond the demonstration of consistency between role expectations and social behavior, meta-analyses have examined the moderators and mediators specified by this theoretical model The outcomes of these moderator and mediator analyses are illustrated from several meta-analyses of gender and social behavior. These meta-analyses thus show that quantitative reviewing is not limited to the mere summarizing of research findings; the technique also allows reviewers to examine the plausibility of theories that are relevant to these findings.
TL;DR: It is shown that in the state-feedback case one can come arbitrarily close to the optimal (even over full information controllers) mixed H/sub 2//H/sub infinity / performance measure using constant gain state feedback.
Abstract: The problem of finding an internally stabilizing controller that minimizes a mixed H/sub 2//H/sub infinity / performance measure subject to an inequality constraint on the H/sub infinity / norm of another closed-loop transfer function is considered. This problem can be interpreted and motivated as a problem of optimal nominal performance subject to a robust stability constraint. Both the state-feedback and output-feedback problems are considered. It is shown that in the state-feedback case one can come arbitrarily close to the optimal (even over full information controllers) mixed H/sub 2//H/sub infinity / performance measure using constant gain state feedback. Moreover, the state-feedback problem can be converted into a convex optimization problem over a bounded subset of (n*n and n*q, where n and q are, respectively, the state and input dimensions) real matrices. Using the central H/sub infinity / estimator, it is shown that the output feedback problem can be reduced to a state-feedback problem. In this case, the dimension of the resulting controller does not exceed the dimension of the generalized plant. >
TL;DR: In this paper, the authors define the weight equilibrium swelling ratio, q, which is defined as the weight of the swollen polymers, as a function of the external environment conditions.
Abstract: or by semipermanent physical crosslinks such as entanglements. They may be neutral, anionic, cationic or ampholytic in nature. Because of their nature, they show swelling behavior dependent on the external environment conditions. Polymer complexes can be broken or polymer networks can be swollen by changing the external environment. This process results in the drastic change in their swelling ratio. Parameters defining their swelling behavior are the weight equilibrium swelling ratio, q, which is defined [1] as the weight of the swollen
TL;DR: In this paper, a general theory of verbal humor focusing on verbal jokes is proposed, which is an extension and revision of Raskin's script-based semantic theory of humor and of Attardo's five-level joke representation model.
Abstract: The article proposes a general theory of verbal humor, focusing on verbal jokes äs its most representative subset. The theory is an extension and revision ofRaskin's script-based semantic theory of humor and of Attardo's five-level joke representation model. After distinguishing the parameters of the various degrees of similarity among the joke examples, six knowledge resources informing thejoke, namely script oppositions, logicalmechanisms, situationst targets, narrative strategies, and language, are put forward. A hierarchical organization for the six knowledge resources is then discovered on the basis of the asymmetrical binary relations, of the proposed and modified content l tooldichotomy, and, especially, ofthe hypothesized perceptions ofthe relative degrees of similarity. It is also argued that the emerging joke representation model is neutral to the process ofjoke production. The proposed hierarchy enables the concepts of joke variants and invariants, introduced previously by Attardo, to be firmed up, generalized, and äug· mented into a full-fledged taxonomy indexed with regard to the shared knowledge resource values (for example, two jokes may be variants on, that ist sharing, the same script oppositions and logical mechanisms). The resulting general theory of verbal humor is discussed in the light of its relations with various academic disciplines and areas ofresearch äs well äs with the script-based semantic theory of humor, special theories of humor, and incongruity-based theories.
TL;DR: F folate is an essential vitamin required in substantial quantities by virtually all cells, and the natural endocytosis pathway for the vitamin folate can be exploited to nondestructively introduce macromolecules into cultured cells if the macromolescule is first covalently linked to folate.
Abstract: Difficulties with the nondestructive delivery of macromolecules into living cells have limited the potential applications of antibodies, genes, enzymes, peptides, and antisense oligonucleotides in biology and medicine. We have found, however, that the natural endocytosis pathway for the vitamin folate can be exploited to nondestructively introduce macromolecules into cultured cells if the macromolecule is first covalently linked to folate. Thus, treatment of KB cells with folate-conjugated ribonuclease, horseradish peroxidase, serum albumin, IgG, or ferritin allowed delivery of greater than 10(6) copies of the macromolecules within a 2-hr period. Cytochemical staining using 4-chloro-1-naphthol further demonstrated that the horseradish peroxidase retained activity for at least 6 hr after internalization. Since folate is an essential vitamin required in substantial quantities by virtually all cells, these observations may open the possibility of scientific and medical applications for many of the above macromolecules.
TL;DR: The primary results were that children's and adolescents' RTs increase linearly as a function of adult RTs in corresponding conditions and the amount of increase becomes smaller with age in a manner that is well described by an exponential function.
Abstract: Throughout childhood and adolescence, there are consistent age differences in speed of processing Here 72 published studies yielded 1,826 pairs of response times (RTs) in which each pair consisted of adults' mean RT for a condition and the corresponding mean RT for a younger group The primary results were that (a) children's and adolescents' RTs increase linearly as a function of adult RTs in corresponding conditions and (b) the amount of increase becomes smaller with age in a manner that is well described by an exponential function These results are consistent with the view that age differences in processing speed reflect some general (ie, nontask specific) component that changes rapidly during childhood and more slowly during adolescence Possible candidates for the general component are discussed
TL;DR: The concept of real rank of a C ∗ -algebra is introduced as a non-commutative analogue of dimension in this paper, and it is shown that real rank zero is equivalent to the previously defined conditions FS and HP, and is invariant under strong Morita equivalence, in particular under stable isomorphism.
TL;DR: The authors develop algorithms for the design of hierarchical tree structured color palettes incorporating performance criteria which reflect subjective evaluations of image quality, which produce higher-quality displayed images and require fewer computations than previously proposed methods.
Abstract: The authors develop algorithms for the design of hierarchical tree structured color palettes incorporating performance criteria which reflect subjective evaluations of image quality. Tree structured color palettes greatly reduce the computational requirements of the palette design and pixel mapping tasks, while allowing colors to be properly allocated to densely populated areas of the color space. The algorithms produce higher-quality displayed images and require fewer computations than previously proposed methods. Error diffusion techniques are commonly used for displaying images which have been quantized to very few levels. Problems related to the application of error diffusion techniques to the display of color images are discussed. A modified error diffusion technique is shown to be easily implemented using the tree structured color palettes developed earlier. >
TL;DR: In this article, laser diode action in the blue green has been observed from (Zn,Cd)Se quantum wells within ZnSe/Zn(S,Se) p•n heterojunctions up to 250 K.
Abstract: Laser diode action in the blue‐green has been observed from (Zn,Cd)Se quantum wells within ZnSe/Zn(S,Se) p‐n heterojunctions up to 250 K. Operation is reported for two different configurations for which the GaAs substrate serves either as the n‐ or p‐type injecting contact. In pulsed operation, output powers exceeding 0.6 W have been measured in devices prepared on both n‐type and p‐type GaAs epitaxial buffer layers and substrates.
TL;DR: In this paper, the equilibrium swelling behavior of hydrogels sensitive to pH or ionic strength changes of the swelling medium was studied using new structural models which are based on the Flory-Huggins thermodynamic theory, the rubber elasticity theory, and ionic interaction deviations therefrom.
TL;DR: The three-dimensional atomic structure of a single-stranded DNA virus has been determined and some of the amino termini of VP-2 run to the exterior in full but not empty virions, which is consistent with the observation that someVP-2 polypeptides in full particles can be cleaved by trypsin.
Abstract: The three-dimensional atomic structure of a single-stranded DNA virus has been determined. Infectious virions of canine parvovirus contain 60 protein subunits that are predominantly VP-2. The central structural motif of VP-2 has the same topology (an eight-stranded antiparallel beta barrel) as has been found in many other icosahedral viruses but represents only about one-third of the capsid protein. There is a 22 angstrom (A) long protrusion on the threefold axes, a 15 A deep canyon circulating about each of the five cylindrical structures at the fivefold axes, and a 15 A deep depression at the twofold axes. By analogy with rhinoviruses, the canyon may be the site of receptor attachment. Residues related to the antigenic properties of the virus are found on the threefold protrusions. Some of the amino termini of VP-2 run to the exterior in full but not empty virions, which is consistent with the observation that some VP-2 polypeptides in full particles can be cleaved by trypsin. Eleven nucleotides are seen in each of 60 symmetry-related pockets on the interior surface of the capsid and together account for 13 percent of the genome.
TL;DR: A recombinant protein-tyrosine-phosphatase expressed in Escherichia coli and purified to a single band by sodium dodecyl sulfate-polyacrylamide gel electrophoresis is suggested to form a covalent thiol phosphate linkage between Cys215 and phosphate.
TL;DR: In this article, the authors determined field-scale pesticide and nutrient losses to subsurface tile drains over a 3-yr period on a low organic matter and poorly structured silt loam soil under typical agricultural management practices.
Abstract: The objectives of this study were to determine field-scale pesticide and nutrient losses to subsurface tile drains over a 3-yr period on a low organic matter and poorly structured silt loam soil under typical agricultural management practices. A subsurface drain spacing study was instrumented to measure drain discharge rates and to collect drainflow samples continuously on a flow-proportional basis. Two replicates of three drain spacings (5,10, and 20 m) were included in the study. (...)
Journal Article•
TL;DR: A multiple resolution algorithm is presented for segmenting images into regions with differing statistical behavior and an algorithm is developed for determining the number of statistically distinct regions in an image and estimating the parameters of those regions.
Abstract: A multiple resolution algorithm is presented for segmenting images into regions with differing statistical behavior. In addition, an algorithm is developed for determining the number of statistically distinct regions in an image and estimating the parameters of those regions. Both algorithms use a causal Gaussian autoregressive model to describe the mean, variance, and spatial correlation of the image textures. Together, the algorithms can be used to perform unsupervised texture segmentation. The multiple resolution segmentation algorithm first segments images at coarse resolution and then progresses to finer resolutions until individual pixels are classified. This method results in accurate segmentations and requires significantly less computation than some previously known methods. The field containing the classification of each pixel in the image is modeled as a Markov random field. Segmentation at each resolution is then performed by maximizing the a posteriori probability of this field subject to the resolution constraint. At each resolution, the a posteriori probability is maximized by a deterministic greedy algorithm which iteratively chooses the classification of individual pixels or pixel blocks. The unsupervised parameter estimation algorithm determines both the number of textures and their parameters by minimizing a global criterion based on the AIC information criterion. Clusters corresponding to the individual textures are formed by alternately estimating the cluster parameters and repartitioning the data into those clusters. Concurrently, the number of distinct textures is estimated by combining clusters until a minimum of the criterion is reached. >
TL;DR: In this article, 10 second grade students participated in a year-long project in which instruction was generally compatible with a socioconstructivist theory of knowledge and recent recommendations of the National Council of Teachers of Mathematics.
Abstract: Ten second-grade classes participated in a year-long project in which instruction was generally compatible with a socioconstructivist theory of knowledge and recent recommendations of the National Council of Teachers of Mathematics. At the end of the school year, the 10 project classes were compared with 8 nonproject classes on a standardized achievement test and on instruments designed to assess students' computational proficiency and conceptual development in arithmetic, their personal goals in mathematics, and their beliefs about reasons for success in mathematics. The levels of computational performance were comparable, but there were qualitative differences in arithmetical algorithms used by students in the two groups. Project students had higher levels of conceptual understanding in mathematics; held stronger beliefs about the importance of understanding and collaborating; and attributed less importance to conforming to the solution methods of others, competitiveness, and task-extrinsic reasons for success. Responses to a questionnaire on pedagogical beliefs indicated that the project teachers' beliefs were more compatible with a socioconstructivist perspective than were those of their nonproject colleagues.
26 Jun 1991
TL;DR: Differences in parental reports of parenting stress, child behavior problems, and dysphoria in 150 families who had children with autism, behavior disorders, Down syndrome, or normal development are assessed.
Abstract: We assessed differences in parental reports of parenting stress, child behavior problems, and dysphoria in 150 families who had children with autism (n = 30), behavior disorders (n = 30), Down syndrome (n = 30), or normal development (n = 60). We measured stress with the Parenting Stress Index, child behavior problems with the Eyberg Child Behavior Inventory, and dysphoria with the Beck Depression Inventory. We controlled data for sociodemographic differences across groups, and results indicated the following: (1) Parents of children with autism and behavior disorders experienced statistically and clinically higher levels of parenting stress than parents in the other two groups. (2) Parents of children with behavior disorders reported that their children presented behavioral difficulties that were statistically and clinically more intense and numerous than those of all other children. (3) Mothers of children with autism and behavior disorders experienced statistically and clinically higher levels...