Showing papers by "University of Maryland, College Park published in 1985"
TL;DR: This paper reviews several sources of the data inaccuracies that commonly affect retrospective data and offers guidelines for reducing the occurrence or magnitude of these inaccuracies.
Abstract: Strategic management studies frequently involve obtaining retrospective data from strategic-level managers. The use of this data acquisition methodology has received relatively little codification and little critical review or comment. This seems unfortunate, as discussion and codification of the methodology could be useful for those academic researchers and corporate staff who study strategic decisions and organizational processes and for those managers who may be asked to provide the retrospective data. This paper is an attempt to remedy the current state of affairs. In particular, the paper reviews several sources of the data inaccuracies that commonly affect retrospective data and offers guidelines for reducing the occurrence or magnitude of these inaccuracies.
1,699 citations
TL;DR: In this paper, survey data from 142 employees and 968 customers from 28 branches of a bank were analyzed with the following results: moderate support was found for previous work on correlates of role stress for boundary role employees and good support for relationships between branch employees' and branch customers' service perceptions and attitudes.
Abstract: : Survey data from 142 employees and 968 customers from 28 branches of a bank were analyzed with the following results: (1) Moderate support was found for previous work on correlates of role stress for boundary role employees and good support was found for relationships between branch employees' and branch customers' service perceptions and attitudes; (2) Some significant relationships were reported between branch employees' perceptions of organizational human resources practices and branch customers' attitudes about service; and (3) employee attitudes and customer attitudes were related to their own and one another's turnover intentions. Results were discussed from the perspective of promoting an integration of consumer and organizational behavior in the service sector.
1,396 citations
TL;DR: In this paper, the authors presented coarse spatial resolution, high temporal frequency satellite data from the NOAA/AVHRR system to demonstrate their utility for monitoring vegetation seasonal dynamics, including forest clearance in Brazil, the productivity of African grasslands, Indian tropical forest and Chinese agriculture.
Abstract: Coarse spatial resolution, high temporal frequency satellite data from the NOAA/AVHRR system are presented to demonstrate their utility for monitoring vegetation seasonal dynamics. The techniques for processing and analysing the data are outlined and examples are given for selected applications at a range of scales. Normalized difference vegetation index images are presented for the entire globe and for the continents of Africa, South America and south-east Asia, with descriptions of the seasonal dynamics of major vegetation formations as portrayed by the transformed AVHRR data. Monitoring of forest clearance in Brazil, the productivity of African grasslands, Indian tropical forest and Chinese agriculture are selected for discussion. The paper concludes that coarse-resolution satellite data provide a valuable tool for vegetation mapping and monitoring at regional and global scales.
1,125 citations
TL;DR: The Baltimore-Washington Infant Study is a regional epidemiologic study of congenital heart disease and the data of the New England Infant Cardiac Program showed similar occurrences of major morphologic abnormalities, suggesting that these are stable basic estimates in the eastern United States.
Abstract: The Baltimore-Washington Infant Study is a regional epidemiologic study of congenital heart disease. Among Infants born in the study area in 1981 and 1982, 664 had a diagnosis of congenital heart disease confirmed in the first year of life by echocardiography, cardiac catheterization, cardiac surgery, or autopsy. The prevalence rate was 3.7/1,000 livebirths for all cases and 2.4/1,000 livebirths for cases confirmed by invasive methods only. Diagnosis-specific prevalence rates of congenital heart disease are compared with those of eight previous case series. Changing diagnostic categorizations in the time span covered and methodological differences resulted in great variation of the data. However, the data of the New England Infant Cardiac Program which used the same case discovery methods showed similar occurrences of major morphologic abnormalities, suggesting that these are stable basic estimates in the eastern United States. For all case series, the rate of confirmed congenital heart disease was approximately 4/1,000 livebirths over the 40-year time span.
940 citations
TL;DR: In this article, the Shapley value for cooperative games is characterized and shown to be monotonic in the sense that if a game changes so that some player's contribution to all coalitions increases or stays the same then the player's allocation should not decrease.
Abstract: The principle of monotonicity for cooperative games states that if a game changes so that some player's contribution to all coalitions increases or stays the same then the player's allocation should not decrease. There is a unique symmetric and efficient solution concept that is monotonic in this most general sense — the Shapley value. Monotonicity thus provides a simple characterization of the value without resorting to the usual “additivity” and “dummy” assumptions, and lends support to the use of the value in applications where the underlying “game” is changing, e.g. in cost allocation problems.
780 citations
TL;DR: The assumption that microorganisms, including pathogens, “die-off” or “decay” in the marine environment must be re-evaluated, since stressed or nutrient starved cells are unable to grow and be enumerated by standard plate count methods.
Abstract: In a series of microcosm and field studies, we have observed that over time V cholerae and related human pathogens enter a viable but non-culturable state Direct viable counts by epifluorescent microscopy are consistently higher than corresponding plate counts Thus, the assumption that microorganisms, including pathogens, “die-off” or “decay” in the marine environment must be re-evaluated, since stressed or nutrient starved cells are unable to grow and be enumerated by standard plate count methods Furthermore, animal passage reveals pathogenicity persisting for such “non-viable”cells Indirect immunofluorescent microscopy offers a more sensitive detection system for environmental sampling for human pathogens and therefore, a more valid estimation of population size One implication of these findings for the release of genetically engineered organisms is that highly specific methods of detection and monitoring are required, with direct detection by fluorescent antibody the most reliable at the present time
751 citations
TL;DR: This article investigated the influence of positive affect, induced in three different ways, on the uniqueness of word associations and found that persons in the positive-affect conditions gave more unusual first-associates to neutral words, according to the Palermo & Jenkins norms, than did subjects in the control conditions.
Abstract: A pilot study and two experiments investigated the influence of positive affect, induced in three differing ways, on the uniqueness of word associations. Persons in the positive-affect conditions gave more unusual first-associates to neutral words, according to the Palermo & Jenkins (1964) norms, than did subjects in the control conditions. In Study 3, where word type (positive, neutral, negative) was a second factor along with affect, in a between-subjects design, associates to positive words were also more unusual and diverse than were those to other words. These results were related to those of studies suggesting that positive affect may facilitate creative problem solving and to other work suggesting an impact of positive feelings on cognitive organization.
662 citations
TL;DR: In this article, the authors used a very high-resolution radiometer on the current series of U.S. National Oceanic and Atmospheric Administration meteorological satellites to study the seasonality of North American natural and cultivated vegetation.
Abstract: Spectral vegetation index measurements derived from remotely sensed observations show great promise as a means to improve knowledge of land vegetation patterns. The daily, global observations acquired by the advanced very high resolution radiometer, a sensor on the current series of U.S. National Oceanic and Atmospheric Administration meteorological satellites, may be particularly well suited for global studies of vegetation. Preliminary results from analysis of North American observations, extending from April to November 1982, show that the vegetation index patterns observed correspond to the known seasonality of North American natural and cultivated vegetation. Integration of the observations over the growing season produced measurements that are related to net primary productivity patterns of the major North American natural vegetation formations. Regions of intense cultivation were observed as anomalous areas in the integrated growing season measurements. Significant information on seasonality, annual extent and interannual variability of vegetation photosynthetic activity at continental and global scales can be derived from these satellite observations.
616 citations
TL;DR: In this paper, the authors restimulate research and theory on the relationship and suggest ingredients in the therapy relationship that are common to all interventions, and examine similarities and differences in how the relationship works within the three dominant approaches to therapy.
Abstract: This two-part article suggests ingredients in the therapy relationship that are common to all interventions. It then examines similarities and differences in how the relationship works within the three dominant approaches to therapy. The overall aim of the article is to restimulate research and theory on the relationship. The first part defines the relationship and proposes three components to all therapeutic relationships: a working alliance, a transference configuration, and a real relationship. Five propositions are offered about the operation of each component within and across theoretical orientations. The second part examines how views of the relationship in perspectives broadly labeled psychoanalytic, humanistic, and learning vary according to three theoretical dimensions: the centrality, real-unreal, and means-end dimensions. Central research findings are reviewed for each theoretical perspective, the current state of research is examined for each, and suggestions are offered for future directions.
545 citations
TL;DR: Results of this study indicate a good correlation between the taxonomy of the Vibrionaceae established using conventional and molecular genetic data and evolutionary relationships deduced from 5S rRNA sequences, however, several species require reconsideration of their taxonomic status, based on the new information obtained in this study.
499 citations
TL;DR: In this paper, the authors investigated fractal basin boundaries for dynamical systems and found that they can lead to great difficulty in predicting to which attractor a system eventually goes, and that fractal basins can be classified as being either locally connected or locally disconnected.
TL;DR: In this article, the spatial and seasonal variations of the continental fields of snow-cover, soil moisture and evapotranspiration are presented and interpreted using a modified version of the method of Thornthwaite.
Abstract: Calculations of the spatial and seasonal variations of the continental fields of snow-cover, soil moisture and evapotranspiration are presented and interpreted. The calculations were made with a water budget analysis that is based on observed average monthly precipitation and an estimate of potential evapotranspiration derived from observed average monthly surface temperature, using a modified version of the method of Thornthwaite. Monthly average water budget analyses were made for 13,332 stations over the globe and, then spatially interpolated to a regular grid at 1° by 1° latitude-longitude intervals. From the monthly fields on a 4° by 5° subset of the 1° by 1° grid, the annual mean and standard deviation as well as the first and second annual harmonics were extracted and are displayed on global maps. Of the three fields, soil moisture has the largest space-time variation; snow-cover the smallest variation; and evapotranspiration an intermediate level of variation.
TL;DR: The estimation of the parameters of a sinusoid from observations of signal samples corrupted by additive noise is investigated, suggesting frequency and phase estimation by linear regression on the signal phase.
Abstract: The estimation of the parameters of a sinusoid from observations of signal samples corrupted by additive noise is investigated. At high signal-to-noise ratios the additive noise is viewed as an equivalent phase noise, suggesting frequency and phase estimation by linear regression on the signal phase. The variances of the regression estimates are shown to achieve the Cramer-Rao bounds. A formula for the variance of the regression frequency estimator is derived in terms of the noise power spectrum. A simple formula for the variance with 1/f^{2} phase noise is presented.
TL;DR: In this article, the authors operateally defined three top-level management priorities and made some suggestions about these priorities' relative levels of importance across three stages of organizational life (organizational life cycle).
Abstract: This research operationally defined three top-level management priorities and made some suggestions about these priorities' relative levels of importance across three stages of organizational life ...
TL;DR: In this article, it was shown that a three times continuously differentiable conductivity is identifiable by boundary measurements, and that a similar result holds for piecewise real-analytic conductivities.
Abstract: : In a recent paper the authors showed that an unknown real-analytic conductivity gamma may be determined from static boundary measurements. In this document they extend this analysis by demonstrating that a similar result holds for piecewise real-analytic conductivities. In addition, for the special case of a layered structure it is shown that a three times continuously differentiable conductivity is identifiable by boundary measurements. Originator-supplied keywords include: Inversion, Convergence, Algorithms, Estimates, Coefficients.
01 May 1985
TL;DR: This paper presents an efficient initial packing technique for creatmg R-trees to index spatial ObJects since pictorial databases are not update mtensive but rather static, the benefits of this technique are very significant.
Abstract: Pictorial databases require efficient and duect spatml search based on the analog form of spatial obJects and relatlonshlps instead of search based on some cumbersome alphanumeric encodings of the pmtures R-trees (two-dimensional B-trees) are excellent devices for indexing spatial ObJects and relationships found on pictures Their most important feature 1s that they provide high level ObJect onented search rather than search based on the low level elements of spatial ObJects This paper presents an efficient initial packing technique for creatmg R-trees to index spatial ObJects Since pictorial databases are not update mtensive but rather static, the beneflts of this technique are very significant
TL;DR: In this paper, a velocity distribution extending up to double the solar wind velocity has been detected in interplanetary space, which unambiguously determines the source: interstellar neutrals, ionized and accelerated in solar wind.
Abstract: Singly-ionized helium with a velocity distribution extending up to double the solar wind velocity has been detected in interplanetary space. This distribution unambiguously determines the source: interstellar neutrals, ionized and accelerated in the solar wind. The observed significant flux increase in early December is due to the gravitational focusing of the interstellar neutral wind on the downwind side of the Sun.
TL;DR: The authors reviewed research on person-environment congruence in Holland's theory of career choice and found significant, positive relationships between congruance and academic performance and persistence, job satisfaction, stability of choice, perceived congruity, and personality.
TL;DR: In this article, the effects of goal setting in sports are discussed, and suggestions regarding the following: setting goals for both practice and game situations, using goals to increase self-confidence, using short-term goals to help attain long-term performance goals, improving performance by increasing...
Abstract: Studies of goal setting both in organizations and the laboratory have found that (a) specific, difficult goals lead to better performance than vague or easy goals; (b) short-term goals can facilitate the achievement of long-term goals; (c) goals affect performance by affecting effort, persistence, and direction of attention, and by motivating strategy development; (d) feedback regarding progress is necessary for goal setting to work; and (e) goals must be accepted if they are to affect performance. The implications of these findings for athletics are discussed. Ten hypotheses, based on previous research, are offered regarding the effects of goal setting in sports. In addition, suggestions are made regarding the following: setting goals for both practice and game situations; setting goals for different elements of athletic skill as well as for strength and stamina; using goals to increase self-confidence; using short-term goals to help attain long-term performance goals; improving performance by increasing...
TL;DR: The results show that the fcc phase is 867 K lower in energy than the bcc phase, which indicates a fundamental deficiency of LSDA in describing the magnetic interactions in transition metals.
Abstract: Using the total-energy general-potential linearized-augmented-plane-wave method, we have tested the adequacy of the local-spin-density approximation for describing the magnetic and structural properties of iron. We find that there are fundamental deficiencies in the local-spin-density approximation, both quantitative and qualitative, in that there are substantial errors in the calculated ground-state volumes and magnetic moments, as well as a prediction of the wrong ground-state crystal structure.
TL;DR: In this paper, the use of cluster analysis as a tool for system modularization is discussed and several clustering techniques are discussed and used on two medium-size systems and a group of small projects.
Abstract: This paper examines the use of cluster analysis as a tool for system modularization. Several clustering techniques are discussed and used on two medium-size systems and a group of small projects. The small projects are presented because they provide examples (that will fit into a paper) of certain types of phenomena. Data bindings between the routines of the system provide the basis for the bindings. It appears that the clustering of data bindings provides a meaningful view of system modularization.
TL;DR: In this article, a mixed-integer programming formulation of the Warehouse Location-Routing Problem (WLRP) is presented, which is a generalization of well-known and difficult location and routing problems, such as the location allocation problem and the multi-depot vehicle dispatch problem.
Abstract: The interdependence between distribution center location and vehicle routing has been recognized by both academics and practitioners. However, only few attempts have been made to incorporate routing in location analysis. This paper defines the Warehouse Location-Routing Problem (WLRP) as one of simultaneously solving the DC location and vehicle routing problems. We present a mixed integer programming formulation of the WLRP. Based on this formulation, it can be seen that the WLRP is a generalization of well-known and difficult location and routing problems, such as the Location-Allocation Problem and the Multi-depot Vehicle Dispatch Problem. It is therefore a large and complex problem which cannot be solved using existing mixed-integer programming techniques. We present a heuristic solution method for the WLRP, based on decomposing the problem into three subproblems. The proposed method solves the subproblems in a sequential manner while accounting for the dependence between them. We discuss a large-scale application of the proposed method to a national distribution company at a regional level.
TL;DR: It is found that for accessible electron densities in the usual three-dimensional metallic systems the scattering time is at most a factor of \ensuremath{\sim}2 larger than the single-particle relaxation time whereas in high-mobility GaAs-based heterojunctions the spatial separation between the impurities and the carriers gives rise to scattering times which can be as much as two orders of magnitude larger.
Abstract: Relative magnitudes of the single-particle relaxation time and the scattering time that enters in conductivity are given for two- and three-dimensional electron gases in the presence of random distributions of charged Coulomb scattering centers. We find that for accessible electron densities in the usual three-dimensional metallic systems the scattering time is at most a factor of \ensuremath{\sim}2 larger than the single-particle relaxation time whereas in high-mobility GaAs-based heterojunctions the spatial separation between the impurities and the carriers gives rise to scattering times which can be as much as two orders of magnitude larger than the corresponding single-particle relaxation times.
01 Apr 1985
TL;DR: An enhanced version of the Entity-Relationship data model called the ECR data model is presented, with the introduction of the concept of a category, which permits the grouping of entities from different entity types according to the roles they play in a relationship.
Abstract: An enhanced version of the Entity-Relationship (ER) data model called the Entity-Category-Relationship (ECR) data model is presented. The principal extension is the introduction of the concept of a category. Categories permit the grouping of entities from different entity types according to the roles they play in a relationship, as well as the representation of ISA and generalization hierarchies. The structures of the ECR data model are defined, and a graphic representation technique for their display is presented. Language operations to define and use an ECR database are defined. Two realistic examples of the use of the ECR model for database design are demonstrated. The examples show how ECR structures can be directly mapped into relational and network structures. The definition of derived relationships on an ECR database gives the power to phrase higher order recursive queries in a first order query language.
TL;DR: Data from two years of field research on the satin bowerbird show an extremely skewed distribution of matings among males, and a consistent pattern of female preference for particular males, especially those with well-constructed, highly-decorated bowers, support the ‘marker’ hypothesis, which suggests that the construction of bowers evolved to provide females with information about the relative quality of males.
TL;DR: In this article, a new derivation of the electrostatic potential for the interaction of a closed-shell atom with a molecule in an electronic state of π-symmetry is presented, which avoids the introduction of a potential dependent on the azimuthal orientation of the molecule.
TL;DR: In this paper, the effect of aerosols on satellite measurements of surface properties for the visible and near-infrared spectrum has been investigated, and the effects on classification of surface features, measuring vegetation index, and measuring surface reflectance are presented.
Abstract: Previous attempts to explain the effect of aerosols on satellite measurements of surface properties for the visible and near-infrared spectrum have emphasized the amount of aerosols without consideration of their absorption properties. In order to estimate the importance of absorption, the radiances of the sunlight scattered from models of the Earth-atmosphere system are computed as functions of the aerosol optical thickness and absorption. The absorption effect is small where the surface reflectance is weak, but is important for strong reflectance. These effects on classification of surface features, measuring vegetation index, and measuring surface reflectance are presented.
TL;DR: In this article, a high performance liquid chromatography procedure using an internal carotenoid standard, echinenone, was described, which uses a C-18, reverse-phase column, an isocratic solvent (acetonitrile:methylene chloride:methanol, 70:20:10) and requires only thirteen minutes.
Abstract: A high performance liquid chromatography procedure using an internal carotenoid standard, echinenone, is described. The method uses a C-18, reverse-phase column, an isocratic solvent (acetonitrile:methylene chloride:methanol, 70:20:10) and requires only thirteen minutes. Most human plasmas gave seven distinct peaks; six carotenoids are identified. The sum of seven peaks is 90 percent or more of the total carotenoids in a total lipid extract.
TL;DR: In this article, the statistical relationship between remotely sensed thermal emissions and reflected spectral radiance was investigated for a complex vegetated land area, for a site near Hartford, CT on a single date.
TL;DR: After one year, performance is equal for old pseudowords and new and old words: all these levels are superior to that for new pseudowording, suggesting that the learned codes for pseudoword are as strong and permanent as the codes for words.
Abstract: The studies presented in this article investigate the memory processes that underlie two phenomena in threshold identification: word superiority over pseudowords and the repetition effect (a prior presentation of an item facilitates later identification of that item). Codification (i.e., the development of a single memory code that can be triggered even by fragmented input information) explains the faster and more accurate identification of words than pseudowords. Our studies trace the development and retention of such codes for repeated pseudowords and examine the growth and loss of the repetition effect for both pseudowords and words. After approximately five prior occurrences, words and pseudowords are identified equally accurately in two types of threshold identification tasks, suggesting codification has been completed for pseudowords. Although the initial word advantage disappears, the accuracy of identification still increases with repetitions. The facilitation caused by repetition is not affected much by spacing within a session, but drops from one day to the next, and after a delay of one year has disappeared (new and old words were identified equally well). These results suggest an episodic basis for the repetition effect. Most important, after one year, performance is equal for old pseudowords and new and old words: all these levels are superior to that for new pseudowords, suggesting that the learned codes for pseudowords are as strong and permanent as the codes for words. A model of identification is presented in which feedback from codes and episodic images in memory facilitates letter processing. An instantiation of the model accounts for the major features of the data.