10 resultados para Ray theoretical Model
em Digital Commons at Florida International University
Resumo:
The dissertation takes a multivariate approach to answer the question of how applicant age, after controlling for other variables, affects employment success in a public organization. In addition to applicant age, there are five other categories of variables examined: organization/applicant variables describing the relationship of the applicant to the organization; organization/position variables describing the target position as it relates to the organization; episodic variables such as applicant age relative to the ages of competing applicants; economic variables relating to the salary needs of older applicants; and cognitive variables that may affect the decision maker's evaluation of the applicant. ^ An exploratory phase of research employs archival data from approximately 500 decisions made in the past three years to hire or promote applicants for positions in one public health administration organization. A logit regression model is employed to examine the probability that the variables modify the effect of applicant age on employment success. A confirmatory phase of the dissertation is a controlled experiment in which hiring decision makers from the same public organization perform a simulated hiring decision exercise to evaluate hypothetical applicants of similar qualifications but of different ages. The responses of the decision makers to a series of bipolar adjective scales add support to the cognitive component of the theoretical model of the hiring decision. A final section contains information gathered from interviews with key informants. ^ Applicant age has tended to have a curvilinear relationship with employment success. For some positions, the mean age of the applicants most likely to succeed varies with the values of the five groups of moderating variables. The research contributes not only to the practice of public personnel administration, but is useful in examining larger public policy issues associated with an aging workforce. ^
Resumo:
A ray tracing model has been developed to investigate the possible focusing effects of the convexly curved epidermal cell walls which characterize a number of shade-adapted plants. The model indicates that such focusing occurs, resulting in higher photosynthetic photon flux densities at certain locations within the leaf. It is postulated that there will be a corresponding increase in the rate of photosynthesis. In addition, leaf reflectance measurements indicate that this is generally less for the shade plants compared with sun species and would be advantageous in increasing the efficiency of energy capture. Either effect is important for plants which must survive at extremely low light levels.
Resumo:
This dissertation had two purposes: first, to analyze how required sequenced college preparatory courses in mathematics, reading, and writing affect students' academic success and, second, to add to a theoretical model for predicting student retention at a community college. Grade point average, number of degree credits earned, and re-enrollment rate were measured as determinants of academic success. The treatment group had a significantly higher grade point average than the control group. There was no significant difference in the number of degree credits earned or re-enrollment rate for the groups. A series of logistic regressions used the independent variables E-ASSET scores in math, reading, and writing; number of college prep areas required; credits earned; grade point average; students' status; academic restrictions/required course sequencing; sex; race; and socio-economic status to determine the predictor variables for retention. The academic variable that showed the greatest potential as a predictor for retention was grade point average. Overall, receiving financial aid was the greatest predictor for re-enrollment. For a financial aid recipient the odds of re-enrollment were 2.70 times more likely than if no financial aid was received.
Resumo:
This dissertation examines the behavior of the exchange rate under two different scenarios. The first one is characterized by, relatively, low inflation or a situation where prices adjust sluggishly. The second is a high inflation economy where prices respond very rapidly even to unanticipated shocks. In the first one, following a monetary expansion, the exchange rate overshoots, i.e. the nominal exchange rate depreciates at a faster pace than the price level. Under high levels of inflation, prices change faster than the exchange rate so the exchange rate undershoots its long run equilibrium value.^ The standard work in this area, Dornbusch (1976), explains the overshooting process in the context of perfect capital mobility and sluggish adjustment in the goods market. A monetary expansion will make the exchange rate increase beyond its long run equilibrium value. This dissertation expands on Dornbusch's model and provides an analysis of the exchange rate under conditions of currency substitution and price flexibility, characteristics of the Peruvian economy during the hyper inflation process that took place at the end of the 1980's. The results of the modified Dornbusch model reveal that, given a monetary expansion, the change in the price level will be larger than the change in the exchange rate if prices react more than proportionally to the monetary shock.^ We will expect this over-reaction in circumstances of high inflation when the velocity of money is increasing very rapidly. Increasing velocity of money, gives rise to a higher relative price variability which in turn contributes to the appearance of new financial (and also non-financial) instruments that report a higher return than the exchange rate, causing people to switch their demand for foreign exchange to this new assets. In the context of currency substitution, economic agents hoard and use foreign exchange as a store of value. The big decline in output originated by hyper inflation induces people to sell this hoarded money to finance current expenses, increasing the supply of foreign exchange in the market. Both, the decrease in demand and the increase in supply reduce the price of foreign exchange i.e. the real exchange rate. The findings mentioned above are tested using Peruvian data for the period January 1985-July 1990, the results of the econometric estimation confirm our findings in the theoretical model. ^
Resumo:
This dissertation examines whether-there exists financial constraints and, if so, their implications for investment in research and development expenditures. It develops a theoretical model of credit rationing and research and development in which both are determined simultaneously and endogenously. The model provides a useful tool to examine different policies that may help alleviate the negative the effect of financial constraints faced by firms.^ The empirical evidence presented deals with two different cases, namely, the motor vehicle industry in Germany (1970-1990) and the electrical machinery industry In Spain (1975-1990).^ The innovation in the empirical analysis is that it follows a novel approach to identify events that allow us to isolate the effect of financial constraints in the determination of research and development.^ Further, empirical evidence is presented to show that in the above two cases financial constraints affect investment in physical capital as well.^ The empirical evidence presented supports the results of the theoretical model developed in this dissertation, showing that financial constraints negatively affect the rate of growth of innovation by reducing the intensity of research and development activity. ^
Resumo:
The purpose of this study was to examine a Higher Education Institution’s (HEI) process of internationalization. The theoretical model developed by Van Dijk and Miejer (1997) was used to review Florida International University (FIU)’s policy, support, and implementation dimensions and determine its position on the Internationalization Cube, and assess how FIU’s international activities fit into its different organizational processes. In addition, the study sought to shed light on student and faculty attitudes toward internationalization. Qualitative and quantitative data were collected from examining organizational documents, interviews, descriptive data on FIU’s international activities using the International Dimension Index, and the Student and Faculty Survey on Internationalization. FIU’s international activities results were analyzed in relation to a panel of experts’ item relevancy index. The Likert-type survey scales’ frequencies and percentages were calculated as well as Spearman Rho correlations between the survey’s three scales and demographic and experiences variables. The study found that FIU is located on position six of a possible eight positions on the Van Dijk and Meijer Internationalization Cube with the following characteristics: Priority Policy, One-Sided Support, and Structured Implementation toward internationalization. The analysis of FIU’s results on international activities showed that FIU exhibits all the activities considered to be strong indicators of internationalization but for position seven placement special attention is needed in the areas of foreign language study, international students, study abroad, faculty movement and involvement in international projects. The survey indicated students and faculty rated the Benefits of Internationalization highly but didn’t perceive strong institutional Support for Internationalization. Faculty age and offshore programs participation; student gender, race/ethnicity and class status; and for both, study abroad and knowledge of students travel grant had significant positive correlations with student and faculty attitudes. The study concluded that an association exists between FIU’s position on the Internationalization Cube and its international activities. Recommendations for policy, implementation, and future studies were made. It was concluded that advancing FIU’s position on the Cube will require adjustments in FIU’s policy, support and implementation dimensions. Differences in student and faculty views toward internationalization should be taken into account when planning internationalization efforts.
Resumo:
This dissertation analyzes rewards and motivations of self-employment. In light of recent research contributions of Barton Hamilton (2000), which find entrepreneurship not as financially rewarding as wage work, my dissertation attempts to both verify and explain this claim. The first essay proposes a theoretical model of evolution of erroneous earnings expectations on part of a nascent entrepreneur. Inability to observe, survey, and take into account all of the returns to entrepreneurship prior to business entry creates a biased set of beliefs on part of the potential entrants. Using Bayesian learning, a nascent entrepreneur starting out with correct perception of profit distribution arrives at erroneous beliefs by incorporating limited information collected from existing businesses. An observed distribution of surviving businesses would exhibit higher earnings because of previous, unobserved, business failure entrepreneur get an overly positive view of her profit potential. Hence, the chapter offers a unique method of modeling overconfidence. The second essay undertakes dynamic empirical comparison of earnings received by business owners and their wage counterparts. Using Survey of Income and Program Participation (SIPP) I examine both short and long run returns to entrepreneurship comparing theses rewards to wage earners returns. I pay particular attention to transitions into and out of business ownership. I estimate entire earnings distribution. To characterize dynamic aspect of changes to individuals’ earnings I split the income distribution into five income quintiles and follow survey participants over the period of seven years. I find that period-to-period transitions to be Markovian. I find business tenure to be short, business ownership is costly in the short and rewarding in the long run. The third essay considered different reporting schemes applied to the self-employed. It is another empirical investigation of entrepreneurial earning uses Panel Study of Income Dynamics (PSID). I find entrepreneurs while reporting lower than wage workers earnings enjoy significant consumption premiums. I observe evidence of income underreporting by entrepreneurs. This finding suggests a need for better earning comparison metrics and proposes to use consumption rather than income metrics for future comparisons.
Resumo:
With the introduction of new input devices, such as multi-touch surface displays, the Nintendo WiiMote, the Microsoft Kinect, and the Leap Motion sensor, among others, the field of Human-Computer Interaction (HCI) finds itself at an important crossroads that requires solving new challenges. Given the amount of three-dimensional (3D) data available today, 3D navigation plays an important role in 3D User Interfaces (3DUI). This dissertation deals with multi-touch, 3D navigation, and how users can explore 3D virtual worlds using a multi-touch, non-stereo, desktop display. ^ The contributions of this dissertation include a feature-extraction algorithm for multi-touch displays (FETOUCH), a multi-touch and gyroscope interaction technique (GyroTouch), a theoretical model for multi-touch interaction using high-level Petri Nets (PeNTa), an algorithm to resolve ambiguities in the multi-touch gesture classification process (Yield), a proposed technique for navigational experiments (FaNS), a proposed gesture (Hold-and-Roll), and an experiment prototype for 3D navigation (3DNav). The verification experiment for 3DNav was conducted with 30 human-subjects of both genders. The experiment used the 3DNav prototype to present a pseudo-universe, where each user was required to find five objects using the multi-touch display and five objects using a game controller (GamePad). For the multi-touch display, 3DNav used a commercial library called GestureWorks in conjunction with Yield to resolve the ambiguity posed by the multiplicity of gestures reported by the initial classification. The experiment compared both devices. The task completion time with multi-touch was slightly shorter, but the difference was not statistically significant. The design of experiment also included an equation that determined the level of video game console expertise of the subjects, which was used to break down users into two groups: casual users and experienced users. The study found that experienced gamers performed significantly faster with the GamePad than casual users. When looking at the groups separately, casual gamers performed significantly better using the multi-touch display, compared to the GamePad. Additional results are found in this dissertation.^
Resumo:
This dissertation had two purposes: first, to analyze how required sequenced college preparatory courses in mathematics, reading, and writing affect students' academic success and, second, to add to a theoretical model for predicting student retention at a community college. Grade point average, number of degree credits earned, and reenrollment rate were measured as determinants of academic success. The treatment group had a significantly higher grade point average than the control group. There was no significant difference in the number of degree credits earned or re-enrollment rate for the groups. A series of logistic regressions used the independent variables E-ASSET scores in math, reading, and writing; number of college prep areas required; credits earned; grade point average; students' status; academic restrictions/required course sequencing; sex; race; and socio-economic status to determine the predictor variables for retention. The academic variable that showed the greatest potential as a predictor for retention was grade point average. Overall, receiving financial aid was the greatest predictor for reenrollment. For a financial aid recipient the odds of reenrollment were 2.70 times more likely than if no financial aid was received.
Resumo:
With the introduction of new input devices, such as multi-touch surface displays, the Nintendo WiiMote, the Microsoft Kinect, and the Leap Motion sensor, among others, the field of Human-Computer Interaction (HCI) finds itself at an important crossroads that requires solving new challenges. Given the amount of three-dimensional (3D) data available today, 3D navigation plays an important role in 3D User Interfaces (3DUI). This dissertation deals with multi-touch, 3D navigation, and how users can explore 3D virtual worlds using a multi-touch, non-stereo, desktop display. The contributions of this dissertation include a feature-extraction algorithm for multi-touch displays (FETOUCH), a multi-touch and gyroscope interaction technique (GyroTouch), a theoretical model for multi-touch interaction using high-level Petri Nets (PeNTa), an algorithm to resolve ambiguities in the multi-touch gesture classification process (Yield), a proposed technique for navigational experiments (FaNS), a proposed gesture (Hold-and-Roll), and an experiment prototype for 3D navigation (3DNav). The verification experiment for 3DNav was conducted with 30 human-subjects of both genders. The experiment used the 3DNav prototype to present a pseudo-universe, where each user was required to find five objects using the multi-touch display and five objects using a game controller (GamePad). For the multi-touch display, 3DNav used a commercial library called GestureWorks in conjunction with Yield to resolve the ambiguity posed by the multiplicity of gestures reported by the initial classification. The experiment compared both devices. The task completion time with multi-touch was slightly shorter, but the difference was not statistically significant. The design of experiment also included an equation that determined the level of video game console expertise of the subjects, which was used to break down users into two groups: casual users and experienced users. The study found that experienced gamers performed significantly faster with the GamePad than casual users. When looking at the groups separately, casual gamers performed significantly better using the multi-touch display, compared to the GamePad. Additional results are found in this dissertation.