Computations and experiments were run to study heat transfer and overall effectiveness for a simulated turbine blade leading edge. Computational predictions were run for a film cooled leading edge model using a conjugate numerical method to predict the normalized “metal” temperatures for the model. This computational study was done in conjunction with a parallel effort to experimentally determine normalized metal temperatures, i.e. overall effectiveness, using a specially designed high conductivity model. Predictions of overall effectiveness were higher than experimentally measured values in the stagnation region, but lower along the downstream section of the leading edge. Reasons for the differences between computational predictions and experimental measurements were examined. Also of interest was the validity of Taw as the driving temperature for heat transfer into the blade, and this was examined via computations. Overall, this assumption gave reasonable results except near the stagnation line. Experiments were also conducted on a leading edge with no film cooling to gain a better understanding of the additional cooling provided by film cooling. Heat flux was also measured and external and internal heat transfer coefficients were determined. The results showed roughly constant overall effectiveness on the external surface. / text

Approved for public release, distribution unlimited / This thesis presents a Computation Fluid Dynamics (CFD) analysis of the aerodynamic performance of circular and elliptical leading edges of compressor blades, with a range of leading-edge droop angles. Specifically, simulations were conducted, with a free stream Mach number of 0.65 to quantify the change in pressure distributions and boundary layer momentum thickness in the leading edge region for a range of incidences on a flat plate with various leading-edge ellipticity ratios, ranging from unity (circular) to 5.5. In addition, the impact of drooping the leading edge was analyzed over a range of incidence angles from zero to 13 degrees. Pressure distributions indicate that elliptical leading edges can eliminate separation bubbles at zero incidence. The results indicated that the minimum loss occurred at an ellipticity ratio of about 3 and elliptical leading edges with a droop slightly greater than the average incidence can significantly decreased aerodynamic losses over a wider range of incidences.

The humpback whale is very maneuverable despite its enormous size and rigid body. This agility has been attributed to the use of its pectoral flippers, along the leading edge of which protuberances are present. The leading edge protuberances are considered by some biologists to be a form of passive flow control and/or drag reduction. Force and moment measurements along with qualitative and quantitative flow visualizations were carried out in water tunnel experiments on full-span and finite-span hydrofoil models with several different planforms and protuberance geometries. A NACA 634-021 cross-sectional airfoil profile was used for the baseline foil in all tests. Four planform geometries chosen included: a full-span set of foils which spanned the breadth of the water tunnel, a finite-span rectangular planform, a finite-span swept hydrofoil, and a scale flipper model that resembled the morphology of the humpback whale flipper. A variety of sinusoidal protuberance geometries which included three amplitudes equal to 2.5%, 5%, and 12% and wavelengths of 25% and 50% of the local chord were examined in combination with the different planform geometries. Testing included force and moment measurements and Particle Image Velocimetry (PIV) to examine the load characteristics and flow field surrounding the modified foils. Load measurements show that modified foils are capable of generating higher lift than the baseline at high angles of attack while at low angle of attack the baseline generally produces a lift coefficient equal to or greater than the modified cases. With the exception of the modified flipper model, the drag coefficients of the modified hydrofoils are either equal to or greater than their baseline counterparts. The increased drag reduces the lift-to-drag ratio. Flow visualizations show that vortical structures emanating from the shoulders of the protuberances are responsible for increased lift and drag at high angles. Cavitation tests show that modified foils cavitate in pockets behind the troughs of protuberances whereas the baseline foils produce cavitation along the entire foil span. Also, the cavitation numbers on modified hydrofoils were consistently higher than their baseline counterparts. This work shows the effect of leading edge protuberances on the aforementioned performance characteristics.

This thesis studies information in financial markets from three perspectives: the role of information asymmetry in alleviating dividend payers’ seasoned equity offering (SEO) announcement returns, the leading behavior of equity analysts who collect and process information, and the pricing of productivity-related information. More specifically, Chapter 1 studies whether the market reacts less negatively to dividend payers’ SEO announcements. Using US data from 1975 to 2002, I find that prior to SEO announcement dates, dividend payers have less information asymmetries than non-dividend payers. This difference was not large before the mid-1980s, but increased dramatically since then. This finding, together with the disappearing dividend puzzle documented in Fama and French (2001), suggests that a firm’s dividend status was not an important signal for SEOs prior to the mid-1980s, but became important since then. The market reacts less negatively to dividend payers’ SEO announcements since the mid-1980s. Chapter 2 studies equity analysts’ leading behavior in equity recommendations. I develop a measure of leading recommendations based on the observation that other recommendations move towards those of the leader. I find that analysts who are more likely to lead are past leaders, past All-American stars, analysts from large brokerage houses, and analysts with fewer recommendations. I find that the market reacts more strongly to recommendations of leaders and leaders are less likely to be terminated from their jobs. Chapter 3 examines the link between productivity and the cross-section of security returns. The CAPM and CCAPM have had problems finding empirical validations. In contrast, by creating factor mimicking portfolios with respect to productivity, I introduce a stock market factor that mimics the driving force behind the CCAPM. First, I find that the productivity factor affects the overall market return and that on average it contributes 0.75 to 2.41 percent annually, for the range of productivity factors I construct. Further, I show that productivity is priced even when the market excess return and factors based on size and book-to-market are included in standard asset pricing tests. However, the market excess return and the book-to-market factor still explain asset returns.

This thesis studies information in financial markets from three perspectives: the role of information asymmetry in alleviating dividend payers’ seasoned equity offering (SEO) announcement returns, the leading behavior of equity analysts who collect and process information, and the pricing of productivity-related information. More specifically, Chapter 1 studies whether the market reacts less negatively to dividend payers’ SEO announcements. Using US data from 1975 to 2002, I find that prior to SEO announcement dates, dividend payers have less information asymmetries than non-dividend payers. This difference was not large before the mid-1980s, but increased dramatically since then. This finding, together with the disappearing dividend puzzle documented in Fama and French (2001), suggests that a firm’s dividend status was not an important signal for SEOs prior to the mid-1980s, but became important since then. The market reacts less negatively to dividend payers’ SEO announcements since the mid-1980s. Chapter 2 studies equity analysts’ leading behavior in equity recommendations. I develop a measure of leading recommendations based on the observation that other recommendations move towards those of the leader. I find that analysts who are more likely to lead are past leaders, past All-American stars, analysts from large brokerage houses, and analysts with fewer recommendations. I find that the market reacts more strongly to recommendations of leaders and leaders are less likely to be terminated from their jobs. Chapter 3 examines the link between productivity and the cross-section of security returns. The CAPM and CCAPM have had problems finding empirical validations. In contrast, by creating factor mimicking portfolios with respect to productivity, I introduce a stock market factor that mimics the driving force behind the CCAPM. First, I find that the productivity factor affects the overall market return and that on average it contributes 0.75 to 2.41 percent annually, for the range of productivity factors I construct. Further, I show that productivity is priced even when the market excess return and factors based on size and book-to-market are included in standard asset pricing tests. However, the market excess return and the book-to-market factor still explain asset returns.

Abstract The theories of leadership seldom explain the difference of male leaders and female leaders. Instead of the assumption that the leaders¡¦ leading traits and leading styles of two sexes are the same, most studies work from the ¡§man¡¨ point of view. Traditionally, the principles and theories of leadership in most cases come from the researches written by male leaders. Many female leaders¡¦ leadership styles are ignored or forgotten. (Sally Helgsen, 1995) General thoughts indicated that there are some differences between male and female, but these differences are seldom used to explain leadership. The master stream of leadership theories still infers female¡¦s leadership by male traits. This research considers that once woman accept the inequality is unfair, then they can create the possibility in working field. As the saying of Peter Senge goes ¡§Remove the unwanted doesn¡¦t mean you can get what you want¡¨. This research wants to draw a picture of real female leaders by finding ¡§What You Want¡¨, focusing on female leaders¡¦ successful leadership traits and leadership styles, then to discuss how they overcome ¡§the Unwanted¡¨. This research adopted case study and in-depth interview methods. After interviewing six female leaders, this research has conclusions listed below: 1. Female leader¡¦s traits: Female leaders not only lead people to achieve the goal of organizations, but also want to make them improve themselves. The female leaders emphasize ex-birth learning even more than pro-birth gift. It is an everlasting improving process. The female leaders who have strong motivation know they should try hard to hold on every chance, but the others must wait the inspiration by environment or other people. 2. Female leaders¡¦ leadership style: Female leaders adapt Y theory to make the attributed assumption of employees, but they would transfer to X theory because of changes of environment and so on. They mainly use democratic leadership style and supply with authoritative and laissez faire styles. They try to achieve the balance of employee-oriented and work-oriented. This research discovered that female leaders usually adapt the neutral characteristics or integrate the characteristics of two sexes in leading process. 3. Female leaders and sex issue: This research shows the notion of female leaders that leaders contain those of two sexes, but they should not be separated into two nouns: male leaders and female leaders. This research discovered that all female leaders never benefit from being a female. The dilemmas they face are: challenging the stereotype and the conflict of family and job roles. The ways they treat to male and female employees have no significant differences, and they respect their differences. When it comes to promotion, they never think about the issue of sex. 4. The working philosophy of female leaders: The most important three factors of their job philosophies are interests, mission and self-actualization. Surprisingly, the working hours of female leaders in case study are all very long. Five out of six leaders work for twelve to fifteen hours or even more a day.

During project execution, the status of the project is periodically evaluated, using traditional methods or standard practices. However, these traditional methods or standard practices may not adequately identify certain issues, such as lack of sufficient identification of warning signs that predict potential project failure. Current methods may lack the ability to provide real time indications of emerging problems that impact project outcomes in a timely manner. To address this problem, the Construction Industry Institute (CII) formed a research team to develop a new tool that can forecast the potential risk of not meeting specific project outcomes based on assessing leading indicators. Thus, the leading indicators were identified and then the new tool was developed and validated. A screening process was conducted through industry surveys after identifying potential leading indicators. Each time, industry professionals were asked to evaluate the negative impact of leading indicators on project outcomes that were identified to measure the impact of leading indicators on project health. Through this process, forty-three leading indicators were acquired finally. Using descriptive statistics, the amount of negative impact of each leading indicator on project outcomes was identified after the analysis of the survey results. Based on these impacts, the tool development was initiated. The tool concept is that no indication of problems based on assessing leading indicators results in the tool output score high. To comply with this concept, specific weights were assigned to each leading indicator to reflect the impact on each project outcome. By this procedure, the Project Health Indicator (PHI) tool was developed. The validation process of the PHI tool was conducted using completed projects and finally negative correlation was observed between project outcomes and health scores generated by the PHI tool.

Taiwan business indicators are announced by CEPD(Council For Economic Planning And Development) , and divided into three categories ¡V business monitoring indications, business expectation indicators and industrial business expectation survey. Business expectation indicators are further divided into the Composite Index of Leading Indicators and the Composite Index of Coincident Indicators. Leading indicators, which are expected to forecast business cycles, are widely used to monitor or even predict the fluctuations of economic activities. They are also used to provide early signals of economic trend and, therefore, considered as a tool to adjust the government¡¦s economic policy. CEPD use the compilation of the USA National Bureau of Economic Research as a reference for a long time, and has announced Taiwan¡¦s ex-business indicators since 1977 without making any revision in the past years, so they announced new business indicators in 2007. As we know, it is difficult to find the leading indicator to make the stable variable of predicting the business cycle, which raises doubts of whether the current leading indicators can done the work concisely. CEPD make the indicators a little bit subjective because of considering government¡¦s policy and the meaning of containing widely economic fields and the convenience of static, so this research try to examine the effect of current seven leading indicators. This thesis focuses on leading indicators to investigate how the seven components are related to the general economy. Composite Index of Leading Indicators is made up of seven indicators in order to predict the business cycle. The seven indicators include Index of export orders, Monetary aggregates, M1B, Stock prices index, Index of producer's inventory, Average monthly overtime in industry & services, Building permits, SEMI book ¡Vto¡Vbill ratio. In the purpose of getting more sample data, we take Industrial production index, one of coincident indicators announced by CEPD as the variable of current economy.

Thesis (M.S. in Aeronautical Engineering)--Naval Postgraduate School, September 1990. / Thesis Advisor(s): Ekaterinaris, John A. ; Platzer, Max. "September 1990." Description based on title screen as viewed on December 21, 2009. DTIC Identifier(s): Dynamics, leading edges, airfoils, dynamic stall, oscillating airfoil, pitching airfoil, leading edge geometry, pressure gradient, theses. Author(s) subject terms: Dynamic stall, oscillating airfoil, pitching airfoil, leading edge geometry, pressure gradient. Includes bibliographical references (p. 111-112). Also available in print.

This thesis presents an investigation into the phenomena of scale effects on cavitation inception and noise of marine propellers. The overall aim is to extend the understanding of these phenomena and improve predicting methods. The investigations, which are largely experimental in nature, are restricted to the tip vortex and sheet types of cavitation. Chapter 1 includes a state-of-the-art review of the scale effect studies based on published papers to form the basis for the main objectives and structure of thesis. The objectives require systematic tests in a cavitation tunnel to explore the viscous scale effects contributing to the phenomena, particularly for the effect of the free-stream turbulence, and to include this effect in extrapolation procedures. Chapter 2 is concernedw ith the background flow measurementsin the cavitation tunnel under the effect of systematically varying levels of the free-stream turbulence generated by using wire meshes. This background information is obtained using a Laser Doppler Anemometry; measurements made with the latter provide a systematic basis on which the analyses of the cavitation inception and noise experiments can be performed. In Chapter 3, a set of cavitation inception tests is described with a NACA66 rectangular foil whose cross-section represents a typical blade section of a marine propeller. The inception measurements for systematically varying levels of the free-stream turbulence and that of the leading edge roughness are presented for different angles of attack and the results are discussed. Chapter 4 includes another set of cavitation inception experiments with a 5-bladed of model propeller of the Meridian Series. The measurements are taken for varying levels of the free-stream turbulence, blade roughness and dissolved gas contents. The results are analysed and discussed with a specific emphasis on the similarities between the effects of the free-stream turbulence and blade roughness. Chapter 5 presents a set of systematic noise measurements, with the same test propeller under the similar effects of the free-stream turbulence, blade roughness and dissolved gas content, using a single external hydrophone. The analyseso f these measurements,in terms of the tunnel background noise and net propeller noise, are presented and discussed for two operating conditions representing a typical non-cavitating and cavitating noise spectrum. In Chapter 6, a semi-empirical tool is developed to predict the inception of cavitation including the effect of the free-stream turbulence based on Lighthill's Leading Edge Correction factor (Lighthill, 1951). This tool is correlated with the inception tests results of the model propeller and its potential to be used as an extrapolator for the full-scale prediction is discussed. An attempt is made to establish a correspondence between the level of the free-stream turbulence and that of the blade roughness and its impact on the current test procedures is discussed. This chapter also includes an analysis of the similarity criteria to incorporate the effect of the free-stream turbulence in the inception of cavitation using the Dimensional Analysis procedure. In Chapter 7, a general review of the study together with the main conclusions from the thesis are presented and some recommendations for future work are made.