Understanding editorial text : a computer model of argument comprehension

Alvarado, Sergio Jose University Microfilms Internatioanl 1989 국내박사

한국증권시장에서의 모멘텀투자전략과 반전투자전략의 성과

Monica, Alvarado 청주대학교 2012 국내석사

Considerable evidence exists that both contrarian and momentum investment strategies produce excess returns. The work of DeBondt and Thaler (1985) supports that the contrarian strategy produces excess returns. According to their study, after sorting stocks by previous returns, then holding those with the worst prior performance and shorting those with the best prior performance produce positive excess returns. On the other hand, the work of Jegadeesh and Titman (1993) reveals that a momentum strategy produces positive excess returns. After sorting firms by previous returns, then holding those with the best prior performance and shorting those with the worst prior performance yield positive excess returns. There is no direct contradiction in the profitability of both contrarian and momentum investment strategies since contrarian strategies work for a sorting period ranging from 3 to 5 years prior and a similar 3 to 5 years holding period, while momentum strategies typically work for a sorting period ranging from 1 month (or more commonly 3 months) to 12 months and a similar 1 (or 3) to 12 month holding period. The results correlate well with the findings of mean reversion at horizons of around 3 to 5 years and the findings of return continuation for horizons up to 12 months. The profitability of momentum and contrarian investment strategies for stocks listed on the Korean Stock Exchange is investigated. The main empirical findings of the study can be summarized as follows: Momentum portfolios, which entail long positions in past best performing stocks (winners) and short positions in past worst performing stocks (losers), have been proven to yield significant positive profits in the medium term (3–12 months). In contrast, a systematic reversal effect is found when a longer holding period (more than 3 years) is considered. 반전 투자전략과 모멘텀 투자전략이 초과수익률을 발생시킨다는 증거가 존재한다. De Bondt and Thaler (1985)의 논문은 직전 기간 수익률의 순서에 따라 주식을 분류한 후, 직전 수익률이 가장 안 좋은 주식들을 보유하거나 직전 수익률이 가장 좋은 주식들을 공매하는 반전투자전략이 초과수익을 가져다 준다는 것을 보였다. Jegadeesh and Titman (1993)의 논문은 직전 기간의 성과가 좋은 주식들을 보유하거나 직전기간의 성과가 안 좋은 주식들을 공매하는 모멘텀 투자전략이 초과수익을 가져다 준다는 것을 보였다. 반전투자전략과 모멘텀 투자전략이 초과수익을 발생시킨다는 것은 직접적인 모순을 일으키는 것은 아니다. 왜냐하면 반전 투자전략은 직전 3~5년의 기간의 투자성과를 가지고 주식들을 분류한 후, 해당 포트폴리오를 향후 3~5년 동안 보유하는 전략을 분석한 반면, 모멘텀 투자전략은 직전 1~12개월 (보통3개월)의 기간의 투자성과를 가지고 주식들을 분류한 후, 해당 포트폴리오를 1~12개월 (보통 3개월) 동안 보유하는 전략을 분석한 것이기 때문이다. 이 결과들은 약 3~5년의 기간에 걸쳐서 나타나는 평균회귀(mean reversion)현상 또는 12개월의 기간에 걸쳐서 나타나는 수익률 연속(return continiuation)현상과 비슷한 것이다. 본 논문은 한국주식시장에서의 모멘텀 투자전략과 반전투자전략의 투자성과를 실증적으로 분석하여 다음과 같은 주요 결과를 발견하였다. 직전 과거의 성과가 우수한 주식(winner portfolio)을 매입하거나 직전 과거 성과가 나쁜 주식들(loser portfolio)을 공매하는 모멘텀 투자전략은 3~12개월의 중간 보유기간에서 초과수익을 발생시켰다. 반면에 3년 이상의 장기 보유기간의 반전투자전략이 초과수익을 가져왔다.

New World primitivism in Harlem and Havana : Constructing modern identities in the Americas, 1924--1945 (Carlos Enriquez, Jacob Lawrence, Aaron Douglas, Wifredo Lam, New York City, Cuba)

Aranda-Alvarado, Rocio City University of New York 2001 해외박사

Development of Deep Learning Neural Network for Underground Cavity Classification Based on Geometric and Numerical Parameters

Elipse, Carlo Alvarado 세종대학교 대학원 2022 국내박사

In the recent years, numerous occurrences of pavement subsidence were observed around Seoul City area that raised concerns of the city government. Underground inspection of Seoul city roadways using ground penetrating radar (GPR) was conducted to discover the cause of the pavement subsidence and it was found to be underground cavity. Typically, to locate the underground cavity from the GPR survey data, an expert manually inspect the location of hyperbola signals that represents cavities in the whole GPR survey, however, this method is very time-consuming. To solve this problem, Tran (2020) developed a RetinaNet-based deep learning neural network that automatically detect and identify underground cavities from the GPR survey data. Although the Tran’s developed method successfully detects cavity locations, there are numerous misclassified locations that are not cavity but has almost the same features with the cavity locations, called non-cavity locations. Therefore, there’s a need for an additional process that can further eliminate non-cavity locations from the candidates while preserving the real cavity locations. In this study, a deep learning neural network, specifically an artificial neural network (ANN), that further classifies cavity and non-cavity locations based on geometric and numerical parameters from the GPR survey data was proposed. To determine the significant parameters to be used as input for the training database, parametric investigation was conducted in a collection 282 cavity and 572 non-cavity locations, summing up to 854 locations. It was found that there are 2 geometric and 2 numerical parameters that has a strong relationship in the classification of the locations. For the geometric parameters, the ratio of the height of the hyperbola signal from the B-scan and D-scan, called the H Ratio, and the ratio of the width of the hyperbola signal from the B-scan and D-scan, called the W Ratio, were considered. Meanwhile, there were also two parameters found in the investigation of numerical data from the GPR survey: polarity ratio standard deviation (PRS) and the pseudo-dielectric constant (PDC). PRS is defined as the standard deviation of the ratio of positive peak signal and the negative peak signal of the points located at the upper half of the hyperbola while PDC represents the effective dielectric constant of the underground object and the medium above it. A training database was formed including the four parameters identified from the parametric investigation and the classification of each location. The total accuracy of the trained model on the whole training database yielded to 95.20%. As a validation, the trained model was applied to 74 locations consist of 37 cavity locations and 37 non-cavity locations. All of these locations were classified as cavity by the RetinaNet-based deep learning neural network and the non-cavity locations selected has the same hyperbola signal appearance to that of the cavity locations. As a result, 35 out of the 37 cavity locations were correctly classified while 28 out of the 37 non-cavity locations were correctly classified as well, yielding to a total accuracy of 85.14%. It was observed that 75.68% of misclassified non-cavity locations were correctly classified as non-cavity and were discarded from the final candidate locations. Furthermore, additional validation was conducted on 30-km GPR survey data of Seoul city. The RetinaNet-based deep learning neural network detected a total of 358 cavity candidates which includes 36 true cavity locations. After applying the proposed model, the number of cavity candidates was reduced to 131 locations including 35 true cavity locations, resulting to an accuracy of 97.22% for cavity detection. Moreover, the over prediction reduced from nine times to four times the number of true cavity locations. Therefore, the proposed model proved its effectivity in eliminating misclassified non-cavity locations while preserving the real cavity locations.

Experimental study about effects of downward inclination on condensation of pure steam in a tube

Luis Andree Pusey Alvarado 경희대학교 대학원 2017 국내석사

Effects of downward inclination angle on two-phase flow structure and heat transfer coefficient were experimentally studied during condensation of pure steam in a tube. Cross-sectional two-phase flow structure was visualized by applying the concept of axial-viewing technique and corresponding heat transfer coefficient was measured. Condensation experiments of saturated steam under atmospheric pressure were conducted in a tube with inner diameter of 17 mm at a steam mass flux of 3.43 kg/m2s and three steam qualities were tested with values of 0.26, 0.54 and 0.93. The heat transfer results showed that the heat transfer coefficient was increased up to 11% independently of the steam quality condition. The obtained cross-sectional two-phase flow structure images indicated that as inclination angle increases, stratified flow is the only flow pattern without transition to annular flow, but geometry of the liquid-vapor interface varied from concave to convex. The information of the image structure obtained from the visualization results allowed to calculate the average condensation heat transfer coefficient by a combination of film condensation and single-phase forced convection. Based on a comparison between the calculated condensation heat transfer coefficient and the measurement data, a plausible approach to incorporate the effects of inclination angle into an existing correlation was discussed.

The interaction of Michigan Environmental Education curriculum, science teachers' pedagogical content knowledge, and environmental action competence

Alvarado, Angelita P Michigan State University 2010 해외박사(DDOD)

One of the main goals of Environmental Education (EE) is to develop people's environmental stewardship, which includes people's capacity to take environmental action -- their action competence (AC). The purposes of my study were to characterize the interactions found in an EE curriculum, science teachers' pedagogical content knowledge (PCK), and their use of AC, and to identify factors that appear to be associated with the use of AC in curriculum and instruction. My study was divided into three parts: (1) content analysis of the Water Quality Unit of the Michigan Environmental Education Curriculum Support (MEECS, nine lessons); (2) a survey of MEECS training participants (N=131 [28.4% response rate]); and (3) an in-depth examination of pedagogical content strategies and use of AC of four science teachers using class observations (December 2007 -- April 2008: N=38), semi-structured interviews (October 2007 -- April 2008: N=20), Content Representations (CoRes: N=6), and surveys (N=4). The extent that individual elements of AC occurred in each data source was variable; that is, some elements were more prevalent in one data source than another. Of the five elements of AC, knowledge/insight, planning and action experiences, and critical thinking and reflection were more prevalent than commitment and visions in two of the three data sources, namely, the Water Quality Unit (EE curriculum) and the four teachers. Visions was consistently the least prevalent element of AC in each of the three data sources. In general, the types of and/or extent that goals and beliefs, pedagogical approaches, instructional methods, student skills foci, and manifestations of PCK occurred helped explain the prevalence of individual elements of AC across the data sources. For example, use of activity-driven, project-based, and process-oriented pedagogical approaches appeared important for engaging students in real world planning and action experiences. Other factors that appeared to be associated with the use of AC include content taught, personal conviction of teachers, barriers or constraints in teaching context, characteristics of students, and teacher education and professional development experiences. To strengthen use of AC in EE curricula and by teachers, some recommendations include: 1) changing standards and assessments to include the use, development and measurement of AC; 2) emphasizing equally all the elements of AC in curriculum development and instruction; and 3) training teachers on the use of multiple approaches and methods for applying AC in and outside of the classroom, as well as the importance of being intentional and reflective about one's teaching, to help build one's PCK for teaching EE and fostering students' AC.

Emic perspectives: The Freshman Interest Group Program at the University of Texas at Austin

Alvarado, Cassandre Giguere The University of Texas at Austin 2004 해외박사(DDOD)

This study explored the emic perspective of participating in the Freshman Interest Group (FIG) Program at The University of Texas at Austin. This study employed a qualitative methodology to capture the emic perspective of participating in a FIG. Initially, student responses to a previously administered course-instructor survey were analyzed using content analysis. Student responses to the question "The most valuable part of being in a FIG was" were coded for the first five years in which the program operated. The patterns, themes and categories that emerged from the content analysis were used to describe the student experience. To further triangulate the data, focus groups of currently enrolled former FIG participants were formed and students were asked to reflect on the theme that emerged from the content analysis. The themes were also reviewed by three comparison institutions with similarly structured FIG programs. The key findings that emerged from the data were incorporated into a model to represent the student experience. Participating in a FIG was found to be an individual experience for each participant. Students distinguished between the structure elements of the program and the individuals with whom they interacted while in the program. The model that emerged describes the emic perspective of participants of the FIG program. By studying the student perspective of participating in a successful learning community, this research sought to inform researchers and administrators about the value of learning communities. A deeper understanding of what particular elements were important to the student experience can also inform practice on creating other learning communities and student retention efforts.

Dietary factors affecting tissue profiles of long chain polyunsaturated fatty acids in cattle

Alvarado-Gilis, Christian A Kansas State University 2014 해외박사(DDOD)

The main goal of this dissertation was to evaluate different methods to protect polyunsaturated fatty acids (PUFA) against biohydrogenation by ruminal microorganisms. The first chapter is a review of literature pertaining to fat and fatty acid metabolism by ruminants and why these fats are relevant in human nutrition. The second chapter discusses effects of supplementing high concentrations of dietary copper to feedlot cattle to assess impact on PUFA profiles in tissues. Two levels of copper (10 or 100 mg/kg) were supplemented to diets with or without flaxseed during the finishing period for beef heifers. Added copper did not affect performance (P > 0.15). Final body weights were similar for cattle fed with or without flaxseed ( P > 0.05), but cattle fed diets with flaxseed consumed less feed (P < 0.05), and therefore were more efficient ( P < 0.01). Carcass traits were unaffected by treatment. Feeding elevated levels of copper did not appreciably alter proportions of PUFA in plasma, but plasma concentrations of omega-3 fatty acids were greater for heifers fed flaxseed (P < 0.05). Chapter 3 describes the evaluation of 3 novel methods to protect PUFA from microbial biohydrogenation activity within the rumen, including a) coextrusion of flaxseed with molasses; b) mixing with soybean meal followed by induction of a non-enzymatic browning reaction; and c) encapsulation of ground flaxseed within a matrix consisting of dolomitic lime hydrate (L-Flaxseed). The resulting products were evaluated using in vitro methods to estimate resistance to biohydrogenation or in 12- to 14-d feeding studies in which plasma concentrations of alpha-linolenic acid (ALA) were measured. Our processing strategies a) and b) did not improve efficiency of omega-3 fatty acid utilization (P > 0.1). The in situ study of L-flaxseed revealed a 2-fold increase in resistance of ALA to ruminal biohydrogenation, and the concentration in plasma after 14 d on feed was more than 4 times that observed in cattle fed ground flaxseed, suggesting the dolomitic lime hydrate was effective as a protective matrix. Chapter 4 evaluated performance, carcass traits, and meat quality of finishing beef heifers in response to feeding diets containing L-Flaxseed. Animals were blocked by weight, randomly assigned to individual pens, and pens to 6 dietary treatments: Control (high concentrate finishing diet), ground flaxseed fed at 3 or 6% of diet DM, L-Flaxseed fed at 2, 4, or 6%. Concentration of ALA in meat increased linearly in response to the level of flaxseed fed ( P < 0.05); Moreover, transfer of dietary ALA to tissues increased by 47% when flaxseed was encapsulated within the dolomitic lime matrix. Cattle that were fed diets with 4 or 6% L-Flaxseed consumed less feed than other treatments (P < 0.05), which adversely affected feedlot performance and carcass traits.

Horizontal distribution alliances: Their formation and success

Alvarado, Ursula Yvonne Northwestern University 1999 해외박사(DDOD)

This research provides insights into horizontal distribution alliances—a strategy as a mode of market entry. Horizontal distribution alliances occur when one manufacturer borrows or shares the distribution resources of another manufacturer. Recently, these types of alliances have grown in popularity, yet the mechanisms for implementing and managing them are not well understood (Terpstra and Yu 1990). Resource Dependence and Transaction Cost Analysis are the two organization theories from which hypotheses are derived to test the incentives for managers to enter these alliances. These theories also serve to ground predictions on how to develop alliance management mechanisms that mitigate some of the risks of horizontal alliances while maximizing the benefits of these relationships. Empirical research is conducted in the global airline industry and the pharmaceutical industry. Findings suggest that benefits, such as access to new markets, distribution capacity utilization, and lower fixed costs are compelling motivations for entering horizontal distribution alliances. On the other hand, certain environmental constraints can affect the firm's decision to enter an alliance. Results also indicate that certain mechanisms can be used to structure the agreement to achieve alliance success.

Empowering community-school engagement in promoting Latino high school graduation at the elementary school level

Alvarado, Celia Garcia University of California, Los Angeles 2009 해외박사(DDOD)

My study focused on addressing the problem of high school dropout rates affecting underprivileged Latino communities. Its purpose was to design an elementary intervention that successfully addressed factors identified by theoretical and empirical research that could impede Latino students from graduating from high school. The project was designed for the student population at a small elementary school site located in a low-income community within a large urban school district. I used both qualitative and quantitative research methods in three interdependent phases. I began by conducting a survey questionnaire to understand parents' and school staff's perceptions about factors that can keep students from graduating from high school and their elementary school's ability to successfully address them. In the second phase, I collaborated with parents and staff members to design this program by taking quantitative and qualitative data as well as research into consideration. In the final phase, I and members of the AR team, elicited staff and parents' feedback in order to create a sustainable strategy that will encourage staff and parents to work together to proactively address barriers that can potentially keep Latino students from receiving a high school diploma. Four key findings emerged in the course of this study. First, data from the survey showed that parents had a significantly lower level of understanding of factors that have been shown to correlate to students dropping out of high school than did the school staff. Second, I found that most parents, even those whose first language was not English, were interested in collaborating with teachers to address barriers at their school site that could potentially be hindering Latino students' ability to graduate from high school. Third, conducting the research led the action research team to create a school wide effort to increase parents' awareness and knowledge of the causes of students' dropping out through parent workshops and a bilingual newsletter. Finally, parents reported acquiring more knowledge about research that affects students' abilities to graduate from high school than did school staff participants. Both sets of stakeholders, however, acquired similar problem-solving skills during the action research process.