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Browsing by Author "Fan, Chuen-mei, committee member"

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    A systematic approach to testing UML designs
    (Colorado State University. Libraries, 2006) Dinh-Trong, Trung T., author; France, Robert B., advisor; Ghosh, Sudipto, advisor; Bieman, James M., committee member; Malaiya, Yashwant K., committee member; Fan, Chuen-mei, committee member
    In Model Driven Engineering (MDE) approaches, developers create and refine design models from which substantial portions of implementations are generated. During refinement, undetected faults in abstract model can traverse into the refined model, and eventually into code. Hence, finding and removing faults in design models is essential for MDE approaches to succeed. This dissertation describes approach to finding faults in design models created using the Unified Modeling Language (UML). Executable forms of UML design models are exercised using generated test inputs that provide coverage with respect to UML-based coverage criteria. The UML designs that are tested consist of class diagrams, sequence diagrams and activity diagrams. The contribution of the dissertation includes (1) a test input generation technique, (2) an approach to execute design models describing sequential behavior with test inputs in order to detect faults, and (3) a set of pilot studies that are carried out to explore the fault detection capability of our testing approach. The test input generation technique involves analyzing design models under test to produce test inputs that satisfy UML sequence diagram coverage criteria. We defined a directed graph structure, named Variable Assignment Graph (VAG), to generate test inputs. The VAG combines information from class and sequence diagrams. Paths are selected from the VAG and constraints are identified to traverse the paths. The constraints are then solved with a constraint solver. The model execution technique involves transforming each design under test into an executable from, which is exercised with the general inputs. Failures are reported if the observed behavior differs from the expected behavior. We proposed an action language, named Java-like Action Language (JAL), that supports the UML action semantics. We developed a prototype tool, named UMLAnT, that performs test execution and animation of design models. We performed pilot studies to evaluate the fault detection effectiveness of our approach. Mutation faults and commonly occurring faults in UML models created by students in our software engineering courses were seeded in three design models. Ninety percent of the seeded faults were detected using our approach.
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    Estimating the shadow economy in Jordan: causes, consequences, and policy implications
    (Colorado State University. Libraries, 2011) Alkhdour, Rajeh, author; Bernasek, Alexandra, advisor; Fan, Chuen-mei, committee member; Pena, Anita Alves, committee member; Yasar, Gamze, committee member
    Economists have been paying increasing attention to the study of the shadow economy in many developed and developing countries in recent years. This attention is due to the consequences and the policy implications related to the shadow economy. Due to the unobserved and hidden nature of the shadow economy, it is difficult to get accurate estimates of its size. However, there are some techniques that have been used by economists to indirectly estimate the size of the shadow economy. This dissertation estimates the annual size of the shadow economy in Jordan during the period 1976-2010 using two methodologies: the currency approach and the multiple indicators multiple causes (MIMIC) approach. It also analyzes the economic consequences and the policy implications of the shadow economy, estimating the amount of tax evasion in Jordan during the aforementioned time period. This is the first study that differentiates the effect of taxes on imports (custom duties) on the shadow economy from the effect of other taxes (income and sales taxes). It hypothesizes, unlike other studies, that taxes on imports negatively affect the size of the shadow economy. The currency approach results are consistent with this hypothesis. This study is also the first one to take into consideration religious factors as one of the determinants of the demand for money in circulation which is used in the currency approach to estimating the shadow economy. It is hypothesizes that the number of Islamic banks in Jordan negatively affects the demand for money in circulation. The coefficient of this variable has a negative sign, which is consistent with this hypothesis; however, this variable is insignificant at the 10 percent level. The other determinants of the demand for money in circulation in Jordan are: the effective tax rate on sales, the effective income tax rate, the effective tax rate on imports, the weighted average of interest rates on savings, and a dummy variable for the depreciation of the Jordanian dinar in 1988. According to the MIMIC approach, the causal variables for the shadow economy in Jordan are found to be: the total effective tax rate (tax revenues/GDP), the unemployment rate, the extent of government regulation (government intervention in the economy), and depreciation of the Jordanian dinar in 1988. The growth rate of real GDP and the growth rate of real private consumption are found to be indicators of the shadow economy in Jordan. The MIMIC approach results are consistent with previous studies that have found taxes and regulations to be the main causes of the shadow economy. The results also support the hypothesis that the depreciation of the Jordanian dinar in 1988 has a positive effect on the shadow economy in Jordan. The unemployment rate is found to have a negative effect on the shadow economy in Jordan. This indicates that the income effect of unemployment is greater than the substitution effect. In this dissertation, the main consequences and the policy implications of the shadow economy are analyzed. Tax evasion in Jordan is estimated for the period of study based on the results of the currency demand and the MIMIC approaches. It has been shown that the shadow economy has a distorting effect on the accuracy of a country's national accounts statistics. In addition, some policy recommendations are presented to reduce the distorting impact of the shadow economy. Taking into consideration the existence of the shadow economy when conducting the economic policy will increase the efficiency of this policy. There is a need for further research into the impact of the shadow economy on some economic policy issues in Jordan.
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    Learning Chinese characters: a comparative study of the learning strategies of western students and Eastern Asian students in Taiwan
    (Colorado State University. Libraries, 2012) Hsu, Jui Fang, author; Flahive, Doug, advisor; Fabiola, Ehlers-Zavala, committee member; Fan, Chuen-mei, committee member
    Vocabulary acquisition is central to learning Chinese as second or foreign language. Little research has been conducted on vocabulary learning strategies in this area. Even less study has been conducted whether students from different native language background would apply vocabulary learning strategies differently. The present study was designed to address this gap. The major concern of this study was to explore whether students from Western alphabetic countries and students from Eastern Asian countries would apply different vocabulary learning strategies in Chinese vocabulary acquisition. All the participants are international students who currently reside in Taiwan and attending the same American School located in Taipei, Taiwan. Learning Chinese is mandatory in the school. An on line survey instrument was used to collect data from the students. Descriptive statistics were used. An independent samples t-test was used to assess whether students of different native language background showed significant differences in the application of vocabulary learning strategies. No significant difference was found, however, suggestions regarding curricula design in learning Chinese vocabularies were made based on the tentative findings of this study.
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    Our childcare problem: three essays on the childcare decision-making process from a gendered perspective
    (Colorado State University. Libraries, 2011) Cole, Paula M., author; Bernasek, Alexandra, advisor; Fan, Chuen-mei, committee member; Braunstein, Elissa, committee member; Kneller, Jane, committee member
    Children bring great joy and love to families, but for many families childcare entails significant stress, worry, sacrifice, and financial hardship. Social and cultures norms in the United States place these care difficulties in the private sphere to be handled by individuals, primarily women. The challenges families face in choosing between quality, affordability, and availability demonstrate that our childcare system is not the best that it could be and that all of us need to become stakeholders in the care of children. This research examines the childcare decisions of families using the ideas of neoclassical, feminist, and institutionalist economists. The childcare choice is explored with quantitative and qualitative methodology enabling critique of both the outcome and the process. Research findings demonstrate the importance of gender in the care of children, the need for more complete data on childcare, and that a solution to the childcare problem requires an ethic of care.
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    Using a computable general equilibrium model to explore economic impacts of agglomeration economies on wages in northern Colorado
    (Colorado State University. Libraries, 2011) Gongwe, Anne Grace, author; Cutler, Harvey, advisor; Fan, Chuen-mei, committee member; Shields, Martin, committee member; Davies, Stephen, committee member
    Agglomeration economies are forces that lead to concentration of workers and businesses in one location, and are also known as external economies of scale. This dissertation explores the economic impacts of agglomeration economies on nominal and real wages using a data intensive computable general equilibrium (CGE) model. The dissertation is divided into three essays. The first essay focuses on establishing the impacts of export-led expansions on nominal and real wages for two cities of different sizes and labor market characteristics in northern Colorado. Results of this essay show that when employment is expanded for each sector separately, nominal and real wages increases more in Loveland (a thinner labor market) than Fort Collins (a thicker labor market). A larger number of households are attracted to Fort Collins as opposed to Loveland and this leads to high supply of labor. Increased labor supply causes a downward pressure on wages in Fort Collins. These results suggest that "labor supply effects" outweigh "productivity effects" in the thicker labor market. The second essay analyzes the performance of nominal and real wages when two cities of different sizes and labor market characteristics are exposed to various levels of production externalities. The results demonstrate that when sector-specific export demand and production externalities is increased, the nominal and real wages increase more in Fort Collins than Loveland supporting previous studies findings that productivity increases with city size. The results also reflect that wages increases more with the level of production externalities. The results also show that different sectors are impacted differently with the same economic shock, making sector-wise analysis more appropriate than the aggregate analysis. The third essay has two major parts. The first part focuses on the economic impacts of consumption externalities on nominal and real wages. The results show that an increase in sector-specific export demand and level of migration elasticity increase nominal wages in all labor groups in all three productive sectors with the exception of labor group three in the retail sector in both cities. The second part of this essay focuses on the net economic impacts of production and consumption externalities wages in these two cities. The results show that nominal wages and real wages increase in all sectors for all labor groups except for the higher skilled workers in the retail case in Loveland. Results also show that, the nominal and real wage increase is less with the higher level of consumption externalities. These results suggest that when the level of consumption externalities is sufficiently higher than production externalities, real wages will decrease.