<p>In this thesis, a study of the rational design and fabrication of microfluidic systems for microsphere generation is presented. The required function of microfluidic systems is to produce microspheres with the following attributes: (i) the microsphere size being around one micron or less, (ii) the size uniformity (in particular coefficient of variation (CV)) being less than 5%, and (iii) the size range being adjustable as widely as possible.</p> <p>Micro-electro-mechanical system (MEMS) technology, largely referring to various micro-fabrication techniques in the context of this thesis, has been applied for decades to develop microfluidic systems that can fulfill the foregoing required function of microsphere generation; however, this goal has yet to be achieved. To change this situation was a motivation of the study presented in this thesis.</p> <p>The philosophy behind this study stands on combining an effective design theory and methodology called Axiomatic Design Theory (ADT) with advanced micro-fabrication techniques for the microfluidic systems development. Both theoretical developments and experimental validations were carried out in this study. Consequently, the study has led to the following conclusions: (i) Existing micro-fluidic systems are coupled designs according to ADT, which is responsible for a limited achievement of the required function; (ii) Existing micro-fabrication techniques, especially for pattern transfer, have difficulty in producing a typical feature of micro-fluidic systems - that is, a large overall size (~ mm) of the device but a small channel size (~nm); and (iii) Contemporary micro-fabrication techniques to the silicon-based microfluidic system may have reached a size limit for microspheres, i.e., ~1 micron.</p> <p>Through this study, the following contributions to the field of the microfluidic system technology have been made: (i) Producing three rational designs of microfluidic systems, device 1 (perforated silicon membrane), device 2 (integration of hydrodynamic flow focusing and crossflow principles), and device 3 (liquid chopper using a piezoelectric actuator), with each having a distinct advantage over the others and together having achieved the requirements, size uniformity (CV ⤠5%) and size controllability (1-186 &#x00B5;m); (ii) Proposing a new pattern transfer technique which combines a photolithography process with a direct writing lithography process (e.g., focused ion beam process); (iii) Proposing a decoupled design principle for micro-fluidic systems, which is effective in improving microfluidic systems for microsphere generation and is likely applicable to microfluidic systems for other applications; and (iv) Developing the mathematical models for the foregoing three devices, which can be used to further optimize the design and the microsphere generation process.</p>

In this thesis we have studied the relationship between mutual fund size and performance by studying 91 Swedish mutual funds during a six year period (2006-2011). Furthermore, we investigated the relationship between fund size and management fees and fund size and persistence in performance. The fund sample has been divided into five subgroups in order to compare and analyze funds with different fund sizes for the whole six-year period as well as two three-year sub periods. Our results are based on regressions and significance tests and for all the five subgroups and over the whole time period our results indicate that there is no significant relationship between fund size and fund performance that is robust over time. Our findings also show that there is no persistence in performance for any of the size-based fund groups which helps us to draw the conclusion that past performance is not a good measure for predicting future performance regardless of the size of the funds. The results also indicate that mutual funds with a larger asset base tend to have lower management fees than smaller funds.

The focus of this thesis is to explore the composition of the Skunk works’ innovation team, which directly influences team performance. Such research is important in order to understand how the Skunk works team deals with innovation. Specifically, how the team’s size, diversity and the roles of team members can influence its performance and have an effect on its success. During the time when we were looking for the definition of Skunk works we mostly found that it is a small group of highly qualified and skilled people in different fields. However, we did not find so many theories about the composition of Skunk works teams. This was due to the high level of secrecy in this field, because Skunk works was originally used only for military purposes. To have a more clear view, we decided to use theories from different research fields, such as research about Skunk works itself, and about team and team composition. We found that it is quite easy to find literature about the role of the leader as a member of the innovation team, who can also be known as the “champion”. However, on another hand we found that it is quite difficult to find information about the whole team, specifically about roles in the team. We believe that, even though the leader has a key role, a well-balanced combination of roles should be also taken into consideration in such teams. The research method deployed in this thesis is multiple-case study, where we have used three cases which are operating in different companies and industries, such as entertainment, scientific research and industrial manufacturing, as well in different geographical positions, such as Sweden and Spain. We have collected data via interviews and secondary data, where we interviewed a representative of these three companies via personal interviews and by e-mail. The findings from this thesis provide evidence that the team composition elements, such as roles in the team, as well its size and diversity can influence on further efficiency of the team. During our research we found that all three companies, especially teams in those companies, could be good examples of Skunk works. Moreover, during the research we found that our findings can be in line with existing studies, that it is unnecessary that the project should be in total secret or fully mandated and that there are a lot of other types of Skunk works teams as well. Also during the research we confirmed with other present studies required characteristics for the “champion” and for other team members. Another finding was about the optimal number of team members in a Skunk works team. The main conclusions drawn from this thesis are that firstly, the composition of a Skunk works team can influence the further team productivity and success of the project. Secondly, that the optimal size of team should not exceed ten people. Thirdly, we can conclude that properly chosen roles as well as characteristics of team members can have an influence on the further success of an innovation project. / Antonio Estevez Luna

Investment of mutual fund has always been popular to the common investor. No matter investing at Systematic Investment Plan or One-time Investment, choosing a ¡§good¡¨ mutual fund is expected for every investor. However, how to find a good one among a large number of funds? In the past reports or theses, there are many reasons of influencing mutual fund performance, which include fund¡¦s size among others. The common sense said that ¡§if you want to invest in mutual fund, you should choose the larger size ¡¨ Is that true? Through the past reports we can find out different opinions. This study mainly research into the relationship between performance and size of domestic open-ended mutual funds. Expect to give a simpler data for reference and lower the risk before general investors put money into funds. The logic of Spearman's Rank Correlation coefficient would be applied as the statistical inference in this study, and the domestic open-ended equity fund, balanced fund, and quasi-money market fund will be used as the observed samples. Monthly performance and size is the observed unit of time in this research period from March 2001 to February 2010. Thus via this mode will know whether the correlation between fund¡¦s performance and size is positive, negative or there is no correlation. The conclusions of this study are presented as follows: 1. There is a low positive correlation between performance and size for equity fund and quasi-money market fund. But the balanced fund does not show any correlation for these two variables. 2. Moreover, the study shows there is better performance for investing in over 4 billion NT asset of equity fund in a short term period. But the result of balanced fund and quasi-money market fund can¡¦t highlight the optimal size in a short term period. 3. From the long term point of view, the optimal interval of size for equity and balanced fund is between 1 billion and 2 billion. And the optimal size to quasi-money market fund is over 40 billion.

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This dissertation analyzes the effect of smaller classes on student performance using student-level test score data from the state of Texas, focusing on three specific issues: heterogeneity in the returns to smaller classes across a score distribution of students, the relationship between class size and students' moving decisions, and the connection between smaller classes and schools' class division procedures. I first examine evidence of heterogeneity in the returns to class size reductions across a score distribution of students. I divide students into decile groups based on their previous year test scores, and I estimate the returns to smaller classes for each of the deciles. The empirical evidence supports the hypothesis that there are significant differences in students' responses to class size, based on their previous test scores. I then model the class size effect simultaneously with students' decisions to switch schools, which is important because movers compose a substantial fraction of the dataset, and because class size effects vary between movers and nonmovers. Recognizing that students move for different reasons, only some of which are school-related, I present a two-type moving model in which students are categorized as endogenous movers or exogenous movers. I estimate the model estimated using maximum likelihood. The results reveal key biases in traditional estimates of the moving effect and suggest significant differences in the class size effect across mover types. I also explore the class size effect in conjunction with schools' decisions to sort students into different classes. Using student-level data in which students are linked to specific classes, I disentangle the class size effect from the sorting effect. Including a variable indicating the sorting index of a school decreases the magnitude and significance of the class size effect. I also examine different types of sorting. The findings suggest that sorting students into more homogeneous groups is beneficial for both high and low scoring students.

Food recalls caused by pathogens receive considerable public attention due to health risk and the potential loss to the companies involved. There are very few studies analyzing the relationship between food recalls and characteristics of the companies involved. Because of the significance of the problem and lack of available research, the association between food recalls caused by pathogen and characteristics of the companies involved is examined in this thesis. To address the problem, data on food product recalls in the United States from January 2000 to October 2009 are used. Only the events caused by pathogens are analyzed in the thesis. The firms that have multiple recall incidents are the units of analysis. The study employs an econometric model with discrete choice modeling approaches: logit and probit. There are two main hypotheses. Firstly, it is hypothesized that branding decreases the likelihood of the occurrence of the repeated recall event. Secondly, size of the firm is hypothesized to be associated with higher likelihood of recurrence. The major finding is that branding and firm size are associated with higher probability of the recurrence of food recall events associated with pathogenic contamination. A firm that produces branded products is around 15 percent more likely to have a recurrence of food recall events than a firm producing unbranded product. This finding points out the interesting and unexpected issue that branding is not associated with improved performance in food safety. Additionally, an increase in firm size has a minute but significant association with rising likelihood to have a recurrence of a food recall event. This study is the first concerning the firm level factors that can influence risk of the recurrence of food recall incidents involving pathogens. Thus, its results are distinctive and can benefit both government and private sectors with respect to food safety policy or food safety standards.

This study is to probe into the quantitative aspects of in vocabulary in the first volumes of the major three senior high (SH) school English textbooks and the major three vocational high (VH) school English textbooks. Not only the vocabulary lists, but also the unlisted new words in the related sections which are categorized into 22 corpora are explored and compared in terms of the size of new words, the consistency between junior high school (JH) vocabulary lists and SH/VH textbooks, the new-word density, and the frequency of word exposures. In addition to the six commercial SH/VH English textbooks from three major publishers (Far East, Lungteng, and Sanmin), four JH word lists are included: two word lists of the old centralized Junior High School Required (Word-JHA) and Elective (Word-JHB) English Course by the National Institute for Compilation and Translation and two new word lists of 1,000 productive vocabulary (Word-JH1000) and 1,000 receptive vocabulary (Word-JH2000) by the MOE. The major findings of this study are as follows: 1. The word size, particularly the unlisted new words, is big. For those SH students who learn both Word-JH1000 and Word-JH2000, they face 9.05%~13.36% of unlisted new words in reading sections and encounter 17.92%~22.55% of unlisted new words in the whole textbooks. For those VH students who learn both Word-JH1000 and Word-JH2000, they face 5.77%~12.62% of unlisted new words in reading sections and encounter 16.05%~21.90% of unlisted new words in the whole textbooks. 2. Even though the new JH vocabulary lists (Word-JH1000 & Word-JH2000) provides a larger proportion of overlapping with the 22 SH/VH corpora than the old JH vocabulary (Word-JHA & Word-JHB), the consistency of vocabulary between JH and SH/VH is not adequate enough to reach the ¡§all-or-nothing threshold¡¨ (80% known words in a certain text). 3. Both SH and VH textbooks are too dense with new words to reach the ¡§probabilistic threshold¡¨ (95% known words in a certain text), the density index of an efficient textbook for the first year. 4. The frequency of word exposures is too low to be well-learned (more than 80% beneath the six-time threshold; more than 40% are one-timers). The findings have some pedagogical implications regarding the suggestions for the policy-makers, publisher, JH/SH/VH teachers and students.

Friction stir process (FSP) was employed to investigate the grain evolution of AA1050 aluminum alloy in this study. The rotation speeds for the tool were set from 500 to 2000 rpm with a constant traverse speed of 0.5mm/s. The temperature under pin was measured by K-type thermocouple imbedded under the pin. Grain sizes were determined by scanning electron microscopy. The maximum temperature at the bottom of pin increased with the increasing of rotation speed but not exceeding 0.8Tm. Grain size at center and bottom of stirred zone was in linear increase at low rotation speed, but increased a little at high rotation speed (>1000rpm). The grain size grew rapidly into a stable size in a 2mm distance measured from the passing of pin. When rotation speed is above 1000rpm, average grain growth rate is 1£gm/s. When rotation speed is lower than 700rpm, average grain growth rate is slower than 0.2£gm/s. BEI/ECCI observations revealed that grains in SZ became equaxied.

The Leslie¡¦s method was employed for the estimation of stock size and catchability coefficient of Sakura shrimp on the southwestern coast of Taiwan from Nov 2002 to May 2004. After analyzing the stock size and catchability coefficient and then applying those estimated value for the optimal conduction of open-access and bioeconomic optimum, the evaluation of the variation under both conductions were available and simulations run by the catch data also can be obtained and useful in comparing with the real situation. By assuming all bioeconomic parameters varied within a reasonable range, we did the comparative static analysis and expected to shed the light on the impact those parameters brought to the stock size.