The need to store large amounts of data is always increasing and this requires better solutions for storing and managing the data. This is often done using a Database Management System (DBMS) which helps manage all data. There are a lot of different options to use today, where all serve a different purpose. This means that it is important to choose the right DBMS for the data that you have. Furthermore, it is not enough to just choose the best DBMS, the database then needs to be designed so that the data can be stored in a structured way. This can be done in many ways. Ericsson wants to implement a database solution in one of their systems to make the workflow more efficient. The system is used to store data for configuring 5G nodes in testing environments. To do this, an investigation about which DBMS fits this data best is to be done. For this purpose, the PostgreSQL database is chosen to represent SQL databases and MongoDB is chosen to represent NoSQL databases. Additionally, proposed designs for each DBMS are produced. These designs are compared with regards to their response time for common queries, as well as in a load test with an expected load on the database. The results show that the two DBMS are good in different aspects. For example, PostgreSQL is faster when relationships between different tables are used, but MongoDB is faster when querying only one document. In conclusion, both implementations serve their purpose and do have their benefits, but MongoDB is chosen to be the better one given the knowledge of how the system is to be used.

In this dissertation, the response time issue of the liquid crystal (LC) devices is investigated in meeting the challenges for display and photonic applications. The correlation between the LC director response time and the optical response time is derived theoretically and confirmed experimentally. A major contribution of this thesis is that, based on the small angle approximation, we derive rigorous analytical solutions for correlating the LC director response time to its consequent optical response times (both rise and decay) of a vertical-aligned nematic LC cell. This work successfully fills the gap in the literature of LCD switching dynamics. An important effect related to response time, backflow is analyzed using a homogeneous LC cell in an infrared wavelength. The Leslie viscosity coefficients can hardly be found in the literature. A new effective approach to estimate the Leslie coefficients of LC mixtures based on MBBA data is proposed in this dissertation. Using this method, the Leslie coefficients of the LC material under study can be extracted based on its order parameters. The simulation results agree with the experimental data very well. This method provides a useful tool for analyzing the dynamic response including backflow. Cell gap is an important factor affecting the LC response time. Usually a thinner cell gap is chosen to achieve faster response time, since normally both rise and decay times are known to be proportional to d2. However, they are valid only in the region. In the large voltage region where , the optical decay time is independent of d. In this thesis, we find that between these two extremes the response time is basically linearly proportional to d. Our analytical derivation is validated by experimental results. Therefore, in the whole voltage region, the physical picture of the optical response time as a function of the cell gap is completed. This analysis is useful for understanding the grayscale switching behaviors of the LC phase modulators. In conclusion, this dissertation has solved some important issues related to LC optical response time and supplied valuable tools for scientists and engineers to numerically analyze the LC dynamics.

Automatic vehicle locator (AVL) systems, utilizing military's global positioning system, may impact response time to law enforcement calls for service. In order to evaluate the impacts of AVL on response time to calls for service at the Altamonte Springs Police Department (ASPD), computer aided dispatch (CAD) data from years 1999 to 2003 were analyzed. The analysis of each of the data sets consisted of an initial sequence chart, an analysis of variance (ANOVA), a means plot and a linear regression. Interviews of ASPD personnel were conducted to understand user perceptions of AVL. Based on the ANOVA results, trends indicate that weekly response time was significantly lower during the AVL partial implementation period than during the pre or post AVL stages across all categories of data analyzed. Based on the regression results, trends indicate that the overall impact of AVL on response time for all categories analyzed is flat and show AVL as having no overall impact on response time across all calls for service analyzed. An exception to this is the findings related to Priority 3 calls for service; however this exception can be attributed to performance during the pre AVL implementation stage. These results do not suggest a capability for AVL to reduce response time to calls for service in a meaningful comprehensive way. Thus, the study's hypotheses are not supported.

This dissertation covers some important topics on the liquid crystal-substrate surface effects, including theoretical derivations and confirming experimental results. The research work is expected to make important impacts on liquid crystal device designs and to open new doors for further research along these topics. In this dissertation, a novel high-electric-field technique is developed to characterize the anchoring energy of vertically-aligned liquid crystal cells. Both theoretical analyses and confirming experimental results are presented. Vertically-aligned liquid crystal cells with buffed polyimide alignment layers are used to validate the measurement techniques. Based on the voltage-dependent transmittance of the liquid crystal cells, a linear fitting can be obtained, which leads to a precise determination of the anchoring energy. If some specific liquid crystal material parameters are known, then the traditional cell capacitance measurements can be avoided. Anchoring energy and cell gap effects on liquid crystal response time is theoretically analyzed and experimentally investigated. A novel theory on the liquid crystal dynamics is developed. In this part, two different theoretical approaches are discussed: one is surface dynamic equation method and the other is effective cell gap method. These two different approaches lead to consistent results, which are also confirmed by our experimental results. This work opens a new door for LCD industry to optimize liquid crystal response time, and it is especially critical for liquid crystal cells with thin cell gap, which is a promising approach for fast response time liquid crystal display. Pretilt angle effects on liquid crystal dynamics are analyzed theoretically and validated experimentally. Analytical expressions are derived to describe liquid crystal response time under nonzero pretilt angle conditions. The theoretical analysis is confirmed experimentally using vertically-aligned liquid crystal cells. These results quantitatively correlate pretilt angles with liquid crystal response time, which is important for optimizing liquid crystal response time.

English learners (ELs) represent one of the fastest growing student populations in the United States. Given that language can serve as a barrier in EL performance, test accommodations are provided to help level the playing field and allow ELs to better demonstrate their true performance level. Test accommodations on the computer offer the ability to collect new types of data difficult to obtain via paper-and-pencil tests. Specifically, these data can be used as additional sources of validity evidence when examining test accommodations. To date, limited research has examined computer-based accommodations, thus limiting these additional sources of validity evidence. The purpose of this study was to evaluate the validity of computer-based test accommodations on high school History and Math assessments using evidence based on response processes, specifically accommodation use and response time. Two direct linguistic accommodations, non-ELs, two EL groups, and five research questions were investigated in this study. Accommodation use results indicated significant differences in use across the three student groups, with ELs using accommodations more frequently than non-ELs. However, there were still high percentages of all three groups not accessing any accommodations on individual items. Accommodation use was more common on History than on Math, and decreased as the assessment progressed. Results suggest future research focus on students actually using the accommodations when conducting research on the effectiveness of accommodations. Response time results showed ELs taking longer to process test items as compared to non-ELs regardless of receiving test accommodations. Receiving accommodations significantly impacted processing time for some of the items on History, but not on Math. Similarly, History showed a relationship between the number of accommodations on test items and response time, but Math did not. These results suggested that the Math content knowledge may have played a larger role in response time than the accommodations. Positive relationships between test performance and response time were found in both subject areas. The most common predictors of both accommodation use and response time across both subject areas were sex, Hispanic status, and socioeconomic status. Implications of the results and suggestions for future research are discussed.

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The increasing popularity of the World Wide Web (WWW) has created a new market: Web access through television to accommodate those who either cannot afford existing hardware or are intimidated by computers. Current efforts to combine the WWW and television have targeted potential novice users. One of the approaches for creating a WWW browsing system that is both simple to use and inexpensive is the utilization of the existing cable system to provide Web access through television. Some unique characteristics of this browsing system are fast access to the Web, the use of nine buttons on a universal remote control, and an index structure for reaching Web sites. Since browsing the Web through television is relatively new, many interface issues need to be examined. The purpose of this research was to investigate potential user interface designs for this WWW browser and to evaluate the usability of the nine-button interface. Sixteen volunteers participated in the experiment and were asked to navigate to specific Web sites with two interface formats, five different system lag times (0.2, 0.7, 1.3, 2.0, and 3.0 seconds), and three feedback styles (active feedback, passive feedback and no feedback). Participants were prescreened for their experience with computers and browsing the Web. The experiment was conducted in a living room setting to simulate real life situations and participants were given a total of 42 tasks to complete throughout the experiment. Each task consisted of navigating through the tree structure with either one of the two interface formats until reaching a designated Web site. The number of errors committed and task completion times were recorded. In addition, participants were asked to rate the WWW browser system after each task as well as after the entire experiment. Participants preferred the 0.2 second system lag and the active feedback style. Overall, they committed fewer errors and took less time to complete tasks with the tabbing interface than with the one-to-one mapping interface. Experienced participants committed more errors than did the inexperienced ones. Increase of system lag time was determined to have a greater adverse effect on the tabbing interface than on the one-to-one mapping interface. / Master of Science