With the development of the wireless communication system, the antenna has been widely used as an important tool in data transmission. However, there are many characteristic parameters for antenna need to be calculated by complex calculation. For example the mutual input impedance of dipole antenna, the Directivity coefficient and the Gain coefficient. Therefore, it is quite practically hard to implement by hand, especially for student who was studying on it. In order to solve this problem, this thesis has establishes the calculation procedure for the complex parameters of antenna by using MATLAB software.

Master of Science / Department of Mechanical and Nuclear Engineering / Donald L. Fenton / Today air cooled chillers are often used in industrial applications where chilled water is pumped through processes or laboratory equipment. Industrial chillers are used for the controlled cooling of products, mechanisms and factory machinery in a wide range of industries. However, there is limited information on condenser coil design for a simulated model that uses R407c in a process chiller system with a focus on the finned tube condenser design. Therefore, a simulation tool that evaluates the performance of a condenser design, e.g. frontal area, cost, and overall system efficiency would be very useful. An optimization calculator for the air cooled fin-tube condenser design was developed. This calculator allows a user to specifically select the condenser geometric design parameters including the overall condenser length and height, number of rows, number of circuits, row and tube spacing, fin thickness, fin density, tube inner and outer diameters, and the quantity and power of the fan motors. This study applied the calculator finding an optimum condenser design for various frontal areas and cost constraints. The calculator developed is appropriate for engineering designers for use in the process chiller industry.

This study examined the effects of using graphing calculators with a numerical approach designed by the researcher on students learning of limits and derivatives in an Applied Calculus course at a community college. The purposes of this study were to investigate the following: (1) students achievement in solving limit problems (Skills, Concepts, and Applications) with a numerical approach compared to that of students who solved limit problems with a traditional approach (primarily an algebraic approach); and (2) students achievement in solving derivative problems (Skills, Concepts, and Applications) with a numerical approach compared to that of students who solved derivative problems with a traditional approach (primarily an algebraic approach). Students (n = 93) in all four daytime sections of an Applied Calculus course in a community college participated in the study during the spring 2005 semester. One of two MWF sections and one of two TR sections served as the treatment groups; the other two sections served as the control groups. Two instructors other than the researcher participated in the study. Instructor A taught one treatment group (a TR section) and one control group (a MWF section); instructor B taught one treatment group (a MWF section) and one control group (a TR section). Dependent variables were achievement to solve skill, concept, and application limit problems and skill, concept, and application derivative problems, measured by two teacher-made tests. A pretest administered on the first day of class determined that no significant difference existed between the groups on prerequisite algebra skills. Separate ANCOVA tests were conducted on the skill, concept, and application portions of each of the limit and derivative exams. Data analyses revealed the following: (1) there was no significant difference found on the skill portion of the limit topic (unit 1 exam) due to instruction or to instructor; (2) there was a significant difference found on the concept portion of the limit topic due to instruction and to instructor; (3) there was a significant difference found on the application portion of the limit topic due to instruction but not due to instructor; (4) the interaction effects between instructor and instruction were not significant on the skill, concept, and application portions of the limit topic; (5) there was a significant difference found on the skill portion of the derivative topic (unit 2 exam) due to instruction but not due to instructor; (6) there was a significant difference found on the concept portion of the derivative topic due to instruction and to instructor; (7) there was a significant difference found on the application portion of the derivative topic due to instruction but not due to instructor; and (8) the interaction effects between instructor and instruction were not significant on the skill, concept, and application portions of the derivative topic. All significant differences were in favor of the treatment group.

Tyrimo medžiaga (žirgelių lervos, išnaros ir suaugėliai) buvo rinkta 2008 – 2009 metais Nemuno ir Dauguvos takoskyroje esančiuose nenuotakiuose ežeriukuose Gražutės regioninio parko bei Smalvų-Smalvykščio kraštovaizdžio draustinio administracinėse teritorijose. Šiame darbe siekiama įvertinti žirgelių rūšių įvairovę ir jų pasiskirstymo ypatumus nenuotakiuose ežeruose. Tyrimams pasirinkta 31 nenuotakus ežeras, kurie pagal dydį, savo apyežerių plotus, hidrologinę būklę buvo suskirstyti į tris atskiras grupes. Juose buvo užregistruotos 35 žirgelių rūšys, iš kurių 6 įrašytos į LRK ir 3 į ES buveinių direktyvos (92/43/EEC) II priedą. Tarp ištirtų ežerų, remiantis rūšinės sudėties stabilumo skaičiuokle (Nestedness temperature calculator (NTC)), patvariausias žirgelių rūšių rinkinys nustatytas tik antros grupės ežeruose T = 31,75° (p = 0,06). Būdingos trijų ežerų grupėse rūšys nesutapo (W > 51%). Nenuotakių nedidelių ežerų kaip žirgelių buveinių svarbą patvirtina indikatorinės rūšys (sutinkamumas nuo 15% iki 40% ežerų), kurios yra skirtingos visoms ežerų grupėms (išskyrus vieną – Leucorrhinia albifrons), kuri sutapo pirmai ir antrai ežerų grupėms). Tarp indikatorinių rūšių patenka net 5 Lietuvos raudonosios knygos rūšys. / Material (dragonfly larvae, exuviae and imagos) for the study were gathered in 2008 - 2009 in closed lakes of Nemunas and Daugava basins watershed, which are located in Gražutė regional park and Smalvas-Smalvykštis landscape reserve. This work aims to evaluate the dragonfly species diversity and distribution characteristics in closed lakes. 31 closed lakes were selected for research, which according to hydrological conditions and shore size were divided into three groups. 35 species of dragonfly were recorded, of which 6 are enrolled in the Red list of Lithuania and 3 to EU Habitats Directive (92/43/EEC) Annex II. According to Nestedness temperature calculator the most durable species complex of dragon-fly among investigated lakes occurred in second group of lakes, only T = 31.75 ° (p = 0.06). Characteristic dragonfly species for all three of groups lakes were differed (W> 51%). The importance of small closed lake as a dragonfly habitat as well confirms the fact that all indicator species (abundant from 15% to 40% of lakes) were different for all groups of lakes(except one Leucorrhinia albifrons which coincided to first and second groups of lakes). Among indicator species there were five species of the Red list of Lithuania.

A large Canadian financial services institution (FSI) is planning to develop a web-based application aimed at helping homeowners calculate the financial and environmental impacts of potential energy conserving upgrades to their dwellings. The algorithm for this calculator, the questions to be posed to the homeowners, and how the homeowners can access some of the scientifically-inclined energy-related information is presented. The potential upgrades considered were: furnace efficiency, heat-pump efficiency, programmable thermostats, window-efficiency, building insulation, lighting efficiency, and refrigerator efficiency. The algorithm developed was used to demonstrate that changing just one of the input variables can, in certain cases, have a drastic effect on the resulting output: upgrades with positive net present values (NPV) can drop to negative NPV, and in certain cases CO2 emissions can increase as a result of the upgrade considered. The effect of future changes in fuel prices, and the price levied on CO2 emissions is also demonstrated.

A large Canadian financial services institution (FSI) is planning to develop a web-based application aimed at helping homeowners calculate the financial and environmental impacts of potential energy conserving upgrades to their dwellings. The algorithm for this calculator, the questions to be posed to the homeowners, and how the homeowners can access some of the scientifically-inclined energy-related information is presented. The potential upgrades considered were: furnace efficiency, heat-pump efficiency, programmable thermostats, window-efficiency, building insulation, lighting efficiency, and refrigerator efficiency. The algorithm developed was used to demonstrate that changing just one of the input variables can, in certain cases, have a drastic effect on the resulting output: upgrades with positive net present values (NPV) can drop to negative NPV, and in certain cases CO2 emissions can increase as a result of the upgrade considered. The effect of future changes in fuel prices, and the price levied on CO2 emissions is also demonstrated.

Due to the scarcity of Human Reliability Analysis (HRA) data, one of the key elements of any HRA analysis is use of engineering judgment. The Electric Power Research Institute (EPRI) HRA Calculator guides the user through the steps of any HRA analysis and allows the user to choose among analytical HRA methods. It applies Accident Sequence Evaluation Program (ASEP), Technique for Human Error Rate Prediction (THERP), the HCR/ORE Correlation, and the Caused Based Decision Tree Method (CBDTM). This program is intended to produce consistent results among different analysts provided that the initial information is similar. Even with this analytical approach, an HRA analyst must still render several judgments. The objective of this study was to evaluate the use of engineering judgment applied to the quantification of post-initiator actions using the HRA Calculator. The Comanche Peak Steam Electric Station (CPSES) Level 1 Probabilistic Risk Assessment (PRA) HRA was used as a database for examples and numerical comparison. Engineering judgments were evaluated in the following ways: 1) Survey of HRA experts. Two surveys were completed, and the participants provided a range of different perspectives on how they individually apply engineering judgment. 2) Numerical comparison among the three methods. 3) Review of CPSES HRA and identification of judgments and the effects on the overall results of the database. The results of this study identified thirteen areas in which an HRA analyst must interpret and render judgments on how to quantify a Human Error Probability (HEP) and recommendations are provided on how current industry practitioners render these same judgments. The areas are: identification and definition of actions to be modeled, identification and definition of actions to be modeled, definition of critical actions, definition of cognitive portion of the action, choice of methodology, stress level, rule-, skill- or knowledge-based designation, timing information, training, procedures, human interactions with hardware, recoveries and dependencies within an action, and review of final HEP.

Abstract The role of collaborative classroom practices, and of technology, in students’ learning of mathematics, is now receiving increased attention in curriculum and policy documents in Australia and internationally. The implementation of pedagogical reforms associated with these areas, however, has been limited due to a range of theoretical and practical concerns. An issue which has emerged from separate interests in technology and collaborative practice is the role of digital tools in enhancing meaningful learning in both individual and collaborative group settings. While the corpus of research literature in the area of technology mediated learning in mathematics is now significant, much of the focus of studies in this area has been concerned with the effect of technology on individual learning outcomes within specific topic domains. Research is needed into the role of digital tools within collaborative classroom environments. This study investigated the various roles of technology in mediating students’ learning, from both individual and collective perspectives, within an authentic, senior secondary classroom setting and sought to identify patterns of student behaviour within this environment. The theoretical framework for the study drew on two bodies of educational research. Firstly, social theories of learning, including Vygotskian socio-cultural ideas, the field of learning discourses, and distributed cognition, were considered. Secondly, research literature associated with approaches to learning mathematics with the assistance of digital technologies, including ideas related to tool co-construction and instrumental genesis, are examined. Because the focus of this study is on authentic systems of activity rather than individual student outcomes, a naturalistic approach to data collection and analysis was employed. Research was conducted in two senior secondary classrooms over a two and a half year period (1997 – 1999). This involved a pilot study (1997 – 1998) and overlapping main study (1998 – 1999) which were conducted with two different cohorts of students. The investigation was carried out by a teacher-researcher with the support of a research assistant. Qualitative and quantitative data were collected using: student surveys; individual and whole class student interviews; stimulated recall procedures; videotaping of episodes of students working as individuals, in small groups and in whole class settings; and longitudinal participant observation. Data analysis techniques were chosen to match the form and nature of available data and were sensitive to the generation and confirmation of categories of emergent student behaviour. This process was iterative and included an additional phase devoted to category refinement and eventually to theory development. Patterns of behaviour for students working with digital technologies were identified and the metaphors of Master, Servant, Partner and Extension-of-self were chosen to describe the categories that emerged. These categories were further developed into a framework which describes students’ interaction with technology while learning mathematics in individual, small group and whole class settings. The theoretical and practical implications of this study include: the identification of the role of digital technologies in mediating the social practices within authentic mathematics classrooms; the potential of technology to empower students as individuals and as collectives of co-dependent learners; and the potential shift in power structures between teachers and students within mainstream classroom when students are so empowered.

Thesis (M.S. - Hydrology and Water Resources)--University of Arizona, 1983. / Includes bibliographical references (leaves 91-93).

Thesis (M. Ed.), Memorial University of Newfoundland, 1998. / Restricted until November1999. Includes bibliographical references.