Examining Pre-service Mathematics Teachers’ Conceptual Structures About “Geometry”

The aim of this study is to examine pre-service mathematics teachers’ conceptual structures about “geometry”. Qualitative research methodology has been adopted in the study. The data of the study is obtained from mathematics teacher candidates who have been students at the faculties of education of an Anatolian university in the academic year of 2015-2016. The free word association test was used to collect the data. The "geometry" stimulus word is presented to participants by the word association test. A total of 65 response words obtained from the test have been arranged in frequency tables. The answer words were divided into 13 categories with the help of content analysis. Considering the frequencies and categories of answer words, a network of concepts has been developed that outlines the conceptual structures of pre-service mathematics teacher about "geometry". At the end of the research, the answer words with the highest frequency of the mathematics teacher candidates related to the "geometry" stimulus word are triangle, angle, area, polygon, etc. and the categories of answer words are triangle, quadrilateral/polygon, basic concepts of geometry, measurement, etc. Keywords: Geometry, conceptual structures, free word association test, pre-service mathematics teachers

Student Views with Regard to Probsol Learning Environmenta

AbstractThe aim of this study is to assess learner views with regard to ProbSol learning environment prepared according to problem solving steps for the teaching of “applications related to equations and inequalities”. In line with this aim, the study was carried out with 15 volunteered 9th graders who are taught with ProbSol. The study is a case study, which is one of the qualitative research paradigms, and a semi-structured interview form with 8 open-ended questions developed by the researchers was used. Data obtained from semi-structured interview form were analyzed with content analysis method. In general, the views of the participants with regard to ProbSol environment were mostly positive

Investigation of Mathematics Teacher Candidates’ Conceptual Structures about “Measurement” through Word Association Test: The Example of Turkey

The purpose of this research is to determine mathematics teacher candidates’ conceptual structures about the concept of “measurement” that is the one of the important learning fields of mathematics. Qualitative research method was used in this study. Participants of this study were 58 mathematics teacher candidates studying in one of the public universities in Turkey. The free word-association test was used as data collection tool. The “Measurement” stimulus concept was presented to mathematics teacher candidates through the free word-association test. A total of 118 response words obtained from the test have been arranged in frequency tables. The response words divided into 9 categories with the help of content analysis. A network of concepts has been created that the conceptual structures of mathematics teacher candidates about “measurement” using the frequencies and categories of response words. The findings of this study indicates that the response words with the highest frequency of the mathematics teacher candidates related to the “measurement” stimulus word are evaluation, exam, length, meter, test, etc. and the categories of response words are meaning of measurement, measurement and evaluation lesson, measurement learning domain, measurement in daily life, measurement units, etc

Analysis of the effects of phase noise and frequency offset in orthogonal frequency division multiplexing (OFDM) systems

Orthogonal frequency division multiplexing (OFDM) is being successfully used in numerous applications. It was chosen for IEEE 802.11a wireless local area network (WLAN) standard, and it is being considered for the fourthgeneration mobile communication systems. Along with its many attractive features, OFDM has some principal drawbacks. Sensitivity to frequency errors is the most dominant of these drawbacks. In this thesis, the frequency offset and phase noise effects on OFDM based communication systems are investigated under a variety of channel conditions covering both indoor and outdoor environments. The simulation performance results of the OFDM system for these channels are presented.http://archive.org/details/analysisofeffect109451712Lieutenant Junior Grade, Turkish NavyApproved for public release; distribution is unlimited

Comparative evaluation of shear bond strength of three flowable compomers on enamel of primary teeth: an in-vitro study

Background: The aim of the present study was to determine Shear bond strength (SBS) of different flowable compomers on the enamel surface of primary teeth. The null hypothesis to be tested was that none of the flowable compomer would differ significantly from the other two with respect to SBS. As a result, the tested materials that have the easiest application on child patient is preferred. Material and Methods: Sixty newly extracted non carious primary molars were selected. The buccal surface was cleaned and polished to obtain a flat enamel surface. The specimens were randomly divided into three groups of 20 teeth each, based on the flowable compomers applied, as follows: group I: Dyract Flow® (Dentsply, Konstanz, Germany); group II: Twinky Star Flow® (Voco, Cuxhaven, Germany); and group III: R&D Series Nova Compomer Flow® (Imicryl, Konya, Turkey). Results: SBS in group II (6.78± 0.45 MPa) were significantly lower than groups I and III (8.30 ± 0.29 and 8.43 ± 0.66 MPa, respectively) ( P <.001). No significant difference was found between groups I and III ( P <.05). Conclusions: Significant differences existed between the SBS of the groups. Therefore, the null hypothesis was rejected. Flowable compomers can provide adequate SBS with self-etching system at restoration of primary teeth. Thus, successful restorations in pediatric patients can be done in a practical way

Neutrophil to Lymphocyte and Platelet to Lymphocyte Ratios in Normal Tension Glaucoma

Normal tension glaucoma (NTG) is a subtype of glaucoma that occurs at relatively low intraocular pressure levels and results in progressive optic neuropathy. Previous studies display some abnormal immune activity against the optic nerve. Neutrophil to lymphocyte (NLR) and platelet to lymphocyte ratios (PLR) are novel markers for inflammation. Here we evaluated the NLR, PLR, Creactive protein (CRP) and erythrocyte sedimentation rate (ESR) levels in NTG. NLR and PLR were resulted by dividing neutrophil and platelet counts to lymphocyte count respectively. Patients with a history of diabetes mellitus, chronic renal failure, rheumatologic disease, anemia, cancer, cigarette smoking, myocardial infarction and a febrile illness within one month of sampling were excluded from the investigation. In total, the blood samples of 28 NTG and 27control patients were analyzed for the study. There were 11 female (40.7%) and 16 male patients (59.3%) in the control group. The NTG group contained 15 (53.6%) female and 13 (46.4%) male patients. All of the NLR, PLR, ESR and CRP, values of NTG patients were not statistically different from the control group (P = 0.07, P = 0.64 and P = 0.44 respectively). Although previous studies have shown significant differences in NLR and PLR levels in other types of glaucoma, we did not find any significant difference in NTG subjects. Our early report may give insight into the differential diagnosis of NTG. Epub: October 1, 2019