Direct Adjustment Method on Aalen\u27s Additive Hazards Model for Competing Risks Data

Aalen’s additive hazards model has gained increasing attention in recently years because it model all covariate effects as time-varying. In this thesis, our goal is to explore the application of Aalen’s model in assessing treatment effect at a given time point with varying covariate effects. First, based on Aalen’s model, we utilize the direct adjustment method to obtain the adjusted survival of a treatment and comparing two direct adjusted survivals, with univariate survival data. Second, we focus on application of Aalen’s model in the setting of competing risks data, to assess treatment effect on a particular type of failure. The direct adjusted cumulative incidence curve is introduced. We further construct the confidence interval of the difference between two direct adjusted cumulative incidences, to compare two treatments on one risk

Nonparametric Inferences for the Hazard Function with Right Truncation

Incompleteness is a major feature of time-to-event data. As one type of incompleteness, truncation refers to the unobservability of the time-to-event variable because it is smaller (or greater) than the truncation variable. A truncated sample always involves left and right truncation. Left truncation has been studied extensively while right truncation has not received the same level of attention. In one of the earliest studies on right truncation, Lagakos et al. (1988) proposed to transform a right truncated variable to a left truncated variable and then apply existing methods to the transformed variable. The reverse-time hazard function is introduced through transformation. However, this quantity does not have a natural interpretation. There exist gaps in the inferences for the regular forward-time hazard function with right truncated data. This dissertation discusses variance estimation of the cumulative hazard estimator, one-sample log-rank test, and comparison of hazard rate functions among finite independent samples under the context of right truncation. First, the relation between the reverse- and forward-time cumulative hazard functions is clarified. This relation leads to the nonparametric inference for the cumulative hazard function. Jiang (2010) recently conducted a research on this direction and proposed two variance estimators of the cumulative hazard estimator. Some revision to the variance estimators is suggested in this dissertation and evaluated in a Monte-Carlo study. Second, this dissertation studies the hypothesis testing for right truncated data. A series of tests is developed with the hazard rate function as the target quantity. A one-sample log-rank test is first discussed, followed by a family of weighted tests for comparison between finite $K$-samples. Particular weight functions lead to log-rank, Gehan, Tarone-Ware tests and these three tests are evaluated in a Monte-Carlo study. Finally, this dissertation studies the nonparametric inference for the hazard rate function for the right truncated data. The kernel smoothing technique is utilized in estimating the hazard rate function. A Monte-Carlo study investigates the uniform kernel smoothed estimator and its variance estimator. The uniform, Epanechnikov and biweight kernel estimators are implemented in the example of blood transfusion infected AIDS data

Turkish Language Teachers’ Intercultural Sensitivity

This study involved qualitative research in the form of a case study to examine the intercultural sensitivity of Turkish language teachers. In the study, criterion sampling was selected and an interview form consisting of seven open-ended questions was applied to 20 Turkish language teachers. Participants working in secondary schools, which are basic education institutions affiliated to the Ministry of National Education, and in units related to assignment in different provinces of Turkey. The research questions were prepared by considering the five following dimensions of the Intercultural Sensitivity Scale developed by Chen and Starosta (2000): interaction engagement, respect for cultural differences, interaction self- confidence, interaction enjoyment, and interaction attentiveness. Content analysis, a qualitative data analysis method, was used. As a result of the study, it was seen that most of the participants exhibited a generally appropriate attitude in terms of having intercultural sensitivity. Some of these participants who exhibited an appropriate attitude had deficiencies in terms of some dimensions of intercultural sensitivity. On the other hand, a significant portion of the participants did not exhibit an appropriate attitude in terms of having intercultural sensitivity in general. At the rest of the paper, some suggestions are made in order to improve teachers’ intercultural sensitivity and to overcome their deficiencies

PERFORMANCE OF ARTIFICIAL NEURAL NETWORKS ON KRIGING METHOD IN MODELING LOCAL GEOID

A transformação das altitudes elipsoidais determinadas por técnicas satelitais emlocais de altitudes niveladas requer o conhecimento da altitude geoidal no ponto deinteresse. Entretanto, as altitudes geoidais de cada ponto nem sempre estãodisponíveis. A fim de determiná-las, um geóide local de transformação deve serdeterminado ou calculado através de métodos apropriados. Uma maneira de fazeristo, é usar pontos de controle de ambos cujas altitudes elipsoidais e niveladasestejam disponíveis. Neste estudo, apresenta-se os resultados da comparação entreo geóide obtido por ANN e o método da Krigagem na modelagem do geóide local. Além disso, a habilidade da transformação dos métodos foi investigada através deuma rede geodésica teste na área metropolitana de Bursa na Turquia. Os resultadossugerem que o modelo por ANN exibe melhores resultados que o método daKrigage

Anatomical and micromorphological properties of some Tanacetum L. (Asteraceae) taxa from Turkey and their systematic implications

In this study, the anatomy and trichome micromorphology of Tanacetum macrophyllum (Waldst.& Kit.) Schultz, T. parthenium (L.) Schultz, T. poteriifolium (Ledeb.) Grierson and T. vulgare L. were examined by light microscopy and scanning electron microscopy. Some anatomical characters such as presence of secretory cavities and pith in root and mesophyll type in leaf provide information of taxonomical significance. In addition, the existence of a parenchymatic layer, which consists of elongated parenchymatic cells in the stem of T. macrophyllum, is a distinguishing character. The results obtained from scanning electron microscope studies showed that trichome micromorphology varies among examined taxa. In T. macrophyllum, the eglandular and glandular trichomes especially on disc florets, ligulate florets and cypselas are more sparse, whereas disc florets and cypselas of the other taxa are covered with abundant glandular trichomes. Additionally, T. poteriifolium and T. parthenium has a distinct distribution of glandular trichomes forming in a row across the entire cypsela surface

A MODEL SUGGESTION FOR BUDGETING ACTIVITY COST REDUCTION UNDER ACTIVITY BASED KAIZEN BUDGETING APPROACH

Nowadays, competitive global business life surrounds various companies around the world. Production technology develops in a very fast manner. Also, companies are in need of advanced budgeting and costing techniques in order to make more profit and stand strong in this fast changing scene. Companies use Activity Based Budgeting (ABB), Activity Based Costing (ABC), and Activity Based Management (ABM) systems to gain successful results. These systems concentrate on overhead costs in order to assign real production cost. In this study, we consider activity based systems and introduce a new model to apply Kaizen Budgeting through ABB and ABC approach in a business organization. Also, we aim to illustrate a case study for an activity center in order to explain our kaizen budgeting model. Our ABB and ABC model has been used in many organizations in Turkey and its success has been proved for years ago. However, our new model will be the first approach for ABB and ABC model via kaizen budgeting. We aim to reduce the organization's variable cost by kaizen budgeting in an efficient manner. Furthermore, we classified costs into four categories such as resource costs on the basis of the volume of activities, resource costs on the basis of activity level, resource costs independent from the volume of activities, and direct resource cost. This approach enables us to reduce the variable costs of activities according to their characteristics

A MODEL SUGGESTION FOR BUDGETING ACTIVITY COST REDUCTION UNDER ACTIVITY BASED KAIZEN BUDGETING APPROACH

Nowadays, competitive global business life surrounds various companies around the world. Production technology develops in a very fast manner. Also, companies are in need of advanced budgeting and costing techniques in order to make more profit and stand strong in this fast changing scene. Companies use Activity Based Budgeting (ABB), Activity Based Costing (ABC), and Activity Based Management (ABM) systems to gain successful results. These systems concentrate on overhead costs in order to assign real production cost. In this study, we consider activity based systems and introduce a new model to apply Kaizen Budgeting through ABB and ABC approach in a business organization. Also, we aim to illustrate a case study for an activity center in order to explain our kaizen budgeting model. Our ABB and ABC model has been used in many organizations in Turkey and its success has been proved for years ago. However, our new model will be the first approach for ABB and ABC model via kaizen budgeting. We aim to reduce the organization's variable cost by kaizen budgeting in an efficient manner. Furthermore, we classified costs into four categories such as resource costs on the basis of the volume of activities, resource costs on the basis of activity level, resource costs independent from the volume of activities, and direct resource cost. This approach enables us to reduce the variable costs of activities according to their characteristics

Views of academicians on teaching Turkish as a foreİgn language course

Bu çalışma, akademisyenlerin Türkçenin Yabancı Dil Olarak Öğretimi dersine ilişkin görüşlerini değerlendirmeye yönelik durum araştırması niteliğindeki nitel bir araştırmadır. Bu doğrultuda akademisyenlerin, derste öğretilenlerin öğrencilerinin bir yabancıya Türkçe öğretmesi için yeterli olup olmadığına, ders kapsamında öğrencilerini kurum veya kişilere uygulama için yönlendirip yönlendirmediklerine ve yönlendiriyorlarsa kurum ve kişilerin bilgisine, dersin son sınıfın son döneminde okutulmasına, ders ile ilgili sorunlara ve önerilere, derse öğrenci ilgisini artırabilmek için yapılabileceklere ilişkin düşüncelerine yer verilmiştir. Araştırmada, amaçsal örneklem çeşitlerinden ölçüt örnekleme yöntemi (alana ilişkin bilimsel çalışma yapmış olmak ve dersi en az bir sefer vermiş olmak) kullanılmıştır. Çalışmada 18 akademisyene açık uçlu altı sorudan oluşan yarı yapılandırılmış görüşme formu uygulanmıştır. Çalışma sonucunda derste öğretilenlerin, öğrencilerinin bir yabancıya Türkçe öğretmesi açısından yeterli olmadığı belirtilmiş, bunun nedeni olarak daha çok dersin süresi ve uygulama kaynaklı durumlar gösterilmiştir. Ders kapsamında öğrencilerin uygulama için ilgili kurum veya kişilere yönlendirildikleri, burada ağırlıklı olarak TÖMER vb. kurumların tercih edildiği görülmektedir. Derse ilişkin belirtilen sorunlarda, süre, uygulama, öğretici ve yayınlardan kaynaklı sorunlar öne çıkmıştır. Yine dersin son sınıfın son döneminde okutulmasına ilişkin genel eğilim bunun uygun olmadığı yönündedir. Dersin daha verimli yürütülmesine ilişkin yapılan önerilerde ağırlıklı olarak, öğretici, uygulama ve gözlem, dersin süresi, kaynak seçimi gibi konular yer almıştır. Derse öğrenci ilgisini artırabilmek için belirtilen düşüncelerde, istihdam olanakları hakkında bilgilendirme, Türkçenin yabancı dil olarak öğretiminin sosyal, ekonomik, siyasi, kültürel vb. katkılarından bahsedilmesi ve öğrencileri ilgili kurum veya kişilere yönlendirerek uygulama yaptırılması öne çıkmaktadır.This study is a qualitative research with a case study approach that examines academicians' views on the subject of Teaching Turkish as a Foreign Language course. Within the scope of this subject, the views of academicians on issues such as whether the course content is sufficient for enabling the students to teach Turkish to a foreign speaker or not, whether the academicians direct students to institutions or persons for application of the training or not, and if they do, the knowledge of these institutions or persons regarding the subject, the course being taught at the last semester of the senior year, problems and their suggestions regarding the course and what can be done to increase students' interest to the course were inquired. Among purposeful sampling types, criterion sampling method (with the criteria of having done a scientific study on the subject and having taught the course at least once) was used in this study. In the study, semi-structured interview forms that consist of six open ended questions have been applied to 18 academicians. As a result of the study, academicians stated that the course content was not sufficient to enable students to teach Turkish to a foreign speaker, and the reason for this was suggested to be issues such as the duration and application of the course. It was observed that students were directed to relevant institutions or persons for application of the course, and institutions such as TÖMER were heavily preferred for this situation. Among specified problems regarding the course, duration and application of the course and problems arising from instructors or publications utilized in the course were prominent. The dominant opinion regarding the situation that the course is taught at the last semester of the senior year was that this situation was not viable. Suggestions related to instructors, application and observation, the duration of the course, choices of teaching materials etc. were the main topics of discussion over how to instruct the course more efficiently. Giving information about employment opportunities, creating discourse on social, economic, political and cultural etc. contributions of teaching Turkish as a foreign language and achieving application of the course by directing the students to relevant institutions and persons were prominent among suggestions on how to increase students' interest in the course