STEM Yaklaşımı ile Basınç Konusu Öğretiminin Ortaokul 7. Sınıf Öğrencilerinin Akademik Başarılarına ve STEM’e Yönelik Tutumlarına Etkisi

The objective of this study is to determine the effect of a teaching module on the topic of pressure, developed with STEM approach, on the academic achievements of the students as well as on their attitudes towards STEM. The study employed the explanatory sequential design, as one of of mixed method research designs. On the quantitative aspect of the study, a pre-test and post-test control group, quasi-experimental design was used, while phenomenological design was utilized for qualitative aspects. The sample group of the research comprises of 33 7th grade students studying in a village school located in a district of one of the metropolitan municipalities in Turkey for the Spring Semester of the 2017-2018 school year. A STEM education approach was used in the experimental group for teaching the subject of “Pressure” while utilizing the approach as stipulated in the curriculum for the control group. An academic achievement test, an attitude scale for STEM, semi-structured interviews, and the student diaries are the data collection tools used in the study. A significant difference was found between the experimental group and the control group, with the former showing increased academic achievement over the latter in the research. A significant difference was also found between the experimental group and the control group, with the former showing more positive attitudes towards STEM than were shown by the latter. The opinions of the students on STEM education were analyzed in order to study the results obtained from quantitative data. Five themes – feelings and opinions, positive aspects, skills gained, features and problems faced, and the learning process were obtained—as well as 26 codes—with the content analysis of semi-structured interviews and students’ diaries. It was concluded that involving STEM-based implementations in teaching the subject “Pressure” increased the academic success rate and attitude scores of students while helping the students to develop positive perceptions of STEM education. In future studies, certain influences of STEM education implementations, such as self-confidence of students, the ability to present creative solutions, communication skills, for example, may be studied.Bu çalışmanın amacı, basınç konusunda STEM yaklaşımı ile geliştirilen bir öğretim modülünün, öğrencilerin akademik başarılarına ve STEM’e yönelik tutumlarına etkisinin belirlenmesidir. Çalışmada karma yöntem araştırması desenlerinden açıklayıcı sıralı desen kullanılmıştır. Çalışmanın nicel boyutunda ön test-son test kontrol gruplu yarı deneysel desen, nitel boyutunda ise olgubilim deseninden faydalanılmıştır. Araştırmanın örneklemi, 2017-2018 eğitim öğretim yılı güz döneminde, Türkiye’de yer alan büyükşehirlerden birinin ilçesine bağlı bir köy okulunda öğrenim görmekte olan 7. sınıf öğrencisi 33 kişiden oluşmaktadır. Basınç konusunun öğretiminde, deney grubunda STEM eğitimi kullanılırken kontrol grubunda öğretim programının ön gördüğü yaklaşım kullanılmıştır. Akademik başarı testi, STEM’e yönelik tutum ölçeği, yarı yapılandırılmış görüşmeler ve öğrenci günlükleri çalışmada kullanılan veri toplama araçlarıdır. Araştırma sonucunda, akademik başarı açısından deney grubu ile kontrol grubu arasında deney grubu lehine anlamlı bir fark bulunmuştur. Aynı zamanda STEM’e yönelik tutumlar açısından da deney grubu ile kontrol grubu arasında deney grubu lehine anlamlı bir farklılık olduğu görülmüştür. Nicel verilerden elde edilen sonuçların daha derinlemesine incelenmesi için öğrencilerin STEM eğitimine ilişkin görüşleri incelenmiştir. Yarı yapılandırılmış görüşmeler ile öğrenci günlüklerinin içerik analizi sonucu duygu ve düşünceler, olumlu yönler, kazanılan beceriler ve özellikler, yaşanan sorunlar ve öğrenme süreci olmak üzere 5 tema ve 26 kod elde edilmiştir. Basınç konusunun öğretiminde STEM temelli uygulamalara yer verilmesinin, öğrencilerin akademik başarı ile tutum puanları üzerinde artış sağladığı ve öğrencilerin STEM eğitimine ilişkin olumlu düşünceler geliştirmelerine yardımcı olduğu görülmüştür. Gelecek çalışmalarda STEM eğitimi uygulamalarının öğrencilerin özyeterlik inançları, yaratıcı problem çözme becerileri, iletişim becerileri gibi farklı değişkenler üzerindeki etkileri araştırılabilir

A two stage solution approach to spare parts distribution under a special cost structure

Ankara : The Department of Industrial Engineering and the Institute of Engineering and Sciences of Bilkent University, 2010.Thesis (Master's) -- Bilkent University, 2010.Includes bibliographical references leaves 62-66.In this thesis, we consider a multicommodity distribution problem. We assume that there is a central depot which houses a number of different types of items. There is a finite number of geographically dispersed demand points which place orders for these items on a daily basis. The demand of these demand points should be satisfied from this central depot. We assume that a finite number of identical trucks with predetermined destinations are used for the distribution of the items from the central depot to each demand point. The demand of each demand point can be split among several trucks and a single truck is allowed to visit several demand points. Our objective is to satisfy the demand of each demand point with the minimum total distribution cost while respecting the capacity of each truck. The cost structure is dictated by the final destinations of trucks used in the distribution of the items and the set of demand points visited by each truck. We propose two different solution approaches. The first approach, called the Direct Approach, is aimed at solving the problem directly using a mixed integer linear programming formulation. Since the Direct Approach becomes computationally infeasible for real-life problems, we propose a so-called Hierarchical Approach that is aimed at solving the problem in two stages using an aggregation followed by a disaggregation scheme. We study the properties of the solutions computed with the Hierarchical Approach. We perform extensive computational studies on a data set adapted from a major automotive manufacturing company in Turkey in an attempt to compare the performances of the two approaches. Our results reveal that the Hierarchical Approach significantly outperforms the Direct Approach on the vast majority of the instances.Koca, EsraM.S

Evaluation of the Wound Healing Potential of Achillea biebersteinii Afan. (Asteraceae) by In Vivo Excision and Incision Models

Achillea species are widely used for diarrhea, abdominal pain, stomachache and healing of wounds in folk medicine. To evaluate the wound healing activity of the plant, extracts were prepared with different solvents; hexane, chloroform, ethyl acetate and methanol, respectively from the roots of Achillea biebersteinii. Linear incision by using tensiometer and circular excision wound models were employed on mice and rats. The wound healing effect was comparatively evaluated with the standard skin ointment Madecassol. The n-hexane extract treated groups of animals showed 84.2% contraction, which was close to contraction value of the reference drug Madecassol (100%). On the other hand the same extract on incision wound model demonstrated a significant increase (40.1%) in wound tensile strength as compared to other groups. The results of histoptological examination supported the outcome of linear incision and circular excision wound models as well. The experimental data demonstrated that A. biebersteinii displayed remarkable wound healing activity

Original Article Wound Healing Activity of Rubus sanctus Schreber (Rosaceae): Preclinical Study in Animal Models

Young shoots of Rubus species have been used for healing of wounds, infected insect bites and pimples in folk medicine for ages. In order to evaluate the wound healing activity of Rubus sanctus, four different extracts were prepared from the whole aerial parts of the plant by using n-hexane, chloroform, ethyl acetate and methanol, respectively. Incision wound healing model by using tensiometer on rats and excision model on mice were employed to assess the activity. Remarkable wound healing activity was observed with the ointment formulation of the methanol extract at 1% concentration on the mentioned models. The results of histopathological examination also supported the outcome of both incision and excision wound models. The wound healing effect was comparatively evaluated with a reference ointment Madecassol. The experimental data confirmed the ethnobotanical usage of R. sanctus

New chromosomal data, karyotype asymmetry and polyploid variations of some Gundelia (Asteraceae) species from Turkey

The genus Gundelia is currently represented with 18 species, of which 16 are in Turkey. In genus Gundelia, the chromosomal data were reported from 12 species. In the present study, it is aimed to eliminate the deficiencies in the knowledge about chromosomal data of Gundelia species. In Genus Gundelia, only a single chromosome number had been detected as 2n=18 so far. The chromosome numbers of four species were reported here for the first time: G. armeniaca, G. cappadocica, G. siirtica, and G. tehranica. In addition, the polyploidy in the genus was rare and G. anatolica was identified as the first polyploid species. All karyotypes except G. tehranica were symmetrical, consisting of metacentric and submetacentric chromosomes. Secondary constrictions were observed in the distal regions of the long arms of the longest metacentric and submetacentric chromosomes. Thus, the chromosomal data of all Turkish Gundelia species were completed. In conclusion, the present study presented new data into the karyological records relating the karyotype evolution and interspecific relations of genus Gundelia

Stochastic lot sizing problem with carbon emission constraints

In this paper, we study the stochastic lot sizing problem with probabilistic carbon emission constraints. To the best of our knowledge, this is the first study that considers this problem. We study the problem under static uncertainty strategy and α service level constraints. We consider both the periodic and global carbon emission constraints and use chance constraints to ensure that the carbon emission constraints are satisfied with the desired probabilities. We formulate the problems as mixed integer program and solve them by a commercial solver. Our computational experiments show that the formulations can be solved for quite large problem instances in reasonable times. We compare the probabilistic global and periodic emission constraints according to their effects on the total cost and carbon emissions

Zeitverlauf bis zur Erstdiagnose bei Patienten mit GEP-NET : monozentrische Analyse

Neuroendokrine Tumoren (NET) sind eine seltene Krankheit mit einem breitgefächerten heterogenen Erscheinungsbild, wodurch sich die Diagnose der Tumoren aus einer Vielzahl aus Gründen häufig um Jahre verzögert (1). In dieser Arbeit analysierten wir einen großen Datensatz in einem tertiären Referenzzentrum (UKF) von 1984-2019, um die Symptomatik vor der Diagnose des Tumors sowie den Zeitraum von der Tumormanifestation bis zur Diagnose weiter zu klären. Für die deskriptiven Analysen kamen SPSS, Cox-Regression und Log-Rank-Test zur Anwendung. Insgesamt schloss die retrospektive Studie 488 gastroenteropankreastische (GEP)-NET mit 486 Patienten ≥ 18 Jahren ein, wovon knapp mehr als die Hälfte männlich (52,9%) waren. Das mittlere Alter bei Erstdiagnose (ED) betrug 58 Jahre (477/486, 9 unbekannt). Die häufigsten Primärtumorlokalisationen stellten Pankreas (143/488 Patienten) und Dünndarm (145/488 Patienten) dar. Die Mehrheit der NET waren langsam wachsende G1-Tumoren mit einem Ki67 < 3% (155/330). Die Hälfte der Patienten entwickelten im Verlauf Fernmetastasen, wobei die meisten bereits bei der ED vorlagen und insbesondere die Leber als Metastasierungsorgan dominierte. Bei mehr als 60% der Patienten konnten Angaben zur klinischen Symptomatik vor der ED detektiert werden, wovon wiederum mehr als die Hälfte symptomatisch waren. 42% der symptomatischen Patienten zeigten NET-spezifische Symptome (Bauchschmerzen 77/128; 60,2%, Durchfall 51/128; 39,8%, Flush 19/128; 14,8%, Karzinoidsyndrom 8/128; 6,3% Tachykardie 6/128; 4,7%). In der primären bildgebenden Diagnostik dominierten konventionelle Bildgebungen wie Sonographie und Computertomographie (CT), wobei nuklearmedizinische Diagnostik eine Seltenheit darstellte. Mehr als 30% der Tumoren wurden als Zufallsbefunde im Rahmen einer bildgebenden Diagnostik oder Operation diagnostiziert. Die Mehrheit der Patienten stellte sich initial außerhalb unserer Klinik vor, nur etwa 15% wurden innerhalb unserer Klinik insbesondere in der Gastroenterologie vorstellig, wo der NET diagnostiziert wurde. Die Phase von der Tumormanifestation bis zur ED aller NET betrug im Median 17 Tage. Das Vorhandensein von Fernmetastasen sowie Symptomen führte zu keiner signifikanten Kürzung der Phase und einer schnelleren ED des NET (Median 65,5 vs. 90 Tage, p = 0,4).NET is a rare disease that shows a wide heterogeneous presentation, so tumor diagnosis is often delayed by years for a variety of reasons. In this work, we analyzed a large dataset in a tertiary referral center (UKF) from 1984-2019 to further clarify the symptoms before tumor diagnosis and the time from tumor manifestation to diagnosis. SPSS, Cox regression, and log-rank test were used for the descriptive analyses. In total, the retrospective study included 488 gastroenteropancreatic (GEP)-NET with 486 patients ≥ 18 years of age, of whom just over half were male (52.9%). The median age at initial diagnosis was 58 years (477/486, 9 unknown). Pancreas 143/488 and small bowel 145/488 represented the most common primary tumor locations. The majority of NET were slow-growing G1 tumors with a Ki67 < 3% (155/330). Half of the patients developed distant metastases during follow-up, with most already present at initial diagnosis and particularly dominating the liver. Clinical symptoms were detected in more than 60% of patients before initial diagnosis, of whom more than half were symptomatic. 42% of symptomatic patients showed NET-specific symptoms (abdominal pain 77/128; 60.2%, diarrhea 51/128; 39.8%, flushing 19/128; 14.8%, carcinoid syndrome 8/128; 6.3% tachycardia 6/128; 4.7%). Conventional imaging such as sonography and computer tomography dominated the primary imaging diagnosis, with nuclear medicine diagnosis being a rarity. More than 30% of tumors were diagnosed as incidental findings during diagnostic imaging or surgery. Most patients initially presented outside our hospital, with only about 15% presenting within our hospital, particularly in gastroenterology, where the NET was diagnosed. The phase from tumor manifestation to initial diagnosis of all NET amounted to a median of 17 days. The presence of distant metastases as well as symptoms did not significantly shorten the phase and resulted in a faster initial diagnosis of NET (median 65.5 vs. 90 days, p = 0.4)

Two-stage stochastic facility location problem with disruptions and restricted shortages

In this study, we consider a reliable facility location problem where an uncertain disruptive event might affect the demand of the nodes, the allocation costs, and the available capacities at the facilities. We assume that the decision maker decides the locations and the types (size and reliability levels) of the facilities under uncertainty, while the allocation and shortage decisions are made in response to the realizations of the uncertain parameters. Motivated from a humanitarian facility location problem, we enforce an upper bound on the risk of shortages under any scenario using the popular risk measure conditional value-at-risk (CVaR). We formulate the problem as a two-stage stochastic programming model, and solve it using the L-Shaped method accelerated with additional enhancements. Our computational experiments show the value of our modeling scheme, and the effectiveness of our solution method

Development of a teaching module for pressure with STEM approach and investigation of its applicability

Bu çalışmanın amacı, 7. sınıf fen bilimleri dersi öğretim programında yer alan basınç konusunun öğretiminde STEM eğitimi yaklaşımı ile geliştirilen bir öğretim modülünün öğrencilerin akademik başarılarına, fene ve STEM'e yönelik tutumları ile STEM'e ilişkin görüşlerine etkisinin belirlenmesidir. Çalışma, karma yöntem araştırma desenlerinden gömülü desende yürütülmüştür. Araştırmanın nicel boyutunda ön test, son test kontrol gruplu yarı deneysel desen, nitel boyutunda ise olgubilim deseni kullanılmıştır. Araştırmanın örneklemini, 2017-2018 eğitim öğretim yılı güz döneminde, bir büyükşehrin ilçesine bağlı bir köy okulunda öğrenim görmekte olan 33 7. sınıf öğrencisi oluşturmaktadır. Basınç konusunun öğretiminde, deney grubunda STEM temelli öğretim modülü uygulanırken, kontrol grubunda ise öğretim programında öngörülen yöntemler kullanılmıştır. Araştırmanın nicel verileri, akademik başarı testi, fene yönelik tutum ölçeği ve STEM'e yönelik tutum ölçeği ile toplanmıştır. Araştırmanın nitel verileri ise yarı yapılandırılmış görüşmeler ve doküman analizi ile elde edilmiştir. Nicel veri toplama araçları ile elde edilen veriler, SPSS 22.0 ve LİSREL 8.80 paket programına aktarılarak analiz edilmiştir. Nitel veriler ise içerik analizi ve betimsel analize tabi tutulmuştur. Araştırma sonucu, deney grubu ile kontrol grubu arasında akademik başarı, fene yönelik tutum ve STEM'e yönelik tutum açısından deney grubu lehine anlamlı bir fark olduğu tespit edilmiştir. Nitel verilerin içerik analizi sonucu duygu ve düşünceler, olumlu yönler, yaşanan sorunlar, öğrenme süreci ile kazanılan beceriler ve özellikler olmak üzere 5 tema ve 26 koda ulaşılmıştır. Ulaşılan kod ve temalar, deney grubu öğrencilerinin başarı ve tutum düzeylerinde yaşanan artışın sebeplerini ortaya koymaktadır. Araştırma ile elde edilen sonuçlar, STEM temelli öğretim modülünün, öğrencilerin akademik başarıları, fene ve STEM'e ilişkin tutumları ile görüşleri üzerinde olumlu bir etkiye sahip olduğunu göstermektedir.The purpose of this study is to determine the impact of a teaching module developed with the STEM approach in the teaching of the pressure subject in the 7th-grade curriculum to the academic achievements of students, their attitudes towards science and STEM, and their opinions. The study was carried out in embedded design from mixed method research designs. While in the quantitative dimension of the research, pre-test, post-test control group semi-experimental design was used; in the qualitative dimension of the research, phenomenology was used. The sample of the research consists of 33 students who are studying in a village school connected to a metropolitan in the Fall semester of the 2017-2018 academic year. While the STEM-based teaching module was applied to the experimental group during the teaching of the pressure topic, the methods included in the curriculum were used in the control group. While quantitative data of the study were collected by academic achievement test, attitude towards science scale and attitude towards STEM scale; qualitative data of the study were obtained by semi-structured interviews and document analysis. The data obtained with quantitative data collection tools were analyzed by transferring them to SPSS 22.0 and LISREL 8.80 package program. Qualitative data also were analyzed by content analysis and descriptive analysis. In the result of this research, in terms of academic achievement, attitude toward science, and attitude toward the STEM; in favor of the experimental group, there was a significant difference between the experimental group and the control group. The content analysis of qualitative data has reached to 5 themes and 26 codes, including emotions and thoughts, positive aspects, experienced problems, skills and features acquired by the learning process. The codes and themes reveal the causes of the increase in the level of success and attitude of the experiment group. The results of the study indicate that the STEM-based teaching module has a positive influence on students' academic achievement, attitudes towards science and STEM, and their opinions