871 research outputs found
Optimal Packet Scheduling on an Energy Harvesting Broadcast Link
The minimization of transmission completion time for a given number of bits
per user in an energy harvesting communication system, where energy harvesting
instants are known in an offline manner is considered. An achievable rate
region with structural properties satisfied by the 2-user AWGN Broadcast
Channel capacity region is assumed. It is shown that even though all data are
available at the beginning, a non-negative amount of energy from each energy
harvest is deferred for later use such that the transmit power starts at its
lowest value and rises as time progresses. The optimal scheduler ends the
transmission to both users at the same time. Exploiting the special structure
in the problem, the iterative offline algorithm, FlowRight, from earlier
literature, is adapted and proved to solve this problem. The solution has
polynomial complexity in the number of harvests used, and is observed to
converge quickly on numerical examples.Comment: 25 pages, 6 figures, added lemma and theorems, added reference,
corrected typo
Treatment approach in ovarian pathologies in children: A single center's experience
Objective: We aimed to retrospectively evaluate the pediatric patients followed up and treated for ovarian pathology by our Pediatric Surgery Clinic.
Materials and methods: In our study, cases with ovarian pathology followed up and treated in the Karaman Training and Research Hospital Pediatric Surgery Clinic between June.2013 and May.2022 were retrospectively analyzed. Data were obtained from the patient’s medical files in the hospital's digital filing system. The cases included in the study were divided into three groups. These were classified as surgical or conservative follow-ups according to the type of treatment.
Results: We identified 62 patients with ovarian pathology from our hospital database. Surgical intervention was performed in 51 (82 %) of the patients and 11 (18 %) were followed up conservatively. The mean age of the patients was 11.9 years (4 days to 17 years) and there was no age difference between the treatment groups (P>0.05). Of 62 patients; non-neoplastic ovarian pathology (NNOP) was found in 37 (59.7%), neoplastic ovarian pathology (NOP) in 6 (9.7%), and ovarian torsion in 19 (30.6%). In group I, %70 (n=26) of patients underwent surgery.
Conclusions: It should be kept in mind that the cause of abdominal pain, especially in girls, may be ovarian pathology, and every patient with suspected ovarian torsion should be evaluated urgently
Efficacy of tongue-tie excision in the treatment of childhood ankyloglossia: 8 years of experience in a single-center
Objective: This study aims to present the results of the frenotomy technique in conditions of ankyloglossia (tongue-tie) identified and cured in the first ten years of life.
Materials and methods: In this study, ankyloglossia cases operated on between April 2014 and March 2022 in the Karaman Training and Research Hospital Pediatric Surgery Clinic were retrospectively reviewed. The number of patients included in the study age group was as follows; 0-90 days 180 (63.3%), 90-360 days, 76 (26.8%), 360 days-10 years 28 (9.9%).
Results: Frenotomy was carried out on 284 patients, 228 (80.3%) boys and 56 girls (19.7%) with tongue-tie between the ages of one day-10 years. The number of them included in the study age groups was as follows; 0-90 days, 180 (63.3%), 90-360 days, 76 (26.8%), 360 days-10 years 28 (9.9%). The patients were classified as 173 patients with type 1, 94 patients with type 2, 6 patients with type 3, and 11 patients with type 4 according to the Coryllos classification defined according to the examination findings. During frenotomy, no anesthesia was performed on the patients in Group 1, general anesthesia was administered to 10 of 48 patients in Group 2, and 11 of 14 patients in Group 3. At follow-up, all patients showed significant improvement in sucking and the baby’s nipple grip. Considering all patients, 54 (75%)of 72 mothers with nipple pain improved.
Conclusions: Frenotomy is a surgical procedure that may require general anesthesia and has few complications, especially in babies older than 3 months
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USING ECONOMIC SENTIMENT IN DESTINATION DEMAND MANAGEMENT
As part of competitive marketing strategies, tourism demand modeling plays an important role in destination management and marketing. This study incorporated the concept of Economic Sentiment Indicator (ESI) into tourism demand studies along with more traditional variables such as interest rate, relative price, and relative exchange rate. The study utilized ARIMA, and ARDL Bound Test approach to cointegration for the long and short-run elasticities using 15 tourist generating countries from the members of EU to Turkey. The study concludes that ESI is an effective tool and good indicator to gauge and monitor tourism demand
Gestational diabetes mellitus is as innocent as you think?
Background: We aimed to compare fetal outcomes, fetal hypoxia, acidemia and maternal chracteristics including hemoglobin A1c, doppler indices between gestational diabetes mellitus (GDM) and pregestational diabetes mellitus (DM) among pregnant women treated with insulin.Methods: Data of pregnant patients with diagnosis of pregestational diabetes (type 1 and 2) and GDM who were treated with insulin (GDM A2 in White classification) was retrospectively collected and compared. Patients with active chronic systemic disease, multiple pregnancies, lost to follow up and detected fetal malformations were exluded. Maternal characteristics, umbilical doppler indices and amnion fluid index, gestational age at delivery, delivery characteristics (including vaginal delivery, or cesarean section) and newborn characteristics such as birth weight, Apgar score and umblical cord pH were all recorded.Results: A total of 130 patients (67 patients with GDM and 63 pregestational DM) were recruited to the study. There were no significant difference regarding type of delivery, fetal birth weight, umbilical cord Hb and gestational birth age. No other significant difference in frequency of low Apgar scores and fetal acidosis or metabolic acidosis were reported. HbA1c and blood glucose levels and insulin dosage were significantly statistically higher in pregestational group.Conclusions: The frequency of fetal distress parameters and poor fetal outcome were similar between groups although pregestaional diabetic patients had higher HbA1c rates. Therefore, patients with GDM (A2) should be followed up as closely as pregestational (overt) diabetic patients
Çeşitli Yüklemelere Maruz Bir Kirişin Evrimsel Yapi Optimizasyonu İle Tasarimi
Konferans Bildirisi -- Teorik ve Uygulamalı Mekanik Türk Milli Komitesi, 2008Conference Paper -- Theoretical and Applied Mechanical Turkish National Committee, 2008Xie ve Steven tarafından sayısal tabanlı yapısal topoloji optimizasyonu problemlerinin üstesinden gelebilmek için 1993 yılında evrimsel yapı optimizasyonu (ESO) yöntemi geliştirilmiştir. Bu yöntem, esasında basit bir temel üzerine oturtulmuş olmasına rağmen takip eden yıllarda farklı araştırmacılar tarafından yapılan katkılarla akademik başarı bir hayli yükseltilmiştir. Yapı tasarımlarını geliştirme ve en uygun hale getirme yönünden nispeten yeni bir tasarım aracı olan ESO, başlangıç tasarım alanındaki elemanların bir döngü içerisinde kademeli olarak kaldırıldığı buluşsal bir yöntemdir. Uygun bir tasarım elde edilene ya da istenilen belirli bir hacme ulaşılana dek bu işlemler devam ettirilmekte ve süreç sonunda elde edilen tasarımın uygulanabilirliği irdelenerek nihai karar verilmektedir. Bu çalışmada evrimsel yapı optimizasyonu yöntemine dayanan bir optimizasyon programı hazırlanarak muhtelif yüklemelere ve mesnet koşullarına maruz kirişlerin en uygun tasarımları aranmıştır. Çözülen problemlerden alınan sonuçlar, söz konusu yöntemin üstünlüklerini de gözler önüne serecektir. Optimizasyon programı, süreç kontrolünü artırmak amacıyla Maple’da hazırlanmış ve statik analiz için ise ANSYS kullanılmıştır. Yapıdaki von Mises gerilmeleri göz önünde bulundurularak gerçekleştirilen optimizasyon işlemleri sonucunda nispeten düzgün yayılı gerilme dağılımına maruz, kafes benzeri tasarımlara ulaşılmış ve elde edilen bu nihai tasarımlarda başlangıç hacmine göre %90’a varan oranlarda azalma görülmüştür.Evolutionary structural optimization (ESO) method has been presented by Xie and Steven in 1993 to deal with numerical structural topology optimization problems. Although this method is based on a simple idea, academic success towards ESO has been raised by the contributions of various researchers in the following years. ESO is a relatively new design tool used to improve and optimize the design of structures. It is a heuristic method where a few elements of an initial design domain of finite elements are iteratively removed. Such a process is carried out repeatedly until an optimum design is achieved, or until a desired given volume is reached and final decision is made by evaluating the applicability of the last design formed after the process. In this study, an optimization program performing evolutionary structural optimization has been coded and optimum design of beams under various loading and support conditions has been searched. The results of the solved problems will show the superiorities of this method. The optimization program has been coded in Maple to increase the control of process and ANSYS has been used for structural analysis. By the optimization progress, considering von Mises stresses of the structure, relatively fully stressed and trusslike designs have been achieved and however, the final designs have shown weight saving up to 90% compared to the initial designs
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THE PERCEIVED IMPACT OF NUCLEAR PLANT (NP) ON A TOURISM DESTINATION: A CASE OF MERSIN
This study is designed to examine the perception of residents, including second home owners of the province of Mersin about their general and tourism specific attitudes of the proposed nuclear power plant (NPP) location and assess the degree to which if there would be variations of perceptions within the local population about the construction of NPP. The study revealed that elder and more educated individuals have stronger opposition attitudes about the construction of the proposed NPP. However, the overall result indicates a matter of degrees of opposition that may need to be managed or mitigated should the project is implemented
A Rare Cause of Acute Abdomen in Children: Heterotopic Gastric Mucosa Located in the Ileum Mimicking Intussusception
Enhanced optical, structural and antibacterial properties of ZnO doped TiO2 composites
Bacterial infections are a common problem in daily life that can affect human
health. Researchers are looking for valuable materials that can help prevent
such infections and environmental pollutants. Thin films are a well-known
application for photocatalytic and biological activity. Therefore, thin-film
formation is an excellent way to address these problems, thanks to its
nanosized thickness and enhanced monolayer or multilayered structure. Titanium
oxide (TiO2) is the most common material used to produce thin films due to its
various traits that enhance the activity of thin films, such as structural and
optical properties. However, the single usage of pure TiO2 has certain
limitations over these problems. Therefore, new techniques, called doping, need
to be implemented to overcome these limitations. Doping is a standard method
for manipulating material properties to provide enhanced functionality. ZnO was
selected as a dopant because of its good bandgap energy and high electron
activity. Thus, this research mainly focused on the differences in
antibacterial, structural, and optical activity between pure TiO2 and ZnO-doped
TiO2. The sol-gel method was used in this research for several different
thin-film deposition methods due to its easy progression at room temperature,
low cost, and homogeneity traits. The antibacterial activity of pure and doped
TiO2 thin films was analyzed using the standard ISO 22196 protocol against
gram-positive Staphylococcus aureus and gram-negative Escherichia coli. As a
result, XRD and UV-vis spectrophotometer measurements show that our dopant ZnO
efficiently enhances the bandgap energy of pure TiO2. The correlation between
dispersibility and homogeneity was achieved in the concentration range ZTA-B-R
(5-10).Comment: 26 pages, 8 figure
Çevrimiçi öğrenme ve karma öğrenme öğrencilerinin teknoloji ile öz-yönelimli öğrenmeleri ve sorgulama topluluğu arasındaki ilişkinin incelenmesi: Yapısal eşitlik modeli
06.03.2018 tarihli ve 30352 sayılı Resmi Gazetede yayımlanan “Yükseköğretim Kanunu İle Bazı Kanun Ve Kanun Hükmünde Kararnamelerde Değişiklik Yapılması Hakkında Kanun” ile 18.06.2018 tarihli “Lisansüstü Tezlerin Elektronik Ortamda Toplanması, Düzenlenmesi ve Erişime Açılmasına İlişkin Yönerge” gereğince tam metin erişime açılmıştır.Bu araştırmada, Sakarya Üniversitesi çevrimiçi öğrenme ve karma öğrenme öğrencilerinin, teknoloji ile öz-yönelimli öğrenmeleri ile sorgulama topluluğu oluşumları arasındaki ilişkinin, yapısal eşitlik modeli kullanarak incelenmesi amaçlanmıştır. Öngörülen model, sorgulama topluluğu (sosyal bulunuşluk, öğretimsel bulunuşluk ve bilişsel bulunuşluk) ve teknoloji ile öz-yönelimli öğrenme arasındaki ilişkiyi açıklamıştır. Araştırmanın örneklemini, Sakarya Üniversitesinde 2013-2014 Bahar döneminde çevrimiçi öğrenme ve karma öğrenme programlarında kayıtlı 587 öğrenci oluşturmaktadır. Araştırmada örnekleme yöntemi olarak uygun örnekleme kullanılmıştır. Veri toplama araçları olarak beşli likert ölçekleri (Arbaugh v.d. (2008) tarafından geliştirilen 34 maddelik sorgulama topluluğu ölçeği; Türkçe'ye uyarlayan Horzum (baskıda) / Teo v.d. (2010) tarafından geliştirilen 6 maddelik teknoloji ile öz-yönelimli öğrenme ölçeği; Türkçe'ye uyarlayan Tercan v.d. (2014)) kullanılmıştır. Elde edilen veri yapısal eşitlik modellemesi ile analiz edilmiştir. Araştırma sonuçlarına göre teknoloji ile öz-yönelimli öğrenme, sosyal bulunuşluğun %63'ünü açıklamıştır. Sosyal bulunuşluk tek başına bilişsel bulunuşluğun %34'ünü açıklarken, teknoloji ile öz-yönelimli öğrenmenin dolaylı etkisi ile birlikte toplam %92'sini açıklamıştır. Sosyal bulunuşluluk öğretimsel bulunuşluğun %28'ini tek başına açıklarken teknoloji ile öz-yönelimli öğrenmenin dolaylı etkisi ile birlikte toplam %76'sını açıklamıştır. Anahtar Kelimeler: Sorgulama Topluluğu, Teknoloji İle Öz-Yönelimli Öğrenme, Yapısal Eşitlik ModeliThis research aimed to examine the relationship between self-directed learning with technology and community of inquiry in Sakarya University's online and blended learning students by using structural equation modeling. Proposed model explained the relationship between community of inquiry (social presence, teaching presence, and cognitive presence) and self-directed learning with technology. Sample of the study consisted of 587 students from online or blended learning students in Sakarya University in the spring semester of 2013-2014. Data have been collected by using convenience-sampling method. Data collection instruments were 5 points likert scales (34 items, community of inquiry instrument was developed by Arbaugh et. all (2008); adapted to Turkish by Horzum (in press) / 6 items, self directed learning with technology scale was developed by Teo et. all (2010), adapted to Turkish by Tercan et. al (2014)), and participants contributed to the study voluntarily. The collected data have been analyzed with structural equation modeling. The findings have shown that self-directed learning with technology explained 63% variance of social presence. Social presence explained 34% variance of cognitive presence alone. When self-directed learning with technology's indirect effect over social presence included, 92% variance of cognitive presence was explained by social presence. In addition, social presence explained 28% variance of teaching presence alone. When self-directed learning with technology's indirect effect over social presence included, 76% variance of teaching presence was explained by social presence. Keywords: Community Of Inquiry, Self-Directed Learning With Technology, Structural Equation Model
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