Using reinforcement learning for dynamic link sharing problems under signaling constraints

Cataloged from PDF version of article.In static link sharing system, users are assigned a fixed bandwidth share of the link capacity irrespective of whether these users are active or not. On the other hand, dynamic link sharing refers to the process of dynamically allocating bandwidth to each active user based on the instantaneous utilization of the link. As an example, dynamic link sharing combined with rate adaptation capability of multimedia applications provides a novel quality of service (QoS) framework for HFC and broadband wireless networks. Frequent adjustment of the allocated bandwidth in dynamic link sharing, yields a scalability issue in the form of a significant amount of message distribution and processing power (i.e. signaling) in the shared link system. On the other hand, if the rate of applications is adjusted once for the highest loaded traffic conditions, a significant amount of bandwidth may be wasted depending on the actual traffic load. There is then a need for an optimal dynamic link sharing system that takes into account the tradeoff between signaling scalability and bandwidth efficiency. In this work, we introduce a Markov decision framework for the dynamic link sharing system, when the desired signaling rate is imposed as a constraint. Reinforcement learning methodology is adopted for the solution of this Markov decision problem, and the results demonstrate that the proposed method provides better bandwidth efficiency without violating the signaling rate requirement compared to other heuristics.Çelik, NuriM.S

AN INVESTIGATION OF THE RELATIONSHIP BETWEEN THE REACTION TIMES AND THE STATE AND TRAIT ANXIETY LEVELS OF THE ATHLETES

Besides supposing that the anxiety levels of the athletes have an impact on their performance it is also important to know the level of this impact. In this study it was aimed to investigate the relationship between the anxiety level and the sporting performance especially the reaction time which is the determinant of the speed requiring sudden movements. The study included 60 university students who participated voluntarily, were actively engaged in sports and were living in Esenyurt district of Istanbul. The average age of the participants was 20,68±2,33, their average height was 179,05±6,43cm, their average body weight was 75,55±9,32 kg and their average sport age was 6,31±3,23years. The State and Trait Anxiety Inventory (STAI) was used in the study in order to determinate and measure the state and trait anxiety levels of participants. The State and Trait Anxiety Inventory (STAI) was developed by Spielberger and his colleagues in 1970 and its reliability and validity study was carried out by Öner and La Compte by translating it into Turkish in 1983. The analyses of the obtained data were carried out with the SPSS Statistic 17.0 package program. The measurement results were given as mean (x) and as standard deviation (SD). Correlation and regression analysis were applied for the statistical evaluation of the data.  In the conducted study the state anxiety level of the athletes was detected to be  29,62±4,46 points, their trait anxiety level was 32,12±6,39 while their double hand reaction time was found to be 0,23±0,02 sec. A positive low level relationship was detected between the trait anxiety levels and the double hand reaction times of the athletes (r=,279,p<,05) while a positive and moderate level relationship was observed between the state anxiety level and the state anxiety level (r=,311, p<,016). Due to the fact that this research is a preliminary study done in the field of sport science, this study is considered to contribute to other studies planned to be done in the future. As a result, it was detected that with the increase in the anxiety level the response time given to an effect from any external factors lengthened. The fact that there was a low level positive relationship with the trait anxiety level revealed the conclusion that with the increase in the trait anxiety level, the reaction time also increases.  Article visualizations

Poliolefin modifiye bitümün Marshall stabilitesi üzerindeki etkisi

It is possible to improve the performance of the hot mix asphalt (HMA) by improving the properties of the materials (aggregate, bitumen) used in the HMA or by the addition of some special materials. In this study; polypropylene (PP) and high density polyethylene (HDPE) waste plastics were co–pyrolyzed at a temperature range of 300–350 °C. 2, 4, 5 and 6 % modified bitumen were made by using the solid product (char–additive) obtained from co–pyrolysis and pure 50/70 penetration grade bitumen. RV (rotational viscometer) tests were applied to pure and modified bitumens at different temperatures (60–165 °C) and the optimum rate of PP–HDPE additive was determined to be 5 %. Then; two different HMA sample series were prepared with Marshall apparatus using pure and 5 % PP–HDPE modified bitumen. For Marshall Mix design, sample series were formed at bitumen rates 3.5; 4; 4.5; 5 and 5.5 % and four HMA samples were produced at each bitumen rate. The samples were weighed in water, dry and saturated surface–dry. The heights of the samples were measured and the Marshall stability and flow values were determined by applying a load at a certain speed (50 mm/min). As a result; compared to the pure HMA, it was observed that the Marshall stability of the modified HMA increases between about 8.5 and 13 %.Bitümlü sıcak karışımda (BSK) kullanılan malzemelerin (agrega, bitüm) özelliklerini iyileştirerek veya bazı özel malzemeler ilave ederek, BSK’nın performansını artırmak mümkündür. Bu çalışmada; polipropilen (PP) ve yüksek yoğunluklu polietilen (YYPE) atık plastikleri 300–350 °C sıcaklık aralığında birlikte piroliz edildi. Pirolizden elde edilen katı ürün (çar–katkı maddesi) ve saf 50/70 penetrasyon dereceli bitüm kullanılarak, % 2, 4, 5 ve 6 oranlarında modifiye bitümler yapıldı. Saf ve modifiye bitümlere, farklı sıcaklıklarda (60–165 °C) RV (dönel viskozimetre) testleri uygulandı ve PP–YYPE katkısının optimum oranı % 5 olarak belirlendi. Sonra; saf ve % 5 PP–YYPE modifiye bitüm kullanılarak, Marshall aparatı ile iki farklı BSK numune serisi hazırlandı. Marshall karışım tasarımı için, % 3,5; 4,0; 4,5; 5,0 ve 5,5 bitüm oranlarında numune serileri oluşturuldu ve her bir bitüm oranında 4 BSK numunesi üretildi. Kuru ve doygun yüzey–kuru olarak tartılan numuneler, su içinde tartıldı. Numunelerin yükseklikleri ölçüldü ve belirli bir hızda (50 mm/dakika) bir yük uygulanarak, Marshall stabilite ve akma değerleri belirlendi. Sonuç olarak; saf BSK ile karşılaştırıldığında, modifiye BSK'nın Marshall stabilitesinin yaklaşık % 8,5 ila 13,0 arasında arttığı gözlenmiştir

Perspectives of Preservice Teachers on the Statements Related to Preservice Teachers and Competence of Lecturers

This study aims to find out the attitude of preservice teachers of Ağrı İ.Ç. University Faculty of Education who study at the Department of Elementary Turkish Education to the statements related to preservice teachers and competence of lecturers. A-) The statements related to preservice teachers includes following statements: “Productivity of the courses taken in the school enable them to understand the qualifications that a teacher must have.”, “Students take advantages of the education process which brings them sufficient teaching experience”, ”During their education, students experience many fascinating features related to teaching professions which they haven’t seen before.”, ”Opportunities and facilities that the students have in the school let them have rich variety of experiences related to communication with people.”, ”The students who have thought that they couldn’t be teacher understand they are in wrong to assume it after they experience teaching.” B-) The statements related to competence of lecturers includes following statements: “Lecturers have enough professional competence since they have received decent undergraduate education.”, “Lecturers can convey their knowledge to students by showing their class related to class management and employing different methods to teach since they don’t teach the lessons with the exception of their professional fields.”, “Lecturers can plan the teaching-learning process successfully thanks to their professional teaching knowledge.”, “Scientific dignity that the lecturers have thanks to their competence makes them reach the exemplary positions.”, “The high level of service delivery qualifications which the lecturers have thanks to their competence makes the students apply their knowledge to real life.” A questionnaire which includes questions related to A-) the statements related to preservice and B-) the statements related to competence of lecturers is conducted to determine the attitudes of preservice teachers towards. A-) The statements related to preservice teachers and B-) The statements related to competence of lecturers. The sample for the research is composed of 121 preservice teachers of Ağrı İ.Ç. University Faculty of Education who study at the Department of Elementary Turkish Education. According to the findings of the research; it is seen that the preservice teachers have answered the questions containing information on A-) the statements related to preservice and B-) the statements related to competence of lecturers with variable rates. The results which are mentioned above make it possible to come to that conclusion that preservice teachers have responded to questionnaire which is reliable according to its Cronbach’s Alpha value (α=0.91) in varying ratios (Field, 2013)

Synthesis, characterization of a new polyacrylic acid superabsorbent, some heavy metal ion sorption, the adsorption isotherms, and quantum chemical investigation

Poly(acrylic acid/Kryptofix 23-Dimethacrylate) superabsorbent polymer [P (AA/Kry23-DM) SAP] was synthesized by solution polymerization to remove Co, Ni, Cu, Cd, Mn, Zn, Pb, Cr, and Fe ions in water and improve the quality of the water. Kry23-DM cross-linker (1,4,7,13,16-Pentaoxa-10,19 diazo cyclohexene icosane di methacrylate) was synthesized using Kry23 and methacryloyl chloride. The characterization of the molecules was done by FTIR, TGA, DSC, and SEM techniques. The effects of parameters such as pH, concentration, and the metal ion interaction on the heavy metal ions uptaking of SAP was investigated. It was observed that P (AA/Kry23-DM) SAP has maximum water absorption, and the absorption increases with the pH increase. Adsorption rates and sorption capacity, desorption ratios, competitive sorption (qcs), and distribution coefficient (log D) of P(AA/Kry23-DM) SAP were studied as a function of time and pH with the heavy metal ion concentration. Langmuir and Freundlich isotherms of the P (AA/Kry23-DM) SAP were investigated to verify the metal uptake. Molecular mechanic (MM2), Assisted Model Building with Energy Refinement (AMBER), and optimized potentials for liquid simulations (OPLS) methods. were used in quantum chemical calculations for the conformational analysis of the cross-linker and the SAP. ∆H0 f calculations of the cross-linker and the superabsorbent were made using Austin Model 1(AM1) method. © 2020 by the authors. Licensee MDPI, Basel, Switzerland

Evaluation and management of neonatal onset hyperinsulinemic hypoglycemia: a single neonatal center experience

Objectives: To evaluate the clinical characteristics and treatment options of neonates requiring prolonged hospitalization due to persistent hyperinsulinemic hypoglycemia (HH). Methods: This retrospective cohort study included infants >34 weeks of gestation at birth who were born in our hospital between 2018 and 2021, diagnosed with HH, and required diazoxide within the first 28 days of life. The baseline clinical characteristics, age at the time of diagnosis and treatment options in diazoxide resistance cases were recorded. Genetic mutation analysis, if performed, was also included. Results: A total of 32 infants diagnosed with neonatal HH were followed up. Among the cohort, 25 infants were classified as having transient form of HH and seven infants were classified as having congenital hyperinsulinemic hypoglycemia (CHI). Thirty-one percent of the infants had no risk factors. The median birth weight was significantly higher in the CHI group, whereas no differences were found in other baseline characteristics. Patients diagnosed with CHI required higher glucose infusion rate, higher doses, and longer duration of diazoxide treatment than those in the transient HH group. Eight patients were resistant to diazoxide, and six of them required treatment with octreotide and finally sirolimus. Sirolimus prevented the need of pancreatectomy in five of six patients without causing major side effects. Homozygous mutations in the ABCC8 gene were found in four patients with CHI. Conclusions: The risk of persistent neonatal hyperinsulinism should be considered in hypoglycemic neonates particularly located in regions with high rates of consanguinity. Our study demonstrated sirolimus as an effective treatment option in avoiding pancreatectomy in severe cases

The relationship between Turkish junior national judo team athletes’ social values beliefs and self-esteem levelsTürk genç milli judo takım sporcularının sosyal değer inançları ile özsaygı seviyeleri arasındaki ilişki

The purpose of this study was to investigate the relationship between the self-esteem and the social value size of national youth judo team athletes. Data were collected by Coopersmith Self-Esteem Inventory adapted to Turkish by Özoğlu (1988) and Multidimensional Social Values Scale developed by Yavuz Bolat (2013) with a questionnaire developed by the researchers to gather personal information. Working group of the research consist of Turkish youths (15-19 years old) are struggling in national judo team between 2015-2016 year in a total 118 athletes including 58 women and 60 men. Data were analysed by using SPSS 20 statistical programme, with oneway anova test. Results showed that there is a positive relation between the selfesteem and the social value size that family values, religious values, traditional values, scientific values but political values  have not found a significant relationship between self-esteem. As a result of that social value perceptions effect on self-esteem levels of young national judoka and that correlates positively with each other. ÖzetBu araştırmanın amacı genç milli judo takım sporcularının sahip oldukları sosyal değer boyutları ile özsaygı düzeyleri arasındaki ilişkiyi incelemektir. Katılımcıların sosyal değer boyutlarının ve özsaygı düzeylerini belirlemek için araştırmacılar tarafından geliştirilen Kişisel Bilgi Formu ve Coopersmith (1959) tarafından geliştirilen, ülkemizde Özoğlu (1988) tarafından geçerlilik ve güvenilirlik çalışması yapılan ‘Benlik Saygısı Envanteri (Coopersmith Self-Esteem Inventory) ve Yavuz Bolat (2013) tarafından geliştirilen Çok Boyutlu Sosyal Değerler Ölçeği (Multidimensional Social Values Scale ) uygulanmıştır. Araştırmanın çalışma grubunu 2015-2016 yılları arasında Türk genç (15-19 yaş arası) milli judo takımında mücadele eden 58 kadın 60 erkek olmak üzere toplam 118 sporcu oluşturmaktadır. Araştırmanın verileri SPSS 20 istatistik programı kullanılarak, çözümlemeler için oneway anova testi kullanılmıştır. Elde edilen bulgularda sosyal değer boyutları olan aile değerleri, dini değerler, geleneksel değerler, bilimsel değerler ve çalışma değerleri ile özsaygı düzeyleri arasında pozitif yönlü anlamlı bir ilişkiye rastlanırken siyasi değerler ve boyutu ile özsaygı arasında anlamlı bir ilişkiye rastlanmamıştır. Sonuç olarak genç milli judocularda sosyal değer algılarının özsaygı seviyeleri üzerine etkisinin olduğu ve birbirleri ile pozitif yönde paralellik gösterdiği söylenebilir

Self-organizing maps with sliding window (SOM+SW)

SOM je popularan algoritam umjetne neuronske mreže za obavljanje racionalnog grupiranja na mnogim različitim skupovima podataka. Postoji nedostatak SOM-e koja se može izvoditi na unaprijed definiranom dovršenom skupu podataka. Na vremenskim tokovima skupova podataka pojavljuju se razni problemi prilikom grupiranja pomoću standardne SOM-e jer se vremenski tokovi podataka generiraju ovisno o vremenu. U ovoj studiji značajka kliznog prozora uključena je u standardnu SOM-u za grupiranje vremenskih tokova podataka. Stoga, kombinacija SOM i kliznog prozora (SOM + SW) daje točnije rezultate prilikom grupiranja podataka na vremenskom toku skupova podataka. Da bi se to dokazalo, testiran je skup podataka o uporabi interneta mobilnog operatora u Turskoj. Uzeti skup podataka mobilnog operatera grupiran je prema klasičnoj SOM-i, a zatim je procijenjena buduća uporaba podataka pretplatnika. Isti skup podataka primijenjen je na SOM + SW za izvođenje istih simulacija.SOM is a popular artificial neural network algorithm to perform rational clustering on many different data sets. There is a disadvantage of the SOM that can run on a predefined completed data set. Various problems are encountered on a time-stream data sets when clustering by using standard SOM since the time-stream data sets are generated dependent on time. In this study, the Sliding Window feature is included into standard SOM for clustering time-stream data sets. Thus, the combination of SOM and Sliding Window (SOM + SW) gives more accurate results when clustering on time-stream data sets. To prove this, a set of internet usage data from a mobile operator in Turkey is taken to test. The taken data set from the mobile operator is clustered according to the classical SOM then the future data usages of subscribers are estimated. The same data set is applied on the SOM + SW to perform the same simulations

Cryobiology and Cryopreservation of Sperm

Low temperature has been utilized to keep living cells and tissues dormant but potentially alive for cryopreservation and biobanking with great impacts on scientific and biomedical applications. However, there is a critical contradiction between the purpose of the cryopreservation and experimental findings: the cryopreserved cells and tissues can be fatally damaged by the cryopreservation process itself. Contrary to popular belief, the challenge to the life of living cells and tissues during the cryopreservation is not their ability to endure storage at cryogenic temperatures (below −190°C); rather it is the lethality associated with mass and energy transport within an intermediate zone of low temperature (−15 to −130°C) that a cell must traverse twice, once during cooling and once during warming. This chapter will focus on (1) the mechanisms of cryoinjury and cryopretection of human sperm in cryopreservation, and (2) cryopreservation techniques and methods developed based on the understanding of the above mechanisms

Vacuum-assisted stereotactic biopsy for isolated BI-RADS 4 microcalcifications: evaluation with histopathology and midterm follow-up results

PURPOSEThe aim of this study was to evaluate the 10-gauge vacuum-assisted stereotactic biopsy (VASB) of isolated Breast Imaging Reporting and Data System (BI-RADS) 4 microcalcifications, using histology and follow-up results.METHODSFrom January 2011 to June 2013, VASB was performed on 132 lesions, and 66 microcalcification-only lesions of BI-RADS 4 were included into our study. VASB was performed using lateral decubitis stereotaxy for all patients. Pathologic results of VASB and further surgical biopsies were reviewed retrospectively. Patients who were diagnosed to have benign lesions by VASB were referred for follow-up. VASB and surgical histopathology results were compared to determine the underestimation ratios.RESULTSFifteen out of 66 lesions from 63 patients (median age, 47 years; range, 34–88 years) were identified as malignant by VASB. Pathological results after surgery revealed three cases of invasive ductal carcinoma among the 12 VASB-diagnosed ductal carcinoma in situ (DCIS) lesions, for a DCIS underestimation rate of 25%. The atypical ductal hyperplasia underestimation rate was 0% for the three lesions. The follow-up period was at least 10 months, with an average of 22.7 months for all patients and 21.2 months for patients with VASB-diagnosed benign lesions. None of the patients had malignancy during the follow-ups. The false-negative rate was 0% in the follow-up of 48 patients. CONCLUSIONVASB should be the standard method of choice for BI-RADS 4 microcalcifications. This method obviates the need for a surgical procedure in 73% of BI-RADS 4 microcalcification-only patients