Browsing by Author "Ser, Gazel"

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Analysis of Random Intercept and Slope Model (Rism) for Data of Repeated Measures From Hy-Line White Laying Hens
(Zoological Soc Pakistan, 2016) Eyduran, Ecevit; Ser, Gazel; Cinli, Harun; Tirink, Cem; Yakar, Yasin; Duru, Metin; Tariq, Mohammad Masood
In animal science, sequential variation on quantitative traits during a certain time period should be precisely identified for regulating managerial conditions in animal experimental data. This study was conducted in order to investigate the effect of including some covariates on performance of covariance structures, fixed and random effects on the scope of random intercept and slope model (RISM) in order to improve model quality criteria. In repeated measurement data of laying hens, cumulative egg weight (CEW) per hen as a dependent variable was recorded per week, and treatment, time and treatment x time interaction effects were added as independent variables. Time effect was considered as a continuous variable in RISM. For better improving quality of RISM, feed intake (FT), feed conversation ratio (FCR), and egg mass (EGGM) per week were also included as covariates. Model quality criteria like-2 Res Log Likelihood, Akaike's Information Criterion (AIC), Bayesian Information Criterion (BIC), and Corrected Akaike's Information Criterion (AICC) criterion were used to identify best covariance structure among Compound Symmetry (CS), Heterogeneous Compound Symmetry (CSH), Unstructured (UN), First-Order Autoregressive (AR(1)), Unstructured correlation (UNR), Heterogeneous First-Order Autoregressive (ARH(1)), Toeplitz (TOEP) and Heterogeneous Toeplitz (TOEPH) with/without adding covariates. The explanation proportion of 90% in the dependent variable (CEW) was estimated for CSH, UNR, ARH(1), TOEPH, and UN as an outcome of adding covariates, which was prominently higher than the RISM without adding covariates. The significant differences in parameter estimates of fixed and random effects were recorded between the RISM with and without covariates. In repeated measures design, adding covariates in improving quality criteria of RISM could be recommended for data of laying hens
Application of Multiple Imputation Method for Missing Data Estimation
(Gazi Univ, 2012) Ser, Gazel
The existence of missing observation in the data collected particularly in different fields of study cause researchers to make incorrect decisions at analysis stage and in generalizations of the results. Problems and solutions which are possible to be encountered at the estimation stage of missing observations were emphasized in this study. In estimating the missing observations, missing observations were assumed to be missing at random and Markov Chain Monte Carlo technique and multiple imputation method were applied. Consequently, results of the multiple imputation performed after data set was logarithmically transformed produced the closest result to the original data.
Application of Quality Control Graphics and Shewhart Control Graphics in Milk Processing Plant
(2004) Ser, Gazel; Türkmut, Levent
Bu çalışmada, değişken nicelikler için kontrol grafikleri (Shewhart), birikimli toplam kontrol grafikleri (CUSUM) ve üstel ağırlıklı hareketli ortalama (EWMA) kontrol grafikleri, süreçte meydana gelebilecek hedef ortalamadan küçük ve büyük ölçekli kaymaları tespit etmek amacıyla kullanılmıştır. Bu kaymalar tespit edilmeden önce süreç boyunca kullanılacak kontrol sınırları hesaplanmıştır. Söz konusu çalışmada kullanılan süt örnekleri Tunceli ilinde bulunan Simge Süt İşletmesi'nden sağlanmıştır. Veri kümesi, günlük olarak ölçümlenen sütteki kalite özelliklerinden (kurumadde, asitlik (pH), yağ) oluşmuştur. Elde edilen veri kümesi, 100 günlük dönemi kapsamaktadır. Buna göre, veri seti beşer günlük dilimler şeklinde düzenlenmiş, günlük olarak her değişkene ait bir ölçüm değeri alınarak, kontrol tablolarına işlenmiş ve alt gruplar 20 haftadan oluşturulmuştur. Düzenlenen veri setine Shewhart kontrol grafikleri uygulanarak süreç hakkında bilgi edinilmiş ve geçici kontrol sınırları belirlenmiştir. Sonraki aşamalarda CUSUM ve EWMA kontrol grafikleri uygulanarak, süreçteki hedef ortalamadan sapmalar belirlenmiş üretim süreci için ileriye dönük tahminlemeler yapılmıştır. Çalışmada, değişkenler için kullanılan kontrol grafikleri uygulaması sonucunda 1 nokta hedef ortalamayı aşarak kontrol dışı sinyal vermektedir. CUSUM ve EWMA kontrol grafikleri uygulaması sonucunda 1 5 noktanın kontrol sınırlarını aşarak sürecin kontrol dışına çıktığı görülmüştür. Bu sonuçlar ışığında değişkenler için kontrol grafikleri, hedef ortalamadan büyük kaymaların tespitinde iyi sonuç verirken, hedef ortalamadan küçük kaymalarda ise CUSUM ve EWMA kontrol grafiklerinin daha hassas sonuçlar verdiği belirlenmiştir. Anahtar kelimeler: İstatistiksel kalite kontrolü, Süreç kontrolü, Kontrol grafikleri, Shewhart kontrol grafiği, CUSUM kontrol grafiği, EWMA kontrol grafiği
Aşırı Yayılımlı Veri Setinin Genelleştirilmiş Doğrusal Karışık Model Yaklaşımı Kullanılarak Değerlendirilmesi
(2016) Ser, Gazel; Yeşilova, Abdullah
Bu çalışmada, Poisson dağılımına sahip veri setlerinde sıkça karşılaşılan varyansın ortalamadan büyük olması durumunda ortaya çıkan, aşırı yayılım sorununun incelenmesi amaçlanmıştır. Çalışmada, Türkiye İstatistik Kurumundan (TÜİK) elde edilen 2010-2015 yılları arasında, 18 ildeki 6 aydan küçük oğlak varlığına ilişkin veriler kullanılmıştır. Veri setinde, aşırı yayılım sorununun incelenmesi amacıyla genelleştirilmiş doğrusal karışık model yaklaşımında, üç model algoritması oluşturulmuştur. Çalışma, iki aşamada gerçekleştirilmiştir. İlk aşamada, veri setinde aşırı yayılım durumu oluşturulan model algoritmasında belirlenmiş, ikinci aşamada ise aşırı yayılım sorununun giderilmesi amacıyla iki farklı model algoritması kullanılmıştır. Aşırı yayılım durumundan elde edilen standart hatalar, aşırı yayılımın giderildiği duruma göre daha küçük elde edilmiştir. Bununla beraber, oğlak varlığına ilişkin olarak aşırı yayılım durumunda, yıllar arasındaki farklılık oldukça önemli (p<0.0001) bulunurken, aşırı yayılımın olmadığı durumda, yılların etkisi önemsiz bulunmuştur.Sonuç olarak, aşırı yayılım sorununun göz ardı edilmesi durumunda elde edilen bulgular yanıltıcı olabilmektedir. Bu nedenle, genelleştirilmiş doğrusal karışık model yaklaşımında Poisson dağılımına alternatif olarak Negatif Binom dağılımının kullanılması ya da oluşturulan model algoritmalarında Poisson dağılımı varsayımı altında şansa bağlı etkilerin ilave edilmesi, aşırı yayılımın giderilmesinde etkili alternatif çözümler olarak belirlenmiştir.
Associations Between Cyp17 Gene Polymorphisms, Temperament and Maternal Behavior in Ewes, and Growth in Their Lambs
(Elsevier Science inc, 2021) Karaca, Serhat; Ser, Gazel; Ulker, Hasan; Yilmaz, Onur; Cakmakci, Cihan; Ata, Nezih; Saribey, Muammer
This study was conducted to determine temperament and maternal care classes, CYP17 gene polymor-phisms, and cortisol status of a group of Norduz ewes. Additionally, the relationships between these fac-tors, their effects on lambs survival and growth characteristics were investigated. A total of 72 ewes were subjected to arena and isolation box tests to determine their temperament classes. The distance the ewe retreated from the lamb during tagging was utilized to assess ewe maternal care classes. Ewes were genotyped for CYP17 628 SNP. Blood samples were collected between lambing and weaning to measure cortisol concentrations of ewes. The survival and growth data for the lambs of these ewes were recorded until weaning. Two temperament (low reactive and high reactive) and 2 maternal care classes (strong and moderate) were present. Two CYP 17 SNP 628 alleles (A and G) and 3 genotypes (AA, AG, and GG) were identified. For the distribution of CYP17 genotype frequencies within the population, the temperament or maternal care classes were not different (P > 0.05). The temperament of ewes did not affect mater-nal care in our flock. Positive partial correlations between cortisol and total cross, distance to stimulus, and sniffing were determined (P < 0.05). CYP17 genotype was an effective factor for some behavioral traits (i.e., total cross) and cortisol release (P < 0.001). Neither temperament (P = 0.636) nor maternal care classes (P = 0.985) differed with cortisol concentrations. CYP17 genotype, cortisol status, tempera-ment or maternal care class of ewes did not affect birth or weaning weight of their lambs (P > 0.05). Although there was no significant relationship among CYP17 genotype, maternal care, and lamb survival and growth, the effect of CYP17 genotype on some behavioral traits and cortisol release was found to be significant. Further studies with larger animal populations are required to elucidate the possible use of CYP17 SNP 628 genotypes as genetic markers for temperament classification. (c) 2021 Elsevier Inc. All rights reserved.
Determination of Appropriate Covariance Structures in Random Slope and Intercept Model Applied in Repeated Measures
(Pakistan Agricultural Scientists Forum, 2012) Ser, Gazel
This study aims to determine variance-covariance structures of dependent variable in data set containing repeated measures and to compare covariance parameter estimation methods. To this end, random intercept and slope model which is among the special cases of linear mixed model was formed and the time variable was involved into the model in a continuous and categorical manner. Also, compound symmetry (CS), toeplitz (TOEP), first-order autoregressive (AR(1)), homogeneous variance-covariance models and unstructured (UN), heterogeneous compound symmetry (CSH), heterogeneous toeplitz (TOEPH), heterogeneous first-order autoregressive (ARH(1)), first-order ante-dependence (ANTE(1)) and unstructured correlation (UNR) heterogeneous variance-covariance models were performed in order to determine the variance-covariance structure between the repeated measures. In addition, comparison of ML and REML was carried out as covariance parameter estimation method. Consequently, random intercept and slope model (RISM) was found to be the most appropriate one in modeling the repeated measure data when ML was used as the parameter estimation method and UN, CSH, ARH(1), TOEPH, ANTE(1), UNR as the covariance models.
The Effect of Feeding System on Slaughter-Carcass Characteristics, Meat Quality, and Fatty Acid Composition of Lambs
(Copernicus Gesellschaft Mbh, 2016) Karaca, Serhat; Yilmaz, Ayhan; Kor, Askin; Bingol, Mehmet; Cavidoglu, Isa; Ser, Gazel
In this study, we aimed to determine the slaughter-carcass characteristics, meat quality, and fatty acid composition in lambs raised under intensive and extensive conditions. The animal material consisted of 30 Norduz male lambs, with an average age of 171 days. The lambs were divided into two groups: concentrate-fed lambs (CO) and pasture-fed lambs (PS). The results showed that the CO lambs had heavier carcasses (p < 0.001), a higher dressing percentage (p < 0.001), and higher intramuscular fat (p < 0.01) than the PS lambs. It was determined that the longissimus thoracis muscle of the CO lambs had a lower ultimate pH and higher L* and water-holding capacity than the PS lambs. In this study, intramuscular fat (longissimus thoracis, semimembranosus, triceps brachii), subcutaneous and tail fat samples were used to evaluate the effect of feeding system on fatty acid composition. The polyunsaturated fatty acid to saturated fatty acid ratio (PUFA / SFA) of intramuscular fat was found to be significantly higher in the CO group than in the PS lambs, while similar subcutaneous and tail fat results were found in both groups. Moreover, the PS lambs had a lower n6 / n3 ratio and higher percentage of omega-3 than the CO lambs in all tissues studied (p < 0.05). Overall, the CO lambs have heavier and fattier carcasses with better meat quality traits than the PS lambs. However, the effects of feeding system have varying results based on the fatty acid composition of different types of fat deposits.
Effect of Maternal Experience and Body Condition on Patterns of Ewe-Lamb Bonding Behaviors and Pre-Weaning Growth Performance of Lambs
(Elsevier Science inc, 2023) Karaca, Serhat; Aydogdu, Neclan; Ser, Gazel
Many factors, involving parity and body condition can have a profound effect on physiological and sensory determinants of maternal behavior and, consequently, the establishment of the ewe-lamb bond. Thus, exploring the factors and their interactions that influence maternal behavior is critical to improve the overall lamb survival and welfare. The aim of this study was to determine the effects of parity and body condition score (BCS) on early ewe-lamb bonding behaviors and pre-weaning growth performance in lambs. The study was carried out with 12 first-parity (primiparous; PP), 12 second-parity (biparous: BP), and 14 third or more parity (multiparous: MP) Norduz ewes and 38 singleton lambs. In the study, ewe-lamb bonding behaviors were analyzed based on parity (PP, BP, and MP) and body condition score groups (BCS <= 3 and BCS > 3). Behaviors of ewes and lambs from each group were monitored for a period of 3 hours after parturition, and the ewe-lamb separation test was performed within the first 24 hours after parturition. Maternal behaviors such as latency to grooming, the number of low and high pitch bleats, and preventing sucking and neonatal behaviors such as latency to successful suck, the number of bleats and the total sucking duration were determined. The live weights of the lambs were recorded every 2 weeks until the 90th day. Ewes were grazed entirely on pasture without extra feed supplementation during the pasture season. Ewes were fed with alfalfa hay and gradually supplemented with barley and concentrate throughout the winter. While the grooming duration was not affected by parity, BCS > 3 ewes had longer grooming duration than BCS <= 3 ewes (P < 0.05). More prevention of sucking, butting, and low and high pitch bleating were counted for PP ewes than BP and MP ewes (P < 0.05). Parallel to these results, PP lambs had the longest latency to successful suck (P = 0.046) and the highest number of sucking attempts (P = 0.033). The mean sucking duration of MP lambs was significantly longer than PP lambs (P < 0.038). Birth weight of PP lambs was lower than MP lambs, but neither parity nor BCS had a significant effect on growth performance of lambs. In conclusion, the findings of the study showed that lack of maternal experience caused a negative effect on co-operation with lamb sucking attempts, but did not significantly affect growth performance. It can be suggested that BCS had little effect on maternal behavior and growth performance of lambs for ewes with a body condition score of 2.85-3.33 during the mating period. (c) 2023 Elsevier Inc. All rights reserved.
Effects of Some Factors on Growth of Lambs and the Determination of Growth Curve Models
(Agricultural Research Communication Centre, 2018) Yilmaz, Ayhan; Karakus, Ferda; Bingol, Mehmet; Kaki, Baris; Ser, Gazel
The aims were to identify the body weight of the several age groups in Norduz lambs and its correlations between these traits were to determine the best non-linear growth curve models for the growth performance of the Norduz sheep breed. A total of 91 male and female of Norduz lambs were evaluated under extensive system conditions. The least square means for weights at birth and at 15, 30, 45, 60, 75, 90, 105, 120, 135, 150, 165, 180, 195 and 210 days of age periods were 4.51 +/- 0.56, 9.28 +/- 0.25, 11.14 +/- 0.29, 14.99 +/- 0.37, 18.21 +/- 0.43, 22.54 +/- 0.54, 22.33 +/- 0.25, 23.59 +/- 0.54, 25.58 +/- 0.55, 28.07 +/- 0.58, 29.45 +/- 0.60, 29.98 +/- 0.84, 32.44 +/- 0.61, 32.03 +/- 0.59 and 31.45 +/- 0.57 kg, respectively. There were differences in favor of lambs of four-year old dams at 15 days of age and also lambs born single at 90 days of age for the body weight. The effect of weight of dam at birth, 30, 45, 60 days of age was significant (P<0.05-P<0.01) and the birth weight in lambs importantly effected the weights at 15, 30, and 45 days of age. All correlations between the body weights of several age periods were significant as statistical (P<0.01). As for the growth models, distinguished models were compared using the coefficient of determination and mean square error for both sexes. As a result, we concluded that von Bertalanffy model were the best model in comparison with the other models for biological growth curves in Norduz male and female lambs.
Evaluation of Machine Learning Hyperparameters Performance for Mice Protein Expression Data in Different Situations
(2021) Ser, Gazel; Bati, Cafer Tayyar
In this study, the aim was to assess the effect and significance of hyperparameters in four different datasets containing different values for observation numbers and variable counts with the machine-learning methods of support vector machines and artificial neural networks. With this aim, a dataset comprising 15 repeats of 77 protein levels from 38 healthy and 34 down syndrome mice was used. A total of 138 different models and model classification performance criteria were obtained from the datasets in the study comprising combinations of hyperparameters in machine-learning methods. Comparison of the models used criteria like accurate classification percentage, kappa statistic, mean absolute error and square root of mean error squares. According to performance criteria, the first dataset with 1080 observations x 77 variables had 71.30% accurate classification percentage for assumed parameters with the support vector machines polynomial kernel function, while changing the hyperparameter variables increased this rate to 99.44%. Similarly, the second dataset had 50.65% accurate classification percentage with the artificial neural network single hidden layer 2 neuron model, while changing the hyperparameter values increased this rate to 90.46%. In conclusion, in situations with low variable and observation numbers, the machine learning methods were determined to display lower performance. However, in datasets, it is very important for classification performance in artificial neural networks and support vector machines, especially polynomial and radial basis function kernel functions, to set hyperparameters according to the dataset. In situations with low variable numbers, especially, the effect of hyperparameters was determined to gain importance.
Evaluation of Parameter Estimation Methods for Determination of Covariance Structure in Repeated Data With Equal and Unequal Time Intervals
(Parlar Scientific Publications (p S P), 2018) Bati, Cafer Tayyar; Ser, Gazel
This study was completed with the aim of researching the effect of repeated measurement data with equal and unequal time intervals on the selection of the covariance structure and the parameter estimation methods of maximum likelihood (ML) and restricted maximum likelihood (REML). With this aim, blood glucose values took from the tail vein of 63 healthy rats administered plant extracts at varying rates over 21 days were used. Accordingly, while the most appropriate covariance structure was determined as Factor Analitic (FA(1)) for the data set at equal time intervals, the most appropriate covariance structure was determined as ANTE (1) for the dataset with unequal time intervals. There was no apparent difference difference determined for the performance of the parameter estimation methods of ML and REML for both data sets. In conclusion, while it is possible to try all homogeneous and heterogeneous variance-covariance structures to select the appropriate variance-covariance structure for equal time interval data sets, priority should be given to structures that take account of the time interval for unequal time interval data sets.
Evaluation of the Physiological and Behavioural Relationships of Yearling Bucks by Generalized Procrustes Analysis
(Publ House Bulgarian Acad Sci, 2022) Karaca, Serhat; Ser, Gazel
The aim of this study is to evaluate the relationships between some sexual behaviours and physiological traits such as serum testosterone concentration, body weight loss and presence of horns of yearling bucks using Generalized Procrustes Analysis (GPA). In the study, 11 yearling bucks being sexually inexperienced were used. The sexual behaviours were determined with a total of four tests, which consisted of exposing the yearling bucks individually to three unrestrained estrous ewes for 15 min. In these tests, some behavioural characteristics such as number of ejaculations, flehmen response, number of mounts and serum testosterone concentration were determined. In the GPA analysis, the first two factors explained approximately 98% of the total variation between animals (Dimension 1 = 95.57%, Dimension 2 = 2.68%). It was determined that there was a positive and high correlation between tests and the number of mounts, which had a high correlation with the first dimension. Ejaculation frequency, flehmen response and testosterone levels decreased in line with increases in the number of mounts. As a result, it can be suggested that GPA can be effectively evaluated quantitative and qualitative behavioural characteristics without requiring any prior assumptions and reducing variability among animals.
The Examination of Productivity of Healthcare Lesson at 9th Grade of High School by Using Multiple Correspondence Analysis
(2017) Apaydın, Hüseyin; Ser, Gazel
Apaydın H, Orta Öğretim Dokuzuncu Sınıflarda Sağlık Bilgisi Dersi Verimliliğinin Çoklu Uyum Analizi ile İncelenmesi. Van Yüzüncü Yıl Üniversitesi Sağlık Bilimleri Enstitüsü, Biyoistatistik Anabilim Dalı, Yüksek Lisans Tezi, Van, 2017. Sağlık bilgisi dersi koruyucu sağlık hizmetleri kapsamında öğrencilerin ve genel olarak toplumun sağlık bilinç düzeyini artırmak amacıyla dokuzuncu sınıflarda okutulan bir derstir. Bu tez çalışmasında, sağlık bilgisi dersinin verimliliği ile ilgili mevcut durumun tespiti ve verimliliği artırmaya yönelik planlanan anket çalışmasından elde edilen verilerin, çoklu uyum analizi ile değerlendirilmesi amaçlanmıştır. Çoklu uyum analizi tekniği ile çalışmada dikkate alınan değişkenler ve değişkenlerin kategorileri arasındaki ilişkiler belirlenmektedir. Çoklu uyum analizi yöntemi değişkenler arasındaki ilişkileri iki boyutlu bir uzayda grafiksel bir gösterim sağlayarak, değişik şekillerde incelenip yorumlanmasına olanak sağlamaktadır. Çalışmada anketler, Van merkezde rasgele alınan 32 lisede eğitim gören 530 öğrenci ve sağlık bilgisi dersini veren 75 öğretmene uygulanmıştır. Analiz sonucunda öğretmenlerin sağlık bilgisi dersinin öğrenciler tarafından zorunlu olarak alınması gereken bir ders olduğu, sağlık bilgisi dersini okutan öğretmenlere yönelik düzenlenen hizmet içi eğitimlerin yetersiz olduğu, Türkiye'de yürütülen sağlık eğitim çalışmalarının yeterli olmadığı, sağlık bilgisi ders saatinin bir saat olmasının öğretmenler tarafından yetersiz bulunduğu, okullarda yürütülen temizlik faaliyetlerinin daha nitelikli yapılması gerektiği, kız öğrencilerin sağlık bilgisi dersini erkek öğrencilere göre daha fazla önemsedikleri ve öğrenciler okullarda yürütülen temizlik faaliyetlerini yetersiz bulmuşlardır. Sonuç olarak, çoklu uyum analizi analitik olarak elde edilen sonuçların görsel olarak incelenmesine olanak sağlayabilmektedir. Böylece, söz konusu değişkenler arasındaki ilişkilerin daha detaylı bilgilere ulaşılmasına ve sonuçların daha kolay yorumlanmasına olanak sağlamaktadır. Bu nedenle, verilerin değerlendirilmesinde çoklu uyum analizi yönteminin kullanımı diğer alternatif yöntemlere göre daha çok tercih edilmesine olanak sağlamaktadır. Anahtar Kelimeler: Çoklu Uyum Analizi, Okul Sağlığı, Sağlık Bilgisi, Sağlık Eğitimi.
Examining of Multiple Imputation Method in Two Missing Observation Mechanisms
(Pakistan Agricultural Scientists Forum, 2016) Ser, Gazel; Keskin, Siddik
This study contains an examination of the missing data structures, occurring in many fields, especially in livestock. It also examines the processes to obtain the solution for the missing data. For this purpose, linolenic acid measurements obtained from four different anatomic regions of two animal species were taken as dependent variables. For the dependent variable, the observations were deleted at the ratio of 10% and 20%, creating the missing structures of missing completely at random (MCAR) and missing at random (MAR). Subsequently, these data sets were completed using multiple imputation (MI) method. Generalized Estimating Equation (GEE) and mixed model methods were used in the missing data structures and for the purpose of evaluating the data completed with MI. The study were obtained almost same results obtained from GEE and mixed model in the missing data structures. At the same time, there was not found difference between the methods in completed data using MI method. As a result, it is stated that valid results obtained in missing data structures by used GEE and mixed model analysis. When these results are also compared, it can be concluded that multiple imputation (with these ratio of missing) is not necessary before GEE and mixed model.
Extreme Variability Modelling of Overdispersed Germination Count Experiments
(inst investigaciones Agropecuarias - inia, 2022) Ser, Gazel
Germination tests are carried out for a wide variety of purposes in weed control. The variability in seed germination counts raises the overdispersion problem. The objective of this study is to compare different approaches used in solving overdispersion and to offer practical solutions to researchers. The data sets were created from seed germination counts, which examined the allelopathic effect of white cabbage (Brassica oleracea L. var. capitata L.) on the germination of some culture and weed seeds. Methanol and aqueous concentrations (30%, 40%, 50%) of dry and fresh white cabbage were used. Assuming the Poisson distribution in the generalized linear mixed model, overdispersion problem was determined in redroot pigweed (Amaranthus retroflexus L.), lamb's quarters (Chenopodium album L.) and sugar beet (Beta vulgaris L.) Equidispersion was determined in corn (Zea mays L.) and it was perfectly adapted to the Poisson distribution. In order to overcome the overdispersion problem, generalized Poisson distribution outperformed negative binomial distribution. The increase concentration in the generalized Poisson in weeds, fresh cabbage methanol and aqueous applications were very effective reducing germination (p < 0.05). The best results in weed seeds were obtained at 50%. Unlike weeds, 30% concentration of dry cabbage methanol and aqueous were considered as the upper limit in order not to adversely affect germination in Z. mays and B. vulgaris. Consequently, in germination tests, the problem of overdispersion is inevitable as a result of excessive variability. For germination count data, generalized Poisson distribution is viable option and powerful alternative to accurately describe mean-variance relationship.
Generalized Procrustes Analysis Method: an Application on Sensory Data
(2019) Aslan, İpek; Ser, Gazel
ÖZET GENELLEŞTİRİLMİŞ PROCRUSTES ANALİZ YÖNTEMİ: DUYUSAL VERİ ÜZERİNE BİR UYGULAMA ASLAN, İpek Yüksek Lisans Tezi, Zootekni Anabilim Dalı Tez Danışmanı Doç. Dr. Gazel SER Haziran 2019, 41 sayfa Bu çalışmada farklı besleme gruplarında yetiştirilen kuzuların et örnekleriyle, duyusal özellikleri arasındaki ilişkilerin Genelleştirilmiş Procructes Analiziyle (Generalized Procructes Analysis, GPA) değerlendirilmesi amaçlanmıştır. Duyusal analizde, et örneklerinin sululuk, lezzet, koku, yumuşaklık ve genel beğeniden oluşan özellikleri, 41 yarı-eğitimli panelist tarafından 1-9 arasında değişen hedonik skala ile değerlendirilmiştir. Buna göre, GPA analizinden elde edilen ilk iki faktör, et örneklerinin duyusal özellikleri arasındaki değişkenliğin yaklaşık % 76.74'ünü açıklamıştır. Toplam değişimin açıklanmasında en fazla katkıyı sağlayan ilk faktörün (% 40.72) oluşumunda, yumuşaklık, sululuk ve genel beğeni özellikleri önemli rol oynamıştır. Et örneklerine ilişkin hatalar genel olarak birbirine yakın bulunmuştur. Aynı zamanda, GPA'dan elde edilen uzlaşma konfigürasyon haritasında, panelistler tarafından et örneklerinin açıkça ayırımı yapılmıştır. Aynı zamanda, panelistlerin çoğunluğu duyusal özellikler bakımından et örnekleri arasında bir uzlaşma sağlamışlardır. Sonuç olarak, duyusal analiz testleri pek çok çalışmada referans metot olarak kullanılmaktadır. Bu nedenle duyusal analize katılan panelistlerin, panel davranışlarının incelenmesi ve panelistler arasındaki değişkenliğin azaltılmasında, GPA yöntemi etkili ve alternatif bir çözüm yolu sunmaktadır. Anahtar kelimeler: Procrustes analiz, Transformasyonlar, Uzlaşma haritası.
Generalized Procrustes Analysis Method: an Application on Sensory Data
(Kahramanmaras Sutcu Imam Univ Rektorlugu, 2022) Aslan, Ipek; Ser, Gazel
In this study, it was aimed at the evaluation of the relationships between lambs sensory properties and meat samples using with Genaralized Procructes Analysis (GPA). In sensory analysis, the characteristics of juiciness, flavor, odour, tenderness and overall liking of the meat samples were evaluated by hedonic scale ranging from 1-9 by 41 semi-trained panelists. Accordingly, the first two factors obtained from the GPA analysis explained approximately 76.74% of the variability between the sensory properties of the meat samples. The tenderness, juiciness and overall liking characteristics played an important role in the formation of the first factor which has the most contributed (40.72%) to the explaining of the total variation. Residuals of the meat samples were generally found close to each other. At the same time, the consensus configuration map obtained from the GPA of the meat samples has clearly distinguished by the panelists. However, the majority of panellists have provided a consensus between the meat samples in terms of sensory properties. As a result, GPA method provides an effective and alternative solution for the examine of the panel behavior and reducing the variability between panelists who are involved in the sensory
Improved Sheep Identification and Tracking Algorithm Based on Yolov5+sort Methods
(Springer London Ltd, 2024) Bati, Cafer Tayyar; Ser, Gazel
This research emphasises the importance of sheep identification and tracking in precision livestock farming and investigates the use of deep learning techniques for this purpose. Since traditional identification methods are time consuming and limiting, it is hypothesised that deep learning based models can make this process more efficient. However, although deep learning-based methods have achieved remarkable results in the field of animal recognition, some problems can be encountered that limit their practical application. Generally, these networks are tested on similar images taken from the dataset on which they are trained. Although the test performance of these models is high, they may perform poorly on images with different features. For this reason, in the present study on the YOLOv5 model, a number of effective preprocesses are included for the model's ability to identify and track sheep from sheep images with different traits from the training data. In addition, some adaptive adjustments were made to the YOLOv5 model to increase its effectiveness in practical applications. According to the experimental results of this study, in which videos of 20 Norduz sheep in the scale and arena tests were used, the YOLOv5l model trained on the scale test reached a mAP value of 0.99. Although the model performed the task of identifying and tracking the sheep in the scale test, it was observed that it could not perform the task of identifying and tracking the sheep in the arena test. Therefore, YOLOV5l (Model II), which was retrained on the scale images segmented from the background, gained the ability to identify and track the sheep in the arena test with some various pre-tuning. The findings of the study indicate the potential of deep learning-based models to improve the effectiveness of animal identification and tracking procedures in precision livestock farming. At the same time, the developmental stages outlined in this study provide a reference for the identification and tracking of sheep or alternative livestock in real-life situations.
Investigation of the Effects of Heat Stress on Milk Yield and Some Physiological Parameters in Dairy Cattle by Meta Analaysis Methods
(2021) Kulaz, Ersin; Ser, Gazel
Meta analizi, aynı amaçlar doğrultusunda farklı yer ve zamanlarda yapılan birbirinden bağımsız çalışma sonuçlarının uygun istatistiki yöntemlerle birleştiren ve ortak sonuçların elde edilmesine sağlayan bir yöntemdir. Bu çalışmada, süt sığırlarında sıcaklık stresinin süt verimi ile bazı fizyolojik parametreler (solunum sayısı, rektal sıcaklık ve deri sıcaklığı) üzerine olan etkisini meta analiziyle değerlendirilmesi amaçlanmıştır. Bu amaçla, 2010-2020 yılları arasında sıcaklık stresinin etkisinin belirlenmesinde önemli bir faktör olan sıcaklık nem indeks değerinin 72'den büyük olduğu ve belirlenen kriterlere göre uygun görülen 16 çalışmadan elde edilen sonuçlar meta analiziyle değerlendirilmiştir. Meta analizine dahil edilen çalışmalar belirlendikten ve veri organizasyonları yapıldıktan sonra, çalışmalar arasında yayın yanlılığının kontrolü ve birleştirme modelinin belirlenmesi amacıyla heterojenlik testleri yapılmıştır. Süt verimi ile solunum sayısı, rektal sıcaklık ve deri sıcaklığı fizyolojik parametrelerinde yayın yanlılığının olmadığı (p>0.05) ve çalışmalar arasında heterojenliğin anlamlı (p<0.001) olduğu belirlenmiştir. Heterojenliğin önemli çıkmasının sonucu olarak, çalışmaların birleştirme modeli şansa bağlı model olarak belirlenmiş ve yorumlamalar bu model üzerinden yapılmıştır. Modelden elde edilen sonuçlara göre; sıcaklık stresinin (SNİ>72) süt verimi, solunum sayısı, rektal sıcaklık ve deri sıcaklıkları üzerinde anlamlı etkiye sahip olmuştur (p<0.001). Sonuç olarak, şansa bağlı modelden elde edilen etki büyüklükleri tahminlerine göre sıcaklık stresinin solunum sayısı ve süt verimi üzerinde daha fazla olumsuz etkiye sahip olduğu tespit edilmiştir.
A Meta-Analysis of Heat Stress in Dairy Cattle: the Increase in Temperature Humidity Index Affects Both Milk Yield and Some Physiological Parameters
(Czech Academy Agricultural Sciences, 2022) Kulaz, Ersin; Ser, Gazel
In this study, the relationships of temperature humidity index (THI) with milk yield and some physiological responses in dairy cattle were investigated. Our goal in the meta-analysis was to find the parameter(s) primarily affected under heat stress. A total of 16 studies with the temperature humidity index value higher than 72, which is an important factor in determining the effect of heat stress, were included in the meta-analysis. The variables of interest in the meta-analysis included: milk yield (kg/day), respiratory rate (breaths/min), rectal temperature (??C). In addition to the meta-analysis, principal component analysis (PCA) was also performed. In the meta-analysis, high variation or heterogeneity (I2 99%) was determined between the results of the studies. This may depend on many factors (climate, region, number of samples and management etc.). Heterogeneity is desirable in the meta-analysis, because it provides accurate and reliable interpretations of the variances of parameters. Due to high heterogeneity, the results of the studies were combined according to the mixed model. According to the mixed model and PCA results, a linear relationship was determined between the temperature humidity index and these physiological parameters. According to the meta-analysis, at THI > 72, the mean effect size of milk yield was 50%, and the effect sizes of respiratory rate and rectal temperature were approximately 65% and 38%. All three parameters have a significant effect under heat stress (P < 0.000 1). As a result, there is a linear relationship between temperature humidity index, milk yield and physiological parameters. According to the other characteristics, the respiratory rate was determined as the primary response parameter in parallel with the increase in temperature humidity index.