Browsing by Author "Mirtagioglu, Hamit"

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Evaluating the Relationship Between Mature Age Milk Yield and Several Traits Using Chaid Analysis in Brown Swiss Cows
(Medwell online, 2009) Bakir, Galip; Keskin, Siddik; Mirtagioglu, Hamit
Milk yield is important in breeding studies because it is one of the economically important traits. Therefore, determining the relationship between milk yield and some other traits could provide some important easiness in animal breeding studies. In this study, the aim was to evaluate the relationship between mature age milk yield and 9 independent variables (cow age, first mating age, lactation order, lactation period, dry period, first calving age, calving season, birth type and sex of calf) using CHAID analysis. Seven hundred and seventy Brown Swiss animals' records (from 1987-1997) taken from Mus State Production Farm (in Turkey) were utilized. CHAID analysis results showed that lactation period was primary, sex of calf and cow age were secondary and first mating age and dry period were the tertiary variables affecting mature age milk yield.
Type I Error Rates and Test Power for Some Outlier Detecting Tests
(Pushpa Publishing House, 2011) Yigit, Soner; Mendes, Mehmet; Mirtagioglu, Hamit
This study is conducted to compare some outlier detection tests such as Grubbs, Dixon, Chauvenet criterion and Weisberg t-test with respect to Type I error rate and test power. For this purpose, random numbers from normal population are generated by Monte Carlo simulation technique. Results of 50,000 simulation trials showed that the Weisberg t-test gave the most reliable results with respect to the others. Chauvenet criterion has followed this test. Dixon and Grubbs tests have not displayed reliable results except for studying with small sample sizes. As a result, regardless of the sample size being studied, Weisberg t-test should be used as detecting whether there is an outlier in the data set or not.