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Winter Squash and Pumpkins

Evranuz, EO | Arduzlar-Kagan, D


Comparing performances of clements, box-cox, johnson methods with weibull distributions for assessing process capability

Senvar, O. | Sennaroglu, B.

Article | 2016 | Journal of Industrial Engineering and Management9 ( 3 ) , pp.634 - 656

Purpose: This study examines Clements’ Approach (CA), Box-Cox transformation (BCT), and Johnson transformation (JT) methods for process capability assessments through Weibull-distributed data with different parameters to figure out the effects of the tail behaviours on process capability and compares their estimation performances in terms of accuracy and precision. Design/methodology/approach: Usage of process performance index (PPI) Ppu is handled for process capability analysis (PCA) because the comparison issues are performed through generating Weibull data without subgroups. Box plots, descriptive statistics, the root-mean-squar . . .e deviation (RMSD), which is used as a measure of error, and a radar chart are utilized all together for evaluating the performances of the methods. In addition, the bias of the estimated values is important as the efficiency measured by the mean square error. In this regard, Relative Bias (RB) and the Relative Root Mean Square Error (RRMSE) are also considered. Findings: The results reveal that the performance of a method is dependent on its capability to fit the tail behavior of the Weibull distribution and on targeted values of the PPIs. It is observed that the effect of tail behavior is more significant when the process is more capable. Research limitations/implications: Some other methods such as Weighted Variance method, which also give good results, were also conducted. However, we later realized that it would be confusing in terms of comparison issues between the methods for consistent interpretations. Practical implications: Weibull distribution covers a wide class of non-normal processes due to its capability to yield a variety of distinct curves based on its parameters. Weibull distributions are known to have significantly different tail behaviors, which greatly affects the process capability. In quality and reliability applications, they are widely used for the analyses of failure data in order to understand how items are failing or failures being occurred. Many academicians prefer the estimation of long term variation for process capability calculations although Process Capability Indices (PCIs) Cp and Cpk are widely used in literature. On the other hand, in industry, especially in automotive industry, the PPIs Pp and Ppk are used for the second type of estimations. Originality/value: Performance comparisons are performed through generating Weibull data without subgroups and for this reason, process performance indices (PPIs) are executed for computing process capability rather than process capability indices (PCIs). Box plots, descriptive statistics, the root-mean-square deviation (RMSD), which is used as a measure of error, and a radar chart are utilized all together for evaluating the performances of the methods. In addition, the bias of the estimated values is important as the efficiency measured by the mean square error. In this regard, Relative Bias (RB) and the Relative Root Mean Square Error (RRMSE) are also considered. To the best of our knowledge, all these issues including of execution of PPIs are performed all together for the first time in the literature. © 2016, Universitat Politecnica de Catalunya. All rights reserved Daha fazlası Daha az

Effects of Network Capabilities on Firm Performance across Cultures

Papastamatelou, J | Busch, R | Otken, B | Okan, EY | Gassemi, K



Ari, Y | Papadopoulos, A


Autoregressive conditionally heteroscedastic (ARCH) models are used to analyze empirical financial data and capture various stylized facts in financial econometrics. The procedure that is most commonly used for estimating the unknown parameters of an ARCH model is the maximum likelihood estimation (MLE). In this study, it is assumed that the parameters of the ARCH model are random variables having known prior probability density functions, and therefore they will be estimated using Bayesian methods. The Bayesian estimators are not in a closed form, and thus Lindley's approximation will be used to estimate them. The Bayesian estimato . . .rs are derived under squared error loss (SEL) and linear exponential (LINEX) loss functions. An example is given in order to illustrate the findings and furthermore, Monte Carlo simulations are performed in order to compare the ML estimates to the Bayesian ones. Finally, conclusions. on the findings are given Daha fazlası Daha az

An analysis on the dynamics of a marathon race and an estimate for the force exerted on a suspension bridge by a large group of runners

Akat, E.

Article | 2016 | Physics Essays29 ( 1 ) , pp.74 - 80

An estimate is obtained for the total force exerted on a suspension bridge in a marathon where thousands of people run at varying velocities. A distribution function n(v) is drawn that gives the number of runners n within possible velocity intervals as a function of velocity. Basic dynamical relationships are applied to the video images of some athletes running as models on the same treadmill one at a time (within a range of speeds) and the data of New York Marathon 2005 are used. The average load on such a bridge is also compared with that due to the everyday traffic. © 2016 Physics Essays Publication.

Age-Related Distribution of Basal Anti-Mullerian Hormone Levels in a Population of Infertile Women

Ozcan, P | Ficicioglu, C | Yesiladali, M | Devranoglu, B | Aydin, S | Batmaz, G

Article | 2016 | JOURNAL OF CLINICAL AND ANALYTICAL MEDICINE7 ( 3 ) , pp.355 - 358

Aim: We aimed to constitute age-specific reference serum values for anti-Mullerian Hormone (AMH) in women, and to analyze the distribution of basal serum AMH levels in Turkish women of reproductive age attending an infertility clinic to provide a framework for expected values according to age. Material and Method: Retrospective analysis of prospectively collected data on cycle day 2-3 serum AMH measurements of 409 women attending a single infertility unit in Turkey through a 12-month-period was performed. Results: Concentrations of serum AMH were shown to decrease with advancing age of the female partner. The mean age of the women w . . .as 34.04 +/- 5.39 years and the mean AMH level of the women was 1.77 +/- 1.82. The AMH levels were grouped according to age as follows: 20-24, 25-29, 30-34,35-39, and >40 years. The median AMH values were 2.16 ng/ml, 2.15 ng/ml, 1.71 ng/ml, 0.80 ng/ml, and 0.47 ng/ml, respectively according to the age groups. Discussion: The present data provide a framework for age-specific serum AMH levels in a Turkish population of infertile women Daha fazlası Daha az


Gurtueva, T

Article | 2016 | ART-SANAT , pp.599 - 603


Tahmazoğlu, Sultan Üzeltürk

Article | 2016 | Anayasa Hukuku Dergisi5 ( 9 ) , pp.13 - 54

Evaluation Of Demographic And Clinicopathological Characteristics Of Panreatic Adenocarcinoma Patients

Helvacı, Kaan | Üyetürk, Ümmügül | Sönmez, Özlem | Türker, İbrahim | Yalçıntaş, Ülkü Arslan

Article | 2016 | ACTA ONCOLOGICA TURCICA49 ( 2 ) , pp.91 - 101

AMAÇ: Pankreas kanserleri hastalarının tanı anında sadece %15-20'si cerrahi olarak çıkarılabilir aşamada olup %52'sinde yaygın hastalık %26'sında bölgesel yayılım mevcuttur (1). Pankreas kanserinin bir yıllık genel sağ kalım oranı %26, beş yıllık ise % 6'dır (2). Bu çalışmanın amacı Türkiye'de merkezi bir bölgede bulunan ve referans merkez olarak kabul edilen Ankara Onkoloji Eğitim Araştırma Hastanesi'ne başvuran pankreas adenokanserli hastaların klinikopatolojik özelliklerinin incelenmesidir. GEREÇ VE YÖNTEM: Çalışma için Ankara Onkoloji Eğitim ve Araştırma Hastanesi'nde 2007-2011 tarihleri arasında izlenmiş 121 erkek ve 72 kadında . . .n oluşan toplam 193 pankreas adenokanseri hastası retrospektif olarak tarandı. BULGULAR: Hastaların 26'sına (%13,5) küratif rezeksiyon uygulanmıştı, 54 hasta (%28) lokal ileri çıkarılamaz, 113 hasta ise (%58,5) metastatik evredeydi. Tüm grup için (n193) ortanca sağ kalım süresi 6 ay olarak bulundu. Yaşın, ortanca yaş olan 61 den büyük olması, ECOG performans durumunun 3 ve üzerinde değer olması, başlangıçta kilo kaybı olması, başlangıçta karın ağrısı olması, tümör gradının yüksek olması, tümörün lokal ileri veya metastatik olması, başlangıç metastaz bölgesinin periton veya karaciğer dışı olması, başlangıçta çoklu metastaza sahip olunması sağ kalıma anlamlı olumsuz yönde etkilemekteydi. Küratif opere edilen hastalar dışlanarak çıkarılamaz ve metastatik hastalar için bakılan CA19-9 değerinin ortanca değer olan 616'nın üzerinde olması kötü sağ kalım ile ilişkili idi (p0,021). Metastatik aşamada kemoterapi almış olmak en iyi destek tedavisine bariz olarak üstündü. Ortanca sağ kalım kemoterapi almayan kol için 1 ay (0,2-1,7) iken almış olan kolda 7 (4,7-9,3) ay idi (p0,0001). Lokal ileri çıkarılamaz grupta ise bu fark gösterilemedi. SONUÇ: Hastaların klinik ve demografik incelenmesi neticesinde daha önceden yapılmış çalışmalarla genellikle benzer sonuçlara ulaşılmıştır. Hastalardaki ortanca yaşın dünya ortancasına göre düşük olması, Türkiye'de sigaraya başlama yaşının daha erken olması ile ilişkili olabileceğini akla getirmektedir. Tedavi kararı verirken yaş durumundan çok performans durumuna ve evresine göre karar vermek akıllıca olacaktır. OBJECTIVE: In patients with pancreatic cancer twenty-six percent are locally advanced, 52% are metastatic and only 2015% are surgically removable at the time of diagnosis (1). One-year overall survival rate of pancreatic cancer is 26% while 5 year overall survival rate is only 6% (2) The aim of this study is to analyze the clinicopathological features of the pancreatic adenocarcinoma patients who admitted to the Ankara Oncology Training and Research hospital. METHODS: Total 193 pancreatic adenocarcinoma patients, including 72 women and 121 men, who were followed in Ankara Oncology Training and Research Hospital between dates 2007-2011, were evaluated retrospectively. RESULTS: Twenty-six of the patients (13,5%) had undergone curative resection, 54 patients (28%) with locally advanced disease were unresectable, while 113 patients (58,5%) had metastatic disease. For the entire group (n193), median survival time was 6 months. Older age (more than median "61"), low performance status (ECOG>3), weight loss or abdominal pain on admission, high grade tumor, locally advanced or metastatic disease, metastasis other than peritonea or liver, multiple metastases at the time of diagnosis were the parameters which significantly affect survival negatively. After excluding the curatively operated patients, high levels of Ca 19-9 (higher than median value:616) were associated with poor survival in patients with locally advanced or metastatic disease (p0,021). Chemotherapy was significantly superior to best supportive care in the metastatic disease. Median overall survival in patients treated with chemotherapy versus best supportive care was 7 months (4,7 to 9,3) and 1 month (0,2 to 1,7) respectively (p<0,0001). There was no significant difference in overall survival with chemotherapy versus best supportive care in locally advanced unresectable group. CONCLUSION: As a result of demographic and clinical examination of patients, we generally reached similar conclusions with previous studies. Low median age of the disease may be associated with an earlier age of onset of smoking in Turkey. It would be wise to consider performance status and stage of the disease rather than the age of the patient while making treatment decisions Daha fazlası Daha az


Aytekin, Sevgi | Dube, Sema

Article | 2016 | Elektronik Sosyal Bilimler Dergisi (elektronik)15 ( 59 ) , pp.1311 - 1326

Literatürde aylık veri kullanan bir çok çalışmanın Borsa İstanbul 100 endeksi, gösterge faizi, döviz kuru ve altın arasındaki ilişkilerle ilgili çelişkili sonuçlara ulaştığı görülmektedir. Bu çalışmada söz konusu değişkenler arasındaki etkileşimleri piyasaların dinamik karakteristiklerini daha iyi kapsayan günlük verilerle inceledik. Borsa İstanbul 100 endeksi yerine uluslararası piyasalarda daha çok takip edilen ve işlem gören Borsa İstanbul 30 endeksi beraberinde daha detaylı nedensellik analizleri uyguladık. Buna ek olarak, kriz dönemlerinde piyasalar arasında etkileşimlerin farklılaşabileceği nedeniyle, örneklem periyodumuzu son . . . küresel kriz dönemine, 2007-2012 yılları arasına kısıtladık. Çalışmamızdan elde edilen sonuçlar değişkenler arasında uzun vadeli ilişki olmadığını, fakat, etki-tepki ve nedensellik analizlerinin kısa vadeli dinamiklerin varlığına işaret ettiğini göstermektedir. Ayrıca, gelişmekte olan başka bir piyasa örneği olarak ve sonuçlarımızı karşılaştırmak üzere Hindistan hisse senedi piyasasını da inceledik. Several studies, using monthly data, find conflicting results for the relationships between BIST-100, benchmark rate, foreign exchange rate and gold data. We examine the relationship between these variables using daily data which may better capture dynamic characteristics of markets. We use BIST-30 which is more traded internationally, and use more detailed causality tests. We also restrict our study to the period around the global crisis 2007 - 2012 since intramarket dynamics may change characteristics during crisis periods. We find no long-term relationships but shortterm dynamics are shown to exist based on impulse response and causality tests. We also examine the Indian stock market as another example of emerging markets for comparison Daha fazlası Daha az

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