Robust ratio-type estimators in simple random sampling

Evrim Oral,Cem Kadilar 한국통계학회 2011 Journal of the Korean Statistical Society Vol.40 No.4

In sampling theory, ratio-type estimators are extensively used to estimate the population mean when the correlation between study and auxiliary variables is positively high. In this study, we incorporate robust modified maximum likelihood estimators (MMLEs)into Kadilar–Cingi estimators and provide their properties theoretically. We support the theoretical results with simulations under numerous super-population models, and study the robustness properties of these modified estimators. We show that utilization of MMLEs in estimating the mean of a finite population leads to robust estimates, which is very advantageous when we have non-normality or other common data anomalies such as outliers.

5-Hydroxymethylfurfural (HMF) formation during subcritical water extraction

Evrim O¨ zkaynak Kanmaz 한국식품과학회 2018 Food Science and Biotechnology Vol.27 No.4

The aim of this study was to investigate the effect of material type (artichoke leave, lemon peel, flaxseed meal), extraction temperature (50, 100, 120, 140, 160, 180, 200 C) and static extraction time (5, 15, 30, 45 min) on 5-hydroxymethylfurfural (5-HMF) formation during subcritical water extraction. 5-HMF content of artichoke leave and lemon peel extracts increased 7.2 and 26.1 times with the rise of extraction temperature from 160 to 180 C for 5 min during subcritical water extraction, respectively. Besides, 5-HMF content of artichoke leave, lemon peel and flaxseed meal extracts increased 1.4, 2.0 and 4.5 times as static extraction time increased from 15 to 45 min at 180 C during subcritical water extraction, respectively. The highest 5-HMF content of artichoke leave and lemon peel extracts were obtained as 58.83 and 231.21 mg/L at 180 C and 45 min, respectively. However, for flaxseed meal, the highest 5-HMF content (222.94 mg/L) was obtained at 200 C and 15 min during subcritical water extraction.

Anti-corrosive properties of polyaniline, poly(2-toluidine) and poly(aniline-co-2-toluidine) coatings on stainless steel

Evrim Hur,Gozen Bereket,Yucel Sahin 한국물리학회 2007 Current Applied Physics Vol.7 No.6

This study examines the use of polyaniline (PANi), poly(2-toluidine) (PT), and poly(aniline-co-2-toluidine) (co-PT) for corrosion pro-tection of 304-stainless steel (SS) in 0.5 M HCl solution. The PANi, PT, and co-PT coatings were synthesized on SS substrates underand perchloric acid (HClO4) as acid. These coatings were characterized by CV, FTIR, and UVvis spectroscopy. The ability of PANi,PT, and co-PT to serve as corrosion protective coatings for SS was examined by open circuit potential-time (Eocp-time), potentiodynamicpolarization, and electrochemical impedance spectroscopy (EIS) measurements. The results of this study reveal that PANi, PT, and co-PT acts as corrosion protective coatings on SS and every coating gives protection eciency of greater than 80% after 48 h of immersion.

Effects of the carbon nanotube and polymer amounts on ultrafiltration membranes

Evrim Celik Madenli,Zeliha Ilkay Ciftci 대한환경공학회 2022 Environmental Engineering Research Vol.27 No.4

Composite membranes with nano-sized inorganic materials have high selectivity, high hydrophilicity, and improved fouling resistance. Blending Carbon Nanotubes (CNTs) in the polymer solution improves membrane properties like hydrophilicity, water permeability, selectivity, and fouling resistance. The effect of the polymer amount, together with the CNT amount in the polymer solution on membrane properties, was investigated in this work. There was more than 10% increase in the hydrophilicity of the membranes with 1% CNT addition, but it was not altered with the polymer amount. The porosity was increased almost 30% by 1% CNT addition in membranes prepared by 10% and 12% polymer concentration (P-10:C-0 and P-12:C-0), but only 16% increase in porosity occurred in membrane prepared by 15% polymer concentration (P-15:C-0). The flux of the P-15:C-0 membrane was increased four times by 1% CNT addition. Besides, fouling resistance of the membranes decreased with increasing polymer amount but increased with increasing CNT amount. BSA rejection increased with increasing polymer amount or CNT amount in the polymer solution. Hence membranes prepared with a higher amount of polymer are more prone to membrane property improvements with CNT addition. The increase in flux and selectivity by CNT addition in all membranes prepared with different polymer concentrations will increase the membrane life-time and reduce the treatment cost.

Timing of Thoracic Radiotherapy in Limited Stage Small Cell Lung Cancer: Results of Early Versus Late Irradiation from a Single Institution in Turkey

Bayman, Evrim,Etiz, Durmus,Akcay, Melek,Ak, Guntulu Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.15

Background: It is standard treatment to combine chemotherapy (CT) and thoracic radiotherapy (TRT) in treating patients with limited stage small cell lung cancer (LS-SCLC). However, optimal timing of TRT is unclear. We here evaluated the survival impact of early versus late TRT in patients with LS-SCLC. Materials and Methods: Follow-up was retrospectively analyzed for seventy consecutive LS-SCLC patients who had successfully completed chemo-TRT between January 2006 and January 2012. Patients received TRT after either 1 to 2 cycles of CT (early TRT) or after 3 to 6 cycles of CT (late TRT). Survival and response rates were evaluated using the Kaplan-Meier method and comparisons were made using the multivariate Cox regression test. Results: Median follow-up was 24 (5 to 57) months. Carboplatin+etoposide was the most frequent induction CT (59%). Median overall, disease free, and metastasis free survivals in all patients were 15 (5 to 57), 5 (0 to 48) and 11 (3 to 57) months respectively. Late TRT was superior to early TRT group in terms of response rate (p=0.05). 3 year overall survival (OS) rates in late versus early TRT groups were 31% versus 17%, respectively (p=0.03). Early TRT (p=0.03), and incomplete response to TRT (p=0.004) were negative predictors of OS. Significant positive prognostic factors for distant metastasis free survival were late TRT (p=0.03), and use of PCI (p=0.01). Use of carboplatin versus cisplatin for induction CT had no significant impact on OS (p=0.634), DFS (p=0.727), and MFS (p=0.309). Conclusions: Late TRT appeared to be superior to early TRT in LS-SCLC treatment in terms of complete response, OS and DMFS. Carboplatin or cisplatin can be combined with etoposide in the induction CT owing to similar survival outcomes.

Effects of Definitive Chemoradiotherapy on Respiratory Function Tests and Quality of Life Scores During Treatment of Lung Cancer

Duman, Evrim,Yildirim, Mustafa,Kaya, Vildan,Ozturk, Duriye,Inal, Aysun,Akarsu, Zeynep,Gunduz, Seyda,Yildiz, Mustafa Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.15

Background: Chemoradiotherapy is an important treatment modality for lung cancers. The aim of this study was to investigate alterations in, as well as the interrelationship between, lung function and quality of life of patients receiving chemoradiotherapy due to locally advanced non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC) limited to the thorax. Materials and Methods: The study included patients receiving definitive chemoradiotherapy for lung carcinoma. The respiratory function of the patients was assessed by measuring forced expiratory volume in 1 s per unit (FEV1) and forced expiratory volume in 1s per unit of vital capacity (FEV1/VC) before, in the middle of and after treatment. During the study, EORTC QLQ C30 and LC13 questionnaires developed by the Committee of the European Organization for Research and Treatment of Cancer (EORTC) were employed to evaluate the quality of life on the same day as respiratory function tests (RFT). Findings: The study included 23 patients in total: 19 (82.6%) diagnosed with NSCLC and 4 (17.4%) with SCLC. The average percentage FEV1 was $55.6{\pm}21.8%$ in the pre-treatment period, $56.2{\pm}19.2%$ in the middle of treatment and $60.4{\pm}22%$ at the end of treatment. The improvement in functional scores, symptom scores and general health scores during treatment was not statistically significant (P= 0.568, P= 0.734, P= 0.680, P=0.757 respectively). Conclusions: Although this study showed an improvement in respiratory function and quality of life of patients during treatment with thoracic chemoradiotherapy, no statistically significant results were obtained. While evaluating the effectiveness of treatments for lung carcinoma, the effects of treatment on respiratory function and quality of life should be considered.

Decrease trends of ultimate loads of eccentrically loaded model strip footings close to a slope

Cure, Evrim,Sadoglu, Erol,Turker, Emel,Uzuner, Bayram Ali Techno-Press 2014 Geomechanics & engineering Vol.6 No.5

A series of bearing capacity tests was conducted with eccentrically loaded model surface and shallow strip footings resting close to a slope to investigate behavior of such footings (ultimate loads, failure surfaces, load-displacement curves, rotation of footing, etc.). Ultimate loads of footing close to slope decreased with increasing eccentricity for both surface and shallow footings. Failure surfaces were not symmetrical, primary failure surfaces occurred on the eccentricity side (the slope side) and secondary failure surfaces occurred on the other side. Lengths of failure surfaces decreased with increasing eccentricity. Footings always rotated towards eccentricity side a few degrees. For eccentrically loaded footing, decrease in ultimate load with increasing eccentricity is roughly in agreement with Customary Analysis.

Prognostic Value of Osteopontin in Patients Treated with Primary Radiotherapy for Head and Neck Cancer

Etiz, Durmus,Ataizi, Fulya Colak,Bayman, Evrim,Akcay, Melek,Acikalin, Mustafa Fuat,Colak, Ertugrul,Ciftci, Evrim Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.9

Background: The prognostic value of tumor osteopontin (OPN) in patients with squamous-cell head and neck cancer (SCHNC) was investigated. Materials and Methods: OPN expression was assessed by immunohistochemical methods in 50 patients, who were treated with primary radiotherapy (RT) for locally advanced SCHNC. The effects of OPN on clinical parameters, local-regional control after RT and metastasis-free survival, was assessed. Results: The rate of OPN expression in tumor tissue was 76%. OPN positive cases had lower Hb levels (p=0.088). Mean time to local recurrence was 53.8 months (SE 3.9) in OPN-negative cases and 39.1 months (SE 4.7) in OPN-positive cases (p=0.047). OPN increased the risk of local recurrence 5.9 times (p=0.085). It had no effect on metastasis-free (p=0.116) or overall survival (p=0.123). OPN was positive in 12 of 19 cases that developed grade 3-4 acute radiation dermatitis (p=0.096). Conclusions: OPN expression is associated with an increase in local recurrence in patients who were treated with primary RT for locally advanced SCHNC.

한·터 증거성 표현 대조 연구

에브렌셀 펠린 에브림(Evrensel Pelin Evrim) 우리말학회 2019 우리말연구 Vol.59 No.-

본 논문은 한국어와 터키어 두 언어의 증거성 표현을 대조적 관점에서 접근하고, 터키인 한국어 학습자들이 한국어 학습에 주는 시사점을 제시하였다. 본고에서는 한국어의 증거성 표지를 직·간접 증거로 분류되어, 직접증거 표지에는 ‘–더, -네, -길래’ 등, 추론을 통해 얻은 정보를 경우 ‘–겠-, –나/은가 보-, -을/은 모양이-’ 등, 전언 표지에는 ‘–다(고 하)-’ 등을 분석했다. 한국어 증거성 체계는 정보를 획득한 주체와 정보를 획득한 방법으로 나누어져 있으며, 정보를 획득한 주체가 화자인 경우와 화자가 아닌 다른 사람으로부터 들은 것을 엄격히 구분한다. 아울러 직접 지각하여 정보를 획득하는 것과 추론을 통해서 정보를 획득하는 경우로 나누며 이를 표현하는 형태들이 잘 발달되어 있다. 반면, 터키어에서는 과거 시제의 어미인 ‘-mIş-’가 유일하다. 터키어에서는 ‘-mIş-’는 기본적으로 과거의 의미를 나타내는데 양태와 증거성을 나타내는 측면에서 한국어와 달리 하나의 행태로서의 화자가 직접적으로 정보를 얻거나 추론을 통해 얻거나 또는 타인한테 들어서 알게 된 정보를 얻을 때도 쓰인다. 한국어의 증거성 어미들이 의미와 기능면에서 유사점을 가지고 있어서, 터키인 한국어 학습자는 증거성 어미의 의미와 사용을 이해하고 구별하는 데 어려움을 겪는다. This paper analyzises the expression of evidence in both Korean and Turkish languages from a contrasting point of view, and puts forward the implications that Turkish learners of Korean language have suggested Korean language learning. In this paper, evidence markers in Korean were classified as direct and indirect evidence, and the direct evidence markers were analyzed ‘te, -ney and killay’ as direct evidential markers and for information obtained through inference ‘-keyss-, -ul kesi-, -na/unka po-’ and ‘–ul/un moyangi-’, and for information obtained through hearsay ‘–ta(ko ha)’. The Korean evidence system is divided into the method who obtained the information and the method by which the information was obtained. First of all, strictly distinguishes between speaker has obtained the information and those who have heard it from someone else. In addition, the forms of expressing information are well developed by dividing it into those directly perceived to obtain information and those obtained through inference. On the other hand, ‘-mIş-’ the past tense, is the only Turkish ending. In Turkish, ‘-mIş-’ not only represents the meaning of the past, but it can also represent modalities and evidence. The main view about the‘-mIş-’ that speaker s belief in the content of the proposition can express directly or indirectly. The similarity between the meaning and function of the Korean language s endings, the Turkish learner has difficulty understanding and distinguishing the meaning and use of them.

Limited field adaptive radiotherapy for glioblastoma: changes in target volume and organ at risk doses

Öznur Şenkesen,Evrim Tezcanlı,Mehmet Ufuk Abacıoğlu,Zeynep Özen,Derya Çöne,Halil Küçücük,Evren Ozan Göksel,Alptekin Arifoğlu,Meriç Şengöz 대한방사선종양학회 2022 Radiation Oncology Journal Vol.40 No.1

Objective: This study aimed to investigate the tumor volume changes occurring during limited-field radiotherapy (RT) for glioblastoma patients and whether a volume-adapted boost planning approach provided any benefit on tumor coverage and normal tissue sparing. Materials and Methods: Twenty-four patients underwent simulation with magnetic resonance (MR) and computed tomography (CT) scans prior to RT (MR_initial, CT_initial) and boost treatment (MR_adapt, CT_adapt). For the boost phase, MR_initial and MR_adapt images were used to delineate GTV2 and GTV2_adapt, respectively. An initial boost plan (Plan_initial) created on CT_initial for PTV2 was then reoptimized on CT_adapt by keeping the same optimization and normalization values. Plan_adapt was generated on CT_adapt for PTV2_adapt volume. Dose volume histogram parameters for target volumes and organs-at-risk were compared using these boost plans generated on CT_adapt. Plan_initial and Plan_adaptive boost plans were summed with the first phase plan and the effect on the total dose was investigated. Results: Target volume expansion was noted in 21% of patients while 79% had shrinkage. The average difference for the initial and adaptive gross tumor volume (GTV), clinical target volume (CTV), and planning target volume (PTV) volumes were statistically significant. Maximum dose differences for brainstem and optic chiasm were significant. Healthy brain tissue V10 and ipsilateral optic nerve maximum doses were found to decrease significantly in Plan_adaptive. Conclusion: Results of this study confirm occurrence of target volume changes during RT for glioblastoma patients. An adaptive plan can provide better normal tissue sparing for patients with lesion shrinkage and avoid undercoverage of treatment volumes in case of target volume expansion especially when limited-fields are used.