Ticari Bilimler Fakültesi / Faculty of Commercial Science

Permanent URI for this collectionhttps://hdl.handle.net/11727/2074

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    Factors Determining Consumer Concerns About Clothing Industry Problems
    (2023) Erol boyaci, Gulay; Senturk ozer, Leyla; HOC-6390-2023
    Although the public concern towards unsustainable current production and consumption is growing, the inadequacy of global regulations on sustainability issues puts the responsibility on consumers. However, despite their concerns, some consumers need help shopping from sustainable brands. The current research examines some antecedents of consumer concern towards the clothing industry's environmental and sweatshop issues. Data is obtained from 372 Turkish fast fashion consumers through online platforms. Level of exposure to informative posts on social media platforms, the perceived knowledge and belief towards the issues positively affect concern. Also, decreasing concern towards these problems with advancing age is observed in Turkiye.
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    Angiotensin receptor neprilysin inhibitor for patients with heart failure and reduced ejection fraction: Real-world experience from Turkey (ARNi-TR)
    (2021) Ekici, Berkay; Yaman, Mehmet; Kucuk, Murathan; Dereli, Seckin; Yenercag, Mustafa; Yigit, Zerrin; Bas, Mehmet Memduh; Karavelioglu, Yusuf; Cakmak, Huseyin Altug; Kivrak, Tarik; Ozkan, Hakan; Altin, Cihan; Sabanoglu, Cengiz; Demirkan, Burcu; Atas, Ali Ekber; Kilicaslan, Fethi; Altay, Hakan; Tengiz, Istemihan; Erkan, Aycan Fahri; Kilicaslan, Baris; Olgun, Fatih Erkam; Durakoglugil, Murtaza Emre; Alhan, Aslihan; Zoghi, Mehdi; 34308869
    Objective: Heart failure (HF) is a growing public health problem with high morbidity and mortality. Recently, angiotensin receptor neprilysin inhibitor (ARNi) has emerged as a promising treatment for HF with reduced ejection fraction (HFrEF). Here, we shared our experience with the use of ARNi in HFrEF from multiple centers in Turkey. Methods: The ARNi-TR is a multicenter, nonintervention al, retrospective, observational study. Overall, 779 patients with HF from 22 centers in Turkey who were prescribed sacubitril/valsartan were examined. Initial clinical status, biochemical and echocardiographic parameters, and New York Heart Association functional class (NYHA-FC) values were compared with follow-up values after 1 year of ARNi use. In addition, the effect of ARNi on number of annual hospitalizations was investigated, and the patients were divided into 2 groups, depending on whether ARNi was initiated at hospitalization or under outpatient clinic control. Results: N-terminal pro-brain natriuretic peptide (NT-proBNP), left-ventricle ejection fraction (LV-EF), and NYHA-FC values improved significantly in both groups (all parameters, p<0.001) within 1-year follow-up. In both groups, a decrease in hemoglobin A1c (HbA1c) values was observed in ARNi use (p<0.001), and a decrease in daily diuretic doses and hospitalizations owing to HF were observed after ARNi use (all comparisons, p<0.001). Hypotension (16.9%) was the most common side effect in patients using ARNi. Conclusion: The ARNi-TR study offers comprehensive real-life data for patients using ARNi in Turkey. The use of ARNi has shown significant improvements in FC, NT-proBNP, HbA1c levels, and LV-EF. Likewise, reductions in the number of annual hospitalizations and daily furosemide doses for HF were seen in this study.
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    Investigation of some machine learning algorithms in fish age classification
    (2021) Benzer, Semra; Garabaghi, Farid Hassanbaki; Benzer, Recep; Mehr, Homay Danaei; 0000-0002-5339-0554; A-5050-2014
    Marine and freshwater scientists use fish scales, vertebrae, otoliths and length-weights values to estimate fish age because reliable fish age estimation plays a very important role in fish stock management. The advances in technology and the widespread use of artificial intelligence have revealed the use of traditional observations and techniques in the fishing industry. The aim of this study was to evaluate the effectiveness of three disesteemed machine learning algorithms (NB, J48 DT, RF) in comparison with ANNs which has been widely used in such studies in the literature. In culmination, all three algorithms outperformed ANNs and can be considered as alternatives in case of coming across noisy and non-linear datasets. Moreover, among these three algorithms J48 DT and RF showed exceptional performance where the data for specific fish age groups weren't abundant.
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    Young tableaux and Arf partitions
    (2019) Tutas, Nesrin; Karakas, Halil İbrahim; Gumusbas, Nihal
    The aim of this work is to exhibit some relations between partitions of natural numbers and Arf semigroups. We also give characterizations of Arf semigroups via the hook-sets of Young tableaux of partitions.
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    Staff Task-Based Shift Scheduling Solution with an ANP and Goal Programming Method in a Natural Gas Combined Cycle Power Plant
    (2019) Ozder, Emir Huseyin; Ozcan, Evrencan; Eren, Tamer; 0000-0002-1895-8060; Q-4772-2017
    Shift scheduling problems (SSPs) are advanced NP-hard problems which are generally evaluated with integer programming. This study presents an applicable shift schedule of workers in a large-scale natural gas combined cycle power plant (NGCCPP), which realize 35.17% of the total electricity generation in Turkey alone, as at of the end of 2018. This study included 80 workers who worked three shifts in the selected NGCCPP for 30 days. The proposed scheduling model was solved according to the skills of the workers, and there were nine criteria by which the workers were evaluated for their abilities. Analytic network process (ANP) is a method used for obtaining the weights of workers' abilities in a particular skill. These weights are used in the proposed scheduling model as concepts in goal programming (GP). The SSP-ANP-GP model sees employees' everyday preferences as their main feature, bringing high-performance to the highest level, and bringing an objective functionality, and lowering the lowest success of daily choice. At the same time, the model introduced large-scale and soft constraints that reflect the nature of the shift requirements of this program by specifying the most appropriate program. The required data were obtained from the selected NGCCPP and the model solutions were approved by the plant experts. The SSP-ANP-GP model was resolved at a reasonable time. Monthly acquisition time was significantly reduced, and the satisfaction of the employees was significantly increased by using the obtained program. When past studies were examined, it was determined that a shift scheduling problem of this size in the energy sector had not previously been studied.
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    Employee deviant behavior: role of culture and organizational relevant support
    (2019) Kalemci, R. Arzu; Kalemci-Tuzun, Ipek; Ozkan-Canbolat, Ela; 0000-0001-6979-2040; ABB-5350-2020
    Purpose The purpose of this paper is to increase the knowledge and understanding of organizational and supervisory support in the context of employee deviant workplace behavior (DWB) by examining the potential associations of employees' cultural value orientations. This paper aims to: clarify DWB; review perceived organizational support (POS) and perceived supervisory support (PSS); discuss the meaning of employees' cultural value orientations (individualism-collectivism, power distance and paternalism); use the fuzzy logic model to analyze relationships between DWB and POS, as well as PSS and employees' cultural value orientations. Design/methodology/approach This research applies a fuzzy-set qualitative comparative analysis. Findings The results show the role of employee perceived organizational and supervisory support and cultural dimension (power distance and paternalism) configurations on employee DWB. Originality/value The main originality of this study is to further increase the understanding of organizational and supervisory support in the context of employee DWB by examining the potential associations of employees' cultural value orientations. This study extends the previous research by providing evidence that organizational and supervisory support influences employees' DWB.
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    Sustainable Personnel Scheduling Problem Optimization in a Natural Gas Combined-Cycle Power Plant
    (2019) Ozder, Emir Huseyin; Ozcan, Evrencan; Eren, Tamer; 0000-0002-1895-8060; Q-4772-2017
    This paper deals with a sustainable personnel scheduling problem of personnel working in a large-scale natural gas combined-cycle power plant in Turkey. The proposed model focuses on employee complaints due to unfair work schedules and the results of balanced assignments based on power plant interruptions. Eighty personnel work in three shifts at this natural gas combined-cycle power plant. The model is solved with respect to some of the workers' skills, and there are 20 criteria regarding skills. The analytic network process method is used to get the weights of workers' skills, which are calculated and included in the model. Goal programming is used in this paper. Our proposed model gives cost minimization and fair work schedules for the power plant. Compared with the literature, the number and set of criteria are unique in terms of personnel competency in the energy sector. Minimizing cost and imbalanced assignments was achieved by the proposed model for the first time without considering the sector.
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    Platform-switched implants vs platform-matched implants placed in different implant-abutment interface positions: A prospective randomized clinical and microbiological study
    (2019) Uraz, Ahu; Isler, Sila C.; Cula, Serpil; Tunc, Samet; Yalim, Mehmet; Cetiner, Deniz; 31808297
    Background Placement of the implant-abutment interface (IAI) away from the bone crest has been suggested to have positive impacts on maintenance of peri-implant tissues. Purpose To assess the effects of platform-switched and platform-matched implants, taking into consideration the IAI at different positions relative to the bone crest, on clinical, radiographic, and microbiological outcomes during 12 months following functional loading. Materials and Methods The present prospective randomized study was performed upon 70 patients. Group I (n = 23) implants presenting a platform-switched implant-abutment connection design was inserted 1 mm subcrestally. Group II (n = 22) implants with similar properties were inserted crestally. Group III (n = 25) implants presenting a platform-matched approach with an internal hexagon connection design was inserted crestally. The periodontal parameters were assessed at baseline, and 3, 6, and 12 months postloading. Radiographic marginal bone level (MBL) changes were analyzed at the 12-month follow-up. The amount of DNA copies of Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Tannerella forsythia, Provetalla intermedia and total bacterial mean load in peri-implant sulcus fluid (PISF) were assessed at the same periods. Results There were no significant differences among the groups with respect to the periodontal parameters for all time periods. At 12-month follow-up, the MBL changes were 0.16 +/- 0.29 mm and 0.17 +/- 0.23 mm for group I, 0.15 +/- 0.25 mm and 0.17 +/- 0.26 mm for group II, 0.17 +/- 0.26 mm and for group III in mesial and distal sites, respectively. The mean total bacterial load was found significantly higher for group III compared to the other groups in the three interval times (P < .05). Conclusion Implants restored with platform-switching and platform-matching performed equally regarding clinical and radiographic outcomes. Platform-matched implants inserted at the crestal level presented higher the mean bacterial total load in PISF.
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    Is crystalloid cardioplegia a strong predictor of intra-operative hemodilution?
    (2014) Gunday, Murat; Bingol, Hakan
    Introduction: Complications due to hemodilution (hematocrit value less than 22%) after cardiopulmonary bypass inevitably resulted with significantly greater intensive care requirements, long hospital stays, more operative costs, and increased mortality rates. We tried to identify whether crystalloid cardioplegia is the strongest predictor of intraoperative hemodilution or not. Materials and methods: One hundred patients were included into this randomized prospective study. Patients were divided into the two groups. Crystalloid cardioplegia were given to the odd-numbered patients (Group 1, n = 50 patients) and blood cardioplegia were given to the even-numbered patients (Group 2, n = 50 patients). St. Thomas-II solution was used in Group-1 and Calafiore cold blood cardioplegia was in Group-2. Results: Average intraoperative hematocrit value was 18.4% +/- 2.3 in crystalloid group 24.2% +/- 3.4 in blood cardioplegia group (p < 0.001). The lowest hematocrit value was 15% and 20% in two groups respectively (p < 0.001). In crystalloid group average intraoperative packed red blood cell (RBC) transfusion was 2.3 +/- 0.41 units, 0.7 +/- 0.6 units blood cardioplegia group (p = 0.001). Average transfused RBC was 2.7 +/- 0.8 units in crystalloid group, 0.9 +/- 0.4 units blood cardioplegia group (p < 0.001). Multivariate analyses confirmed age (p = 0.005, OR = 3.78), female gender (p = 0.003, OR = 2.91), longer cross-clamp time (>60 minutes) (p = 0.001, OD = 0.97), body surface area <1.6 m(2) (p = 0.001, OR = 6.01) and crystalloid cardioplegia (p < 0.001, OR = 0.19) as predictor of intraoperative hemodilution. Conclusion: Crystalloid cardioplegia, compared to blood cardioplegia not only causes much more intra-operative hemodilution but also increases the blood transfusion requirement. Hemodilution and increased transfusion increases the intensive care unit and hospital stay, in the early postoperative period.
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    Concurrent Chemoradiotherapy with Vinorelbine plus Split-Dose Cisplatin may be an Option in Inoperable Stage III Non-Small Cell Lung Cancer: A Single-Center Experience
    (2015) Mertsoylu, Huseyin; Kose, Fatih; Sumbul, Ahmet Taner; Sedef, Ali Murat; Dogan, Ozlem; Besen, Ali Ayberk; Parlak, Cem; Findikcioglu, Alper; Muallaoglu, Sadik; Sezer, Ahmet; Sakalli, Hakan; Ozyilkan, Ozgur; 25731741
    Background: Concurrent chemoradiotherapy is the current standard treatment for inoperable stage III non-small cell lung cancer (NSCLC). In this study we aimed to investigate the efficacy and toxicity of CCRT with split dose of cisplatin (30 mg/m(2)) and vinorelbine (20 mg/m(2)) in patients with inoperable stage III NSCLC followed in our oncology clinic. Material/Methods: Medical records of 97 patients with inoperable stage III NSCLC treated with concurrent chemoradiotherapy with cisplatin-vinorelbine were retrospectively analyzed. Cisplatin (30 mg/m(2)) and vinorelbine (20 mg/m(2)) were administered on days 1, 8, 22, and 29 during radiotherapy. Two cycles of consolidation chemotherapy were given. All patient data, including pathological, clinical, radiological, biochemical, and hematological data, were assessed retrospectively using our database system. Results: Our study included 97 unresectable stage III NSCLC patients who were treated with CCRT. Median age was 58 years old (range 39-75) and 87 (89.7%) of the patients were men. ECOG performance score was 0-1 in 93 patients (95.9%). Squamous histology, the most common histology, was diagnosed in 46 patients (47.4%). Median follow-up time was 23.8 months. Median progression-free survival (PFS) and median overall survival time (OS) were 10.3 months and 17.8 months, respectively. Objective response rate and clinical benefit rate were 75.3% and 83.5%, respectively. Distant and local relapse rate were 57.1% and 42.9%, respectively. Hematological and non-hematological grade 3-4 toxicities were seen in 13 (13.4%) and 16 (16.5%) patients, respectively. Six (6.1%) patients died due to toxicity. Conclusions: The results of this study suggest that split-dose cisplatin may offer fewer grade III-IV toxicities without sacrificing efficacy and could be an option in patients with inoperable stage III NSCLC during CCRT. Similar to past studies, despite high response rate during CCRT, distant relapse is the major parameter that influences patient survival in long-term in NSCLC.