Yayınlar
Koleksiyondaki öğeler
- BildiriYalnız künye2012PERFORMANCE EVALUATION OF TURKISH RETAIL FIRMS USING THE FUZZY AHP, PROMETHEE, ELECTRE AND VIKOR METHODS
Bölükbas, Ufuk; Çelik, Erkan; Güneri, Ali Fuat
The performance evaluation of firms determines capabilities of firms to compete in the sector and has a critical importance for the development of the sector. In this study, a fuzzy multi-criteria decision model is proposed to evaluate the performances of retail firms. The eight Turkish retail firms are analyzed and firms are evaluated in terms of ten different financial ratios in six separate groups. Fuzzy Analytic Hierarchy Process (FAHP), Preference Ranking Organization Method for Enrichment Evaluation (PROMETHEE), Elimination Et Choix Traduisant la Realit (ELECTRE) and Multicriteria Optimization and Compromise Solution (VIKOR) methods are integrated in the proposed model. A hierarchical model of financial performance evaluation is structured by the decision makers. FAHP is used to determine the weights of the criteria. These criteria weights and financial ratio values are input to the PROMETHEE, ELECTRE and VIKOR method to rank the firms. The rankings of methods are compared to each other's in the conclusion.
AtıfWoS1
İncele - MakaleAçık Erişim2014Scopus SJRQ4Antimicrobial Activity of the Methanol Extracts and Essential Oil with the Composition of Endemic Origanum acutidens (Lamiaceae)
Gulec, Azime Kucukgul; Erecevit, Pinar; Yuce, Ebru; Arslan, Ali; Bagci, Eyup; Kirbag, Sevda
The chemical composition of hydro distilled essential oil from Origanum acutidens (Hand. and Mazz.) Ietswaart was collected from Tunceli (Turkey) were analyzed by GC and GC-MS. Essential oil and methanol extract of Origanum acutidens were tested against Yersinia ruckeri (ATCC 29473), Aeromonas hydrophila (ATCC 607920), Lactococcus garviae (ATCC 43921) Staphylococcus aureus (ATCC 29213) fish pathogenic bacterial strains. The analysis of the essential oil of Origanum acutidens showed the presence of 6 components accounting for 93.8 % of the total amount. Calvacrol (61.8 %), p-cymene (15.5 %) and thymol (12.7 %) that possessed antimicrobial activity were found as the major component. The final concentrations of the methanol extract and the essential oil were determined by using disk diffusion assay. Mean inhibition zones of bacterial strains for Origanum acutidens essential oil varied from 28.0 +/- 1.2 and 36.7 +/- 0.7 mm. The inhibition zones of methanol extract (10 mu L and 20 mu L) of Origanum acutidens against bacterial strains were in the range 8.7 +/- 0.7 - 11.0 +/- 0.6 mm and 12.7 +/- 0.67 - 22.7 +/- 1.3 mm, respectively. Our results suggest that both the methanol extract and the essential oil of Origanum acutidens may be valuable as potential antibacterial agents against the major fish pathogens.
AtıfWoS7OpenAlex12İncele - MakaleYalnız künye2015Scopus SJRQ2Determination of Volatile Compounds of Sucuk with Different Orange Fiber and Fat Levels
Yalinkiliç, Baris; Kaban, Guzin; Ertekin, Ozlem; Kaya, Mukerrem
In this study, the effects of fat (10, 15 and 20%) and orange fiber (0, 2 and 4%) levels on volatile compounds of sucuk (Turkish dry-fermented sausage) were investigated. The volatile compound profile of sucuk samples was analyzed by gas chromatography/mass spectrometry (GC-MS) by using a solid phase microextraction (SPME). 75 volatile compounds were identified in the sucuk samples. The volatile compounds identified were 11 aldehydes, 7 aliphatic hydrocarbons, 2 acids, 10 esters, 1 furan, 5 alcohols, 8 aromatic hydrocarbons, 6 ketones, 6 sulphur compounds, and 19 terpenes. It was determined that the use of orange fiber had significant (P<0.05) effects on a few volatile compounds (allyl methyl sulfide, copaene and caryophyllene). Alpha-thujene was significantly affected by fat level (P<0.05). Fat level also showed very significant effect on p-xylene and allyl methyl sulfide (P<0.01). As result, orange fiber and fat level had no significant effects on volatile profile of sucuk samples.
AtıfWoS8İncele - MakaleYalnız künye2015Scopus SJRQ3A COMPARATIVE STUDY ON THE EFFECTS OF LEAD AND ZEOLITE ON SERUM BIOCHEMISTRY OF CARP FISH, Cyprinus Carpio Linnaeus, 1758 (Cyprinidae)
Mutlu, Ekrem; Demir, Tugba; Kutlu, Bann
One of the pollutants leading to heavy metal pollution is the lead element. The studies on exposure of fish to lead have shown that this exposure leads to negative effects on body weight, and digestive enzymes and lipase. In humans, the symptoms of chronic lead toxicity are renal malfunction, anemia, brain and liver damage, cancer, hyperactivity, and general psychological impairment. For struggling with this heavy metal contamination, we have a useful tool named Zeolite. Zeolites are used in many fields such as agriculture, metal industry, energy sector, manufacturing industry, water treatment, animal husbandry, struggling with environmental pollution, and etc. In this study, we utilized the biochemical parameters of carp fish (Cyprinus carpio) in order to reveal the effects of zeolite on fish health and production. The experiments were performed within 100 L glass aquariums with 85x40x30 dimensions. The study was planned for 3 different durations as 35 days, 90 days, and 120 days. The subjects were divided into 4 groups for each of experiment durations. The groups were named Pb(NO3)(2) group, Pb(NO3)(2) + Zeolite group, Zeolite group, and control group. At the end of each of the experiment period (on 35(th), 90(th), and 120(th) days), the fish in groups were weighed, and the average growth rates of each of the groups were calculated. The parameters used in blood analyses are glucose (GLU), blood urea nitrogen (BUN), total protein (TP), albumin (ALB), globulin (GLB), creatinine (CR), total bilirubin (TBIL), uric acid ([JA), and direct bilirubin (DBlL).
AtıfWoS2İncele - BildiriYalnız künye2017An Identity-Based Encryption Scheme with Performance Optimization for Privacy Preservation in Smart Grid Communication
Baloglu, Ulas Baran; Demir, Yakup
Smart grids are expected to replace existing electrical grids with advanced mechanisms and intelligent entities, which have excessive data processing and communication tasks. It is important for the sensitive consumer data, such as meter readings, to be secured at these intelligent entities. Novel digital communication mechanisms should be developed to protect privacy. Existing smart grid architectures do not have sufficient and efficient security functionalities for data transmission. In this paper, we propose an Identity-Based Encryption scheme, which is more promising than the classical form regarding performance and security. The proposed scheme focuses on the data structure of meter readings and optimizes this structure to achieve a better privacy preservation. This novel structure further improves the performance of the scheme by reducing communication overhead caused by public key creation and distribution operations, as evaluations demonstrated.
AtıfWoS1İncele - MakaleYalnız künye2017Scopus SJRQ3Synthesis and characterization of Bioglass-based bone grafts with Gelatine substitution for biomedical applications
Aksakal, B.; Demirel, M.
Background: Syntesizing alternative bone graft materials are important in biomedical applications. Their morphology, mechanical properties and cell viability plays an important role in tissue engineering. OBJECTIVE: Bioglass (B) based bone grafts with Gelatin (G) substitution were syntesized via the sol-gel method and were compared with various Gelatin and Bioglass concentrations (wt%). METHODS: Syntesized bone grafts were characterized by Scanning Electron Microscopy (SEM) and X-ray diffraction (XRD) to show the structural and morphological changes of the fabricated B-based bone grafts. RESULTS: It was demonstrated that the concentration of pore size increased with increasing amounts of Gelatin in wt%. The biograft-B40G20 produced the highest flexture strength and hardness. Increasing the pore size caused a decrease in hardness and flexture stress of B-based biografts. CONCLUSIONS: Cell viability tests were conducted on the fabricated biografts and it was shown that the cell viability increased in fabricated B-based bone grafts.
AtıfScopus1WoS1OpenAlex1
İncele - BildiriYalnız künye2017Forecasting daily patient visits in an emergency department by ga-ann hybrid approach
Pekel, Engin; Gul, Muhammet; Celik, Erkan
An Emergency Department (ED) plays a crucial role in the health system by providing acute care for patients who attend hospital without prior appointment. An accurate forecasting of patient visits in EDs contributes to health care decision makers to better allocate ED human resources and medical equipment. In this paper, a hybrid genetic algorithm–artificial neural network (GA–ANN) approach is developed. The forecasting performance of the hybrid approach is obtained using the real-world data set collected from a public hospital in Istanbul, Turkey. The hybrid GA–ANN model is shown to perform well in terms of forecasting accuracy. In order to contribute to the current knowledge, this paper is a novel attempt of applying GA-ANN to model ED patient arrivals, and the results can be used to aid in strategic decision-making on ED resource planning in response to predictable arrival variations.
AtıfScopus4İncele - BildiriYalnız künye2017An efficient heuristic algorithm for solving robotic assembly line balancing problem
Çil, Zeynel Abidin; Mete, Süleyman; Özceylan, Eren
In the assembly system, robots provide to increase flexibility of the system and automation. The balancing robotic assembly line (RALB) problem consists two main works, which are not only assigning task to station, but also allocation robots in stations. Because each robots can perform different performance on the same tasks due to their capabilities. In this study, iterative beam search algorithm is developed to minimize cycle time. The performance of the algorithm outperforms other algorithm in the literature.
AtıfScopus2OpenAlex1İncele - MakaleAçık Erişim2017Scopus SJRQ1Application of AHP and VIKOR methods under interval type 2 fuzzy environment in maritime transportation
Soner, Omer; Celik, Erkan; Akyuz, Emre
The aim of this paper is to provide not only a hybrid theoretical methodology in multiple-attribute decision making problems but also a practical application in maritime transportation industry. The proposed hybrid approach integrates Analytic Hierarchy Process (AHP) method into VlseKriterijumska Optimizacijia I Kompromisno Resenje, (VIKOR) technique under interval type-2 fuzzy (IT2F) environment. While AHP and VIKOR provides a comprehensive framework to solve multiple-attribute decision making (MADM) problems in maritime transportation industry, the IT2F enables to deal with much uncertainty during linguistic assessment of decision-makers. The proposed approach is demonstrated with a hatch cover design selection problem since it has utmost importance in structure of bulk carrier ships to prevent water ingress and protect cargo form the external damages. Besides its robust theoretical insight, the paper has practical contribution to the naval engineers, classification societies and ship owners who have difficulty in deciding appropriate hatch cover type during construction of the ship.
AtıfScopus117WoS103OpenAlex122İncele - MakaleYayıncıda açık erişim2017Scopus SJRQ2The Native Symbols Engaging Turkish Players to Digital Games in a Playability Perspective
Aslan, Alper; Coban, Murat; Karakus Yilmaz, Turkan; Goktas, Yuksel
Background. The satisfaction of a player’s gaming experience has a great impact on their game preferences. The goal of this study was to investigate the opinions and experiences of Turkish players of computer games in order to examine the effects of native symbols on their game preferences. Method. The data collection tools were games developed in Turkey, websites for these games, user comments made on the video records of the games, online forums, and an open-ended questionnaire. Results. The results indicate that although native symbols from the players’ home society play a role in shaping the users’ playability perception, it cannot be argued that they change the game preferences. These results may be applied to computer games’ designs, development strategies, and advertising methods to attract all players.
AtıfScopus4WoS3OpenAlex3İncele - MakaleYalnız künye2017Scopus SJRQ3Box-Behnken design approach for optimizing removal of copper from wastewater using a novel and green adsorbent
Ince, Muharrem; Ince, Olcay Kaplan
The aim of the present research was to apply the Box-Behnken experimental design and response surface methodology for modeling of copper (Cu2+) ions from an industrial wastewater and leachate pretreated astragalus herbal plant. A three factor, three level Box-Behnken experimental design combined with response surface modeling (RSM) and quadratic programming (QP) was employed for maximizing Cu(ID removal from aqueous solution based on 17 different experimental data obtained in a batch experimental study. Three independent variables (pH ranging from 2.0 to 8.0, contact time from 10 to 180 minutes, and adsorbent amount from 0.1 to 1 g) were studied. The significance of the independent variables and their interactions were tested by means of the analysis of variance (ANOVA) with 95% confidence limits. The standardized effects of the independent variables and their interactions on the dependent variable were also investigated by preparing a Pareto chart. The optimum values of the selected variables were obtained by solving the quadratic regression model as well as by analyzing the response surface contour plots. Using the experimental conditions of pH = 5.0, contact time = 92.5 minutes, adsorbent dosage = 0.25 g, the recovery efficiency of Cu(II) was found to be 100%. Copper-free and copperloaded astragalus was analyzed using fourier transform infrared spectrometry (FTIR) which evidenced the functional groups involved in copper uptake. Adsorption equilibrium for copper was described by using the Freundlich and Langmiur adsorption isotherms. This adsorbent was applied to different industrial wastewater and leachate samples for copper removal.
AtıfScopus17İncele - MakaleAçık Erişim2017Scopus SJRQ2Novel hyperbolic behaviors to some important models arising in quantum science
Bulut, Hasan; Sulaiman, Tukur Abdulkadir; Baskonus, Haci Mehmet; Yazgan, Tugba
In this study, with the help of Wolfram Mathematica 9 software, the powerful sine-Gordon expansion method is used in constructing new hyperbolic function solutions to the two well known nonlinear differential equations that arise in the field of nonlinear sciences, namely; the modified Zakharov–Kuznetsov and the (2+1)-dimensional cubic Klein–Gordon equations. We also plot the two- and three-dimensional graphics of all the obtained solutions in this paper by utilizing the same program in the Wolfram Mathematica 9 software.
AtıfScopus17WoS18OpenAlex19İncele - BildiriAçık Erişim2017Economic Analysis of Hybrid Renewable Energy Systems with V2G Integration Considering Battery Life
Baloglu, Ulas Baran; Demir, Yakup
Hybrid renewable energy systems considered as candidate solutions for environmental problems. Solar energy and wind energy are important components of these systems, but both of them cause fluctuations in the grid. Batteries of Electric Vehicles (EVs) can be connected to the grid to create an ancillary resource. These systems known as Vehicle to Grid (V2G) and they could be the most suitable solution to the fluctuation problems of renewable resources. In this paper, economic analysis of V2G is investigated from various perspectives. The findings of this study indicate that battery aging costs of a V2G system can be minimized with an intelligent energy management system, and these systems are both economically and environmentally better alternatives to fossil-fuelled generators.
AtıfScopus15WoS13OpenAlex16İncele - MakaleAçık Erişim2017Scopus SJRQ3Automatic Mining of Quantitative Association Rules with Gravitational Search Algorithm
Can, Umit; Alatas, Bilal
The classical optimization algorithms are not efficient in solving complex search and optimization problems. Thus, some heuristic optimization algorithms have been proposed. In this paper, exploration of association rules within numerical databases with Gravitational Search Algorithm (GSA) has been firstly performed. GSA has been designed as search method for quantitative association rules from the databases which can be regarded as search space. Furthermore, determining the minimum values of confidence and support for every database which is a hard job has been eliminated by GSA. Apart from this, the fitness function used for GSA is very flexible. According to the interested problem, some parameters can be removed from or added to the fitness function. The range values of the attributes have been automatically adjusted during the time of mining of the rules. That is why there is not any requirements for the pre-processing of the data. Attributes interaction problem has also been eliminated with the designed GSA. GSA has been tested with four real databases and promising results have been obtained. GSA seems an effective search method for complex numerical sequential patterns mining, numerical classification rules mining, and clustering rules mining tasks of data mining.
AtıfScopus27WoS18OpenAlex28İncele - MakaleYalnız künye2016Scopus SJRQ2Application of interval type-2 fuzzy sets DEMATEL methods in maritime transportation: The case of ship collision
Celik, E.; Akyuz, E.
Accident analyse in marine industry is one of the critical issues for safety practitioners to prevent loss of life. Although considerable efforts were undertaken to prevent marine accident, numerous researches revealed that marine accidents are still on-going. In order to minimize accidents in the marine transportation, this paper presents a proactive decisionmaking tool which is integrating Decision-Making Trail and Evaluation Laboratory (DEMATEL) method with interval type-2 fuzzy sets (IT2FSs). As the DEMATEL enables to analyse cause and effect relationship in decision-making, the IT2FSs overcome ambiguity and vagueness of linguistic assessment of decision-makers through the DEMATEL. Thus, significant accident causal factors and their effects can be analysed on the basis of cause-effect diagram. The application of proposed approach is demonstrated with a real ship collision case. Beside its theoretical contribution, the proposed approach provides practical benefits to ship owners and operators to perceive cause and effect relationship and to avoid marine accident.
AtıfScopus30WoS27İncele - MakaleYalnız künye2017Scopus SJRQ3Determination of element concentrations in commercial infant formulas using atomic absorption spectrometry
Unuvar, Songul; Savan, Ebru Kuyumcu; Karaaslan, Nagihan M.
The presence of heavy metals, inadequate minerals and elements in infant foods is of great concern. In this study, the heavy metals aluminum (Al) and lead (Pb), essential elements such as iron (Fe) and zinc (Zn), and minerals such as calcium (Ca), potassium (K), magnesium (Mg), and sodium (Na) were determined by atomic absorption spectrometry (AAS) in five different brands of 20 infant formula samples obtained from pharmacies and supermarkets in Malatya, Turkey. The Joint FAO/ WHO Expert Committee on Food Additives (JECFA) has set the maximum concentration levels of heavy metals in infant formula and levels of provisional tolerable weekly intake (PTWI) of these metals by infants. The levels of Al and Pb in the analyzed samples were found to be under legal limits. The recommended daily intake (RDI) of the essential elements and minerals were found within normal and permissible ranges, showing that the formulas are safe for infants.
AtıfScopus1İncele - MakaleYalnız künye2017Scopus SJRQ2Effect of Cobalt on Sperm Motility in an Endangered Trout Species, Salmo coruhensis
Kocabaş, Mehmet; Kutluyer, Filiz
Experiments were designed to examine the in vitro effect of cobalt on sperm motility of the endangered trout species (Salmo coruhensis). Sperm samples were diluted in an immobilizing solution, and activated in a motility-activation solution that was supplemented with cobalt at concentrations of 1, 10, 100 and 1000 mg/L. The percentage of motile sperm and duration of motility were determined. Cobalt concentrations of 1–100 mg/L had a positive effect on the percentage of motile sperm and duration of motility compared to the control group, while a concentration of 1000 mg/L resulted in decreases in these parameters (p < 0.05). The percentages of motile sperm at cobalt concentrations of 0, 1, 10, 100 and 1000 mg/L were 83.33% ± 0.25%, 88.33% ± 0.34%, 89.00% ± 0.57%, 90.00% ± 0.87% and 42.50% ± 0.45%, respectively; and the time durations over which the sperm remained motile were 72.00 ± 0.63, 74.83 ± 0.28, 77.40 ± 0.47, 81.14 ± 0.78, and 50.25 ± 0.67 s, respectively. This study has shown that sperm motility and duration were significantly enhanced (p < 0.05) at cobalt concentrations of 1, 10 and 100 mg/L, relative to controls, and significantly decreased at 1000 mg/L.
AtıfScopus11WoS9OpenAlex14İncele - MakaleYalnız künye2018Scopus SJRQ2An occupational risk assessment approach for construction and operation period of wind turbines
Gul, M.; Guneri, A.F.; Baskan, M.
As wind energy is one of the most important renewable energy sources over the globe, need for increasing safety for this type of energy is gaining importance. Although this sector is not suffering an excessive amount of fatal injury accidents, there are many aspects open for improvements in occupational health and safety management. The construction and operation processes of wind turbines include several hazards that must be reduced. This study aims to present a risk assessment for the construction and operation period of wind tribunes using a new fuzzy based method. Fuzzy analytical hierarchy process, a common used multi criteria decision making method, is applied to assign weights to the parameters of Fine-Kinney risk analysis method. Then, fuzzy VIKOR method is used to prioritize hazards. A case study is carried out for an onshore wind turbine in Turkey by using occupational health and safety experts in weighting risk parameters and evaluating compromised rankings of the hazards. Results reveal the most important hazards both for construction and operation period of the wind tribune. On conclusion of the current study, control measures for those risks and possible corrective-preventive actions for improvement are also provided.
AtıfScopus40WoS35OpenAlex35İncele - MakaleYalnız künye2017Scopus SJRQ3The epiphytic bryophyte flora and vegetation of boraboy and destek forests (Amasya, Turkey)
Alataş, Mevlüt; Batan, Nevzat; Ezer, Tülay; Uyar, Güray
In this study, epiphytic bryophyte flora and vegetation were investigated of Boraboy and Destek forests in Amasya province (Turkey). A total of 22 bryophyte taxa (19 mosses, 3 liverworts) were recorded in the research site. As a result of the investigation of 32 sampling releves taken from the trunks by the Braun-Blanquet method, two epiphytic bryophyte associations (Orthotrichetum pallentisand Orthotrichetum striati) belonging to the Ulotion crispaealliance were detected. Among these syntaxa Orthotrichetum pallentiswas recorded for the first time from Turkey. Furthermore, the life forms and life strategies spectrum in syntaxa were analyzed. Analysis result indicates a distinct correlation between life forms, strategies and ecological conditions of the area. Weft and cushion are dominant life forms, Perennial stayers with high sexual reproductive effort is dominant life strategy in the syntaxa. In addition, the ecological characteristics of bryophyte taxa were evaluated. According to these results the largest number of epiphytic bryophytes in the area are mesophytic, sciophyte and subneutrophyte.
AtıfScopus8İncele - MakaleYalnız künye2017Scopus SJRQ2Ethnopharmacological survey of medicinal plants in Karaisalı and its surrounding (Adana-Turkey)
Güneş, Suzan; Savran, Ahmet; Paksoy, Mehmet Yavuz; Koşar, Müberra; Çakılcıoğlu, Uğur
This study identifies wild plants collected for medical purposes by local people of Karaisalı County in the Mediterranean Region of Turkey, together with the uses and local names of these plants. A field study was carried out over a period of approximately 2 years (2008–2010). During this period, 129 vascular plant specimens were collected. Demographic characteristics of participants, local plant names, parts used and methods of preparation of the plants were investigated and recorded. Within the scope of the study, relevant plant species were collected; herbarium materials were prepared; and the specimens were labelled. In addition, the use-value of the species was determined and calculated for the medicinal plants included in the study. A total of 129 medical plants belonging to 59 families were identified in the region. The most common families were: Lamiaceae (14 plants), Asteraceae (11 plants), Rosaceae (10 plants), Apiaceae (5 plants), Euphorbiaceae (5 plants). A comparison of the data obtained in this study with experimental data obtained in previous laboratory studies, confirmed most of the ethnobotanical uses. The plant flora of Karaisalı is threatened by such factors as grazing, expansion of new agricultural lands, and unsustainable harvesting of plants to generate income. Steps should be taken immediately to ensure the inclusion of relevant flora within conservation designations.
AtıfScopus89WoS76OpenAlex95İncele
