Şırnak Araştırma ve Akademik Performans Sistemi
DSpace@Şırnak, Şırnak Üniversitesi’nin bilimsel araştırma ve akademik performansını izleme, analiz etme ve raporlama süreçlerini tek çatı altında buluşturan bütünleşik bilgi sistemidir.
Güncel Gönderiler
Öğe Türü:Öğe, Machine learning approaches to credit risk: Evaluating Turkish participation and conventional banks(Elsevier, 2025) Sugozu, Ibrahim Halil; Verberi, Can; Yasar, SemaThis study investigates the impact of competition on credit risk in the Turkish banking system, focusing on Islamic (participation) and conventional banking under the same regulatory conditions regarding credit risk. The credit risk model is trained using CatBoost, extreme gradient boosting (XGBoost), random forest, and LightGBM algorithms, and the results are analyzed using Tree SHAP (SHapley Additive exPlanation) algorithms with swarmplots. The empirical analysis covers 33 conventional and 6 Islamic banks in T & uuml;rkiye, using annual data between 2009 and 2022. The findings reveal that (1) credit risk is relatively higher at participation banks than conventional banks; (2) competition increases credit risk; (3) loan size is a key determinant of credit risk; (4) profitability increases credit risk; and (5) economic growth reduces credit risk. This study recommends some policy measures, such as increasing the economy of scale at Islamic banks and implementing specific regulations at participation banks to reduce risk.Öğe Türü:Öğe, The impact of personality, behavior, and geography on participation in the private pension system in Türkiye: A machine learning approach(Elsevier, 2025) Verberi, Can; Kaplan, MuhittinThis study examines regional disparities in the factors that affect participation in the Private Pension System (PPS) in T & uuml;rkiye, focusing on sociodemographic characteristics, personality traits and behavior, and pension and financial literacy. The behavioral factors identified encompass procrastination, locus of control, pessimism, compulsive buying, and time perspective, and the personality traits include openness, agreeableness, extraversion, neuroticism, and conscientiousness. The study employs data on two provinces in T & uuml;rkiye, S,& imath;rnak and Istanbul, and uses XGBoost and Tree SHAP algorithms and a probit model. Our findings indicate that personality traits such as openness, agreeableness, and conscientiousness have a positive influence on individual engagement in pension plans, whereas extraversion has a negative impact. Additionally, basic pension literacy is more influential than advanced pension literacy. The results also show that regional geography significantly influences personality and behavioral factors. Finally, a perception of protection is a critical factor in PPS participation.Öğe Türü:Öğe, The role of perceived consumer value dimensions in predicting behavioral intention toward car-sharing: An empirical study based on the extended technology acceptance model(Elsevier Sci Ltd, 2025) Akel, Gokhan; Bayir, TalhaThe sharing economy holds a significant promise for fostering a sustainable economy and society. However, the dimensions of consumer behavior remain largely untapped. This study employs the technology acceptance model as its principal methodological framework to intricately dissect consumer behavior within the context of car-sharing services. A novel examination of consumer-perceived functional, social, environmental, and situational values revealed how these factors affect the reception of car-sharing platforms. This study integrates privacy concern, highlighting their critical role in shaping consumer attitudes and usage intentions. Utilizing multiple structural equation modeling on responses from 395 valid questionnaires, this study rigorously tested the proposed hypotheses. The findings indicate a significant influence of perceived value on attitudes towards car-sharing services mediated by perceived ease of use and usefulness. Furthermore, this study underscores that both attitudes and privacy concern critically shape the intention to use car-sharing services. This study offers a comprehensive understanding of the factors influencing consumer behavior in the car sharing sector, providing valuable insights for both academic research and practical applications.Öğe Türü:Öğe, Insecticide resistance status and vector potential of Bemisia tabaci populations on vegetable crops in Türkiye(Elsevier Sci Ltd, 2025) Inak, Arda; Demirci, Berke; Erdem, Esengul; Randa-Zelyut, Filiz; Karanfil, Ali; Idan, Ahmednur Yusuf; Toprak, UmutThe sweet potato whitefly Bemisia tabaci (Gennadius, 1889) (Hemiptera: Aleyrodidae), is an economically important polyphagous pest species with a global distribution. This pest not only causes direct damage by sucking plant phloem sap but also transmits viruses and excretes honeydew, which can lead to the formation of black sooty mould, thereby intensifying its significance in agricultural regions. Although chemical insecticides have been extensively used for whitefly control, the development of resistance leading to control failures has been frequently documented. Here, we have initially assessed the efficacy of four commonly used insecticides (acetamiprid, sulfoxaflor, spirotetramat, cyantraniliprole) against whitefly populations through greenhouse trials across eight distinct locations. Additionally, we conducted a comprehensive molecular screening of 35 field populations to identify resistance mutations at the insecticide target sites and to detect plant pathogenic viruses. The results revealed that sulfoxaflor and cyantraniliprole exhibited the highest efficacy against nymphal stages of whiteflies, whereas acetamiprid was determined to be the most effective insecticide against adult stages. Several well-known target-site mutations in acetylcholinesterase (F331W), voltage-gated sodium channel (VGSC; M918L, L925I, T929V), and acetyl-CoA carboxylase (A2083V) were found to be widespread in Turkish B. tabaci populations. Additionally, two mutations, I936V and I936F, previously associated with pyrethroid resistance, were identified for the first time in the VGSC of B. tabaci. Conversely, no amino acid substitutions were detected in the amplified fragments of the ryanodine and nicotinic acetylcholine receptors. Furthermore, tomato chlorosis virus (ToCV) was detected in five field populations from Antalya. The widespread distribution of whitefly populations with multiple resistance mutations underscores the necessity of implementing integrated pest management programs in Turkish vegetable production areas.Öğe Türü:Öğe, Effects of microencapsulated phase change material on physico-mechanical and thermoregulation performance of lightweight geopolymer concrete with zeolite and perlite(Elsevier, 2025) Oren, Osman Hulusi; Mandev, Emre; Kaya, Mehmet; Sari, Ahmet; Hekimoglu, Gokhan; Cikman, Ismail Umit; Subasi, SerkanThis study examines impact of microencapsulated phase change material (MPCM) additives on physical and mechanical characteristics of geopolymers produced using natural zeolite and slaked lime. The binder composition consists of 90 % zeolite and 10 % slaked lime, activated with NaOH at a Na/binder ratio of 14 % by weight. Basalt-based sand and perlite were used as aggregates with a water/binder ratio of 0.60. MPCM was added in varying proportions of 8 %, 16 %, and 24 % relative to the binder weight. Samples were molded in dimensions of 50 x 50 x 50 mm and 200 x 200 x 20 mm, then cured at 95 degrees C for 24 h. Differential Scanning Calorimetry (DSC) outcomes presented that geopolymer composite with MPCM has a melting degree of 26.45 degrees C and a melting enthalpy of 17.8 J/g. Fourier Transform Infrared Spectroscopy (FTIR) results confirmed physical integration of MPCM into geopolymer structure. The study also evaluated compressive strength, ultrasound pulse velocity (UPV), dry unit weight, and microstructural properties using Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS). Thermoregulation performance experiments demonstrated that the MPCMenhanced samples effectively moderated temperature fluctuations, maintaining lower temperatures for controlled heating and higher temperatures for natural cooling phases compared to the control sample. Thermal regulation capabilities of MPCM-infused geopolymers were evidenced by their property of absorbing and releasing heat, which is critical for energy-efficient building materials. Additionally, the durability and stability of the geopolymer matrix were enhanced by the uniform dispersion of MPCMs, which also improved the composite's mechanical performance. The successful integration of MPCMs highlights their potential in developing sustainable construction materials that contribute to energy savings and environmental conservation.
