Steady State Voltage Stability Estimation by Using Local Bus Parameters

Gümüş Talha Enes,Yalçın Mehmet Ali,Turan Mustafa,Aksoy Tırmıkçı Ceyda,Yavuz Cenk 대한전기학회 2021 Journal of Electrical Engineering & Technology Vol.16 No.2

In this study, an estimation approach based on local bus measurements of voltage, current and phase angle is presented to assess voltage stability at any of the system load bus. For this purpose, Thevenin equivalent circuit parameters of the IEEE 30-bus standard test system are estimated by using local measurements from Bus k which is selected to be evaluated in terms of voltage stability. Estimated Thevenin equivalent circuit parameters are used to calculate critical voltage values and voltage stability margin values of Bus k online for the voltage stability assessment. In conclusion, the voltage stability margin results of the proposed approach are compared with three diff erent Thevenin equivalent based voltage stability estimation approaches. Simulation results show that the proposed approach successfully estimates the voltage stability margins of any load bus in the system. From the perspective of voltage stability, estimated voltage stability margins can be used to assess the loading levels of any load bus, to defi ne critical busses and to make decision for load shedding.

TG Index, its Graphical Matrix Representation and Application on Polyenes

Selçuk Gümüş,Lemi Türker 대한화학회 2014 Bulletin of the Korean Chemical Society Vol.35 No.5

A novel topological index (TG Index) has been introduced. The graphical matrix representation of the TG index includes the use of directed subgraphs for the first time in graph theory literature. The application of the TG index on certain properties of polyenes yielded very well correlation data.

Experimental evaluation of different spectral methods for damage estimation of an electrical panel bracket mounted on a military wheeled vehicle

Mehmet Sefa Gümüş,Abdullah Erdemir,Veysel Alver,Mete Kalyoncu 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.12

This study evaluates different frequency domain vibration fatigue methods by verifying the results of the analyses with the experimental data on the bracket of an electrical panel mounted on a military vehicle. Loadings are defined considering composite wheeled vehicle vibration exposure as stated in the MIL-STD-810G Standard. The electrical panel and the bracket are simulated by FEM. Response PSDs are created on critical points. The experiment is carried out by using a uniaxial electrodynamic shaker. In this study, the Dirlik method proposes the most reliable and accurate fatigue life, while the Wirsching-Light method overestimates. Ortiz-Chen has made a very conservative prediction among other methods in this case study.

Computerized analysis of occlusal contacts in bruxism patients treated with occlusal splint therapy

Hasan Önder Gümüş,Halil İbrahim Kılınç,Süleyman Hakan Tuna,Nihal Özcan 대한치과보철학회 2013 The Journal of Advanced Prosthodontics Vol.5 No.3

PURPOSE. Occlusal splints are commonly used to prevent tooth wear caused by bruxism. However, the effects of splints on occlusion are still unclear. Although it is rarely alluded in literature, splints can provoke severe occlusal alterations and other complications. This study was aimed to identify differences in the responses of individuals with bruxism and healthy individuals to a full-arch maxillary stabilization splint in terms of occlusal changes. MATERIALS AND METHODS. Occlusal contacts in 20 (5 male, 15 female) bruxism patients and 20 (5 male, 15 female) controls with normal occlusion were evaluated before and after occlusal splint therapy. T-Scan III, a computerized occlusal analysis system, was used to simultaneously measure occlusion and disclusion times as well as left-right and anterior-posterior contact distributions before splint therapy and 3 months after therapy. Wilcoxon and Mann-Whitney U tests were used for statistical analyses (α=.05). RESULTS. No differences were found in the posterior contact of bruxism patients before and after stabilization splint treatment. However, differences in posterior contact were observed between bruxists and normal individuals prior to treatment, and this difference disappeared following treatment. CONCLUSION. The results of this study showed the use of a stabilization splint may not have an effect on occlusion. However, the area of posterior occlusal contact among bruxists was found to be greater than that of normal individuals. According to this study, the clinical use of splints may be harmless.

Translator Training and Employability in Turkey : What Do Curricula and Translator Trainers Tell Us?

Volga Yılmaz-Gümüş 한국외국어대학교 통번역연구소 2021 한국외국어대학교 통번역연구소 학술대회 Vol.2021 No.01

Employability in translation curriculum has been one of the most debated topics in translatortraining practice and research particularly with the start of the Bologna process. The literature abounds with studies referring to employability with specific reference to the notorious gap between what is offered in translator-training programs and what is expected on the translation market. Preparing students to the labor market is certainly one the responsibilities of translatortraining programs. However, as noted by Rodríguez de Céspedes, “employability does not only entail the means of finding a job but also of developing a set of skills, attitudes and aptitudes that evolve through our lives” (2017: 108). So, what is the role of university translation programs in the development of employability skills – lifelong learning skills that help students adapt and respond to the changing market? In translation programs, employability is either embedded in courses of translation theory and practice (use of authentic tasks, translation projects, etc.), or addressed separately (e.g. incorporation of courses on the translation profession or a work placement component into the curriculum). The focus of this study is on employability in translator-training in the Turkish context. As the number of translator-training programs in university settings has proliferated constantly since the emergence of first programs over three decades ago, the number of translation graduates trying to enter the competitive labor market is increasing. Thus, employability skills become important together with pure translation skills. Using data from the curricula of university programs, course descriptions and the results of an online survey for translator trainers, this study seeks to find out to what extent employability is embedded into translator training in Turkey, and to what extent training programs respond to a constantly changing translation market especially with the extensive use of technologies in translation, need for post-editing, changing work modes and finally the global effect of the COVID-19 pandemic. The study sets out to explore the paradigm shift in the translation profession from the perspective of training.

The meaning of the concept of lacunary statistical convergence in G-metric spaces

Şerife Selcan Küçük,Hafize Gümüş 강원경기수학회 2022 한국수학논문집 Vol.30 No.4

In this study, the concept of lacunary statistical convergence is studied in G-metric spaces. The G-metric function is based on the concept of distance between three points. Considering this new concept of distance, we examined the relationships between $GS,$ $GS_{\theta },G\sigma _{1}$ and $GN_{\theta} $ sequence spaces.

Structural and Molecular Orbital Properties of Some Boroxine Derivatives-A Theoretical Study

Lemi Türker,Selçuk Gümüş,Taner Atalar 대한화학회 2009 Bulletin of the Korean Chemical Society Vol.30 No.10

In the present study, firstly, the variations of the geometric parameters induced by different substituents on boroxine skeleton (symmetrically H, CH3, Cl, F, NO2 substituted boroxines) are investigated by using B3LYP/6-31G(d,p), RHF/6-31G(d,p), and MP2/6-31G(d,p) levels of the theory. The second objective is to estimate the substituent effect on the molecular aromaticity of boroxine derivatives using energetic and NICS criteria. Moreover, the effects of different theoretical levels on NICS values have been investigated in a systematic approach. Lastly, a rotational analysis has been performed to investigate the effect of rotation around the B-Me and B-NO2 bonds on total energy of the system. It has been found that electron withdrawing substituents contribute the aromaticity of boroxine affirmatively. Conversely, electron donors make the system less aromatic. Also, the theoretical vibrational spectra for these boroxine derivatives are presented and compared with the experimental data from the literature.

C-reactive protein-albumin ratio and procalcitonin in predicting intensive care unit mortality in traumatic brain injury

Canan Gürsoy,Güven Gürsoy,Semra Gümüş Demirbilek 대한중환자의학회 2022 Acute and Critical Care Vol.37 No.3

Background Prediction of intensive care unit (ICU) mortality in traumatic brain injury (TBI), which is a common cause of death in children and young adults, is important for injury management. Neuroinflammation is responsible for both primary and secondary brain injury, and C-reactive protein-albumin ratio (CAR) has allowed use of biomarkers such as procalcitonin (PCT) in predicting mortality. Here, we compared the performance of CAR and PCT in predicting ICU mortality in TBI. Methods Adults with TBI were enrolled in our study. The medical records of 82 isolated TBI patients were reviewed retrospectively. Results The mean patient age was 49.0 ± 22.69 years; 59 of all patients (72%) were discharged, and 23 (28%) died. There was a statistically significant difference between PCT and CAR values according to mortality (P<0.05). The area under the curve (AUC) was 0.646 with 0.071 standard error for PCT and 0.642 with 0.066 standard error for CAR. The PCT showed a similar AUC of the receiver operating characteristic to CAR. Conclusions This study shows that CAR and PCT are usable biomarkers to predict ICU mortality in TBI. When the determined cut-off values are used to predict the course of the disease, the CAR and PCT biomarkers will provide more effective information for treatment planning and for preparation of the family for the treatment process and to manage their outcome expectations.

Studies on the Different Reaction Pathways between 3-Acetyl-5-benzoyl-6-methyl-2-phenyl-4H-pyran-4-one and Alkylamines

Kwang Yeon Hwang,Meltem Tan,Selçuk Gümüş,Nurettin Mengeş,İshak Bildirici,Ahmet Şener 대한화학회 2010 Bulletin of the Korean Chemical Society Vol.31 No.9

3-Acetyl-5-benzoyl-6-methyl-2-phenyl-4H-pyran-4-one has been subjected to condensation with a series of primary amines (ethylamine – octylamine) to clarify the proposed mechanism in our previous study. The reactions of the shorter amines of the series (ethylamine – butylamine) yielded unsymmetric pyridinone products, whereas the other amines (pentylamine – octylamine) yielded symmetrical pyridinones. The starting material and the products as well as the intermediates have been subjected to theoretical analysis by quantum chemical calculations at B3LYP/6-31G(d,p)level, which provided supporting data for the experimental findings.

Synthesis of Some Novel Pyrimidine Derivatives and Investigation of their Electrochemical Behavior

Esvet Akbas,Abdulkadir Levent,Selçuk Gümüş,Mehmet Rauf Sümer,İnci Akyazı 대한화학회 2010 Bulletin of the Korean Chemical Society Vol.31 No.12

2-Iminopyrimidines (1a-e) and 2-thioxopyrimidine (2) were synthesized using the Biginelli three component cyclocondensation reaction of an appropriate β-diketone, arylaldehyde, and guanidine (for 1a-e) or thiourea (for 2). The electrochemical properties of the novel systems were investigated by CV and DPV. Moreover, B3LYP/6-31G(d,p) method was applied to the present structures in order to gather some structural and physicochemical data.