http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Fatih Yildiz (검색결과 8 건)
- 무료
- 기관 내 무료
- 유료
-
Power Quality Improvement Using Hybrid Passive Filter Configuration for Wind Energy Systems
O. Fatih Kececioglu,Hakan Acikgoz,Ceyhun Yildiz,Ahmet Gani,Mustafa Sekkeli 대한전기학회 2017 Journal of Electrical Engineering & Technology Vol.12 No.1
Wind energy conversion systems (WECS) which consist of wind turbines with permanent magnet synchronous generator (PMSG) and full-power converters have become widespread in the field of renewable power systems. Generally, conventional diode bridge rectifiers have used to obtain a constant DC bus voltage from output of PMSG based wind generator. In recent years, together advanced power electronics technology, Pulse Width Modulation (PWM) rectifiers have used in WECS. PWM rectifiers are used in many applications thanks to their characteristics such as high power factor and low harmonic distortion. In general, L, LC and LCL-type filter configurations are used in these rectifiers. These filter configurations are not exactly compensate current and voltage harmonics. This study proposes a hybrid passive filter configuration for PWM rectifiers instead of existing filters. The performance of hybrid passive filter was tested via MATLAB/Simulink environment under various operational conditions and was compared with LCL filter structure. In addition, neuro-fuzzy controller (NFC) was preferred to increase the performance of PWM rectifier in DC bus voltage control against disturbances because of its robust and nonlinear structure. The study demonstrates that the hybrid passive filter configuration proposed in this study successfully compensates current and voltage harmonics, and improves total harmonic distortion and true power factor.
-
Observation of nano powders and fly ash usage effects on the fluidity features of grouts
Celik, Fatih,Yildiz, Oguzhan,Bozkir, Samet M. Techno-Press 2022 Advances in nano research Vol.13 No.1
The pumpability of the grouts is significant issue in concept of the rheological and workability properties during penetrating to voids and cracks. To improve the fluidity features of the grout mixes, the usage of Colloidal Nano Particular Powders (CNPPs) with mineral additives such as fly ash (FA) can contribute. Therefore, the main purpose of this study can be explained as investigating the usage effects of four types of Colloidal Nano Particular Powders (n-TiO<sub>2</sub>, n-ZnO, n-Al<sub>2</sub>O<sub>3</sub> and n-SiO<sub>2</sub>) as nano additives on the rheological, workability and bleeding properties of cement-based grout incorporated with fly as. Test results showed that the usage of FA in the grout samples positively contribute to increase on the fluidity of the grout samples as expected. The dilatant behavior was observed from the results for all mixes. Observing the effect of nano-sized additives in such cement-based grout mixtures with high fluidity has presented remarkable effects in this study.
-
-
Burak Altintas,Fatih Yildiz,Gokcer Uzer,Mehmet Kapicioglu,Kerem Bilsel 대한견주관절의학회 2017 대한견주관절학회지 Vol.20 No.2
Background: The purpose of this study was to examine the clinical and radiological results of the all-arthroscopic, suture-button fixation technique to treat acute acromioclavicular (AC) joint separations. Methods: All patients with acute AC joint separations received all-arthroscopic, single suture-button (TightRope) procedure without a special guide. Postoperative Constant score (CS), pain level according to visual analogue scale, and range of motion (ROM) were evaluated. For radiological evaluation, coracoclavicular distances were measured bilaterally. Results: Between December 2010 and June 2012, 18 consecutive patients (4 women and 14 men; mean age, 29.3 years) with acute AC joint separations underwent surgical treatment after 6.4 days (range, 2–20 days) following the initial trauma. The average postoperative follow-up was 16.9 months. The mean CS was 92.4 (range, 84–96). The mean external rotation, forward flexion, and abduction were 75.8° (range, 50°–90°), 170° (range, 150°–180°), and 163.8° (range, 140°–180°), respectively. Five patients exhibited coracoclavicular ossifications. In two patients, superficial wound infections were successfully treated with antibiotic therapy. In one patient, a coracoid fracture was observed. No significant differences were found regarding pain, ROM, or strength parameters between both sides. The coracoclavicular distance was discovered to be approximately 2.8 mm greater on the affected side; however, this minimal reduction loss did not affect the functional results. Conclusions: The findings of this study suggests that all-arthroscopic treatment of AC joint separations using the single suture-button technique without a drill guide is safe, yielding good to excellent clinical results.
-
Power Quality Improvement Using Hybrid Passive Filter Configuration for Wind Energy Systems
Kececioglu, O. Fatih,Acikgoz, Hakan,Yildiz, Ceyhun,Gani, Ahmet,Sekkeli, Mustafa The Korean Institute of Electrical Engineers 2017 Journal of Electrical Engineering & Technology Vol.12 No.1
Wind energy conversion systems (WECS) which consist of wind turbines with permanent magnet synchronous generator (PMSG) and full-power converters have become widespread in the field of renewable power systems. Generally, conventional diode bridge rectifiers have used to obtain a constant DC bus voltage from output of PMSG based wind generator. In recent years, together advanced power electronics technology, Pulse Width Modulation (PWM) rectifiers have used in WECS. PWM rectifiers are used in many applications thanks to their characteristics such as high power factor and low harmonic distortion. In general, L, LC and LCL-type filter configurations are used in these rectifiers. These filter configurations are not exactly compensate current and voltage harmonics. This study proposes a hybrid passive filter configuration for PWM rectifiers instead of existing filters. The performance of hybrid passive filter was tested via MATLAB/Simulink environment under various operational conditions and was compared with LCL filter structure. In addition, neuro-fuzzy controller (NFC) was preferred to increase the performance of PWM rectifier in DC bus voltage control against disturbances because of its robust and nonlinear structure. The study demonstrates that the hybrid passive filter configuration proposed in this study successfully compensates current and voltage harmonics, and improves total harmonic distortion and true power factor.
-
Bilici, Ahmet,Selcukbiricik, Fatih,Demir, Nazan,Ustaalioglu, Bala Basak Oven,Dikilitas, Mustafa,Yildiz, Ozcan Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.20
Background: Docetaxel and cisplatin in combination with fluorouracil (DCF) regimen is accepted to be one of the standard regimens in the treatment of advanced gastric cancer. However, substantial toxicity has limited its use in daily clinical practice. Therefore, modification of DCF regimens, including introduction of capecitabine has been investigated to improve the safety profiles. In the present study, the efficacy and toxicity of a regimen with a modified dose of docetaxel and cisplatin in combination with oral capecitabine (DCX) was evaluated in untreated patients with HER2-negative advanced gastric cancer. Materials and Methods: Fifty-four patients with HER2-negative locally advanced or metastatic gastric cancer were included in this cohort. Patients received docetaxel $60mg/m^2$ plus cisplatin $60mg/m^2$ (day 1) combined with capecitabine $1650mg/m^2$ (days 1-14) every 3 weeks. Treatment response, survival, and toxicity were retrospectively analyzed. Results: The median age was 54 years (range: 24-76). The majority of patients (70%) had metastatic disease, while 11 patients (21%) had recurrent disease and underwent curative gastrectomy, and 5 patients (9%) had locally advanced disease (LAD). The median number of DCX cycles was 4. There were 28 partial responses and 11 complete responses, with an overall response rate of 72%. Curative surgery could be performed in four patients among five with LAD. At the median follow-up of 10 months, the median progression-free survival (PFS) and overall survival (OS) of the entire cohort of patients were 7.4 and 12.1 months, respectively. Dose modification was done in 12 patients due to toxicity in 8 and noncompliance in 4 patients. The most common hematological toxicity was neutropenia, which occurred at grade 3-4 intensity in 10 of 54 patients (27.7%). Febrile neutropenia was diagnosed only in two cases. Conclusions: DCX regimen offers prominent anti-tumor activity and considered to be effective first-line treatment with manageable toxicity for patients with HER2-negative advanced gastric cancer.
-
Gultekin Batuhan,Bulut Fatih,Yildiz Hatice,Us Hakan,Ogul Hasan 한국원자력학회 2023 Nuclear Engineering and Technology Vol.55 No.12
Radiation is the main safety issue for almost all nuclear applications, which must be controlled to protect living organisms and the surrounding materials. In this context, radiation shielding materials have been investigated and used in nuclear technologies. The choice of materials depends on the radiation usage area, type, and energy. Polymer materials are preferred in radiation shielding applications due to their superior characteristics such as chemical inertness, resistivity, low weight, flexibility, strength, and low cost. In the presented work, ABS polymer material, which is possibly the most commonly used material in 3D printers, is mixed with Gd2O3 and Er2O3 nanoparticles. ABS filaments containing these rare-earth elements are then produced using a filament extruder. These produced filaments are used in a 3D printer to create shielding samples. Following the production of shielding samples, SEM, EDS, and gamma-ray shielding analyses (including experiments, WinXCOM, GEANT4, and FLUKA) are performed. The results show that 3D printing technology offers significant enhancements in creating homogeneous and well-structured materials that can be effectively used in gamma-ray shielding applications.
-
( Gulcin Gungor Olcum ),( Guven Koc ),( Fidan Canan Celik Yagan ),( Ece Yigit Taskin ),( Senem Ertilav ),( Hanife Serife Aktas ),( Sati Sena Yildiz ),( Demet Ataman Tasan ),( Fatih Akdogan ),( Sema Ba 대한내과학회 2014 대한내과학회 추계학술대회 Vol.2014 No.1
Background: RA is a chronic systemic disease manifest with multiple joint infi ammation. Vasculitis, heart, lung disease, extra-articular symptoms can also be present. TNF-a,IL-6 and mediators such as cytokines, have been shown to have an important role in this infi ammatory process. Anti-TNF drugs considered to be effective in preventing; RA,disability and joint destruction. CRP is one of the best indicators of infi ammation though, ESR is an indirect indicator of infi ammation and ESR levels affected by age, sex, status and anemia. ESR and CRP levels in patients with RA, disease activity and has been shown to correlate with radiographic fi ndings In this study, we aim to to show the correlation between ESR, CRP levels with disease activity in patients receiving anti-TNF alpha therapy. Methods: In this Retrospective study between January 2006 to March 2010 patients diagnosed with RA were evaluated in two groups. In the study group patients receiving at least one year of TNF-alpha were included where as in the control group patients only receiving DMARD were include. Only female patients were involved in both groups. There were 46 women in the study and 47 women in the control group. Disease severity and DAS 28 score was used to determine the disease activity. For statistical analysis Number Cruncher Statistical System 2007 & PASS 2008 Statistical Software (Utah,USA) was used. Results: In patients receiving anti-TNF alpha therapy DAS 28 scores showed statisticallysignifi cant correlation with the ESR. A statistically signifi cance between DAS 28 and CRP were not found. In control group with only DMARD treatment, the DAS 28.
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
