CERTAIN SUBCLASSES OF ANALYTIC FUNCTIONS ASSOCIATED WITH MILLER-ROSS-TYPE POISSON DISTRIBUTION SERIES

( Bilal Şeker ),( Sevtap Sümer Eker ),( Bilal Çekiç ) 호남수학회 2022 호남수학학술지 Vol.44 No.4

The purpose of the present paper is to obtain some sufficient conditions for analytic functions, whose coefficients are probabilities of the Miller-Ross type-Poisson distribution series, to belong to classes G(λ, δ) and K(λ, δ).

Subclasses of k-uniformly convex and k-starlike functions defined by S[문자]l[문자]gean operator

Bilal [문자]eker,Mugur Acu,Sevtap S[문자]mer Eker 대한수학회 2011 대한수학회보 Vol.48 No.1

The main object of this paper is to introduce and investigate new subclasses of normalized analytic functions in the open unit disc U, which generalize the familiar class of k-starlike functions. The various properties and characteristics for functions belonging to these classes derived here include (for example) coefficient inequalities, distortion theorems involving fractional calculus, extreme points, integral operators and integral means inequalities.

Acute Onset of Intracerebral Hemorrhage due to Autonomic Dysreflexia

Eker, Amber,Yigitoglu, Pembe Hare,Ipekdal, H. Ilker,Tosun, Aliye The Korean Neurosurgical Society 2014 Journal of Korean neurosurgical society Vol.55 No.5

Autonomic dysreflexia is a clinical emergency syndrome of uncontrolled sympathetic output that can occur in patients who have a history of spinal cord injury. Despite its frequency in spinal cord injury patients, central nervous system complications are very rare. We report a man with traumatic high level incomplete spinal cord injury who suffered hypertensive right thalamic hemorrhage secondary to an episode of autonomic dysreflexia. Prompt recognition and removal of the triggering factor, the suprapubic catheter obstruction which led to hypertensive attack, the patient had a favorable functional outcome after the resorption of the hematoma and effective rehabilitation programme.

Design of Self-Starting Hybrid Axial Flux Permanent Magnet Synchronous Motor Connected Directly to Line

Eker, Mustafa,Akar, Mehmet,Emeksiz, Cem,Dogan, Zafer,Fenercioglu, Ahmet The Korean Institute of Electrical Engineers 2018 Journal of Electrical Engineering & Technology Vol.13 No.5

In view of the current state of the reserves of electric energy generated resources and the share of electric motors in electricity consumption, many researches and studies related to efficiency in electric motors are being made. The presented work is related to the Axial Flux Permanent Magnet Synchronous Motor (AF-PMSM), which has recently undergone significant work based on the development of magnet and motor technology. In this study, a novel AF-PMSM was designed analytically through Finite Element Method (FEM) which can be started by connecting to a line such as an asynchronous motor in a transient state and can operate with high efficiency and power factor after synchronization in steady state without the need for an expensive motor drive. According to the obtained FEM results, a design with an efficiency class of IE4 of 5.5 kW shaft power, a 4 poles motor was obtained. As a result, economic calculations indicate that the extra cost of the designed Line start AF-PMSM with respect to the asynchronous motor is rapidly compensated by energy saving due to a more efficient operation, especially constant speed operations. As a result of the analysis obtained, the targeted values are reached. For induction motors and radial flux permanent magnet synchronous motors, a good alternative motor that can operate with high efficiency and power factor has been obtained.

Factors Affecting Prognosis in Metastatic Colorectal Cancer Patients

Eker, Baki,Ozaslan, Ersin,Karaca, Halit,Berk, Veli,Bozkurt, Oktay,Inanc, Mevlude,Duran, Ayse Ocak,Ozkan, Metin Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.7

Background: Colorectal cancer (CRC) is a major cause of mortality in developed countries, and it is the third most frequent malignancy in Turkey. There are many biological, genetic, molecular, and tissue-derived prognostic factors for CRCs. In this study, we evaluated prognostic factors in patients who were metastatic at diagnosis or progressed to metastatic disease during follow-up. Patients and Methods: This study included 116 patients with malignancies either in the colon or rectum. Of these, 65 had metastatic disease at diagnosis, and 51 progressed to metastatic disease during the course of the disease. The parameters evaluated were age, gender, comorbidity, performance status and stage of the disease at the beginning, localization, history of surgery, chemotherapy regimen, response to first-line treatment, K-RAS status, site and number of metastases, expression of tumor predictors (CEA, CA19-9), and survival times. A multivariate analysis conducted with factors that considered statistically significant in the univariate analysis. Findings: Median age was 56 (32-82) years and the male/female ratio was 80/36. Eleven patients were at stage II, 40 at stage III, and 65 at stage IV at diagnosis. Twenty three patients had tumor in the right colon, 48 in the left colon, and 45 in the rectum. Ninety seven patients were operated, and 27 had surgical metastasectomy. Ninety three patients received targeted therapy. At the end of follow-up, 61 patients had died, and 55 survived. Metastatic period survival times were longer in the adjuvant group, but the difference did not reach the level of statistical significance (adjuvant group: median 29 months, metastatic group: median 22 months; p=0.285). In the adjuvant group before the metastatic first-line therapy, CEA and CA 19-9 levels were significiantly lower compared to the metastatic group (p<0.005). We also found that patients with elevated tumor predictor (CEA, CA 19-9) levels before the first-line therapy had significiantly poorer prognosis and shorter survival time. Survival was significiantly better with the patients who were younger than 65 years of age, had better initial performance status, a history of primary surgery and metastatectomy, and single site of metastasis. Those who benefitted from the first-line therapy were K-RAS wild type and whose tumor markers (CEA, CA 19-9) were not elevated before the first line therapy. Conclusions: Among the patients with metastatic CRC, those who benefited from first-line therapy, had history of metastasectomy, were K-RAS wild type and had low CA 19-9 levels before the first-line therapy, showed better prognosis independent of other factors.

SEIBERG-WITTEN-LIKE EQUATIONS ON THE STRICTLY PSEUDOCONVEX CR-3 MANIFOLDS

Eker, Serhan Korean Mathematical Society 2019 대한수학회보 Vol.56 No.6

In this paper, Seiberg-Witten-like equations are written down on 3-manifolds. Then, it has been proved that the $L^2$-solutions of these equations are trivial on ${\mathbb{R}}^3$. Finally, a global solution is obtained on the strictly pseudoconvex CR-3 manifolds for a given constant negative scalar curvature.

Design of Self-Starting Hybrid Axial Flux Permanent Magnet Synchronous Motor Connected Directly to Line

Mustafa Eker,Mehmet Akar,Cem Emeksiz,Zafer Dogan,Ahmet Fenercioglu 대한전기학회 2018 Journal of Electrical Engineering & Technology Vol.13 No.5

In view of the current state of the reserves of electric energy generated resources and the share of electric motors in electricity consumption, many researches and studies related to efficiency in electric motors are being made. The presented work is related to the Axial Flux Permanent Magnet Synchronous Motor (AF-PMSM), which has recently undergone significant work based on the development of magnet and motor technology. In this study, a novel AF-PMSM was designed analytically through Finite Element Method (FEM) which can be started by connecting to a line such as an asynchronous motor in a transient state and can operate with high efficiency and power factor after synchronization in steady state without the need for an expensive motor drive. According to the obtained FEM results, a design with an efficiency class of IE4 of 5.5 kW shaft power, a 4 poles motor was obtained. As a result, economic calculations indicate that the extra cost of the designed Line start AF-PMSM with respect to the asynchronous motor is rapidly compensated by energy saving due to a more efficient operation, especially constant speed operations. As a result of the analysis obtained, the targeted values are reached. For induction motors and radial flux permanent magnet synchronous motors, a good alternative motor that can operate with high efficiency and power factor has been obtained.

The effects of ventilation with high density oxygen on the strength of gastrointestinal anastomosis

Tevfik Eker,Volkan Genc,Yusuf Sevim,Ozge Cumaogullari,Menekse Ozcelik,Akin Firat Kocaay,Cemal Ozben Ensari,Ozge Tugce Pasaoglu 대한외과학회 2015 Annals of Surgical Treatment and Research(ASRT) Vol.89 No.1

Purpose: The aim of our study is to evaluate the effects of administration of perioperative supplemental oxygen on anastomoses. Methods: Forty male Wistar albino rats were used in the study and randomized into 4 groups. Ischemia-reperfusion models were built in groups 3 and 4. Jejunojejunostomy was performed in all rats and assigned to an oxygen/nitrous oxide mixture with a fraction of inspired oxygen of 30% in groups 1 and 3 and 80% in groups 2 and 4. The measurements of perianastomotic tissue oxygen pressure, bursting pressure, level of hydroxyproline were evaluated and compared in all groups. Results: The perianastomotic tissue oxygen pressures, bursting pressures and levels of hydroxyproline were identified as significantly high in groups 2 and 4, administered a fraction of inspired oxygen of 80%, compared to groups 1 and 3, administered a fraction of inspired oxygen of 30%. Conclusion: Perioperative supplemental oxygen contributes positively to the anastomotic healing.

Seiberg-Witten-like equations on the strictly pseudoconvex $CR$-3 manifolds

Serhan Eker 대한수학회 2019 대한수학회보 Vol.56 No.6

In this paper, Seiberg-Witten-like equations are written down on $3$-manifolds. Then, it has been proved that the $L^{2}$-solutions of these equations are trivial on $\mathbb{R}^3$. Finally, a global solution is obtained on the strictly pseudoconvex $CR$-3 manifolds for a given constant negative scalar curvature.

Effect of demagnetization faults on line start AF‑PMSM performance

Mustafa Eker,Mustafa Ozsoy 전력전자학회 2022 JOURNAL OF POWER ELECTRONICS Vol.22 No.6

This study is concerned with irreversible demagnetization faults in axial fl ux permanent magnet synchronous motors (AFPMSM). Line start capability was provided to the AF-PMSM by making changes in its traditional rotor architecture. With this architecture, the motor operates as an asynchronous motor in the transient state and as a synchronous motor in the steady state. In this study, the impacts of an irreversible demagnetization fault on motor performance, which occurs in motors due to various reasons, is investigated. The four poles of the used AF-PMSM have 5.5 kW of shaft power. Each pole is comprised of fi ve identical magnets. Diff erent rates (20%, 40%, and 60%) of demagnetization failure were created in a single pole. The data acquired from the faulty motors were compared to data from a healthy motor. The results indicate that irreversible demagnetization faults have an adverse impact on motor performance. It was observed that the experimentally created demagnetization faults increase the current drawn by the motor. In addition, they cause a decrease in both the power factor and effi ciency. However, the faults did not have an adverse impact on the starting capability of the motor. The unique aspect of the present study is that it is the fi rst time the impacts of demagnetization faults on the performance of line start AF-PMSMs have been examined.