Numerical studies on non-linearity of added resistance and ship motions of KVLCC2 in short and long waves

Olgun Hizir,Mingyu Kim,Osman Turan,Alexander Day,Atilla Incecik,Yongwon Lee 대한조선학회 2019 International Journal of Naval Architecture and Oc Vol.11 No.1

In this study, numerical simulations for the prediction of added resistance for KVLCC2 with varying wave steepness are performed using a Computational Fluid Dynamics (CFD) method and a 3-D linear potential method, and then the non-linearities of added resistance and ship motions are investigated in regular short and long waves. Firstly, grid convergence tests in short and long waves are carried out to establish an optimal mesh system for CFD simulations. Secondly, numerical simulations are performed to predict ship added resistance and vertical motion responses in short and long waves and the results are verified using the available experimental data. Finally, the non-linearities of added resistance and ship motions with unsteady wave patterns in the time domain are investigated with the increase in wave steepness in both short and long waves. The present systematic study demonstrates that the numerical results have a reasonable agreement with the experimental data and emphasizes the non-linearity in the prediction of the added resistance and the ship motions with the increasing wave steepness in short and long waves.

Numerical studies on non-linearity of added resistance and ship motions of KVLCC2 in short and long waves

Hizir, Olgun,Kim, Mingyu,Turan, Osman,Day, Alexander,Incecik, Atilla,Lee, Yongwon The Society of Naval Architects of Korea 2019 International Journal of Naval Architecture and Oc Vol.11 No.1

In this study, numerical simulations for the prediction of added resistance for KVLCC2 with varying wave steepness are performed using a Computational Fluid Dynamics (CFD) method and a 3-D linear potential method, and then the non-linearities of added resistance and ship motions are investigated in regular short and long waves. Firstly, grid convergence tests in short and long waves are carried out to establish an optimal mesh system for CFD simulations. Secondly, numerical simulations are performed to predict ship added resistance and vertical motion responses in short and long waves and the results are verified using the available experimental data. Finally, the non-linearities of added resistance and ship motions with unsteady wave patterns in the time domain are investigated with the increase in wave steepness in both short and long waves. The present systematic study demonstrates that the numerical results have a reasonable agreement with the experimental data and emphasizes the non-linearity in the prediction of the added resistance and the ship motions with the increasing wave steepness in short and long waves.

Prognostic factors and treatment outcomes in surgically­staged non­invasive uterine clear cell carcinoma: a Turkish Gynecologic Oncology Group study

Mustafa Erkan Sarı,Mehmet Mutlu Meydanlı,Osman Türkmen,Günsü Kimyon Cömert,Ahmet Taner Turan,Alper Karalök,Hanifi Şahin,Ali Haberal,Eda Kocaman,Özgür Akbayır,Baki Erdem,Ceyhun Numanoğlu,Kemal Güngördü 대한부인종양학회 2017 Journal of Gynecologic Oncology Vol.28 No.4

Objective: To assess the prognosis of surgically-staged non-invasive uterine clear cell carcinoma (UCCC), and to determine the role of adjuvant therapy. Methods: A multicenter, retrospective department database review was performed to identify patients with UCCC who underwent surgical treatment between 1997 and 2016 at 8 Gynecologic Oncology Centers. Demographic, clinicopathological, and survival data were collected. Results: A total of 232 women with UCCC were identified. Of these, 53 (22.8%) had surgically-staged non-invasive UCCC. Twelve patients (22.6%) were upstaged at surgical assessment, including a 5.6% rate of lymphatic dissemination (3/53). Of those, 1 had stage IIIA, 1 had stage IIIC1, 1 had stage IIIC2, and 9 had stage IVB disease. Of the 9 women with stage IVB disease, 5 had isolated omental involvement indicating omentum as the most common metastatic site. UCCC limited only to the endometrium with no extra-uterine disease was confirmed in 41 women (73.3%) after surgical staging. Of those, 13 women (32%) were observed without adjuvant treatment whereas 28 patients (68%) underwent adjuvant therapy. The 5-year disease-free survival rates for patients with and without adjuvant treatment were 100.0% vs. 74.1%, respectively (p=0.060). Conclusion: Extra-uterine disease may occur in the absence of myometrial invasion (MMI), therefore comprehensive surgical staging including omentectomy should be the standard of care for women with UCCC regardless of the depth of MMI. Larger cohorts are needed in order to clarify the necessity of adjuvant treatment for women with UCCC truly confined to the endometrium.

Early and Late Complications after Inguinofemoral Lymphadenectomy for Vulvar Cancer

Cirik, Derya Akdag,Karalok, Alper,Ureyen, Isin,Tasci, Tolga,Kalyoncu, Rukiye,Turkmen, Osman,Kose, M Faruk,Tulunay, Gokhan,Turan, Taner Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.13

Background: We aimed to determine the frequency of early and late complications following groin surgery for vulvar cancer and analyze possible risk factors. Materials and Methods: This retrospective cohort study included 99 women who underwent for vulvar cancer. The early (${\leq}1$ month) complications were wound infection, breakdown and lymphocyst and late (>1 month) complications were lower limb lymphedema, incontinence and erysipelas. The risk factors for developing each of the complications were analyzed with regression analysis. Results: In the entire cohort, 29 (29.3%) women experienced early and 12 (12.1%) had late complications. Wound complications including infection and breakdown were the leading early complications (23.2%). In the multivariate analysis, both obesity (body mass index ${\geq}30kg/m^2$) and advanced age (${\geq}65years$) were found as independent predictive factors for early complications. Obese women of advanced age had 6.32 times more risk of experiencing any of the early complications, when compared to non-obese and young women (55.6% vs 8.7%). The most common late complication was lower limb lymphedema (10.1%) that was more frequently seen in young women. However, neither age nor lymph node count were significantly associated with the occurrence of lower limb lymphedema. Conclusions: More than 40% of the women suffered from postoperative complications after inguinofemoral lymphadenectomy in the current study. While advanced age and obesity were the significant predictors for any of the early complications, there was no identified risk factor for lower limb lymphedema.

Bilirubin Level is Associated with Left Ventricular Hypertrophy Independent of Blood Pressure in Previously Untreated Hypertensive Patients

Teslime Ayaz,Murtaza Emre Durakog˘lugil,Sinan Altan Kocaman,Tug˘ba Durakog˘lugil,Turan Erdog˘an,Osman Zikrullah S¸ahin,Serap Baydur S¸ahin,Yüksel C¸ic¸ek,Ömer S¸atirog˘lu 대한심장학회 2014 Korean Circulation Journal Vol.44 No.5

Background and Objectives: Left ventricular hypertrophy (LVH), a sign of subclinical cardiovascular disease, is an important predictor of cardiovascular morbidity and mortality. The aim of our study was to determine the association of left ventricular mass (LVM) with possible causative anthropometric and biochemical parameters as well as carotid intima-media thickness (CIMT) and brachial flow-mediated dilation (FMD) as surrogates of atherosclerosis and endothelial dysfunction, respectively, in previously untreated hypertensive patients. Subjects and Methods: Our study included 114 consecutive previously untreated hypertensive patients who underwent echocardiography and ultrasonography to evaluate their vascular status and function via brachial artery CIMT and FMD. Results: Among all study parameters, age, systolic blood pressure (BP), diastolic BP, pulse pressure, plasma glucose, uric acid, total bilirubin, direct bilirubin, hemoglobin, and CIMT were positively correlated with the LVM index. Multiple logistic regression analysis revealed that office systolic BP, age, male gender, and total bilirubin were independent predictors of LVH. Conclusion: Bilirubin seems to be related to LVM and LVH. The positive association of bilirubin with these parameters is novel and requires further research.

Impact of lymph node ratio on survival in stage IIIC endometrioid endometrial cancer: a Turkish Gynecologic Oncology Group study

Ali Ayhan,Nazlı Topfedaisi Ozkan,Murat Özdemir,Günsu Kimyon Comert,Zeliha Firat Cuylan,Gonca Çoban,Osman Turkmen,Baki Erdem,Hanifi Şahin,Özgür Akbayır,Murat Dede,Ahmet Taner Turan,Husnu Celik,Tayfun G 대한부인종양학회 2018 Journal of Gynecologic Oncology Vol.29 No.4

OBJECTIVE: The purpose of this study was to investigate the prognostic value of lymph node ratio (LNR) in women with stage IIIC endometrioid endometrial cancer (EC). METHODS: A multicenter, retrospective department database review was performed to identify patients with stage IIIC pure endometrioid EC at 6 gynecologic oncology centers in Turkey. A total of 207 women were included. LNR, defined as the percentage of positive lymph nodes (LNs) to total nodes recovered, was stratified into 2 groups: LNR1 (≤0.15), and LNR2 (>0.15). Kaplan-Meier method was used to generate survival data. Factors predictive of outcome were analyzed using Cox proportional hazards models. RESULTS: One hundred and one (48.8%) were classified as stage IIIC1 and 106 (51.2%) as stage IIIC2. The median age at diagnosis was 58 (range, 30-82) and the median duration of follow-up was 40 months (range, 1-228 months). There were 167 (80.7%) women with LNR ≤0.15, and 40 (19.3%) women with LNR >0.15. The 5-year progression-free survival (PFS) rates for LNR ≤0.15 and LNR >0.15 were 76.1%, and 58.5%, respectively (p=0.045). An increased LNR was associated with a decrease in 5-year overall survival (OS) from 87.0% for LNR ≤0.15 to 62.3% for LNR >0.15 (p=0.005). LNR >0.15 was found to be an independent prognostic factor for both PFS (hazard ratio [HR]=2.05; 95% confidence interval [CI]=1.07-3.93; p=0.03) and OS (HR=3.35; 95% CI=1.57-7.19; p=0.002). CONCLUSION: LNR seems to be an independent prognostic factor for decreased PFS and OS in stage IIIC pure endometrioid EC.