COMPARISON THEOREMS ON THE OSCILLATION OF A CLASS OF NEUTRAL DIFFERENCE EQUATIONS WITH CONTINUOUS VARIABLES

BasŞak Karpuz,Özkan Öcalan 대한수학회 2010 대한수학회보 Vol.47 No.2

In this paper, we introduce an iterative method to study oscillatory properties of delay difference equations of the following form ∇α [x (t) − r (t) x (t − κ)] + p (t) x (t − τ) − q (t) x (t − σ) = 0, t ≥ t0,where t0 ∈ R, t varies in the real interval [t0,∞), α > 0, κ, τ, σ ≥ 0,r ∈ C([t0 − α,∞) ,R+), p, q ∈ C([t0,∞) ,R+) and ∇αx (t) = x (t) −x (t − α) for t ≥ t0.

What are the Endoscopic and Pathological Characteristics of Colorectal Polyps?

Bas, Bilge,Dinc, Bulent,Oymaci, Erkan,Mayir, Burhan,Gunduz, Umut Riza Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.13

Background: Colon polyps need to be excised upon detection during colonoscopy due to the risk of malignancy irrespective of their size. In our study, we retrospectively evaluated the clinicopathological characteristics of polyps detected during colonoscopy. Materials and Methods: We assessed 379 patients with polyps detected during colonoscopy between January 2010 and May 2012. The demographics, complaints, colonoscopy findings (shape, place and size of the polyp) and histopathological findings were recorded. We carried out statistical analysis using PASW 18.0 for Windows. Results: There were 227 males (59.9%) and 152 females (40.1%) in the trial. The mean age was 53.8 years (32-90). The most common complaint was rectal bleeding (36.1%), followed by abdominal pain (35.4%). Polyps were detected most commonly in the rectosigmoid region (43.8%), followed by the descending colon (17.4%). Some 239 patients had a single polyp (63.1%) while 140 were found to have multiple polyps (36.9%). While tubular adenoma was the most common pathological type, occurring in 181 patients (47.8%), tubulovillous adenoma (14.2%) and hyperplastic polyp (12.7%) followed, occurring in 54 and 48 patients respectively. While 313 patients (82.6%) did not feature dysplasia, 37 patients (9.7%) exhibited low-grade dysplasia, 28 (7.7%) had high-grade dysplasia and 4 had cancer (1.1%). The rates of villous components and dysplasia were detected to be high among pedunculated polyps and polyps larger than 1 cm (p<0.001). Conclusions: Due to the fact that large-diameter polyps with malignant potential are commonly located in the left colon and have a high prevalence among the middle-aged individuals, it would be appropriate to screen this population at regular intervals via rectosigmoidoscopy.

Hypopituitarism and Legg-Calve-Perthes disease related to difficult delivery

Bas, Veysel Nijat,Uytun, Salih,Vurdem, Umit Erkan,Torun, Yasemin Altuner The Korean Pediatric Society 2015 Clinical and Experimental Pediatrics (CEP) Vol.58 No.7

Legg-Calve-Perthes (LCP) disease is characterized by idiopathic avascular osteonecrosis of the epiphysis of the femur head. The main factor that plays a role in the etiology of the disease is decreased blood flow to the epiphysis. Many predisposing factors have been suggested in the etiology of LCP disease, and most have varying degrees of effects. Here we present the case of a boy aged 4 years and 10 months with complaints of short stature and a diagnosis of multiple hypophyseal hormone deficiency, in whom LCP disease and difficult birth-related pituitary stalk interruption syndrome were identified by anamnesis. The present case revealed that LCP disease and hypophyseal hormone deficiency could be secondary to difficult birth and that LCP disease could be secondary to insulin-like growth factor 1 deficiency. Additionally, to the best of our knowledge there is no published case on the relation between LCP disease and insulin-like growth factor 1 deficiency. Therefore, we believe that this case is worthy of presentation.

Understanding Success and Failure in Establishing New Multilateral Development Banks: The SCO Development Bank, the NDB, and the AIIB

Bas Hooijmaaijers 경남대학교 극동문제연구소 2021 ASIAN PERSPECTIVE Vol.45 No.2

During the 2010s, a number of new multilateral development banks (MDBs) were established, including the BRICS (Brazil, Russia, India, China, and South Africa) New Development Bank (NDB) and the China-led Asian Infrastructure Investment Bank (AIIB). In 2010, China had proposed establishing a Shanghai Cooperation Organization (SCO) development bank. However, progress made toward establishing an SCO development bank has been minimal. This article identifies key factors influencing whether efforts to establish a new MDB are successes or failures by studying the failed attempt to establish an SCO development bank and contrasting it with the successful foundations of the NDB and the AIIB. It thus contributes to a better understanding of the drivers, the difficulties, and the challenges of these new MDB initiatives.

Public Awareness of Colorectal Cancer in a Turkish Population: Importance of Fecal Occult Blood Testing

Bas, Koray,Guler, Tolga,Gunay, Levent Mert,Besim, Hasan,Uygur, Dilek Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.1

To date, there was no controlled-study regarding awareness and knowledge of colorectal cancer in the Turkish population. We therefore designed a questionnaire consisting of items related to socio-demographic parameters, medical and family history and questions of awareness and knowledge about colorectal cancer for use in a descriptive cross-sectional study. An interviewer-administered technique was applied and 450 subjects were interviewed in the outpatient clinics at Near East University Hospital. Among all subjects, 337 were found to be eligible for the study group. Exclusion criteria were age below 18 years, any cancer history, family history of colorectal cancer, current colorectal problems, history of any diagnostic or therapeutic interventions for colorectal diseases. All participants stated that they heard about colorectal cancer. When asked about the lifetime risk of colorectal carcinoma, only 25.4% of women and 37.9% of men estimated correctly. Univariate analysis revealed that the total awareness score was significantly correlated with age, marital status, parenthood and fecal occult blood testing history. On multivariate analysis of independent predictors for awareness of colorectal cancer were found to be history of fecal occult blood testing, age and marital status were found to be the most important determinants. As a conclusion, opportunistic screening with fecal occult blood test by physicians from non-gastrointestinal specialties not only helps to reduce the mortality but also increases the awareness of colorectal cancer.

Sources of and Reponses to the Liability of Foreignness: The Case of Korean Companies in the Netherlands

Bas Daamen,김동재,Jean-Francois Hennart,박영렬 연세대학교 동서문제연구원 2007 Global economic review Vol.36 No.1

This study aims to investigate the liability of foreignness, or the additional difficulties of foreign companies compared to their local competitors. Past studies have found fair amount of empirical evidences for the liability of foreignness. The present study attempts to take one step further by addressing two questions: what are the sources of such disadvantages and what are the solutions sought by the companies? To do this, we conducted a field study exploring the on-going dynamics of foreign multinationals. Specifically, we collected primary data through interviews with Dutch and Korean managers of Korean multinational companies. Through the interviews, we found evidence for the existence of such disadvantages. We identified four sources of the liability of foreignness*cross-border transfer, interaction with the local government, local discrimination, and interaction within the multinational*and two ways in which these companies actively reduced their exposure to the problem*localization and unfamiliarity reduction. This study should be useful to both practitioners and theorists in international business with an interest in disadvantages connected to the foreign status of a company.

Schlunzopie, 40 X 30cm, Print, Acrylic, Varnisch on Canvas, 2011

Gleb Bas 한국콘텐츠학회 2012 ICCC International Digital Design Invitation Exhib Vol.8 No.2

Parameter space exploration for the probabilistic damage stability method for dry cargo ships

Milatz Bas,de Winter Roy,van de Ridder Jelle D.J.,van Engeland Martijn,Mauro Francesco,Kana Austin A. 대한조선학회 2023 International Journal of Naval Architecture and Oc Vol.15 No.-

The prediction of the statutory attained subdivision index is a challenging issue for the initial design of ships due to the design freedom offered by a probabilistic damage stability assessment. To this end, optimisation techniques integrated with a parametric model of the internal layout may generate a preliminary subdivision design, fulfilling damage stability regulations and cargo volume requirements. The present study explores using a multiobjective constrained optimisation algorithm coupled with a parametric model of a single hold cargo vessel, first investigating two design goal alternatives and secondly performing a global sensitivity analysis on the design variables for the most promising solution. The adoption, in parallel, of state-of-the-art practices shows the validity of the obtained solutions and the time benefits for designers. Nonetheless, the non-linear nature of probabilistic damage stability does not allow for clearly identifying the most impactful parameters on the attained survivability index.

Sources of and Responses to the Liability of Foreignness: The Case of Korean Companies in the Netherlands

Daamen, Bas,Hennart, Jean-Francois,Kim, Dong-Jae,Park, Young-Ryeol Routledge 2007 Global economic review Vol.36 No.1

<P> This study aims to investigate the liability of foreignness, or the additional difficulties of foreign companies compared to their local competitors. Past studies have found fair amount of empirical evidences for the liability of foreignness. The present study attempts to take one step further by addressing two questions: what are the sources of such disadvantages and what are the solutions sought by the companies? To do this, we conducted a field study exploring the on-going dynamics of foreign multinationals. Specifically, we collected primary data through interviews with Dutch and Korean managers of Korean multinational companies. Through the interviews, we found evidence for the existence of such disadvantages. We identified four sources of the liability of foreignness - cross-border transfer, interaction with the local government, local discrimination, and interaction within the multinational - and two ways in which these companies actively reduced their exposure to the problem - localization and unfamiliarity reduction. This study should be useful to both practitioners and theorists in international business with an interest in disadvantages connected to the foreign status of a company.</P>

The effects of vertical earthquake motion on an R/C structure

Selcuk Bas,Ilker Kalkan 국제구조공학회 2016 Structural Engineering and Mechanics, An Int'l Jou Vol.59 No.4

The present study investigated the earthquake behavior of R/C structures considering the vertical earthquake motion with the help of a comparative study. For this aim, the linear time-history analyses of a high-rise R/C structure designed according to TSC-2007 requirements were conducted including and excluding the vertical earthquake motion. Earthquake records used in the analyses were selected based on the ratio of vertical peak acceleration to horizontal peak acceleration (V/H). The frequency-domain analyses of the earthquake records were also performed to compare the dominant frequency of the records with that of the structure. Based on the results obtained from the time-history analyses under the earthquake loading with (H+V) and without the vertical earthquake motion (H), the value of the overturning moment and the top-story vertical displacement were found to relatively increase when considering the vertical earthquake motion. The base shear force was also affected by this motion; however, its increase was lower compared to the overturning moment and the top-story vertical displacement. The other two parameters, the top-story lateral displacement and the top-story rotation angle, barely changed under H and H+V loading cases. Modal damping ratios and their variations in horizontal and vertical directions were also estimated using response acceleration records. No significant change in the horizontal damping ratio was observed whereas the vertical modal damping ratio noticeably increased under H+V loading. The results obtained from this study indicate that the desired structural earthquake performance cannot be provided under H+V loading due to the excessive increase in the overturning moment, and that the vertical damping ratio should be estimated considering the vertical earthquake motion.