A powerful test for unit root and an application to GNP of seven OECD countries

Ankara : The Department of Economics, Bilkent Univ., 2000.Thesis (Master's) -- Bilkent University, 2000.Includes bibliographical references leaves 19.This thesis uses a powerful test, Dickey-Fuller Generalized Least Squares (DF-GLS), to see whether unit root exists or not in real GNP of OECD Countries - Australia, Canada, Germany, Japan, Italy, U.K. and U.S. - for the years between the first quarter of 1960 and the second quarter of 1998 by using quarterly data that takes 1995 as base year. For this purpose a simple model with a deterministic component plus an error term, which is assumed to be AR (1), is used. The results of the regressions show the existence of unit root for all of the considered countries. Furthermore, we give flnite sample performances of Augmented Dickey-Fuller (ADF) test and DF-GLS tests which Elliott et al. (1996) conducted by using Monte Carlo experiment.Ustundag, AliyeM.S

A thoracic-epidural granulocytic sarcoma case that was diagnosed preceding the onset of and that recurred co-incidental to acute promyelocytic leukemia, which developed after surgical treatment.

Granulocytic sarcoma or chloroma is a tumor seen in myelocytic leukemia. Spinal epidural onset is rare and is generally seen before or together with the onset of myelocytic leukemia. An epidural mass located at the 2nd-5th thoracic levels in an 18-year-old male patient was pathologically diagnosed as granulocytic sarcoma. Radiotherapy was performed after surgical intervention. Ten months later, he was re-admitted with abdominal pain. At this time, an epidural mass at the 6th-9th thoracic levels was detected on magnetic resonance imaging, and acute promyelocytic leukemia was diagnosed. After systemic chemotherapy, partial remission was achieved. We aimed to present this rare case with its remarkable follow-up findings.</p

Successfully Managing the Literature Review and Write-up Process When Using Grounded Theory Methodology - A Dialogue in Exploration

For researchers unaccustomed to using grounded theory methodology (GTM), it can be daunting. To help address this issue, in this article we present a dialogue between a doctoral candidate who is using GTM and an academic who has experience working with this methodology. Through dialogue, we tackle several important points relating to the methodology, focusing on two key aspects which often create challenges for researchers new to GTM: 1. how and when to engage with existing literature, and 2. what significant implications which using this methodology has for the overall written structure of a grounded theory study, not simply the presentation of the grounded theory itself. This format, which ends with a reflection on the dialogue, aims to facilitate a clearer understanding of the methodology, clarify problematic issues, and offer practical guidance on how to apply it, thereby shedding light on "the long, rocky walk through the dark forest of the research process using the GT methods" (WU & BEAUNAE, 2014, p.249).Für unerfahrene Forscher*innen kann der Versuch, die Ground-Theory-Methodologie (GTM) anzuwenden, entmutigend sein. Um diesem Problem zu begegnen, präsentieren wir in diesem Artikel den Dialog zwischen einer Doktorandin, die die GTM für ihre Dissertation nutzt und einem Wissenschaftler mit langjähriger GTM-Erfahrung. Wir greifen verschiedene wichtige Fragen auf, fokussieren uns aber auf zwei zentrale Aspekte, die für Noviz*innen oft besonders herausfordernd sind: Wann und in welcher Weise kann/soll 1. auf bereits verfügbare Literatur zurückgegriffen werden, und welche Implikationen ergeben sich 2. für die Verschriftlichung der gesamten Studie, nicht nur der Präsentation der Theorie im engeren Sinne. Durch das Dialogformat, das wir abschließend reflektieren, erhoffen wir ein besseres Verständnis der GTM und versuchen, praktische Hilfen zu geben für "the long, rocky walk through the dark forest of the research process using the GT methods" (WU & BEAUNAE 2014, S.249)

Vitamin D Insufficiency in Children with Chronic Neurological Diseases: Frequency and Causative Factors

&nbsp; Objective Vitamin D insufficiency/rickets is a metabolic bone disease that leads to insufficient mineralization of bone. Chronic neurological diseases, including cerebral palsy (CP), convulsive disorders, neural tube defects, myopathy, immobility, lack of sun exposure, inadequate nutrition, and antiepileptic drugs (AEDs) can cause vitamin D insufficiency and osteopenia in children. Materials &amp; Methods In this study, the authors searched the frequency and causative factors of vitamin D insufficiency in children with chronic neurological diseases such as CP, hypoxic-ischemic encephalopathy, mental motor retardation, epilepsy, neurodegenerative and neuromuscular diseases, meningitis-encephalitis sequelae, neural tube defects, paralysis, and paresis. This cross-sectional study included 108 children (forty-five [41.6%] females; sixty-three [58.4%] males), aged between one and 18 years with chronic neurological diseases, and a control group of thirty age-matched healthy children (16 [53.3%] females; 14 [46.7%] males. Results Vitamin D levels were significantly lower, and parathyroid hormone (PTH) levels were significantly higher in the patient group than in the control group (p&lt;0.05). The patient group was divided into four subgroups: (i) Epilepsy (n=41; 38%), (ii) Neural tubedefects (n=14; 13%), (iii) CP (n=21; 19%), and (iv) other diseases (neurodegenerative and neuromuscular diseases, meningitis sequelae, intracranial hemorrhage, psychomotor retardation, hypoxic-ischemic encephalopathy) (n=32; 30%) to identify any differences in the measured levels. In the patient group, eighty-three (76.9%) had vitamin D deficiency, and 17 (15.7%) had vitamin D insufficiency, while in the control group, twenty-one (70%) had vitamin D insufficiency. The use of AEDs had no significant effect on serum Ca, P, ALP, PTH, orvitamin D levels (p&gt;0.05), and serum Ca levels were significantly higher in ambulant patients than in non-ambulant patients (p&lt;0.05). Vitamin D levels were significantly higher in the non-ambulant than in the ambulant patients (p&lt;0.05). No rickets was determined in the control group, while in the patient group, nine (8.3%) had level-1 rickets, six (5.6%) had level-2 rickets, and two (1.9%) had level-3rickets. Conclusion Children with chronic neurological diseases have low serum vitamin D levels, and vitamin D prophylaxis is essential in this grou

Pseudo-binary phase diagram for Zr-based in situ ß phase composites

The pseudo-binary (quasi-equilibrium) phase diagram for Zr-based bulk metallic glasses with crystalline in situ precipitates (ß phase) has been constructed from high-temperature phase information and chemical composition analysis. The phase evolution was detected in situ by high-energy synchrotron x-ray diffraction followed by Rietveld analysis of the data for volume fraction estimation. The phase diagram delineates phase fields and allows the control of phase fractions. Combined with related previous work by the authors, this diagram offers a unique opportunity to control both the morphology and volume of the dendritic ß phase precipitates to enhance the properties of the composites

The use of platelet indices, plateletcrit, mean platelet volume and platelet distribution width in emergency non-traumatic abdominal surgery: a systematic review.

Platelet indices (PI) — plateletcrit, mean platelet volume (MPV) and platelet distribution width (PDW) — are a group of derived platelet parameters obtained as a part of the automatic complete blood count. Emerging evidence suggests that PIs may have diagnostic and prognostic value in certain diseases. This study aimed to summarize the current scientific knowledge on the potential role of PIs as a diagnostic and prognostic marker in patients having emergency, non-traumatic abdominal surgery. In December 2015, we searched Medline/PubMed, Scopus and Google Scholar to identify all articles on PIs. Overall, considerable evidence suggests that PIs are altered with acute appendicitis. Although the role of PI in the differential diagnosis of acute abdomen remains uncertain, low MPV might be useful in acute appendicitis and acute mesenteric ischemia, with high MPV predicting poor prognosis in acute mesenteric ischemia. The current lack of consistency and technical standards in studies involving PIs should be regarded as a serious limitation to comparing these studies. Further large, multicentre prospective studies concurrently collecting data from different ethnicities and genders are needed before they can be used in routine clinical practice

On the free vibration behavior of cylindrical shell structures

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2011.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Cataloged from student-submitted PDF version of thesis.Includes bibliographical references (p. 105-106).Shell structures, especially cylindrical shells, are widely used in aerospace and naval architectural industries. Submarine hulls and aircraft bodies can be idealized as cylindrical shell structures. The study of vibrations of cylindrical shells is an important aspect in the successful applications of the cylindrical shells. The free vibration characteristics of a submarine hull have an important influence on the noise signature of the submarine. That makes the free vibration problem of the submarine hull a particular interest for the submarine community. The natural frequencies of cylindrical shells are clustered in a very narrow band and they are thus more prone to becoming involved in resonant vibrations. The determination and control of these frequencies is significant to manage the acoustic signature of the submarine. This thesis focuses on the free vibration characteristics of stiffened and unstiffened cylindrical shells. The analysis is carried out mainly in two parts. First, the unstiffened cylindrical shell is modeled and the free vibration problem is analyzed as the shell thickness decreases. Then the cylindrical shell is stiffened with ring stiffeners and the free vibration problem of the stiffened cylindrical shell is studied. The vibration modes of the unstiffened cylindrical shell are studied for four shells with different thicknesses. Initial tensile and compressive membrane stresses are applied separately to the shells to study the effect of the initial stresses on the free vibration modes. The vibration modes of the stiffened cylindrical shell are studied in two steps. First, the influence of the positions of two ring stiffeners on the fundamental frequencies is studied; second, the free vibration modes of the stiffened cylindrical shell are studied. Two cylindrical shells with different thicknesses are used and they are stiffened with different numbers of ring stiffeners, which are uniformly distributed along the longitudinal axis of the shell. The results are compared with available analytical results and finite element solutions of similar problems from the literature.by Burak Ustundag.S.M

A Web Based Optimization System Using Goal Programming for Supply Chain Network

Considering high competitive nature of todays industries,being on plan is very vital for supply chain network of an organization. Allthe flows of materials from initial suppliers to final customers need to besmooth. Hence, distribution network design is an important strategic decisionproblem for the supply chain managers. The aim of this research is to propose a web-based Decision Support System (DSS) foroptimizing fuzzy distribution network in the context of supply-chain management. A fuzzy goal-programming model has been designedfor the proposed DSS to consider the uncertain and imprecise data. Thisresearch focuses on four conflict fuzzy goals of (i). all demands must be covered by distribution center, (ii).investment goals for opening new sites considering fix costs, (iii). Investmentgoals for opening new distribution centers considering fix costs, (iv). Supplycosts goals, to meet the optimized results. Hence with those attributes ofmembership function of goals, the decision makers can apply this model toobtain the investment policy and the achieved level of each individual goal

A modular software architecture for UAVs

There have been several attempts to create scalable and hardware independent software architectures for Unmanned Aerial Vehicles (UAV). In this work, we propose an onboard architecture for UAVs where hardware abstraction, data storage and communication between modules are efficiently maintained. All processing and software development is done on the UAV while state and mission status of the UAV is monitored from a ground station. The architecture also allows rapid development of mission-specific third party applications on the vehicle with the help of the core module