Disconnected Skeleton: Shape at its Absolute Scale

We present a new skeletal representation along with a matching framework to address the deformable shape recognition problem. The disconnectedness arises as a result of excessive regularization that we use to describe a shape at an attainably coarse scale. Our motivation is to rely on the stable properties of the shape instead of inaccurately measured secondary details. The new representation does not suffer from the common instability problems of traditional connected skeletons, and the matching process gives quite successful results on a diverse database of 2D shapes. An important difference of our approach from the conventional use of the skeleton is that we replace the local coordinate frame with a global Euclidean frame supported by additional mechanisms to handle articulations and local boundary deformations. As a result, we can produce descriptions that are sensitive to any combination of changes in scale, position, orientation and articulation, as well as invariant ones.Comment: The work excluding {\S}V and {\S}VI has first appeared in 2005 ICCV: Aslan, C., Tari, S.: An Axis-Based Representation for Recognition. In ICCV(2005) 1339- 1346.; Aslan, C., : Disconnected Skeletons for Shape Recognition. Masters thesis, Department of Computer Engineering, Middle East Technical University, May 200

Prenatal diagnosis and postnatal follow-up of congenitally corrected transposition of the great arteries and recurrent supraventricular tachycardia

The prenatal sonographic diagnosis of congenitally corrected transposition of the great arteries (ccTGA), a rare form of congenital heart disease is very difficult. A24-year-old woman was referred to our center at 28 weeks’ gestation because of suspected fetal cardiac anomalies. This article reports a case of ccTGA with supraventricular tachycardia, ventricular septal defect, pulmonary valve stenosis, tricuspid valvar displacement and moderate tricuspid regurgitation during her pregnancy. The combined presence of SVT and ccTGA are occasionally present in the literature.peer-reviewe

The impact of alkali-vanadate(s) in supported vanadia catalysts on the propane oxidation reaction

Introducing additives to supported vanadia catalysts has been intensively studied with the aim to improve catalyst performance in oxidative dehydrogenation of propane. It has been shown that alkali additives influence dispersion of vanadia as well as acid-base and redox properties of supported vanadium oxide species. Possibly formed alkali vanadate(s) can have a melting temperatures in the range of reaction temperatures of propane oxidation (e.g., K3V5O14 melts at 410°C). However, little is known about the formation of mixed alkali-vanadium oxide compounds and the influence of melting of surface alkali-vanadate phase(s) on the catalytic properties of alkali-containing supported vanadium oxide catalysts. To investigate the possible impact of melting of alkali-vanadate phase(s), a series of silica supported A/V catalysts (A: alkali, i.e., Li, Na, K, Rb, and Cs) with a systematic variation of A: V ratios were synthesized and tested in propane oxidation reaction. Catalysts were prepared by a fusion of alkali carbonates, V2O5 and SiO2 (by keeping total metal oxide loading as 10 wt. %). Catalyst precursors were in situ activated (21O2/79N2 at 520°C) and tested in an eight-fold parallel reactor (C3H8/O2/N2=7.5/7.5/85). Fluxing agents such as K-, Rb-, and Cs- decreases melting temperatures of silica supported VxOy catalysts to the temperature range where propane oxidation reaction is applied. However Li-, and Na- added catalysts have much higher melting temperatures so that catalysts remain as solid during reaction. Both catalytic test in a fixed bed reactor as well as operando Differential Scanning Calorimetry revealed a drastic change in catalytic performance if melting occurs. Activity drops and selectivity to propylene increases markedly when the supported V-A oxide layer and/or segregated crystalline alkali vanadate phases are melting. Structural reasons behind the drastic change in catalytic properties were investigated based spectroscopic investigations of the materials under operation. Detailed characterization was conducted for silica supported K/V=0.6 catalyst since this catalyst exhibited only one crystalline phase (K3V5O14) beyond amorphous SiO2 as detected by XRD. Operando Raman spectroscopy showed the structural alterations of K3V5O14 (532 nm laser) due to incongruent melting and how the melting impacts the dispersion of vanadium oxide species (266 nm laser) over the support. Melting initiated the formation of oligomeric vanadium oxide species already in the in situ activation step upon melting of potassium-vanadate. This explained the source of catalytic activity in alkali-containing supported vanadia catalyst. The possible role of melting in propane oxidation was first demonstrated with path-finder experiment (physical mixture of K3V5O14 and V/SBA-15) in which the activity of supported vanadia catalyst sharply decreased due to the wetting behaviour of the potassium-vanadate. The coverage of active site(s) by the melt was seen. NAP-NEXAFS was further conducted as a complimentary technique for Raman spectroscopy and as well as to validate the possible role of melting. The spectral features of V L3-edge NEXAFS of activated K/V=0.6 catalyst varied in terms of the intensity of the peaks at ~516.2 eV and ~517.6 eV upon heating in propane oxidation. The spectra suggests the monomeric/polymeric vanadium oxide species as well as potassium-vanadate exist in activated catalyst which is in agreement with the Raman findings. Based on a fitting model in Athena (Demeter) software, the contribution from alkali-vanadate species increases while the contribution from the dispersed vanadium oxide species decreases upon melting. K L-edge proofed an increase in potassium content over the surface upon heating in propane oxidation. Together with path-finder experiment and spectroscopy techniques, the inhibition effect of melting on the activity of surface vanadium oxide species were explained. Analogous behaviour was found in Rb- and Cs- containing catalysts in terms of at least a change in spectral shape of V L3-edge. Overall, the melting correlates with a drop in activity and an increase in selectivity to propylene in the oxidative dehydrogenation of propane. This is a general phenomenon for K-, Rb-, and Cs- containing catalysts, but not for Li- and Na- containing counterparts that do not exhibit melting. The alkali-vanadate phase itself not active for propane oxidation however it has a great impact on reaction kinetics. The mobility of alkali vanadate phase(s) due to melting inhibits the reactivity of surface vanadium oxide species. These results deepen our understanding on the influence of strain on the activity of surface VOx species in propane oxidation.Die Zugabe von Additiven zu geträgerten Vanadiumoxid basierten Katalysatoren wurde intensiv mit dem Ziel untersucht, die Katalysatorleistung bei der oxidativen Dehydrierung von Propan zu verbessern. Es hat sich gezeigt, dass Alkalizusätze die Dispersion von Vanadiumoxid sowie die Säure-Base- und Redox-Eigenschaften von Vanadiumoxid-Trägerverbindungen beeinflussen. Gebildete Alkalivanadate können Schmelztemperaturen im Bereich der Reaktionstemperaturen der Propanoxidation aufweisen (z. B. schmilzt K3V5O14 bei 410 °C). Über die Bildung von gemischten Alkali-Vanadiumoxid-Verbindungen und den Einfluss des Schmelzens der Alkali-Vanadat-Oberflächenphase(n) auf die katalytischen Eigenschaften von alkalihaltigen Vanadiumoxid-Trägerkatalysatoren ist jedoch wenig bekannt. Um den möglichen Einfluss des Schmelzens der Alkali-Vanadat-Phase(n) zu untersuchen, wurde eine Reihe von A/V-Katalysatoren auf Siliciumdioxidträger (A: Alkali, d.h. Li, Na, K, Rb und Cs), mit einer systematischen Variation des A:V-Verhältnisse, synthetisiert und in der Propan-Oxidationsreaktion getestet. Die Katalysatoren wurden durch Verschmelzung von Alkalicarbonaten, V2O5 und SiO2 hergestellt (wobei der Gesamtgehalt an Metalloxiden bei 10 Gew.-% lag). Die Katalysatorvorläufer wurden in situ aktiviert (21O2/79N2 bei 520°C) und in einem achtfachen Parallelreaktor getestet (C3H8/O2/N2=7.5/7.5/85). Flussmittel wie K-, Rb- und Cs- senken die Schmelztemperaturen von VxOy-Katalysatoren auf Siliziumdioxidträgern in dem Temperaturbereich, in dem die Propanoxidationsreaktion untersucht wurde. Mit Li- und Na- versetzte Katalysatoren haben jedoch viel höhere Schmelztemperaturen, so dass die Katalysatoren während der Reaktion fest bleiben. Sowohl die katalytischen Tests in einem Festbettreaktor als auch die „Differential Scanning Calorimetry“ zeigten eine drastische Veränderung der katalytischen Leistung, wenn es zu einem Schmelzen kommt. Die Aktivität sinkt und die Selektivität steigt deutlich, wenn die geträgerten V-A-Oxidschicht und/oder segregierte kristalline Alkalivanadatphasen schmelzen. Die strukturellen Gründe für die drastische Veränderung der katalytischen Eigenschaften wurden mittels spektroskopischen Untersuchungen an den Materialien unter Reaktionsbedingungen untersucht. Eine detaillierte Charakterisierung wurde für den K/V=0.6-Katalysator auf Siliziumdioxidträger durchgeführt, da dieser Katalysator neben dem amorphen SiO2 nur eine kristalline Phase (K3V5O14) aufwies, wie durch XRD festgestellt wurde. Operando-Raman-Spektroskopie zeigte strukturellen Veränderungen von K3V5O14 (532-nm-Laser) aufgrund des inkongruenten Schmelzens und die Auswirkung des Schmelzen auf die Dispersion der Vanadiumoxid-Spezies (266-nm-Laser). Das Schmelzen initiierte die Bildung oligomerer Vanadiumoxid-Spezies bereits in der In-situ-Aktivierungsphase. Spektrale Bestandteile der V L3-Kante (NEXAFS) des aktivierten K/V=0.6-Katalysators variieren in Bezug auf die Intensität der Peaks bei ~516.2 eV und ~517.6 eV beim Erhitzen in der Propanoxidation. Die Spektren deuten darauf hin, dass im aktivierten Katalysator sowohl monomere/polymere Vanadiumoxid-Spezies als auch Alkalivanadate vorhanden sind, was mit den Raman-Ergebnissen übereinstimmt. Basierend auf einem Fit-Modell in der Software Athena (Demeter), kann gezeigt werden das der Anteil an Alkalivanadat-Spezies zu nimmt, während der Anteil an dispergierten Vanadiumoxid-Spezies beim Schmelzen abnimmt. Mittels „Pathfinder“-Experiment und der angewendeten Spektroskopie konnte die hemmende Wirkung des Schmelzens auf die Aktivität der Vanadiumoxid-Spezies an der Oberfläche aufgeklärt werden. Ein analoges Verhalten wurde bei Rb- und Cs-haltigen Katalysatoren festgestellt, zumindest in Form einer Änderung der spektralen Form der V L3-Kante. Insgesamt korreliert das Schmelzen mit einer Abnahme der Aktivität und einer Zunahme der Selektivität gegenüber Propylen bei der oxidativen Dehydrierung von Propan. Dies ist ein allgemeines Phänomen für K-, Rb- und Cs-haltige Katalysatoren, nicht aber für Li- und Na-haltige Gegenstücke, die kein Schmelzen aufweisen. Die Alkali-Vanadat-Phase selbst ist für die Propanoxidation nicht aktiv, hat jedoch aber einen großen Einfluss auf die Reaktionskinetik. Die Mobilität der geschmolzenen Alkalivanadat-Phase(n) hemmt die Reaktivität der Vanadiumoxid-Spezies an der Oberfläche. Es zeigt sich das nicht nur die Bildung einer aktiver Spezies notwendig ist, sondern auch die Umgebung der aktiven Spezies kontrolliert werden muss. Diese Ergebnisse vertiefen unser Verständnis des Einflusses der Verspannung der Oberflächen-VOx-Spezies auf die Aktivität bei der Propanoxidation

Application of AA-PSP to hypersonic flows: the double ramp model

Anodized Aluminium Pressure Sensitive Paint (AA-PSP) is known for its rapid response characteristics, making it a highly desirable technique when studying high-speed phenomenon on a global scale. The current study examines the efficacy of the AA-PSP technique, which is prepared with a more practical approach than that reported in literature, in analysing the flow characteristics of a double ramp model placed in hypersonic flow of M = 5. Three different flow angles of 0°, −2°, and −4° are studied. Two-dimensional colour schlieren visualisation, using a colour wheel, is employed alongside high sensitivity Kulite pressure tap data to corroborate the AA-PSP findings. The AA-PSP results show good correlation between the qualitative schlieren and ±8.9% discrepency with the quantitative pressure tap data. The more practical AA-PSP preparation proposed in the current study, which uses aluminium alloy 6-series rather than pure aluminium, is proved to have the response time and the accuracy to be applied to unsteady high-speed flows

The anatomy of sovereign risk contagion

The channels for the cross-border propagation of sovereign risk in the international sovereign debt market are analysed. Identifying sovereign credit events as extraordinary jumps in CDS spreads, we distinguish between the immediate effects of such events and their longer term spillover effects. To analyse “fast and furious” contagion, we use daily CDS data to conduct event studies around a total of 89 identified credit events in a global country sample. To analyse “slow-burn” spillover effects, we apply a multifactor risk model, distinguishing between global and regional risk factors. We find that “fast and furious” contagion has been primarily a regional phenomenon, whilst “slow-burn” spillover effects can often be global in scope, especially those of the recent European debt crisis. The global risk factors are found to be driven by investor risk appetites and debt levels, whilst the regional factors depend on economic fundamentals of countries within a region

Object and Relation Centric Representations for Push Effect Prediction

Pushing is an essential non-prehensile manipulation skill used for tasks ranging from pre-grasp manipulation to scene rearrangement, reasoning about object relations in the scene, and thus pushing actions have been widely studied in robotics. The effective use of pushing actions often requires an understanding of the dynamics of the manipulated objects and adaptation to the discrepancies between prediction and reality. For this reason, effect prediction and parameter estimation with pushing actions have been heavily investigated in the literature. However, current approaches are limited because they either model systems with a fixed number of objects or use image-based representations whose outputs are not very interpretable and quickly accumulate errors. In this paper, we propose a graph neural network based framework for effect prediction and parameter estimation of pushing actions by modeling object relations based on contacts or articulations. Our framework is validated both in real and simulated environments containing different shaped multi-part objects connected via different types of joints and objects with different masses. Our approach enables the robot to predict and adapt the effect of a pushing action as it observes the scene. Further, we demonstrate 6D effect prediction in the lever-up action in the context of robot-based hard-disk disassembly.Comment: Project Page: https://fzaero.github.io/push_learning

Hippocampus and retrosplenial cortex combine path integration signals for successful navigation

The current study used fMRI in humans to examine goal-directed navigation in an open field environment. We designed a task that required participants to encode survey-level spatial information and subsequently navigate to a goal location in either first person, third person, or survey perspectives. Critically, no distinguishing landmarks or goal location markers were present in the environment, thereby requiring participants to rely on path integration mechanisms for successful navigation. We focused our analysis on mechanisms related to navigation and mechanisms tracking linear distance to the goal location. Successful navigation required translation of encoded survey-level map information for orientation and implementation of a planned route to the goal. Our results demonstrate that successful first and third person navigation trials recruited the anterior hippocampus more than trials when the goal location was not successfully reached. When examining only successful trials, the retrosplenial and posterior parietal cortices were recruited for goal-directed navigation in both first person and third person perspectives. Unique to first person perspective navigation, the hippocampus was recruited to path integrate self-motion cues with location computations toward the goal location. Last, our results demonstrate that the hippocampus supports goal-directed navigation by actively tracking proximity to the goal throughout navigation. When using path integration mechanisms in first person and third person perspective navigation, the posterior hippocampus was more strongly recruited as participants approach the goal. These findings provide critical insight into the neural mechanisms by which we are able to use map-level representations of our environment to reach our navigational goals

A comparative analysis of handling level of lifelong learning competences in social education curricula, Turkey and Ireland sample

Developing and ever-changing information technology brings together many innovations by renewing the human profile societies need in a significant way. “Lifelong Learning Understanding” which is one of the most important of these innovations, makes it necessary to change the basic competences and skills stand in the curricula. Accordingly, the education curricula are expected to provide lifelong learning understanding.  In this study it was aimed to analyze the handling level of the lifelong learning competences in the social education curricula of Turkey and Ireland comparatively. Eight key competences, recommended EU member countries to conduct their educational policies within the context of lifelong learning by the European Union (EU), was used as references in the analysis of the curricula.  It has been tried to determine whether lifelong learning competences are included in the curricula or not and which competences have been mentioned the most and which has been mentioned the least. Data required was collected in accordance with “document analysis” method, which is one of the qualitative research methods, and utilized from “content analysis” technique for the analysis of the collected data. According to the findings of the study it was found that the most frequent competences were mathematical competence and basic competences in science and technology in TSCC.  It was also seen that the competences of communication in the mother tongue, social and civic competences, the learning to learn competence, and mathematical competence and basic competences in science are of leading importance in SPHE.  Absence of the communication in foreign languages competence in TSSC can be said as the most prominent difference between the ISSC and TSSC

Classroom teachers’ professional development activities within the scope of life long learning in Turkey

Among all the factors affecting education, teachers have more important role in ensuring the effectiveness of the teaching process. Teachers’ professional development is a subject that directly affect the teaching process. Researches on the development of teaching profession indicate that professional training is a necessity for better education and better schools. Because if the teacher learns during performing the teaching profession, the quality of the education offered by the teacher will be higher. Teachers who develop themselves in terms of profession provide both a better education and a positive learning environment for the students. In this context, the aim of this research is to investigate the activities of the classroom teachers participate in Turkey in order to ensure their professional development. The study is prepared depending on the views of the classroom teachers. The data were obtained from the classroom teachers who teach 1, 2, 3, and 4. classes in public and private elementary schools in Ankara, in the 2014-2015 academic year. Questionnaire developed by the researchers was used for collecting the data

Early age corrosion of mild steel in aggressive media

Effect of exposure time, section type and solution concentration on mild steel early age corrosion was studied. Steel specimens section types were box, tube and corner. They were subjected to 3.5%; 5.0% and 7.0% NaCl solutions. It was established that solution concentration effects the corrosion until reaching the saturation value.Вивчено вплив тривалості експозиції, типу сталевого профілю та концентрації розчину на ранню стадію корозії вуглецевої сталі. Використано сталеві зразки у вигляді куба, трубки та кутника. Досліджували в 3,5-, 5,0- та 7,0%-их розчинах NaCl. Встановлено, що після досягнення граничної концентрації розчину хлориду натрію подальше збільшення вмісту солі не впливає на корозію сталі.Изучено влияние продолжительности экспозиции, типа стального профиля и концентрации раствора на раннюю стадию коррозии углеродистой стали. Использованы стальные образцы в виде куба, трубки и угольника. Исследовали в 3,5-, 5,0- и 7,0%-ых растворах NaCl. Установлено, что после достижения предельной концентрации раствора хлорида натрия, последующее увеличение содержания соли не влияет на коррозию стали