Miracle-dz/UniFAR-FTUs huggingface dataset:
Numerical study of the effect of the tip gap size and using a single circumferential groove on the performance of a multistage compressor

The effect of the tip gap size on the performance of a multistage axial compressor was studied by means of computational fluid dynamics (CFD). It was found that the performance of the compressor was very sensitive to the size of the tip gap. By increasing the gap size, the stall margin value, the total pressure ratio and the compressor efficiency reduced considerably. The flow field at the tip region of the blades at the near-stall point showed that the size of the blockage grew with an increase in the gap size. Afterward, the effect of various single circumferential grooves- having specified widths and depths at different placement positions- on the performance were investigated in the reference gap. The stall margin increased about 7% with negligible reduction of the peak efficiency using one of the grooves which placed next to the trailing edge of the first-stage rotor. Also, this groove increased the stall margin in other tip gap sizes. Investigation of the flow field of the tip region in the reference gap showed that when the groove was used, there was a reduction in the back-flow near the trailing edge of the first-stage rotor. Consequently, the stall occurred at a lower mass flow rate.
The Application of Content-based Indexing and Retrieval of Digital Pictures and Range Images to the 3 D Virtual Reconstruction of Complex Sites and Architectures

The modelling of complex objects and sites involve the acquisition of a large number of texture maps and range images; each one of them representing a particular viewing angle. These views must be combined and registered in order to create an accurate model of the original. The complexity of the resultant models, and consequently the number of views required, has increased tremendously over the past decade. Furthermore many major projects involve multinational and multilingual teams, each with different underlying methodologies. In addition, different teams may survey the same object or site over a number of years, producing complimentary results on different platforms utilizing a variety of (possible outdated) technologies. In such conditions, it is difficult to make sense of the annotation and to determine which views should be registered together. We propose a new approach in which similar views are found by content-based indexing and retrieval of textures (2D) and range images (3D). The views are described automatically, according to their appearance and their 3D geometry. A search engine allows retrieving similar and related views for registration. * eric.paquet@nrc-cnrc.ca. ca
A Fast Method for Reconstruction of Total-Variation MR Images With a Periodic Boundary Condition

We use a small positive parameter to change the total-variation function for unconstrained MR image reconstruction to a strictly convex perturbed function. Bregman iteration is applied to solve the modified total-variation MR image (TVMRI) reconstruction problem. A lagged diffusivity fixed-point algorithm is applied to solve the minimization problem in the Bregman iteration. We use the periodic boundary condition and a Fourier transform to accelerate TVMRI reconstruction. Real MR images are used to test the approach in numerical experiments. The experimental results demonstrate that the proposed method is very efficient for TVMRI reconstruction.
Baggage Fees and Airline Stock Performance: A Case Study of Initial Investor Misperception

In response to increasing fuel costs, airlines began introducing baggage fees as a new source of revenue, fees which have since been increased. In this study, an event study methodology is used to examine the impact of these announcements on airline stock prices. The results indicate that the initial announcements led to negative abnormal returns for the announcing firm and other competing airlines, as they were interpreted as a sign of industry weakness. However, the results also show that subsequent increases in baggage fees, which had been shown to positively impact the airline’s financial performance, are associated with positive abnormal returns.
Droplet Microfluidics for the Production of Microparticles and Nanoparticles

Droplet microfluidics technology is recently a highly interesting platform in material fabrication. Droplets can precisely monitor and control entire material fabrication processes and are superior to conventional bulk techniques. Droplet production is controlled by regulating the channel geometry and flow rates of each fluid. The micro-scale size of droplets results in rapid heat and mass-transfer rates. When used as templates, droplets can be used to develop reproducible and scalable microparticles with tailored sizes, shapes and morphologies, which are difficult to obtain using traditional bulk methods. This technology can revolutionize material processing and application platforms. Generally, microparticle preparation methods involve three steps: (1) the formation of micro-droplets using a microfluidics generator; (2) shaping the droplets in micro-channels; and (3) solidifying the droplets to form microparticles. This review discusses the production of microparticles produced by droplet microfluidics according to their morphological categories, which generally determine their physicochemical properties and applications.
Robotic Vision: Understanding Improves the Geometric Accuracy

Paraphrasing Olivier Faugeras in the foreword of [1], making a robot see is still an unsolved and challenging task after several decades of research. The traditional research has been based on the geometric models of multiple views of a scene, estimating a sparse 3D map of the scene and the camera pose. Recent advances have led to fully dense and real-time 3D reconstructions. Also, there are relevant recent works on the semantic annotation of the 3D maps. This extended abstract summarizes the work of [2], [3], [4], [5], [6] in this direction; in particular using mid and high-level features to improve the accuracy of dense maps.
A Simultaneous Inline Measurement Mechanism for Capacity and Available Bandwidth of End-to-End Network Path

We previously proposed a new version of TCP, called Inline measurement TCP (ImTCP), in [2], [3]. The ImTCP sender adjusts the transmission intervals of data packets and then utilizes the arrival intervals of ACK packets for available bandwidth estimation. This type of active measurement is preferred because the obtained results are as accurate as those of other conventional types of active measurement, even though no extra probe traffic is injected onto the network. In the present research, we develop a new capacity measurement function and combine it with ImTCP in order to enable simultaneous measurement of both capacity and available bandwidth in ImTCP. The capacity measurement algorithm is a new packet-pair-based measurement technique that utilizes the estimated available bandwidth values for capacity calculation. This new algorithm promises faster measurement than current packet-pair-based measurement algorithms for various situations and works well for high-load networks, in which current algorithms do not work properly. Moreover, the new algorithm provides a confidence interval for the measurement result.
Modelling the Dynamics of Emotional Awareness

In this paper, based on literature from Cognitive and Affective Neuroscience, a computational agent model is introduced incorporating the role of emotional awareness states in the dynamics of action generation. More specifically, it covers both automatic, unconscious (bottom-up) and more cognitive and conscious (top-down) emotion generation processes, and their mutual interaction. The model was formalised in a dynamical system format. In different scenarios the model shows simulation results that are in line with patterns reported in literature.
Optimization of capacitive micromachined ultrasound transducers (CMUTs) for a high-frequency medical ultrasonic imaging system

Conventional ultrasonic imaging systems use piezoelectric transducers for the generation and reception of the acoustic signal. Since its invention in 1994, the Capacitive Micromachined Ultrasound Transducer (CMUT) has been subjected to research as an alternative technology. Major advantages of the CMUT over traditional piezoelectric ultrasound transducers include higher bandwidth, higher sensitivity, CMOS compatibility, and ease of manufacturing (by the use of standard lithography techniques.) Increasing the dynamic range, decreasing the parasitic capacitance and cross coupling are the major goals in CMUT designing specially for medical imaging applications. The work in this thesis aims the optimization of a high-frequency (20 MHz) CMUT array to be used for high-resolution medical imaging. The figure of merit has been chosen as the signal-to-noise ratio of the electrical return signal, which required the construction of a model for the entire pulse-echo operation. Such a model consists of: (1) a circuit model for the device itself, (2) a model for the radiation impedance, and (3) a model for the propagation medium. The CMUT model has been extensively studied in the literature. An already existing circuit model has been used in the simulations. The radiation impedance of the CMUT array was computed using Finite Element Analysis (FEA) software packages COMSOL Multiphysics® and ANSYS®, and converted to an equivalent circuit to represent the load in the circuit simulator. The pulse-echo model, which is entirely implemented in LTspice circuit simulator, was then used to optimize CMUT parameters that include radius, membrane thickness, and gap height to maximize signal-to-noise ratio.
A new texture algorithm for complex surface construction by fast smooth seamless splicing

To realize complex surface smooth seamless splicing, a new texture algorithm of improved mosaic by intelligent controlling and subdivision (IMIS) was developed. With advantages of mosaic in tiles arrangement and subdivision in freeform surface shaping, the designed features of aesthetical or functional surface were kept in manufacture model under optimum quality controlling. Stability and reliability of this algorithm were proved by an example trading in the self-developed software in Visual C++.
Impact of Data Organization on Distributed Storage System

With the explosive growth of data stored in digital format, there is a need for a new approach to data storage. Large amount of stored data requires modern storage systems to be scalable and easily extendable on-line. Moreover, the data must be resilient and highly available, which in turn requires failure-tolerant and highly available storage. To address these needs a new storage segment called scalable distributed storage systems (DSS) has recently emerged. One of the key architectural decisions for a DSS system is the design of its data organization defining data distribution among multiple nodes as well as local data placement on each node. The fulfillment of almost all the requirements of DSS systems depends directly on proper data organization. In this thesis we describe DSS requirements dependent on data placement. Moreover, we identify trade-offs among these requirements and discuss how tradeoff resolution is related to design choices for data organization. Next, we propose a novel data organization that resolves the trade-offs in a reasonable way. This is verified by using the proposed organization in a commercial DSS system called HYDRAstor. We have a substantial first-hand experience with this system, as for the last few years we have been part of a core team designing and implementing HYDRAstor. In this system, data is organized around a distributed hash table with virtual supernodes spanned over physical nodes. Data resiliency is provided with erasure codes, with fragments of erasure-coded blocks distributed among supernode components. Fragments are stored in containers that are organized into chains to allow fast storage of data streams and enable efficient data consistency management, data health verification and data reconstruction. We conclude that the design of data organization in HYDRAstor allows for the balancing of conflicting DSS requirements which has resulted in the creation of a break-through, highly innovative storage system.
COMPARISON OF SOFTWARE METRICS TOOLS FOR . NET

In this paper we will compare tools for calculating software metrics. We will examine tools that are available free on the internet and capable of calculating software metrics for C# language. The purpose of this paper is to compare the calculations of software metrics and determine if the tools are providing the same results. We would like to discover if choosing a different tool can provide different results and consequently bring different decisions.
Periodic excitability changes across the receptive fields of complex cells in the striate and parastriate cortex of the cat.

1. Complex cells in cortical areas 17 and 18 of the cat have been studied in response to narrow slits and edges moving across the receptive field in the preferred direction and also to stationary slits of different widths. 2. Average response histograms, recorded as a narrow slit was moved across the receptive field, displayed a periodic series of peaks above a base line level. The response histogram for most area 17 and 18 cells contained five principal peaks; sometimes one or two weaker peaks were present at receptive field borders. The histogram for one cell located at the area 17–18 border showed thirteen distinct peaks. Periodic response patterns were also generated as an extended edge was moved across the receptive field. Plots of cell responses versus slit width for stationary slits of different widths also indicated periodic response pattern. 3. The accuracy of determining the preferred slit orientation was the single most important requirement for demonstrating the periodic response pattern. Significant changes in the appearance of the periodic pattern occurred even upon 5 degrees rotations away from the preferred orientation. 4. Average response histograms were also studied over a wide range of moving slit velocities. The number of peaks across corresponding spacings within the recewptive field remained constant over a range of velocities. Response amplitudes, however, were velocity dependent. Thus the response peaks remain associated with fixed positions within visual space independent of stimulus velocity, even though temporal as well as spatial factors may be involved in response selectivity and the periodic modulation. The most striking periodic response histograms were generated at the velocities which produced the greatest cell firing rates. Area 17 complex cells responded well to velocities of less than 0–5 degrees to 6–0 degrees/sec, but cells in area 18 generally required higher velocities, sometimes as high as 20 degrees‐‐30 degrees/sec, for a good response. 5. Spatial frequencies for the periodic component of the receptive field for area 17 cells in the central visual area covered a range of three octaves up to 5 cycles/degree, and area 18 cells included another octave on the low frequency side. The spatial frequency of a cell was found to be roughly inversely proportional to the receptive field width. Only a small sample of area 18 cells was studied, but these cells tended to represent low spatial frequencies and to respond selectively to high velocity stimuli.
A Block Mixture Model for Pattern Discovery in Preference Data

This paper presents a probabilistic co-clustering approach to pattern discovery in preference data. We extended the original formulation of the block mixture model to handle rating data, the resulting model allows the simultaneous clustering of users and items in homogeneous user communities and item categories. The parameter of the model are determined using a variational approximation and a two-phase application of the EM algorithm. The experimental evaluation showed that proposed approach can be used both for rating prediction and pattern discovery tasks, such as the analysis of common trends within the same user community and the identification of interesting relationships between products belonging to the same item category. In particular, using Movie Lens data, we show how it is possibile to infer topics for each item category, and how to model community interests and transition among topics of interest.
A Real Object-Oriented Visual Design Language for Distributed Software Systems

State-of-the-art object-oriented analysis and design combined with techniques handling concurrency and distribution on the design level ease the development of distributed systems. A novel approach and language for the visual design of distributed software systems is introduced and illustrated by means of an example. The language of OCoNs (Object Coordination Nets) integrates the structuring mechanisms of object-oriented concepts which are crucial for handling complex software systems with the graphical expressive power of Petri-Nets for describing concurrency and coordination. The same visual language is used to specify the interfaces of software components, the resource handling within a component as well as the control flow in methods.
Assessment of Toxicity and Beneficiary Effects of Garcinia pedunculata on the Hematological, Biochemical, and Histological Homeostasis in Rats

This study was undertaken to investigate the toxicological profile of a methanolic extract of Garcinia pedunculata fruit in rats by conducting hematological, biochemical, and histopathological examinations. Long Evans rats were divided into four groups, each with 6 animals, and were treated with three oral doses (250, 500, and 1000 mg/kg) once daily for 21 days. The extract did not cause significant changes in body and relative organ weight, percent water content, or hematological parameters at any administered doses. However, a significant dose-dependent positive effect in serum lipid profile and all atherogenic indices including the cardiac risk ratio, Castelli's risk index-2, and the atherogenic coefficient were observed. Significant increases in the levels of iron and decreases in serum alkaline phosphatase, alanine transaminase, and lactate dehydrogenase activities and the levels of serum glucose were noted when the extract was administered at the highest dose (1000 mg/kg). Histopathological examination of the target tissues further confirmed that the extract was safe and had no observed toxicological features. Our study indicates that G. pedunculata fruit is nontoxic, has the potential to be effective against atherosclerosis, and may be used as a hepatoprotectant. The fruit extract is also beneficial to those with iron deficiency and hyperglycemia.
Bi-directional Carving Based on Saliency Map via Absorbing Markov Chain

Traditional methods for image retargeting such as scaling and cropping cannot generate satisfactory results because of their neglect of the content of the image. In order to consider the content of the image, saliency detection for finding the regions of interest (ROIs) plays an important role in the process of retargeting an image. In this paper, we present a novel image retargeting method using bi-directional seam carving technique combining scaling. Guided by an important map based on a saliency map via absorbing Markov chain combining with gradient map, the proposed method can effectively protect the ROIs in the image when downsizing or enlarging an image. Extensive experiments demonstrate the efficiency of the proposed method against the traditional methods and several other methods.
Machine Learning Ensembles: An Empirical Study and Novel Approach

Two learning ensemble methods, Bagging and Boosting, have been applied to decision trees to improve classification accuracy over that of a single decision tree learner. We introduce Bagging and propose a variant of it — Improved Bagging — which, in general, outperforms the original bagging algorithm. We experiment on 22 datasets from the UCI repository, with emphasis on the ensemble’s accuracy as the main performance measure. The variant of Bagging that we propose utilizes the “out of bag” samples in determining a decision tree’s voting power, whereas in the classical Bagging algorithm, all trees have the same voting power. Our proposed algorithm creates bootstrap samples from the training data according to a forced probability distribution that emulates random sampling with replacement. We thus achieve a uniformly distributed training set for each base learner, and also identically-sized “out of bag” verification sets for each learner. Our 10-fold cross-validation results and single runs on large data sets show our novel Bagging variant to improve classification accuracy relative to both the original Bagging ensemble and standard Boosting.
Human nature, corruption, and the African social order

Transparency International has consistently maintained two prominent assertions: that corruption remains a global threat because no human society in the world has a clean record, and that Africa is the most corrupt region in the world. These assertions raise some fundamental philosophical concerns. The former assertion re-opens the need to ascertain whether corruption is an essence of humans, or an acquired disposition. Howsoever this is resolved forms the fulcrum of concerns on the second assertion. This paper engages these philosophical concerns. The paper takes two paths to achieve this goal. The first draws from Aristotle’s essentialism and Thomas Hobbes’ accounts on human nature to engage the debate on the relationship between human nature and corruption. The second derives and discusses the plausibility and fundamental implications of the claim that Africa is the most corrupt region in the world. It was found that neither on the basis of Aristotle’s nor Thomas Hobbes’, nor even a possible African cosmology as discussed, can it be said that official corruption is essential to humans. The paper concludes that what is at issue concerning corruption as measured by Transparency International pertains to different African expectations of recompense in a protective communalism from which relatives in public offices must have drawn care, now termed “corruption” by Transparency International, which is not so regarded in the African social order.
Doctoral Student Connectedness in Open Distance Learning: A Case of Students and Supervisors

ABSTRACT The focus of this quantitative study was to investigate doctoral students’ perception of connectedness in an open distance learning (ODL) environment. The study focused exclusively on Ethiopian doctoral students and investigated feelings of student-to-student and student-to-supervisor connectedness in an ODL environment. A total of 100 Ethiopian doctoral students attending studying at an ODL university were selected to take part in the study. Descriptive statistics, t-test and correlation analysis were conducted. The results showed that doctoral students experience less than desirable levels of connectedness with each other and also a slightly above average perception of connectedness with their supervisors. Moreover, the findings also showed that there is a positive relationship between student-to-student and student-to-supervisor connectedness scores. Based on the findings it is recommended that the university should implement initiatives to support socialisation and interaction among students and also with supervisors.